Reconnaissance of ground-water quality in the Papio-Missouri River Natural Resources District, eastern Nebraska, July through September 1992

USGS Publications Warehouse

Verstraeten, Ingrid M.; Ellis, M.J.

1995-01-01

A reconnaissance of ground-water quality was conducted in the Papio-Missouri River Natural Resources District of eastern Nebraska. Sixty-one irrigation, municipal, domestic, and industrial wells completed in the principal aquifers--the unconfined Elkhorn, Missouri, and Platte River Valley alluvial aquifers, the upland area alluvial aquifers, and the Dakota aquifer--were selected for water-quality sampling during July, August, and September 1992. Analyses of water samples from the wells included determination of dissolved nitrate as nitrogen and triazine and acetanilide herbicides. Waterquality analyses of a subset of 42 water samples included dissolved solids, major ions, metals, trace elements, and radionuclides. Concentrations of dissolved nitrate as nitrogen in water samples from 2 of 13 wells completed in the upland area alluvial aquifers exceeded the U.S. Environmental Protection Agency Maximum Contaminant Level for drinking water of 10 milligrams per liter. Thirty-nine percent of the dissolved nitrate-as-nitrogen concentrations were less than the detection level of 0.05 milligram per liter. The largest median dissolved nitrate-as-nitrogen concentrations were in water from the upland area alluvial aquifers and the Dakota aquifer. Water from all principal aquifers, except the Dakota aquifer, had detectable concentrations of herbicides. Herbicides detected included alachlor (1 detection), atrazine (13 detections), cyanazine (5 detections), deisopropylatrazine (6 detections), deethylatrazine (9 detections), metolachlor (6 detections), metribuzin (1 detection), prometon (6 detections), and simazine (2 detections). Herbicide concentrations did not exceed U.S. Environmental Protection Agency Maximum Contaminant Levels for drinking water. In areas where the hydraulic gradient favors loss of surface water to ground water, the detection of herbicides in water from wells along the banks of the Platte River indicates that the river could act as a line source of herbicides. Water from the alluvial and bedrock aquifers generally was a calcium bicarbonate type and was hard. Two of nine water samples collected from the Dakota aquifer contained calcium sulfate type water. Results of analyses of 42 groundwater samples for major ions, metals, trace elements, and radionuclide constituents indicated that statistically at least one principal aquifer had significant differences in its water chemistry. In general, the water chemistry of the Dakota aquifer was similar to the water chemistry of the upland area alluvial aquifers in areas where there was a hydraulic connection. The water from the Dakota aquifer had large dissolved-solids, calcium, sulfate, chloride, iron, lithium, manganese, and strontium concentrations in areas where the aquifer is thought not to be in hydraulic connection with the Missouri River Valley and upland area alluvial aquifers. Ground-water quality in the Papio-MissouriRiver Natural Resources District is generally suitable for most uses. However, the numerous occurrences of herbicides in water of the Elkhorn and Platte River Valley alluvial aquifers, especially near the Platte River, are of concern because U.S. Environmental Protection Agency Maximum Contaminant Levels could be exceeded. Concentrations in three of nine water samples collected from wells completed in the Dakota aquifer exceeded the U.S. Environmental Protection Agency Maximum Contaminant Levels or Secondary Maximum Contaminant Levels for gross alpha activity, radon-222 activity, dissolved solids, sulfate, or iron. Also of concern are the exceedances of the U.S Environmental Protection Agency proposed Maximum Contaminant Level for radon-222 activity.

From the Cover: Environmental and biotic controls on the evolutionary history of insect body size

NASA Astrophysics Data System (ADS)

Clapham, Matthew E.; Karr, Jered A.

2012-07-01

Giant insects, with wingspans as large as 70 cm, ruled the Carboniferous and Permian skies. Gigantism has been linked to hyperoxic conditions because oxygen concentration is a key physiological control on body size, particularly in groups like flying insects that have high metabolic oxygen demands. Here we show, using a dataset of more than 10,500 fossil insect wing lengths, that size tracked atmospheric oxygen concentrations only for the first 150 Myr of insect evolution. The data are best explained by a model relating maximum size to atmospheric environmental oxygen concentration (pO2) until the end of the Jurassic, and then at constant sizes, independent of oxygen fluctuations, during the Cretaceous and, at a smaller size, the Cenozoic. Maximum insect size decreased even as atmospheric pO2 rose in the Early Cretaceous following the evolution and radiation of early birds, particularly as birds acquired adaptations that allowed more agile flight. A further decrease in maximum size during the Cenozoic may relate to the evolution of bats, the Cretaceous mass extinction, or further specialization of flying birds. The decoupling of insect size and atmospheric pO2 coincident with the radiation of birds suggests that biotic interactions, such as predation and competition, superseded oxygen as the most important constraint on maximum body size of the largest insects.

Occurrence and effects of tire wear particles in the environment--a critical review and an initial risk assessment.

PubMed

Wik, Anna; Dave, Göran

2009-01-01

This review summarizes the existing knowledge on the occurrence of tire wear particles in the environment, and their ecotoxicological effects. A meta-analysis on tire components in the environment revealed that tire wear particles are present in all environmental compartments, including air, water, soils/sediments, and biota. The maximum Predicted Environmental Concentrations (PECs) of tire wear particles in surface waters range from 0.03 to 56 mg l(-1) and the maximum PECs in sediments range from 0.3 to 155 g kg(-1) d.w. The results from our previous long-term studies with Ceriodaphnia dubia and Pseudokirchneriella subcapitata were used to derive Predicted No Effect Concentrations (PNECs). The upper ranges for PEC/PNEC ratios in water and sediment were >1, meaning that tire wear particles present potential risks for aquatic organisms. We suggest that management should be directed towards development and production of more environmentally friendly tires and improved road runoff treatment.

Meta-analysis for deriving age- and gender-specific dose-response relationships between urinary cadmium concentration and {beta} {sub 2}-microglobulinuria under environmental exposure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gamo, Masashi; Ono, Kyoko; Nakanishi, Junko

2006-05-15

A meta-analysis was conducted to derive age- and gender-specific dose-response relationships between urinary cadmium (Cd) concentration and {beta} {sub 2}-microglobulinuria ({beta}2MG-uria) under environmental exposure. {beta}2MG-uria was defined by a cutoff point of 1000 {mu}g {beta} {sub 2}-microglobulin/g creatinine. We proposed a model for describing the relationships among the interindividual variabilities in urinary Cd concentration, the ratio of Cd concentrations in the target organ and in urine, and the threshold Cd concentration in the target organ. The parameters in the model were determined so that good agreement might be achieved between the prevalence rates of {beta}2MG-uria reported in the literature andmore » those estimated by the model. In this analysis, only the data from the literature on populations environmentally exposed to Cd were used. Using the model and estimated parameters, the prevalence rate of {beta}2MG-uria can be estimated for an age- and gender-specific subpopulation for which the distribution of urinary Cd concentrations is known. The maximum permissible level of urinary Cd concentration was defined as the maximum geometric mean of the urinary Cd concentration in an age- and gender-specific subpopulation that would not result in a statistically significant increase in the prevalence rate of {beta}2MG-uria. This was estimated to be approximately 3 {mu}g/g creatinine for a population in a small geographical area and approximately 2 {mu}g/g creatinine for a nationwide population.« less

Quality of water on the Prairie Band Potawatomi Reservation, northeastern Kansas, February 1999 through February 2001

USGS Publications Warehouse

Trombley, T.J.

2001-01-01

Water-quality samples were collected from 20 surface-water sites and 7 ground-water sites across the Prairie Band Potawatomi Reservation in northeastern Kansas as part of a water-quality study begun in 1996. Water quality is a very important consideration for the tribe. Three creeks draining the reservation, Soldier, Little Soldier, and South Cedar Creeks, are important tribal resources used for maintaining subsistence fishing and hunting needs for tribal members. Samples were collected twice during June 1999 and June 2000 at all 20 surface-water sites after herbicide application, and nine quarterly samples were collected at 5 of the 20 sampling sites from February 1999 through February 2001. Samples were collected once at six wells and twice at one well from September through December 2000. Surface-water-quality constituents analyzed included nutrients, pesticides, and bacteria. In addition to nutrients, pesticides, and bacteria, ground-water constituents analyzed included major dissolved ions, arsenic, boron, and dissolved iron and manganese. The median nitrite plus nitrate concentration was 0.376 mg/L (milligram per liter) for 81 surface-water samples, and the maximum concentration was 4.18 mg/L as nitrogen, which is less than one-half the U.S. Environmental Protection Agency's Maximum Contaminant Level (MCL) for drinking water of 10 mg/L as nitrogen. Fifty-one of the 81 surface-water-quality samples exceeded the U.S. Environmental Protection Agency's recommended goal for total phosphorus of 0.10 mg/L for the protection of aquatic life. Triazine concentrations in 26 surface-water-quality samples collected during May and June 1999 and 2000 exceeded 3.0 ?g/L (micrograms per liter), the Maximum Contaminant Level established for drinking water by the U.S. Environmental Protection Agency. Triazine herbicide concentrations tended to be highest during late spring runoff after herbicide application. High concentrations of fecal indicator bacteria in surface water are a concern on the reservation with fecal coliform concentrations ranging from 4 to greater than 31,000 colonies per 100 milliliters of water with a median concentration of 570 colonies per 100 milliliters. More than one-half of the surface-water-quality samples exceeded the Kansas Department of Health and Environment contact recreation criteria of 200 and 2,000 colonies per 100 milliliters of water and were collected mostly during the spring and summer. Two wells had sodium concentrations of about 10 times the U.S. Environmental Protection Agengy health advisory level (HAL) of 20 mg/L; concentrations ranged from 241 to 336 mg/L. In water from two wells, sulfate concentrations exceeded 800 mg/L, more than three times the U.S. Environmental Protection Agency Secondary Maximum Contaminant Level (SMCL) for drinking water of 250 mg/L. All but two of the eight ground-water-quality samples had dissolved-solids concentrations exceeding the SMCL of 500 mg/L. The highest concentration of 2,010 mg/L was more than four times the SMCL. Dissolved boron concentrations exceeded the U.S. Environmental Protection Agency 600-?g/L HAL in water from two of the seven wells sampled. Because the HAL is for a lifetime of exposure, the anticipated health risk due to dissolved boron is low. Dissolved iron concentrations in ground-water samples exceeded the 300-?g/L SMCL for treated drinking water in three of the seven wells sampled. Dissolved manganese concentrations in water from the same three wells also exceeded the established SMCL of 50 ?g/L. Dissolved pesticides were not detected in any of the well samples; however, there were degradation products of the herbicides alachlor and metolachlor in several samples. Insecticides were not detected in any ground-water-quality samples. Low concentrations of E. coli and fecal coliform bacteria were detected in water from two wells, and E. coli was detected in water from one well. Much higher concentrations of E. coli, fecal coliform, and fecal strepto

Ground-Water Quality in the Delaware River Basin, New York, 2001 and 2005-2006

USGS Publications Warehouse

Nystrom, Elizabeth A.

2007-01-01

The Federal Clean Water Act Amendments of 1977 require that States monitor and report on the quality of ground water and surface water. To satisfy part of these requirements, the U.S. Geological Survey and New York State Department of Environmental Conservation have developed a program in which ground-water quality is assessed in 2 to 3 of New York State's 14 major basins each year. To characterize the quality of ground water in the Delaware River Basin in New York, water samples were collected from December 2005 to February 2006 from 10 wells finished in bedrock. Data from 9 samples collected from wells finished in sand and gravel in July and August 2001 for the National Water Quality Assessment Program also are included. Ground-water samples were collected and processed using standard U.S. Geological Survey procedures. Samples were analyzed for more than 230 properties and compounds, including physical properties, major ions, nutrients, trace elements, radon-222, pesticides and pesticide degradates, volatile organic compounds, and bacteria. Concentrations of most compounds were less than drinking-water standards established by the U.S. Environmental Protection Agency and New York State Department of Health; many of the organic analytes were not detected in any sample. Drinking-water standards that were exceeded at some sites include those for color, turbidity, pH, aluminum, arsenic, iron, manganese, radon-222, and bacteria. pH ranged from 5.6 to 8.3; the pH of nine samples was less than the U.S. Environmental Protection Agency secondary drinking-water standard range of 6.5 to 8.5. Water in the basin is generally soft to moderately hard (hardness 120 milligrams per liter as CaCO3 or less). The cation with the highest median concentration was calcium; the anion with the highest median concentrations was bicarbonate. Nitrate was the predominant nutrient detected but no sample exceeded the 10 mg/L U.S. Environmental Protection Agency maximum contaminant level. The trace elements detected with the highest median concentrations were strontium and iron in unfiltered water and strontium and barium in filtered water. Concentrations of trace elements in several samples exceeded U.S. Environmental Protection Agency secondary drinking-water standards, including aluminum (50-200 micrograms per liter, three wells), arsenic (10 micrograms per liter, one well), iron (300 micrograms per liter, three wells), and manganese (50 micrograms per liter, four wells). The median concentration of radon-222 was 1,580 picoCuries per liter. Radon-222 is not currently regulated, but the U.S. Environmental Protection Agency has proposed a maximum contaminant level of 300 picoCuries per liter along with an alternative maximum contaminant level of 4,000 picoCuries per liter, to be in effect in states that have programs to address radon in indoor air. Concentrations of radon-222 exceeded the proposed maximum contaminant level in all 19 of the samples and exceeded the proposed alternative maximum contaminant level in 1 sample. Eleven pesticides and pesticide degradates were detected in samples from ten wells; all were herbicides or herbicide degradates. Three volatile organic compounds were detected, including disinfection byproducts such as trichloromethane and gasoline components or additives such as methyl tert-butyl ether. No pesticides, pesticide degradates, or volatile organic compounds were detected above established limits. Coliform bacteria were detected in samples from five wells, four of which were finished in sand and gravel; Escherichia coli was not detected in any sample.

OUTCROP-BASED LITHOFACIES AND DEPOSITIONAL SETTING OF ARSENIC-BEARING PERMIAN RED BEDS IN THE CENTRAL OKLAHOMA AQUIFER (COA), CLEVELAND COUNTY, OKLAHOMA

EPA Science Inventory

In January 2001, the Environmental Protection Agency established safe drinking water standards for arsenic at a maximum concentration of 10 mg/L. Results from the National Water-Quality Assessment Program (USGS), however, document the occurrence of arsenic concentrations in drin...

Environmental fate of Ra in cation-exchange regeneration brine waste disposed to septic tanks, New Jersey Coastal Plain, USA: migration to the water table.

PubMed

Szabo, Zoltan; Jacobsen, Eric; Kraemer, Thomas F; Parsa, Bahman

2010-01-01

Fate of radium (Ra) in liquid regeneration brine wastes from water softeners disposed to septic tanks in the New Jersey Coastal Plain was studied. Before treatment, combined Ra ((226)Ra plus (228)Ra) concentrations (maximum, 1.54 Bq L(-1)) exceeded the 0.185 Bq L(-1) Maximum Contaminant Level in 4 of 10 studied domestic-well waters (median pH, 4.90). At the water table downgradient from leachfields, combined Ra concentrations were low (commonly < or =0.019 Bq L(-1)) when pH was >5.3, indicating sequestration; when pH was < or =5.3 (acidic), concentrations were elevated (maximum, 0.985 Bq L(-1) - greater than concentrations in corresponding discharged septic-tank effluents (maximum, 0.243 Bq L(-1))), indicating Ra mobilization from leachfield sediments. Confidence in quantification of Ra mass balance was reduced by study design limitations, including synoptic sampling of effluents and ground waters, and large uncertainties associated with analytical methods. The trend of Ra mobilization in acidic environments does match observations from regional water-quality assessments.

Reconstructing Historical VOC Concentrations in Drinking Water for Epidemiological Studies at a U.S. Military Base: Summary of Results

PubMed Central

Maslia, Morris L.; Aral, Mustafa M.; Ruckart, Perri Z.; Bove, Frank J.

2017-01-01

A U.S. government health agency conducted epidemiological studies to evaluate whether exposures to drinking water contaminated with volatile organic compounds (VOC) at U.S. Marine Corps Base Camp Lejeune, North Carolina, were associated with increased health risks to children and adults. These health studies required knowledge of contaminant concentrations in drinking water—at monthly intervals—delivered to family housing, barracks, and other facilities within the study area. Because concentration data were limited or unavailable during much of the period of contamination (1950s–1985), the historical reconstruction process was used to quantify estimates of monthly mean contaminant-specific concentrations. This paper integrates many efforts, reports, and papers into a synthesis of the overall approach to, and results from, a drinking-water historical reconstruction study. Results show that at the Tarawa Terrace water treatment plant (WTP) reconstructed (simulated) tetrachloroethylene (PCE) concentrations reached a maximum monthly average value of 183 micrograms per liter (μg/L) compared to a one-time maximum measured value of 215 μg/L and exceeded the U.S. Environmental Protection Agency’s current maximum contaminant level (MCL) of 5 μg/L during the period November 1957–February 1987. At the Hadnot Point WTP, reconstructed trichloroethylene (TCE) concentrations reached a maximum monthly average value of 783 μg/L compared to a one-time maximum measured value of 1400 μg/L during the period August 1953–December 1984. The Hadnot Point WTP also provided contaminated drinking water to the Holcomb Boulevard housing area continuously prior to June 1972, when the Holcomb Boulevard WTP came on line (maximum reconstructed TCE concentration of 32 μg/L) and intermittently during the period June 1972–February 1985 (maximum reconstructed TCE concentration of 66 μg/L). Applying the historical reconstruction process to quantify contaminant-specific monthly drinking-water concentrations is advantageous for epidemiological studies when compared to using the classical exposed versus unexposed approach. PMID:28868161

ARSENIC IN DRINKING WATER: USING SOUND SCIENCE FOR RISK MANAGEMENT AND ASSISTING COMMUNITY DECISION-MAKERS - A MULTI-AGENCY, COMMUNITY-BASED RESEARCH PROJECT

EPA Science Inventory

Studies have indicated that arsenic concentrations greater than the new U.S. Environmental Protection Agency (U.S. EPA) maximum contaminant level (MCL) concentration of 10 micrograms per liter (ug/L) occur in numerous aquifers around the United States. One such aquifer is the Cen...

Hydrogeology and quality of ground water in the Boone Formation and Cotter Dolomite in karst terrain of northwestern Boone County, Arkansas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leidy, V.A.; Morris, E.E.

1991-01-01

Shallow groundwater flow systems in karst terrain of northwestern Boone County, Arkansas, are particularly susceptible to contamination. The potential for groundwater contamination probably is greater in the northern one-half of the study area where there are more photolineaments and presumably subsurface fractures. Groundwater samples from 17 springs discharging from the Boone Formation and 17 wells completed in the Cotter Dolomite were analyzed to determine ambient groundwater quality and to document water quality variations. The chemical constituents in groundwater generally did not exceed US Environmental Protection Agency primary or secondary maximum contaminant levels. However, fecal coliform and fecal streptococcus bacteria weremore » detected in most springs and in three wells. One spring, located near an abandoned wood-treatment plant (a designated Superfund site), had maximum iron, manganese, lead, and pentachlorophenol concentration that exceeded US Environmental Protection Agency's primary or secondary maximum contamination levels for drinking water. Water samples collected from selected springs emerging from the Boone Formation exhibited an overall decrease in specific conductance and total alkalinity, calcium, magnesium, sodium, and chloride concentrations and an overall increase in nitrate, fecal coliform, and fecal streptococcus bacteria concentrations 3 to 8 hours after a rainstorm.« less

Ground-water quality, Cook Inlet Basin, Alaska, 1999

USGS Publications Warehouse

Glass, Roy L.

2001-01-01

As part of the U.S. Geological Survey?s National Water-Quality Assessment Program, ground-water samples were collected from 34 existing wells in the Cook Inlet Basin in south-central Alaska during 1999. All ground-water samples were from aquifers composed of glacial or alluvial sediments. The water samples were used to determine the occurrence and distribution of selected major ions, nutrients, trace elements, volatile organic compounds, pesticides, radioisotopes, and environmental isotopes. Of 34 samples, 29 were from wells chosen by using a grid-based random-selection process. Water samples from five major public-supply wells also were collected. Radon-222 and arsenic concentrations exceeded drinking-water standards proposed by the U.S. Environmental Protection Agency in 39 and 18 percent of sampled wells, respectively. The highest radon concentration measured during this study was 610 picocuries per liter; 12 of 31 samples exceeded the proposed maximum contaminant level of 300 picocuries per liter. The highest arsenic concentration was 29 micrograms per liter; 6 of 34 samples exceeded the proposed maximum contaminant level of 10 micrograms per liter. Human activities may be increasing the concen- tration of nitrate in ground water, but nitrate concentrations in all samples were less than the maximum contaminant level of 10 milligrams per liter as nitrogen. Concentrations of nitrate were highest in Anchorage and were as great as 4.8 milligrams per liter as nitrogen. Dissolved-solids concentrations ranged from 77 to 986 milligrams per liter; only 2 of 34 wells yielded water having greater than 500 milligrams per liter. Iron and manganese concentrations exceeded secondary maximum contaminant levels in 18 and 42 percent of samples, respectively. Concentrations of all pesticides and volatile organic compounds detected in ground-water samples were very low, less than 1 microgram per liter. No pesticide or volatile organic compounds were detected at concentrations exceeding drinking-water standards or guidelines. Water samples from one-half of the wells sampled had no detectable concentrations of pesticides or volatile organic carbons, at the parts-per-billion level. Concentrations of stable isotopes of hydrogen and oxygen in ground-water samples were similar to concentrations expected for modern precipitation and for water that has been affected by evaporation. Tritium activities and concentrations of chlorofluorocarbons indicated that the water samples collected from most wells were recharged less than 50 years ago.

Glyphosate, other herbicides, and transformation products in Midwestern streams, 2002

USGS Publications Warehouse

Battaglin, W.A.; Kolpin, D.W.; Scribner, E.A.; Kuivila, K.M.; Sandstrom, M.W.

2005-01-01

The use of glyphosate has increased rapidly, and there is limited understanding of its environmental fate. The objective of this study was to document the occurrence of glyphosate and the transformation product aminomethylphosphonic acid (AMPA) in Midwestern streams and to compare their occurrence with that of more commonly measured herbicides such as acetochlor, atrazine, and metolachlor. Water samples were collected at sites on 51 streams in nine Midwestern states in 2002 during three runoff events: after the application of pre-emergence herbicides, after the application of post-emergence herbicides, and during harvest season. All samples were analyzed for glyphosate and 20 other herbicides using gas chromatography/mass spectrometry or high performance liquid chromatography/mass spectrometry. The frequency of glyphosate and AMPA detection, range of concentrations in runoff samples, and ratios of AMPA to glyphosate concentrations did not vary throughout the growing season as substantially as for other herbicides like atrazine, probably because of different seasonal use patterns. Glyphosate was detected at or above 0.1 μg/1 in 35 percent of pre-emergence, 40 percent of post-emergence, and 31 percent of harvest season samples, with a maximum concentration of 8.7 μg/1. AMPA was detected at or above 0.1 μg/1 in 53 percent of pre-emergence, 83 percent of post-emergence, and 73 percent of harvest season samples, with a maximum concentration of 3.6 μg/1. Glyphosate was not detected at a concentration at or above the U.S. Environmental Protection Agency's maximum contamination level (MCL) of 700 μg/1 in any sample. Atrazine was detected at or above 0.1 μg/1 in 94 percent of pre-emergence, 96 percent of post-emergence, and 57 percent of harvest season samples, with a maximum concentration of 55 μg/1. Atrazine was detected at or above its MCL (3 μg/1) in 57 percent of pre-emergence and 33 percent of post-emergence samples

Glyphasate, other herbicides, and transformation products in midwestern streams, 2002

USGS Publications Warehouse

Battaglin, William A.; Koplin, Dana W.; Scribner, Elizabeth A.; Kuivila, Kathryn; Sandstrom, Mark W.

2005-01-01

The use of glyphosate has increased rapidly, and there is limited understanding of its environmental fate. The objective of this study was to document the occurrence of glyphosate and the transformation product aminomethylphosphonic acid (AMPA) in Midwestern streams and to compare their occurrence with that of more commonly measured herbicides such as acetochlor, atrazine, and metolachlor. Water samples were collected at sites on 51 streams in nine Midwestern states in 2002 during three runoff events: after the application of pre-emergence herbicides, after the application of post-emergence herbicides, and during harvest season. All samples were analyzed for glyphosate and 20 other herbicides using gas chromatography/mass spectrometry or high performance liquid chromatography/mass spectrometry. The frequency of glyphosate and AMPA detection, range of concentrations in runoff samples, and ratios of AMPA to glyphosate concentrations did not vary throughout the growing season as substantially as for other herbicides like atrazine, probably because of different seasonal use patterns. Glyphosate was detected at or above 0.1 μg/1 in 35 percent of pre-emergence, 40 percent of post-emergence, and 31 percent of harvest season samples, with a maximum concentration of 8.7 μg/1. AMPA was detected at or above 0.1 μg/1 in 53 percent of pre-emergence, 83 percent of post-emergence, and 73 percent of harvest season samples, with a maximum concentration of 3.6 μg/1. Glyphosate was not detected at a concentration at or above the U.S. Environmental Protection Agency's maximum contamination level (MCL) of 700 μg/1 in any sample. Atrazine was detected at or above 0.1 μg/1 in 94 percent of pre-emergence, 96 percent of post-emergence, and 57 percent of harvest season samples, with a maximum concentration of 55 μg/1. Atrazine was detected at or above its MCL (3 μg/1) in 57 percent of pre-emergence and 33 percent of post-emergence samples.

Nonylphenol: Properties, legislation, toxicity and determination.

PubMed

Araujo, Frederico G DE; Bauerfeldt, Glauco F; Cid, Yara Peluso

2017-08-07

This paper aims to gather and discuss important information about nonylphenol, such as physical chemistry properties, toxicity and analytical methods in various matrices. As a degradation product of ethoxylated alkylphenols, nonylphenol presents a higher degree of reactivity than its precursor. Due to its harmful effects on the environment, use and production of nonylphenol has been banned in European Union countries, alongside their precursors. The guide on quality of drinking water (USEPA) recommends a maximum concentration of 28 µg L-1 for fresh water. In Brazil, there is no clear legislation containing values ​​of maximum concentration of nonylphenol. Due to this lack of regulation, a continuous monitoring is necessary of this pollutant in environmental samples. This paper aims to encourage further studies on nonylphenol, seen as a critical environmental pollutant. For proper monitoring is necessary to have reliable analytical methods and easy to perform in routine analysis.

Baseline groundwater quality in national park units within the Marcellus and Utica Shale gas plays, New York, Pennsylvania, and West Virginia, 2011

USGS Publications Warehouse

Eckhardt, David A.V.; Sloto, Ronald A.

2012-01-01

Groundwater samples were collected from 15 production wells and 1 spring at 9 national park units in New York, Pennsylvania, and West Virginia in July and August 2011 and analyzed to characterize the quality of these water supplies. The sample sites generally were selected to represent areas of potential effects on water quality by drilling and development of gas wells in Marcellus Shale and Utica Shale areas of the northeastern United States. The groundwater samples were analyzed for 53 constituents, including nutrients, major inorganic constituents, trace elements, chemical oxygen demand, radioactivity, and dissolved gases, including methane and radon-222. Results indicated that the groundwater used for water supply at the selected national park units is generally of acceptable quality, although concentrations of some constituents exceeded at least one drinking-water guideline at several wells. Nine analytes were detected in concentrations that exceeded Federal drinking-water standards, mostly secondary standards that define aesthetic properties of water, such as taste and odor. One sample had an arsenic concentration that exceeded the U.S. Environmental Protection Agency maximum contaminant level (MCL) of 10 micrograms per liter (μg/L). The pH, which is a measure of acidity (hydrogen ion activity), ranged from 4.8 to 8.4, and in 5 of the 16 samples, the pH values were outside the accepted U.S. Environmental Protection Agency secondary maximum contaminant level (SMCL) range of 6.5 to 8.5. The concentration of total dissolved solids exceeded the SMCL of 500 milligrams per liter (mg/L) at four sites. The sulfate concentration exceeded the SMCL of 250 mg/L concentration in one sample, and the fluoride concentration exceeded the SMCL of 2 mg/L in one sample. Sodium concentrations exceeded the U.S. Environmental Protection Agency drinking water health advisory of 60 mg/L at four sites. Iron concentrations exceeded the SMCL of 300 μg/L in two samples, and manganese concentrations exceeded the SMCL of 50 μg/L in five samples. Radon-222 concentrations exceeded the proposed U.S. Environmental Protection Agency MCL of 300 picocuries per liter in eight samples.

A rapid approach for measuring silver nanoparticle concentration and dissolution in seawater by UV-Vis.

PubMed

Sikder, Mithun; Lead, Jamie R; Chandler, G Thomas; Baalousha, Mohammed

2018-03-15

Detection and quantification of engineered nanoparticles (NPs) in environmental systems is challenging and requires sophisticated analytical equipment. Furthermore, dissolution is an important environmental transformation process for silver nanoparticles (AgNPs) which affects the size, speciation and concentration of AgNPs in natural water systems. Herein, we present a simple approach for the detection, quantification and measurement of dissolution of PVP-coated AgNPs (PVP-AgNPs) based on monitoring their optical properties (extinction spectra) using UV-vis spectroscopy. The dependence of PVP-AgNPs extinction coefficient (ɛ) and maximum absorbance wavelength (λ max ) on NP size was experimentally determined. The concentration, size, and extinction spectra of PVP-AgNPs were characterized during dissolution in 30ppt synthetic seawater. AgNPs concentration was determined as the difference between the total and dissolved Ag concentrations measured by inductively coupled plasma-mass spectroscopy (ICP-MS); extinction spectra of PVP-AgNPs were monitored by UV-vis; and size evolution was monitored by atomic force microscopy (AFM) over a period of 96h. Empirical equations for the dependence of maximum absorbance wavelength (λ max ) and extinction coefficient (ɛ) on NP size were derived. These empirical formulas were then used to calculate the size and concentration of PVP-AgNPs, and dissolved Ag concentration released from PVP-AgNPs in synthetic seawater at variable particle concentrations (i.e. 25-1500μgL -1 ) and in natural seawater at particle concentration of 100μgL -1 . These results suggest that UV-vis can be used as an easy and quick approach for detection and quantification (size and concentration) of sterically stabilized PVP-AgNPs from their extinction spectra. This approach can also be used to monitor the release of Ag from PVP-AgNPs and the concurrent NP size change. Finally, in seawater, AgNPs dissolve faster and to a higher extent with the decrease in NP concentration toward environmentally relevant concentrations. Copyright © 2017 Elsevier B.V. All rights reserved.

Environmental implications of material leached from coal.

PubMed

Moyo, Stanley; Mujuru, Munyaradzi; McCrindle, Rob I; Mokgalaka-Matlala, Ntebogeng

2011-05-01

Samples of coal were collected from different seams at a South African coal mine and comparative leaching experiments were carried out under various pH conditions and times to investigate the leaching behavior and potential environmental impact of possibly hazardous elements such as As, Cd, Co, Cr, Mn, Ni, Pb, Th and U. The calculated leaching intensities, sequential extraction results and cumulative percentages demonstrate that the leaching behavior of the elements is strongly influenced by the pH, the leaching time and the properties and occurrences of the elements. The leached concentrations of As, Cd, Co, Cr, Mn, Ni and Pb exceeded the maximum concentrations recommended by the Environmental Protection Agency (EPA) for surface water.

Concentrations of selected pharmaceuticals and antibiotics in south-central Pennsylvania waters, March through September 2006

USGS Publications Warehouse

Loper, Connie A.; Crawford, J. Kent; Otto, Kim L.; Manning, Rhonda L.; Meyer, Michael T.; Furlong, Edward T.

2007-01-01

This report presents environmental and quality-control data from analyses of 15 pharmaceutical and 31 antibiotic compounds in water samples from streams and wells in south-central Pennsylvania. The analyses are part of a study by the U.S. Geological Survey (USGS) in cooperation with the Pennsylvania Department of Environmental Protection (PADEP) to define concentrations of selected emerging contaminants in streams and well water in Pennsylvania. Sampling was conducted at 11 stream sites and at 6 wells in 9 counties of south-central Pennsylvania. Five of the streams received municipal wastewater and 6 of the streams received runoff from agricultural areas dominated by animal-feeding operations. For all 11 streams, samples were collected at locations upstream and downstream of the municipal effluents or animal-feeding operations. All six wells were in agricultural settings. A total of 120 environmental samples and 21 quality-control samples were analyzed for the study. Samples were collected at each site in March/April, May, July, and September 2006 to obtain information on changes in concentration that could be related to seasonal use of compounds.For streams, 13 pharmaceuticals and 11 antibiotics were detected at least 1 time. Detections included analytical results that were estimated or above the minimum reporting limits. Seventy-eight percent of all detections were analyzed in samples collected downstream from municipal-wastewater effluents. For streams receiving wastewater effluents, the pharmaceuticals caffeine and para-xanthine (a degradation product of caffeine) had the greatest concentrations, 4.75 μg/L (micrograms per liter) and 0.853 μg/L, respectively. Other pharmaceuticals and their respective maximum concentrations were carbamazepine (0.516 μg/L) and ibuprofen (0.277 μg/L). For streams receiving wastewater effluents, the antibiotic azithromycin had the greatest concentration (1.65 μg/L), followed by sulfamethoxazole (1.34 μg/L), ofloxacin (0.329 μg/L), and trimethoprim (0.256 μg/L).For streams receiving runoff from animal-feeding operations, the only pharmaceuticals detected were acetaminophen, caffeine, cotinine, diphenhydramine, and carbamazepine. The maximum concentration for pharmaceuticals was 0.053 μg/L. Three streams receiving runoff from animal-feeding operations had detections of one or more antibiotic compound--oxytetracycline, sulfadimethoxine, sulfamethoxazole, and tylosin. The maximum concentration for antibiotics was 0.157 μg/L. The average number of compounds (pharmaceuticals and antibiotics) detected in sites downstream from animal-feeding operations was three. The average number of compounds detected downstream from municipal-wastewater effluents was 13.For wells used to supply livestock, four compounds were detected--two pharmaceuticals (cotinine and diphenhydramine) and two antibiotics (tylosin and sulfamethoxazole). There were five detections in all the well samples. The maximum concentration detected in well water was for cotinine, estimated to be 0.024 μg/L.Seasonal occurrence of pharmaceutical and antibiotic compounds in stream water varied by compound and site type. At four stream sites, the same compounds were detected in all four seasonal samples. At other sites, pharmaceutical or antibiotic compounds were detected only one time in seasonal samples. Winter samples collected in streams receiving municipalwastewater effluent had the greatest number of compounds detected (21). Research analytical methods were used to determine concentrations for pharmaceuticals and antibiotics. To assist in evaluating the quality of the analyses, detailed information is presented on laboratory methodology and results from qualitycontrol samples. Quality-control data include results for nine blanks, nine duplicate environmental sample pairs, and three laboratory-spiked environmental samples as well as the recoveries of compounds in laboratory surrogates and laboratory reagent spikes.

Multiple extreme environmental conditions of intermittent soda pans in the Carpathian Basin (Central Europe).

PubMed

Boros, Emil; Katalin, V-Balogh; Vörös, Lajos; Horváth, Zsófia

2017-01-01

Soda lakes and pans represent saline ecosystems with unique chemical composition, occurring on all continents. The purpose of this study was to identify and characterise the main environmental gradients and trophic state that prevail in the soda pans (n=84) of the Carpathian Basin in Central Europe. Underwater light conditions, dissolved organic matter, phosphorus and chlorophyll a were investigated in 84 pans during 2009-2010. Besides, water temperature was measured hourly with an automatic sensor throughout one year in a selected pan. The pans were very shallow (median depth: 15 cm), and their extremely high turbidity (Secchi depth median: 3 cm, min: 0.5 cm) was caused by high concentrations of inorganic suspended solids (median: 0.4 g L -1 , max: 16 g L -1 ), which was the dominant (>50%) contributing factor to the vertical attenuation coefficient in 67 pans (80%). All pans were polyhumic (median DOC: 47 mg L -1 ), and total phosphorus concentration was also extremely high (median: 2 mg L -1 , max: 32 mg L -1 ). The daily water temperature maximum (44 °C) and fluctuation maximum (28 °C) were extremely high during summertime. The combination of environmental boundaries: shallowness, daily water temperature fluctuation, intermittent hydroperiod, high turbidity, polyhumic organic carbon concentration, high alkalinity and hypertrophy represent a unique extreme aquatic ecosystem.

Plant trait-species abundance relationships vary with environmental properties in subtropical forests in eastern china.

PubMed

Yan, En-Rong; Yang, Xiao-Dong; Chang, Scott X; Wang, Xi-Hua

2013-01-01

Understanding how plant trait-species abundance relationships change with a range of single and multivariate environmental properties is crucial for explaining species abundance and rarity. In this study, the abundance of 94 woody plant species was examined and related to 15 plant leaf and wood traits at both local and landscape scales involving 31 plots in subtropical forests in eastern China. Further, plant trait-species abundance relationships were related to a range of single and multivariate (PCA axes) environmental properties such as air humidity, soil moisture content, soil temperature, soil pH, and soil organic matter, nitrogen (N) and phosphorus (P) contents. At the landscape scale, plant maximum height, and twig and stem wood densities were positively correlated, whereas mean leaf area (MLA), leaf N concentration (LN), and total leaf area per twig size (TLA) were negatively correlated with species abundance. At the plot scale, plant maximum height, leaf and twig dry matter contents, twig and stem wood densities were positively correlated, but MLA, specific leaf area, LN, leaf P concentration and TLA were negatively correlated with species abundance. Plant trait-species abundance relationships shifted over the range of seven single environmental properties and along multivariate environmental axes in a similar way. In conclusion, strong relationships between plant traits and species abundance existed among and within communities. Significant shifts in plant trait-species abundance relationships in a range of environmental properties suggest strong environmental filtering processes that influence species abundance and rarity in the studied subtropical forests.

Carbon Dioxide Concentrations and Temperatures within Tour Buses under Real-Time Traffic Conditions.

PubMed

Chiu, Chun-Fu; Chen, Ming-Hung; Chang, Feng-Hsiang

2015-01-01

This study monitored the carbon dioxide (CO2) concentrations and temperatures of three 43-seat tour buses with high-passenger capacities in a course of a three-day, two-night school excursion. Results showed that both driver zones and passenger zones of the tour buses achieved maximum CO2 concentrations of more than 3000 ppm, and maximum daily average concentrations of 2510.6 and 2646.9 ppm, respectively. The findings confirmed that the CO2 concentrations detected in the tour buses exceeded the indoor air quality standard of Taiwan Environmental Protection Administration (8 hr-CO2: 1000 ppm) and the air quality guideline of Hong Kong Environmental Protection Department (1 hr-CO2: 2500 ppm for Level 1 for buses). Observations also showed that high-capacity tour bus cabins with air conditioning system operating in recirculation mode are severely lacking in air exchange rate, which may negatively impact transportation safety. Moreover, the passenger zones were able to maintain a temperature of between 20 and 25°C during travel, which effectively suppresses the dispersion of volatile organic compounds. Finally, the authors suggest that in the journey, increasing the ventilation frequency of tour bus cabin, which is very beneficial to maintain the travel safety and enhance the quality of travel.

Carbon Dioxide Concentrations and Temperatures within Tour Buses under Real-Time Traffic Conditions

PubMed Central

Chiu, Chun-Fu; Chen, Ming-Hung; Chang, Feng-Hsiang

2015-01-01

This study monitored the carbon dioxide (CO2) concentrations and temperatures of three 43-seat tour buses with high-passenger capacities in a course of a three-day, two-night school excursion. Results showed that both driver zones and passenger zones of the tour buses achieved maximum CO2 concentrations of more than 3000 ppm, and maximum daily average concentrations of 2510.6 and 2646.9 ppm, respectively. The findings confirmed that the CO2 concentrations detected in the tour buses exceeded the indoor air quality standard of Taiwan Environmental Protection Administration (8 hr-CO2: 1000 ppm) and the air quality guideline of Hong Kong Environmental Protection Department (1 hr-CO2: 2500 ppm for Level 1 for buses). Observations also showed that high-capacity tour bus cabins with air conditioning system operating in recirculation mode are severely lacking in air exchange rate, which may negatively impact transportation safety. Moreover, the passenger zones were able to maintain a temperature of between 20 and 25°C during travel, which effectively suppresses the dispersion of volatile organic compounds. Finally, the authors suggest that in the journey, increasing the ventilation frequency of tour bus cabin, which is very beneficial to maintain the travel safety and enhance the quality of travel. PMID:25923722

Effects of environmental ozone on the lung function of senior citizens

NASA Astrophysics Data System (ADS)

Höppe, Peter; Lindner, Jutta; Praml, Georg; Brönner, Norman

1995-09-01

Measurements with a body plethysmograph of lung function parameters and reports of unusual complaints or irritations were taken from 41 senior citizens in the situations where they usually spend their daytime hours. The subjects belonged to a group commonly assumed to be at risk from ozone. Each subject was examined on 8 days both in the morning and in the afternoon. The object was to obtain for every subject an equal distribution of measuring days between those with elevated ozone concentrations (maximum 0.5 h mean values between 1.00 and 4.00 p.m. of at least 0.050 ppm) and those with low ozone concentrations (maximum 0.5 h mean values between 1.00 and 4.00 p.m. of at most 0.040 ppm). The results showed no relevant ozone related effects on the lung function parameters or the subjective reports of irritations. Thus there was no indication that senior citizens represent a group at particular risk with respect to moderately elevated concentrations of environmental ozone, as occur in central Europe.

Mercury concentrations in snapping turtles (Chelydra serpentina) correlate with environmental and landscape characteristics.

PubMed

Turnquist, Madeline A; Driscoll, Charles T; Schulz, Kimberly L; Schlaepfer, Martin A

2011-10-01

Mercury (Hg) deposited onto the landscape can be transformed into methylmercury (MeHg), a neurotoxin that bioaccumulates up the aquatic food chain. Here, we report on Hg concentrations in snapping turtles (Chelydra serpentina) across New York State, USA. The objectives of this study were to: (1) test which landscape, water, and biometric characteristics correlate with total Hg (THg) concentrations in snapping turtles; and (2) determine whether soft tissue THg concentrations correlate with scute (shell) concentrations. Forty-eight turtles were sampled non-lethally from ten lakes and wetlands across New York to observe patterns under a range of ecosystem variables and water chemistry conditions. THg concentrations ranged from 0.041 to 1.50 μg/g and 0.47 to 7.43 μg/g wet weight of muscle tissue and shell, respectively. The vast majority of mercury (~94%) was in the MeHg form. Sixty-one percent of turtle muscle samples exceeded U.S. Environmental Protection Agency (U.S. EPA) consumption advisory limit of 0.3 μg Hg/g for fish. Muscle THg concentrations were significantly correlated with sulfate in water and the maximum elevation of the watershed. Shell THg concentrations were significantly correlated with the acid neutralizing capacity (ANC) of water, the maximum elevation of the watershed, the percent open water in the watershed, the lake to watershed size, and various forms of atmospheric Hg deposition. Thus, our results demonstrate that THg concentrations in snapping turtles are spatially variable, frequently exceed advisory limits, and are significantly correlated with several landscape and water characteristics.

Quality analysis, miceller behavior, and environmental impact of some laundry detergents available in Bangladesh.

PubMed

Nur-E-Alam, M; Islam, M Monirul; Islam, M Nazrul; Rima, Farhana Rahman; Islam, M Nurul

2016-03-01

The cleansing efficiencies of laundry detergents depend on composition and variation of ingredients such as surfactants, phosphate, and co-builders. Among these ingredients, surfactants and phosphate are considered as hazardous materials. Knowledge on compositions and micellar behavior is very useful for understanding their cleansing efficiencies and environmental impact. With this view, composition, critical micelle concentration, and dissolved oxygen level in aqueous solution of some laundry detergents available in Bangladesh such as keya, Wheel Power White, Tibet, Surf Excel, and Chaka were determined. Surfactant and phosphate were found to be maximum in Surf Excel and Wheel Power White, respectively, while both of the ingredients were found to be minimum in Tibet. The critical micelle concentration decreased with increasing surfactant content. The amount of laundry detergents required for efficient cleansing was found to be minimum for Surf Excel and maximum for Chaka; however, cleansing cost was the highest for Surf Excel and the lowest for Tibet. The maximum amount of surfactants and phosphate was discharged by Surf Excel and Wheel Power White, respectively, while discharges of both of the ingredients were minimum for Tibet. The maximum decrease of dissolved oxygen level was caused by Surf Excel and the minimum by Tibet. Therefore, it can be concluded that Tibet is cost-effective and environment friendly, whereas Surf Excel and Wheel Power White are expensive and pose a threat to water environment.

Streamflow and water-quality properties in the West Fork San Jacinto River Basin and regression models to estimate real-time suspended-sediment and total suspended-solids concentrations and loads in the West Fork San Jacinto River in the vicinity of Conroe, Texas, July 2008-August 2009

USGS Publications Warehouse

Bodkin, Lee J.; Oden, Jeannette H.

2010-01-01

To better understand the hydrology (streamflow and water quality) of the West Fork San Jacinto River Basin downstream from Lake Conroe near Conroe, Texas, including spatial and temporal variation in suspended-sediment (SS) and total suspended-solids (TSS) concentrations and loads, the U.S. Geological Survey, in cooperation with the Houston-Galveston Area Council and the Texas Commission on Environmental Quality, measured streamflow and collected continuous and discrete water-quality data during July 2008-August 2009 in the West Fork San Jacinto River Basin downstream from Lake Conroe. During July 2008-August 2009, discrete samples were collected and streamflow measurements were made over the range of flow conditions at two streamflow-gaging stations on the West Fork San Jacinto River: West Fork San Jacinto River below Lake Conroe near Conroe, Texas (station 08067650) and West Fork San Jacinto River near Conroe, Texas (station 08068000). In addition to samples collected at these two main monitoring sites, discrete sediment samples were also collected at five additional monitoring sites to help characterize water quality in the West Fork San Jacinto River Basin. Discrete samples were collected semimonthly, regardless of flow conditions, and during periods of high flow resulting from storms or releases from Lake Conroe. Because the period of data collection was relatively short (14 months) and low flow was prevalent during much of the study, relatively few samples collected were representative of the middle and upper ranges of historical daily mean streamflows. The largest streamflows tended to occur in response to large rainfall events and generally were associated with the largest SS and TSS concentrations. The maximum SS and TSS concentrations at station 08067650 (180 and 133 milligrams per liter [mg/L], respectively) were on April 19, 2009, when the instantaneous streamflow was the third largest associated with a discrete sample at the station. SS concentrations were 25 mg/L or less in 26 of 29 environmental samples and TSS concentrations were 25 mg/L or less in 25 of 28 environmental samples. Median SS and TSS concentrations were 7.0 and 7.6 mg/L, respectively. At station 08068000, the maximum SS concentration (1,270 mg/L) was on April 19, 2009, and the maximum TSS concentration (268 mg/L) was on September 18, 2008. SS concentrations were 25 mg/L or less in 16 of 27 of environmental samples and TSS concentrations were 25 mg/L or less in 18 of 26 environmental samples at the station. Median SS and TSS concentrations were 18.0 and 14.0 mg/L, respectively. The maximum SS and TSS concentrations for all five additional monitoring sites were 3,110 and 390 mg/L, respectively, and the minimum SS and TSS concentrations were 5.0 and 1.0 mg/L, respectively. Median concentrations ranged from 14.0 to 54.0 mg/L for SS and from 11.0 to 14.0 mg/L for TSS. Continuous measurements of streamflow and selected water-quality properties at stations 08067650 and 08068000 were evaluated as possible variables in regression equations developed to estimate SS and TSS concentrations and loads. Surrogate regression equations were developed to estimate SS and TSS loads by using real-time turbidity and streamflow data; turbidity and streamflow resulted in the best regression models for estimating near real-time SS and TSS concentrations for stations 08097650 and 08068000. Relatively large errors are associated with the regression-computed SS and TSS concentrations; the 90-percent prediction intervals for SS and TSS concentrations were (+/-)48.9 and (+/-)43.2 percent, respectively, for station 08067650 and (+/-)47.7 and (+/-)43.2 percent, respectively, for station 08068000. Regression-computed SS and TSS concentrations were corrected for bias before being used to compute SS and TSS loads. The total estimated SS and TSS loads during July 2008-August 2009 were about 3,540 and 1,900 tons, respectively, at station 08067650 and about 156,000 an

Comparison of predicted pesticide concentrations in groundwater from SCI-GROW and PRZM-GW models with historical monitoring data.

PubMed

Estes, Tammara L; Pai, Naresh; Winchell, Michael F

2016-06-01

A key factor in the human health risk assessment process for the registration of pesticides by the US Environmental Protection Agency (EPA) is an estimate of pesticide concentrations in groundwater used for drinking water. From 1997 to 2011, these estimates were obtained from the EPA empirical model SCI-GROW. Since 2012, these estimates have been obtained from the EPA deterministic model PRZM-GW, which has resulted in a significant increase in estimated groundwater concentrations for many pesticides. Historical groundwater monitoring data from the National Ambient Water Quality Assessment (NAWQA) Program (1991-2014) were compared with predicted groundwater concentrations from both SCI-GROW (v.2.3) and PRZM-GW (v.1.07) for 66 different pesticides of varying environmental fate properties. The pesticide environmental fate parameters associated with over- and underprediction of groundwater concentrations by the two models were evaluated. In general, SCI-GROW2.3 predicted groundwater concentrations were close to maximum historically observed groundwater concentrations. However, for pesticides with soil organic carbon content values below 1000 L kg(-1) and no simulated hydrolysis, PRZM-GW overpredicted, often by greater than 100 ppb. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Plant Trait-Species Abundance Relationships Vary with Environmental Properties in Subtropical Forests in Eastern China

PubMed Central

Yan, En-Rong; Yang, Xiao-Dong; Chang, Scott X.; Wang, Xi-Hua

2013-01-01

Understanding how plant trait-species abundance relationships change with a range of single and multivariate environmental properties is crucial for explaining species abundance and rarity. In this study, the abundance of 94 woody plant species was examined and related to 15 plant leaf and wood traits at both local and landscape scales involving 31 plots in subtropical forests in eastern China. Further, plant trait-species abundance relationships were related to a range of single and multivariate (PCA axes) environmental properties such as air humidity, soil moisture content, soil temperature, soil pH, and soil organic matter, nitrogen (N) and phosphorus (P) contents. At the landscape scale, plant maximum height, and twig and stem wood densities were positively correlated, whereas mean leaf area (MLA), leaf N concentration (LN), and total leaf area per twig size (TLA) were negatively correlated with species abundance. At the plot scale, plant maximum height, leaf and twig dry matter contents, twig and stem wood densities were positively correlated, but MLA, specific leaf area, LN, leaf P concentration and TLA were negatively correlated with species abundance. Plant trait-species abundance relationships shifted over the range of seven single environmental properties and along multivariate environmental axes in a similar way. In conclusion, strong relationships between plant traits and species abundance existed among and within communities. Significant shifts in plant trait-species abundance relationships in a range of environmental properties suggest strong environmental filtering processes that influence species abundance and rarity in the studied subtropical forests. PMID:23560114

Multiple extreme environmental conditions of intermittent soda pans in the Carpathian Basin (Central Europe)

PubMed Central

Boros, Emil; Katalin, V.-Balogh; Vörös, Lajos; Horváth, Zsófia

2017-01-01

Soda lakes and pans represent saline ecosystems with unique chemical composition, occurring on all continents. The purpose of this study was to identify and characterise the main environmental gradients and trophic state that prevail in the soda pans (n=84) of the Carpathian Basin in Central Europe. Underwater light conditions, dissolved organic matter, phosphorus and chlorophyll a were investigated in 84 pans during 2009–2010. Besides, water temperature was measured hourly with an automatic sensor throughout one year in a selected pan. The pans were very shallow (median depth: 15 cm), and their extremely high turbidity (Secchi depth median: 3 cm, min: 0.5 cm) was caused by high concentrations of inorganic suspended solids (median: 0.4 g L–1, max: 16 g L–1), which was the dominant (>50%) contributing factor to the vertical attenuation coefficient in 67 pans (80%). All pans were polyhumic (median DOC: 47 mg L–1), and total phosphorus concentration was also extremely high (median: 2 mg L–1, max: 32 mg L–1). The daily water temperature maximum (44 °C) and fluctuation maximum (28 °C) were extremely high during summertime. The combination of environmental boundaries: shallowness, daily water temperature fluctuation, intermittent hydroperiod, high turbidity, polyhumic organic carbon concentration, high alkalinity and hypertrophy represent a unique extreme aquatic ecosystem. PMID:28572691

Short term serum pharmacokinetics of diammine silver fluoride after oral application.

PubMed

Vasquez, Elsa; Zegarra, Graciela; Chirinos, Edgar; Castillo, Jorge L; Taves, Donald R; Watson, Gene E; Dills, Russell; Mancl, Lloyd L; Milgrom, Peter

2012-12-31

There is growing interest in the use of diammine silver fluoride (DSF) as a topical agent to treat dentin hypersensitivity and dental caries as gauged by increasing published research from many parts of the world. While DSF has been available in various formulations for many years, most of its pharmacokinetic aspects within the therapeutic concentration range have never been fully characterized. This preliminary study determined the applied doses (3 teeth treated), maximum serum concentrations, and time to maximum serum concentration for fluoride and silver in 6 adults over 4 h. Fluoride was determined using the indirect diffusion method with a fluoride selective electrode, and silver was determined using inductively coupled plasma-mass spectrometry. The mean amount of DSF solution applied to the 3 teeth was 7.57 mg (6.04 μL). Over the 4 hour observation period, the mean maximum serum concentrations were 1.86 μmol/L for fluoride and 206 nmol/L for silver. These maximums were reached 3.0 h and 2.5 h for fluoride and silver, respectively. Fluoride exposure was below the U.S. Environmental Protection Agency (EPA) oral reference dose. Silver exposure exceeded the EPA oral reference dose for cumulative daily exposure over a lifetime, but for occasional use was well below concentrations associated with toxicity. This preliminary study suggests that serum concentrations of fluoride and silver after topical application of DSF should pose little toxicity risk when used in adults. NCT01664871.

Short term serum pharmacokinetics of diammine silver fluoride after oral application

PubMed Central

2012-01-01

Background There is growing interest in the use of diammine silver fluoride (DSF) as a topical agent to treat dentin hypersensitivity and dental caries as gauged by increasing published research from many parts of the world. While DSF has been available in various formulations for many years, most of its pharmacokinetic aspects within the therapeutic concentration range have never been fully characterized. Methods This preliminary study determined the applied doses (3 teeth treated), maximum serum concentrations, and time to maximum serum concentration for fluoride and silver in 6 adults over 4 h. Fluoride was determined using the indirect diffusion method with a fluoride selective electrode, and silver was determined using inductively coupled plasma-mass spectrometry. The mean amount of DSF solution applied to the 3 teeth was 7.57 mg (6.04 μL). Results Over the 4 hour observation period, the mean maximum serum concentrations were 1.86 μmol/L for fluoride and 206 nmol/L for silver. These maximums were reached 3.0 h and 2.5 h for fluoride and silver, respectively. Conclusions Fluoride exposure was below the U.S. Environmental Protection Agency (EPA) oral reference dose. Silver exposure exceeded the EPA oral reference dose for cumulative daily exposure over a lifetime, but for occasional use was well below concentrations associated with toxicity. This preliminary study suggests that serum concentrations of fluoride and silver after topical application of DSF should pose little toxicity risk when used in adults. Clinical trials registration NCT01664871. PMID:23272643

Ground-water quality in the West Salt River Valley, Arizona, 1996-98: relations to hydrogeology, water use, and land use

USGS Publications Warehouse

Edmonds, Robert J.; Gellenbeck, Dorinda J.

2002-01-01

The U.S. Geological Survey collected and analyzed ground-water samples in the West Salt River Valley from 64 existing wells selected by a stratified-random procedure. Samples from an areally distributed group of 35 of these wells were used to characterize overall ground-water quality in the basin-fill aquifer. Analytes included the principal inorganic constituents, trace constituents, pesticides, and volatile organic compounds. Additional analytes were tritium, radon, and stable isotopes of hydrogen and oxygen. Analyses of replicate samples and blank samples provided evidence that the analyses of the ground-water samples were adequate for interpretation. The median concentration of dissolved solids in samples from the 35 wells was 560 milligrams per liter, which exceeded the U.S. Environmental Protection Agency Secondary Maximum Contaminant Level for drinking water. Eleven of the 35 samples had a nitrate concentration (as nitrogen) that exceeded the U.S. Environmental Protection Agency Maximum Contaminant Level for drinking water of 10 milligrams per liter. Pesticides were detected in eight samples; concentrations were below the Maximum Contaminant Levels. Deethylatrazine was most commonly detected. The pesticides were detected in samples from wells in agricultural or urban areas that have been irrigated. Concentrations of all trace constituents, except arsenic, were less than the Maximum Contaminant Levels. The concentration of arsenic exceeded the Maximum Contaminant Level of 50 micrograms per liter in two samples. Nine monitoring wells were constructed in an area near Buckeye to assess the effects of agricultural land use on shallow ground water. The median concentration of dissolved solids was 3,340 milligrams per liter in samples collected from these wells in August 1997. The nitrate concentration (as nitrogen) exceeded the Maximum Contaminant Level (10 milligrams per liter) in samples from eight of the nine monitoring wells in August 1997 and again in February 1998. Analyses of all samples collected from the monitoring wells indicated low concentrations of pesticides and volatile organic compounds. The most frequently detected pesticides were deethylatrazine and atrazine. Trichloromethane (chloroform) and tetrachloroethene (PCE) were the most frequently detected volatile organic compounds in the monitoring wells. Two compounds [dieldrin and 1,1-dichloro-2,2-bis(p-dichlorodiphenyl)ethylene (DDE)], decomposition products of two banned pesticides, aldrin and dichlorodiphenylethylene (DDT), were detected at low concentrations in samples analyzed for the agricultural land-use study. In the West Salt River Valley, a high concentration of the heavier oxygen isotope?oxygen-18?in ground water generally indicates effects of evaporation on recharge water from irrigation. Wells in undeveloped areas and wells that have openings beneath a confining bed generally yield ground water that is free of the effects of irrigation seepage. Samples from these wells did not contain detectable concentrations of pesticides. The median concentrations of nitrate (as nitrogen) and dissolved solids in samples from wells in undeveloped areas were 1.7 milligrams per liter and 257 milligrams per liter, respectively. The median concentrations of nitrate (as nitrogen) and dissolved solids in samples from wells that yield water from below confining beds were 2.0 and 747 milligrams per liter, respectively.

Using tsunami deposits to determine the maximum depth of benthic burrowing

PubMed Central

Shirai, Kotaro; Murakami-Sugihara, Naoko

2017-01-01

The maximum depth of sediment biomixing is directly related to the vertical extent of post-depositional environmental alteration in the sediment; consequently, it is important to determine the maximum burrowing depth. This study examined the maximum depth of bioturbation in a natural marine environment in Funakoshi Bay, northeastern Japan, using observations of bioturbation structures developed in an event layer (tsunami deposits of the 2011 Tohoku-Oki earthquake) and measurements of the radioactive cesium concentrations in this layer. The observations revealed that the depth of bioturbation (i.e., the thickness of the biomixing layer) ranged between 11 and 22 cm, and varied among the sampling sites. In contrast, the radioactive cesium concentrations showed that the processing of radioactive cesium in coastal environments may include other pathways in addition to bioturbation. The data also revealed the nature of the bioturbation by the heart urchin Echinocardium cordatum (Echinoidea: Loveniidae), which is one of the important ecosystem engineers in seafloor environments. The maximum burrowing depth of E. cordatum in Funakoshi Bay was 22 cm from the seafloor surface. PMID:28854254

Using tsunami deposits to determine the maximum depth of benthic burrowing.

PubMed

Seike, Koji; Shirai, Kotaro; Murakami-Sugihara, Naoko

2017-01-01

The maximum depth of sediment biomixing is directly related to the vertical extent of post-depositional environmental alteration in the sediment; consequently, it is important to determine the maximum burrowing depth. This study examined the maximum depth of bioturbation in a natural marine environment in Funakoshi Bay, northeastern Japan, using observations of bioturbation structures developed in an event layer (tsunami deposits of the 2011 Tohoku-Oki earthquake) and measurements of the radioactive cesium concentrations in this layer. The observations revealed that the depth of bioturbation (i.e., the thickness of the biomixing layer) ranged between 11 and 22 cm, and varied among the sampling sites. In contrast, the radioactive cesium concentrations showed that the processing of radioactive cesium in coastal environments may include other pathways in addition to bioturbation. The data also revealed the nature of the bioturbation by the heart urchin Echinocardium cordatum (Echinoidea: Loveniidae), which is one of the important ecosystem engineers in seafloor environments. The maximum burrowing depth of E. cordatum in Funakoshi Bay was 22 cm from the seafloor surface.

Limnological Conditions and Occurrence of Taste-and-Odor Compounds in Lake William C. Bowen and Municipal Reservoir #1, Spartanburg County, South Carolina, 2006-2009

USGS Publications Warehouse

Journey, Celeste A.; Arrington, Jane M.; Beaulieu, Karen M.; Graham, Jennifer L.; Bradley, Paul M.

2011-01-01

Limnological conditions and the occurrence of taste-and-odor compounds were studied in two reservoirs in Spartanburg County, South Carolina, from May 2006 to June 2009. Lake William C. Bowen and Municipal Reservoir #1 are relatively shallow, meso-eutrophic, warm monomictic, cascading impoundments on the South Pacolet River. Overall, water-quality conditions and phytoplankton community assemblages were similar between the two reservoirs but differed seasonally. Median dissolved geosmin concentrations in the reservoirs ranged from 0.004 to 0.006 microgram per liter. Annual maximum dissolved geosmin concentrations tended to occur between March and May. In this study, peak dissolved geosmin production occurred in April and May 2008, ranging from 0.050 to 0.100 microgram per liter at the deeper reservoir sites. Peak dissolved geosmin production was not concurrent with maximum cyanobacterial biovolumes, which tended to occur in the summer (July to August), but was concurrent with a peak in the fraction of genera with known geosmin-producing strains in the cyanobacteria group. Nonetheless, annual maximum cyanobacterial biovolumes rarely resulted in cyanobacteria dominance of the phytoplankton community. In both reservoirs, elevated dissolved geosmin concentrations were correlated to environmental factors indicative of unstratified conditions and reduced algal productivity, but not to nutrient concentrations or ratios. With respect to potential geosmin sources, elevated geosmin concentrations were correlated to greater fractions of genera with known geosmin-producing strains in the cyanobacteria group and to biovolumes of a specific geosmin-producing cyanobacteria genus (Oscillatoria), but not to actinomycetes concentrations. Conversely, environmental factors that correlated with elevated cyanobacterial biovolumes were indicative of stable water columns (stratified conditions), warm water temperatures, reduced nitrogen concentrations, longer residence times, and high phosphorus concentrations in the hypolimnion. Biovolumes of Cylindrospermopsis, Planktolyngbya, Synechococcus, Synechocystis, and Aphanizomenon correlated with the greater cyanobacteria biovolumes and were the dominant taxa in the cyanobacteria group. Related environmental variables were selected as input into multiple logistic regression models to evaluate the likelihood that geosmin concentrations could exceed the threshold level for human detection. In Lake William C. Bowen, the likelihood that dissolved geosmin concentrations exceeded the human detection threshold was estimated by greater mixing zone depths and differences in the 30-day prior moving window averages of overflow and flowthrough at Lake Bowen dam and by lower total nitrogen concentrations. At the R.B. Simms Water Treatment Plant, the likelihood that total geosmin concentrations in the raw water exceeded the human detection threshold was estimated by greater outflow from Reservoir #1 and lower concentrations of dissolved inorganic nitrogen. Overall, both models indicated greater likelihood that geosmin could exceed the human detection threshold during periods of lower nitrogen concentrations and greater water movement in the reservoirs.

RESTORATION OF MUNICIPAL DRINKING WATER SUPPLY WELLS IMPACTED BY NATURALLY OCCURRING ARSENIC

EPA Science Inventory

Studies have indicated that arsenic concentrations greater than the newly proposed U.S. Environmental Protection Agency (EPA) maximum contaminant level (MCL) of 10 micrograms per liter (ug/L) occur in specific parts of numerous aquifers around the United States. One such aquifer...

Quality of water and chemistry of bottom sediment in the Rillito Creek basin, Tucson, Arizona, 1992-93

USGS Publications Warehouse

Tadayon, Saeid

1995-01-01

Physical and chemical data were collected from four surface-water sites, six ground-water sites, and two bottom-sediment sites during 1992-93. Specific conductance, hardness, alkalinity, and dissolved- solids concentrations generally were higher in ground water than in surface water. The median concentrations of dissolved major ions, with the exception of potassium, were higher in ground water than in surface water. In surface water and ground water, calcium was the dominant cation, and bicarbonate was the dominant anion. Concentrations of dissolved nitrite and nitrite plus nitrate in surface water and ground water did not exceed the U.S. Environmental Protection Agency maximum contaminant levels of 1 and 10 milligrams per liter for drinking water, respectively. Ammonium plus organic nitrogen in bottom sediment was detected at the highest concentration of any nitrogen species. Median values for most of the dissolved trace elements in surface water and ground water were below the detection levels. Dissolved trace elements in surface water and ground water did not exceed the U.S. Environmental Protection Agency maximum contaminant levels for drinking water. Trace-element concentrations in bottom sediment were similar to trace-element concentrations reported for soils of the western conterminous United States. Several organochlorine pesticides and priority pollutants were detected in surface-water and bottom-sediment samples; however, they did not exceed water-quality standards. Pesticides or priority pollutants were not detected in ground-water samples.

Ground-water quality in the Chemung River Basin, New York, 2003

USGS Publications Warehouse

Hetcher-Aguila, Kari K.

2005-01-01

Water samples were collected from 24 public-supply wells and 13 private residential wells during the summer of 2003 and analyzed to describe the chemical quality of ground water throughout the Chemung River basin, upgradient from Waverly, N.Y, on the Pennsylvania border. Wells were selected to represent areas of heaviest ground-water use and greatest vulnerability to contamination, and to obtain a geographical distribution across the 1,130 square-mile basin. Samples were analyzed for physical properties, inorganic constituents, nutrients, metals and radionuclides, pesticides, volatile organic compounds, and bacteria.The cations that were detected in the highest concentrations were calcium and sodium; the anions that were detected in the greatest concentrations were bicarbonate, chloride, and sulfate. The predominant nutrient was nitrate. Nitrate concentrations in samples from wells finished in sand and gravel were greater than in those from wells finished in bedrock, except for one bedrock well, which had the highest nitrate concentration of any sample in this study. The most commonly detected metals were aluminum, barium, iron, manganese, and strontium. The range of tritium concentrations (0.6 to 12.5 tritium units) indicates that the water ages ranged from less than 10 years old to more than 50 years old. All but one of the 15 pesticides detected were herbicides; those detected most frequently were atrazine, deethylatrazine, and two degradation products of metolachlor (metachlor ESA and metachlor OA), which were the pesticides detected at the highest concentrations. Not every sample collected was analyzed for pesticides, and pesticides were detected only in wells finished in sand and gravel. Volatile organic compounds were detected in 15 samples, and the concentrations were at or near the analytical detection limits. Total coliform were detected in 12 samples; fecal coliform were detected in 7 samples; and Escherichia coli was detected in 6 samples. These bacteria were detected in water from bedrock as well as sand-and-gravel aquifers.Federal and State water-quality standards were exceeded in several samples. Two samples exceeded the chloride U.S. Environmental Protection Agency Secondary Maximum Contaminant Level of 250 milligrams per liter. The U.S. Environmental Protection Agency Drinking Water Advisory for sodium (30 to 60 milligrams per liter) was exceeded in 11 samples. The upper limit of the Secondary Maximum Contaminant Level range for aluminum (200 micrograms per liter) was exceeded in one sample. The Maximum Contaminant Level for barium (2,000 micrograms per liter) was exceeded in one sample. The Secondary Maximum Contaminant Level for iron (300 micrograms per liter) was exceeded in 11 samples. The Secondary Maximum Contaminant Level for manganese (50 micrograms per liter) was exceeded in 20 samples. The proposed Maximum Contaminant Level for radon (300 picocuries per liter) was exceeded in 34 samples.

REAGENTLESS FIELD-USABLE FIXED-SITE AND PORTABLE ANALYZER FOR TRIHALOMETHANE (THM) CONCENTRATIONS IN DRINKING WATER - PHASE I

EPA Science Inventory

Environmental Protection Agency rules stipulate that corrective action be taken for drinking water distribution systems that exceed the maximum contaminant level (MCL) for total Trihalomethanes (TTHMs) 80μg/L.  Real-time, or even periodic, monitoring of drinking water i...

Concentrations and environmental fate of Ra in cation-exchange regeneration brine waste disposed to septic tanks and accumulation in sludge, New Jersey Coastal Plain, USA.

PubMed

Szabo, Zoltan; Jacobsen, Eric; Kraemer, Thomas F; Parsa, Bahman

2008-06-01

Concentrations of Ra in liquid and solid wastes generated from 15 softeners treating domestic well waters from New Jersey Coastal Plain aquifers (where combined Ra ((226)Ra plus (228)Ra) concentrations commonly exceed 0.185 Bq L(-1)) were determined. Softeners, when maintained, reduced combined Ra about 10-fold (<0.024 Bq L(-1)). Combined Ra exceeded 0.185 Bq L(-1) at 1 non-maintained system. Combined Ra was enriched in regeneration brine waste (maximum, 81.2 Bq L(-1)), but concentrations in septic-tank effluents receiving brine waste were less than in the untreated ground waters. The maximum combined Ra concentration in aquifer sands (40.7 Bq kg(-1) dry weight) was less than that in sludge from the septic tanks (range, 84-363 Bq kg(-1)), indicating Ra accumulation in sludge from effluent. The combined Ra concentration in sludge from the homeowners' septic systems falls within the range reported for sludge samples from publicly owned treatment works within the region.

Concentrations and environmental fate of Ra in cation-exchange regeneration brine waste disposed to septic tanks and accumulation in sludge, New Jersey Coastal Plain, USA

USGS Publications Warehouse

Szabo, Z.; Jacobsen, E.; Kraemer, T.F.; Parsa, B.

2008-01-01

Concentrations of Ra in liquid and solid wastes generated from 15 softeners treating domestic well waters from New Jersey Coastal Plain aquifers (where combined Ra (226Ra plus 228Ra) concentrations commonly exceed 0.185 Bq L-1) were determined. Softeners, when maintained, reduced combined Ra about 10-fold (<0.024 Bq L-1). Combined Ra exceeded 0.185 Bq L-1 at 1 non-maintained system. Combined Ra was enriched in regeneration brine waste (maximum, 81.2 Bq L-1), but concentrations in septic-tank effluents receiving brine waste were less than in the untreated ground waters. The maximum combined Ra concentration in aquifer sands (40.7 Bq kg-1 dry weight) was less than that in sludge from the septic tanks (range, 84-363 Bq kg-1), indicating Ra accumulation in sludge from effluent. The combined Ra concentration in sludge from the homeowners' septic systems falls within the range reported for sludge samples from publicly owned treatment works within the region.

Concentration dependence of biotransformation in fish liver S9: Optimizing substrate concentrations to estimate hepatic clearance for bioaccumulation assessment.

PubMed

Lo, Justin C; Allard, Gayatri N; Otton, S Victoria; Campbell, David A; Gobas, Frank A P C

2015-12-01

In vitro bioassays to estimate biotransformation rate constants of contaminants in fish are currently being investigated to improve bioaccumulation assessments of hydrophobic contaminants. The present study investigates the relationship between chemical substrate concentration and in vitro biotransformation rate of 4 environmental contaminants (9-methylanthracene, pyrene, chrysene, and benzo[a]pyrene) in rainbow trout (Oncorhynchus mykiss) liver S9 fractions and methods to determine maximum first-order biotransformation rate constants. Substrate depletion experiments using a series of initial substrate concentrations showed that in vitro biotransformation rates exhibit strong concentration dependence, consistent with a Michaelis-Menten kinetic model. The results indicate that depletion rate constants measured at initial substrate concentrations of 1 μM (a current convention) could underestimate the in vitro biotransformation potential and may cause bioconcentration factors to be overestimated if in vitro biotransformation rates are used to assess bioconcentration factors in fish. Depletion rate constants measured using thin-film sorbent dosing experiments were not statistically different from the maximum depletion rate constants derived using a series of solvent delivery-based depletion experiments for 3 of the 4 test chemicals. Multiple solvent delivery-based depletion experiments at a range of initial concentrations are recommended for determining the concentration dependence of in vitro biotransformation rates in fish liver fractions, whereas a single sorbent phase dosing experiment may be able to provide reasonable approximations of maximum depletion rates of very hydrophobic substances. © 2015 SETAC.

Water quality of surficial aquifers in the Georgia-Florida Coastal Plain

USGS Publications Warehouse

Crandall, C.A.; Berndt, M.P.

1996-01-01

The National Water Quality Assessment Program of the U.S. Geological Survey established the Georgia-Florida Coastal Plain study unit in 1991. The ground-water study-unit survey was conducted in 1993 to provide a broad over-view of water quality in surficial aquifers. Three land resource provinces were included in the Georgia-Florida Coastal Plain study-unit survey: the Central Florida Ridge, the Coastal Flatwoods, and the Southern Coastal Plain. The U.S. Geological Survey sampled 37 wells in surficial aquifers, 18 in the Coastal Flatwoods and 19 in the Southern Coastal Plain. The Florida Department of Environmental Protection sampled 27 wells tapping surficial aquifers in the Central Florida Ridge as part of the background ground-water quality monitoring network from 1985 through 1989. The data were used to characterize water quality in surficial aquifers of the Central Florida Ridge. Results of the study-unit survey indicated that dissolved solids concentrations in ground water were mostly less than 100 mg/L (milligrams per liter). Higher medians of pH, specific conductance, and concentrations of calcium, bicarbonate, and dissolved solids were measured in samples from the Central Florida Ridge compared to the Southern Coastal Plain and Coastal Flatwoods, probably because of a greater percentage of carbonate minerals in aquifer materials. The U.S. Environmental Protection Agency secondary maximum contaminant level for iron of 300 ug/L (micrograms per liter) in drinking water was exceeded in 15 of 45 samples. Concentrations of nitrate as nitrogen were less than 3.0 mg/L in most samples (74 percent), indicating little or no influence from human activity. Only five samples (9 percent) had concentrations above 10 mg/L, the U.S. Environmental Protection Agency maximum contaminant level for nitrate concentration in drinking water. Significantly lower median concentrations of nitrate were measured in samples from polyvinyl chloride monitoring wells with diameters less than 6 inches than in large diameter, uncased, or iron-cased wells. The median nitrate concentration was 0.05 mg/L in water from monitoring wells, 1.0 mg/L in samples from iron cased wells, and 2.0 mg/L in samples from uncased wells. Concentrations of volatile organic compounds were mostly less than the detection levels and exceeded 1 ug/L in only four samples. Compounds detected at concentrations greater than 1 ug/L were: tetrachloroethane (8.77 ug/L), toluene (23 ug/L) and chloromethane (21 ug/L). Atrazine, desethyl-atrazine, and metolachlor were the only pesticides detected; concentrations were less than 0.02 ug/L, except for metolachlor (2.5 ug/L). Detection of organic compounds in surficial aquifer may be associated with specific activities or sources near the well. Concentrations of radon exceeded the U.S. Environmental Protection Agency proposed maximum contaminant level of 300 picocuries per liter (pCi/L) in 33 samples from wells on the Coastal Flatwoods and the Southern Coastal Plain. Concentrations as high as 13,000 pCi/L were detected in northern Florida. Although uranium concentrations were less than 1 ug/L in all but one sample (1.3 ug/L) from the Southern Coastal Plain, elevated radon concentrations indicate that uranium is present in aquifer material. Uranium is most likely sorbed to iron oxides and clays in subsurface materials. Tritium concentrations indicated that ground water was recharged by precipitation during the past 40 years. Higher concentrations of tritium in ground water were found in the northern part of the study area and may be related to Savannah River Nuclear Facility.

Blood lead and carboxyhemoglobin levels in chainsaw operators.

PubMed

van Netten, C; Brubaker, R L; Mackenzie, C J; Godolphin, W J

1987-06-01

Fallers in the British Columbia west coast lumber industry often work in climatic and local conditions where little ventilation in their immediate environment is possible. Under these conditions carbon monoxide (CO) and lead fumes from exhaust gases could build up and become a serious occupational hazard. This study monitored the environmental exposure of six fallers to carbon monoxide, nitrogen oxides, and lead under conditions where buildup of these agents would be expected. At the same time blood samples were taken to correlate these environmental concentrations to carboxyhemoglobin (COHb) and blood lead levels. Although there was a highly significant difference between the fallers and the controls regarding the exposure to CO and lead as well as their corresponding COHb and blood lead levels, the environmental and blood concentration of the agents in question did not exceed the maximum allowable concentrations. Temporary short fluctuations in carboxyhemoglobin levels were not monitored in this study and cannot be ruled out as a potential occupational hazard.

Dissolved oxygen, stream temperature, and fish habitat response to environmental water purchases.

PubMed

Null, Sarah E; Mouzon, Nathaniel R; Elmore, Logan R

2017-07-15

Environmental water purchases are increasingly used for ecological protection. In Nevada's Walker Basin (western USA), environmental water purchases augment streamflow in the Walker River and increase lake elevation of terminal Walker Lake. However, water quality impairments like elevated stream temperatures and low dissolved oxygen concentrations also limit ecosystems and species, including federally-threatened Lahontan cutthroat trout. In this paper, we prioritize water volumes and locations that most enhance water quality for riverine habitat from potential environmental water rights purchases. We monitored and modeled streamflows, stream temperatures, and dissolved oxygen concentrations using River Modeling System, an hourly, physically-based hydrodynamic and water quality model. Modeled environmental water purchases ranged from average daily increases of 0.11-1.41 cubic meters per second (m 3 /s) during 2014 and 2015, two critically dry years. Results suggest that water purchases consistently cooled maximum daily stream temperatures and warmed nightly minimum temperatures. This prevented extremely low dissolved oxygen concentrations below 5.0 mg/L, but increased the duration of moderate conditions between 5.5 and 6.0 mg/L. Small water purchases less than approximately 0.71 m 3 /s per day had little benefit for Walker River habitat. Dissolved oxygen concentrations were affected by upstream environmental conditions, where suitable upstream water quality improved downstream conditions and vice versa. Overall, this study showed that critically dry water years degrade environmental water quality and habitat, but environmental water purchases of at least 0.71 m 3 /s were promising for river restoration. Published by Elsevier Ltd.

Satellite Remote Sensing of Chlorophyll a in Support of Nutrient Management in the Neuse and Tar-Pamlico River Estuaries

EPA Science Inventory

The North Carolina Environmental Management Commission (EMC) has adopted as a water quality standard that chlorophyll a concentration should not exceed 40 ug/L in sounds, estuaries and other slow-moving waters. Exceedances require regulators to develop a Total Maximum Daily Limit...

Satellite remote sensing of chlorophyll a in support of nutrient management in the Neuse and Tar-Pamlico River (North Carolina) estuaries

EPA Science Inventory

The North Carolina Environmental Management Commission (EMC) has adopted as a water quality standard that chlorophyll a concentration should not exceed 40 ug/L in sounds, estuaries and other slow-moving waters. Exceedances require regulators to develop a Total Maximum Daily Limit...

STRONTIUM-90 IN PLANTS AND ANIMALS OF ARCTIC ALASKA, 1959-61.

PubMed

WATSON, D G; HANSON, W C; DAVIS, J J

1964-05-22

The strontium-90 content of the biota near Cape Thompson, Alaska, was related to environmental factors. In plants, perennials with persistent aerial parts had maximum and similar concentrations of strontium-90. The content of caribou muscle varied seasonally and was highest in winter when lichens were an important caribou food.

Sustainable Design of EPA's Campus in Research Triangle Park, NC—Environmental Performance Specifications in Construction Contracts—Section 01445 Testing for Indoor Air Quality, Baseline IAQ, and Materials

EPA Pesticide Factsheets

More information on testing for maximum indoor pollutant concentrations for acceptance of the facility, as well as requirements for Independent Materials Testing of specific materials anticipated to have major impact on indoor air quality.

Effects of agricultural and residential land use on ground-water quality, Anoka Sand Plain Aquifer, east-central Minnesota

USGS Publications Warehouse

Anderson, H.W.

1993-01-01

Triazine herbicides were detected in 11 of 18 samples analyzed for pesticides. Concentrations of atrazine were less than the 3 (J-g/L maximum contaminant level set for atrazine by the Minnesota Department of Health and by the U.S. Environmental Protection Agency.

ICPP environmental monitoring report, CY 1989

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1991-01-01

Summarized in this report are the data collected through Environmental Monitoring programs conducted at the Idaho Chemical Processing Plant (ICPP) by the Environmental Assurance (EA) Section of the Environmental Compliance and SIS Operations (EC/SIS) Department. Published in response to DOE Order 5484.1, Chap. 3, this report covers the period from December 20, 1988 through December 19, 1989. The ICPP is responsible for complying with all applicable Federal, State, Local and DOE Rules, Regulations and Orders. Radiological effluent and emissions are regulated by the DOE in accordance with the Derived Concentration Guides (DCGs) as presented in DOE Order 5,400.05, and themore » State of Idaho Maximum Permissible Concentrations (MPCs). The Environmental Protection Agency (EPA) regulates all nonradiological waste resulting from the ICPP operations including all airborne, liquid, and solid waste. The EA Section completed a Quality Assurance (QA) Plan for Environmental Monitoring activities during the third quarter of 1986. QA activities have resulted in the ICPP's implementation of the Environmental Protection Agency rules and guidelines pertaining to the Collection, analyses, and reporting of environmentally related samples. Where no approved methods for analyses existed for radionuclides, currently used methods were submitted for the EPA approval. 17 figs., 11 tabs.« less

Ground-Water Data for Indian Wells Valley, Kern, Inyo, and San Bernardino Counties, California, 1977-84

USGS Publications Warehouse

Berenbrock, Charles

1987-01-01

Ground water is the sole source of water in Indian Wells Valley. Since 1966, annual ground-water pumpage has exceeded estimates of mean annual recharge, and continued and increased stresses on the aquifer system of the valley are expected. In 1981 the U.S. Geological Survey began a 10-year program to develop a data base that could be used in evaluating future water-management alternatives for the valley. This report tabulates existing water-level and water-quality data in order to provide a basis for the design of a ground-water monitoring network for Indian Wells Valley. Water-levels were measured in 131 wells during 1977-84. About 62 percent of the wells that have water-level measurements spanning at least 3 years during the period 1977-84 show a net water-level decline; the decline in 23 percent of the wells is greater than 5 feet. Water-quality samples from 85 wells were analyzed for major dissolved constituents. At selected wells water samples were also analyzed for nutrients and trace metals. Seventy-nine of the wells sampled contained water with concentrations of one or more dissolved constituents that equaled or exceeded U.S. Environmental Protection Agency primary or secondary maximum contaminant levels for drinking water. Dissolved-solids concentrations, which ranged from 190 to 67,000 milligrams per liter, equaled or exceeded 500 milligrams per liter (the Environmental Protection Agency secondary maximum contaminant level) in 85 percent of the sampled wells and 1,000 milligrams per liter in 59 percent. Water samples collected in 1984 from eight wells near the industrial-waste ponds of the China Lake Naval Weapons Center were analyzed for the presence of organic compounds designated 'priority pollutants' by the U.S. Environmental Protection Agency. Priority pollutants were detected in three wells. Trichloroethylene, methylene chloride, vinyl chloride, and chloroform were identified; concentrations were less than 10 micrograms per liter except for trichloroethylene and chloroform, at 94 and 12 micrograms per liter, respectively. Trichloroethylene in one sample and vinyl chloride in another exceeded Environmental Protection Agency proposed maximum contaminant levels.

Ground-water quality in the Central High Plains Aquifer, Colorado, Kansas, New Mexico, Oklahoma, and Texas, 1999

USGS Publications Warehouse

Becker, Mark F.; Bruce, Breton W.; Pope, Larry M.; Andrews, William J.

2002-01-01

A network of 74 randomly distributed domestic water-supply wells completed in the central High Plains aquifer was sampled and analyzed from April to August 1999 as part of the High Plains Regional Ground-Water Study conducted by the U. S. Geological Survey National Water-Quality Assessment Program to provide a broad-scale assessment of the ground-water-quality in this part of the High Plains aquifer. Water properties were relatively consistent across the aquifer, with water being alkaline and well oxidized. Water was mostly of the calcium and magnesium-bicarbonate type and very hard. Sulfate concentrations in water from three wells and chloride concentration in water from one well exceeded Secondary Maximum Contaminant Levels. Fluoride concentration was equal to the Maximum Contaminant Level in one sample. Nitrate concentrations was relatively small in most samples, with the median concentration of 2.3 milligrams per liter. Dissolved organic carbon concentration was relatively low, with a median concentration of 0.5 milligram per liter. The Maximum Contaminant Level set by the U.S. Environmental Protection Agency for nitrate as nitrogen of 10 milligrams per liter was exceeded by water samples from three wells. Most samples contained detectable concentrations of the trace elements aluminum, arsenic, barium, chromium, molybdenum, selenium, zinc, and uranium. Only a few samples had trace element concentrations exceeding Maximum Contaminant Levels. Fifty-five of the samples had radon concentrations exceeding the proposed Maximum Contaminant Level of 300 picocuries per liter. The greatest radon concentrations were detected where the Ogallala Formation overlies sandstones, shales and limestones of Triassic, Jurassic, or Cretaceous age. Volatile organic compounds were detected in 9 of 74 samples. Toluene was detected in eight of those nine samples. All volatile organic compound concentrations were substantially less than Maximum Contaminant Levels. Detections of toluene may have been artifacts of the sampling and analytical processes. Pesticides were detected in 18 of the 74 water samples. None of the pesticide concentrations exceeded Maximum Contaminant Levels. The most frequently detected pesticides were atrazine and its metabolite deethylatrazine, which were detected in water from 15 and 17 wells, respectively. Most of the samples with a detectable pesticide had at least two detectable pesticides. Six of the samples had more than two detectable pesticides. Tritium concentrations was greater than 0.5 tritium unit in 10 of 51 samples, indicating recent recharge to the aquifer. Twenty-one of the samples that had nitrate concentrations greater than 4.0 milligrams per liter were assumed to have components of recent recharge. Detection of volatile organic compounds was not associated with those indicators of recent recharge, with most of volatile organic compounds being detected in water from wells with small tritium and nitrate concentrations. Detection of pesticides was associated with greater tritium or nitrate concentrations, with 16 of the 18 wells producing water with pesticides also having tritium or nitrate concentrations indicating recent recharge.

Assessment of groundwater quality data for the Turtle Mountain Indian Reservation, Rolette County, North Dakota

USGS Publications Warehouse

Lundgren, Robert F.; Vining, Kevin C.

2013-01-01

The Turtle Mountain Indian Reservation relies on groundwater supplies to meet the demands of community and economic needs. The U.S. Geological Survey, in cooperation with the Turtle Mountain Band of Chippewa Indians, examined historical groundwater-level and groundwater-quality data for the Fox Hills, Hell Creek, Rolla, and Shell Valley aquifers. The two main sources of water-quality data for groundwater were the U.S. Geological Survey National Water Information System database and the North Dakota State Water Commission database. Data included major ions, trace elements, nutrients, field properties, and physical properties. The Fox Hills and Hell Creek aquifers had few groundwater water-quality data. The lack of data limits any detailed assessments that can be made about these aquifers. Data for the Rolla aquifer exist from 1978 through 1980 only. The concentrations of some water-quality constituents exceeded the U.S. Environmental Protection Agency secondary maximum contaminant levels. No samples were analyzed for pesticides and hydrocarbons. Numerous water-quality samples have been obtained from the Shell Valley aquifer. About one-half of the water samples from the Shell Valley aquifer had concentrations of iron, manganese, sulfate, and dissolved solids that exceeded the U.S. Environmental Protection Agency secondary maximum contaminant levels. Overall, the data did not indicate obvious patterns in concentrations.

Size-selective toxicity effects of the antimicrobial tylosin on estuarine phytoplankton communities.

PubMed

Kline, Allison; Pinckney, James L

2016-09-01

The purpose of this study was to determine the lethal and sublethal effects of the antimicrobial tylosin on natural estuarine phytoplankton communities. Bioassays were used in experimental treatments with final concentrations of 5 to 1000 μg tylosin l(-1). Maximum percent inhibition ranged from 57 to 85% at concentrations of 200-400 μg tylosin l(-1). Half maximum inhibition concentrations of tylosin were ca. 5x lower for small phytoplankton (<20 μm) relative to larger phytoplankton (>20 μm) and suggests that small phytoplankton are more sensitive to tylosin exposure. Sublethal effects occurred at concentrations as low as 5 μg tylosin l(-1). Environmental concentrations of tylosin (e.g., 0.2-3 μg l(-1)) may have a significant sublethal effect that alters the size structure and composition of phytoplankton communities. The results of this study highlight the potential importance of cell size on toxicity responses of estuarine phytoplankton. Copyright © 2016 Elsevier Ltd. All rights reserved.

Water quality in alluvial aquifers of the southern Rocky Mountains Physiographic Province, upper Colorado River basin, Colorado, 1997

USGS Publications Warehouse

Apodaca, Lori Estelle; Bails, Jeffrey B.

2000-01-01

Water-quality samples were collected in the summer of 1997 from 45 sites (43 wells and 2 springs) in selected alluvial aquifers throughout the Southern Rocky Mountains physiographic province of the Upper Colorado River Basin study unit as part of the U.S. Geological Survey National Water-Quality Assessment Program. The objective of this study was to assess the water-quality conditions in selected alluvial aquifers in the Southern Rocky Mountains physiographic province. Alluvial aquifers are productive aquifers in the Southern Rocky Mountains physiographic province and provide for easily developed wells. Water-quality samples were collected from areas where ground water is used predominantly for domestic or public water supply. Twenty-three of the 45 sites sampled were located in or near mining districts. No statistical differences were observed between the mining sites and sites not associated with mining activities for the majority of the constituents analyzed. Water samples were analyzed for major ions, nutrients, dissolved organic carbon, trace elements, radon-222, pesticides, volatile organic compounds, bacteria, and methylene blue active substances. In addition, field parameters consisting of water temperature, specific conductance, dissolved oxygen, pH, turbidity, and alkalinity were measured at all sites.Specific conductance for the ground-water sites ranged from 57 to 6,650 microsiemens per centimeter and had higher concentrations measured in areas such as the northwestern part of the study unit. Dissolved oxygen ranged from 0.1 to 6.0 mg/L (milligrams per liter) and had a median concentration of 2.9 mg/L. The pH field values ranged from 6.1 to 8.1; about 4 percent of the sites (2 of 45) had pH values outside the range of 6.5 to 8.5 and so did not meet the U.S. Environmental Protection Agency secondary maximum contaminant level standard for drinking water. About 5 percent (2 of 43) of the samples exceeded the U.S. Environmental Protection Agency recommended turbidity value of 5 nephelometric turbidity units; one of these samples was from a monitoring well. The U.S. Environmental Protection Agency secondary maximum contaminant levels for dissolved solids, sulfate, iron, and manganese were exceeded at some of the sites. Higher dissolved-solids concentrations were detected where sedimentary rocks are exposed, such as in the northwestern part of the Southern Rocky Mountains physiographic province. The dominant water compositions for the sites sampled are calcium, magnesium, and bicarbonate. However, sites in areas where sedimentary rocks are exposed and sites located in or near mining areas show more sulfate-dominated waters. Nutrient concentrations were less than the U.S. Environmental Protection Agency drinking-water standards. Only one site had a nitrate concentration greater than 3.0 mg/L, a level indicating possible influence from human activities. No significant differences among land-use/land-cover classifications (forest, rangeland, and urban) for drinking-water wells (42 sites) were identified for dissolved-solids, sulfate, nitrate, iron or manganese concentrations. Radon concentrations were higher in parts of the study unit where Precambrian rocks are exposed. All radon concentrations in ground water exceeded the previous U.S. Environmental Protection Agency proposed maximum contaminant level for drinking water, which has been withdrawn pending further review.Pesticide detections were at concentrations below the reporting limits and were too few to allow for comparison of the data. Eight volatile organic compounds were detected at six sites; all concentrations complied with U.S. Environmental Protection Agency drinking-water standards. Total coliform bacteria were detected at six sites, but no Escherichia coli (E. coli) was detected. Methylene blue active substances were detected at three sites at concentrations just above the reporting limit. Overall, the water quality in the Southern Rocky Mountains physiograph

Draft Environmental Assessment for the Combat Support Training Complex, Tyndall Air Force Base, Florida.

DTIC Science & Technology

1989-07-25

nwdas Green Seaturtle PK E E 1,19 FISH Acipenser oxyrhynchus &esotoi Gulf Sturgeon SR SSC UR2 17,19 Mustela vison lutensis Florida Mink P - UR2 13...immediately dangerous to life and health (IDLH) with respect to respiratory irritation. This represents the maximum concentration from which one could...Threshold 0.004 mg/m3 ACGIH’ Median effective concentration 1-5 mg/m3 ACGIH Respiratory irritation Permissible exposure limit (PEL) 0.4 mg/m3

Environmental setting, water quality, and ecological indicators of surface-water quality in the Mermentau River Basin, southwestern Louisiana, 1998-2001

USGS Publications Warehouse

Skrobialowski, Stanley C.; Mize, Scott V.; Demcheck, Dennis K.

2004-01-01

The U.S. Geological Survey collected data from 29 wells and 24 surface-water sites in the Mermentau River Basin, 1998-2001, to better understand ground-water and surface-water quality; aquatic invertebrate communities; and habitat conditions, in relation to land use. This study was apart of the National Water-Quality Assessment Program, which was designed to assess water quality as it relates to various land uses. Water-quality data were evaluated with criteria established for the protection of drinking water and aquatic life, and bed-sediment data were compared to aquatic life criteria. Water-quality and ecological data were analyzed statistically in relation to drainage area and agricultural land-use integrity. Concentrations of nutrients and major inorganic ions in ground water and surface water generally were highest in the southeastern part of the study area where soils contain thick loess deposits. Peak concentrations of nutrients in surface water occurred March-may at two sites with high agricultural intensity; the lowest concentrations occurred August-January. The greatest potential for eutrophic conditions in surface water, based on nutrient concentrations, existed March-May, at about the same time or shortly after ricefields were drained. Secondary Maximum Contaminant Levels established by the U.S. Environmental Protection Agency (USEPA) were exceeded for sulfate, chloride, iron, or manganese in samples from 20 wells, and for iron or manganese in samples from all surface-water sites. Fewer pesticides were detected in ground water than in surface water. In 11 of of the 29 wells sampled, at least one pesticide or pesticide degradation product was detected. The most frequently detected pesticides or pesticide degradation products in ground water were the herbicides benzaton and atrazine. Concentrations of 47 pesticides and degradation products were detected in surface water. At least 3 pesticides were detected in all surface-water samples. In 72 percent of the samples at least 5 hydrophilic pesticides were detected, and in more than 70 percent of the samples at least 3 hydrophobic pesticides were detected. Although atrazine concentrations in three samples collected in the spring exceeded 3 micrograms per liter, the USEPA Maximum Contaminant Level of 3 micrograms per liter was not exceeded because it is based on an annual average of quarterly samples. Concentrations larger than 3.0 micrograms per liter were not detected in samples collected during other times of the year. Tebuthiuron was detected at all surface-water sites; the largest concentration (6.33 micrograms per liter) was detected at a site on Bayou des Cannes, and was the only detection that exceeded the criterion (1.6 micrograms per liter) for the protection of aquatic life. Malathion was detected at 16 surface-water sites; the largest concentration (0.113 micrograms per liter) was detected at a site on Bayou Lacassine and was the only detection that exceeded the criterion (0.1 micrograms per liter) for the protection of aquatic life. Concentrations of fipronil exceeded numeric targets for acute total maximum daily loads (2.3 micrograms per liter) at 3 sites and chronic total maximum daily loads (4.6 micrograms per liter) at 14 sites. Maximum pesticide concentrations in surface water usually occurred in the spring at about the same time or shortly after ricefields were drained. Concentrations of DDE in bed sediment at two sites exceeded interim freshwater sediment quality guidelines for the protection of aquatic life. Fipronil sulfide and desulfinylpronil were detected at all 17 sites from which bed-sediment samples were collected, but there are no current (2002) guidelines with which to evaluate the environmental effects of fipronil and degradation products. Two methods were used to group the ecological data-collection sites: (1) Sites were grouped before data collection (according to the study design) using drainage area

A summary of pesticides in ground-water data collected by government agencies in Indiana, December 1985 to April 1991

USGS Publications Warehouse

Risch, M.R.

1994-01-01

More than 1 pesticide was present in 16 of the 51 samples that had detections, for a total of 90 individual pesticide detections. Concentrations of the detected pesticides ranged from 0.04 to 49 micrograms per liter, and two-thirds of the detected concentrations were less than 1 microgram per liter. In about 29 percent of all detections, the concentration of 9 pesticides alachlor, aldrin, atrazine, dieldrin, EDB, heptachlor, heptachlor epoxide, simazine, and terbufos exceeded either the U.S. Environmental Protection Agency's Maximum Contaminant Level or adult lifetime Health Advisory.

Nutrient input from the Loxahatchee River Environmental Control District sewage-treatment plant to the Loxahatchee River Estuary, southeastern Florida

USGS Publications Warehouse

Sonntag, W.H.; McPherson, B.F.

1984-01-01

Two test discharges of treated-sewage effluent were made to the Loxahatchee River in February and September 1981 from the ENCON sewage-treatment plant to document nutrient loading and downstream transport of the effluent to the estuary under maximum daily discharge allowable by law (4 million gallons per day). Concentrations of total nitrogen in the effluent exceeded background concentrations by as much as 7 times during the February test, while concentrations of total phosphorus exceeded background concentrations by as much as 112 times during the September test. The effluent was transported downstream to the estuary in less than 24 hours. Discharge of treated sewage effluent to the river-estuary system in the 1981 water year accounted for less than 0.5 percent of the total nitrogen and 8 percent of the total phosphorus discharged from the major tributaries to the estuary. If maximum discharges of effluent (4 million gallons per day) were sustained throughout the year, annual nitrogen loading from the effluent would account for 5 to 18 percent of the total nitrogen input by the major tributaries to the estuary. With maximum discharges of effluent, annual phosphorus loading would exceed the amount of phosphorus input by the major tributaries to the estuary by 54 to 167 percent. (USGS)

Assisted phytoremediation of Cd-contaminated soil using poplar rooted cuttings

NASA Astrophysics Data System (ADS)

Alizadeh, S.; Zahedi-Amiri, G.; Savaghebi-Firoozabadi, G.; Etemad, V.; Shirvany, A.; Shirmardi, M.

2012-07-01

To investigate the effect of amended substrates on cadmium uptake by one-year old poplar rooted cuttings a pot culture was carried out. Pots were filled with three substrates. Four treatments of Cd supply including were organized. The results showed that higher biomass productions in substrates A and B compare to substrate C, led to an increase total Cd uptake two times more than that in substrate C, at 150 mg kg-1 concentration. Meanwhile maximum total uptake occurred in substrate B at 100 mg kg-1 concentration. Using synthetic chelators such as ethylenediaminetetraacetic acid in order to achieve high removal rate led to increased environmental impacts while they are not expected when such environmental friendly approaches are applied.

Stormflow chemistry in the Santa Ana River below Prado Dam and at the diversion downstream from Imperial Highway, southern California, 1995-98

USGS Publications Warehouse

Izbicki, John A.; Mendez, Gregory O.; Burton, Carmen A.

2000-01-01

The Santa Ana River drains about 2,670 square miles of the densely populated coastal area of southern California, near Los Angeles. Almost all the flow in the river, more than 200,000 acre-feet annually, is diverted into ponds where it infiltrates and recharges underlying aquifers. About 2 million people are dependent on these aquifers for water supply. Stormflow in the Santa Ana River is considered a source of 'high-quality' water suitable for use as a source of ground-water recharge. To test this assumption, stormflow samples were collected at two locations--below Prado Dam and at the diversion point downstream from Imperial Highway--for 12 winter storms between 1995 and 1998. Nitrate concentrations decreased during stormflow from a median concentration of 7.8 milligrams per liter in base flow to concentrations less than 1 milligram per liter in some large storms. Concentrations of chemically reduced forms of nitrogen (nitrite, ammonia, and organic nitrogen) increased during stormflow and are the predominant forms of nitrogen in large stormflows. Dissolved organic carbon (DOC) concentrations increased from a median concentration of 4.6 milligrams per liter in base flow to more than 20 milligrams per liter in some stormflows. Concentrations of DOC were especially high during the first storm of the rainy season, and large increases in DOC concentrations were measured even as a result of small early season storms that did not cause large increases in streamflow. DOC present during early season stormflow had less ultraviolet absorbance at 254 nanometers (UV254 ) per unit of carbon than did DOC from late season stormflows. DOC in water held in storage behind Prado Dam had the highest UV254 absorbance per unit of carbon. Maximum pesticide concentrations in stormflow did not exceed U.S. Environmental Protection Agency Maximum Contaminant Levels. Most pesticide concentrations were less than 1 microgram per liter and less than the detection limits obtained using standard drinking water analyses. Increases in concentrations of pesticides such as diazinon, malathion, and chlorpyrifos in stormflow result from runoff from urban areas downstream from Prado Dam. In general, large late season stormflows have the most pesticide detections of all stormflows sampled. Concentrations of methyl tert-butyl ether (MTBE), a gasoline additive, during base flow were as high as 0.9 microgram per liter and concentrations decreased during stormflow. Like pesticides, the concentrations did not exceed the U.S. Environmental Protection Agency Maximum Contaminant Levels for MTBE.

Uses and biases of volunteer water quality data

USGS Publications Warehouse

Loperfido, J.V.; Beyer, P.; Just, C.L.; Schnoor, J.L.

2010-01-01

State water quality monitoring has been augmented by volunteer monitoring programs throughout the United States. Although a significant effort has been put forth by volunteers, questions remain as to whether volunteer data are accurate and can be used by regulators. In this study, typical volunteer water quality measurements from laboratory and environmental samples in Iowa were analyzed for error and bias. Volunteer measurements of nitrate+nitrite were significantly lower (about 2-fold) than concentrations determined via standard methods in both laboratory-prepared and environmental samples. Total reactive phosphorus concentrations analyzed by volunteers were similar to measurements determined via standard methods in laboratory-prepared samples and environmental samples, but were statistically lower than the actual concentration in four of the five laboratory-prepared samples. Volunteer water quality measurements were successful in identifying and classifying most of the waters which violate United States Environmental Protection Agency recommended water quality criteria for total nitrogen (66%) and for total phosphorus (52%) with the accuracy improving when accounting for error and biases in the volunteer data. An understanding of the error and bias in volunteer water quality measurements can allow regulators to incorporate volunteer water quality data into total maximum daily load planning or state water quality reporting. ?? 2010 American Chemical Society.

Global Assessment of Bisphenol A in the Environment

PubMed Central

Corrales, Jone; Kristofco, Lauren A.; Steele, W. Baylor; Yates, Brian S.; Breed, Christopher S.; Williams, E. Spencer

2015-01-01

Because bisphenol A (BPA) is a high production volume chemical, we examined over 500 peer-reviewed studies to understand its global distribution in effluent discharges, surface waters, sewage sludge, biosolids, sediments, soils, air, wildlife, and humans. Bisphenol A was largely reported from urban ecosystems in Asia, Europe, and North America; unfortunately, information was lacking from large geographic areas, megacities, and developing countries. When sufficient data were available, probabilistic hazard assessments were performed to understand global environmental quality concerns. Exceedances of Canadian Predicted No Effect Concentrations for aquatic life were >50% for effluents in Asia, Europe, and North America but as high as 80% for surface water reports from Asia. Similarly, maximum concentrations of BPA in sediments from Asia were higher than Europe. Concentrations of BPA in wildlife, mostly for fish, ranged from 0.2 to 13 000 ng/g. We observed 60% and 40% exceedences of median levels by the US Centers for Disease Control and Prevention’s National Health and Nutrition Examination Survey in Europe and Asia, respectively. These findings highlight the utility of coordinating global sensing of environmental contaminants efforts through integration of environmental monitoring and specimen banking to identify regions for implementation of more robust environmental assessment and management programs. PMID:26674671

75 FR 76336 - Notice of Data Availability Regarding Two Studies of Ambient Lead Concentrations Near a General...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-08

... Division, C304-06, Environmental Protection Agency, U.S. EPA (C304-06), AQAD/AAMG, Research Triangle Park... airport where piston-engine aircraft are operated. The study also included an assessment of the maximum 3... piston engine aircraft. Model inputs also included considerations of aircraft-induced wake turbulence...

Measurement of metal bioaccessibility in vegetables to improve human exposure assessments: field study of soil-plant-atmosphere transfers in urban areas, South China.

PubMed

Xiong, TianTian; Dumat, Camille; Pierart, Antoine; Shahid, Muhammad; Kang, Yuan; Li, Ning; Bertoni, Georges; Laplanche, Christophe

2016-12-01

The quality of cultivated consumed vegetables in relation to environmental pollution is a crucial issue for urban and peri-urban areas, which host the majority of people at the global scale. In order to evaluate the fate of metals in urban soil-plant-atmosphere systems and their consequences on human exposure, a field study was conducted at two different sites near a waste incinerator (site A) and a highway (site B). Metal concentrations were measured in the soil, settled atmospheric particulate matter (PM) and vegetables. A risk assessment was performed using both total and bioaccessible metal concentrations in vegetables. Total metal concentrations in PM were (mg kg -1 ): (site A) 417 Cr, 354 Cu, 931 Zn, 6.3 Cd and 168 Pb; (site B) 145 Cr, 444 Cu, 3289 Zn, 2.9 Cd and 396 Pb. Several total soil Cd and Pb concentrations exceeded China's Environmental Quality Standards. At both sites, there was significant metal enrichment from the atmosphere to the leafy vegetables (correlation between Pb concentrations in PM and leaves: r = 0.52, p < 0.05) which depended on the plant species. Total Cr, Cd and Pb concentrations in vegetables were therefore above or just under the maximum limit levels for foodstuffs according to Chinese and European Commission regulations. High metal bioaccessibility in the vegetables (60-79 %, with maximum value for Cd) was also observed. The bioaccessible hazard index was only above 1 for site B, due to moderate Pb and Cd pollution from the highway. In contrast, site A was considered as relatively safe for urban agriculture.

Field screening of water quality, bottom sediment, and biota associated with irrigation drainage in the Yuma Valley, Arizona, 1995

USGS Publications Warehouse

Tadayon, Saeid; King, K.A.; Andrews, Brenda; Roberts, William

1997-01-01

Because of concerns expressed by the U.S. Congress and the environmental community, the Department of the Interior began a program in late 1985 to identify the nature and extent of water-quality problems induced by irrigation that might exist in the western States. Surface water, bottom sediment, and biota were collected from March through September 1995 along the lower Colorado River and in agricultural drains at nine sites in the Yuma Valley, Arizona, and analyzed for selected inorganic and organic constituents. Analyses of water, bottom sediment, and biota were completed to determine if irrigation return flow has caused, or has the potential to cause, harmful effects on human health, fish, and wildlife in the study area. Concentrations of dissolved solids in surface-water samples collected in March generally did not vary substantially from surface-water samples collected in June. Concentrations of dissolved solids ranged from 712 to 3,000 milligrams per liter and exceeded the U.S. Environmental Protection Agency secondary maximum contaminant level of 500 milligrams per liter for drinking water. Concentrations of chloride in 9 of 18 water samples and concentrations of sulfate in 16 of 18 water samples exceeded the U.S. Environmental Protection Agency secondary maximum contaminant level of 250 milligrams per liter for drinking water. Calcium and sodium were the dominant cations, and chloride and sulfate were the dominant anions. The maximum selenium concentration of 8 micrograms per liter exceeded the U.S. Environmental Protection Agency aquatic-life chronic criterion of 5 micrograms per liter. Concentrations of lead in 7 of 18 water samples and concentrations of mercury in 4 of 18 water samples exceeded the aquatic-life cronic criteria of 3.2 and 0.012 micrograms per liter, respectively. Concentrations of antimony, beryllium, cadmium, and silver in the water samples were below analytical reporting limits. Arsenic was detected in 3 of 9 bottom-sediment samples, and concentrations ranged from 11 to 16 micrograms per gram. Concentrations ofaluminum, beryllium, boron, copper, lead, and zinc were highest in samples from Main Drain at southerly international boundary near San Luis, Arizona. Selenium was detected in all bottom-sediment samples, and concentrations ranged from 0.1 to 0.7 micrograms per gram. Concentrations of cadmium, europium, homium, mercury, molybdenum, silver, tantalum, tin, and uranium were below analytical reporting limits in the bottom-sediment samples. Concentrations of trace elements in bottom-sediment samples were within the ranges found in a study of soils of the western United States and did not indicate a significant accumulation of these constituents. p,p'Dichlorodiphenyldichloroethylene (commonly referred to as p,-p'-DDE) was detected in one bottom-sediment sample at a concentration of 1.4 micrograms per gram. No other organochlorine compounds were detected in the bottom-sediment samples. DDE was present in all fish and bird samples. Almost one-half of the fish samples contained DDE residues that were two times higher than the mean calculated for a national study in 1984-85. Twenty-tree percent of the fish contained more than three times the national mean. Fish from downstream parts of the Main Drain had the highest concentrations of DDE. Although concentrations of DDE in fish and in bird carcasses and eggs were above background levels, residues generally were below thresholds associated with chronic poisoning and reproductive problems in figh and wildlife. Concentrations of 18 trace elements were detected in cattail (Typha sp.) roots, freshwater clam (Corbicula fluminea), fish, and bird samples. Selenium in most fish and in livers of red-winged (Agelaius phoeniceus) and yellow-headed (Xanthocephalus xanthocephalus) blackbirds was above background concentrations but below toxic concentrations. In contrast, selenium was present in a killdeer (Charadrium vociferus) liver sample at potentially toxic con

Tylosin production by Streptomyces fradiae using raw cornmeal in airlift bioreactor.

PubMed

Choi, Dubok; Choi, On You; Shin, Hyun-Jae; Chung, Dong-Ok; Shin, Dae-Yewn

2007-07-01

Using a 50-l airlift bioreactor, for the effective production of tylosin from Streptomyces fradiae TM-224 using raw cornmeal as the energy source, various environmental factors were studied in flask cultures. The maximum tylosin concentration was obtained at 32 degrees C and pH between 7.0 and 7.5. When seed was inoculated after 24 h of culture, the maximum tylosin concentration, 5.7 g/l, was obtained after 4 days of culture. Various concentrations of raw cornmeal were tested to investigate the optimum initial concentration for the tylosin production. An initial raw cornmeal concentration of 80 g/l gave the highest tylosin concentration, 5.8 g/l, after 5 days of culture. Of the various nitrogen sources, soybean meal and fish meal were found to be the most effective for the production of tylosin. In particular, with the optimal mixing ratio, 12 g/l of soybean meal to 14 g/l of fish meal, 7.2 g/l of tylosin was obtained after 5 days of culture. To compare raw cornmeal and glucose for the production oftylosin in the 50-1 airlift bioreactor for 10 days, fed-batch cultures were carried out under the optimum culture conditions. When raw corn meal was used as the energy source, the tylosin production increased with increasing culture time. The maximum tylosin concentration after 10 days of culture was 13.5 g/l, with a product yield from raw cornmeal of 0.123 g/g of consumed carbon source, which was about 7.2 times higher than that obtained when glucose was used as the carbon source.

Concentrations of trace elements in Pacific and Atlantic salmon

NASA Astrophysics Data System (ADS)

Khristoforova, N. K.; Tsygankov, V. Yu.; Boyarova, M. D.; Lukyanova, O. N.

2015-09-01

Concentrations of Hg, As, Cd, Pb, Zn, and Cu were analyzed in the two most abundant species of Pacific salmon, chum and pink salmon, caught in the Kuril Islands at the end of July, 2013. The concentrations of toxic elements (Hg, As, Pb, Cd) in males and females of these species are below the maximum permissible concentrations for seafood. It was found that farmed filleted Atlantic salmon are dominated by Zn and Cu, while muscles of wild salmon are dominated by Pb. Observed differences are obviously related to peculiar environmental geochemical conditions: anthropogenic impact for Atlantic salmon grown in coastal waters and the influence of the natural factors volcanism and upwelling for wild salmon from the Kuril waters.

Environmental land use conflicts in catchments: A major cause of amplified nitrate in river water.

PubMed

Pacheco, F A L; Sanches Fernandes, L F

2016-04-01

Environmental land use conflicts are uses of the land that ignore soil capability. In this study, environmental land use conflicts were investigated in mainland Portugal, using Partial Least Squares (PLS) regression combined with GIS modeling and a group of 85 agricultural watersheds (with >50% occupation by agriculture) as work sample. The results indicate a dominance of conflicts in a region where vineyards systematically invaded steep hillsides (the River Douro basin), where forests would be the most appropriate use. As a consequence of the conflicts, nitrate concentrations in rivers and lakes from these areas have increased, sometimes beyond the legal limit of 50mg/L imposed by the European and Portuguese laws. Excessive nitrate concentrations were also observed along the Atlantic coast of continental Portugal, but associated to a combination of other factors: large population densities, and incomplete coverage by sewage systems and inadequate functioning of wastewater treatment plants. Before this study, environmental land use conflicts were never recognized as possible boost of nitrate concentrations in surface water. Bearing in mind the consequences of drinking water nitrate for human health, a number of land use change scenarios were investigated to forecast their impact on freshwater nitrate concentrations. It was seen that an aggravation of the conflicts would duplicate the number of watersheds with maximum nitrate concentrations above 50mg/L (from 11 to 20 watersheds), while the elimination of the conflicts would greatly reduce that number (to 3 watersheds). Copyright © 2016 Elsevier B.V. All rights reserved.

Photochemical modeling of emissions trading of highly reactive volatile organic compounds in Houston, Texas. 1. Reactivity based trading and potential for ozone hot spot formation.

PubMed

Wang, Linlin; Thompson, Tammy; McDonald-Buller, Elena C; Webb, Alba; Allen, David T

2007-04-01

As part of the State Implementation Plan for attaining the National Ambient Air Quality Standard for ozone, the Texas Commission of Environmental Quality has created a Highly Reactive Volatile Organic Compounds (HRVOC) Emissions Cap and Trade Program for industrial point sources in the Houston/Galveston/Brazoria area. This program has a number of unique features, including its focus on a limited group of ozone precursors and its provisions for trading emissions based on atmospheric reactivity. This series of papers examines the potential air quality impacts of this new emission trading program through photochemical modeling of potential trading scenarios; this first paper in the series describes the air quality modeling methods used to assess potential trades, the potential for localized increases in ozone concentrations (ozone "hot spots") due to HRVOC emission trading, and the use of reactivity scales in the trading. When HRVOC emissions are traded on a mass basis, the simulations indicate that trading of HRVOC allowances between facilities resulted in less than 0.15 ppb (<0.13%) and 0.06 ppb (<0.06%) increases in predicted maximum, area-wide 1-h averaged and 8-h averaged ozone concentrations, respectively. Maximum decreases in ozone concentrations associated with trading, as opposed to across-the-board reductions, were larger than the increases. All of these changes are small compared to the maximum changes in ozone concentrations due to the VOC emissions from these sources (up to 5-10 ppb for 8 h averages; up to 30 ppb for 1-h averages). When emissions of HRVOCs are traded for other, less reactive emissions, on a reactivity weighted basis, air quality simulations indicate that daily maximum ozone concentrations increased by less than 0.3%. Because these relatively small changes (< 1%) are for unlikely trading scenarios designed to produce a maximum change in ozone concentrations (all emissions traded into localized regions), the simulations indicate that the implementation of the trading program, as currently configured and possibly expanded, is unlikely to cause localized increases in ozone concentrations ("hot spots").

Effectiveness of Halogen-Based Disinfectants Against Acinetobacter Baumannii: Wound Care and Environmental Decontamination

DTIC Science & Technology

2006-11-01

EFFECTIVENESS OF HALOGEN-BASED DISINFECTANTS AGAINST Acinetobacter baumannii: WOUND CARE AND ENVIROMENTAL DECONTAMINATION James...a standard E. coli comparator, in a novel bacterial culture system that incorporated a three log range of organic growth media concentrations. We...report the highest dilutions of stock disinfectant able to inhibit replication or kill the bacteria , denoted as the maximum inhibitory dilution

What are the main environmental factors driving the development of the neurotoxic dinoflagellate Vulcanodinium rugosum in a Mediterranean ecosystem (Ingril lagoon, France)?

PubMed

Abadie, Eric; Chiantella, Claude; Crottier, Anaïs; Rhodes, Lesley; Masseret, Estelle; Berteaux, Tom; Laabir, Mohamed

2018-05-01

Vulcanodinium rugosum, a dinoflagellate developing in Ingril Lagoon (Mediterranean, France) is responsible for shellfish intoxications due to the neurotoxin pinnatoxin G. A one year survey (March 2012-April 2013) was conducted in this oligotrophic shallow lagoon and key environmental parameters were recorded (temperature, salinity and nutrients). The spatio-temporal distribution of V. rugosum in water column and on macrophytes was also determined. Planktonic cells of V. rugosum were observed at all sampling stations, but in relatively low concentrations (maximum of 1000 cell/L). The highest abundances were observed from June to September 2012. There was a positive correlation between cell densities and both temperature and salinity. Non-motile cells were detected on macrophytes, with a maximum concentration of 6300 cells/g wet weight. Nitrite and ammonium were negatively related to V. rugosum abundance whereas total nitrogen, total phosphorus and phosphates showed a positive correlation. Altogether, in situ results suggest that V. rugosum is rather thermophilic and that organic nutrients should be considered when studying the nutrition requirements for this noxious expanding dinoflagellate. Copyright © 2018 Elsevier B.V. All rights reserved.

Public health risk assessment of groundwater contamination in Batman, Turkey.

PubMed

Nalbantcilar, M Tahir; Pinarkara, Sukru Yavuz

2016-08-01

In this study, a comprehensive analysis of groundwater was performed to assess contamination and phenol content in Batman, Turkey, particularly in residential areas near agriculture, livestock and oil industry facilities. From these areas, where potentially contaminated groundwater used for drinking and irrigation threatens public health, 30 groundwater samples were collected and analyzed for heavy metal concentrations (Al, As, B, Ba, Ca, Cd, Cl, Co, Cr, Cu, Fe, Hg, Li, Mg, Mn, Mo, Na, Ni, NO3, P, Pb, phenol, S, Sb, Se, SO4, Sr, U, and Zn). Compared with the standards of the Environmental Protection Agency, Al, Fe, and Mn concentrations in groundwater exceeded secondary drinking water regulations, NO3 concentrations were high for maximum contaminant levels, and As, Pb, and U concentrations exceeded maximum contaminant level goals in all samples. Ni, Sb, and Se concentrations also exceeded limits set by the Turkish Standards Institution. Nearly all samples revealed concentrations of Se, Sb, Hg, and phenol due to nearby petroleum refineries, oil storage plants, and agricultural and livestock areas. The results obtained from this study indicate that the groundwater in Batman contains elements in concentrations that approach or exceed limits and thus threatens public health with increased blood cholesterol, decreased blood sugar, and circulatory problems.

Assessment of concentrations of trace elements in ground water and soil at the Small-Arms Firing Range, Shaw Air Force Base, South Carolina

USGS Publications Warehouse

Landmeyer, J.E.

1994-01-01

Ground-water samples were collected from four shallow water-table aquifer observation wells beneath the Small-Arms Firing Range study area at Shaw Air Force Base. Water-chemistry analyses indicated that total lead concentrations in shallow ground water beneath the study area do not exceed the U.S. Environmental Protection Agency maximum contaminant level established for lead in drinking water (0.05 milligrams per liter). All other trace element total concentrations in ground water beneath the study area were at or below the detection limit of the analytical methodology.

Measured and predicted environmental concentrations of carbamazepine, diclofenac, and metoprolol in small and medium rivers in northern Germany.

PubMed

Meyer, Wibke; Reich, Margrit; Beier, Silvio; Behrendt, Joachim; Gulyas, Holger; Otterpohl, Ralf

2016-08-01

This study evaluated the impact of secondary municipal effluent discharge on carbamazepine, diclofenac, and metoprolol concentrations in small and medium rivers in northern Germany and compared the measured environmental concentrations (MECs) to the predicted environmental concentrations (PECs) calculated with four well-established models. During a 1-year sampling period, secondary effluent grab samples were collected at four wastewater treatment plants (WWTPs) together with grab samples from the receiving waters upstream and downstream from the wastewater discharge points. The carbamazepine, diclofenac, and metoprolol concentrations were analyzed with high-performance liquid chromatography-tandem mass spectrometry (HPLC/MS-MS) after solid phase extraction. In the secondary effluents, 84-790 ng/L carbamazepine, 395-2100 ng/L diclofenac, and 745-5000 ng/L metoprolol were detected. The carbamazepine, diclofenac, and metoprolol concentrations analyzed in the rivers downstream from the secondary effluent discharge sites ranged from <5 to 68, 370, and 520 ng/L, respectively. Most of the downstream pharmaceutical concentrations were markedly higher than the corresponding upstream concentrations. The impact of wastewater discharge on the MECs in rivers downstream from the WWTPs was clearly demonstrated, but the correlations of the MECs with dilution factors were poor. The smallest rivers exhibited the largest maximum MECs and the widest ranges of MECs downstream from the wastewater discharge point. Three of the four tested models were conservative, as they showed higher PECs than the MECs in the rivers downstream from the WWTPs. However, the most detailed model underestimated the diclofenac concentrations.

Red fox Vulpes vulpes (L., 1758) as a bioindicator of mercury contamination in terrestrial ecosystems of north-western Poland.

PubMed

Kalisinska, Elzbieta; Lisowski, Piotr; Kosik-Bogacka, Danuta Izabela

2012-02-01

In this study, we determined the concentrations of total mercury (Hg) in samples of liver, kidney and skeletal muscle of 27 red foxes Vulpes vulpes (L., 1758) from north-western Poland, and examined the morphometric characteristics of the collected specimens. The analysis also included the relationship between Hg concentration and the fox size, and the suitability of individual organs as bioindicators in indirect evaluation of environmental mercury contamination. Determination of Hg concentration was performed by atomic absorption spectroscopy. In the analysed samples, the Hg concentration was low and the maximum value did not exceed 0.85 mgHg/kg dry weight (dw). There were no significant differences in Hg concentrations in the analysed material between males and females or between immature and adult groups. The median concentrations of Hg in the liver, kidney and skeletal muscle were 0.22, 0.11 and 0.05 mgHg/kg dw, respectively. The correlation coefficients were significant between the concentrations of mercury in the liver, kidney and skeletal muscle (positive) and between the kidney Hg concentration and kidney mass (negative). Taking into account our results and findings of other authors, it may be argued that the red fox exhibits a measurable response to mercury environmental pollution and meets the requirements of a bioindicator.

Distribution and ecological risk of antibiotics in a typical effluent-receiving river (Wangyang River) in north China.

PubMed

Jiang, Yonghai; Li, Mingxiao; Guo, Changsheng; An, Da; Xu, Jian; Zhang, Yuan; Xi, Beidou

2014-10-01

In this study, the occurrence and distribution of sixteen antibiotics belonging to four groups in surface water, sediment and groundwater samples from the Wangyang River (WYR), a typical river receiving sewage discharges were investigated. Laboratory analyses revealed that antibiotics were widely distributed in the studied area. The aqueous samples were unavoidably contaminated with antibiotics, and the target antibiotics present in high levels were oxytetracycline, tetracycline, chlortetracycline, ofloxacin, sulfamethoxazole, and trimethoprim, with maximum concentrations of the individual contaminant at 3.6×10(5), 9.7×10(3), 6.9×10(4), 1.2×10(4), 4.8×10(3), and 1.1×10(3) ng L(-1), respectively. Oxytetracycline, tetracycline, ciprofloxacin and roxithromycin were the most frequently detected compounds in sediment samples, with maximum concentrations of the individual contaminant at 1.6×10(5), 1.7×10(4), 2.1×10(3) and 2.5×10(3) ng g(-1), respectively. The results also revealed that the high intensity of aquaculture activities could contribute to the increasing levels of antibiotics in the area. According to the ratios of measured environmental concentration (MEC) to predicted no-effect concentration (PNEC), chlortetracycline, tetracycline, ofloxacin, ciprofloxacin, erythromycin-H2O and sulfamethoxazole may present possible environmental risk to Pseudokirchneriella subcapitata, Synechococcus leopoliensis and M. aeruginosa. Attention should be given to the long-term ecological effects caused by the continuous discharge of antibiotics in the WYR area. Copyright © 2014 Elsevier Ltd. All rights reserved.

Radiochemical and Chemical Constituents in Water from Selected Wells and Springs from the Southern Boundary of the Idaho National Engineering and Environmental Laboratory to the Hagerman Area, Idaho, 2002

USGS Publications Warehouse

Rattray, Gordon W.; Campbell, Linford J.

2004-01-01

The U.S. Geological Survey, Idaho Department of Water Resources, and the State of Idaho INEEL Oversight Program, in cooperation with the U.S. Department of Energy, sampled water from 17 sites as part of the sixth round of a long-term project to monitor water quality of the eastern Snake River Plain aquifer from the southern boundary of the Idaho National Engineering and Environmental Laboratory to the Hagerman area. The samples were collected from eight irrigation wells, three domestic wells, one stock well, one dairy well, one commercial well, one observation well, and two springs and analyzed for selected radiochemical and chemical constituents. One quality-assurance sample, a sequential replicate, also was collected and analyzed. Many of the radionuclide and inorganic-constituent concentrations were greater than the reporting levels and most of the organic-constituent concentrations were less than the reporting levels. However, none of the reported radiochemical- or chemical-constituent concentrations exceeded the maximum contaminant levels for drinking water established by the U.S. Environmental Protection Agency. Statistical evaluation of the replicate sample pair indicated that, with 95 percent confidence, 132 of the 135 constituent concentrations of the replicate pair were equivalent.

High frequency monitoring of pesticides in runoff water to improve understanding of their transport and environmental impacts.

PubMed

Lefrancq, Marie; Jadas-Hécart, Alain; La Jeunesse, Isabelle; Landry, David; Payraudeau, Sylvain

2017-06-01

Rainfall-induced peaks in pesticide concentrations can occur rapidly. Low frequency sampling may therefore largely underestimate maximum pesticide concentrations and fluxes. Detailed storm-based sampling of pesticide concentrations in runoff water to better predict pesticide sources, transport pathways and toxicity within the headwater catchments is lacking. High frequency monitoring (2min) of seven pesticides (Dimetomorph, Fluopicolide, Glyphosate, Iprovalicarb, Tebuconazole, Tetraconazole and Triadimenol) and one degradation product (AMPA) were assessed for 20 runoff events from 2009 to 2012 at the outlet of a vineyard catchment in the Layon catchment in France. The maximum pesticide concentrations were 387μgL -1 . Samples from all of the runoff events exceeded the legal limit of 0.1μgL -1 for at least one pesticide (European directive 2013/39/EC). High resolution sampling used to detect the peak pesticide levels revealed that Toxic Units (TU) for algae, invertebrates and fish often exceeded the European Uniform principles (25%). The point and average (time or discharge-weighted) concentrations indicated up to a 30- or 4-fold underestimation of the TU obtained when measuring the maximum concentrations, respectively. This highlights the important role of sampling methods for assessing peak exposure. High resolution sampling combined with concentration-discharge hysteresis analyses revealed that clockwise responses were predominant (52%), indicating that Hortonian runoff is the prevailing surface runoff trigger mechanism in the study catchment. The hysteresis patterns for suspended solids and pesticides were highly dynamic and storm- and chemical-dependent. Intense rainfall events induced stronger C-Q hysteresis (magnitude). This study provides new insights into the complexity of pesticide dynamics in runoff water and highlights the ability of hysteresis analysis to improve understanding of pesticide supply and transport. Copyright © 2017 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pucci, A.A. Jr.; Gordon, A.; Harriman, D.A.

The US Geological Survey collected ground-water samples from the upper and middle aquifers of the Potomac-Raritan-Magothy aquifer system in a 400-square-mile are of New Jersey from 1984 through 1986. Concentrations of lead were greater than the US Environmental Protection Agency maximum contaminant level (MCL) of 50 micrograms per liter in water from 16 to 239 wells. The concentrations of cadmium were greater than the MCL of 10 micrograms per liter in water from 10 to 241 wells. One-half of the wells that exceeded the lead MCL were in known areas of saltwater intrusion, as were all 10 wells that exceededmore » the cadmium MCL. The association of elevated concentrations of these metals with elevated concentrations of chloride indicates a mechanism related to saltwater intrusion.« less

Calculated maximum Hl ground-level concentrations downwind from launch pad aborts of the space shuttle and Titan 3 C vehicles at Kennedy Space Center

NASA Technical Reports Server (NTRS)

Dumbauld, R. K.; Bjorklund, J. R.

1972-01-01

A quantitative assessment is described of the potential environmental hazard posed by the atmospheric release of HCl resulting from the burning of solid propellant during two hypothetical on-pad aborts of the Titan 3 C and space shuttle vehicles at Kennedy Space Center. In one pad-abort situation, it is assumed that the cases of the two solid-propellant engines are ruptured and the burning propellant falls to the ground in the immediate vicinity of the launch pad where it continues to burn for 5 minutes. In the other pad-abort situation considered, one of the two solid engines on each vehicle is assumed to ignite and burn at the normal rate while the vehicle remains on the launch pad. Calculations of maximum HCl ground-level concentration for the above on-pad abort situations were made using the computerized NASA/MSFC multilayer diffusion models in conjunction with appropriate meteorological and source inputs. Three meteorological regimes are considered-fall, spring, and afternoon sea-breeze. Source inputs for the hazard calculations were developed. The principal result of the calculations is that maximum ground-level HCl concentrations at distances greater than 1 kilometer from the launch pad are less than 3 parts per million in all cases considered.

Summary and evaluation of pesticides in field blanks collected for the National Water-Quality Assessment Program, 1992-95

USGS Publications Warehouse

Martin, Jeffrey D.; Gilliom, Robert J.; Schertz, Terry L.

1999-01-01

Field blanks did show evidence of contamination by some pesticides. Most of the pesticides detected in field blanks, however, were detected more frequently and at higher concentrations in environmental water samples. Two criteria were used to evaluate the need to consider contamination in water-quality assessments: (1) a ratio of the frequency of pesticide detection in environmental water samples to the frequency of detection in field blanks of 5.0 or less and (2) a ratio of the median concentration detected in environmental water samples to the maximum concentration detected in field blanks of 2.0 or less. These criteria indicate that contamination, for the majority of the pesticide data collected for the NAWQA Program, probably does not need to be considered in the analysis and interpretation of (1) the frequency of pesticide detection or (2) the median concentration of pesticides detected. Contamination must be considered, however, in detection frequency for cispermethrin, pronamide, p,p' -DDE, pebulate, propargite, ethalfluralin, and triallate in surface water and fenuron, benfluralin, pronamide, cis-permethrin, triallate, chlorpyrifos, trifluralin, propanil, p,p' -DDE, bromacil, dacthal, diazinon, and diuron in ground water. Contamination also must be considered in median concentrations detected for pronamide, p,p' -DDE, propargite, napropamide, and triallate in surface water and benfluralin, cis-permethrin, triallate, chlorpyrifos, trifluralin, p,p' -DDE, dacthal, and diazinon in ground water.

Sludge stabilization through aerobic digestion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hartman, R.B.; Smith, D.G.; Bennett, E.R.

1979-10-01

The aerobic digestion process with certain modifications is evaluated as an alternative for sludge processing capable of developing a product with characteristics required for land application. Environmental conditions, including temperature, solids concentration, and digestion time, that affect the aerobic digestion of a mixed primary sludge-trickling filter humus are investigated. Variations in these parameters that influence the characteristics of digested sludge are determined, and the parameters are optimized to: provide the maximum rate of volatile solids reduction; develop a stable, nonodorous product sludge; and provide the maximum rate of oxidation of the nitrogenous material present in the feed sludge. (3 diagrams,more » 9 graphs, 15 references, 3 tables)« less

Reconnaissance-level assessment of water and bottom-sediment quality, including pesticides and mercury, in Yankton Sioux Tribe wetlands, Charles Mix County, South Dakota, June-July 2005

USGS Publications Warehouse

Schaap, Bryan D.; Bartholomay, Roy C.

2006-01-01

During June and July 2005, water and bottom-sediment samples were collected from selected Yankton Sioux Tribe wetlands within the historic Reservation area of eastern Charles Mix County as part of a reconnaissance-level assessment by the U.S. Geological Survey and Yankton Sioux Tribe. The water samples were analyzed for pesticides and mercury species. In addition, the water samples were analyzed for physical properties and chemical constituents that might help further characterize the water quality of the wetlands. The bottom-sediment samples were analyzed for mercury species. During June 2005, water samples were collected from 19 wetlands and were analyzed for 61 widely used pesticide compounds. Many pesticides were not detected in any of the water samples and many others were detected only at low concentrations in a few of the samples. Thirteen pesticides were detected in water samples from at least one of the wetlands. Atrazine and de-ethyl atrazine were detected at each of the 19 wetlands. The minimum, maximum, and median dissolved atrazine concentrations were 0.056, 0.567, and 0.151 microgram per liter (?g/L), respectively. Four pesticides (alachlor, carbaryl, chlorpyrifos, and dicamba) were detected in only one wetland each. The number of pesticides detected in any of the 19 wetlands ranged from 3 to 8, with a median of 6. In addition to the results for this study, recent previous studies have frequently found atrazine in Lake Andes and the Missouri River, but none of the atrazine concentrations have been greater than 3 ?g/L, the U.S. Environmental Protection Agency's Maximum Contaminant Level for atrazine in drinking water. During June and July 2005, water and bottom-sediment samples were collected from 10 wetlands. Water samples from each of the wetlands were analyzed for major ions, organic carbon, and mercury species, and bottom-sediment samples were analyzed for mercury species. For the whole-water samples, the total mercury concentrations ranged from 1.11 to 29.65 nanograms per liter (ng/L), with a median of 10.56 ng/L. The methylmercury concentrations ranged from 0.45 to 14.03 ng/L, with a median of 2.28 ng/L. For the bottom-sediment samples, the total mercury concentration ranged from 21.3 to 74.6 nanograms per gram (ng/g), with a median of 54.2 ng/g. The methylmercury concentrations ranged from <0.11 to 2.04 ng/g, with a median of 0.78 ng/g. The total mercury concentrations in the water samples were all much less than 2 ?g/L (2,000 ng/L), the U.S. Environmental Protection Agency's Maximum Contaminant Level for mercury in drinking water. However, water samples from four of the wetlands had concentrations larger than 0.012 ?g/L (12 ng/L), the State of South Dakota's chronic standard for surface waters, including wetlands. Maximum methylmercury concentrations for this study are larger than reported concentrations for wetlands in North Dakota and concentrations reported for the Cheyenne River Indian Reservation in South Dakota.

Radiochemical and Chemical Constituents in Water from Selected Wells and Springs from the Southern Boundary of the Idaho National Engineering and Environmental Laboratory to the Hagerman Area, Idaho, 1998

DOE Office of Scientific and Technical Information (OSTI.GOV)

R. C. Bartholomay; B. V. Twining; L. J. Campbell

1999-06-01

The U.S. Geological Survey and the Idaho Department of Water Resources, in cooperation with the U.S. Department of Energy, sampled 18 sites as part of the fourth round of a long-term project to monitor water quality of the Snake River Plain aquifer from the southern boundary of the Idaho National Engineering and Environmental Laboratory to the Hagerman area. The samples were analyzed for selected radiochemical and chemical constituents. The samples were collected from 2 domestic wells, 12 irrigation wells, 2 stock wells, 1 spring, and 1 public supply well. Two quality-assurance samples also were collected and analyzed. None of themore » reported radiochemical or chemical constituent concentrations exceeded the established maximum contaminant levels for drinking water. Many of the radionuclide- and inorganic-constituent concentrations were greater than the respective reporting levels. Most of the organic-constituent concentrations were less than the reporting levels.« less

Concentration levels of new-generation fungicides in throughfall released by foliar wash-off from vineyards.

PubMed

Pérez-Rodríguez, P; Soto-Gómez, D; Paradelo, M; López-Periago, J E

2017-12-01

The presence of agricultural pesticides in the environment and their effects on ecosystems are major concerns addressed in a significant number of articles. However, limited information is available on the pesticide concentrations released from crops. This study reports losses of new-generation fungicides by foliar wash-off from vineyards and their potential impact on the concentrations of their main active substances (AS) in surface waters. Two experimental plots devoted to vineyards were treated with various combinations of commercial new-generation fungicide formulations. Then, up to sixteen throughfall collectors were installed under the canopy. Concentrations of sixteen different AS in throughfall were determined along nine rainfall episodes. Concentrations in throughfall far exceeded the maximum permissible levels for drinking water established by the European Union regulations. Dynamics of fungicide release indicated a first-flush effect in the wash-off founding the highest concentrations of AS in the first rain episodes after application of the fungicides. This article shows that foliar spray application of commercial formulations of new-generation fungicides does not prevent the release of their AS to soil or the runoff. Concentration data obtained in this research can be valuable in supporting the assessment of environmental effects of new-generation fungicides and modeling their environmental fate. Copyright © 2017 Elsevier Ltd. All rights reserved.

Environmental impact of CO2, Rn, Hg degassing from the rupture zones produced by Wenchuan M s 8.0 earthquake in western Sichuan, China.

PubMed

Zhou, Xiaocheng; Chen, Zhi; Cui, Yueju

2016-10-01

The concentrations and flux of CO2, (222)Radon (Rn), and gaseous elemental mercury (Hg) in soil gas were investigated based on the field measurements in June 2010 at ten sites along the seismic rupture zones produced by the May 12, 2008, Wenchuan M s 8.0 earthquake in order to assess the environmental impact of degassing of CO2, Rn and Hg. Soil gas concentrations of 344 sampling points were obtained. Seventy measurements of CO2, Rn and Hg flux by the static accumulation chamber method were performed. The results of risk assessment of CO2, Rn and Hg concentration in soil gas showed that (1) the concentration of CO2 in the epicenter of Wenchuan M s 8.0 earthquake and north end of seismic ruptures had low risk of asphyxia; (2) the concentrations of Rn in the north segment of seismic ruptures had high levels of radon, Maximum was up to level 4, according to Chinese code (GB 50325-2001); (3) the average geoaccumulation index I geo of soil Hg denoted the lack of soil contamination, and maximum values classified the soil gas as moderately to strongly polluted in the epicenter. The investigation of soil gas CO2, Rn and Hg degassing rate indicated that (1) the CO2 in soil gas was characterized by a mean [Formula: see text] of -20.4 ‰ and by a mean CO2 flux of 88.1 g m(-2) day(-1), which were in the range of the typical values for biologic CO2 degassing. The maximum of soil CO2 flux reached values of 399 g m(-2) day(-1) in the epicenter; (2) the soil Rn had higher exhalation in the north segment of seismic ruptures, the maximum reached value of 1976 m Bq m(-2) s(-1); (3) the soil Hg flux was lower, ranging from -2.5 to 18.7 n g m(-2) h(-1) and increased from south to north. The mean flux over the all profiles was 4.2 n g m(-2) h(-1). The total output of CO2 and Hg degassing estimated along seismic ruptures for a survey area of 18.17 km(2) were approximately 0.57 Mt year(-1) and 688.19 g year(-1). It is recommended that land-use planners should incorporate soil gas and/or gas flux measurements in the environmental assessment of areas of possible risk. A survey of all houses along seismic ruptures is advised as structural measures to prevent the ingress of soil gases, including CO2 and Rn, were needed in some houses.

Quantity and quality of seepage from two earthen basins used to store livestock waste in southern Minnesota during the first year of operation, 1997-98

USGS Publications Warehouse

Ruhl, James F.

1999-01-01

Seepage from the site B basin (based on 10 samples each from the bottom and sidewall) had chloride concentrations of 11 to 100 mg/L; ammonium-N concentrations of 2.58 mg/L or less; nitrate-N concentrations of 25.7 mg/L or less (except for one concentration of 146 mg/L); and organic-N concentrations of 0.92 mg/L or less. Nitrate-N concentrations in the seepage exceeded the U.S. Environmental Protection Agency (1996). MCL (maximum contaminant level) of 10 mg/L in 17 of 22 samples. Background ground-water quality, however, indicated that nitrate-N concentrations were greater than the MCL prior to operation of the basin. Fecal Coliform bacteria, as at the site A basin, were abundant in the basin wastewater, but not in the seepage.

Naturally occurring contaminants in the Piedmont and Blue Ridge crystalline-rock aquifers and Piedmont Early Mesozoic basin siliciclastic-rock aquifers, eastern United States, 1994–2008

USGS Publications Warehouse

Chapman, Melinda J.; Cravotta, Charles A.; Szabo, Zoltan; Lindsay, Bruce D.

2013-01-01

Groundwater quality and aquifer lithologies in the Piedmont and Blue Ridge Physiographic Provinces in the eastern United States vary widely as a result of complex geologic history. Bedrock composition (mineralogy) and geochemical conditions in the aquifer directly affect the occurrence (presence in rock and groundwater) and distribution (concentration and mobility) of potential naturally occurring contaminants, such as arsenic and radionuclides, in drinking water. To evaluate potential relations between aquifer lithology and the spatial distribution of naturally occurring contaminants, the crystalline-rock aquifers of the Piedmont and Blue Ridge Physiographic Provinces and the siliciclastic-rock aquifers of the Early Mesozoic basin of the Piedmont Physiographic Province were divided into 14 lithologic groups, each having from 1 to 16 lithochemical subgroups, based on primary rock type, mineralogy, and weathering potential. Groundwater-quality data collected by the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Program from 1994 through 2008 from 346 wells and springs in various hydrogeologic and land-use settings from Georgia through New Jersey were compiled and analyzed for this study. Analyses for most constituents were for filtered samples, and, thus, the compiled data consist largely of dissolved concentrations. Concentrations were compared to criteria for protection of human health, such as U.S. Environmental Protection Agency (USEPA) drinking water maximum contaminant levels and secondary maximum contaminant levels or health-based screening levels developed by the USGS NAWQA Program in cooperation with the USEPA, the New Jersey Department of Environmental Protection, and Oregon Health & Science University. Correlations among constituent concentrations, pH, and oxidation-reduction (redox) conditions were used to infer geochemical controls on constituent mobility within the aquifers. Of the 23 trace-element constituents evaluated, arsenic, manganese, and zinc were detected in one or more water samples at concentrations greater than established human health-based criteria. Arsenic concentrations typically were less than 1 microgram per liter (µg/L) in most groundwater samples; however, concentrations of arsenic greater than 1 µg/L frequently were detected in groundwater from clastic lacustrine sedimentary rocks of the Early Mesozoic basin aquifers and from metamorphosed clastic sedimentary rocks of the Piedmont and Blue Ridge crystalline rock aquifers. Groundwater from these rock units had elevated pH compared to other rock units evaluated in this study. Of the nine samples for which arsenic concentration was greater than 10 µg/L, six were classified as oxic and three as anoxic, and seven had pH of 7.2 or greater. Manganese concentrations typically were less than 10 µg/L in most samples; however, 8.3 percent of samples from the Piedmont and Blue Ridge crystalline-rock aquifers and 3.0 percent of samples from the Early Mesozoic basin siliciclastic rock aquifers had manganese concentrations greater than the 300-µg/L health-based screening level. The positive correlation of manganese with iron and ammonia and the negative correlation of manganese with dissolved oxygen and nitrate are consistent with the reductive dissolution of manganese oxides in the aquifer. Zinc concentrations typically were less than 10 µg/L in the groundwater samples considered in the study, but 0.4 percent and 5.5 percent of the samples had concentrations greater than the health-based screening level of 2,000 µg/L and one-tenth of the health-based screening level, respectively. The mean rank concentration of zinc in groundwater from the quartz-rich sedimentary rock lithologic group was greater than that for other lithologic groups even after eliminating samples collected from wells constructed with galvanized casing. Approximately 90 percent of 275 groundwater samples had radon-222 concentrations that were greater than the proposed alternative maximum contaminant level of 300 picocuries per liter. In contrast, only 2.0 percent of 98 samples had combined radium (radium-226 plus radium-228) concentrations greater than the maximum contaminant level of 5.0 picocuries per liter, and 0.6 percent of 310 samples had uranium concentrations greater than the maximum contaminant level of 30 µg/L. Radon concentrations were highest in the Piedmont and Blue Ridge crystalline-rock aquifers, especially in granite, and elevated median concentrations were noted in the Piedmont Early Mesozoic basin aquifers, but without the extreme maximum concentrations found in the crystalline rocks (granites). Although the siliciclastic lithologies had a greater frequency of elevated uranium concentrations, radon and radium were commonly detected in water from both siliciclastic and crystalline lithologies. Uranium concentrations in groundwater from clastic sedimentary and clastic lacustrine/evaporite sedimentary lithologic groups within the Early Mesozoic basin aquifers, which had median concentrations of 3.6 and 3.1 µg/L, respectively, generally were higher than concentrations for other siliciclastic lithologic groups, which had median concentrations less than 1 µg/L. Although 89 percent of the 260 samples from crystalline-rock aquifers had uranium concentrations less than 1 µg/L, 0.8 percent had uranium concentrations greater than the 30-µg/L maximum contaminant level, and 6.5 percent had concentrations greater than 3 µg/L.

NITRO MUSK ADDUCTS OF RAINBOW TROUT ...

EPA Pesticide Factsheets

Rainbow trout and other fish species can serve as 'sentinel' species for the assessment of ecological status and the presence of certain environmental contaminants. As such they act as bioindicators of exposure. Here we present seminal data regarding dose-response and toxicokinetics of trout hemoglobin adduct formation from exposure to nitro musks that are frequently used as fragrance ingredients in formulations of personal care products. Hemoglobin adducts serve as biomarkers of exposure of the sentinel species as we have shown in previous studies of hemoglobin adducts formed in trout and environmental carp exposed to musk xylene (MX) and musk ketone (MK). Gas chromatography-electron capture negative ion chemical ionization-mass spectrometry (GC-NICI-MS) employing selected ion monitoring is used to measure 4-amino-MX (4-AMX), 2-amino-MX (2-AMX), and 2-amino-MK (2-AMK) released by alkaline hydrolysis from the sulfinamide adducts of hemoglobin. Dose-response and toxicokinetics were investigated using this sensitive method for analysis of these metabolites. In the dose-response investigation, the concentrations of 4-AMX and 2-2AMX are observed to pass through a maximum at 0.10 mg/g. In the case of 2-AMK, the adduct concentration is almost the same at dosages in the range of 0.030 to 0.10 mg/g. For toxicokinetics, the concentration of the metabolites in the Hb reaches a maximum in the 3-day sample after administration of MX or MK. Further elimination of the metabo

Radiochemical and chemical constituents in water from selected wells and springs from the southern boundary of the Idaho National Laboratory to the Hagerman Area, Idaho, 2003

USGS Publications Warehouse

Rattray, Gordon W.; Wehnke, Amy J.; Hall, L. Flint; Campbell, Linford J.

2005-01-01

The U.S. Geological Survey and the Idaho Department of Water Resources, in cooperation with the U.S. Department of Energy, sampled water from 14 sites as part of an ongoing study to monitor the water quality of the eastern Snake River Plain aquifer between the southern boundary of the Idaho National Laboratory (INL) and the Burley-Twin Falls-Hagerman area. The State of Idaho, Department of Environmental Quality, Division of INL Oversight and Radiation Control cosampled with the U.S. Geological Survey and the Idaho Department of Water Resources and their analytical results are included in this report. The samples were collected from four domestic wells, two dairy wells, two springs, four irrigation wells, one observation well, and one stock well and analyzed for selected radiochemical and chemical constituents. Two quality-assurance samples, sequential replicates, also were collected and analyzed. None of the concentrations of radiochemical or organic-chemical constituents exceeded the maximum contaminant levels for drinking water established by the U.S. Environmental Protection Agency. However, the concentration of one inorganic-chemical constituent, nitrate (as nitrogen), in water from site MV-43 was 20 milligrams per liter which exceeded the maximum contaminant level for that constituent. Of the radiochemical and chemical concentrations analyzed for in the replicate-sample pairs, 267 of the 270 pairs (with 95 percent confidence) were statistically equivalent.

Algal culture studies for CELSS

NASA Technical Reports Server (NTRS)

Radmer, R.; Behrens, P.; Arnett, K.; Gladue, R.; Cox, J.; Lieberman, D.

1987-01-01

Microalgae are well-suited as a component of a Closed Environmental Life Support System (CELSS), since they can couple the closely related functions of food production and atmospheric regeneration. The objective was to provide a basis for predicting the response of CELSS algal cultures, and thus the food supply and air regeneration system, to changes in the culture parameters. Scenedesmus growth was measured as a function of light intensity, and the spectral dependence of light absorption by the algae as well as algal respiration in the light were determined as a function of cell concentration. These results were used to test and confirm a mathematical model that describes the productivity of an algal culture in terms of the competing processes of photosynthesis and respiration. The relationship of algal productivity to cell concentration was determined at different carbon dioxide concentrations, temperatures, and light intensities. The maximum productivity achieved by an air-grown culture was found to be within 10% of the computed maximum productivity, indicating that CO2 was very efficiently removed from the gas stream by the algal culture. Measurements of biomass productivity as a function of cell concentration at different light intensities indicated that both the productivity and efficiency of light utilization were greater at higher light intensities.

IMPACT OF SULPHUR DIOXIDE ON THE RESPIRATORY SYSTEM OF TBILISI POPULATION.

PubMed

Vepkhvadze, N; Kiladze, N; Khorbaladze, M; Kochoradze, T; Kugoti, I

2017-04-01

The possible relationship between levels of sulphur dioxide (SO2) in the air and the rate of respiratory diseases has been studied. Results of monitoring of main contaminants of outdoor air were analyzed and they are reflected in Environmental Report 2015. Information on morbidity by respiratory system diseases of Tbilisi population is has been taken from 2011-2015 reports of the National Center of Disease Control. Identified that there is no consistent correlation between sulphur dioxide concentration in the air and respiratory system disease rates in the population, including children. Obtained data demonstrated that during the study period maximum SO2 concentration was registered in 2015 - 0,14 mg/m3 (exceeding almost 3 times maximum permissible concentration - 0,5 mg/m3) and in the same year high morbidity rates are registered (incidence -18106,08), though the lowest rates are registered in 2011 (0,09 mg/m3), when incidence of respiratory system diseases in this period (13103.2) exceeds the rates registered in 2012, 2013 and 2014 (12736.4, 11336.3, 13009.0 accordingly). There is no direct correlation between the morbidity rates of 0-15 year old children and SO2 concentration. Maximum incidence rate is registered in 2015 (48487.0) and in the same year is also registered maximum concentration of SO2 (0,14 mg/m3), whereas the lowest rate is registered in 2013 (35538,70), when SO2 concentration in 2013 is lower only by 0.02 mg/m3 compared to the concentration in 2015. Direct correlation between morbidity with asthma in children and concentration of SO2 was not identified. Prevalence of asthma is minimal in 2014 (65,4), maximal in 2012 (207,1), whereas SO2 concentration in 2014 (0,13 mg/m3) exceeds the concentration in 2012 (0,12 mg/m3). It has to be considered, that besides SO2 there are many small intensity adverse factors, which are also risk factors for development of respiratory diseases. Isolated action of these factors with certain concentrations may not demonstrate any adverse effects on human health, but the combined effect of their action is stronger and obviously will affect general health and specifically - respiratory system. Implementation of urgent measures for further improvement of their ambient air quality has been recommended, which will be the basis for minimizing of many chronic diseases.

Development and validation of a simulation method, PeCHREM, for evaluating spatio-temporal concentration changes of paddy herbicides in rivers.

PubMed

Imaizumi, Yoshitaka; Suzuki, Noriyuki; Shiraishi, Fujio; Nakajima, Daisuke; Serizawa, Shigeko; Sakurai, Takeo; Shiraishi, Hiroaki

2018-01-24

In pesticide risk management in Japan, predicted environmental concentrations are estimated by a tiered approach, and the Ministry of the Environment also performs field surveys to confirm the maximum concentrations of pesticides with risk concerns. To contribute to more efficient and effective field surveys, we developed the Pesticide Chemicals High Resolution Estimation Method (PeCHREM) for estimating spatially and temporally variable emissions of various paddy herbicides from paddy fields to the environment. We used PeCHREM and the G-CIEMS multimedia environmental fate model to predict day-to-day environmental concentration changes of 25 herbicides throughout Japan. To validate the PeCHREM/G-CIEMS model, we also conducted a field survey, in which river waters were sampled at least once every two weeks at seven sites in six prefectures from April to July 2009. In 20 of 139 sampling site-herbicide combinations in which herbicides were detected in at least three samples, all observed concentrations differed from the corresponding prediction by less than one order of magnitude. We also compared peak concentrations and the dates on which the concentrations reached peak values (peak dates) between predictions and observations. The peak concentration differences between predictions and observations were less than one order of magnitude in 66% of the 166 sampling site-herbicide combinations in which herbicide was detected in river water. The observed and predicted peak dates differed by less than two weeks in 79% of these 166 combinations. These results confirm that the PeCHREM/G-CIEMS model can improve the efficiency and effectiveness of surveys by predicting the peak concentrations and peak dates of various herbicides.

Arsenic in ground water in selected parts of southwestern Ohio, 2002-03

USGS Publications Warehouse

Thomas, Mary Ann; Schumann, Thomas L.; Pletsch, Bruce A.

2005-01-01

Arsenic concentrations were measured in 57 domestic wells in Preble, Miami, and Shelby Counties, in southwestern Ohio. The median arsenic concentration was 7.1 ?g/L (micrograms per liter), and the maximum was 67.6 ?g/L. Thirty-seven percent of samples had arsenic concentrations greater than the U.S. Environmental Protection Agency drinking-water standard of 10 ?g/L. Elevated arsenic concentrations (>10 ?g/L) were detected over the entire range of depths sampled (42 to 221 feet) and in each of three aquifer types, Silurian carbonate bedrock, glacial buried-valley deposits, and glacial till with interbedded sand and gravel. One factor common in all samples with elevated arsenic concentrations was that iron concentrations were greater than 1,000 ?g/L. The observed correlations of arsenic with iron and alkalinity are consistent with the hypothesis that arsenic was released from iron oxides under reducing conditions (by reductive dissolution or reductive desorption). Comparisons among the three aquifer types revealed some differences in arsenic occurrence. For buried-valley deposits, the median arsenic concentration was 4.6 ?g/L, and the maximum was 67.6 ?g/L. There was no correlation between arsenic concentrations and depth; the highest concentrations were at intermediate depths (about 100 feet). Half of the buried-valley samples were estimated to be methanic. Most of the samples with elevated arsenic concentrations also had elevated concentrations of dissolved organic carbon and ammonia. For carbonate bedrock, the median arsenic concentration was 8.0 ?g/L, and the maximum was 30.7 ?g/L. Arsenic concentrations increased with depth. Elevated arsenic concentrations were detected in iron- or sulfate-reducing samples. Arsenic was significantly correled with molybdenum, strontium, fluoride, and silica, which are components of naturally ocurring minerals. For glacial till with interbedded sand and gravel, half of the samples had elevated arsenic concentrations. The median was 11.4 ?g/L, and the maximum was 27.6 ?g/L. At shallow depths (<100 feet), this aquifer type had higher arsenic and iron concentrations than carbonate bedrock. It is not known whether these observed differences among aquifer types are related to variations in (1) arsenic content of the aquifer material, (2) organic carbon content of the aquifer material, (3) mechanisms of arsenic mobilization (or uptake), or (4) rates of arsenic mobilization (or uptake). A followup study that includes solid-phase analyses and geochemical modeling was begun in 2004 in northwestern Preble County.

Health-risk assessment based on an additive to paints made from isobutyric aldehyde condensation products

NASA Astrophysics Data System (ADS)

Jan Tic, Wilhelm

2017-10-01

Solvents are primarily used for making protective coatings. Considering their chemical nature, there are a great variety of coatings, including those based on liquid hydrocarbons and organic chloroderivatives. These products are a serious load to the environment because of their physicochemical properties, therefore, they have for some time been replaced with more-environmentally friendly, new generation products. One of them is the hydroxyester HE-1: made from isobutyric aldehyde condensation products, it is an alternative to those coalescents for paints and varnishes which are intended to be replaced or their use restricted. The results of selected toxicological tests relating to the human health risk effect of the hydroxyester HE-1 - environmentally-friendly additive to paints and varnishes are presented. The test results indicate that HE-1 causes skin irritation in rabbit only when used at its maximum concentrations. No lesions in the cornea or iris were observed in any of the test rabbits after the application of the hydroxyester HE-1. In the mutagenic effect test of HE-1 on the bacteria Salmonella typhimurium, the result was negative. Based on the test results, it was found that the hydroxyester HE-1 may only have a human health risk effect when used at its maximum concentrations.

Assessing toxicant effects in a complex estuary: A case study of effects of silver on reproduction in the bivalve, Potamocorbula amurensis, in San Francisco Bay

USGS Publications Warehouse

Brown, C.L.; Parchaso, F.; Thompson, J.K.; Luoma, S.N.

2003-01-01

Contaminant exposures in natural systems can be highly variable. This variability is superimposed upon cyclic variability in biological processes. Together, these factors can confound determination of contaminant effects. Long term, multidisciplined studies with high frequency sampling can be effective in overcoming such obstacles. While studying trace metal contamination in the tissues of the clam, Potamocorbula amurensis, in the northern reach of San Francisco Bay, an episode of high Ag concentrations was identified (maximum of 5.5 ??g g-1) at two mid-estuary sites. High concentrations were not seen in clams up-estuary (maximum of 1.92 ??g g-1) from these sites and were reduced down-estuary (maximum of 2.67 ??g g-1). Silver is not common naturally in the environment, so its elevated presence is usually indicative of anthropogenic influences such as municipal and industrial discharge. Monthly sampling of reproductive status of clams characterized the reproductive cycle and differences in the patterns of reproductive activity that corresponded to changes in Ag tissue concentrations. The proportion of reproductive clams was less than 60% during periods when tissue concentrations were high (generally >2 ??g g-1). When tissue concentrations of Ag decreased (???1 ??g g-1), the proportion of reproductive clams was 80 to 100%. A comparison between the annual proportion of reproductive clams and annual Ag tissue concentrations showed a significant negative correlation. No other measured environmental variables were correlated with reproductive impairment. The weight-of-evidence approach strongly supports a cause and effect relationship between Ag contamination and reduced reproductive activity in P. amurensis.

Assessing toxicant effects in a complex estuary--A case study of effects of silver on reproduction in the bivalve, Potamocurbula amurensis, in San Francisco Bay

USGS Publications Warehouse

Brown, Cynthia L.; Parchaso, Francis; Thompson, Janet K.; Luoma, Samuel N.

2003-01-01

Contaminant exposures in natural systems can be highly variable. This variability is superimposed upon cyclic variability in biological processes. Together, these factors can confound determination of contaminant effects. Long term, multidisciplined studies with high frequency sampling can be effective in overcoming such obstacles. While studying trace metal contamination in the tissues of the clam, Potamocorbula amurensis, in the northern reach of San Francisco Bay, an episode of high Ag concentrations was identified (maximum of 5.5 µg g−1) at two mid-estuary sites. High concentrations were not seen in clams up-estuary (maximum of 1.92 µg g−1) from these sites and were reduced down-estuary (maximum of 2.67 µg g−1). Silver is not common naturally in the environment, so its elevated presence is usually indicative of anthropogenic influences such as municipal and industrial discharge. Monthly sampling of reproductive status of clams characterized the reproductive cycle and differences in the patterns of reproductive activity that corresponded to changes in Ag tissue concentrations. The proportion of reproductive clams was less than 60% during periods when tissue concentrations were high (generally >2 µg g−1). When tissue concentrations of Ag decreased (≤1 µg g−1), the proportion of reproductive clams was 80 to 100%. A comparison between the annual proportion of reproductive clams and annual Ag tissue concentrations showed a significant negative correlation. No other measured environmental variables were correlated with reproductive impairment. The weight-of-evidence approach strongly supports a cause and effect relationship between Ag contamination and reduced reproductive activity in P. amurensis.

Mapping chemicals in air using an environmental CAT scanning system: evaluation of algorithms

NASA Astrophysics Data System (ADS)

Samanta, A.; Todd, L. A.

A new technique is being developed which creates near real-time maps of chemical concentrations in air for environmental and occupational environmental applications. This technique, we call Environmental CAT Scanning, combines the real-time measuring technique of open-path Fourier transform infrared spectroscopy with the mapping capabilitites of computed tomography to produce two-dimensional concentration maps. With this system, a network of open-path measurements is obtained over an area; measurements are then processed using a tomographic algorithm to reconstruct the concentrations. This research focussed on the process of evaluating and selecting appropriate reconstruction algorithms, for use in the field, by using test concentration data from both computer simultation and laboratory chamber studies. Four algorithms were tested using three types of data: (1) experimental open-path data from studies that used a prototype opne-path Fourier transform/computed tomography system in an exposure chamber; (2) synthetic open-path data generated from maps created by kriging point samples taken in the chamber studies (in 1), and; (3) synthetic open-path data generated using a chemical dispersion model to create time seires maps. The iterative algorithms used to reconstruct the concentration data were: Algebraic Reconstruction Technique without Weights (ART1), Algebraic Reconstruction Technique with Weights (ARTW), Maximum Likelihood with Expectation Maximization (MLEM) and Multiplicative Algebraic Reconstruction Technique (MART). Maps were evaluated quantitatively and qualitatively. In general, MART and MLEM performed best, followed by ARTW and ART1. However, algorithm performance varied under different contaminant scenarios. This study showed the importance of using a variety of maps, particulary those generated using dispersion models. The time series maps provided a more rigorous test of the algorithms and allowed distinctions to be made among the algorithms. A comprehensive evaluation of algorithms, for the environmental application of tomography, requires the use of a battery of test concentration data before field implementation, which models reality and tests the limits of the algorithms.

A Framework to Evaluate the Impact of Armourstones on the Chemical Quality of Surface Water.

PubMed

Duester, Lars; Wahrendorf, Dierk-Steffen; Brinkmann, Corinna; Fabricius, Anne-Lena; Meermann, Björn; Pelzer, Juergen; Ecker, Dennis; Renner, Monika; Schmid, Harald; Ternes, Thomas A; Heininger, Peter

2017-01-01

Today, basic requirements for construction works include the protection of human health and of the environment. In the tension area between economic demands, circular flow economy and environmental safety, a link between the results from standardized leaching tests and the respective environmental quality standards must be created. To derive maximum release limits of metals and metalloids for armourstones in hydraulic engineering, this link is accomplished via a simple model approach. By treating natural materials and industrial by-products the same way, the article delivers an overview on the recent regulative situation in Europe as well as describes and discusses an innovative approach to derive maximum release limits for monolithic construction products in hydraulic engineering on a conceptual level. On a practical level, a list of test parameters is derived by connecting an extensive dataset (seven armourstone materials with five repetitions and 31 elements tested with the worldwide applied dynamic surface leaching test) with surface water quality standards and predicted no effect concentrations. Finally, the leaching tests results are compared with the envisaged maximum release limits, offering a direct comparison between natural materials and industrial by-products.

Predicting ground level impacts of solid rocket motor testing

NASA Technical Reports Server (NTRS)

Douglas, Willard L.; Eagan, Ellen E.; Kennedy, Carolyn D.; Mccaleb, Rebecca C.

1993-01-01

Beginning in August of 1988 and continuing until the present, NASA at Stennis Space Center, Mississippi has conducted environmental monitoring of selected static test firings of the solid rocket motor used on the Space Shuttle. The purpose of the study was to assess the modeling protocol adapted for use in predicting plume behavior for the Advanced Solid Rocket Motor that is to be tested in Mississippi beginning in the mid-1990's. Both motors use an aluminum/ammonium perchlorate fuel that produces HCl and Al2O3 particulates as the major combustion products of concern. A combination of COMBUS.sr and PRISE.sr subroutines and the INPUFF model are used to predict the centerline stabilization height, the maximum concentration of HCl and Al2O3 at ground level, and distance to maximum concentration. Ground studies were conducted to evaluate the ability of the model to make these predictions. The modeling protocol was found to be conservative in the prediction of plume stabilization height and in the concentrations of the two emission products predicted.

Seasonal determination of trace and ultra-trace content in Macrocystis pyrifera from San Jorge Gulf (Patagonia) by Total Reflection X-ray Fluorescence

NASA Astrophysics Data System (ADS)

Salomone, Vanesa N.; Riera, Marina; Cerchietti, Luciana; Custo, Graciela; Muniain, Claudia

2017-05-01

Seaweed have a great capacity to accumulate heavy metals in their tissues. The chemical characterization of seaweed is important due to their use in environmental monitoring and human or animal food. The aim of the present study was to evaluate the multi-elemental composition of seaweed from San Jorge Gulf (Patagonia, Argentina) by Total Reflection X-ray Fluorescence (TXRF). The elements As, Br, Cu, Cr, Fe, Mn, Ni, Pb, Rb, Sr, V and Zn were seasonally analyzed and quantified in blades of Macrocystis pyrifera. TXRF showed to be a suitable technique for simultaneous multi-element analysis in this kind of samples. The results revealed seasonal variations in the chemical content for some elements; arsenic content was maximum in summer and autumn, iron concentration increased to the winter and zinc concentration was maximum in autumn. The sum of principal micronutrients (Fe + Zn + Mn + Cu) varied between 114 and 171 mg k- 1 g dw. The total As concentration ranged between 36 and 66 mg kg- 1. Lead, nickel and copper were not detected.

Drinking-Water Standards and Regulations. Volume 2. Manual for 1982-88

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, L.K.; Wang, M.H.S.

1988-04-10

The following 11 important documents are compiled for Drinking Water Standards and Regulations: (1) U.S. Environmental Agency Water Programs, National Interim Primary Drinking Water Regulations; (2) New Jersey Safe Drinking Water Act; (3) Summary of New Jersey Drinking Water Standards; (4) U.S. Environmental Protection Agency Safe Drinking Water Act of 1986 Amendments; (5) U.S. Environmental Protection Agency National Primary Drinking Water Standards; (6) Canadian National Health and Welfare Drinking Water Quality Guidelines--Maximum Acceptable Concentrations; (7) U.S. Environmental Protection Agency, National Primary Drinking Water Regulations, Filtration and Disinfection Turbidity, Giardia Lamblia, Viruses, Legionella, and Heterotrophic Bacteria; (8) Public Water Supply Manual--Guidemore » to the Safe Drinking Water Program; (9) Public Water Supply Manual--Emergency Response; (10) U.S. EPA Approved Krofta Chemicals; (11) NY-DOH Approved Krofta Chemicals.« less

Concentrations of the UV filter ethylhexyl methoxycinnamate in the aquatic compartment: a comparison of modelled concentrations for Swiss surface waters with empirical monitoring data.

PubMed

Straub, Jürg Oliver

2002-05-10

UV filters in sunscreens and cosmetics protect the skin from damage through UV radiation. Many tonnes per year of UV filters are being used in Europe and will be present, at least seasonally, in detectable concentrations in surface waters similar to common pharmaceutically active substances. Predicted environmental concentrations (PECs) of ethylhexyl methoxycinnamate (EHMC; CAS 5466-77-3) were extrapolated for Switzerland, taking into consideration substance-specific environmental fate data and marketing estimates, by crude worst-case reckoning and by applying two environmental models (Mackay Level III; USES 3.0), both configured for Swiss hydrological and area data. By worst-case reckoning the summer PEC is 70.8-81.3 ng/l while for the remaining 8 months of the year the PEC is 13.1-15.1 ng/l. The Level III model results in concentrations of 2.4 ng/l during the summer and 0.44 ng/l during the rest of the year, while the USES 3.0 model gives an average PEC for the whole year of 7.6 ng/l. Pooling summer monitoring data (90 single analyses) from the River Rhine below Basel in the year 1997 (Water Protection Board of Basel) and from Lakes Zurich and Hüttner in 1998 (Poiger et al., in preparation) allowed a derivation of a probabilistic median concentration of 4.6 ng/l, a 95th-percentile concentration of 18.6 ng/l and a 99th-percentile concentration of 33.5 ng/l. The 6-fold range from the median value to the maximum calls for caution in interpreting published monitoring concentrations. Comparison of modelled PECs with realistic median concentrations shows that crude reckoning overestimates actual concentrations by a factor of about 10, probably through insufficient consideration of (further) degradation of EHMC in sewage works, surface waters, sediments or river banks. Both computer models, in contrast, are within the same order of magnitude as the actual summer concentrations. Based on the available data, both these environmental fate and distribution models give realistic PECs.

Occurrence of selected radionuclides in ground water used for drinking water in the United States; a reconnaissance survey, 1998

USGS Publications Warehouse

Focazio, Michael J.; Szabo, Zoltan; Kraemer, Thomas F.; Mullin, Ann H.; Barringer, Thomas H.; dePaul, Vincent T.

2001-01-01

The U.S. Geological Survey, in collaboration with the U.S. Environmental Protection Agency, the American Water Works Association, and the American Water Works Service Company, completed a targeted national reconnaissance survey of selected radionuclides in public ground-water supplies. Radionuclides analyzed included radium-224 (Ra-224), radium-226 (Ra-226), radium-228 (Ra-228), polonium-210 (Po-210) and lead-210 (Pb-210).This U.S. Geological Survey reconnaissance survey focused intentionally on areas with known or suspected elevated concentrations of radium in ground water to determine if Ra-224 was also present in the areas where other isotopes of radium had previously been detected and to determine the co-occurrence characteristics of the three radium isotopes (Ra-224, Ra-226, and Ra-228) in those areas. Ninety-nine raw-water samples (before water treatment) were collected once over a 6-month period in 1998 and 1999 from wells (94 of which are used for public drinking water) in 27 States and 8 physiographic provinces. Twenty-one of the 99 samples exceeded the current U.S. Environmental Protection Agency drinking-water maximum contaminant level of 5 picocuries per liter (pCi/L) for combined radium (Ra-226 + Ra-228). Concentrations of Ra-224 were reported to exceed 1 pCi/L in 30 percent of the samples collected, with a maximum concentration of 73.6 pCi/L measured in water from a nontransient, noncommunity, public-supply well in Maryland. Radium-224 concentrations generally were higher than those of the other isotopes of radium. About 5 percent of the samples contained concentrations of Ra-224 greater than 10 pCi/L, whereas only 2 percent exceeded 10 pCi/L for either Ra-226 or Ra-228. Concentrations of Ra-226 greater than 1 pCi/L were reported in 33 percent of the samples, with a maximum concentration of 16.9 pCi/L measured in water from a public-supply well in Iowa. Concentrations of Ra-228 greater than 1 pCi/L were reported in 22 samples, with a maximum concentration of 72.3 pCi/L measured in water from a non-transient, noncommunity, public-supply well in Maryland.Radium-224, which is a decay product of Ra-228 in the Th-232 decay series, was significantly correlated with Ra-228 (Spearman?s rank correlation coefficient ?r? equals 0.82) and to a lesser degree with Ra-226 (r equals 0.69), which is an isotope in the U-238 decay series. The rank correlation coefficient between Ra-226 and Ra-228 was 0.63. The high correlation between Ra-224 and Ra-228 concentrations and the corresponding isotopic ratios of the two (about 1:1 in 90 percent of the samples) indicates that the two radionuclides occur in approximately equal concentrations in most ground water sampled. Thus, Ra-228 can be considered as a reasonable proxy indicator for the occurrence of Ra-224 in ground water.The maximum concentration of Po-210 was 4.85 pCi/L and exceeded 1 pCi/L in only two samples. The maximum concentration of Pb-210 was 4.14 pCi/L, and about 10 percent of the samples exceeded 1 pCi/L. Areas with known, or suspected, elevated concentrations of polonium and lead were not targeted in this survey.Three major implications are drawn for future radionuclide monitoring on the basis of this information: (1) grossalpha particle analyses of ground water should be done within about 48?72 hours after collection to determine the presence of the short-lived, alpha-particle emitting isotopes, such as Ra-224, which was detected in elevated concentrations in many of the samples collected for this survey; (2) the isotope ratios of Ra-224 to Ra-228 in ground water are variable on a national scale, but the two radioisotopes generally occur in ratios near 1:1, therefore, the more commonly measured Ra-228 can be used as an indicator of Ra-224 occurrence for some general purposes other than compliance; and (3) the isotopic ratios of Ra-226 to Ra-228 were less than 3:2 in many samples. These ratios corroborate results of previous studies that have shown the presence of Ra-228

Fecal coliform and Escherichia coli bacteria in the St. Croix National Scenic Riverway, Summer 1999

USGS Publications Warehouse

Kroening, Sharon E.

1999-01-01

Fecal coliform and Escherichia coli (E. coli) concentrations were determined in the St. Croix National Scenic Riverway to assess whether pathogenic organisms pose a potential problem for recreational use. Samples were collected from May through September 1999 at 22 locations on the St. Croix and Namekagon Rivers. No concentrations exceeded water-quality criteria or standards set by the U.S. Environmental Protection Agency or the states of Minnesota and Wisconsin. Maximum fecal coliform and E. coli concentrations were measured in the St. Croix River at St. Croix Falls, Wisconsin. Median fecal coliform and E. coli concentrations were greater in the St. Croix River near Woodland Corner, Wisconsin, and at Marine on St. Croix, Minnesota than at other locations sampled. There were no consistent short-term variations in fecal coliform or E. coli concentrations during the summer period or any significant relations between concentrations and stream discharge, based on these results.

A meta-analysis and statistical modelling of nitrates in groundwater at the African scale

NASA Astrophysics Data System (ADS)

Ouedraogo, Issoufou; Vanclooster, Marnik

2016-06-01

Contamination of groundwater with nitrate poses a major health risk to millions of people around Africa. Assessing the space-time distribution of this contamination, as well as understanding the factors that explain this contamination, is important for managing sustainable drinking water at the regional scale. This study aims to assess the variables that contribute to nitrate pollution in groundwater at the African scale by statistical modelling. We compiled a literature database of nitrate concentration in groundwater (around 250 studies) and combined it with digital maps of physical attributes such as soil, geology, climate, hydrogeology, and anthropogenic data for statistical model development. The maximum, medium, and minimum observed nitrate concentrations were analysed. In total, 13 explanatory variables were screened to explain observed nitrate pollution in groundwater. For the mean nitrate concentration, four variables are retained in the statistical explanatory model: (1) depth to groundwater (shallow groundwater, typically < 50 m); (2) recharge rate; (3) aquifer type; and (4) population density. The first three variables represent intrinsic vulnerability of groundwater systems to pollution, while the latter variable is a proxy for anthropogenic pollution pressure. The model explains 65 % of the variation of mean nitrate contamination in groundwater at the African scale. Using the same proxy information, we could develop a statistical model for the maximum nitrate concentrations that explains 42 % of the nitrate variation. For the maximum concentrations, other environmental attributes such as soil type, slope, rainfall, climate class, and region type improve the prediction of maximum nitrate concentrations at the African scale. As to minimal nitrate concentrations, in the absence of normal distribution assumptions of the data set, we do not develop a statistical model for these data. The data-based statistical model presented here represents an important step towards developing tools that will allow us to accurately predict nitrate distribution at the African scale and thus may support groundwater monitoring and water management that aims to protect groundwater systems. Yet they should be further refined and validated when more detailed and harmonized data become available and/or combined with more conceptual descriptions of the fate of nutrients in the hydrosystem.

Nutrient and pesticide contamination bias estimated from field blanks collected at surface-water sites in U.S. Geological Survey Water-Quality Networks, 2002–12

USGS Publications Warehouse

Medalie, Laura; Martin, Jeffrey D.

2017-08-14

Potential contamination bias was estimated for 8 nutrient analytes and 40 pesticides in stream water collected by the U.S. Geological Survey at 147 stream sites from across the United States, and representing a variety of hydrologic conditions and site types, for water years 2002–12. This study updates previous U.S. Geological Survey evaluations of potential contamination bias for nutrients and pesticides. Contamination is potentially introduced to water samples by exposure to airborne gases and particulates, from inadequate cleaning of sampling or analytic equipment, and from inadvertent sources during sample collection, field processing, shipment, and laboratory analysis. Potential contamination bias, based on frequency and magnitude of detections in field blanks, is used to determine whether or under what conditions environmental data might need to be qualified for the interpretation of results in the context of comparisons with background levels, drinking-water standards, aquatic-life criteria or benchmarks, or human-health benchmarks. Environmental samples for which contamination bias as determined in this report applies are those from historical U.S. Geological Survey water-quality networks or programs that were collected during the same time frame and according to the same protocols and that were analyzed in the same laboratory as field blanks described in this report.Results from field blanks for ammonia, nitrite, nitrite plus nitrate, orthophosphate, and total phosphorus were partitioned by analytical method; results from the most commonly used analytical method for total phosphorus were further partitioned by date. Depending on the analytical method, 3.8, 9.2, or 26.9 percent of environmental samples, the last of these percentages pertaining to all results from 2007 through 2012, were potentially affected by ammonia contamination. Nitrite contamination potentially affected up to 2.6 percent of environmental samples collected between 2002 and 2006 and affected about 3.3 percent of samples collected between 2007 and 2012. The percentages of environmental samples collected between 2002 and 2011 that were potentially affected by nitrite plus nitrate contamination were 7.3 for samples analyzed with the low-level method and 0.4 for samples analyzed with the standard-level method. These percentages increased to 14.8 and 2.2 for samples collected in 2012 and analyzed using replacement low- and standard-level methods, respectively. The maximum potentially affected concentrations for nitrite and for nitrite plus nitrate were much less than their respective maximum contamination levels for drinking-water standards. Although contamination from particulate nitrogen can potentially affect up to 21.2 percent and that from total Kjeldahl nitrogen can affect up to 16.5 percent of environmental samples, there are no critical or background levels for these substances.For total nitrogen, orthophosphate, and total phosphorus, contamination in a small percentage of environmental samples might be consequential for comparisons relative to impairment risks or background levels. At the low ends of the respective ranges of impairment risk for these nutrients, contamination in up to 5 percent of stream samples could account for at least 23 percent of measured concentrations of total nitrogen, for at least 40 or 90 percent of concentrations of orthophosphate, depending on the analytical method, and for 31 to 76 percent of concentrations of total phosphorus, depending on the time period.Twenty-six pesticides had no detections in field blanks. Atrazine with 12 and metolachlor with 11 had the highest number of detections, mostly occurring in spring or early summer. At a 99-percent level of confidence, contamination was estimated to be no greater than the detection limit in at least 98 percent of all samples for 38 of 40 pesticides. For metolachlor and atrazine, potential contamination was no greater than 0.0053 and 0.0093 micrograms per liter in 98 percent of samples. For 11 of 14 pesticides with at least one detection, the maximum potentially affected concentration of the environmental sample was less than their respective human-health or aquatic-life benchmarks. Small percentages of environmental samples had concentrations high enough that atrazine contamination potentially could account for the entire aquatic-life benchmark for acute effects on nonvascular plants, that dieldrin contamination could account for up to 100 percent of the cancer health-based screening level, or that chlorpyrifos contamination could account for 13 or 12 percent of the concentrations in the aquatic-life benchmarks for chronic effects on invertebrates or the criterion continuous concentration for chronic effects on aquatic life.

Quantile-based Bayesian maximum entropy approach for spatiotemporal modeling of ambient air quality levels.

PubMed

Yu, Hwa-Lung; Wang, Chih-Hsin

2013-02-05

Understanding the daily changes in ambient air quality concentrations is important to the assessing human exposure and environmental health. However, the fine temporal scales (e.g., hourly) involved in this assessment often lead to high variability in air quality concentrations. This is because of the complex short-term physical and chemical mechanisms among the pollutants. Consequently, high heterogeneity is usually present in not only the averaged pollution levels, but also the intraday variance levels of the daily observations of ambient concentration across space and time. This characteristic decreases the estimation performance of common techniques. This study proposes a novel quantile-based Bayesian maximum entropy (QBME) method to account for the nonstationary and nonhomogeneous characteristics of ambient air pollution dynamics. The QBME method characterizes the spatiotemporal dependence among the ambient air quality levels based on their location-specific quantiles and accounts for spatiotemporal variations using a local weighted smoothing technique. The epistemic framework of the QBME method can allow researchers to further consider the uncertainty of space-time observations. This study presents the spatiotemporal modeling of daily CO and PM10 concentrations across Taiwan from 1998 to 2009 using the QBME method. Results show that the QBME method can effectively improve estimation accuracy in terms of lower mean absolute errors and standard deviations over space and time, especially for pollutants with strong nonhomogeneous variances across space. In addition, the epistemic framework can allow researchers to assimilate the site-specific secondary information where the observations are absent because of the common preferential sampling issues of environmental data. The proposed QBME method provides a practical and powerful framework for the spatiotemporal modeling of ambient pollutants.

Quality of water from shallow wells in the rice-growing area in southwestern Louisiana, 1999 through 2001

USGS Publications Warehouse

Tollett, Roland W.; Fendick, Robert B.

2004-01-01

In 1999-2001, the U.S. Geological Survey installed and sampled 27 shallow wells in the rice-growing area in southwestern Louisiana as part of the Acadian-Pontchartrain Study Unit of the National Water-Quality Assessment Program. The purpose of this report is to describe the waulity of water from shallow wells in the rice-growing area and to relate that water quality to natural and anthropogenic activities, particularly rice agriculture. Ground-water samples were analyzed for general ground-water properties and about 150 water-quality constituents, including major inorganic ions, trace elements, nutrients, dissolved organic carbon (DOC), pesticides, radon, chloroflourocarbons, and selected stable isotopes. Dissolved solids concentrations for 17 wells exceeded the U.S. Environmental Protection Agency secondary minimum containment level of 500 milligrams per liter (mg/L) for drinking water. Concentrations for major pesticides generally were less than the maximum contaminant levels for drinking water. Two major inorganic ions, sulfate and chloride, and two trace elements, iron and manganese, had concentrations that were greater than the secondary maximum containment levels. Three nutrient concentrations were greater than 2 mg/L, a level that might indicate contamination from human activities, and one nutrient concentration (that for nitrite plus nitrite as nitrogen) was greater than the maximum contaminant level of 10 mg/L for drinking water. The median concentration for DOC was 0.5 mg/L, indicating naturally-occurring DOC conditions in the study area. Thirteen pesticides and 7 pesticide degradation products were detected in 14 of the 27 wells sampled. Bentazon, 2, 4-D, and molinate (three rice herbicides) were detected in water from four, one, and one wells, respectively, and malathion (a rice insecticide) was deteced in water fromone well. Low-level concentrations and few detections of nutrients and pesticides indicated that ground-water quality was affected slightly by anthropogenic activities. Quality-control samples, including field blanks, replicates, and spikes, indicated no bias in ground-water data from collection on analysis. Radon concentrations for 22 of the 24 wells sampled wer at or greater than the U.S. Environmental Protection Agency proposed maximum contaminant level of 300 picocuries per liter. Chlorofluorocarbon concentrations in selected wells indicated the apparent ages of the ground water varied with depth water level and ranged from about 17 to 49 years. The stable isotopes of hydrogen and oxygen in water molecules indicated the origin of ground water in the study area was rainwater that originated near the study area and that few geochemical or physical processes influenced the stable isotopic composition of the shallow ground water. The Spearman rank correlation was used to detemrine whther significant correlations existed between physical properties, selected chemical constituents, the number of pesticides detected, and the apparent age of water. The depth to ground water was positively correlated to the well depth and inversely correlated to dissolved solids and other constituents, such as radon, indicating the ground water was under unconfined or semiconfined conditions and more dilute with increasing depth. As the depth to ground water increased, the concentrations of dissolved solids and other constituents decreased, possibly because the deeper sands had a greater transmittal of ground water, which, over time, would flush out, or dilute, the concentrations of dissolved solids in the natural sediments. The apparent age of water was correlated inversely with nitrite plus nitrite concentration, indicating that as apparent age increased, the nitrite plus nitrite concentration decreased. No significant correlations existed between the number of pesticides detected and any of the physical or chemica

Effects of environmental conditions on growth and survival of Salmonella in pasteurized whole egg.

PubMed

Jakočiūnė, Džiuginta; Bisgaard, Magne; Hervé, Gaëlle; Protais, Jocelyne; Olsen, John Elmerdahl; Chemaly, Marianne

2014-08-01

This study investigated the influence of three parameters (time, temperature and NaCl concentration) on survival and four parameters (temperature, NaCl and lysozyme concentrations and pH) on growth of Salmonella enterica serovar Enteritidis (S. Enteritidis) in pasteurized whole egg (PWE). Doehlert uniform shell design was employed to choose conditions for trials and data was fitted to polynomial models and were presented as estimated response surfaces. A model for prediction of reduction of S. Enteritidis in PWE within temperatures between 50 and 58°C, NaCl concentrations of 0-12%, and heating times between 30 and 210s and a model for prediction of growth rate of S. Enteritidis in PWE in the temperature range of 1-25°C, NaCl concentration of 0-12%, pH between 5 and 9, and lysozyme concentrations of 107-1007 U/mg proteins were developed. The maximum reduction condition was 58°C, 0% of NaCl at a fixed heating time of 120s, while maximum growth rate was estimated at 25°C and 0% of NaCl. pH and lysozyme concentration were shown not to influence growth performance significantly in the range of values studied. Results inform industry of the optimal pasteurization and storage parameters for liquid whole egg. Copyright © 2014 Elsevier B.V. All rights reserved.

Concentrations of arsenic, cadmium and lead in human hair and typical foods in eleven Chinese cities.

PubMed

Zhou, Tong; Li, Zhu; Zhang, Fan; Jiang, Xiaosan; Shi, Weiming; Wu, Longhua; Christie, Peter

2016-12-01

Concentrations of arsenic (As), cadmium (Cd) and lead (Pb) were determined in 384 human hair samples and 445 purchased food samples from 11 cities in China. The mean concentrations of hair As, Cd and Pb were 0.23, 0.062 and 2.45mgkg -1 , respectively. The As, Cd and Pb concentrations in different foods were lower than the national maximum allowable contaminant levels. By comparison, males had higher hair As concentrations but lower Cd concentrations than females. When the interaction effects of gender and age were considered, males had the higher hair As, Cd and Pb concentrations in the 51-65 year-old age group. Residents of rural areas had higher hair As, Cd and Pb concentrations than people living in urban areas. Further analysis indicates that hair As, Cd and Pb concentrations and their changes with biological and environmental factors cannot be satisfactorily explained by the estimated intakes from purchased food. Copyright © 2016 Elsevier B.V. All rights reserved.

Characterization of the quality of water, bed sediment, and fish in Mittry Lake, Arizona, 2014–15

USGS Publications Warehouse

Hermosillo, Edyth; Coes, Alissa L.

2017-03-01

Water, bed-sediment, and fish sampling was conducted in Mittry Lake, Arizona, in 2014–15 to establish current water-quality conditions of the lake. The parameters of temperature, dissolved-oxygen concentration, specific conductance, and alkalinity were measured in the field. Water samples were collected and analyzed for dissolved major ions, dissolved trace elements, dissolved nutrients, dissolved organic carbon, dissolved pesticides, bacteria, and suspended-sediment concentrations. Bed-sediment and fish samples were analyzed for trace elements, halogenated compounds, total mercury, and methylmercury.U.S. Environmental Protection Agency secondary maximum contaminant levels in drinking water were exceeded for sulfate, chloride, and manganese in the water samples. Trace-element concentrations were relatively similar between the inlet, middle, and outlet locations. Concentrations for nutrients in all water samples were below the Arizona Department of Environmental Quality’s water-quality standards for aquatic and wildlife uses, and all bacteria levels were below the Arizona Department of Environmental Quality’s recommended recreational water-quality criteria. Three out of 81 pesticides were detected in the water samples.Trace-element concentrations in bed sediment were relatively consistent between the inlet, middle, and outlet locations. Lead, manganese, nickel, and zinc concentrations, however, decreased from the inlet to outlet locations. Concentrations for lead, nickel, and zinc in some bed-sediment samples exceeded consensus-based sediment-quality guidelines probable effect concentrations. Eleven out of 61 halogenated compounds were detected in bed sediment at the inlet location, whereas three were detected at the middle location, and five were detected at the outlet location. No methylmercury was detected in bed sediment. Total mercury was detected in bed sediment at concentrations below the consensus-based sediment-quality guidelines probable effect concentration.Sixteen trace elements were detected in at least one of the fish-tissue samples, and trace-element concentrations were relatively consistent between the three fish-tissue samples. Seven halogenated compounds were detected in at least one of the whole-body fish samples; four to five compounds were detected in each fish. One fish-tissue sample exceeded the U.S. Environmental Protection Agency human health consumption criteria for methylmercury.

Fluctuations in coral health of four common inshore reef corals in response to seasonal and anthropogenic changes in water quality.

PubMed

Browne, Nicola K; Tay, Jason K L; Low, Jeffrey; Larson, Ole; Todd, Peter A

2015-04-01

Environmental drivers of coral condition (maximum quantum yield, symbiont density, chlorophyll a content and coral skeletal growth rates) were assessed in the equatorial inshore coastal waters of Singapore, where the amplitude of seasonal variation is low, but anthropogenic influence is relatively high. Water quality variables (sediments, nutrients, trace metals, temperature, light) explained between 52 and 83% of the variation in coral condition, with sediments and light availability as key drivers of foliose corals (Merulina ampliata, Pachyseris speciosa), and temperature exerting a greater influence on a branching coral (Pocillopora damicornis). Seasonal reductions in water quality led to high chlorophyll a concentrations and maximum quantum yields in corals, but low growth rates. These marginal coral communities are potentially vulnerable to climate change, hence, we propose water quality thresholds for coral growth with the aim of mitigating both local and global environmental impacts. Copyright © 2015 Elsevier Ltd. All rights reserved.

Adjustments of the Pesticide Risk Index Used in Environmental Policy in Flanders

PubMed Central

Fevery, Davina; Peeters, Bob; Lenders, Sonia; Spanoghe, Pieter

2015-01-01

Indicators are used to quantify the pressure of pesticides on the environment. Pesticide risk indicators typically require weighting environmental exposure by a no effect concentration. An indicator based on spread equivalents (ΣSeq) is used in environmental policy in Flanders (Belgium). The pesticide risk for aquatic life is estimated by weighting active ingredient usage by the ratio of their maximum allowable concentration and their soil halflife. Accurate estimates of total pesticide usage in the region are essential in such calculations. Up to 2012, the environmental impact of pesticides was estimated on sales figures provided by the Federal Government. Since 2013, pesticide use is calculated based on results from the Farm Accountancy Data Network (FADN). The estimation of pesticide use was supplemented with data for non-agricultural use based on sales figures of amateur use provided by industry and data obtained from public services. The Seq-indicator was modified to better reflect reality. This method was applied for the period 2009-2012 and showed differences between estimated use and sales figures of pesticides. The estimated use of pesticides based on accountancy data is more accurate compared to sales figures. This approach resulted in a better view on pesticide use and its respective environmental impact in Flanders. PMID:26046655

Adjustments of the Pesticide Risk Index Used in Environmental Policy in Flanders.

PubMed

Fevery, Davina; Peeters, Bob; Lenders, Sonia; Spanoghe, Pieter

2015-01-01

Indicators are used to quantify the pressure of pesticides on the environment. Pesticide risk indicators typically require weighting environmental exposure by a no effect concentration. An indicator based on spread equivalents (ΣSeq) is used in environmental policy in Flanders (Belgium). The pesticide risk for aquatic life is estimated by weighting active ingredient usage by the ratio of their maximum allowable concentration and their soil halflife. Accurate estimates of total pesticide usage in the region are essential in such calculations. Up to 2012, the environmental impact of pesticides was estimated on sales figures provided by the Federal Government. Since 2013, pesticide use is calculated based on results from the Farm Accountancy Data Network (FADN). The estimation of pesticide use was supplemented with data for non-agricultural use based on sales figures of amateur use provided by industry and data obtained from public services. The Seq-indicator was modified to better reflect reality. This method was applied for the period 2009-2012 and showed differences between estimated use and sales figures of pesticides. The estimated use of pesticides based on accountancy data is more accurate compared to sales figures. This approach resulted in a better view on pesticide use and its respective environmental impact in Flanders.

Quality of water in domestic wells in the Chicot and Chicot equivalent aquifer systems, southern Louisiana and southwestern Mississippi, 2000-2001

USGS Publications Warehouse

Tollett, Roland W.; Fendick, Robert B.; Simmons, Lane B.

2003-01-01

In 2000-2001, water-quality data were collected from 60 randomly selected domestic wells in the Acadian-Pontchartrain Study Unit, as part of the National Water-Quality Assessment Program. The data were collected from wells screened in shallow sands (less than 350 feet below land surface) in two major aquifer systems--the Chicot aquifer system in southwestern Louisiana and the Chicot equivalent aquifer system in southeastern Louisiana and southwestern Mississippi. The Chicot equivalent aquifer system is part of the Southern Hills regional aquifer system, and both the Chicot aquifer system and the Southern Hills regional aquifer systems are designated as sole-source aquifers by the U.S. Environmental Protection Agency (USEPA). The well depths ranged from 40 to 340 feet below land surface with a median depth of 120 feet. The ground-water-quality data included 5 physiochemical properties, dissolved solids, 9 major inorganic ions, 24 trace elements, 6 nutrients, dissolved organic carbon, 109 pesticides and degradation products, and 85 volatile organic compounds (VOC's); and a subset of the wells were sampled for radon, chlorofluorocarbons, and stable isotopes. Water from 35 of the 60 domestic wells sampled had pH values less than the USEPA Seconday Maximum Contaminant Level (SMCL) range of 6.5 to 8.5 standard units. Specific conductance ranged from 17 to 1,420 microsiemens per centimeter at 25 degrees Celsius. Dissolved-solids concentrations in water from two wells exceeded the SMCL of 500 mg/L (milligrams per liter); the maximum concentration was 858 mg/L. Sodium and calcium were the dominant cations, and bicarbonate and chloride were the dominant anions. One chloride concentration (264 mg/L) exceeded the SMCL of 250 mg/L. One arsenic concentration (55.3 micrograms per liter) exceeded the USEPA Maximum Contaminant Level (MCL) of 10 micrograms per liter. Iron concentrations in water from 22 wells exceeded the SMCL of 300 micrograms per liter; the maximum concentration was 8,670 micrograms per liter. Manganese concentrations in water from 26 wells exceeded the SMCL of 50 micrograms per liter; the maximum concentration was 481 micrograms per liter. Health Advisories have been established for six of the trace elements analyzed; no concentrations were greater than these nonenforceable standards. Radon concentrations in water from 9 of 50 wells sampled were greater thanthe proposed USEPA MCL of 300 picocuries per liter. Concentrations of ammonia, ammonia plus organic nitrogen, and nitrite plus nitrate in water from four wells were greater than 2 mg/L, a level that might indicate anthropogenic influences. The median dissolved organic carbon concentration was an estimated 0.30 mg/L, which indicated naturally occurring dissolved organic carbon conditions in the study area. Eight pesticides and two degradation products were detected in water from five wells. Twenty-four VOC's were detected in water from 44 wells. All concentrations of pesticides and VOC's were less than USEPA drinking-water standards. Quality-control samples, which included field-blank samples, replicates, and field and laboratory spikes, indicated no bias in ground-water data from collection procedures or analyses. VAriance between the environmental sampls and he corresponding replicate samples was typically less than 5 percent, indicating and acceptable degree of laboratory precision and data collection reproducibility. The Mann-Whitney rank-sum test was used to compare depth to top of screen and selected physicochemical properties and chemical constituents between six groups of wells. Values for selected physicochemical and chemical constituents were typically greater in wells located in the Chicot aquifer system than in the Chicot equivalent aquifer system. Values for specific conductance, pH, calcium, sodium, bicarbonate, chloride, dis

Trapping effect of estuarine turbidity maximum on particulate organic carbon and its response to a typhoon event in a macro-tidal estuary

NASA Astrophysics Data System (ADS)

Wang, Aijun; Ye, Xiang; Cheng, Peng; Wang, Liang

2017-04-01

Estuaries are key nodes of land-ocean interaction, the associated suspended sediment processes being crucial for global and regional material fluxes and environmental health. Within estuaries, there is commonly a reach where the water turbidity is markedly higher than both landward and seaward. This elevated suspended sediment concentration (SSC) is termed the estuarine turbidity maximum (ETM). The ETM has important influences on harbor siltation, ecological conservation, and biogeochemical dynamics. Jiulongjiang estuary is a small macro-tidal estuary in southeast China coastal area, which is a typical example for estuarine ecosystem conservation and its response to catchment management. Observed results show that the tidal current is the main factor which control the variations of SSC in ETM under the normal condition. However, under the influence of typhoon event, the hydrodynamic action was strengthened and the salt water intrusion was also enhanced, and the fresh water and sediment discharged from river system increased, which led to the complicated variations of the ETM. Under the normal conditions, the maximum width of ETM was about 10 km in spring tide. However, before typhoon landed, the maximum width of the ETM was about 14 km; after the typhoon landed, the maximum width of the ETM was more than 20 km, and during the low tide stage, the width of the ETM was still 19 km which was induced by high turbidity water input from river system. The particulate organic carbon (POC) concentration reached 19.26 mg/L within the ETM at the next day after typhoon landed, which was much higher than that under normal weather condition (the maximum value was only 3.15 mg/L). During the low tide level, the POC concentration increased remarkably from upstream to the core of ETM and then decreased toward downstream, while the POC concentration decreased toward downstream during high tide level. Compared with normal weather condition, the POC concentration varied not obviously along the river channel except at the core of ETM. The existence of ETM plays a much significant role for POC trapping during the influence of typhoon event. Acknowledgement: This research was supported by the NSFC (41376070). The authors with thank Shu-ren Huang, Hai-huang Chen and Peng-fa Chen for their help in the field work.

Quantifying the capacity of compost buffers for treating agricultural runoff

NASA Astrophysics Data System (ADS)

Naranjo, S. A.; Beighley, R. E.; Buyuksonmez, F.

2007-12-01

Agricultural operations, specifically, avocado and commercial nurseries require frequent and significant fertilizing and irrigating which tends to result in excessive nutrient leaching and off-site runoff. The increased runoff contains high concentrations of nutrients which negatively impacts stream water quality. Researcher has demonstrated that best management practices such as compost buffers can be effective for reducing nutrient and sediment concentrations in agricultural runoff. The objective of this research is to evaluate both the hydraulic capacity and the nutrient removal efficiency of: (a) compost buffers and (b) buffers utilizing a combination of vegetation and compost. A series of experiments will be performed in the environmental hydraulics laboratory at San Diego State University. A tilting flume 12-m long, 27-cm wide and 25-cm deep will be used. Discharge is propelled by an axial flow pump powered by a variable speed motor with a maximum capacity of 30 liters per second. The experiments are designed to measure the ratio compost mass per flow rate per linear width. Two different discharges will be measured: (a) treatment discharge (maximum flow rate such that the buffer decreases the incoming nitrogen and phosphorus concentrations below a maximum allowable limit) and (b) breaking discharge (maximum flow rate the buffer can tolerate without structural failure). Experimental results are presented for the hydraulic analysis, and preliminary results are presented for the removal of nitrogen and phosphorus from runoff. The results from this project will be used to develop guidelines for installing compost buffers along the perimeters of nursery sites and avocado groves in southern California.

A review of odour impact criteria in selected countries around the world.

PubMed

Brancher, Marlon; Griffiths, K David; Franco, Davide; de Melo Lisboa, Henrique

2017-02-01

Exposure to environmental odour can result in annoyance, health effects and depreciation of property values. Therefore, many jurisdictions classify odour as an atmospheric pollutant and regulate emissions and/or impacts from odour generating activities at a national, state or municipal level. In this work, a critical review of odour regulations in selected jurisdictions of 28 countries is presented. Individual approaches were identified as: comparing ambient air odour concentration and individual chemicals statistics against impact criteria (maximum impact standard); using fixed and variable separation distances (separation distance standard); maximum emission rate for mixtures of odorants and individual chemical species (maximum emission standard); number of complaints received or annoyance level determined via community surveys (maximum annoyance standard); and requiring use of best available technologies (BAT) to minimize odour emissions (technology standard). The comparison of model-predicted odour concentration statistics against odour impact criteria (OIC) is identified as one of the most common tools used by regulators to evaluate the risk of odour impacts in planning stage assessments and is also used to inform assessment of odour impacts of existing facilities. Special emphasis is given to summarizing OIC (concentration percentile and threshold) and the manner in which they are applied. The way short term odour peak to model time-step mean (peak-to-mean) effects is also captured. Furthermore, the fundamentals of odorant properties, dimensions of nuisance odour, odour sampling and analysis methods and dispersion modelling guidance are provided. Common elements of mature and effective odour regulation frameworks are identified and an integrated multi-tool strategy is recommended. Copyright © 2016 Elsevier Ltd. All rights reserved.

Seasonal and long-term changes in elemental concentrations and ratios of marine particulate organic matter

NASA Astrophysics Data System (ADS)

Talarmin, Agathe; Lomas, Michael W.; Bozec, Yann; Savoye, Nicolas; Frigstad, Helene; Karl, David M.; Martiny, Adam C.

2016-11-01

What is the temporal variability of the elemental stoichiometry of marine microbial communities across ocean regions? To answer this question, we present an analysis of environmental conditions, particulate organic carbon, nitrogen, and phosphorus concentrations and their ratios across 20 time series (3-25 years duration) representing estuarine, coastal, and open ocean environments. The majority of stations showed significant seasonal oscillations in particulate organic elemental concentrations and ratios. However, shorter-term changes contributed most to overall variance in particulate organic matter concentrations and ratios. We found a correlation between the seasonal oscillations of environmental conditions and elemental ratios at many coastal but not open ocean and estuarine stations. C:N peaked near the seasonal temperature minimum and nutrient maximum, but some stations showed other seasonal links. C:N ratios declined with time over the respective observation periods at all open ocean and estuarine stations as well as at five coastal station but increased at the nine other coastal stations. C:P (but not N:P) declined slightly at Bermuda Atlantic Time-series Study but showed large significant increases at Hawaii Ocean Time-series and Arendal stations. The relationships between long-term changes in environmental conditions and particulate organic matter concentrations or ratios were ambiguous, but interactions between changes in temperature and nutrient availability were important. Overall, our analysis demonstrates significant changes in elemental ratios at long-term and seasonal time scales across regions, but the underlying mechanisms are currently unclear. Thus, we need to better understand the detailed mechanisms driving the elemental composition of marine microbial ecosystems in order to predict how oceans will respond to environmental changes.

Modelling and optimization of environmental conditions for kefiran production by Lactobacillus kefiranofaciens.

PubMed

Cheirsilp, B; Shimizu, H; Shioya, S

2001-12-01

A mathematical model for kefiran production by Lactobacillus kefiranofaciens was established, in which the effects of pH, substrate and product on cell growth, exopolysaccharide formation and substrate assimilation were considered. The model gave a good representation both of the formation of exopolysaccharides (which are not only attached to cells but also released into the medium) and of the time courses of the production of galactose and glucose in the medium (which are produced and consumed by the cells). Since pH and both lactose and lactic acid concentrations differently affected production and growth activity, the model included the effects of pH and the concentrations of lactose and lactic acid. Based on the mathematical model, an optimal pH profile for the maximum production of kefiran in batch culture was obtained. In this study, a simplified optimization method was developed, in which the optimal pH profile was determined at a particular final fermentation time. This was based on the principle that, at a certain time, switching from the maximum specific growth rate to the critical one (which yields the maximum specific production rate) results in maximum production. Maximum kefiran production was obtained, which was 20% higher than that obtained in the constant-pH control fermentation. A genetic algorithm (GA) was also applied to obtain the optimal pH profile; and it was found that practically the same solution was obtained using the GA.

Ecotoxicity of diethylene glycol and risk assessment for marine environment.

PubMed

Manfra, L; Tornambè, A; Savorelli, F; Rotini, A; Canepa, S; Mannozzi, M; Cicero, A M

2015-03-02

Diethylene glycol (DEG) is a chemical compound used during offshore oil activities to prevent hydrate formation, and it may be released into the sea. A full ecotoxicological characterization is required according to European and Italian regulations for chemical substances. We have evaluated long-term toxic effects of DEG on indicator species of the marine environment as algae (Phaeodactylum tricornutum), crustaceans (Artemia franciscana), molluscs (Tapes philippinarum) and fish (Dicentrarchus labrax). A range of no observed effect concentrations (365-25,000 mg/L) has been identified. Based on the toxicity results and the ratio between predicted environmental concentration and predicted no-effect concentration, we have estimated the maximum allowable value of DEG in the marine environment. Copyright © 2014 Elsevier B.V. All rights reserved.

Quality of shallow ground water in areas of recent residential and commercial development, Wichita, Kansas, 2000

USGS Publications Warehouse

Pope, Larry M.; Bruce, Breton W.; Rasmussen, Patrick P.; Milligan, Chad R.

2002-01-01

Water samples from 30 randomly distributed monitoring wells in areas of recent residential and commercial development (1960-96), Wichita, Kansas, were collected in 2000 as part of the High Plains Regional Ground-Water Study conducted by the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program. The samples were analyzed for about 170 water-quality constituents that included chlorofluorocarbons, physical properties, dissolved solids and major ions, nutrients and dissolved organic carbon, trace elements, pesticide compounds, and volatile organic compounds. The purpose of this report is to provide an assessment of water quality in recharge to shallow ground water underlying areas of recent residential and commercial development and to determine the relation of ground-water quality to overlying urban land use. Analyses of water from the 30 monitoring wells for chlorofluorocarbons were used to estimate apparent dates of recharge. Water from 18 wells with nondegraded and uncontaminated chlorofluorocarbon concentrations had calculated apparent recharge dates that ranged from 1979 to 1990 with an average date of 1986. Water from 14 monitoring wells (47 percent) exceeded the 500-milligrams-per-liter Secondary Maximum Contaminant Level established by the U.S. Environmental Protection Agency for dissolved solids in drinking water. The Secondary Maximum Contaminant Levels of 250 milligrams per liter for chloride and sulfate were exceeded in water from one well. The source of the largest concentrations of dissolved solids and associated ions, such as chloride and sulfate, in shallow ground water in the study area probably is highly mineralized water moving out of the Arkansas River into the adjacent, unconsolidated deposits and mixing with the dominant calcium bicarbonate water in the deposits. Concentrations of most nutrients in water from the sampled wells were small, with the exception of nitrate. Although water from the sampled wells did not have nitrate concentrations larger than the 10-milligram-per-liter Maximum Contaminant Level for drinking water, water from 50 percent of the sampled wells showed nitrate enrichment (concentrations greater than 2.0 milligrams per liter). Most trace elements in water from the sampled wells were detected only in small concentrations, and few exceeded respective water-quality standards. Twenty percent of iron concentrations, 40 percent of manganese concentrations, 3 percent of arsenic concentrations, and 13 percent of uranium concentrations exceeded respective Maximum Contaminant Levels or Secondary Maximum Contaminant Levels. A total of 47 pesticide compounds were analyzed in ground-water samples during this study. Water from 73 percent of the wells sampled had detectable concentrations of one or more of 8 of these 47 compounds. The herbicide atrazine or its degradation product deethylatrazine were detected most frequently (in water from 70 percent of the sampled wells). Metolachlor was detected in water from 10 percent of the wells, and simazine was detected in water from 30 percent of the wells sampled. Other pesticides detected included dieldrin, pendimethalin, prometon, and tebuthiuron (each in water from 3 percent of the wells). All concentrations of these compounds were less than established Maximum Contaminant Levels. A total of 85 volatile organic compounds (VOCs) were analyzed in ground-water samples during this study. Water from 43 percent of the wells had a detectable concentration of one or more VOCs. Chloroform was the most frequently detected VOC (23 percent of the wells sampled).Seven other VOCs were detected in water at frequencies of 13 percent or less in the wells sampled. Concentrations of VOCs were less than respective Maximum Contaminant Levels, except one sample with a concentration of 9.0 micrograms per liter for tetrachloroethylene (Maximum Contaminant Level of 5.0 micrograms per liter). An analysis of hydraulic gradient, flow velocity

Ground-water-quality assessment of the Central Oklahoma aquifer, Oklahoma; hydrologic, water-quality, and quality-assurance data 1987-90

USGS Publications Warehouse

Ferree, D.M.; Christenson, S.C.; Rea, A.H.; Mesander, B.A.

1992-01-01

This report presents data collected from 202 wells between June 1987 and September 1990 as part of the Central Oklahoma aquifer pilot study of the National Water-Quality Assessment Program. The report describes the sampling networks, the sampling procedures, and the results of the ground-water quality and quality-assurance sample analyses. The data tables consist of information about the wells sampled and the results of the chemical analyses of ground water and quality-assurance sampling. Chemical analyses of ground-water samples in four sampling networks are presented: A geochemical network, a low-density survey bedrock network, a low-density survey alluvium and terrace deposits network, and a targeted urban network. The analyses generally included physical properties, major ions, nutrients, trace substances, radionuclides, and organic constituents. The chemical analyses of the ground-water samples are presented in five tables: (1) Physical properties and concentrations of major ions, nutrients, and trace substances; (2) concentrations of radionuclides and radioactivities; (3) carbon isotope ratios and delta values (d-values) of selected isotopes; (4) concentrations of organic constituents; and (5) organic constituents not reported in ground-water samples. The quality of the ground water sampled varied substantially. The sum of constituents (dissolved solids) concentrations ranged from 71 to 5,610 milligrams per liter, with 38 percent of the wells sampled exceeding the Secondary Maximum Contaminant Level of 500 milligrams per liter established under the Safe Drinking Water Act. Values of pH ranged from 5.7 to 9.2 units with 20 percent of the wells outside the Secondary Maximum Contaminant Level of 6.5 to 8.5 units. Nitrite plus nitrate concentrations ranged from less than 0.1 to 85 milligrams per liter with 8 percent of the wells exceeding the proposed Maximum Contaminant Level of 10 milligrams per liter. Concentrations of trace substances were highly variable, ranging from below the reporting level to concentrations over the Maximum Contaminant Levels for several constituents (arsenic, barium, cadmium, chromium, lead, and selenium). Radionuclide activities also were highly variable. Gross alpha radioactivity ranged from 0.1 to 210 picocuries per liter as 230thorium. Of the wells sampled, 20 percent exceeded the proposed Maximum Contaminant Level of 15 picocuries per liter for gross alpha radioactivity. Organic constituents were detected in 39 percent of the 170 wells sampled for organic constituents; in most cases concentrations were at or near the laboratory minimum reporting levels. Ten of the wells sampled for organic constituents had one or more constituents (chlordane, dieldrin, heptachlor epoxide, trichloroethylene, 1,1-dichloroethylene, 1,1,1-trichloroethane) at concentrations equal to or greater than the Maximum Contaminant Level or acceptable concentrations as suggested in the Environmental Protection Agency's Health Advisory Summaries. Quality-assurance sampling included duplicate samples, repeated samples, blanks, spikes, and blind samples. These samples proved to be essential in evaluating the accuracy of the data, particularly in the case of volatile organic constituents.

Sediment studies in the Assabet River, central Massachusetts, 2003

USGS Publications Warehouse

Zimmerman, Marc J.; Sorenson, Jason R.

2005-01-01

From its headwaters in Westborough, Massachusetts, to its confluence with the Sudbury River, the 53-kilometer-long Assabet River passes through a series of small towns and mixed land-use areas. Along the way, wastewater-treatment plants release nutrient-rich effluents that contribute to the eutrophic state of this waterway. This condition is most obvious where the river is impounded by a series of dams that have sequestered large amounts of sediment and support rooted and floating macrophytes and epiphytic algae. The water in parts of these impoundments may also have low concentrations of dissolved oxygen, another symptom of eutrophication. All of the impoundments had relatively shallow maximum water depths, which ranged from approximately 2.4 to 3.4 meters, and all had extensive shallow areas. Sediment volumes estimated for the six impoundments ranged from approximately 380 cubic meters in the Aluminum City impoundment to 580,000 cubic meters in the Ben Smith impoundment. The other impoundments had sediment volumes of 120,000 cubic meters (Powdermill), 67,000 cubic meters (Gleasondale), 55,000 cubic meters (Hudson), and 42,000 cubic meters (Allen Street). The principal objective of this study was the determination of sediment volume, extent, and chemistry, in particular, the characterization of toxic inorganic and organic chemicals in the sediments. To determine the bulk-sediment chemical-constituent concentrations, more than one hundred sediment cores were collected in pairs from the six impoundments. One core from each pair was sampled for inorganic constituents and the other for organic constituents. Most of the cores analyzed for inorganics were sectioned to provide information on the vertical distribution of analytes; a subset of the cores analyzed for organics was also sectioned. Approximately 200 samples were analyzed for inorganic constituents and 100 for organics; more than 10 percent were quality-control replicate or blank samples. Maximum bulk-sediment phosphorus concentrations in surface samples from the impoundments increased along a downstream gradient, with the exception of samples from the last impoundment, where the concentrations decreased. In addition, the highest phosphorus concentrations were generally in the surface samples; this finding may prove helpful if surface dredging is selected as a means to control phosphorus release from sediments. There is no known relation, however, between bulk-sediment concentration of phosphorus and the concentrations of phosphorus available to biota. Potentially toxic metals, including arsenic, cadmium, chromium, copper, nickel, lead, and zinc were frequently measured at concentrations that exceeded U.S. Environmental Protection Agency sediment-quality guidelines for the protection of aquatic life and that occasionally exceeded Massachusetts Department of Environmental Protection guidelines governing landfill disposal (reuse). Due to the effects of matrix interference and sample dilution on laboratory analyses, neither pesticides nor volatile organic compounds were detected at any sites. However, samples collected in other studies from nearby streams indicated the possibility that pesticides might have been detected in the impoundments if not for these analytical problems. Although polychlorinated biphenyl concentrations, as individual Aroclors, generally exceeded published U.S. Environmental Protection Agency guideline concentrations for potential effects on aquatic life, the U.S. Environmental Protection Agency guideline concentrations for human contact or the Massachusetts guidelines for landfill reuse were rarely exceeded. Concentrations of polycyclic aromatic hydrocarbons, both individually and total, frequently were greater than guideline concentrations. Concentrations of total extractable petroleum hydrocarbons did not exceed Massachusetts guideline concentrations in any samples. When the sediment analytes from surface samples are considered togethe

An ecological risk assessment of the acute and chronic toxicity of the herbicide picloram to the threatened bull trout (salvelinus confluentus) and the rainbow trout (onchorhyncus mykiss)

USGS Publications Warehouse

Fairchild, J.F.; Feltz, K.P.; Sappington, L.C.; Allert, A.L.; Nelson, K.J.; Valle, J.

2009-01-01

We conducted acute and chronic toxicity studies of the effects of picloram acid on the threatened bull trout (Salvelinus confluentus) and the standard coldwater surrogate rainbow trout (Oncorhynchus mykiss). Juvenile fish were chronically exposed for 30 days in a proportional flow-through diluter to measured concentrations of 0, 0.30, 0.60, 1.18, 2.37, and 4.75 mg/L picloram. No mortality of either species was observed at the highest concentration. Bull trout were twofold more sensitive to picloram (30-day maximum acceptable toxic concentration of 0.80 mg/L) compared to rainbow trout (30-day maximum acceptable toxic concentration of 1.67 mg/L) based on the endpoint of growth. Picloram was acutely toxic to rainbow trout at 36 mg/L (96-h ALC50). The acute:chronic ratio for rainbow trout exposed to picloram was 22. The chronic toxicity of picloram was compared to modeled and measured environmental exposure concentrations (EECs) using a four-tiered system. The Tier 1, worst-case exposure estimate, based on a direct application of the current maximum use rate (1.1 kg/ha picloram) to a standardized aquatic ecosystem (water body of 1-ha area and 1-m depth), resulted in an EEC of 0.73 mg/L picloram and chronic risk quotients of 0.91 and 0.44 for bull trout and rainbow trout, respectively. Higher-tiered exposure estimates reduced chronic risk quotients 10-fold. Results of this study indicate that picloram, if properly applied according to the manufacturer's label, poses little risk to the threatened bull trout or rainbow trout in northwestern rangeland environments on either an acute or a chronic basis. ?? 2008 Springer Science+Business Media, LLC.

Photochemical modeling of emissions trading of highly reactive volatile organic compounds in Houston, Texas. 2. Incorporation of chlorine emissions.

PubMed

Wang, Linlin; Thompson, Tammy; McDonald-Buller, Elena C; Allen, David T

2007-04-01

As part of the State Implementation Plan for attaining the National Ambient Air Quality Standard for ozone, the Texas Commission of Environmental Quality has created a Highly Reactive Volatile Organic Compounds (HRVOC) Emissions Cap and Trade Program for industrial point sources in the Houston/Galveston/Brazoria area. This series of papers examines the potential air quality impacts of this new emission trading program through photochemical modeling of potential trading scenarios; this paper examines the air quality impact of allowing facilities to trade chlorine emission reductions for HRVOC allocations on a reactivity weighted basis. The simulations indicate that trading of anthropogenic chlorine emission reductions for HRVOC allowances at a single facility or between facilities, in general, resulted in improvements in air quality. Decreases in peak 1-h averaged and 8-h averaged ozone concentrations associated with trading chlorine emissions for HRVOC allocations on a Maximum Incremental Reactivity (MIR) basis were up to 0.74 ppb (0.63%) and 0.56 ppb (0.61%), respectively. Air quality metrics based on population exposure decreased by up to 3.3% and 4.1% for 1-h and 8-h averaged concentrations. These changes are small compared to the maximum changes in ozone concentrations due to the VOC emissions from these sources (5-10 ppb for 8-h averages; up to 30 ppb for 1-h averages) and the chlorine emissions from the sources (5-10 ppb for maximum concentrations over wide areas and up to 70 ppb in localized areas). The simulations indicate that the inclusion of chlorine emissions in the trading program is likely to be beneficial to air quality and is unlikely to cause localized increases in ozone concentrations ("hot spots").

Evaluating the spatial distribution of pollutants and associated maintenance requirements in an 11 year-old bioretention cell in urban Charlotte, NC.

PubMed

Johnson, Jeffrey P; Hunt, William F

2016-12-15

Bioretention cells (BRCs) are an increasingly popular Stormwater Control Measure used to mitigate the hydrologic and water quality impacts of urbanization. Previous BRC research has demonstrated a strong capacity for pollutant removal; however, long-term sequestration of pollutants within soil media can elevate concentrations to levels fostering environmental and human health risks. Soil media samples were collected from an 11 year-old BRC in Charlotte, NC, and analyzed for the accumulation and spatial distribution of zinc, copper, and phosphorus. Pollutant distribution varied significantly with respect to depth and ordinate distance from the BRC inlet. Zinc concentrations (0.9-228.6 mg kg -1 soil) exceeded environmental thresholds and phosphorus concentrations (5.1-173.3 mg kg -1 soil) increased from initial levels by a factor of seven; however, notable accumulation was restricted to the BRC forebay. Maximum zinc and copper concentrations in soil media did not exceed 1% of mandatory cleanup levels and with regular maintenance of the forebay, the effective life of BRC media should exceed the life of the developments they treat. Copyright © 2016 Elsevier Ltd. All rights reserved.

Study and Search for Main Reason of Lung Cancers Based on Cherenkov Radiation in Environmental Radiation

NASA Astrophysics Data System (ADS)

Ito, Hiroshi; Emoto, Yusaku; Fujihara, Kento; Kawai, Hideyuki; Kimura, Shota; Kodama, Satoshi; Mizuno, Takahiro

2018-01-01

The number of lung-cancer-related death is highest among all cancers in the world, and it is increasing in Japan where population aging in progressing. The main reason for the lung cancer of non-smokers is regarded to be environmental pollution or exposure of the lung to radon in the nature. The risk of lung cancer was estimated to increase by 8 to 13% per every 100 Bq m-3 concentration of radon in the air. We observed beta rays with maximum energy of 3.27 MeV emitted from 214Bi as one of the progenies based on a detection of Cherenkov radiation. The surface radioactivity concentration of 214Bi on the sample was measured; the relation between the concentration and exposure time for the sample at the room air is researched. The behavior of the radon progenies in the air is discussed by a research for the progenies attaching on the sample after the radon decay. The inhalation of the radon progenies is not clear. Thus, to understand the behavior of progenies in the air make to clear the causal relation between the radon concentration and lung cancers.

Hydrochemical Regions of the Glacial Aquifer System, Northern United States, and Their Environmental and Water-Quality Characteristics

USGS Publications Warehouse

Arnold, Terri L.; Warner, Kelly L.; Groschen, George E.; Caldwell, James P.; Kalkhoff, Stephen J.

2008-01-01

The glacial aquifer system in the United States is a large (953,000 square miles) regional aquifer system of heterogeneous composition. As described in this report, the glacial aquifer system includes all unconsolidated geologic material above bedrock that lies on or north of the line of maximum glacial advance within the United States. Examining ground-water quality on a regional scale indicates that variations in the concentrations of major and minor ions and some trace elements most likely are the result of natural variations in the geologic and physical environment. Study of the glacial aquifer system was designed around a regional framework based on the assumption that two primary characteristics of the aquifer system can affect water quality: intrinsic susceptibility (hydraulic properties) and vulnerability (geochemical properties). The hydrochemical regions described in this report were developed to identify and explain regional spatial variations in ground-water quality in the glacial aquifer system within the hypothetical framework context. Data analyzed for this study were collected from 1991 to 2003 at 1,716 wells open to the glacial aquifer system. Cluster analysis was used to group wells with similar ground-water concentrations of calcium, chloride, fluoride, magnesium, potassium, sodium, sulfate, and bicarbonate into five unique groups. Maximum Likelihood Classification was used to make the extrapolation from clustered groups of wells, defined by points, to areas of similar water quality (hydrochemical regions) defined in a geospatial model. Spatial data that represented average annual precipitation, average annual temperature, land use, land-surface slope, vertical soil permeability, average soil clay content, texture of surficial deposits, type of surficial deposit, and potential for ground-water recharge were used in the Maximum Likelihood Classification to classify the areas so the characteristics of the hydrochemical regions would resemble the characteristics of the clusters. The result of the Maximum Likelihood Classification is a map showing five hydrochemical regions of the glacial aquifer system. Statistical analysis of ion concentrations (calcium, chloride, fluoride, magnesium, sodium, potassium, sulfate, and bicarbonate) in samples collected from wells completed in the glacial aquifer system illustrates that variations in water quality can be explained, in part, by related environmental characteristics that control the movement of ground water through the aquifer system. A comparison of median concentrations of chemical constituents in ground water among the five hydrochemical regions indicates that ground water in the Midwestern Agricultural Region, the Urban-Influenced Region, and the Western Agriculture and Grassland Region has the highest concentrations of major and minor ions, whereas ground water in the Northern and Great Lakes Forested Region and the Mountain and Coastal Forested Region has the lowest concentrations of these ions. Median concentrations of barium, arsenic, lithium, boron, strontium, and nitrite plus nitrate as nitrogen also are significantly different among the hydrochemical regions.

Herbicides and nitrates in the Iowa River alluvial aquifer prior to changing land use, Iowa County, Iowa, 1996

USGS Publications Warehouse

Savoca, Mark E.; Tobias, Jennifer L.; Sadorf, Eric M.; Birkenholtz, Trevor L.

1997-01-01

Four herbicides (alachlor, atrazine, cyanazine, and metolachlor) and one nutrient (nitrate) were selected for study on the basis of frequent usage in Iowa and high detection rates in ground water (Detroy and Kuzniar, 1988). Alachlor was not detected at concentrations greater than the method detection limit (MDL). Atrazine was detected at concentrations greater than the MDL in samples from 48 percent of the 23 wells, cyanazine from 13 percent, metolachlor from 26 percent, and nitrate from 91 percent. None of the four herbicides were detected at concentrations greater than the respective U.S. Environmental Protection Agency's (USEPA) Maximum Contaminant Level (MCL) for drinking water. Thirteen percent of the samples had nitrate concentrations above the USEPA's MCL of 10 mg/L (milligrams per liter). Relations between constituent concentration and well depth were observed for specific constituents at individual well nests.

How Diffusivity, Thermocline and Incident Light Intensity Modulate the Dynamics of Deep Chlorophyll Maximum in Tyrrhenian Sea

PubMed Central

Valenti, Davide; Denaro, Giovanni; Spagnolo, Bernardo; Conversano, Fabio; Brunet, Christophe

2015-01-01

During the last few years theoretical works have shed new light and proposed new hypotheses on the mechanisms which regulate the spatio-temporal behaviour of phytoplankton communities in marine pelagic ecosystems. Despite this, relevant physical and biological issues, such as effects of the time-dependent mixing in the upper layer, competition between groups, and dynamics of non-stationary deep chlorophyll maxima, are still open questions. In this work, we analyze the spatio-temporal behaviour of five phytoplankton populations in a real marine ecosystem by using a one-dimensional reaction-diffusion-taxis model. The study is performed, taking into account the seasonal variations of environmental variables, such as light intensity, thickness of upper mixed layer and profiles of vertical turbulent diffusivity, obtained starting from experimental findings. Theoretical distributions of phytoplankton cell concentration was converted in chlorophyll concentration, and compared with the experimental profiles measured in a site of the Tyrrhenian Sea at four different times (seasons) of the year, during four different oceanographic cruises. As a result we find a good agreement between theoretical and experimental distributions of chlorophyll concentration. In particular, theoretical results reveal that the seasonal changes of environmental variables play a key role in the phytoplankton distribution and determine the properties of the deep chlorophyll maximum. This study could be extended to other marine ecosystems to predict future changes in the phytoplankton biomass due to global warming, in view of devising strategies to prevent the decline of the primary production and the consequent decrease of fish species. PMID:25629963

Do insect repellents induce drift behaviour in aquatic non-target organisms?

PubMed

Fink, Patrick; Moelzner, Jana; Berghahn, Ruediger; von Elert, Eric

2017-01-01

Synthetic insect repellents are compounds applied to surfaces to discourage insects, mainly mosquitoes, from landing on those surfaces. As some of these repellents have repeatedly been detected in surface waters at significant concentrations, they may also exert repellent effects on aquatic non-target organisms. In running water systems, aquatic invertebrates actively enter downstream drift in order to avoid unfavourable environmental conditions. We thus tested the hypothesis that the widely used insect repellents DEET (N,N-Diethyl-m-toluamide), EBAAP (3-[N-butyl-N-acetyl]-aminopropionic acid ethyl ester) and Icaridin (1-piperidinecarboxylic acid 2-(2-hydroxyethyl)-1-methylpropyl ester) induce downstream drift behaviour in the aquatic invertebrates Gammarus pulex (Crustacea, Amphipoda) and Cloeon dipterum (Insecta, Ephemeroptera), using a laboratory-scale drift assay. We found no clear increase in the drift behaviour of both invertebrate species across a concentration gradient of eight orders of magnitude and even beyond maximum environmental concentrations for any of the three repellents. We found no evidence for a direct drift-inducing activity of insect repellents on aquatic non-target organisms. Copyright © 2016 Elsevier Ltd. All rights reserved.

Development of a circulation direct sampling and monitoring system for O2 and CO2 concentrations in the gas-liquid phases of shake-flask systems during microbial cell culture.

PubMed

Takahashi, Masato; Sawada, Yoshisuke; Aoyagi, Hideki

2017-08-23

Monitoring the environmental factors during shake-flask culture of microorganisms can help to optimise the initial steps of bioprocess development. Herein, we developed a circulation direct monitoring and sampling system (CDMSS) that can monitor the behaviour of CO 2 and O 2 in the gas-liquid phases and obtain a sample without interrupting the shaking of the culture in Erlenmeyer flasks capped with breathable culture plugs. Shake-flask culturing of Escherichia coli using this set-up indicated that a high concentration of CO 2 accumulated not only in the headspace (maximum ~100 mg/L) but also in the culture broth (maximum ~85 mg/L) during the logarithmic phase (4.5-9.0 h). By packing a CO 2 absorbent in the gas circulation unit of CDMSS, a specialised shake-flask culture was developed to remove CO 2 from the headspace. It was posited that removing CO 2 from the headspace would suppress increases in the dissolved CO 2 concentration in the culture broth (maximum ~15 mg/L). Furthermore, the logarithmic growth phase (4.5-12.0 h) was extended, the U.O.D. 580 and pH value increased, and acetic acid concentration was reduced, compared with the control. To our knowledge, this is the first report of a method aimed at improving the growth of E. coli cells without changing the composition of the medium, temperature, and shaking conditions.

Assessing the Variability of Heavy Metal Concentrations in Liquid-Solid Two-Phase and Related Environmental Risks in the Weihe River of Shaanxi Province, China

PubMed Central

Song, Jinxi; Yang, Xiaogang; Zhang, Junlong; Long, Yongqing; Zhang, Yan; Zhang, Taifan

2015-01-01

Accurate estimation of the variability of heavy metals in river water and the hyporheic zone is crucial for pollution control and environmental management. The biotoxicities and potential ecological risks of heavy metals (Cu, Zn, Pb, Cd) in a solid-liquid two-phase system were estimated using the Geo-accumulation Index, Potential Ecological Risk Assessment and Quality Standard Index methods in the Weihe River of Shaanxi Province, China. Water and sediment samples were collected from five study sites during spring, summer and winter, 2013. The dominant species in the streambed sediments were chironomids and flutter earthworm, whose bioturbation mainly ranged from 0 to 20 cm. The concentrations of heavy metals in surface water and pore water varied obviously in spring and summer. The degrees of concentration of Cu and Cd in spring and summer were higher than the U.S. water quality Criteria Maximum Concentrations. Furthermore, the biotoxicities of Pb and Zn demonstrated season-spatial variations. The concentrations of Cu, Zn, Pb and Cd in spring and winter were significantly higher than those in summer, and the pollution levels also varied obviously in different layers of the sediments. Moreover, the pollution level of Cd was the most serious, as estimated by all three assessment methods. PMID:26193293

Major-ion and selected trace-metal chemistry of the Biscayne Aquifer, Southeast Florida

USGS Publications Warehouse

Radell, M.J.; Katz, B.G.

1991-01-01

The major-ion and selected trace-metal chemistry of the Biscayne aquifer was characterized as part of the Florida Ground-Water Quality Monitoring Network Program, a multiagency cooperative effort concerned with delineating baseline water quality for major aquifer systems in the State. The Biscayne aquifer is unconfined and serves as the sole source of drinking water for more than 3 million people in southeast Florida. The Biscayne aquifer consists of highly permeable interbedded limestone and sandstone of Pleistocene and Pliocene age underlying most of Dade and Broward Counties and parts of Palm Beach and Monroe Counties. The high permeability is largely caused by extensive carbonate dissolution. Water sampled from 189 wells tapping the Biscayne aquifer was predominantly a calcium bicarbonate type with some mixed types occurring in coastal areas and near major canals. Major - ion is areally uniform throughout the aquifer. According to nonparametric statistical tests of major ions and dissolved solids, the concentrations of calcium, sodium, bicarbonate, and dissolved solids increased significantly with well depth ( 0.05 significance level ), probably a result of less circulation at depth. Potassium and nitrate concentrations decreased significantly with depth. Although the source of recharge to the aquifer varies seasonally, there was no statistical difference in the concentration of major ions in pared water samples from 27 shallow wells collected during wet and dry seasons. Median concentrations for barium, chromium, copper, lead, and manganese were below maximum or secondary maximum contaminant levels set by the US Environmental Protection Agency. The median iron concentration only slightly exceeded the secondary maximum contaminant level. The concentration of barium was significantly related (0.05 significance level) to calcium and bicarbonate concentration. No distinct areal pattern or vertical distribution of the selected trace metals was evident in water from the Biscayne aquifer. Sources for trace metals found in water from the Biscayne aquifer may include local contamination, well-construction techniques, canal - aquifer interactions, and natural occurrence in area soils and rock.

An ecological risk assessment of the acute and chronic effects of the herbicide clopyralid to rainbow trout (Oncorhynchus mykiss)

USGS Publications Warehouse

Fairchild, J.F.; Allert, A.L.; Feltz, K.P.; Nelson, K.J.; Valle, J.A.

2009-01-01

Clopyralid (3,6-dichloro-2-pyridinecarboxylic acid) is a pyridine herbicide frequently used to control invasive, noxious weeds in the northwestern United States. Clopyralid exhibits low acute toxicity to fish, including the rainbow trout (Oncorhynchus mykiss) and the threatened bull trout (Salvelinus confluentus). However, there are no published chronic toxicity data for clopyralid and fish that can be used in ecological risk assessments. We conducted 30-day chronic toxicity studies with juvenile rainbow trout exposed to the acid form of clopyralid. The 30-day maximum acceptable toxicant concentration (MATC) for growth, calculated as the geometric mean of the no observable effect concentration (68 mg/L) and the lowest observable effect concentration (136 mg/L), was 96 mg/L. No mortality was measured at the highest chronic concentration tested (273 mg/L). The acute:chronic ratio, calculated by dividing the previously published 96-h acutely lethal concentration (96-h ALC50; 700 mg/L) by the MATC was 7.3. Toxicity values were compared to a four-tiered exposure assessment profile assuming an application rate of 1.12 kg/ha. The Tier 1 exposure estimation, based on direct overspray of a 2-m deep pond, was 0.055 mg/L. The Tier 2 maximum exposure estimate, based on the Generic Exposure Estimate Concentration model (GEENEC), was 0.057 mg/L. The Tier 3 maximum exposure estimate, based on previously published results of the Groundwater Loading Effects of Agricultural Management Systems model (GLEAMS), was 0.073 mg/L. The Tier 4 exposure estimate, based on published edge-of-field monitoring data, was estimated at 0.008 mg/L. Comparison of toxicity data to estimated environmental concentrations of clopyralid indicates that the safety factor for rainbow trout exposed to clopyralid at labeled use rates exceeds 1000. Therefore, the herbicide presents little to no risk to rainbow trout or other salmonids such as the threatened bull trout. ?? 2009 US Government.

Assessing the risk associated with the presence of emerging organic contaminants in sludge-amended soil: A country-level analysis.

PubMed

Thomaidi, Vasiliki S; Stasinakis, Athanasios S; Borova, Viola L; Thomaidis, Nikolaos S

2016-04-01

Greece was used as case study and the environmental risk associated with the existence of 99 emerging organic contaminants (EOCs) in sludge-amended soil was estimated using risk quotient (RQ) approach. Data on the concentration levels of EOCs in sewage sludge was collected after literature review. Chemical analyses were also conducted for 50 pharmaceuticals and illicit drugs in sludge samples from Athens Sewage Treatment Plant. Risk assessment was based on both terrestrial and aquatic acute toxicity data, using both the maximum and the average measured concentrations of the target compounds. EC50/LC50 values were collected through literature review or using the ECOSAR program in cases that experimental values were not available. Triclosan seems to pose an environmental risk on the soil environment, as its RQ values exceeded 1, both in terrestrial and aquatic toxicity data based risk assessment. Calculations based on aquatic toxicity data showed that another eleven compounds had RQs higher than 1, most of them belonging to the classes of synthetic phenolic compounds and siloxanes. Tetradecamethylhexasiloxane presented the highest RQ, while high RQs were also calculated for decamethylcyclopentasiloxane and caffeine. No environmental risk for the terrestrial environment is expected due to the individual action of illicit drugs, perfluorinated compounds and benzotriazoles. The sludge source and the day of sampling affected the estimated threat due to nonylphenolic compounds; however these factors did not affect the estimated risk for siloxanes, caffeine and ofloxacin. Calculation of RQ values for the mixture of EOCs, using either the maximum or the average concentrations, far exceeded 1 (253 and 209, respectively), indicating a presumable threat for the terrestrial environment due to the baseline toxicity of these compounds. Countries that reuse sludge for agricultural purposes should include specific EOCs in national monitoring campaigns and study more thoroughly on their effects to the terrestrial environment. Copyright © 2016 Elsevier B.V. All rights reserved.

Uranium and radon in ground water in the lower Illinois River basin

USGS Publications Warehouse

Morrow, William S.

2001-01-01

Uranium and radon are present in ground water throughout the United States, along with other naturally occurring radionuclides. The occurrence and distribution of uranium and radon are of concern because these radionuclides are carcinogens that can be ingested through drinking water. As part of the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) program, water samples were collected and analyzed for uranium and radon from 117 wells in four aquifers in the lower Illinois River Basin (LIRB) from 1996 to 1997. The aquifers were the shallow glacial drift deposits of the Bloomington Ridged Plain (BRP) not overlying a buried bedrock valley (BRP N/O BV), shallow glacial drift deposits of the BRP overlying the Mahomet Buried Bedrock Valley (BRP O/L MBBV), shallow glacial drift deposits of the Galesburg/Springfield Plain not overlying a buried bedrock valley (GSP N/O BV), and the deep glacial drift deposits of the Mahomet Buried Bedrock Valley (MBBV). Uranium was detected in water samples from all aquifers except the MBBV and ranged in concentration from less than 1 microgram per liter ( ? g/L) to 17 ? g/L. Uranium concentrations did not exceed 20 ? g/L, the proposed U.S. Environmental Protection Agency (USEPA) Maximum Contaminant Level (MCL) at the time of sampling (1996?97). The current (2001) promulgated MCL is 30 ? g/L (U.S. Environmental Protection Agency, 2000). The highest median uranium concentration (2.0 ? g/L) among the four aquifers was in the BRP N/O BV. Uranium most often occurred in oxidizing and sulfate-rich water. Radon was detected in water samples from all aquifers in the LIRB. Radon concentrations in all aquifers ranged from less than 80 picocuries per liter (pCi/L) to 1,300 pCi/L. Of 117 samples, radon concentrations exceeded 300 pCi/L (the proposed USEPA MCL) in 34 percent of the samples. Radon concentrations exceeded 300 pCi/L in more than one-half of the samples from the GSP N/O BV and the BRP O/L MBBV. No sample exceeded the proposed Alternative Maximum Contaminant Level (AMCL) of 4,000 pCi/L. Concentrations of uranium and radon were not correlated.

Occurrence of steroid estrogens, endocrine-disrupting phenols, and acid pharmaceutical residues in urban riverine water of the Pearl River Delta, South China.

PubMed

Peng, Xianzhi; Yu, Yiyi; Tang, Caiming; Tan, Jianhua; Huang, Qiuxin; Wang, Zhendi

2008-07-01

A scoping study was conducted to investigate the residues of nineteen pharmaceuticals and personal care products (PPCPs), including 4 natural and 3 synthetic steroid estrogens, 7 endocrine-disrupting phenols, and 5 acid pharmaceuticals in three urban streams and the Major Pearl River at Guangzhou, a megapolis in the Pearl River Delta, South China. Estrone was detected in >60% water samples with a maximum concentration of 65 ng L(-1). Endocrine-disrupting phenols (nonylphenol, bisphenol A, triclosan, 2-phenylphenol, methyparaben, and propylparaben) were found to be widely present at rather high concentrations in the urban riverine water of Guangzhou. Salicylic acid, clofibric acid and ibuprofen were detected in most water samples with maximum concentrations of 2098, 248 and 1417 ng L(-1) respectively, whereas naproxen was less frequently detected and also at lower concentration. Both the detection frequencies and median concentrations of the PPCPs appeared higher during the low-flow season than during the high-flow season. The seasonal difference in PPCPs occurrence was probably attributed to the dilution effect caused by the rainfall. PPCPs in the urban riverine water of Guangzhou originated mainly from random discharge and/or leakage of municipal wastewater. PPCPs contamination in the Major Pearl River may be of a potential environmental issue, especially during the low-flow season.

Estimation of environmental capacity of phosphorus in Gorgan Bay, Iran, via a 3D ecological-hydrodynamic model.

PubMed

Ranjbar, Mohammad Hassan; Hadjizadeh Zaker, Nasser

2016-11-01

Gorgan Bay is a semi-enclosed basin located in the southeast of the Caspian Sea in Iran and is an important marine habitat for fish and seabirds. In the present study, the environmental capacity of phosphorus in Gorgan Bay was estimated using a 3D ecological-hydrodynamic numerical model and a linear programming model. The distribution of phosphorus, simulated by the numerical model, was used as an index for the occurrence of eutrophication and to determine the water quality response field of each of the pollution sources. The linear programming model was used to calculate and allocate the total maximum allowable loads of phosphorus to each of the pollution sources in a way that eutrophication be prevented and at the same time maximum environmental capacity be achieved. In addition, the effect of an artificial inlet on the environmental capacity of the bay was investigated. Observations of surface currents in Gorgan Bay were made by GPS-tracked surface drifters to provide data for calibration and verification of numerical modeling. Drifters were deployed at five different points across the bay over a period of 5 days. The results indicated that the annual environmental capacity of phosphorus is approximately 141 t if a concentration of 0.0477 mg/l for phosphorus is set as the water quality criterion. Creating an artificial inlet with a width of 1 km in the western part of the bay would result in a threefold increase in the environmental capacity of the study area.

An environmental forensic procedure to analyse anthropogenic pressures of urban origin on surface water of protected coastal agro-environmental wetlands (L'Albufera de Valencia Natural Park, Spain).

PubMed

Pascual-Aguilar, Juan; Andreu, Vicente; Picó, Yolanda

2013-12-15

Detection and spatial distribution of 14 drugs of abuse and 17 pharmaceuticals in surface waters was investigated to determine transport hydrological connectivity between urban, agriculture and natural environments. Solid-phase extraction and liquid chromatography tandem mass spectrometry was applied to all samples. To determine spatial incidence of contaminants, analytical results of target compounds were georeferenced and integrated into a geographical information systems structure together with layers of municipal population, location of sewage water treatment plants and irrigation channels and sectors. The methodology was applied to L'Albufera Natural Park in Valencia (Spain). A total of 9 drugs of abuse were detected at 16 points (76% of the sample sites). Cocaine and its metabolite, benzoylecgonine, were the most detected substances, being found in 12 and 16 samples, respectively. Maximum concentrations were found in benzoylecgonine (78.71 ng/L) and codeine (51.60 ng/L). Thirteen pharmaceuticals were found at 16 points. The most detected compounds were carbamazepine (15 samples) and ibuprofen (11 samples). Maximum concentrations were detected in acetaminophen (17,699.4 ng/L), ibuprofen (3913.7 ng/L) and codeine (434.0 ng/L). Spatial distribution of pharmaceuticals showed a clear relationship between irrigation areas, high population densities municipalities (above 1000 h/km(2)) and sewage water treatment plants. Copyright © 2013 Elsevier B.V. All rights reserved.

Evaluation of Parameter Uncertainty Reduction in Groundwater Flow Modeling Using Multiple Environmental Tracers

NASA Astrophysics Data System (ADS)

Arnold, B. W.; Gardner, P.

2013-12-01

Calibration of groundwater flow models for the purpose of evaluating flow and aquifer heterogeneity typically uses observations of hydraulic head in wells and appropriate boundary conditions. Environmental tracers have a wide variety of decay rates and input signals in recharge, resulting in a potentially broad source of additional information to constrain flow rates and heterogeneity. A numerical study was conducted to evaluate the reduction in uncertainty during model calibration using observations of various environmental tracers and combinations of tracers. A synthetic data set was constructed by simulating steady groundwater flow and transient tracer transport in a high-resolution, 2-D aquifer with heterogeneous permeability and porosity using the PFLOTRAN software code. Data on pressure and tracer concentration were extracted at well locations and then used as observations for automated calibration of a flow and transport model using the pilot point method and the PEST code. Optimization runs were performed to estimate parameter values of permeability at 30 pilot points in the model domain for cases using 42 observations of: 1) pressure, 2) pressure and CFC11 concentrations, 3) pressure and Ar-39 concentrations, and 4) pressure, CFC11, Ar-39, tritium, and He-3 concentrations. Results show significantly lower uncertainty, as indicated by the 95% linear confidence intervals, in permeability values at the pilot points for cases including observations of environmental tracer concentrations. The average linear uncertainty range for permeability at the pilot points using pressure observations alone is 4.6 orders of magnitude, using pressure and CFC11 concentrations is 1.6 orders of magnitude, using pressure and Ar-39 concentrations is 0.9 order of magnitude, and using pressure, CFC11, Ar-39, tritium, and He-3 concentrations is 1.0 order of magnitude. Data on Ar-39 concentrations result in the greatest parameter uncertainty reduction because its half-life of 269 years is similar to the range of transport times (hundreds to thousands of years) in the heterogeneous synthetic aquifer domain. The slightly higher uncertainty range for the case using all of the environmental tracers simultaneously is probably due to structural errors in the model introduced by the pilot point regularization scheme. It is concluded that maximum information and uncertainty reduction for constraining a groundwater flow model is obtained using an environmental tracer whose half-life is well matched to the range of transport times through the groundwater flow system. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

DOE Office of Scientific and Technical Information (OSTI.GOV)

M. L. Abbott; K. N. Keck; R. E. Schindler

This screening level risk assessment evaluates potential adverse human health and ecological impacts resulting from continued operations of the calciner at the New Waste Calcining Facility (NWCF) at the Idaho Nuclear Technology and Engineering Center (INTEC), Idaho National Engineering and Environmental Laboratory (INEEL). The assessment was conducted in accordance with the Environmental Protection Agency (EPA) report, Guidance for Performing Screening Level Risk Analyses at Combustion Facilities Burning Hazardous Waste. This screening guidance is intended to give a conservative estimate of the potential risks to determine whether a more refined assessment is warranted. The NWCF uses a fluidized-bed combustor to solidifymore » (calcine) liquid radioactive mixed waste from the INTEC Tank Farm facility. Calciner off volatilized metal species, trace organic compounds, and low-levels of radionuclides. Conservative stack emission rates were calculated based on maximum waste solution feed samples, conservative assumptions for off gas partitioning of metals and organics, stack gas sampling for mercury, and conservative measurements of contaminant removal (decontamination factors) in the off gas treatment system. Stack emissions were modeled using the ISC3 air dispersion model to predict maximum particulate and vapor air concentrations and ground deposition rates. Results demonstrate that NWCF emissions calculated from best-available process knowledge would result in maximum onsite and offsite health and ecological impacts that are less then EPA-established criteria for operation of a combustion facility.« less

Satellite derived smoke climatology for the United States and surface particulate pollution implications

NASA Astrophysics Data System (ADS)

Kaulfus, A. S.; Nair, U.; Jaffe, D. A.; Christopher, S. A.; Goodrick, S.

2017-12-01

Biomass burning smoke is a significant contributor to the degradation of air quality with well-documented impacts on the human respiratory system. Despite this, documentation of the distribution of smoke and assessing environmental impacts is largely limited to individual or seasonal events. This study presents a 12-year satellite based distribution of smoke across the Continental United States and describes seasonal and regional differences. The impact of smoke on surface fine particulate matter (PM2.5) concentrations is quantified by the enhancement in PM2.5 over "smoke free" conditions and the relative number of Environmental Protection Agency standard exceedances in the presence of smoke. Smoke occurrence frequency is at a maximum during the summer over the northern Great Plains region of the US and least frequent over the Southwest. Approximately 20% of exceedances of the 24-hour federal standard for particulate matters occur in the presences of smoke. Particulate impacts are at a maximum in the spring and summer in the southeast and northwest respectively corresponding to regional maximums in smoke occurrence. Air quality monitor specific climatological documentation of smoke and corresponding PM2.5 has relevance in EPA exceptional event data exclusion. Near real time evaluation of the dataset can aid in impact mitigation and regulation compliance.

Radium-226 and radium-228 in shallow ground water, southern New Jersey

USGS Publications Warehouse

Szabo, Zoltan; dePaul, Vincent T.

1998-01-01

Concentrations of total radium (the sum of radium-226 and radium-228) and gross alpha-particle activities in drinking water that exceed the U.S. Environmental Protection Agency (USEPA) Maximum Contaminant Levels (MCLs) are known to cause cancer. Results of investigations by the U.S. Geological Survey (USGS) in cooperation with the New Jersey Department of Environmental Protection (NJDEP) indicate that concentrations of total radium in water samples from 33 percent of 170 wells in the Kirkwood-Cohansey aquifer system in southern New Jersey exceeded the MCL of 5 pCi/L (picocuries per liter) (fig. 1). Wells containing water in which concentrations of total radium were greater than the MCL typically are found where the Bridgeton Formation crops out, in or near an agricultural area, where ground water is acidic (pH less than 5), and where nitrate concentrations generally exceed 5 mg/L (milligrams per liter). Leaching of nitrogen, calcium, and magnesium from agricultural chemicals (fertilizer, lime) applied to cropland may increase the mobility of radium in ground water. Gross alphaparticle activities exceeded the USEPA MCL of 15 pCi/L in water from 14 percent of 127 wells. A statistically significant 2:1 ratio between gross alpha-particle activity and concentration of total radium indicates that gross alpha-particle activity can be used as a screening tool to predict the presence of water that may have a high total-radium concentration.

Nationwide reconnaissance of contaminants of emerging concern in source and treated drinking waters of the United States: Pharmaceuticals.

PubMed

Furlong, Edward T; Batt, Angela L; Glassmeyer, Susan T; Noriega, Mary C; Kolpin, Dana W; Mash, Heath; Schenck, Kathleen M

2017-02-01

Mobile and persistent chemicals that are present in urban wastewater, such as pharmaceuticals, may survive on-site or municipal wastewater treatment and post-discharge environmental processes. These pharmaceuticals have the potential to reach surface and groundwaters, essential drinking-water sources. A joint, two-phase U.S. Geological Survey-U.S. Environmental Protection Agency study examined source and treated waters from 25 drinking-water treatment plants from across the United States. Treatment plants that had probable wastewater inputs to their source waters were selected to assess the prevalence of pharmaceuticals in such source waters, and to identify which pharmaceuticals persist through drinking-water treatment. All samples were analyzed for 24 pharmaceuticals in Phase I and for 118 in Phase II. In Phase I, 11 pharmaceuticals were detected in all source-water samples, with a maximum of nine pharmaceuticals detected in any one sample. The median number of pharmaceuticals for all 25 samples was five. Quantifiable pharmaceutical detections were fewer, with a maximum of five pharmaceuticals in any one sample and a median for all samples of two. In Phase II, 47 different pharmaceuticals were detected in all source-water samples, with a maximum of 41 pharmaceuticals detected in any one sample. The median number of pharmaceuticals for all 25 samples was eight. For 37 quantifiable pharmaceuticals in Phase II, median concentrations in source water were below 113ng/L. For both Phase I and Phase II campaigns, substantially fewer pharmaceuticals were detected in treated water samples than in corresponding source-water samples. Seven different pharmaceuticals were detected in all Phase I treated water samples, with a maximum of four detections in any one sample and a median of two pharmaceuticals for all samples. In Phase II a total of 26 different pharmaceuticals were detected in all treated water samples, with a maximum of 20 pharmaceuticals detected in any one sample and a median of 2 pharmaceuticals detected for all 25 samples. Source-water type influences the presence of pharmaceuticals in source and treated water. Treatment processes appear effective in reducing concentrations of most pharmaceuticals. Pharmaceuticals more consistently persisting through treatment include carbamazepine, bupropion, cotinine, metoprolol, and lithium. Pharmaceutical concentrations and compositions from this study provide an important base data set for further sublethal, long-term exposure assessments, and for understanding potential effects of these and other contaminants of emerging concern upon human and ecosystem health. Copyright © 2016. Published by Elsevier B.V.

Occurrence of perfluoroalkyl acids in environmental waters in Vietnam.

PubMed

Duong, Hanh Thi; Kadokami, Kiwao; Shirasaka, Hanako; Hidaka, Rento; Chau, Hong Thi Cam; Kong, Lingxiao; Nguyen, Trung Quang; Nguyen, Thao Thanh

2015-03-01

This is the first nationwide study of perfluoroalkyl acids (PFAAs) in environmental waters in Vietnam. Twenty-eight river water and 22 groundwater samples collected in four major cities and 14 river water samples from the Red River were screened to investigate the occurrence and sources of 16 PFAAs. Perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) were the most prevalent of 11 detected PFAAs with maximum concentrations in urban river water of 5.3, 18 and 0.93ngL(-1), respectively, and in groundwater of 8.2, 4.5 and 0.45ngL(-1), respectively. PFAAs in the Red River water were detected at low levels. PFAA concentrations in river water were higher in the rainy season than in the dry season, possibly due to storm water runoff, a common phenomenon in Southeast Asian countries. The highest concentrations of PFAAs in river water were observed in samples from highly populated and industrialized areas, perhaps sourced from sewage. The PFAA concentrations observed were similar to those in other Southeast Asian countries, but lower than in developed nations. From the composition profiles of PFAAs, industrial products containing PFAAs imported from China and Japan might be one of the major sources of PFAAs in the Vietnamese aquatic environment. According to the health-based values and advisory issued by the United States Environmental Protection Agency (USEPA), the concentrations of detected PFAAs in this study do not pose an immediate health risk to humans and aquatic organisms. Copyright © 2014 Elsevier Ltd. All rights reserved.

Hydrogeology and chemical quality of water and soil at Carroll Island, Aberdeen Proving Ground, Maryland

USGS Publications Warehouse

Tenbus, F.J.; Phillips, S.W.

1996-01-01

Carroll Island was used for open-air testing of chemical warfare agents from the late 1940's until 1971. Testing and disposal activities weresuspected of causing environmental contamination at 16 sites on the island. The hydrogeology and chemical quality of ground water, surface water, and soil at these sites were investigated with borehole logs, environmental samples, water-level measurements, and hydrologic tests. A surficial aquifer, upper confining unit, and upper confined aquifer were defined. Ground water in the surficial aquifer generally flows from the east-central part of the island toward the surface-water bodies, butgradient reversals caused by evapotranspiration can occur during dry seasons. In the confined aquifer, hydraulic gradients are low, and hydraulic head is affected by tidal loading and by seasonal pumpage from the west. Inorganic chemistry in the aquifers is affected by brackish-water intrusion from gradient reversals and by dissolution ofcarboniferous shell material in the confining unit.The concentrations of most inorganic constituents probably resulted from natural processes, but some concentrations exceeded Federal water-quality regulations and criteria. Organic compounds were detected in water and soil samples at maximum concentrations of 138 micrograms per liter (thiodiglycol in surface water) and 12 micrograms per gram (octadecanoic acid in soil).Concentrations of organic compounds in ground water exceeded Federal drinking-water regulations at two sites. The organic compounds that weredetected in environmental samples were variously attributed to natural processes, laboratory or field- sampling contamination, fallout from industrial air pollution, and historical military activities.

Mo isotopes as redox indicators for the Southern Tethys during the PETM

NASA Astrophysics Data System (ADS)

Wouters, H.; Dickson, A.; Porcelli, D.; Hesselbo, S. P.; van den Boorn, S.; Gomez, V. G.; Mutterlose, J.

2014-12-01

As several ocean and climate models predict a decline in dissolved ocean oxygen concentrations associated with future global warming [1], recent research is increasingly focusing on past episodes of low ocean oxygen levels. Trace metals are generally enriched in organic-rich sediments deposited under such low oxygen conditions, and the concentration and isotopic signatures of several of these elements (e.g. Mo, U, Cr) may be applied as proxies to reconstruct the processes involved in these redox changes [2,3]. This project investigates the use of the molybdenum isotope system as a proxy for redox changes during an interval of abrupt environmental change spanning the Paleocene/Eocene boundary (the Paleocene/Eocene Thermal Maximum, PETM, ~56 Ma). The PETM is characterized by global warming and environmental and ecological changes including decreased ocean oxygen levels [4]. Study of the PETM can therefore offer us a valuable insight into how marine ecosystems and biogeochemical cycles may respond to future climate changes, and the predicted decrease of oxygen concentrations in seawater. The molybdenum concentrations and isotope compositions of organic-rich sediments spanning the PETM have been obtained from a Jordan oil shale drill core (OS-28). The obtained δ98/95Mo isotopic ratios range between -0.12‰ and 1.59‰ and coincide with significant fluctuations in trace metal abundances. The data together demonstrate that the global environmental changes associated with the PETM were manifest in the Jordanian basin as significant changes in basin hydrography and dissolved oxygen levels.

Watershed Regressions for Pesticides (WARP) for Predicting Annual Maximum and Annual Maximum Moving-Average Concentrations of Atrazine in Streams

USGS Publications Warehouse

Stone, Wesley W.; Gilliom, Robert J.; Crawford, Charles G.

2008-01-01

Regression models were developed for predicting annual maximum and selected annual maximum moving-average concentrations of atrazine in streams using the Watershed Regressions for Pesticides (WARP) methodology developed by the National Water-Quality Assessment Program (NAWQA) of the U.S. Geological Survey (USGS). The current effort builds on the original WARP models, which were based on the annual mean and selected percentiles of the annual frequency distribution of atrazine concentrations. Estimates of annual maximum and annual maximum moving-average concentrations for selected durations are needed to characterize the levels of atrazine and other pesticides for comparison to specific water-quality benchmarks for evaluation of potential concerns regarding human health or aquatic life. Separate regression models were derived for the annual maximum and annual maximum 21-day, 60-day, and 90-day moving-average concentrations. Development of the regression models used the same explanatory variables, transformations, model development data, model validation data, and regression methods as those used in the original development of WARP. The models accounted for 72 to 75 percent of the variability in the concentration statistics among the 112 sampling sites used for model development. Predicted concentration statistics from the four models were within a factor of 10 of the observed concentration statistics for most of the model development and validation sites. Overall, performance of the models for the development and validation sites supports the application of the WARP models for predicting annual maximum and selected annual maximum moving-average atrazine concentration in streams and provides a framework to interpret the predictions in terms of uncertainty. For streams with inadequate direct measurements of atrazine concentrations, the WARP model predictions for the annual maximum and the annual maximum moving-average atrazine concentrations can be used to characterize the probable levels of atrazine for comparison to specific water-quality benchmarks. Sites with a high probability of exceeding a benchmark for human health or aquatic life can be prioritized for monitoring.

Water quality and possible sources of nitrate in the Cimarron Terrace Aquifer, Oklahoma, 2003

USGS Publications Warehouse

Masoner, Jason R.; Mashburn, Shana L.

2004-01-01

Water from the Cimarron terrace aquifer in northwest Oklahoma commonly has nitrate concentrations that exceed the maximum contaminant level of 10 milligrams per liter of nitrite plus nitrate as nitrogen (referred to as nitrate) set by the U.S. Environmental Protection Agency for public drinking water supplies. Starting in July 2003, the U.S. Geological Survey, in cooperation with the Oklahoma Department of Environmental Quality, conducted a study in the Cimarron terrace aquifer to assess the water quality and possible sources of nitrate. A qualitative and quantitative approach based on multiple lines of evidence from chemical analysis of nitrate, nitrogen isotopes in nitrate, pesticides (indicative of cropland fertilizer application), and wastewater compounds (indicative of animal or human wastewater) were used to indicate possible sources of nitrate in the Cimarron terrace aquifer. Nitrate was detected in 44 of 45 ground-water samples and had the greatest median concentration (8.03 milligrams per liter) of any nutrient analyzed. Nitrate concentrations ranged from <0.06 to 31.8 milligrams per liter. Seventeen samples had nitrate concentrations exceeding the maximum contaminant level of 10 milligrams per liter. Nitrate concentrations in agricultural areas were significantly greater than nitrate concentrations in grassland areas. Pesticides were detected in 15 of 45 ground-water samples. Atrazine and deethylatrazine, a metabolite of atrazine, were detected most frequently. Deethylatrazine was detected in water samples from 9 wells and atrazine was detected in samples from 8 wells. Tebuthiuron was detected in water samples from 5 wells; metolachlor was detected in samples from 4 wells; prometon was detected in samples from 4 wells; and alachlor was detected in 1 well. None of the detected pesticide concentrations exceeded the maximum contaminant level or health advisory level set by the U.S. Environmental Protection Agency. Wastewater compounds were detected in 28 of 45 groundwater samples. Of the 20 wastewater compounds detected, 11 compounds were from household chemicals, 3 compounds were hydrocarbons, 2 compounds were industrial chemicals, 2 compounds were pesticides, 1 compound was of animal source, and 1 compound was a detergent compound. The most frequently detected wastewater compound was phenol, which was detected in 23 wells. N,N-diethyl-meta-toluamide (DEET) was detected in water samples from 5 wells. Benzophenone, ethanol- 2-butoxy-phosphate, and tributylphosphate were detected in water samples from 3 wells. Fertilizer was determined to be the possible source of nitrate in samples from 13 of 45 wells sampled, with a15N values ranging from 0.43 to 3.46 permil. The possible source of nitrate for samples from the greatest number of wells (22 wells) was from mixed sources of nitrate from fertilizer, septic or manure, or natural sources. Mixed nitrate sources had a 15N values ranging from 0.25 to 9.83 permil. Septic or manure was determined as the possible source of nitrate in samples from 2 wells. Natural sources were determined to be the possible source of nitrate in samples from 7 wells, with a 15N values ranging from 0.83 to 9.44 permil.

A novel biosensor for p-nitrophenol based on an aerobic anode microbial fuel cell.

PubMed

Chen, Zhengjun; Niu, Yongyan; Zhao, Shuai; Khan, Aman; Ling, Zhenmin; Chen, Yong; Liu, Pu; Li, Xiangkai

2016-11-15

P-nitrophenol is one of the most common contaminants in chemical industrial wastewater, and in situ real-time monitoring of PNP cannot be achieved by conventional analytical techniques. Here, a two-chamber microbial fuel cell with an aerobic anode chamber was tested as a biosensor for in situ real-time monitoring of PNP. Pseudomonas monteilii LZU-3, which was used as the biological recognition element, can form a biofilm on the anode electrode using PNP as a sole substrate. The optimal operation parameters of the biosensor were as follows: external resistance 1000Ω, pH 7.8, temperature 30°C, and maximum PNP concentration 50mgL(-1). Under these conditions, the maximum voltages showed a linear relationship with PNP concentrations ranging from 15±5 to 44±4.5mgL(-1). Furthermore, we developed a novel portable device for in situ real-time monitoring of PNP. When the device was applied to measure PNP in wastewater containing various additional aromatic compounds and metal ions, the performance of the biosensor was not affected and the correlation between the maximum voltages and the PNP concentrations ranging from 9±4mgL(-1) to 36 ± 5mgL(-1) was conserved. The results demonstrated that the MFC biosensor provides a rapid and cost-efficient analytical method for real-time monitoring of toxic and recalcitrant pollutants in environmental samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Spatiotemporal Variability of Dimethylsulphoniopropionate on a Fringing Coral Reef: The Role of Reefal Carbonate Chemistry and Environmental Variability

PubMed Central

Burdett, Heidi L.; Donohue, Penelope J. C.; Hatton, Angela D.; Alwany, Magdy A.; Kamenos, Nicholas A.

2013-01-01

Oceanic pH is projected to decrease by up to 0.5 units by 2100 (a process known as ocean acidification, OA), reducing the calcium carbonate saturation state of the oceans. The coastal ocean is expected to experience periods of even lower carbonate saturation state because of the inherent natural variability of coastal habitats. Thus, in order to accurately project the impact of OA on the coastal ocean, we must first understand its natural variability. The production of dimethylsulphoniopropionate (DMSP) by marine algae and the release of DMSP’s breakdown product dimethylsulphide (DMS) are often related to environmental stress. This study investigated the spatiotemporal response of tropical macroalgae (Padina sp., Amphiroa sp. and Turbinaria sp.) and the overlying water column to natural changes in reefal carbonate chemistry. We compared macroalgal intracellular DMSP and water column DMSP+DMS concentrations between the environmentally stable reef crest and environmentally variable reef flat of the fringing Suleman Reef, Egypt, over 45-hour sampling periods. Similar diel patterns were observed throughout: maximum intracellular DMSP and water column DMS/P concentrations were observed at night, coinciding with the time of lowest carbonate saturation state. Spatially, water column DMS/P concentrations were highest over areas dominated by seagrass and macroalgae (dissolved DMS/P) and phytoplankton (particulate DMS/P) rather than corals. This research suggests that macroalgae may use DMSP to maintain metabolic function during periods of low carbonate saturation state. In the reef system, seagrass and macroalgae may be more important benthic producers of dissolved DMS/P than corals. An increase in DMS/P concentrations during periods of low carbonate saturation state may become ecologically important in the future under an OA regime, impacting larval settlement and increasing atmospheric emissions of DMS. PMID:23724073

Effects of an environmentally-relevant mixture of pyrethroid insecticides on spontaneous activity in primary cortical networks on microelectrode arrays.

PubMed

Johnstone, Andrew F M; Strickland, Jenna D; Crofton, Kevin M; Gennings, Chris; Shafer, Timothy J

2017-05-01

Pyrethroid insecticides exert their insecticidal and toxicological effects primarily by disrupting voltage-gated sodium channel (VGSC) function, resulting in altered neuronal excitability. Numerous studies of individual pyrethroids have characterized effects on mammalian VGSC function and neuronal excitability, yet studies examining effects of complex pyrethroid mixtures in mammalian neurons, especially in environmentally relevant mixture ratios, are limited. In the present study, concentration-response functions were characterized for five pyrethroids (permethrin, deltamethrin, cypermethrin, β-cyfluthrin and esfenvalerate) in an in vitro preparation containing cortical neurons and glia. As a metric of neuronal network activity, spontaneous mean network firing rates (MFR) were measured using microelectorde arrays (MEAs). In addition, the effect of a complex and exposure relevant mixture of the five pyrethroids (containing 52% permethrin, 28.8% cypermethrin, 12.9% β-cyfluthrin, 3.4% deltamethrin and 2.7% esfenvalerate) was also measured. Data were modeled to determine whether effects of the pyrethroid mixture were predicted by dose-addition. At concentrations up to 10μM, all compounds except permethrin reduced MFR. Deltamethrin and β-cyfluthrin were the most potent and reduced MFR by as much as 60 and 50%, respectively, while cypermethrin and esfenvalerate were of approximately equal potency and reduced MFR by only ∼20% at the highest concentration. Permethrin caused small (∼24% maximum), concentration-dependent increases in MFR. Effects of the environmentally relevant mixture did not depart from the prediction of dose-addition. These data demonstrate that an environmentally relevant mixture caused dose-additive effects on spontaneous neuronal network activity in vitro, and is consistent with other in vitro and in vivo assessments of pyrethroid mixtures. Published by Elsevier B.V.

Characterization of the hydrogeology and water quality at the Management Systems Evaluation Area near Princeton, Minnesota, 1991-92

USGS Publications Warehouse

Delin, G.N.; Landon, M.K.; Lamb, J.A.; Anderson, J.L.

1994-01-01

Atrazine was detected by gas chromatography mass spectroscopy in 2 of the 7 wells in the research area at concentrations of 0.04 and 0.17 micrograms per liter (ug/L), well below the U.S. Environmental Protection Agency's recommended maximum contaminant level of 3 ug/L. The median concentration in these Wells was less than the qualitative detection limit of 0.01 ug/L. Atrazine metabolite de-ethylatrazine was the most frequently detected herbicide or herbicide metabolite. De-ethylatrazine was detected in 5 of the 7 wells in the research area at concentrations ranging from 0.12 to 0.32 ug/L with a median concentration of 0.14 ug/L. Atrazine metabolite de-isopropylatrazine was not detected above the qualitative detection limit of 0.06 ug/L. The most likely sources of atrazine are applications to the research area during 1990 or from precipitation.

Ecological risk assessment of pharmaceuticals in the receiving environment of pharmaceutical wastewater in Pakistan.

PubMed

Ashfaq, Muhammad; Nawaz Khan, Khujasta; Saif Ur Rehman, Muhammad; Mustafa, Ghulam; Faizan Nazar, Muhammad; Sun, Qian; Iqbal, Javed; Mulla, Sikandar I; Yu, Chang-Ping

2017-02-01

The pharmaceutical industry of Pakistan is growing with an annual growth rate of 10%. Besides this growth, this industry is not complying with environmental standards, and discharging its effluent into domestic wastewater network. Only limited information is available about the occurrence of pharmaceutical compounds (PCs) in the environmental matrices of Pakistan that has motivated us to aim at the occurrence and ecological risk assessment of 11 PCs of different therapeutic classes in the wastewater of pharmaceutical industry and in its receiving environmental matrices such as sludge, solid waste and soil samples near the pharmaceutical formulation units along Shiekhupura road, Lahore, Pakistan. Target PCs (paracetamol, naproxen, diclofenac, ibuprofen, amlodipine, rosuvastatin, ofloxacin, ciprofloxacin, moxifloxacin, sparfloxacin and gemifloxacin) were quantified using in-house developed HPLC-UV. Ibuprofen (1673µg/L, 6046µg/kg, 1229µg/kg and 610µg/kg), diclofenac (836µg/L, 4968µg/kg, 6632µg/kg and 257µg/kg) and naproxen (464µg/L, 7273µg/kg, 4819µg/kg and 199µg/kg) showed the highest concentrations among 11 target PCs in wastewater, sludge, solid waste and soil samples, respectively. Ecological risk assessment, in terms of risk quotient (RQ), was also carried out based on the maximum measured concentration of PCs in wastewater. The maximum RQ values obtained were with paracetamol (64 against daphnia), naproxen (177 against fish), diclofenac (12,600 against Oncorhynchus mykiss), ibuprofen (167,300 against Oryzias latipes), ofloxacin (81,000 against Pseudomonas putida) and ciprofloxacin (440 against Microcystis aeruginosa). These results show a high level of ecological risk due to the discharge of untreated wastewater from pharmaceutical units. This risk may further lead to food web contamination and drug resistance in pathogens. Thus, further studies are needed to detect the PCs in crops as well as the government should strictly enforce environmental legislation on these pharmaceutical units. Copyright © 2016 Elsevier Inc. All rights reserved.

Mathematical model of device for slurry concentration and desludging in near-bottom zone

NASA Astrophysics Data System (ADS)

Shishkin, P. V.; Trufanova, I. S.

2017-10-01

There are many systems for extracting minerals from the bottom of water bodies, but none of them meets the requirements, so the actual task is to create technical means that provide the best performance and environmental safety. Increase the efficiency of the hydromechanical mining method is possible due to the maximum concentration and desludging of the slurry in the near-bottom zone, which allows reducing the energy and material consumption of hydrotransport of minerals. To achieve this goal, it is proposed to use a perforated section adjacent to the power unit, with a transverse cross section that reduces in its length in the direction of flow, in the pressure pulp pipeline system.

Environmental risk assessment of cobalt and manganese from industrial sources in an estuarine system.

PubMed

Barrio-Parra, F; Elío, J; De Miguel, E; García-González, J E; Izquierdo, M; Álvarez, R

2018-04-01

A total of 74 samples of soil, sediment, industrial sludge, and surface water were collected in a Mediterranean estuarine system in order to assess the potential ecological impact of elevated concentrations of Co and Mn associated with a Terephthalic (PTA) and Isophthalic (PIPA) acids production plant. Samples were analyzed for elemental composition (37 elements), pH, redox potential, organic carbon, and CaCO 3 content, and a group of 16 selected samples were additionally subjected to a Tessier sequential extraction. Co and Mn soil concentrations were significantly higher inside the industrial facility and around its perimeter than in background samples, and maximum dissolved Co and Mn concentrations were found in a creek near the plant's discharge point, reaching values 17,700 and 156 times higher than their respective background concentrations. The ecological risk was evaluated as a function of Co and Mn fractionation and bioavailability which were controlled by the environmental conditions generated by the advance of seawater into the estuarine system during high tide. Co appeared to precipitate near the river mouth due to the pH increase produced by the influence of seawater intrusion, reaching hazardous concentrations in sediments. In terms of their bioavailability and the corresponding risk assessment code, both Co and Mn present sediment concentrations that result in medium to high ecological risk whereas water concentrations of both elements reach values that more than double their corresponding Secondary Acute Values.

An evaluation of the results of alluvial groundwater sampling from 1987--1990 at the Durango disposal site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1991-04-01

This evaluation was conducted to determine if surface discharges of contaminated water from a retention pond and seepage of tailings pore water from the disposal cell have affected ground I water quality in the alluvial deposits east and northeast of the Bodo Canyon disposal cell. The question of whether corrective remedial action is needed for the alluvial groundwater downgradient of the disposal cell is also addressed. Maximum observed concentrations of seven hazardous constituents equalled or exceeded proposed US Environmental Protection Agency (EPA) maximum concentration limits (MCLs) in the alluvial groundwater downgradient of the disposal cell. These constituents include chromium, lead,more » molybdenum, net gross alpha, radium-226 and -228, selenium, and uranium. Concentrations greater than MCLs for molybdenum, net gross alpha, and radium-226 and -228 may be naturally occurring in the alluvial groundwater. There is no statistical evidence that these hazardous constituents are groundwater contaminants with concentrations that exceed the MCLs in alluvial groundwater. However, the median selenium concentration in monitor well 608 exceeds the MCL. Therefore, selenium contamination in the alluvial groundwater in the area of monitor well 608 is possible. Selenium concentrations show no definite increasing or decreasing trend. Since groundwater contamination by selenium is possible in one monitor well, but concentrations are not increasing, corrective action is not warranted at this time. Alluvial groundwater quality will continue to be monitored quarterly and the discharge from the retention pond should be sampled after treatment to ascertain its potential affects on groundwater quality.« less

Utilization of moving bed biofilm reactor for industrial wastewater treatment containing ethylene glycol: kinetic and performance study.

PubMed

Hassani, Amir Hessam; Borghei, Seyed Mehdi; Samadyar, Hassan; Ghanbari, Bastam

2014-01-01

One of the requirements for environmental engineering, which is currently being considered, is the removal of ethylene glycol (EG) as a hazardous environmental pollutant from industrial wastewater. Therefore, in a recent study, a moving bed biofilm reactor (MBBR) was applied at pilot scale to treat industrial effluents containing different concentrations of EG (600, 800, 1200, and 1800 mg L-1 ). The removal efficiency and kinetic analysis of the system were examined at different hydraulic retention times of 6, 8, 10, and 12 h as well as influent chemical oxygen demand (COD) ranged between values of 1000 and 3000mg L-1. In minimum and maximum COD Loadings, the MBBR showed 95.1% and 60.7% removal efficiencies, while 95.9% and 66.2% EG removal efficiencies were achieved in the lowest and highest EG concentrations. The results of the reactor modelling suggested compliance of the well-known modified Stover-Kincannon model with the system.

Production of laccase by Pynoporus sanguineus using 2,5 - Xylidine and ethanol

PubMed Central

Valeriano, Viviane S.; Silva, Anna Maria F.; Santiago, Mariângela F.; Bara, Maria T. F.; Garcia, Telma A.

2009-01-01

Enzyme application in biotechnological and environmental processes has had increasing interest due to its efficiency, selectivity and mainly for being environmentally healthful, but these applications require a great volume of enzymes. In this work the effect of different concentrations of ethanol and 2,5-xylidine on growth and production of laccase by Pycnoporus sanguineus was investigated. In a medium containing 200 mg.L-1 of 2,5-xylidine or 50 g.L-1 of ethanol, the maximum activity of laccase was 2019 U.L-1 and 1035 U.L-1, respectively. No direct correlation between biomass and activity of laccase was observed for any of the inducers used during the tests. Ethanol concentrations, larger than or equal to 20 g.L-1, inhibited the radial growth of P. sanguineus. This study showed that ethanol, which has less toxicity and cost than the majority of the studied inducers, presents promising perspectives for laccase production by P. sanguineus. PMID:24031426

Determination of fluoroquinolones in chicken feces - a new liquid-liquid extraction method combined with LC-MS/MS.

PubMed

Janusch, Franziska; Scherz, Gesine; Mohring, Siegrun A I; Hamscher, Gerd

2014-11-01

The application of antibiotics including fluoroquinolones to farming animals is widespread and may lead to the development of antibiotic resistance and other environmental effects. To calculate environmental loads and for a proper risk assessment it is necessary to determine the antibiotic concentration in feces. Therefore, a new liquid-liquid extraction method combined with HPLC-MS/MS for the detection of marbofloxacin, ciprofloxacin, enrofloxacin and difloxacin in chicken feces was developed. Recoveries ranged from 51.0% to 83.5%. LOQs were between 0.10 and 1.09μg/kg. Feces of chickens treated with an enrofloxacin dosage of 10mg/kg bodyweight revealed maximum enrofloxacin and ciprofloxacin concentrations of 61.3 and 18.8mg/kg. Both antibiotics could be detected in feces up to two days after the last application in notable amounts (∼1mg/kg). Thus, feces of recently medicated chickens should not be used as a fertilizer without any further processing. Copyright © 2014 Elsevier B.V. All rights reserved.

Arsenic in ground water in Tuscola County, Michigan

USGS Publications Warehouse

Haack, Sheridan K.; Rachol, Cynthia M.

2000-01-01

Previous studies of ground-water resources in Michigan by the Michigan Department of Community Health (MDCH), the Michigan Department of Environmental Quality (MDEQ), and the U.S. Geological Survey (USGS) indicate that in several counties in the southeastern part of the State the concentrations of arsenic in ground water may exceed the U.S. Environmental Protection Agency (USEPA) maximum contaminant level (MCL) of 50 micrograms per liter [µg/L]. This MCL was established in 1986. The Safe Drinking Water Act, as amended in 1996, requires USEPA to revise this standard in 2000. In June 2000, the USEPA proposed a revised MCL of 5 µg/L. In 1996, the USGS, in cooperation with the MDEQ and the Health Departments of Genesee, Huron, Lapeer, Livingston, Oakland, Sanilac, Shiawassee, Tuscola and Washtenaw counties, began a study of the factors controlling arsenic occurrence and concentrations in ground water in southeastern Michigan. This study is one of four USGS Drinking Water Initiative projects throughout the United States.

Drinking Water Uranium and Potential Health Effects in the German Federal State of Bavaria.

PubMed

Banning, Andre; Benfer, Mira

2017-08-18

Mainly due to its nephrotoxic and osteotoxic potential, uranium (U) increasingly finds itself in the spotlight of environmental and health-related research. Germany decided on a binding U guideline value in drinking water of 10 µg/L, valid since 2011. It is yet widely unknown if and how public health was affected by elevated U concentrations before that. In this ecological study we summarized available drinking water U data for the German federal state of Bavaria (703 analyses in total for 553 different municipalities) at county level (for 76 out of 96 Bavarian counties, representing about 83% of Bavaria's and about 13% of Germany's total population) in terms of mean and maximum U concentration. Bavaria is known to regionally exhibit mainly geogenically elevated groundwater U with a maximum value of 40 µg/L in the database used here. Public health data were obtained from federal statistical authorities at county resolution. These included incidence rates of diagnosed diseases suspected to be potentially associated with chronic U uptake, e.g., diseases of the skeleton, the liver or the thyroid as well as tumor and genito-urinary diseases. The datasets were analyzed for interrelations and mutual spatial occurrence using statistical approaches and GIS as well as odds ratios and relative risks calculations. Weak but significant positive associations between maximum U concentrations and aggregated ICD-10 diagnose groups for growths/tumors as well as liver diseases were observed, elevated incidence rates of thyroid diseases seem to occur where mean drinking water U concentrations exceed 2 µg/L. Here, we discuss obtained results and their implications for potential impacts of hydrochemistry on public health in southeast Germany.

Drinking Water Uranium and Potential Health Effects in the German Federal State of Bavaria

PubMed Central

Benfer, Mira

2017-01-01

Mainly due to its nephrotoxic and osteotoxic potential, uranium (U) increasingly finds itself in the spotlight of environmental and health-related research. Germany decided on a binding U guideline value in drinking water of 10 µg/L, valid since 2011. It is yet widely unknown if and how public health was affected by elevated U concentrations before that. In this ecological study we summarized available drinking water U data for the German federal state of Bavaria (703 analyses in total for 553 different municipalities) at county level (for 76 out of 96 Bavarian counties, representing about 83% of Bavaria’s and about 13% of Germany’s total population) in terms of mean and maximum U concentration. Bavaria is known to regionally exhibit mainly geogenically elevated groundwater U with a maximum value of 40 µg/L in the database used here. Public health data were obtained from federal statistical authorities at county resolution. These included incidence rates of diagnosed diseases suspected to be potentially associated with chronic U uptake, e.g., diseases of the skeleton, the liver or the thyroid as well as tumor and genito-urinary diseases. The datasets were analyzed for interrelations and mutual spatial occurrence using statistical approaches and GIS as well as odds ratios and relative risks calculations. Weak but significant positive associations between maximum U concentrations and aggregated ICD-10 diagnose groups for growths/tumors as well as liver diseases were observed, elevated incidence rates of thyroid diseases seem to occur where mean drinking water U concentrations exceed 2 µg/L. Here, we discuss obtained results and their implications for potential impacts of hydrochemistry on public health in southeast Germany. PMID:28820453

Organophosphate flame retardants and plasticizers in indoor dust, air and window wipes in newly built low-energy preschools.

PubMed

Persson, Josefin; Wang, Thanh; Hagberg, Jessika

2018-07-01

The construction of extremely airtight and energy efficient low-energy buildings is achieved by using functional building materials, such as age-resistant plastics, insulation, adhesives, and sealants. Additives such as organophosphate flame retardants (OPFRs) can be added to some of these building materials as flame retardants and plasticizers. Some OPFRs are considered persistent, bioaccumulative and toxic. Therefore, in this pilot study, the occurrence and distribution of nine OPFRs were determined for dust, air, and window wipe samples collected in newly built low-energy preschools with and without environmental certifications. Tris(1,3-dichloroisopropyl) phosphate (TDCIPP) and triphenyl phosphate (TPHP) were detected in all indoor dust samples at concentrations ranging from 0.014 to 10μg/g and 0.0069 to 79μg/g, respectively. Only six OPFRs (predominantly chlorinated OPFRs) were detected in the indoor air. All nine OPFRs were found on the window surfaces and the highest concentrations, which occurred in the reference preschool, were measured for 2-ethylhexyl diphenyl phosphate (EHDPP) (maximum concentration: 1500ng/m 2 ). Interestingly, the OPFR levels in the environmental certified low-energy preschools were lower than those in the reference preschool and the non-certified low-energy preschool, probably attributed to the usage of environmental friendly and low-emitting building materials, interior decorations, and consumer products. Copyright © 2018 Elsevier B.V. All rights reserved.

A regional assessment of chemicals of concern in surface waters of four Midwestern United States national parks

USGS Publications Warehouse

Elliott, Sarah M.; VanderMeulen, David

2017-01-01

Anthropogenic chemicals and their potential for adverse biological effects raise concern for aquatic ecosystem health in protected areas. During 2013–15, surface waters of four Midwestern United States national parks were sampled and analyzed for wastewater indicators, pharmaceuticals, personal care products, and pesticides. More chemicals and higher concentrations were detected at the two parks with greater urban influences (Mississippi National River and Recreation Area and Indiana Dunes National Lakeshore) than at the two more remote parks (Apostle Islands National Lakeshore and Isle Royale National Park). Atrazine (10–15 ng/L) and N,N-diethyl-meta-toluamide (16–120 ng/L) were the only chemicals detected in inland lakes of a remote island national park (Isle Royale National Park). Bisphenol A and organophosphate flame retardants were commonly detected at the other sampled parks. Gabapentin and simazine had the highest observed concentrations (> 1000 ng/L) in three and two samples, respectively. At the two parks with urban influences, metolachlor and simazine concentrations were similar to those reported for other major urban rivers in the United States. Environmental concentrations of detected chemicals were often orders of magnitude less than standards or reference values with three exceptions: (1) hydrochlorothiazide exceeded a human health-based screening value in seven samples, (2) estrone exceeded a predicted critical environmental concentration for fish pharmacological effects in one sample, and (3) simazine was approaching the 4000 ng/L Maximum Contaminant Level in one sample even though this concentration is not expected to reflect peak pesticide use. Although few environmental concentrations were approaching or exceeded standards or reference values, concentrations were often in ranges reported to elicit effects in aquatic biota. Data from this study will assist in establishing a baseline for chemicals of concern in Midwestern national parks and highlight the need to better understand the sources, pathways, and potential adverse effects to aquatic systems in national parks.

A regional assessment of chemicals of concern in surface waters of four Midwestern United States national parks.

PubMed

Elliott, Sarah M; VanderMeulen, David D

2017-02-01

Anthropogenic chemicals and their potential for adverse biological effects raise concern for aquatic ecosystem health in protected areas. During 2013-15, surface waters of four Midwestern United States national parks were sampled and analyzed for wastewater indicators, pharmaceuticals, personal care products, and pesticides. More chemicals and higher concentrations were detected at the two parks with greater urban influences (Mississippi National River and Recreation Area and Indiana Dunes National Lakeshore) than at the two more remote parks (Apostle Islands National Lakeshore and Isle Royale National Park). Atrazine (10-15ng/L) and N,N-diethyl-meta-toluamide (16-120ng/L) were the only chemicals detected in inland lakes of a remote island national park (Isle Royale National Park). Bisphenol A and organophosphate flame retardants were commonly detected at the other sampled parks. Gabapentin and simazine had the highest observed concentrations (>1000ng/L) in three and two samples, respectively. At the two parks with urban influences, metolachlor and simazine concentrations were similar to those reported for other major urban rivers in the United States. Environmental concentrations of detected chemicals were often orders of magnitude less than standards or reference values with three exceptions: (1) hydrochlorothiazide exceeded a human health-based screening value in seven samples, (2) estrone exceeded a predicted critical environmental concentration for fish pharmacological effects in one sample, and (3) simazine was approaching the 4000ng/L Maximum Contaminant Level in one sample even though this concentration is not expected to reflect peak pesticide use. Although few environmental concentrations were approaching or exceeded standards or reference values, concentrations were often in ranges reported to elicit effects in aquatic biota. Data from this study will assist in establishing a baseline for chemicals of concern in Midwestern national parks and highlight the need to better understand the sources, pathways, and potential adverse effects to aquatic systems in national parks. Copyright © 2016. Published by Elsevier B.V.

Informal e-waste recycling: environmental risk assessment of heavy metal contamination in Mandoli industrial area, Delhi, India.

PubMed

Pradhan, Jatindra Kumar; Kumar, Sudhir

2014-01-01

Nowadays, e-waste is a major source of environmental problems and opportunities due to presence of hazardous elements and precious metals. This study was aimed to evaluate the pollution risk of heavy metal contamination by informal recycling of e-waste. Environmental risk assessment was determined using multivariate statistical analysis, index of geoaccumulation, enrichment factor, contamination factor, degree of contamination and pollution load index by analysing heavy metals in surface soils, plants and groundwater samples collected from and around informal recycling workshops in Mandoli industrial area, Delhi, India. Concentrations of heavy metals like As (17.08 mg/kg), Cd (1.29 mg/kg), Cu (115.50 mg/kg), Pb (2,645.31 mg/kg), Se (12.67 mg/kg) and Zn (776.84 mg/kg) were higher in surface soils of e-waste recycling areas compared to those in reference site. Level exceeded the values suggested by the US Environmental Protection Agency (EPA). High accumulations of heavy metals were also observed in the native plant samples (Cynodon dactylon) of e-waste recycling areas. The groundwater samples collected form recycling area had high heavy metal concentrations as compared to permissible limit of Indian Standards and maximum allowable limit of WHO guidelines for drinking water. Multivariate analysis and risk assessment studies based on total metal content explains the clear-cut differences among sampling sites and a strong evidence of heavy metal pollution because of informal recycling of e-waste. This study put forward that prolonged informal recycling of e-waste may accumulate high concentration of heavy metals in surface soils, plants and groundwater, which will be a matter of concern for both environmental and occupational hazards. This warrants an immediate need of remedial measures to reduce the heavy metal contamination of e-waste recycling sites.

Fetal Environment Is a Major Determinant of the Neonatal Blood Thyroxine Level: Results of a Large Dutch Twin Study.

PubMed

Zwaveling-Soonawala, Nitash; van Beijsterveldt, Catharina E M; Mesfum, Ertirea T; Wiedijk, Brenda; Oomen, Petra; Finken, Martijn J J; Boomsma, Dorret I; van Trotsenburg, A S Paul

2015-06-01

The interindividual variability in thyroid hormone function parameters is much larger than the intraindividual variability, suggesting an individual set point for these parameters. There is evidence to suggest that environmental factors are more important than genetic factors in the determination of this individual set point. This study aimed to quantify the effect of genetic factors and (fetal) environment on the early postnatal blood T4 concentration. This was a classical twin study comparing the resemblance of neonatal screening blood T4 concentrations in 1264 mono- and 2566 dizygotic twin pairs retrieved from the population-based Netherlands Twin Register. Maximum-likelihood estimates of variance explained by genetic and environmental influences were obtained by structural equation modeling in data from full-term and preterm twin pairs. In full-term infants, genetic factors explained 40%/31% of the variance in standardized T4 scores in boys/girls, and shared environment, 27%/22%. The remaining variance of 33%/47% was due to environmental factors not shared by twins. For preterm infants, genetic factors explained 34%/0% of the variance in boys/girls, shared environment 31%/57%, and unique environment 35%/43%. In very preterm twins, no significant contribution of genetic factors was observed. Environment explains a large proportion of the resemblance of the postnatal blood T4 concentration in twin pairs. Because we analyzed neonatal screening results, the fetal environment is the most likely candidate for these environmental influences. Genetic influences on the T4 set point diminished with declining gestational age, especially in girls. This may be due to major environmental influences such as immaturity and nonthyroidal illness in very preterm infants.

Speciation of Cr(VI) in environmental samples in the vicinity of the ferrochrome smelter.

PubMed

Sedumedi, Hilda N; Mandiwana, Khakhathi L; Ngobeni, Prince; Panichev, Nikolay

2009-12-30

The impact of ferrochrome smelter on the contamination of its environment with toxic hexavalent chromium, Cr(VI), was assessed by analyzing smelter dusts, soil, grass and tree barks. For the separation of Cr(VI) from Cr(III), solid samples were treated with 0.1M Na(2)CO(3) and filtered through hydrophilic PDVF 0.45 microm filter prior to the determination of Cr(VI) by electrothermal atomic absorption spectrometry (ET-AAS). Ferrochrome smelter dust was found to contain significant levels of Cr(VI), viz. 43.5 microg g(-1) (cyclone dust), 2710 microg g(-1) (fine dust), and 7800 microg g(-1) (slimes dust) which exceeded the maximum acceptable risk concentration (20 microg g(-1)). The concentration of Cr(VI) in environmental samples of grass (3.4+/-0.2), soil (7.7+/-0.2), and tree bark (11.8+/-1.2) collected in the vicinity of the chrome smelter were higher as compared with the same kind of samples collected from uncontaminated area. The results of the investigation show that ferrochrome smelter is a source of environmental pollution with contamination factors of Cr(VI) ranging between 10 and 50.

Groundwater-quality characteristics for the Wyoming Groundwater-Quality Monitoring Network, November 2009 through September 2012

USGS Publications Warehouse

Boughton, Gregory K.

2014-01-01

Groundwater samples were collected from 146 shallow (less than or equal to 500 feet deep) wells for the Wyoming Groundwater-Quality Monitoring Network, from November 2009 through September 2012. Groundwater samples were analyzed for physical characteristics, major ions and dissolved solids, trace elements, nutrients and dissolved organic carbon, uranium, stable isotopes of hydrogen and oxygen, volatile organic compounds, and coliform bacteria. Selected samples also were analyzed for gross alpha radioactivity, gross beta radioactivity, radon, tritium, gasoline range organics, diesel range organics, dissolved hydrocarbon gases (methane, ethene, and ethane), and wastewater compounds. Water-quality measurements and concentrations in some samples exceeded numerous U.S. Environmental Protection Agency (EPA) drinking water standards. Physical characteristics and constituents that exceeded EPA Maximum Contaminant Levels (MCLs) in some samples were arsenic, selenium, nitrite, nitrate, gross alpha activity, and uranium. Total coliforms and Escherichia coli in some samples exceeded EPA Maximum Contaminant Level Goals. Measurements of pH and turbidity and concentrations of chloride, sulfate, fluoride, dissolved solids, aluminum, iron, and manganese exceeded EPA Secondary Maximum Contaminant Levels in some samples. Radon concentrations in some samples exceeded the alternative MCL proposed by the EPA. Molybdenum and boron concentrations in some samples exceeded EPA Health Advisory Levels. Water-quality measurements and concentrations also exceeded numerous Wyoming Department of Environmental Quality (WDEQ) groundwater standards. Physical characteristics and constituents that exceeded WDEQ Class I domestic groundwater standards in some samples were measurements of pH and concentrations of chloride, sulfate, dissolved solids, iron, manganese, boron, selenium, nitrite, and nitrate. Measurements of pH and concentrations of chloride, sulfate, dissolved solids, aluminum, iron, manganese, boron, and selenium exceeded WDEQ Class II agriculture groundwater standards in some samples. Measurements of pH and concentrations of sulfate, dissolved solids, aluminum, boron, and selenium exceeded WDEQ Class III livestock groundwater standards in some samples. The concentrations of dissolved solids in two samples exceeded the WDEQ Class IV industry groundwater standard. Measurements of pH and concentrations of dissolved solids, aluminum, iron, manganese, and selenium exceeded WDEQ Class special (A) fish and aquatic life groundwater standards in some samples. Stable isotopes of hydrogen and oxygen measured in water samples were compared to the Global Meteoric Water Line and Local Meteoric Water Lines. Results indicated that recharge to all of the wells was derived from precipitation and that the water has undergone some fractionation, possibly because of evaporation. Concentrations of organic compounds did not exceed any State or Federal water-quality standards. Few volatile organic compounds were detected in samples, whereas gasoline range organics, diesel range organics, and methane were detected most frequently. Concentrations of wastewater compounds did not exceed any State or Federal water-quality standards. The compounds N,N-diethyl-meta-toluamide (DEET), benzophenone, and phenanthrene were detected most frequently. Bacteria samples were collected, processed, incubated, and enumerated in the field or at the U.S. Geological Survey Wyoming-Montana Water Science Center. Total coliforms and Escherichia coli were detected in some samples.

Antagonistic effects of humic acid and iron oxyhydroxide grain-coating on biochar nanoparticle transport in saturated sand.

PubMed

Wang, Dengjun; Zhang, Wei; Zhou, Dongmei

2013-05-21

Biochar land application may result in multiple agronomic and environmental benefits (e.g., carbon sequestration, improving soil quality, and immobilizing environmental contaminants). However, our understanding of biochar particle transport is largely unknown in natural environments with significant heterogeneity in solid (e.g., patches of iron oxyhydroxide coating) and solution chemistry (e.g., the presence of natural organic matter), which represents a critical knowledge gap in assessing the environmental impact of biochar land application. Transport and retention kinetics of nanoparticles (NPs) from wheat straw biochars produced at two pyrolysis temperatures (i.e., 350 and 550 °C) were investigated in water-saturated sand columns at environmentally relevant concentrations of dissolved humic acid (HA, 0, 1, 5, and 10 mg L(-1)) and fractional surface coverage of iron oxyhydroxide coatings on sand grains (ω, 0.16, 0.28, and 0.40). Transport of biochar NPs increased with increasing HA concentration, largely because of enhanced repulsive interaction energy between biochar NPs and sand grains. Conversely, transport of biochar NPs decreased significantly with increasing ω due to enhanced electrostatic attraction between negatively charged biochar NPs and positively charged iron oxyhydroxides. At a given ω of 0.28, biochar NPs were less retained with increasing HA concentration due to increased electrosteric repulsion between biochar NPs and sand grains. Experimental breakthrough curves and retention profiles were well described using a two-site kinetic retention model that accounted for Langmuirian blocking or random sequential adsorption at one site. Consistent with the blocking effect, the often observed flat retention profiles stemmed from decreased retention rate and/or maximum retention capacity at a higher HA concentration or smaller ω. The antagonistic effects of HA and iron oxyhydroxide grain-coating imparted on the mobility of biochar NPs suggest that biochar colloid transport potential will be dependent on competitive influences exerted by a number of environmental factors (e.g., natural organic matter and metal oxides).

Hydrogeology and ground-water quality of Valley Forge National Historical Park, Montgomery County, Pennsylvania

USGS Publications Warehouse

Sloto, Ronald A.; McManus, B. Craig

1996-01-01

Valley Forge National Historical Park is just southwest of the Commodore Semiconductor Group (CSG) National Priorities List (Superfund) Site, a source of volatile organic compounds (VOC's) in ground water. The 7.5-square-mile study area includes the part of the park in Lower Providence and West Norriton Townships in Montgomery County, Pa., and surrounding vicinity. The park is underlain by sedimentary rocks of the Upper Triassic age stockton Formation. A potentiometric-surface map constructed from water levels measured in 59 wells shows a cone of depression, approximately 0.5 mile in diameter, centered near the CSG Site. The cone of depression is caused by the pumping of six public supply wells. A ground-water divide between the cone of depression and Valley Forge National Historical Park provides a hydraulic barrier to the flow of ground water and contaminants from the CSG Site to the park. If pumping in the cone of depression was to cease, water levels would recover, and the ground-water divide would shift to the north. A hydraulic gradient between the CSG Site and the Schuylkill River would be established, causing contaminated ground water to flow to the park.Water samples were collected from 12 wells within the park boundary and 9 wells between the park boundary and the ground-water divide to the north of the park. All water samples were analyzed for physical properties (field determinations), nutrients, common ions, metals and other trace constituents, and VOC's. Water samples from the 12 wells inside the park boundary also were analyzed for pesticides. Concentrations of inorganic constituents in the water samples did not exceed U.S. Environmental Protection Agency maximum contaminant levels. Very low concentrations of organic compounds were detected in some of the water samples. VOC's were detected in water from 76 percent of the wells sampled; the maximum concentration detected was 5.8 micrograms per liter of chloroform. The most commonly detected VOC was chloroform. The second most commonly detected compound was methyl tert-butyl ether (MTBE), which was detected in water from 24 percent of wells sampled. Several pesticides were detected in water samples collected from within the park boundaries.: chlordane, DDD, dieldrin, endrin, heptachlor epoxide, and simazine. Concentrations of the detected pesticides were 0.1 micrograms per liter or less and did not exceed U.S. Environmental Protection Agency maximum contaminant levels.

The Ecological and Economic Assessment of Efficiency of Environmental Technologies for CHPP (Combined Heat And Power Plant)

NASA Astrophysics Data System (ADS)

Rostuntsova, I. A.; Novichkov, S. V.; Zakharov, O. V.; Kochetkov, A. V.

2017-11-01

The analysis of the trial-industrial research of the effectiveness of burning water fuel mixtures in steam boilers of medium and high pressure at the combustion of natural gas and fuel oil is carried out. As a result of a research decrease in nitrogen oxide concentration is depending on the amount of moisture pumped to the boilers and type of the incinerated fuel. The theoretical model of the formation of nitrogen oxides in the furnace of the boiler in order to optimize the combustion process with the introduction of moisture, whereby to determine the concentrations of nitrogen oxides formed in the combustion process of the method of expansion of the exponential is received. The dependences of the maximal temperature of a torch, reaction rate of formation of nitrogen oxides, the conditional time of reaction, theoretical concentration of nitrogen oxides taking into account input of moisture in a fire chamber of a copper and coefficient of an exit of nitrogen oxides are defined at combustion of fuel taking into account moisture input. The divergence between the experimental and the theoretical value of the NOx concentration does not exceed 3.8%. The methodical provisions of the economic assessment of concentrations of pollutants reduction when entering the water are drafted. The rate the net present value (NPV) is applied. The optimal water-fuel ratio is selected based on the maximum value of the net present value (NPV). The evaluation of the application of environmental protection measures carried out taking into account the fact that by reducing the emission values in the implementation of this activity will decrease the amount of payment for emissions of polluting substances, which are collected from the profits of the enterprise. The cost estimate for the implementation of environmental activities carried out on the basis of lump-sum costs and current costs in environmental technology (increased fuel and water consumption).

Characterization of stormwater discharges from Las Flores Industrial Park, Rio Grande, Puerto Rico, 1998-99

USGS Publications Warehouse

Rodriguez, Jose M.

2000-01-01

Stormwater discharges from Las Flores Industrial Park, Rio Grande, Puerto Rico, were characterized from June 1998 to July 1999 by measuring the flow rate at two outfalls, delineating the drainage areas for each outfall, and calculating the volume of the stormwater discharges. Stormwater-discharge samples were collected and analyzed to determine the quality of the discharges. Constituent loads and loads per area were estimated for each drainage area. The studied drainage subareas covered approximately 46 percent of the total area of the Las Flores Industrial Park. Industrial groups represented in the study areas include manufacturers of textile, electronics, paper, fabricated metal, plastic, and chemical products. The concentrations of oil and grease (1 to 6 milligrams per liter), biochemical oxygen demand (4.7 to 16 milligrams per liter), total organic carbon (5.8 to 36 milligrams per liter), total suspended solids (28 to 100 milligrams per liter), and total phosphorous (0.11 to 0.78 milligrams per liter) from all the samples collected were less than the U.S. Environmental Protection Agency stormwater benchmark concentrations. Concentrations of chemical oxygen demand (15.8 to 157 milligrams per liter) and nitrate and nitrite (0.06 to 1.75 milligrams per liter) exceeded benchmark concentrations at one of the studied drainage areas. Total Kjeldahl nitrogen concentrations (1.00 to 3.20 milligrams per liter) exceeded the benchmark concentrations at the two studied drainage areas. Maximum concentrations for oil and grease, biochemical oxygen demand, chemical oxygen demand, total organic carbon, total Kjeldahl nitrogen, nitrate plus nitrite, and total phosphorous were detected in an area where electronics, plastics, and chemical products are currently manufactured. The maximum concentration of total suspended solids was detected at an area where textile, paper, plastic, chemical, and fabricated metal products are manufactured.

Simulated ground-water flow and water quality of the Mississippi River alluvium near Burlington, Iowa, 1999

USGS Publications Warehouse

Boyd, Robert A.

2001-01-01

Water samples collected from the alluvium indicated ground water can be classified as a calcium-magnesium-bicarbonate type. Reducing conditions likely occur in some localized areas of the alluvium, as suggested by relatively large concentrations of dissolved iron (4,390 micrograms per liter) and manganese (2, 430 micrograms per liter) in some ground-water samples. Nitrite plus nitrate was detected at concentrations greater than or equal to 8 milligrams per liter in three samples collected from observation wells completed in close proximity to cropland; the nitrite plus nitrate concentration in one groundwater sample exceeded the U.S. Environmental Protection Agency Maximum Contaminant Level for nitrate in drinking water (10 milligrams per liter as N). Triazine herbicides (atrazine, cyanazine, propazine, simazine, and selected degradation products) and chloroacetanilide herbicides (acetochlor, alachlor, and metolachlor) were detected in some water samples. A greater number of herbicide compounds were detected in surface-water samples than in ground-water samples. Herbicide concentrations typically were at least an order of magnitude greater in surfacewater samples than in ground-water samples. The Maximum Contaminant Level for alachlor (2 micrograms per liter) was exceeded in a sample from Dry Branch Creek at Tama Road and for atrazine (3 micrograms per liter) was exceeded in samples collected from Dry Branch Creek at Tama Road and the county drainage ditch at Tama Road.

Identification of nitrogen sources to four small lakes in the agricultural region of Khorezm, Uzbekistan

USGS Publications Warehouse

Shanafield, M.; Rosen, M.; Saito, L.; Chandra, S.; Lamers, J.; Nishonov, Bakhriddin

2010-01-01

Pollution of inland waters by agricultural land use is a concern in many areas of the world, and especially in arid regions, where water resources are inherently scarce. This study used physical and chemical water quality and stable nitrogen isotope (δ15N) measurements from zooplankton to examine nitrogen (N) sources and concentrations in four small lakes of Khorezm, Uzbekistan, an arid, highly agricultural region, which is part of the environmentally-impacted Aral Sea Basin. During the 2-year study period, ammonium concentrations were the highest dissolved inorganic N species in all lakes, with a maximum of 3.00 mg N l−1 and an average concentration of 0.62 mg N l−1. Nitrate levels were low, with a maximum concentration of 0.46 mg N l−1 and an average of 0.05 mg N l−1 for all four lakes. The limited zooplankton δ15N values did not correlate with the high loads of synthetic fertilizer applied to local croplands during summer months. These results suggest that the N cycles in these lakes may be more influenced by regional dynamics than agricultural activity in the immediate surroundings. The Amu-Darya River, which provides the main source of irrigation water to the region, was identified as a possible source of the primary N input to the lakes.

The origin, historical variations, and distribution of heavy metals in the Qiongzhou Strait and nearby marine areas

NASA Astrophysics Data System (ADS)

Zhang, Zhiqiang; Chen, Liang; Wang, Weiping; Li, Tuanjie; Zu, Tingting

2017-04-01

We analyzed heavy metal concentrations in a number of surface sediments and cores from the Qiongzhou Strait and surrounding marine areas. The areas of high concentrations are primarily outside the eastern mouth of the Qiongzhou Strait and on the west side of the Leizhou Peninsula, whereas the areas of low concentrations are located primarily in the eastern Qiongzhou Strait. The maximum Cd, Pb and Zn concentrations in the samples collected in our study do not exceed the official standards for marine sediments, whereas the concentrations of Cr and Cu slightly exceed the standards. Correlations exist between the concentrations of Cu, Pb, Zn, Cr and Cd, and the concentrations of these metals are positively correlated with the mean particle size (φ value), indicating that the finer sediments have adsorbed greater amounts of heavy metal elements than the coarser sediments. An evaluation of the potential environmental risks demonstrates that certain indices of heavy metal pollution and environmental risks are relatively low and may be assigned low risk levels, thereby indicating that, in terms of heavy metals, the marine sedimentary environment in this region is only mildly impacted. Our analysis of the contaminant origins shows that the heavy metals in this region primarily originate in the Pearl River Estuary and that a small amount of them is derived from local runoff. The elevated heavy metal concentrations from the upper sections of the cores started 130 years ago, which indicats that heavy metals in the surface sediments are primarily due to human activities associated with industrialization.

Risk Assessment for Criteria Pollutants and Air Toxics in two Sites of Mexico City During 2003 Field Campaign

NASA Astrophysics Data System (ADS)

García, A. R.; Grutter, M. M.; Volkamer, R. M.

2007-05-01

An environmental risk assessment for criteria pollutants and air toxics in Mexico City is presented. The data used in the study were collected by FTIR and DOAS systems during the Mexico City Metropolitan Area field campaign on April 2003 (MCMA2003). The systems were deployed in two different sites: One in downtown (Merced) and the other in the south east (CENICA). Concentrations of criteria pollutants and air toxics were obtained every 5 min and were used to obtain hourly average concentrations and the month average for April. The concentration values were used to estimate the risks of acute and chronic exposure to ambient concentrations using risk measures like hazard index, life cancer probability, life lost expectancy and maximum individual cancer risk. Results revealed that both sites have similar risk values. For acute exposure, criteria pollutants have larger risks than air toxics, but air toxics have larger risks for chronic exposure. Ambient concentrations of benzene showed the largest carcinogenic risk of the measured air toxics.

The metrological assurance of quality petroleum products. Methods for determining octane and sulfur numbers in the petroleum products

NASA Astrophysics Data System (ADS)

Shalkov, A. V.; Fadeev, Y. A.

2018-01-01

At present, solving environmental problems in industrially developed regions with a large concentration of mining and machine building enterprises is one of the main socially important tasks. Taking into account the increase in the volume of mining, there is an increase in the environmental burden, which affects the internal migration of the population. This is particularly evident in the examples of single-industry towns, in which a gradual decrease in the young workable population occurs. The article presents an analysis of the sources of maximum pollution of the environment by coal mining enterprises. Modern methods of controlling automobile fuel were analyzed. The analysis of fuel quality and the environmental assessment of combustion products was carried out. The equipment used in the article makes it possible to exclude substandard fuel and to reduce harmful emissions of vehicles to the atmosphere.

Environmental occurrence and shallow ground water detection of the antibiotic monensin from dairy farms

USGS Publications Warehouse

Watanabe, N.; Harter, T.H.; Bergamaschi, B.A.

2008-01-01

Pharmaceuticals used in animal feeding operations have been detected in various environmental settings. There is a growing concern about the impact on terrestrial and aquatic organisms and the development of antibiotic-resistant strains of microorganisms. Pharmaceutical use in milking cows is relatively limited compared with other livestock operations, except for the ionophore monensin, which is given to lactating cows as a feed. By weight, monensin can be the most significant antibiotic used in a dairy farm. This study investigates the potential of monensin to move from dairy operations into the surrounding ground water. Using two dairy farms in California as study sites, we twice collected samples along the environmental pathway-from flush lanes, lagoon waters, and shallow ground water beneath the dairies and beneath its associated manured fields. Monensin concentrations were determined using solid-phase extraction and liquid chromatography-tandem mass spectrometry with positive electrospray ionization. Monensin was detected in all of the flush lane and lagoon water samples. Theoretical maximum concentration estimated from the actual dosing rate and the theoretical excretion rate assuming no attenuation was one order of magnitude greater than observed concentrations, suggesting significant attenuation in the manure collection and storage system. Monensin was also detected, at levels ranging from 0.04 to 0.39 microg L(-1), in some of the ground water samples underneath the production area of the dairy but not from the adjacent manured fields. Concentrations in ground water immediately downgradient of the lagoons were one to two orders of magnitude lower than the concentrations detected in lagoons, suggesting attenuation in the subsurface. The data suggest the possibility of monensin transport into shallow (2-5 m) alluvial ground water from dairy management units, including manure storage lagoons and freestalls occupied by heifers, lactating cows, and dry cows.

Ground-water quality assessment of the Georgia-Florida Coastal Plain study unit; analysis of available information on nutrients, 1972-92

USGS Publications Warehouse

Berndt, M.P.

1996-01-01

The U.S. Geological Survey is conducting an assessment of water quality in the Georgia-Florida Coastal Plain study unit as part of the National Water-Quality Assessment Program. An initial activity of the program is to compile and analyze existing water-quality data for nutrients in each study unit. Ground-water quality data were compiled from three data sources, the U.S. Geological Survey, Florida Department of Environmental Protection, and Georgia Geologic Survey. A total of 2,246 samples of ground water nutrient data for nitrogen and phosphorus species were compiled from these three data sources. Estimates of 1990 nitrogen and phosphorus inputs by county in the study area were calculated from livestock manure, fertilizers, septic tanks, and rainfall. Data for nitrate nitrogen concentrations in ground water were available from the greatest number of wells; samples from 1,233 wells were available in the U.S. Geological Survey, 820 wells from the Florida Department of Environmental Protection, and 680 wells from the Georgia Geologic Survey. The maximum contaminant level for nitrate nitrogen in drinking water of 10 milligrams per liter was exceeded in a higher percentage of samples from the U.S. Geological Survey, mostly because this data contained numerous samples near known contamination areas. The maximum contaminant level for nitrate nitrogen was exceeded in 3 percent of samples from Upper Floridan aquifer and 12 percent of samples from surficial aquifer system in U.S. Geological Survey data and less than 1 percent and 2 percent of samples from the Upper Floridan aquifer and surficial aquifer system, respectively, in Florida Department of Environmental Protection data. In Georgia Geologic Survey data, 1 percent of samples had concentrations of nitrate nitrogen exceeding 10 milligrams per liter. Nutrient concentration data were grouped into categories based on land use, hydrogeology (aquifer and confinement of the Upper Floridan aquifer), and land resource provinces (Central Florida Ridge, Coastal Flatwoods and Southern Coastal Plain) for the surficial aquifer system. The highest median nitrate nitrogen concentrations in the U.S. Geological Survey data were 0.4 milligrams per liter in ground-water samples from the unconfined Upper Floridan aquifer in agricultural areas and 9.0 milligrams per liter in samples from the surficial aquifer system in agricultural areas in the Central Florida Ridge. In Florida Department of Environmental Protection data, the highest median nitrate nitrogen concentrations were much lower and did not exceed 0.2 milligrams per liter in either the Upper Floridan aquifer or the surficial aquifer system. In Georgia Geologic Survey data the highest median nitrate nitrogen concentration was 1.4 milligrams per liter in agricultural areas in the Coastal Flatwoods. Highest median concentrations of total nitrogen of 10 milligrams per liter (includes nitrate, ammonia, and organic nitrogen) were in U.S. Geological Survey data in the surficial aquifer system in agricultural areas in the Central Florida Ridge. Median concentrations of ammonia nitrogen, orthophosphate phosphorus, and total phosphorus did not exceed 0.5 milligrams per liter in all categories from the Upper Floridan aquifer or the surficial aquifer system.

Biomass production of multipopulation microalgae in open air pond for biofuel potential.

PubMed

Selvakumar, P; Umadevi, K

2016-04-01

Biodiesel gains attention as it is made from renewable resources and has considerable environmental benefits. The present investigation has focused on large scale cultivation of multipopulation microalgae in open air pond using natural sea water without any additional nutritive supplements for low cost biomass production as a possible source of biofuel in large scale. Open air algal pond attained average chlorophyll concentration of 11.01 µg/L with the maximum of 43.65 µg/L as well as a higher lipid concentration of 18% (w/w) with lipid content 9.3 mg/L on the 10th day of the culture; and maximum biomass of 0.36 g/L on the 7th day of the culture. Composition analysis of fatty acid methyl ester (FAME) was performed by gas chromatography and mass spectrometry (GCMS). Multipopulation of algal biomass had 18% of total lipid content with 55% of total saturated fatty acids (SFA), 35.3% of monounsaturated fatty acids (MUFA) and 9.7% of polyunsaturated fatty acids (PUFA), revealing a potential source of biofuel production at low cost.

Groundwater level and nitrate concentration trends on Mountain Home Air Force Base, southwestern Idaho

USGS Publications Warehouse

Williams, Marshall L.

2014-01-01

Mountain Home Air Force Base in southwestern Idaho draws most of its drinking water from the regional aquifer. The base is located within the State of Idaho's Mountain Home Groundwater Management Area and is adjacent to the State's Cinder Cone Butte Critical Groundwater Area. Both areas were established by the Idaho Department of Water Resources in the early 1980s because of declining water levels in the regional aquifer. The base also is listed by the Idaho Department of Environmental Quality as a nitrate priority area. The U.S. Geological Survey, in cooperation with the U.S. Air Force, began monitoring wells on the base in 1985, and currently monitors 25 wells for water levels and 17 wells for water quality, primarily nutrients. This report provides a summary of water-level and nitrate concentration data collected primarily between 2001 and 2013 and examines trends in those data. A Regional Kendall Test was run to combine results from all wells to determine an overall regional trend in water level. Groundwater levels declined at an average rate of about 1.08 feet per year. Nitrate concentration trends show that 3 wells (18 percent) are increasing in nitrate concentration trend, 3 wells (18 percent) show a decreasing nitrate concentration trend, and 11 wells (64 percent) show no nitrate concentration trend. Six wells (35 percent) currently exceed the U.S. Environmental Protection Agency's maximum contaminant limit of 10 milligrams per liter for nitrate (nitrite plus nitrate, measured as nitrogen).

The criteria for establishing an acceptable range of chemical, physical and biological indicators for the purpose of ecological standards developing

NASA Astrophysics Data System (ADS)

Evdokimova, Maria; Glazunov, Gennady; Yakovlev, Aleksandr

2017-04-01

The basis for development of standards for soil quality is based on the assessment of their resistance to external influences. The main criterion for assessing the environmental sustainability of soils and lands is the ability to perform their ecological functions (Nkonya et al, 2011, 2013; Costanza et al, 2014, Dobrovolsky and Nikitin, 1990; Yakovlev, Evdokimova, 2011). The limiting value of indicators of the state of the environment (physical, chemical, biological and other) corresponds to the value at which stability of environmental components is preserved (the ability to heal itself). Tht threshold for effect of stressor should be identified by the methods of bioindication and biotesting. The analysis obtained by these methods aimed to identify the highest indicator values of physical or chemical (concentration or dose of the stressor) effects, which have not yet fairly established negative changes in the organism, population of organisms or community. Using a theoretical model (Yakovlev et al, 2009, Gendugov., 2013) the problem of finding the threshold concentration is reduced to the finding of the singular points characterizing macroscopic "kinetics" of response in the phase space of dependence of the response rate upon the impact indicator. Singular points are determined by the analysis of derivatives. The theoretical model allows to calculate the singular points of the model (six of them), one of which, the maximum point corresponds to the highest concentration of the stressor at which it had no adverse effects on the test organisms. This point corresponds to the lowest concentration of the stressor at which it has no longer a stimulatory (hormesis) effect. Six singular points divide the whole range of stressors values (concentration) on seven bands with a unique range for each set of values of "macrokinetic" indicators of the living cells response to the impact of the stressor (concentration). Thus, the use of theoretical equations allowed us 1) to establish categories (borders) of soil quality on an the empirical scale of environmental quality and 2) to detail the category of quality in the range of hormesis, that is, in the range of weak positive effects of the stressor. The solution of the equation in the phase space of dependence of response upon exposure is: q=C/z^b*exp(-K/z), where q - is a measurable response of living organisms on exposure to the stressor, the concentration of which is equal to z; C -the constant of integration that makes sense of coefficient, which is scaling the value of q; b - the coefficient of the growth rate responding on the increase of z; K - the coefficient of the decline rate of q responding with increasing z. The equation coefficients C, b, K are found by fitting the model to the experimental data got by the method of nonlinear regression using an available software package. The abscissa of the maximum point is of a particular interest, because it corresponds to: 1. the lowest concentration of the stressor, which does not manifest its stimulatory (hormesis) effect, and at the same time - 2. the largest concentration of the stressor, which has not shown its negative effect. That is, it meets the requirements for threshold concentrations of the stressor and can be used in the development of the environmental quality standards. Acknowledgments: This study was supported by the Russian Science Foundation, project no. 143800023.

Nationwide reconnaissance of contaminants of emerging ...

EPA Pesticide Factsheets

Mobile and persistent chemicals that are present in urban wastewater, such as pharmaceuticals, may survive on-site or municipal wastewater treatment and post-discharge environmental processes. These pharmaceuticals have the potential to reach surface and groundwaters, essential drinking-water sources. A joint, two-phase U.S. Geological Survey-U.S. Environmental Protection Agency study examined source and treated waters from 25 drinking-water treatment plants from across the United States. Treatment plants that had probable wastewater inputs to their source waters were selected to assess the prevalence of pharmaceuticals in such source waters, and to identify which pharmaceuticals persist through drinking-water treatment. All samples were analyzed for 24 pharmaceuticals in Phase I and for 118 in Phase II. In Phase I, 11 pharmaceuticals were detected in all source-water samples, with a maximum of nine pharmaceuticals detected in any one sample. The median number of pharmaceuticals for all 25 samples was five. Quantifiable pharmaceutical detections were fewer, with a maximum of five pharmaceuticals in any one sample and a median for all samples of two. In Phase II, 47 different pharmaceuticals were detected in all source-water samples, with a maximum of 41 pharmaceuticals detected in any one sample. The median number of pharmaceuticals for all 25 samples was eight. For 37 quantifiable pharmaceuticals in Phase II, median concentrations in source water were below 11

Assessment of ambient background concentrations of elements in soil using combined survey and open-source data.

PubMed

Mikkonen, Hannah G; Clarke, Bradley O; Dasika, Raghava; Wallis, Christian J; Reichman, Suzie M

2017-02-15

Understanding ambient background concentrations in soil, at a local scale, is an essential part of environmental risk assessment. Where high resolution geochemical soil surveys have not been undertaken, soil data from alternative sources, such as environmental site assessment reports, can be used to support an understanding of ambient background conditions. Concentrations of metals/metalloids (As, Mn, Ni, Pb and Zn) were extracted from open-source environmental site assessment reports, for soils derived from the Newer Volcanics basalt, of Melbourne, Victoria, Australia. A manual screening method was applied to remove samples that were indicated to be contaminated by point sources and hence not representative of ambient background conditions. The manual screening approach was validated by comparison to data from a targeted background soil survey. Statistical methods for exclusion of contaminated samples from background soil datasets were compared to the manual screening method. The statistical methods tested included the Median plus Two Median Absolute Deviations, the upper whisker of a normal and log transformed Tukey boxplot, the point of inflection on a cumulative frequency plot and the 95th percentile. We have demonstrated that where anomalous sample results cannot be screened using site information, the Median plus Two Median Absolute Deviations is a conservative method for derivation of ambient background upper concentration limits (i.e. expected maximums). The upper whisker of a boxplot and the point of inflection on a cumulative frequency plot, were also considered adequate methods for deriving ambient background upper concentration limits, where the percentage of contaminated samples is <25%. Median ambient background concentrations of metals/metalloids in the Newer Volcanic soils of Melbourne were comparable to ambient background concentrations in Europe and the United States, except for Ni, which was naturally enriched in the basalt-derived soils of Melbourne. Copyright © 2016 Elsevier B.V. All rights reserved.

Mercury Loads in the South River and Simulation of Mercury Total Maximum Daily Loads (TMDLs) for the South River, South Fork Shenandoah River, and Shenandoah River: Shenandoah Valley, Virginia

USGS Publications Warehouse

Eggleston, Jack

2009-01-01

Due to elevated levels of methylmercury in fish, three streams in the Shenandoah Valley of Virginia have been placed on the State's 303d list of contaminated waters. These streams, the South River, the South Fork Shenandoah River, and parts of the Shenandoah River, are downstream from the city of Waynesboro, where mercury waste was discharged from 1929-1950 at an industrial site. To evaluate mercury contamination in fish, this total maximum daily load (TMDL) study was performed in a cooperative effort between the U.S. Geological Survey, the Virginia Department of Environmental Quality, and the U.S. Environmental Protection Agency. The investigation focused on the South River watershed, a headwater of the South Fork Shenandoah River, and extrapolated findings to the other affected downstream rivers. A numerical model of the watershed, based on Hydrological Simulation Program-FORTRAN (HSPF) software, was developed to simulate flows of water, sediment, and total mercury. Results from the investigation and numerical model indicate that contaminated flood-plain soils along the riverbank are the largest source of mercury to the river. Mercury associated with sediment accounts for 96 percent of the annual downstream mercury load (181 of 189 kilograms per year) at the mouth of the South River. Atmospherically deposited mercury contributes a smaller load (less than 1 percent) as do point sources, including current discharge from the historic industrial source area. In order to determine how reductions of mercury loading to the stream could reduce methylmercury concentrations in fish tissue below the U.S. Environmental Protection Agency criterion of 0.3 milligrams per kilogram, multiple scenarios were simulated. Bioaccumulation of mercury was expressed with a site-specific exponential relation between aqueous total mercury and methylmercury in smallmouth bass, the indicator fish species. Simulations indicate that if mercury loading were to decrease by 98.9 percent from 189 to 2 kilograms per year, fish tissue methylmercury concentrations would drop below 0.3 milligrams per kilogram. Based on the simulations, the estimated maximum load of total mercury that can enter the South River without causing fish tissue methylmercury concentrations to rise above 0.3 milligrams per kilogram is 2.03 kilograms per year for the South River, and 4.12 and 6.06 kilograms per year for the South Fork Shenandoah River and Shenandoah River, respectively.

Chlorine toxicity to early life stages of freshwater mussels (Bivalvia: Unionidae)

USGS Publications Warehouse

Valenti, T.W.; Cherry, D.S.; Currie, R.J.; Neves, R.J.; Jones, J.W.; Mair, R.; Kane, C.M.

2006-01-01

Chlorine (Cl) is a highly toxic, widely used halogen disinfectant that is present in point-source pollution discharges from wastewater treatment plants and industrial facilities. The U.S. Environmental Protection Agency freshwater criteria for Cl are 19 ??g total residual Cl (TRC)/L as a maximum 1-h average concentration and 11 ??g TRC/L as a maximum 4-d average; however, toxicological data for unionids were not used in these calculations. To address this void in the data, we conducted acute tests with glochidia from several species and 21-d bioassays with three-month-old Epioblasma capsaeformis and three-, six-, and 12-month-old Villosa iris juveniles. The 24-h lethal concentration 50 values for glochidia were between 70 and 220 ??g TRC/L, which are 2.5 to 37 times higher than those reported in other studies for cladocerans. Significant declines in growth and survivorship were observed in the 21-d test with E. capsaeformis at 20 ??g TRC/L. Lowest-observed-adverse- effects concentrations in bioassays with juvenile V. iris were higher (30-60 ??g TRC/L) but showed a significant trend of declining toxicity with increased age. Although endpoints were above water quality criteria, the long life spans of unionids and potential implications of chronic exposure to endangered juvenile mussels still warrant concern. ?? 2006 SETAC.

Surface-water-quality assessment of the upper Illinois River Basin in Illinois, Indiana, and Wisconsin; pesticides and other synthetic organic compounds in water, sediment, and biota, 1975-90

USGS Publications Warehouse

Sullivan, Daniel J.; Stinson, Troy W.; Crawford, J. Kent; Schmidt, Arthur R.; Colman, John A.

1998-01-01

The distribution of pesticides and other synthetic organic compounds in water, sediment, and biota in the upper Illinois River Basin in Illinois, Indiana, and Wisconsin was examined from 1987 through 1990 as part of the pilot National Water-Quality Assesssment Program conducted by the U.S. Geological Survey. Historical data for water and sediment collected from 1975 through 1986 were similar to data collected from 1987 through 1990. Some compounds were detected in concentrations that exceed U.S. Environmental Protection Agency water-quality criteria. Results from pesticide sampling at four stations in 1988 and 1989 identified several agricultural pesticides that were detected more frequently and at higher concentrations in urban areas than in agricultural areas. Results from herbicide sampling at 17 stations in the Kankakee and Iroquois River Basins in 1990 indicated that atrazine concentrations exceeded the U.S. Environmental Protection Agency's maximum contaminant level for drinking water during runoff periods. Results from sampling for volatile and semivolatile organic compounds in water indicate that, with one exception, all stations at which more than one compound was detected were within 2 miles downstream from the nearest point source. Detections at two stations in the Chicago urban area accounted for 37 percent of the total number of detections. Concentrations of tetrachloroethylene, trichloroethylene, and 1,2-dichlorethane from stations in the Des Plaines River Basin exceeded the U.S. Environmental Protection Agency's maximum contaminant level for drinking water in one and two samples from the two stations in the Chicago area. Phenols and pentachlorophenols were detected most frequently in the Des Plaines River Basin where point-source discharges were common. Phenol concentrations were significantly different among the Des Plaines, Kankakee, and Fox River Basins. Phenols and pentachlorophenols never exceeded the general use and secondary contact standards. Results from a 1989 synoptic survey of semivolatile organic compounds in sediment indicate that these compounds were detected most frequently at sites in the Chicago urban area. Of the 17 stations at which 10 or more compounds were detected, 14 were located in the Des Plaines River subbasin, and 1 was on the Illinois River mainstem. As was the case with organic compounds in water, each of these sites was located within 2 miles downstream from point sources. Biota samples were collected and analyzed for organochlorines and polynuclear aromatic hydrocarbons in 1989 and 1990. The most commonly detected compound in both years was p,p'-DDE. National Academy of Science recommendations for chlordane and dieldrin for protection of predators were exceeded in 19 and 10 samples, respectively, when the 1989 and 1990 data were combined. In the nine fish-fillet samples collected in 1989, concentrations exceeded U.S. Environmental Protection Agency fish-tissue criteria in nine fillets for p,p'-DDE and five fillets for dieldrin.

Evaluation of low-cost electro-chemical sensors for environmental monitoring of ozone, nitrogen dioxide, and carbon monoxide.

PubMed

Afshar-Mohajer, Nima; Zuidema, Christopher; Sousan, Sinan; Hallett, Laura; Tatum, Marcus; Rule, Ana M; Thomas, Geb; Peters, Thomas M; Koehler, Kirsten

2018-02-01

Development of an air quality monitoring network with high spatio-temporal resolution requires installation of a large number of air pollutant monitors. However, state-of-the-art monitors are costly and may not be compatible with wireless data logging systems. In this study, low-cost electro-chemical sensors manufactured by Alphasense Ltd. for detection of CO and oxidative gases (predominantly O 3 and NO 2 ) were evaluated. The voltages from three oxidative gas sensors and three CO sensors were recorded every 2.5 sec when exposed to controlled gas concentrations in a 0.125-m 3 acrylic glass chamber. Electro-chemical sensors for detection of oxidative gases demonstrated sensitivity to both NO 2 and O 3 with similar voltages recorded when exposed to equivalent environmental concentrations of NO 2 or O 3 gases, when evaluated separately. There was a strong linear relationship between the recorded voltages and target concentrations of oxidative gases (R 2 > 0.98) over a wide range of concentrations. Although a strong linear relationship was also observed for CO concentrations below 12 ppm, a saturation effect was observed wherein the voltage only changes minimally for higher CO concentrations (12-50 ppm). The nonlinear behavior of the CO sensors implied their unsuitability for environments where high CO concentrations are expected. Using a manufacturer-supplied shroud, sensors were tested at 2 different flow rates (0.25 and 0.5 Lpm) to mimic field calibration of the sensors with zero air and a span gas concentration (2 ppm NO2 or 15 ppm CO). As with all electrochemical sensors, the tested devices were subject to drift with a bias up to 20% after 9 months of continuous operation. Alphasense CO sensors were found to be a proper choice for occupational and environmental CO monitoring with maximum concentration of 12 ppm, especially due to the field-ready calibration capability. Alphasense oxidative gas sensors are usable only if it is valuable to know the sum of the NO 2 and O 3 concentrations.

A computer program for estimating instream travel times and concentrations of a potential contaminant in the Yellowstone River, Montana

USGS Publications Warehouse

McCarthy, Peter M.

2006-01-01

The Yellowstone River is very important in a variety of ways to the residents of southeastern Montana; however, it is especially vulnerable to spilled contaminants. In 2004, the U.S. Geological Survey, in cooperation with Montana Department of Environmental Quality, initiated a study to develop a computer program to rapidly estimate instream travel times and concentrations of a potential contaminant in the Yellowstone River using regression equations developed in 1999 by the U.S. Geological Survey. The purpose of this report is to describe these equations and their limitations, describe the development of a computer program to apply the equations to the Yellowstone River, and provide detailed instructions on how to use the program. This program is available online at [http://pubs.water.usgs.gov/sir2006-5057/includes/ytot.xls]. The regression equations provide estimates of instream travel times and concentrations in rivers where little or no contaminant-transport data are available. Equations were developed and presented for the most probable flow velocity and the maximum probable flow velocity. These velocity estimates can then be used to calculate instream travel times and concentrations of a potential contaminant. The computer program was developed so estimation equations for instream travel times and concentrations can be solved quickly for sites along the Yellowstone River between Corwin Springs and Sidney, Montana. The basic types of data needed to run the program are spill data, streamflow data, and data for locations of interest along the Yellowstone River. Data output from the program includes spill location, river mileage at specified locations, instantaneous discharge, mean-annual discharge, drainage area, and channel slope. Travel times and concentrations are provided for estimates of the most probable velocity of the peak concentration and the maximum probable velocity of the peak concentration. Verification of estimates of instream travel times and concentrations for the Yellowstone River requires information about the flow velocity throughout the 520 mi of river in the study area. Dye-tracer studies would provide the best data about flow velocities and would provide the best verification of instream travel times and concentrations estimated from this computer program; however, data from such studies does not currently (2006) exist and new studies would be expensive and time-consuming. An alternative approach used in this study for verification of instream travel times is based on the use of flood-wave velocities determined from recorded streamflow hydrographs at selected mainstem streamflow-gaging stations along the Yellowstone River. The ratios of flood-wave velocity to the most probable velocity for the base flow estimated from the computer program are within the accepted range of 2.5 to 4.0 and indicate that flow velocities estimated from the computer program are reasonable for the Yellowstone River. The ratios of flood-wave velocity to the maximum probable velocity are within a range of 1.9 to 2.8 and indicate that the maximum probable flow velocities estimated from the computer program, which corresponds to the shortest travel times and maximum probable concentrations, are conservative and reasonable for the Yellowstone River.

Analysis of Level of Technogenic Impact on Water Area of Uglovoy Bay

NASA Astrophysics Data System (ADS)

Petukhov, V. I.; Petrova, E. A.; Losev, O. V.

2017-11-01

Industrial effluent discharge and man-induced soil fills play a decisive role in increased pollutant concentrations. Several areas which are unfavorable in terms of the heavy metal and oil product content have been identified by the environmental monitoring results in the Uglovoy Bay in February 2015. Maximum permissible concentrations (MPC) of heavy metals and oil products were exceeded in the northeastern part of the Uglovoy Bay in locations where the Peschanka River and the Aerodromnaya River drain into the sea. Integral heavy-metal index calculations showed that this area is the most polluted in the Uglovoy Bay. Other significantly polluted areas were identified off the Zima Yuzhnaya settlement in the mouth of the bay and in vicinity of the low-level bridge.

Context-dependent environmental quality standards of soil nitrate for terrestrial plant communities.

PubMed

van Goethem, Thomas M W J; Schipper, Aafke M; Wamelink, G W Wieger; Huijbregts, Mark A J

2016-10-01

Environmental quality standards (EQS) specify the maximum permissible concentration or level of a specific environmental stressor. Here, a procedure is proposed to derive EQS that are specific to a representative species pool and conditional on confounding environmental factors. To illustrate the procedure, a dataset was used with plant species richness observations of grasslands and forests and accompanying soil nitrate-N and pH measurements collected from 981 sampling sites in the Netherlands. Species richness was related to soil nitrate-N and pH with quantile regression allowing for interaction effects. The resulting regression models were used to derive EQS for nitrate conditional on pH, quantified as the nitrate-N concentrations at a specific pH level corresponding with a species richness equal to 95% of the species pool, for both grasslands and forest communities. The EQS varied between 1.8 mg/kg nitrate-N at pH 9-65 mg/kg nitrate-N at pH 4. EQS for forests and grasslands were similar, but EQS based on Red List species richness were considerably lower (more stringent) than those based on overall species richness, particularly at high pH levels. The results indicate that both natural background pH conditions and Red List species are important factors to consider in the derivation of EQS for soil nitrate-N for terrestrial ecosystems. Copyright © 2016 Elsevier Ltd. All rights reserved.

Temporal variability in detritus resource maintains diversity of bacterial communities

NASA Astrophysics Data System (ADS)

Hiltunen, Teppo; Laakso, Jouni; Kaitala, Veijo; Suomalainen, Lotta-Riina; Pekkonen, Minna

2008-05-01

Competition theory generally predicts that diversity is maintained by temporal environmental fluctuations. One of the many suggested mechanisms for maintaining diversity in fluctuating environments is the gleaner-opportunist trade-off, whereby gleaner species have low threshold resource levels and low maximum growth rates in high resource concentration while opportunist species show opposite characteristics. We measured the growth rates of eight heterotrophic aquatic bacteria under different concentrations of chemically complex plant detritus resource. The growth rates revealed gleaner-opportunist trade-offs. The role of environmental variability in maintaining diversity was tested in a 28-day experiment with three different resource fluctuation regimes imposed on two four-species bacterial communities in microcosms. We recorded population densities with serial dilution plating and total biomass as turbidity. Changes in resource availability were measured from filter-sterilised medium by re-introducing the consumer species and recording short-term growth rates. The type of environmental variation had no effect on resource availability, which declined slowly during the experiment and differed in level between the communities. However, the slowly fluctuating environment had the highest Shannon diversity index, biomass, and coefficient of variation of biomass in both communities. We did not find a clear link between the gleaner-opportunist trade-off and diversity in fluctuating environments. Nevertheless, our results do not exclude this explanation and support the general view that temporal environmental variation maintains species diversity also in communities feeding chemically complex resource.

Bilastine: an environmental risk assessment.

PubMed

Lucero, María Luisa; Peither, Armin; Ledo, Francisco

2015-10-01

Bilastine is a new oral selective, non-sedating histamine H1 antagonist for the symptomatic treatment of allergic rhinoconjunctivitis and urticaria. The European Medicines Agency requires an Environmental Risk Assessment (ERA) for all novel medicines for human use. To calculate the bilastine predicted environmental concentration in surface water (PECsw; phase I ERA), and to determine the effects of bilastine on aquatic systems (phase II [tier A]). Bilastine PECsw was calculated using the maximum daily dosage (20 mg), assuming that all administered bilastine was released into the aquatic environment. A persistence, bioaccumulation and toxicity assessment was conducted using the log Kow from the molecular structure. In phase II (tier A), a ready biodegradability test was performed, and bilastine's potential toxicity to various aquatic and sediment-dwelling micro-organisms was evaluated. Bilastine PECSW was calculated as 0.1 μg L(-1), and the compound was not readily biodegradable. Bilastine had no significant effects on Chironomus riparius midges, or on the respiration rate of activated sludge. For green algae, the bilastine no observed effect concentration (NOEC) was 22 mg L(-1); bilastine had no effect on zebra fish development, or on the reproduction rate of daphnids. Bilastine NOEC values against zebra fish, algae, daphnids, and aerobic organisms in activated sludge were at least 130 000-fold greater than the calculated PECSW value. No environmental concerns exist from bilastine use in patients with allergic rhinoconjunctivitis or urticaria.

Highly Effective Polyphosphate Synthesis, Phosphate Removal, and Concentration Using Engineered Environmental Bacteria Based on a Simple Solo Medium-Copy Plasmid Strategy.

PubMed

Wang, Xin; Wang, Xiaomeng; Hui, Kaimin; Wei, Wei; Zhang, Wen; Miao, Aijun; Xiao, Lin; Yang, Liuyan

2018-01-02

Microbial polyphosphate (polyP) production is vital to the removal of phosphate from wastewater. However, to date, engineered polyP synthesis using genetically accessible environmental bacteria remains a challenge. This study develops a simple solo medium-copy plasmid-based polyphosphate kinase (PPK1) overexpression strategy for achieving maximum intracellular polyphosphate accumulation by environmental bacteria. The polyP content of the subsequently engineered Citrobacter freundii (CPP) could reach as high as 12.7% of its dry weight. The biomass yield of CPP was also guaranteed because of negligible metabolic burden effects resulting from the medium plasmid copy number. Consequently, substantial removal of phosphate (P i ) from the ambient environment was achieved simultaneously. Because of the need for exogenous P i for in vivo ATP regeneration, CPP could thoroughly remove P i from synthetic municipal wastewater when it was applied for the "one-step" removal of P i with a bench-scale sequence batch membrane reactor. Almost all the phosphorus except for that assimilated by CPP for cellular growth could be recovered in the form of more concentrated P i . Overall, engineering environmental bacteria to overexpress PPK1 via a solo medium-copy plasmid strategy may represent a valuable general option for not only biotechnological research based on sufficient intracellular polyP production but also removal of P i from wastewater and P i enrichment.

Midlatitude and high-latitude N2O distributions in the Northern Hemisphere in early and late Arctic polar vortex breakup years

NASA Astrophysics Data System (ADS)

Akiyoshi, H.; Zhou, L. B.

2007-09-01

Simulated N2O distributions at midlatitudes and high latitudes in the Northern Hemisphere are analyzed in early and late vortex breakup years with the probability distribution function (PDF) technique. The data are from a Center for Climate System Research/National Institute for Environmental Studies (CCSR/NIES) nudging chemical transport model (CTM) for 24 years from 1979 to 2002. Results show that there is a large difference in midlatitude and high-latitude N2O concentrations on the 600 K isentrope between early and late vortex breakup years. In the early breakup years, the N2O concentration with the maximum area shows low values in the lower stratosphere in the springtime after the vortex breakup. In the late breakup years, the maximum area concentration shows constant high values from the winter to the summer. Our analyses show that the winter and springtime meridional circulation is a main factor for these differences in N2O concentration. In the early breakup years, a larger eddy heat flux causes a stronger winter meridional circulation and a stronger downward advection of low-N2O concentration air at higher altitudes to the lower stratosphere, which leads to the low values of N2O concentration in the lower stratosphere in late winter and early spring. Inside the Arctic vortex, however, the importance of vertical advection is smaller than or comparable to other processes such as horizontal divergence and subgrid-scale motions. These results are consistent with the previous studies on tracer distribution, which showed that not only the vertical advection but also the horizontal eddy transport are important for tracer concentration tendency in the polar vortex.

A geochemical examination of humidity cell tests

USGS Publications Warehouse

Maest, Ann; Nordstrom, D. Kirk

2017-01-01

Humidity cell tests (HCTs) are long-term (20 to >300 weeks) leach tests that are considered by some to be the among the most reliable geochemical characterization methods for estimating the leachate quality of mined materials. A number of modifications have been added to the original HCT method, but the interpretation of test results varies widely. We suggest that the HCTs represent an underutilized source of geochemical data, with a year-long test generating approximately 2500 individual chemical data points. The HCT concentration peaks and valleys can be thought of as a “chromatogram” of reactions that may occur in the field, whereby peaks in concentrations are associated with different geochemical processes, including sulfate salt dissolution, sulfide oxidation, and dissolution of rock-forming minerals, some of which can neutralize acid. Some of these reactions occur simultaneously, some do not, and geochemical modeling can be used to help distinguish the dominant processes. Our detailed examination, including speciation and inverse modeling, of HCTs from three projects with different geology and mineralization shows that rapid sulfide oxidation dominates over a limited period of time that starts between 40 and 200 weeks of testing. The applicability of laboratory tests results to predicting field leachate concentrations, loads, or rates of reaction has not been adequately demonstrated, although early flush releases and rapid sulfide oxidation rates in HCTs should have some relevance to field conditions. Knowledge of possible maximum solute concentrations is needed to design effective treatment and mitigation approaches. Early flush and maximum sulfide oxidation results from HCTs should be retained and used in environmental models. Factors that complicate the use of HCTs include: sample representation, time for microbial oxidizers to grow, sample storage before testing, geochemical reactions that add or remove constituents, and the HCT results chosen for use in modeling the environmental performance at mine sites. Improved guidance is needed for more consistent interpretation and use of HCT results that rely on identifying: the geochemical processes; the mineralogy, including secondary mineralogy; the available surface area for reactions; and the influence of hydrologic processes on leachate concentrations in runoff, streams, and groundwater.

Application of health-based screening levels to ground-water quality data in a state-scale pilot effort

USGS Publications Warehouse

Toccalino, Patricia L.; Norman, Julia E.; Phillips, Robyn H.; Kauffman, Leon J.; Stackelberg, Paul E.; Nowell, Lisa H.; Krietzman, Sandra J.; Post, Gloria B.

2004-01-01

A state-scale pilot effort was conducted to evaluate a Health-Based Screening Level (HBSL) approach developed for communicating findings from the U.S. Geological Survey (USGS) National Water-Quality Assessment Program in a human-health context. Many aquifers sampled by USGS are used as drinking-water sources, and water-quality conditions historically have been assessed by comparing measured contaminant concentrations to established drinking-water standards and guidelines. Because drinking-water standards and guidelines do not exist for many analyzed contaminants, HBSL values were developed collaboratively by the USGS, U.S. Environmental Protection Agency (USEPA), New Jersey Department of Environmental Protection, and Oregon Health & Science University, using USEPA toxicity values and USEPA Office of Water methodologies. The main objective of this report is to demonstrate the use of HBSL approach as a tool for communicating water-quality data in a human-health context by conducting a retrospective analysis of ground-water quality data from New Jersey. Another important objective is to provide guidance on the use and interpretation of HBSL values and other human-health benchmarks in the analyses of water-quality data in a human-health context. Ground-water samples collected during 1996-98 from 30 public-supply, 82 domestic, and 108 monitoring wells were analyzed for 97 pesticides and 85 volatile organic compounds (VOCs). The occurrence of individual pesticides and VOCs was evaluated in a human-health context by calculating Benchmark Quotients (BQs), defined as ratios of measured concentrations of regulated compounds (that is, compounds with Federal or state drinking-water standards) to Maximum Contaminant Level (MCL) values and ratios of measured concentrations of unregulated compounds to HBSL values. Contaminants were identified as being of potential human-health concern if maximum detected concentrations were within a factor of 10 of the associated MCL or HBSL (that is, maximum BQ value (BQmax) greater than or equal to 0.1) in any well type (public supply, domestic, monitoring). Most (57 of 77) pesticides and VOCs with human-health benchmarks were detected at concentrations well below these levels (BQmax less than 0.1) for all three well types; however, BQmax values ranged from 0.1 to 3,000 for 6 pesticides and 14 VOCs. Of these 20 contaminants, one pesticide (dieldrin) and three VOCs (1,2-dibromoethane, tetrachloroethylene, and trichloroethylene) both (1) were measured at concentrations that met or exceeded MCL or HBSL values, and (2) were detected in more than 10 percent of samples collected from raw ground water used as sources of drinking water (public-supply and (or) domestic wells) and, therefore, are particularly relevant to human health. The occurrence of multiple pesticides and VOCs in individual wells also was evaluated in a human-health context because at least 53 different contaminants were detected in each of the three well types. To assess the relative human-health importance of the occurrence of multiple contaminants in different wells, the BQ values for all contaminants in a given well were summed. The median ratio of the maximum BQ to the sum of all BQ values for each well ranged from 0.83 to 0.93 for all well types, indicating that the maximum BQ makes up the majority of the sum for most wells. Maximum and summed BQ values were statistically greater for individual public-supply wells than for individual domestic and monitoring wells. The HBSL approach is an effective tool for placing water-quality data in a human-health context. For 79 of the 182 compounds analyzed in this study, no USEPA drinking-water standards or guidelines exist, but new HBSL values were calculated for 39 of these 79 compounds. The new HBSL values increased the number of detected pesticides and VOCs with human-health benchmarks from 65 to 77 (of 97 detected compounds), thereby expanding the basis for interpreting contaminant-occu

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dam, William; Gil, Dr. April; Johnson, Raymond H.

The US Department of Energy Office of Legacy Management (LM) is responsible for maintaining protective public health and environmental conditions at former uranium mill tailings sites nationwide via long-term stewardship. One of these sites, a former uranium mill near Riverton, Wyoming, is within the boundary of the Wind River Indian Reservation and operated from 1958 to 1963. Tailings and contaminated material associated with mill operations were removed and transported to an offsite disposal cell in 1989. The remedial action was completed under Title I of the Uranium Mill Tailings Radiation Control Act of 1978. Milling operations, which included an unlinedmore » tailings impoundment and an unlined evaporation pond, contaminated the shallow groundwater, resulting in a downgradient groundwater plume that discharges to the Little Wind River. A natural flushing compliance strategy was implemented in 1998. This strategy allows contaminants of concern to naturally flush from the groundwater, provided that contaminants flush below US Environmental Protection Agency maximum concentration limits within 100 years. As part of the compliance strategy, LM has implemented a groundwater monitoring program along with institutional controls that include the installation of an alternate water supply, continued sampling of private wells, and restrictions on well drilling and gravel pit construction. LM works closely with local stakeholders and community members to ensure that these institutional controls are in place and maintained. The Riverton site provides an interesting case study where contaminant remobilization due to river flooding prompted a reevaluation of the conceptual site model to verify if the current compliance strategy would remain protective of human health and the environment. Concentrations of groundwater contaminants, which include sulfate, molybdenum, and uranium, were transiently elevated following flooding of the Little Wind River in 2010 and 2016. These flood events provided the impetus to investigate other aspects of the hydrologic system, including the unsaturated zone, naturally reduced (sulfidic) zones, and evaporite deposits. New site conceptual models, field and laboratory studies, and numerical models are being developed to explain how biogeochemical sediment–water interactions contribute to plume persistence and flood-related increases in groundwater concentrations. Updated human health and ecological risk assessments are progressing to evaluate the risk to human health and the environment based on current site conditions. Groundwater concentrations may remain above US Environmental Protection Agency maximum concentration limits beyond the 100-year natural flushing regulatory time frame. LM in its capacity as a long-term steward continues to monitor the site to ensure protectiveness is maintained and to determine the feasibility of alternative compliance and remediation strategies.« less

Weldon Spring Site environmental report for calendar year 1993. Weldon Springs Site Remedial Action Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1994-05-01

This Site Environmental Report for Calendar Year 1993 describes the environmental monitoring programs at the Weldon Spring Site Remedial Action Project (WSSRAP). The objectives of these programs are to assess actual or potential exposure to contaminant effluents from the project area by providing public use scenarios and dose estimates, to demonstrate compliance with Federal and State permitted levels, and to summarize trends and/or changes in contaminant concentrations from environmental monitoring program. In 1993, the maximum committed dose to a hypothetical individual at the chemical plant site perimeter was 0.03 mrem (0.0003 mSv). The maximum committed dose to a hypothetical individualmore » at the boundary of the Weldon Spring Quarry was 1.9 mrem (0.019 mSv). These scenarios assume an individual walking along the perimeter of the site-once a day at the chemical plant/raffinate pits and twice a day at the quarry-250 days per year. This hypothetical individual also consumes fish, sediment, and water from lakes and other bodies of water in the area. The collective dose, based on an effected population of 112,000 was 0.12 person-rem (0.0012 person-Sv). This calculation is based on recreational use of the August A. Busch Memorial Conservation Area and the Missouri Department of Conservation recreational trail (the Katy Trail) near the quarry. These estimates are below the U.S. Department of Energy requirement of 100 mrem (I mSv) annual committed effective dose equivalent for all exposure pathways. Results from air monitoring for the National Emission Standards for Hazardous Air Pollutants (NESHAPs) program indicated that the estimated dose was 0.38 mrem, which is below the U.S. Environmental Protection Agency (EPA) standard of 10 mrem per year.« less

Methods for the preparation and analysis of solids and suspended solids for methylmercury

USGS Publications Warehouse

DeWild, John F.; Olund, Shane D.; Olson, Mark L.; Tate, Michael T.

2004-01-01

This report presents the methods and method performance data for the determination of methylmercury concentrations in solids and suspended solids. Using the methods outlined here, the U.S. Geological Survey's Wisconsin District Mercury Laboratory can consistently detect methylmercury in solids and suspended solids at environmentally relevant concentrations. Solids can be analyzed wet or freeze dried with a minimum detection limit of 0.08 ng/g (as-processed). Suspended solids must first be isolated from aqueous matrices by filtration. The minimum detection limit for suspended solids is 0.01 ng per filter resulting in a minimum reporting limit ranging from 0.2 ng/L for a 0.05 L filtered volume to 0.01 ng/L for a 1.0 L filtered volume. Maximum concentrations for both matrices can be extended to cover nearly any amount of methylmercury by limiting sample size.

Effect and interaction study of acetamiprid photodegradation using experimental design.

PubMed

Tassalit, Djilali; Chekir, Nadia; Benhabiles, Ouassila; Mouzaoui, Oussama; Mahidine, Sarah; Merzouk, Nachida Kasbadji; Bentahar, Fatiha; Khalil, Abbas

2016-10-01

The methodology of experimental research was carried out using the MODDE 6.0 software to study the acetamiprid photodegradation depending on the operating parameters, such as the initial concentration of acetamiprid, concentration and type of the used catalyst and the initial pH of the medium. The results showed the importance of the pollutant concentration effect on the acetamiprid degradation rate. On the other hand, the amount and type of the used catalyst have a considerable influence on the elimination kinetics of this pollutant. The degradation of acetamiprid as an environmental pesticide pollutant via UV irradiation in the presence of titanium dioxide was assessed and optimized using response surface methodology with a D-optimal design. The acetamiprid degradation ratio was found to be sensitive to the different studied factors. The maximum value of discoloration under the optimum operating conditions was determined to be 99% after 300 min of UV irradiation.

Wild brown trout affected by historical mining in the Cévennes National Park, France.

PubMed

Monna, F; Camizuli, E; Revelli, P; Biville, C; Thomas, C; Losno, R; Scheifler, R; Bruguier, O; Baron, S; Chateau, C; Ploquin, A; Alibert, P

2011-08-15

In the protected area of the Cévennes National Park (Southern France), 114 wild brown trout (Salmo trutta fario) were captured at six locations affected to different extents by historical mining and metallurgy dating from the Iron Age to Modern Times. Cadmium and lead in trout livers and muscles reflect high sediment contamination, although an age-related effect was also detected for hepatic metal concentrations. Lead isotope signatures confirm exposure to drainage from mining and metallurgical waste. Developmental instability, assessed by fluctuating asymmetry, is significantly correlated with cadmium and lead concentrations in trout tissues, suggesting that local contamination may have affected fish development. Nowadays, the area is among the least industrialized in France. However, our results show that 60% of the specimens at one site exceed EU maximum allowed cadmium or lead concentration in foodstuffs. The mining heritage should not be neglected when establishing strategies for long-term environmental management.

The Empirical Relationship between Mining Industry Development and Environmental Pollution in China.

PubMed

Li, Gerui; Lei, Yalin; Ge, Jianping; Wu, Sanmang

2017-03-02

This study uses a vector autoregression (VAR) model to analyze changes in pollutants among different mining industries and related policy in China from 2001 to 2014. The results show that: (1) because the pertinence of standards for mining waste water and waste gas emissions are not strong and because the maximum permissible discharge pollutant concentrations in these standards are too high, ammonia nitrogen and industrial sulfur dioxide discharges increased in most mining industries; (2) chemical oxygen demand was taken as an indicator of sewage treatment in environmental protection plans; hence, the chemical oxygen demand discharge decreased in all mining industries; (3) tax reduction policies, which are only implemented in coal mining and washing and extraction of petroleum and natural gas, decreased the industrial solid waste discharge in these two mining industries.

Ecophysiological responses of three evergreen woody Mediterranean species to water stress

NASA Astrophysics Data System (ADS)

Abril, Mireia; Hanano, Ralph

1998-08-01

The ecophysiological response to drought in three different evergreen Mediterranean species were compared. For a better interpretation of the mechanisms regulating physiological processes, the choice of species was based on evident differences in morphological and structural features (leaf size, leaf specific weight, water-conducting system). Seedlings of Ceanothus thyrsiflorus, Quercus agrifolia and Buxus microphylla grown in pots were subjected to natural stressing conditions during late spring in Southern California. Gas exchange, xylem water potential and abscisic acid concentration in xylem sap were measured in control (irrigated) and water-stressed plants, from predawn to sunset. Environmental, hydraulic and hormonal effects on water control and limitations to photosynthesis were analyzed. Q. agrifolia had the highest maximums of net photosynthesis, stomatal conductance and transpiration, which were significantly different from C. thyrsiflorus and B. microphylla. B. microphylla had the lowest values. Stressed individuals of C. thyrsiflorus and B. microphylla reached absolute minimum water potentials during the day and at predawn. Q. agrifolia plants had a water conservative behaviour and did not show these low values. Control plants from Q. agrifolia had the lowest values of hydraulic resistance with high maximum stomatal conductance, while B. microphylla control plants had the lowest maximum stomatal conductance due to higher hydraulic resistance. Changes in plant hydraulic resistance during soil drying were found, which differed among the species. In general, water-use efficiency was reduced during the day by water stress but increased as seasonal drought proceeded. On a long-term basis, Q. agrifolia was the most efficient species in water use. The results support the hypothesis that information on abscisic acid concentration in xylem sap may be one of the most important physiological keys when modelling stomatal conductance and canopy gas exchange over seasons as drought develops on Mediterranean vegetation. Nevertheless, we believe it is necessary to integrate all known factors that control stomatal behaviour in order to construct general models of the vegetation response to environmental changes.

Considering the summation of the effect of harmful substances during the calculation of the environmentally safe waste water discharge

NASA Astrophysics Data System (ADS)

Sokolov, A. K.

2017-09-01

This article presents the technique of assessing the maximum allowable (standard) discharge of waste waters with several harmful substances into a water reservoir. The technique makes it possible to take into account the summation of their effect provided that the limiting harmful indices are the same. The expressions for the determination of the discharge limit of waste waters have been derived from the conditions of admissibility of the effect of several harmful substances on the waters of a reservoir. Mathematical conditions of admissibility of the effect of wastewaters on a reservoir are given for the characteristic combinations of limiting harmful indices and hazard classes of several substances. The conditions of admissibility of effects are presented in the form of logical products of the sums of relative concentrations that should not exceed the value of 1. It is shown that the calculation of the process of wastewater dilution in a flowing water reservoir is possible only on the basis of a numerical method to assess the wastewater discharge limit. An example of the numerical calculation of the standard limit of industrial enterprise wastewater discharges that contain polysulfide oil, flocculant VPK-101, and fungicide captan is given to test this method. In addition to these three harmful substances, the water reservoir also contained a fourth substance, namely, Zellek-Super herbicide, above the waste discharge point. The summation of the harmful effect was taken into account for VPK-101, captan, and Zellek-Super. The reliability of the technique was tested by the calculation of concentrations of the four substances in the control point of the flowing reservoir during the estimated maximum allowable wastewater discharge. It is shown that the value of the maximum allowable discharge limit was almost two times higher for the example under consideration, taking into account that the effect of harmful substances was unidirectional, which provides a higher level of environmental safety for them.

Probabilistic Prognosis of Environmental Radioactivity Concentrations due to Radioisotopes Discharged to Water Bodies from Nuclear Power Plants.

PubMed

Tomás Zerquera, Juan; Mora, Juan C; Robles, Beatriz

2017-11-15

Due to their very low values, the complexity of comparing the contribution of nuclear power plants (NPPs) to environmental radioactivity with modeled values is recognized. In order to compare probabilistic prognosis of radioactivity concentrations with environmental measurement values, an exercise was performed using public data of radioactive routine discharges from three representative Spanish nuclear power plants. Specifically, data on liquid discharges from three Spanish NPPs: Almaraz, Vandellós II, and Ascó to three different aquatic bodies (river, lake, and coast) were used. Results modelled using generic conservative models together with Monte Carlo techniques used for uncertainties propagation were compared with values of radioactivity concentrations in the environment measured in the surroundings of these NPPs. Probability distribution functions were inferred for the source term, used as an input to the model to estimate the radioactivity concentrations in the environment due to discharges to the water bodies. Radioactivity concentrations measured in bottom sediments were used in the exercise due to their accumulation properties. Of all the radioisotopes measured in the environmental monitoring programs around the NPPs, only Cs-137, Sr-90, and Co-60 had positive values greater than their respective detection limits. Of those, Sr-90 and Cs-137 are easily measured in the environment, but significant contribution from the radioactive fall-out due to nuclear explosions in the atmosphere exists, and therefore their values cannot be attributed to the NPPs. On the contrary, Co-60 is especially useful as an indicator of the radioactive discharges from NPPs because its presence in the environment can solely be attributed to the impact of the closer nuclear facilities. All the modelled values for Co-60 showed a reasonable correspondence with measured environmental data in all cases, being conservative in two of them. The more conservative predictions obtained with the models were the activity concentrations in the sediments of a lake (Almaraz) where, on average, values two times higher were obtained. For the case of rivers (Ascó), calculated results were adequately conservative-up to 3.4 times on average. However, the results for coasts (Vandellos II) were in the same range as the environmental measurements, obtaining predictions that are only-at maximum-1.1 times higher than measured values. Only for this specific case of coasts could it be established that the models are not conservative enough, although the results, on average, are relatively close to the real values.

Examination of body burden and taint for Iceland scallop (Chlamys islandica) and American plaice (Hippoglossoides platessoides) near the Terra Nova offshore oil development over ten years of drilling on the Grand Banks of Newfoundland, Canada

NASA Astrophysics Data System (ADS)

DeBlois, Elisabeth M.; Kiceniuk, Joe W.; Paine, Michael D.; Kilgour, Bruce W.; Tracy, Ellen; Crowley, Roger D.; Williams, Urban P.; Gregory Janes, G.

2014-12-01

This paper presents results of analyses of body burdens of metals and hydrocarbons, and taste tests for taint, in Iceland scallop and American plaice performed as part of the Environmental Effects Monitoring (EEM) program for the Terra Nova offshore oil development (Grand Banks of Newfoundland, Canada). Scallop and plaice were collected in a Study Area located within approximately 1 km of drill centres at Terra Nova and in a Reference Area located approximately 20 km from the development. Samples were collected in 1997 to establish a baseline, and from 2000 to 2010, during drilling periods. Scallop adductor muscle tissue was contaminated with >C10-C21 aliphatic hydrocarbons resembling the drilling fluid in the synthetic drilling mud (SBM) used at Terra Nova in 2000, 2002 and 2004, but contamination of adductor muscle was not noted in 2006, 2008 and 2010. The maximum concentration in muscle was 28 mg/kg wet weight, noted in 2002. Scallop viscera was contaminated with hydrocarbons resembling drilling fluid in SBMs near drill centres in all EEM years except 2010. Viscera contamination with >C10-C21 hydrocarbons gradually decreased from a maximum of 150 mg/kg in 2000, to a maximum of 27 mg/kg in 2008; all values were below the laboratory reporting detection limit of 15 mg/kg in 2010. Therefore, evidence from both muscle and viscera indicates a decrease in tissue hydrocarbon contamination in recent years. Barium, another major constituent in drilling muds, has not been noted in scallop adductor muscles at concentrations above the reporting detection limit, but barium was detected in viscera in baseline and EEM years. The maximum concentration of barium in viscera during baseline sampling was 8 mg/kg. The maximum concentration in EEM years (29 mg/kg) was noted in 2000. The maximum concentration in 2010 was 25 mg/kg. The concentration of metals other than barium in scallop tissues was similar between the Terra Nova Study Area and the Reference Area. Hydrocarbons resembling the fluid in SBMs were noted in one American plaice liver sample collected near drill centres in 2000. Otherwise, there has been no evidence of project-related metals or hydrocarbon contamination in plaice liver or fillet samples. There has been no evidence of taint (off-taste) for scallop adductor muscle and plaice fillet tissue in baseline or EEM years. Combined with a parallel study on fish bioindicators at Terra Nova that showed that fish health at Terra Nova was similar to that at the Reference Area (Mathieu et al., 2011), these results indicate little to no detectable biological effects on Iceland scallop and American plaice as a result of Terra Nova activities.

A Terrestrial Single Chamber Microbial Fuel Cell-based Biosensor for Biochemical Oxygen Demand of Synthetic Rice Washed Wastewater

PubMed Central

Logroño, Washington; Guambo, Alex; Pérez, Mario; Kadier, Abudukeremu; Recalde, Celso

2016-01-01

Microbial fuel cells represent an innovative technology which allow simultaneous waste treatment, electricity production, and environmental monitoring. This study provides a preliminary investigation of the use of terrestrial Single chamber Microbial Fuel Cells (SMFCs) as biosensors. Three cells were created using Andean soil, each one for monitoring a BOD concentration of synthetic washed rice wastewater (SRWW) of 10, 100, and 200 mg/L for SMFC1, SMFC2 and SMFC3, respectively. The results showed transient, exponential, and steady stages in the SMFCs. The maximum open circuit voltage (OCV) peaks were reached during the elapsed time of the transient stages, according to the tested BOD concentrations. A good linearity between OCV and time was observed in the increasing stage. The average OCV in this stage increased independently of the tested concentrations. SMFC1 required less time than SMFC2 to reach the steady stage, suggesting the BOD concentration is an influencing factor in SMFCs, and SMFC3 did not reach it. The OCV ratios were between 40.6–58.8 mV and 18.2–32.9 mV for SMFC1 and SMFC2. The reproducibility of the SMFCs was observed in four and three cycles for SMFC1 and SMFC2, respectively. The presented SMFCs had a good response and reproducibility as biosensor devices, and could be an alternative for environmental monitoring. PMID:26784197

[Spatial-temporal distributions of dissolved inorganic carbon and its affecting factors in the Yellow River estuary].

PubMed

Guo, Xing-Sen; Lü, Ying-Chun; Sun, Zhi-Gao; Wang, Chuan-Yuan; Zhao, Quan-Sheng

2015-02-01

Estuary is an important area contributing to the global carbon cycle. In order to analyze the spatial-temporal distribution characteristics of the dissolved inorganic carbon (DIC) in the surface water of Yellow River estuary. Samples were collected in spring, summer, fall, winter of 2013, and discussed the correlation between the content of DIC and environmental factors. The results show that, the DIC concentration of the surface water in Yellow River estuary is in a range of 26.34-39.43 mg x L(-1), and the DIC concentration in freshwater side is higher than that in the sea side. In some areas where the salinity is less than 15 per thousand, the DIC concentration appears significant losses-the maximum loss is 20.46%. Seasonal distribution of performance in descending order is spring, fall, winter, summer. Through principal component analysis, it shows that water temperature, suspended solids, salinity and chlorophyll a are the main factors affecting the variation of the DIC concentration in surface water, their contribution rate is as high as 83% , and alkalinity, pH, dissolved organic carbon, dissolved oxygen and other factors can not be ignored. The loss of DIC in the low area is due to the calcium carbonate sedimentation. DIC presents a gradually increasing trend, which is mainly due to the effects of water retention time, temperature, outside input and environmental conditions.

A Terrestrial Single Chamber Microbial Fuel Cell-based Biosensor for Biochemical Oxygen Demand of Synthetic Rice Washed Wastewater.

PubMed

Logroño, Washington; Guambo, Alex; Pérez, Mario; Kadier, Abudukeremu; Recalde, Celso

2016-01-15

Microbial fuel cells represent an innovative technology which allow simultaneous waste treatment, electricity production, and environmental monitoring. This study provides a preliminary investigation of the use of terrestrial Single chamber Microbial Fuel Cells (SMFCs) as biosensors. Three cells were created using Andean soil, each one for monitoring a BOD concentration of synthetic washed rice wastewater (SRWW) of 10, 100, and 200 mg/L for SMFC1, SMFC2 and SMFC3, respectively. The results showed transient, exponential, and steady stages in the SMFCs. The maximum open circuit voltage (OCV) peaks were reached during the elapsed time of the transient stages, according to the tested BOD concentrations. A good linearity between OCV and time was observed in the increasing stage. The average OCV in this stage increased independently of the tested concentrations. SMFC1 required less time than SMFC2 to reach the steady stage, suggesting the BOD concentration is an influencing factor in SMFCs, and SMFC3 did not reach it. The OCV ratios were between 40.6-58.8 mV and 18.2-32.9 mV for SMFC1 and SMFC2. The reproducibility of the SMFCs was observed in four and three cycles for SMFC1 and SMFC2, respectively. The presented SMFCs had a good response and reproducibility as biosensor devices, and could be an alternative for environmental monitoring.

Combustion performance evaluation of air staging of palm oil blends.

PubMed

Mohd Jaafar, Mohammad Nazri; Eldrainy, Yehia A; Mat Ali, Muhammad Faiser; Wan Omar, W Z; Mohd Hizam, Mohd Faizi Arif

2012-02-21

The problems of global warming and the unstable price of petroleum oils have led to a race to develop environmentally friendly biofuels, such as palm oil or ethanol derived from corn and sugar cane. Biofuels are a potential replacement for fossil fuel, since they are renewable and environmentally friendly. This paper evaluates the combustion performance and emission characteristics of Refined, Bleached, and Deodorized Palm Oil (RBDPO)/diesel blends B5, B10, B15, B20, and B25 by volume, using an industrial oil burner with and without secondary air. Wall temperature profiles along the combustion chamber axis were measured using a series of thermocouples fitted axially on the combustion chamber wall, and emissions released were measured using a gas analyzer. The results show that RBDPO blend B25 produced the maximum emission reduction of 56.9% of CO, 74.7% of NOx, 68.5% of SO(2), and 77.5% of UHC compared to petroleum diesel, while air staging (secondary air) in most cases reduces the emissions further. However, increasing concentrations of RBDPO in the blends also reduced the energy released from the combustion. The maximum wall temperature reduction was 62.7% for B25 at the exit of the combustion chamber.

Bioaccumulation of mercury in the trophic chain of flatfish from the Baltic Sea.

PubMed

Polak-Juszczak, Lucyna

2012-10-01

Mercury concentrations in three flatfish species - flounder (Platichtys flesus), plaice (Pleuronectes platessa), and Baltic turbot (Scophthalmus maximus), netted in the southern Baltic Sea were assessed and compared to concentrations of this metal in sediments, sea water, and flatfish food - bivalve Macoma balthica, isopod Saduria entomon, and sprat (Sprattus sprattus). Collected simultaneously with flatfish in 2009 and 2010. Different concentrations of mercury depending on species, tissue or organ, sex, individual length, kind of food, and region were determined. The muscle tissues of turbot had the highest concentrations of the metal. The bioaccumulation (BF) and biomagnification (BMF) factors has been counted showing that the muscle tissues of turbot have maximum affinity for mercury, and thus best reflected the metal contamination of the Baltic Sea environment. The data suggest that the common Baltic turbot (S. maximus) is an important model species, suitable and cost-effective to biomonitor environmental mercury pollution for ecological research. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of total solid content and pretreatment on the production of lactic acid from mixed culture dark fermentation of food waste.

PubMed

Yousuf, Ahasa; Bastidas-Oyanedel, Juan-Rodrigo; Schmidt, Jens Ejbye

2018-04-28

Food waste landfilling causes environmental degradation, and this work assesses a sustainable food valorization technique. In this study, food waste is converted into lactic acid in a batch assembly by dark fermentation without pH control and without the addition of external inoculum at 37 °C. The effect of total solid (TS), enzymatic and aeration pretreatment was investigated on liquid products concentration and product yield. The maximum possible TS content was 34% of enzymatic pretreated waste, and showed the highest lactic acid concentration of 52 g/L, with a lactic acid selectivity of 0.6 g lactic /g totalacids . The results indicated that aeration pretreatment does not significantly improve product concentration or yield. Non-pretreated waste in a 29% TS system showed a lactic acid concentration of 31 g/L. The results showed that enzymatic pretreated waste at TS of 34% results in the highest production of lactic acid. Copyright © 2018 Elsevier Ltd. All rights reserved.

Glyphosate and AMPA, "pseudo-persistent" pollutants under real-world agricultural management practices in the Mesopotamic Pampas agroecosystem, Argentina.

PubMed

Primost, Jezabel E; Marino, Damián J G; Aparicio, Virginia C; Costa, José Luis; Carriquiriborde, Pedro

2017-10-01

In the Pampas, public concern has strongly risen because of the intensive use of glyphosate for weed control and fallow associated with biotech crops. The present study was aimed to evaluate the occurrence and concentration of the herbicide and its main metabolite (AMPA) in soil and other environmental compartments of the mentioned agroecosystem, including groundwater, in relation to real-world agricultural management practices in the region. Occurrence was almost ubiquitous in solid matrices (83-100%) with maximum concentrations among the higher reported in the world (soil: 8105 and 38939; sediment: 3294 and 7219; suspended particulate matter (SPM): 584 and 475 μg/kg of glyphosate and AMPA). Lower detection frequency was observed in surface water (27-55%) with maximum concentrations in whole water of 1.80 and 1.90 μg/L of glyphosate and AMPA, indicating that SPM analysis would be more sensitive for detection in the aquatic ecosystem. No detectable concentrations of glyphosate or AMPA were observed in groundwater. Glyphosate soil concentrations were better correlated with the total cumulative dose and total number of applications than the last spraying event dose, and an increment of 1 mg glyphosate/kg soil every 5 spraying events was estimated. Findings allow to infer that, under current practices, application rates are higher than dissipation rates. Hence, glyphosate and AMPA should be considered "pseudo-persistent" pollutants and a revisions of management procedures, monitoring programs, and ecological risk for soil and sediments should be also recommended. Copyright © 2017 Elsevier Ltd. All rights reserved.

Monitoring Metal Pollution Levels in Mine Wastes around a Coal Mine Site Using GIS

NASA Astrophysics Data System (ADS)

Sanliyuksel Yucel, D.; Yucel, M. A.; Ileri, B.

2017-11-01

In this case study, metal pollution levels in mine wastes at a coal mine site in Etili coal mine (Can coal basin, NW Turkey) are evaluated using geographical information system (GIS) tools. Etili coal mine was operated since the 1980s as an open pit. Acid mine drainage is the main environmental problem around the coal mine. The main environmental contamination source is mine wastes stored around the mine site. Mine wastes were dumped over an extensive area along the riverbeds, and are now abandoned. Mine waste samples were homogenously taken at 10 locations within the sampling area of 102.33 ha. The paste pH and electrical conductivity values of mine wastes ranged from 2.87 to 4.17 and 432 to 2430 μS/cm, respectively. Maximum Al, Fe, Mn, Pb, Zn and Ni concentrations of wastes were measured as 109300, 70600, 309.86, 115.2, 38 and 5.3 mg/kg, respectively. The Al, Fe and Pb concentrations of mine wastes are higher than world surface rock average values. The geochemical analysis results from the study area were presented in the form of maps. The GIS based environmental database will serve as a reference study for our future work.

Water Quality, Sediment Characteristics and Benthic Status of the Razim-Sinoie Lagoon System, Romania

NASA Astrophysics Data System (ADS)

Catianis, Irina; Secrieru, Dan; Pojar, Iulian; Grosu, Dumitru; Scrieciu, Albert; Pavel, Ana Bianca; Vasiliu, Dan

2018-03-01

Razim Lake is the biggest of Romania's freshwater lakes and along with other basins as Golovita, Zmeica and Sinoie constitutes a system of great ecological significance, playing also an essential role in the supply of water for irrigation, fishery exploitation, farming, flood prevention, recreational navigation and water tourism. Due to their importance, the environmental conditions in the Razim - Sinoie coastal lakes have attracted an increased public attention in contemporary society. To assess the levels, dissemination and potential sources of contamination in the above-mentioned lagoon system, random sampling was used to collect water and sediment samples from every lake and several analytical techniques were performed to investigate their environmental characteristics. The results obtained from this study indicated that, in water, concentrations of various physico-chemical parameters are, mostly, in agreement with correlated environmental standards. Slight variations and/or occasional exceeding of the maximum admissible limits were generally limited to small areas showing levels that would not warrant special concern. In sediments, the mean concentrations of some specific trace metals were below the levels of potential effect. Benthic samples revealed 31 taxa belonging to 16 zoo-benthal subdivisions. The results of this study showed good ecological status despite local several natural and anthropogenic stressors as fishery exploitation, farming, recreational navigation and water tourism.

Colorimetric assay of copper ions based on the inhibition of peroxidase-like activity of MoS2 nanosheets

NASA Astrophysics Data System (ADS)

Chen, Huan; Li, Zhihong; Liu, Xueting; Zhong, Jianhai; Lin, Tianran; Guo, Liangqia; Fu, Fengfu

2017-10-01

The peroxidase-like catalytic activity of MoS2 nanomaterials has been utilized for colorimetric bioassays and medical diagnostics. However, the application of peroxidase-like catalytic activity of MoS2 nanomaterials in environmental analysis was seldom explored. Herein, copper ions were found to inhibit the peroxidase-like catalytic activity of MoS2 nanosheets, which can catalyze the oxidation of 3, 3‧, 5, 5‧-tetramethylbenzidine by H2O2 to produce a colorimetric product. Based on this finding, a simple sensitive colorimetric method for the detection of copper ions was developed. In the presence of copper ions, the absorbance and color of the solution decreased with the increasing concentration of copper ions. The color of the solution can be used to semi-quantitative on-site assay of copper ions by naked eyes. A linear relationship between the absorbance and the concentration of copper ions was observed in the range of 0.4-4.0 μmol L- 1 with a detection limit of 92 nmol L- 1, which was much lower than the maximum contaminant level of copper in drinking water legislated by the Environmental Protection Agency of USA and the World Health Organization. The method was applied to detect copper ions in environmental water samples with satisfactory results.

Environmental factors controlling fluxes of dimethyl sulfide in a New Hampshire fen

NASA Technical Reports Server (NTRS)

Demello, William Zamboni; Hines, Mark E.

1992-01-01

The major environmental factors controlling fluxes of dimethyl sulfide (DMS) in a Sphagnum-dominated peatland were investigated in a poor fen in New Hampshire. DMS emissions from the surface of the peatland varied greatly over 24 hours and seasonally. Maximum DMS emissions occurred in summer with minima in the late fall. Temperature was the major environmental factor controlling these variabilities. There was also some evidence that the changes in water table height might have contributed to the seasonable variability in DMS emission. The influence of the water table was greater during periods of elevated temperature. DMS and MSH were the most abundant dissolved volatile sulfur compound (VSC) in the surface of the water table. Concentrations of dissolved VSC's varied with time and space throughout the fen. Dissolved MDS, MSH, and OCS in the surface of the water table were supersaturated with respect to their concentrations in the atmosphere suggesting that the peat surface was a source of VSC's in the peatland. VCS in peatlands seemed to be produced primarily by microbial processes in the anoxic surface layers of the peat rich in organic matter and inorganic sulfide. Sphagnum mosses were not a direct source of VSC's. However, they increased transport of DMS from the peat surface to the atmosphere.

Tritium concentrations in flow from selected springs that discharge to the Snake River, Twin Falls-Hagerman area, Idaho

USGS Publications Warehouse

Mann, L.J.

1989-01-01

Concern has been expressed that some of the approximately 30,900 curies of tritium disposed to the Snake River Plain aquifer from 1952 to 1988 at the INEL (Idaho National Engineering Laboratory) have migrated to springs discharging to the Snake River in the Twin Falls-Hagerman area. To document tritium concentrations in springflow, 17 springs were sampled in November 1988 and 19 springs were sampled in March 1989. Tritium concentrations were less than the minimum detectable concentration of 0.5 pCi/mL (picocuries/mL) in November 1988 and less than the minimum detectable concentration of 0.2 pCi/mL in March 1989; the minimum detectable concentration was smaller in March 1989 owing to a longer counting time in the liquid scintillation system. The maximum contaminant level of tritium in drinking water as established by the U.S. Environmental Protection Agency is 20 pCi/mL. U.S. Environmental Protection Agency sample analyses indicate that the tritium concentration has decreased in the Snake River near Buhl since the 1970's. In 1974-79, tritium concentrations were less than 0.3 +/-0.2 pCi/mL in 3 of 20 samples; in 1983-88, 17 of 23 samples contained less than 0.3 +/-0.2 pCi/mL of tritium; the minimum detectable concentration is 0.2 pCi/mL. On the basis of decreasing tritium concentrations in the Snake River, their correlation to cessation of atmospheric weapons tests tritium concentrations in springflow less than the minimum detectable concentration, and the distribution of tritium in groundwater at the INEL, aqueous disposal of tritium at the INEL has had no measurable effect on tritium concentrations in springflow from the Snake River Plain aquifer and in the Snake River near Buhl. (USGS)

Perfluoroalkyl substance contamination of the Llobregat River ecosystem (Mediterranean area, NE Spain).

PubMed

Campo, Julian; Pérez, Francisca; Masiá, Ana; Picó, Yolanda; Farré, Marinel la; Barceló, Damià

2015-01-15

The occurrence and sources of 21 perfluoroalkyl substances (PFASs: C4-C14, C16, C18 carboxylate, C4, C6-C8 and C10 sulfonates and C8 sulfonamide) were determined in water, sediment, and biota of the Llobregat River basin (NE Spain). Analytes were extracted by solid phase extraction (SPE) and determined by liquid chromatography triple quadrupole mass spectrometer (LC-QqQ-MS). All samples were contaminated with at least one PFAS, being the most frequently found perfluorobutanoate (PFBA), perfluorooctanoate (PFOA) and perfluorooctane sulfonate (L-PFOS). In general, mean PFAS concentrations measured in sediments (0.01-3.67 ng g(-1)) and biota (0.79-431 μg kg(-1)) samples were higher than those found in water (0.01-233 ng L(-1)). L-PFOS presented very high levels in biota and water, particularly in the Anoia River where a maximum concentration of 2.71 μg L(-1) was related to important industrial activities. However, this pollution does not extend down the Llobregat River according to cumulated values. None of the hazard quotients (HQ) calculated indicate potential risk for the different tropic levels considered (algae, Daphnia sp. and fish). According to Maximum Allowable Concentration (MAC) proposed by the European Commission (L-PFOS) and to Provisional Health Advisory (PHA) values (PFOA, L-PFOS) established by the United States Environmental Protection Agency (US EPA), only two water samples exceeded PHA concentration for L-PFOS. Copyright © 2014 Elsevier B.V. All rights reserved.

Arsenic and skin cancer in the USA: the current evidence regarding arsenic-contaminated drinking water.

PubMed

Mayer, Jonathan E; Goldman, Rose H

2016-11-01

Studies carried out in developing countries, such as Bangladesh and Taiwan, have reported an association between exposure to arsenic in drinking water and increased rates of non-melanoma skin cancer. However, it is unclear whether this correlation can be extended to the populations of developed countries such as the USA, which have lower levels of arsenic exposure and differ in other factors, such as genetics, nutrition, sun exposure, and socioeconomic status. This report examines the current evidence in an attempt to resolve whether populations in the USA have rates of skin cancer that correlate with higher arsenic concentrations. A systematic literature search was conducted using the PubMed, EMBASE, CINAHL, and Cochrane databases. Six key studies were found and reviewed. Several studies conducted in US populations indicate an association between arsenic-contaminated water and skin cancer, which may in some cases occur at arsenic concentrations of <10 μg/l, the 2001 Environmental Protection Agency (EPA) maximum allowable concentration for municipal water. Private wells are not regulated by the EPA's rule, and many have concentrations above the EPA maximum. In order to help curb the rising incidence of skin cancer, arsenic contamination of water warrants the attention of policymakers. Greater testing of well water and increased education and skin cancer surveillance by dermatologists in arsenic-endemic areas may help to reduce exposure to arsenic and facilitate the early recognition of skin cancer. © 2016 The International Society of Dermatology.

Determination of carboxyhaemoglobin in humans following low-level exposures to carbon monoxide.

PubMed

Gosselin, Nathalie H; Brunet, Robert C; Carrier, Gaétan

2009-11-01

This study proposes to estimate carboxyhaemoglobin (COHb) levels in the blood of men and women of various ages exposed to common concentrations of carbon monoxide (CO) using a model with only one free parameter while integrating alveoli-blood and blood-tissue CO exchanges. The model retained is essentially that of Coburn et al. (1965) with two important additions: an alveoli compartment for the dynamics of CO exchanges between alveoli and blood, and a compartment for the significant amounts of CO bound to heme proteins in extravascular spaces. The model was validated by comparing its simulations with various published data sets for the COHb time profiles of volunteers exposed to known CO concentrations. Once the model was validated, it was used to simulate various situations of interest for their impact on public health. This approach yields reliable estimations of the time profiles of COHb levels resulting from different levels of CO exposure over various periods of time and under various conditions (resting, exercise, working, and smoking). The non-linear kinetics of CO, observed experimentally, were correctly reproduced by simulations with the model. Simulations were also carried out iteratively to determine the exposure times and CO concentrations in ambient air needed to reach the maximum levels of COHb recommended by Health Canada, the U.S. Environmental Protection Agency (EPA), and the World Health Organisation (WHO) for each age group of the general population. The lowest CO concentrations leading to maximum COHb levels of 1.5, 2, and 2.5% were determined.

Environmental status of groundwater affected by chromite ore processing residue (COPR) dumpsites during pre-monsoon and monsoon seasons.

PubMed

Matern, Katrin; Weigand, Harald; Singh, Abhas; Mansfeldt, Tim

2017-02-01

Chromite ore processing residue (COPR) is generated by the roasting of chromite ores for the extraction of chromium. Leaching of carcinogenic hexavalent chromium (Cr(VI)) from COPR dumpsites and contamination of groundwater is a key environmental risk. The objective of the study was to evaluate Cr(VI) contamination in groundwater in the vicinity of three COPR disposal sites in Uttar Pradesh, India, in the pre-monsoon and monsoon seasons. Groundwater samples (n = 57 pre-monsoon, n = 70 monsoon) were taken in 2014 and analyzed for Cr(VI) and relevant hydrochemical parameters. The site-specific ranges of Cr(VI) concentrations in groundwater were <0.005 to 34.8 mg L -1 (Rania), <0.005 to 115 mg L -1 (Chhiwali), and <0.005 to 2.0 mg L -1 (Godhrauli). Maximum levels of Cr(VI) were found close to the COPR dumpsites and significantly exceeded safe drinking water limits (0.05 mg L -1 ). No significant dependence of Cr(VI) concentration on monsoons was observed.

Smaller predator-prey body size ratios in longer food chains.

PubMed Central

Jennings, Simon; Warr, Karema J

2003-01-01

Maximum food-chain length has been correlated with resource availability, ecosystem size, environmental stability and colonization history. Some of these correlations may result from environmental effects on predator-prey body size ratios. We investigate relationships between maximum food-chain length, predator-prey mass ratios, primary production and environmental stability in marine food webs with a natural history of community assembly. Our analyses provide empirical evidence that smaller mean predator-prey body size ratios are characteristic of more stable environments and that food chains are longer when mean predator-prey body size ratios are small. We conclude that environmental effects on predator-prey body size ratios contribute to observed differences in maximum food-chain length. PMID:12965034

In-Vitro Performance of the Enlite Sensor in Various Glucose Concentrations during Hypobaric and Hyperbaric Conditions

PubMed Central

Adolfsson, Peter; Örnhagen, Hans; Eriksson, Bengt M.; Gautham, Raghavendhar; Jendle, Johan

2012-01-01

Background There is a need for reliable methods of glucose measurement in different environmental conditions. The objective of this in vitro study was to evaluate the performance of the Enlite® Sensor when connected to either the iPro™ Continuous Glucose Monitor recording device or the Guardian® REAL-Time transmitting device, in hypobaric and hyperbaric conditions. Methods Sixteen sensors connected to eight iPro devices and eight Guardian REAL-Time devices were immersed in three beakers containing separate glucose concentrations: 52, 88, and 207 mg/dl (2.9, 4.9, and 11.3 mmol/liter). Two different pressure tests were conducted: a hypobaric test, corresponding to maximum 18000 ft/5500 m height, and a hyperbaric test, corresponding to maximum 100 ft/30 m depth. The linearity of the sensor signals in the different conditions was evaluated. Results The sensors worked continuously, and the sensor signals were collected without interruption at all pressures tested. When comparing the input signals for glucose (ISIGs) and the different glucose concentrations during altered pressure, linearity (R2) of 0.98 was found. During the hypobaric test, significant differences (p < .005) were seen when comparing the ISIGs during varying pressure at two of the glucose concentrations (52 and 207 mg/dl), whereas no difference was seen at the 88 mg/dl glucose concentration. During the hyperbaric test, no differences were found. Conclusions The Enlite Sensors connected to either the iPro or the Guardian REAL-Time device provided values continuously. In hyperbaric conditions, no significant differences were seen during changes in ambient pressure; however, during hypobaric conditions, the ISIG was significantly different in the low and high glucose concentrations. PMID:23294783

In-vitro performance of the Enlite Sensor in various glucose concentrations during hypobaric and hyperbaric conditions.

PubMed

Adolfsson, Peter; Ornhagen, Hans; Eriksson, Bengt M; Gautham, Raghavendhar; Jendle, Johan

2012-11-01

There is a need for reliable methods of glucose measurement in different environmental conditions. The objective of this in vitro study was to evaluate the performance of the Enlite® Sensor when connected to either the iPro™ Continuous Glucose Monitor recording device or the Guardian® REAL-Time transmitting device, in hypobaric and hyperbaric conditions. Sixteen sensors connected to eight iPro devices and eight Guardian REAL-Time devices were immersed in three beakers containing separate glucose concentrations: 52, 88, and 207 mg/dl (2.9, 4.9, and 11.3 mmol/liter). Two different pressure tests were conducted: a hypobaric test, corresponding to maximum 18000 ft/5500 m height, and a hyperbaric test, corresponding to maximum 100 ft/30 m depth. The linearity of the sensor signals in the different conditions was evaluated. The sensors worked continuously, and the sensor signals were collected without interruption at all pressures tested. When comparing the input signals for glucose (ISIGs) and the different glucose concentrations during altered pressure, linearity (R(2)) of 0.98 was found. During the hypobaric test, significant differences (p < .005) were seen when comparing the ISIGs during varying pressure at two of the glucose concentrations (52 and 207 mg/dl), whereas no difference was seen at the 88 mg/dl glucose concentration. During the hyperbaric test, no differences were found. The Enlite Sensors connected to either the iPro or the Guardian REAL-Time device provided values continuously. In hyperbaric conditions, no significant differences were seen during changes in ambient pressure; however, during hypobaric conditions, the ISIG was significantly different in the low and high glucose concentrations. © 2012 Diabetes Technology Society.

Hydrogeology and quality of ground water on Guemes Island, Skagit County, Washington

USGS Publications Warehouse

Kahle, S.C.; Olsen, T.D.

1995-01-01

Guemes Island, located in Puget Sound of Washington State, is experiencing population growth and seawater intrusion. The island consists of Pleistocene glacial deposits overlying bedrock. Geologic sections and a map of surficial geology were constructed and used to delineate six hydrogeologic units, three of which are aquifers. The most productive aquifer is the Double Bluff aquifer, situated at or below sea level. Water budget estimates indicate that of the 21-29 inches of precipitation received in a typical year, 0-4 inches runs off, 12-22 inches evapotranspires, and 2-10 inches recharges the ground-water system. Of the water recharged, 0.1-0.3 inches is withdrawn by wells; the remainder recharges deeper aquifer(s) or discharges from the ground-water system to drainage ditches or the sea. The median dissolved-solids concentration was 236 mg/L (milligrams per liter). Half of the samples were classified as moderately hard, the remainder as hard or very hard. Although magnesium-calcium/bicarbonate water types dominate, some samples contained large amounts of sodium and chloride. The median concentration of 0.08 mg/L for nitrate indicates that no widespread contamination from septic systems or livestock exists. Small concentrations of arsenic were present in 5 of 24 samples. Trace concentrations of volatile organic compounds were detected in three of five samples. None of the U.S. Environmental Protection Agency's maximum contaminant levels was exceeded. However, secondary maximum contaminant levels were exceeded for dissolved solids, chloride, manganese, and iron. Seasonal variability of chloride concentration was apparent in water from coastal wells that had chloride concentrations greater than 100 mg/L. Higher values occurred from April through September because of increased pumping and lower recharge.

Nearshore concentration of pink shrimp (Farfantepenaeus duorarum) postlarvae in northern Florida bay in relation to nocturnal flood tide

USGS Publications Warehouse

Criales, Maria M.; Robblee, M.B.; Browder, Joan A.; Cardenas, H.; Jackson, Thomas L.

2010-01-01

We address the question of whether the low abundance of juvenile pink shrimp Farfantepenaeus duorarum (Burkenroad, 1939) in northern-central Florida Bay results from (i) limiting environmental conditions, (ii) a reduced postlarval transport, or (iii) both. To explore this question, postlarvae were collected during the new moon in both summer and fall of 2004 and 2005 at six stations located on a transect from the bay's western margin to its interior. The highest concentrations of postlarvae occurred at two mid-transect stations located in shallow channels with moderate tidal amplitudes (15-20 cm) and dense seagrass beds. At the two interiormost stations postlarval concentrations decreased together with a reduction of the tidal amplitude (= 1 cm). Estimates of the cumulative flood-tide displacement with the semidiurnal M2 constituent indicated that the tide moves a maximum of 15 km in four nights, a distance that corresponds to the location of the highest concentrations of postlarvae. The size of postlarvae also reached a maximum at the location of the highest concentrations of postlarvae. Results suggest that postlarvae move into the bay's interior by a cumulative flood tidal process, advancing onshore during successive nights as far as they can go with the tide. Analyses indicate that, in addition to the tidal amplitude, cross-shelf wind stress and salinity also affect the concentrations of postlarvae. Peaks of postlarvae occurred at times of low salinity and strong southeasterly winds. While tidal transport appears to be insufficient for postlarvae to reach Florida Bay's interior, salinity and winds may also contribute to the observed distribution patterns of early pink shrimp recruits. ?? 2010 Rosenstiel School of Marine and Atmospheric Science of the University of Miami.

Performance Analysis and Optimization of Concentrating Solar Thermoelectric Generator

NASA Astrophysics Data System (ADS)

Lamba, Ravita; Manikandan, S.; Kaushik, S. C.

2018-06-01

A thermodynamic model for a concentrating solar thermoelectric generator considering the Thomson effect combined with Fourier heat conduction, Peltier, and Joule heating has been developed and optimized in MATLAB environment. The temperatures at the hot and cold junctions of the thermoelectric generator were evaluated by solving the energy balance equations at both junctions. The effects of the solar concentration ratio, input electrical current, number of thermocouples, and electrical load resistance ratio on the power output and energy and exergy efficiencies of the system were studied. Optimization studies were carried out for the STEG system, and the optimum number of thermocouples, concentration ratio, and resistance ratio determined. The results showed that the optimum values of these parameters are different for conditions of maximum power output and maximum energy and exergy efficiency. The optimum values of the concentration ratio and load resistance ratio for maximum energy efficiency of 5.85% and maximum exergy efficiency of 6.29% were found to be 180 and 1.3, respectively, with corresponding power output of 4.213 W. Furthermore, at higher concentration ratio (C = 600), the optimum number of thermocouples was found to be 101 for maximum power output of 13.75 W, maximum energy efficiency of 5.73%, and maximum exergy efficiency of 6.16%. Moreover, the optimum number of thermocouple was the same for conditions of maximum power output and energy and exergy efficiency. The results of this study may provide insight for design of actual concentrated solar thermoelectric generator systems.

The legacy of leaded gasoline in bottom sediment of small rural reservoirs

USGS Publications Warehouse

Juracek, K.E.; Ziegler, A.C.

2006-01-01

The historical and ongoing lead (Pb) contamination caused by the 20th-century use of leaded gasoline was investigated by an analysis of bottom sediment in eight small rural reservoirs in eastern Kansas, USA. For the reservoirs that were completed before or during the period of maximum Pb emissions from vehicles (i.e., the 1940s through the early 1980s) and that had a major highway in the basin, increased Pb concentrations reflected the pattern of historical leaded gasoline use. For at least some of these reservoirs, residual Pb is still being delivered from the basins. There was no evidence of increased Pb deposition for the reservoirs completed after the period of peak Pb emissions and (or) located in relatively remote areas with little or no highway traffic. Results indicated that several factors affected the magnitude and variability of Pb concentrations in reservoir sediment including traffic volume, reservoir age, and basin size. The increased Pb concentrations at four reservoirs exceeded the U.S. Environmental Protection Agency threshold-effects level (30.2 mg kg-1) and frequently exceeded a consensus-based threshold-effects concentration (35.8 mg kg-1) for possible adverse biological effects. For two reservoirs it was estimated that it will take at least 20 to 70 yr for Pb in the newly deposited sediment to return to baseline (pre-1920s) concentrations (30 mg kg-1) following the phase out of leaded gasoline. The buried sediment with elevated Pb concentrations may pose a future environmental concern if the reservoirs are dredged, the dams are removed, or the dams fail. ?? ASA, CSSA, SSSA.

Ground-water quality in the Lake Champlain basin, New York, 2004

USGS Publications Warehouse

Nystrom, Elizabeth A.

2006-01-01

Water samples were collected from 11 public-supply wells and 11 private domestic wells in the Lake Champlain basin in New York during the fall of 2004 to characterize the chemical quality of ground water. Wells were selected for sampling based on location and focused on areas of greatest ground-water use. Samples were analyzed for 219 physical properties and constituents, including inorganic compounds, nutrients, metals, radionuclides, pesticides and pesticide degradates, volatile organic compounds, and bacteria. Sixty-eight constituents were detected at concentrations above laboratory reporting levels. The cation and anion with the highest median concentration were calcium (34.8 mg/L) bicarbonate (134 mg/L), respectively. The predominant nutrient was nitrate, which was detected in 14 (64 percent) of the 22 samples. The two metals with the highest median concentrations were iron (175 ?g/L) and strontium (124 ?g/L); concentrations of iron, manganese, aluminum, and zinc exceeded U.S. Environmental Protection Agency secondary drinking-water standards in one or more samples. Radon concentrations were less than 1,000 picocuries per liter (pCi/L) in most samples, but concentrations as high as 6,900 pCi/L were detected and, in eight samples, exceeded the U.S. Environmental Protection Agency proposed maximum contaminant level (300 pCi/L) for radon. The most frequently detected pesticides were degradates of the broadleaf herbicides metolachlor, alachlor, and atrazine. Volatile organic compounds were detected in only three samples; those that were detected typically were fuel oxygenates, such as methyl tert-butyl ether. Coliform bacteria were detected in four samples, two of which also tested positive for E. coli.

Mercury in Indiana watersheds: retrospective for 2001-2006

USGS Publications Warehouse

Risch, Martin R.; Baker, Nancy T.; Fowler, Kathleen K.; Egler, Amanda L.; Lampe, David C.

2010-01-01

Information about total mercury and methylmercury concentrations in water samples and mercury concentrations in fish-tissue samples was summarized for 26 watersheds in Indiana that drain most of the land area of the State. Mercury levels were interpreted with information on streamflow, atmospheric mercury deposition, mercury emissions to the atmosphere, mercury in wastewater, and landscape characteristics. Unfiltered total mercury concentrations in 411 water samples from streams in the 26 watersheds had a median of 2.32 nanograms per liter (ng/L) and a maximum of 28.2 ng/L. When these concentrations were compared to Indiana water-quality criteria for mercury, 5.4 percent exceeded the 12-ng/L chronic-aquatic criterion, 59 percent exceeded the 1.8-ng/L Great Lakes human-health criterion, and 72.5 percent exceeded the 1.3-ng/L Great Lakes wildlife criterion. Mercury concentrations in water were related to streamflow, and the highest mercury concentrations were associated with the highest streamflows. On average, 67 percent of total mercury in streams was in a particulate form, and particulate mercury concentrations were significantly lower downstream from dams than at monitoring stations not affected by dams. Methylmercury is the organic fraction of total mercury and is the form of mercury that accumulates and magnifies in food chains. It is made from inorganic mercury by natural processes under specific conditions. Unfiltered methylmercury concentrations in 411 water samples had a median of 0.10 ng/L and a maximum of 0.66 ng/L. Methylmercury was a median 3.7 percent and maximum 64.8 percent of the total mercury in 252 samples for which methylmercury was reported. The percentages of methylmercury in water samples were significantly higher downstream from dams than at other monitoring stations. Nearly all of the total mercury detected in fish tissue was assumed to be methylmercury. Fish-tissue samples from the 26 watersheds had wet-weight mercury concentrations that exceeded the 0.3 milligram per kilogram (mg/kg) U.S. Environmental Protection Agency (USEPA) methylmercury criterion in 12.4 percent of the 1,731 samples. The median wet-weight concentration in the fish-tissue samples was 0.13 mg/kg, and the maximum was 1.07 mg/kg. A coarse-scale analysis of all fish-tissue data in each watershed and a fine-scale analysis of data within 5 kilometers (km) of the downstream end of each watershed showed similar results overall. Mercury concentrations in fish-tissue samples were highest in the White River watershed in southern Indiana and the Fall Creek watershed in central Indiana. In fish-tissue samples within 5 km of the downstream end of a watershed, the USEPA methylmercury criterion was exceeded by 45 percent of mercury concentrations from the White River watershed and 40 percent of the mercury concentration from the Fall Creek watershed. A clear relation between mercury concentrations in fish-tissue samples and methylmercury concentrations in water was not observed in the data from watersheds in Indiana. Average annual atmospheric mercury wet-deposition rates were mapped with data at 156 locations in Indiana and four surrounding states for 2001-2006. These maps revealed an area in southeastern Indiana with high mercury wet-deposition rates-from 15 to 19 micrograms per square meter per year (ug/m2/yr). Annual atmospheric mercury dry-deposition rates were estimated with an inferential method by using concentrations of mercury species in air samples at three locations in Indiana. Mercury dry deposition-rates were 5.6 to 13.6 ug/m2/yr and were 0.49 to 1.4 times mercury wet-deposition rates. Total mercury concentrations were detected in 96 percent of 402 samples of wastewater effluent from 50 publicly owned treatment works in the watersheds; the median concentration was 3.0 ng/L, and the maximum was 88 ng/L. When these concentrations were compared to Indiana water-quality criteria for mercury, 12 percent exceeded the 12-n

Health-Related Benefits of Attaining the 8-Hr Ozone Standard

PubMed Central

Hubbell, Bryan J.; Hallberg, Aaron; McCubbin, Donald R.; Post, Ellen

2005-01-01

During the 2000–2002 time period, between 36 and 56% of ozone monitors each year in the United States failed to meet the current ozone standard of 80 ppb for the fourth highest maximum 8-hr ozone concentration. We estimated the health benefits of attaining the ozone standard at these monitors using the U.S. Environmental Protection Agency’s Environmental Benefits Mapping and Analysis Program. We used health impact functions based on published epidemiologic studies, and valuation functions derived from the economics literature. The estimated health benefits for 2000 and 2001 are similar in magnitude, whereas the results for 2002 are roughly twice that of each of the prior 2 years. The simple average of health impacts across the 3 years includes reductions of 800 premature deaths, 4,500 hospital and emergency department admissions, 900,000 school absences, and > 1 million minor restricted activity days. The simple average of benefits (including premature mortality) across the 3 years is $5.7 billion [90% confidence interval (CI), 0.6–15.0] for the quadratic rollback simulation method and $4.9 billion (90% CI, 0.5–14.0) for the proportional rollback simulation method. Results are sensitive to the form of the standard and to assumptions about background ozone levels. If the form of the standard is based on the first highest maximum 8-hr concentration, impacts are increased by a factor of 2–3. Increasing the assumed hourly background from zero to 40 ppb reduced impacts by 30 and 60% for the proportional and quadratic attainment simulation methods, respectively. PMID:15626651

Water-quality assessment of the Delmarva Peninsula, Delaware, Maryland, and Virginia; effects of agricultural activities on, and distribution of, nitrate and other inorganic constituents in the surficial aquifer

USGS Publications Warehouse

Hamilton, P.A.; Denver, J.M.; Phillips, P.J.; Shedlock, R.J.

1993-01-01

Agricultural applications of inorganic fertilizers and manure have changed the natural chemical com- position of water in the surficial aquifer through- out the Delmarva Peninsula. Nitrate, derived from nitrification of ammonia in inorganic fertilizers and manure, is the dominant anion in agricultural areas. Concentrations of nitrate in 185 water samples collected in agricultural areas ranged from 0.4 to 48 mg/L as nitrogen, with a median concen- tration of 8.2 mg/L as nitrogen. Nitrate concen- trations exceeded the U.S. Environmental Protection Agency's maximum contaminant level for drinking water of 10 mg/L as nitrogen in about 33% of the 185 water samples. Groundwater affected by agricultural activities contains significantly higher concentrations of dissolved constituents than does natural groundwater. Concentrations of calcium and magnesium are higher because of liming of soils, and concentrations of potassium and chloride are higher because of applications of potash, a supple- ment to the nitrogen-based fertilizers. Alkalinity concentrations commonly are decreased because the bicarbonate ion is consumed in buffering reactions with acid that is produced during nitrification. Effects of agricultural activities on groundwater quality are not limited to the near-surface parts of the aquifer underlying farm fields. Elevated concentrations are common in aerobic water at or near the base of the aquifer, 80 to 100 ft below land surface. The median concentration of nitrate in water beneath agricultural areas collected from 24 wells deeper than 80 ft below land surface was 8.5 mg/L as nitrogen, and concentrations in 9 of these water samples exceeded the maximum contaminant level. Regional variations in concentrations of nitrate and other agriculture related constituents in the surficial aquifer in the Delmarva Peninsula depend on a number of factors that include geomorphology, geology, soils, land use, and groundwater-flow patterns. (USGS)

Chloride in Groundwater and Surface Water in Areas Underlain by the Glacial Aquifer System, Northern United States

USGS Publications Warehouse

Mullaney, John R.; Lorenz, David L.; Arntson, Alan D.

2009-01-01

A study of chloride in groundwater and surface water was conducted for the glacial aquifer system of the northern United States in forested, agricultural, and urban areas by analyzing data collected for the National Water-Quality Assessment Program from 1991 to 2004. Groundwater-quality data from a sampling of 1,329 wells in 19 states were analyzed. Chloride concentrations were greater than the secondary maximum contaminant level established by the U.S. Environmental Protection Agency of 250 milligrams per liter in 2.5 percent of samples from 797 shallow monitoring wells and in 1.7 percent of samples from 532 drinking-water supply wells. Water samples from shallow monitoring wells in urban areas had the largest concentration of chloride, followed by water samples from agricultural and forested areas (medians of 46, 12, and 2.9 milligrams per liter, respectively). An analysis of chloride:bromide ratios, by mass, and chloride concentrations compared to binary mixing curves for dilute groundwater, halite, sewage and animal waste, potassium chloride fertilizer, basin brines, seawater, and landfill leachate in samples from monitoring wells indicated multiple sources of chloride in samples from wells in urban areas and agricultural areas. Water from shallow monitoring wells in urban areas had the largest chloride:bromide ratio, and samples with chloride:bromide ratios greater than 1,000 and chloride concentrations greater than 100 milligrams per liter were dominated by halite; however, the samples commonly contained mixtures that indicated input from sewage or animal waste. Chloride:bromide ratios were significantly larger in samples from public-supply drinking-water wells than from private drinking-water wells, and ratios were significantly larger in all drinking-water wells in eastern and central regions of the glacial aquifer system than in west-central and western regions of the glacial aquifer system. Surface-water-quality data collected regularly during varying time periods from 1991-2004 from 100 basins dominated by forested, agricultural, or urban land in 15 states were analyzed to determine maximum measured chloride concentrations. Samples from 15 sites in east, central, and west-central areas, collected primarily in winter, had chloride concentrations higher than the U.S. Environmental Protection Agency recommended chronic criterion concentration for aquatic life of 230 milligrams per liter. Concentrations of chloride in base-flow samples were predictive of maximum measured chloride concentrations, indicating that inputs of chloride from groundwater and (or) point-source wastewater discharges increase the likelihood of samples exceeding the recommended chronic aquatic criterion. Multiple linear regression analyses showed that the density of major roads, potential evapotranspiration, and the percentage of annual runoff from saturated overland flow were significant factors in describing the range of maximum measured chloride concentrations in the basins studied. Chloride loads and yields were determined at 95 surface-water-monitoring stations in basins dominated by forested, agricultural, or urban land. Annual chloride yield was largest in the urban basins (median of 88 tons per square mile) and smallest in the forested basins (median of 6.4 tons per square mile). The median chloride yield in the agricultural basins was 15.4 tons per square mile. Multiple linear regression analyses showed that the density of highways (roads in U.S. highway system), the number of major wastewater discharges in the basin, potential evapotranspiration, and urban minus agricultural land area were significant factors in describing the range of average annual chloride yields. Upward trends in chloride loads were apparent in several urban basins for which additional long-term data were available. Increases in chloride loads over time may be related to a variety of factors, including increases in road area and consequent deicing, incr

Socio-Environmental Health Analysis in Nogales, Sonora, Mexico.

PubMed

Norman, Laura M; Caldeira, Felipe; Callegary, James; Gray, Floyd; O' Rourke, Mary Kay; Meranza, Veronica; Van Rijn, Saskia

2012-06-01

In Nogales, Sonora, Mexico, some neighborhoods, or colonias, have intermittent delivery of water through pipes from the city of Nogales's municipal water-delivery system while other areas lack piped water and rely on water delivered by truck or pipas. This research examined how lifestyles, water quality, and potential disease response, such as diarrhea, differs seasonally from a colonia with access to piped water as opposed to one using alternative water-delivery systems. Water samples were collected from taps or spigots at homes in two Nogales colonias. One colonia reflected high socio-environmental conditions where residents are supplied with municipal piped water (Colonia Lomas de Fatima); the second colonia reflected low socio-environmental conditions, lacking access to piped water and served by pipas (Colonia Luis Donaldo Colosio). A survey was developed and implemented to characterize perceptions of water quality, health impacts, and quality of life. Water samples were analyzed for microbial and inorganic water-quality parameters known to impact human health including, Escherichia coli (E. coli), total coliform bacteria, arsenic, and lead. A total of 21 households agreed to participate in the study (14 in Colosio and 7 in Fatima). In both colonias metal concentrations from water samples were all well below the United States Environmental Protection Agency's (US EPA's) maximum contaminant levels. E. coli concentrations exceeded the US EPA's drinking-water standard in Colosio but not Fatima. Total coliform bacteria were present in over 50 % of households in both colonias. Microbial contamination was significantly higher in the summer than in the winter in both colonias. Resulting analysis suggests that residents in colonias without piped water are at a greater risk of gastrointestinal illness from consumption of compromised drinking water. Our survey corroborated reports of gastrointestinal illness in the summer months but not in the winter. Chloride was found to be significantly greater in Colosio (median 29.2 mg/L) although still below the US EPA's maximum contaminant levels of 250 mg/L. Ongoing binational collaboration can promote mechanisms to improve water quality in cities located in the US-Mexico border.

Socio-environmental health analysis in Nogales, Sonora, Mexico

USGS Publications Warehouse

Norman, Laura M.; Caldeira, Felipe; Callegary, James; Gray, Floyd; O’ Rourke, Mary Kay; Meranza, Veronica; Van Rijn, Saskia

2012-01-01

In Nogales, Sonora, Mexico, some neighborhoods, or colonias, have intermittent delivery of water through pipes from the city of Nogales’s municipal water-delivery system while other areas lack piped water and rely on water delivered by truck or pipas. This research examined how lifestyles, water quality, and potential disease response, such as diarrhea, differs seasonally from a colonia with access to piped water as opposed to one using alternative water-delivery systems. Water samples were collected from taps or spigots at homes in two Nogales colonias. One colonia reflected high socio-environmental conditions where residents are supplied with municipal piped water (Colonia Lomas de Fatima); the second colonia reflected low socio-environmental conditions, lacking access to piped water and served by pipas (Colonia Luis Donaldo Colosio). A survey was developed and implemented to characterize perceptions of water quality, health impacts, and quality of life. Water samples were analyzed for microbial and inorganic water-quality parameters known to impact human health including, Escherichia coli (E. coli), total coliform bacteria, arsenic, and lead. A total of 21 households agreed to participate in the study (14 in Colosio and 7 in Fatima). In both colonias metal concentrations from water samples were all well below the United States Environmental Protection Agency’s (US EPA’s) maximum contaminant levels. E. coli concentrations exceeded the US EPA’s drinking-water standard in Colosio but not Fatima. Total coliform bacteria were present in over 50 % of households in both colonias. Microbial contamination was significantly higher in the summer than in the winter in both colonias. Resulting analysis suggests that residents in colonias without piped water are at a greater risk of gastrointestinal illness from consumption of compromised drinking water. Our survey corroborated reports of gastrointestinal illness in the summer months but not in the winter. Chloride was found to be significantly greater in Colosio (median 29.2 mg/L) although still below the US EPA’s maximum contaminant levels of 250 mg/L. Ongoing binational collaboration can promote mechanisms to improve water quality in cities located in the US–Mexico border.

The use of olive tree (Olea europaea L.) leaves as a bioindicator for environmental pollution in the Province of Aydın, Turkey.

PubMed

Turan, Dilek; Kocahakimoglu, Cemre; Kavcar, Pınar; Gaygısız, Handan; Atatanir, Levent; Turgut, Cafer; Sofuoglu, Sait C

2011-03-01

In this study, olive tree leaves, collected from 50 sampling sites throughout the Province of Aydın, Turkey, were used to estimate level of pollution by measuring Al, As, B, Ba, Ca, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Sr, and Zn concentrations and calculating pollution factor (PF) values. After sample preparation, collected leaves were microwave digested, and extracts were analyzed by an inductively coupled plasma-mass spectrometer. The maximum PF values were ≥10 for a number of elements ranging from 11-13 (Al, As, Cr, Fe, Mn, Ni) to >100 for Cu, Li, and Na. Urban-rural and roadside-nonroadside concentration comparisons showed that some of the elements (As, Cu, and Pb) were at significantly higher levels on urban and/or roadside sampling sites. Correlations and factor analysis showed that there may be common sources for some elements, which included several soil types and anthropogenic activities. Based on the results of the statistical source apportionment, possible sources were narrowed down with help of the constructed elemental concentration maps. In conclusion, utilization of olive tree leaves for biomonitoring and assessment of environmental pollution was shown to be possible in the Mediterranean region where they are indigenous and cultivated.

Remedial Action Plan and site design for stabilization of the inactive uranium mill tailings site at Durango, Colorado: Attachment 4, Water resources protection strategy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1991-12-01

To achieve compliance with the proposed US Environmental Protection Agency (EPA) groundwater protection standards (Subpart A of 40 CFR 192), the US Department of Energy (DOE) proposes to meet background concentrations or the EPA maximum concentration limits (MCLS) for hazardous constituents in groundwater in the uppermost aquifer (Cliff House/Menefee aquifer) at the point of compliance (POC) at the Uranium Mill Tailings Remedial Action (UMTRA) Project disposal site in Bodo Canyon near Durango, Colorado (DOE, 1989). Details of hydrologic site characterization at the disposal site are provided in Attachment 3, Groundwater Hydrology Report. The principal features of the water resources protectionmore » strategy for the Bodo Canyon disposal site are presented in this document.« less

Metal contamination in environmental media in residential areas around Romanian mining sites.

PubMed

Neamtiu, Iulia A; Al-Abed, Souhail R; McKernan, John L; Baciu, Calin L; Gurzau, Eugen S; Pogacean, Anca O; Bessler, Scott M

2017-03-01

Hard-rock mining for metals, such as gold, silver, copper, zinc, iron and others, is recognized to have a significant impact on the environmental media, soil and water, in particular. Toxic contaminants released from mine waste to surface water and groundwater is the primary concern, but human exposure to soil contaminants either directly, via inhalation of airborne dust particles, or indirectly, via food chain (ingestion of animal products and/or vegetables grown in contaminated areas), is also, significant. In this research, we analyzed data collected in 2007, as part of a larger environmental study performed in the Rosia Montana area in Transylvania, to provide the Romanian governmental authorities with data on the levels of metal contamination in environmental media from this historical mining area. The data were also considered in policy decision to address mining-related environmental concerns in the area. We examined soil and water data collected from residential areas near the mining sites to determine relationships among metals analyzed in these different environmental media, using the correlation procedure in the SAS statistical software. Results for residential soil and water analysis indicate that the average values for arsenic (As) (85 mg/kg), cadmium (Cd) (3.2 mg/kg), mercury (Hg) (2.3 mg/kg) and lead (Pb) (92 mg/kg) exceeded the Romanian regulatory exposure levels [the intervention thresholds for residential soil in case of As (25 mg/kg) and Hg (2 mg/kg), and the alert thresholds in case of Pb (50 mg/kg) and Cd (3 mg/kg)]. Average metal concentrations in drinking water did not exceed the maximum contaminant level (MCL) imposed by the Romanian legislation, but high metal concentrations were found in surface water from Rosia creek, downstream from the former mining area.

Atmospheric methane at Cape Meares - Analysis of a high-resolution data base and its environmental implications

NASA Technical Reports Server (NTRS)

Khalil, M. A. K.; Rasmussen, R. A.; Moraes, F.

1993-01-01

Between 1979 and 1992 we took some 120,000 measurements of atmospheric methane at Cape Meares on the Oregon coast. The site is representative of methane concentrations in the northern latitudes (from 30 deg N to 90 deg N). The average concentration during the experiment was 1698 parts per billion by volume (ppbv). Methane concentration increased by 190 ppbv (or 11.9 percent) during the 13-year span of the experiment. The rate of increase was about 20 +/- 4 ppbv/yr in the first 2 yr and 10 +/- 2 ppbv/yr in the last 2 yr of the experiment, suggesting a substantial decline in the trend at northern middle and high latitudes. Prominent seasonal cycles were observed. During the year, the concentration stays more or less constant until May and then starts falling, reaching lowest levels in July and August, then rises rapidly to nearly maximum concentrations in October. Interannual variations with small amplitudes of 2-3 ppbv occur with periods of 1.4 and 6.5 yr.

[Radioactive nuclides in the marine environment--distribution and behaviour of 95Zr, 95Nb originated from fallout].

PubMed

Yamato, A; Miyagawa, N; Miyanaga, N

1984-07-01

To investigate behaviour of 95Zr, 95Nb in the marine environment, various samples have been collected and measured by means of Ge(Li) gamma-ray spectrometry and/or radiochemical analysis during a period from 1974 to 1982 at coastal area of Tokai-mura, Ibaraki prefecture. Concentration of the nuclides in seaweeds increased remarkably after atmospheric nuclear detonation by P.R. of China, and the activity ratio between the nuclides changed by time was not fit well by the transient decay equation. Concentration variation in sea water was smaller than that in sea weeds, and the minimum change in sea sediment. Increase of concentration in these environmental samples was observed in chronological order of sea water, sea weeds then sediment after detonations, suggesting that the uptake of the nuclides by these sea weeds from sea water is faster than that via root. Observed concentration factors on the nuclides by sea weeds were calculated from the observed concentrations in sea water and sea weeds. Maximum values on 95Zr and 95Nb were 2110, 2150, respectively for Ecklonia cava and Eisenia bicyclis.

A Procedure for Setting Environmentally Safe Total Maximum Daily Loads (TMDLs) for Selenium

Treesearch

A. Dennis Lemly

2002-01-01

This article presents a seven-step procedure for developing environmentally safe total maximum daily loads (TMDLs) for selenium. The need for this information stems from recent actions taken by the U.S. Environmental Protection Agency (EPA) that may require TMDLs for selenium and other contaminants that are impairing water bodies. However, there is no technical...

Potential impacts of discharging tertiary-treated wastewater into Port Royal Sound, South Carolina

USGS Publications Warehouse

Speiran, G.K.; Belval, D.L.

1985-01-01

An assessment of physical characteristics of Port Royal Sound was combined with the results of a dye tracer study and with data collected from a previous environmental study to describe the impact on the water quality from discharging tertiary treated wastewater into the sound. Calculated velocities for the time of maximum velocity in the tidal cycle ranged from 2.32 ft/sec near the bottom to 4.65 ft/sec near the surface of the sound in a cross section in the vicinity of a proposed wastewater outfall. Vertical velocity distributions calculated for the time of maximum velocity were similar at all stations at which velocities were measured except the station in shallow water near the shore. A recent bathymetric chart of the vicinity of the proposed outfall indicates that a bar extends farther along the northern shore of Hilton Head Island than indicated on earlier nautical charts of Port Royal Sound. Continued extension of this bar could alter the impact on water quality from discharge of treated wastewater into the sound. Further study may be needed to monitor changes in the bar if the outfall is located between the bar and Hilton Head Island. Conservative calculations based on the results of the dye tracer study indicate that the discharge of 10.9 million gallons/day of wastewater having concentrations of biochemical oxygen demand and suspended solids of 15 mg/L will result in a maximum cumulative increase in concentrations of biochemical oxygen demand of < 0.01 mg/L and no increase in concentrations of suspended solids at high slack tide in the part of Port Royal Sound most affected by the proposed wastewater discharge. (Author 's abstract)

Phthalates in Commercial Chinese Rice Wines: Concentrations and the Cumulative Risk Assessment to Adult Males in Shanghai.

PubMed

Huang, Yue; Lu, Wen Wei; Chen, Bo; You, Jie; Wu, Min; Li, Shu Guang

2014-10-01

The concentrations of 16 phthalates in 164 commercial Chinese rice wines (CRW) were detected by GC-MS, and consumption data on CRW in different packaging types was investigated from 634 adult males in Shanghai using a food frequency questionnaire. Based on the principles of probabilistic modelling and cumulative risk assessment, the exposure and health risk of phthalates from CRW to adult males in Shanghai was evaluated. DMP, DEP, DIBP, DnBP, BBP, and DEHP were detected in the samples, the range of detection frequency of individual phthalates varied from 6.10% for BBP to 15.24% for DIBP, and the detected concentrations were 51.06-200.34 ng/mL. All the respondents consumed CRW, 90.69% of them consumed CRW 0.01-49.9 mL/d, the minimum value of the average daily intake of CRW was 6.25 mL/d, the median was 13.72 mL/d and the maximum was 300 mL/d. The median exposure level of the 6 detected Phthalates to adult males in Shanghai were 6.58-7.10 ng/(d•kg), and the maximum exposure level were 137.38-540.47 ng/(d•kg). The cumulative exposure health risk index (HI) based on the median and maximum exposure level of the 6 Phthalates (DMP, DEP, DIBP, DnBP, BBP, and DEHP) were 0.001147 and 0.063396, both were far less than 1. In conclusion, CRW were generally consumed by the adult males in Shanghai, although multiple phthalates were detected in commercial CRW, health risk of such exposure levels from commercial CRW to the target adult males in Shanghai was very low. Copyright © 2014 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Occurrence and removal of progestagens in two representative swine farms: Effectiveness of lagoon and digester treatment.

PubMed

Liu, Shuang-Shuang; Ying, Guang-Guo; Liu, You-Sheng; Yang, Yuan-Yuan; He, Liang-Ying; Chen, Jun; Liu, Wang-Rong; Zhao, Jian-Liang

2015-06-15

A total of 21 progestagens were screened in animal wastes and environmental samples from two representative swine farms and surrounding environments of South China using ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) to assess the effectiveness of simple lagoon (and digester) treatment. The results showed that 11, 8 and 8 of 21 target progestagens were detected with the minimum concentration of 2.31 ng/L and maximum of 6150 ng/L in the water samples, with the minimum of 1.36 ng/L and maximum of 98.3 ng/L in the suspended particles, and with the minimum of 1.57 ng/g dry weight (dw) and maximum of 3310 ng/g dw in the solid samples, respectively. Trace levels (a few ng/L or ng/g levels) of dydrogesterone, 5α-dihydroprogesterone, norgestrel and progesterone were found in samples from nearby surface waters and vegetable fields impacted by animal wastes. The residual progestagens at the reported levels may still pose potential risks to aquatic organisms such as fish in the receiving aquatic environments. This finding suggests that swine wastewater and feces could lead to contamination of some detectable progestagens in the surrounding environments. Significant reduction in total progestagen concentrations were observed from the fresh swine wastewaters to the fish ponds, indicating effective removal of these compounds by the lagoon (and digester) treatment. In addition, the biogas digesters provided high removal of the progestagens in the waste streams. This low-cost and eco-friendly treatment system should be promoted in developing countries with concentrated animal operations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Theoretical foundation for measuring the groundwater age distribution.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gardner, William Payton; Arnold, Bill Walter

2014-01-01

In this study, we use PFLOTRAN, a highly scalable, parallel, flow and reactive transport code to simulate the concentrations of 3H, 3He, CFC-11, CFC-12, CFC-113, SF6, 39Ar, 81Kr, 4He and themean groundwater age in heterogeneous fields on grids with an excess of 10 million nodes. We utilize this computational platform to simulate the concentration of multiple tracers in high-resolution, heterogeneous 2-D and 3-D domains, and calculate tracer-derived ages. Tracer-derived ages show systematic biases toward younger ages when the groundwater age distribution contains water older than the maximum tracer age. The deviation of the tracer-derived age distribution from the true groundwatermore » age distribution increases with increasing heterogeneity of the system. However, the effect of heterogeneity is diminished as the mean travel time gets closer the tracer age limit. Age distributions in 3-D domains differ significantly from 2-D domains. 3D simulations show decreased mean age, and less variance in age distribution for identical heterogeneity statistics. High-performance computing allows for investigation of tracer and groundwater age systematics in high-resolution domains, providing a platform for understanding and utilizing environmental tracer and groundwater age information in heterogeneous 3-D systems. Groundwater environmental tracers can provide important constraints for the calibration of groundwater flow models. Direct simulation of environmental tracer concentrations in models has the additional advantage of avoiding assumptions associated with using calculated groundwater age values. This study quantifies model uncertainty reduction resulting from the addition of environmental tracer concentration data. The analysis uses a synthetic heterogeneous aquifer and the calibration of a flow and transport model using the pilot point method. Results indicate a significant reduction in the uncertainty in permeability with the addition of environmental tracer data, relative to the use of hydraulic measurements alone. Anthropogenic tracers and their decay products, such as CFC11, 3H, and 3He, provide significant constraint oninput permeability values in the model. Tracer data for 39Ar provide even more complete information on the heterogeneity of permeability and variability in the flow system than the anthropogenic tracers, leading to greater parameter uncertainty reduction.« less

Pharmaceuticals and iodinated contrast media in a hospital wastewater: A case study to analyse their presence and characterise their environmental risk and hazard.

PubMed

Mendoza, A; Aceña, J; Pérez, S; López de Alda, M; Barceló, D; Gil, A; Valcárcel, Y

2015-07-01

This work analyses the presence of twenty-five pharmaceutical compounds belonging to seven different therapeutic groups and one iodinated contrast media (ICM) in a Spanish medium-size hospital located in the Valencia Region. Analysis of the target compounds in the hospital wastewater was performed by means of solid phase extraction (SPE) followed by liquid chromatography-tandem mass spectrometry analysis (HPLC-MS/MS). A screening level risk assessment combining the measured environmental concentrations (MECs) with dose-response data based on Predicted No Effect Concentration (PNEC) was also applied to estimate Hazard Quotients (HQs) for the compounds investigated. Additionally, the environmental hazard associated to the various compounds measured was assessed through the calculation of the Persistence, Bioaccumulation and Toxicity (PBT) Index, which categorizes compounds according to their environmentally damaging characteristics. The results of the study showed the presence of twenty-four out of the twenty-six compounds analysed at individual concentrations ranging from 5 ng L(-1) to 2 mg L(-1). The highest concentrations corresponded to the ICM iomeprol, found at levels between 424 and 2093 μg L(-1), the analgesic acetaminophen (15-44 μg L(-1)), the diuretic (DIU) furosemide (6-15 μg L(-1)), and the antibiotics (ABIs) ofloxacin and trimethoprim (2-5 μg L(-1)). The lowest levels corresponded to the anti-inflammatory propyphenazone, found at concentrations between 5 and 44 ng L(-1). Differences in terms of concentrations of the analysed compounds have been observed in all the therapeutic groups when comparing the results obtained in this and other recent studies carried out in hospitals with different characteristics from different geographical areas and in different seasons. The screening level risk assessment performed in raw water from the hospital effluent showed that the analgesics and anti-inflammatories (AAFs) acetaminophen, diclofenac, ibuprofen and naproxen, the antibiotics (ABIs) clarithromycin, ofloxacin and trimethoprim, and the β-blocker (BBL) propranolol were present at concentrations leading to HQ values higher than 10, thus indicating high risk. When applying a factor to take into account potential dilution and degradation processes, only the compound ibuprofen showed a HQ higher than 1. Likewise, the cumulative HQ or Toxic Units (TUs) calculated in the raw water for each of the therapeutic groups studied showed that these three classes of drugs were at concentrations high enough to potentially generate high risk to aquatic organisms while taking into account possible dilution and degradation processes only one of them, the AAFs can be considered to represent high risk. Finally, the environmental hazard assessment performed showed that the AAFs diclofenac and ibuprofen and the ABI clarithromycin have the highest, maximum value of 9 of PBT Index due to their inherent environmentally damaging characteristics of persistence, bioaccumulation and toxicity. The methodology followed in the present case study can be taken as a novel approach to classify and categorize pharmaceuticals on the basis of their occurrence in hospital effluents, their derived environmental risks, and their associated environmental hazard. This classification becomes important because it can be used as a model or orientation for hospitals in the process of developing environmentally sustainable policies and as an argument to justify the adoption of advanced, specific treatments for hospital effluents before being discharged into the public sewage system. Copyright © 2015 Elsevier Inc. All rights reserved.

40 CFR 35.145 - Maximum federal share.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 35.145 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Environmental Program Grants Air Pollution Control (section 105) § 35.145 Maximum federal share. (a) The Regional Administrator may provide air pollution control agencies, as...

40 CFR 35.145 - Maximum federal share.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 35.145 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Environmental Program Grants Air Pollution Control (section 105) § 35.145 Maximum federal share. (a) The Regional Administrator may provide air pollution control agencies, as...

40 CFR 35.145 - Maximum federal share.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 35.145 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Environmental Program Grants Air Pollution Control (section 105) § 35.145 Maximum federal share. (a) The Regional Administrator may provide air pollution control agencies, as...

Translocation of the neonicotinoid seed treatment clothianidin in maize

PubMed Central

Krupke, Christian H.

2017-01-01

Neonicotinoid seed treatments, typically clothianidin or thiamethoxam, are routinely applied to >80% of maize (corn) seed grown in North America where they are marketed as a targeted pesticide delivery system. Despite this widespread use, the amount of compound translocated into plant tissue from the initial seed treatment to provide protection has not been reported. Our two year field study compared concentrations of clothianidin seed treatments in maize to that of maize without neonicotinoid seed treatments and found neonicotinoids present in root tissues up to 34 days post planting. Plant-bound clothianidin concentrations followed an exponential decay pattern with initially high values followed by a rapid decrease within the first ~20 days post planting. A maximum of 1.34% of the initial seed treatment was successfully recovered from plant tissues in both study years and a maximum of 0.26% was recovered from root tissue. Our findings show neonicotinoid seed treatments may provide protection from some early season secondary maize pests. However, the proportion of the neonicotinoid seed treatment clothianidin translocated into plant tissues throughout the growing season is low overall and this observation may provide a mechanism to explain reports of inconsistent efficacy of this pest management approach and increasing detections of environmental neonicotinoids. PMID:28282441

Influence of surface oxides on the adsorption of naphthalene onto multiwalled carbon nanotubes.

PubMed

Cho, Hyun-Hee; Smith, Billy A; Wnuk, Joshua D; Fairbrother, D Howard; Ball, William P

2008-04-15

As greater quantities of carbon nanotubes (CNTs) enter the environment, they will have an increasingly important effect on the availability and transport of aqueous contaminants. As a consequence of purification, deliberate surface functionalization, and/or exposure to oxidizing agents after release to the environment, CNTs often contain surface oxides (i.e., oxygen containing functional groups). To probe the influence that surface oxides exert on CNT sorption properties, multiwalled CNTs (MWCNTs) with varying oxygen concentrations were studied with respect to their sorption properties toward naphthalene. For pristine (as-received) MWCNTs, the sorption capacity was intermediate between that of a natural char and a granular activated carbon. Sorption data also reveal that a linear relationship exists between the oxygen content of MWCNTs and their maximum adsorption capacity for naphthalene, with 10% surface oxygen concentration resulting in a roughly 70% decrease in maximum adsorption capacity. The relative distribution of sorption energies, as characterized by Freundlich isotherm exponents was, however, unaffected by oxidation. Thus, the data are consistent with the idea that incorporated surface oxides create polar regions that reduce the surface area available for naphthalene sorption. These results highlight the important role of surface chemistry in controlling the environmental properties of CNTs.

Tree-ring formation as an indicator of forest capacity to adapt to the main threats of environmental changes in Lithuania.

PubMed

Augustaitis, Algirdas; Augustaitienė, Ingrida; Baugarten, Manuela; Bičenkienė, Steigvilė; Girgždienė, Raselė; Kulbokas, Gintaras; Linkevičius, Edgaras; Marozas, Vitas; Mikalajūnas, Marius; Mordas, Genrik; Mozgeris, Gintautas; Petrauskas, Edmundas; Pivoras, Ainis; Šidlauskas, Giedrius; Ulevičius, Vidmantas; Vitas, Adomas; Matyssek, Rainer

2018-02-15

Global changes occurring under different environmental conditions have changed stand competition, as well as nutrient and light availability, which has resulted in changes in productivity. Therefore, in the present study, the characteristics of tree-ring width formation of the prevailing Lithuanian tree species, Norway spruce, Scots pine and silver and downy birch, and key factors resulting in their differences during the last 36-year period were investigated at forest sites located on poor mineral oligotrophic and on nutrient-rich organic mesoeutrophic soils. The aim of the study was as follows: first, to separately detect the maximum possible seasonal effect of three groups of variables - meteorology, acidifying pollutants and surface ozone on the stem basal area increment (BAI) of the evaluated tree species; second, to assess the significance of each group of variables affecting the BAI of these tree species integrally with the remaining groups of variables. Norway spruce was found to be well adapted to recent environmental changes, which makes it one of the most favourable tree species for silviculture in the northeastern part of Europe. The rapid increases recorded in growth intensity since 1980 were attributed to the increase in air temperature, precipitation amount, nitrogen deposition during the vegetative stage and reductions in SO 2 concentrations and S deposition. Scots pine demonstrated the highest level of resilience and capacity to adapt to recent global changes because its reaction to both negative and favourable environmental factors was best expressed. Silver and downy birch tree reactions to the effects of air concentrations of acidifying compounds, their deposition and surface ozone concentrations were the least expressed; however, a significant decline in growth intensity indicated that these tree species experienced a reduced resistance to recent changes in environmental conditions in the mature and over-mature age groups. Copyright © 2017 Elsevier B.V. All rights reserved.

40 CFR Table 2 to Subpart Dddd of... - Operating Requirements

Code of Federal Regulations, 2012 CFR

2012-07-01

... THC concentration a in the thermal oxidizer exhaust below the maximum concentration established during... average THC concentration a in the catalytic oxidizer exhaust below the maximum concentration established... the range established according to § 63.2262(m) Maintain the 24-hour block average THC concentration a...

40 CFR Table 2 to Subpart Dddd of... - Operating Requirements

Code of Federal Regulations, 2013 CFR

2013-07-01

... THC concentration a in the thermal oxidizer exhaust below the maximum concentration established during... average THC concentration a in the catalytic oxidizer exhaust below the maximum concentration established... the range established according to § 63.2262(m) Maintain the 24-hour block average THC concentration a...

40 CFR Table 2 to Subpart Dddd of... - Operating Requirements

Code of Federal Regulations, 2014 CFR

2014-07-01

... THC concentration a in the thermal oxidizer exhaust below the maximum concentration established during... average THC concentration a in the catalytic oxidizer exhaust below the maximum concentration established... the range established according to § 63.2262(m) Maintain the 24-hour block average THC concentration a...

DNA damage in earthworms (Eisenia spp.) as an indicator of environmental stress in the industrial zone of Coatzacoalcos, Veracruz, Mexico.

PubMed

Espinosa-Reyes, Guillermo; Ilizaliturri, Cesar A; Gonzalez-Mille, Donaji J; Costilla, Rogelio; Diaz-Barriga, Fernando; Carmen Cuevas, Maria Del; Martinez, Miguel Angel; Mejia-Saavedra, Jesus

2010-01-01

Coatzacoalcos, Veracruz is one of the major industrial areas of Mexico. Presently, the Coatzacoalcos River and the areas surrounding the industrial complex are considered by various authors to be some of most polluted sites in Mexico. The objective of this study was to determine if earthworms could be used as indicators of environmental stress in the Coatzacoalcos industrial zone. Often, detritivores and decomposers such as earthworms are the first to be affected when the soil is contaminated. We collected soil samples to be used for persistent organic pollutants (POPs) quantification by gas chromatography. Concentrations of hexachlorobenzene, lindane and total polychlorinated biphenyls (PCBs) in the soil were above the maximum permissible limits of the Canadian Environmental Quality Guidelines (CEQG). Comet assay was conducted in coelomocytes of wild earthworms collected in Coatzacoalcos and compared with the control earthworms. We found DNA damage in earthworms from Coatzacoalcos that was significantly higher (P < 0.05) in comparison to laboratory earthworms. Earthworms are an appropriate organism to use as an indicator of environmental impact in contaminated sites. DNA damage recorded in the earthworms provides clear evidence of environmental impacts by the chemical industry on the wildlife of this region.

Natural and environmental vulnerability analysis through remote sensing and GIS techniques: a case study of Indigirka River basin, Eastern Siberia, Russia

NASA Astrophysics Data System (ADS)

Boori, Mukesh S.; Choudhary, Komal; Kupriyanov, Alexander; Sugimoto, Atsuko; Evers, Mariele

2016-10-01

The aim of this research work is to understand natural and environmental vulnerability situation and its cause such as intensity, distribution and socio-economic effect in the Indigirka River basin, Eastern Siberia, Russia. This paper identifies, assess and classify natural and environmental vulnerability using landscape pattern from multidisciplinary approach, based on remote sensing and Geographical Information System (GIS) techniques. A model was developed by following thematic layers: land use/cover, vegetation, wetland, geology, geomorphology and soil in ArcGIS 10.2 software. According to numerical results vulnerability classified into five levels: low, sensible, moderate, high and extreme vulnerability by mean of cluster principal. Results are shows that in natural vulnerability maximum area covered by moderate (29.84%) and sensible (38.61%) vulnerability and environmental vulnerability concentrated by moderate (49.30%) vulnerability. So study area has at medial level vulnerability. The results found that the methodology applied was effective enough in the understanding of the current conservation circumstances of the river basin in relation to their environment with the help of remote sensing and GIS. This study is helpful for decision making for eco-environmental recovering and rebuilding as well as predicting the future development.

Simultaneous degradation of tetracycline and denitrification by a novel bacterium, Klebsiella sp. SQY5.

PubMed

Shao, Sicheng; Hu, Yongyou; Cheng, Ce; Cheng, Jianhua; Chen, Yuancai

2018-06-14

Polluted waters with a high residue of tetracycline also have a high concentration of nitrate. Thus, screening for both, highly efficient tetracycline biodegradation and nitrate transformation, is a key technical strategy. In this study, a novel tetracycline degrading strain, SQY5, which was identified as Klebsiella sp., was isolated from municipal sludge. Biodegradation characteristics of tetracycline were studied under various environmental conditions; including inoculation dose (v/v), initial tetracycline concentration, temperature, and pH. Response surface methodology (RSM) analysis demonstrated that the maximum degradation ratio of tetracycline can be obtained under the condition with an initial tetracycline concentration of 61.27 mg L -1 , temperature of 34.96 °C, pH of 7.17, and inoculation dose of 29.89%. Furthermore, this was the first report on the relationship between the degradation of tetracycline and the denitrification effect, showing that a maximum tetracycline reduction rate of 0.113 mg L -1 ·h -1 and denitrification rate of 4.64 mg L -1 ·h -1 were observed within 32 h and 92 h of SQY5 inoculation, respectively. The data of this study has the potential for use in engineering processes designed for the simultaneous biological removal of nitrates while degrading antibiotics. Copyright © 2018 Elsevier Ltd. All rights reserved.

Maximum availability and mineralogical control of chromium released from AOD slag.

PubMed

Li, Junguo; Liu, Bao; Zeng, Yanan; Wang, Ziming; Gao, Zhiyuan

2017-03-01

AOD (argon oxygen decarburization) slag is the by-product in the stainless steel refining process. Chromium existing in AOD slag can leach out and probably poses a serious threat to the environment. To assess the leaching toxicity of chromium released from AOD slag, the temperature-dependent maximum availability leaching test was performed. To determine the controlling mineralogical phases of chromium released from AOD slag, a Visual MINTEQ simulation was established based on Vminteq30 and the FactSage 7.0 database. The leaching tests indicated that the leaching availability of chromium was slight and mainly consisted of trivalent chromium. Aging of AOD slag under the atmosphere can oxidize trivalent chromium to hexavalent chromium, which could be leached out by rainwater. According to the simulation, the chromium concentration in leachates was controlled by the freely soluble pseudo-binary phases in the pH = 7.0 leaching process and controlled by the Cr 2 O 3 phase in the pH = 4.0 leaching process. Chromium concentrations were underestimated when the controlling phases were determined to be FeCr 2 O 4 and MgCr 2 O 4 . Facilitating the generation of the insoluble spinel-like phases during the cooling and disposal process of the molten slag could be an effective approach to decreasing the leaching concentration of chromium and its environmental risk.

The Multimedia Environmental Pollutant Assessment System (MEPAS){reg_sign}: Atmospheric pathway formulations. Revision

DOE Office of Scientific and Technical Information (OSTI.GOV)

Droppo, J.G.; Buck, J.W.

1996-03-01

The Multimedia Environmental Pollutant Assessment System (MEPAS) is an integrated software implementation of physics-based fate and transport models for health and environmental risk assessments of both radioactive and hazardous pollutants. This atmospheric component report is one of a series of formulation reports that document the MEPAS mathematical models. MEPAS is a multimedia model; pollutant transport is modeled within, through, and between multiple media (air, soil, groundwater, and surface water). The estimated concentrations in the various media are used to compute exposures and impacts to the environment, to maximum individuals, and to populations. The MEPAS atmospheric component for the air mediamore » documented in this report includes models for emission from a source to the air, initial plume rise and dispersion, airborne pollutant transport and dispersion, and deposition to soils and crops. The material in this report is documentation for MEPAS Versions 3.0 and 3.1 and the MEPAS version used in the Remedial Action Assessment System (RAAS) Version 1.0.« less

Dissolved Phosphorus Pools and Alkaline Phosphatase Activity in the Euphotic Zone of the Western North Pacific Ocean

PubMed Central

Suzumura, Masahiro; Hashihama, Fuminori; Yamada, Namiha; Kinouchi, Shinko

2012-01-01

We measured pools of dissolved phosphorus (P), including dissolved inorganic P (DIP), dissolved organic P (DOP) and alkaline phosphatase (AP)-hydrolyzable labile DOP (L-DOP), and kinetic parameters of AP activity (APA) in the euphotic zone in the western North Pacific Ocean. Samples were collected from one coastal station in Sagami Bay, Japan, and three offshore stations between the North Pacific subtropical gyre (NPSG) and the Kuroshio region. Although DIP concentrations in the euphotic zone at all stations were equally low, around the nominal method detection limit of 20 nmol L-1, chlorophyll a (Chl a) concentrations were one order of magnitude greater at the coastal station. DOP was the dominant P pool, comprising 62–92% of total dissolved P at and above the Chl a maximum layer (CML). L-DOP represented 22–39% of the total DOP at the offshore stations, whereas it accounted for a much higher proportion (about 85%) in the coastal surface layers. Significant correlations between maximum potential AP hydrolysis rates and DIP concentrations or bacterial cell abundance in the offshore euphotic zone suggest that major APA in the oligotrophic surface ocean is from bacterial activity and regulated largely by DIP availability. Although the range of maximum potential APA was comparable among the environmental conditions, the in situ hydrolysis rate of L-DOP in the coastal station was 10 times those in the offshore stations. L-DOP turnover time at the CML ranged from 4.5 days at the coastal station to 84.4 days in the NPSG. The ratio of the APA half-saturation constant to the ambient L-DOP concentration decreased markedly from the NPSG to the coastal station. There were substantial differences in the rate and efficiency of DOP remineralization and its contribution as the potential P source between the low-phosphate/high-biomass coastal ecosystem and the low-phosphate/low biomass oligotrophic ocean. PMID:22457661

Prospective power calculations for the Four Lab study of a multigenerational reproductive/developmental toxicity rodent bioassay using a complex mixture of disinfection by-products in the low-response region.

PubMed

Dingus, Cheryl A; Teuschler, Linda K; Rice, Glenn E; Simmons, Jane Ellen; Narotsky, Michael G

2011-10-01

In complex mixture toxicology, there is growing emphasis on testing environmentally representative doses that improve the relevance of results for health risk assessment, but are typically much lower than those used in traditional toxicology studies. Traditional experimental designs with typical sample sizes may have insufficient statistical power to detect effects caused by environmentally relevant doses. Proper study design, with adequate statistical power, is critical to ensuring that experimental results are useful for environmental health risk assessment. Studies with environmentally realistic complex mixtures have practical constraints on sample concentration factor and sample volume as well as the number of animals that can be accommodated. This article describes methodology for calculation of statistical power for non-independent observations for a multigenerational rodent reproductive/developmental bioassay. The use of the methodology is illustrated using the U.S. EPA's Four Lab study in which rodents were exposed to chlorinated water concentrates containing complex mixtures of drinking water disinfection by-products. Possible experimental designs included two single-block designs and a two-block design. Considering the possible study designs and constraints, a design of two blocks of 100 females with a 40:60 ratio of control:treated animals and a significance level of 0.05 yielded maximum prospective power (~90%) to detect pup weight decreases, while providing the most power to detect increased prenatal loss.

Prospective Power Calculations for the Four Lab Study of A Multigenerational Reproductive/Developmental Toxicity Rodent Bioassay Using A Complex Mixture of Disinfection By-Products in the Low-Response Region

PubMed Central

Dingus, Cheryl A.; Teuschler, Linda K.; Rice, Glenn E.; Simmons, Jane Ellen; Narotsky, Michael G.

2011-01-01

In complex mixture toxicology, there is growing emphasis on testing environmentally representative doses that improve the relevance of results for health risk assessment, but are typically much lower than those used in traditional toxicology studies. Traditional experimental designs with typical sample sizes may have insufficient statistical power to detect effects caused by environmentally relevant doses. Proper study design, with adequate statistical power, is critical to ensuring that experimental results are useful for environmental health risk assessment. Studies with environmentally realistic complex mixtures have practical constraints on sample concentration factor and sample volume as well as the number of animals that can be accommodated. This article describes methodology for calculation of statistical power for non-independent observations for a multigenerational rodent reproductive/developmental bioassay. The use of the methodology is illustrated using the U.S. EPA’s Four Lab study in which rodents were exposed to chlorinated water concentrates containing complex mixtures of drinking water disinfection by-products. Possible experimental designs included two single-block designs and a two-block design. Considering the possible study designs and constraints, a design of two blocks of 100 females with a 40:60 ratio of control:treated animals and a significance level of 0.05 yielded maximum prospective power (~90%) to detect pup weight decreases, while providing the most power to detect increased prenatal loss. PMID:22073030

Water-quality assessment of the Rio Grande Valley, Colorado, New Mexico, and Texas; shallow ground-water quality of a land-use area in the San Luis Valley, south-central Colorado, 1993

USGS Publications Warehouse

Anderholm, S.K.

1996-01-01

This report describes the quality of shallow ground water in an agricultural area in the San Luis Valley, Colorado, and discusses how natural and human factors affect the quality of shallow ground water. Thirty-five wells were installed, and water samples were collected from these wells and analyzed for selected dissolved common constituents, nutrients, trace elements, radionuclides, and synthetic organic compounds. The San Luis Valley is a high intermontane valley that is partially drained by the Rio Grande. The San Luis Valley land-use study area was limited to a part of the valley where the depth to water is generally less than 25 feet. The area where the 35 monitor wells were installed was further limited to the part of the study area where center-pivot overhead sprinklers are used to irrigate crops. Precipitation, runoff from adjacent mountainous areas, and ground-water inflow from the adjacent mountainous areas are the main sources of water to the aquifers in the San Luis Valley. Discharge of water from the shallow, unconfined aquifer in the valley is mainly from evapotranspiration. The dominant land use in the San Luis Valley is agriculture, although nonirrigated land and residential land are interspersed with agricultural land. Alfalfa, native hay, barley, wheat, potatoes, and other vegetables are the main crops. Dissolved-solids concentrations in shallow ground water sampled ranged from 75 to 1,960 milligrams per liter. The largest median concentration of cations was for calcium, and the largest median concentration of anions was for bicarbonate in shallow ground water in the San Luis Valley. Calcium concentrations ranged from 7.5 to 300 milligrams per liter, and bicarbonate concentrations ranged from 28 to 451 milligrams per liter. Nitrite plus nitrate concentrations ranged from less than 0.1 to 58 milligrams per liter as N; water from 11 wells had nitrite plus nitrate concentrations greater than 10 milligrams per liter as N. With the exception of the following trace elements--aluminum, barium, iron, manganese, molybdenum, and uranium--the concentrations of trace elements were less than 10 micrograms per liter in 90 percent of the samples. All trace-element concentrations measured were below the maximum contaminant levels set by the U.S. Environmental Protection Agency. Five samples exceeded the proposed maximum contaminant level of 0.02 milligram per liter for uranium. All samples collected exceeded the proposed maximum contaminant level for radon-222. The volatile organic compound methyltertbutylether was detected in one sample at a concentration of 0.6 microgram per liter. Of the pesticides analyzed for, one or more were detected in water from 5 of the 35 wells sampled. Metribuzin was the most commonly detected pesticide and was detected in water from three wells at concentrations ranging from an estimated 0.005 to 0.017 microgram per liter. Metolachlor (detected in one sample at a concentration of 0.072 microgram per liter), prometon (detected in one sample at a concentration of 0.01 microgram per liter), and p,p'-DDE (detected in one sample at an estimated concentration of 0.002 microgram per liter) were the other pesticides detected. The U.S. Environmental Protection Agency lifetime health advisory for metolachlor, metribuzin, and prometon is 100 micrograms per liter, which is much larger than the concentrations measured in the shallow ground water sampled for this study. The elevated nitrite plus nitrate concentrations in shallow ground water are indicative of leaching of fertilizers from the land surface. This conclusion is consistent with conclusions made in other investigations of the San Luis Valley. On the basis of areal distribution and range of trace-element concentrations, human activities have not caused widespread trace-element contamination in the shallow grou

The effect of isoenzyme-selective PDE inhibitors on methacholine-induced contraction of guinea-pig and rat ileum.

PubMed Central

Tomkinson, A.; Raeburn, D.

1996-01-01

1. We have examined the effects of the isoenzyme-selective phosphodiesterase (PDE) inhibitors, vinpocetine (type 1), siguazodan (type 3), rolipram (type 4) and zaprinast (type 5) and the non-selective PDE inhibitor enprofylline on methacholine (MCh) contractile concentration-response curves on guinea-pig and rat isolated ileum. 2. In guinea-pig ileum, vinpocetine (10-300 microM), zaprinast (1-300 microM) and enprofylline (100-1000 microM) produced a concentration-dependent depression of the maximum response (Emax) to MCh only without effect on the MCh EC50 values (rank order of potency: zaprinast > vinpocetine > enprofylline). In contrast, siguazodan (10-300 microM) and rolipram (10-300 microM) produced a rightward displacement of the MCh concentration-response curve (increase in EC50: rank order; rolipram > siguazodan), with effects on the MCh maximum seen only at higher concentrations. 3. In the rat ileum, vinpocetine (10-300 microM), zaprinast (0.1-300 microM) and enprofylline (100-1000 microM) caused depression of the MCh maximum contraction (rank order: zaprinast > vinpocetine > enprofylline). Low concentrations of rolipram and siguazodan had no significant effect on the MCh maximum. In the presence of higher concentrations (> 100 microM) of rolipram and siguazodan, a maximum response was not achieved at the highest concentration of MCh tested. As in the guinea-pig ileum, only rolipram (10-300 microM) and siguazodan (10-300 microM) produced a significant, concentration-dependent, rightward displacement of the MCh concentration-response curve (increase in EC50: rank order: rolipram > siguazodan). 4. In the guinea-pig ileum, isoprenaline (0.1 microM) produced a rightward displacement (approximately 3 fold) of the MCh concentration-response curve, accompanied by a significant depression of the maximum response. Increasing the isoprenaline concentration (1 microM) had no further effect on either parameter. Sodium nitroprusside (SNP, > or = 10 microM) produced a concentration-dependent depression of the MCh maximum without an effect on the EC50. 5. In the rat ileum, isoprenaline (1 microM) produced a concentration-dependent rightward displacement (approximately 2.8 fold) of the MCh concentration-response curve with depression of the MCh maximum at higher (> or = 100 microM) concentrations. SNP produced depression of the MCh maximum at a concentration of 10 microM and above. Effects on the MCh EC50 were seen only at 100 and 300 microM. 6. In guinea-pig ileum, isoprenaline (0.1 microM) in combination with rolipram (10 microM) further increased the MCh EC50 and reduced the MCh maximum. The combination of SNP (10 microM) with zaprinast (0.1 microM) produced no further significant effect than SNP alone. 7. In rat ileum, isoprenaline (1 microM) in combination with rolipram (10 microM) further increased the EC50 and reduced the maximum. SNP (10 microM) had no significant effect on either the MCh maximum or EC50. A combination with zaprinast (1 microM) had no further effect. 8. In conclusion, all the PDE inhibitors tested produced a concentration-dependent inhibition of the MCh concentration-response curve, indicating a modulator role for the PDE isoenzymes in gastrointestinal smooth muscle contractility. The PDE inhibitors that elevate cyclic GMP produced a depression of the MCh maximum response only, whilst those that elevate cyclic AMP produced a rightward displacement of the MCh concentration-response curve. This was confirmed by the use of isoprenaline and SNP. This difference in the type of inhibition produced by these PDE isoenzyme inhibitors may reflect a different intracellular site/mechanism by which the cyclic AMP- and cyclic GMP-activated kinases act functionally to antagonize the contractile response. PMID:8864552

40 CFR 35.415 - Maximum federal share.

Code of Federal Regulations, 2011 CFR

2011-07-01

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40 CFR 35.364 - Maximum federal share.

Code of Federal Regulations, 2011 CFR

2011-07-01

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40 CFR 35.364 - Maximum federal share.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Maximum federal share. 35.364 Section 35.364 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Environmental Program Grants Water Quality Cooperative Agreements (section...

40 CFR 35.415 - Maximum federal share.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Maximum federal share. 35.415 Section 35.415 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Environmental Program Grants Water Quality Management Planning Grants...

40 CFR 35.349 - Maximum federal share.

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2013-07-01

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40 CFR 35.669 - Maximum federal share.

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... 35.669 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Environmental Program Grants for Tribes Pollution Prevention Grants (section 6605) § 35.669 Maximum federal share. The federal share for Pollution Prevention Grants will not exceed...

40 CFR 35.669 - Maximum federal share.

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2013-07-01

... 35.669 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Environmental Program Grants for Tribes Pollution Prevention Grants (section 6605) § 35.669 Maximum federal share. The federal share for Pollution Prevention Grants will not exceed...

40 CFR 35.349 - Maximum federal share.

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2014-07-01

... 35.349 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Environmental Program Grants Pollution Prevention State Grants (section 6605) § 35.349 Maximum federal share. The federal share for Pollution Prevention State Grants will not exceed...

40 CFR 35.421 - Maximum federal share.

Code of Federal Regulations, 2013 CFR

2013-07-01

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40 CFR 35.738 - Maximum federal share.

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40 CFR 35.421 - Maximum federal share.

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2014-07-01

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40 CFR 35.738 - Maximum federal share.

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2014-07-01

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40 CFR 35.738 - Maximum federal share.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Maximum federal share. 35.738 Section 35.738 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Environmental Program Grants for Tribes Tribal Response Program Grants...

40 CFR 35.421 - Maximum federal share.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Maximum federal share. 35.421 Section 35.421 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Environmental Program Grants State Response Program Grants (cercla Section...

40 CFR 35.421 - Maximum federal share.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Maximum federal share. 35.421 Section 35.421 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Environmental Program Grants State Response Program Grants (cercla Section...

40 CFR 35.738 - Maximum federal share.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Maximum federal share. 35.738 Section 35.738 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Environmental Program Grants for Tribes Tribal Response Program Grants...

40 CFR 35.738 - Maximum federal share.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 1 2012-07-01 2012-07-01 false Maximum federal share. 35.738 Section 35.738 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Environmental Program Grants for Tribes Tribal Response Program Grants...

40 CFR 35.421 - Maximum federal share.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 1 2012-07-01 2012-07-01 false Maximum federal share. 35.421 Section 35.421 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Environmental Program Grants State Response Program Grants (cercla Section...

The Empirical Relationship between Mining Industry Development and Environmental Pollution in China

PubMed Central

Li, Gerui; Lei, Yalin; Ge, Jianping; Wu, Sanmang

2017-01-01

This study uses a vector autoregression (VAR) model to analyze changes in pollutants among different mining industries and related policy in China from 2001 to 2014. The results show that: (1) because the pertinence of standards for mining waste water and waste gas emissions are not strong and because the maximum permissible discharge pollutant concentrations in these standards are too high, ammonia nitrogen and industrial sulfur dioxide discharges increased in most mining industries; (2) chemical oxygen demand was taken as an indicator of sewage treatment in environmental protection plans; hence, the chemical oxygen demand discharge decreased in all mining industries; (3) tax reduction policies, which are only implemented in coal mining and washing and extraction of petroleum and natural gas, decreased the industrial solid waste discharge in these two mining industries. PMID:28257126

Effects of ACTH, capture, and short term confinement on glucocorticoid concentrations in harlequin ducks (Histrionicus histrionicus)

USGS Publications Warehouse

Nilsson, P.B.; Hollmén, Tuula E.; Atkinson, S.; Mashburn, K.L.; Tuomi, P.A.; Esler, Daniel N.; Mulcahy, D.M.; Rizzolo, D.J.

2008-01-01

Little is known about baseline concentrations of adrenal hormones and hormonal responses to stress in sea ducks, although significant population declines documented in several species suggest that sea ducks are exposed to increased levels of environmental stress. Such declines have been observed in geographically distinct harlequin duck populations. We performed an adrenocorticotropic hormone (ACTH) challenge to evaluate adrenal function and characterize corticosterone concentrations in captive harlequin ducks and investigated the effects of capture, surgery, and short term confinement on corticosterone concentrations in wild harlequin ducks. Harlequin ducks responded to the ACTH challenge with an average three-fold increase in serum corticosterone concentration approximately 90 min post injection, and a four- to five-fold increase in fecal glucocorticoid concentration 2 to 4 h post injection. Serum corticosterone concentrations in wild harlequin ducks increased within min of capture and elevated levels were found for several hours post capture, indicating that surgery and confinement maintain elevated corticosterone concentrations in this species. Mean corticosterone concentrations in wild harlequin ducks held in temporary captivity were similar to the maximum response levels during the ACTH challenge in captive birds. However, large variation among individuals was observed in responses of wild birds, and we found additional evidence suggesting that corticosterone responses varied between hatch year and after hatch year birds.

Thermal Energy for Lunar In Situ Resource Utilization: Technical Challenges and Technology Opportunities

NASA Technical Reports Server (NTRS)

Gordon, Pierce E. C.; Colozza, Anthony J.; Hepp, Aloysius F.; Heller, Richard S.; Gustafson, Robert; Stern, Ted; Nakamura, Takashi

2011-01-01

Oxygen production from lunar raw materials is critical for sustaining a manned lunar base but is very power intensive. Solar concentrators are a well-developed technology for harnessing the Sun s energy to heat regolith to high temperatures (over 1375 K). The high temperature and potential material incompatibilities present numerous technical challenges. This study compares and contrasts different solar concentrator designs that have been developed, such as Cassegrains, offset parabolas, compound parabolic concentrators, and secondary concentrators. Differences between concentrators made from lenses and mirrors, and between rigid and flexible concentrators are also discussed. Possible substrate elements for a rigid mirror concentrator are selected and then compared, using the following (target) criteria: (low) coefficient of thermal expansion, (high) modulus of elasticity, and (low) density. Several potential lunar locations for solar concentrators are compared; environmental and processing-related challenges related to dust and optical surfaces are addressed. This brief technology survey examines various sources of thermal energy that can be utilized for materials processing on the lunar surface. These include heat from nuclear or electric sources and solar concentrators. Options for collecting and transporting thermal energy to processing reactors for each source are examined. Overall system requirements for each thermal source are compared and system limitations, such as maximum achievable temperature are discussed.

Estimate of Solar Maximum Using the 1-8 Angstrom Geostationary Operational Environmental Satellites X-Ray Measurements

DTIC Science & Technology

2014-12-12

AFRL-RV-PS- AFRL-RV-PS- TR-2015-0005 TR-2015-0005 ESTIMATE OF SOLAR MAXIMUM USING THE 1–8 Å GEOSTATIONARY OPERATIONAL ENVIRONMENTAL SATELLITES X... Geostationary Operational Environmental Satellites X-Ray Measurements (Postprint) 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 61102F 6...of the solar cycle through an analysis of the solar X-ray background. Our results are based on the NOAA Geostationary Operational Environmental

Lead distribution and its potential risk to the environment: lesson learned from environmental monitoring of abandon mine.

PubMed

Nobuntou, Wanida; Parkpian, Preeda; Oanh, Nguyen Thi Kim; Noomhorm, Athapol; Delaune, R D; Jugsujinda, Aroon

2010-11-01

There are many abandon and existing mines (tin, lead and zinc) in the mountainous areas of Thailand. Toxic elements including heavy metals such as lead (Pb), cadmium (Cd) and arsenic (As) have been released and transported from the mining sites to the adjacent landscape. In Thong Pha Phum District, Kanchanaburi Province, Thailand Pb contamination in the vicinity of the mine has occurred which could lead to potential health problems in downstream communities. To better understand current status of Pb contamination and accumulation in the surrounding environment and potential health impact, surface sediment, soil and plant samples were collected seasonally from representative monitoring sites along the aquatic track or flow regime. Potential health risk was determined using hazard quotient (HQ) as an index for local inhabitants who consume rice. Environmental monitoring illustrated that Pb concentrations in the surface sediment was as high as 869.4 mg kg(-1) dry weight and varied differently among stations sampled. Lead content in agricultural soil ranged between 137.8 to 613.5 mg kg(-1) dry weight and was inversely proportion to the distance from the point source. Moreover Pb was transported from the point source to down hill areas. At the highly polluted monitoring stations (S1, S2, and S3), concentrations of Pb exceeded the maximum allowable concentration for Pb in agricultural soil (300 mg kg(-1)) by 1.7-2 times. The Pb in soil was primarily associated with Fe/Mn oxides bound fraction (46-56%) followed by the organic bound fraction (25-30%). Lead uptake by plant varied and was species dependent. However root and tuber crops like cassava (19.92 mg Pb kg(-1) dry weight) and curcumin (3.25 mg Pb kg(-1) dry weight) could have removed Pb from the soil which suggest growing root crops in Pb contaminated soils should be avoided. However Cd, a co-contaminant at one of monitored stations (S4) yielded rice grain with Cd exceeding the maximum allowable concentration suggesting some potential health risk (HQ = 5.34) if people consume rice grown at this station. Overall result shows a low risk associated with Pb release into the environment.

Detection of surface algal blooms using the newly developed algorithm surface algal bloom index (SABI)

NASA Astrophysics Data System (ADS)

Alawadi, Fahad

2010-10-01

Quantifying ocean colour properties has evolved over the past two decades from being able to merely detect their biological activity to the ability to estimate chlorophyll concentration using optical satellite sensors like MODIS and MERIS. The production of chlorophyll spatial distribution maps is a good indicator of plankton biomass (primary production) and is useful for the tracing of oceanographic currents, jets and blooms, including harmful algal blooms (HABs). Depending on the type of HABs involved and the environmental conditions, if their concentration rises above a critical threshold, it can impact the flora and fauna of the aquatic habitat through the introduction of the so called "red tide" phenomenon. The estimation of chlorophyll concentration is derived from quantifying the spectral relationship between the blue and the green bands reflected from the water column. This spectral relationship is employed in the standard ocean colour chlorophyll-a (Chlor-a) product, but is incapable of detecting certain macro-algal species that float near to or at the water surface in the form of dense filaments or mats. The ability to accurately identify algal formations that sometimes appear as oil spill look-alikes in satellite imagery, contributes towards the reduction of false-positive incidents arising from oil spill monitoring operations. Such algal formations that occur in relatively high concentrations may experience, as in land vegetation, what is known as the "red-edge" effect. This phenomena occurs at the highest reflectance slope between the maximum absorption in the red due to the surrounding ocean water and the maximum reflectance in the infra-red due to the photosynthetic pigments present in the surface algae. A new algorithm termed the surface algal bloom index (SABI), has been proposed to delineate the spatial distributions of floating micro-algal species like for example cyanobacteria or exposed inter-tidal vegetation like seagrass. This algorithm was specifically modelled to adapt to the marine habitat through its inclusion of ocean-colour sensitive bands in a four-band ratio-based relationship. The algorithm has demonstrated high stability against various environmental conditions like aerosol and sun glint.

An assessment of dispersing pollutants from the pre-harvest burning of sugarcane in rural areas in the northeast of Brazil

NASA Astrophysics Data System (ADS)

Rangel, Maria Gabriela L.; Henríquez, Jorge R.; Costa, José A. P.; de Lira Junior, José C.

2018-04-01

In recent years, the Brazilian government has been applying several restrictions with regard to preventing environmental pollution. Although Brazilian legislation is becoming stricter as to the pre-harvest burning of sugarcane, this practice is frequently used in order to assist manual harvesting. In the northeast region of Brazil, sugarcane is an important crop, which accounts for about 15% of the national production in a total area of 1,060,660 ha, the average production being 51,119 kg per hectare. The pre-harvest burning of sugarcane generates smoke, which has a high concentration of atmospheric pollutants such as carbon dioxide (CO2), carbon monoxide (CO), particulate matter (P.M. 2.5 and 10), polycyclic aromatic hydrocarbons (PAH), volatile organic compounds (VOC) and nitrogen oxides (NOX). This article estimates the volume of CO, P.M. 2.5 and NOX generated and how they are dispersed in the atmosphere when this arises from the burning of sugarcane biomass in rural areas of Northeast Brazil, and does so by using AERMOD VIEW® simulation software. Using the characteristics of the emissions and environmental (meteorological and topographical) data, quality air profiles based on pollutant dispersion were obtained. Three studies were taken into account in order to determine the relationship between pollutant dispersion and some parameters of the burning process, such as those for the spatial distribution of resources, the duration of pre-harvest burning and the influence of undertaking burning in different months. As to spatial distribution, to divide an area into small lots contributes to decreasing the maximum concentration of pollutants by 53% compared to burning a single area of equivalent size. The study of the burning duration indicated that doing so gradually (using a lengthier procedure) could decrease the maximum concentration of the pollutants by an inverse relation. The harvesting period in this region is between November and April. The pollutants dispersion process was greatest in February. April presented the worst dispersion conditions, and was associated with the highest pollutant concentrations.

Ground-water quality in the Appalachian Plateaus, Kanawha River basin, West Virginia

USGS Publications Warehouse

Sheets, Charlynn J.; Kozar, Mark D.

2000-01-01

Water samples collected from 30 privately-owned and small public-supply wells in the Appalachian Plateaus of the Kanawha River Basin were analyzed for a wide range of constituents, including bacteria, major ions, nutrients, trace elements, radon, pesticides, and volatile organic compounds. Concentrations of most constituents from samples analyzed did not exceed U.S. Environmental Protection Agency (USEPA) standards. Constituents that exceeded drinking-water standards in at least one sample were total coliform bacteria, Escherichia coli (E. coli), iron, manganese, and sulfate. Total coliform bacteria were present in samples from five sites, and E. coli were present at only one site. USEPA secondary maximum contaminant levels (SMCLs) were exceeded for three constituents -- sulfate exceeded the SMCL of 250 mg/L (milligrams per liter) in samples from 2 of 30 wells; iron exceeded the SMCL of 300 ?g/L (micrograms per liter) in samples from 12 of the wells, and manganese exceeded the SMCL of 50 ?g/L in samples from 17 of the wells sampled. None of the samples contained concentrations of nutrients that exceeded the USEPA maximum contaminant levels (MCLs) for these constituents. The maximum concentration of nitrate detected was only 4.1 mg/L, which is below the MCL of 10 mg/L. Concentrations of nitrate in precipitation and shallow ground water are similar, potentially indicating that precipitation may be a source of nitrate in shallow ground water in the study area. Radon concentrations exceeded the recently proposed maximum contaminant level of 300 pCi/L at 50 percent of the sites sampled. The median concentration of radon was only 290 pCi/L. Radon-222 is a naturally occurring, carcinogenic, radioactive decay product of uranium. Concentrations, however, did not exceed the alternate maximum contaminant level (AMCL) for radon of 4,000 pCi/L in any of the 30 samples. Arsenic concentrations exceeded the proposed MCL of 5?g/L at 4 of the 30 sites. No samples exceeded the current MCL of 50 ?g/L. Neither pesticides nor volatile organic compounds (VOCs) were prevalent in the study area, and the concentrations of the compounds that were detected did not exceed any USEPA MCLs. Pesticides were detected in only two of the 30 wells sampled, but four pesticides -- atrazine, carbofuran, DCPA, and deethylatrazine -- were detected in one well; molinate was detected in the other well. All of the pesticides detected were at estimated concentrations of only 0.002 ?g/L. Of the VOCs detected, trihalomethane compounds (THMs), which can result from chlorination of a well, were the most common. THMs were detected in 13 of the 30 wells sampled. Gasoline by-products, such as benzene, toluene, ethylbenzene and xylene (BTEX compounds) were detected in 10 of the 30 wells sampled. The maximum concentration of any of the VOCs detected in this study, however, was only 1.040 ?g/L, for the THM dichlorofluoromethane. Water samples from 25 of the wells were analyzed for chlorofluorocarbons (CFCs) to estimate the apparent age of ground water. The analyses indicated that age of water ranged from 10 to greater than 57 years, and that the age of ground water could be correlated with the topographic setting of the wells sampled. Thus the apparent age of water in wells on hilltops was youngest (median of 13 years) and that of water in wells in valleys was oldest (median of 42 years). Water from wells on hillsides was intermediate in age (median of 29 years). These data can be used to define contributing areas to wells, corroborate or revise conceptual ground-water flow models, estimate contaminant travel times from spills to other sources such as nearby domestic or public supply wells, and to manage point and nonpoint source activities that may affect critical aquifers.

40 CFR 75.72 - Determination of NOX mass emissions for common stack and multiple stack configurations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... the affected units as the difference between NOX mass emissions measured in the common stack and NOX... emissions using the maximum potential NOX emission rate, the maximum potential flow rate, and either the maximum potential CO2 concentration or the minimum potential O2 concentration (as applicable). The maximum...

Environmental occurrence and shallow ground water detection of the antibiotic monensin from dairy farms

USGS Publications Warehouse

Watanabe, N.; Harter, T.H.; Bergamaschi, B.A.

2008-01-01

Pharmaceuticals used in animal feeding operations have been detected in various environmental settings. There is a growing concern about the impact on terrestrial and aquatic organisms and the development of antibiotic-resistant strains of microorganisms. Pharmaceutical use in milking cows is relatively limited compared with other livestock operations, except for the ionophore monensin, which is given to lactating cows as a feed. By weight, monensin can be the most significant antibiotic used in a dairy farm. This study investigates the potential of monensin to move from dairy operations into the surrounding ground water. Using two dairy farms in California as study sites, we twice collected samples along the environmental pathway - from flush lanes, lagoon waters, and shallow ground water beneath the dairies and beneath its associated manured fields. Monensin concentrations were determined using solid-phase extraction and liquid chromatography-tandem mass spectrometry with positive electrospray ionization. Monensin was detected in all of the flush lane and lagoon water samples. Theoretical maximum concentration estimated from the actual dosing rate and the theoretical excretion rate assuming no attenuation was one order of magnitude greater than observed concentrations, suggesting significant attenuation in the manure collection and storage system. Monensin was also detected, at levels ranging from 0.04 to 0.39 ??g L-1, in some of the ground water samples underneath the production area of the dairy but not from the adjacent manured fields. Concentrations in ground water immediately downgradient of the lagoons were one to two orders of magnitude lower than the concentrations detected in lagoons, suggesting attenuation in the subsurface. The data suggest the possibility of monensin transport into shallow (2-5 m) alluvial ground water from dairy management units, including manure storage lagoons and freestalls occupied by heifers, lactating cows, and dry cows. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

Does ammonia trigger hyperventilation in the elasmobranch, Squalus acanthias suckleyi?

PubMed

De Boeck, Gudrun; Wood, Chris M

2015-01-15

We examined the ventilatory response of the spiny dogfish, to elevated internal or environmental ammonia. Sharks were injected via arterial catheters with ammonia solutions or their Na salt equivalents sufficient to increase plasma total ammonia concentration [TAmm]a by 3-5 fold from 145±21μM to 447±150μM using NH4HCO3 and a maximum of 766±100μM using (NH4)2SO4. (NH4)2SO4 caused a small increase in ventilation frequency (+14%) and a large increase in amplitude (+69%), while Na2SO4 did not. However, CO2 partial pressure (PaCO2) also increased and arterial pHa and plasma bicarbonate concentration ([HCO3(-)]a) decreased. NH4HCO3 caused a smaller increase in plasma ammonia resulting in a smaller but significant, short lived increases in ventilation frequency (+6%) and amplitude (36%), together with a rise in PaCO2 and [HCO3(-)]a. Injection with NaHCO3 which increased pHa and [HCO3(-)]a did not change ventilation. Plasma ammonia concentration correlated significantly with ventilation amplitude, while ventilation frequency showed a (negative) correlation with pHa. Exposure to high environmental ammonia (1500μM NH4HCO3) did not induce changes in ventilation until plasma [TAmm]a increased and ventilation amplitude (but not frequency) increased in parallel. We conclude that internal ammonia stimulates ventilation in spiny dogfish, especially amplitude or stroke volume, while environmental ammonia only stimulates ventilation after ammonia diffuses into the bloodstream. Copyright © 2014 Elsevier B.V. All rights reserved.

A site-specific screening comparison of modeled and monitored air dispersion and deposition for perfluorooctanoate.

PubMed

Barton, Catherine A; Zarzecki, Charles J; Russell, Mark H

2010-04-01

This work assessed the usefulness of a current air quality model (American Meteorological Society/Environmental Protection Agency Regulatory Model [AERMOD]) for predicting air concentrations and deposition of perfluorooctanoate (PFO) near a manufacturing facility. Air quality models play an important role in providing information for verifying permitting conditions and for exposure assessment purposes. It is important to ensure traditional modeling approaches are applicable to perfluorinated compounds, which are known to have unusual properties. Measured field data were compared with modeling predictions to show that AERMOD adequately located the maximum air concentration in the study area, provided representative or conservative air concentration estimates, and demonstrated bias and scatter not significantly different than that reported for other compounds. Surface soil/grass concentrations resulting from modeled deposition flux also showed acceptable bias and scatter compared with measured concentrations of PFO in soil/grass samples. Errors in predictions of air concentrations or deposition may be best explained by meteorological input uncertainty and conservatism in the PRIME algorithm used to account for building downwash. In general, AERMOD was found to be a useful screening tool for modeling the dispersion and deposition of PFO in air near a manufacturing facility.

Increase in Lead Concentration in the Drinking Water of an Animal Care Facility.

PubMed

Davidowitz, Bradley; Boehm, Kirk; Banovetz, Sandra; Binkley, Neil

1998-01-01

We report here the unexpected detection, and subsequent correction, of a problem that resulted in an increase in lead concentration in the drinking water of an animal research facility. At the initiation of a study, analysis of a water sample obtained from the drinking spout of an animal cage revealed a lead concentration nearly twice the Environmental Protection Agency's maximum acceptable concentration. Because the municipal water supply routinely had been tested and found to be free of lead, it was assumed that this contamination was within the animal care facility. It was hypothesized that the brass fitting connecting the drinking spout to a polyvinyl chloride (PVC) pipe was the source of contamination. Water samples were obtained hourly from 0700 to 1600 hours before and after replacement of the brass fitting with a PVC fitting. After this change, lead concentrations in all samples were within acceptable limits. Although blood lead concentrations were undetectable in 47 rhesus monkeys (Macaca mulatta) housed in the facility, subclinical lead toxicosis could have resulted and potentially complicated studies in which these monkeys were used. We recommend that the water supply of research facilities be monitored periodically.

Impact of forest fires on the concentrations of polychlorinated dibenzo-p-dioxin and dibenzofurans in coastal waters of central Chile.

PubMed

Salamanca, Marco; Chandía, Cristian; Hernández, Aldo

2016-12-15

The relationship between the occurrence of forest fires in central Chile and the total concentration of dioxins and furans (PCDD/F) in nearby coastal waters was analyzed. The data for this analysis was obtained from a long-term environmental monitoring program (PROMNA) in the Bio-Bio Region. Quantification of PCDD/F was performed using HRGC/HRMS at the MSS laboratory in England. Between 2006 and 2014, peaks were observed in February 2007 and 2012. These concentration maxima coincided with major forest fires in the Bio-Bio Region and particularly with those in the Itata River Basin. The January 2012 fires generated an intense short-term response that was associated with atmospheric transport which increases medium toxicity furan-type congeners concentrations (TCDF, PCDF and HxCDF) and six months later a concentration increase of low toxicity dioxin-type congeners was observed (OCDD, HpCDD and HxCDD) coinciding with maximum winter river flow. These results suggest that forest fires near the coastal zone are responsible for increases in PCDD/F concentration observed in the study area. Copyright © 2016 Elsevier B.V. All rights reserved.

Fraser River watershed, Colorado : assessment of available water-quantity and water-quality data through water year 1997

USGS Publications Warehouse

Apodaca, Lori Estelle; Bails, Jeffrey B.

1999-01-01

The water-quantity and water-quality data for the Fraser River watershed through water year 1997 were compiled for ground-water and surface-water sites. In order to assess the water-quality data, the data were related to land use/land cover in the watershed. Data from 81 water-quantity and water-quality sites, which consisted of 9 ground-water sites and 72 surface-water sites, were available for analysis. However, the data were limited and frequently contained only one or two water-quality analyses per site.The Fraser River flows about 28 miles from its headwaters at the Continental Divide to the confluence with the Colorado River. Ground-water resources in the watershed are used for residential and municipal drinking-water supplies. Surface water is available for use, but water diversions in the upper parts of the watershed reduce the flow in the river. Land use/land cover in the watershed is predominantly forested land, but increasing urban development has the potential to affect the quantity and quality of the water resources.Analysis of the limited ground-water data in the watershed indicates that changes in the land use/land cover affect the shallow ground-water quality. Water-quality data from eight shallow monitoring wells in the alluvial aquifer show that iron and manganese concentrations exceeded the U.S. Environmental Protection Agency secondary maximum contaminant level. Radon concentrations from these monitoring wells exceeded the U.S. Environmental Protection Agency proposed maximum contaminant level. The proposed radon contaminant level is currently being revised. The presence of volatile organic compounds at two monitoring wells in the watershed indicates that land use affects the shallow ground water. In addition, bacteria detected in three samples are at concentrations that would be a concern for public health if the water was to be used as a drinking supply. Methylene blue active substances were detected in the ground water at some sites and are a possible indication of contamination from wastewater. Age of the alluvial ground water ranged from 10 to 30 years; therefore, results of land-management practices to improve water quality may not be apparent for many years.Surface-water-quality data for the Fraser River watershed are sparse. The surface-water-quality data show that elevated concentrations of selected constituents generally are related to specific land uses in the watershed. For one sample (about 2 percent; 1 of 53), dissolved manganese concentration exceeded the U.S. Environmental Protection Agency secondary maximum contaminant level. Two samples from two surface-water sites in the watershed exceeded the un-ionized ammonia chronic criterion. Spatial distribution of nutrient species (ammonia, nitrite, nitrate, and total phosphorus) shows that elevated concentrations occur primarily downstream from urban areas. Sites with five or more years of record were analyzed for temporal trends in concentration of nutrient species. Downward trends were identified for ammonia and nitrite for three surface-water sites. For nitrate, no trends were observed at two sites and a downward trend was observed at one site. Total phosphorus showed no trend for the site near the mouth of the Fraser River. Downward trends in the nutrient species may reflect changes in the wastewater-treatment facilities in the watershed. Bacteria sampling completed in the watershed indicates that more bacteria are present in the water near urban settings.The limited ground-water and surface-water data for the Fraser River watershed provide a general assessment of the quantity and quality of these resources. Concentrations of most water-quality constituents generally are less than ground- and surface-water-quality standards, but the presence of bacteria, some volatile organic compounds, methylene blue active substances, and increased nutrients in the water may indicate that land use is affecting the water quality..

Geochemistry and potential environmental impact of the mine tailings at Rosh Pinah, southern Namibia

NASA Astrophysics Data System (ADS)

Nejeschlebová, L.; Sracek, O.; Mihaljevič, M.; Ettler, V.; Kříbek, B.; Knésl, I.; Vaněk, A.; Penížek, V.; Dolníček, Z.; Mapani, B.

2015-05-01

Mine tailings at Rosh Pinah located in semiarid southern Namibia were investigated by the combination of mineralogical methods and leaching using water and simulated gastric solution. They are well-neutralized with leachate pH > 7 and neutralization potential ratios (NPR) up to 4. Neutralization is mainly due to abundant Mn-rich dolomite in the matrix. Concentrations of released contaminants in water leachate follow the order Zn > Pb > Cu > As. Relatively high leached concentrations of Zn and partly also of Pb are caused by their link to relatively soluble carbonates and Mn-oxyhydroxides. In contrast, As is almost immobile by binding into Fe-oxyhydroxides, which are resistant to dissolution. Barium is released by the dissolution of Ba-carbonate (norsethite) and precipitates in sulfate-rich pore water as barite. Dissolved concentrations in neutral mine drainage water collected in the southern pond are low, but when total concentrations including colloidal fraction are taken into account, more than 70% of Zn is in colloidal form. Groundwater upgradient of the mine tailings is of poor quality and there seems to be no negative impact on groundwater downgradient from mine tailings. Contaminant concentrations in simulated gastric leachates are in the order Ba > Pb > Zn > Cu > As with a maximum gastric bioaccessibility of 86.6% for Ba and a minimum of 3.3% for As. These results demonstrate that total contaminant content and toxicity in the solid phase are poor predictors of risk, and therefore mineralogical and bioavailability/bioaccessibility studies are necessary for evaluation of contaminant environmental impact.

Long-term variations of the riverine input of potentially toxic dissolved elements and the impacts on their distribution in Jiaozhou Bay, China.

PubMed

Wang, Changyou; Guo, Jinqiang; Liang, Shengkang; Wang, Yunfei; Yang, Yanqun; Wang, Xiulin

2018-03-01

The concentrations of the potentially toxic dissolved elements (PTEs) As, Hg, Cr, Pb, Cd, and Cu in the main rivers into Jiaozhou Bay (JZB) during 1981-2006 were measured, and the impact of the fluvial PTE fluxes on their distributions in the bay was investigated. The overall average concentration in the rivers into JZB ranged from 8.8 to 39.6 μg L -1 for As, 10.1 to 632.6 ng L -1 for Hg, 4.1 to 3003.6 μg L -1 for Cr, 8.5 to 141.9 μg L -1 for Pb, 1.1 to 34.2 μg L -1 for Cd, and 13.2 to 1042.8 μg L -1 for Cu. The interannual average concentration variations of the PTEs in these rivers were enormous, with maximum differences of 41-21,680 times, while their relative seasonal changes were far smaller with maximum differences of 3-12 times. The total annual fluvial fluxes for As, Hg, and Cr into JZB exhibited the inverse "U" pattern, while those for Pb and Cd showed the "N" pattern. As a whole, the total annual Cu flux presented a growing tendency from 1998 to 2006. In general, the changing trends of the PTE concentrations in JZB were similar to those of their annual fluxes from the rivers, indicating a great impact of their fluvial fluxes on their distributions in JZB. The annual concentration of Cd in the bay almost remained constant and differed from the fluvial flux of Cd. The diversified pattern of the environmental Kuznets curve (EKC) represented China's approach to industrialization as "improving while developing."

Occurrence, fate and ecotoxicological risk of personal care products in urban river-groundwater interface

NASA Astrophysics Data System (ADS)

Jurado, Anna; Pau Serra, Maria; Díaz-Cruz, M. Silvia; Vázquez-Suñé, Enric; Pujades, Estanislao; Barceló, Damià

2016-04-01

This work presents the occurrence and fate of selected personal care products (PCPs) in the urban river-groundwater interface. To this end, urban groundwater and river samples were collected in Sant Adrià del Besòs (NE of Spain) and a total of 16 PCPs were analyzed including benzophenone derivatives, camphor derivatives, p-aminobenzoic acid derivatives, triazoles and parabens in three different campaigns (from May 2010 to July 2014). These compounds reach the aquifer through the recharge of River Besòs that receives large amounts of effluents from waste water treatment plants. Results shown that most of compounds were not or barely detected (maximum concentrations around 30 ng/L) in groundwater samples during the different sampling campaigns. Only two triazoles, named as benzotriazole (BZT) and methyl benzotriazol (MeBZT) were found at high concentrations in groundwater samples (maximum concentration around 2000 ng/L). The fate of PCPs in the aquifer was assessed using mixing analysis considering the temporal variability of the River Besòs. Overall, measured groundwater concentrations were significantly much lower than those estimated by the mixing of the river water. This observation suggested that most of the PCPs are naturally removed when river water infiltrates the aquifer. However, some compounds were more persistent in the aquifer. These compounds were in descending order: the triazoles MeBZT and BZT followed by the camphor derivative 4MBC. The measured concentrations allowed us to assess the environmental risk posed by the selected UV-Fs (e.g. benzophenone derivatives) in the river-groundwater samples. Hazard Quotients (HQs) for diferent aquatic species were calculated in order to characterise the ecotoxicity potential of the studied compounds in the river-groundwater interface. HQ values will be presented and discussed in the presentation.

Natural Airborne Dust and Heavy Metals: A Case Study for Kermanshah, Western Iran (2005–2011)

PubMed Central

PIRSAHEB, Meghdad; ZINATIZADEH, Aliakbar; KHOSRAVI, Touba; ATAFAR, Zahra; DEZFULINEZHAD, Saeed

2014-01-01

Abstract Background Dust pollution has become a serious environmental problem especially in recent decades. The present study aim was the investigation of the levels of PM10 concentration in Kermanshah, western Iran and also measured five important heavy metals (Pb, Cd, As, Hg and Cr) in some samples during 2005 to 2011. Methods A total 2277 samples were collected from air pollution measurement station belonging to the Department of Environment in Kermanshah. Furthermore, four samples were collected during dusty days to determine the selected heavy metals concentration. The samples were analyzed statistically using the SPSS Ver.16 Results The highest seasonal average concentration in spring was recorded in 2008 with 216.63μg/m3, and the maximum values of 267.79 and 249.09μg/m3 were observed in summer and winter in 2009, respectively. The maximum concentration of 127.1μg/m3 was in autumn in 2010. The metals concentration (Pb, Cd, As, Hg and Cr) of samples were 42.32±5.40, 37.45±9.29, 3.51±2.07, 1.88±1.64 and 0μg/g in July, 2009, respectively. Conclusion According to National Ambient Air Quality of USEPA guidelines, the most days with non-standard, warning, emergency and critical conditions were related to 2009 (120 days) while the least polluted days were recorded in 2006 (16 days). There are concerns about the increasing frequency and intensity trend of dust storms in recent years as a result of special condition in neighboring Western countries which it could endanger public health and environment. All measured heavy metals except mercury was higher than the standard level of WHO and USEPA. PMID:26005656

Intra- and interannual dynamics of dinoflagellate bloom species in the James River, an urban tidal estuary in Virginia, USA

NASA Astrophysics Data System (ADS)

Echevarria, M. A.; Mulholland, M. R.; Filippino, K.; Egerton, T.

2016-02-01

Algal blooms occur throughout the year in the tidal tributaries of Chesapeake Bay. The James River is the largest river in Virginia and third largest tributary of the Bay. Of the nearly 1500 species found in the estuary, two dinoflagellates; Heterocapsa triquetra and Cochlodinium polykrikoides have historically formed large seasonal algal blooms in spring and summer respectively, lasting several weeks to months annually. Additionally, the toxic dinoflagellate Alexandrium monilatum has emerged as an annual late summer bloom producer with increasing abundance in the region over the last nine years. These blooms have occurred in the lower James River, including meso- and polyhaline waters. Presented here are comparisons of the temporal and spatial extent and magnitude of these three dinoflagellate species over a two-year period (2014-2015). In 2014 dinoflagellate abundance was low compared to prior years. In contrast, massive spring and summer blooms occurred in 2015 with extended durations. In 2015, H. triquetra reached a maximum concentration of >84,000 cells/ml, with densities >103 cells/mL observed over a six week period, compared to no visible bloom the year before and a maximum of only 6200 cells/ml. Similarly in 2015, C. polykrikoides reached maximum cell densities of >41,000 cells/ml, with densities >103 cells/mL observed over a seven week period, compared to a maximum the year before of <11,000 cells/ml. A. monilatum reached a maximum of >7,500 cells/ml over a three week period in August 2015, with no bloom recorded in 2014. Multiple environmental parameters likely contributed to the interannual variability in bloom formation and duration. Temperature appeared to be a significant factor, with cooler than average surface water during the summer of 2014. In addition, the effect of prevailing wind patterns, precipitation, salinity, nutrient concentrations and sediment re-suspension were examined.

Numerical modelling of organic waste dispersion from fjord located fish farms

NASA Astrophysics Data System (ADS)

Ali, Alfatih; Thiem, Øyvind; Berntsen, Jarle

2011-07-01

In this study, a three-dimensional particle tracking model coupled to a terrain following ocean model is used to investigate the dispersion and the deposition of fish farm particulate matter (uneaten food and fish faeces) on the seabed due to tidal currents. The particle tracking model uses the computed local flow field for advection of the particles and random movement to simulate the turbulent diffusion. Each particle is given a settling velocity which may be drawn from a probability distribution according to settling velocity measurements of faecal and feed pellets. The results show that the maximum concentration of organic waste for fast sinking particles is found under the fish cage and continue monotonically decreasing away from the cage area. The maximum can split into two maximum peaks located at both sides of the centre of the fish cage area in the current direction. This process depends on the sinking time (time needed for a particle to settle at the bottom), the tidal velocity and the fish cage size. If the sinking time is close to a multiple of the tidal period, the maximum concentration point will be under the fish cage irrespective of the tide strength. This is due to the nature of the tidal current first propagating the particles away and then bringing them back when the tide reverses. Increasing the cage size increases the likelihood for a maximum waste accumulation beneath the fish farm, and larger farms usually means larger biomasses which can make the local pollution even more severe. The model is validated by using an analytical model which uses an exact harmonic representation of the tidal current, and the results show an excellent agreement. This study shows that the coupled ocean and particle model can be used in more realistic applications to help estimating the local environmental impact due to fish farms.

Determination of heavy metal concentrations in street dusts in Istanbul E-5 highway.

PubMed

Sezgin, Naim; Ozcan, H Kurtulus; Demir, Goksel; Nemlioglu, Semih; Bayat, Cuma

2004-01-01

Components and quantity of street dust are environmental pollution indicators especially in big cities. Street dust is generally composed of car exhaust gas originated particles and wind-transported particles. Heavy metals, which are found in street dust, such as Pb, Cu, Mn, Zn, Cd and Ni are significant for environmental pollution. According to the kind of vehicle in traffic, quantity and type of heavy metals vary in street dust. The use of leaded gasoline gives a boost to the importance of lead level especially in street dust even at the start of 21st century. These metals possess bioaccumulation property, and the possibility of the amount of these metals reaching a critical value and threatening human health increases the importance of this issue. In this study, street dusts have been collected from E-5 Highway from Topkapi to Avcilar regions that spans about 18 km in Istanbul, Turkey, and Pb, Cu, Mn, Zn, Cd and Ni concentrations have been detected in street dust. Twenty-two street dust samples were taken from a total of 22 different points at previously decided 14 main areas. Analyses were conducted using Leeds Public Analyst method. According to the results of this study, Pb, Cu and Zn concentrations in E-5 Highway between Topkapi and Avcilar region in Istanbul were higher than maximum concentration levels of these heavy metals in normal soil. This situation indicates that there is heavy metal pollution in the inspected area in E-5 Highway in Istanbul.

Spatiotemporal Dynamics of Microcystin Variants and Relationships with Environmental Parameters in Lake Taihu, China

PubMed Central

Su, Xiaomei; Xue, Qingju; Steinman, Alan D.; Zhao, Yanyan; Xie, Liqiang

2015-01-01

Excessive anthropogenically-caused nutrient loading from both external and internal sources has promoted the growth of cyanobacteria in Lake Taihu from 2005 to 2014, suggesting increased production and release of cyanotoxins. In order to explain the spatial distribution and temporal variation of microcystins (MCs), the intracellular concentrations of MCs (MC-LR, -RR and -YR, L, R and Y are abbreviations of leucine, arginine and tyrosine) were monitored monthly from July 2013 to June 2014. Three MC variants are present simultaneously in Lake Taihu; the MC-LR and -RR variants were dominant (accounting for 40% and 39% of the total), followed by MC-YR (21%). However, MC-YR accounted for a higher proportion in colder months, especially in March. The highest concentrations of intracellular MCs were found in July and October when cyanobacteria cell density also reached the maximum. The average concentrations of MC-LR, -RR and -YR in July were 4.69, 4.23 and 2.01 μg/L, respectively. In terms of the entire lake, toxin concentrations in northern parts were significantly higher than the eastern part in summer, when MC concentrations were several times higher than the guideline value by WHO throughout much of Lake Taihu. Results from correlation and redundancy analysis (RDA) showed that total MCs, including all variants, were strongly and positively correlated with cyanobacteria cell density, water temperature, total phosphorus (TP) and pH, whereas each variant had different correlation coefficients with each of the considered environmental variables. MC-RR showed a stronger relationship with temperature, in contrast to MC-YR and -LR. Dissolved inorganic carbon (DIC) showed a negative relationship with each variant, suggesting that rising DIC concentrations may inhibit cyanobacterial growth and thereby reduce MC production in the future. PMID:26295260

DOE Office of Scientific and Technical Information (OSTI.GOV)

T. R. Saffle; R. G. Mitchell; R. B. Evans

The results of the various monitoring programs for 1998 indicated that radioactivity from the DOE's Idaho National Engineering and Environmental Laboratory (INEEL) operations could generally not be distinguished from worldwide fallout and natural radioactivity in the region surrounding the INEEL. Although some radioactive materials were discharged during INEEL operations, concentrations in the offsite environment and doses to the surrounding population were far less than state of Idaho and federal health protection guidelines. Gross alpha and gross beta measurements, used as a screening technique for air filters, were investigated by making statistical comparisons between onsite or boundary location concentrations and themore » distant community group concentrations. Gross alpha activities were generally higher at distant locations than at boundary and onsite locations. Air samples were also analyzed for specific radionuclides. Some human-made radionuclides were detected at offsite locations, but most were near the minimum detectable concentration and their presence was attributable to natural sources, worldwide fallout, and statistical variations in the analytical results rather than to INEEL operations. Low concentrations of 137Cs were found in muscle tissue and liver of some game animals and sheep. These levels were mostly consistent with background concentrations measured in animals sampled onsite and offsite in recent years. Ionizing radiation measured simultaneously at the INEEL boundary and distant locations using environmental dosimeters were similar and showed only background levels. The maximum potential population dose from submersion, ingestion, inhalation, and deposition to the approximately 121,500 people residing within an 80-km (50-mi) radius from the geographical center of the INEEL was estimated to be 0.08 person-rem (8 x 10-4 person-Sv) using the MDIFF air dispersion model. This population dose is less than 0.0002 percent of the estimated 43,7 00 person-rem (437 person-Sv) population dose from background radioactivity.« less

Phytotoxicity of Four Photosystem II Herbicides to Tropical Seagrasses

PubMed Central

Flores, Florita; Collier, Catherine J.; Mercurio, Philip; Negri, Andrew P.

2013-01-01

Coastal waters of the Great Barrier Reef (GBR) are contaminated with agricultural pesticides, including the photosystem II (PSII) herbicides which are the most frequently detected at the highest concentrations. Designed to control weeds, these herbicides are equally potent towards non-target marine species, and the close proximity of seagrass meadows to flood plumes has raised concerns that seagrasses may be the species most threatened by herbicides from runoff. While previous work has identified effects of PSII herbicides on the photophysiology, growth and mortality in seagrass, there is little comparative quantitative toxicity data for seagrass. Here we applied standard ecotoxicology protocols to quantify the concentrations of four priority PSII herbicides that inhibit photochemistry by 10, 20 and 50% (IC10, IC20 and IC50) over 72 h in two common seagrass species from the GBR lagoon. The photosystems of seagrasses Zostera muelleri and Halodule uninervis were shown to be generally more sensitive to the PSII herbicides Diuron, Atrazine, Hexazinone and Tebuthiuron than corals and tropical microalgae. The herbicides caused rapid inhibition of effective quantum yield (∆F/F m ′), indicating reduced photosynthesis and maximum effective yields (Fv/Fm) corresponding to chronic damage to PSII. The PSII herbicide concentrations which affected photosynthesis have been exceeded in the GBR lagoon and all of the herbicides inhibited photosynthesis at concentrations lower than current marine park guidelines. There is a strong likelihood that the impacts of light limitation from flood plumes and reduced photosynthesis from PSII herbicides exported in the same waters would combine to affect seagrass productivity. Given that PSII herbicides have been demonstrated to affect seagrass at environmental concentrations, we suggest that revision of environmental guidelines and further efforts to reduce PSII herbicide concentrations in floodwaters may both help protect seagrass meadows of the GBR from further decline. PMID:24098726

Phytotoxicity of four photosystem II herbicides to tropical seagrasses.

PubMed

Flores, Florita; Collier, Catherine J; Mercurio, Philip; Negri, Andrew P

2013-01-01

Coastal waters of the Great Barrier Reef (GBR) are contaminated with agricultural pesticides, including the photosystem II (PSII) herbicides which are the most frequently detected at the highest concentrations. Designed to control weeds, these herbicides are equally potent towards non-target marine species, and the close proximity of seagrass meadows to flood plumes has raised concerns that seagrasses may be the species most threatened by herbicides from runoff. While previous work has identified effects of PSII herbicides on the photophysiology, growth and mortality in seagrass, there is little comparative quantitative toxicity data for seagrass. Here we applied standard ecotoxicology protocols to quantify the concentrations of four priority PSII herbicides that inhibit photochemistry by 10, 20 and 50% (IC10, IC20 and IC50) over 72 h in two common seagrass species from the GBR lagoon. The photosystems of seagrasses Zosteramuelleri and Haloduleuninervis were shown to be generally more sensitive to the PSII herbicides Diuron, Atrazine, Hexazinone and Tebuthiuron than corals and tropical microalgae. The herbicides caused rapid inhibition of effective quantum yield (∆F/F m '), indicating reduced photosynthesis and maximum effective yields (Fv/Fm ) corresponding to chronic damage to PSII. The PSII herbicide concentrations which affected photosynthesis have been exceeded in the GBR lagoon and all of the herbicides inhibited photosynthesis at concentrations lower than current marine park guidelines. There is a strong likelihood that the impacts of light limitation from flood plumes and reduced photosynthesis from PSII herbicides exported in the same waters would combine to affect seagrass productivity. Given that PSII herbicides have been demonstrated to affect seagrass at environmental concentrations, we suggest that revision of environmental guidelines and further efforts to reduce PSII herbicide concentrations in floodwaters may both help protect seagrass meadows of the GBR from further decline.

Spatiotemporal Dynamics of Microcystin Variants and Relationships with Environmental Parameters in Lake Taihu, China.

PubMed

Su, Xiaomei; Xue, Qingju; Steinman, Alan D; Zhao, Yanyan; Xie, Liqiang

2015-08-18

Excessive anthropogenically-caused nutrient loading from both external and internal sources has promoted the growth of cyanobacteria in Lake Taihu from 2005 to 2014, suggesting increased production and release of cyanotoxins. In order to explain the spatial distribution and temporal variation of microcystins (MCs), the intracellular concentrations of MCs (MC-LR, -RR and -YR, L, R and Y are abbreviations of leucine, arginine and tyrosine) were monitored monthly from July 2013 to June 2014. Three MC variants are present simultaneously in Lake Taihu; the MC-LR and -RR variants were dominant (accounting for 40% and 39% of the total), followed by MC-YR (21%). However, MC-YR accounted for a higher proportion in colder months, especially in March. The highest concentrations of intracellular MCs were found in July and October when cyanobacteria cell density also reached the maximum. The average concentrations of MC-LR, -RR and -YR in July were 4.69, 4.23 and 2.01 μg/L, respectively. In terms of the entire lake, toxin concentrations in northern parts were significantly higher than the eastern part in summer, when MC concentrations were several times higher than the guideline value by WHO throughout much of Lake Taihu. Results from correlation and redundancy analysis (RDA) showed that total MCs, including all variants, were strongly and positively correlated with cyanobacteria cell density, water temperature, total phosphorus (TP) and pH, whereas each variant had different correlation coefficients with each of the considered environmental variables. MC-RR showed a stronger relationship with temperature, in contrast to MC-YR and -LR. Dissolved inorganic carbon (DIC) showed a negative relationship with each variant, suggesting that rising DIC concentrations may inhibit cyanobacterial growth and thereby reduce MC production in the future.

St. Louis Airport Site. Annual site environmental report, calendar year 1985. Formerly Utilized Sites Remedial Action Program (FUSRAP). Revision 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1986-09-01

During 1985, the environmental monitoring program was continued at the St. Louis Airport Site (SLAPS) in St. Louis County, Missouri. The ditches north and south of the site have been designated for cleanup as part of the Formerly Utilized Sites Remedial Action Program (FUSRAP). The monitoring program at the SLAPS measures radon gas concentrations in air; external gamma radiation dose rates; and uranium, thorium, and radium concentrations in surface water, groundwater, and sediment. Potential radiation doses to the public are also calculated. Because the site is not controlled or regulated by the DOE, the DOE Derived Concentration Guides (DCGs) aremore » not applicable to SLAPS, but are included only as a basis for comparison. The DOE DCGs and the DOE radiation protection standard have been revised. (Appendix B). During 1985, annual average radon levels in air at the SLAPS were below the DCG for uncontrolled areas. External gamma monitoring in 1985 showed measured annual gamma dose rates ranging from 3 to 2087 mrem/y, with the highest value occurring in an area known to be contaminated. The calculated maximum dose at the site boundary, assuming limited occupancy, would be 6 mrem/y. Average annual concentrations of /sup 230/Th, /sup 226/Ra, and total uranium in surface waters remained below the DOE DCG. The on-site groundwater measurements showed that average annual concentrations of /sup 230/Th, /sup 226/Ra and total uranium were within the DOE DCGs. Although there are no DCGs for sediments, all concentrations of total uraniu, /sup 230/Th, and /sup 226/Ra were below the FUSRAP Guidelines.« less

Analysis of lead concentration in forager stingless bees Trigona sp. (hymenoptera: Apidae) and propolis at Cilutung and Maribaya, West Java

NASA Astrophysics Data System (ADS)

Safira, Nabila; Anggraeni, Tjandra

2015-09-01

Several studies had shown that lead (Pb) in the environment could accumulate in bees, which in turn could affect the quality of the resulting product. In this study, forager stingless bees (Trigona sp.) and its product (propolis) collected from a stingless bees apiculture. This apiculture had two apiary sites which were distinguished by its environmental setting. Apiary site in Cilutung had a forest region environmental setting, while apiary site in Maribaya was located beside the main road. The objective of this study was to determine the extent of lead concentration in propolis originated from both apiary sites and establish the correlation between lead concentration in propolis and lead level in forager stingless bees. Forager bees and propolis samples were originated from 50 bees colonies (Cilutung) and 44 bees colonies (Maribaya). They were analyzed using AAS-GF (Atomic Absorption Spectrometre-Graphite Furnace) to determine the level of lead concentration. The results showed that the average level of lead in propolis originated from Cilutung (298.08±73.71 ppb) was lower than the average level of lead in forager bees which originated from Maribaya (330.64±156.34 ppb). However, these values did not show significant difference (p>0.05). There was no significant difference (p>0.05) between the average level of lead in forager bees which originated from Cilutung (118.08±30.46 ppb) and Maribaya (128.82±39.66 ppb). However, these values did not show significant difference (p>0.05). In conclusion, the average level of lead concentration in propolis in both sites had passed the maximum permission standard of lead for food in Indonesia. There was no correlation between lead concentration in propolis and forager stingless bees.

Ecological risk assessment of sedimentary hydrocarbons in a subtropical estuary as tools to select priority areas for environmental management.

PubMed

Dauner, Ana L L; Dias, Thais H; Ishii, Fernanda K; Libardoni, Bruno G; Parizzi, Rafael A; Martins, César C

2018-06-23

The concentration, distribution, and ecological risk of hydrocarbons, as well as bulk parameters, were determined in surface sediments of the Babitonga Bay, a subtropical human-impacted estuary in South Atlantic. Total aliphatic and polycyclic aromatic hydrocarbons (PAHs) ranged between 0.8 and 201.2 μg g -1 and from 8.7 to 5489 ng g -1 , respectively. Saguaçú Lagoon, the region near the ferry boat and the vicinity of São Francisco harbour (SFH), presented high hydrocarbon concentrations. Despite the low accumulation trend in this region, the SFH and city may act as a punctual hydrocarbon source. The inner portion of the estuary had the finest sediment grains and the highest concentrations of carbon, nitrogen, and sulphur, indicating its importance as a depositional and cumulative area. The occurrence of unresolved complex mixture suggested chronic oil contamination. Petrogenic (based on the high percentage of alkylated PAHs) and pyrolytic (according to the diagnostic ratios of PAH isomer pairs) sources were confirmed. Ecological risk assessment was evaluated by the risk quotient (RQ). All samples had at least one priority PAH present at above the negligible concentration, including naphthalene, which was observed in all samples. Only the sites near the ferry boat and at the Saguaçú Lagoon contained compounds with concentrations above their maximum permissible concentrations, while all other sampling sites are classified as "Low-risk." The spatial distribution of RQs coincides with PAHs distribution, indicating that the regions near SFH, ferry-boat, and the Saguaçú Lagoon should be considered to be priority areas when making environmental monitoring policies. Copyright © 2018 Elsevier Ltd. All rights reserved.

Deep-sea benthic megafaunal habitat suitability modelling: A global-scale maximum entropy model for xenophyophores

NASA Astrophysics Data System (ADS)

Ashford, Oliver S.; Davies, Andrew J.; Jones, Daniel O. B.

2014-12-01

Xenophyophores are a group of exclusively deep-sea agglutinating rhizarian protozoans, at least some of which are foraminifera. They are an important constituent of the deep-sea megafauna that are sometimes found in sufficient abundance to act as a significant source of habitat structure for meiofaunal and macrofaunal organisms. This study utilised maximum entropy modelling (Maxent) and a high-resolution environmental database to explore the environmental factors controlling the presence of Xenophyophorea and two frequently sampled xenophyophore species that are taxonomically stable: Syringammina fragilissima and Stannophyllum zonarium. These factors were also used to predict the global distribution of each taxon. Areas of high habitat suitability for xenophyophores were highlighted throughout the world's oceans, including in a large number of areas yet to be suitably sampled, but the Northeast and Southeast Atlantic Ocean, Gulf of Mexico and Caribbean Sea, the Red Sea and deep-water regions of the Malay Archipelago represented particular hotspots. The two species investigated showed more specific habitat requirements when compared to the model encompassing all xenophyophore records, perhaps in part due to the smaller number and relatively more clustered nature of the presence records available for modelling at present. The environmental variables depth, oxygen parameters, nitrate concentration, carbon-chemistry parameters and temperature were of greatest importance in determining xenophyophore distributions, but, somewhat surprisingly, hydrodynamic parameters were consistently shown to have low importance, possibly due to the paucity of well-resolved global hydrodynamic datasets. The results of this study (and others of a similar type) have the potential to guide further sample collection, environmental policy, and spatial planning of marine protected areas and industrial activities that impact the seafloor, particularly those that overlap with aggregations of these conspicuously large single-celled eukaryotes.

Potential effects of climate change on the distribution range of the main silicate sinker of the Southern Ocean.

PubMed

Pinkernell, Stefan; Beszteri, Bánk

2014-08-01

Fragilariopsis kerguelensis, a dominant diatom species throughout the Antarctic Circumpolar Current, is coined to be one of the main drivers of the biological silicate pump. Here, we study the distribution of this important species and expected consequences of climate change upon it, using correlative species distribution modeling and publicly available presence-only data. As experience with SDM is scarce for marine phytoplankton, this also serves as a pilot study for this organism group. We used the maximum entropy method to calculate distribution models for the diatom F. kerguelensis based on yearly and monthly environmental data (sea surface temperature, salinity, nitrate and silicate concentrations). Observation data were harvested from GBIF and the Global Diatom Database, and for further analyses also from the Hustedt Diatom Collection (BRM). The models were projected on current yearly and seasonal environmental data to study current distribution and its seasonality. Furthermore, we projected the seasonal model on future environmental data obtained from climate models for the year 2100. Projected on current yearly averaged environmental data, all models showed similar distribution patterns for F. kerguelensis. The monthly model showed seasonality, for example, a shift of the southern distribution boundary toward the north in the winter. Projections on future scenarios resulted in a moderately to negligibly shrinking distribution area and a change in seasonality. We found a substantial bias in the publicly available observation datasets, which could be reduced by additional observation records we obtained from the Hustedt Diatom Collection. Present-day distribution patterns inferred from the models coincided well with background knowledge and previous reports about F. kerguelensis distribution, showing that maximum entropy-based distribution models are suitable to map distribution patterns for oceanic planktonic organisms. Our scenario projections indicate moderate effects of climate change upon the biogeography of F. kerguelensis.

Taxonomically-linked growth phenotypes during arsenic stress among arsenic resistant bacteria isolated from soils overlying the Centralia coal seam fire.

PubMed

Dunivin, Taylor K; Miller, Justine; Shade, Ashley

2018-01-01

Arsenic (As), a toxic element, has impacted life since early Earth. Thus, microorganisms have evolved many As resistance and tolerance mechanisms to improve their survival outcomes given As exposure. We isolated As resistant bacteria from Centralia, PA, the site of an underground coal seam fire that has been burning since 1962. From a 57.4°C soil collected from a vent above the fire, we isolated 25 unique aerobic As resistant bacterial strains spanning seven genera. We examined their diversity, resistance gene content, transformation abilities, inhibitory concentrations, and growth phenotypes. Although As concentrations were low at the time of soil collection (2.58 ppm), isolates had high minimum inhibitory concentrations (MICs) of arsenate and arsenite (>300 mM and 20 mM respectively), and most isolates were capable of arsenate reduction. We screened isolates (PCR and sequencing) using 12 published primer sets for six As resistance genes (AsRGs). Genes encoding arsenate reductase (arsC) and arsenite efflux pumps (arsB, ACR3(2)) were present, and phylogenetic incongruence between 16S rRNA genes and AsRGs provided evidence for horizontal gene transfer. A detailed investigation of differences in isolate growth phenotypes across As concentrations (lag time to exponential growth, maximum growth rate, and maximum OD590) showed a relationship with taxonomy, providing information that could help to predict an isolate's performance given As exposure in situ. Our results suggest that microbiological management and remediation of environmental As could be informed by taxonomically-linked As tolerance, potential for resistance gene transferability, and the rare biosphere.

Development of a guideline on vegetation area to reduce the risk of weed pollinosis in Korea

NASA Astrophysics Data System (ADS)

Rang Kim, Kyu; Lee, Hye-Rim; Kim, Mijin; Baek, Won-ki; Oh, Jae-Won; Choi, Young-Jean; Jung, Hyun-Sook

2013-04-01

Allergenic pollens are influenced by the environmental conditions so that the daily number of pollens varies by temperature, humidity, wind speed, etc. The relationship between the daily pollens and meteorological conditions were determined and utilized to forecast daily risk level of pollen allergy in Korea. Another important factor for the daily risk level of pollens is the vegetation area of the allergenic plants. In this study, the relationship between the area and pollen concentration was identified for two major weed species: Ragweed and Japanese Hop. It was then utilized to determine the upper limit of vegetation area to confine the risk level to a certain degree in the field. Three sites with different levels of pollen concentration were selected among twelve pollen observation sites in Korea based on the historical observation of the weed pollens. The vegetation area of the two weed species within four square kilometers at each site was surveyed. The maximum daily pollen concentration was highly correlated with the vegetation area and it was selected as a dependent variable for the regression equations, which were used as the guideline for vegetation area. According to the guideline, to limit the maximum daily pollen concentration under the moderate risk level or less than 50 pollen grains per cubic meter for Ragweed, the vegetation area should remain less than 0.6% of the ground area. For the moderate risk of Japanese Hop, pollen grains should be limited less than 100 and the area be less than 0.4%.

Ambient Ozone Concentrations and the Risk of Perforated and Nonperforated Appendicitis: A Multicity Case-Crossover Study

PubMed Central

Tanyingoh, Divine; Dixon, Elijah; Johnson, Markey; Wheeler, Amanda J.; Myers, Robert P.; Bertazzon, Stefania; Saini, Vineet; Madsen, Karen; Ghosh, Subrata; Villeneuve, Paul J.

2013-01-01

Background: Environmental determinants of appendicitis are poorly understood. Past work suggests that air pollution may increase the risk of appendicitis. Objectives: We investigated whether ambient ground-level ozone (O3) concentrations were associated with appendicitis and whether these associations varied between perforated and nonperforated appendicitis. Methods: We based this time-stratified case-crossover study on 35,811 patients hospitalized with appendicitis from 2004 to 2008 in 12 Canadian cities. Data from a national network of fixed-site monitors were used to calculate daily maximum O3 concentrations for each city. Conditional logistic regression was used to estimate city-specific odds ratios (ORs) relative to an interquartile range (IQR) increase in O3 adjusted for temperature and relative humidity. A random-effects meta-analysis was used to derive a pooled risk estimate. Stratified analyses were used to estimate associations separately for perforated and nonperforated appendicitis. Results: Overall, a 16-ppb increase in the 7-day cumulative average daily maximum O3 concentration was associated with all appendicitis cases across the 12 cities (pooled OR = 1.07; 95% CI: 1.02, 1.13). The association was stronger among patients presenting with perforated appendicitis for the 7-day average (pooled OR = 1.22; 95% CI: 1.09, 1.36) when compared with the corresponding estimate for nonperforated appendicitis [7-day average (pooled OR = 1.02, 95% CI: 0.95, 1.09)]. Heterogeneity was not statistically significant across cities for either perforated or nonperforated appendicitis (p > 0.20). Conclusions: Higher levels of ambient O3 exposure may increase the risk of perforated appendicitis. PMID:23842601

Arsenic and lead contamination in urban soils of Villa de la Paz (Mexico) affected by historical mine wastes and its effect on children's health studied by micronucleated exfoliated cells assay.

PubMed

Gamiño-Gutiérrez, Sandra P; González-Pérez, C Ivonne; Gonsebatt, María E; Monroy-Fernández, Marcos G

2013-02-01

Environmental geochemical and health studies were carried out in urban areas of Villa de la Paz, S.L.P. (Mexico), where mining activities have been developed for more of 200 years, leading to the pollution of surface soil by arsenic and heavy metals (Pb, Cd, Cu, Zn). The analysis of urban soils to determine total and bioaccessibility concentrations of As and Pb, demonstrated a combined contribution of the natural and anthropogenic concentrations in the site, at levels higher than the environmental guideline values that provoke a human health risk. Contour soil mapping confirmed that historical mine waste deposits without environmental control measures, are the main source of pollution soil by As and Pb in the site. Exposure (Pb in blood and As in urine) and effect (micronucleated exfoliated cells assay) biological monitoring were then carried out in the childhood population of the site and in a control site. The exposure biological monitoring demonstrated that at least 20-30 % of children presented Pb and As exposure values higher than the national and international maximum intervention values. The effect biomonitoring by MEC assay confirmed that there is a genotoxic damage in local childhood population that could be associated with the arsenic exposure in the site.

Environmental Risk Implications of Metals in Sludges from Waste Water Treatment Plants: The Discovery of Vast Stores of Metal-Containing Nanoparticles.

PubMed

Tou, Feiyun; Yang, Yi; Feng, Jingnan; Niu, Zuoshun; Pan, Hui; Qin, Yukun; Guo, Xingpan; Meng, Xiangzhou; Liu, Min; Hochella, Michael F

2017-05-02

Nanoparticle (NP) assessment in sludge materials, although of growing importance in eco- and biotoxicity studies, is commonly overlooked and, at best, understudied. In the present study, sewage sludge samples from across the mega-city of Shanghai, China were investigated for the first time using a sequential extraction method coupled with single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) to quantify the abundance of metal-containing NPs in the extraction fractions and transmission electron microscopy to specifically identify the nanophases present. In general, most sludges observed showed high concentrations of Cr, Cu, Cd, Ni, Zn, and Pb, exceeding the maximum permitted values in the national application standard of acid soil in China. NPs in these sludges contribute little to the volume and mass but account for about half of the total particle number. Based on electron microscopy techniques, various NPs were further identified, including Ti-, Fe-, Zn-, Sn-, and Pb-containing NPs. All NPs, ignored by traditional metal risk evaluation methods, were observed at a concentration of 10 7 -10 11 particles/g within the bioavailable fraction of metals. These results indicate the underestimate or misestimation in evaluating the environmental risks of metals based on traditional sequential extraction methods. A new approach for the environmental risk assessment of metals, including NPs, is urgently needed.

Development of a real-time radon monitoring system for simultaneous measurements in multiple sites

NASA Astrophysics Data System (ADS)

Yamamoto, S.; Yamasoto, K.; Iida, T.

1999-12-01

A real-time radon monitoring system that can simultaneously measure radon concentrations in multiple sites was developed and tested. The system consists of maximum of four radon detectors, optical fiber cables and a data acquisition personal computer. The radon detector uses a plastic scintillation counter that collects radon daughters in the chamber electrostatically. The applied voltage on the photocathode for the photomultiplier tube (PMT) acts as an electrode for radon daughters. The thickness of the plastic scintillator was thin, 50 /spl mu/m, so as to minimize the background counts due to the environmental gamma rays or beta particles. The energy discriminated signals from the radon detectors are fed to the data acquisition personal computer via optical fiber cables. The system made it possible to measure the radon concentrations in multiple sites simultaneously.

β-Sitosterol: supercritical carbon dioxide extraction from sea buckthorn (Hippophae rhamnoides L.) seeds.

PubMed

Sajfrtová, Marie; Licková, Ivana; Wimmerová, Martina; Sovová, Helena; Wimmer, Zdenek

2010-04-22

Supercritical fluid extraction represents an efficient and environmentally friendly technique for isolation of phytosterols from different plant sources. Sea buckthorn (Hippophae rhamnoides L.) seeds were extracted with supercritical carbon dioxide at pressures ranging from 15-60 MPa and temperatures of 40-80 degrees C. Oil and β-sitosterol yields were measured in the extraction course and compared with Soxhlet extraction with hexane. The average yield of β-sitosterol was 0.31 mg/g of seeds. The maximum concentration of β-sitosterol in the extract, 0.5% w/w, was achieved at 15 MPa, 40 degrees C, and a carbon dioxide consumption of 50 g/g of seeds. The extraction rate was maximal at 60 MPa and 40 degrees C. Both β-sitosterol yield and its concentration in the extract obtained with hexane were lower than with carbon dioxide.

Remedial Action Plan and site design for stabilization of the inactive uranium mill tailings site at Durango, Colorado: Attachment 4, Water resources protection strategy. Revised final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1991-12-01

To achieve compliance with the proposed US Environmental Protection Agency (EPA) groundwater protection standards (Subpart A of 40 CFR 192), the US Department of Energy (DOE) proposes to meet background concentrations or the EPA maximum concentration limits (MCLS) for hazardous constituents in groundwater in the uppermost aquifer (Cliff House/Menefee aquifer) at the point of compliance (POC) at the Uranium Mill Tailings Remedial Action (UMTRA) Project disposal site in Bodo Canyon near Durango, Colorado (DOE, 1989). Details of hydrologic site characterization at the disposal site are provided in Attachment 3, Groundwater Hydrology Report. The principal features of the water resources protectionmore » strategy for the Bodo Canyon disposal site are presented in this document.« less

Inner filter effect and the onset of concentration dependent red shift of synchronous fluorescence spectra.

PubMed

Tarai, Madhumita; Mishra, Ashok Kumar

2016-10-12

The phenomenon of concentration dependent red shift, often observed in synchronous fluorescence spectra (SFS) of monofluorophoric as well as multifluorophoric systems at high chromophore concentrations, is known to have good analytical advantages. This was previously understood in terms of large inner filter effect (IFE) through the introduction of a derived absorption spectral profile that closely corresponds to the SFS profile. Using representative monofluorophoric and multifluorophoric systems, it is now explained how the SF spectral maximum changes with concentration of the fluorophore. For dilute solutions of monofluorophores the maximum is unchanged as expected. It is shown here that the onset of red shift of SFS maximum of both the mono as well as the multifluorophoric systems must occur at the derived absorption spectral parameter value of 0.32 that corresponds to the absorbance value of 0.87. This value is unique irrespective of the nature of the fluorophore under study. For monofluorophoric systems, the wavelength of derived absorption spectral maximum and the wavelength of synchronous fluorescence spectral maximum closely correspond with each other in the entire concentration range. In contrast, for multifluorophoric systems like diesel and aqueous humic acid, large deviations were noted that could be explained as to be due to the presence of non-fluorescing chromophores in the system. This work bridges the entire fluorophore concentration range over which the red shift of SFS maximum sets in; and in the process it establishes the importance of the derived absorption spectral parameter in understanding the phenomenon of concentration dependent red shift of SFS maximum. Copyright © 2016 Elsevier B.V. All rights reserved.

Environmental Survival of Mycobacterium avium subsp. paratuberculosis in Different Climatic Zones of Eastern Australia

PubMed Central

Begg, Douglas J.; Dhand, Navneet K.; Watt, Bruce; Whittington, Richard J.

2014-01-01

The duration of survival of both the S and C strains of Mycobacterium avium subsp. paratuberculosis in feces was quantified in contrasting climatic zones of New South Wales, Australia, and detailed environmental temperature data were collected. Known concentrations of S and C strains in feces placed on soil in polystyrene boxes were exposed to the environment with or without the provision of shade (70%) at Bathurst, Armidale, Condobolin, and Broken Hill, and subsamples taken every 2 weeks were cultured for the presence of M. avium subsp. paratuberculosis. The duration of survival ranged from a minimum of 1 week to a maximum of 16 weeks, and the provision of 70% shade was the most important factor in extending the survival time. The hazard of death for exposed compared to shaded samples was 20 and 9 times higher for the S and C strains, respectively. Site did not affect the survival of the C strain, but for the S strain, the hazard of death was 2.3 times higher at the two arid zone sites (Broken Hill and Condobolin) than at the two temperate zone sites (Bathurst and Armidale). Temperature measurements revealed maximum temperatures exceeding 60°C and large daily temperature ranges at the soil surface, particularly in exposed boxes. PMID:24463974

Evaluation of Environmentally Assisted Cracking of Armour Wires in Flexible Pipes, Power Cables and Umbilicals

NASA Astrophysics Data System (ADS)

Zhang, Zhiying

Environmentally assisted cracking (EAC) of armour wires in flexible pipes, power cables and umbilicals is a major concern with the development of oil and gas fields and wind farms in harsh environments. Hydrogen induced cracking (HIC) or hydrogen embrittlement (HE) of steel armour wires used in deep-water and ultra-deep-water has been evaluated. Simulated tests have been carried out in simulated sea water, under conditions where the susceptibility is the highest, i.e. at room temperature, at the maximum negative cathodic potential and at the maximum stress level expected in service for 150 hours. Examinations of the tested specimens have not revealed cracking or blistering, and measurement of hydrogen content has confirmed hydrogen charging. In addition, sulphide stress cracking (SSC) and chloride stress cracking (CSC) of nickel-based alloy armour wires used in harsh down-hole environments has been evaluated. Simulated tests have been carried out in simulated solution containing high concentration of chloride, with high hydrogen sulphide partial pressure, at high stress level and at 120 °C for 720 hours. Examinations of the tested specimens have not revealed cracking or blistering. Subsequent tensile tests of the tested specimens at ambient pressure and temperature have revealed properties similar to the as-received specimens.

Mercury Emission From Phragmites in a Contaminated Wetland

NASA Astrophysics Data System (ADS)

Bubb, M.; Peters, S.

2008-12-01

Characterizing the role of vegetation has been an elusive component to a complete understanding of the mercury cycle. Defining this contribution is of ecological and environmental significance as it pertains to contaminated industrial sites. Various studies have demonstrated that foliar exchange of gaseous mercury is bi-directional and may depend on atmospheric concentrations of mercury as well as other environmental parameters. In particular emergent aquatic vegetation such as Typha, Cladium, and Phragmites, in areas of elevated mercury soil concentrations have been shown to generate relatively high daytime fluxes of ~30ng/m2/hr, ~20ng/m2/hr, and in one case 90ng/m2/hr, respectively. For this research mercury fluxes were measured from foliar surfaces of Phragmites australis in a highly contaminated portion of the New Jersey Hackensack Meadowlands using a dynamic flux chamber. The chamber is constructed from UV transparent acrylic sheets sized to average Phragmites leaves and employs a sheath-like design so that it may be easily slid over foliage with minimal interference. The design also circumvents the use of foams or silicone as sealant which in the past have been shown to emit or absorb mercury. Laboratory and field tests have shown good agreement between ambient air and chamber blank mercury levels. During field excursions generally 5-7 adjacent plants would be sampled for 20-30 min each.Over one 6-hour sampling period in late summer 2008 mean Phragmites flux was - 0.12ng/m2/hr±0.25 with a maximum negative flux of -0.64ng/m2/hr. Another sampling period showed a positive average of 0.07ng/m2/hr±0.07 with a maximum of 0.11ng/m2/hr. These values, as well as those observed in earlier literature, are likely the result of significant environmental parameters operating on the mechanism by which foliar flux is produced. Such parameters include, incoming solar radiation, wind velocity, air temperature, air quality, humidity, sediment pore water mercury concentrations, as well as internal leaf properties such as transpiration and relative humidity. It is the ongoing goal of this study to relate the magnitude of mercury flux with said parameters in order to better understand the controls by which emission is enhanced or diminished.

Isolation by environmental distance in mobile marine species: molecular ecology of franciscana dolphins at their southern range.

PubMed

Mendez, Martin; Rosenbaum, Howard C; Subramaniam, Ajit; Yackulic, Charles; Bordino, Pablo

2010-06-01

The assessment of population structure is a valuable tool for studying the ecology of endangered species and drafting conservation strategies. As we enhance our understanding about the structuring of natural populations, it becomes important that we also understand the processes behind these patterns. However, there are few rigorous assessments of the influence of environmental factors on genetic patterns in mobile marine species. Given their dispersal capabilities and localized habitat preferences, coastal cetaceans are adequate study species for evaluating environmental effects on marine population structure. The franciscana dolphin, a rare coastal cetacean endemic to the Western South Atlantic, was studied to examine these issues. We analysed genetic data from the mitochondrial DNA and 12 microsatellite markers for 275 franciscana samples utilizing frequency-based, maximum-likelihood and Bayesian algorithms to assess population structure and migration patterns. This information was combined with 10 years of remote sensing environmental data (chlorophyll concentration, water turbidity and surface temperature). Our analyses show the occurrence of genetically isolated populations within Argentina, in areas that are environmentally distinct. Combined evidence of genetic and environmental structure suggests that isolation by distance and a process here termed isolation by environmental distance can explain the observed correlations. Our approach elucidated important ecological and conservation aspects of franciscana dolphins, and has the potential to increase our understanding of ecological processes influencing genetic patterns in other marine species.

Environmental and biological monitoring of platinum-containing drugs in two hospital pharmacies using positive air pressure isolators.

PubMed

Kopp, Bettina; Crauste-Manciet, Sylvie; Guibert, Agnès; Mourier, Wilhelmine; Guerrault-Moro, Marie-Noelle; Ferrari, Sylvie; Jomier, Jean-Yves; Brossard, Denis; Schierl, Rudolf

2013-04-01

Environmental and biological monitoring of platinum containing drugs was implemented in two French hospital pharmacies using positive air pressure isolators and having similar working procedures when preparing antineoplastic drugs. Wipe sampling of surfaces, gloves, and vials was performed in the preparation room and in storage areas. All employees involved in the preparation of antineoplastic drugs were tested for urinary platinum on Monday before work and Friday after shift. Only traces of platinum were detected on surfaces in the preparation room outside the isolators (less than 1.61 pg cm(-2)). However, in one center, significant contamination was found in the storage area of the drug vials, which can most likely be linked to the rupture of a platinum vial and due to inefficient cleaning procedures. Surfaces inside the isolators were found to be contaminated (maximum: 198.4 pg cm(-2)). A higher level of contamination was detected in one pharmacy and could be explained by the lack of overgloving with regular changes during the preparation process. Nitrile gloves used during drug handling outside the isolator showed the highest platinum concentration (maximum: 5.86 ng per pair). With regards to platinum urine concentration, no significant difference was found between exposed and unexposed pharmacy personnel. Isolator technology combined with individual protective measures seems to be efficient to protect workers from occupational exposure to antineoplastic drugs, whereas specific individual protective procedures implemented were focussing on the risk of handling vials outside the isolator (e.g. high frequency of glove changing). Moreover, overgloving inside the isolator would contribute to substantially decrease inner surface contamination and should be recommended in order to limit the transfer of chemical contamination to the end products.

Experimental study of using wastewater sludge as a new drag reduction agent.

PubMed

Mohamed, Hadj Djelloul; Mansour, Belhadri; Nasr-Eddine, Boudjenane

2017-07-01

Siltation is considering as a huge risk to the life and security of dams. Forced to preserve their useful volumes, managers use sediment dredging operations through different techniques. The aim of our work is to investigate the wastewater sludge derived from wastewater treatment as a new natural lubricating instrument during transport of sediment in the pipes and to reduce head losses. From an economic and environmental point of view, this technique is more effective than the use of industrial polymers. The rheological study is done using an RS600 rheometer. Head losses and friction reducing are measured on three horizontal pipes (30, 50 and 80 mm). The mud from the dam and sludge are added at different volumes concentrations. The results revealed that the mud follows the Herschel-Bulkley model at 10-20% volume concentration, even after adding wastewater sludge proportions from 0.1- 0.4%. The mud flow head losses in pipes increase with increasing solids concentration. A maximum reduction in yield stress and frictional head loss are observed at 0.25 to 0.35% of sludge concentration, which can be the most effective choice.

Seasonal study of concentration of heavy metals in waters from lower São Francisco River basin, Brazil.

PubMed

Souza, A M; Salviano, A M; Melo, J F B; Felix, W P; Belém, C S; Ramos, P N

2016-01-01

In this study we determined the concentration of metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) in the water lower São Francisco River basin, to evaluate the influence of urbanization and industrialization on environmental changes in the water resource. All samples were analyzed using the IUPAC adapted method and processed in an atomic absorption spectrophotometer. The sampling stations located near the industrial areas were influenced by industrialization because they presented higher concentrations of Cd, Cr, Ni and Cu. The other sampled locations showed changes with regard the trace elements probably originating in the soil, like Fe, Zn and Pb. There was a gradual increase in the concentrations of metals, in general, in the period of highest rainfall of the hydrographic network. Overall, except for Zn and Mn, the trace elements exceeded the maximum allowed value established by national legislation (CONAMA). Lower São Francisco River basin has suffered interference from urbanization and industrialization, so awareness programs should be developed so as to control and lessen future problems.

Pollution Assessment of Toxic and Potentially Toxic Elements in Agricultural Soils of the City Addis Ababa, Ethiopia.

PubMed

Aschale, Minbale; Sileshi, Yilma; Kelly-Quinn, Mary; Hailu, Dereje

2017-02-01

Due to the significantly fast urban expansion and increased industrial activities, the soils in the farms in Addis Ababa are contaminated by some toxic and potentially toxic elements (As, V, Cr, Fe, Co, Ni, Cu, B, Ba, Sr, Zn, Mn, Pb and Cd) in varying degrees. The mean concentrations of Cr, Ni, As and B in most of the soil farms were found to be higher than the maximum recommended limits. The mean concentrations of Cd, Cu, Pb, Co, Ni and Mn were found to be higher than the background soil concentrations given for uncontaminated soils. Multivariate analyses coupled with correlation analysis were used to identify possible sources. The geo-accumulation index values for Cr, Mn and Pb indicated that the farm soils were unpolluted to moderately polluted as a result of anthropogenic activities. A comprehensive environmental management strategy should be formulated by the government to measure further pollution of the farmland soil.

Mercury contamination in Khramulia (Capoeta capoeta) from the Cheshme Kile and Zarrin Gol Rivers in Iran and human health risk assessment.

PubMed

Malvandi, Hassan; Sari, Abbas Esmaili; Aliabadian, Mansour

2014-10-01

Total mercury concentrations were determined in muscle tissue of Khramulia (Capoeta capoeta) captured in the Cheshme Kile and Zarrin Gol Rivers, Iran. In Cheshme Kile River, 49 fish samples were collected. The mean total mercury concentration in the muscles of C. capoeta from this area was 249 ng g(-1) dw. In Zarrin Gol River, where 62 fish samples were collected, the total mercury in muscles averaged 164 ng g(-1) dw. A significant difference was found between means of mercury in the rivers (p < 0.001). All samples from the two rivers had mean mercury concentrations below the maximum allowable limits for mercury set by the Food and Agriculture Organization, World Health Organization, Standardization Administration of China and Environmental Protection Agency. The results of this study indicate that the values of hazard target quotient and estimated weekly intake are low and represent a negligible risk for human health.

Separation of sodium chloride from the evaporated residue of the reverse osmosis reject generated in the leather industry--optimization by response surface methodology.

PubMed

Boopathy, R; Sekaran, G

2014-08-01

Reverse osmosis (RO) concentrate is being evaporated by solar/thermal evaporators to meet zero liquid discharge standards. The resulted evaporated residue (ER) is contaminated with both organic and inorganic mixture of salts. The generation of ER is exceedingly huge in the leather industry, which is being collected and stored under the shelter to avoid groundwater contamination by the leachate. In the present investigation, a novel process for the separation of sodium chloride from ER was developed, to reduce the environmental impact on RO concentrate discharge. The sodium chloride was selectively separated by the reactive precipitation method using hydrogen chloride gas. The selected process variables were optimized for maximum yield ofNaCl from the ER (optimum conditions were pH, 8.0; temperature, 35 degrees C; concentration of ER, 600 g/L and HCl purging time, 3 min). The recovered NaCl purity was verified using a cyclic voltagramm.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Metzler, D.; Gibb, J.P.; Glover, W.A.

Compliance with the mandate of the Uranium Mill Tailings Radiation Control Act (UMTRCA) at Uranium Mill Tailings Remedial Action (UMTRA) Project sites requires implementation of a groundwater remedial action plan that meets the requirements of Subpart B of the US Environmental Protection Agency`s proposed groundwater protection standards (40 CFR 192). The UMTRA Groundwater Project will ensure that unacceptable current risk or potential risk to the public health, safety and the environment resulting from the groundwater contamination attributable to the UMTRA sites, is mitigated in a timely and cost-efficient manner. For each UMTRA processing site and vicinity property where contamination exists,more » a groundwater remedial action plan must be developed that identifies hazardous constituents and establishes acceptable concentration limits for the hazardous constituents as either (a) alternate concentration limits (ACL), (b) maximum concentration limits (MCLs), (c) supplemental standards, or (d) background groundwater quality levels. Project optimization is a strategy that will aggressively work within the current regulatory framework using all available options to meet regulatory requirements. This strategy is outlined within.« less

Ground-water quality in the Red River of the North Basin, Minnesota and North Dakota, 1991-95

USGS Publications Warehouse

Cowdery, T.K.

1998-01-01

Agricultural land use and soil texture can explain pesticide distributions; soil texture best explains nutrient distributions in waters in surficial aquifers. Confining beds protect waters in buried glacial aquifers from land use effects, resulting in no or low concentrations of nutrients and pesticides. Upward movement of bedrock waters high in dissolved solids concentration can increase concentrations in waters in buried glacial and, to a lesser degree, waters in surficial aquifers in the Lake Plain and Drift Prairie areas. Waters in surficial aquifers exceeded the U.S. Environmental Protection Agency (USEPA) maximum contaminant level in drinking water for nitrate in the Drift Prairie (27 percent) and Moraine (8 percent) areas. Their limited areal extent and susceptibility to contamination restrict the usefulness of surficial aquifers as a drinking water source. Waters in buried glacial aquifers exceeded USEPA health advisories for dissolved solids, sodium, and manganese. Sixty-six percent of waters in surficial aquifers also exceeded the Health Advisory for manganese.

Water quality of the Mississippian carbonate aquifer in parts of middle Tennessee and northern Alabama, 1999

USGS Publications Warehouse

Kingsbury, James A.; Shelton, John M.

2002-01-01

Water-quality data for nitrate, fecal-indicator bacteria, pesticides, and volatile organic compounds collected in parts of Middle Tennessee and northern Alabama indicate that the Mississippian carbonate aquifer in these areas is susceptible to contamination from point and nonpoint sources. Thirty randomly located wells (predominantly domestic), two springs, and two additional public-supply wells were sampled in the summer of 1999 as part of the U.S. Geological Survey?s National Water-Quality Assessment (NAWQA) Program. These wells and springs were sampled to characterize the occurrence and distribution of the above constituents in this karst aquifer of Mississippian age and to determine the principal environmental factors related to their occurrence.Nitrate and fecal indicator bacteria were frequently detected at the sampled sites. Nitrate exceeded the drinking-water maximum contaminant level of 10 milligrams per liter in two samples; the median concentration for all samples was about 1.5 milligrams per liter. Correlation of nitrate concentrations to the amount of cropland near a site and to pesticide detections indicates that fertilizer application is the predominant source of nitrogen to the aquifer. Fecal-indicator bacteria were present in samples from about 40 percent of the sites. The presence of fecal-indicator bacteria is weakly correlated to the depth to ground water but is not correlated to a specific land use near the sites.Pesticides and pesticide breakdown products (metabolites) were detected at 74 percent of the sites sampled. Concentrations generally were less than 1 microgram per liter and no pesticide detections exceeded drinking-water maximum contaminant levels. The maximum total pesticide concentration measured was about 4 micrograms per liter. Intensity of pesticide use, proximity of sites to areas of pesticide application, and soil hydrologic group were the primary factors affecting the occurrence of pesticides.Volatile organic compounds were detected at generally low concentrations at about 81 percent of the sites sampled. Concentrations of trichloroethylene, tetrachloroethylene, and 1,2-dichloropropane at three sites equalled or exceeded drinking-water maximum contaminant levels. The maximum concentration measured was 7.5 micrograms per liter of trichloroethylene. The presence of volatile organic compounds in the Mississippian carbonate aquifer was not related to hydrogeology, soil properties, or land use near the sites; although higher total volatile organic compound concentrations and greater numbers of compounds in samples generally were associated with a higher percentage of urban land use near a site. Chloroform was the most frequently detected compound, and correlation of low-level detections to the amount of wetlands near sites having these detections may indicate biogenic formation of chloroform.The relation between land use and water quality was stronger for constituents that are contributed to the environment systematically (fertilizer and pesticide applications), than those contributed inadvertently (leaking septic tanks or chemical spills or leaks). Land use and soils characterized in circular buffer areas near sites sampled in this karst aquifer explained some of the variation in nitrate concentration and presence of pesticides. Use of land use and soil data with greater detail than the large scale data used in this analysis and buffer areas based on well capacities and ground-water withdrawals might strengthen this type of analysis.

Assessing the guidelines for potassium replacement in pediatric oncology patients receiving amphotericin B.

PubMed

Lafreniere, Janet A; Hamilton, Donald P; Carr, Roxane R

2006-10-01

To examine the practice of potassium chloride (KCl) replacement in pediatric oncology patients receiving amphotericin B (amp-B). A retrospective observational chart review was conducted of patients who received amp-B on the oncology unit between August 2000 and May 2001. A survey was distributed to pediatric oncology pharmacists at other pediatric institutions to assess KCl infusion guidelines across North America. Twenty hypokalemic episodes were identified within 22 patient admissions. Fifty-five percent used KCl replacement (by all combined routes) at rates exceeding the institution's guidelines. Other pediatric institutions varied with respect to the maximum rates and concentration of KCl permitted on non-intensive care units. Based on the data from this review, the KCl administration guidelines for our hospital were changed. We now allow a maximum peripheral line concentration of 60 mEq/L, a maximum central line concentration of 120 mEq/L and a maximum KCl infusion rate of 0.4 mEq/kg/hr without the requirement of a heart monitor. Parenteral Nutrition is now restricted to maximum potassium concentration of 80 mEq/L and fluid-restricted patients are restricted to a maximum concentration of 150 mEq/L.

Atmospherically deposited trace metals from bulk mineral concentrate port operations.

PubMed

Taylor, Mark Patrick

2015-05-15

Although metal exposures in the environment have declined over the last two decades, certain activities and locations still present a risk of harm to human health. This study examines environmental dust metal and metalloid hazards (arsenic, cadmium, lead and nickel) associated with bulk mineral transport, loading and unloading port operations in public locations and children's playgrounds in the inner city of Townsville, northern Queensland. The mean increase in lead on post-play hand wipes (965 μg/m(2)/day) across all sites was more than 10-times the mean pre-play loadings (95 μg/m(2)/day). Maximum loading values after a 10-minute play period were 3012 μg/m(2), more than seven times the goal of 400 μg/m(2) used by the Government of Western Australia (2011). Maximum daily nickel post-play hand loadings (404 μg/m(2)) were more than 26 times above the German Federal Immission Control Act 2002 annual benchmark of 15 μg/m(2)/day. Repeat sampling over the 5-day study period showed that hands and surfaces were re-contaminated daily from the deposition of metal-rich atmospheric dusts. Lead isotopic composition analysis of dust wipes ((208)Pb/(207)Pb and (206)Pb/(207)Pb) showed that surface dust lead was similar to Mount Isa type ores, which are exported through the Port of Townsville. While dust metal contaminant loadings are lower than other mining and smelting towns in Australia, they exceeded national and international benchmarks for environmental quality. The lessons from this study are clear - even where operations are considered acceptable by managing authorities, targeted assessment and monitoring can be used to evaluate whether current management practices are truly best practice. Reassessment can identify opportunities for improvement and maximum environmental and human health protection. Copyright © 2015 Elsevier B.V. All rights reserved.

Performances of metal concentrations from three permeable pavement infiltrates.

PubMed

Liu, Jiayu; Borst, Michael

2018-06-01

The U.S. Environmental Protection Agency constructed a 4000-m 2 parking lot in Edison, New Jersey in 2009. The parking lot is surfaced with three permeable pavements [permeable interlocking concrete pavers (PICP), pervious concrete (PC), and porous asphalt (PA)]. Samples of each permeable pavement infiltrate, surface runoff from traditional asphalt, and rainwater were analyzed in duplicate for 22 metals (total and dissolved) for 6 years. In more than 99% of the samples, the concentration of barium, chromium, copper, manganese, nickel and zinc, and in 60%-90% of the samples, the concentration of arsenic, cadmium, lead, and antimony in infiltrates from all three permeable pavements met both the groundwater effluent limitations (GEL) and maximum contaminant levels (MCL). The concentration of aluminum (50%) and iron (93%) in PICP infiltrates samples exceed the GELs; however, the concentration in more than 90% samples PA and PC infiltrates met the GELs. No measurable difference in metal concentrations was found from the five sources for arsenic, cadmium, lead, antimony, and tin. Large concentrations of eleven metals, including manganese, copper, aluminum, iron, calcium, magnesium, sodium, potassium, silica, strontium and vanadium, were detected in surface runoff than the rainwater. Chromium, copper, manganese, nickel, aluminum, zinc, iron and magnesium concentrations in PICP infiltrates; calcium, barium, and strontium concentrations in PA infiltrates; sodium, potassium and vanadium concentrations in PC infiltrates were statistically larger than the other two permeable pavement infiltrates. Published by Elsevier Ltd.

Arsenic in Ground-Water Resources of the United States

USGS Publications Warehouse

Welch, Alan H.; Watkins, Sharon A.; Helsel, Dennis R.; Focazio, Michael J.

2000-01-01

Arsenic is a naturally occurring element in rocks, soils, and the waters in contact with them. Recognized as a toxic element for centuries, arsenic today also is a human health concern because it can contribute to skin, bladder, and other cancers (National Research Council, 1999). Recently, the National Research Council (1999) recommended lowering the current maximum contaminant level (MCL) allowed for arsenic in drinking water of 50 ?g/L (micrograms per liter), citing risks for developing bladder and other cancers. The U.S. Environmental Protection Agency (USEPA) will propose a new, and likely lower, arsenic MCL during 2000 (U.S. Environmental Protection Agency, 2000). This fact sheet provides information on where and to what extent natural concentrations of arsenic in ground water exceed possible new standards. The U.S. Geological Survey (USGS) has collected and analyzed arsenic in potable (drinkable) water from 18,850 wells in 595 counties across the United States during the past two decades. These wells are used for irrigation, industrial purposes, and research, as well as for public and private water supply. Arsenic concentrations in samples from these wells are similar to those found in nearby public supplies (see Focazio and others, 1999). The large number of samples, broad geographic coverage, and consistency of methods produce a more accurate and detailed picture of arsenic concentrations than provided by any previous studies.

Bioaccumulation of heavy metals in crop plants grown near Almeda Textile Factory, Adwa, Ethiopia.

PubMed

Gitet, Hintsa; Hilawie, Masho; Muuz, Mehari; Weldegebriel, Yirgaalem; Gebremichael, Dawit; Gebremedhin, Desta

2016-09-01

The contents of heavy metals cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) present in water (wastewater and wetland), soils, and food crops collected from the vicinity of Almeda Textile Factory were quantified using Flame Atomic Absorption Spectrometer (FAAS) in order to assess the environmental impact of the textile factory. The contents of heavy metals determined in the wastewater were found below the recommended limit set by WHO and United States Environmental Protection Agency (US EPA) except for Cr, which was found slightly higher than WHO permissible limit. Besides, the contents of the heavy metals determined in soils were below the permissible level of FAO/WHO and Canada maximum allowable limits. Moreover, only the concentrations of Cd and Pb were found above the permissible level set by FAO/WHO in the crop plants studied. Generally, the mean concentrations of heavy metals in the plants were in the decreasing order of: Mn > Zn > Cu > Pb > Ni > Co > Cr > Cd. Nevertheless, higher bioconcentration factor (BCF) was found for Cd (0.108-1.156) followed by Zn (0.081-0.499). In conclusion, comparison of heavy metal concentrations with the permissible limits in all collected sample types i.e. water, soil, and crop plants did not show significant pollution from the factory.

Arsenic in Drinking Water—A Global Environmental Problem

NASA Astrophysics Data System (ADS)

Shaofen Wang, Joanna; Wai, Chien M.

2004-02-01

Arsenic contamination of groundwater is a global environmental problem affecting a large number of populations, especially in developing countries. The "blackfoot disease"that occurred in Taiwan more than half of a century ago was attributed to drinking arsenic-contaminated water from deep wells containing high concentrations of the trivalent arsenite species. Similar arsenic poisoning cases were reported later in Chinese Inner Mongolia, Bangladesh, and India—all related to drinking groundwater contaminated with arsenic. The maximum contaminant level (MCL) of arsenic in drinking water has been changed recently by the U.S. EPA from 50 ppb to 10 ppb; the compliance date is January 2006. This article summarizes documented global arsenic contamination problems, the regulatory controversy regarding MCL of arsenic in drinking water, and available technologies for removing arsenic from contaminated waters. Methods for analyzing total arsenic and arsenic species in water are also described.

Water-quality assessment of the Trinity River basin, Texas : ground-water quality of the Trinity, Carrizo-Wilcox, and Gulf Coast aquifers, February-August 1994

USGS Publications Warehouse

Reutter, David C.; Dunn, David D.

2000-01-01

Ground-water samples were collected from wells in the outcrops of the Trinity, Carrizo-Wilcox, and Gulf Coast aquifers during February-August 1994 to determine the quality of ground water in the three major aquifers in the Trinity River Basin study unit, Texas. These samples were collected and analyzed for selected properties, nutrients, major inorganic constituents, trace elements, pesticides, dissolved organic carbon, total phenols, methylene blue active substances, and volatile organic compounds as part of the U.S. Geological Survey National Water-Quality Assessment Program. Quality-control practices included the collection and analysis of blank, duplicate, and spiked samples. Samples were collected from 12 shallow wells (150 feet or less) and from 12 deep wells (greater than 150 feet) in the Trinity aquifer, 11 shallow wells and 12 deep wells in the Carrizo-Wilcox aquifer, and 14 shallow wells and 10 deep wells in the Gulf Coast aquifer. The three aquifers had similar water chemistries-calcium was the dominant cation and bicarbonate the dominant anion. Statistical tests relating well depths to concentrations of nutrients and major inorganic constituents indicated correlations between well depth and concentrations of ammonia nitrogen, nitrite plus nitrate nitrogen, bicarbonate, sodium, and dissolved solids in the Carrizo-Wilcox aquifer and between well depth and concentrations of sulfate in the Gulf Coast aquifer. The tests indicated no significant correlations for the Trinity aquifer. Concentrations of dissolved solids were larger than the secondary maximum contaminant level of 500 milligrams per liter established for drinking water by the U.S. Environmental Protection Agency in 12 wells in the Trinity aquifer, 4 wells in the Carrizo-Wilcox aquifer, and 6 wells in the Gulf Coast aquifer. Iron concentrations were larger than the secondary maximum contaminant level of 300 micrograms per liter in at least 3 samples from each aquifer, and manganese concentrations were larger than the secondary maximum contaminant level of 50 micrograms per liter in at least 2 samples from each aquifer. The pesticides atrazine, deethylatrazine, and pp'-DDE were detected in at least one sample from each aquifer. Diazinon was detected in 11 Trinity aquifer samples and 4 Carrizo-Wilcox aquifer samples. Each aquifer had one detection of a volatile organic compound-benzene in the Trinity aquifer, trichlorofluoromethane in the Carrizo-Wilcox aquifer, and trichloromethane in the Gulf Coast aquifer.

Impact of downward-mixing ozone on surface ozone accumulation in southern Taiwan.

PubMed

Lin, Ching-Ho

2008-04-01

The ozone that initially presents in the previous day's afternoon mixing layer can remain in the nighttime atmosphere and then be carried over to the next morning. Finally, this ozone can be brought to the ground by downward mixing as mixing depth increases during the daytime, thereby increasing surface ozone concentrations. Variation of ozone concentration during each of these periods is investigated in this work. First, ozone concentrations existing in the daily early morning atmosphere at the altitude range of the daily maximum mixing depth (residual ozone concentrations) were measured using tethered ozonesondes on 52 experimental days during 2004-2005 in southern Taiwan. Daily downward-mixing ozone concentrations were calculated by a box model coupling the measured daily residual ozone concentrations and daily mixing depth variations. The ozone concentrations upwind in the previous day's afternoon mixing layer were estimated by the combination of back air trajectory analysis and known previous day's surface ozone distributions. Additionally, the relationship between daily downward-mixing ozone concentration and daily photochemically produced ozone concentration was examined. The latter was calculated by removing the former from daily surface maximum ozone concentration. The measured daily residual ozone concentrations distributed at 12-74 parts per billion (ppb) with an average of 42 +/- 17 ppb are well correlated with the previous upwind ozone concentration (R2 = 0.54-0.65). Approximately 60% of the previous upwind ozone was estimated to be carried over to the next morning and became the observed residual ozone. The daily downward-mixing ozone contributes 48 +/- 18% of the daily surface maximum ozone concentration, indicating that the downward-mixing ozone is as important as daily photochemically produced ozone to daily surface maximum ozone accumulation. The daily downward-mixing ozone is poorly correlated with the daily photochemically produced ozone and contributes significantly to the daily variation of surface maximum ozone concentrations (R2 = 0.19). However, the contribution of downward-mixing ozone to daily ozone variation is not included in most existing statistical models developed for predicting daily ozone variation. Finally, daily surface maximum ozone concentration is positively correlated with daily afternoon mixing depth, attributable to the downward-mixing ozone.

Contamination levels, toxicity profiles, and emission sources of polycyclic aromatic hydrocarbons (PAHs) in the soils of an emerging industrial town and its environs in the Southeastern Nigeria.

PubMed

Ofomatah, Anthony C; Okoye, Chukwuma O B

2017-11-09

Polycyclic aromatic hydrocarbon (PAH) concentrations in Nnewi and its environs were determined. Soil samples were extracted by sonication using hexane:dichloromethane (3:1) mixture and determined by gas chromatography-flame ionization detection. The total PAHs concentrations (μg/kg) were 16.681 to 46.815, being three orders of magnitude lower than the maximum permissible level recommended by the Agency for Toxic Substances and Disease Registry (ATSDR). These concentrations followed this order: industrial ˃ farmlands ˃ commercial ˃ residential. Industrialized areas showed higher concentrations (p ˂ 0.05) than the other areas. Diagnostic ratios show that the major source of PAHs was the open burning of industrial and agricultural wastes, as shown by the occurrence of highest concentrations in the industrial areas, followed by agricultural areas. Benzo[a]pyrene equivalent values showed non-pollution and very low toxicity. Nevertheless, it was clear that industrialization has had some impact on the PAHs levels in soils and the total environment in this area and could be problematic with time, except with proper environmental management.

Long-term Metal Performance of Three Permeable Pavements ...

EPA Pesticide Factsheets

EPA constructed a 4,000-m2 parking lot surfaced with three permeable pavements (permeable interlocking concrete pavers, pervious concrete, and porous asphalt) on the Edison Environmental Center in Edison, NJ in 2009. Samples from each permeable pavement infiltrate were collected for six years beginning in January 2010 and analyzed for twenty-two metals. Although the infiltrate metals concentrations varied by surface, metal concentrations in more than 99% of the permeable pavement infiltrate samples met both the groundwater effluent limitations and maximum contaminant levels in national primary drinking water regulations for barium, chromium, copper, manganese, nickel and zinc. Arsenic, cadmium, lead and antimony met those standards in 60% to 98% of the samples with no measurable difference found among pavements. Aluminum and iron in pervious concrete and porous asphalt infiltrates met standards at more than 90%, however permeable interlocking concrete paver infiltrates have 50% and 93% samples exceeds standards, respectively. Concentrations of arsenic, iron, potassium, lithium, magnesium, antimony, tin, manganese, and zinc in all permeable pavement infiltrates decreased with time, whereas, aluminum, barium, calcium, chromium and strontium in porous asphalt infiltrates increased. Most metal concentrations in permeable pavement infiltrates either exhibited no significant difference between snow/no-snow seasons or showed statistically larger concentrations

In Situ Production of Chlorine-36 in the Eastern Snake River Plain Aquifer, Idaho: Implications for Describing Ground-Water Contamination Near a Nuclear Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

L. D. Cecil; L. L. Knobel; J. R. Green

2000-06-01

The purpose of this report is to describe the calculated contribution to ground water of natural, in situ produced 36Cl in the eastern Snake River Plain aquifer and to compare these concentrations in ground water with measured concentrations near a nuclear facility in southeastern Idaho. The scope focused on isotopic and chemical analyses and associated 36Cl in situ production calculations on 25 whole-rock samples from 6 major water-bearing rock types present in the eastern Snake River Plain. The rock types investigated were basalt, rhyolite, limestone, dolomite, shale, and quartzite. Determining the contribution of in situ production to 36Cl inventories inmore » ground water facilitated the identification of the source for this radionuclide in environmental samples. On the basis of calculations reported here, in situ production of 36Cl was determined to be insignificant compared to concentrations measured in ground water near buried and injected nuclear waste at the INEEL. Maximum estimated 36Cl concentrations in ground water from in situ production are on the same order of magnitude as natural concentrations in meteoric water.« less

Tree-based modeling of complex interactions of phosphorus loadings and environmental factors.

PubMed

Grunwald, S; Daroub, S H; Lang, T A; Diaz, O A

2009-06-01

Phosphorus (P) enrichment has been observed in the historic oligotrophic Greater Everglades in Florida mainly due to P influx from upstream, agriculturally dominated, low relief drainage basins of the Everglades Agricultural Area (EAA). Our specific objectives were to: (1) investigate relationships between various environmental factors and P loads in 10 farm basins within the EAA, (2) identify those environmental factors that impart major effects on P loads using three different tree-based modeling approaches, and (3) evaluate predictive models to assess P loads. We assembled thirteen environmental variable sets for all 10 sub-basins characterizing water level management, cropping practices, soils, hydrology, and farm-specific properties. Drainage flow and P concentrations were measured at each sub-basin outlet from 1992-2002 and aggregated to derive monthly P loads. We used three different tree-based models including single regression trees (ST), committee trees in Bagging (CTb) and ARCing (CTa) modes and ten-fold cross-validation to test prediction performances. The monthly P loads (MPL) during the monitoring period showed a maximum of 2528 kg (mean: 103 kg) and maximum monthly unit area P loads (UAL) of 4.88 kg P ha(-1) (mean: 0.16 kg P ha(-1)). Our results suggest that hydrologic/water management properties are the major controlling variables to predict MPL and UAL in the EAA. Tree-based modeling was successful in identifying relationships between P loads and environmental predictor variables on 10 farms in the EAA indicated by high R(2) (>0.80) and low prediction errors. Committee trees in ARCing mode generated the best performing models to predict P loads and P loads per unit area. Tree-based models had the ability to analyze complex, non-linear relationships between P loads and multiple variables describing hydrologic/water management, cropping practices, soil and farm-specific properties within the EAA.

Conditions for a partial summation of SO2 and NO2 hazardous effect in gas emission regulations

NASA Astrophysics Data System (ADS)

Sokolov, A. K.

2017-12-01

In order to provide environmental safety, the concentrations of SO2 and SO2 in the surface layer of atmospheric air should not exceed corresponding one-time values accepted for maximum permissible concentrations (MPCs). The only document that provides a normative calculation of hazardous substance dispersion in the atmospheric air up to the present time is presented by regulations OND-86. It has established that, in taking into account the summation (unidirectionality) of hazardous action of substances (including SO2 and NO2 gases), the sum of their relative concentrations should not exceed unity. A novel standard GN 2.1.6.2326-08 stipulates that "nitrogen dioxide and sulfur dioxide have a partial summation of action; therefore the sum of their relative concentrations should not exceed 1.6." This paper is devoted to analyzing the calculation of the summation of action for SO2 and NO2 gases and proving that the condition established in GN 2.1.6.2326-08 is not quite correct. According to the condition required by standard GN 2.1.6.2326-08, it turns out that, for some combinations of concentrations, the hazardous effect of gases is not added together, but one gas compensates an effect of the other, which contradicts the points of OND-86. For example, at SO2 and NO2 concentrations amounting to 0.6 and 0.04, respectively, the condition required by standard GN 2.1.6.2326-08 is satisfied, although the concentration of SO2 exceeds a normatively fixed value of MPC = 0.5. The graphical analysis of a concentration region for SO2 and NO2 gases clearly shows the areas where the condition required by standard GN 2.1.6.2326-08 is satisfied, but the environmental safety according to OND-86 is not provided. Recommendations are proposed for the correction of requirements established by standard GN 2.1.6.2326-08.

Water Quality Conditions Associated with Cattle Grazing and Recreation on National Forest Lands

PubMed Central

Roche, Leslie M.; Kromschroeder, Lea; Atwill, Edward R.; Dahlgren, Randy A.; Tate, Kenneth W.

2013-01-01

There is substantial concern that microbial and nutrient pollution by cattle on public lands degrades water quality, threatening human and ecological health. Given the importance of clean water on multiple-use landscapes, additional research is required to document and examine potential water quality issues across common resource use activities. During the 2011 grazing-recreation season, we conducted a cross sectional survey of water quality conditions associated with cattle grazing and/or recreation on 12 public lands grazing allotments in California. Our specific study objectives were to 1) quantify fecal indicator bacteria (FIB; fecal coliform and E. coli), total nitrogen, nitrate, ammonium, total phosphorus, and soluble-reactive phosphorus concentrations in surface waters; 2) compare results to a) water quality regulatory benchmarks, b) recommended maximum nutrient concentrations, and c) estimates of nutrient background concentrations; and 3) examine relationships between water quality, environmental conditions, cattle grazing, and recreation. Nutrient concentrations observed throughout the grazing-recreation season were at least one order of magnitude below levels of ecological concern, and were similar to U.S. Environmental Protection Agency (USEPA) estimates for background water quality conditions in the region. The relative percentage of FIB regulatory benchmark exceedances widely varied under individual regional and national water quality standards. Relative to USEPA’s national E. coli FIB benchmarks–the most contemporary and relevant standards for this study–over 90% of the 743 samples collected were below recommended criteria values. FIB concentrations were significantly greater when stream flow was low or stagnant, water was turbid, and when cattle were actively observed at sampling. Recreation sites had the lowest mean FIB, total nitrogen, and soluble-reactive phosphorus concentrations, and there were no significant differences in FIB and nutrient concentrations between key grazing areas and non-concentrated use areas. Our results suggest cattle grazing, recreation, and provisioning of clean water can be compatible goals across these national forest lands. PMID:23826370

Identification of Watershed-scale Critical Source Areas Using Bayesian Maximum Entropy Spatiotemporal Analysis

NASA Astrophysics Data System (ADS)

Roostaee, M.; Deng, Z.

2017-12-01

The states' environmental agencies are required by The Clean Water Act to assess all waterbodies and evaluate potential sources of impairments. Spatial and temporal distributions of water quality parameters are critical in identifying Critical Source Areas (CSAs). However, due to limitations in monetary resources and a large number of waterbodies, available monitoring stations are typically sparse with intermittent periods of data collection. Hence, scarcity of water quality data is a major obstacle in addressing sources of pollution through management strategies. In this study spatiotemporal Bayesian Maximum Entropy method (BME) is employed to model the inherent temporal and spatial variability of measured water quality indicators such as Dissolved Oxygen (DO) concentration for Turkey Creek Watershed. Turkey Creek is located in northern Louisiana and has been listed in 303(d) list for DO impairment since 2014 in Louisiana Water Quality Inventory Reports due to agricultural practices. BME method is proved to provide more accurate estimates than the methods of purely spatial analysis by incorporating space/time distribution and uncertainty in available measured soft and hard data. This model would be used to estimate DO concentration at unmonitored locations and times and subsequently identifying CSAs. The USDA's crop-specific land cover data layers of the watershed were then used to determine those practices/changes that led to low DO concentration in identified CSAs. Primary results revealed that cultivation of corn and soybean as well as urban runoff are main contributing sources in low dissolved oxygen in Turkey Creek Watershed.

The relationship between UV-irradiance, photoprotective compounds and DNA damage in two intertidal invertebrates with contrasting mobility characteristics.

PubMed

Cubillos, Victor Mauricio; Burritt, David J; Lamare, Miles D; Peake, Barrie M

2015-08-01

The photoprotective role of mycosporine-like amino acids (MAA) against the generation of DNA cyclobutane pyrimidine dimers (CPD) was studied in the sessile intertidal anemone Actinia tenebrosa and the mobile intertidal gastropod Diloma aethiops through 27months at a mid-latitude New Zealand location. MAA were sequestered by A. tenebrosa and D. aethiops from their diet, although maximum total MAA levels in both species were not correlated with seasonal variation in maximum ambient UV-B levels recorded at the collection site. Temporal changes in total MAA in A. tenebrosa showed a six months lag-time in their concentration regarding to the environmental UV-B levels. This lag period corresponded to an observed increase in CPD production from spring to summer; suggesting that MAA do not completely protect the anemone from UV-B during summer. For D. aethiops, total MAA concentrations did not change significantly during the study, although qualitative changes in MAA were apparent. A month lag-time in MAA concentration in D. aethiops and possibly the physical barrier that the shell confers to the animal, can explain reduced CPD levels in comparative terms with A. tenebrosa. Although MAA are used by invertebrates for photoprotection, contrasting mobility characteristics and the presence of physical adaptations can confer them important protection levels during temporal changes of UV-B at mid-latitude places of the Southern Hemisphere. Copyright © 2015 Elsevier B.V. All rights reserved.

Occurrence of veterinary antibiotics and progesterone in broiler manure and agricultural soil in Malaysia.

PubMed

Ho, Yu Bin; Zakaria, Mohamad Pauzi; Latif, Puziah Abdul; Saari, Nazamid

2014-08-01

Repeated applications of animal manure as fertilizer are normal agricultural practices that may release veterinary antibiotics and hormones into the environment from treated animals. Broiler manure samples and their respective manure-amended agricultural soil samples were collected in selected locations in the states of Selangor, Negeri Sembilan and Melaka in Malaysia to identify and quantify veterinary antibiotic and hormone residues in the environment. The samples were analyzed using ultrasonic extraction followed by solid phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The broiler manure samples were found to be contaminated with at least six target analytes, namely, doxycycline, enrofloxacin, flumequine, norfloxacin, trimethoprim and tylosin. These analytes were detected in broiler manure samples with maximum concentrations reaching up to 78,516 μg kg(-1) dry weight (DW) (doxycycline). For manure-amended agricultural soil samples, doxycycline and enrofloxacin residues were detected in every soil sample. The maximum concentration of antibiotic detected in soil was 1331 μg kg(-1) DW (flumequine). The occurrence of antibiotics and hormones in animal manure at high concentration poses a risk of contaminating agricultural soil via fertilization with animal manure. Some physico-chemical parameters such as pH, total organic carbon (TOC) and metal content played a considerable role in the fate of the target veterinary antibiotics and progesterone in the environment. It was suggested that these parameters can affect the adsorption of pharmaceuticals to solid environmental matrices. Copyright © 2014 Elsevier B.V. All rights reserved.

Assessment of both environmental cytotoxicity and trace metal pollution using Populus simonii Carr. as a bioindicator.

PubMed

Sluchyk, Victor; Sluchyk, Iryna; Shyichuk, Alexander

2014-10-01

The level of environmental pollution in the city of Ivano-Frankivsk (Western Ukraine) has been assessed by means of roadside poplar trees as bioindicators. Dividable apical meristem cells of rudimentary leaves were quantitatively analysed for mitotic activity and distribution. Anaphases were further examined for chromosomal aberrations. Male catkins were also examined for sterile pollens. Accumulation of trace elements in vegetative buds was also evaluated in order to reveal source(s) of environmental pollution. Poplar trees growing in the urban environment proved to have increased chromosomal aberrations (up to 4-fold) and increased pollen sterility (up to 4-fold) as well as decreased mitotic activity (by factor 1.5) as compared to control sampling site. The biomarker data correlate moderately with increased (up to 4-fold) concentrations of Ni, Zn, Pb, Cd and Cu in vegetative tissues suggesting that probable cause of the environmental cytotoxicity may be vehicle emissions. The maximum increase in chromosomal aberrations (7-fold) and the minimum mitotic activity (half of the control one) were recorded in poplar trees growing in industrial suburb in vicinity of large cement production plant. Taking in mind insignificant bioaccumulation of trace elements in the industrial suburb, the high environmental toxicity has been ascribed to contamination in cement and asbestos particulates.

Occurrence and distribution of fecal indicator bacteria, and physical and chemical indicators of water quality in streams receiving discharge from Dallas/Fort Worth International Airport and vicinity, North-Central Texas, 2008

USGS Publications Warehouse

Harwell, Glenn R.; Mobley, Craig A.

2009-01-01

This report, done by the U.S. Geological Survey in cooperation with Dallas/Fort Worth International (DFW) Airport in 2008, describes the occurrence and distribution of fecal indicator bacteria (fecal coliform and Escherichia [E.] coli), and the physical and chemical indicators of water quality (relative to Texas Surface Water Quality Standards), in streams receiving discharge from DFW Airport and vicinity. At sampling sites in the lower West Fork Trinity River watershed during low-flow conditions, geometric mean E. coli counts for five of the eight West Fork Trinity River watershed sampling sites exceeded the Texas Commission on Environmental Quality E. coli criterion, thus not fully supporting contact recreation. Two of the five sites with geometric means that exceeded the contact recreation criterion are airport discharge sites, which here means that the major fraction of discharge at those sites is from DFW Airport. At sampling sites in the Elm Fork Trinity River watershed during low-flow conditions, geometric mean E. coli counts exceeded the geometric mean contact recreation criterion for seven (four airport, three non-airport) of 13 sampling sites. Under low-flow conditions in the lower West Fork Trinity River watershed, E. coli counts for airport discharge sites were significantly different from (lower than) E. coli counts for non-airport sites. Under low-flow conditions in the Elm Fork Trinity River watershed, there was no significant difference between E. coli counts for airport sites and non-airport sites. During stormflow conditions, fecal indicator bacteria counts at the most downstream (integrator) sites in each watershed were considerably higher than counts at those two sites during low-flow conditions. When stormflow sample counts are included with low-flow sample counts to compute a geometric mean for each site, classification changes from fully supporting to not fully supporting contact recreation on the basis of the geometric mean contact recreation criterion. All water temperature measurements at sampling sites in the lower West Fork Trinity River watershed were less than the maximum criterion for water temperature for the lower West Fork Trinity segment. Of the measurements at sampling sites in the Elm Fork Trinity River watershed, 95 percent were less than the maximum criterion for water temperature for the Elm Fork Trinity River segment. All dissolved oxygen concentrations were greater than the minimum criterion for stream segments classified as exceptional aquatic life use. Nearly all pH measurements were within the pH criterion range for the classified segments in both watersheds, except for those at one airport site. For sampling sites in the lower West Fork Trinity River watershed, all annual average dissolved solids concentrations were less than the maximum criterion for the lower West Fork Trinity segment. For sampling sites in the Elm Fork Trinity River, nine of the 13 sites (six airport, three non-airport) had annual averages that exceeded the maximum criterion for that segment. For ammonia, 23 samples from 12 different sites had concentrations that exceeded the screening level for ammonia. Of these 12 sites, only one non-airport site had more than the required number of exceedances to indicate a screening level concern. Stormflow total suspended solids concentrations were significantly higher than low-flow concentrations at the two integrator sites. For sampling sites in the lower West Fork Trinity River watershed, all annual average chloride concentrations were less than the maximum annual average chloride concentration criterion for that segment. For the 13 sampling sites in the Elm Fork Trinity River watershed, one non-airport site had an annual average concentration that exceeded the maximum annual average chloride concentration criterion for that segment.

Co-concentration effect of silane with natural extract on biodegradable polymeric films for food packaging.

PubMed

Bashir, Anbreen; Jabeen, Sehrish; Gull, Nafisa; Islam, Atif; Sultan, Misbah; Ghaffar, Abdul; Khan, Shahzad Maqsood; Iqbal, Sadia Sagar; Jamil, Tahir

2018-01-01

Novel biodegradable films were prepared by blending guar gum, chitosan and poly (vinyl alcohol) having mint (ME) and grapefruit peel (GE) extracts and crosslinked with nontoxic tetraethoxysilane (TEOS). The co-concentration effect of TEOS with natural extracts on the films was studied. FTIR analysis confirmed the presence of incorporated components and the developed interactions among the polymer chains. The surface morphology of the films by SEM showed the hydrophilic character due to porous network structure. The films having both ME and GE with maximum amount of crosslinker (100μL), showed maximum swelling (58g/g) and stability while the optical properties showed increased protection against UV light. This film sample showed compact network structure which enhanced the ultimate tensile strength (40.03MPa) and elongation at break (104.8%). ME/GE conferred the antioxidant properties determined by radical scavenging activity and total phenolic contents (TPC) as ME films have greater TPC compared to GE films. The soil burial test exhibited the degradation of films rapidly (6days) confirming their strong microbial activity in soil. The lower water vapour transmission rate and water vapour permeability showed better shelf life; hence, these biodegradable films are environmental friendly and have potential for food and other packaging. Copyright © 2017 Elsevier B.V. All rights reserved.

Study of copper (Cu) contents in blood cockles (Anadara sp.) at Surabaya coastal waters

NASA Astrophysics Data System (ADS)

Alfionita, S.; Pursetyo, K. T.; Sahidu, A. M.

2018-04-01

Heavy metal pollution categorized as harmful effect on the environment. This study aims to determine the content and the rate of accumulation of heavy metals copper (Cu) in the mussel of cockles (Anadara sp.) This study uses observation method with descriptive analysis. The test results Cu in sea water was <0.0223 mg/L. The results have exceeded the water quality standard according to state environmental ministerial decree number 51 2004 on marine water quality standards for marine biota maximum limit of Cu in sea water is 0.008 mg/L. Copper concentration in the sediment of 6.16 mg/kg at the Wonokromo station and at the Dadapan station is 4.03 mg/kg. According to the US-EPA in 2004 on the instructions of sediment pollution classification 49.98 mg Cu/kg. The results of shells fur Cu on Wonokromo was 1.833 mg/kg and Dadapan was 1.352 mg/kg. According to the MOH Decree No.0375/B/SK/1989 about Quality Standard Biota Consumption of Metals to the maximum limit of the existing Cu concentrations in marine biota was 20 ppm or 20 mg / kg so that the content of Cu in shellfish feathers still below the limit of existing quality standards.

Modelling of Radiological Health Risks from Gold Mine Tailings in Wonderfonteinspruit Catchment Area, South Africa.

PubMed

Mathuthu, Manny; Kamunda, Caspah; Madhuku, Morgan

2016-06-07

Mining is one of the major causes of elevation of naturally-occurring radionuclide material (NORM) concentrations on the Earth's surface. The aim of this study was to evaluate the human risk associated with exposure to NORMs in soils from mine tailings around a gold mine. A broad-energy germanium detector was used to measure activity concentrations of these NORMs in 66 soil samples (56 from five mine tailings and 10 from the control area). The RESidual RADioactivity (RESRAD) OFFSITE modeling program (version 3.1) was then used to estimate the radiation doses and the cancer morbidity risk of uranium-238 ((238)U), thorium-232 ((232)Th), and potassium-40 ((40)K) for a hypothetical resident scenario. According to RESRAD prediction, the maximum total effective dose equivalent (TEDE) during 100 years was found to be 0.0315 mSv/year at year 30, while the maximum total excess cancer morbidity risk for all the pathways was 3.04 × 10(-5) at year 15. The US Environmental Protection Agency considers acceptable for regulatory purposes a cancer risk in the range of 10(-6) to 10(-4). Therefore, results obtained from RESRAD OFFSITE code has shown that the health risk from gold mine tailings is within acceptable levels according to international standards.

Modelling of Radiological Health Risks from Gold Mine Tailings in Wonderfonteinspruit Catchment Area, South Africa

PubMed Central

Mathuthu, Manny; Kamunda, Caspah; Madhuku, Morgan

2016-01-01

Mining is one of the major causes of elevation of naturally-occurring radionuclide material (NORM) concentrations on the Earth’s surface. The aim of this study was to evaluate the human risk associated with exposure to NORMs in soils from mine tailings around a gold mine. A broad-energy germanium detector was used to measure activity concentrations of these NORMs in 66 soil samples (56 from five mine tailings and 10 from the control area). The RESidual RADioactivity (RESRAD) OFFSITE modeling program (version 3.1) was then used to estimate the radiation doses and the cancer morbidity risk of uranium-238 (238U), thorium-232 (232Th), and potassium-40 (40K) for a hypothetical resident scenario. According to RESRAD prediction, the maximum total effective dose equivalent (TEDE) during 100 years was found to be 0.0315 mSv/year at year 30, while the maximum total excess cancer morbidity risk for all the pathways was 3.04 × 10−5 at year 15. The US Environmental Protection Agency considers acceptable for regulatory purposes a cancer risk in the range of 10−6 to 10−4. Therefore, results obtained from RESRAD OFFSITE code has shown that the health risk from gold mine tailings is within acceptable levels according to international standards. PMID:27338424

Passive micromixer for luminol-peroxide chemiluminescence detection.

PubMed

Lok, Khoi Seng; Kwok, Yien Chian; Nguyen, Nam-Trung

2011-06-21

This paper reports a microchip with an integrated passive micromixer based on chaotic advection. The micromixer with staggered herringbone structures was used for luminol-peroxide chemiluminescence detection. The micromixer was examined to assess its suitability for chemiluminescence reaction. The relationship between the flow rate and the location of maximum chemiluminescence intensity was investigated. The light intensity was detected using an optical fiber attached along the mixing channel and a photon detector. A linear correlation between chemiluminescence intensity and the concentration of cobalt(ii) ions or hydrogen peroxide was observed. This microchip has a potential application in environmental monitoring for industries involved in heavy metals and in medical diagnostics.

Multiobjective optimization for Groundwater Nitrate Pollution Control. Application to El Salobral-Los Llanos aquifer (Spain).

NASA Astrophysics Data System (ADS)

Llopis-Albert, C.; Peña-Haro, S.; Pulido-Velazquez, M.; Molina, J.

2012-04-01

Water quality management is complex due to the inter-relations between socio-political, environmental and economic constraints and objectives. In order to choose an appropriate policy to reduce nitrate pollution in groundwater it is necessary to consider different objectives, often in conflict. In this paper, a hydro-economic modeling framework, based on a non-linear optimization(CONOPT) technique, which embeds simulation of groundwater mass transport through concentration response matrices, is used to study optimal policies for groundwater nitrate pollution control under different objectives and constraints. Three objectives were considered: recovery time (for meeting the environmental standards, as required by the EU Water Framework Directive and Groundwater Directive), maximum nitrate concentration in groundwater, and net benefits in agriculture. Another criterion was added: the reliability of meeting the nitrate concentration standards. The approach allows deriving the trade-offs between the reliability of meeting the standard, the net benefits from agricultural production and the recovery time. Two different policies were considered: spatially distributed fertilizer standards or quotas (obtained through multi-objective optimization) and fertilizer prices. The multi-objective analysis allows to compare the achievement of the different policies, Pareto fronts (or efficiency frontiers) and tradeoffs for the set of mutually conflicting objectives. The constraint method is applied to generate the set of non-dominated solutions. The multi-objective framework can be used to design groundwater management policies taking into consideration different stakeholders' interests (e.g., policy makers, agricultures or environmental groups). The methodology was applied to the El Salobral-Los Llanos aquifer in Spain. Over the past 30 years the area has undertaken a significant socioeconomic development, mainly due to the intensive groundwater use for irrigated crops, which has provoked a steady decline of groundwater levels as well as high nitrate concentrations at certain locations (above 50 mg/l.). The results showed the usefulness of this multi-objective hydro-economic approach for designing sustainable nitrate pollution control policies (as fertilizer quotas or efficient fertilizer pricing policies) with insight into the economic cost of satisfying the environmental constraints and the tradeoffs with different time horizons.

40 CFR 141.11 - Maximum contaminant levels for inorganic chemicals.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant levels for inorganic chemicals. 141.11 Section 141.11 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... § 141.11 Maximum contaminant levels for inorganic chemicals. (a) The maximum contaminant level for...

40 CFR 141.11 - Maximum contaminant levels for inorganic chemicals.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Maximum contaminant levels for inorganic chemicals. 141.11 Section 141.11 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... § 141.11 Maximum contaminant levels for inorganic chemicals. (a) The maximum contaminant level for...

40 CFR 141.11 - Maximum contaminant levels for inorganic chemicals.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Maximum contaminant levels for inorganic chemicals. 141.11 Section 141.11 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... § 141.11 Maximum contaminant levels for inorganic chemicals. (a) The maximum contaminant level for...

Subsurface chlorophyll maximum layers: enduring enigma or mystery solved?

PubMed

Cullen, John J

2015-01-01

The phenomenon of subsurface chlorophyll maximum layers (SCMLs) is not a unique ecological response to environmental conditions; rather, a broad range of interacting processes can contribute to the formation of persistent layers of elevated chlorophyll a concentration (Chl) that are nearly ubiquitous in stratified surface waters. Mechanisms that contribute to the formation and maintenance of the SCMLs include a local maximum in phytoplankton growth rate near the nutricline, photoacclimation of pigment content that leads to elevated Chl relative to phytoplankton biomass at depth, and a range of physiologically influenced swimming behaviors in motile phytoplankton and buoyancy control in diatoms and cyanobacteria that can lead to aggregations of phytoplankton in layers, subject to grazing and physical control. A postulated typical stable water structure characterizes consistent patterns in vertical profiles of Chl, phytoplankton biomass, nutrients, and light across a trophic gradient structured by the vertical flux of nutrients and characterized by the average daily irradiance at the nutricline. Hypothetical predictions can be tested using a nascent biogeochemical global ocean observing system. Partial results to date are generally consistent with predictions based on current knowledge, which has strong roots in research from the twentieth century.

Geochemical Effects of Induced Stream-Water and Artificial Recharge on the Equus Beds Aquifer, South-Central Kansas, 1995-2004

USGS Publications Warehouse

Schmidt, Heather C. Ross; Ziegler, Andrew C.; Parkhurst, David L.

2007-01-01

Artificial recharge of the Equus Beds aquifer is part of a strategy implemented by the city of Wichita, Kansas, to preserve future water supply and address declining water levels in the aquifer of as much as 30 feet caused by withdrawals for water supply and irrigation since the 1940s. Water-level declines represent a diminished water supply and also may accelerate migration of saltwater from the Burrton oil field to the northwest and the Arkansas River to the southwest into the freshwater of the Equus Beds aquifer. Artificial recharge, as a part of the Equus Beds Ground-Water Recharge Project, involves capturing flows larger than base flow from the Little Arkansas River and recharging the water to the Equus Beds aquifer by means of infiltration or injection. The geochemical effects on the Equus Beds aquifer of induced stream-water and artificial recharge at the Halstead and Sedgwick sites were determined through collection and analysis of hydrologic and water-quality data and the application of statistical, mixing, flow and solute-transport, and geochemical model simulations. Chloride and atrazine concentrations in the Little Arkansas River and arsenic concentrations in ground water at the Halstead recharge site frequently exceeded regulatory criteria. During 30 percent of the time from 1999 through 2004, continuous estimated chloride concentrations in the Little Arkansas River at Highway 50 near Halstead exceeded the Secondary Drinking-Water Regulation of 250 milligrams per liter established by the U.S. Environmental Protection Agency. Chloride concentrations in shallow monitoring wells located adjacent to the stream exceeded the drinking-water criterion five times from 1995 through 2004. Atrazine concentrations in water sampled from the Little Arkansas River had large variability and were at or near the drinking-water Maximum Contaminant Level of 3.0 micrograms per liter as an annual average established by the U.S. Environmental Protection Agency. Atrazine concentrations were much smaller than the drinking-water criterion and were detected at much smaller concentrations in shallow monitoring wells and diversion well water located adjacent to the stream probably because of sorption on aquifer sediment. Before and after artificial recharge, large, naturally occurring arsenic concentrations in the recharge water for the Halstead diversion well and recharge site exceeded the Maximum Contaminant Level of 10 micrograms per liter established by the U.S. Environmental Protection Agency for drinking water. Arsenic and iron concentrations decreased when water was recharged through recharge basins or a trench; however, chemical precipitation and potential biofouling eventually may decrease the artificial recharge efficiency through basins and trenches. At the Sedgwick site, chloride concentrations infrequently exceeded regulatory criteria. Large concentrations of atrazine were treated to decrease concentrations to less than regulatory criteria. Recharge of treated stream water through recharge basins avoids potentially large concentrations of arsenic and iron that exist at the Halstead diversion site. Results from a simple mixing model using chloride as a tracer indicated that the water chemistry in shallow monitoring well located adjacent to the Little Arkansas River was 80 percent of stream water, demonstrating effective recharge of the alluvial aquifer by the stream. Results also indicated that about 25 percent of the water chemistry of the diversion well water was from the shallow part of the aquifer. Additionally, diverting water through a diversion well located adjacent to the stream removed about 75 percent of the atrazine, probably through sorption to aquifer sediment, and decreased the need for additional water treatment to remove atrazine. A flow and solute-transport model was developed using water-level and chloride concentration data to simulate and better evaluate the quantity of stream-water flow to the p

Application of RAD-BCG calculator to Hanford's 300 area shoreline characterization dataset

DOE Office of Scientific and Technical Information (OSTI.GOV)

Antonio, Ernest J.; Poston, Ted M.; Tiller, Brett L.

2003-07-01

Abstract. In 2001, a multi-agency study was conducted to characterize potential environmental effects from radiological and chemical contaminants on the near-shore environment of the Columbia River at the 300 Area of the U.S. Department of Energy’s Hanford Site. Historically, the 300 Area was the location of nuclear fuel fabrication and was the main location for research and development activities from the 1940s until the late 1980s. During past waste handling practices uranium, copper, and other heavy metals were routed to liquid waste streams and ponds near the Columbia River shoreline. The Washington State Department of Health and the Pacific Northwestmore » National Laboratory’s Surface Environmental Surveillance Project sampled various environmental components including river water, riverbank spring water, sediment, fishes, crustaceans, bivalve mollusks, aquatic insects, riparian vegetation, small mammals, and terrestrial invertebrates for analyses of radiological and chemical constituents. The radiological analysis results for water and sediment were used as initial input into the RAD-BCG Calculator. The RAD-BCG Calculator, a computer program that uses an Excel® spreadsheet and Visual Basic® software, showed that maximum radionuclide concentrations measured in water and sediment were lower than the initial screening criteria for concentrations to produce dose rates at existing or proposed limits. Radionuclide concentrations measured in biota samples were used to calculate site-specific bioaccumulation coefficients (Biv) to test the utility of the RAD-BCG-Calculator’s site-specific screening phase. To further evaluate site-specific effects, the default Relative Biological Effect (RBE) for internal alpha particle emissions was reduced by half and the program’s kinetic/allometric calculation approach was initiated. The subsequent calculations showed the initial RAD-BCG Calculator results to be conservative, which is appropriate for screening purposes.« less

The U.S. Department of Energy's Regulatory and Evaluation Framework for Demonstrating Radiation Protection of the Environment: Implementation at the Hanford Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Antonio, Ernest J.; Tiller, Brett L.; Domotor, S. L.

2005-08-01

Abstract. In 2001, a multi-agency study was conducted to characterize potential environmental effects from radiological and chemical contaminants on the near-shore environment of the Columbia River at the 300 Area of the U.S. Department of Energy’s Hanford Site. Historically, the 300 Area was the location of nuclear fuel fabrication and was the main location for research and development activities from the 1940s until the late 1980s. During past waste handling practices uranium, copper, and other heavy metals were routed to liquid waste streams and ponds near the Columbia River shoreline. The Washington State Department of Health and the Pacific Northwestmore » National Laboratory’s Surface Environmental Surveillance Project sampled various environmental components including river water, riverbank spring water, sediment, fishes, crustaceans, bivalve mollusks, aquatic insects, riparian vegetation, small mammals, and terrestrial invertebrates for analyses of radiological and chemical constituents. The radiological analysis results for water and sediment were used as initial input into the RESRAD BIOTA. The RESRAD BIOTA code showed that maximum radionuclide concentrations measured in water and sediment were lower than the initial screening criteria for concentrations to produce dose rates at existing or proposed limits. Radionuclide concentrations measured in biota samples were used to calculate site-specific bioaccumulation coefficients (Biv) to test the utility of the RESRAD BIOTA’s site-specific screening phase. To further evaluate site-specific effects, the default Relative Biological Effect (RBE) for internal alpha particle emissions was reduced by half and the program’s kinetic/allometric calculation approach was initiated. The subsequent calculations showed the initial RESRAD BIOTA results to be conservative, which is appropriate for screening purposes.« less

Assessment of hydrogen sulfide emission from a sewage treatment plant using AERMOD.

PubMed

Baawain, Mahad; Al-Mamun, Abdullah; Omidvarborna, Hamid; Al-Jabri, Abdullah

2017-06-01

Air quality modeling plays an important role in prediction of air pollutants in urban areas. Moreover, it is also an essential component to make crucial decisions in environmental management. In this study, environmental protection agency (EPA) regulatory model (AERMOD) was implemented in order to assess the urban air quality in the city of Muscat, Sultanate of Oman. Dispersion modeling was employed for the prediction of hydrogen sulfide (H 2 S) emissions, a neighborhood claimed issue, from Al-Ansab sewage treatment plant (STP). Meteorological, elevation data, and H 2 S survey results were implemented into the model. From the site survey study, four different H 2 S emission sources were identified as sewage tanker connection points, biofilter, old odor control unit (OCU), and open channels of raw sewage. It was observed that based on maximum 24-h analysis, the ground level concentration outside the STP exceeded the concentration limit, 40 μg/m 3 , recommended by the local regulating agency in Oman. By applying a sensitivity analysis study, the locations with the highest predicted H 2 S levels were identified. The most affected area in the worst-case scenario was the nearby expressway with 450.9 μg/m 3 of H 2 S. The highest ground level concentration of H 2 S was detected in March, while the lowest was measured in December. The model also predicted that the impact of odor nuisance is greater at the summer season than that of other seasons due to the elevated temperatures. The study revealed an adverse environmental impact from the STPs on urban air quality, which may pose a threat to the public health.

Pesticides in Water and Suspended Sediment of the Alamo and New Rivers, Imperial Valley/Salton Sea Basin, California, 2006-2007

USGS Publications Warehouse

Orlando, James L.; Smalling, Kelly L.; Kuivila, Kathryn

2008-01-01

Water and suspended-sediment samples were collected at eight sites on the Alamo and New Rivers in the Imperial Valley/Salton Sea Basin of California and analyzed for both current-use and organochlorine pesticides by the U.S. Geological Survey. Samples were collected in the fall of 2006 and spring of 2007, corresponding to the seasons of greatest pesticide use in the basin. Large-volume water samples (up to 650 liters) were collected at each site and processed using a flow-through centrifuge to isolate suspended sediments. One-liter water samples were collected from the effluent of the centrifuge for the analysis of dissolved pesticides. Additional samples were collected for analysis of dissolved organic carbon and for suspended-sediment concentrations. Water samples were analyzed for a suite of 61 current-use and organochlorine pesticides using gas chromatography/mass spectrometry. A total of 25 pesticides were detected in the water samples, with seven pesticides detected in more than half of the samples. Dissolved concentrations of pesticides observed in this study ranged from below their respective method detection limits to 8,940 nanograms per liter (EPTC). The most frequently detected compounds in the water samples were chlorpyrifos, DCPA, EPTC, and trifluralin, which were observed in more than 75 percent of the samples. The maximum concentrations of most pesticides were detected in samples from the Alamo River. Maximum dissolved concentrations of carbofuran, chlorpyrifos, diazinon, and malathion exceeded aquatic life benchmarks established by the U.S. Environmental Protection Agency for these pesticides. Suspended sediments were analyzed for 87 current-use and organochlorine pesticides using microwave-assisted extraction, gel permeation chromatography for sulfur removal, and either carbon/alumina stacked solid-phase extraction cartridges or deactivated Florisil for removal of matrix interferences. Twenty current-use pesticides were detected in the suspended-sediment samples, including pyrethroid insecticides and fungicides. Fourteen legacy organochlorine pesticides also were detected in the suspended-sediment samples. Greater numbers of current-use and organochlorine pesticides were observed in the Alamo River samples in comparison with the New River samples. Maximum concentrations of current-use pesticides in suspended-sediment samples ranged from below their method detection limits to 174 micrograms per kilogram (pendimethalin). Most organochlorine pesticides were detected at or below their method detection limits, with the exception of p,p'-DDE, which had a maximum concentration of 54.2 micrograms per kilogram. The most frequently detected current-use pesticides in the suspended-sediment samples were chlorpyrifos, permethrin, tetraconazole, and trifluralin, which were observed in more than 83 percent of the samples. The organochlorine degradates p,p'-DDD and p,p'-DDE were detected in all suspended-sediment samples.

Appraisal of water-quality conditions, lower Black River, Windsor County, Vermont

USGS Publications Warehouse

Toppin, K.W.

1983-01-01

Six hydroelectric power dams are planned along a 22-mile reach of the lower Black River in southeastern Windsor County, Vermont. Data were collected at 10 stations, during water years 1977-81, to appraise quality conditions before construction. Average specific conductance of Black River is 101 micromhos indicating low concentrations of dissolved solids. Concentrations of common constituents and minor elements were generally low and within safe levels for aquatic life. Near-saturated dissolved oxygen concentrations and relatively low mean total organic carbon concentrations indicate little oxygen-consuming substances in Black River. Mean total nitrogen concentrations ranged from 0.31 mg/L (milligrams per liter) to 0.61 mg/L. The highest concentrations were most likely due to secondary waste discharges entering the river. Nitrate was the primary form of inorganic nitrogen, mean concentrations ranged from 0.13 to 0.27 mg/L. Concentrations seem high enough to promote excessive algal growth in the proposed Hawks Mountain Reservoir. Mean concentrations of total phosphorus ranged from 0.014 to 0.112 mg/L as P. Maximum concentrations at all stations generally exceeded U.S. Environmental Protection Agency suggested levels for water entering lakes and reservoirs. Mean orthophosphorus concentrations ranged from 0.005 to 0.029 mg/L, suggesting a potential for nuisance algal conditions to develop in the proposed reservoir. Mean algal growth potential concentrations ranged from 1.3 to 8.8 mg/L, falling within the moderately high to high productivity range. No pesticides and polychlorinated biphenyls were detected. (USGS)

Entrainment of stratospheric air and Asian pollution by the convective boundary layer in the southwestern U.S.

NASA Astrophysics Data System (ADS)

Langford, A. O.; Alvarez, R. J.; Brioude, J.; Fine, R.; Gustin, M. S.; Lin, M. Y.; Marchbanks, R. D.; Pierce, R. B.; Sandberg, S. P.; Senff, C. J.; Weickmann, A. M.; Williams, E. J.

2017-01-01

A series of deep stratospheric intrusions in late May 2013 increased the daily maximum 8 h surface ozone (O3) concentrations to more than 70 parts per billion by volume (ppbv) at rural and urban surface monitors in California and Nevada. This influx of ozone-rich lower stratospheric air and entrained Asian pollution persisted for more than 5 days and contributed to exceedances of the 2008 8 h national ambient air quality standard of 75 ppbv on 21 and 25 May in Clark County, NV. Exceedances would also have occurred on 22 and 23 May had the new standard of 70 ppbv been in effect. In this paper, we examine this episode using lidar measurements from a high-elevation site on Angel Peak, NV, and surface measurements from NOAA, the Clark County, Nevada Department of Air Quality, the Environmental Protection Agency Air Quality System, and the Nevada Rural Ozone Initiative. These measurements, together with analyses from the National Centers for Environmental Prediction/North American Regional Reanalysis; NOAA Geophysical Fluid Dynamics Laboratory AM3 model; NOAA National Environmental Satellite, Data, and Information Service Real-time Air Quality Modeling System; and FLEXPART models, show that the exceedances followed entrainment of 20 to 40 ppbv of lower stratospheric ozone mingled with another 0 to 10 ppbv of ozone transported from Asia by the unusually deep convective boundary layers above the Mojave desert. Our analysis suggests that this vigorous mixing can affect both high and low elevations and help explain the springtime ozone maximum in the southwestern U.S.

Evaluation of polar organic micropollutants as indicators for wastewater-related coastal water quality impairment.

PubMed

Nödler, Karsten; Tsakiri, Maria; Aloupi, Maria; Gatidou, Georgia; Stasinakis, Athanasios S; Licha, Tobias

2016-04-01

Results from coastal water pollution monitoring (Lesvos Island, Greece) are presented. In total, 53 samples were analyzed for 58 polar organic micropollutants such as selected herbicides, biocides, corrosion inhibitors, stimulants, artificial sweeteners, and pharmaceuticals. Main focus is the application of a proposed wastewater indicator quartet (acesulfame, caffeine, valsartan, and valsartan acid) to detect point sources and contamination hot-spots with untreated and treated wastewater. The derived conclusions are compared with the state of knowledge regarding local land use and infrastructure. The artificial sweetener acesulfame and the stimulant caffeine were used as indicators for treated and untreated wastewater, respectively. In case of a contamination with untreated wastewater the concentration ratio of the antihypertensive valsartan and its transformation product valsartan acid was used to further refine the estimation of the residence time of the contamination. The median/maximum concentrations of acesulfame and caffeine were 5.3/178 ng L(-1) and 6.1/522 ng L(-1), respectively. Their detection frequency was 100%. Highest concentrations were detected within the urban area of the capital of the island (Mytilene). The indicator quartet in the gulfs of Gera and Kalloni (two semi-enclosed embayments on the island) demonstrated different concentration patterns. A comparatively higher proportion of untreated wastewater was detected in the gulf of Gera, which is in agreement with data on the wastewater infrastructure. The indicator quality of the micropollutants to detect wastewater was compared with electrical conductivity (EC) data. Due to their anthropogenic nature and low detection limits, the micropollutants are superior to EC regarding both sensitivity and selectivity. The concentrations of atrazine, diuron, and isoproturon did not exceed the annual average of their environmental quality standards (EQS) defined by the European Commission. At two sampling locations irgarol 1051 exceeded its annual average EQS value but not the maximum allowable concentration of 16 ng L(-1). Copyright © 2016 Elsevier Ltd. All rights reserved.

Testing of two different strains of green microalgae for Cu and Ni removal from aqueous media.

PubMed

Rugnini, L; Costa, G; Congestri, R; Bruno, L

2017-12-01

The concentration of metal ions in aqueous media is a major environmental problem due to their persistence and non-biodegradability that poses hazards to the ecosystem and human health. In this study, the effect of Cu and Ni on the growth of two green microalgal strains, Chlorella vulgaris and Desmodesmus sp., was evaluated along with the removal capacity from single metal solutions (12days exposure; metal concentration range: 1.9-11.9mgL -1 ). Microalgal growth showed to decrease at increasing metal concentrations, but promising metal removal efficiencies were recorded: up to 43% and 39% for Cu by Desmodesmus sp. and C. vulgaris, respectively, with a sorption capacity of 33.4mggDW -1 for Desmodesmus sp. As for Ni, at the concentration of 5.7mgL -1 , the removal efficiency reached 32% for C. vulgaris and 39% for Desmodesmus sp. In addition, Desmodesmus sp. growth and metal removal were evaluated employing bimetallic solutions. In these tests, the removal efficiency for Cu was higher than that of Ni for all the mix solutions tested with a maximum of 95%, while Ni-removal reached 90% only for the lowest concentrations tested. Results revealed that the biosorption of both metals reached maximum removal levels within the fourth day of incubation (with metal uptakes of 67mgCugDW -1 and 37mgNigDW -1 ). Intracellular bioaccumulation of metals in Desmodesmus sp. was evaluated by confocal laser scanning microscopy after DAPI staining of cells exposed or not to Cu during their growth. Imaging suggested that Cu is sequestered in polyphosphate bodies within the cells, as observable also in phosphorus deprived cultures. Our results indicate the potential of employing green microalgae for bioremediation of metal-polluted waters, due to their ability to grow in the presence of high metal concentrations and to remove them efficiently. Copyright © 2017 Elsevier B.V. All rights reserved.

Occurrence, fate and risk assessment of personal care products in river-groundwater interface.

PubMed

Serra-Roig, Maria Pau; Jurado, Anna; Díaz-Cruz, M Silvia; Vázquez-Suñé, Enric; Pujades, Estanislao; Barceló, Damià

2016-10-15

This work presents the occurrence and fate of selected personal care products (PCPs) in the urban river-groundwater interface. To this end, urban river and groundwater samples were collected in Sant Adrià del Besòs (NE of Spain) and a total of 16 PCPs were analyzed including benzophenone derivatives, camphor derivatives, p-aminobenzoic acid derivatives, triazoles and parabens in three different campaigns (from May 2010 to July 2014). These compounds reach the aquifer through the recharge of Besòs River that receives large amounts of effluents from waste water treatment plants. Results have shown that most of the compounds were not or barely detected (maximum concentrations around 200ng/L) in groundwater samples during the different sampling campaigns. Only two triazoles, namely benzotriazole (BZT) and methyl benzotriazol (MeBZT) were found at high concentrations in groundwater samples (maximum concentration around 2000ng/L). The fate of PCPs in the aquifer was assessed using mixing analysis considering the seasonal variability of the Besòs River. Overall, measured groundwater concentrations were significantly much lower than those estimated by the mixing of the river water. This observation suggested that most of the PCPs are naturally removed when river water infiltrates the aquifer. However, some compounds were more persistent in the aquifer. These compounds were in descending order: the triazoles BZT and MeBZT followed by the camphor derivative 4MBC and the paraben MePB. The measured concentrations allowed us to assess the environmental risk posed by the selected UV-filters and parabens in the river and groundwater samples. Hazard Quotients (HQs) for different aquatic species were calculated in order to characterize the ecotoxicity potential of the studied compounds in the river-groundwater interface. HQ values were always below 1 indicating that at the concentrations observed in the surface or aquifer water of Besòs River these compounds pose no risk to the selected aquatic organisms. Copyright © 2016 Elsevier B.V. All rights reserved.

Hydrogeology and ground-water quality of northern Bucks County, Pennsylvania

USGS Publications Warehouse

Sloto, Ronald A.; Schreffler, Curtis L.

1994-01-01

Water from wells in the crystalline rocks has the lowest median pH (5.8), the lowest median specific conductance (139 microsiemens per centimeter), the lowest median alkalinity [16 mg/L (milligrams per liter) as CaCOg], and the highest dissolved oxygen concentration (9.0 mg/L) of the hydrogeologic units. Water from wells in carbonate rocks has the highest median pH (7.8) and the highest median alkalinity (195 mg/L as CaCO3) of the hydrogeologic units. Water from wells in the Lockatong Formation has the highest median specific conductance (428 microsiemens per centimeter) and the lowest dissolved oxygen concentration (0.8 mg/L) of the hydrogeologic units. Water from wells in crystalline rocks contains the lowest concentrations of total dissolved solids (TDS) of the hydrogeologic units. Water from the Lockatong Formation contains the highest concentration of TDS of the hydrogeologic units. Water from only 1 of 83 wells sampled exceeded the U.S. Environmental Protection Agency (USEPA) secondary maximum contaminant level (SMCL) for TDS; the well is in the Lockatong Formation. Five of 86 samples (6 percent) and 6 of 75 samples (8 percent) exceed the USEPA SMCL for iron and manganese, respectively. Nitrate is the most prevalent nitrogen species in ground water. The median nitrate concentration for all hydrogeologic units is 2.3 mg/L. Of 71 water samples from wells, no concentrations of nitrate exceed the USEPA maximum contaminant level. The median dissolved radon-222 activity was highest for water samples from wells in crystalline rock [3,600 pCi/L (picocuries per liter)] and lowest for water samples from wells in the Lockatong Formation (340 pCi/L) and diabase (350 pCi/L). Water samples for analysis for volatile organic compounds (VOC's) were collected from 34 wells in areas where the potential existed for the presence of VOC's in ground water. VOC's were detected in 23 percent of the 34 wells sampled. The most commonly detected compound was trichloroethylene (13 percent of sampled wells).

Geochemistry and mineralogy of arsenic in mine wastes and stream sediments in a historic metal mining area in the UK.

PubMed

Rieuwerts, J S; Mighanetara, K; Braungardt, C B; Rollinson, G K; Pirrie, D; Azizi, F

2014-02-15

Mining generates large amounts of waste which may contain potentially toxic elements (PTE), which, if released into the wider environment, can cause air, water and soil pollution long after mining operations have ceased. The fate and toxicological impact of PTEs are determined by their partitioning and speciation and in this study, the concentrations and mineralogy of arsenic in mine wastes and stream sediments in a former metal mining area of the UK are investigated. Pseudo-total (aqua-regia extractable) arsenic concentrations in all samples from the mining area exceeded background and guideline values by 1-5 orders of magnitude, with a maximum concentration in mine wastes of 1.8×10(5)mgkg(-1) As and concentrations in stream sediments of up to 2.5×10(4)mgkg(-1) As, raising concerns over potential environmental impacts. Mineralogical analysis of the wastes and sediments was undertaken by scanning electron microscopy (SEM) and automated SEM-EDS based quantitative evaluation (QEMSCAN®). The main arsenic mineral in the mine waste was scorodite and this was significantly correlated with pseudo-total As concentrations and significantly inversely correlated with potentially mobile arsenic, as estimated from the sum of exchangeable, reducible and oxidisable arsenic fractions obtained from a sequential extraction procedure; these findings correspond with the low solubility of scorodite in acidic mine wastes. The work presented shows that the study area remains grossly polluted by historical mining and processing and illustrates the value of combining mineralogical data with acid and sequential extractions to increase our understanding of potential environmental threats. Copyright © 2013 Elsevier B.V. All rights reserved.

Reconnaissance of Organic Wastewater Compounds at a Concentrated Swine Feeding Operation in the North Carolina Coastal Plain, 2008

USGS Publications Warehouse

Harden, Stephen L.

2009-01-01

Water-quality and hydrologic data were collected during 2008 to examine the occurrence of organic wastewater compounds at a concentrated swine feeding operation located in the North Carolina Coastal Plain. Continuous groundwater level and stream-stage data were collected at one monitoring well and one stream site, respectively, throughout 2008. One round of environmental and quality-control samples was collected in September 2008 following a period of below-normal precipitation and when swine waste was not being applied to the spray fields. Samples were collected at one lagoon site, seven shallow groundwater sites, and one surface-water site for analysis of 111 organic wastewater compounds, including household, industrial, and agricultural-use compounds, sterols, pharmaceutical compounds, hormones, and antibiotics. Analytical data for environmental samples collected during the study provide preliminary information on the occurrence of organic wastewater compounds in the lagoon-waste source material, groundwater beneath fields that receive spray applications of the lagoon wastes, and surface water in the tributary adjacent to the site. Overall, 28 organic wastewater compounds were detected in the collected samples, including 11 household, industrial, and agricultural-use compounds; 3 sterols; 2 pharmaceutical compounds; 5 hormones; and 7 antibiotics. The lagoon sample had the greatest number (20) and highest concentrations of compounds compared to groundwater and surface-water samples. The antibiotic lincomycin had the maximum detected concentration (393 micrograms per liter) in the lagoon sample. Of the 11 compounds identified in the groundwater and surface-water samples, all with reported concentrations less than 1 microgram per liter, only lincomycin identified in groundwater at 1 well and 3-methyl-1H-indole and indole identified in surface water at 1 site also were identified in the lagoon waste material.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Safira, Nabila, E-mail: safira.nabila@ymail.com; Anggraeni, Tjandra, E-mail: tjandra@sith.itb.ac.id

Several studies had shown that lead (Pb) in the environment could accumulate in bees, which in turn could affect the quality of the resulting product. In this study, forager stingless bees (Trigona sp.) and its product (propolis) collected from a stingless bees apiculture. This apiculture had two apiary sites which were distinguished by its environmental setting. Apiary site in Cilutung had a forest region environmental setting, while apiary site in Maribaya was located beside the main road. The objective of this study was to determine the extent of lead concentration in propolis originated from both apiary sites and establish themore » correlation between lead concentration in propolis and lead level in forager stingless bees. Forager bees and propolis samples were originated from 50 bees colonies (Cilutung) and 44 bees colonies (Maribaya). They were analyzed using AAS-GF (Atomic Absorption Spectrometre–Graphite Furnace) to determine the level of lead concentration. The results showed that the average level of lead in propolis originated from Cilutung (298.08±73.71 ppb) was lower than the average level of lead in forager bees which originated from Maribaya (330.64±156.34 ppb). However, these values did not show significant difference (p>0.05). There was no significant difference (p>0.05) between the average level of lead in forager bees which originated from Cilutung (118.08±30.46 ppb) and Maribaya (128.82±39.66 ppb). However, these values did not show significant difference (p>0.05). In conclusion, the average level of lead concentration in propolis in both sites had passed the maximum permission standard of lead for food in Indonesia. There was no correlation between lead concentration in propolis and forager stingless bees.« less

Evaluation of a Public Health Intervention to Lower Mercury Exposure from Fish Consumption in Bermuda

PubMed Central

Dewailly, Eric; Rouja, Philippe; Forde, Martin; Peek-Ball, Cheryl; Côté, Suzanne; Smith, Emma; Drescher, Olivia; Robertson, Lyndon

2012-01-01

Objectives To assess the efficacy of a public health intervention to reduce blood mercury (Hg) concentration levels in pregnant Bermudian women. Methods In 2003, we conducted a study entitled “Prenatal exposure of the Bermudian Population to Environmental Contaminants” which provided Bermuda’s first baseline data on prenatal exposure to several environmental contaminants, including Hg. The mean Hg concentration from 42 healthy newborns measured in umbilical cord blood was 41.3 nmol/L, ranging from 5–160 nmol/L. This concentration was much higher than expected, being approximately 8 times the general levels found in Canada and the U.S. Furthermore, we estimated that 85% of total Hg measured was in the form of methylmercury (MeHg), indicating that seafood consumption was the primary source of Hg exposure during pregnancy in Bermuda. Locally sourced seafood was identified as the most significant possible contributory source of Hg exposure. In 2005 the authors began a complementary research programme to study the levels of Hg in local commercial fish species. Coming out of this research were specific local fish consumption guidelines issued by the Department of Health advising pregnant women to avoid those local fish species found to be high in Hg while still encouraging consumption of fish species having lower Hg levels. Results In 2010, under another research initiative, we returned to Bermuda to carry out another evaluation of Hg in human blood. Hg was measured in the blood of 49 pregnant women. The arithmetic mean Hg blood concentration was 6.6 nmol/L and the geometric mean 4.2 nmol/L. The maximum concentration found was 24 nmol/L. Conclusions Hg exposure of Bermudian pregnant women has dropped significantly by a factor of around 5 since the foetal cord blood study in 2003. PMID:23077607

Evaluation of a public health intervention to lower mercury exposure from fish consumption in Bermuda.

PubMed

Dewailly, Eric; Rouja, Philippe; Forde, Martin; Peek-Ball, Cheryl; Côté, Suzanne; Smith, Emma; Drescher, Olivia; Robertson, Lyndon

2012-01-01

To assess the efficacy of a public health intervention to reduce blood mercury (Hg) concentration levels in pregnant Bermudian women. In 2003, we conducted a study entitled "Prenatal exposure of the Bermudian Population to Environmental Contaminants" which provided Bermuda's first baseline data on prenatal exposure to several environmental contaminants, including Hg. The mean Hg concentration from 42 healthy newborns measured in umbilical cord blood was 41.3 nmol/L, ranging from 5-160 nmol/L. This concentration was much higher than expected, being approximately 8 times the general levels found in Canada and the U.S. Furthermore, we estimated that 85% of total Hg measured was in the form of methylmercury (MeHg), indicating that seafood consumption was the primary source of Hg exposure during pregnancy in Bermuda. Locally sourced seafood was identified as the most significant possible contributory source of Hg exposure. In 2005 the authors began a complementary research programme to study the levels of Hg in local commercial fish species. Coming out of this research were specific local fish consumption guidelines issued by the Department of Health advising pregnant women to avoid those local fish species found to be high in Hg while still encouraging consumption of fish species having lower Hg levels. In 2010, under another research initiative, we returned to Bermuda to carry out another evaluation of Hg in human blood. Hg was measured in the blood of 49 pregnant women. The arithmetic mean Hg blood concentration was 6.6 nmol/L and the geometric mean 4.2 nmol/L. The maximum concentration found was 24 nmol/L. Hg exposure of Bermudian pregnant women has dropped significantly by a factor of around 5 since the foetal cord blood study in 2003.

75 FR 43160 - Clean Water Act Section 303(d): Final Agency Action on One Arkansas Total Maximum Daily Load (TMDL)

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-23

... ENVIRONMENTAL PROTECTION AGENCY [FRL-9179-3 ] Clean Water Act Section 303(d): Final Agency Action on One Arkansas Total Maximum Daily Load (TMDL) AGENCY: Environmental Protection Agency (EPA). ACTION: Notice of availability. SUMMARY: This notice announces the final agency action on one TMDL established by...

Considerations involved with the use of semipermeable membrane devices for monitoring environmental contaminants

USGS Publications Warehouse

Petty, J.D.; Orazio, C.E.; Huckins, J.N.; Gale, R.W.; Lebo, J.A.; Meadows, J.C.; Echols, K.R.; Cranor, W.L.

2000-01-01

Semipermeable membrane devices (SPMDs) are used with increasing frequency, and throughout the world as samplers of organic contaminants. The devices can be used to detect a variety of lipophilic chemicals in water, sediment/soil, and air. SPMDs are designed to sample nonpolar, hydrophobic chemicals. The maximum concentration factor achievable for a particular chemical is proportional to its octanol–water partition coefficient. Techniques used for cleanup of SPMD extracts for targeted analytes and for general screening by full-scan mass spectrometry do not differ greatly from techniques used for extracts of other matrices. However, SPMD extracts contain potential interferences that are specific to the membrane–lipid matrix. Procedures have been developed or modified to alleviate these potential interferences. The SPMD approach has been demonstrated to be applicable to sequestering and analyzing a wide array of environmental contaminants including organochlorine pesticides, polychlorinated biphenyls, polycyclic aromatic hydrocarbons, polychlorinated dioxins and dibenzofurans, selected organophosphate pesticides and pyrethroid insecticides, and other nonpolar organic chemicals. We present herein an overview of effective procedural steps for analyzing exposed SPMDs for trace to ultra-trace levels of contaminants sequestered from environmental matrices.

The distribution and modeling of nitrate transport in the Carson Valley alluvial aquifer, Douglas County, Nevada

USGS Publications Warehouse

Naranjo, Ramon C.; Welborn, Toby L.; Rosen, Michael R.

2013-01-01

The distribution of nitrate as nitrogen (referred to herein as nitrate-N) concentrations in groundwater was determined by collecting more than 200 samples from 8 land-use categories: single family residential, multifamily residential, rural (including land use for agriculture), vacant land, commercial, industrial, utilities, and unclassified. Nitrate-N concentrations ranged from below detection (less than 0.05 milligrams per liter) to 18 milligrams per liter. The results of nitrate-N concentrations that were sampled from three wells equalled or exceeded the maximum contaminant level of 10 milligrams per liter set by the U.S. Environmental Protection Agency. Nitrate-N concentrations in sampled wells showed a positive correlation between elevated nitrate-N concentrations and the percentage of single-family land use and septic-system density. Wells sampled in other land-use categories did not have any correlation to nitrate-N concentrations. In areas with greater than 50-percent single-family land use, nitrate-N concentrations were two times greater than in areas with less than 50 percent single-family land use. Nitrate-N concentrations in groundwater near septic systems that had been used more than 20 years were more than two times greater than in areas where septic systems had been used less than 20 years. Lower nitrate-N concentrations in the areas where septic systems were less than 20 years old probably result from temporary storage of nitrogen leaching from septic systems into the unsaturated zone. In areas where septic systems are abundant, nitrate-N concentrations were predicted to 2059 by using numerical models within the Ruhenstroth and Johnson Lane subdivisions in the Carson Valley. Model results indicated that nitrate-N concentrations will continue to increase and could exceed the maximum contaminant level over extended areas inside and outside the subdivisions. Two modeling scenarios were used to simulate future transport as a result of removal of septic systems (source of nitrate-N contamination) and the termination of domestic pumping of groundwater. The models showed the largest decrease in nitrate-N concentrations when septic systems were removed and wells continued to pump. Nitrate-N concentrations probably will continue to increase in areas that are dependent on septic systems for waste disposal either under current land-use conditions in the valley or with continued growth and change in land use in the valley.

40 CFR Appendix I to Part 257 - Maximum Contaminant Levels (MCLs)

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Maximum Contaminant Levels (MCLs) I Appendix I to Part 257 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES... Part 257—Maximum Contaminant Levels (MCLs) Maximum Contaminant Levels (MCLs) Promulgated Under the Safe...

40 CFR 35.175 - Maximum federal share.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Maximum federal share. 35.175 Section 35.175 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE...)) § 35.175 Maximum federal share. The Regional Administrator may provide a maximum of 75 percent of the...

40 CFR 35.195 - Maximum federal share.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Maximum federal share. 35.195 Section 35.195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE... 1443(b)) § 35.195 Maximum federal share. The Regional Administrator may provide a maximum of 75 percent...

Reduction of Nicardipine-Related Phlebitis in Patients with Acute Stroke by Diluting Its Concentration.

PubMed

Kawada, Kei; Ohta, Tsuyoshi; Tanaka, Koudai; Miyamoto, Norifumi

2018-03-05

Nicardipine is frequently used in the treatment of hypertension for patients with acute stroke; however, its dosing is complicated by a high risk of phlebitis. In the present study, we examined whether restricting nicardipine concentration under a specific value could reduce the incidence of nicardipine-related phlebitis in patients with acute stroke. Intravenous nicardipine-related phlebitis was retrospectively analyzed. From July 2015, a simple proposition was made to dilute maximum intravenous nicardipine concentration to lower than 130 µg/mL. The maximum intravenous nicardipine concentration and the incidence of phlebitis were compared between patients treated from July 2014 to June 2015 (preproposition group) and patients treated from July 2015 to June 2016 (postproposition group). A total of 300 patients (preproposition group, 138; postproposition group, 162) were included. The postproposition group demonstrated significantly lower maximum intravenous nicardipine concentration (in µg/mL, 76.9, 47.6-104.5 versus 130.4, 69.8-230.8; P < .001) and incidence of phlebitis (9.9%, 16/162 vs. 30%, 42/138; P < .001) than the preproposition group. Multivariable logistic regression analysis revealed that the maximum intravenous nicardipine concentration lower than 130 µg/mL (odds ratio [OR] .15; 95% confidence interval [CI] .06-.35; P < .001) and National Institutes of Health Stroke Scale on admission (OR .95; 95% CI .91-.99; P = .007) were the statistically significant independent factors for phlebitis, which indicated the usefulness of the proposition to dilute maximum intravenous nicardipine concentration to lower than 130 µg/mL. The simple and appropriate proposition about nicardipine administration lowered maximum nicardipine concentration and reduced the incidence of nicardipine-related phlebitis in patients with acute stroke. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Modelling the maximum voluntary joint torque/angular velocity relationship in human movement.

PubMed

Yeadon, Maurice R; King, Mark A; Wilson, Cassie

2006-01-01

The force exerted by a muscle is a function of the activation level and the maximum (tetanic) muscle force. In "maximum" voluntary knee extensions muscle activation is lower for eccentric muscle velocities than for concentric velocities. The aim of this study was to model this "differential activation" in order to calculate the maximum voluntary knee extensor torque as a function of knee angular velocity. Torque data were collected on two subjects during maximal eccentric-concentric knee extensions using an isovelocity dynamometer with crank angular velocities ranging from 50 to 450 degrees s(-1). The theoretical tetanic torque/angular velocity relationship was modelled using a four parameter function comprising two rectangular hyperbolas while the activation/angular velocity relationship was modelled using a three parameter function that rose from submaximal activation for eccentric velocities to full activation for high concentric velocities. The product of these two functions gave a seven parameter function which was fitted to the joint torque/angular velocity data, giving unbiased root mean square differences of 1.9% and 3.3% of the maximum torques achieved. Differential activation accounts for the non-hyperbolic behaviour of the torque/angular velocity data for low concentric velocities. The maximum voluntary knee extensor torque that can be exerted may be modelled accurately as the product of functions defining the maximum torque and the maximum voluntary activation level. Failure to include differential activation considerations when modelling maximal movements will lead to errors in the estimation of joint torque in the eccentric phase and low velocity concentric phase.

Effects of electrolysis time and electric potential on chlorine generation of electrolyzed deep ocean water.

PubMed

Hsu, Guoo-Shyng Wang; Lu, Yi-Fa; Hsu, Shun-Yao

2017-10-01

Electrolyzed water is a sustainable disinfectant, which can comply with food safety regulations and is environmentally friendly. A two-factor central composite design was adopted for studying the effects of electrolysis time and electric potential on the chlorine generation efficiency of electrolyzed deep ocean water (DOW). DOW was electrolyzed in a glass electrolyzing cell equipped with platinum-plated titanium anode and cathode. The results showed that chlorine concentration reached maximal level in the batch process. Prolonged electrolysis reduced chlorine concentration in the electrolyte and was detrimental to electrolysis efficiency, especially under high electric potential conditions. Therefore, the optimal choice of electrolysis time depends on the electrolyzable chloride in DOW and cell potential adopted for electrolysis. The higher the electric potential, the faster the chlorine level reaches its maximum, but the lower the electric efficiency will be. Copyright © 2016. Published by Elsevier B.V.

Widespread occurrence of neonicotinoid insecticides in streams in a high corn and soybean producing region, USA

USGS Publications Warehouse

Hladik, Michelle; Kolpin, Dana W.; Kuivila, Kathryn

2014-01-01

Neonicotinoid insecticides are of environmental concern, but little is known about their occurrence in surface water. An area of intense corn and soybean production in the Midwestern United States was chosen to study this issue because of the high agricultural use of neonicotinoids via both seed treatments and other forms of application. Water samples were collected from nine stream sites during the 2013 growing season. The results for the 79 water samples documented similar patterns among sites for both frequency of detection and concentration (maximum:median) with clothianidin (75%, 257 ng/L:8.2 ng/L) > thiamethoxam (47%, 185 ng/L: imidacloprid (23%, 42.7 ng/L: <2 ng/L). Neonicotinoids were detected at all nine sites sampled even though the basin areas spanned four orders of magnitude. Temporal patterns in concentrations reveal pulses of neonicotinoids associated with rainfall events during crop planting, suggesting seed treatments as their likely source.

Aerobic and heterotrophic nitrogen removal by Enterobacter cloacae CF-S27 with efficient utilization of hydroxylamine.

PubMed

Padhi, Soumesh Kumar; Tripathy, Swetaleena; Mohanty, Sriprakash; Maiti, Nikhil Kumar

2017-05-01

Heterotrophic bacterium, Enterobacter cloacae CF-S27 exhibited simultaneous nitrification and aerobic denitrification in presence of high concentration of hydroxylamine. With the initial nitrogen concentration of 100mgL -1 h -1 , ammonium, nitrate and nitrite removal efficiencies were 81%, 99.9% and 92.8%, while the corresponding maximum removal rates reached as high as 11.6, 15.1 and 11.2mgL -1 h -1 respectively. Quantitative amplification by real time PCR and enzyme assay demonstrated that hydroxylamine reductase gene (hao) is actively involved in hetrotrophic nitrification and aerobic denitrification process of Enterobacter cloacae CF-S27. PCR primers were designed targeting amplification of hao gene from diversified environmental soil DNA. The strain Enterobacter cloacae CF-S27 significantly maintained the undetectable amount of dissolved nitrogen throughout 60days of zero water exchange fish culture experiment in domestic wastewater. Copyright © 2017 Elsevier Ltd. All rights reserved.

β-Sitosterol: Supercritical Carbon Dioxide Extraction from Sea Buckthorn (Hippophae rhamnoides L.) Seeds

PubMed Central

Sajfrtová, Marie; Ličková, Ivana; Wimmerová, Martina; Sovová, Helena; Wimmer, Zdeněk

2010-01-01

Supercritical fluid extraction represents an efficient and environmentally friendly technique for isolation of phytosterols from different plant sources. Sea buckthorn (Hippophae rhamnoides L.) seeds were extracted with supercritical carbon dioxide at pressures ranging from 15–60 MPa and temperatures of 40–80 °C. Oil and β-sitosterol yields were measured in the extraction course and compared with Soxhlet extraction with hexane. The average yield of β-sitosterol was 0.31 mg/g of seeds. The maximum concentration of β-sitosterol in the extract, 0.5% w/w, was achieved at 15 MPa, 40 °C, and a carbon dioxide consumption of 50 g/g of seeds. The extraction rate was maximal at 60 MPa and 40 °C. Both β-sitosterol yield and its concentration in the extract obtained with hexane were lower than with carbon dioxide. PMID:20480045

An upper-bound assessment of the benefits of reducing perchlorate in drinking water.

PubMed

Lutter, Randall

2014-10-01

The Environmental Protection Agency plans to issue new federal regulations to limit drinking water concentrations of perchlorate, which occurs naturally and results from the combustion of rocket fuel. This article presents an upper-bound estimate of the potential benefits of alternative maximum contaminant levels for perchlorate in drinking water. The results suggest that the economic benefits of reducing perchlorate concentrations in drinking water are likely to be low, i.e., under $2.9 million per year nationally, for several reasons. First, the prevalence of detectable perchlorate in public drinking water systems is low. Second, the population especially sensitive to effects of perchlorate, pregnant women who are moderately iodide deficient, represents a minority of all pregnant women. Third, and perhaps most importantly, reducing exposure to perchlorate in drinking water is a relatively ineffective way of increasing iodide uptake, a crucial step linking perchlorate to health effects of concern. © 2014 Society for Risk Analysis.

Early genotoxic response and accumulation induced by waterborne copper, lead, and arsenic in European seabass, Dicentrarchus labrax.

PubMed

Canalejo, Antonio; Diaz-de-Alba, Margarita; Granado-Castro, M Dolores; Cordoba, Francisco; Espada-Bellido, Estrella; Galindo-Riaño, M Dolores; Torronteras, Rafael

2016-02-01

Cu, Pb, and As, which are among the most abundant metals in the aquatic environment, are also among the most health-threatened by causing diverse cellular injuries. The aim of this study was to assess and compare the potential early induction of genotoxic effects after waterborne Cu, Pb, and As exposure in European seabass, Dicentrarchus labrax, a commercial widely cultured fish, using the micronucleus (MN) assay in peripheral blood erythrocytes. Fish were exposed under laboratory conditions to nominal solutions ranging 0-10 mg/L for 24 and 96 h. Furthermore, actual metal ion concentrations were measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES) or differential pulse anodic stripping voltammetry (DPASV) in water and four fish tissues differentially related to environmental exposition and metal accumulation, i.e. the gills, liver, muscle, and brain. Dose-dependent increases of micronuclei (MNi) frequency were observed after these very short exposures; based on measured metal concentrations in water, the genotoxic effect ordered as Cu > As > Pb. Significant genotoxic effect at 0.009 mg/L Cu, 0.57 mg/L Pb, and 0.01 mg/L As was seen. For Cu and Pb these are only slightly higher, but for As it is notably lower than the USEPA criteria of maximum concentration to prevent acute toxicity in aquatic organisms. Furthermore, genotoxicity was differentially related to metal accumulation. MNi frequency correlated positively with the content of Pb in all the organs, with the content of As in liver and gills and only with the content of Cu in the brain. In conclusion, our findings raised environmental concerns because these depicted a genotoxic potential of Cu, Pb, and As after a very short exposure to low but environmentally relevant concentrations, too close to regulatory thresholds. In addition, the MN test in D. labrax could be considered an early biomarker of genotoxicity induced by these metals in fish.

Illustration of a fingerprinting method to isolate Gold King ...

EPA Pesticide Factsheets

Detecting the Gold King Mine metals as the release plume passed was difficult once it entered the San Juan River on August 8, 2015. Plume metals concentrations were relatively low after 200 km of travel and deposition in the Animas River while background concentrations of the same metals were high due to high sediment load in the San Juan River. A metal fingerprinting technique was used to isolate metals in the Gold King release from background using the measured concentrations of the 23 TAL metals (Metal/Cynaide Target Analyte List) available with most water samples. The method associates the concentration of trace metals to that of aluminum or iron as representative of the dominant metals in the geologic substrate. Metal concentrations can be plotted together, as in Figure 1A, or the ratio can be computed for each sample for use as a value, such as plotted in time in Figure 1B. The correlation technique allowed maximum use of typically available water sample data to isolate Gold King metals as contaminants within the varying background concentrations associated with the natural sediments of the San Juan River. To be presented at the New Mexico Water Institute Symposium, 2nd Annual Conference on Environmental Conditionsof the Animas and San Juan Watersheds with Emphasis on Gold King Mine and Other Mine Waste Issues.

Utility of Ochrobactrum anthropi YC152 in a Microbial Fuel Cell as an Early Warning Device for Hexavalent Chromium Determination.

PubMed

Wang, Guey-Horng; Cheng, Chiu-Yu; Liu, Man-Hai; Chen, Tzu-Yu; Hsieh, Min-Chi; Chung, Ying-Chien

2016-08-16

Fast hexavalent chromium (Cr(VI)) determination is important for environmental risk and health-related considerations. We used a microbial fuel cell-based biosensor inoculated with a facultatively anaerobic, Cr(VI)-reducing, and exoelectrogenic Ochrobactrum anthropi YC152 to determine the Cr(VI) concentration in water. The results indicated that O. anthropi YC152 exhibited high adaptability to pH, temperature, salinity, and water quality under anaerobic conditions. The stable performance of the microbial fuel cell (MFC)-based biosensor indicated its potential as a reliable biosensor system. The MFC voltage decreased as the Cr(VI) concentration in the MFC increased. Two satisfactory linear relationships were observed between the Cr(VI) concentration and voltage output for various Cr(VI) concentration ranges (0.0125-0.3 mg/L and 0.3-5 mg/L). The MFC biosensor is a simple device that can accurately measure Cr(VI) concentrations in drinking water, groundwater, and electroplating wastewater in 45 min with low deviations (<10%). The use of the biosensor can help in preventing the violation of effluent regulations and the maximum allowable concentration of Cr(VI) in water. Thus, the developed MFC biosensor has potential as an early warning detection device for Cr(VI) determination even if O. anthropi YC152 is a possible opportunistic pathogen.

Assessment of heavy metal pollution risks in Yonki Reservoir environmental matrices affected by gold mining activity.

PubMed

Kapia, Samuel; Rao, B K Rajashekhar; Sakulas, Harry

2016-10-01

This study reports the heavy metal (Hg, Cd, Cr, Cu, and Pb) contamination risks to and safety of two species of fresh water fish (tilapia, Oreochromis mossambicus and carp, Cyprinus carpio) that are farmed in the Yonki Reservoir in the Eastern Highlands of Papua New Guinea (PNG). The upper reaches of the reservoir are affected by alluvial and large-scale gold mining activities. We also assessed heavy metal levels in the surface waters and sediments and in selected aquatic plant species from the reservoir and streams that intersect the gold mining areas. The water quality was acceptable, except for the Cr concentration, which exceeded the World Health Organization (WHO) standard for water contamination. The sediments were contaminated with Cd and Cu in most of the sampling stations along the upstream waters and the reservoir. The Cd concentration in the sediments exceeded the US Environmental Protection Agency's Sediment Quality Guideline (SQG) values, and the geoaccumulation index (Igeo) values indicated heavy to extreme pollution. In addition, the Cd, Cu, and Pb concentrations in aquatic plants exceeded the WHO guidelines for these contaminants. Between the fish species, tilapia accumulated significantly higher (P < 0.05) Cu in their organ tissues than carp, confirming the bioaccumulation of some metals in the aquatic fauna. The edible muscles of the fish specimens had metal concentrations below the maximum permissible levels established by statutory guidelines. In addition, a human health risk assessment, performed using the estimated weekly intake (EWI) values, indicated that farmed fish from the Yonki Reservoir are safe for human consumption.

Determination of radon concentration in water using RAD7 with RAD H{sub 2}O accessories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malik, M. F. I.; Rabaiee, N. A.; Jaafar, M. S.

In the last decade, the radon issue has become one of the major problems of radiation protection. Radon exposure occurs when using water for showering, washing dishes, cooking and drinking water. RAD7 and Rad H20 accessories were used in order to measure radon concentration in water sample. In this study, four types of water were concerns which are reverse osmosis (drinking water), mineral water, tap water and well water. Reverse osmosis (drinking water) and mineral water were bought from the nearest supermarket while tap water and well water were taken from selected areas of Pulau Pinang and Kedah. Total 20more » samples were taken with 5 samples for each type of water. The measured radon concentration ranged from 2.9±2.9 to 79.5±17 pCi/L, 2.9±2.9 to 67.8±16 pCi/L, 15.97±7 to 144.25±24 pCi/L and 374.89±37 to 6409.03±130 pCi/L in reverse osmosis (drinking water), mineral water, tap water and well water. Well water has the highest radon compared to others. It was due to their geological element such as granite. Results for all types of water are presented and compared with maximum contamination limit (MCL) recommended by United State Environmental Protection Agency (USEPA) which is 300pCi/L. Reverse osmosis water, mineral water and tap water were fall below MCL. However, well water was exceeded maximum level that was recommended. Thus, these findings were suggested that an action should be taken to reduce radon concentration level in well water as well as reduce a health risk towards the public.« less

Spatio-temporal evaluation of emerging contaminants and their partitioning along a Brazilian watershed.

PubMed

de Sousa, Diana Nara Ribeiro; Mozeto, Antonio Aparecido; Carneiro, Renato Lajarim; Fadini, Pedro Sergio

2018-02-01

The occurrence, partitioning, and spatio-temporal distribution of seven pharmaceuticals for human use, three steroid hormones and one personal care product were determined in surface water, suspended particulate matter (SPM), and sediment of Piraí Creek and Jundiaí River (Jundiaí River Basin, São Paulo, Brazil). The maximum average detected concentrations of the compounds in the Piraí River samples were < 30 ng L -1 , except for caffeine (222 ng L -1 ). In Jundiaí River samples, most of the compounds were frequently detected, wherein caffeine had the highest concentration, with maximum average concentrations of 14,050 ng L -1 , followed by atenolol (431 ng L -1 ), ibuprofen (268 ng L -1 ) and diclofenac (214 ng L -1 ). Atenolol, propranolol, estrone, and triclosan were the contaminants most frequently detected in sediment and SPM samples. Triclosan had the highest average proportion of SPM as opposed to in the aqueous phase (> 75%). Contaminants with acid functional groups showed, in general, a lower tendency to bind to particulate matter and sediments. In addition, hydrophobicity had an important effect on their environmental partitioning. The spatial distribution of contaminants along the Jundiaí River was mainly affected by the higher concentration of contaminants in water samples collected downstream from a sewage treatment plant (STP). The results obtained here clearly showed the importance of the analysis of some contaminants in the whole water, meaning both dissolved and particulate compartments in the water, and that the partitioning is ruled by a set of parameters associated to the physicochemical characteristics of contaminants and the matrix properties of the studied, which need be considered in an integrated approach to understand the fate of emerging chemical contaminants in aquatic environments.

Taxonomically-linked growth phenotypes during arsenic stress among arsenic resistant bacteria isolated from soils overlying the Centralia coal seam fire

PubMed Central

Dunivin, Taylor K.; Miller, Justine

2018-01-01

Arsenic (As), a toxic element, has impacted life since early Earth. Thus, microorganisms have evolved many As resistance and tolerance mechanisms to improve their survival outcomes given As exposure. We isolated As resistant bacteria from Centralia, PA, the site of an underground coal seam fire that has been burning since 1962. From a 57.4°C soil collected from a vent above the fire, we isolated 25 unique aerobic As resistant bacterial strains spanning seven genera. We examined their diversity, resistance gene content, transformation abilities, inhibitory concentrations, and growth phenotypes. Although As concentrations were low at the time of soil collection (2.58 ppm), isolates had high minimum inhibitory concentrations (MICs) of arsenate and arsenite (>300 mM and 20 mM respectively), and most isolates were capable of arsenate reduction. We screened isolates (PCR and sequencing) using 12 published primer sets for six As resistance genes (AsRGs). Genes encoding arsenate reductase (arsC) and arsenite efflux pumps (arsB, ACR3(2)) were present, and phylogenetic incongruence between 16S rRNA genes and AsRGs provided evidence for horizontal gene transfer. A detailed investigation of differences in isolate growth phenotypes across As concentrations (lag time to exponential growth, maximum growth rate, and maximum OD590) showed a relationship with taxonomy, providing information that could help to predict an isolate’s performance given As exposure in situ. Our results suggest that microbiological management and remediation of environmental As could be informed by taxonomically-linked As tolerance, potential for resistance gene transferability, and the rare biosphere. PMID:29370270

Effects of suspension of air-conditioning on airtight-type racks.

PubMed

Kanzaki, M; Fujieda, M; Furukawa, T

2001-10-01

Although isolation racks are superior to open-type racks in terms of securing breeding conditions for laboratory animals, the contingency-proofing capability of the former has yet to be determined. Therefore, from the view of risk management, we studied the environmental change in isolation racks by forcibly suspending ventilation and air-conditioning and confirming the maximal time length for complete recovery to the original condition after restarting their operations. The isolation racks were placed in a room that was equipped with an independent air-conditioning system. When the inside condition of the racks reached 22-24 degrees C and 59-64% of relative humidity, the air-conditioning and ventilation were forcibly suspended and the subsequent temperature, relative humidity, ammonium and CO2 concentrations in the racks were measured over time. We found that after suspending the air-conditioning and ventilation, it took 40-60 min for temperature, and about 10 min for relative humidity to exceed the maximum values (temperature and relative humidity) referred to in the Showa 58 Nenban Guideline Jikken Doubutsu Shisetsu no Kenchiku oyobi Setsubi (Guidelines of buildings and facilities for experimental animals in Japan; Year 1983 edition). After 17 hr 25 min of the suspension of air-conditioning and ventilation, two rats were found dead. Then, the air-conditioning and ventilation were restarted. It took about 2 hr for temperature, and 50 min for relative humidity to regain the guideline values. The ammonium concentration stayed within the guideline value with a maximum concentration of 2 ppm in the experimental period, whereas the CO2 concentration was found to exceed 9% at the time of animal death.

In Vivo potassium-39 NMR spectra by the burg maximum-entropy method

NASA Astrophysics Data System (ADS)

Uchiyama, Takanori; Minamitani, Haruyuki

The Burg maximum-entropy method was applied to estimate 39K NMR spectra of mung bean root tips. The maximum-entropy spectra have as good a linearity between peak areas and potassium concentrations as those obtained by fast Fourier transform and give a better estimation of intracellular potassium concentrations. Therefore potassium uptake and loss processes of mung bean root tips are shown to be more clearly traced by the maximum-entropy method.

Flux balance analysis of different carbon source fermentation with hydrogen producing Clostridium butyricum using Cell Net Analyzer.

PubMed

Rafieenia, Razieh; Chaganti, Subba Rao

2015-01-01

A metabolic network model for Clostridium butyricum was developed using six different carbon sources (sucrose, fructose, galactose, mannose, trehalose and ribose) to study the fermentative H2 production. The model was used for investigation of H2 production and the ability of growth on different substrates to predict the maximum abilities for fermentative H2 production that each substrate can support. NADH fluxes were calculated by the model as an important cofactor affecting on H2 production. Butyrate and acetate production were used as model assumptions and biomass formation was chosen as the objective function for flux analysis calculations. Among the substrates selected, sucrose and trehalose supported the maximum growth and H2 yields. The Cell Net Analyzer metabolic network model developed for H2 estimation revealed good correlation with experimental data and could be further used to study the effect of environmental conditions and substrates concentration on H2 yield. Copyright © 2014 Elsevier Ltd. All rights reserved.

Utilization of Drinking Water Treatment Slurry to Produce Aluminum Sulfate Coagulant.

PubMed

Fouad, Mahmoud M; Razek, Taha M A; Elgendy, Ahmed S

2017-02-01

  In Egypt, water treatment consumes about 365 000 tons of aluminum sulfate and produces more than 100 million tons of sludge per year. The common disposal system of sludge in Egypt is to discharge it into natural waterways. Toxicity of aluminum, environmental regulations and costs of chemicals used in water treatment and sludge treatment processes led to an evaluation of coagulant recovery and subsequent reuse. The present work aimed at aluminum recovery from sludge of El-Shiekh Zayd water treatment plant (WTP) to produce aluminum sulfate coagulant. Sludge was characterized and the effect of five variables was tested and the process efficiency was evaluated at different operating conditions. Maximum recovery is 94.2% at acid concentration 1.5 N, sludge weight 5 g, mixing speed 60 rpm, temperature 60 °C and leaching time 40 min. Then optimum conditions were applied to get maximum recovery for aluminum sulfate and compared to commercial coagulant on raw water of El-Shiekh Zayd (WTP).

Assessment of the Physicochemical Quality of Drinking Water Resources in the Central Part of Iran.

PubMed

Nikaeen, Mahnaz; Shahryari, Ali; Hajiannejad, Mehdi; Saffari, Hossein; Kachuei, Zahra Moosavian; Hassanzadeh, Akbar

2016-01-01

The aim of the study described in this article was to assess the physicochemical quality of water resources in Isfahan province, located in the central part of Iran, from June to November 2012. Comparison of the results with the acceptable limits recommended by the World Health Organization (WHO) for drinking water showed that nitrate, chloride, iron, and fluoride concentrations exceeded the maximum acceptable level in 12.3%, 9.2%, 6.8%, and 1.5% of samples, respectively. Total dissolved solids (TDS) and turbidity values also exceeded the maximum acceptable level in 9.2% and 3.1% of samples, respectively. In general, the quality of drinking water resources in the central part of Iran at present is mostly acceptable and satisfactory. It may be deteriorated in the future, however, because water quantity and quality in arid and semiarid areas are highly variable over time. Therefore, continued monitoring of the water resources quality is extremely important to environmental safety.

Groundwater quality in West Virginia, 1993-2008

USGS Publications Warehouse

Chambers, Douglas B.; Kozar, Mark D.; White , Jeremy S.; Paybins, Katherine S.

2012-01-01

Approximately 42 percent of all West Virginians rely on groundwater for their domestic water supply. However, prior to 2008, the quality of the West Virginia’s groundwater resource was largely unknown. The need for a statewide assessment of groundwater quality prompted the U.S. Geological Survey (USGS), in cooperation with West Virginia Department of Environmental Protection (WVDEP), Division of Water and Waste Management, to develop an ambient groundwater-quality monitoring program. The USGS West Virginia Water Science Center sampled 300 wells, of which 80 percent were public-supply wells, over a 10-year period, 1999–2008. Sites for this statewide ambient groundwater-quality monitoring program were selected to provide wide areal coverage and to represent a variety of environmental settings. The resulting 300 samples were supplemented with data from a related monitoring network of 24 wells and springs. All samples were analyzed for field measurements (water temperature, pH, specific conductance, and dissolved oxygen), major ions, trace elements, nutrients, volatile organic compounds, fecal indicator bacteria, and radon-222. Sub-sets of samples were analyzed for pesticides or semi-volatile organic compounds; site selection was based on local land use. Samples were grouped for comparison by geologic age of the aquifer, Groups included Cambrian, Ordovician, Silurian, Devonian, Pennsylvanian, Permian, and Quaternary aquifers. A comparison of samples indicated that geologic age of the aquifer was the largest contributor to variability in groundwater quality. This study did not attempt to characterize drinking water provided through public water systems. All samples were of raw, untreated groundwater. Drinking-water criteria apply to water that is served to the public, not to raw water. However, drinking water criteria, including U.S. Environmental Protection Agency (USEPA) maximum contaminant level (MCL), non-enforceable secondary maximum contaminant level (SMCL), non-enforceable proposed MCL, or non-enforceable advisory health-based screening level (HBSL), were used as benchmarks against which to compare analytical results. Constituent concentrations were less than the MCLs in most samples. However, some samples exceeded non-enforceable SMCLs, proposed MCLs, or advisory HBSLs. Radon-222 concentrations exceeded the proposed MCL of 300 pCi/L in 45 percent of samples, and iron concentrations exceeded the SMCL of 300 µg/L in 57 percent of samples. Manganese concentrations were greater than the SMCL (50 µg/L) in 62 percent of samples and greater than the HBSL (300 µg/L) in 25 percent of the samples. Other sampled constituents, including organic compounds and trace elements, exceeded drinking-water criteria at much lower frequencies. The radon-222 median concentrations in samples from Cambrian, Ordovician, Silurian, Permian, and Quaternary aquifers exceeded the proposed 300 pCi/L MCL. Although median radon concentrations for wells in Devonian, Mississippian, and Pennsylvanian aquifers were less than the proposed MCL, radon concentrations greater than the proposed MCL were measured in samples from aquifers of all geologic ages. The median iron concentrations for samples from Devonian and Pennsylvanian aquifers were greater than the 300 µg/L SMCL. Iron concentrations exceeded the SMCL in aquifers of all geologic ages, except Cambrian. Median concentrations of manganese exceeded the SMCL in samples from Devonian, Pennsylvanian, and Quaternary aquifers. As with iron, manganese concentrations were found to exceed the SMCL in at least one sample from aquifers of all geologic ages, except Cambrian. Pesticides were detected most frequently and in higher concentrations in limestone-dominated areas. Most of West Virginia’s agriculture is concentrated in those areas. This study, the most comprehensive assessment of West Virginia groundwater quality to date, indicates the water quality of West Virginia’s groundwater is generally good; in the majority of cases raw-water samples met primary drinking water-criteria. However, some constituents, notably iron and manganese, exceeded the secondary drinking criteria in more than half the samples.

Polymer-surfactant complex formation and its effect on turbulent wall shear stress.

PubMed

Suksamranchit, Siriluck; Sirivat, Anuvat; Jamieson, Alexander M

2006-02-01

Turbulent drag reduction in Couette flow was investigated in terms of a decrease in wall shear stress for aqueous solutions of a nonionic polymer, poly(ethylene oxide) (PEO), a cationic surfactant, hexadecyltrimethylammonium chloride (HTAC), and their mixtures. Consistent with literature data, drag reduction was observed for PEO solutions above a critical molecular weight, 0.91 x 10(5) < Mc < 3.04 x 10(5) g/mol. Maximum drag reduction occurred at an optimum concentration, c(PEO)*, which scales inversely with molecular weight, and the % maximum drag reduction increases with molecular weight. For aqueous HTAC solutions, wall shear stress decreased with increasing HTAC concentration and leveled off at an optimum concentration, c(HTAC)*, comparable to the critical micelle concentration. For HTAC/PEO mixtures, the critical PEO molecular weight for drag reduction decreases, interpreted as due to an increase in hydrodynamic volume because of binding of HTAC micelles to PEO. Consistent with this interpretation, at fixed PEO concentration, maximum drag reduction was observed at an optimum HTAC concentration, c(HTAC/PEO)*, comparable to the maximum binding concentration, MBC. Also, with HTAC concentration fixed at the MBC, the optimum PEO concentration for drag reduction, c(PEO/HTAC)*, decreases relative to that, c(PEO)*, in the absence of HTAC.

Diffusion via space discretization method to study the concentration dependence of self-diffusivity under confinement

NASA Astrophysics Data System (ADS)

Sant, Marco; Papadopoulos, George K.; Theodorou, Doros N.

2010-04-01

The concentration dependence of self-diffusivity is investigated by means of a novel method, extending our previously developed second-order Markov process model to periodic media. Introducing the concept of minimum-crossing surface, we obtain a unique decomposition of the self-diffusion coefficient into two parameters with specific physical meanings. Two case studies showing a maximum in self-diffusivity as a function of concentration are investigated, along with two cases where such a maximum cannot be present. Subsequently, the method is applied to the large cavity pore network of the ITQ-1 (Mobil tWenty tWo, MWW) zeolite for methane (displaying a maximum in self-diffusivity) and carbon dioxide (no maximum), explaining the diffusivity trend on the basis of the evolution of the model parameters as a function of concentration.

Distribution and geochemical composition of suspended particulate material in the shallow embayment of northern Thermaikos Gulf, Greece

NASA Astrophysics Data System (ADS)

Tsompanoglou, K.; Anagnostou, Ch.; Krasakopoulou, E.; Pagou, K.; Karageorgis, A. P.; Pavlidou, A.; Albanakis, K.; Tsirambides, A.

2017-07-01

The distribution and the chemical composition of Suspended Particulate Matter (SPM), in the northern Thermaikos Gulf, were studied during an annual experiment, carried out from June 2004 to June 2005. Water samples were collected at three depths (1 m below surface, 10 m depth, and 2 m above bottom) and filtered to obtain SPM, particulate organic carbon (POC), total particulate nitrogen (PNtot) and particulate phosphorus (PP) concentrations. SPM and POC concentrations exhibited strong spatial and temporal variations, related to the different environmental characteristics in the study area such as river network, biological productivity, anthropogenic interferences, wind regime, and resuspension of the bottom sediments. The highest SPM concentrations were recorded at the surface (mean = 1.45 ± 0.75 mg/l, maximum value = 11.60 mg/l) and close to the bottom (mean = 1.49 ± 0.67 mg/l, maximum value = 11.72 mg/l), creating surface and bottom nepheloid layers (SNL and BNL), respectively. The maximum values were recorded close to the river mouths; the rivers are identified as the major sources of SPM. The Axios and Aliakmon rivers supplied the gulf with particulate matter, during the entire sampling period. Chemical analysis has revealed the significant correlation among the elements Al, Si, Fe, Ti, K, V, Mg and Ba suggesting the presence of terrigenous aluminosilicate minerals. Silica and Ca have terrigenous origin, but also come from autochthonous biogenic fraction. Chromium, Ni and Co, are of natural origin and derived from mafic and ultramafic rocks of the Axios and Aliakmon watersheds. Copper and Zn are correlated with each other and their distributions follow that of POC; these two metals are derived from partially treated domestic and industrial effluents. The vertical distribution of organic matter implies increased primary production within the upper layer of the water column. Phosphorus is present mainly in an organic form. During the sampling period, the water column was well-oxygenated. Early diagenesis only affected the concentrations of Mn and to a lesser extent Fe in the recently deposited seabed sediment.

Effects of wastewater effluent discharge and treatment facility upgrades on environmental and biological conditions of the upper Blue River, Johnson County, Kansas and Jackson County, Missouri, January 2003 through March 2009

USGS Publications Warehouse

Graham, Jennifer L.; Stone, Mandy L.; Rasmussen, Teresa J.; Poulton, Barry C.

2010-01-01

The Johnson County Blue River Main Wastewater Treatment Facility discharges into the upper Blue River near the border between Johnson County, Kansas and Jackson County, Missouri. During 2005 through 2007 the wastewater treatment facility underwent upgrades to increase capacity and include biological nutrient removal. The effects of wastewater effluent on environmental and biological conditions of the upper Blue River were assessed by comparing an upstream site to two sites located downstream from the wastewater treatment facility. Environmental conditions were evaluated using previously and newly collected discrete and continuous data, and were compared with an assessment of biological community composition and ecosystem function along the upstream-downstream gradient. This evaluation is useful for understanding the potential effects of wastewater effluent on water quality, biological community structure, and ecosystem function. In addition, this information can be used to help achieve National Pollution Discharge Elimination System (NPDES) wastewater effluent permit requirements after additional studies are conducted. The effects of wastewater effluent on the water-quality conditions of the upper Blue River were most evident during below-normal and normal streamflows (about 75 percent of the time), when wastewater effluent contributed more than 20 percent to total streamflow. The largest difference in water-quality conditions between the upstream and downstream sites was in nutrient concentrations. Total and inorganic nutrient concentrations at the downstream sites during below-normal and normal streamflows were 4 to 15 times larger than at the upstream site, even after upgrades to the wastewater treatment facility were completed. However, total nitrogen concentrations decreased in wastewater effluent and at the downstream site following wastewater treatment facility upgrades. Similar decreases in total phosphorus were not observed, likely because the biological phosphorus removal process was not optimized until after the study was completed. Total nitrogen and phosphorus from the wastewater treatment facility contributed a relatively small percentage (14 to 15 percent) to the annual nutrient load in the upper Blue River, but contributed substantially (as much as 75 percent) to monthly loads during seasonal low-flows in winter and summer. During 2007 and 2008, annual discharge from the wastewater treatment facility was about one-half maximum capacity, and estimated potential maximum annual loads were 1.6 to 2.4 times greater than annual loads before capacity upgrades. Even when target nutrient concentrations are met, annual nutrient loads will increase when the wastewater treatment facility is operated at full capacity. Regardless of changes in annual nutrient loads, the reduction of nutrient concentrations in the Blue River Main wastewater effluent will help prevent further degradation of the upper Blue River. The Blue River Main Wastewater Treatment Facility wastewater effluent caused changes in concentrations of several water-quality constituents that may affect biological community structure and function including larger concentrations of bioavailable nutrients (nitrate and orthophosphorus) and smaller turbidities. Streambed-sediment conditions were similar along the upstream-downstream gradient and measured constituents did not exceed probable effect concentrations. Habitat conditions declined along the upstream-downstream gradient, largely because of decreased canopy cover and riparian buffer width and increased riffle-substrate fouling. Algal biomass, primary production, and the abundance of nutrient-tolerant diatoms substantially increased downstream from the wastewater treatment facility. Likewise, the abundance of intolerant macroinvertebrate taxa and Kansas Department of Health and Environment aquatic-life-support scores, derived from macroinvertebrate data, significantly decreased downstream from the wastewater

Volatile organic compounds in samples from domestic and public wells, 1985-2002

USGS Publications Warehouse

Rowe, Barbara L.; Zogorski, John S.; Valder, Joshua F.

2006-01-01

The U.S. Geological Survey's (USGS) National Water-Quality Assessment (NAWQA) Program recently completed a national study of volatile organic compounds (VOCs) in the Nation's ground water (Zogorski and others, 2006). Part of this assessment emphasizes the occurrence of 55 VOCs in samples from 2,401 domestic wells and 1,096 public wells during 1985-2002. Samples were collected prior to any treatment or blending of water. Domestic wells are privately owned, self-supplied sources used for drinking water and household use (Moran and others, 2002). Public wells are privately or publicly owned and supply water to public water systems (PWSs). Samples from public wells in this assessment characterize the quality of water captured by wells that supply drinking water to PWSs. These systems supply drinking water to at least 15 service connections or regularly serve at least 25 individuals daily at least 60 days a year (U.S. Environmental Protection Agency, 2005). For a screening-level assessment, VOC concentrations were compared to human-health benchmarks. Concentrations greater than the U.S. Environmental Protection Agency's (USEPA) Maximum Contamination Levels (MCLs) (U.S. Environmental Protection Agency, 2004) or the USGS's Health-Based Screening Levels (HBSLs) (Zogorski and others, 2006) were considered of potential human-health concern. The findings from the well samples provide an important perspective on the quality of the Nation's ground water used for drinking-water supplies. More information about this national assessment of VOCs is available (http://water.usgs.gov/nawqa/vocs/national_assessment).

Triggering the ExoS regulon of Pseudomonas aeruginosa: A GFP-reporter analysis of exoenzyme (Exo) S, ExoT and ExoU synthesis.

PubMed

Hornef, M W; Roggenkamp, A; Geiger, A M; Hogardt, M; Jacobi, C A; Heesemann, J

2000-12-01

The ExoS regulon of Pseudomonas aeruginosa encodes diverse type III secreted effector proteins which have been shown to exert cytotoxic effects in cell culture experiments. However, little information exists about the environmental conditions and stimuli for upregulation of the ExoS regulon. Translational reporter fusion proteins of exoenzyme (Exo) S, ExoT and ExoU, as well as the type II secreted exotoxin A (ETA) to the green fluorescent protein (GFP), were constructed in order to compare exoprotein production under diverse growth conditions. Reporter protein activity was recorded by FACS-analysis and by conventional and confocal laser scanning microscopy. Low ion concentration induced co-ordinated upregulation of ExoS, ExoT and ExoU with a maximum effect at 37 degrees C. A dose-dependent upregulation was seen with human serum or increasing NaCl concentrations. A type III secretion-negative pcrD mutant of P. aeruginosa showed a weak ExoS response to environmental stimuli, compared with the parental strain, suggesting a negative regulatory mechanism. Co-culture with the mammalian cell lines J774A.1 or HeLa led to rapid upregulation of ExoS, ExoT and ExoU synthesis. These data suggest that the ExoS regulon of P. aeruginosa can be triggered by a variety of environmental signals as well as by cell contact with eukaryotic cells. Copyright 2000 Academic Press.

[Monitoring plan of environmental contaminants in sheep milk from areas next to an Italian contaminated site named «Aree industriali di Porto Torres e discarica di Calancoi» (Industrial areas of Porto Torres and landfill of Calancoi) in Sardinia Region (Southern Italy)].

PubMed

Sgarangella, Francesco; Bitti, Giuseppe; Suelzu, Maria Caterina; Desini, Pietro; Piras, Patrizia; Fiori, Gianuario; Cossu, Maurizio; Chessa, Giannina

2016-01-01

to assess concentration levels of dioxins, PCBs, and chemical elements in sheep milk produced in areas close to the Italian contaminated site (CS) located in the North-West of Sardinia (Southern Italy), named «Aree industriali di Porto Torres e discarica di Calancoi» (i.e., industrial areas of Porto Torres and landfill of Calancoi). monitoring plan of environmental contaminants on zootechnical productions based on analysis of dioxins, PCBs, heavy metals (Cd, Hg, Pb), and other elements (As, Be, Cr, Ni, Tl , Zn) in sheep bulk milk. 60 samples of sheep bulk milk were collected in rural farms where animals were fed mainly with forage and feed produced in the CS: 30 samples from farms located near the industrial area of Porto Torres and 30 taken from farms spread out the landfill area of Calancoi, a former waste dump in the East of Sassari city. the concentration levels of target substances were determined and compared to legal thresholds fixed on EU regulations. concentrations of target substances in all samples were below the maximum limits set by EU regulations. Dioxins and DL-PCBs (expressed as the sum) were in the range 0.20-1.30 pg WHO-TEQ/g fat, NDL-PCB (sum of the six marker congeners) were in the range 0.50-7.50 ng/g, while concentrations of all heavy metals were not detectable or were near the limit of quantitation of the method. Undetectable concentrations were also observed for the toxic elements beryllium and thallium. concentration levels of micro-pollutants in milk samples were significantly lower than the legal thresholds. Concentrations and congener profiles showed no relevant differences compared to milk samples from areas with low environmental impact, therefore consumption of milk from the studied area do not produce a higher intake of contaminants respect to the regional milk. The results of this study do not make the resident population safe from health risks caused by critical issue of the CS, but provide information limited to the safety of the milk from these areas, without showing peculiar contamination and hazard for food from local sheep farms.

Evaluation of measured and predicted environmental concentrations of selected human pharmaceuticals and personal care products.

PubMed

Liebig, Markus; Moltmann, Johann F; Knacker, Thomas

2006-03-01

In the past few years, there was an increasing awareness of the occurrence of pharmaceuticals and personal care products (PPCPs) in surface water and drinking water resources, and measurements in surface water, sediment or waste water were done for a number of PPCPs. In the regulatory context, an environmental risk assessment (ERA) has become essential for new PPCPs. Reliably predicted or measured environmental concentrations (PECs or MECs) of chemicals are essential for the exposure assessment, which is one of the two main pillars of environmental risk assessment (ERA). This paper reports on measured data of selected PPCPs in surface waters and compares the measured values with predicted environmental concentrations from exposure models. Such models have been proposed by the European Agency for the Evaluation of Medicinal Products (EMEA) and the Technical Guidance Document on Risk Assessment for New Notified and Existing Chemical Substances (TGD). Four pharmaceuticals and one personal care product were in the scope of the investigation reported here: 17alpha-ethinylestradiol, carbamazepine, sulfamethoxazole and iopromide as well as tonalide. Measured environmental concentrations in surface waters for these PPCPs were reviewed in the scientific literature. The appropriateness of these data was evaluated according to criteria for monitoring data recommended by the TGD. A total of 38 references were evaluated with emphasis on the adequacy of chemical analysis and the representativeness of sampling. Measurements of concentrations in surface water (MECsw), which were found to be adequate for use in exposure assessment according to the monitoring quality criteria, were averaged and compared with respective PECs in surface water (PECsw) derived from exposure modelling (cf. EMEA and TGD). Measured environmental concentrations adequate for use in exposure assessment were found in 20 out of 38 references. Several of the measurements from Germany could be used for a comparison with calculated PECs. Average MECs(sw) in Germany were < 0.58 ng/L for 17alpha-ethinylestradiol, 454 ng/L for carbamazepine, 126 ng/L for sulfamethoxazole, 1105 ng/L for iopromide and 311 ng/L for tonalide. In comparison to the measured concentrations, PECs calculated with the model proposed by the EMEA in 2001 were in the same range, but slightly higher than the MECs. The EMEA model from 2001 is based on a production/use volume of the PPCPs. The more recent EMEA model (2003/2005) overestimated the PECs by more than one order of magnitude for carbamazepine and sulfamethoxazole, but underestimated the concentration of 17alpha-ethinylestradiol by a factor of almost 5 compared to the MECs. This model is based on maximum daily doses and the assumption that 1% of the population is consuming the pharmaceutical (default value). Calculations with the European Union System for the Evaluation of Substances (EUSES), which is part of the TGD describing the risk assessment of chemicals and biocides, resulted for the investigated pharmaceuticals in almost the same PECs as derived by the older EMEA model (2001). For the PCP tonalide, to which the recent EMEA model (2003/ 2005) cannot be applied, the PEC was overestimated by a factor of 3 with the older EMEA model (2001), but underestimated with EUSES by a factor of 5 compared to the averaged MECsw in Germany. Conclusions. It was shown that PEC calculations with exposure models provided by EMEA and the TGD, resulted in PECs very close to the corresponding MECs in most cases. However, environmental concentrations can be underestimated by models in cases, where, e.g. due to high lipophilicity, sorption to sewage sludge is assumed which does not occur to that extent under real conditions. Thus, it appears that the exposure models do not come up to the complexity of the real environment. However, the main factor with the highest impact on predicted environmental concentrations and a high degree of uncertainty is the production volume. Recommendations and Outlook. References and their data evaluated as not adequate for use in exposure assessment were mainly rejected due to missing or insufficient specifications related to the sampling procedure and/or representativeness of the samples. Several of the evaluated studies aimed at the introduction and establishment of a new analytical methodology. A detailed description of sampling frequency and pattern, for example, was therefore neglected. Often, a more accurate description of analytical procedure, sampling pattern and statistical analysis of data would be sufficient to provide an adequate basis for exposure assessment and hence establish confidence in environmental risk assessment procedures. For new substances, an exposure assessment is solely based on estimations using environmental fate models. To avoid unacceptable risks for the environment, PECs should not underestimate actual environmental concentrations. Since it was shown that under specific conditions the models applied in this study underestimated measured environmental concentrations, further development of the calculation models appears to be necessary.

The influence of screening of the polyion electrostatic potential on the counterion dynamics in polyelectrolyte solutions

NASA Astrophysics Data System (ADS)

Schipper, F. J. M.; Hollander, J. G.; Leyte, J. C.

1998-10-01

The self-diffusion coefficient of tetra-methylammonium counterion in solutions of polymethacrylic acid in 0953-8984/10/41/004/img1 has been measured over a broad polyion concentration range at a constant degree of neutralization and at different ratios of added monovalent or bivalent salt to polyions. A maximum counterion self-diffusion coefficient was observed as a function of polyion concentration. The value of the self-diffusion coefficient at the maximum did not depend on the valency of the added salt. The maximum was found at lower polymer concentrations and with a higher value, when the ratio of added salt to polyions was increased, as predicted by the Poisson-Boltzmann-Smoluchowski equation in the cylindrical cell model for polyelectrolytes. At higher polyion concentrations a maximum counterion self-diffusion coefficient against the ratio of added salt and polyions was observed, which has not been reported before. Upon increasing this ratio the electrostatic potential of the polyelectrolyte gets screened, leading to an increase of the counterion self-diffusion coefficient. Concentration effects of the added salt on the other hand ultimately lead to a decrease of the counterion self-diffusion coefficient, which explains the occurrence of a maximum.

A comparison of in-cloud HCl concentrations from the NASA/MSFC MDM to measurements for the space shuttle launch

NASA Technical Reports Server (NTRS)

Glasser, M. E.

1981-01-01

The Multilevel Diffusion Model (MDM) Version 5 was modified to include features of more recent versions. The MDM was used to predict in-cloud HCl concentrations for the April 12 launch of the space Shuttle (STS-1). The maximum centerline predictions were compared with measurements of maximum gaseous HCl obtained from aircraft passes through two segments of the fragmented shuttle ground cloud. The model over-predicted the maximum values for gaseous HCl in the lower cloud segment and portrayed the same rate of decay with time as the observed values. However, the decay with time of HCl maximum predicted by the MDM was more rapid than the observed decay for the higher cloud segment, causing the model to under-predict concentrations which were measured late in the life of the cloud. The causes of the tendency for the MDM to be conservative in over-estimating the HCl concentrations in the one case while tending to under-predict concentrations in the other case are discussed.

The relationship between the deep-level structure in crust and brewing of strong earthquakes in Xingtai area

NASA Astrophysics Data System (ADS)

Xiao, Lan-Xi; Zhu, Yuan-Qing; Zhang, Shao-Quan; Liu, Xu; Guo, Yu

1999-11-01

In this paper, crust medium is treated as Maxwell medium, and crust model includes hard inclusion, soft inclusion, deep-level fault. The stress concentration and its evolution with time are obtained by using three-dimensional finite element method and differential method. The conclusions are draw as follows: (1) The average stress concentration and maximum shear stress concentration caused by non-heterogeneous of crust are very high in hard inclusion and around the deep fault. With the time passing by, the concentration of average stress in the model gradually trends to uniform. At the same time, the concentration of maximum shear stress in hard inclusion increases gradually. This character is favorable to transfer shear strain energy from soft inclusion to hard inclusion. (2) When the upper mantle beneath the inclusion upheave at a certain velocity of 1 cm/a, the changes of average stress concentration with time become complex, and the boundary of the hard and soft inclusion become unconspicuous, but the maximum shear stress concentration increases much more in the hard inclusion with time at a higher velocity. This feature make for transformation of energy from the soft inclusion to the hard inclusion. (3) The changes of average stress concentration and maximum shear stress concentration with time around the deep-level fault result in further accumulation of maximum shear stress concentration and finally cause the deep-level fault instable and accelerated creep along fault direction. (4) The changes of vertical displacement on the surface of the model, which is caused by the accelerated creep of the deep-level fault, is similar to that of the observation data before Xingtai strong earthquake.

Contribution of biomass burning to particles matter smaller than ten microns in Mexico City during April 2013.

NASA Astrophysics Data System (ADS)

Mendoza Campos, Alejandra; Agustin Garcia Reynoso, Jóse; Castro Romero, Telma; Carbajal Perez, Jóse Noel; Gerardo Ruiz Suarez, Luis; Peralta Rosales, Oscar Augusto

2015-04-01

A forest fire is a natural combustion process in a specific geographic area, it's depends on meteorological variables, topography and vegetation type, The wildfires are potential sources of large amounts of pollutants. The main air pollutants emitted in a forest fire are the particles (PM10 and PM2.5) Carbon Monoxide (CO), Nitrogen Oxides (NOx), Volatile Organic Compounds (VOCs) and a negligible amount of Sulfur Dioxide (SO2) (Chow 1995), The study of the impact of air quality in Mexico City for a forest fire occurred on April 14 of 2013 was conducted a duration of 26 hours of grassland burning and consuming an extension of 150 ha, the WRF-Chem, WRF-fire and METv3 models were used to perform the study, for the study two modeling were made, one including emissions from forest fires and the other one no emission-fire, when interpolation is made between the two modeling and obtained the impact of air quality in Mexico City, performing calculating emissions and modeling, the impact on air quality for PM10particles were observed arriving at a concentration of 350 mg/m3 due to wildfire occurred, this issue exceeds the maximum permissible limit of PM10particles governed by NOM-025-SSA1-1993 that establishes a maximum of 120 mg/m3 on average for 24 hours, the modeling results with measured data is corroborated weather Stations the environmental monitoring network of the Mexico City, that alerts an environmental contingency for particles for the post-wildfire day. Until now is review the rule which establishes a maximum of 75 mg/m3 on average for 24 hours, implying greater involvement in air quality.

INCA Modelling of the Lee System: strategies for the reduction of nitrogen loads

NASA Astrophysics Data System (ADS)

Flynn, N. J.; Paddison, T.; Whitehead, P. G.

The Integrated Nitrogen Catchment model (INCA) was applied successfully to simulate nitrogen concentrations in the River Lee, a northern tributary of the River Thames for 1995-1999. Leaching from urban and agricultural areas was found to control nitrogen dynamics in reaches unaffected by effluent discharges and abstractions; the occurrence of minimal flows resulted in an upward trend in nitrate concentration. Sewage treatment works (STW) discharging into the River Lee raised nitrate concentrations substantially, a problem which was compounded by abstractions in the Lower Lee. The average concentration of nitrate (NO3) for the simulation period 1995-96 was 7.87 mg N l-1. Ammonium (NH4) concentrations were simulated less successfully. However, concentrations of ammonium rarely rose to levels which would be of environmental concern. Scenarios were run through INCA to assess strategies for the reduction of nitrate concentrations in the catchment. The conversion of arable land to ungrazed vegetation or to woodland would reduce nitrate concentrations substantially, whilst inclusion of riparian buffer strips would be unsuccessful in reducing nitrate loading. A 50% reduction in nitrate loading from Luton STW would result in a fall of up to 5 mg N l-1 in the reach directly affected (concentrations fell from maxima of 13 to 8 mg N l-1 , nearly a 40 % reduction), whilst a 20% reduction in abstractions would reduce maximum peaks in concentration in the lower Lee by up to 4 mg l-1 (from 17 to 13 mg N l-1, nearly a 25 % reduction),.

40 CFR 143.3 - Secondary maximum contaminant levels.

Code of Federal Regulations, 2013 CFR

2013-07-01

.... 143.3 Section 143.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL SECONDARY DRINKING WATER REGULATIONS § 143.3 Secondary maximum contaminant levels. The secondary maximum contaminant levels for public water systems are as follows: Contaminant...

40 CFR 143.3 - Secondary maximum contaminant levels.

Code of Federal Regulations, 2011 CFR

2011-07-01

.... 143.3 Section 143.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL SECONDARY DRINKING WATER REGULATIONS § 143.3 Secondary maximum contaminant levels. The secondary maximum contaminant levels for public water systems are as follows: Contaminant...

40 CFR 143.3 - Secondary maximum contaminant levels.

Code of Federal Regulations, 2014 CFR

2014-07-01

.... 143.3 Section 143.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL SECONDARY DRINKING WATER REGULATIONS § 143.3 Secondary maximum contaminant levels. The secondary maximum contaminant levels for public water systems are as follows: Contaminant...

40 CFR 143.3 - Secondary maximum contaminant levels.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... 143.3 Section 143.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL SECONDARY DRINKING WATER REGULATIONS § 143.3 Secondary maximum contaminant levels. The secondary maximum contaminant levels for public water systems are as follows: Contaminant...

ESTIMATE OF SOLAR MAXIMUM USING THE 1-8 Å GEOSTATIONARY OPERATIONAL ENVIRONMENTAL SATELLITES X-RAY MEASUREMENTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Winter, L. M.; Balasubramaniam, K. S., E-mail: lwinter@aer.com

We present an alternate method of determining the progression of the solar cycle through an analysis of the solar X-ray background. Our results are based on the NOAA Geostationary Operational Environmental Satellites (GOES) X-ray data in the 1-8 Å band from 1986 to the present, covering solar cycles 22, 23, and 24. The X-ray background level tracks the progression of the solar cycle through its maximum and minimum. Using the X-ray data, we can therefore make estimates of the solar cycle progression and the date of solar maximum. Based upon our analysis, we conclude that the Sun reached its hemisphere-averagedmore » maximum in solar cycle 24 in late 2013. This is within six months of the NOAA prediction of a maximum in spring 2013.« less

Shallow Ground-Water Quality in Agricultural Areas of Northern Alabama and Middle Tennessee, 2000-2001

USGS Publications Warehouse

Kingsbury, James A.

2003-01-01

As part of the U.S. Geological Survey National Water-Quality Assessment Program, 32 monitoring wells were installed near cropland in parts of northern Alabama and Middle Tennessee to characterize the effect of row-crop agriculture on shallow ground-water quality. The wells were completed in regolith overlying carbonate bedrock. These geologic units are part of the Mississippian carbonate aquifer, a source of drinking water for domestic and municipal supply in the area. The majority of these wells were sampled in the spring of 2000 for inorganic constituents, nutrients, pesticides, and selected pesticide degradates. Land use and soil characteristics were delineated for a 1,640-foot radius buffer area around each well to relate water quality to environmental factors. A strong association among soil characteristics, land use, and hydrogeology limited the analysis of the effect of these factors on nitrate and pesticide occurrence. Nitrate and pesticide concentrations generally were low, and no samples exceeded established drinking-water maximum contaminant levels. The maximum concentration of nitrate was about 8 milligrams per liter as nitrogen, and the median concentration was 1 milligram per liter. Nitrate concentrations were strongly correlated to dissolved-oxygen concentrations, and ratios of chloride to nitrate indicate nitrate concentrations were affected by denitrification in about a third of the samples. A pesticide or pesticide degradate was detected at concentrations greater than 0.01 microgram per liter in 91 percent of the samples. Pesticides with the highest use typically were detected most frequently and at the highest concentrations; however, glyphosate had the highest estimated use but was not detected in any samples. Fluometuron and atrazine, two high-use pesticides, were detected in 83 and 70 percent, respectively, of the samples from wells where the pesticide was applied in the buffer area. Maximum concentrations of fluometuron and atrazine were 2.13 and 1.83 micrograms per liter, respectively. Detection rates of pesticide degradates were similar to parent pesticides, and concentrations of degradates generally were comparable to or greater than the parent pesticide. Pesticide detections were correlated to dissolved-oxygen concentrations, suggesting that pesticides are most likely to be detected at high concentrations where ground-water residence time is short and the rate of recharge is fast. Nitrate and pesticide data collected in this study were compared to data collected from similar agricultural land-use studies conducted by the National Water-Quality Assessment Program throughout the Nation. Nitrate concentrations generally were lower in this study than in samples from other agricultural areas; however, pesticides were detected more frequently in samples from wells in this study. For example, atrazine and its degradate, deethylatrazine, were detected in 62 and 47 percent, respectively, of water samples in this study but were detected in about 25 percent of the 851 wells sampled for agricultural land-use studies nationwide. In national study areas where atrazine use is greater than in the lower Tennessee River Basin, atrazine was detected in 30 percent of the water samples. Pesticides used on cotton were detected much more frequently in this study, but many of the study areas nationwide have smaller amounts of cotton acreage than the lower Tennessee River Basin. Similarities in nitrate concentrations and the pesticides detected frequently in this agricultural land-use study and a network of drinking-water wells in the same area completed in bedrock in the Mississippian carbonate aquifer (sampled in a previous study) indicate the aquifer is susceptible to contamination from nonpoint sources. Nitrate concentrations were not statistically different for the two well networks and were correlated to total pesticide concentrations in both networks. Although detection frequencies and maximum concentrations

Fault parameters and macroseismic observations of the May 10, 1997 Ardekul-Ghaen earthquake

NASA Astrophysics Data System (ADS)

Amini, H.; Zare, M.; Ansari, A.

2018-01-01

The Ardekul (Zirkuh) earthquake (May 10, 1997) is the largest recent earthquake that occurred in the Ardekul-Ghaen region of Eastern Iran. The greatest destruction was concentrated around Ardekul, Haji-Abad, Esfargh, Pishbar, Bashiran, Abiz-Qadim, and Fakhr-Abad (completely destroyed). The total surface fault rupture was about 125 km with the longest un-interrupted segment in the south of the region. The maximum horizontal and vertical displacements were reported in Korizan and Bohn-Abad with about 210 and 70 cm, respectively; moreover, other building damages and environmental effects were also reported for this earthquake. In this study, the intensity value XI on the European Macroseismic Scale (EMS) and Environmental Seismic Intensity (ESI) scale was selected for this earthquake according to the maximum effects on macroseismic data points affected by this earthquake. Then, according to its macroseismic data points of this earthquake and Boxer code, some macroseismic parameters including magnitude, location, source dimension, and orientation of this earthquake were also estimated at 7.3, 33.52° N-59.99° E, 75 km long and 21 km wide, and 152°, respectively. As the estimated macroseismic parameters are consistent with the instrumental ones (Global Centroid Moment Tensor (GCMT) location and magnitude equal 33.58° N-60.02° E, and 7.2, respectively), this method and dataset are suggested not only for other instrumental earthquakes, but also for historical events.

The effect of the addition of sorbitol and glycerol towards the edible film characteristics of the belitung taro starch and the lime leaves as antimicrobial

NASA Astrophysics Data System (ADS)

Asria, Merry; Elizarni, Samah, dan Selfa Dewati

2015-12-01

Plastics have been generally used for food packaging, but plastics using causing environmental problem for as non biodegradable. Resolving the problem need another alternative packaging that environmental friendly such as the edible film as biodegradable packing material. This research intend to determination the effects of sorbitol and glycerol (concentration of 1%, 2%, 3%, and 4%) as addition to the edible film characteristics from the belitung taro starch (Xanthosoma sagitifolium). Lime leaves (Citrus aurantifolia) extract used as an antimicrobial film (2%, 4%, 6%, 8%, and 10% respectively). From the research obtained that using sorbitol has given more rigid and hard film texture, while glycerol provides more elastic and flexible texture. Sorbitol give best performance at 2% where thickness 0.17 mm; tensile strength 41.60 MPa; yield strength 34.28 MPa; modulus of elasticity 7983.71 MPa; and maximum strain 29,8%. While, glycerol (2%) provides thickness 0.18 mm; tensile strength 35.72 MPa; yield strength 30.78 MPa; modulus of elasticity 9065.90 MPa; and maximum strain 14.4% for best performance. SEM and FTIR analysis applied to determine film surface morphology's characterization and determine the functional groups of the film materials. The addition of lime leaves extract as antimicrobial gives the growth inhibition activity against the Staphylococcus aureus bacteria.

Host-specific variation in infection by toxigenic fungi and contamination by mycotoxins in pearl millet and corn.

PubMed

Wilson, J P; Jurjevic, Z; Hanna, W W; Wilson, D M; Potter, T L; Coy, A E

2006-02-01

Pearl millet is widely consumed in regions of Africa and Asia, and is increasingly being grown as an alternative grain in drought-prone regions of the United States. Pearl millet and corn were grown in dryland conditions at Tifton, Georgia, USA and grains were compared for pre-harvest infection by potentially toxigenic fungi and contamination by mycotoxins. Corn hybrids Agripro 9909 and Pioneer 3146, and pearl millet Tifgrain 102 were grown in 2000 and 2001; pearl millet HGM 100 was included in the test in 2001. Hybrids were sown on multiple planting dates in each year to induce variation in flowering time. Host species differed in the frequency of isolation of potentially toxigenic fungal species in both years. Across years, corn hybrids were more prone to infection by Aspergillus flavus Link (maximum isolation frequency = 8.8%) and Fusarium moniliforme Sheldon sensu lato (maximum isolation frequency = 72.8%), with corresponding greater concentrations of aflatoxins (maximum concentration = 204.9 microg kg(-1)) and fumonisins (maximum concentration = 34,039 microg kg(-1)). Pearl millet was more prone to infection by F. semitectum Berk. & Ravenel (maximum isolation = 74.2%) and F. chlamydosporum Wollenweb & Reinking (maximum isolation = 33.0%), and contamination by moniliformin (maximum contamination = 92.1 microg kg(-1)). Beauvericin (maximum concentration = 414.6 microg kg(-1)) was present in both hosts. Planting date of corn affected aflatoxin and beauvericin contamination in 2000, and fumonisin concentration in 2001. The observed differences in mycotoxin contamination of the grains, which are likely due to host-specific differences in susceptibility to pre-harvest mycoflora, may affect food safety when the crops are grown under stress conditions.

Occurrence of fungicides and other pesticides in surface water, groundwater, and sediment from three targeted-use areas in the United States, 2009

USGS Publications Warehouse

Orlando, James L.; Smalling, Kelly L.; Reilly, Timothy J.; Boehlke, Adam; Meyer, Michael T.; Kuivila, Kathryn

2013-01-01

Surface-water, groundwater, and suspended- and bedsediment samples were collected in three targeted-use areas in the United States where potatoes were grown during 2009 and analyzed for an extensive suite of fungicides and other pesticides by gas chromatograph/mass spectrometry and liquid chromatography with tandem mass spectrometry. Fungicides were detected in all environmental matrices sampled during the study. The most frequently detected fungicides were azoxystrobin, boscalid, chlorothalonil, and pyraclostrobin. Other pesticides that were detected frequently included amino phosphonic acid (AMPA), atrazine, metolaclor, and the organochlorine insecticide p,p’-DDT and its degradates p,p’-DDD and p,p’-DDE. A greater number of pesticides were detected in surface water relative to the other environmental matrices sampled, and at least one pesticide was detected in 62 of the 63 surfacewater samples. The greatest numbers of pesticides and the maximum observed concentrations for most pesticides were measured in surface-water samples from Idaho. In eight surface- water samples (six from Idaho and two from Wisconsin), concentrations of bifenthrin, metolachlor, or malathion exceeded U.S. Environmental Protection Agency freshwater aquatic-life benchmarks for chronic toxicity to invertebrates. Thirteen pesticides, including seven fungicides, were detected in groundwater samples. Shallow groundwater samples collected beneath recently harvested potato fields contained more pesticides and had higher concentrations of pesticides than samples collected from other groundwater sources sampled during the study. Generally, pesticide concentrations were lower in groundwater samples than in surfacewater or sediment samples, with the exception of the fungicide boscalid, which was found to have its highest concentration in a shallow groundwater sample collected in Wisconsin. Thirteen pesticides, including four fungicides, were detected in suspended-sediment samples. The most frequently detected compounds were the fungicides boscalid, pyraclostrobin, and zoxamide, and the degradates p,p’-DDD and p,p’-DDE. Twenty pesticides, including six fungicides, were detected in bed-sediment samples. The most frequently detected compounds were pyraclostrobin, p,p’-DDT, p,p’-DDD, and p,p’-DDE.

Arsenic in midwestern glacial deposits? Occurrence and relation to selected hydrogeologic and geochemical factors

USGS Publications Warehouse

Thomas, Mary Ann

2003-01-01

Ground-water-quality data collected as part of 12 U.S. Geological Survey National Water-Quality Assessment studies during 1996-2001 were analyzed to (1) document arsenic occurrence in four types of gla-cial deposits that occur in large areas of the Midwest, (2) identify hydrogeologic or geochemical factors asso-ciated with elevated arsenic concentrations, and (3) search for clues as to arsenic source(s) or mechanism(s) of mobilization that could be useful for designing future studies. Arsenic and other water-quality constituents were sampled in 342 monitor and domestic wells in parts of Illinois Indiana Ohio Michigan and Wisconsin. Arsenic was detected (at a concentration >1 ?g/L) in one-third of the samples. The maximum concentration was 84 ?g/L, and the median was less than 1 ?g/L. Eight percent of samples had arsenic concentrations that exceeded the U.S. Environmental Protection Agency Maximum Contaminant Level (MCL) of 10?g/L. Samples were from four aquifer types?confined valley fill, unconfined valley fill, outwash plain, and till with sand lenses. Highest arsenic concentrations were found in reducing waters from valley-fill depos-its. In confined valley fill, all waters were reducing and old (recharged before 1953), and almost half of sam-ples had arsenic concentrations greater than the MCL. In unconfined valley fill, redox conditions and ages were varied, and elevated arsenic concentrations were sporadic. In both types of valley fill, elevated arsenic concentrations are linked to the underlying bedrock on the basis of spatial relations and geochemical correla-tions. In shallow (150 ft), all deep wells were from a distinctive aquifer type (confined valley fill). It is not known whether wells at similar depths in other aquifer types would produce waters with simi-larly high arsenic concentrations. Correlations of arsenic with fluoride, strontium, and barium suggest that arsenic might be related to epi-genetic (Mississippi Valley-type) sulfide deposits in Paleozoic bedrock. Arsenic is typically released from sulfides by oxidation, but in the current study, the highest arsenic concentrations in glacial deposits were detected in reducing waters. Therefore, a link between epigenetic sulfides and elevated arsenic concentrations in glacial deposits would probably require a multi-step process.

40 CFR 463.34 - New source performance standards.

Code of Federal Regulations, 2013 CFR

2013-07-01

... pollutant concentrations: Subpart C [Finishing water] Concentration used to calculate NSPS Pollutant or pollutant property Maximum for any 1 day (mg/l) Maximum for monthly average (mg/l) TSS 130 37 pH (1) (1) 1...

Effects of pH and sugar concentration in Zygosaccharomyces rouxii growth and time for spoilage in concentrated grape juice at isothermal and non-isothermal conditions.

PubMed

Rojo, M C; Arroyo López, F N; Lerena, M C; Mercado, L; Torres, A; Combina, M

2014-04-01

The effect of pH (1.7-3.2) and sugar concentration (64-68 °Brix) on the growth of Zygosaccharomyces rouxii MC9 using response surface methodology was studied. Experiments were carried out in concentrated grape juice inoculated with Z. rouxii at isothermal conditions (23 °C) for 60 days. pH was the variable with the highest effect on growth parameters (potential maximum growth rate and lag phase duration), although the effect of sugar concentration were also significant. In a second experiment, the time for spoilage by this microorganism in concentrated grape juice was evaluated at isothermal (23 °C) and non-isothermal conditions, in an effort to reproduce standard storage and overseas shipping temperature conditions, respectively. Results show that pH was again the environmental factor with the highest impact on delaying the spoilage of the product. Thereby, a pH value below 2.0 was enough to increase the shelf life of the product for more than 60 days in both isothermal and non-isothermal conditions. The information obtained in the present work could be used by producers and buyers to predict the growth and time for spoilage of Z. rouxii in concentrated grape juice. Copyright © 2013 Elsevier Ltd. All rights reserved.

Quality of ground water in the Columbia Basin, Washington, 1983

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turney, G.L.

1986-01-01

Groundwater from 188 sites in the Columbia Basin of central Washington was sampled and analyzed in 1983 for pH, specific conductance, and concentrations of fecal coliform bacteria, major dissolved ions, and dissolved iron, manganese, and nitrate. Twenty of the samples were also analyzed for concentrations of dissolved trace metals including aluminum, arsenic, barium, cadmium, chromium, copper, lead, mercury, selenium, silver, and zinc. The predominant water types were sodium bicarbonate and calcium bicarbonate. The sodium bicarbonate water samples had higher pH, fluoride, and sodium:adsorption ratio values than samples with other water types. Most trace metal concentrations were also < 10 ug/Lmore » except for barium and zinc, which had maximum concentrations of 170 and 600 ug/L, respectively. Nitrate concentrations were < 1.0 mg/L in water from more than half the wells sampled. US EPA (Environmental Protection Agency) drinking water regulations were exceeded in several samples, most commonly involving pH and concentrations of fluoride, nitrate, and dissolved solids in samples from Adams and Grant Counties. Generally, the historical data lead to similar conclusions about the quality of groundwater in the Columbia Basin region. However, historical samples had higher dissolved solids concentrations in Douglas County. Historical samples also included fewer sodium bicarbonate type waters in the region as a whole than the 1983 samples. 24 refs., 2 figs., 4 tabs.« less

Bathymetric mapping, sediment quality, and water quality of Lake Delhi, Iowa, 2001-02

USGS Publications Warehouse

Schnoebelen, Douglas J.; McVay, Jason C.; Barnes, Kimberlee K.; Becher, Kent D.

2003-01-01

Water-quality sampling results indicate areas affected by elevated nutrient and bacteria concentrations in the lake and tributary streams. The tributary streams had the highest median nitrate concentrations (12.1 milligrams per liter) when compared to median nitrate concentrations in the lake (8.7 milligrams per liter) or the Maquoketa River (10.5 milligrams per liter). The maximum nitrate concentrations detected for Maquoketa River, lake, and tributary sites were 13.5, 13.5, and 18.6 milligrams per liter, respectively. Nitrate concentrations in the late summer decreased from 2 Bathymetric Mapping, Sediment Quality, and Water Quality of Lake Delhi, Iowa, 2001–02 the upstream (7.8 milligrams per liter) to the downstream (5.0 milligrams per liter) one-third of Lake Delhi and most likely were the result of uptake of nitrate by algae and aquatic biota in the lake. Median concentrations of total coliform and E. coli bacteria for the lake sites were 450 and 17 colonies per 100 milliliters of sample, respectively. The U.S. Environmental Protection Agency criteria for full body contact (swimming or bathing) are 200 colonies per 100 milliliters for fecal bacteria and 126 colonies per 100 milliliters for E. coli bacteria. The highest bacteria concentrations in the lake occurred after a rain and were 25,000 colonies per 100 milliliters total coliform and 1,900 colonies per 100 milliliters E. coli.

Environmental estrogens inhibit mRNA and functional expression of growth hormone receptors as well as growth hormone signaling pathways in vitro in rainbow trout (Oncorhynchus mykiss).

PubMed

Hanson, Andrea M; Ickstadt, Alicia T; Marquart, Dillon J; Kittilson, Jeffrey D; Sheridan, Mark A

2017-05-15

Fish in aquatic habitats are exposed to increasing concentrations and types of environmental contaminants, including environmental estrogens (EE). While there is growing evidence to support the observation that endocrine-disrupting compounds (EDCs) possess growth-inhibiting effects, the mechanisms by which these physiological effects occur are poorly understood. In this study, we examined the direct effects of EE, specifically 17β-estradiol (E2), β-sitosterol (βS), and 4-n-nonylphenol (NP), on GH sensitivity as assessed by mRNA expression and functional expression of growth hormone receptor in hepatocytes, gill filaments, and muscle in rainbow trout (Oncorhynchus mykiss). Additionally, we examined the effects of EE on signaling cascades related to growth hormone signal transduction (i.e., JAK-STAT, MAPK, and PI3K-Akt). Environmental estrogens directly suppressed the expression of GHRs in a tissue- and compound-related manner. The potency and efficacy varied with EE; effects were most pronounced with E2 in liver. EE treatment deactivated the JAK-STAT, MAPK, and PI3K-Akt pathways in liver a time-, EE- and concentration-dependent manner. Generally, E2 and NP were most effective in deactivating pathway elements; maximum suppression for each pathway was rapid, typically occurring at 10-30min. The observed effects occurred via an estrogen-dependent pathway, as indicated by treatment with an ER antagonist, ICI 182,780. These findings suggest that EEs suppress growth by reducing GH sensitivity in terms of reduced GHR synthesis and reduced surface GHR expression and by repressing GH signaling pathways. Copyright © 2016. Published by Elsevier Inc.

Seasonal occurrence, removal, mass loading and environmental risk assessment of 55 pharmaceuticals and personal care products in a municipal wastewater treatment plant in Central Greece.

PubMed

Papageorgiou, Myrsini; Kosma, Christina; Lambropoulou, Dimitra

2016-02-01

A comprehensive study, which contains the seasonal occurrence, removal, mass loading and environmental risk assessment of 55 multi-class pharmaceuticals and personal care products (PPCPs), took place in the wastewater treatment plant (WWTP) of Volos, Greece. A one year monitoring study was performed and the samples were collected from the influent and the effluent of the WWTP. Solid phase extraction was used for the pre-concentration of the samples followed by an LC-DAD-ESI/MS analysis. Positive samples were further confirmed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The maximum concentrations of the PPCPs varied between 21 ng/L and 15,320 ng/L in the influents and between 18 ng/L and 9965 ng/L in the effluents. The most commonly detected PPCPs were the diuretic furosemide, the beta-blockers atenolol and metoprolol, the analgesics paracetamol, nimesulide, salicylic acid and diclofenac and the psychomotor stimulant caffeine. The removal efficiencies ranged between negative and high removal rates, demonstrating that the WWTP is not able to efficiently remove the complex mixture of PPCPs. The estimated mass loads ranged between 5.1 and 3513 mg/day/1000 inhabitants for WWTP influent and between 4.1 to 2141 mg/day/1000 inhabitants for WWTP effluent. Finally, environmental risk assessment has been regarded a necessary part of the general research. According to the results produced from the calculation of the risk quotient on three trophic levels, the anti-inflammatory drug diclofenac and the antibiotics, trimethoprim and ciprofloxacin, identified to be of high potential environmental risk for acute toxicity, while diclofenac also for chronic toxicity. Copyright © 2015 Elsevier B.V. All rights reserved.

40 CFR 141.13 - Maximum contaminant levels for turbidity.

Code of Federal Regulations, 2010 CFR

2010-07-01

... turbidity. 141.13 Section 141.13 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Levels § 141.13... part. The maximum contaminant levels for turbidity in drinking water, measured at a representative...

2016 Annual Reuse Report for the Idaho National Laboratory Site’s Advanced Test Reactor Complex Cold Waste Ponds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lewis, Michael George

This report describes conditions and information, as required by the state of Idaho, Department of Environmental Quality Reuse Permit I-161-02, for the Advanced Test Reactor Complex Cold Waste Ponds located at Idaho National Laboratory from November 1, 2015–October 31, 2016. The effective date of Reuse Permit I-161-02 is November 20, 2014 with an expiration date of November 19, 2019. This report contains the following information: • Facility and system description • Permit required effluent monitoring data and loading rates • Permit required groundwater monitoring data • Status of compliance activities • Issues • Discussion of the facility’s environmental impacts. Duringmore » the 2016 permit year, 180.99 million gallons of wastewater were discharged to the Cold Waste Ponds. This is well below the maximum annual permit limit of 375 million gallons. As shown by the groundwater sampling data, sulfate and total dissolved solids concentrations are highest in well USGS-065, which is the closest downgradient well to the Cold Waste Ponds. Sulfate and total dissolved solids concentrations decrease rapidly as the distance downgradient from the Cold Waste Ponds increases. Although concentrations of sulfate and total dissolved solids are significantly higher in well USGS-065 than in the other monitoring wells, both parameters remained below the Ground Water Quality Rule Secondary Constituent Standards in well USGS-065. The facility was in compliance with the Reuse Permit during the 2016 permit year.« less

Heavy Metals Technogenic Pollution of Plough Lands Arable Layer in the Chelyabinsk Region

NASA Astrophysics Data System (ADS)

Mantorova, G. F.

2017-11-01

Environmental protection and rational use of natural resources in agriculture are the main directions of this scientific research. Contamination is caused by the substances of chemical, radiation and biological origin above the maximum permissible concentration (MPC). The main source of soil contamination in the arable land, hayfields and pastures is the waste of livestock complexes, agricultural chemicals (fertilizers, pesticides), motor vehicle exhausts, industrial emissions, sewage from settlements, etc. The ecological state of the soil and vegetation cover is largely determined by agricultural activities. The agricultural production technology complicating is accompanied by increase in the degree of environmental risk, especially in the chemicalization of agriculture. Pollution also enters the soil with atmospheric precipitation, surface waste. They are also introduced into the soil layer by soil and groundwater. The most dangerous for human health is considered to be contamination with heavy metals (HM)-lead, mercury and cadmium. However, the concentration of the rest elements is no less harmful. The paradox of heavy metals is that in certain quantities they are necessary to ensure the normal life of plants and organisms but their excess can lead to serious diseases and even death. A nutritional cycle causes harmful compounds to enter the human body and often cause great harm to health. The present work reveals the results of the research of a long-term experience on accumulation and distribution of heavy metals on the arable layer profile depending on the concentration in humus soil and the system of ground processing.

Concentrations of nitrate in drinking water in the lower Yakima River Basin, Groundwater Management Area, Yakima County, Washington, 2017

USGS Publications Warehouse

Huffman, Raegan L.

2018-05-29

The U.S. Geological Survey, in cooperation with the lower Yakima River Basin Groundwater Management Area (GWMA) group, conducted an intensive groundwater sampling collection effort of collecting nitrate concentration data in drinking water to provide a baseline for future nitrate assessments within the GWMA. About every 6 weeks from April through December 2017, a total of 1,059 samples were collected from 156 wells and 24 surface-water drains. The domestic wells were selected based on known location, completion depth, ability to collect a sample prior to treatment on filtration, and distribution across the GWMA. The drains were pre-selected by the GWMA group, and further assessed based on ability to access sites and obtain a representative sample. More than 20 percent of samples from the domestic wells and 12.8 percent of drain samples had nitrate concentrations that exceeded the maximum contaminant level (MCL) of 10 milligrams per liter established by the U.S. Environmental Protection Agency. At least one nitrate concentration above the MCL was detected in 26 percent of wells and 33 percent of drains sampled. Nitrate was not detected in 13 percent of all samples collected.

Water supply implications of herbicide sampling: Hydrologic conditions may affect concentrations of organonitrogen herbicides and may be important considerations in complying with drinking water regulations

USGS Publications Warehouse

Stamer, J.K.

1996-01-01

The temporal distribution of the herbicides alachlor, atrazine, cyanazine, and metolachlor was documented from September 1991 through August 1992 in the Platte River at Louisville, Neb., the drainage of the Central Nebraska Basins. Lincoln, Ornaha, and other municipalities withdraw groundwater for public supplies from the adjacent alluvium, which is hydraulically connected to the Platte River. Data were collected, in part, to provide information to managers, planners, and public utilities on the likelihood of water supplies being adversely affected by these herbicides. Three computational procedures - monthly means, monthly subsampling, and quarterly subsampling - were used to calculate annual mean herbicide concentrations. When the sampling was conducted quarterly rather than monthly, alachlor and atrazine concentrations were more likely to exceed their respective maximum contaminant levels (MCLs) of 2.0 μg/L and 3.0 μg/L, and cyanazine concentrations were more likely to exceed the health advisory level of 1.0 μg/L. The US Environmental Protection Agency has established a tentative MCL of 1.0 μg/L for cyanazine; data indicate that cyanazine is likely to exceed this level under most hydrologic conditions.

Maximum power point tracking algorithm based on sliding mode and fuzzy logic for photovoltaic sources under variable environmental conditions

NASA Astrophysics Data System (ADS)

Atik, L.; Petit, P.; Sawicki, J. P.; Ternifi, Z. T.; Bachir, G.; Della, M.; Aillerie, M.

2017-02-01

Solar panels have a nonlinear voltage-current characteristic, with a distinct maximum power point (MPP), which depends on the environmental factors, such as temperature and irradiation. In order to continuously harvest maximum power from the solar panels, they have to operate at their MPP despite the inevitable changes in the environment. Various methods for maximum power point tracking (MPPT) were developed and finally implemented in solar power electronic controllers to increase the efficiency in the electricity production originate from renewables. In this paper we compare using Matlab tools Simulink, two different MPP tracking methods, which are, fuzzy logic control (FL) and sliding mode control (SMC), considering their efficiency in solar energy production.

Comparison of the Force-, Velocity- and Power-Time Curves Between the Concentric-Only and Eccentric-Concentric Bench Press Exercises.

PubMed

Pérez-Castilla, Alejandro; Comfort, Paul; McMahon, John J; Pestaña-Melero, Francisco Luis; García-Ramos, Amador

2018-01-17

The aim of this study was to compare the temporal and mechanical variables between the concentric-only and eccentric-concentric bench press (BP) variants. Twenty-one men (age: 22.0±4.2 years, body mass: 73.4±7.7 kg, height: 177.2±8.0 cm; one-repetition maximum [1RM]: 1.12±0.12 kg⋅kg) were evaluated during the concentric-only and eccentric-concentric BP variants using 80% 1RM. Temporal (concentric phase duration, propulsive phase duration, and time to reach the maximum values of force, velocity, and power) and mechanical variables (force, velocity, and power), determined using a linear velocity transducer, were compared between both BP variants. All temporal variables were significantly lower during the eccentric-concentric BP compared to the concentric-only BP (P < 0.05; effect size [ES] range: 0.80-2.52). Maximum force as well as the mean values of velocity and power were significantly higher for the eccentric-concentric BP compared to the concentric-only BP (all P < 0.001; ES range: 2.87-3.58). However, trivial to small differences between both BP variants were observed for mean force (ES: 0.00-0.36) as well as for maximum velocity (ES: 0.40) and power (ES: 0.41). The stretch-shortening cycle (i.e., eccentric-concentric BP) mainly enhanced force production at the early portion of the concentric phase, but this potentiation effect gradually reduced over the latter part of the movement. Finally, force was higher for the concentric-only BP during 49% of the concentric phase duration. These results suggest that both BP variants should be included during resistance training programs in order to optimize force output at different points of the concentric phase.

[The epidemiological validation of the MPEL for grain dust in the atmosphere].

PubMed

Pinigin, M A; Cherepov, E M; Safiulin, A A; Petrova, I V; Mukhambetova, L Kh; Osipova, E M; Veselov, A P

1998-01-01

The use of calculating and gravimetric methods for examining the grain dust pollution of the ambient air at the site of an elevator determined the maximum single, mean daily, and mean annual concentrations at different distances from the source of dust emission. The mean ratio of these concentrations was 12.1:4.3:1, respectively. The calculated concentration-effect and concentration-time relationships provided evidence for the maximum single, mean daily, and mean annual allowable concentrations for grain dust in the ambient air.

Line-averaging measurement methods to estimate the gap in the CO2 balance closure - possibilities, challenges, and uncertainties

NASA Astrophysics Data System (ADS)

Ziemann, Astrid; Starke, Manuela; Schütze, Claudia

2017-11-01

An imbalance of surface energy fluxes using the eddy covariance (EC) method is observed in global measurement networks although all necessary corrections and conversions are applied to the raw data. Mainly during nighttime, advection can occur, resulting in a closing gap that consequently should also affect the CO2 balances. There is the crucial need for representative concentration and wind data to measure advective fluxes. Ground-based remote sensing techniques are an ideal tool as they provide the spatially representative CO2 concentration together with wind components within the same voxel structure. For this purpose, the presented SQuAd (Spatially resolved Quantification of the Advection influence on the balance closure of greenhouse gases) approach applies an integrated method combination of acoustic and optical remote sensing. The innovative combination of acoustic travel-time tomography (A-TOM) and open-path Fourier-transform infrared spectroscopy (OP-FTIR) will enable an upscaling and enhancement of EC measurements. OP-FTIR instrumentation offers the significant advantage of real-time simultaneous measurements of line-averaged concentrations for CO2 and other greenhouse gases (GHGs). A-TOM is a scalable method to remotely resolve 3-D wind and temperature fields. The paper will give an overview about the proposed SQuAd approach and first results of experimental tests at the FLUXNET site Grillenburg in Germany. Preliminary results of the comprehensive experiments reveal a mean nighttime horizontal advection of CO2 of about 10 µmol m-2 s-1 estimated by the spatially integrating and representative SQuAd method. Additionally, uncertainties in determining CO2 concentrations using passive OP-FTIR and wind speed applying A-TOM are systematically quantified. The maximum uncertainty for CO2 concentration was estimated due to environmental parameters, instrumental characteristics, and retrieval procedure with a total amount of approximately 30 % for a single measurement. Instantaneous wind components can be derived with a maximum uncertainty of 0.3 m s-1 depending on sampling, signal analysis, and environmental influences on sound propagation. Averaging over a period of 30 min, the standard error of the mean values can be decreased by a factor of at least 0.5 for OP-FTIR and 0.1 for A-TOM depending on the required spatial resolution. The presented validation of the joint application of the two independent, nonintrusive methods is in the focus of attention concerning their ability to quantify advective fluxes.

Donor impurity incorporation during layer growth of Zn II-VI semiconductors

NASA Astrophysics Data System (ADS)

Barlow, D. A.

2017-12-01

The maximum halogen donor concentration in Zn II-VI semiconductors during layer growth is studied using a standard model from statistical mechanics. Here the driving force for incorporation is an increase in entropy upon mixing of the donor impurity into the available anion lattice sites in the host binary. A formation energy opposes this increase and thus equilibrium is attained at some maximum concentration. Considering the halogen donor impurities within the Zn II-VI binary semiconductors ZnO, ZnS, ZnSe and ZnTe, a heat of reaction obtained from reported diatomic bond strengths is shown to be directly proportional to the log of maximum donor concentration. The formation energy can then be estimated and an expression for maximum donor concentration derived. Values for the maximum donor concentration with each of the halogen impurities, within the Zn II-VI compounds, are computed. This model predicts that the halogens will serve as electron donors in these compounds in order of increasing effectiveness as: F, Br, I, Cl. Finally, this result is taken to be equivalent to an alternative model where donor concentration depends upon impurity diffusion and the conduction band energy shift due to a depletion region at the growing crystal's surface. From this, we are able to estimate the diffusion activation energy for each of the impurities mentioned above. Comparisons are made with reported values and relevant conclusions presented.

Production of carbonate sediments by a unicellular green alga

USGS Publications Warehouse

Yates, K.K.; Robbins, L.L.

1998-01-01

This study investigates the ability of the unicellular green alga Natmochloris atoimis to precipitate CaCO3, quantifies mineral precipitation rates, estimates sediment production in a N. atomiis bloom, and discusses the implications of microbial calcification for carbonate sediment deposition. A series of N. atomus cultures, isolated from Lake Reeve, Australia, were incubated at various pH and calcium concentrations to determine environmental parameters for calcification. Rates of calcification were calculated from initial and postincubation alkalinity, pH, and calcium measurements. Replicate experiments and controls consisting of non-calcifying cultures, uninoculated media, and dead cell cultures were performed using environmental culture parameters determined in series cultures. Average calcification rates from replicate experiments were used to predict daily sediment production rates in a small bloom of N. atomus. N. atomus precipitates 0.138 g/L of calcite in approximately 4 h when incubated at pH 8.5, 14.24 mM calcium concentration, 33 ??C, 100 ??E/m2/s light intensity, and a cell population density of 107 cells/mL. Assuming continuous precipitation, this corresponds to a maximum estimated sediment production rate of 1.6 ?? 106 kg of CaCO3, per 12 h day in a single bloom of 3.2 ?? 109 L. Our results suggest that microbial calcification contributes significantly to the carbonate sediment budget.

Characterization of soil heavy metal contamination and potential health risk in metropolitan region of northern China.

PubMed

Qiao, Min; Cai, Chao; Huang, Yizong; Liu, Yunxia; Lin, Aijun; Zheng, Yuanming

2011-01-01

Soil in metropolitan region suffers great contamination risk due to the rapid urbanization especially in developing countries. Beijing and Tianjin, together with their surrounding regions, form a mega-metropolitan region in northern China. To assess the soil environmental quality, a total of 458 surface soil samples were collected from this area. Concentrations of Cr, Cu, Pb, Zn, As, Cd, and Hg were analyzed and compared to the Chinese environmental quality standards for soil. Multivariate analysis was carried out to identify the possible sources and Geographic Information Systems techniques were applied to visualize the spatial data. It was found that the primary inputs of As were due to pedogenic sources, whereas Hg was mainly of anthropogenic source. Other elements including Cr, Cu, Pb, Zn, and Cd were from both lithogenic and anthropogenic origins. Health risk assessment based on the maximum heavy metal concentration indicated that As derived from sewage irrigation area can result in carcinogenic lifetime risk due to ingestion and/or dermal contact of soil. The potential non-carcinogenic risk for children is significant for Pb and the cumulative effect of multiple metals is of concern for children in the vicinity of mining site. The results increased our knowledge for understanding natural and anthropogenic sources as well as health risk for metals in metropolitan soil.

Heavy metals accumulation by Athyrium yokoscence in a mine area, Southwestern Japan

NASA Astrophysics Data System (ADS)

Prasetia, Hendra; Sakakibara, Masayuki; Takehara, Akinari; Sueoka, Yuri

2017-06-01

Mine dumps pose environmental problems worldwide. Phytoremediation is a remediation technique that uses plants to clean polluted environments. Athyrium yokoscence, a fern of the family Aspidiaceae, is a well-known Cd hyperaccumulator used in phytoremediation. The aim of the current study is to determine the extent of heavy metal absorption by A. yokoscence and evaluate its potential use in phytoremediation. The shoots, stems, and roots of A. yokoscence were analysed by inductively coupled plasma-optical emission spectrometry (ICP-OES) to determine the concentrations of Cd, As, Pb, Cu, and Zn, yielding maximum concentrations in the shoots of 851, 215, 192, 60.9, and 769 mg/kg-DW, in the stems of 481, 140, 881, 28.9, and 495 mg/kg-DW, and in the roots of 1210, 1868, 6473, 2484, and 5446 mg/kg-DW, respectively. The results indicate that A. yokoscence is a hyperaccumulator of Cd and can be used for the translocation of As, Pb, Cu, and Zn within the shoot tissue. The roots translocate heavy metals through the stems and they finally reside within the shoot tissue. The results suggest that A. yokoscence has considerable potential use as an environmental assessment tool for Cd, As, Pb, Cu, and Zn, and in helping to remediate mine dumps.

Leaf gas exchange of Andropogon gerardii Vitman, Panicum virgatum L., and Sorghastrum nutans (L.) Nash in a tallgrass prairie

NASA Technical Reports Server (NTRS)

Polley, H. W.; Norman, J. M.; Arkebauer, T. J.; Walter-Shea, E. A.; Greegor, D. H., Jr.; Bramer, B.

1992-01-01

Net CO2 assimilation as a function of internal CO2 and stomatal conductance to water vapor were measured on blades of the C4 grasses Andropogon gerardii Vitman, Panicum virgatrum L., and Sorghastrum nutans (L.) Nash in northeast Kansas over two growing seasons to determine the comparative physiological responses of these dominant grasses of the tallgrass prairie to environmental variables. The response of dark respiration to temperature and of net assimilation to CO2 concentration and absorbed quantum flux differed little among species. A. gerardii had lower potential photosynthetic rates at internal CO2 concentrations below saturation than P. virgatum and S. nutans, but net assimilation under ambient conditions was similar in the three species. Net assimilation and both the initial slope of assimilation versus internal CO2 curves and the maximum potential assimilation rate decreased as leaf water potential declined in blades of A. gerardii and S. nutans. Changes in assimilation capacity were paralleled by changes in stomatal conductance that were similar in all three species. The strong correlations among processes regulating leaf CO2 assimilation and transpiration in A. gerardii, P. virgatum, and S. nutans suggest that the processes are tightly and similarly coupled in these grasses over a wide range of environmental conditions encountered in the tallgrass prairie.

Multilevel ecotoxicity assessment of environmentally relevant bisphenol A concentrations using the soil invertebrate Eisenia fetida.

PubMed

Babić, Sanja; Barišić, Josip; Bielen, Ana; Bošnjak, Ivana; Sauerborn Klobučar, Roberta; Ujević, Ivana; Strunjak-Perović, Ivančica; Topić Popović, Natalija; Čož-Rakovac, Rozelindra

2016-11-15

Bisphenol A (BPA) presents a serious threat to soil ecosystems, yet its effects on soil-inhabiting organisms are mostly unexplored. Therefore, the impact of environmentally relevant BPA concentrations on a terrestrial model organism, the earthworm Eisenia fetida, was assessed. Animals were cutaneously exposed to 100nM and 10μM BPA up to 10days (10-d). Next, a battery of biomarkers was used for ecotoxicological evaluation on a cellular, tissue and behavioural level. HPLC analysis showed that after a 10-d exposure, BPA accumulation reached a maximum of 2.50μg BPA per g of wet tissue weight. On the cellular level, up to 3-d BPA exposure caused increased lipid oxidation indicating oxidative stress. Histopathological assessment of cell wall and ovaries after 7- and 10-d BPA exposure showed multiple abnormalities, i.e. hyperplasia of epidermis, increased body wall thickness and ovarian atrophy. Detection of these changes was facilitated by a newly proposed semi-quantitative scoring system. Finally, behavioural changes were detected after only 3days of exposure to 100nM BPA. Altogether, the presented multilevel toxicity evaluation indicates high sensitivity of earthworms to low BPA doses. Copyright © 2016 Elsevier B.V. All rights reserved.

Enzymatic saccharification and fermentation of cellulosic date palm wastes to glucose and lactic acid.

PubMed

Alrumman, Sulaiman A

2016-01-01

The bioconversion of cellulosic wastes into high-value bio-products by saccharification and fermentation processes is an important step that can reduce the environmental pollution caused by agricultural wastes. In this study, enzymatic saccharification of treated and untreated date palm cellulosic wastes by the cellulases from Geobacillus stearothermophilus was optimized. The alkaline pre-treatment of the date palm wastes was found to be effective in increasing the saccharification percentage. The maximum rate of saccharification was found at a substrate concentration of 4% and enzyme concentration of 30 FPU/g of substrate. The optimum pH and temperature for the bioconversions were 5.0 and 50°C, respectively, after 24h of incubation, with a yield of 31.56mg/mL of glucose at a saccharification degree of 71.03%. The saccharification was increased to 94.88% by removal of the hydrolysate after 24h by using a two-step hydrolysis. Significant lactic acid production (27.8mg/mL) was obtained by separate saccharification and fermentation after 72h of incubation. The results indicate that production of fermentable sugar and lactic acid is feasible and may reduce environmental pollution by using date palm wastes as a cheap substrate. Copyright © 2015 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Radiation absorption and optimization of solar photocatalytic reactors for environmental applications.

PubMed

Colina-Márquez, Jose; Machuca-Martínez, Fiderman; Li Puma, Gianluca

2010-07-01

This study provides a systematic and quantitative approach to the analysis and optimization of solar photocatalytic reactors utilized in environmental applications such as pollutant remediation and conversion of biomass (waste) to hydrogen. Ray tracing technique was coupled with the six-flux absorption scattering model (SFM) to analyze the complex radiation field in solar compound parabolic collectors (CPC) and tubular photoreactors. The absorption of solar radiation represented by the spatial distribution of the local volumetric rate of photon absorption (LVRPA) depends strongly on catalyst loading and geometry. The total radiation absorbed in the reactors, the volumetric rate of absorption (VRPA), was analyzed as a function of the optical properties (scattering albedo) of the photocatalyst. The VRPA reached maxima at specific catalyst concentrations in close agreement with literature experimental studies. The CPC has on average 70% higher photon absorption efficiency than a tubular reactor and requires 39% less catalyst to operate under optimum conditions. The "apparent optical thickness" is proposed as a new dimensionless parameter for optimization of CPC and tubular reactors. It removes the dependence of the optimum catalyst concentration on tube diameter and photocatalyst scattering albedo. For titanium dioxide (TiO(2)) Degussa P25, maximum photon absorption occurs at apparent optical thicknesses of 7.78 for CPC and 12.97 for tubular reactors.

Enzymatic saccharification and fermentation of cellulosic date palm wastes to glucose and lactic acid

PubMed Central

Alrumman, Sulaiman A.

2016-01-01

The bioconversion of cellulosic wastes into high-value bio-products by saccharification and fermentation processes is an important step that can reduce the environmental pollution caused by agricultural wastes. In this study, enzymatic saccharification of treated and untreated date palm cellulosic wastes by the cellulases from Geobacillus stearothermophilus was optimized. The alkaline pre-treatment of the date palm wastes was found to be effective in increasing the saccharification percentage. The maximum rate of saccharification was found at a substrate concentration of 4% and enzyme concentration of 30 FPU/g of substrate. The optimum pH and temperature for the bioconversions were 5.0 and 50 °C, respectively, after 24 h of incubation, with a yield of 31.56 mg/mL of glucose at a saccharification degree of 71.03%. The saccharification was increased to 94.88% by removal of the hydrolysate after 24 h by using a two-step hydrolysis. Significant lactic acid production (27.8 mg/mL) was obtained by separate saccharification and fermentation after 72 h of incubation. The results indicate that production of fermentable sugar and lactic acid is feasible and may reduce environmental pollution by using date palm wastes as a cheap substrate. PMID:26887233

Dimensionless Analysis Applied to Bacterial Chemotaxis towards NAPL Contaminants

NASA Astrophysics Data System (ADS)

Wang, X.; GAO, B.; Zhong, W.; Kihaule, K. S.; Ford, R.

2017-12-01

The use of chemotactic bacteria in bioremediation may improve the efficiency and decrease the cost of restoration, which means it has the potential to address environmental problems caused by oil spills. However, most previous studies were focused at the laboratory-scale and there lacks a formalism that can use these laboratory-scale results as input to evaluate the relative importance of chemotaxis at the field scale. In this study, a dimensionless equation is formulated to solve this problem. First, the main influential factors were extracted based on previous researches in environmental bioremediation and then five sets of dimensionless numbers were obtained according to Buckingham theory. After collecting basic parameter values and supplementary calculations to determine the concentration gradient of the chemoattractant, all dimensionless numbers were calculated and categorized into two types, those that were sensitive to chemotaxis or those to groundwater velocity. The bacteria ratio (BR), defined as the ratio of maximum bacteria concentration to its original value, was correlated with a combination of dimensionless numbers to yield, BR=cP1-0.085P20.329P30.1P4-0.098. For a bacterial ratio greater than one, the bioremediation strategy based on chemotaxis is expected to be effective, and chemotactic bacteria are expected to accumulate around NAPL contaminant sources efficiently.

Distribution and assessment of residual mercury from gold mining in Changbai Mountain Range Northeastern China

NASA Astrophysics Data System (ADS)

Meng, D.; Wang, N.; Ai, J. C.; Zhang, G.; Liu, X. J.

2016-08-01

Gold mining was first initiated in Jiapigou area, Huadian city of Northeastern China about 200 years ago. Before 2006, the mercury amalgamation technique was used in the gold mining process, which led to severe mercury contamination. The aim of this paper is to explore the influences of residual mercury on the environment media after eliminating the amalgamation process to extract gold. The mercury concentrations of the atmosphere and the soil were determined in autumn of 2011 and spring of 2012. The soil environmental quality was assessed by the index of geoaccumulation. The results indicated that the maximum value of gaseous mercury was 25ng•m-3 in autumn and 19.5ng•m-3 in spring; the maximum value of mercury in the soil was 2.06mg•kg-1 in autumn and 2.51mg•kg-1in spring. It can be seen that the peak concentrations of the gaseous mercury happened at the gold mine area and tailings, while the peak mercury concentrations in the soil were located at the places near the mining sites and the residential area in the valley. Furthermore, the regression analysis of the total mercury contents between the atmosphere and the soil showed a significant correlation, which indicated that there was certain circulation of the mercury between the regional atmosphere and soil. In general, after the elimination of the amalgamation technique in gold extraction, the distance to the mercury source, the special conditions of hilly weather and landforms and the mercury exchange flux are the main factors of mercury contamination.

Impact of aircraft emissions on air quality in the vicinity of airports. Volume II. An updated model assessment of aircraft generated air pollution at LAX, JFK, and ORD. Final report Jan 1978-Jul 1980

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamartino, R.J.; Smith, D.G.; Bremer, S.A.

1980-07-01

This report documents the results of the Federal Aviation Administration (FAA)/Environmental Protection Agency (EPA) air quality study which has been conducted to assess the impact of aircraft emissions of carbon monoxide (CO), hydrocarbons (HC), and oxides of nitrogen (NOx) in the vicinity of airports. This assessment includes the results of recent modeling and monitoring efforts at Washington National (DCA), Los Angeles International (LAX), Dulles International (IAD), and Lakeland, Florida airports and an updated modeling of aircraft generated pollution at LAX, John F. Kennedy (JFK) and Chicago O'Hare (ORD) airports. The Airport Vicinity Air Pollution (AVAP) model which was designed formore » use at civil airports was used in this assessment. In addition the results of the application of the military version of the AVAP model the Air Quality Assessment Model (AQAM), are summarized. Both the results of the pollution monitoring analyses in Volume I and the modeling studies in Volume II suggest that: maximum hourly average CO concentrations from aircraft are unlikely to exceed 5 parts per million (ppm) in areas of public exposure and are thus small in comparison to the National Ambient Air Quality Standard of 35 ppm; maximum hourly HC concentrations from aircraft can exceed 0.25 ppm over an area several times the size of the airport; and annual average NO2 concentrations from aircraft are estimated to contribute only 10 to 20 percent of the NAAQS limit level.« less

Safety of the molluscicide Zequanox (R) to nontarget macroinvertebrates Gammarus lacustris (Amphipoda: Gammaridae) and Hexagenia spp. (Ephemeroptera: Ephemeridae)

USGS Publications Warehouse

Waller, Diane L.; Luoma, James A.; Erickson, Richard A.

2016-01-01

Zequanox® is a commercial formulation of the killed bacterium, Pseudomonas fluorescens (strain CL145A), that was developed to control dreissenid mussels. In 2014, Zequanox became the second product registered by the United States Environmental Protection Agency (USEPA) for use in open water environments as a molluscicide. Previous nontarget studies demonstrated the safety and selectivity of P. fluorescens CL154A, but the database on the toxicity of the formulation (Zequanox) is limited for macroinvertebrate taxa and exposure conditions. We evaluated the safety of Zequanox to the amphipod Gammarus lacustris lacustris, and nymphs of the burrowing mayfly, Hexagenia spp. at the maximum approved concentration (100 mg/L active ingredient, A.I.) and exposure duration (8 h). Survival of animals was assessed after 8 h of exposure and again at 24 and 96 h post-exposure. Histopathology of the digestive tract of control and treated animals was compared at 96 h post-exposure. The results showed no significant effect of Zequanox on survival of either species. Survival of G. lacustris exceeded 85% in all concentrations at all three sampling time points. Survival of Hexagenia spp. ranged from 71% (control) to 91% at 8 h, 89–93% at 24 h post-exposure, and 70–73% at 96 h post-exposure across all treatments. We saw no evidence of pathology in the visceral organs of treated animals. Our results indicate that application of Zequanox at the maximum approved concentration and exposure duration did not cause significant mortality or treatment-related histopathological changes to G. lacustris and Hexagenia spp.

Food safety aspects of primary environmental contaminants in the edible tissues of roe deer (Capreolus capreolus).

PubMed

Lehel, József; Zwillinger, Dóra; Bartha, András; Lányi, Katalin; Laczay, Péter

2017-11-01

The muscle, liver, kidney and fat samples of 20 roe deer of both sexes originating from a hunting area in central Hungary were investigated for the presence of heavy metals such as As, Cd, Hg and Pb, and their contents were evaluated for possible health risk to consumers. Both As and Hg were found at a level below the limit of detection (< 0.5 mg/kg wet weight) in all samples. The median of the measured Cd concentrations was significantly higher in both the kidney and the liver (p = 0.0011) of bucks than of does. In bucks, Cd levels exceeded the respective maximum limits laid down in the European legislation in four kidney and three muscle samples, whereas in does, the measured concentrations were below the respective limits in all samples. The detected amounts of Pb exceeded the maximum limits in the kidney of one buck and eight does, in the liver of two bucks and six does, in the muscle of six bucks and nine does, whereas in all fat tissues of both bucks and does. The concentration of Pb (p = 0.02) was significantly greater in the kidney of does compared to roebucks. Based on data obtained from the present study, the consumption of organs and tissues of the investigated roe deer could be objectionable from food-toxicological point of view and may pose risk to the high consumers of wild game due to their cadmium and lead contents.

Event-driven time-optimal control for a class of discontinuous bioreactors.

PubMed

Moreno, Jaime A; Betancur, Manuel J; Buitrón, Germán; Moreno-Andrade, Iván

2006-07-05

Discontinuous bioreactors may be further optimized for processing inhibitory substrates using a convenient fed-batch mode. To do so the filling rate must be controlled in such a way as to push the reaction rate to its maximum value, by increasing the substrate concentration just up to the point where inhibition begins. However, an exact optimal controller requires measuring several variables (e.g., substrate concentrations in the feed and in the tank) and also good model knowledge (e.g., yield and kinetic parameters), requirements rarely satisfied in real applications. An environmentally important case, that exemplifies all these handicaps, is toxicant wastewater treatment. There the lack of online practical pollutant sensors may allow unforeseen high shock loads to be fed to the bioreactor, causing biomass inhibition that slows down the treatment process and, in extreme cases, even renders the biological process useless. In this work an event-driven time-optimal control (ED-TOC) is proposed to circumvent these limitations. We show how to detect a "there is inhibition" event by using some computable function of the available measurements. This event drives the ED-TOC to stop the filling. Later, by detecting the symmetric event, "there is no inhibition," the ED-TOC may restart the filling. A fill-react cycling then maintains the process safely hovering near its maximum reaction rate, allowing a robust and practically time-optimal operation of the bioreactor. An experimental study case of a wastewater treatment process application is presented. There the dissolved oxygen concentration was used to detect the events needed to drive the controller. (c) 2006 Wiley Periodicals, Inc.

Pharmaceutical wastewater being composite mixture of environmental pollutants may be associated with mutagenicity and genotoxicity.

PubMed

Sharif, Ali; Ashraf, Muhammad; Anjum, Aftab Ahmed; Javeed, Aqeel; Altaf, Imran; Akhtar, Muhammad Furqan; Abbas, Mateen; Akhtar, Bushra; Saleem, Ammara

2016-02-01

Pharmaceutical industries are amongst the foremost contributor to industrial waste. Ecological well-being is endangered owing to its facile discharge. In the present study, heavy metals and organic contaminants in waste water were characterized using atomic absorption spectrophotometer and GC-MS, respectively. Mutagenicity and genotoxic potential of pharmaceutical waste water were investigated through bacterial reverse mutation assay and in vitro comet assay, respectively. Ames test and comet assay of first sample were carried out at concentrations of 100, 50, 25, 12.5, 6.25 % v/v effluent with distilled water. Chromium (Cr), lead (Pb), arsenic (As), and cadmium (Cd) were found in high concentrations as compared to WHO- and EPA-recommended maximum limits. Arsenic was found to be the most abundant metal and its maximum concentration was 0.8 mg.L(-1). GC-MS revealed the presence of lignocaine, digitoxin, trimethoprim, caffeine, and vitamin E in waste water. Dose-dependent decrease in mutagenic index was observed in both strains. Substantial increase in mutagenicity was observed for TA-100, when assay was done by incorporating an enzyme activation system, whereas a slight increase was detected for TA-102. In vitro comet assay of waste water exhibited decrease in damage index and percentage fragmentation with the increase in dilution of waste water. Tail length also decreased with an increase in the dilution factor of waste water. These findings suggest that pharmaceutical waste water being a mix of different heavy metals and organic contaminants may have a potent mutagenic and genotoxic effect on exposed living organisms.

Development of health-based screening levels for use in state- or local-scale water-quality assessments

USGS Publications Warehouse

Toccalino, Patricia L.; Nowell, Lisa; Wilber, William; Zogorski, John S.; Donohue, Joyce; Eiden, Catherine; Krietzman, Sandra; Post, Gloria

2003-01-01

The U.S. Geological Survey (USGS) has a need to communicate the significance of the water-quality findings of its National Water-Quality Assessment (NAWQA) Program in a human-health context. Historically, the USGS has assessed water-quality conditions by comparing water concentration data against established drinking-water standards and guidelines. However, because drinking- water standards and guidelines do not exist for many of the contaminants analyzed by the NAWQA Program and other USGS studies, this approach has proven to be insufficient for placing USGS data in a human-health context. To help meet this need, health-based screening level (HBSL) concentrations or ranges are being determined for unregulated compounds (that is, those for which Federal or State drinking-water standards have not been established), using a consensus approach that was developed collaboratively by the USGS, U.S. Environmental Protection Agency(USEPA), New Jersey Department of Environmental Protection, and Oregon Health & Science University. USEPA Office of Water methodologies for calculating Lifetime Health Advisory and Risk-Specific Dose values for drinking water are being used to develop HBSL concentrations (for unregulated noncarcinogens) and HBSL concentration ranges (for most unregulated carcinogens). This report describes the methodologies used to develop HBSL concentrations and ranges for unregulated compounds in State- and local-scale analyses, and discusses how HBSL values can be used as tools in water-quality assessments. Comparisons of measured water concentrations with Maximum Contaminant Level values and HBSL values require that water-quality data be placed in the proper context, with regard to both hydrology and human health. The use of these HBSL concentrations and ranges by USGS will increase by 27 percent the number of NAWQA contaminants for which health-based benchmarks are available for comparison with USGS water-quality data. USGS can use HBSL values to assist the USEPA and State and local agencies by providing them with comparisons of measured water concentrations to scientifically defensible human health-based benchmarks, and by alerting them when measured concentrations approach or exceed these benchmarks.

PAH composition of Water Based Drilling Mud and drill cuttings in the offshore region, east coast of India.

PubMed

Jagwani, Devaanshi; Kulkarni, Atul; Shukla, Parth; Ramteke, Dilip S; Juneja, Harjeet D

2011-11-01

As a consequence of offshore drilling, used Water Based Drilling Muds (WBMs) are typically disposed off, by discharging into the sea; such a disposal does not fully eliminate the environmental hazards. Hence, in this study, 2, 3, 4 and 5 ringed polycyclic aromatic hydrocarbons (PAHs i.e. naphthalene, fluorene, phenanthrene, fluoranthene, chrysene and benzo (a) pyrene) were determined from the WBMs and associated drill cuttings obtained from varying depths(viz. 150, 300 and 600 m) from three offshore wells present in East coast of India. In both WBMs and drill cuttings, concentration of naphthalene was maximum i.e. 81.59 ± 2.73 and 39.87 ± 2.40 mg/kg respectively, while benzo (a) pyrene was minimum i.e. 0.19 ± 0.07 and 0.12 ± 0.03 mg/kg respectively. The WBMs contained significantly (p < 0.05) higher PAH concentration than drill cuttings. The individual PAH concentration significantly (p < 0.01) increased with increasing depth in each well.

Antimony, arsenic and lead distribution in soils and plants of an agricultural area impacted by former mining activities.

PubMed

Álvarez-Ayuso, E; Otones, V; Murciego, A; García-Sánchez, A; Regina, I Santa

2012-11-15

An agricultural area impacted by the former exploitation of an arsenical lead-antimony deposit was studied in order to assess the current and eventual environmental and health impacts. Samples of soils and cultivated (wheat) and spontaneously growing plants were collected at different distances from the mine pits and analyzed for the toxic element content and distribution. The soil total concentrations of Sb, As and Pb found in the uppermost soil layer (14.1-324, 246-758 and 757-10,660 mg kg(-1), respectively) greatly surpass their maximum tolerable levels in agricultural soils. Wheat grain Pb concentrations (0.068-1.36 mg kg(-1)) exceed the prescribed health standard, whereas Sb (<0.05-0.103 mg kg(-1)) and As (<0.05-0.126 mg kg(-1)) concentrations are below the permissible limits fixed for cereals. Of the spontaneously growing plants, Dactylis glomerata L. shows a relatively high root Pb accumulation and a very low Pb translocation, suggesting its feasibility to be used in Pb phytostabilization strategies. Copyright © 2012 Elsevier B.V. All rights reserved.

Quality of major ion and total dissolved solids data from groundwater sampled by the National Water-Quality Assessment Program, 1992–2010

USGS Publications Warehouse

Gross, Eliza L.; Lindsey, Bruce D.; Rupert, Michael G.

2012-01-01

Field blank samples help determine the frequency and magnitude of contamination bias, and replicate samples help determine the sampling variability (error) of measured analyte concentrations. Quality control data were evaluated for calcium, magnesium, sodium, potassium, chloride, sulfate, fluoride, silica, and total dissolved solids. A 99-percent upper confidence limit is calculated from field blanks to assess the potential for contamination bias. For magnesium, potassium, chloride, sulfate, and fluoride, potential contamination in more than 95 percent of environmental samples is less than or equal to the common maximum reporting level. Contamination bias has little effect on measured concentrations greater than 4.74 mg/L (milligrams per liter) for calcium, 14.98 mg/L for silica, 4.9 mg/L for sodium, and 120 mg/L for total dissolved solids. Estimates of sampling variability are calculated for high and low ranges of concentration for major ions and total dissolved solids. Examples showing the calculation of confidence intervals and how to determine whether measured differences between two water samples are significant are presented.

Batch leaching tests of motherboards to assess environmental contamination by bromine, platinum group elements and other selected heavy metals.

PubMed

Almeida, César; Grosselli, Melina; González, Patricia; Martínez, Dante; Gil, Raúl

2016-02-01

In this study, a batch leaching test was executed to evaluate the toxicity associated with chemicals contained in motherboards. The leaching solutions used were distilled water, nitric acid, acetic acid and synthetic acid rain solution. A total of 21 elements including Ag, As, Au, Br, Cd, Co, Cr, Cu, Hf, Ir, Mn, Ni, Os, Pb, Pd, Pt, Rd, Rh, Se, U and Zn were analyzed. In this study, the pH values of all the leachates fell within the range of 2.33-4.88. The highest concentrations of metals were obtained from the acid rain solution, whilst the maximum value of bromine was achieved with solution of acetic acid. Appreciable concentrations of platinum group elements were detected with concentrations around 3.45, 1.43, 1.21 and 22.19 µg L(-1) for Ir, Pd, Pt and Rh, respectively. The different leaching of the motherboards revealed the predominant presence of the toxic substances in the leached from the e-waste. Copyright © 2015 Elsevier Ltd. All rights reserved.

Arsenic and lead distribution and mobility in lake sediments in the south-central Puget Sound watershed: the long-term impact of a metal smelter in Ruston, Washington, USA.

PubMed

Gawel, James E; Asplund, Jessica A; Burdick, Sarah; Miller, Michelle; Peterson, Shawna M; Tollefson, Amanda; Ziegler, Kara

2014-02-15

The American Smelting and Refining Company (ASARCO) smelter in Ruston, Washington, contaminated the south-central Puget Sound region with heavy metals, including arsenic and lead. Arsenic and lead distribution in surface sediments of 26 lakes is significantly correlated with atmospheric model predictions of contaminant deposition spatially, with concentrations reaching 208 mg/kg As and 1,375 mg/kg Pb. The temporal distribution of these metals in sediment cores is consistent with the years of operation of the ASARCO smelter. In several lakes arsenic and lead levels are highest at the surface, suggesting ongoing inputs or redistribution of contaminants. Moreover, this study finds that arsenic is highly mobile in these urban lakes, with maximum dissolved arsenic concentrations proportional to surface sediment levels and reaching almost 90 μg/L As. With 83% of the lakes in the deposition zone having surface sediments exceeding published "probable effects concentrations" for arsenic and lead, this study provides evidence for possible ongoing environmental health concerns. Copyright © 2013 Elsevier B.V. All rights reserved.

Relation of water chemistry of the Edwards aquifer to hydrogeology and land use, San Antonio Region, Texas

USGS Publications Warehouse

Buszka, Paul M.

1987-01-01

In general, the quality of ground water in the freshwater parts of the aquifer (north of the "bad-water" line) is suitable for all uses including human consumption. Two areas that are exceptions are: (1) Northeast of Garner Field in Uvalde, Texas, where PCE (tetrachloroethylene) has been detected in groundwater samples, and (2) north-central Bexar County near the former West Avenue landfill where PCE and benzene have been detected in ground-water samples. Concentrations of these organic compounds in water from many wells in the two areas exceed the maximum contaminant level for human consumption set by the U.S. Environmental Protection Agency.