Occurrence and status of volatile organic compounds in ground water from rural, untreated, self-supplied domestic wells in the United States, 1986-99

USGS Publications Warehouse

Moran, Michael J.; Lapham, Wayne W.; Rowe, Barbara L.; Zogorski, John S.

2002-01-01

Samples of untreated ground water from 1,926 rural, self-supplied domestic wells were analyzed for volatile organic compounds (VOCs) during 1986-99. This information was used to characterize the occurrence and status of VOCs in domestic well water. The samples were either collected as part of the U.S. Geological Survey?s National Water-Quality Assessment (NAWQA) Program occurrence-assessment studies or were compiled by NAWQA from existing ambient ground-water or source-water-quality monitoring programs conducted by local, State, and other Federal agencies. Water samples were collected at the wellhead prior to treatment or storage. In most samples, 55 target VOCs were analyzed, and occurrence and status information generally was computed at an assessment level of 0.2 mg/L (microgram per liter). At least one VOC was detected in 12 percent of samples (232 samples) at an assessment level of 0.2 mg/L. This detection frequency is relatively low compared to the 26 percent detection frequency of at least one VOC in public sup-ply wells sampled by NAWQA, and the difference may be due, in part, to the higher pumping rates, pumping stress factors, and larger contributing areas of public supply wells. Samples with detections of at least one VOC were collected from wells located in 31 of 39 States. Solvents were the most frequently detected VOC group with detections in 4.6 percent of samples (89 samples) at an assessment level of 0.2 mg/L. The geographic distribution of detections of some VOC groups, such as fumigants and oxygenates, relates to the use pattern of com-pounds in that group. With the exception of com-pounds used in organic synthesis, detection frequencies of VOCs by group are proportional to the average half-life of compounds in the group. When the organic synthesis group is excluded from the analysis, a good correlation exists between the detection frequency of VOCs by group and average half-life of compounds in the group. Individually, VOCs were not commonly detected at an assessment level of 0.2 mg/L, with the seven most frequently detected VOCs found in only 1 to 5 percent of samples. Mixtures (two or more compounds) were a common mode of occurrence for VOCs when no assessment level was applied, and mixtures occurred in one-half of all samples that contained at least one VOC. Only 1.4 percent of samples (27 samples) had one or more VOC concentrations that exceeded a federally established drinking-water standard or health criterion. Only 0.1 percent of samples (2 samples) had one or more VOC concentrations that exceeded a taste/odor threshold. Potential point sources of VOCs near domestic wells are numerous. Leaks from under-ground storage tanks and aboveground storage tanks that hold gasoline, diesel fuel, or heating oil have the potential to be major point sources of contaminants to domestic wells. Shock chlorination may be a source of trichloromethane and other trihalomethanes in some domestic wells. Septic systems are believed to be an important source of contaminants to domestic wells, but extensive research on this subject does not exist. VOCs frequently are ingredients in household products such as cleansers and insecticides, and some VOCs have been found in septic systems.

Determining the sources of fine-grained sediment using the Sediment Source Assessment Tool (Sed_SAT)

USGS Publications Warehouse

Gorman Sanisaca, Lillian E.; Gellis, Allen C.; Lorenz, David L.

2017-07-27

A sound understanding of sources contributing to instream sediment flux in a watershed is important when developing total maximum daily load (TMDL) management strategies designed to reduce suspended sediment in streams. Sediment fingerprinting and sediment budget approaches are two techniques that, when used jointly, can qualify and quantify the major sources of sediment in a given watershed. The sediment fingerprinting approach uses trace element concentrations from samples in known potential source areas to determine a clear signature of each potential source. A mixing model is then used to determine the relative source contribution to the target suspended sediment samples.The computational steps required to apportion sediment for each target sample are quite involved and time intensive, a problem the Sediment Source Assessment Tool (Sed_SAT) addresses. Sed_SAT is a user-friendly statistical model that guides the user through the necessary steps in order to quantify the relative contributions of sediment sources in a given watershed. The model is written using the statistical software R (R Core Team, 2016b) and utilizes Microsoft Access® as a user interface but requires no prior knowledge of R or Microsoft Access® to successfully run the model successfully. Sed_SAT identifies outliers, corrects for differences in size and organic content in the source samples relative to the target samples, evaluates the conservative behavior of tracers used in fingerprinting by applying a “Bracket Test,” identifies tracers with the highest discriminatory power, and provides robust error analysis through a Monte Carlo simulation following the mixing model. Quantifying sediment source contributions using the sediment fingerprinting approach provides local, State, and Federal land management agencies with important information needed to implement effective strategies to reduce sediment. Sed_SAT is designed to assist these agencies in applying the sediment fingerprinting approach to quantify sediment sources in the sediment TMDL framework.

Can Sanitary Surveys Replace Water Quality Testing? Evidence from Kisii, Kenya.

PubMed

Misati, Aaron Gichaba; Ogendi, George; Peletz, Rachel; Khush, Ranjiv; Kumpel, Emily

2017-02-07

Information about the quality of rural drinking water sources can be used to manage their safety and mitigate risks to health. Sanitary surveys, which are observational checklists to assess hazards present at water sources, are simpler to conduct than microbial tests. We assessed whether sanitary survey results were associated with measured indicator bacteria levels in rural drinking water sources in Kisii Central, Kenya. Overall, thermotolerant coliform (TTC) levels were high: all of the samples from the 20 tested dug wells, almost all (95%) of the samples from the 25 tested springs, and 61% of the samples from the 16 tested rainwater harvesting systems were contaminated with TTC. There were no significant associations between TTC levels and overall sanitary survey scores or their individual components. Contamination by TTC was associated with source type (dug wells and springs were more contaminated than rainwater systems). While sanitary surveys cannot be substituted for microbial water quality results in this context, they could be used to identify potential hazards and contribute to a comprehensive risk management approach.

Assessment of arsenic in coastal sediments, seawaters and molluscs in the Tarut Island, Arabian Gulf, Saudi Arabia

NASA Astrophysics Data System (ADS)

El-Sorogy, Abdelbaset S.; Youssef, Mohamed; Al-Kahtany, Khaled; Al-Otaiby, Naif

2016-01-01

In order to assess arsenic on the Tarut coast, Saudi Arabian Gulf, 38 sediment samples, 26 seawater samples and 40 gastropod and bivalve specimens were collected for analyses by Inductively Coupled Plasma-Mass Spectrometer. The Enrichment Factor (EF), the Geoaccumulation Index (Igeo) and the Contamination Factor (CF) indicated that coastal sediments of Tarut Island are severely enriched, strongly polluted and very highly contaminated with arsenic as a result of anthropogenic inputs. Comparison with arsenic in coastal sediments, seawaters and molluscs in the Red Sea, the Arabian Gulf and abroad coasts suggested that the studied samples have higher concentrations of As. The suggested natural sources of arsenic in the study area are the weathering and decomposition of neighboring deserts. The anthropogenic sources include the land reclamation, petrochemical industries, boat exhaust emissions, oil leakage, desalination plants and sewage effluents. These anthropogenic sources are the dominant sources of As in the study area and mostly came from Al Jubail industrial city to the north.

Area Source Emission Measurements Using EPA OTM 10

EPA Science Inventory

Measurement of air pollutant emissions from area and non-point sources is an emerging environmental concern. Due to the spatial extent and non-homogenous nature of these sources, assessment of fugitive emissions using point sampling techniques can be difficult. To help address th...

Assessment of fecal pollution sources in a small northern-plains watershed using PCR and phylogenetic analyses of Bacteroidetes 16S rRNA gene

USGS Publications Warehouse

Lamendella, R.; Domingo, J.W.S.; Oerther, D.B.; Vogel, J.R.; Stoeckel, D.M.

2007-01-01

We evaluated the efficacy, sensitivity, host-specificity, and spatial/temporal dynamics of human- and ruminant-specific 16S rRNA gene Bacteroidetes markers used to assess the sources of fecal pollution in a fecally impacted watershed. Phylogenetic analyses of 1271 fecal and environmental 16S rRNA gene clones were also performed to study the diversity of Bacteroidetes in this watershed. The host-specific assays indicated that ruminant feces were present in 28-54% of the water samples and in all sampling seasons, with increasing frequency in downstream sites. The human-targeted assays indicated that only 3-5% of the water samples were positive for human fecal signals, although a higher percentage of human-associated signals (19-24%) were detected in sediment samples. Phylogenetic analysis indicated that 57% of all water clones clustered with yet-to-be-cultured Bacteroidetes species associated with sequences obtained from ruminant feces, further supporting the prevalence of ruminant contamination in this watershed. However, since several clusters contained sequences from multiple sources, future studies need to consider the potential cosmopolitan nature of these bacterial populations when assessing fecal pollution sources using Bacteroidetes markers. Moreover, additional data is needed in order to understand the distribution of Bacteroidetes host-specific markers and their relationship to water quality regulatory standards. ?? 2006 Federation of European Microbiological Societies.

Ecological risk assessment of heavy metals and polycyclic aromatic hydrocarbons in sediments of rivers Niger and Benue confluence, Lokoja, Central Nigeria.

PubMed

Ekere, Nwachukwu; Yakubu, Newman; Ihedioha, Janefrances

2017-08-01

The concentrations of six heavy metals (HMs) and 16 US EPA priority polycyclic aromatic hydrocarbons (PAHs) in sediment samples of the confluence of rivers Niger and Benue were investigated. The ecological risk assessment of the contaminants was carried out. The results showed that the sediment samples were heavily polluted with iron and moderately polluted with Cd while other metals posed no pollution problem when compared with USEPA sediment quality guidelines. Only six out of the 16 priority PAHs were detected in the samples, and source apportionment of the PAHs indicated that they are of pyrogenic origin. The ∑PAHs in the samples were lower than many of similar studies and were of no pollution risk. The ecological risk assessment result of the heavy metals showed that the sediments were of considerable risk due majorly to Cd levels. The HM concentration results statistically showed significant difference between seasons at probability value (P < .05). Data analysis by PCA classified the metals into three different components according to sources. The levels of HMS and PAHs detected in the sediments were correlated for source identification, and the correlation showed that the majority of the pollutants were mainly from anthropogenic sources. There is increasing level of anthropogenic activities at the vicinity of the confluence due to urbanization which may call for periodic monitoring of the sediment quality.

Variation in the Profile of Anxiety Disorders in Boys with an ASD According to Method and Source of Assessment

ERIC Educational Resources Information Center

Bitsika, Vicki; Sharpley, Christopher F.

2015-01-01

To determine any variation that might occur due to the type of assessment and source used to assess them, the prevalence of 7 anxiety disorders were investigated in a sample of 140 boys with an Autism spectrum disorder (ASD) and 50 non-ASD (NASD) boys via the Child and Adolescent Symptom Inventory and the KIDSCID Clinical Interview. Boys with an…

Muddying the Waters: A New Area of Concern for Drinking Water Contamination in Cameroon

PubMed Central

Healy Profitós, Jessica M.; Mouhaman, Arabi; Lee, Seungjun; Garabed, Rebecca; Moritz, Mark; Piperata, Barbara; Tien, Joe; Bisesi, Michael; Lee, Jiyoung

2014-01-01

In urban Maroua, Cameroon, improved drinking water sources are available to a large majority of the population, yet this water is frequently distributed through informal distribution systems and stored in home containers (canaries), leaving it vulnerable to contamination. We assessed where contamination occurs within the distribution system, determined potential sources of environmental contamination, and investigated potential pathogens. Gastrointestinal health status (785 individuals) was collected via health surveys. Drinking water samples were collected from drinking water sources and canaries. Escherichia coli and total coliform levels were evaluated and molecular detection was performed to measure human-associated faecal marker, HF183; tetracycline-resistance gene, tetQ; Campylobacter spp.; and Staphylococcus aureus. Statistical analyses were performed to evaluate the relationship between microbial contamination and gastrointestinal illness. Canari samples had higher levels of contamination than source samples. HF183 and tetQ were detected in home and source samples. An inverse relationship was found between tetQ and E. coli. Presence of tetQ with lower E. coli levels increased the odds of reported diarrhoeal illness than E. coli levels alone. Further work is warranted to better assess the relationship between antimicrobial-resistant bacteria and other pathogens in micro-ecosystems within canaries and this relationship’s impact on drinking water quality. PMID:25464137

Muddying the waters: a new area of concern for drinking water contamination in Cameroon.

PubMed

Profitós, Jessica M Healy; Mouhaman, Arabi; Lee, Seungjun; Garabed, Rebecca; Moritz, Mark; Piperata, Barbara; Tien, Joe; Bisesi, Michael; Lee, Jiyoung

2014-11-28

In urban Maroua, Cameroon, improved drinking water sources are available to a large majority of the population, yet this water is frequently distributed through informal distribution systems and stored in home containers (canaries), leaving it vulnerable to contamination. We assessed where contamination occurs within the distribution system, determined potential sources of environmental contamination, and investigated potential pathogens. Gastrointestinal health status (785 individuals) was collected via health surveys. Drinking water samples were collected from drinking water sources and canaries. Escherichia coli and total coliform levels were evaluated and molecular detection was performed to measure human-associated faecal marker, HF183; tetracycline-resistance gene, tetQ; Campylobacter spp.; and Staphylococcus aureus. Statistical analyses were performed to evaluate the relationship between microbial contamination and gastrointestinal illness. Canari samples had higher levels of contamination than source samples. HF183 and tetQ were detected in home and source samples. An inverse relationship was found between tetQ and E. coli. Presence of tetQ with lower E. coli levels increased the odds of reported diarrhoeal illness than E. coli levels alone. Further work is warranted to better assess the relationship between antimicrobial-resistant bacteria and other pathogens in micro-ecosystems within canaries and this relationship's impact on drinking water quality.

X-ray transport and radiation response assessment (XTRRA) experiments at the National Ignition Facility.

PubMed

Fournier, K B; Brown, C G; Yeoman, M F; Fisher, J H; Seiler, S W; Hinshelwood, D; Compton, S; Holdener, F R; Kemp, G E; Newlander, C D; Gilliam, R P; Froula, N; Lilly, M; Davis, J F; Lerch, Maj A; Blue, B E

2016-11-01

Our team has developed an experimental platform to evaluate the x-ray-generated stress and impulse in materials. Experimental activities include x-ray source development, design of the sample mounting hardware and sensors interfaced to the National Ignition Facility's diagnostics insertion system, and system integration into the facility. This paper focuses on the X-ray Transport and Radiation Response Assessment (XTRRA) test cassettes built for these experiments. The test cassette is designed to position six samples at three predetermined distances from the source, each known to within ±1% accuracy. Built-in calorimeters give in situ measurements of the x-ray environment along the sample lines of sight. The measured accuracy of sample responses as well as planned modifications to the XTRRA cassette is discussed.

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

Survey methods for assessing land cover map accuracy

USGS Publications Warehouse

Nusser, S.M.; Klaas, E.E.

2003-01-01

The increasing availability of digital photographic materials has fueled efforts by agencies and organizations to generate land cover maps for states, regions, and the United States as a whole. Regardless of the information sources and classification methods used, land cover maps are subject to numerous sources of error. In order to understand the quality of the information contained in these maps, it is desirable to generate statistically valid estimates of accuracy rates describing misclassification errors. We explored a full sample survey framework for creating accuracy assessment study designs that balance statistical and operational considerations in relation to study objectives for a regional assessment of GAP land cover maps. We focused not only on appropriate sample designs and estimation approaches, but on aspects of the data collection process, such as gaining cooperation of land owners and using pixel clusters as an observation unit. The approach was tested in a pilot study to assess the accuracy of Iowa GAP land cover maps. A stratified two-stage cluster sampling design addressed sample size requirements for land covers and the need for geographic spread while minimizing operational effort. Recruitment methods used for private land owners yielded high response rates, minimizing a source of nonresponse error. Collecting data for a 9-pixel cluster centered on the sampled pixel was simple to implement, and provided better information on rarer vegetation classes as well as substantial gains in precision relative to observing data at a single-pixel.

Multi-source recruitment strategies for advancing addiction recovery research beyond treated samples

PubMed Central

Subbaraman, Meenakshi Sabina; Laudet, Alexandre B.; Ritter, Lois A.; Stunz, Aina; Kaskutas, Lee Ann

2014-01-01

Background The lack of established sampling frames makes reaching individuals in recovery from substance problems difficult. Although general population studies are most generalizable, the low prevalence of individuals in recovery makes this strategy costly and inefficient. Though more efficient, treatment samples are biased. Aims To describe multi-source recruitment for capturing participants from heterogeneous pathways to recovery; assess which sources produced the most respondents within subgroups; and compare treatment and non-treatment samples to address generalizability. Results Family/friends, Craigslist, social media and non-12-step groups produced the most respondents from hard-to-reach groups, such as racial minorities and treatment-naïve individuals. Recovery organizations yielded twice as many African-Americans and more rural dwellers, while social media yielded twice as many young people than other sources. Treatment samples had proportionally fewer females and older individuals compared to non-treated samples. Conclusions Future research on recovery should utilize previously neglected recruiting strategies to maximize the representativeness of samples. PMID:26166909

Occurrence, Source, and Human Infection Potential of Cryptosporidium and Giardia spp. in Source and Tap Water in Shanghai, China▿

PubMed Central

Feng, Yaoyu; Zhao, Xukun; Chen, Jiaxu; Jin, Wei; Zhou, Xiaonong; Li, Na; Wang, Lin; Xiao, Lihua

2011-01-01

Genotyping studies on the source and human infection potential of Cryptosporidium oocysts in water have been almost exclusively conducted in industrialized nations. In this study, 50 source water samples and 30 tap water samples were collected in Shanghai, China, and analyzed by the U.S. Environmental Protection Agency (EPA) Method 1623. To find a cost-effective method to replace the filtration procedure, the water samples were also concentrated by calcium carbonate flocculation (CCF). Of the 50 source water samples, 32% were positive for Cryptosporidium and 18% for Giardia by Method 1623, whereas 22% were positive for Cryptosporidium and 10% for Giardia by microscopy of CCF concentrates. When CCF was combined with PCR for detection, the occurrence of Cryptosporidium (28%) was similar to that obtained by Method 1623. Genotyping of Cryptosporidium in 17 water samples identified the presence of C. andersoni in 14 water samples, C. suis in 7 water samples, C. baileyi in 2 water samples, C. meleagridis in 1 water sample, and C. hominis in 1 water sample. Therefore, farm animals, especially cattle and pigs, were the major sources of water contamination in Shanghai source water, and most oocysts found in source water in the area were not infectious to humans. Cryptosporidium oocysts were found in 2 of 30 tap water samples. The combined use of CCF for concentration and PCR for detection and genotyping provides a less expensive alternative to filtration and fluorescence microscopy for accurate assessment of Cryptosporidium contamination in water, although the results from this method are semiquantitative. PMID:21498768

Evaluation of Airborne Particulate Matter and Metals Data in Personal, Indoor and Outdoor Environments using ED-XRF and ICP-MS and Co-located Duplicate Samples

EPA Science Inventory

Factors and sources affecting measurement uncertainty in airborne particulate matter (PM) gravimetric measurements and elemental analyses were investigated as part of the Windsor Ontario Exposure Assessment Study (WOEAS). The assessment was made using co-located duplicate sample...

Low-Level detections of halogenated volatile organic compounds in groundwater: Use in vulnerability assessments

USGS Publications Warehouse

Plummer, Niel; Busenberg, E.; Eberts, S.M.; Bexfield, L.M.; Brown, C.J.; Fahlquist, L.S.; Katz, B.G.; Landon, M.K.

2008-01-01

Concentrations of halogenated volatile organic compounds (VOCs) were determined by gas chromatography (GC) with an electron-capture detector (GC-ECD) and by gas chromatography with mass spectrometry (GC-MS) in 109 groundwater samples from five study areas in the United States. In each case, the untreated water sample was used for drinking-water purposes or was from a monitoring well in an area near a drinking-water source. The minimum detection levels (MDLs) for 25 VOCs that were identified in GC-ECD chromatograms, typically, were two to more than four orders of magnitude below the GC-MS MDLs. At least six halogenated VOCs were detected in all of the water samples analyzed by GC-ECD, although one or more VOCs were detected in only 43% of the water samples analyzed by GC-MS. In nearly all of the samples, VOC concentrations were very low and presented no known health risk. Most of the low-level VOC detections indicated post-1940s recharge, or mixtures of recharge that contained a fraction of post-1940s water. Concentrations of selected halogenated VOCs in groundwater from natural and anthropogenic atmospheric sources were estimated and used to recognize water samples that are being impacted by nonatmospheric sources. A classification is presented to perform vulnerability assessments at the scale of individual wells using the number of halogenated VOC detections and total dissolved VOC concentrations in samples of untreated drinking water. The low-level VOC detections are useful in vulnerability assessments, particularly for samples in which no VOCs are detected by GC-MS analysis.

Weak acid extractable metals in Bramble Bay, Queensland, Australia: temporal behaviour, enrichment and source apportionment.

PubMed

Brady, James P; Ayoko, Godwin A; Martens, Wayde N; Goonetilleke, Ashantha

2015-02-15

Sediment samples were taken from six sampling sites in Bramble Bay, Queensland, Australia between February and November in 2012. They were analysed for a range of heavy metals including Al, Fe, Mn, Ti, Ce, Th, U, V, Cr, Co, Ni, Cu, Zn, As, Cd, Sb, Te, Hg, Tl and Pb. Fraction analysis, Enrichment Factors and Principal Component Analysis-Absolute Principal Component Scores (PCA-APCS) were carried out in order to assess metal pollution, potential bioavailability and source apportionment. Cr and Ni exceeded the Australian Interim Sediment Quality Guidelines at some sampling sites, while Hg was found to be the most enriched metal. Fraction analysis identified increased weak acid soluble Hg and Cd during the sampling period. Source apportionment via PCA-APCS found four sources of metals pollution, namely, marine sediments, shipping, antifouling coatings and a mixed source. These sources need to be considered in any metal pollution control measure within Bramble Bay. Copyright © 2014 Elsevier Ltd. All rights reserved.

Occurrence of Selected Organic Compounds in Groundwater Used for Public Supply in the Plio-Pleistocene Deposits in East-Central Nebraska and the Dawson and Denver Aquifers near Denver, Colorado, 2002-2004

USGS Publications Warehouse

Bails, Jeffrey B.; Dietsch, Benjamin J.; Landon, Matthew K.; Paschke, Suzanne S.

2009-01-01

The National Water-Quality Assessment Program of the U.S. Geological Survey has an ongoing Source Water-Quality Assessment program designed to characterize the quality of water in aquifers used as a source of drinking-water supply for some of the largest metropolitan areas in the Nation. In addition to the sampling of the source waters, sampling of finished or treated waters was done in the second year of local studies to evaluate if the organic compounds detected in the source waters also were present in the water supplied to the public. An evaluation of source-water quality used in selected groundwater-supplied public water systems in east-central Nebraska and in the south Denver metropolitan area of Colorado was completed during 2002 through 2004. Fifteen wells in the Plio-Pleistocene alluvial and glacial deposits in east-central Nebraska (the High Plains study) and 12 wells in the Dawson and Denver aquifers, south of Denver (the South Platte study), were sampled during the first year to obtain information on the occurrence and distribution of selected organic chemicals in the source waters. During the second year of the study, two wells in east-central Nebraska were resampled, along with the associated finished water derived from these wells, to determine if organic compounds detected in the source water also were present in the finished water. Selection of the second-phase sampling sites was based on detections of the most-frequently occurring organic compounds from the first-year Source Water-Quality Assessment study results. The second-year sampling also required that finished waters had undergone water-quality treatment processes before being distributed to the public. Sample results from the first year of sampling groundwater wells in east-central Nebraska show that the most-frequently detected organic compounds were the pesticide atrazine and its degradate, deethylatrazine (DEA, otherwise known as 2-chloro-4-isopropylamino-6-amino-s-triazine or CIAT), which were detected in 9 of the 15 wells (60 percent of the samples). The second most frequently detected organic compound was tetrachloroethylene, detected in 4 of the 15 wells (27 percent of the samples), followed by chloroform, trichloroethylene, and 2-hydroxyatrazine (2-hydroxy-4-isopropylamino-6-ethylamino-s-triazine, or OIET), present in 3 of the 15 wells (20 percent of the samples). The pesticide compounds deisopropylatrazine (2-chloro-6-ethylamino-4-amino-s-triazine, or CEAT), metolachlor, and simazine and the volatile organic compound cis-1,2-dichloroethylene were detected in 2 of the 15 wells, and the compounds diuron and 1,2-dichloroethane were detected in only 1 of the 15 wells during the first-year sampling. Most detections of these compounds were at or near the minimum reporting levels, and none were greater than their regulatory maximum contaminant level. There were few detections of organic compounds during the first year of sampling groundwater wells in the South Platte study area. The compounds atrazine, deethylatrazine, picloram, tetrachloroethylene, methyl-tert-butyl-ether (MTBE), tris(2-butoxyethyl)phosphate, and bromoform were detected only once in all the samples from the 12 wells. Most detections of these compounds were at or near the minimum reporting levels, and none were greater than their regulatory maximum contaminant level. Second-year sampling, which included the addition of paired source- and finished-water samples, was completed at two sites in the High Plains study area. Source-water samples from the second-year sampling had detections of atrazine and deethylatrazine; at one site deisopropylatrazine and chloroform also were detected. The finished-water samples, which represent the source water after blending with water from other wells and treatment, indicated a decrease in the concentrations of the pesticides at one site, whereas concentrations remained nearly constant at a second site. The trihalomethanes (THMs or disinfec

ESTIMATION OF DIFFUSION LOSSES WHEN SAMPLING DIESEL AEROSOL: A QUALITY ASSURANCE MEASURE

EPA Science Inventory

A fundamental component of the QA work for the assessment of instruments and sampling system performance was the investigation of particle losses in sampling lines. Along the aerosol sample pathway from its source to the collection media or measuring instrument, some nano-size p...

Comparison of a multispectral vision system and a colorimeter for the assessment of meat color.

PubMed

Trinderup, Camilla H; Dahl, Anders; Jensen, Kirsten; Carstensen, Jens Michael; Conradsen, Knut

2015-04-01

The color assessment ability of a multispectral vision system is investigated by a comparison study with color measurements from a traditional colorimeter. The experiment involves fresh and processed meat samples. Meat is a complex material; heterogeneous with varying scattering and reflectance properties, so several factors can influence the instrumental assessment of meat color. In order to assess whether two methods are equivalent, the variation due to these factors must be taken into account. A statistical analysis was conducted and showed that on a calibration sheet the two instruments are equally capable of measuring color. Moreover the vision system provides a more color rich assessment of fresh meat samples with a glossier surface, than the colorimeter. Careful studies of the different sources of variation enable an assessment of the order of magnitude of the variability between methods accounting for other sources of variation leading to the conclusion that color assessment using a multispectral vision system is superior to traditional colorimeter assessments. Copyright © 2014 Elsevier Ltd. All rights reserved.

Arsenic and heavy metals contamination, risk assessment and their source in drinking water of the Mardan District, Khyber Pakhtunkhwa, Pakistan.

PubMed

Gul, Nida; Shah, Mohammad Tahir; Khan, Sardar; Khattak, Nimat Ullah; Muhammad, Said

2015-12-01

The present study was conducted to investigate the physico-chemical characteristics in drinking water of Mardan District, Pakistan. Furthermore, water quality was evaluated for the risk assessment of arsenic and heavy metals (HMs) and their contamination sources. Representative groundwater samples of shallow and deep sources were collected in the study area. These samples were analyzed for physical parameters, anions, light metals (LMs) and HMs. Results were compared with the drinking water guideline values set by the World Health Organization and the US Environmental Protection Agency. Average concentrations of anions, LMs and HMs were found within the maximum allowable contaminant levels except for bicarbonates, Fe, Cu, and Pb. Results revealed that hazard quotients >1 were observed for shallow groundwater for 10% samples only, suggesting potential health risk from water consumption. Correlation analysis and principal component analysis showed a relationship among various physico-chemical parameters in both shallow and deep groundwater. Statistical analyses suggested the geogenic and anthropogenic sources for possible enhancement of various physico-chemical parameters in the aquifer system of the study area.

Can Sanitary Surveys Replace Water Quality Testing? Evidence from Kisii, Kenya

PubMed Central

Misati, Aaron Gichaba; Ogendi, George; Peletz, Rachel; Khush, Ranjiv; Kumpel, Emily

2017-01-01

Information about the quality of rural drinking water sources can be used to manage their safety and mitigate risks to health. Sanitary surveys, which are observational checklists to assess hazards present at water sources, are simpler to conduct than microbial tests. We assessed whether sanitary survey results were associated with measured indicator bacteria levels in rural drinking water sources in Kisii Central, Kenya. Overall, thermotolerant coliform (TTC) levels were high: all of the samples from the 20 tested dug wells, almost all (95%) of the samples from the 25 tested springs, and 61% of the samples from the 16 tested rainwater harvesting systems were contaminated with TTC. There were no significant associations between TTC levels and overall sanitary survey scores or their individual components. Contamination by TTC was associated with source type (dug wells and springs were more contaminated than rainwater systems). While sanitary surveys cannot be substituted for microbial water quality results in this context, they could be used to identify potential hazards and contribute to a comprehensive risk management approach. PMID:28178226

X-ray transport and radiation response assessment (XTRRA) experiments at the National Ignition Facility

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

Fournier, K. B., E-mail: fournier2@llnl.gov; Brown, C. G.; Yeoman, M. F.

2016-11-15

Our team has developed an experimental platform to evaluate the x-ray-generated stress and impulse in materials. Experimental activities include x-ray source development, design of the sample mounting hardware and sensors interfaced to the National Ignition Facility’s diagnostics insertion system, and system integration into the facility. This paper focuses on the X-ray Transport and Radiation Response Assessment (XTRRA) test cassettes built for these experiments. The test cassette is designed to position six samples at three predetermined distances from the source, each known to within ±1% accuracy. Built-in calorimeters give in situ measurements of the x-ray environment along the sample lines ofmore » sight. The measured accuracy of sample responses as well as planned modifications to the XTRRA cassette is discussed.« less

X-ray transport and radiation response assessment (XTRRA) experiments at the National Ignition Facility

DOE PAGES

Fournier, K. B.; Brown, Jr., C. G.; Yeoman, M. F.; ...

2016-08-10

Our team has developed an experimental platform to evaluate the x-ray-generated stress and impulse in materials. Experimental activities include x-ray source development, design of the sample mounting hardware and sensors interfaced to the NIF’s diagnostics insertion system, and system integration into the facility. This paper focuses on the X-ray Transport and Radiation Response Assessment (XTRRA) test cassettes built for these experiments. The test cassette is designed to position six samples at three predetermined distances from the source, each known to within ±1% accuracy. Built in calorimeters give in situ measurements of the x-ray environment along the sample lines of sight.more » We discuss the measured accuracy of sample responses, as well as planned modifications to the XTRRA cassette.« less

Changing sources of polychlorinated dibenzo-p-dioxins and furans in sediments and ecological risk for nekton in the lower Passaic River and Newark Bay, New Jersey, USA.

PubMed

Khairy, Mohammed; Barrett, Kirk; Lohmann, Rainer

2016-03-01

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were measured in sediments (surface and deeper sediments) and porewater of the lower Passaic River and Newark Bay (New Jersey, USA) to apportion their sources and conduct an ecological risk assessment. Positive matrix factorization was applied to identify sources of PCDD/Fs. Five source profiles were extracted from the positive matrix factorization model applied to the sediment samples including chloranil, combustion, polychlorinated biphenyl impurities, mixed urban sources, and the historical contamination from the former Diamond Alkali plant. The ecological risk assessment was estimated using several lines of evidence depending on site-specific data (blue crab and fish samples representing different feeding habits and positions in the trophic wood web of the river). Porewater concentrations gave the best estimates of lipid concentrations especially in the blue crab samples (with an average factor difference of 3.8). Calculated hazard quotients (HQs) for the fish samples and blue crab were >1 based on the no-effect concentration and tissue screening concentration approaches. At the same time, calculated porewater toxic units were >1. Sediment concentrations exceeded the published sediment quality guidelines for the protection of fish and benthic species, indicating the existence of significant risk to the aquatic life in the Passaic River. Accordingly, further actions and control measures are needed to reduce the emission of PCDD/Fs from ongoing sources. © 2015 SETAC.

Quantitative assessment of Pb sources in isotopic mixtures using a Bayesian mixing model.

PubMed

Longman, Jack; Veres, Daniel; Ersek, Vasile; Phillips, Donald L; Chauvel, Catherine; Tamas, Calin G

2018-04-18

Lead (Pb) isotopes provide valuable insights into the origin of Pb within a sample, typically allowing for reliable fingerprinting of their source. This is useful for a variety of applications, from tracing sources of pollution-related Pb, to the origins of Pb in archaeological artefacts. However, current approaches investigate source proportions via graphical means, or simple mixing models. As such, an approach, which quantitatively assesses source proportions and fingerprints the signature of analysed Pb, especially for larger numbers of sources, would be valuable. Here we use an advanced Bayesian isotope mixing model for three such applications: tracing dust sources in pre-anthropogenic environmental samples, tracking changing ore exploitation during the Roman period, and identifying the source of Pb in a Roman-age mining artefact. These examples indicate this approach can understand changing Pb sources deposited during both pre-anthropogenic times, when natural cycling of Pb dominated, and the Roman period, one marked by significant anthropogenic pollution. Our archaeometric investigation indicates clear input of Pb from Romanian ores previously speculated, but not proven, to have been the Pb source. Our approach can be applied to a range of disciplines, providing a new method for robustly tracing sources of Pb observed within a variety of environments.

Sediment source apportionment in Laurel Hill Creek, PA, using Bayesian chemical mass balance and isotope fingerprinting

USGS Publications Warehouse

Stewart, Heather; Massoudieh, Arash; Gellis, Allen C.

2015-01-01

A Bayesian chemical mass balance (CMB) approach was used to assess the contribution of potential sources for fluvial samples from Laurel Hill Creek in southwest Pennsylvania. The Bayesian approach provides joint probability density functions of the sources' contributions considering the uncertainties due to source and fluvial sample heterogeneity and measurement error. Both elemental profiles of sources and fluvial samples and 13C and 15N isotopes were used for source apportionment. The sources considered include stream bank erosion, forest, roads and agriculture (pasture and cropland). Agriculture was found to have the largest contribution, followed by stream bank erosion. Also, road erosion was found to have a significant contribution in three of the samples collected during lower-intensity rain events. The source apportionment was performed with and without isotopes. The results were largely consistent; however, the use of isotopes was found to slightly increase the uncertainty in most of the cases. The correlation analysis between the contributions of sources shows strong correlations between stream bank and agriculture, whereas roads and forest seem to be less correlated to other sources. Thus, the method was better able to estimate road and forest contributions independently. The hypothesis that the contributions of sources are not seasonally changing was tested by assuming that all ten fluvial samples had the same source contributions. This hypothesis was rejected, demonstrating a significant seasonal variation in the sources of sediments in the stream.

Neighborhood diversity of potentially pathogenic bacteria in drinking water from the city of Maroua, Cameroon.

PubMed

Healy-Profitós, Jessica; Lee, Seungjun; Mouhaman, Arabi; Garabed, Rebecca; Moritz, Mark; Piperata, Barbara; Lee, Jiyoung

2016-06-01

This study examined the spatial variation of potential gastrointestinal pathogens within drinking water sources and home storage containers in four neighborhoods in Maroua, Cameroon. Samples were collected from source (n = 28) and home containers (n = 60) in each study neighborhood. Pathogen contamination was assessed using quantitative polymerase chain reaction, targeting Campylobacter spp., Shiga toxin producing Escherichia coli (virulence genes, stx1 and stx2), and Salmonella spp. Microbial source tracking (MST) targeted three different host-specific markers: HF183 (human), Rum2Bac (ruminant) and GFD (poultry) to identify contamination sources. Staphylococcus aureus and the tetracycline-resistance gene (tetQ) were assessed to measure human hand contact and presence of antibiotic-resistant bacteria. Pathogen/MST levels were compared statistically and spatially, and neighborhood variation was compared with previously collected demographic information. All the test fecal markers and pathogens (except Arcobacter) were detected in home and source samples. Two neighborhoods tested positive for most pathogens/MST while the others only tested positive for one or two. Spatial variation of pathogens/MST existed between sources, storage containers, and neighborhoods. Differing population density and ethno-economic characteristics could potentially explain variation. Future research should explore the influence of demographic and ethno-economic factors on water quality during microbial risk assessments in urban Africa.

Impact of sampling techniques on measured stormwater quality data for small streams

USDA-ARS?s Scientific Manuscript database

Science-based sampling methodologies are needed to enhance water quality characterization for developing Total Maximum Daily Loads (TMDLs), setting appropriate water quality standards, and managing nonpoint source pollution. Storm event sampling, which is vital for adequate assessment of water qual...

Occurrence and health risk assessment of organotins in waterworks and the source water of the Three Gorges Reservoir Region, China.

PubMed

Deng, Ting; Wu, Lei; Gao, Jun-Min; Zhou, Bin; Zhang, Ya-Li; Wu, Wen-Nan; Tang, Zhuo-Heng; Jiang, Wen-Chao; Huang, Wei-Lin

2018-05-01

The occurrence and health risks of organotins (OTs) in the waterworks and source water in the Three Gorges Reservoir Region (TGRR), China were assessed in this study. Water samples were collected at four waterworks (A, B, C, and D) in March and July 2012 to analyze butyltins (BTs) and phenyltins (PTs) using a gas chromatography-mass spectrometry (GC-MS) system. Our results showed that both the waterworks and their nearby water sources were polluted by OTs, with PTs being the most dominant species. Monobutyltin (MBT), monophenyltin (MPT), diphenyltin (DPT), and triphenyltin (TPT) were detected in most of the analyzed water samples. The highest concentrations of OTs in influents, effluents, and source water in March were 52.81, 17.93, and 55.32 ng Sn L -1 , respectively. Furthermore, significant seasonal changes in OTs pollution were observed in all samples, showing pollution worse in spring compared with summer. The removal of OTs by the conventional treatment processes was not stable among the waterworks. The removal efficiency of OTs in July reached 100% at plant B, while that at plant C was only 38.8%. The source water and influents shared similar composition profiles, concentrations, and seasonal change of OTs, which indicated that OTs in the waterworks were derived from the source water. A health risk assessment indicated that the presence of OTs in the waterworks would not pose a significant health risk to the population, yet their presence should not be ignored.

Assessing Drinking Water Quality and Water Safety Management in Sub-Saharan Africa Using Regulated Monitoring Data.

PubMed

Kumpel, Emily; Peletz, Rachel; Bonham, Mateyo; Khush, Ranjiv

2016-10-18

Universal access to safe drinking water is prioritized in the post-2015 Sustainable Development Goals. Collecting reliable and actionable water quality information in low-resource settings, however, is challenging, and little is known about the correspondence between water quality data collected by local monitoring agencies and global frameworks for water safety. Using 42 926 microbial water quality test results from 32 surveillance agencies and water suppliers in seven sub-Saharan African countries, we determined the degree to which water sources were monitored, how water quality varied by source type, and institutional responses to results. Sixty-four percent of the water samples were collected from piped supplies, although the majority of Africans rely on nonpiped sources. Piped supplies had the lowest levels of fecal indicator bacteria (FIB) compared to any other source type: only 4% of samples of water piped to plots and 2% of samples from water piped to public taps/standpipes were positive for FIB (n = 14 948 and n = 12 278, respectively). Among other types of improved sources, samples from harvested rainwater and boreholes were less often positive for FIB (22%, n = 167 and 31%, n = 3329, respectively) than protected springs or protected dug wells (39%, n = 472 and 65%, n = 505). When data from different settings were aggregated, the FIB levels in different source types broadly reflected the source-type water safety framework used by the Joint Monitoring Programme. However, the insufficient testing of nonpiped sources relative to their use indicates important gaps in current assessments. Our results emphasize the importance of local data collection for water safety management and measurement of progress toward universal safe drinking water access.

A preliminary assessment of the spatial sources of contemporary suspended sediment in the Ohio River basin, United States, using water quality data from the NASQAN programme in a source tracing procedure

USGS Publications Warehouse

Zhang, Y.-S.; Collins, A.L.; Horowitz, A.J.

2012-01-01

Reliable information on catchment scale suspended sediment sources is required to inform the design of management strategies for helping abate the numerous environmental issues associated with enhanced sediment mobilization and off-site loadings. Since sediment fingerprinting techniques avoid many of the logistical constraints associated with using more traditional indirect measurement methods at catchment scale, such approaches have been increasingly reported in the international literature and typically use data sets collected specifically for sediment source apportionment purposes. There remains scope for investigating the potential for using geochemical data sets assembled by routine monitoring programmes to fingerprint sediment provenance. In the United States, routine water quality samples are collected as part of the US Geological Survey's revised National Stream Quality Accounting Network programme. Accordingly, the geochemistry data generated from these samples over a 10-year period (1996-2006) were used as the basis for a fingerprinting exercise to assess the key tributary sub-catchment spatial sources of contemporary suspended sediment transported by the Ohio River. Uncertainty associated with the spatial source estimates was quantified using a Monte Carlo approach in conjunction with mass balance modelling. Relative frequency weighted means were used as an alternative way of summarizing the spatial source contributions, thereby avoiding the need to use confidence limits. The results should be interpreted in the context of the routine, but infrequent nature, of the suspended sediment samples used to assemble geochemistry as a basis for the sourcing exercise. Nonetheless, the study demonstrates how routine monitoring samples can be used to provide some preliminary information on sediment provenance in large drainage basins. ?? 2011 John Wiley & Sons, Ltd.

Anthropogenic organic compounds in source water of select community water systems in the United States, 2002-10

USGS Publications Warehouse

Valder, Joshua F.; Delzer, Gregory C.; Kingsbury, James A.; Hopple, Jessica A.; Price, Curtis V.; Bender, David A.

2014-01-01

Drinking water delivered by community water systems (CWSs) comes from one or both of two sources: surface water and groundwater. Source water is raw, untreated water used by CWSs and is usually treated before distribution to consumers. Beginning in 2002, the U.S. Geological Survey’s (USGS) National Water-Quality Assessment Program initiated Source Water-Quality Assessments (SWQAs) at select CWSs across the United States, primarily to characterize the occurrence of a large number of anthropogenic organic compounds that are predominantly unregulated by the U.S. Environmental Protection Agency. Source-water samples from CWSs were collected during 2002–10 from 20 surface-water sites (river intakes) and during 2002–09 from 448 groundwater sites (supply wells). River intakes were sampled approximately 16 times during a 1-year sampling period, and supply wells were sampled once. Samples were monitored for 265 anthropogenic organic compounds. An additional 3 herbicides and 16 herbicide degradates were monitored in samples collected from 8 river intakes and 118 supply wells in areas where these compounds likely have been used. Thirty-seven compounds have an established U.S. Environmental Protection Agency (EPA) Maximum Contaminant Level (MCL) for drinking water, 123 have USGS Health-Based Screening Levels (HBSLs), and 29 are included on the EPA Contaminant Candidate List 3. All compounds detected in source water were evaluated both with and without an assessment level and were grouped into 13 categories (hereafter termed as “use groups”) based on their primary use or source. The CWS sites were characterized in a national context using an extract of the EPA Safe Drinking Water Information System to develop spatially derived and system-specific ancillary data. Community water system information is contained in the EPA Public Supply Database, which includes 2,016 active river intakes and 112,099 active supply wells. Ancillary variables including population served, watershed size, land use, population density, and recharge were characterized for each of the watersheds for river intakes and contributing areas for supply wells. A total of 313 samples were collected from 20 river intakes. Between the years of 2002 through 2010, samples were collected approximately 16 times over the course of a year. Seventy-one compounds from 12 of the 13 use groups commonly occurred (detected in greater than or equal to 1 percent of samples using an assessment level of 0.05 microgram per liter or when a compound was detected in greater than or equal to 10 percent of samples without an assessment level) indicating a wide variety of sources and pathways to these rivers and highlighting the importance of source-water protection strategies. A total of 448 supply wells were sampled once during 2002–10 as part of 30 independent groundwater studies. About 15 CWS supply wells were sampled for each independent groundwater study. Twenty-eight compounds from 7 of the 13 use groups commonly occurred indicating a wide variety of sources and pathways exist for these compounds to reach these wells and highlighting the importance of wellhead protection strategies. About one-half the 265 compounds monitored (122) were detected in both surface water and groundwater samples. A more diverse suite of compounds were detected in surface water in comparison to groundwater. However, herbicides and herbicide degradates were the most frequent group of compounds detected in both surface water and groundwater. Sixty-five of the most commonly occurring compounds were detected in one or more samples from both surface water and groundwater. Human-health benchmarks (MCLs for regulated compounds and HBSLs for unregulated compounds) were available for more than one-half the compounds (160 of the 265) monitored in this study. Fifty-eight percent (41 of 71) of the commonly occurring compounds in surface water have a human-health benchmark to which concentrations can be compared; 19 have MCLs and 22 have HBSLs. Eighty-three percent (24 of 28) of the most commonly occurring compounds in groundwater have a human-health benchmark for which concentrations can be compared; 14 have MCLs and 10 have HBSLs. To put results from this study into context with the national distribution of river intakes and supply wells used by CWSs, sites were grouped into the respective national population of land-use quartiles. The increase in compound occurrence with increasing urban and agricultural land use in the watershed or contributing area was more evident for rivers than for supply wells. The increase in detection frequency of herbicides and herbicide degradates with increasing agricultural land use was more evident for rivers than for supply wells. The occurrence of solvents did not change substantially with increasing urban land use for rivers or supply wells. Basic co-occurrence analyses were completed with and without an assessment level. Considering all detections in surface water without an assessment level, approximately 86 percent of source-water samples contained 2 or more compounds, and 50 percent of samples contained at least 14 compounds. Considering all detections in groundwater without an assessment level, 50 percent of samples contained at least three compounds. For the most part, the compounds detected most frequently as individual compounds in the environment often composed the most frequent unique mixtures. Five of the 10 most frequently co-occurring unique mixtures in both surface water and groundwater were the same: atrazine and deethylatrazine; atrazine and chloroform; deethylatrazine and simazine; atrazine and simazine; and deethylatrazine, atrazine, and simazine. Because similar mixtures were identified in both surface water and groundwater without an assessment level, future studies could be directed toward better understanding the toxicological importance of these unique mixtures. Summed concentrations of herbicide degradates were compared to concentrations of the parent herbicides in surface-water and groundwater samples collected from 8 river intakes and 118 CWS wells, from which samples were analyzed for an additional 3 herbicides and 16 degradates. The toxicity to humans for many of these degradate products is largely unknown and thus points to the importance of monitoring these compounds (both the parent and degradate) in the environment. This study highlights the importance of anthropogenic organic compounds in source water of select CWSs in the United States by characterizing their occurrence in surface-water and groundwater samples. Compound concentrations and occurrence are summarized and evaluated in a human-health context, when possible. Additionally, compounds found to co-occur as mixtures for both surface water and groundwater highlight the significance of low-level compound co-occurrence.

Preliminary assessment of the occurrence and possible sources of MTBE in groundwater in the United States, 1993-1994

USGS Publications Warehouse

Squillace, P.J.; Zogorski, J.S.; Wilber, W.G.; Price, C.V.

1996-01-01

The 1990 Clean Air Act Amendments require fuel oxygenates to be added to gasoline used in some metropolitan areas to reduce atmospheric concentrations of carbon monoxide or ozone. Methyl tert-butyl ether (MTBE) is the most commonly used fuel oxygenate and is a relatively new gasoline additive. Nevertheless, out of 60 volatile organic chemicals analyzed, MTBE was the second most frequently detected chemical in samples of shallow ambient groundwater from urban areas that were collected during 1993-1994 aspart of the U.S. Geological Survey's National Water-Quality Assessment program. Samples were collected from five drinking water wells, 12 springs, and 193 monitoring wells in urban areas. No MTBE was detected in drinking water wells. At a reporting level of 0.2 ??g/L, MTBE was detected most frequently in shallow groundwater from urban areas (27% of 210 wells and springs sampled in eight areas) as compared to shallow groundwater from agricultural areas (1.3% of 549 wells sampled in 21 areas) or deeper groundwater from major aquifers (1.0% of 412 wells sampled in nine areas). Only 3% of the shallow wells sampled in urban areas had concentrations of MTBE that exceed 20 ??g/L, which is the estimated lower limit of the United States Environmental Protection Agency draft drinking water health advisory. Because MTBE is persistent and mobile in groundwater, it can move from shallow to deeper aquifers with time. In shallow urban groundwater, MTBE generally was not found with benzene, toluene, ethylbenzene, or xylene (BTEX) compounds, which commonly are associated with gasoline spills. This disassociation causes uncertainty as to the source of MTBE. Possible sources of MTBE in groundwater include point sources, such as leaking storage tanks, and non-point sources, such as recharge of precipitation and stormwater runoff.

Inferring source attribution from a multiyear multisource data set of Salmonella in Minnesota.

PubMed

Ahlstrom, C; Muellner, P; Spencer, S E F; Hong, S; Saupe, A; Rovira, A; Hedberg, C; Perez, A; Muellner, U; Alvarez, J

2017-12-01

Salmonella enterica is a global health concern because of its widespread association with foodborne illness. Bayesian models have been developed to attribute the burden of human salmonellosis to specific sources with the ultimate objective of prioritizing intervention strategies. Important considerations of source attribution models include the evaluation of the quality of input data, assessment of whether attribution results logically reflect the data trends and identification of patterns within the data that might explain the detailed contribution of different sources to the disease burden. Here, more than 12,000 non-typhoidal Salmonella isolates from human, bovine, porcine, chicken and turkey sources that originated in Minnesota were analysed. A modified Bayesian source attribution model (available in a dedicated R package), accounting for non-sampled sources of infection, attributed 4,672 human cases to sources assessed here. Most (60%) cases were attributed to chicken, although there was a spike in cases attributed to a non-sampled source in the second half of the study period. Molecular epidemiological analysis methods were used to supplement risk modelling, and a visual attribution application was developed to facilitate data exploration and comprehension of the large multiyear data set assessed here. A large amount of within-source diversity and low similarity between sources was observed, and visual exploration of data provided clues into variations driving the attribution modelling results. Results from this pillared approach provided first attribution estimates for Salmonella in Minnesota and offer an understanding of current data gaps as well as key pathogen population features, such as serotype frequency, similarity and diversity across the sources. Results here will be used to inform policy and management strategies ultimately intended to prevent and control Salmonella infection in the state. © 2017 Blackwell Verlag GmbH.

Pharmaceutical compounds in Merrimack River water used for public supply, Lowell, Massachusetts, 2008-09

USGS Publications Warehouse

Massey, Andrew J.; Waldron, Marcus C.

2011-01-01

This report presents results of a study conducted by the U.S. Geological Survey (USGS), in cooperation with the Massachusetts Department of Environmental Protection, to determine the occurrence of 14 commonly used human-health pharmaceutical compounds and fecal-indicator bacteria in Merrimack River water used as a drinking-water source by 135,000 residents in eastern Massachusetts. The study was designed to complement the USGS National Water-Quality Assessment Program's Source Water-Quality Assessment, which identifies patterns of occurrence of 280 primarily unregulated organic wastewater contaminants in source water used by community water systems and determines whether these patterns also occur in treated drinking water prior to distribution. The study involved periodic collection and analysis of raw Merrimack River water and treated drinking water over the course of 1 year. Water samples were collected periodically without regard to flow regime or antecedent weather conditions at the Lowell Regional Water Utility's Merrimack River intake upstream from Lowell, Mass. The same parcel of water was then sampled as finished water following treatment. Despite the presence of many potential sources of contamination in the drinking-water source area, only 2 of the 14 pharmaceutical analytes were detected at reportable concentrations in the source-water samples, and these occurred in only one set of periodic samples. Acetaminophen, a nonprescription analgesic, and caffeine were detected in the September source-water samples at concentrations of 0.084 and 0.068 micrograms per liter, respectively. Three other compounds-carbamazepine, an antiepileptic; cotinine, a metabolite of nicotine; and diphenhydramine, a nonprescription antihistamine-were detected in source-water samples, but at concentrations too low to be reliably quantified. None of the 14 pharmaceuticals was found in the finished water at a reportable concentration, defined as two times the long-term detection limit used by the analytical laboratory. In addition to the pharmaceutical analyses, measurements of fecal-indicator bacteria (Escherichia coli) concentrations and several physical characteristics were made on all source-water samples. Values for these constituents were consistently within State standards. It is possible that the monthly sampling schedule missed hydrologic events that would have transported greater concentrations of sewage contaminants to the sampling site, or that the large flow volume of the river at the study site effectively diluted the contaminant signal, but it is also likely that recent efforts to separate stormwater- and wastewater-discharge systems in the reaches upstream from the Lowell Regional Water Utility have greatly reduced the potential for sewage contamination at the intake.

Evaluating Quality of Aged Archival Formalin-Fixed Paraffin-Embedded Samples for RNA-Sequencing

EPA Science Inventory

Archival formalin-fixed paraffin-embedded (FFPE) samples offer a vast, untapped source of genomic data for biomarker discovery. However, the quality of FFPE samples is often highly variable, and conventional methods to assess RNA quality for RNA-sequencing (RNA-seq) are not infor...

Forensic applications of nitrogen and oxygen isotopes in tracing nitrate sources in urban environments

USGS Publications Warehouse

Silva, S.R.; Ging, P.B.; Lee, R.W.; Ebbert, J.C.; Tesoriero, A.J.; Inkpen, E.L.

2002-01-01

Ground and surface waters in urban areas are susceptible to nitrate contamination from septic systems, leaking sewer lines, and fertilizer applications. Source identification is a primary step toward a successful remediation plan in affected areas. In this respect, nitrogen and oxygen isotope ratios of nitrate, in conjunction with hydrologic data and water chemistry, have proven valuable in urban studies from Austin, Texas, and Tacoma, Washington. In Austin, stream water was sampled during stremflow and baseflow conditions to assess surface and subsurface sources of nitrate, respectively. In Tacoma, well waters were sampled in adjacent sewered and un-sewered areas to determine if locally high nitrate concentrations were caused by septic systems in the un-sewered areas. In both studies, sewage was identified as a nitrate source and mixing between sewage and other sources of nitrate was apparent. In addition to source identification, combined nitrogen and oxygen isotopes were important in determining the significance of denitrification, which can complicate source assessment by reducing nitrate concentrations and increasing ??15N values. The two studies illustrate the value of nitrogen and oxygen isotopes of nitrate for forensic applications in urban areas. ?? Published by Elsevier Science Ltd. on behalf of AEHS.

A preliminary assessment of sources of nitrate in springwaters, Suwannee River basin, Florida

USGS Publications Warehouse

Katz, B.G.; Hornsby, H.D.

1998-01-01

A cooperative study between the Suwannee River Water Management District (SRWMD) and the U.S. Geological Survey (USGS) is evaluating sources of nitrate in water from selected springs and zones in the Upper Floridan aquifer in the Suwannee River Basin. A multi-tracer approach, which consists of the analysis of water samples for naturally occurring chemical and isotopic indicators, is being used to better understand sources and chronology of nitrate contamination in the middle Suwannee River region. In July and August 1997, water samples were collected and analyzed from six springs and two wells for major ions, nutrients, and dissolved organic carbon. These water samples also were analyzed for environmental isotopes [18O/16O, D/H, 13C/12C, 15N/14N] to determine sources of water and nitrate. Chlorofluorocarbons (CCl3F, CCl2F2, and C2Cl3F3) and tritium (3H) were analyzed to assess the apparent ages (residence time) of springwaters and water from the Upper Floridan aquifer. Delta 15N-NO3 values in water from the six springs range from 3.94 per mil (Little River Springs) to 8.39 per mil (Lafayette Blue Spring). The range of values indicates that nitrate in the sampled springwaters most likely originates from a mixture of inorganic (fertilizers) and organic (animal wastes) sources, although the higher delta 15N-NO3 value for Lafayette Blue Spring indicates that an organic source of nitrogen is likely at this site. Water samples from the two wells sampled in Lafayette County have high delta 15N-NO3 values of 10.98 and 12.1 per mil, indicating the likelihood of an organic source of nitrate. These two wells are located near dairy and poultry farms, where leachate from animal wastes may contribute nitrate to ground water. Based on analysis of chlorofluorocarbons in ground water, the mean residence time of water in springs ranges from about 12 to 25 years. Chlorofluorocarbons-modeled recharge dates for water samples from the two shallow zones in the Upper Floridan aquifer range from 1985 to 1989.

Development of EPA OTM 10 for Landfill Applications, Interim Report

EPA Science Inventory

Quantification of greenhouse gas emissions from area sources is of increasing importance. Due to the spatial extent and non homogenous nature of many area sources, assessment of fugitive emissions using traditional point sampling techniques can be problematic. To address this, th...

Sampling for Lead in Drinking Water

EPA Science Inventory

Sampling protocols for lead in water can be broadly categorized based on their intended purpose of 1) Pb regulatory compliance/corrosion control efficacy, 2) Pb plumbing source determination or Pb type identification, and 3) Pb exposure assessment. Choosing the appropriate protoc...

Organic Compounds in Truckee River Water Used for Public Supply near Reno, Nevada, 2002-05

USGS Publications Warehouse

Thomas, Karen A.

2009-01-01

Organic compounds studied in this U.S. Geological Survey (USGS) assessment generally are man-made, including, in part, pesticides, solvents, gasoline hydrocarbons, personal care and domestic-use products, and refrigerants and propellants. Of 258 compounds measured, 28 were detected in at least 1 source water sample collected approximately monthly during 2002-05 at the intake of the Chalk Bluff Treatment Plant, on the Truckee River upstream of Reno, Nevada. The diversity of compounds detected indicate various sources and uses (including wastewater discharge, industrial, agricultural, domestic, and others) and different pathways (including point sources from treated wastewater outfalls upstream of the sampling location, overland runoff, and groundwater discharge) to drinking-water supply intakes. Three compounds were detected in more than 20 percent of the source-water intake samples at low concentrations (less than 0.1 microgram per liter), including caffeine, p-cresol (a wood preservative), and toluene (a gasoline hydrocarbon). Sixteen of the 28 compounds detected in source water also were detected in finished water (after treatment, but prior to distribution; 2004-05). Additionally, two disinfection by-products not detected in source water, bromodichloromethane and dibromochloromethane, were detected in all finished water samples. Two detected compounds, cholesterol and 3-beta-coprostanol, are among five naturally occurring biochemicals analyzed in this study. Concentrations for all detected compounds in source and finished water generally were less than 0.1 microgram per liter and always less than human-health benchmarks, which are available for about one-half of the compounds. Seven compounds (toluene, chloroform, bromodichloromethane, dibromodichloromethane, bisphenol A, cholesterol, and 3-beta-coprostanol) were measured at concentrations greater than 0.1 microgram per liter. On the basis of this screening-level assessment, adverse effects to human health are expected to be negligible (subject to limitations of available human-health benchmarks).

Assessment of Contribution of Contemporary Carbon Sources to Size-Fractionated Particulate Matter and Time-Resolved Bulk Particulate Matter Using the Measurement of Radiocarbon

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

Hwang, H M; Young, T M; Buchholz, B A

2009-04-16

This study was motivated by a desire to improve understanding of the sources contributing to the carbon that is an important component of airborne particulate matter (PM). The ultimate goal of this project was to lay a ground work for future tools that might be easily implemented with archived or routinely collected samples. A key feature of this study was application of radiocarbon measurement that can be interpreted to indicate the relative contributions from fossil and non-fossil carbon sources of atmospheric PM. Size-resolved PM and time-resolved PM{sub 10} collected from a site in Sacramento, CA in November 2007 (Phase I)more » and March 2008 (Phase II) were analyzed for radiocarbon and source markers such as levoglucosan, cholesterol, and elemental carbon. Radiocarbon data indicates that the contributions of non-fossil carbon sources were much greater than that from fossil carbon sources in all samples. Radiocarbon and source marker measurements confirm that a greater contribution of non-fossil carbon sources in Phase I samples was highly likely due to residential wood combustion. The present study proves that measurement of radiocarbon and source markers can be readily applied to archived or routinely collected samples for better characterization of PM sources. More accurate source apportionment will support ARB in developing more efficient control strategies.« less

Assessment of Ecological Risk of Heavy Metal Contamination in Coastal Municipalities of Montenegro.

PubMed

Mugoša, Boban; Đurović, Dijana; Nedović-Vuković, Mirjana; Barjaktarović-Labović, Snežana; Vrvić, Miroslav

2016-03-31

Assessment of heavy metal concentrations in the soil samples of urban parks and playgrounds is very important for the evaluation of potential risks for residents, especially children. Until recently, there has been very little data about urban parks pollution in Montenegro. To evaluate the sources of potential contamination and concentration of heavy metals, soil samples from coastal urban parks and kindergartens of Montenegro were collected. Based on the heavy metal concentrations, multivariate analysis combined with geochemical approaches showed that soil samples in coastal areas of Montenegro had mean Pb and Cd concentrations that were over two times higher than the background values, respectively. Based on principal component analysis (PCA), soil pollution with Pb, Cd, Cu, and Zn is contributed by anthropogenic sources. Results for Cr in the surface soils were primarily derived from natural sources. Calculation of different ecological contamination factors showed that Cd is the primary contribution to ecological risk index (RI) origins from anthropogenic, industry, and urbanization sources. This data provides evidence about soil pollution in coastal municipalities of Montenegro. Special attention should be paid to this problem in order to continue further research and to consider possible ways of remediation of the sites where contamination has been observed.

Assessment of diesel particulate matter exposure in the workplace: freight terminals†

PubMed Central

Sheesley, Rebecca J.; Schauer, James J.; Smith, Thomas J.; Garshick, Eric; Laden, Francine; Marr, Linsey C.; Molina, Luisa T.

2008-01-01

A large study has been undertaken to assess the exposure to diesel exhaust within diesel trucking terminals. A critical component of this assessment is an analysis of the variation in carbonaceous particulate matter (PM) across trucking terminal locations; consistency in the primary sources can be effectively tracked by analyzing trends in elemental carbon (EC) and organic molecular marker concentrations. Ambient samples were collected at yard, dock and repair shop work stations in 7 terminals in the USA and 1 in Mexico. Concentrations of EC ranged from 0.2 to 12 μg m−3 among the terminals, which corresponds to the range seen in the concentration of summed hopanes (0.5 to 20.5 ng m−3). However, when chemical mass balance (CMB) source apportionment results were presented as percent contribution to organic carbon (OC) concentrations, the contribution of mobile sources to OC are similar among the terminals in different cities. The average mobile source percent contribution to OC was 75.3 ± 17.1% for truck repair shops, 65.4 ± 20.4% for the docks and 38.4 ± 9.5% for the terminal yard samples. A relatively consistent mobile source impact was present at all the terminals only when considering percentage of total OC concentrations, not in terms of absolute concentrations. PMID:18392272

Regional Assessment of Human Fecal Contamination in Southern California Coastal Drainages

PubMed Central

Cao, Yiping; Raith, Meredith R.; Smith, Paul D.; Griffith, John F.; Weisberg, Stephen B.; Schriewer, Alexander; Sheldon, Andrew; Crompton, Chris; Gregory, Jason; Guzman, Joe; Othman, Laila; Manasjan, Mayela; Choi, Samuel; Rapoport, Shana; Steele, Syreeta; Nguyen, Tommy; Yu, Xueyuan

2017-01-01

Host-associated genetic markers that allow for fecal source identification have been used extensively as a diagnostic tool to determine fecal sources within watersheds, but have not been used in routine monitoring to prioritize remediation actions among watersheds. Here, we present a regional assessment of human marker prevalence among drainages that discharge to the U.S. southern California coast. Approximately 50 samples were analyzed for the HF183 human marker from each of 22 southern California coastal drainages under summer dry weather conditions, and another 50 samples were targeted from each of 23 drainages during wet weather. The HF183 marker was ubiquitous, detected in all but two sites in dry weather and at all sites during wet weather. However, there was considerable difference in the extent of human fecal contamination among sites. Similar site ranking was produced regardless of whether the assessment was based on frequency of HF183 detection or site average HF183 concentration. However, site ranking differed greatly between dry and wet weather. Site ranking also differed greatly when based on enterococci, which do not distinguish between pollution sources, vs. HF183, which distinguishes higher risk human fecal sources from other sources, indicating the additional value of the human-associated marker as a routine monitoring tool. PMID:28777324

Regional Assessment of Human Fecal Contamination in Southern California Coastal Drainages.

PubMed

Cao, Yiping; Raith, Meredith R; Smith, Paul D; Griffith, John F; Weisberg, Stephen B; Schriewer, Alexander; Sheldon, Andrew; Crompton, Chris; Amenu, Geremew G; Gregory, Jason; Guzman, Joe; Goodwin, Kelly D; Othman, Laila; Manasjan, Mayela; Choi, Samuel; Rapoport, Shana; Steele, Syreeta; Nguyen, Tommy; Yu, Xueyuan

2017-08-04

Host-associated genetic markers that allow for fecal source identification have been used extensively as a diagnostic tool to determine fecal sources within watersheds, but have not been used in routine monitoring to prioritize remediation actions among watersheds. Here, we present a regional assessment of human marker prevalence among drainages that discharge to the U.S. southern California coast. Approximately 50 samples were analyzed for the HF183 human marker from each of 22 southern California coastal drainages under summer dry weather conditions, and another 50 samples were targeted from each of 23 drainages during wet weather. The HF183 marker was ubiquitous, detected in all but two sites in dry weather and at all sites during wet weather. However, there was considerable difference in the extent of human fecal contamination among sites. Similar site ranking was produced regardless of whether the assessment was based on frequency of HF183 detection or site average HF183 concentration. However, site ranking differed greatly between dry and wet weather. Site ranking also differed greatly when based on enterococci, which do not distinguish between pollution sources, vs. HF183, which distinguishes higher risk human fecal sources from other sources, indicating the additional value of the human-associated marker as a routine monitoring tool.

Data-quality measures for stakeholder-implemented watershed-monitoring programs

USGS Publications Warehouse

Greve, Adrienne I.

2002-01-01

Community-based watershed groups, many of which collect environmental data, have steadily increased in number over the last decade. The data generated by these programs are often underutilized due to uncertainty in the quality of data produced. The incorporation of data-quality measures into stakeholder monitoring programs lends statistical validity to data. Data-quality measures are divided into three steps: quality assurance, quality control, and quality assessment. The quality-assurance step attempts to control sources of error that cannot be directly quantified. This step is part of the design phase of a monitoring program and includes clearly defined, quantifiable objectives, sampling sites that meet the objectives, standardized protocols for sample collection, and standardized laboratory methods. Quality control (QC) is the collection of samples to assess the magnitude of error in a data set due to sampling, processing, transport, and analysis. In order to design a QC sampling program, a series of issues needs to be considered: (1) potential sources of error, (2) the type of QC samples, (3) inference space, (4) the number of QC samples, and (5) the distribution of the QC samples. Quality assessment is the process of evaluating quality-assurance measures and analyzing the QC data in order to interpret the environmental data. Quality assessment has two parts: one that is conducted on an ongoing basis as the monitoring program is running, and one that is conducted during the analysis of environmental data. The discussion of the data-quality measures is followed by an example of their application to a monitoring program in the Big Thompson River watershed of northern Colorado.

Accuracy assessment, using stratified plurality sampling, of portions of a LANDSAT classification of the Arctic National Wildlife Refuge Coastal Plain

NASA Technical Reports Server (NTRS)

Card, Don H.; Strong, Laurence L.

1989-01-01

An application of a classification accuracy assessment procedure is described for a vegetation and land cover map prepared by digital image processing of LANDSAT multispectral scanner data. A statistical sampling procedure called Stratified Plurality Sampling was used to assess the accuracy of portions of a map of the Arctic National Wildlife Refuge coastal plain. Results are tabulated as percent correct classification overall as well as per category with associated confidence intervals. Although values of percent correct were disappointingly low for most categories, the study was useful in highlighting sources of classification error and demonstrating shortcomings of the plurality sampling method.

Imaging using a supercontinuum laser to assess tumors in patients with breast carcinoma

NASA Astrophysics Data System (ADS)

Sordillo, Laura A.; Sordillo, Peter P.; Alfano, R. R.

2016-03-01

The supercontinuum laser light source has many advantages over other light sources, including broad spectral range. Transmission images of paired normal and malignant breast tissue samples from two patients were obtained using a Leukos supercontinuum (SC) laser light source with wavelengths in the second and third NIR optical windows and an IR- CCD InGaAs camera detector (Goodrich Sensors Inc. high response camera SU320KTSW-1.7RT with spectral response between 900 nm and 1,700 nm). Optical attenuation measurements at the four NIR optical windows were obtained from the samples.

Advancing the Use of Passive Sampling in Risk Assessment and Management of Sediments Contaminated with Hydrophobic Organic Chemicals: Results of an International Ex Situ Passive Sampling Interlaboratory Comparison

EPA Science Inventory

This work presents the results of an international interlaboratory comparison on ex situ passive sampling in sediments. The main objectives were to map the state of the science in passively sampling sediments, identify sources of variability, provide recommendations and practica...

Advancing the Use of Passive Sampling in Risk Assessment and Management of Sediments Contaminated with Hydrophobic Organic Chemicals: Results of an International Ex Situ Passive Sampling Interlaboratory Comparison

EPA Science Inventory

This work presents the results of an international interlaboratory comparison on ex situ passive sampling in sediments. The main objectives were to map the state of the science in passively sampling sediments, identify sources of variability, provide recommendations and practical...

Assessment of Giardia and Cryptosporidium spp. as a microbial source tracking tool for surface water: application in a mixed-use watershed.

PubMed

Prystajecky, Natalie; Huck, Peter M; Schreier, Hans; Isaac-Renton, Judith L

2014-04-01

Knowledge of host specificity, combined with genomic sequencing of Giardia and Cryptosporidium spp., has demonstrated a microbial source tracking (MST) utility for these common waterborne microbes. To explore the source attribution potential of these pathogens, water samples were collected in a mixed rural-urban watershed in the Township of Langley, in southwestern British Columbia (BC), Canada, over a 2-year period. Cryptosporidium was detected in 63% of surface water samples at concentrations ranging from no positive detection (NPD) to 20,600 oocysts per 100 liters. Giardia was detected in 86% of surface water samples at concentrations ranging from NPD to 3,800 cysts per 100 liters of water. Sequencing at the 18S rRNA locus revealed that 50% of Cryptosporidium samples and 98% of Giardia samples contained species/genotypes (Cryptosporidium) or assemblages (Giardia) that are capable of infecting humans, based on current knowledge of host specificity and taxonomy. Cryptosporidium genotyping data were more promising for source tracking potential, due to the greater number of host-adapted (i.e., narrow-host-range) species/genotypes compared to Giardia, since 98% of Giardia isolates were zoonotic and the potential host could not be predicted. This report highlights the benefits of parasite genomic sequencing to complement Method 1623 (U.S. Environmental Protection Agency) and shows that Cryptosporidium subtyping for MST purposes is superior to the use of Giardia subtyping, based on better detection limits for Cryptosporidium-positive samples than for Giardia-positive samples and on greater host specificity among Cryptosporidium species. These additional tools could be used for risk assessment in public health and watershed management decisions.

Assessment of Giardia and Cryptosporidium spp. as a Microbial Source Tracking Tool for Surface Water: Application in a Mixed-Use Watershed

PubMed Central

Huck, Peter M.; Schreier, Hans; Isaac-Renton, Judith L.

2014-01-01

Knowledge of host specificity, combined with genomic sequencing of Giardia and Cryptosporidium spp., has demonstrated a microbial source tracking (MST) utility for these common waterborne microbes. To explore the source attribution potential of these pathogens, water samples were collected in a mixed rural-urban watershed in the Township of Langley, in southwestern British Columbia (BC), Canada, over a 2-year period. Cryptosporidium was detected in 63% of surface water samples at concentrations ranging from no positive detection (NPD) to 20,600 oocysts per 100 liters. Giardia was detected in 86% of surface water samples at concentrations ranging from NPD to 3,800 cysts per 100 liters of water. Sequencing at the 18S rRNA locus revealed that 50% of Cryptosporidium samples and 98% of Giardia samples contained species/genotypes (Cryptosporidium) or assemblages (Giardia) that are capable of infecting humans, based on current knowledge of host specificity and taxonomy. Cryptosporidium genotyping data were more promising for source tracking potential, due to the greater number of host-adapted (i.e., narrow-host-range) species/genotypes compared to Giardia, since 98% of Giardia isolates were zoonotic and the potential host could not be predicted. This report highlights the benefits of parasite genomic sequencing to complement Method 1623 (U.S. Environmental Protection Agency) and shows that Cryptosporidium subtyping for MST purposes is superior to the use of Giardia subtyping, based on better detection limits for Cryptosporidium-positive samples than for Giardia-positive samples and on greater host specificity among Cryptosporidium species. These additional tools could be used for risk assessment in public health and watershed management decisions. PMID:24463970

Statistical aspects of carbon fiber risk assessment modeling. [fire accidents involving aircraft

NASA Technical Reports Server (NTRS)

Gross, D.; Miller, D. R.; Soland, R. M.

1980-01-01

The probabilistic and statistical aspects of the carbon fiber risk assessment modeling of fire accidents involving commercial aircraft are examined. Three major sources of uncertainty in the modeling effort are identified. These are: (1) imprecise knowledge in establishing the model; (2) parameter estimation; and (3)Monte Carlo sampling error. All three sources of uncertainty are treated and statistical procedures are utilized and/or developed to control them wherever possible.

Quality of Source Water from Public-Supply Wells in the United States, 1993-2007

USGS Publications Warehouse

Toccalino, Patricia L.; Norman, Julia E.; Hitt, Kerie J.

2010-01-01

More than one-third of the Nation's population receives their drinking water from public water systems that use groundwater as their source. The U.S. Geological Survey (USGS) sampled untreated source water from 932 public-supply wells, hereafter referred to as public wells, as part of multiple groundwater assessments conducted across the Nation during 1993-2007. The objectives of this study were to evaluate (1) contaminant occurrence in source water from public wells and the potential significance of contaminant concentrations to human health, (2) national and regional distributions of groundwater quality, and (3) the occurrence and characteristics of contaminant mixtures. Treated finished water was not sampled. The 932 public wells are widely distributed nationally and include wells in selected parts of 41 states and withdraw water from parts of 30 regionally extensive aquifers used for public water supply. These wells are distributed among 629 unique public water systems-less than 1 percent of all groundwater-supplied public water systems in the United States-but the wells were randomly selected within the sampled hydrogeologic settings to represent typical aquifer conditions. Samples from the 629 systems represent source water used by one-quarter of the U.S. population served by groundwater-supplied public water systems, or about 9 percent of the entire U.S. population in 2008. One groundwater sample was collected prior to treatment or blending from each of the 932 public wells and analyzed for as many as six water-quality properties and 215 contaminants. Consistent with the terminology used in the Safe Drinking Water Act (SDWA), all constituents analyzed in water samples in this study are referred to as 'contaminants'. More contaminant groups were assessed in this study than in any previous national study of public wells and included major ions, nutrients, radionuclides, trace elements, pesticide compounds, volatile organic compounds (VOCs), and fecal-indicator microorganisms. Contaminant mixtures were assessed in subsets of samples in which most contaminants were analyzed. Contaminant concentrations were compared to human-health benchmarks-regulatory U.S. Environmental Protection Agency (USEPA) Maximum Contaminant Levels (MCLs) for contaminants regulated in drinking water under the SDWA or non-regulatory USGS Health-Based Screening Levels (HBSLs) for unregulated contaminants, when available. Nearly three-quarters of the contaminants assessed in this study are unregulated in drinking water, and the USEPA uses USGS data on the occurrence of unregulated contaminants in water resources to fulfill part of the SDWA requirements for determining whether specific contaminants should be regulated in drinking water in the future. More than one in five (22 percent) source-water samples from public wells contained one or more naturally occurring or man-made contaminants at concentrations greater than human-health benchmarks, and 80 percent of samples contained one or more contaminants at concentrations greater than one-tenth of benchmarks. Most individual contaminant detections, however, were less than one-tenth of human-health benchmarks. Public wells yielding water with contaminant concentrations greater than benchmarks, as well as those with concentrations greater than one-tenth of benchmarks, were distributed throughout the United States and included wells that withdraw water from all principal aquifer rock types included in this study. Ten contaminants individually were detected at concentrations greater than human-health benchmarks in at least 1 percent of source-water samples and collectively accounted for most concentrations greater than benchmarks. Seven of these 10 contaminants occur naturally, including three radionuclides (radon, radium, and gross alpha-particle radioactivity) and four trace elements (arsenic, manganese, strontium, and boron); three of these 10 contaminants (dieldrin, nitrate, and perchl

Selecting Communication Channels for Substance Misuse Prevention with At-Risk African-American Emerging Adults Living in the Southern United States

ERIC Educational Resources Information Center

Tucker, Jalie A.; Cheong, JeeWon; Chandler, Susan D.

2016-01-01

Natural health information sources used by African-American emerging adults were investigated to identify sources associated with high and low substance-related risk. Participants (110 males, 234 females; M age = 18.9 years) were recruited using respondent-driven sampling, and structured interviews assessed substance use, sources of health…

Verifying Sediment Fingerprinting Results with Known Mixtures

NASA Astrophysics Data System (ADS)

Gellis, A.; Gorman-Sanisaca, L.; Cashman, M. J.

2017-12-01

Sediment fingerprinting is a widely used approach to determine the specific sources of fluvial sediment within a watershed. It relies on the principle that potential sediment sources can be identified using a set of chemical tracers (or fingerprints), and comparison of these source fingerprints with fluvial (target) sediment allows for source apportionment of the fluvial sediment. There are numerous source classifications, fingerprints, and statistical approaches used in the literature to apportion sources of sediment. However, few of these studies have sought to test the method by creating controls on the ratio of sources in the target sediment. Without a controlled environment for inputs and outputs, such verification of results is ambiguous. Here, we generated artificial mixtures of source sediment from an agricultural/forested watershed in Virginia, USA (Smith Creek, 246 km2) to verify the apportionment results. Target samples were established from known mixtures of the four major sediment sources in the watershed (forest, pasture, cropland, and streambanks). The target samples were sieved to less than 63 microns and analyzed for elemental and isotopic chemistry. The target samples and source samples were run through the Sediment Source Assessment Tool (Sed_SAT) to verify if the statistical operations provided the correct apportionment. Sed_SAT uses a multivariate parametric approach to identify the minimum suite of fingerprints that discriminate the source areas and applies these fingerprints through an unmixng model to apportion sediment. The results of this sediment fingerprinting verification experiment will be presented in this session.

Characterization of metals emitted from motor vehicles.

PubMed

Schauer, James J; Lough, Glynis C; Shafer, Martin M; Christensen, William F; Arndt, Michael F; DeMinter, Jeffrey T; Park, June-Soo

2006-03-01

A systematic approach was used to quantify the metals present in particulate matter emissions associated with on-road motor vehicles. Consistent sampling and chemical analysis techniques were used to determine the chemical composition of particulate matter less than 10 microm in aerodynamic diameter (PM10*) and particulate matter less than 2.5 microm in aerodynamic diameter (PM2.5), including analysis of trace metals by inductively coupled plasma mass spectrometry (ICP-MS). Four sources of metals were analyzed in emissions associated with motor vehicles: tailpipe emissions from gasoline- and diesel-powered vehicles, brake wear, tire wear, and resuspended road dust. Profiles for these sources were used in a chemical mass balance (CMB) model to quantify their relative contributions to the metal emissions measured in roadway tunnel tests in Milwaukee, Wisconsin. Roadway tunnel measurements were supplemented by parallel measurements of atmospheric particulate matter and associated metals at three urban locations: Milwaukee and Waukesha, Wisconsin, and Denver, Colorado. Ambient aerosol samples were collected every sixth day for one year and analyzed by the same chemical analysis techniques used for the source samples. The two Wisconsin sites were studied to assess the spatial differences, within one urban airshed, of trace metals present in atmospheric particulate matter. The measurements were evaluated to help understand source and seasonal trends in atmospheric concentrations of trace metals. ICP-MS methods have not been widely used in analyses of ambient aerosols for metals despite demonstrated advantages over traditional techniques. In a preliminary study, ICP-MS techniques were used to assess the leachability of trace metals present in atmospheric particulate matter samples and motor vehicle source samples in a synthetic lung fluid.

Concentration data for anthropogenic organic compounds in groundwater, surface water, and finished water of selected community water systems in the United States, 2002-10

USGS Publications Warehouse

Carter, Janet M.; Kingsbury, James A.; Hopple, Jessica A.; Delzer, Gregory C.

2010-01-01

The National Water-Quality Assessment Program of the U.S. Geological Survey began implementing Source Water-Quality Assessments (SWQAs) in 2001 that focus on characterizing the quality of source water and finished water of aquifers and major rivers used by some of the larger community water systems in the United States. As used in SWQA studies, source water is the raw (ambient) water collected at the supply well before water treatment (for groundwater) or the raw (ambient) water collected from the river near the intake (for surface water), and finished water is the water that has been treated and is ready to be delivered to consumers. Finished-water samples are collected before the water enters the distribution system. The primary objective of SWQAs is to determine the occurrence of more than 250 anthropogenic organic compounds in source water used by community water systems, many of which currently are unregulated in drinking water by the U.S. Environmental Protection Agency. A secondary objective is to understand recurrence patterns in source water and determine if these patterns also occur in finished water before distribution. SWQA studies were conducted in two phases for most studies completed by 2005, and in one phase for most studies completed since 2005. Analytical results are reported for a total of 295 different anthropogenic organic compounds monitored in source-water and finished-water samples collected during 2002-10. The 295 compounds were classified according to the following 13 primary use or source groups: (1) disinfection by-products; (2) fumigant-related compounds; (3) fungicides; (4) gasoline hydrocarbons, oxygenates, and oxygenate degradates; (5) herbicides and herbicide degradates; (6) insecticides and insecticide degradates; (7) manufacturing additives; (8) organic synthesis compounds; (9) pavement- and combustion-derived compounds; (10) personal-care and domestic-use products; (11) plant- or animal-derived biochemicals; (12) refrigerants and propellants; and (13) solvents. This report presents the analytical results of source- water samples from 448 community water system wells and 21 surface-water sites. This report also presents the analytical results of finished-water samples from 285 wells and 20 surface-water sites from community water systems. Results of quality-assurance/quality-control samples also are presented including data for equipment blanks, field blanks, source solution blanks, and replicate samples.

Preliminary assessment of the risk of Salmonella infection in dogs fed raw chicken diets.

PubMed

Joffe, Daniel J; Schlesinger, Daniel P

2002-06-01

This preliminary study assessed the presence of Salmonella spp. in a bones and raw food (BARF) diet and in the stools of dogs consuming it. Salmonella was isolated from 80% of the BARF diet samples (P < 0.001) and from 30% of the stool samples from dogs fed the diet (P = 0.105). Dogs fed raw chicken may therefore be a source of environmental contamination.

Performance of maximum likelihood mixture models to estimate nursery habitat contributions to fish stocks: a case study on sea bream Sparus aurata

PubMed Central

Darnaude, Audrey M.

2016-01-01

Background Mixture models (MM) can be used to describe mixed stocks considering three sets of parameters: the total number of contributing sources, their chemical baseline signatures and their mixing proportions. When all nursery sources have been previously identified and sampled for juvenile fish to produce baseline nursery-signatures, mixing proportions are the only unknown set of parameters to be estimated from the mixed-stock data. Otherwise, the number of sources, as well as some/all nursery-signatures may need to be also estimated from the mixed-stock data. Our goal was to assess bias and uncertainty in these MM parameters when estimated using unconditional maximum likelihood approaches (ML-MM), under several incomplete sampling and nursery-signature separation scenarios. Methods We used a comprehensive dataset containing otolith elemental signatures of 301 juvenile Sparus aurata, sampled in three contrasting years (2008, 2010, 2011), from four distinct nursery habitats. (Mediterranean lagoons) Artificial nursery-source and mixed-stock datasets were produced considering: five different sampling scenarios where 0–4 lagoons were excluded from the nursery-source dataset and six nursery-signature separation scenarios that simulated data separated 0.5, 1.5, 2.5, 3.5, 4.5 and 5.5 standard deviations among nursery-signature centroids. Bias (BI) and uncertainty (SE) were computed to assess reliability for each of the three sets of MM parameters. Results Both bias and uncertainty in mixing proportion estimates were low (BI ≤ 0.14, SE ≤ 0.06) when all nursery-sources were sampled but exhibited large variability among cohorts and increased with the number of non-sampled sources up to BI = 0.24 and SE = 0.11. Bias and variability in baseline signature estimates also increased with the number of non-sampled sources, but tended to be less biased, and more uncertain than mixing proportion ones, across all sampling scenarios (BI < 0.13, SE < 0.29). Increasing separation among nursery signatures improved reliability of mixing proportion estimates, but lead to non-linear responses in baseline signature parameters. Low uncertainty, but a consistent underestimation bias affected the estimated number of nursery sources, across all incomplete sampling scenarios. Discussion ML-MM produced reliable estimates of mixing proportions and nursery-signatures under an important range of incomplete sampling and nursery-signature separation scenarios. This method failed, however, in estimating the true number of nursery sources, reflecting a pervasive issue affecting mixture models, within and beyond the ML framework. Large differences in bias and uncertainty found among cohorts were linked to differences in separation of chemical signatures among nursery habitats. Simulation approaches, such as those presented here, could be useful to evaluate sensitivity of MM results to separation and variability in nursery-signatures for other species, habitats or cohorts. PMID:27761305

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.

Urban air quality assessment using monitoring data of fractionized aerosol samples, chemometrics and meteorological conditions.

PubMed

Yotova, Galina I; Tsitouridou, Roxani; Tsakovski, Stefan L; Simeonov, Vasil D

2016-01-01

The present article deals with assessment of urban air by using monitoring data for 10 different aerosol fractions (0.015-16 μm) collected at a typical urban site in City of Thessaloniki, Greece. The data set was subject to multivariate statistical analysis (cluster analysis and principal components analysis) and, additionally, to HYSPLIT back trajectory modeling in order to assess in a better way the impact of the weather conditions on the pollution sources identified. A specific element of the study is the effort to clarify the role of outliers in the data set. The reason for the appearance of outliers is strongly related to the atmospheric condition on the particular sampling days leading to enhanced concentration of pollutants (secondary emissions, sea sprays, road and soil dust, combustion processes) especially for ultra fine and coarse particles. It is also shown that three major sources affect the urban air quality of the location studied-sea sprays, mineral dust and anthropogenic influences (agricultural activity, combustion processes, and industrial sources). The level of impact is related to certain extent to the aerosol fraction size. The assessment of the meteorological conditions leads to defining of four downwind patterns affecting the air quality (Pelagic, Western and Central Europe, Eastern and Northeastern Europe and Africa and Southern Europe). Thus, the present study offers a complete urban air assessment taking into account the weather conditions, pollution sources and aerosol fractioning.

Concentration data for anthropogenic organic compounds in ground water, surface water, and finished water of selected community water systems in the United States, 2002-05

USGS Publications Warehouse

Carter, Janet M.; Delzer, Gregory C.; Kingsbury, James A.; Hopple, Jessica A.

2007-01-01

The National Water-Quality Assessment Program of the U.S. Geological Survey began implementing Source Water-Quality Assessments (SWQAs) in 2001 that focus on characterizing the quality of source water and finished water of aquifers and major rivers used by some of the larger community water systems (CWSs) in the United States. As used for SWQA studies, source water is the raw (ambient) water collected at the supply well prior to water treatment (for ground water) or the raw (ambient) water collected from the river near the intake (for surface water), and finished water is the water that is treated and ready to be delivered to consumers. Finished water is collected before entering the distribution system. SWQA studies are conducted in two phases, and the objectives of SWQA studies are twofold: (1) to determine the occurrence and, for rivers, seasonal changes in concentrations of a broad list of anthropogenic organic compounds (AOCs) in aquifers and rivers that have some of the largest withdrawals for drinking-water supply (phase 1), and (2) for those AOCs found to occur most frequently in source water, characterize the extent to which these compounds are present in finished water (phase 2). These objectives were met for SWQA studies by collecting ground-water and surface-water (source) samples and analyzing these samples for 258 AOCs during phase 1. Samples from a subset of wells and surface-water sites located in areas with substantial agricultural production in the watershed were analyzed for 19 additional AOCs, for a total of 277 compounds analyzed for SWQA studies. The 277 compounds were classified according to the following 13 primary use or source groups: (1) disinfection by-products; (2) fumigant-related compounds; (3) fungicides; (4) gasoline hydrocarbons, oxygenates, and oxygenate degradates; (5) herbicides and herbicide degradates; (6) insecticides and insecticide degradates; (7) manufacturing additives; (8) organic synthesis compounds; (9) pavement- and combustion-derived compounds; (10) personal care and domestic use products; (11) plant- or animal-derived biochemicals; (12) refrigerants and propellants; and (13) solvents. Source and finished water samples were collected during phase 2 and analyzed for constituents that were detected frequently during phase 1. This report presents concentration data for AOCs in ground water, surface water, and finished water of CWSs sampled for SWQA studies during 2002-05. Specifically, this report presents the analytical results of samples collected during phase 1 including (1) samples from 221 wells that were analyzed for 258 AOCs; (2) monthly samples from 9 surface-water sites that were analyzed for 258 AOCs during phase 1; and (3) samples from a subset of the wells and surface-water sites located in areas with substantial agricultural production that were analyzed for 3 additional pesticides and 16 pesticide degradates. Samples collected during phase 2 were analyzed for selected AOCs that were detected most frequently in source water during phase 1 sampling; analytical results for phase 2 are presented for (1) samples of source water and finished water from 94 wells; and (2) samples of source water and finished water samples that were collected monthly and during selected flow conditions at 8 surface-water sites. Results of quality-assurance/quality-control samples collected for SWQA studies during 2002-05 also are presented.

SPECIATION OF ARSENIC IN DIETARY AND DIETARY COMPOSITE SAMPLES TO PROVIDE A MORE COMPLETE ASSESSMENT OF ARSENIC EXPOSURE FROM DIETARY SOURCES

EPA Science Inventory

The FDA's market basket study reports total arsenic concentrations from composite diet samples. The use of composite diets, based on market basket sampling, is the most cost effective means of obtaining a generic arsenic exposure estimate for a population. For example, the tota...

PRELIMINARY DATABASE DEVELOPMENT IN TARGET DIETARY SAMPLES AND COMPOSITE DIET SAMPLES

EPA Science Inventory

Food may surpass drinking water as the major source of ingestion of total elemental arsenic for the general population. For this reason, accurate assessments of inorganic arsenic intake via food are needed to provide estimates for dietary exposure within future epidemiology stud...

Lead Sampling Protocols: Why So Many and What Do They Tell You?

EPA Science Inventory

Sampling protocols can be broadly categorized based on their intended purpose of 1) Pb regulatory compliance/corrosion control efficacy, 2) Pb plumbing source determination or Pb type identification, and 3) Pb exposure assessment. Choosing the appropriate protocol is crucial to p...

Psychometric Evaluation of Lexical Diversity Indices: Assessing Length Effects.

PubMed

Fergadiotis, Gerasimos; Wright, Heather Harris; Green, Samuel B

2015-06-01

Several novel techniques have been developed recently to assess the breadth of a speaker's vocabulary exhibited in a language sample. The specific aim of this study was to increase our understanding of the validity of the scores generated by different lexical diversity (LD) estimation techniques. Four techniques were explored: D, Maas, measure of textual lexical diversity, and moving-average type-token ratio. Four LD indices were estimated for language samples on 4 discourse tasks (procedures, eventcasts, story retell, and recounts) from 442 adults who are neurologically intact. The resulting data were analyzed using structural equation modeling. The scores for measure of textual lexical diversity and moving-average type-token ratio were stronger indicators of the LD of the language samples. The results for the other 2 techniques were consistent with the presence of method factors representing construct-irrelevant sources. These findings offer a deeper understanding of the relative validity of the 4 estimation techniques and should assist clinicians and researchers in the selection of LD measures of language samples that minimize construct-irrelevant sources.

Uncertainty Assessment of Synthetic Design Hydrographs for Gauged and Ungauged Catchments

NASA Astrophysics Data System (ADS)

Brunner, Manuela I.; Sikorska, Anna E.; Furrer, Reinhard; Favre, Anne-Catherine

2018-03-01

Design hydrographs described by peak discharge, hydrograph volume, and hydrograph shape are essential for engineering tasks involving storage. Such design hydrographs are inherently uncertain as are classical flood estimates focusing on peak discharge only. Various sources of uncertainty contribute to the total uncertainty of synthetic design hydrographs for gauged and ungauged catchments. These comprise model uncertainties, sampling uncertainty, and uncertainty due to the choice of a regionalization method. A quantification of the uncertainties associated with flood estimates is essential for reliable decision making and allows for the identification of important uncertainty sources. We therefore propose an uncertainty assessment framework for the quantification of the uncertainty associated with synthetic design hydrographs. The framework is based on bootstrap simulations and consists of three levels of complexity. On the first level, we assess the uncertainty due to individual uncertainty sources. On the second level, we quantify the total uncertainty of design hydrographs for gauged catchments and the total uncertainty of regionalizing them to ungauged catchments but independently from the construction uncertainty. On the third level, we assess the coupled uncertainty of synthetic design hydrographs in ungauged catchments, jointly considering construction and regionalization uncertainty. We find that the most important sources of uncertainty in design hydrograph construction are the record length and the choice of the flood sampling strategy. The total uncertainty of design hydrographs in ungauged catchments depends on the catchment properties and is not negligible in our case.

Ultrafiltration and Microarray for Detection of Microbial Source Tracking Marker and Pathogen Genes in Riverine and Marine Systems

PubMed Central

Li, Xiang; Harwood, Valerie J.; Nayak, Bina

2016-01-01

Pathogen identification and microbial source tracking (MST) to identify sources of fecal pollution improve evaluation of water quality. They contribute to improved assessment of human health risks and remediation of pollution sources. An MST microarray was used to simultaneously detect genes for multiple pathogens and indicators of fecal pollution in freshwater, marine water, sewage-contaminated freshwater and marine water, and treated wastewater. Dead-end ultrafiltration (DEUF) was used to concentrate organisms from water samples, yielding a recovery efficiency of >95% for Escherichia coli and human polyomavirus. Whole-genome amplification (WGA) increased gene copies from ultrafiltered samples and increased the sensitivity of the microarray. Viruses (adenovirus, bocavirus, hepatitis A virus, and human polyomaviruses) were detected in sewage-contaminated samples. Pathogens such as Legionella pneumophila, Shigella flexneri, and Campylobacter fetus were detected along with genes conferring resistance to aminoglycosides, beta-lactams, and tetracycline. Nonmetric dimensional analysis of MST marker genes grouped sewage-spiked freshwater and marine samples with sewage and apart from other fecal sources. The sensitivity (percent true positives) of the microarray probes for gene targets anticipated in sewage was 51 to 57% and was lower than the specificity (percent true negatives; 79 to 81%). A linear relationship between gene copies determined by quantitative PCR and microarray fluorescence was found, indicating the semiquantitative nature of the MST microarray. These results indicate that ultrafiltration coupled with WGA provides sufficient nucleic acids for detection of viruses, bacteria, protozoa, and antibiotic resistance genes by the microarray in applications ranging from beach monitoring to risk assessment. PMID:26729716

Photonic Breast Tomography and Tumor Aggressiveness Assessment

DTIC Science & Technology

2012-07-01

c) Raw Image 11 The entrance face of the slab sample (source plane) was illuminated by a 100-mW 790-nm diode laser beam. The multi-source...schematically shown in Figure 6. A 10mW 785 nm diode laser beam was used to illuminate the first sample, while a 100mW 785 nm diode laser beam was used for the...signal transmitting narrow-band filter; TS = translation stage; CCD = charge cou- pled device; and PC = computer. Continuous wave 790-nm diode laser

Drinking water quality assessment.

PubMed

Aryal, J; Gautam, B; Sapkota, N

2012-09-01

Drinking water quality is the great public health concern because it is a major risk factor for high incidence of diarrheal diseases in Nepal. In the recent years, the prevalence rate of diarrhoea has been found the highest in Myagdi district. This study was carried out to assess the quality of drinking water from different natural sources, reservoirs and collection taps at Arthunge VDC of Myagdi district. A cross-sectional study was carried out using random sampling method in Arthunge VDC of Myagdi district from January to June,2010. 84 water samples representing natural sources, reservoirs and collection taps from the study area were collected. The physico-chemical and microbiological analysis was performed following standards technique set by APHA 1998 and statistical analysis was carried out using SPSS 11.5. The result was also compared with national and WHO guidelines. Out of 84 water samples (from natural source, reservoirs and tap water) analyzed, drinking water quality parameters (except arsenic and total coliform) of all water samples was found to be within the WHO standards and national standards.15.48% of water samples showed pH (13) higher than the WHO permissible guideline values. Similarly, 85.71% of water samples showed higher Arsenic value (72) than WHO value. Further, the statistical analysis showed no significant difference (P<0.05) of physico-chemical parameters and total coliform count of drinking water for collection taps water samples of winter (January, 2010) and summer (June, 2010). The microbiological examination of water samples revealed the presence of total coliform in 86.90% of water samples. The results obtained from physico-chemical analysis of water samples were within national standard and WHO standards except arsenic. The study also found the coliform contamination to be the key problem with drinking water.

A Systematic Review of Surgical Randomized Controlled Trials: Part 2. Funding Source, Conflict of Interest, and Sample Size in Plastic Surgery.

PubMed

Voineskos, Sophocles H; Coroneos, Christopher J; Ziolkowski, Natalia I; Kaur, Manraj N; Banfield, Laura; Meade, Maureen O; Chung, Kevin C; Thoma, Achilleas; Bhandari, Mohit

2016-02-01

The authors examined industry support, conflict of interest, and sample size in plastic surgery randomized controlled trials that compared surgical interventions. They hypothesized that industry-funded trials demonstrate statistically significant outcomes more often, and randomized controlled trials with small sample sizes report statistically significant results more frequently. An electronic search identified randomized controlled trials published between 2000 and 2013. Independent reviewers assessed manuscripts and performed data extraction. Funding source, conflict of interest, primary outcome direction, and sample size were examined. Chi-squared and independent-samples t tests were used in the analysis. The search identified 173 randomized controlled trials, of which 100 (58 percent) did not acknowledge funding status. A relationship between funding source and trial outcome direction was not observed. Both funding status and conflict of interest reporting improved over time. Only 24 percent (six of 25) of industry-funded randomized controlled trials reported authors to have independent control of data and manuscript contents. The mean number of patients randomized was 73 per trial (median, 43, minimum, 3, maximum, 936). Small trials were not found to be positive more often than large trials (p = 0.87). Randomized controlled trials with small sample size were common; however, this provides great opportunity for the field to engage in further collaboration and produce larger, more definitive trials. Reporting of trial funding and conflict of interest is historically poor, but it greatly improved over the study period. Underreporting at author and journal levels remains a limitation when assessing the relationship between funding source and trial outcomes. Improved reporting and manuscript control should be goals that both authors and journals can actively achieve.

A Randomized Controlled Trial to Assess the Impact of Ceramic Water Filters on Prevention of Diarrhea and Cryptosporidiosis in Infants and Young Children-Western Kenya, 2013.

PubMed

Morris, Jamae Fontain; Murphy, Jennifer; Fagerli, Kirsten; Schneeberger, Chandra; Jaron, Peter; Moke, Fenny; Juma, Jane; Ochieng, J Ben; Omore, Richard; Roellig, Dawn; Xiao, Lihua; Priest, Jeffrey W; Narayanan, Jothikumar; Montgomery, Joel; Hill, Vince; Mintz, Eric; Ayers, Tracy L; O'Reilly, Ciara E

2018-04-02

Cryptosporidium is a leading cause of diarrhea among Kenyan infants. Ceramic water filters (CWFs) are used for household water treatment. We assessed the impact of CWFs on diarrhea, cryptosporidiosis prevention, and water quality in rural western Kenya. A randomized, controlled intervention trial was conducted in 240 households with infants 4-10 months old. Twenty-six weekly household surveys assessed infant diarrhea and health facility visits. Stool specimens from infants with diarrhea were examined for Cryptosporidium . Source water, filtered water, and filter retentate were tested for Cryptosporidium and/or microbial indicators. To estimate the effect of CWFs on health outcomes, logistic regression models using generalized estimating equations were performed; odds ratios (ORs) and 95% confidence intervals (CIs) are reported. Households reported using surface water (36%), public taps (29%), or rainwater (17%) as their primary drinking water sources, with no differences in treatment groups. Intervention households reported less diarrhea (7.6% versus 8.9%; OR: 0.86 [0.64-1.16]) and significantly fewer health facility visits for diarrhea (1.0% versus 1.9%; OR: 0.50 [0.30-0.83]). In total, 15% of intervention and 12% of control stools yielded Cryptosporidium ( P = 0.26). Escherichia coli was detected in 93% of source water samples; 71% of filtered water samples met World Health Organization recommendations of < 1 E. coli /100 mL. Cryptosporidium was not detected in source water and was detected in just 2% of filter rinses following passage of large volumes of source water. Water quality was improved among CWF users; however, the short study duration and small sample size limited our ability to observe reductions in cryptosporidiosis.

Preliminary assessment of the risk of Salmonella infection in dogs fed raw chicken diets

PubMed Central

Joffe, Daniel J.; Schlesinger, Daniel P.

2002-01-01

This preliminary study assessed the presence of Salmonella spp. in a bones and raw food (BARF) diet and in the stools of dogs consuming it. Salmonella was isolated from 80% of the BARF diet samples (P < 0.001) and from 30% of the stool samples from dogs fed the diet (P = 0.105). Dogs fed raw chicken may therefore be a source of environmental contamination. PMID:12058569

Assessment of Ecological Risk of Heavy Metal Contamination in Coastal Municipalities of Montenegro

PubMed Central

Mugoša, Boban; Đurović, Dijana; Nedović-Vuković, Mirjana; Barjaktarović-Labović, Snežana; Vrvić, Miroslav

2016-01-01

Assessment of heavy metal concentrations in the soil samples of urban parks and playgrounds is very important for the evaluation of potential risks for residents, especially children. Until recently, there has been very little data about urban parks pollution in Montenegro. To evaluate the sources of potential contamination and concentration of heavy metals, soil samples from coastal urban parks and kindergartens of Montenegro were collected. Based on the heavy metal concentrations, multivariate analysis combined with geochemical approaches showed that soil samples in coastal areas of Montenegro had mean Pb and Cd concentrations that were over two times higher than the background values, respectively. Based on principal component analysis (PCA), soil pollution with Pb, Cd, Cu, and Zn is contributed by anthropogenic sources. Results for Cr in the surface soils were primarily derived from natural sources. Calculation of different ecological contamination factors showed that Cd is the primary contribution to ecological risk index (RI) origins from anthropogenic, industry, and urbanization sources. This data provides evidence about soil pollution in coastal municipalities of Montenegro. Special attention should be paid to this problem in order to continue further research and to consider possible ways of remediation of the sites where contamination has been observed. PMID:27043601

Assessment of sewer source contamination of drinking water wells using tracers and human enteric viruses

USGS Publications Warehouse

Hunt, R.J.; Borchardt, M. A.; Richards, K.D.; Spencer, S. K.

2010-01-01

This study investigated the source, transport, and occurrence of human enteric viruses in municipal well water, focusing on sanitary sewer sources. A total of 33 wells from 14 communities were sampled once for wastewater tracers and viruses. Wastewater tracers were detected in four of these wells, and five wells were virus- positive by qRT-PCR. These results, along with exclusion of wells with surface water sources, were used to select three wells for additional investigation. Viruses and wastewater tracers were found in the groundwater at all sites. Some wastewater tracers, such as ionic detergents, flame retardants, and cholesterol, were considered unambiguous evidence of wastewater. Sampling at any given time may not show concurrent virus and tracer presence; however, given sufficient sampling over time, a relation between wastewater tracers and virus occurrence was identified. Presence of infectious viruses at the wellhead demonstrates that high-capacity pumping induced sufficiently short travel times for the transport of infectious viruses. Therefore, drinking-water wells are vulnerable to contaminants that travel along fast groundwater flowpaths even if they contribute a small amount of virus-laden water to the well. These results suggest that vulnerability assessments require characterization of "low yield-fast transport" in addition to traditional "high yield-slow transport", pathways. ?? 2010 American Chemical Society.

Integrated Cryptosporidium Assay To Determine Oocyst Density, Infectivity, and Genotype for Risk Assessment of Source and Reuse Water

PubMed Central

King, Brendon; Fanok, Stella; Phillips, Renae; Swaffer, Brooke

2015-01-01

Cryptosporidium continues to be problematic for the water industry, with risk assessments often indicating that treatment barriers may fail under extreme conditions. However, risk analyses have historically used oocyst densities and not considered either oocyst infectivity or species/genotype, which can result in an overestimation of risk if the oocysts are not human infective. We describe an integrated assay for determining oocyst density, infectivity, and genotype from a single-sample concentrate, an important advance that overcomes the need for processing multiple-grab samples or splitting sample concentrates for separate analyses. The assay incorporates an oocyst recovery control and is compatible with standard primary concentration techniques. Oocysts were purified from primary concentrates using immunomagnetic separation prior to processing by an infectivity assay. Plate-based cell culture was used to detect infectious foci, with a monolayer washing protocol developed to allow recovery and enumeration of oocysts. A simple DNA extraction protocol was developed to allow typing of any wells containing infectious Cryptosporidium. Water samples from a variety of source water and wastewater matrices, including a semirural catchment, wastewater, an aquifer recharge site, and storm water, were analyzed using the assay. Results demonstrate that the assay can reliably determine oocyst densities, infectivity, and genotype from single-grab samples for a variety of water matrices and emphasize the varying nature of Cryptosporidium risk extant throughout source waters and wastewaters. This assay should therefore enable a more comprehensive understanding of Cryptosporidium risk for different water sources, assisting in the selection of appropriate risk mitigation measures. PMID:25769833

Integrated cryptosporidium assay to determine oocyst density, infectivity, and genotype for risk assessment of source and reuse water.

PubMed

King, Brendon; Fanok, Stella; Phillips, Renae; Swaffer, Brooke; Monis, Paul

2015-05-15

Cryptosporidium continues to be problematic for the water industry, with risk assessments often indicating that treatment barriers may fail under extreme conditions. However, risk analyses have historically used oocyst densities and not considered either oocyst infectivity or species/genotype, which can result in an overestimation of risk if the oocysts are not human infective. We describe an integrated assay for determining oocyst density, infectivity, and genotype from a single-sample concentrate, an important advance that overcomes the need for processing multiple-grab samples or splitting sample concentrates for separate analyses. The assay incorporates an oocyst recovery control and is compatible with standard primary concentration techniques. Oocysts were purified from primary concentrates using immunomagnetic separation prior to processing by an infectivity assay. Plate-based cell culture was used to detect infectious foci, with a monolayer washing protocol developed to allow recovery and enumeration of oocysts. A simple DNA extraction protocol was developed to allow typing of any wells containing infectious Cryptosporidium. Water samples from a variety of source water and wastewater matrices, including a semirural catchment, wastewater, an aquifer recharge site, and storm water, were analyzed using the assay. Results demonstrate that the assay can reliably determine oocyst densities, infectivity, and genotype from single-grab samples for a variety of water matrices and emphasize the varying nature of Cryptosporidium risk extant throughout source waters and wastewaters. This assay should therefore enable a more comprehensive understanding of Cryptosporidium risk for different water sources, assisting in the selection of appropriate risk mitigation measures. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Elemental Composition of Mars Return Samples Using X-Ray Fluorescence Imaging at the National Synchrotron Light Source II

NASA Astrophysics Data System (ADS)

Thieme, J.; Hurowitz, J. A.; Schoonen, M. A.; Fogelqvist, E.; Gregerson, J.; Farley, K. A.; Sherman, S.; Hill, J.

2018-04-01

NSLS-II at BNL provides a unique and critical capability to perform assessments of the elemental composition and the chemical state of Mars returned samples using synchrotron radiation X-ray fluorescence imaging and X-ray absorption spectroscopy.

NHEXAS PHASE I REGION 5 STUDY--METALS IN DUST ANALYTICAL RESULTS

EPA Science Inventory

This data set includes analytical results for measurements of metals in 1,906 dust samples. Dust samples were collected to assess potential residential sources of dermal and inhalation exposures and to examine relationships between analyte levels in dust and in personal and bioma...

Preliminary assessment of the occurrence and possible sources of MTBE in groundwater in the United States, 1993-1994

USGS Publications Warehouse

Squillace, P.T.; Zogorski, J.S.; Wilber, W.G.; Price, C.V.

1997-01-01

The 1990 Clean Air Act Amendments require fuel oxygenates to be added to gasoline used in some metropolitan areas to reduce atmospheric concentrations of carbon monoxide or ozone. Methyl tert-butyl ether (MTBE), is the most commonly used fuel oxygenate and is a relatively new gasoline additive. Nevertheless, out of 60 volatile organic chemicals analyzed, MTBE was the second most frequently detected chemical in samples of shallow ambient groundwater from urban areas that were collected during 1993-94 as part of the U.S. Geological Survey's National Water-Quality Assessment Program. Samples were collected from 5 drinking-water wells, 12 springs, and 1g3 monitoring wells in urban areas. No MTBE was detected in drinking-water wells. At a reporting level of 0.2 ??g/L, MTBE was detected most frequently in shallow groundwater from urban areas (27% of 210 wells and springs sampled in 8 areas) as compared to shallow groundwater from agricultural areas (1.3% of 549 wells sampled in 21 areas) or deeper groundwater from major aquifers (1.0% of 412 wells sampled in 9 areas). Only 3% of the shallow wells sampled in urban areas had concentrations of MTBE that exceed 20 ??g/L, which is the estimated lower limit of the United States Environmental Protection Agency draft lifetime drinking water health advisory. Because MTBE is persistent and mobile in groundwater) it can move from shallow to deeper aquifers with time. In shallow urban groundwater, MTBE generally was not found with benzene, toluene, ethylbenzene, or xylenes (BTEX) compounds which commonly are associated with gasoline spills. This disassociation causes uncertainty as to the source of MTBE. Possible sources of MTBE in groundwater include point sources, such as leaking storage tanks, and nonpoint sources, such as recharge of precipitation and storm-water runoff.

A preliminary assessment of the occurrence and possible sources of MTBE in ground water of the United States, 1993-94

USGS Publications Warehouse

Squillace, P.J.

1995-01-01

The 1990 Clean Air Act Amendments require fuel oxygenates to be added to gasoline used in some metropolitan areas to reduce atmospheric concen- trations of carbon monoxide or ozone. Methyl tert-butyl ether (MTBE), is the most commonly used fuel oxygenate and is a relatively new gasoline additive. Nevertheless, out of 60 volatile organic chemicals analyzed, MTBE was the second most frequently detected chemical in samples of shallow ambient ground water from urban areas that were collected during 1993-94 as part of the U.S. Geological Survey's National Water-Quality Assessment program. Samples were collected from 5 drinking-water wells, 12 springs, and 193 monitoring wells in urban areas. No MTBE was detected in drinking-water wells. At a reporting level of 0.2 ug/L (micrograms per liter), MTBE was detected most frequently in shallow ground water from urban areas (27 percent of 210 wells and springs sampled in 8 areas) as compared to shallow ground water from agricultural areas (1.3 percent of 549 wells sampled in 21 areas) or deeper ground water from major aquifers (1 percent of 412 wells sampled in 9 areas). Only 3 percent of the shallow wells sampled in urban areas had concentrations of MTBE that exceed 20 ug/L, which is the estimated lower limit of the U.S. Environmental Protection Agency draft drinking-water health advisory. Because MTBE is persistent and mobile in ground water, it can move from shallow to deeper aquifers with time. In shallow urban ground water, MTBE generally was not found with benzene, toluene, ethylbenzene, or xylenes (BTEX) compounds which commonly are associated with gasoline spills. This disassociation causes uncertainty as to the source of MTBE. Possible sources of MTBE in ground water include point sources, such as leaking storage tanks, and nonpoint sources, such as recharge of precipitation and storm-water runoff.

Occurrence of anthropogenic organic compounds in ground water and finished water of community water systems in Eagle and Spanish Springs Valleys, Nevada, 2002-2004

USGS Publications Warehouse

Rosen, Michael R.; Shaefer, Donald H.; Toccalino, Patricia A.; Delzer, Gregory C.

2006-01-01

As a part of the U.S. Geological Survey's National Water-Quality Assessment Program, an effort to characterize the quality of major rivers and aquifers used as a source of supply to some of the largest community water systems (CWSs) in the United States has been initiated. These studies, termed Source Water-Quality Assessments (SWQAs), consist of two sampling phases. Phase 1 was designed to determine the frequency of detection and concentrations of about 260 volatile organic compounds (VOCs), pesticides and pesticide degradates, and other anthropogenic organic compounds in source water of 15 CWS wells in each study. Phase 2 monitors concentrations in the source water and also the associated finished water of CWSs for compounds most frequently detected during phase 1. One SWQA was completed in the Nevada Basin and Range area in Nevada. Ten CWS wells in Eagle Valley and five CWS wells in Spanish Springs Valley were sampled. For phase 2, two wells were resampled in Eagle Valley. Samples were collected during 2002-2004 for both phases. Water use in Eagle Valley is primarily for domestic purposes and is supplied through CWSs. Ground-water sources provide about 55 percent of the public-water supply, and surface-water sources supply about 45 percent. Lesser amounts of water are provided by domestic wells. Very little water is used for agriculture or manufacturing. Spanish Springs Valley has water-use characteristics similar to those in Eagle Valley, although there is more agricultural water use in Spanish Springs Valley than in Eagle Valley. Maximum contaminant concentrations were compared to two human-health benchmarks, if available, to describe the water-quality data in a human-health context for these findings. Measured concentrations of regulated contaminants were compared to U.S. Environmental Protection Agency and Nevada Maximum Contaminant Level (MCL) values. Measured concentrations of unregulated contaminants were compared to Health-Based Screening Levels, which are not regulatory standards and are not legally enforceable values. All of the contaminants detected in this study were found at concentrations less than available human-health benchmarks. In the source waters sampled in phase 1, 10 contaminants of the approximately 260 measured were detected in samples collected from Eagle Valley, and 4 contaminants were detected in samples from Spanish Springs Valley. The most frequently detected compounds in the Eagle Valley source water were chloroform (a disinfection by-product), which was detected in samples from four wells, and deethylatrazine (a degradation product of the herbicide atrazine), which was detected in samples from three wells. Each of the four contaminants detected in the Spanish Springs Valley source waters was detected in samples from one well. The detection frequencies of VOCs and pesticides in samples from the SWQA wells were similar to those in samples from both shallow and deep monitoring wells in Carson City, Reno, and Spanish Springs. This indicates that the SWQA sampling is representative of the organic chemical compounds likely to be detected in the aquifers sampled. However, more organic compounds were detected at low frequencies and concentrations in samples from the monitoring wells than in samples from SWQA wells. Three contaminants were detected in one finished-water sample collected from Eagle Valley. Comparison of SWQA results in the Nevada Basin and Range Study Unit to results of an SWQA in the larger urban area of Salt Lake City showed that fewer anthropogenic compounds were detected in Eagle and Spanish Springs Valleys and generally at lower concentrations than in the Salt Lake City study.

Implications of sampling design and sample size for national carbon accounting systems.

PubMed

Köhl, Michael; Lister, Andrew; Scott, Charles T; Baldauf, Thomas; Plugge, Daniel

2011-11-08

Countries willing to adopt a REDD regime need to establish a national Measurement, Reporting and Verification (MRV) system that provides information on forest carbon stocks and carbon stock changes. Due to the extensive areas covered by forests the information is generally obtained by sample based surveys. Most operational sampling approaches utilize a combination of earth-observation data and in-situ field assessments as data sources. We compared the cost-efficiency of four different sampling design alternatives (simple random sampling, regression estimators, stratified sampling, 2-phase sampling with regression estimators) that have been proposed in the scope of REDD. Three of the design alternatives provide for a combination of in-situ and earth-observation data. Under different settings of remote sensing coverage, cost per field plot, cost of remote sensing imagery, correlation between attributes quantified in remote sensing and field data, as well as population variability and the percent standard error over total survey cost was calculated. The cost-efficiency of forest carbon stock assessments is driven by the sampling design chosen. Our results indicate that the cost of remote sensing imagery is decisive for the cost-efficiency of a sampling design. The variability of the sample population impairs cost-efficiency, but does not reverse the pattern of cost-efficiency of the individual design alternatives. Our results clearly indicate that it is important to consider cost-efficiency in the development of forest carbon stock assessments and the selection of remote sensing techniques. The development of MRV-systems for REDD need to be based on a sound optimization process that compares different data sources and sampling designs with respect to their cost-efficiency. This helps to reduce the uncertainties related with the quantification of carbon stocks and to increase the financial benefits from adopting a REDD regime.

An assessment of polyurethane foam passive samplers for atmospheric metals compared with active samplers.

PubMed

Li, Qilu; Yang, Kong; Li, Jun; Zeng, Xiangying; Yu, Zhiqiang; Zhang, Gan

2018-05-01

In this study, we conducted an assessment of polyurethane foam (PUF) passive sampling for metals combining active sampling. Remarkably, we found that the metals collected in the passive samples differed greatly from those collected in active samples. By composition, Cu and Ni accounted for significantly higher proportions in passive samples than in active samples, leading to significantly higher uptake rates of Cu and Ni. In assessing seasonal variation, metals in passive samples had higher concentrations in summer (excluding Heshan), which differed greatly from the pattern of active samples (winter > summer), indicating that the uptake rates of most metals were higher in summer than in winter. Overall, due to the stable passive uptake rates, we considered that PUF passive samplers can be applied to collect atmospheric metals. Additionally, we created a snapshot of the metal pollution in the Pearl River Delta using principal component analysis of PUF samples and their source apportionment. Copyright © 2018 Elsevier Ltd. All rights reserved.

Utility of Microbial Source-Tracking Markers for Assessing Fecal Contamination in the Portage River Watershed, Northwestern Ohio, 2008

USGS Publications Warehouse

Kephart, Christopher M.; Bushon, Rebecca N.

2010-01-01

An influx of concentrated animal feeding operations in northwest Ohio has prompted local agencies to examine the effects of these industrial farms on water quality in the upper Portage River watershed. The utility of microbial source-tracking (MST) tools as a means of characterizing sources of fecal contamination in the watershed was evaluated. From 2007 to 2008, scientists with the U.S. Geological Survey, Bowling Green State University, and the Wood County Health Department collected and analyzed 17 environmental samples and 13 fecal source samples for Bacteroides-based host-associated DNA markers. At many of the environmental sites tested, MST marker results corroborated the presumptive fecal contamination sources. Results from this demonstration study support the utility of using MST with host-specific molecular markers to characterize the sources of fecal contamination in the Portage River watershed.

Organic compounds in White River water used for public supply near Indianapolis, Indiana, 2002-05

USGS Publications Warehouse

Lathrop, Tim; Moran, Dan

2011-01-01

The National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS) characterized the occurrence of 277 organic compounds in source water (stream water collected before treatment) and finished water (treated water before distribution) from the White River North treatment plant, one of several community water systems that use the White River as its primary water supply (fig. 1). Samples were collected at least monthly during 2002-05 and included 30 source- and 13 finished-water samples. The samples were analyzed for pesticides and selected pesticide degradates (or 'breakdown products'), solvents, gasoline hydrocarbons, disinfection by-products, personal-care and domestic-use products, and other organic compounds. Community water systems are required to monitor for compounds regulated under the Safe Drinking Water Act. Most of the compounds tested in this study are not regulated under U.S. Environmental Protection Agency (USEPA) federal drinking-water standards (U.S. Environmental Protection Agency, 2007a). The White River study is part of the ongoing Source Water-Quality Assessment (SWQA) investigation of community water systems that withdraw from rivers across the United States. More detailed information and references on the sampling-design methodology, specific compounds monitored, and the national study are described by Carter and others (2007).

An assessment of nonpoint-source discharges, streamflow, and water quality in Onion River, Wisconsin

USGS Publications Warehouse

Field, S.J.; Lidwin, R.A.

1984-01-01

All samples at both Hingham and Sheboygan Falls contained concentrations of un-ionized ammonia that were less than the U.S. Environmental Protection Agency's criteria (0.02 milligrams per liter), except the March 1980 samples. No samples exceeded the Wisconsin Department of Natural Resources criteria for un-ionized ammonia (0.04 milligrams per liter).

Rationale and Methods for Archival Sampling and Analysis of Atmospheric Trace Chemical Contaminants On Board Mir and Recommendations for the International Space Station

NASA Technical Reports Server (NTRS)

Perry, J. L.; James, J. T.; Cole, H. E.; Limero, T. F.; Beck, S. W.

1997-01-01

Collection and analysis of spacecraft cabin air samples are necessary to assess the cabin air quality with respect to crew health. Both toxicology and engineering disciplines work together to achieve an acceptably clean cabin atmosphere. Toxicology is concerned with limiting the risk to crew health from chemical sources, setting exposure limits, and analyzing air samples to determine how well these limits are met. Engineering provides the means for minimizing the contribution of the various contaminant generating sources by providing active contamination control equipment on board spacecraft and adhering to a rigorous material selection and control program during the design and construction of the spacecraft. A review of the rationale and objectives for sampling spacecraft cabin atmospheres is provided. The presently-available sampling equipment and methods are reviewed along with the analytical chemistry methods employed to determine trace contaminant concentrations. These methods are compared and assessed with respect to actual cabin air quality monitoring needs. Recommendations are presented with respect to the basic sampling program necessary to ensure an acceptably clean spacecraft cabin atmosphere. Also, rationale and recommendations for expanding the scope of the basic monitoring program are discussed.

Special Education Teachers under Stress: Evidence from a Greek National Study

ERIC Educational Resources Information Center

Kokkinos, Constantinos M.; Davazoglou, Aggeliki M.

2009-01-01

The present study examines the sources of job stress in a national sample of 373 Greek special education teachers, using a self-report questionnaire assessing job stress, its perceived sources, and its demographic and professional characteristics. Although the participants in general considered their job moderately stressful, they felt stressed by…

Using an In Vitro Cell Line to Assess Source and Treated Drinking Water Extracts for Estrogenic Activity.

EPA Science Inventory

While in vitro assays have been used to determine presence of estrogenic activity in many types of water, few studies have evaluated the potential estrogenic activity in source and treated drinking water samples. In a collaborative research study the U.S. Environmental Protection...

RECOMMENDED OPERATING PROCEDURE NO. 51: GLASS SOURCE ASSESSMENT SAMPLING SYSTEM (GLASS SASS)

EPA Science Inventory

The report is a recommended operating procedure (ROP), prepared for use in research activities conducted by EPA's Air and Energy Engineering Research Laboratory (AEERL). he method described is applicable to the stack sampling of flue gas from a rotary kiln and to associated equip...

Profiling oil sands mixtures from industrial developments and natural groundwaters for source identification.

PubMed

Frank, Richard A; Roy, James W; Bickerton, Greg; Rowland, Steve J; Headley, John V; Scarlett, Alan G; West, Charles E; Peru, Kerry M; Parrott, Joanne L; Conly, F Malcolm; Hewitt, L Mark

2014-01-01

The objective of this study was to identify chemical components that could distinguish chemical mixtures in oil sands process-affected water (OSPW) that had potentially migrated to groundwater in the oil sands development area of northern Alberta, Canada. In the first part of the study, OSPW samples from two different tailings ponds and a broad range of natural groundwater samples were assessed with historically employed techniques as Level-1 analyses, including geochemistry, total concentrations of naphthenic acids (NAs) and synchronous fluorescence spectroscopy (SFS). While these analyses did not allow for reliable source differentiation, they did identify samples containing significant concentrations of oil sands acid-extractable organics (AEOs). In applying Level-2 profiling analyses using electrospray ionization high resolution mass spectrometry (ESI-HRMS) and comprehensive multidimensional gas chromatography time-of-flight mass spectrometry (GC × GC-TOF/MS) to samples containing appreciable AEO concentrations, differentiation of natural from OSPW sources was apparent through measurements of O2:O4 ion class ratios (ESI-HRMS) and diagnostic ions for two families of suspected monoaromatic acids (GC × GC-TOF/MS). The resemblance between the AEO profiles from OSPW and from 6 groundwater samples adjacent to two tailings ponds implies a common source, supporting the use of these complimentary analyses for source identification. These samples included two of upward flowing groundwater collected <1 m beneath the Athabasca River, suggesting OSPW-affected groundwater is reaching the river system.

Trust in Sources of Advice about Infant Care Practices: The SAFE Study.

PubMed

Hwang, Sunah S; Rybin, Denis V; Heeren, Timothy C; Colson, Eve R; Corwin, Michael J

2016-09-01

Objectives (1) Determine the prevalence of maternal trust in advice sources on infant care practices; (2) Investigate the association of maternal and infant characteristics with trust in advice sources on infant care practices. Methods Using probability sampling methods, we recruited mothers from 32 U.S. maternity hospitals with oversampling of Black and Hispanic women resulting in a nationally representative sample of mothers of infants aged 2-6 months. Survey questions assessed maternal trust in advice sources (physicians, nurses, family, friends, and media) regarding infant care practices including infant sleep practices (sleep position, bed sharing, and pacifier use), feeding, and vaccination. Weighted frequencies of maternal trust in advice sources were calculated to obtain prevalence estimates. Multivariable logistic regression was used to assess the association of maternal and infant characteristics with maternal trust in advice sources. Results Mothers had the greatest trust in doctors for advice on all infant care practices (56-89 %), while trust was lowest for friends (13-22 %) and the media (10-14 %). In the adjusted analyses, there were significant associations of maternal race/ethnicity, education, and age with trust in advice sources. Conclusions for Practice Maternal trust in advice about infant care practices varied significantly by source. A better understanding of which advice sources are most trusted by mothers, as well as the factors associated with maternal trust, may guide the development of more effective strategies to improve adherence to health promoting infant care practices.

Evaluation of seasonal variation of water quality using multivariate statistical analysis and irrigation parameter indices in Ajakanga area, Ibadan, Nigeria

NASA Astrophysics Data System (ADS)

Ganiyu, S. A.; Badmus, B. S.; Olurin, O. T.; Ojekunle, Z. O.

2018-03-01

The variation of groundwater quality across different regions is of great importance in the study of groundwater so as to ascertain the sources of contaminants to available water sources. Geochemical assessment of groundwater samples from hand-dug wells were done within the vicinity of Ajakanga dumpsite, Ibadan, Southwestern, Nigeria, with the aim of assessing their suitability for domestic and irrigation purposes. Ten groundwater samples were collected both in dry and wet seasons for analysis of physicochemical parameters such as: pH, EC, TDS, Na+, K+, Ca2+, Mg2+, HCO3^{ - } Cl-, SO4^{2 - }, NO3^{2 - } principal component analysis (PCA) and cluster analysis (CA) were used to determine probable sources of groundwater contamination. The results of the analyses showed the groundwater samples to be within permissible limits of WHO/NSDWQ, while elevated values of concentrations of most analyzed chemical constituents in water samples were noticed in S1 and S10 due to their nearness to the dumpsite and agricultural overflow, respectively. Groundwater in the study area is of hard, fresh and alkaline nature. There are very strong associations between EC and TDS, HCO3^{ - } and CO3^{2 - } in both seasons. PCA identified five and three major factors accounting for 95.7 and 88.7% of total variation in water quality for dry and wet seasons, respectively. PCA also identified factors influencing water quality as those probably related to mineral dissolution, groundwater-rock interaction, weathering process and anthropogenic activities from the dumpsite. Results of CA show groups based on similar water quality characteristics and on the extent of proximity to the dumpsite. Assessment for irrigation purpose showed that most of the water samples were suitable for agricultural purpose except in a few locations.

Advancing the Use of Passive Sampling in Risk Assessment and Management of Sediments Contaminated with Hydrophobic Organic Chemicals: Results of an International Ex Situ Passive Sampling Interlaboratory Comparison

PubMed Central

2018-01-01

This work presents the results of an international interlaboratory comparison on ex situ passive sampling in sediments. The main objectives were to map the state of the science in passively sampling sediments, identify sources of variability, provide recommendations and practical guidance for standardized passive sampling, and advance the use of passive sampling in regulatory decision making by increasing confidence in the use of the technique. The study was performed by a consortium of 11 laboratories and included experiments with 14 passive sampling formats on 3 sediments for 25 target chemicals (PAHs and PCBs). The resulting overall interlaboratory variability was large (a factor of ∼10), but standardization of methods halved this variability. The remaining variability was primarily due to factors not related to passive sampling itself, i.e., sediment heterogeneity and analytical chemistry. Excluding the latter source of variability, by performing all analyses in one laboratory, showed that passive sampling results can have a high precision and a very low intermethod variability (

Tracing Sources of Organic Matter and Nitrate in the San Francisco Bay-Delta-River Ecosystem Using Isotopic Techniques: Comparison of Insights Gained from Fixed-site, Synoptic, and Diel Sampling Strategies

NASA Astrophysics Data System (ADS)

Kendall, C.; Silva, S. R.; Doctor, D. H.; Wankel, S. D.; Chang, C. C.; Bergamaschi, B. A.; Kratzer, C. R.; Dahlgren, R. A.; Fleenor, W. E.

2005-12-01

Understanding the sources and sinks for organics and nitrate is critical for devising effective strategies to reduce their loads in ecosystems and mitigate local problems of low dissolved oxygen levels and/or production of disinfection byproducts during water treatment. Since isotopic techniques are effective methods for quantifying the sources and sinks of organics and nutrients, we have analyzed particulate organic matter (POM), nitrate, dissolved inorganic and organic carbon (DIC, DOC), and water isotope samples from selected sites since 2000. Our studies indicate that isotope data are a useful adjunct to traditional methods for assessing and monitoring sources of organics and nutrients. The original sampling in 2000-2001 used the classical fixed-site and fixed-time interval sampling approach, where sites on the San Joaquin River and its major tributaries were sampled bimonthly from July to October for chemistry and isotopes (Kratzer et al., 2004: see URL below). Subsequently, samples were collected during 4 transects along the San Joaquin River (10/02, 3/03, 9/03, and 7/04); the first and last of these transects extended through the Delta to the Bay. Several sites were sampled during diel studies in 8/04 and 7/05. Although fixed-site sampling is the norm in watershed studies, we have found that isotope and chemical data collected during longitudinal transects of the river and diel sampling of several sites along short river reaches have been more useful in convincing colleagues that isotope measurements are extremely useful adjuncts to traditional methods for assessing and monitoring sources of organics and nutrients during ecosystem restoration programs. Furthermore, we have concluded that while the obvious value of isotopes for water resources management is to tell us things about water resources that we didn't know before, what convinces the skeptic is when the isotopes tell us things about water resources that contradict what we thought we knew before. This work will highlight these and other insights developed using varied sampling strategies, and suggest guidelines for how to approach future studies in biologically active and human impacted rivers like the San Joaquin River system.

A Comparative Analysis of Vibrio cholerae Contamination in Point-of-Drinking and Source Water in a Low-Income Urban Community, Bangladesh.

PubMed

Ferdous, Jannatul; Sultana, Rebeca; Rashid, Ridwan B; Tasnimuzzaman, Md; Nordland, Andreas; Begum, Anowara; Jensen, Peter K M

2018-01-01

Bangladesh is a cholera endemic country with a population at high risk of cholera. Toxigenic and non-toxigenic Vibrio cholerae ( V. cholerae ) can cause cholera and cholera-like diarrheal illness and outbreaks. Drinking water is one of the primary routes of cholera transmission in Bangladesh. The aim of this study was to conduct a comparative assessment of the presence of V. cholerae between point-of-drinking water and source water, and to investigate the variability of virulence profile using molecular methods of a densely populated low-income settlement of Dhaka, Bangladesh. Water samples were collected and tested for V. cholerae from "point-of-drinking" and "source" in 477 study households in routine visits at 6 week intervals over a period of 14 months. We studied the virulence profiles of V. cholerae positive water samples using 22 different virulence gene markers present in toxigenic O1/O139 and non-O1/O139 V. cholerae using polymerase chain reaction (PCR). A total of 1,463 water samples were collected, with 1,082 samples from point-of-drinking water in 388 households and 381 samples from 66 water sources. V. cholerae was detected in 10% of point-of-drinking water samples and in 9% of source water samples. Twenty-three percent of households and 38% of the sources were positive for V. cholerae in at least one visit. Samples collected from point-of-drinking and linked sources in a 7 day interval showed significantly higher odds ( P < 0.05) of V. cholerae presence in point-of-drinking compared to source [OR = 17.24 (95% CI = 7.14-42.89)] water. Based on the 7 day interval data, 53% (17/32) of source water samples were negative for V. cholerae while linked point-of-drinking water samples were positive. There were significantly higher odds ( p < 0.05) of the presence of V. cholerae O1 [OR = 9.13 (95% CI = 2.85-29.26)] and V. cholerae O139 [OR = 4.73 (95% CI = 1.19-18.79)] in source water samples than in point-of-drinking water samples. Contamination of water at the point-of-drinking is less likely to depend on the contamination at the water source. Hygiene education interventions and programs should focus and emphasize on water at the point-of-drinking, including repeated cleaning of drinking vessels, which is of paramount importance in preventing cholera.

Ecological risk of heavy metals in sediments of the Luan River source water.

PubMed

Liu, Jingling; Li, Yongli; Zhang, Bao; Cao, Jinling; Cao, Zhiguo; Domagalski, Joseph

2009-08-01

Distribution and characteristics of heavy metals enrichment in sediment were surveyed including the bio-available form analyzed for assessment of the Luan River source water quality. The approaches of sediment quality guidelines (SQG), risk assessment code and Hakanson potential ecological risk index were used for the ecological risk assessment. According to SQG, The results show that in animal bodies, Hg at the sampling site of Wuliehexia was 1.39 mg/kg, Cr at Sandaohezi was 152.37 mg/kg and Cu at Hanjiaying was 178.61 mg/kg exceeding the severe effect screening level. There were 90% of sampling sites of Cr and Pb and 50% sites of Cu exceeded the lowest effect screening level. At Boluonuo and Wuliehexia, the exchangeable and carbonate fractions for above 50% of sites were at high risk levels and that for above 30% of sites at Xiahenan and Wulieheshang were also at high risk levels. Other sites were at medium risk level. Compared to soil background values of China, Hg and Cd showed very strong ecological risk, and the seven heavy metals of Hg, Cd, Cu, As, Pb, Cr, Zn at ecological risk levels were in the descending order. The results could give insight into risk assessment of environmental pollution and decision-making for water source security.

External Threat Risk Assessment Algorithm (ExTRAA)

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

Powell, Troy C.

Two risk assessment algorithms and philosophies have been augmented and combined to form a new algorit hm, the External Threat Risk Assessment Algorithm (ExTRAA), that allows for effective and statistically sound analysis of external threat sources in relation to individual attack methods . In addition to the attack method use probability and the attack method employment consequence, t he concept of defining threat sources is added to the risk assessment process. Sample data is tabulated and depicted in radar plots and bar graphs for algorithm demonstration purposes. The largest success of ExTRAA is its ability to visualize the kind ofmore » r isk posed in a given situation using the radar plot method.« less

Composition and source of butyltins in sediments of Kaohsiung Harbor, Taiwan

NASA Astrophysics Data System (ADS)

Dong, Cheng-Di; Chen, Chih-Feng; Chen, Chiu-Wen

2015-04-01

Fifty-eight sediment samples were collected from the Kaohsiung Harbor (Taiwan) for analyses of monobutyltin (MBT), dibutyltin (DBT) and tributyltin (TBT), using gas chromatography/flame photometric detector (GC/FPD). The concentration of total butyltins (ΣBTs), sum of MBT, DBT, and TBT, varied from 3.9 to 158.5 ng Sn/g dw in sediment samples with TBT being the major component of the sediment samples, except for the vicinity of the Love River mouth where MBT was the most abundant BT compound (a proportion of over 57%). Based on the BTs concentration, distribution, composition and correlations, the sources of BTs found in harbor sediments are shipping activities, and TBT is the main pollutant; the estuary (i.e. Love River) has been the anthropogenic source of MBT from upstream inputs. Influences of TBT on aquatic organisms are evaluated using the toxicity guidelines proposed by the US EPA (US Environmental Protection Agency) and the ACCI (assessment class criterion for imposex) proposed by OSPAR (Oslo and Paris Commission). The evaluation shows that the TBT contained in the sediment at Kaohsiung Harbor is likely to have a negative influence at ACCI class C because gastropods present imposex and TBT levels are above ecotoxicological assessment criteria (EAC) limits.

Multiple correspondence analysis and random amplified polymorphic DNA molecular typing to assess the sources of Staphylococcus aureus contamination in alheira production lines.

PubMed

Esteves, A; Patarata, L; Aymerich, T; Garriga, M; Martins, C

2007-03-01

Sources and tracing of Staphylococcus aureus in alheira (garlic sausage) production were evaluated by multifactorial correspondence analysis (MCA) of occurrence data and a random amplified polymorphic DNA (RAPD) on S. aureus isolates. Samples from four production lines, four different production batches, and 14 different sampling sites (including raw material, different contact surfaces, and several stages of alheira manufacturing) were analyzed at four sampling times. From the 896 microbial analyses completed, a collection of 170 S. aureus isolates was obtained. Although analysis of the occurrence data alone was not elucidative enough, MCA and RAPD-PCR were able to assess the sources of contamination and to trace the spread of this microorganism along the production lines. MCA results indicated that the presence of S. aureus in alheira was related to its presence in the intermediate manufacturing stages after heat treatment but before stuffing in the casings. It was also possible to associate a cross-contamination path related to handler procedures. RAPD-PCR typing in accordance to MCA results confirmed the cross-contamination path between the raw material and casings and the role of handlers as an important cross-contamination vehicle.

Microplastics in Freshwater River Sediments in Shanghai, China: A Case Study of Risk Assessment in Mega Cities

NASA Astrophysics Data System (ADS)

Peng, G.; Xu, P.

2017-12-01

Microplastics are plastics that measure less than 5 mm, which attracted exponential interest in recent years. Microplastics are widely distributed in water, sediments, and biotas. Most of distribution studies focus on the marine environment, yet methods to conduct risk assessment are limited. Widespread of microplastics has raised alarm for the well-being of marine living resources because of its negative ecological effects that has been proved. To understand the distribution of microplastics in urban rivers and source of marine microplastics, we investigated into river sediments in Shanghai, the biggest city in China. Seven sampling sites covered most of city central districts including one sampling site from a tidal flat. Density separation, microscopic inspection and identification were conducted to analyze microplastic abundance, shape and color. It is found that pellets were the most prevalent shape, followed by fiber and fragment. White microplastics were the most common type in terms of color. White foamed microplastic pellets were widely distributed in urban river sediments. Microplastic abundance from rivers was one to two orders of magnitude higher than that from the tidal flat. The significant difference between river and tidal flat samples lead to the conclusion that coastal rivers may be the source of microplastics, therefore in situ data and legitimate estimation should be considered by policy-makers. Seven types of microplastics were identified by μ-FT-IR analysis, indicating a secondary source. Comparison between two types of μ-FT-IR instruments was summarized. Framework for environmental risk assessment for microplastics in sediments was proposed. Indicators and ranks were select for the assessment of microplastic in sediments. It is recommended to select the index, integrate statistical data, follow expert opinions extensively and construct comprehensive evaluation method and ecological risk assessment system for the Chinese context.

Soil heavy metal pollution and risk assessment associated with the Zn-Pb mining region in Yunnan, Southwest China.

PubMed

Cheng, Xianfeng; Danek, Tomas; Drozdova, Jarmila; Huang, Qianrui; Qi, Wufu; Zou, Liling; Yang, Shuran; Zhao, Xinliang; Xiang, Yungang

2018-03-07

The environmental assessment and identification of sources of heavy metals in Zn-Pb ore deposits are important steps for the effective prevention of subsequent contamination and for the development of corrective measures. The concentrations of eight heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) in soils from 40 sampling points around the Jinding Zn-Pb mine in Yunnan, China, were analyzed. An environmental quality assessment of the obtained data was performed using five different contamination and pollution indexes. Statistical analyses were performed to identify the relations among the heavy metals and the pH in soils and possible sources of pollution. The concentrations of As, Cd, Pb, and Zn were extremely high, and 23, 95, 25, and 35% of the samples, respectively, exceeded the heavy metal limits set in the Chinese Environmental Quality Standard for Soils (GB15618-1995, grade III). According to the contamination and pollution indexes, environmental risks in the area are high or extremely high. The highest risk is represented by Cd contamination, the median concentration of which exceeds the GB15618-1995 limit. Based on the combination of statistical analyses and geostatistical mapping, we identified three groups of heavy metals that originate from different sources. The main sources of As, Cd, Pb, Zn, and Cu are mining activities, airborne particulates from smelters, and the weathering of tailings. The main sources of Hg are dust fallout and gaseous emissions from smelters and tailing dams. Cr and Ni originate from lithogenic sources.

Psychological testing and psychological assessment. A review of evidence and issues.

PubMed

Meyer, G J; Finn, S E; Eyde, L D; Kay, G G; Moreland, K L; Dies, R R; Eisman, E J; Kubiszyn, T W; Reed, G M

2001-02-01

This article summarizes evidence and issues associated with psychological assessment. Data from more than 125 meta-analyses on test validity and 800 samples examining multimethod assessment suggest 4 general conclusions: (a) Psychological test validity is strong and compelling, (b) psychological test validity is comparable to medical test validity, (c) distinct assessment methods provide unique sources of information, and (d) clinicians who rely exclusively on interviews are prone to incomplete understandings. Following principles for optimal nomothetic research, the authors suggest that a multimethod assessment battery provides a structured means for skilled clinicians to maximize the validity of individualized assessments. Future investigations should move beyond an examination of test scales to focus more on the role of psychologists who use tests as helpful tools to furnish patients and referral sources with professional consultation.

Constrained Maximum Likelihood Estimation for Model Calibration Using Summary-level Information from External Big Data Sources

PubMed Central

Chatterjee, Nilanjan; Chen, Yi-Hau; Maas, Paige; Carroll, Raymond J.

2016-01-01

Information from various public and private data sources of extremely large sample sizes are now increasingly available for research purposes. Statistical methods are needed for utilizing information from such big data sources while analyzing data from individual studies that may collect more detailed information required for addressing specific hypotheses of interest. In this article, we consider the problem of building regression models based on individual-level data from an “internal” study while utilizing summary-level information, such as information on parameters for reduced models, from an “external” big data source. We identify a set of very general constraints that link internal and external models. These constraints are used to develop a framework for semiparametric maximum likelihood inference that allows the distribution of covariates to be estimated using either the internal sample or an external reference sample. We develop extensions for handling complex stratified sampling designs, such as case-control sampling, for the internal study. Asymptotic theory and variance estimators are developed for each case. We use simulation studies and a real data application to assess the performance of the proposed methods in contrast to the generalized regression (GR) calibration methodology that is popular in the sample survey literature. PMID:27570323

Association of Supply Type with Fecal Contamination of Source Water and Household Stored Drinking Water in Developing Countries: A Bivariate Meta-analysis.

PubMed

Shields, Katherine F; Bain, Robert E S; Cronk, Ryan; Wright, Jim A; Bartram, Jamie

2015-12-01

Access to safe drinking water is essential for health. Monitoring access to drinking water focuses on water supply type at the source, but there is limited evidence on whether quality differences at the source persist in water stored in the household. We assessed the extent of fecal contamination at the source and in household stored water (HSW) and explored the relationship between contamination at each sampling point and water supply type. We performed a bivariate random-effects meta-analysis of 45 studies, identified through a systematic review, that reported either the proportion of samples free of fecal indicator bacteria and/or individual sample bacteria counts for source and HSW, disaggregated by supply type. Water quality deteriorated substantially between source and stored water. The mean percentage of contaminated samples (noncompliance) at the source was 46% (95% CI: 33, 60%), whereas mean noncompliance in HSW was 75% (95% CI: 64, 84%). Water supply type was significantly associated with noncompliance at the source (p < 0.001) and in HSW (p = 0.03). Source water (OR = 0.2; 95% CI: 0.1, 0.5) and HSW (OR = 0.3; 95% CI: 0.2, 0.8) from piped supplies had significantly lower odds of contamination compared with non-piped water, potentially due to residual chlorine. Piped water is less likely to be contaminated compared with other water supply types at both the source and in HSW. A focus on upgrading water services to piped supplies may help improve safety, including for those drinking stored water.

Assessing the pollution risk of a groundwater source field at western Laizhou Bay under seawater intrusion

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

Zeng, Xiankui; Wu, Jichun; Wang, Dong, E-mail: wangdong@nju.edu.cn

Coastal areas have great significance for human living, economy and society development in the world. With the rapid increase of pressures from human activities and climate change, the safety of groundwater resource is under the threat of seawater intrusion in coastal areas. The area of Laizhou Bay is one of the most serious seawater intruded areas in China, since seawater intrusion phenomenon was firstly recognized in the middle of 1970s. This study assessed the pollution risk of a groundwater source filed of western Laizhou Bay area by inferring the probability distribution of groundwater Cl{sup −} concentration. The numerical model ofmore » seawater intrusion process is built by using SEAWAT4. The parameter uncertainty of this model is evaluated by Markov Chain Monte Carlo (MCMC) simulation, and DREAM{sub (ZS)} is used as sampling algorithm. Then, the predictive distribution of Cl{sup -} concentration at groundwater source field is inferred by using the samples of model parameters obtained from MCMC. After that, the pollution risk of groundwater source filed is assessed by the predictive quantiles of Cl{sup -} concentration. The results of model calibration and verification demonstrate that the DREAM{sub (ZS)} based MCMC is efficient and reliable to estimate model parameters under current observation. Under the condition of 95% confidence level, the groundwater source point will not be polluted by seawater intrusion in future five years (2015–2019). In addition, the 2.5% and 97.5% predictive quantiles show that the Cl{sup −} concentration of groundwater source field always vary between 175 mg/l and 200 mg/l. - Highlights: • The parameter uncertainty of seawater intrusion model is evaluated by MCMC. • Groundwater source field won’t be polluted by seawater intrusion in future 5 years. • The pollution risk is assessed by the predictive quantiles of Cl{sup −} concentration.« less

Contribution of flavonoids to the overall radical scavenging activity of olive (Olea europaea L.) leaf polar extracts.

PubMed

Goulas, Vlassios; Papoti, Vassiliki T; Exarchou, Vassiliki; Tsimidou, Maria Z; Gerothanassis, Ioannis P

2010-03-24

The contribution of flavonoids to the overall radical scavenging activity of olive leaf polar extracts, known to be good sources of oleuropein related compounds, was examined. Off line and on line HPLC-DPPH(*) assays were employed, whereas flavonoid content was estimated colorimetrically. Individual flavonoid composition was first assessed by RP-HPLC coupled with diode array and fluorescence detectors and verified by LC-MS detection system. Olive leaf was found a robust source of flavonoids regardless sampling parameters (olive cultivar, leaf age or sampling date). Total flavonoids accounted for the 13-27% of the total radical scavenging activity assessed using the on line protocol. Luteolin 7-O-glucoside was one of the dominant scavengers (8-25%). Taking into consideration frequency of appearance the contribution of luteolin (3-13%) was considered important, too. Our findings support that olive leaf, except for oleuropein and related compounds, is also a stable source of bioactive flavonoids.

Assessment of light extinction at a European polluted urban area during wintertime: Impact of PM1 composition and sources.

PubMed

Vecchi, R; Bernardoni, V; Valentini, S; Piazzalunga, A; Fermo, P; Valli, G

2018-02-01

In this paper, results from receptor modelling performed on a well-characterised PM 1 dataset were combined to chemical light extinction data (b ext ) with the aim of assessing the impact of different PM 1 components and sources on light extinction and visibility at a European polluted urban area. It is noteworthy that, at the state of the art, there are still very few papers estimating the impact of different emission sources on light extinction as we present here, although being among the major environmental challenges at many polluted areas. Following the concept of the well-known IMPROVE algorithm, here a tailored site-specific approach (recently developed by our group) was applied to assess chemical light extinction due to PM 1 components and major sources. PM 1 samples collected separately during daytime and nighttime at the urban area of Milan (Italy) were chemically characterised for elements, major ions, elemental and organic carbon, and levoglucosan. Chemical light extinction was estimated and results showed that at the investigated urban site it is heavily impacted by ammonium nitrate and organic matter. Receptor modelling (i.e. Positive Matrix Factorization, EPA-PMF 5.0) was effective to obtain source apportionment; the most reliable solution was found with 7 factors which were tentatively assigned to nitrates, sulphates, wood burning, traffic, industry, fine dust, and a Pb-rich source. The apportionment of aerosol light extinction (b ext,aer ) according to resolved sources showed that considering all samples together nitrate contributed at most (on average 41.6%), followed by sulphate, traffic, and wood burning accounting for 18.3%, 17.8% and 12.4%, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Reducing sampling error in faecal egg counts from black rhinoceros (Diceros bicornis).

PubMed

Stringer, Andrew P; Smith, Diane; Kerley, Graham I H; Linklater, Wayne L

2014-04-01

Faecal egg counts (FECs) are commonly used for the non-invasive assessment of parasite load within hosts. Sources of error, however, have been identified in laboratory techniques and sample storage. Here we focus on sampling error. We test whether a delay in sample collection can affect FECs, and estimate the number of samples needed to reliably assess mean parasite abundance within a host population. Two commonly found parasite eggs in black rhinoceros (Diceros bicornis) dung, strongyle-type nematodes and Anoplocephala gigantea, were used. We find that collection of dung from the centre of faecal boluses up to six hours after defecation does not affect FECs. More than nine samples were needed to greatly improve confidence intervals of the estimated mean parasite abundance within a host population. These results should improve the cost-effectiveness and efficiency of sampling regimes, and support the usefulness of FECs when used for the non-invasive assessment of parasite abundance in black rhinoceros populations.

Genetic diversity demonstrated by pulsed field gel electrophoresis of Salmonella enterica isolates obtained from diverse sources in Mexico

USDA-ARS?s Scientific Manuscript database

This study was conducted to determine the genetic diversity of Salmonella isolates recovered from a variety of sources using pulsed-field gel electrophoresis (PFGE) to assess their possible relatedness. Salmonella was isolated from ca. 52% of samples from a pepper var. Bell production system. A to...

Urinary and breast milk biomarkers to assess exposure to naphthalene in pregnant women: an investigation of personal and indoor air sources

PubMed Central

2014-01-01

Background Naphthalene exposures for most non-occupationally exposed individuals occur primarily indoors at home. Residential indoor sources include pest control products (specifically moth balls), incomplete combustion such as cigarette smoke, woodstoves and cooking, some consumer and building products, and emissions from gasoline sources found in attached garages. The study aim was to assess naphthalene exposure in pregnant women from Canada, using air measurements and biomarkers of exposure. Methods Pregnant women residing in Ottawa, Ontario completed personal and indoor air sampling, and questionnaires. During pregnancy, pooled urine voids were collected over two 24-hour periods on a weekday and a weekend day. At 2–3 months post-birth, they provided a spot urine sample and a breast milk sample following the 24-hour air monitoring. Urines were analyzed for 1-naphthol and 2-naphthol and breast milk for naphthalene. Simple linear regression models examined associations between known naphthalene sources, air and biomarker samples. Results Study recruitment rate was 11.2% resulting in 80 eligible women being included. Weekday and weekend samples were highly correlated for both personal (r = 0.83, p < 0.0001) and indoor air naphthalene (r = 0.91, p < 0.0001). Urine specific gravity (SG)-adjusted 2-naphthol concentrations collected on weekdays and weekends (r = 0.78, p < 0.001), and between pregnancy and postpartum samples (r = 0.54, p < 0.001) were correlated. Indoor and personal air naphthalene concentrations were significantly higher post-birth than during pregnancy (p < 0.0001 for signed rank tests); concurrent urine samples were not significantly different. Naphthalene in breast milk was associated with urinary 1-naphthol: a 10% increase in 1-naphthol was associated with a 1.6% increase in breast milk naphthalene (95% CI: 0.2%-3.1%). No significant associations were observed between naphthalene sources reported in self-administered questionnaires and the air or biomarker concentrations. Conclusions Median urinary concentrations of naphthalene metabolites tended to be similar to (1-naphthol) or lower (2-naphthol) than those reported in a Canadian survey of women of reproductive age. Only urinary 1-naphthol and naphthalene in breast milk were associated. Potential reasons for the lack of other associations include a lack of sources, varying biotransformation rates and behavioural differences over time. PMID:24767676

Assessment of swine-specific bacteriophages of Bacteroides fragilis in swine farms with different antibiotic practices.

PubMed

Leknoi, Yuranan; Mongkolsuk, Skorn; Sirikanchana, Kwanrawee

2017-04-01

We assessed the occurrence and specificity of bacteriophages of Bacteroides fragilis in swine farms for their potential application in microbial source tracking. A local B. fragilis host strain, SP25 (DSM29413), was isolated from a pooled swine feces sample taken from a non-antibiotic farm. This strain was highly specific to swine fecal materials because it did not detect bacteriophages in any samples from human sewage, sheep, goats, cattle, dogs, and cats. The reference B. fragilis strain, RYC2056, could detect phages in swine samples but also detected phages in most human sewage and polluted urban canal samples. Phages of SP25 exist in the proximity of certain swine farms, regardless of their antibiotic use (p > 0.05). B. fragilis strain SP25 exhibited relatively high resistance to most of the veterinary antimicrobial agents tested. Interestingly, most farms that were positive for SP25 phages were also positive for RYC2056 phages. In conclusion, the swine-specific SP25 strain has the potential to indicate swine fecal contamination in certain bodies of water. Bacterial isolates with larger distributions are being studied and validated. This study highlights the importance of assessing the abundance of phages in local swine populations before determining their potential applicability for source tracking in local surface waters.

Heavy metals and polycyclic aromatic hydrocarbons: pollution and ecological risk assessment in street dust of Tehran.

PubMed

Saeedi, Mohsen; Li, Loretta Y; Salmanzadeh, Mahdiyeh

2012-08-15

50 street dust samples from four major streets in eastern and southern Tehran, the capital of Iran, were analyzed for metal pollution (Cu, Cr, Pb, Ni, Cd, Zn, Fe, Mn and Li). Hakanson's method was used to determine the Risk Index (RI) and ecological risks. Amongst these samples, 21 were also analyzed for polycyclic aromatic hydrocarbons (PAHs). Correlation, cluster and principal component analyses identified probable natural and anthropogenic sources of contaminants. The dust had elevated concentrations of Pb, Cd, Cu, Cr, Ni, Zn, Fe and PAHs. Enrichment factors of Cu, Pb, Cd and Zn showed that the dust is extremely enriched in these metals. Multivariate statistical analyses revealed that Cu, Pb, Zn, Fe and PAHs and, to a lesser extent, Cr and Ni have common anthropogenic sources. While Mn and Li were identified to have natural sources, Cd may have different anthropogenic origins. All samples demonstrated high ecological risk. Traffic and related activities, petrogenic and pyrogenic sources are likely to be the main anthropogenic sources of heavy metals and PAHs in Tehran dust. Copyright © 2012 Elsevier B.V. All rights reserved.

Sources of errors and uncertainties in the assessment of forest soil carbon stocks at different scales-review and recommendations.

PubMed

Vanguelova, E I; Bonifacio, E; De Vos, B; Hoosbeek, M R; Berger, T W; Vesterdal, L; Armolaitis, K; Celi, L; Dinca, L; Kjønaas, O J; Pavlenda, P; Pumpanen, J; Püttsepp, Ü; Reidy, B; Simončič, P; Tobin, B; Zhiyanski, M

2016-11-01

Spatially explicit knowledge of recent and past soil organic carbon (SOC) stocks in forests will improve our understanding of the effect of human- and non-human-induced changes on forest C fluxes. For SOC accounting, a minimum detectable difference must be defined in order to adequately determine temporal changes and spatial differences in SOC. This requires sufficiently detailed data to predict SOC stocks at appropriate scales within the required accuracy so that only significant changes are accounted for. When designing sampling campaigns, taking into account factors influencing SOC spatial and temporal distribution (such as soil type, topography, climate and vegetation) are needed to optimise sampling depths and numbers of samples, thereby ensuring that samples accurately reflect the distribution of SOC at a site. Furthermore, the appropriate scales related to the research question need to be defined: profile, plot, forests, catchment, national or wider. Scaling up SOC stocks from point sample to landscape unit is challenging, and thus requires reliable baseline data. Knowledge of the associated uncertainties related to SOC measures at each particular scale and how to reduce them is crucial for assessing SOC stocks with the highest possible accuracy at each scale. This review identifies where potential sources of errors and uncertainties related to forest SOC stock estimation occur at five different scales-sample, profile, plot, landscape/regional and European. Recommendations are also provided on how to reduce forest SOC uncertainties and increase efficiency of SOC assessment at each scale.

A cautionary note on substituting spatial subunits for repeated temporal sampling in studies of site occupancy

USGS Publications Warehouse

Kendall, William L.; White, Gary C.

2009-01-01

1. Assessing the probability that a given site is occupied by a species of interest is important to resource managers, as well as metapopulation or landscape ecologists. Managers require accurate estimates of the state of the system, in order to make informed decisions. Models that yield estimates of occupancy, while accounting for imperfect detection, have proven useful by removing a potentially important source of bias. To account for detection probability, multiple independent searches per site for the species are required, under the assumption that the species is available for detection during each search of an occupied site. 2. We demonstrate that when multiple samples per site are defined by searching different locations within a site, absence of the species from a subset of these spatial subunits induces estimation bias when locations are exhaustively assessed or sampled without replacement. 3. We further demonstrate that this bias can be removed by choosing sampling locations with replacement, or if the species is highly mobile over a short period of time. 4. Resampling an existing data set does not mitigate bias due to exhaustive assessment of locations or sampling without replacement. 5. Synthesis and applications. Selecting sampling locations for presence/absence surveys with replacement is practical in most cases. Such an adjustment to field methods will prevent one source of bias, and therefore produce more robust statistical inferences about species occupancy. This will in turn permit managers to make resource decisions based on better knowledge of the state of the system.

Incorporating Computer-Aided Language Sample Analysis into Clinical Practice

ERIC Educational Resources Information Center

Price, Lisa Hammett; Hendricks, Sean; Cook, Colleen

2010-01-01

Purpose: During the evaluation of language abilities, the needs of the child are best served when multiple types and sources of data are included in the evaluation process. Current educational policies and practice guidelines further dictate the use of authentic assessment data to inform diagnosis and treatment planning. Language sampling and…

A Review of Selected Engineered Nanoparticles in the Atmosphere: Sources, Transformations, and Techniques for Sampling and Analysis

EPA Science Inventory

A state-of-the-science review was undertaken to identify and assess sampling and analysis methods to detect and quantify selected nanomaterials (NMs) in the ambient atmosphere. The review is restricted to five types of NMs of interest to the Office of Research and Development Nan...

Environmental assessment of a watertube boiler firing a coal-water slurry. Volume 2. Data supplement. Final report, January 1984-March 1985

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

DeRosier, R.; Waterland, L.R.

1986-02-01

This report is a compendium of detailed test sampling and analysis data obtained in field tests of a watertube industrial boiler burning a coal/water slurry (CWS). Test data reported include preliminary stack test data, boiler operating data, and complete flue-gas emission results. Flue-gas emission measurements included continuous monitoring for criteria pollutants; onsite gas chromatography (GC) for volatile hydrocarbons (Cl-C6); Methods 5/8 sampling for particulate, SO/sub 2/, and SO/sub 3/ emissions; source assessment sampling system (SASS) for total organics in two boiling point ranges (100 to 300 C and > 300 C), organic compound category information using infrared spectrometry (IR), liquidmore » column (LC) chromatography separation, and low-resolution mass spectrometry (LRMS), specific quantitation of the semivolatile organic priority pollutants using gas chromatography/mass spectrometry (GC/MS), and trace-element emissions using spark-source mass spectrometry (SSMS) and atomic absorption spectroscopy (AAS); N/sub 2/O emissions by gas chromatography/electron-capture detector (GC/ECD); and biological assay testing of SASS and ash-stream samples.« less

Lead isotope ratios in lichen samples evaluated by ICP-ToF-MS to assess possible atmospheric pollution sources in Havana, Cuba.

PubMed

Alvarez, Alfredo Montero; Estévez Alvarez, Juan R; do Nascimento, Clístenes Williams Araújo; González, Iván Pupo; Rizo, Oscar Díaz; Carzola, Lázaro Lima; Torres, Roberto Ayllón; Pascual, Jorge Gómez

2017-01-01

Epiphytic lichens, collected from 119 sampling sites grown over "Roistonea Royal Palm" trees, were used to assess the spatial distribution pattern of lead (Pb) and identify possible pollution sources in Havana (Cuba). Lead concentrations in lichens and topsoils were determined by flame atomic absorption spectrophotometry and inductively coupled plasma (ICP) atomic emission spectrometry, respectively, while Pb in crude oils and gasoline samples were measured by ICP-time of flight mass spectrometry (ICP-ToF-MS). Lead isotopic ratios measurements for lichens, soils, and crude oils were obtained by ICP-ToF-MS. We found that enrichment factors (EF) reflected a moderate contamination for 71% of the samples (EF > 10). The 206 Pb/ 207 Pb ratio values for lichens ranged from 1.17 to 1.20 and were a mixture of natural radiogenic and industrial activities (e.g., crude oils and fire plants). The low concentration of Pb found in gasoline (<7.0 μg L -1 ) confirms the official statement that leaded gasoline is no longer used in Cuba.

Trends and sources for heavy metals in urban atmosphere

NASA Astrophysics Data System (ADS)

Kemp, Kåre

2002-04-01

The concentrations of a number of heavy metals in the air in three Danish cities have been measured by means of PIXE for more than two decades. The well-known capability of PIXE for fast and efficient analysis of aerosol samples has been employed for analysis of daily samples from several sites during the whole period. The main sources are traffic, domestic heating and long-range transport. Source apportionment and trends for single metals are assessed by means of simple statistical methods. The most striking change has occurred for the Pb concentration, which is reduced by almost a factor of 100 following the reduction of the Pb content in petrol. The main source of Cu, Cr and Zn is the traffic. The concentrations of these elements have been slightly increasing. The concentrations for most of the other heavy metals, which originate mainly from sources outside the cities, have been decreasing.

A Comparative Analysis of Vibrio cholerae Contamination in Point-of-Drinking and Source Water in a Low-Income Urban Community, Bangladesh

PubMed Central

Ferdous, Jannatul; Sultana, Rebeca; Rashid, Ridwan B.; Tasnimuzzaman, Md.; Nordland, Andreas; Begum, Anowara; Jensen, Peter K. M.

2018-01-01

Bangladesh is a cholera endemic country with a population at high risk of cholera. Toxigenic and non-toxigenic Vibrio cholerae (V. cholerae) can cause cholera and cholera-like diarrheal illness and outbreaks. Drinking water is one of the primary routes of cholera transmission in Bangladesh. The aim of this study was to conduct a comparative assessment of the presence of V. cholerae between point-of-drinking water and source water, and to investigate the variability of virulence profile using molecular methods of a densely populated low-income settlement of Dhaka, Bangladesh. Water samples were collected and tested for V. cholerae from “point-of-drinking” and “source” in 477 study households in routine visits at 6 week intervals over a period of 14 months. We studied the virulence profiles of V. cholerae positive water samples using 22 different virulence gene markers present in toxigenic O1/O139 and non-O1/O139 V. cholerae using polymerase chain reaction (PCR). A total of 1,463 water samples were collected, with 1,082 samples from point-of-drinking water in 388 households and 381 samples from 66 water sources. V. cholerae was detected in 10% of point-of-drinking water samples and in 9% of source water samples. Twenty-three percent of households and 38% of the sources were positive for V. cholerae in at least one visit. Samples collected from point-of-drinking and linked sources in a 7 day interval showed significantly higher odds (P < 0.05) of V. cholerae presence in point-of-drinking compared to source [OR = 17.24 (95% CI = 7.14–42.89)] water. Based on the 7 day interval data, 53% (17/32) of source water samples were negative for V. cholerae while linked point-of-drinking water samples were positive. There were significantly higher odds (p < 0.05) of the presence of V. cholerae O1 [OR = 9.13 (95% CI = 2.85–29.26)] and V. cholerae O139 [OR = 4.73 (95% CI = 1.19–18.79)] in source water samples than in point-of-drinking water samples. Contamination of water at the point-of-drinking is less likely to depend on the contamination at the water source. Hygiene education interventions and programs should focus and emphasize on water at the point-of-drinking, including repeated cleaning of drinking vessels, which is of paramount importance in preventing cholera. PMID:29616005

Possible sources of nitrate in ground water at swine licensed-managed feeding operations in Oklahoma, 2001

USGS Publications Warehouse

Becker, Mark F.; Peter, Kathy D.; Masoner, Jason

2002-01-01

Samples collected and analyzed by the Oklahoma Department of Agriculture, Food, and Forestry from 1999 to 2001 determined that nitrate exceeded the U.S. Environmental Protection Agency maximum contaminant level for public drinking-water supplies of 10 milligrams per liter as nitrogen in 79 monitoring wells at 35 swine licensed-managed feeding operations (LMFO) in Oklahoma. The LMFOs are located in rural agricultural settings where long-term agriculture has potentially affected the ground-water quality in some areas. Land use prior to the construction of the LMFOs was assessed to evaluate the types of agricultural land use within a 500-meter radius of the sampled wells. Chemical and microbiological techniques were used to determine the possible sources of nitrate in water sampled from 10 wastewater lagoons and 79 wells. Samples were analyzed for dissolved major ions, dissolved trace elements, dissolved nutrients, nitrogen isotope ratios of nitrate and ammonia, wastewater organic compounds, and fecal coliform bacteria. Bacteria ribotyping analysis was done on selected samples to identify possible specific animal sources. A decision process was developed to identify the possible sources of nitrate. First, nitrogen isotope ratios were used to define sources as animal, mixed animal and fertilizer, or fertilizer. Second, wastewater organic compound detections, nitrogen-isotope ratios, fecal coliform bacteria detections, and ribotyping were used to refine the identification of possible sources as LFMO waste, fertilizer, or unidentified animal or mixtures of these sources. Additional evidence provided by ribotyping and wastewater organic compound data can, in some cases, specifically indicate the animal source. Detections of three or more wastewater organic compounds that are indicators of animal sources and detections of fecal coliform bacteria provided additional evidence of an animal source. LMFO waste was designated as a possible source of nitrate in water from 10 wells. The source of waste in water from five of those wells was determined through ribotyping, and the source of waste in water from the remaining five wells was determined by detections of three or more animal-waste compounds in the well samples. LMFO waste in the water from wells with unidentified animal source of nitrate does not indicate that LMFO waste was not the source, but indicated that multiple animal sources, including LMFO waste, may be the source of the nitrate.

Organic compounds assessed in Neuse River water used for public supply near Smithfield, North Carolina, 2002-2005

USGS Publications Warehouse

Moorman, Michelle C.

2012-01-01

Organic compounds studied in a U.S. Geological Survey (USGS) assessment of water samples from the Neuse River and the public supply system for the Town of Smithfield, North Carolina, generally are manmade and include pesticides, gasoline hydrocarbons, solvents, personal-care and domestic-use products, disinfection by-products, and manufacturing additives. Of the 277 compounds assessed, a total of 113 compounds were detected in samples collected approximately monthly during 2002–2005 at the drinking-water intake for the town's water-treatment plant on the Neuse River. Fifty-two organic compounds were commonly detected (in at least 20 percent of the samples) in source water and (or) finished water. The diversity of compounds detected suggests a variety of sources and uses, including wastewater discharges, industrial, agricultural, domestic, and others. Only once during the study did an organic compound concentration exceed a human-health benchmark (benzo[a]pyrene). A human-health benchmark is a chemical concentration specific to water above which there is a risk to humans, however, benchmarks were available for only 18 of the 42 compounds with detected concentrations greater than 0.1 micrograms per liter. On the basis of this assessment, adverse effects to human health are assumed to be negligible.

Assessment of hydrocarbon source rock potential of Polish bituminous coals and carbonaceous shales

USGS Publications Warehouse

Kotarba, M.J.; Clayton, J.L.; Rice, D.D.; Wagner, M.

2002-01-01

We analyzed 40 coal samples and 45 carbonaceous shale samples of varying thermal maturity (vitrinite reflectance 0.59% to 4.28%) from the Upper Carboniferous coal-bearing strata of the Upper Silesian, Lower Silesian, and Lublin basins, Poland, to evaluate their potential for generation and expulsion of gaseous and liquid hydrocarbons. We evaluated source rock potential based on Rock-Eval pyrolysis yield, elemental composition (atomic H/C and O/C), and solvent extraction yields of bitumen. An attempt was made to relate maceral composition to these source rock parameters and to composition of the organic matter and likely biological precursors. A few carbonaceous shale samples contain sufficient generation potential (pyrolysis assay and elemental composition) to be considered potential source rocks, although the extractable hydrocarbon and bitumen yields are lower than those reported in previous studies for effective Type III source rocks. Most samples analysed contain insufficient capacity for generation of hydrocarbons to reach thresholds required for expulsion (primary migration) to occur. In view of these findings, it is improbable that any of the coals or carbonaceous shales at the sites sampled in our study would be capable of expelling commercial amounts of oil. Inasmuch as a few samples contained sufficient generation capacity to be considered potential source rocks, it is possible that some locations or stratigraphic zones within the coals and shales could have favourable potential, but could not be clearly delimited with the number of samples analysed in our study. Because of their high heteroatomic content and high amount of asphaltenes, the bitumens contained in the coals are less capable of generating hydrocarbons even under optimal thermal conditions than their counterpart bitumens in the shales which have a lower heteroatomic content. Published by Elsevier Science B.V.

Interlaboratory comparison of three microbial source tracking quantitative polymerase chain reaction (qPCR) assays from fecal-source and environmental samples

USGS Publications Warehouse

Stelzer, Erin A.; Strickler, Kriston M.; Schill, William B.

2012-01-01

During summer and early fall 2010, 15 river samples and 6 fecal-source samples were collected in West Virginia. These samples were analyzed by three laboratories for three microbial source tracking (MST) markers: AllBac, a general fecal indicator; BacHum, a human-associated fecal indicator; and BoBac, a ruminant-associated fecal indicator. MST markers were analyzed by means of the quantitative polymerase chain reaction (qPCR) method. The aim was to assess interlaboratory precision when the three laboratories used the same MST marker and shared deoxyribonucleic acid (DNA) extracts of the samples, but different equipment, reagents, and analyst experience levels. The term assay refers to both the markers and the procedure differences listed above. Interlaboratory precision was best for all three MST assays when using the geometric mean absolute relative percent difference (ARPD) and Friedman's statistical test as a measure of interlaboratory precision. Adjustment factors (one for each MST assay) were calculated using results from fecal-source samples analyzed by all three laboratories and applied retrospectively to sample concentrations to account for differences in qPCR results among labs using different standards and procedures. Following the application of adjustment factors to qPCR results, ARPDs were lower; however, statistically significant differences between labs were still observed for the BacHum and BoBac assays. This was a small study and two of the MST assays had 52 percent of samples with concentrations at or below the limit of accurate quantification; hence, more testing could be done to determine if the adjustment factors would work better if the majority of sample concentrations were above the quantification limit.

Use of dust fall filters as passive samplers for metal concentrations in air for communities near contaminated mine tailings

PubMed Central

Beamer, P.I.; Sugeng, A. J.; Kelly, M.D.; Lothrop, N.; Klimecki, W.; Wilkinson, S.T.; Loh, M.

2014-01-01

Mine tailings are a source of metal exposures in many rural communities. Multiple air samples are necessary to assess the extent of exposures and factors contributing to these exposures. However, air sampling equipment is costly and requires trained personnel to obtain measurements, limiting the number of samples that can be collected. Simple, low-cost methods are needed to allow for increased sample collection. The objective of our study was to assess if dust fall filters can serve as passive air samplers and be used to characterize potential exposures in a community near contaminated mine tailings. We placed filters in cylinders, concurrently with active indoor air samplers, in 10 occupied homes. We calculated an estimated flow rate by dividing the mass on each dust fall filter by the bulk air concentration and the sampling duration. The mean estimated flow rate for dust fall filters was significantly different during sampling periods with precipitation. The estimated flow rate was used to estimate metal concentration in the air of these homes, as well as in 31 additional homes in another rural community impacted by contaminated mine tailings. The estimated air concentrations had a significant linear association with the measured air concentrations for beryllium, manganese and arsenic (p<0.05), whose primary source in indoor air is resuspended soil from outdoors. In the second rural community, our estimated metal concentrations in air were comparable to active air sampling measurements taken previously. This passive air sampler is a simple low-cost method to assess potential exposures near contaminated mining sites. PMID:24469149

Factors associated with sources, transport, and fate of chloroform and three other trihalomethanes in untreated groundwater used for drinking water

USGS Publications Warehouse

Carter, Janet M.; Moran, Michael J.; Zogorski, John S.; Price, Curtis V.

2012-01-01

Multiple lines of evidence for indicating factors associated with the sources, transport, and fate of chloroform and three other trihalomethanes (THMs) in untreated groundwater were revealed by evaluating low-level analytical results and logistic regression results for THMs. Samples of untreated groundwater from wells used for drinking water were collected from 1996-2007 from 2492 wells across the United States and analyzed for chloroform, bromodichloromethane, dibromochloromethane, and bromoform by a low-level analytical method implemented in April 1996. Using an assessment level of 0.02 μg/L, chloroform was detected in 36.5% of public-well samples and 17.6% of domestic-well samples, with most concentrations less than 1 μg/L. Brominated THMs occurred less frequently than chloroform but more frequently in public-well samples than domestic-well samples. For both public and domestic wells, THMs occurred most frequently in urban areas. Logistic regression analyses showed that the occurrence of THMs was related to nonpoint sources such as urban land use and to point sources like septic systems. The frequent occurrence and concentration distribution pattern of THMs, as well as their frequent co-occurrence with other organic compounds and nitrate, all known to have anthropogenic sources, and the positive associations between THM occurrence and dissolved oxygen and recharge indicate the recycling of water that contains THMs and other anthropogenic contaminants.

Collection methods and quality assessment for Esche-richia coli, water quality, and microbial source tracking data within Tumacácori National Historical Park and the upper Santa Cruz River, Arizona, 2015-16

USGS Publications Warehouse

Paretti, Nicholas; Coes, Alissa L.; Kephart, Christopher M.; Mayo, Justine

2018-03-05

Tumacácori National Historical Park protects the culturally important Mission, San José de Tumacácori, while also managing a portion of the ecologically diverse riparian corridor of the Santa Cruz River. This report describes the methods and quality assurance procedures used in the collection of water samples for the analysis of Escherichia coli (E. coli), microbial source tracking markers, suspended sediment, water-quality parameters, turbidity, and the data collection for discharge and stage; the process for data review and approval is also described. Finally, this report provides a quantitative assessment of the quality of the E. coli, microbial source tracking, and suspended sediment data.The data-quality assessment revealed that bias attributed to field and laboratory contamination was minimal, with E. coli detections in only 3 out of 33 field blank samples analyzed. Concentrations in the field blanks were several orders of magnitude lower than environmental concentrations. The microbial source tracking (MST) field blank was below the detection limit for all MST markers analyzed. Laboratory blanks for E. coli at the USGS Arizona Water Science Center and laboratory blanks for MST markers at the USGS Ohio Water Microbiology Laboratory were all below the detection limit. Irreplicate data for E. coli and suspended sediment indicated that bias was not introduced to the data by combining samples collected using discrete sampling methods with samples collected using automatic sampling methods.The split and sequential E. coli replicate data showed consistent analytical variability and a single equation was developed to explain the variability of E. coli concentrations. An additional analysis of analytical variability for E. coli indicated analytical variability around 18 percent relative standard deviation and no trend was observed in the concentration during the processing and analysis of multiple split-replicates. Two replicate samples were collected for MST and individual markers were compared for a base flow and flood sample. For the markers found in common between the two types of samples, the relative standard deviation for the base flow sample was more than 3 times greater than the markers in the flood sample. Sequential suspended sediment replicates had a relative standard deviation of about 1.3 percent, indicating that environmental and analytical variability was minimal.A holding time review and laboratory study analysis supported the extended holding times required for this investigation. Most concentrations for flood and base-flow samples were within the theoretical variability specified in the most probable number approach suggesting that extended hold times did not overly influence the final concentrations reported.

Potential sources of bacteriological pollution for two bays with marinas in Trinidad.

PubMed

Bullock, Christine Ann; Moonesar, Indar

2005-05-01

Welcome Bay and Chaguaramas Bay in the northwest peninsula of Trinidad contain large marinas and smaller sections of bathing beaches. Bacteriological surveys were conducted at both bays to assess water quality and to determine potential sources of pollution. These surveys were conducted during the wet season of 1996 and the dry season of 1997. Eleven sample stations were established at Welcome Bay and 12 at Chaguaramas Bay. Freshwater samples were collected from rivers and drains within the survey area. Marine water samples were collected from marinas, bathing beaches and inshore and outer areas at both bays. Five water samples were collected from each sampling station during the wet season of 1996 and six during the dry season of 1997. The membrane filter technique was used to determine faecal coliform and Escherichia coli levels in all samples. There was a seasonal effect on water quality, with significantly higher faecal coliform levels in the wet season, when water quality was not in compliance with international standards. This represents a potential health risk in bathing areas. Water quality was better at the outer area of both bays. Water quality at the inner bay areas was most likely adversely affected by land-based sources of pollution identified in this study. These sources include three drains and two rivers, which discharged into the bays. Yachts were apparently not a source of sewage pollution: there was no significant relationship between yacht number and faecal coliform levels.

Assessment of spatial distribution of soil heavy metals using ANN-GA, MSLR and satellite imagery.

PubMed

Naderi, Arman; Delavar, Mohammad Amir; Kaboudin, Babak; Askari, Mohammad Sadegh

2017-05-01

This study aims to assess and compare heavy metal distribution models developed using stepwise multiple linear regression (MSLR) and neural network-genetic algorithm model (ANN-GA) based on satellite imagery. The source identification of heavy metals was also explored using local Moran index. Soil samples (n = 300) were collected based on a grid and pH, organic matter, clay, iron oxide contents cadmium (Cd), lead (Pb) and zinc (Zn) concentrations were determined for each sample. Visible/near-infrared reflectance (VNIR) within the electromagnetic ranges of satellite imagery was applied to estimate heavy metal concentrations in the soil using MSLR and ANN-GA models. The models were evaluated and ANN-GA model demonstrated higher accuracy, and the autocorrelation results showed higher significant clusters of heavy metals around the industrial zone. The higher concentration of Cd, Pb and Zn was noted under industrial lands and irrigation farming in comparison to barren and dryland farming. Accumulation of industrial wastes in roads and streams was identified as main sources of pollution, and the concentration of soil heavy metals was reduced by increasing the distance from these sources. In comparison to MLSR, ANN-GA provided a more accurate indirect assessment of heavy metal concentrations in highly polluted soils. The clustering analysis provided reliable information about the spatial distribution of soil heavy metals and their sources.

Study on induced radioactivity of China Spallation Neutron Source

NASA Astrophysics Data System (ADS)

Wu, Qing-Biao; Wang, Qing-Bin; Wu, Jing-Min; Ma, Zhong-Jian

2011-06-01

China Spallation Neutron Source (CSNS) is the first High Energy Intense Proton Accelerator planned to be constructed in China during the State Eleventh Five-Year Plan period, whose induced radioactivity is very important for occupational disease hazard assessment and environmental impact assessment. Adopting the FLUKA code, the authors have constructed a cylinder-tunnel geometric model and a line-source sampling physical model, deduced proper formulas to calculate air activation, and analyzed various issues with regard to the activation of different tunnel parts. The results show that the environmental impact resulting from induced activation is negligible, whereas the residual radiation in the tunnels has a great influence on maintenance personnel, so strict measures should be adopted.

Aquifer Susceptibility in Virginia: Data on Chemical and Isotopic Composition, Recharge Temperature, and Apparent Age of Water from Wells and Springs, 1998-2000

USGS Publications Warehouse

Nelms, David L.; Harlow, George E.

2003-01-01

The determination of aquifer susceptibility to contamination from near-surface sources by the use of ground-water dating techniques is a critical part of Virginia's Source Water Assessment Program. As part of the Virginia Aquifer Susceptibility study, water samples were collected between 1998 and 2000 from 145 wells and 6 springs in various hydrogeologic settings across the Commonwealth. Samples were analyzed to determine water chemistry?including nitrate (NO3), dissolved organic carbon (DOC), and radon-222 (222Rn), major dissolved and noble gases?nitrogen (N2), argon (Ar), oxygen (O2), carbon dioxide (CO2), methane (CH4), helium (He), and neon (Ne), environmental tracers?chlorofluorocarbons (CFCs), sulfur hexafluoride (SF6), tritium (3H), and tritium/helium-3 (3H/3He), carbon isotopes?carbon-14 (14C) and carbon-13 (d13C), and stable isotopes of oxygen (d18O) and hydrogen (d2H). The chemical and isotopic composition, recharge temperatures, and apparent ages of these water samples are presented in this report. Data collected between 1999 and 2000 from 18 wells in Virginia as part of two other studies by the U.S. Geological Survey also are presented. Most of the sites sampled serve as public water supplies and are included in the comprehensive Source Water Assessment Program for the Commonwealth.

Preliminary assessment of sources of nitrogen in groundwater at a biosolids-application area near Deer Trail

USGS Publications Warehouse

Yager, Tracy J.B.; McMahon, Peter B.

2012-01-01

Concentrations of dissolved nitrite plus nitrate increased fairly steadily in samples from four shallow groundwater monitoring wells after biosolids applications to nonirrigated farmland began in 1993. The U.S. Geological Survey began a preliminary assessment of sources of nitrogen in shallow groundwater at part of the biosolids-application area near Deer Trail, Colorado, in 2005 in cooperation with the Metro Wastewater Reclamation District. Possible nitrogen sources in the area include biosolids, animal manure, inorganic fertilizer, atmospheric deposition, and geologic materials (bedrock and soil). Biosolids from the Metro Wastewater Reclamation District plant in Denver and biosolids, cow manure, geologic materials (bedrock and soil), and groundwater from the study area were sampled to measure nitrogen content and nitrogen isotopic compositions of nitrate or total nitrogen. Biosolids also were leached, and the leachates were analyzed for nitrogen content and other concentrations. Geologic materials from the study area also were sampled to determine mineralogy. Estimates of nitrogen contributed from inorganic fertilizer and atmospheric deposition were calculated from other published reports. The nitrogen information from the study indicates that each of the sources contain sufficient nitrogen to potentially affect groundwater nitrate concentrations. Natural processes can transform the nitrogen in any of the sources to nitrate in the groundwater. Load calculations indicate that animal manure, inorganic fertilizer, or atmospheric deposition could have contributed the largest nitrogen load to the study area in the 13 years before biosolids applications began, but biosolids likely contributed the largest nitrogen load to the study area in the 13 years after biosolids applications began. Various approaches provided insights into sources of nitrate in the groundwater samples from 2005. The isotopic data indicate that, of the source materials considered, biosolids and (or) animal manure were the most likely sources of nitrate in the wells at the time of sampling (2005), and that inorganic fertilizer, atmospheric deposition, and geologic materials were not substantial sources of nitrate in the wells in 2005. The large total nitrogen content of the biosolids and animal-manure samples and biosolids leachates also indicates that the biosolids and animal manure had potential to leach nitrogen and produce large dissolved nitrate concentrations in groundwater. The available data, however, could not be used to distinguish between biosolids or manure as the dominant source of nitrate in the groundwater because the nitrogen isotopic composition of the two materials is similar. Major-ion data also could not be used to distinguish between biosolids or manure as the dominant source of nitrate in the groundwater because the major-ion composition (as well as the isotopic composition) of the two materials is similar. Without additional data, chloride/bromide mass ratios do not necessarily support or refute the hypothesis that biosolids and (or) animal manure were the primary sources of nitrate in water from the study-area wells in 2005. Concentrations of water-extractable nitrate in the soil indicate that biosolids could be an important source of nitrate in the groundwater recharge. Nitrogen inventories in the soil beneath biosolids-application areas and the nitrogen-input estimates for the study area both support the comparisons of isotopic composition, which indicate that some type of human waste (such as biosolids) and (or) animal manure was the source of nitrate in groundwater sampled from the wells in 2005. The nitrogen-load estimates considered with the nitrogen isotopic data and the soil-nitrogen inventories indicate that biosolids applications likely are a major source of nitrogen to the shallow groundwater at these monitoring wells.

ENVIRONMENTAL ASSESSMENT OF A FIRETUBE BOILER FIRING COAL/OIL/WATER MIXTURES. VOLUME 1. TECHNICAL RESULTS

EPA Science Inventory

This volume describes emission results from sampling of flue gas from a firetube boiler burning a coal/oil/water (COW) mixture and COW with soda ash added (COW+SA) to control SO2 emissions. Measurements included: continuous monitoring of flue gas emissions; source assessment samp...

Natural environmental water sources in endemic regions of northeastern Brazil are potential reservoirs of viable Mycobacterium leprae.

PubMed

Arraes, Maria Luisa Bezerra de Macedo; Holanda, Maísa Viana de; Lima, Luana Nepomuceno Gondim Costa; Sabadia, José Antônio Beltrão; Duarte, Cynthia Romariz; Almeida, Rosa Livia Freitas; Kendall, Carl; Kerr, Ligia Regina Sansigolo; Frota, Cristiane Cunha

2017-12-01

The detection of live Mycobacterium leprae in soil and animals other than humans suggests that the environment plays a role in the transmission of leprosy. The objective of this study was to investigate the presence of viable M. leprae in natural water sources used by the local population in five municipalities in the state of Ceará, northeastern Brazil. Samples were collected from 30 different sources. Viable bacilli were identified by reverse transcriptase polymerase chain reaction (PCR) of the M. leprae gyrA gene and sequencing of the PCR products. Physicochemical properties of each water source were also assessed. M. leprae gyrA mRNA was found in 23 (76.7%) of the water sources. No association was found between depth of the water and sample positivity, nor was there any association between the type of water used by the population and sample positivity. An association between viable M. leprae and temperature and pH was found. Georeferencing showed a relation between the residences of leprosy cases and water source containing the bacterium. The finding of viable M. leprae in natural water sources associated with human contact suggests that the environment plays an important role in maintaining endemic leprosy in the study region.

Using stable isotopes of hydrogen to quantify biogenic and thermogenic atmospheric methane sources: A case study from the Colorado Front Range

NASA Astrophysics Data System (ADS)

Townsend-Small, Amy; Botner, E. Claire; Jimenez, Kristine L.; Schroeder, Jason R.; Blake, Nicola J.; Meinardi, Simone; Blake, Donald R.; Sive, Barkley C.; Bon, Daniel; Crawford, James H.; Pfister, Gabriele; Flocke, Frank M.

2016-11-01

Global atmospheric concentrations of methane (CH4), a powerful greenhouse gas, are increasing, but because there are many natural and anthropogenic sources of CH4, it is difficult to assess which sources may be increasing in magnitude. Here we present a data set of δ2H-CH4 measurements of individual sources and air in the Colorado Front Range, USA. We show that δ2H-CH4, but not δ13C, signatures are consistent in air sampled downwind of landfills, cattle feedlots, and oil and gas wells in the region. Applying these source signatures to air in ground and aircraft samples indicates that at least 50% of CH4 emitted in the region is biogenic, perhaps because regulatory restrictions on leaking oil and natural gas wells are helping to reduce this source of CH4. Source apportionment tracers such as δ2H may help close the gap between CH4 observations and inventories, which may underestimate biogenic as well as thermogenic sources.

Bench-scale biodegradation tests to assess natural attenuation potential of 1,4-dioxane at three sites in California.

PubMed

Li, Mengyan; Van Orden, E Tess; DeVries, David J; Xiong, Zhong; Hinchee, Rob; Alvarez, Pedro J

2015-02-01

1,4-Dioxane (dioxane) is relatively recalcitrant to biodegradation, and its physicochemical properties preclude effective removal from contaminated groundwater by volatilization or adsorption. Through this microcosm study, we assessed the biodegradation potential of dioxane for three sites in California. Groundwater and sediment samples were collected at various locations at each site, including the presumed source zone, middle and leading edge of the plume. A total of 16 monitoring wells were sampled to prepare the microcosms. Biodegradation of dioxane was observed in 12 of 16 microcosms mimicking natural attenuation within 28 weeks. Rates varied from as high as 3,449 ± 459 µg/L/week in source-zone microcosms to a low of 0.3 ± 0.1 µg/L/week in microcosms with trace level of dioxane (<10 µg/L as initial concentration). The microcosms were spiked with (14)C-labeled dioxane to assess the fate of dioxane. Biological oxidizer-liquid scintillation analysis of bound residue infers that 14C-dioxane was assimilated into cell material only in microcosms exhibiting significant dioxane biodegradation. Mineralization was also observed per (14)CO2 recovery (up to 44% of the amount degraded in 28 weeks of incubation). Degradation and mineralization activity significantly decreased with increasing distance from the contaminant source area (p < 0.05), possibly due to less acclimation. Furthermore, both respiked and repeated microcosms prepared with source-zone samples from Site 1 confirmed relatively rapid dioxane degradation (i.e., 100 % removal by 20 weeks). These results show that indigenous microorganisms capable of degrading dioxane are present at these three sites, and suggest that monitored natural attenuation should be considered as a remedial response.

Can rapid assessment protocols be used to judge sediment impairment in gravel-bed streams? A commentary

Treesearch

Thomas E. Lisle; John M. Buffington; Peter R. Wilcock; Kristin Bunte

2015-01-01

Land management agencies commonly use rapid assessments to evaluate the impairment of gravel-bed streams by sediment inputs from anthropogenic sources. We question whether rapid assessment can be used to reliably judge sediment impairment at a site or in a region. Beyond the challenges of repeatable and accurate sampling, we argue that a single metric or protocol is...

Assessment of nonpoint source chemical loading potential to watersheds containing uranium waste dumps associated with uranium exploration and mining, Browns Hole, Utah

USGS Publications Warehouse

Marston, Thomas M.; Beisner, Kimberly R.; Naftz, David L.; Snyder, Terry

2012-01-01

During August of 2008, 35 solid-phase samples were collected from abandoned uranium waste dumps, undisturbed geologic background sites, and adjacent streambeds in Browns Hole in southeastern Utah. The objectives of this sampling program were (1) to assess impacts on human health due to exposure to radium, uranium, and thorium during recreational activities on and around uranium waste dumps on Bureau of Land Management lands; (2) to compare concentrations of trace elements associated with mine waste dumps to natural background concentrations; (3) to assess the nonpoint source chemical loading potential to ephemeral and perennial watersheds from uranium waste dumps; and (4) to assess contamination from waste dumps to the local perennial stream water in Muleshoe Creek. Uranium waste dump samples were collected using solid-phase sampling protocols. Solid samples were digested and analyzed for major and trace elements. Analytical values for radium and uranium in digested samples were compared to multiple soil screening levels developed from annual dosage calculations in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act's minimum cleanup guidelines for uranium waste sites. Three occupancy durations for sites were considered: 4.6 days per year, 7.0 days per year, and 14.0 days per year. None of the sites exceeded the radium soil screening level of 96 picocuries per gram, corresponding to a 4.6 days per year exposure. Two sites exceeded the radium soil screening level of 66 picocuries per gram, corresponding to a 7.0 days per year exposure. Seven sites exceeded the radium soil screening level of 33 picocuries per gram, corresponding to a 14.0 days per year exposure. A perennial stream that flows next to the toe of a uranium waste dump was sampled, analyzed for major and trace elements, and compared with existing aquatic-life and drinking-water-quality standards. None of the water-quality standards were exceeded in the stream samples.

Tracing Sources and Contamination Assessments of Heavy Metals in Road and Foliar Dusts in a Typical Mining City, China

PubMed Central

Yang, Jie; Teng, Yanguo; Song, Liuting; Zuo, Rui

2016-01-01

Road and foliar dust samples from four land-use districts of Panzhihua City, a famous V-Ti magnetite production area of China, were collected to investigate the sources and distribution characteristics of 9 heavy metals (V, Pb, Cd, Cu, Zn, Ni, Cr, Fe, and Mn). The results suggest that foliar samples had smaller particle size and higher heavy metal contents than road dusts. The contamination assessments of heavy metals were as follows: Pb and V (significant enrichment) > Zn, Ni, Cr, Fe, and Mn (moderate enrichment) > Cd and Ni (minimal enrichment). Statistical analyses showed Pb, as the primary pollution element, originated from waste incineration and lead-fuel combustion. The sources of Zn, Ni, Cr, Fe, V, and Mn were fugitive dust and traffic activities. Potential origins of Cu were corrosion of alloys used in vehicle components, vehicle covers, or other metallic surfaces and materials. The sources of Cd were different from any other heavy metals. Traffic and industrial activities were the main anthropogenic origins of heavy metals in dusts of Panzhihua, and more attention should be paid to heavy metal pollution in agricultural area. PMID:27992518

Tracing Sources and Contamination Assessments of Heavy Metals in Road and Foliar Dusts in a Typical Mining City, China.

PubMed

Yang, Jie; Teng, Yanguo; Song, Liuting; Zuo, Rui

2016-01-01

Road and foliar dust samples from four land-use districts of Panzhihua City, a famous V-Ti magnetite production area of China, were collected to investigate the sources and distribution characteristics of 9 heavy metals (V, Pb, Cd, Cu, Zn, Ni, Cr, Fe, and Mn). The results suggest that foliar samples had smaller particle size and higher heavy metal contents than road dusts. The contamination assessments of heavy metals were as follows: Pb and V (significant enrichment) > Zn, Ni, Cr, Fe, and Mn (moderate enrichment) > Cd and Ni (minimal enrichment). Statistical analyses showed Pb, as the primary pollution element, originated from waste incineration and lead-fuel combustion. The sources of Zn, Ni, Cr, Fe, V, and Mn were fugitive dust and traffic activities. Potential origins of Cu were corrosion of alloys used in vehicle components, vehicle covers, or other metallic surfaces and materials. The sources of Cd were different from any other heavy metals. Traffic and industrial activities were the main anthropogenic origins of heavy metals in dusts of Panzhihua, and more attention should be paid to heavy metal pollution in agricultural area.

Fecal contamination of drinking-water in low- and middle-income countries: a systematic review and meta-analysis.

PubMed

Bain, Robert; Cronk, Ryan; Wright, Jim; Yang, Hong; Slaymaker, Tom; Bartram, Jamie

2014-05-01

Access to safe drinking-water is a fundamental requirement for good health and is also a human right. Global access to safe drinking-water is monitored by WHO and UNICEF using as an indicator "use of an improved source," which does not account for water quality measurements. Our objectives were to determine whether water from "improved" sources is less likely to contain fecal contamination than "unimproved" sources and to assess the extent to which contamination varies by source type and setting. Studies in Chinese, English, French, Portuguese, and Spanish were identified from online databases, including PubMed and Web of Science, and grey literature. Studies in low- and middle-income countries published between 1990 and August 2013 that assessed drinking-water for the presence of Escherichia coli or thermotolerant coliforms (TTC) were included provided they associated results with a particular source type. In total 319 studies were included, reporting on 96,737 water samples. The odds of contamination within a given study were considerably lower for "improved" sources than "unimproved" sources (odds ratio [OR] = 0.15 [0.10-0.21], I2 = 80.3% [72.9-85.6]). However over a quarter of samples from improved sources contained fecal contamination in 38% of 191 studies. Water sources in low-income countries (OR = 2.37 [1.52-3.71]; p<0.001) and rural areas (OR = 2.37 [1.47-3.81] p<0.001) were more likely to be contaminated. Studies rarely reported stored water quality or sanitary risks and few achieved robust random selection. Safety may be overestimated due to infrequent water sampling and deterioration in quality prior to consumption. Access to an "improved source" provides a measure of sanitary protection but does not ensure water is free of fecal contamination nor is it consistent between source types or settings. International estimates therefore greatly overstate use of safe drinking-water and do not fully reflect disparities in access. An enhanced monitoring strategy would combine indicators of sanitary protection with measures of water quality.

Assessment of water sources to plant growth in rice based cropping systems by stable water isotopes

NASA Astrophysics Data System (ADS)

Mahindawansha, Amani; Kraft, Philipp; Racela, Heathcliff; Breuer, Lutz

2016-04-01

Rice is one of the most water-consuming crops in the world. Understanding water source utilization of rice will help us to improve water use efficiency (WUE) in paddy management. The objectives of our study are to evaluate the isotopic compositions of surface ponded water, soil water, irrigation water, groundwater, rain water and plant water and based on stable water isotope signatures to evaluate the contributions of various water sources to plant growth (wet rice, aerobic rice and maize) together with investigating the contribution of water from different soil horizons for plant growth in different maturity periods during wet and dry seasons. Finally we will compare the water balances and crop yields in both crops during both seasons and calculate the water use efficiencies. This will help to identify the most efficient water management systems in rice based cropping ecosystems using stable water isotopes. Soil samples are collected from 9 different depths at up to 60 cm in vegetative, reproductive and matured periods of plant growth together with stem samples. Soil and plant samples are extracted by cryogenic vacuum extraction. Root samples are collected up to 60 cm depth from 10 cm intercepts leading calculation of root length density and dry weight. Groundwater, surface water, rain water and irrigation water are sampled weekly. All water samples are analyzed for hydrogen and oxygen isotope ratios (d18O and dD) using Los Gatos Research DLT100. Rainfall records, ground water level, surface water level fluctuations and the amount of water irrigated in each field will be measured during the sampling period. The direct inference approach which is based on comparing isotopic compositions (dD and d18O) between plant stem water and soil water will be used to determine water sources taken up by plant. Multiple-source mass balance assessment can provide the estimated range of potential contributions of water from each soil depth to root water uptake of a crop. These evaluations will be used to determine the proportion of water from upper soil horizons and deep horizons for rice and maize in different maturity periods during wet and dry seasons. Finally we will estimate the influence of groundwater and surface water by irrigation water and/or by precipitation. First results of the sampling during the wet season 2015 will be presented.

Correlation of quantitative PCR for a poultry-specific brevibacterium marker gene with bacterial and chemical indicators of water pollution in a watershed impacted by land application of poultry litter.

PubMed

Weidhaas, Jennifer L; Macbeth, Tamzen W; Olsen, Roger L; Harwood, Valerie J

2011-03-01

The impact of fecal contamination from human and agricultural animal waste on water quality is a major public health concern. Identification of the dominant source(s) of fecal pollution in a watershed is necessary for assessing the safety of recreational water and protecting water resources. A field study was conducted using quantitative PCR (qPCR) for the 16S rRNA gene of Brevibacterium sp. LA35 to track feces-contaminated poultry litter in environmental samples. Based on sensitivity and specificity characteristics of the qPCR method, the Bayesian conditional probability that detection of the LA35 marker gene in a water sample represented a true-positive result was 93%. The marker's covariance with fecal indicator bacteria (FIB) and metals associated with poultry litter was also assessed in litter, runoff, surface water, and groundwater samples. LA35 was detected in water and soil samples collected throughout the watershed, and its concentration covaried with concentrations of Escherichia coli, enterococci, As, Cu, P, and Zn. Significantly greater concentrations of FIB, As, Cu, P, and Zn were observed in edge-of-field runoff samples in which LA35 was detected, compared to samples in which it was not detected. Furthermore, As, Cu, P, and Zn concentrations covaried in environmental samples in which LA35 was detected and typically did not in samples in which the marker gene was not detected. The covariance of the poultry-specific LA35 marker gene with these known contaminants from poultry feces provides further evidence that it is a useful tool for assessing the impact of poultry-derived fecal pollution in environmental waters.

Thermal Maturity Data Used by the U.S. Geological Survey for the U.S. Gulf Coast Region Oil and Gas Assessment

USGS Publications Warehouse

Dennen, Kristin O.; Warwick, Peter D.; McDade, Elizabeth Chinn

2010-01-01

The U.S. Geological Survey is currently assessing the oil and natural gas resources of the U.S. Gulf of Mexico region using a total petroleum system approach. An essential part of this geologically based method is evaluating the effectiveness of potential source rocks in the petroleum system. The purpose of this report is to make available to the public RockEval and vitrinite reflectance data from more than 1,900 samples of Mesozoic and Tertiary rock core and coal samples in the Gulf of Mexico area in a format that facilitates inclusion into a geographic information system. These data provide parameters by which the thermal maturity, type, and richness of potential sources of oil and gas in this region can be evaluated.

Illuminating the NARS data entry black box: what happens between sample collection and data availability for use in assessments?

EPA Science Inventory

The steps between field collection of data and samples and availability of the resulting data from National Aquatic Resource Surveys (NARS) can appear to be a black box. This presentation is intended to shed some light on that process. The pathway for data depends on their source...

Towards a Comparative Index of Seaport Climate-Risk: Development of Indicators from Open Data

NASA Astrophysics Data System (ADS)

McIntosh, R. D.; Becker, A.

2016-02-01

Seaports represent an example of coastal infrastructure that is at once critical to global trade, constrained to the land-sea interface, and exposed to weather and climate hazards. Seaports face impacts associated with projected changes in sea level, sedimentation, ocean chemistry, wave dynamics, temperature, precipitation, and storm frequency and intensity. Port decision-makers have the responsibility to enhance resilience against these impacts. At the multi-port (regional or national) scale, policy-makers must prioritize adaptation efforts to maximize the efficiency of limited physical and financial resources. Prioritization requires comparing across seaports, and comparison requires a standardized assessment method, but efforts to date have either been limited in scope to exposure-only assessments or limited in scale to evaluate one port in isolation from a system of ports. In order to better understand the distribution of risk across ports and to inform transportation resilience policy, we are developing a comparative assessment method to measure the relative climate-risk faced by a sample of ports. Our mixed-methods approach combines a quantitative, data-driven, indicator-based assessment with qualitative data collected via expert-elicitation. In this presentation, we identify and synthesize over 120 potential risk indicators from open data sources. Indicators represent exposure, sensitivity, and adaptive capacity for a pilot sample of 20 ports. Our exploratory data analysis, including Principal Component Analysis, uncovered sources of variance between individual ports and between indicators. Next steps include convening an expert panel representing the perspectives of multiple transportation system agencies to find consensus on a suite of robust indicators and metrics for maritime freight node climate risk assessment. The index will be refined based on expert feedback, the sample size expanded, and additional indicators sought from closed data sources. Developing standardized indicators from available data is an essential step in risk assessment, as robust indicators can help policy-makers monitor resilience strategy implementation, target and justify resource expenditure for adaptation schemes, communicate adaptation to stakeholders, and benchmark progress.

Audio-visual interactions in environment assessment.

PubMed

Preis, Anna; Kociński, Jędrzej; Hafke-Dys, Honorata; Wrzosek, Małgorzata

2015-08-01

The aim of the study was to examine how visual and audio information influences audio-visual environment assessment. Original audio-visual recordings were made at seven different places in the city of Poznań. Participants of the psychophysical experiments were asked to rate, on a numerical standardized scale, the degree of comfort they would feel if they were in such an environment. The assessments of audio-visual comfort were carried out in a laboratory in four different conditions: (a) audio samples only, (b) original audio-visual samples, (c) video samples only, and (d) mixed audio-visual samples. The general results of this experiment showed a significant difference between the investigated conditions, but not for all the investigated samples. There was a significant improvement in comfort assessment when visual information was added (in only three out of 7 cases), when conditions (a) and (b) were compared. On the other hand, the results show that the comfort assessment of audio-visual samples could be changed by manipulating the audio rather than the video part of the audio-visual sample. Finally, it seems, that people could differentiate audio-visual representations of a given place in the environment based rather of on the sound sources' compositions than on the sound level. Object identification is responsible for both landscape and soundscape grouping. Copyright © 2015. Published by Elsevier B.V.

Hydrogeochemistry of the drinking water sources of Derebogazi Village (Kahramanmaras) and their effects on human health.

PubMed

Uras, Yusuf; Uysal, Yagmur; Arikan, Tugba Atilan; Kop, Alican; Caliskan, Mustafa

2015-06-01

The aim of this study was to investigate the sources of drinking water for Derebogazi Village, Kahramanmaras Province, Turkey, in terms of hydrogeochemistry, isotope geochemistry, and medical geology. Water samples were obtained from seven different water sources in the area, all of which are located within quartzite units of Paleozoic age, and isotopic analyses of (18)O and (2)H (deuterium) were conducted on the samples. Samples were collected from the region for 1 year. Water quality of the samples was assessed in terms of various water quality parameters, such as temperature, pH, conductivity, alkalinity, trace element concentrations, anion-cation measurements, and metal concentrations, using ion chromatography, inductively coupled plasma (ICP) mass spectrometry, ICP-optical emission spectrometry techniques. Regional health surveys had revealed that the heights of local people are significantly below the average for the country. In terms of medical geology, the sampled drinking water from the seven sources was deficient in calcium and magnesium ions, which promote bone development. Bone mineral density screening tests were conducted on ten females using dual energy X-ray absorptiometry to investigate possible developmental disorder(s) and potential for mineral loss in the region. Of these ten women, three had T-scores close to the osteoporosis range (T-score < -2.5).

Preliminary assessment of water chemistry related to groundwater flooding in Wawarsing, New York, 2009-11

USGS Publications Warehouse

Brown, Craig J.; Eckhardt, David A.; Stumm, Frederick; Chu, Anthony

2012-01-01

Water-quality samples collected in an area prone to groundwater flooding in Wawarsing, New York, were analyzed and assessed to better understand the hydrologic system and to aid in the assessment of contributing water sources. Above average rainfall over the past decade, and the presence of a pressurized water tunnel that passes about 700 feet beneath Wawarsing, could both contribute to groundwater flooding. Water samples were collected from surface-water bodies, springs, and wells and analyzed for major and trace inorganic constituents, dissolved gases, age tracers, and stable isotopes. Distinct differences in chemistry exist between tunnel water and groundwater in unconsolidated deposits and in bedrock, and among groundwater samples collected from some bedrock wells during high head pressure and low head pressure of the Rondout-West Branch Tunnel. Samples from bedrock wells generally had relatively higher concentrations of sulfate (SO42-), strontium (Sr), barium (Ba), and lower concentrations of calcium (Ca) and bicarbonate (HCO3-), as compared to unconsolidated wells. Differences in stable-isotope ratios among oxygen-18 to oxygen-16 (δ18O), hydrogen-2 to hydrogen-1 (δ2H), sulfur-34 to sulfur-32(δ34S) of SO42-, Sr-87 to Sr-86 (87Sr/86Sr), and C-13 to C-12 (δ13C) of dissolved inorganic carbon (DIC) indicate a potential for distinguishing water in the Delaware-West Branch Tunnel from native groundwater. For example, 87Sr/86Sr ratios were more depleted in groundwater samples from most bedrock wells, as compared to samples from surface-water sources, springs, and wells screened in unconsolidated deposits in the study area. Age-tracer data provided useful information on pathways of the groundwater-flow system, but were limited by inherent problems with dissolved gases in bedrock wells. The sulfur hexafluoride (SF6) and (or) chlorofluorocarbons (CFCs) apparent recharge years of most water samples from wells screened in unconsolidated deposits and springs ranged from 2003 to 2010 (current) and indicate short flow paths from the point of groundwater recharge. All but three of the samples from bedrock wells had interference problems with dissolved gases, mainly caused by excess air from degassing of hydrogen sulfide and methane. The SF6 and (or) CFC apparent recharge years of samples from three of the bedrock wells ranged from the 1940s to the early 2000s; the sample with the early 2000s recharge year was from a flowing artesian well that was chemically similar to water samples collected at the influent to the tunnel at Rondout Reservoir and the most hydraulically responsive to water tunnel pressure compared to other bedrock wells. Data described in this report can be used, together with hydrogeologic data, to improve the understanding of source waters and groundwater-flow patterns and pathways, and to help assess the mixing of different source waters in water samples. Differences in stable isotope ratios, major and trace constituent concentrations, saturation indexes, tritium concentrations, and apparent groundwater ages will be used to estimate the proportion of water that originates from Rondout-West Branch Tunnel leakage.

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.

SEM-EDX analysis in the source apportionment of particulate matter on Hypogymnia physodes lichen transplants around the Cu smelter and former mining town of Karabash, South Urals, Russia.

PubMed

Williamson, B J; Mikhailova, I; Purvis, O W; Udachin, V

2004-04-25

Scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDX) of particulate matter on lichen transplant thalli (Hypogymnia physodes) was assessed as a complementary technique to wet chemical analysis for source apportionment of airborne contaminants. Transplants (2 month exposure) stationed in the Cu smelter and former mining town of Karabash were compared with those from a control site 30 km south. Particulate matter in Karabash samples (715 analyses) showed higher levels of S, Pb, Cu, Sn and Zn compared with the control (598 analyses). Complex element associations among the particles confounded detailed mineralogical identifications, and therefore a simplified particle classification scheme was devised for source apportionment. Karabash samples contained high levels of particles classified as mining-related (MRP), and these were also identified in control samples, indicating wide spatial dispersion from the smelter and highlighting the sensitivity of the method. It was noted that MRP <2.5-microm diameter were poorly represented on lichen surfaces suggesting this may limit the usefulness of Hypogymnia transplants as proxies when assessing human health impacts from airborne particulates. Analyses of the lichen thallus surface (away from surface particulates) revealed high levels of Cu, Zn, Fe and Pb associated with organics in the Karabash samples compared with the control, with a proportionate loss of K, interpreted as being due to a stress-related increase in cell membrane permeability. This type of analysis may provide a novel SEM-EDX-based method for assessing lichen vitality. The techniques developed are presented and further implications of the study are discussed.

Methods for the isolation, culture and assessment of the status of anaerobic rumen chytrids in both in vitro and in vivo systems.

PubMed

Rezaeian, Mohammad; Beakes, Gordon W; Parker, David S

2004-10-01

Anaerobic fungi were isolated from both the rumen and faeces of nine sheep and a cow. A reliable and simple method for the isolation of anaerobic fungi using 24 h rumen incubated milled straw as the inoculum source was developed. We also evaluate the use of chitin measurements as an assay of rumen fungal biomass. Chitin levels were determined from various sample sources (milled barley straw used as the fungal culture substrate in vitro; plant particulate digests from the rumen (PLP) and centrifuged strained rumen fluid (CSRF) using both HPLC and colorimetric methods. Both methods were highly correlated and consequently the simpler colorimetric method was adopted for subsequent studies. There was also a high degree of correlation between anaerobic fungal cellulase activities with the assayed chitin content of milled barley straw cultures over 12 d of an in vitro experiment. The colorimetric chitin assay protocol was then used to assess the diurnal variation and abundance of rumen fungi in in vivo assays. We assessed the distribution of chitin (mg g(-1) dry matter) in various fractions of the strained rumen fluid (SRF) and PLP samples from the rumen of sheep. Chitin was detected in all fractions of strained rumen fluid but the main source of chitin in the samples may be attributed to the fungal biomass. We did not detect any significant differences in chitin levels over a 24 h sampling period. Finally, an SEM study on subsamples of milled straw and plant particulate matter used in the chitin assays, revealed that the pattern of the fungal development on substrate material differs from the culture medium to the rumen.

Environmental assessment of a wood-waste-fired industrial firetube boiler. Volume 1. Technical results. Final report, January 1981-March 1984

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

DeRosier, R.; Waterland, L.R.

1987-03-01

The report gives emission results from field tests of a wood-waste-fired industrial firetube boiler. Emission measurements included: continuous monitoring of flue gas emissions: source assessment sampling system (SASS) sampling of the flue-gas with subsequent laboratory analysis of samples to give total flue gas organics in two boiling point ranges, compound category information within these ranges, specific quantitation of the semivolatile organic priority pollutants, and flue gas concentrations of 65 trace elements; Method 5 sampling for particulates; controlled condensation system (CSS) sampling for SO/sub 2/ and SO/sub 3/; and grab sampling of boiler bottom ash for trace element content determinations. Totalmore » organic emissions from the boiler were 5.7 mg/dscm, about 90% of which consisted of volatile compounds.« less

Ecological risk of heavy metals in sediments of the luan river source water

USGS Publications Warehouse

Liu, J.; Li, Y.; Zhang, B.; Cao, J.; Cao, Z.; Domagalski, Joseph L.

2009-01-01

Distribution and characteristics of heavy metals enrichment in sediment were surveyed including the bio-available form analyzed for assessment of the Luan River source water quality. The approaches of sediment quality guidelines (SQG), risk assessment code and Hakanson potential ecological risk index were used for the ecological risk assessment. According to SQG, The results show that in animal bodies, Hg at the sampling site of Wuliehexia was 1.39 mg/kg, Cr at Sandaohezi was 152.37 mg/kg and Cu at Hanjiaying was 178.61 mg/kg exceeding the severe effect screening level. There were 90% of sampling sites of Cr and Pb and 50% sites of Cu exceeded the lowest effect screening level. At Boluonuo and Wuliehexia, the exchangeable and carbonate fractions for above 50% of sites were at high risk levels and that for above 30% of sites at Xiahenan and Wulieheshang were also at high risk levels. Other sites were at medium risk level. Compared to soil background values of China, Hg and Cd showed very strong ecological risk, and the seven heavy metals of Hg, Cd, Cu, As, Pb, Cr, Zn at ecological risk levels were in the descending order. The results could give insight into risk assessment of environmental pollution and decision-making for water source security. ?? 2009 Springer Science+Business Media, LLC.

Probabilistic analysis showing that a combination of bacteroides and methanobrevibacter source tracking markers is effective for identifying waters contaminated by human fecal pollution

USGS Publications Warehouse

Johnston, Christopher; Byappanahalli, Muruleedhara N.; Gibson, Jacqueline MacDonald; Ufnar, Jennifer A.; Whitman, Richard L.; Stewart, Jill R.

2013-01-01

Microbial source tracking assays to identify sources of waterborne contamination typically target genetic markers of host-specific microorganisms. However, no bacterial marker has been shown to be 100% host-specific, and cross-reactivity has been noted in studies evaluating known source samples. Using 485 challenge samples from 20 different human and animal fecal sources, this study evaluated microbial source tracking markers including the Bacteroides HF183 16S rRNA, M. smithii nifH, and Enterococcus esp gene targets that have been proposed as potential indicators of human fecal contamination. Bayes' Theorem was used to calculate the conditional probability that these markers or a combination of markers can correctly identify human sources of fecal pollution. All three human-associated markers were detected in 100% of the sewage samples analyzed. Bacteroides HF183 was the most effective marker for determining whether contamination was specifically from a human source, and greater than 98% certainty that contamination was from a human source was shown when both Bacteroides HF183 and M. smithii nifH markers were present. A high degree of certainty was attained even in cases where the prior probability of human fecal contamination was as low as 8.5%. The combination of Bacteroides HF183 and M. smithii nifH source tracking markers can help identify surface waters impacted by human fecal contamination, information useful for prioritizing restoration activities or assessing health risks from exposure to contaminated waters.

Completeness of reporting of patient-relevant clinical trial outcomes: comparison of unpublished clinical study reports with publicly available data.

PubMed

Wieseler, Beate; Wolfram, Natalia; McGauran, Natalie; Kerekes, Michaela F; Vervölgyi, Volker; Kohlepp, Petra; Kamphuis, Marloes; Grouven, Ulrich

2013-10-01

Access to unpublished clinical study reports (CSRs) is currently being discussed as a means to allow unbiased evaluation of clinical research. The Institute for Quality and Efficiency in Health Care (IQWiG) routinely requests CSRs from manufacturers for its drug assessments. Our objective was to determine the information gain from CSRs compared to publicly available sources (journal publications and registry reports) for patient-relevant outcomes included in IQWiG health technology assessments (HTAs) of drugs. We used a sample of 101 trials with full CSRs received for 16 HTAs of drugs completed by IQWiG between 15 January 2006 and 14 February 2011, and analyzed the CSRs and the publicly available sources of these trials. For each document type we assessed the completeness of information on all patient-relevant outcomes included in the HTAs (benefit outcomes, e.g., mortality, symptoms, and health-related quality of life; harm outcomes, e.g., adverse events). We dichotomized the outcomes as "completely reported" or "incompletely reported." For each document type, we calculated the proportion of outcomes with complete information per outcome category and overall. We analyzed 101 trials with CSRs; 86 had at least one publicly available source, 65 at least one journal publication, and 50 a registry report. The trials included 1,080 patient-relevant outcomes. The CSRs provided complete information on a considerably higher proportion of outcomes (86%) than the combined publicly available sources (39%). With the exception of health-related quality of life (57%), CSRs provided complete information on 78% to 100% of the various benefit outcomes (combined publicly available sources: 20% to 53%). CSRs also provided considerably more information on harms. The differences in completeness of information for patient-relevant outcomes between CSRs and journal publications or registry reports (or a combination of both) were statistically significant for all types of outcomes. The main limitation of our study is that our sample is not representative because only CSRs provided voluntarily by pharmaceutical companies upon request could be assessed. In addition, the sample covered only a limited number of therapeutic areas and was restricted to randomized controlled trials investigating drugs. In contrast to CSRs, publicly available sources provide insufficient information on patient-relevant outcomes of clinical trials. CSRs should therefore be made publicly available. Please see later in the article for the Editors' Summary.

Microbial Groundwater Sampling Protocol for Fecal-Rich Environments

PubMed Central

Harter, Thomas; Watanabe, Naoko; Li, Xunde; Atwill, Edward R; Samuels, William

2014-01-01

Inherently, confined animal farming operations (CAFOs) and other intense fecal-rich environments are potential sources of groundwater contamination by enteric pathogens. The ubiquity of microbial matter poses unique technical challenges in addition to economic constraints when sampling wells in such environments. In this paper, we evaluate a groundwater sampling protocol that relies on extended purging with a portable submersible stainless steel pump and Teflon® tubing as an alternative to equipment sterilization. The protocol allows for collecting a large number of samples quickly, relatively inexpensively, and under field conditions with limited access to capacity for sterilizing equipment. The protocol is tested on CAFO monitoring wells and considers three cross-contamination sources: equipment, wellbore, and ambient air. For the assessment, we use Enterococcus, a ubiquitous fecal indicator bacterium (FIB), in laboratory and field tests with spiked and blank samples, and in an extensive, multi-year field sampling campaign on 17 wells within 2 CAFOs. The assessment shows that extended purging can successfully control for equipment cross-contamination, but also controls for significant contamination of the well-head, within the well casing and within the immediate aquifer vicinity of the well-screen. Importantly, our tests further indicate that Enterococcus is frequently entrained in water samples when exposed to ambient air at a CAFO during sample collection. Wellbore and air contamination pose separate challenges in the design of groundwater monitoring strategies on CAFOs that are not addressed by equipment sterilization, but require adequate QA/QC procedures and can be addressed by the proposed sampling strategy. PMID:24903186

Construction and operation of a 10 cfm (cubic feet per minute) sampling system with a 10:1 dilution ratio for measuring condensable emissions. Final report

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

Steele, W.J.; Williamson, A.D.; McCain, J.D.

1988-04-01

The report describes a transportable sampling apparatus designed to sample incineration sources at municipal and hazardous-waste disposal facilities, and to provide non-contaminated samples of condensable materials. The sample gas, at a flow rate of 10 cubic feet per minute (c f/m), passes through a modified Source Assessment Sampling System (SASS) cyclone and is then diluted with clean air at 100 cf/m by a novel, perforated cone assembly. Rapid uniform dilution takes place through the vigorous mixing of the sample and clean air streams in the dilution chamber. The resultant gas, cooled to about atmospheric conditions, is passed through a mixingmore » section that provides a residence time of about 3 seconds. The resulting aerosol particles are collected on a Teflon-coated glass-fiber filter. These solids, along with those collected in the cyclone, are subsequently provided for chemical and biological assay analysis.« less

Pattern recognition methods and air pollution source identification. [based on wind direction

NASA Technical Reports Server (NTRS)

Leibecki, H. F.; King, R. B.

1978-01-01

Directional air samplers, used for resolving suspended particulate matter on the basis of time and wind direction were used to assess the feasibility of characterizing and identifying emission source types in urban multisource environments. Filters were evaluated for 16 elements and X-ray fluorescence methods yielded elemental concentrations for direction, day, and the interaction of direction and day. Large numbers of samples are necessary to compensate for large day-to-day variations caused by wind perturbations and/or source changes.

Bacteriological assessment of urban water sources in Khamis Mushait Governorate, southwestern Saudi Arabia.

PubMed

AlOtaibi, Eed L Sh

2009-03-21

Urban water sources of Khamis Mushait Governorate, southwestern Saudi Arabia, were studied to assess their bacteriological characteristics and suitability for potable purposes. A cross-sectional epidemiological method was adopted to investigate the four main urban water sources (i.e. bottled, desalinated, surface, and well water). These were sampled and examined between February and June 2007. A total of 95 water samples from bottled, desalinated, surface, and well water were collected randomly from the study area using different gathering and analysing techniques. The bacteriological examination of water samples included the most probable number of presumptive coliforms, faecal coliforms, and faecal streptococci (MPN/100 ml). The results showed that the total coliform count (MPN/100 ml) was not detected in any samples taken from bottled water, while it was detected in those taken from desalinated, surface, and well water: percentages were 12.9, 80.0, and 100.0, respectively. Faecal coliforms were detected in desalinated, surface, and well water, with percentages of 3.23, 60.0 and 87.88, respectively. About 6.45% of desalinated water, 53.33% of surface water, and 57.58% of well water was found positive for faecal streptococci. Colonies of coliforms were identified in different micro-organisms with various percentages. Water derived from traditional sources (wells) showed increases in most of the investigated bacteriological parameters, followed by surface water as compared to bottled or desalinated water. This may be attributed to the fact that well and surface water are at risk of contamination as indicated by the higher levels of most bacteriological parameters. Moreover, well water is exposed to point sources of pollution such as septic wells and domestic and farming effluents, as well as to soil with a high humus content. The lower bacteriological characteristics in samples from bottled water indicate that it is satisfactory for human drinking purposes. Contamination of desalinated water that is the main urban water source may occur during transportation from the desalination plant or in the house reservoir of the consumer. Improving and expanding the existing water treatment and sanitation systems is more likely to provide safe and sustainable sources of water over the long term. Strict hygienic measures should be applied to improve water quality and to avoid deleterious effects on public health, by using periodical monitoring programmes to detect sewage pollution running over local hydrological networks and valleys.

Bacteriological assessment of urban water sources in Khamis Mushait Governorate, southwestern Saudi Arabia

PubMed Central

Sh AlOtaibi, Eed L

2009-01-01

Background Urban water sources of Khamis Mushait Governorate, southwestern Saudi Arabia, were studied to assess their bacteriological characteristics and suitability for potable purposes. A cross-sectional epidemiological method was adopted to investigate the four main urban water sources (i.e. bottled, desalinated, surface, and well water). These were sampled and examined between February and June 2007. Results A total of 95 water samples from bottled, desalinated, surface, and well water were collected randomly from the study area using different gathering and analysing techniques. The bacteriological examination of water samples included the most probable number of presumptive coliforms, faecal coliforms, and faecal streptococci (MPN/100 ml). The results showed that the total coliform count (MPN/100 ml) was not detected in any samples taken from bottled water, while it was detected in those taken from desalinated, surface, and well water: percentages were 12.9, 80.0, and 100.0, respectively. Faecal coliforms were detected in desalinated, surface, and well water, with percentages of 3.23, 60.0 and 87.88, respectively. About 6.45% of desalinated water, 53.33% of surface water, and 57.58% of well water was found positive for faecal streptococci. Colonies of coliforms were identified in different micro-organisms with various percentages. Conclusion Water derived from traditional sources (wells) showed increases in most of the investigated bacteriological parameters, followed by surface water as compared to bottled or desalinated water. This may be attributed to the fact that well and surface water are at risk of contamination as indicated by the higher levels of most bacteriological parameters. Moreover, well water is exposed to point sources of pollution such as septic wells and domestic and farming effluents, as well as to soil with a high humus content. The lower bacteriological characteristics in samples from bottled water indicate that it is satisfactory for human drinking purposes. Contamination of desalinated water that is the main urban water source may occur during transportation from the desalination plant or in the house reservoir of the consumer. Improving and expanding the existing water treatment and sanitation systems is more likely to provide safe and sustainable sources of water over the long term. Strict hygienic measures should be applied to improve water quality and to avoid deleterious effects on public health, by using periodical monitoring programmes to detect sewage pollution running over local hydrological networks and valleys. PMID:19302710

Breastfeeding and Mental and Motor Development at 5 ½ Years

PubMed Central

Clark, Katy M.; Castillo, Marcela; Calatroni, Agustin; Walter, Tomas; Cayazzo, Marisol; Pino, Paulina; Lozoff, Betsy

2006-01-01

Objective Breastfeeding is associated with better child development outcomes, but uncertainty remains primarily due to the close relationship between breastfeeding and socioeconomic status. This study assesses the issue in a low socioeconomic status sample where breastfeeding was close to universal. Methods 784 Chilean children were followed longitudinally from infancy. All but 4 were initially breastfed, 40% nursed beyond 12 months, and infant growth was normal. Child development was assessed at 5 ½ years by a cognitive, language, and motor test battery. The duration of breastfeeding as the sole milk source was analyzed as a continuous variable, adjusting for a comprehensive set of background factors. Results The relationship between breastfeeding and most 5 ½ -year developmental outcomes was non-linear, with poorer outcome for periods of breastfeeding as the sole milk source for < 2 months or > 8 months – statistically significant for language, motor, and one comprehensive cognitive test, with a suggestive trend for IQ. Conclusions The observed non-linear relationships showed that breastfeeding as the sole milk source for < 2 months or > 8 months, compared to 2–8 months, was associated with poorer development in this sample. The latter finding requires replication in other samples where long breastfeeding is common and socioeconomic status is relatively homogeneous. PMID:16530141

Presence of enteric viruses in source waters for drinking water production in The Netherlands.

PubMed

Lodder, W J; van den Berg, H H J L; Rutjes, S A; de Roda Husman, A M

2010-09-01

The quality of drinking water in The Netherlands has to comply with the Dutch Drinking Water Directive: less than one infection in 10,000 persons per year may occur due to consumption of unboiled drinking water. Since virus concentrations in drinking waters may be below the detection limit but entail a public health risk, the infection risk from drinking water consumption requires the assessment of the virus concentrations in source waters and of the removal efficiency of treatment processes. In this study, samples of source waters were taken during 4 years of regular sampling (1999 to 2002), and enteroviruses, reoviruses, somatic phages, and F-specific phages were detected in 75% (range, 0.0033 to 5.2 PFU/liter), 83% (0.0030 to 5.9 PFU/liter), 100% (1.1 to 114,156 PFU/liter), and 97% (0.12 to 14,403 PFU/liter), respectively, of 75 tested source water samples originating from 10 locations for drinking water production. By endpoint dilution reverse transcription-PCR (RT-PCR), 45% of the tested source water samples were positive for norovirus RNA (0.22 to 177 PCR-detectable units [PDU]/liter), and 48% were positive for rotavirus RNA (0.65 to 2,249 PDU/liter). Multiple viruses were regularly detected in the source water samples. A significant correlation between the concentrations of the two phages and those of the enteroviruses could be demonstrated. The virus concentrations varied greatly between 10 tested locations, and a seasonal effect was observed. Peak concentrations of pathogenic viruses occur in source waters used for drinking water production. If seasonal and short-term fluctuations coincide with less efficient or failing treatment, an unacceptable public health risk from exposure to this drinking water may occur.

Source impacts by volatile organic compounds in an industrial city of southern Taiwan.

PubMed

Liu, Pao-Wen Grace; Yao, Yung-Chen; Tsai, Jiun-Horng; Hsu, Yi-Chyun; Chang, Li-Peng; Chang, Ken-Hui

2008-07-15

This study investigates source impacts by airborne volatile organic compounds (VOC) at two sites designated for traffic and industry, in the largest industrial area Kaohsiung, southern Taiwan. The samples were collected at the two sites simultaneously during rush and non-rush hours in summer and autumn seasons. Same pattern of VOC groups were found at both sites: most abundant aromatics (78-95%) followed by alkanes (2-16%) and alkenes (0-6%). The BTEX concentration measured at the two sites ranged from 69 to 301 ppbC. Toluene, isopentane, ethylbenzene, and benzene were found to be the most abundant species. Speciation of VOCs was characterized with several skills including principal component factor analysis and BTEX characteristic ratios. Each of the resulted principal factors at the two sites explained over 80% of the VOCs data variance, and indicated that both of the sampling sites were influenced by both traffic and industrial sources with separately different levels. The remarkable patterns of the first two factors described not only the similarity but also the discrepancy at the two sampling sites, in terms of the source impacts. The high T/B ratios (7.56-14.25) observed at the industrial site implied the important impact from mobile emissions. The indicators, m,p-xylene/benzene and o-xylene/benzene, also confirmed the potential source of motor vehicles at both of the sampling sites. Air age assessment showed that more than half of the total observations located in the domain of fresh air. Low X/E ratios implied somewhat aged air mass transported to the sampling sites. The industrial site might not only encounter emissions from the industry sources, but also under unavoidable impact from the traffic sources.

Metabarcoding of environmental DNA samples to explore the use of uranium mine containment ponds as a water source for wildlife

USGS Publications Warehouse

Klymus, Katy E.; Richter, Cathy; Thompson, Nathan; Hinck, Jo E.

2017-01-01

Understanding how anthropogenic impacts on the landscape affect wildlife requires a knowledge of community assemblages. Species surveys are the first step in assessing community structure, and recent molecular applications such as metabarcoding and environmental DNA analyses have been proposed as an additional and complementary wildlife survey method. Here, we test eDNA metabarcoding as a survey tool to examine the potential use of uranium mine containment ponds as water sources by wildlife. We tested samples from surface water near mines and from one mine containment pond using two markers, 12S and 16S rRNA gene amplicons, to survey for vertebrate species. We recovered large numbers of sequence reads from taxa expected to be in the area and from less common or hard to observe taxa such as the tiger salamander and gray fox. Detection of these two species is of note because they were not observed in a previous species assessment, and tiger salamander DNA was found in the mine containment pond sample. We also found that sample concentration by centrifugation was a more efficient and more feasible method than filtration in these highly turbid surface waters. Ultimately, the use of eDNA metabarcoding could allow for a better understanding of the area’s overall biodiversity and community composition as well as aid current ecotoxicological risk assessment work.

An assessment of optical properties of dissolved organic material as quantitative source indicators in the Santa Ana River basin, Southern California

USGS Publications Warehouse

Bergamaschi, Brian A.; Kalve, Erica; Guenther, Larry; Mendez, Gregory O.; Belitz, Kenneth

2005-01-01

The ability to rapidly, reliably, and inexpensively characterize sources of dissolved organic material (DOM) in watersheds would allow water management agencies to more quickly identify problems in water sources, and to more efficiently allocate water resources by, for example, permitting real-time identification of high-quality water suitable for ground-water recharge, or poor-quality water in need of mitigation. This study examined the feasibility of using easily measurable intrinsic optical properties' absorbance and fluorescence spectra, as quantitative indicators of DOM sources and, thus, a predictor of water quality. The study focused on the Santa Ana River Basin, in southern California, USA, which comprises an area of dense urban development and an area of intense dairy production. Base flow in the Santa Ana Basin is primarily tertiary treated wastewater discharge. Available hydrologic data indicate that urban and agricultural runoff degrades water quality during storm events by introducing pathogens, nutrients, and other contaminants, including significant amounts of DOM. These conditions provide the basis for evaluating the use of DOM optical properties as a tracer of DOM from different sources. Sample spectra representing four principal DOM sources were identified among all samples collected in 1999 on the basis of basin hydrology, and the distribution of spectral variability within all the sample data. A linear mixing model provided quantitative estimates of relative endmember contribution to sample spectra for monthly, storm, and diurnal samples. The spectral properties of the four sources (endmembers), Pristine Water, Wastewater, Urban Water, and Dairy Water, accounted for 94 percent of the variability in optical properties observed in the study, suggesting that all important DOM sources were represented. The scale and distribution of the residual spectra, that not explained by the endmembers, suggested that the endmember spectra selected did not adequately represent Urban Water base flow. However, model assignments of sources generally agreed well with those expected, based on sampling location and hydrology. The results suggest that with a fuller characterization of the endmember spectra, analysis of optical properties will provide rapid quantitative estimates of the relative contribution of DOM sources in the Santa Ana Basin.

Organic Compounds in Potomac River Water Used for Public Supply near Washington, D.C., 2003-05

USGS Publications Warehouse

Brayton, Michael J.; Denver, Judith M.; Delzer, Gregory C.; Hamilton, Pixie A.

2008-01-01

Organic compounds studied in this U.S. Geological Survey (USGS) assessment generally are man-made, including, in part, pesticides, solvents, gasoline hydrocarbons, personal care and domestic-use products, and refrigerants and propellants. A total of 85 of 277 compounds were detected at least once among the 25 samples collected approximately monthly during 2003-05 at the intake of the Washington Aqueduct, one of several community water systems on the Potomac River upstream from Washington, D.C. The diversity of compounds detected indicate a variety of different sources and uses (including wastewater discharge, industrial, agricultural, domestic, and others) and different pathways (including treated wastewater outfalls located upstream, overland runoff, and ground-water discharge) to drinking-water supplies. Seven compounds were detected year-round in source-water intake samples, including selected herbicide compounds commonly used in the Potomac River Basin and in other agricultural areas across the United States. Two-thirds of the 26 compounds detected most commonly in source water (in at least 20 percent of the samples) also were detected most commonly in finished water (after treatment but prior to distribution). Concentrations for all detected compounds in source and finished water generally were less than 0.1 microgram per liter and always less than human-health benchmarks, which are available for about one-half of the detected compounds. On the basis of this screening-level assessment, adverse effects to human health are expected to be negligible (subject to limitations of available human-health benchmarks).

Sewage pollution in urban stormwater runoff as evident from the widespread presence of multiple microbial and chemical source tracking markers.

PubMed

Sidhu, J P S; Ahmed, W; Gernjak, W; Aryal, R; McCarthy, D; Palmer, A; Kolotelo, P; Toze, S

2013-10-01

The concurrence of human sewage contamination in urban stormwater runoff (n=23) from six urban catchments across Australia was assessed by using both microbial source tracking (MST) and chemical source tracking (CST) markers. Out of 23 stormwater samples human adenovirus (HAv), human polyomavirus (HPv) and the sewage-associated markers; Methanobrevibacter smithii nifH and Bacteroides HF183 were detected in 91%, 56%, 43% and 96% of samples, respectively. Similarly, CST markers paracetamol (87%), salicylic acid (78%) acesulfame (96%) and caffeine (91%) were frequently detected. Twenty one samples (91%) were positive for six to eight sewage related MST and CST markers and remaining two samples were positive for five and four markers, respectively. A very good consensus (>91%) observed between the concurrence of the HF183, HAv, acesulfame and caffeine suggests good predictability of the presence of HAv in samples positive for one of the three markers. High prevalence of HAv (91%) also suggests that other enteric viruses may also be present in the stormwater samples which may pose significant health risks. This study underscores the benefits of employing a set of MST and CST markers which could include monitoring for HF183, adenovirus, caffeine and paracetamol to accurately detect human sewage contamination along with credible information on the presence of human enteric viruses, which could be used for more reliable public health risk assessments. Based on the results obtained in this study, it is recommended that some degree of treatment of captured stormwater would be required if it were to be used for non-potable purposes. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Rapid analysis of inner and outer bark composition of southern yellow pine bark from industrial sources

Treesearch

Chi-Leung So; Thomas L. Eberhardt

2006-01-01

Differences in bark chemistry between inner and outer bark are well known and may affect the suitability of various bark supplies for a particular application. Accordingly, there is a need for quality control protocols to assess variability and predict product yields. Southern yellow pine bark samples from two industrial sources were separated into inner and outer bark...

Assessment of the anthropogenic influx of metallic pollutants in the Sefidrud delta, Gilan Province, Iran.

PubMed

Rafiei, Behrouz; Ahmadi-Ghomi, Fatemeh; Karimkhani, Afshin

2017-08-15

Understanding the anthropogenic effects on the Sefidrud delta, the concentration of six metals (Cr, Co, Cu, Ni, Pb and Zn) was measured in two sites included the old Sefidrud delta (Amirabad, 23 samples) and the new Sefidrud delta (Kiashahr, 24 samples). Geoaccumulation Index (I geo ), Enrichment Factor (EF), Contamination Factor (CF) and Pollution Load Index (PLI) were used to determine the metal pollution in all sediment samples. Although the EF, I geo , CF and PLI results in the old delta indicate no significant pollution, sediment samples in the new delta show a considerable pollution. Since the sediment source and the lithology of the Sefidrud River drainage basin did not change in the past 500years, the metal pollution in the new delta must be from anthropogenic sources. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of human enteric viruses in surface water and drinking water resources in southern Ghana.

PubMed

Gibson, Kristen E; Opryszko, Melissa C; Schissler, James T; Guo, Yayi; Schwab, Kellogg J

2011-01-01

An estimated 884 million people worldwide do not have access to an improved drinking water source, and the microbial quality of these sources is often unknown. In this study, a combined tangential flow, hollow fiber ultrafiltration (UF), and real-time PCR method was applied to large volume (100 L) groundwater (N = 4), surface water (N = 9), and finished (i.e., receiving treatment) drinking water (N = 6) samples for the evaluation of human enteric viruses and bacterial indicators. Human enteric viruses including norovirus GI and GII, adenovirus, and polyomavirus were detected in five different samples including one groundwater, three surface water, and one drinking water sample. Total coliforms and Escherichia coli assessed for each sample before and after UF revealed a lack of correlation between bacterial indicators and the presence of human enteric viruses.

Evaluation of Human Enteric Viruses in Surface Water and Drinking Water Resources in Southern Ghana

PubMed Central

Gibson, Kristen E.; Opryszko, Melissa C.; Schissler, James T.; Guo, Yayi; Schwab, Kellogg J.

2011-01-01

An estimated 884 million people worldwide do not have access to an improved drinking water source, and the microbial quality of these sources is often unknown. In this study, a combined tangential flow, hollow fiber ultrafiltration (UF), and real-time PCR method was applied to large volume (100 L) groundwater (N = 4), surface water (N = 9), and finished (i.e., receiving treatment) drinking water (N = 6) samples for the evaluation of human enteric viruses and bacterial indicators. Human enteric viruses including norovirus GI and GII, adenovirus, and polyomavirus were detected in five different samples including one groundwater, three surface water, and one drinking water sample. Total coliforms and Escherichia coli assessed for each sample before and after UF revealed a lack of correlation between bacterial indicators and the presence of human enteric viruses. PMID:21212196

Assessing the Utility of Hydrogen, Carbon and Nitrogen Stable Isotopes in Estimating Consumer Allochthony in Two Shallow Eutrophic Lakes.

PubMed

Syväranta, Jari; Scharnweber, Kristin; Brauns, Mario; Hilt, Sabine; Mehner, Thomas

2016-01-01

Hydrogen stable isotopes (δ2H) have recently been used to complement δ13C and δ15N in food web studies due to their potentially greater power to separate sources of organic matter in aquatic food webs. However, uncertainties remain regarding the use of δ2H, since little is known about the potential variation in the amount of exchangeable hydrogen (Hex) among common sample materials or the patterns of δ2H when entire food webs are considered. We assessed differences in Hex among the typical sample materials in freshwater studies and used δ2H, δ13C and δ15N to compare their effectiveness in tracing allochthonous matter in food webs of two small temperate lakes. Our results showed higher average amounts of Hex in animal tissues (27% in fish and macroinvertebrates, 19% in zooplankton) compared to most plant material (15% in terrestrial plants and 8% in seston/periphyton), with the exception of aquatic vascular plants (23%, referred to as macrophytes). The amount of Hex correlated strongly with sample lipid content (inferred from C:N ratios) in fish and zooplankton samples. Overall, the three isotopes provided good separation of sources (seston, periphyton, macrophytes and allochthonous organic matter), particularly the δ2H followed by δ13C. Aquatic macrophytes revealed unexpectedly high δ2H values, having more elevated δ2H values than terrestrial organic matter with direct implications for estimating consumer allochthony. Organic matter from macrophytes significantly contributed to the food webs in both lakes highlighting the need to include macrophytes as a potential source when using stable isotopes to estimate trophic structures and contributions from allochthonous sources.

Assessing the Utility of Hydrogen, Carbon and Nitrogen Stable Isotopes in Estimating Consumer Allochthony in Two Shallow Eutrophic Lakes

PubMed Central

Syväranta, Jari; Scharnweber, Kristin; Brauns, Mario; Hilt, Sabine; Mehner, Thomas

2016-01-01

Hydrogen stable isotopes (δ2H) have recently been used to complement δ13C and δ15N in food web studies due to their potentially greater power to separate sources of organic matter in aquatic food webs. However, uncertainties remain regarding the use of δ2H, since little is known about the potential variation in the amount of exchangeable hydrogen (Hex) among common sample materials or the patterns of δ2H when entire food webs are considered. We assessed differences in Hex among the typical sample materials in freshwater studies and used δ2H, δ13C and δ15N to compare their effectiveness in tracing allochthonous matter in food webs of two small temperate lakes. Our results showed higher average amounts of Hex in animal tissues (27% in fish and macroinvertebrates, 19% in zooplankton) compared to most plant material (15% in terrestrial plants and 8% in seston/periphyton), with the exception of aquatic vascular plants (23%, referred to as macrophytes). The amount of Hex correlated strongly with sample lipid content (inferred from C:N ratios) in fish and zooplankton samples. Overall, the three isotopes provided good separation of sources (seston, periphyton, macrophytes and allochthonous organic matter), particularly the δ2H followed by δ13C. Aquatic macrophytes revealed unexpectedly high δ2H values, having more elevated δ2H values than terrestrial organic matter with direct implications for estimating consumer allochthony. Organic matter from macrophytes significantly contributed to the food webs in both lakes highlighting the need to include macrophytes as a potential source when using stable isotopes to estimate trophic structures and contributions from allochthonous sources. PMID:27167517

Occurrence, distribution, and sources of emerging organic contaminants in tropical coastal sediments of anthropogenically impacted Klang River estuary, Malaysia.

PubMed

Omar, Tuan Fauzan Tuan; Aris, Ahmad Zaharin; Yusoff, Fatimah Md; Mustafa, Shuhaimi

2018-06-01

This baseline assessment reports on the occurrence, distribution, and sources of emerging organic contaminants (EOCs) in tropical coastal sediments of anthropogenically impacted Klang River estuary, Malaysia. Bisphenol A was the highest concentration detected at 16.84 ng g -1 dry weight, followed by diclofenac (13.88 ng g -1 dry weight) and E1 (12.47 ng g -1 dry weight). Five compounds, namely, amoxicillin, progesterone, diazinon, bisphenol A, and E1, were found in all sampling stations assessed, and other compounds such as primidone, diclofenac, testosterone, E2, and EE2 were ubiquitously present in sediment samples, with percentage of detection range from 89.04% to 98.38%. Organic carbon content and pH were the important factors controlling the fate of targeted compounds in the tropical estuarine sediment. On the basis of the literature from other studies, the sources of EOCs are thought to be from wastewater treatment plants, domestic/medical waste discharge, livestock activities, industrial waste discharge, and agricultural activities. Copyright © 2018 Elsevier Ltd. All rights reserved.

Gender, ethnicity and environmental risk perception revisited: the importance of residential location

PubMed Central

Laws, M. Barton; Yeh, Yating; Reisner, Ellin; Stone, Kevin; Wang, Tina; Brugge, Doug

2015-01-01

Objectives Studies in the U.S. have found that white men are less concerned about pollution than are women or people of other ethnicity. These studies have not assessed respondents’ proximity to localized sources of pollution. Our objective was to assess lay perceptions of risk from air pollution in an ethnically diverse sample in which proximity to a major perceptible source of pollution is known. Methods Cross sectional interview study of combined area probability and convenience sample of individuals 40 and older in the Boston area, selected according to proximity to high traffic controlled access highways. Results Of 697 respondents 46% were white, 37% Asian (mostly Chinese), 6.3% African-American, 6.3% Latino, and 7.6% other ethnicity. While white respondents, and particularly white men, were less concerned about air pollution than others, this effect disappeared when controlling for distance from the highway. White men were slightly less supportive than others of government policy to control pollution Conclusions The “white male” effect may in part be accounted for by the greater likelihood of minority respondents to live near perceptible localized sources of pollution. PMID:25822317

Fecal contamination of drinking water within peri-urban households, Lima, Peru.

PubMed

Oswald, William E; Lescano, Andrés G; Bern, Caryn; Calderon, Maritza M; Cabrera, Lilia; Gilman, Robert H

2007-10-01

We assessed fecal contamination of drinking water in households in 2 peri-urban communities of Lima, Peru. We measured Escherichia coli counts in municipal source water and, within households, water from principal storage containers, stored boiled drinking water, and water in a serving cup. Source water was microbiologically clean, but 26 (28%) of 93 samples of water stored for cooking had fecal contamination. Twenty-seven (30%) of 91 stored boiled drinking water samples grew E. coli. Boiled water was more frequently contaminated when served in a drinking cup than when stored (P < 0.01). Post-source contamination increased successively through the steps of usage from source water to the point of consumption. Boiling failed to ensure safe drinking water at the point of consumption because of easily contaminated containers and poor domestic hygiene. Hygiene education, better point-of-use treatment and storage options, and in-house water connections are urgently needed.

Drivers of microbiological quality of household drinking water - a case study in rural Ethiopia.

PubMed

Usman, Muhammed A; Gerber, Nicolas; Pangaribowo, Evita H

2018-04-01

This study aims at assessing the determinants of microbiological contamination of household drinking water under multiple-use water systems in rural areas of Ethiopia. For this analysis, a random sample of 454 households was surveyed between February and March 2014, and water samples from community sources and household storage containers were collected and tested for fecal contamination. The number of Escherichia coli (E. coli) colony-forming units per 100 mL water was used as an indicator of fecal contamination. The microbiological tests demonstrated that 58% of household stored water samples and 38% of protected community water sources were contaminated with E. coli. Moreover, most improved water sources often considered to provide safe water showed the presence of E. coli. The result shows that households' stored water collected from unprotected wells/springs had higher levels of E. coli than stored water from alternative sources. Distance to water sources and water collection containers are also strongly associated with stored water quality. To ensure the quality of stored water, the study suggests that there is a need to promote water safety from the point-of-source to point-of-use, with due considerations for the linkages between water and agriculture to advance the Sustainable Development Goal 6 of ensuring access to clean water for everyone.

Sources of Life Strengths Appraisal Scale: A Multidimensional Approach to Assessing Older Adults' Perceived Sources of Life Strengths

PubMed Central

Fry, Prem S.; Debats, Dominique L.

2014-01-01

Both cognitive and psychosocial theories of adult development stress the fundamental role of older adults' appraisals of the diverse sources of cognitive and social-emotional strengths. This study reports the development of a new self-appraisal measure that incorporates key theoretical dimensions of internal and external sources of life strengths, as identified in the gerontological literature. Using a pilot study sample and three other independent samples to examine older adults' appraisals of their sources of life strengths which helped them in their daily functioning and to combat life challenges, adversity, and losses, a psychometric instrument having appropriate reliability and validity properties was developed. A 24-month followup of a randomly selected sample confirmed that the nine-scale appraisal measure (SLSAS) is a promising instrument for appraising older adults' sources of life strengths in dealing with stresses of daily life's functioning and also a robust measure for predicting outcomes of resilience, autonomy, and well-being for this age group. A unique strength of the appraisal instrument is its critically relevant features of brevity, simplicity of language, and ease of administration to frail older adults. Dedicated to the memory of Shanta Khurana whose assistance in the pilot work for the study was invaluable PMID:24772352

Source apportionment and pollution evaluation of heavy metals in water and sediments of Buriganga River, Bangladesh, using multivariate analysis and pollution evaluation indices.

PubMed

Bhuiyan, Mohammad Amir Hossain; Dampare, Samuel B; Islam, M A; Suzuki, Shigeyuki

2015-01-01

Concentrations of heavy metals in water and sediment samples of Buriganga River in the capital city Dhaka, Bangladesh, were studied to understand the level of heavy metals and their source apportionment. The results showed that the mean concentrations of heavy metals both in water and sediment samples were very high and, in most cases, exceeded the permissible limits recommended by the Bangladesh government and other international organizations. Significantly higher concentrations of Pb, Cr, Mn, Co, Ni, Cu, Zn, As, and Cd were found in sediment samples. However, average concentrations of metals both in water and sediment samples were above the effect range median. The heavy metal pollution index (HPI) and degree of contamination (Cd) yielded different results in water samples despite significant correlations between them. The heavy metal evaluation index (HEI) showed strong correlations with HPI and Cd and provided better assessment of pollution levels. The enrichment factor (EF) and geoaccumulation index (Igeo) showed the elevated value of Cr, Pb, and Cd in access of background values. The measured elements were subjected to positive matrix factorization (PMF) and examining correlations in order to explain the content, behavior, and source apportionment of metals. PMF resulted in a successful partitioning of variances into sources related to background geochemistry and contaminant influences. However, the PMF approach successfully demarcated the major sources of metals from tannery, paint, municipal sewage, textiles, and agricultural activities.

Using host-associated genetic markers to investigate sources of fecal contamination in two Vermont streams

USGS Publications Warehouse

Medalie, Laura; Matthews, Leslie J.; Stelzer, Erin A.

2011-01-01

The use of host-associated Bacteroidales-based 16S ribosomal ribonucleic acid genetic markers was investigated as a tool for providing information to managers on sources of bacterial impairment in Vermont streams. The study was conducted during 2009 in two watersheds on the U.S. Environmental Protection Agency's 303(d) List of Impaired Waters, the Huntington and the Mettawee Rivers. Streamwater samples collected during high-flow and base-flow conditions were analyzed for concentrations of Escherichia coli (E. coli) and Bacteroidales genetic markers (General AllBac, Human qHF183 and BacHum, Ruminant BoBac, and Canid BacCan) to identify humans, ruminants, and canids as likely or unlikely major sources of fecal contamination. Fecal reference samples from each of the potential source groups, as well as from common species of wildlife, were collected during the same season and from the same watersheds as water samples. The results were combined with data from other states to assess marker cross reaction and to relate marker results to E. coli, the regulated water-quality parameter, with a higher degree of statistical significance. Results from samples from the Huntington River collected under different flow conditions on three dates indicated that humans were unlikely to be a major source of fecal contamination, except for a single positive result at one station that indicated the potential for human sources. Ruminants (deer, moose, cow, or sheep) were potential sources of fecal contamination at all six stations on the Huntington River during one high-flow event and at all but two stations during the other high-flow event. Canids were potential sources of fecal contamination at some stations during two high-flow events, with genetic-marker concentrations in samples from two of the six stations showing consistent positive results for canids for both storm dates. A base-flow sample showed no evidence of major fecal contamination in the Huntington River from humans, ruminants, or canids. Results from samples from the Mettawee River watershed collected during high-flow conditions (12 storm samples on 2 dates at 6 stations) indicated that there was no evidence of fecal contamination from humans in seven samples and possible evidence in five samples. Results for humans were positive for only one station during both storm events. For two of the five samples with evidence for human fecal contamination, results for two different human genetic markers agreed, but results from three samples were inconsistent. In samples from five of the six Mettawee stations, ruminants were a potential source of fecal contamination on at least one of the three sampled dates, including three positive results for the base-flow sample. Yet samples from all of the stations that showed positive results for ruminants did so for only one or two of the three sampled dates. Samples from only one of the six stations gave consistent results, which were negative for ruminants for all three dates. In the Mettawee River base-flow sample, humans were an unlikely source of major fecal contamination. Factors that may influence results and conclusions include the timing of sample collection relative to the storm event; variability of E. coli and Bacteroidales concentrations in fecal reference samples and in water; sampling and analytical errors; the potential cross reactivity of host-associated genetic markers; and different persistence and survival rates of E. coli bacteria and Bacteroidales genetic markers on land, in water, and by season. These factors interfere with the ability to directly relate Bacteroidales concentrations to E. coli concentrations in river samples. It must be recognized that while use of Bacteroidales genetic markers as a source tracking tool coupled with the interpretive approach described in this report cannot be used quantitatively to pinpoint sources, it can be used to exclude potential sources as major contributors to fecal contamination.

Who Are the Turkers? A Characterization of MTurk Workers Using the Personality Assessment Inventory.

PubMed

McCredie, Morgan N; Morey, Leslie C

2018-02-01

As online data collection services such as Amazon's Mechanical Turk (MTurk) gain popularity, the quality and representativeness of such data sources have gained research attention. To date, the majority of existing studies have compared MTurk workers with undergraduate samples, localized community samples, or other Internet-based samples, and thus, there remains little known about the personality and mental health constructs of MTurk workers relative to a national representative sample. The present study addresses these limitations and broadens the scope of existing research through the use of the Personality Assessment Inventory, a multiscale, self-report questionnaire which provides information regarding data validity and personality and psychopathology features standardized against a national U.S. census-matched normative sample. Results indicate that MTurk workers generally provide high-quality data and are reasonably representative of the general population across most psychological dimensions assessed. However, several distinguishing features of MTurk workers emerged that were consistent with prior findings of such individuals, primarily involving somewhat higher negative affect and lower social engagement.

Anthropogenic Organic Compounds in Ground Water and Finished Water of Community Water Systems in the Northern Tampa Bay Area, Florida, 2002-04

USGS Publications Warehouse

Metz, Patricia A.; Delzer, Gregory C.; Berndt, Marian P.; Crandall, Christy A.; Toccalino, Patricia L.

2007-01-01

As part of the U.S. Geological Survey's (USGS's) National Water-Quality Assessment (NAWQA) Program, a Source Water-Quality Assessment (SWQA) was conducted in the unconfined and semiconfined portions of the Upper Floridan aquifer system during 2002-04. SWQAs are two-phased sampling activities, wherein phase 1 was designed to evaluate the occurrence of 258 anthropogenic organic compounds (AOCs) in ground water used as source water for 30 of the largest-producing community water system (CWS) wells in the northern Tampa Bay area, Florida. The 258 AOCs included volatile organic compounds (VOCs), pesticides, and other anthropogenic organic compounds (OAOCs). Phase 2 was designed to monitor concentrations in the source water and also the finished water of CWSs for compounds most frequently detected during phase 1. During phase 1 of the SWQA study, 31 of the 258 AOCs were detected in source-water samples collected from CWS wells at low concentrations (less than 1.0 microgram per liter (ug/L)). Twelve AOCs were detected in at least 10 percent of samples. Concentrations from 16 of the 31 detected AOCs were about 2 to 5 orders of magnitude below human-health benchmarks indicating that concentrations were unlikely to be of potential human-health concern. The potential human-health relevance for the remaining 15 detected unregulated AOCs could not be evaluated because no human-health benchmarks were available for these compounds. Hydrogeology, population, and land use were examined to evaluate the effects of these variables on the source water monitored. Approximately three times as many detections of VOCs (27) and pesticides (34) occurred in unconfined areas than in the semiconfined areas (8 VOCs, 14 pesticides). In contrast, 1 OAOC was detected in unconfined areas, and 13 OAOCs were detected in semiconfined areas with 9 of the OAOC detections occurring in samples from two wells located near septic systems. Analyses of population and land use indicated that the number of compounds detected increased as the population surrounding each well increased. Detection frequencies and concentrations for VOCs (particularly chloroform) and pesticides were highest in residential land-use areas. The results of source-water samples from the 30 CWS wells monitored during phase 1 of this SWQA study were compared to four locally conducted studies. These general comparisons indicate that the occurrence of VOCs in other studies is similar to their occurrence in source water of CWSs monitored as part of this SWQA. However, pesticide compounds, especially atrazine and its breakdown products, occurred more frequently in the SWQA study than in the other four studies. Phase 2 of the SWQA assessed AOCs in samples from 11 of the 30 CWS wells and the associated finished water. Overall, 42 AOCs were detected in either source water or finished water and more compounds were detected in finished water than in source water. Specifically, 22 individual AOCs were detected in source water and 27 AOCs were detected in finished water. The total number of detections was greater in the finished water (80) than in the source water (49); however, this was largely due to the creation of disinfection by-products (DBPs) during water treatment. Excluding DBPs, about the same number of total detections was observed in source water (40) and finished water (44). During phase 2, AOC detected concentrations ranged from E0.003 (estimated) to 1,140 ug/L in the source water and from E0.003 to 36.3 ug/L in the finished water. Concentrations of 24 of the 42 compounds were compared to human-health benchmarks and were about 1 to 5 orders of magnitude below their human-health benchmarks indicating that concentrations are unlikely to be of potential human-health concern, excluding DBPs. Concentrations of carbon tetrachloride, however, were within 10 percent of its human-health benchmark, which is considered a level that may warrant inclusion of the compound in a low-concentration, t

Distribution Characteristics and Risk Assessment of Polycyclic Aromatic Hydrocarbons in the Momoge Wetland, China

PubMed Central

Xu, Jianling; Wang, Hanxi; Sheng, Lianxi; Liu, Xuejun; Zheng, Xiaoxue

2017-01-01

The Momoge Nature Reserve is the research object of this study. Through field sampling, laboratory experiments and analysis, the contents, distribution characteristics, source identification, pollution levels and risk levels of polycyclic aromatic hydrocarbons (PAHs) in wetland soils were studied. The results show that the sum content of 16 types of PAHs (Σ16 PAH) in the wetland soil was within the range (0.029–0.4152) mg/kg. PAHs in wetland soil are primarily 2–3-rings PAHs. PAHs in the Momoge wetland soil have multiple sources: petroleum, combustion of petroleum and coal, and others, of which petroleum and the sum of combustion of petroleum and coal account for 38.0% and 59.3%, respectively. Research, using the standard index and pollution range methods, shows that the content of the PAH labelled Nap, found in the Momoge wetland soil, is excessive; some sampling sites exhibit a low level of pollution. The result of a biotoxicity assessment shows that there are two sampling sites that occasionally present an ecological toxicity hazard. The result of the organic carbon normalization process shows that an ecological risk exists only at sampling site No. 10. PMID:28106776

Attenuation of X and Gamma Rays in Personal Radiation Shielding Protective Clothing.

PubMed

Kozlovska, Michaela; Cerny, Radek; Otahal, Petr

2015-11-01

A collection of personal radiation shielding protective clothing, suitable for use in case of accidents in nuclear facilities or radiological emergency situations involving radioactive agents, was gathered and tested at the Nuclear Protection Department of the National Institute for Nuclear, Chemical and Biological Protection, Czech Republic. Attenuating qualities of shielding layers in individual protective clothing were tested via spectra measurement of x and gamma rays, penetrating them. The rays originated from different radionuclide point sources, the gamma ray energies of which cover a broad energy range. The spectra were measured by handheld spectrometers, both scintillation and High Purity Germanium. Different narrow beam geometries were adjusted using a special testing bench and a set of various collimators. The main experimentally determined quantity for individual samples of personal radiation shielding protective clothing was x and gamma rays attenuation for significant energies of the spectra. The attenuation was assessed comparing net peak areas (after background subtraction) in spectra, where a tested sample was placed between the source and the detector, and corresponding net peak areas in spectra, measured without the sample. Mass attenuation coefficients, which describe attenuating qualities of shielding layers materials in individual samples, together with corresponding lead equivalents, were determined as well. Experimentally assessed mass attenuation coefficients of the samples were compared to the referred ones for individual heavy metals.

Water for human and livestock consumption in rural settings of Ethiopia: assessments of quality and health aspects.

PubMed

Amenu, Kebede; Markemann, André; Valle Zárate, Anne

2013-11-01

The study aimed to assess the quality and health aspects of water intended for human and livestock consumption in two rural districts of the Rift Valley of Ethiopia. The study involved two parts: the first consisted of a questionnaire survey and farmers' group discussions, complemented by secondary health data, and the second part determined the chemical (total dissolved solids, pH, manganese, hexa-valent chromium, fluoride) and microbiological quality of different water sources during dry and wet seasons. The result showed a lack of sustainable access to safe water in the communities. Industrial pollution and mismanagement of water sources by human and livestock was found to be a source of potential health risk. Potentially linked human health problems like malaria, diarrhoea and gastrointestinal parasites were common in the districts. Overall, 76% of the assessed water sources (n = 25) failed to comply with World Health Organization guidelines for human drinking water, for at least one assessed parameter, mostly irrespective of the season. The non-compliance was mainly attributed to Escherichia coli contamination and/or high fluoride concentration. At least 20% of the water samples were also found to be unfit for livestock consumption based on assessed chemical parameters in both dry and wet seasons. To minimize the health risk associated with mismanagement and poor quality of water sources in the area, targeted action in the protection of surface water sources should be given priority.

(I Can't Get No) Saturation: A simulation and guidelines for sample sizes in qualitative research.

PubMed

van Rijnsoever, Frank J

2017-01-01

I explore the sample size in qualitative research that is required to reach theoretical saturation. I conceptualize a population as consisting of sub-populations that contain different types of information sources that hold a number of codes. Theoretical saturation is reached after all the codes in the population have been observed once in the sample. I delineate three different scenarios to sample information sources: "random chance," which is based on probability sampling, "minimal information," which yields at least one new code per sampling step, and "maximum information," which yields the largest number of new codes per sampling step. Next, I use simulations to assess the minimum sample size for each scenario for systematically varying hypothetical populations. I show that theoretical saturation is more dependent on the mean probability of observing codes than on the number of codes in a population. Moreover, the minimal and maximal information scenarios are significantly more efficient than random chance, but yield fewer repetitions per code to validate the findings. I formulate guidelines for purposive sampling and recommend that researchers follow a minimum information scenario.

Passive sampling methods for contaminated sediments: Risk assessment and management

PubMed Central

Greenberg, Marc S; Chapman, Peter M; Allan, Ian J; Anderson, Kim A; Apitz, Sabine E; Beegan, Chris; Bridges, Todd S; Brown, Steve S; Cargill, John G; McCulloch, Megan C; Menzie, Charles A; Shine, James P; Parkerton, Thomas F

2014-01-01

This paper details how activity-based passive sampling methods (PSMs), which provide information on bioavailability in terms of freely dissolved contaminant concentrations (Cfree), can be used to better inform risk management decision making at multiple points in the process of assessing and managing contaminated sediment sites. PSMs can increase certainty in site investigation and management, because Cfree is a better predictor of bioavailability than total bulk sediment concentration (Ctotal) for 4 key endpoints included in conceptual site models (benthic organism toxicity, bioaccumulation, sediment flux, and water column exposures). The use of passive sampling devices (PSDs) presents challenges with respect to representative sampling for estimating average concentrations and other metrics relevant for exposure and risk assessment. These challenges can be addressed by designing studies that account for sources of variation associated with PSMs and considering appropriate spatial scales to meet study objectives. Possible applications of PSMs include: quantifying spatial and temporal trends in bioavailable contaminants, identifying and evaluating contaminant source contributions, calibrating site-specific models, and, improving weight-of-evidence based decision frameworks. PSM data can be used to assist in delineating sediment management zones based on likelihood of exposure effects, monitor remedy effectiveness, and, evaluate risk reduction after sediment treatment, disposal, or beneficial reuse after management actions. Examples are provided illustrating why PSMs and freely dissolved contaminant concentrations (Cfree) should be incorporated into contaminated sediment investigations and study designs to better focus on and understand contaminant bioavailability, more accurately estimate exposure to sediment-associated contaminants, and better inform risk management decisions. Research and communication needs for encouraging broader use are discussed. Integr Environ Assess Manag 2014;10:224–236. © 2014 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of SETAC. PMID:24343931

Use of diverse geochemical data sets to determine sources and sinks of nitrate and methane in groundwater, Garfield County, Colorado, 2009

USGS Publications Warehouse

McMahon, P.B.; Thomas, J.C.; Hunt, A.G.

2011-01-01

Previous water-quality assessments reported elevated concentrations of nitrate and methane in water from domestic wells screened in shallow zones of the Wasatch Formation, Garfield County, Colorado. In 2009, the U.S. Geological Survey, in cooperation with the Colorado Department of Public Health and Environment, analyzed samples collected from 26 domestic wells for a diverse set of geochemical tracers for the purpose of determining sources and sinks of nitrate and methane in groundwater from the Wasatch Formation. Nitrate concentrations ranged from less than 0.04 to 6.74 milligrams per liter as nitrogen (mg/L as N) and were significantly lower in water samples with dissolved-oxygen concentrations less than 0.5 mg/L than in samples with dissolved-oxygen concentrations greater than or equal to 0.5 mg/L. Chloride/bromide mass ratios and tracers of groundwater age (tritium, chlorofluorocarbons, and sulfur hexafluoride) indicate that septic-system effluent or animal waste was a source of nitrate in some young groundwater (less than 50 years), although other sources such as fertilizer also may have contributed nitrate to the groundwater. Nitrate and nitrogen gas (N2) concentrations indicate that denitrification was the primary sink for nitrate in anoxic groundwater, removing 99 percent of the original nitrate content in some samples that had nitrate concentrations greater than 10 mg/L as N at the time of recharge. Methane concentrations ranged from less than 0.0005 to 32.5 mg/L and were significantly higher in water samples with dissolved-oxygen concentrations less than 0.5 mg/L than in samples with dissolved-oxygen concentrations greater than or equal to 0.5 mg/L. High methane concentrations (greater than 1 mg/L) in some samples were biogenic in origin and appeared to be derived from a relatively deep source on the basis of helium concentrations and isotopic data. One such sample had water-isotopic and major-ion compositions similar to that of produced water from the underlying Mesaverde Group, which was the primary natural-gas producing interval in the study area. Methane in the Mesaverde Group was largely thermogenic in origin so biogenic methane in the sample probably was derived from deeper zones in the Wasatch Formation. The primary methane sink in the aquifer appeared to be methane oxidation on the basis of dissolved-oxygen and methane concentrations and methane isotopic data. The diverse data sets used in this study enhance previous water-quality assessments by providing new and more complete insights into the sources and sinks of nitrate and methane in groundwater. Field measurements of dissolved oxygen in groundwater were useful indicators of the Wasatch Formation's vulnerability to nitrate and methane contamination or enrichment. Results from this study also provide new evidence for the movement of water, ions, and gases into the shallow Wasatch Formation from sources such as the Mesaverde Group and deeper Wasatch Formation.

Level 1 environmental assessment performance evaluation. Final report jun 77-oct 78

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

Estes, E.D.; Smith, F.; Wagoner, D.E.

1979-02-01

The report gives results of a two-phased evaluation of Level 1 environmental assessment procedures. Results from Phase I, a field evaluation of the Source Assessment Sampling System (SASS), showed that the SASS train performed well within the desired factor of 3 Level 1 accuracy limit. Three sample runs were made with two SASS trains sampling simultaneously and from approximately the same sampling point in a horizontal duct. A Method-5 train was used to estimate the 'true' particulate loading. The sampling systems were upstream of the control devices to ensure collection of sufficient material for comparison of total particulate, particle sizemore » distribution, organic classes, and trace elements. Phase II consisted of providing each of three organizations with three types of control samples to challenge the spectrum of Level 1 analytical procedures: an artificial sample in methylene chloride, an artificial sample on a flyash matrix, and a real sample composed of the combined XAD-2 resin extracts from all Phase I runs. Phase II results showed that when the Level 1 analytical procedures are carefully applied, data of acceptable accuracy is obtained. Estimates of intralaboratory and interlaboratory precision are made.« less

Tracking the release of IPCC AR5 on Twitter: Users, comments, and sources following the release of the Working Group I Summary for Policymakers.

PubMed

Newman, Todd P

2017-10-01

Using the immediate release of the Working Group 1 Summary for Policymakers of the Intergovernmental Panel on Climate Change Fifth Assessment Report as a case study, this article seeks to describe what type of actors were most active during the summary release, the substance of the most propagated tweets during the summary release, and the media sources that attracted the most attention during the summary release. The results from the study suggest that non-elite actors, such as individual bloggers and concerned citizens, accounted for the majority of the most propagated tweets in the sample. This study also finds that the majority of the most propagated tweets in the sample focused on public understanding of the report. Finally, while mainstream media sources were the most frequently discussed media sources, a number of new media and science news and information sources compete for audience attention.

Young Adolescents' Beliefs Concerning Menstruation

ERIC Educational Resources Information Center

Clarke, Anne E.; Ruble, Diane N.

1978-01-01

A sample of 54 young adolescent girls (both pre- and postmenarcheal) and boys responded to a questionnaire assessing evaluative attitudes toward menstruation, expected symptomatology, perceived effects on moods and activities, and sources of information for these beliefs. (Author/JMB)

Perspectives on NO, NOy, and fine aerosol sources and variability during SONEX

NASA Astrophysics Data System (ADS)

Thompson, Anne M.; Sparling, Lynn C.; Kondo, Yutaka; Anderson, Bruce E.; Gregory, Gerald L.; Sachse, Glen W.

Distributions of upper tropospheric tracer data on each of the 14 science flights of SONEX (SASS [Subsonics Assessment] Ozone and Nitrogen Oxides Experiment) provide a statistical overview of NO, NOy and fine aerosol variability during SONEX (an aircraft mission conducted in October and November 1997). The wide range of variability of NO from all sources provides a perspective on the aircraft perturbation. Background distributions of NOy are somewhat elevated inside flight corridors relative to outside; fine aerosol and NO/NOy in and out of corridors are similar. The potential vorticity of air sampled during SONEX is low relative to the NAFC (North Atlantic Flight Corridor) as a whole, due either to advection of lower latitude air into the corridor or biases in sampling to avoid the stratosphere. High NO/NOy (>0.4) from fresh lightning and aircraft sources was usually associated with pv much lower than the NAFC as a whole. Air masses identified as tropospheric by a low ozone criterion nevertheless have high pv, a marker for stratospheric air. Thus, stratospheric and surface sources also contribute to overall variability. A statistically robust assessment of the relative aircraft NO contribution during SONEX, based on data alone, is unlikely, given the mixture of other NO sources within which the aircraft signal is embedded. This underscores the need for more data and modeling studies.

Organic Compounds in Clackamas River Water Used for Public Supply near Portland, Oregon, 2003-05

USGS Publications Warehouse

Carpenter, Kurt D.; McGhee, Gordon

2009-01-01

Organic compounds studied in this U.S. Geological Survey (USGS) assessment generally are man-made, including pesticides, gasoline hydrocarbons, solvents, personal care and domestic-use products, disinfection by-products, and manufacturing additives. In all, 56 compounds were detected in samples collected approximately monthly during 2003-05 at the intake for the Clackamas River Water plant, one of four community water systems on the lower Clackamas River. The diversity of compounds detected suggests a variety of different sources and uses (including wastewater discharges, industrial, agricultural, domestic, and others) and different pathways to drinking-water supplies (point sources, precipitation, overland runoff, ground-water discharge, and formation during water treatment). A total of 20 organic compounds were commonly detected (in at least 20 percent of the samples) in source water and (or) finished water. Fifteen compounds were commonly detected in source water, and five of these compounds (benzene, m- and p-xylene, diuron, simazine, and chloroform) also were commonly detected in finished water. With the exception of gasoline hydrocarbons, disinfection by-products, chloromethane, and the herbicide diuron, concentrations in source and finished water were less than 0.1 microgram per liter and always less than human-health benchmarks, which are available for about 60 percent of the compounds detected. On the basis of this screening-level assessment, adverse effects to human health are assumed to be negligible (subject to limitations of available human-health benchmarks).

From streets to streams: assessing the toxicity potential of urban sediment by particle size

USGS Publications Warehouse

Corsi, Steven R.; Selbig, William R.; Roger T. Bannerman,; ,

2013-01-01

Urban sediment can act as a transport mechanism for a variety of pollutants to move towards a receiving water body. The concentrations of these pollutants oftentimes exceed levels that are toxic to aquatic organisms. Many treatment structures are designed to capture coarse sediment but do not work well to similarly capture the fines. This study measured concentrations of select trace metals and PAHs in both the silt and sand fractions of urban sediment from four sources: stormwater bed, stormwater suspended, street dirt, and streambed. Concentrations were used to assess the toxic potential of sediment based on published sediment quality guidelines. All sources of sediment showed some level of toxic potential with stormwater bed sediment the highest followed by stormwater suspended, street dirt, and streambed. Both metal and PAH concentration distributions were highly correlated between the four sampling locations suggesting the presence of one or perhaps only a few sources of these pollutants which remain persistent as sediment is transported from street to stream. Comparison to other forms of combustion- and vehicle-related sources of PAHs revealed coal tar sealants to have the strongest correlation, in both the silt and sand fractions, at all four sampling sites. This information is important for environmental managers when selecting the most appropriate Best Management Practice (BMP) as a way to mitigate pollution conveyed in urban stormwater from source to sink.

Why Do I Feel More Confident? Bandura's Sources Predict Preservice Teachers' Latent Changes in Teacher Self-Efficacy

PubMed Central

Pfitzner-Eden, Franziska

2016-01-01

Teacher self-efficacy (TSE) is associated with a multitude of positive outcomes for teachers and students. However, the development of TSE is an under-researched area. Bandura (1997) proposed four sources of self-efficacy: mastery experiences, vicarious experiences, verbal persuasion, and physiological and affective states. This study introduces a first instrument to assess the four sources for TSE in line with Bandura's conception. Gathering evidence of convergent validity, the contribution that each source made to the development of TSE during a practicum at a school was explored for two samples of German preservice teachers. The first sample (N = 359) were beginning preservice teachers who completed an observation practicum. The second sample (N = 395) were advanced preservice teachers who completed a teaching practicum. The source measure showed good reliability, construct validity, and convergent validity. Latent true change modeling was applied to explore how the sources predicted changes in TSE. Three different models were compared. As expected, results showed that TSE changes in both groups were significantly predicted by mastery experiences, with a stronger relationship in the advanced group. Further, the results indicated that mastery experiences were largely informed by the other three sources to varying degrees depending on the type of practicum. Implications for the practice of teacher education are discussed in light of the results. PMID:27807422

Why Do I Feel More Confident? Bandura's Sources Predict Preservice Teachers' Latent Changes in Teacher Self-Efficacy.

PubMed

Pfitzner-Eden, Franziska

2016-01-01

Teacher self-efficacy (TSE) is associated with a multitude of positive outcomes for teachers and students. However, the development of TSE is an under-researched area. Bandura (1997) proposed four sources of self-efficacy: mastery experiences, vicarious experiences, verbal persuasion, and physiological and affective states. This study introduces a first instrument to assess the four sources for TSE in line with Bandura's conception. Gathering evidence of convergent validity, the contribution that each source made to the development of TSE during a practicum at a school was explored for two samples of German preservice teachers. The first sample ( N = 359) were beginning preservice teachers who completed an observation practicum. The second sample ( N = 395) were advanced preservice teachers who completed a teaching practicum. The source measure showed good reliability, construct validity, and convergent validity. Latent true change modeling was applied to explore how the sources predicted changes in TSE. Three different models were compared. As expected, results showed that TSE changes in both groups were significantly predicted by mastery experiences, with a stronger relationship in the advanced group. Further, the results indicated that mastery experiences were largely informed by the other three sources to varying degrees depending on the type of practicum. Implications for the practice of teacher education are discussed in light of the results.

Environmental assessment of a wood-waste-fired industrial firetube boiler. Volume 2. Data supplement. Final report, January 1981-March 1984

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

DeRosier, R.; Waterland, L.R.

1987-03-01

The report gives emission results from field tests of a wood-waste-fired industrial firetube boiler. Emission measurements included: continuous monitoring of flue-gas emissions; source assessment sampling system (SASS) sampling of the flue gas with subsequent laboratory analysis of samples to give total flue-gas organics in two boiling-point ranges, compound category information within these ranges, specific quantitation of the semivolatile organic priority pollutants, and flue-gas concentrations of 65 trace elements; Method 5 sampling for particulates; controlled condensation system (CSS) sampling for SO/sub 2/ and SO/sub 3/; and grab sampling of boiler bottom ash for trace-element-content determinations. Emission levels of five polycyclic organicmore » matter species and phenol were quantitated: except for naphthalene, all were emitted at less than 0.4 microgram/dscm.« less

Design tradeoffs for trend assessment in aquatic biological monitoring programs

USGS Publications Warehouse

Gurtz, Martin E.; Van Sickle, John; Carlisle, Daren M.; Paulsen, Steven G.

2013-01-01

Assessments of long-term (multiyear) temporal trends in biological monitoring programs are generally undertaken without an adequate understanding of the temporal variability of biological communities. When the sources and levels of variability are unknown, managers cannot make informed choices in sampling design to achieve monitoring goals in a cost-effective manner. We evaluated different trend sampling designs by estimating components of both short- and long-term variability in biological indicators of water quality in streams. Invertebrate samples were collected from 32 sites—9 urban, 6 agricultural, and 17 relatively undisturbed (reference) streams—distributed throughout the United States. Between 5 and 12 yearly samples were collected at each site during the period 1993–2008, plus 2 samples within a 10-week index period during either 2007 or 2008. These data allowed calculation of four sources of variance for invertebrate indicators: among sites, among years within sites, interaction among sites and years (site-specific annual variation), and among samples collected within an index period at a site (residual). When estimates of these variance components are known, changes to sampling design can be made to improve trend detection. Design modifications that result in the ability to detect the smallest trend with the fewest samples are, from most to least effective: (1) increasing the number of years in the sampling period (duration of the monitoring program), (2) decreasing the interval between samples, and (3) increasing the number of repeat-visit samples per year (within an index period). This order of improvement in trend detection, which achieves the greatest gain for the fewest samples, is the same whether trends are assessed at an individual site or an average trend of multiple sites. In multiple-site surveys, increasing the number of sites has an effect similar to that of decreasing the sampling interval; the benefit of adding sites is greater when a new set of different sites is selected for each sampling effort than when the same sites are sampled each time. Understanding variance components of the ecological attributes of interest can lead to more cost-effective monitoring designs to detect trends.

Assessing Pyrite-Derived Sulfate in the Mississippi River with Four Years of Sulfur and Triple-Oxygen Isotope Data.

PubMed

Killingsworth, Bryan A; Bao, Huiming; Kohl, Issaku E

2018-05-17

Riverine dissolved sulfate (SO 4 2- ) sulfur and oxygen isotope variations reflect their controls such as SO 4 2- reduction and reoxidation, and source mixing. However, unconstrained temporal variability of riverine SO 4 2- isotope compositions due to short sampling durations may lead to mischaracterization of SO 4 2- sources, particularly for the pyrite-derived sulfate load. We measured the sulfur and triple-oxygen isotopes (δ 34 S, δ 18 O, and Δ' 17 O) of Mississippi River SO 4 2- with biweekly sampling between 2009 and 2013 to test isotopic variability and constrain sources. Sulfate δ 34 S and δ 18 O ranged from -6.3‰ to -0.2‰ and -3.6‰ to +8.8‰, respectively. Our sampling period captured the most severe flooding and drought in the Mississippi River basin since 1927 and 1956, respectively, and a first year of sampling that was unrepresentative of long-term average SO 4 2- . The δ 34 S SO4 data indicate pyrite-derived SO 4 2- sources are 74 ± 10% of the Mississippi River sulfate budget. Furthermore, pyrite oxidation is implicated as the dominant process supplying SO 4 2- to the Mississippi River, whereas the Δ' 17 O SO4 data shows 18 ± 9% of oxygen in this sulfate is sourced from air O 2 .

A remote acceptance probe and illumination configuration for spectral assessment of internal attributes of intact fruit

NASA Astrophysics Data System (ADS)

Greensill, Colin V.; Walsh, Kerry B.

2000-12-01

Near infrared spectroscopy can be employed in the non-invasive assessment of intact fruit for eating quality attributes such as soluble solid content (SSC). Rapid sorting is dependent on a suitable non-contact geometry of fruit, light source and detector assembly, optimized for a given fruit commodity. An optical system was designed with reference to distribution of SSC and light penetration into rockmelon fruit. SSC of mesocarp tissue was not significantly different over the greater part of the proximal-distal axis of the fruit, particularly in the vicinity of the fruit equator. There was also no consistent variation in SSC of mesocarp tissue with respect to radial position of sampling. Mesocarp SSC was higher (~3% w/v) closer to the seed cavity. The optical sampling system was therefore designed to assess an equatorial position on the fruit. Light penetrating a rockmelon fruit was empirically assessed to be diffuse at a depth of <15 mm from the fruit surface. Signal decreased in an exponential proportionality with depth into the fruit, but was still detectable at depths in excess of the seed cavity of rockmelons. A partial transmittance optical design was employed, with a collimated light source interrupted by a central light stop, and a detector viewing the shadowed region of the sample. This system did not physically contact the sample. It was compared to a system with a light excluding `contacting' shroud between the detector and the fruit surface. The performance of calibrations generated using the non-contact configuration was not significantly different than for the configuration requiring contact.

Bioavailability of Polycyclic Aromatic Hydrocarbons and their Potential Application in Eco-risk Assessment and Source Apportionment in Urban River Sediment

PubMed Central

Yang, Xunan; Yu, Liuqian; Chen, Zefang; Xu, Meiying

2016-01-01

Traditional risk assessment and source apportionment of sediments based on bulk polycyclic aromatic hydrocarbons (PAHs) can introduce biases due to unknown aging effects in various sediments. We used a mild solvent (hydroxypropyl-β-cyclodextrin) to extract the bioavailable fraction of PAHs (a-PAHs) from sediment samples collected in Pearl River, southern China. We investigated the potential application of this technique for ecological risk assessments and source apportionment. We found that the distribution of PAHs was associated with human activities and that the a-PAHs accounted for a wide range (4.7%–21.2%) of total-PAHs (t-PAHs), and high risk sites were associated with lower t-PAHs but higher a-PAHs. The correlation between a-PAHs and the sediment toxicity assessed using tubificid worms (r = −0.654, P = 0.021) was greater than that from t-PAH-based risk assessment (r = −0.230, P = 0.472). Moreover, the insignificant correlation between a-PAH content and mPEC-Q of low molecular weight PAHs implied the potiential bias of t-PAH-based risk assessment. The source apportionment from mild extracted fractions was consistent across different indicators and was in accordance with typical pollution sources. Our results suggested that mild extraction-based approaches reduce the potential error from aging effects because the mild extracted PAHs provide a more direct indicator of bioavailability and fresher fractions in sediments. PMID:26976450

Elevated blood-lead levels among children living in the rural Philippines.

PubMed

Riddell, Travis J; Solon, Orville; Quimbo, Stella A; Tan, Cheryl May C; Butrick, Elizabeth; Peabody, John W

2007-09-01

Generally, lead poisoning is not considered a significant environmental hazard for children in rural areas of developing countries. With a prospectively designed policy experiment, the research community and the government are conducting a broad-based investigation to introduce and evaluate the impact of health policy reforms on children in a rural area of the Philippines - the Quality Improvement Demonstration Study (QIDS). As part of this study, we researched lead exposure in children under the age of five. We sampled a population of children from the Visayas region in the central Philippines, covering approximately one third of the country's geographical area. From December 2003 to September 2004, the survey collected blood lead levels (BLL) together with demographic, socioeconomic and child health data points. Supplemental field-testing among a sub-sample of the most exposed children assessed the sources of environmental lead exposure. Among children in this study, 21% (601 of 2861 children) had BLL greater than 10 microg/dl. BLL were associated independently with age, haemoglobin concentration, water source, roofing material, expenditures and history of breastfeeding. A follow-up assessment of possible environmental exposures among the sub-sample of children with elevated BLL revealed no single or predominant exposure source. Instead, there appear to be multiple potential sources, such as fossil-fuel combustion, lead paint (in or around 38% of homes) and household items. Elevated BLL are common among children in the Visayas, and may signify an under-recognized threat to children living in rural areas of other developing nations. This setting has varied environmental sources of lead. Observed correlates of BLL may be of clinical, environmental and public health utility to identify and mitigate the consequences of lead toxicity.

“ADHD Knowledge, Perceptions and Information Sources: Perspectives from a Community Sample of Adolescents and their Parents”

PubMed Central

Bussing, Regina; Zima, Bonnie T.; Mason, Dana M.; Meyer, Johanna.M.; White, Kimberly; Garvan, Cynthia W.

2012-01-01

PURPOSE The chronic illness model advocates for psychoeducation within a collaborative care model to enhance outcomes. To inform psychoeducational approaches for attention-deficit/hyperactivity disorder (ADHD), this study describes parent and adolescent knowledge, perceptions and information sources and explores how these vary by sociodemographic characteristics, ADHD risk, and past child mental health service use. METHODS Parents and adolescents were assessed 7.7 years after initial school district screening for ADHD risk. The study sample included 374 adolescents (56% high and 44% low ADHD risk), on average 15.4 (SD 1.8) years old, and 36% were African American. Survey questions assessed ADHD knowledge, perceptions, and cues to action, and elicited utilized and preferred information sources. Multiple logistic regression was used to determine potential independent predictors of ADHD knowledge. McNemar's tests compared information source utilization against preference. RESULTS Despite relatively high self-rated ADHD familiarity, misperceptions among parents and adolescents were common, including a sugar etiology (25% and 27%, respectively) and medication overuse (85% and 67%). African American respondents expressed lower ADHD awareness and greater belief in sugar etiology than Caucasians. Parents used a wide range of ADHD information sources while adolescents relied on social network members and teachers/school. However, parents and adolescents expressed similar strong preferences for the Internet (49% and 51%) and doctor (40% and 27%) as ADHD information sources. CONCLUSION Culturally appropriate psychoeducational strategies are needed that combine doctor-provided ADHD information with reputable Internet sources. Despite time limitations during patient visits, both parents and teens place high priority on receiving information from their doctor. PMID:23174470

In vitro assessment of thyroid hormone disrupting activities in drinking water sources along the Yangtze River.

PubMed

Hu, Xinxin; Shi, Wei; Zhang, Fengxian; Cao, Fu; Hu, Guanjiu; Hao, Yingqun; Wei, Si; Wang, Xinru; Yu, Hongxia

2013-02-01

The thyroid hormone disrupting activities of drinking water sources from the lower reaches of Yangtze River were examined using a reporter gene assay based on African green monkey kidney fibroblast (CV-1) cells. None of the eleven tested samples showed thyroid receptor (TR) agonist activity. Nine water samples exhibited TR antagonist activities with the equivalents referring to Di-n-butyl phthalate (DNBP) (TR antagonist activity equivalents, ATR-EQ(50)s) ranging from 6.92 × 10(1) to 2.85 × 10(2) μg DNBP/L. The ATR-EQ(50)s and TR antagonist equivalent ranges (ATR-EQ(30-80) ranges) for TR antagonist activities indicated that the water sample from site WX-8 posed the greatest health risks. The ATR-EQ(80)s of the water samples ranging from 1.56 × 10(3) to 6.14 × 10(3) μg DNBP/L were higher than the NOEC of DNBP. The results from instrumental analysis showed that DNBP might be responsible for the TR antagonist activities in these water samples. Water sources along Yangtze River had thyroid hormone disrupting potential. Copyright © 2012 Elsevier Ltd. All rights reserved.

Assessment of possible sources of microbiological contamination and water-quality characteristics of the Jacks Fork, Ozark National Scenic Riverways, Missouri; phase II

USGS Publications Warehouse

Davis, Jerri V.; Richards, Joseph M.

2002-01-01

In 1998, an 8-mile reach of the Jacks Fork was included on Missouri?s list of impaired waters as required by Section 303(d) of the Federal Clean Water Act. The identified pollutant on the Jacks Fork was fecal coliform bacteria. Potential sources of fecal contamination to the Jacks Fork include a wastewater treatment plant; campground pit-toilet or septic-system effluent; a large commercial, cross-country horseback trail riding facility; canoeists, boaters, and tubers; and cows.The U.S. Geological Survey, in cooperation with the National Park Service, conducted a study to better understand the extent and sources of microbiological contamination within the Jacks Fork from Alley Spring to the mouth, which includes the 8-mile 303(d) reach. Identification of the sources would provide the National Park Service and the State of Missouri with the information needed to craft a solution of abatement, regulation, prevention, and mitigation with the end result being the removal of the Jacks Fork from the 303(d) list. Fifteen sites were sampled from November 1999 through December 2000. An additional site was sampled one time. Samples were collected mostly during base-flow conditions during a variety of nonrecreational and recreational season river uses. Samples were analyzed for selected fecal indicator bacteria, physical properties, nutrients, and wastewater organic compounds. During the sampling period, the whole-body-contact recreation standard for fecal coliform (200 colonies per 100 milliliters of sample) was exceeded at three sites on August 10, 2000, and also at one site on May 11, June 7, and October 3, 2000. Fecal coliform densities and instantaneous loads generally increased from background concentrations at the Eminence site, peaked about 2 river miles downstream, and then decreased until the most downstream site sampled. Generally, the largest densities and loads at sites downstream from Eminence not related to wet-weather flow were observed during a trail ride held August 6 to12, 2000. A 24-hour sample collection effort was conducted the weekend of July 15 and 16, 2000, to investigate the effect that large numbers of swimmers, canoeists, and tubers had on fecal coliform densities in the Jacks Fork. Five or six samples were collected at six sites between Saturday morning and the following Sunday afternoon. No fecal coliform density at any of the sites sampled exceeded the whole-body-contact recreation standard. Because bacteria survive longer in stream-bed sediments than in water, a source of bacteria in the water column could be from resuspension of accumulated bacteria from streambed sediments. Water and streambed-sediment samples were collected at three sites on August 3, 2000, 1 week before a trail ride and again at three sites on 2 Assessment of Possible Sources of Microbiological Contamination of the Jacks Fork, Missouri?Phase II August 8, 2000, during a trail ride. Results indicate that fecal coliform bacteria densities increased substantially in the streambed sediment and the water column during the trail ride.Sixty-five Escherichia coli isolates obtained from water samples collected at 9 sites and 23 Escherichia coli isolates obtained from stream-bed-sediment samples collected at 5 sites were submitted for ribotyping analysis. Samples were collected in 2000 during a variety of nonrecreational and recreational season river uses, including trail rides, canoeing, tubing, and swimming. Of the 65 isolates from water samples, 40 percent were identified as originating from sewage, 29 percent from horse, 11 percent from cow, and 20 percent from an unknown source. Of the 23 isolates from streambed-sediment samples, 39 percent were identified as originating from sewage, 35 percent from horse, 13 percent from cow, and 13 percent from unknown sources.Analysis of physical property (dissolved oxygen, pH, specific conductance, and temperature) and nutrient (dissolved nitrite plus nitrate and total phosphorus) data

A National survey of methyl tert-butyl ether and other volatile organic compounds in drinking-water sources: Results of the random source-water survey

USGS Publications Warehouse

Grady, Stephen J.

2002-01-01

Methyl tert-butyl ether (MTBE) was detected in source water used by 8.7 percent of randomly selected community water systems (CWSs) in the United States at concentrations that ranged from 0.2 to 20 micrograms per liter (μg/L). The Random Survey conducted by the U.S. Geological Survey, in cooperation with the Metropolitan Water District of Southern California and the Oregon Health & Science University, was designed to provide an assessment of the frequency of detection, concentration, and distribution of MTBE, three other ether gasoline oxygenates, and 62 other volatile organic compounds (VOCs) in ground- and surface-water sources used for drinking-water supplies. The Random Survey was the first of two components of a national assessment of the quality of source water supplying CWSs sponsored by the American Water Works Association Research Foundation. A total of 954 CWSs were selected for VOC sampling from the population of nearly 47,000 active, self-supplied CWSs in all 50 States, Native American Lands, and Puerto Rico based on a statistical design that stratified on CWS size (population served), type of source water (ground and surface water), and geographic distribution (State).At a reporting level of 0.2 μg/L, VOCs were detected in 27 percent of source-water samples collected from May 3, 1999 through October 23, 2000. Chloroform (in 13 percent of samples) was the most frequently detected of 42 VOCs present in the source-water samples, followed by MTBE. VOC concentrations were generally less than 10 μg/L 95 percent of the 530 detections and 63 percent were less than 1.0 μg/L. Concentrations of 1,1-dichloroethene, tetrachloroethene, trichloroethene, vinyl chloride, and total trihalomethanes (TTHMs), however, exceeded drinking-water regulations in eight samples.Detections of most VOCs were more frequent in surface-water sources than in ground-water sources, with gasoline compounds collectively and MTBE individually detected significantly more often in surface water. Use of personal and commercial motorized watercraft on surface-water bodies that are drinking-water sources is probably the reason for the elevated detections of gasoline contaminants relative to ground water. MTBE detections demonstrated a seasonal pattern with more frequent detections in surface water in summer months, which is consistent with seasonal watercraft use.The detection frequency of most VOCs was significantly related to urban land use and population density. Detections of any VOC, non-trihalo-methane compounds, gasoline compounds collectively, the specific gasoline compounds benzene, toluene, ethylbenzene, and xylenes (BTEX), MTBE, solvents, and refrigerants were significantly greater in areas with more than 60 percent urban land use and (or) population density greater than 1,000 people per square mile than in source waters from less urbanized or lower population-density areas. MTBE detections were five times more frequent in source waters from areas with high MTBE use than in source waters from low or no MTBE use, but, unlike other gasoline compounds, MTBE detections were not significantly related to the density of gasoline storage tanks near drinking-water sources.

Assessment of region, farming system, irrigation source and sampling time as food safety risk factors for tomatoes.

PubMed

Pagadala, Sivaranjani; Marine, Sasha C; Micallef, Shirley A; Wang, Fei; Pahl, Donna M; Melendez, Meredith V; Kline, Wesley L; Oni, Ruth A; Walsh, Christopher S; Everts, Kathryne L; Buchanan, Robert L

2015-03-02

In the mid-Atlantic region of the United States, small- and medium-sized farmers use varied farm management methods and water sources to produce tomatoes. It is unclear whether these practices affect the food safety risk for tomatoes. This study was conducted to determine the prevalence, and assess risk factors for Salmonella enterica, Shiga toxin-producing Escherichia coli (STEC) and bacterial indicators in pre-harvest tomatoes and their production areas. A total of 24 organic and conventional, small- to medium-sized farms were sampled for six weeks in Maryland (MD), Delaware (DE) and New Jersey (NJ) between July and September 2012, and analyzed for indicator bacteria, Salmonella and STEC. A total of 422 samples--tomato fruit, irrigation water, compost, field soil and pond sediment samples--were collected, 259 of which were tomato samples. A low level of Salmonella-specific invA and Shiga toxin genes (stx1 or stx2) were detected, but no Salmonella or STEC isolates were recovered. Of the 422 samples analyzed, 9.5% were positive for generic E. coli, found in 5.4% (n=259) of tomato fruits, 22.5% (n=102) of irrigation water, 8.9% (n=45) of soil, 3/9 of pond sediment and 0/7 of compost samples. For tomato fruit, farming system (organic versus conventional) was not a significant factor for levels of indicator bacteria. However, the total number of organic tomato samples positive for generic E. coli (1.6%; 2/129) was significantly lower than for conventional tomatoes (6.9% (9/130); (χ(2) (1)=4.60, p=0.032)). Region was a significant factor for levels of Total Coliforms (TC) (p=0.046), although differences were marginal, with western MD having the highest TC counts (2.6 log CFU/g) and NJ having the lowest (2.0 log CFU/g). Tomatoes touching the ground or plastic mulch harbored significantly higher levels of TC compared to vine tomatoes, signaling a potential risk factor. Source of irrigation water was a significant factor for all indicator bacteria (p<0.0001), and groundwater had lower bacterial levels than surface water. End of line surface water samples were not significantly different from source water samples, but end of line groundwater samples had significantly higher bacterial counts than source (p<0.0001), suggesting that Good Agricultural Practices that focus on irrigation line maintenance might be beneficial. In general, local effects other than cropping practices, including topography, land use and adjacent industries, might be important factors contributing to microbiological inputs on small- and medium-sized farms in the mid-Atlantic region. Copyright © 2014 Elsevier B.V. All rights reserved.

Identification of possible sources of particulate matter in the personal cloud using SEM/EDX

NASA Astrophysics Data System (ADS)

Conner, Teri L.; Williams, Ronald W.

2004-10-01

The United States Environmental Protection Agency (US EPA) conducted the Baltimore Particulate Matter (PM) Epidemiology-Exposure Study of the Elderly during the summer of 1998. The study design included PM2.5 samples obtained from elderly (65+ years of age) retirement facility residents using personal exposure sampling devices. These sampling devices were also used to obtain PM2.5 samples at fixed locations within the personal monitoring subjects' apartments. Selected personal and apartment samples were examined using scanning electron microscopy with individual-particle X-ray analysis (SEM/EDX), providing a qualitative assessment of the chemical and physical characteristics of geological and trace element particles collected within these micro-environments at the retirement facility. This information was used to identify possible indoor source particles. The manual surveys of the personal samples revealed that some particles larger than 2.5 μm reached the filter surface. Using SEM/EDX, several particle types with possible indoor origins were identified. The Al-Zr-Cl particle is likely to have originated from a personal antiperspirant product. Particles with a talc or alumino-silicate composition point to cosmetics as a possible source. Large cadmium-containing particles were also found, which may indicate the use of art pigments or ceramic glazes, or emissions from television screen phosphors. A greater variety of particles was observed in a personal sample compared with its corresponding fixed-location apartment sample.

Quality of Water from Public-Supply Wells in the United States, 1993-2007Overview of Major Findings

USGS Publications Warehouse

Toccalino, Patricia L.; Hopple, Jessica A.

2010-01-01

Summary of Major Findings and Implications About 105 million people in the United States-more than one-third of the Nation's population-receive their drinking water from about 140,000 public water systems that use groundwater as their source. Although the quality of finished drinking water (after treatment and before distribution) from these public water systems is regulated by the U.S. Environmental Protection Agency (USEPA) under the Safe Drinking Water Act (SDWA), long-term protection and management of groundwater, a vital source of drinking water, requires an understanding of the occurrence of contaminants in untreated source water. Sources of drinking water are potentially vulnerable to a wide range of man-made and naturally occurring contaminants, including many that are not regulated in drinking water under the SDWA. In this study by the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS), chemical water-quality conditions were assessed in source (untreated) groundwater from 932 public-supply wells, hereafter referred to as public wells, and in source and finished water from a subset of 94 wells. The public wells are located in selected parts of 41 states and withdraw water from parts of 30 regionally extensive water-supply aquifers, which constitute about one-half of the principal aquifers in the United States. Although the wells sampled in this study represent less than 1 percent of all groundwater-supplied public water systems in the United States, they are widely distributed nationally and were randomly selected within the sampled hydrogeologic settings to represent typical aquifer conditions. All source-water samples were collected prior to any treatment or blending that potentially could alter contaminant concentrations. As a result, the sampled groundwater represents the quality of the source water and not necessarily the quality of finished water ingested by the people served by these public wells. A greater number of chemical contaminants-as many as 337-both naturally occurring and man-made, were assessed in this study than in any previous national study of public wells (Appendixes 1 and 2). Consistent with the terminology used in the SDWA, all constituents analyzed in water samples in this study are referred to as 'contaminants,' regardless of their source, concentration, or potential for health effects (see sidebar on page 3). Eighty-three percent (279) of the contaminants analyzed in this study are not regulated in drinking water under the SDWA. The USEPA uses USGS data on the occurrence of unregulated contaminants to fulfill part of the SDWA requirements for determining whether specific contaminants should be regulated in drinking water in the future. By focusing primarily on source-water quality, and by analyzing many contaminants that are not regulated in drinking water by USEPA, this study complements the extensive sampling of public water systems that is routinely conducted for the purposes of regulatory compliance monitoring by federal, state, and local drinking-water programs. The objectives of this study were to evaluate (1) the occurrence of contaminants in source water from public wells and their potential significance to human health, (2) whether contaminants that occur in source water also occur in finished water after treatment, and (3) the occurrence and characteristics of contaminant mixtures. To evaluate the potential significance of contaminant occurrence to human health, contaminant concentrations were compared to regulatory Maximum Contaminant Levels (MCLs) or non-regulatory Health-Based Screening Levels (HBSLs)-collectively referred to as human-health benchmarks in this study (see sidebars on pages 4 and 19). The major findings and implications of this study are summarized below and the results are described in greater detail in the remainder of the report. These findings build upon water-quality data from previous public-well studies and

Rapid habitability assessment of Mars samples by pyrolysis-FTIR

NASA Astrophysics Data System (ADS)

Gordon, Peter R.; Sephton, Mark A.

2016-02-01

Pyrolysis Fourier transform infrared spectroscopy (pyrolysis FTIR) is a potential sample selection method for Mars Sample Return missions. FTIR spectroscopy can be performed on solid and liquid samples but also on gases following preliminary thermal extraction, pyrolysis or gasification steps. The detection of hydrocarbon and non-hydrocarbon gases can reveal information on sample mineralogy and past habitability of the environment in which the sample was created. The absorption of IR radiation at specific wavenumbers by organic functional groups can indicate the presence and type of any organic matter present. Here we assess the utility of pyrolysis-FTIR to release water, carbon dioxide, sulfur dioxide and organic matter from Mars relevant materials to enable a rapid habitability assessment of target rocks for sample return. For our assessment a range of minerals were analyzed by attenuated total reflectance FTIR. Subsequently, the mineral samples were subjected to single step pyrolysis and multi step pyrolysis and the products characterised by gas phase FTIR. Data from both single step and multi step pyrolysis-FTIR provide the ability to identify minerals that reflect habitable environments through their water and carbon dioxide responses. Multi step pyrolysis-FTIR can be used to gain more detailed information on the sources of the liberated water and carbon dioxide owing to the characteristic decomposition temperatures of different mineral phases. Habitation can be suggested when pyrolysis-FTIR indicates the presence of organic matter within the sample. Pyrolysis-FTIR, therefore, represents an effective method to assess whether Mars Sample Return target rocks represent habitable conditions and potential records of habitation and can play an important role in sample triage operations.

Using temporal sampling to improve attribution of source populations for invasive species.

PubMed

Goldstien, Sharyn J; Inglis, Graeme J; Schiel, David R; Gemmell, Neil J

2013-01-01

Numerous studies have applied genetic tools to the identification of source populations and transport pathways for invasive species. However, there are many gaps in the knowledge obtained from such studies because comprehensive and meaningful spatial sampling to meet these goals is difficult to achieve. Sampling populations as they arrive at the border should fill the gaps in source population identification, but such an advance has not yet been achieved with genetic data. Here we use previously acquired genetic data to assign new incursions as they invade populations within New Zealand ports and marinas. We also investigated allelelic frequency change in these recently established populations over a two-year period, and assessed the effect of temporal genetic sampling on our ability to assign new incursions to their population of source. We observed shifts in the allele frequencies among populations, as well as the complete loss of some alleles and the addition of alleles novel to New Zealand, within these recently established populations. There was no significant level of genetic differentiation observed in our samples between years, and the use of these temporal data did alter the assignment probability of new incursions. Our study further suggests that new incursions can add genetic variation to the population in a single introduction event as the founders themselves are often more genetically diverse than theory initially predicted.

Anthropogenic organic compounds in source water of selected community water systems that use groundwater, 2002-05

USGS Publications Warehouse

Hopple, Jessica A.; Delzer, Gregory C.; Kingsbury, James A.

2009-01-01

Source water, defined as groundwater collected from a community water system well prior to water treatment, was sampled from 221 wells during October 2002 to July 2005 and analyzed for 258 anthropogenic organic compounds. Most of these compounds are unregulated in drinking water and include pesticides and pesticide degradates, gasoline hydrocarbons, personal-care and domestic-use products, and solvents. The laboratory analytical methods used in the study have detection levels that commonly are 100 to 1,000 times lower than State and Federal standards and guidelines for protecting water quality. Detections of anthropogenic organic compounds do not necessarily indicate a concern to human health but rather help to identify emerging issues and track changes in occurrence and concentrations over time. Less than one-half (120) of the 258 compounds were detected in at least one source-water sample. Chloroform, in 36 percent of samples, was the most commonly detected of the 12 compounds that were in about 10 percent or more of source-water samples. The herbicides atrazine, metolachlor, prometon, and simazine also were among the commonly detected compounds. The commonly detected degradates of atrazine - deethylatrazine and deisopropylatrazine - as well as degradates of acetochlor and alachlor, generally were detected at concentrations similar to or greater than concentrations of the parent herbicide. The compounds perchloroethene, trichloroethene, 1,1,1-trichloroethane, methyl tert-butyl ether, and cis-1,2-dichloroethene also were detected commonly. The most commonly detected compounds in source-water samples generally were among those detected commonly across the country and reported in previous studies by the U.S. Geological Survey's National Water-Quality Assessment Program. Relatively few compounds were detected at concentrations greater than human-health benchmarks, and 84 percent of the concentrations were two or more orders of magnitude less than benchmarks. Five compounds (perchloroethene, trichloroethene, 1,2-dibromoethane, acrylonitrile, and dieldrin) were detected at concentrations greater than their human-health benchmark. The human-health benchmarks used for comparison were U.S. Environmental Protection Agency Maximum Contaminant Levels (MCLs) for regulated compounds and Health-Based Screening Levels developed by the U.S. Geological Survey in collaboration with the U.S. Environmental Protection Agency and other agencies for unregulated compounds. About one-half of all detected compounds do not have human-health benchmarks or adequate toxicity information to evaluate results in a human-health context. Ninety-four source-water and finished-water (water that has passed through all the treatment processes but prior to distribution) sites were sampled at selected community water systems during June 2004 to September 2005. Most of the samples were analyzed for compounds that were detected commonly or at relatively high concentrations during the initial source-water sampling. The majority of the finished-water samples represented water blended with water from one or more other wells. Thirty-four samples were from water systems that did not blend water from sampled wells with water from other wells prior to distribution. The comparison of source- and finished-water samples represents an initial assessment of whether compounds present in source water also are present in finished water and is not intended as an evaluation of water-treatment efficacy. The treatment used at the majority of the community water systems sampled is disinfection, which, in general, is not designed to remove the compounds monitored in this study. Concentrations of all compounds detected in finished water were less than their human-health benchmarks. Two detections of perchloroethene and one detection of trichloroethene in finished water had concentrations within an order of magnitude of the MCL. Concentrations of disinfection by-products were

Association of Supply Type with Fecal Contamination of Source Water and Household Stored Drinking Water in Developing Countries: A Bivariate Meta-analysis

PubMed Central

Bain, Robert E.S.; Cronk, Ryan; Wright, Jim A.; Bartram, Jamie

2015-01-01

Background Access to safe drinking water is essential for health. Monitoring access to drinking water focuses on water supply type at the source, but there is limited evidence on whether quality differences at the source persist in water stored in the household. Objectives We assessed the extent of fecal contamination at the source and in household stored water (HSW) and explored the relationship between contamination at each sampling point and water supply type. Methods We performed a bivariate random-effects meta-analysis of 45 studies, identified through a systematic review, that reported either the proportion of samples free of fecal indicator bacteria and/or individual sample bacteria counts for source and HSW, disaggregated by supply type. Results Water quality deteriorated substantially between source and stored water. The mean percentage of contaminated samples (noncompliance) at the source was 46% (95% CI: 33, 60%), whereas mean noncompliance in HSW was 75% (95% CI: 64, 84%). Water supply type was significantly associated with noncompliance at the source (p < 0.001) and in HSW (p = 0.03). Source water (OR = 0.2; 95% CI: 0.1, 0.5) and HSW (OR = 0.3; 95% CI: 0.2, 0.8) from piped supplies had significantly lower odds of contamination compared with non-piped water, potentially due to residual chlorine. Conclusions Piped water is less likely to be contaminated compared with other water supply types at both the source and in HSW. A focus on upgrading water services to piped supplies may help improve safety, including for those drinking stored water. Citation Shields KF, Bain RE, Cronk R, Wright JA, Bartram J. 2015. Association of supply type with fecal contamination of source water and household stored drinking water in developing countries: a bivariate meta-analysis. Environ Health Perspect 123:1222–1231; http://dx.doi.org/10.1289/ehp.1409002 PMID:25956006

A review of the validity and reliability of alcohol retail sales data for monitoring population levels of alcohol consumption: a Scottish perspective.

PubMed

Robinson, Mark; Thorpe, Rachel; Beeston, Clare; McCartney, Gerry

2013-01-01

To assess the validity and reliability of using alcohol retail sales data to measure and monitor population levels of alcohol consumption. Potential sources of bias that could lead to under- or overestimation of population alcohol consumption based on alcohol retail sales data were identified and, where possible, quantified. This enabled an assessment of the potential impact of each bias on alcohol consumption estimates in Scotland. Overall, considering all the possible sources of overestimation and underestimation, and taking into account the potential for sampling variability to impact on the results, the range of uncertainty of consumption during 2010 was from an overestimate of 0.3 l to an underestimate of 2.4 l of pure alcohol per adult. This excludes the impacts of alcohol stockpiling and alcohol sold through outlets not included in the sampling frame. On balance, there is therefore far greater scope for alcohol retail sales data to be underestimating per adult alcohol consumption in Scotland than there is for overestimation. Alcohol retail sales data offer a robust source of data for monitoring per adult alcohol consumption in Scotland. Consideration of the sources of bias and a comprehensive understanding of data collection methods are essential for using sales data to monitor trends in alcohol consumption.

Antidepressant Use in Persons Aged 12 and Over: United States, 2005-2008

MedlinePlus

... received from primary care providers. Data sources and methods NHANES is a continuous survey conducted to assess ... percentages were estimated using Taylor series linearization, a method that incorporates the sample design and weights. Overall ...

BIOMONITORING OF SOURCE WATER QUALITY

EPA Science Inventory

Living organisms are commonly used to determine the toxicity of environmental samples but are usually limited to survival, growth, or reproduction. With advances in electronic and computer technology, biomonitors are being developed that can assess the toxicity of water by monit...

Specificity of coliphages in evaluating marker efficacy: a new insight for water quality indicators.

PubMed

Mookerjee, Subham; Batabyal, Prasenjit; Halder, Madhumanti; Palit, Anup

2014-11-01

Conventional procedures for qualitative assessment of coliphage are time consuming multiple step approach for achieving results. A modified and rapid technique has been introduced for determination of coliphage contamination among potable water sources during water borne outbreaks. During December 2013, 40 water samples from different potable water sources, were received for water quality analyses, from a jaundice affected Municipality of West Bengal, India. Altogether, 30% water samples were contaminated with coliform (1-20 cfu/ml) and 5% with E. coli (2-5 cfu/ml). Among post-outbreak samples, preponderance of coliform has decreased (1-4 cfu/ml) with total absence of E. coli. While standard technique has detected 55% outbreak samples with coliphage contamination, modified technique revealed that 80%, double than that of bacteriological identification rate, were contaminated with coliphages (4-20 pfu/10 ml). However, post-outbreak samples were detected with 1-5 pfu/10 ml coliphages among 20% samples. Coliphage detection rate through modified technique was nearly double (50%) than that of standard technique (27.5%). In few samples (with coliform load of 10-100 cfu/ml), while modified technique could detect coliphages among six samples (10-20 pfu/10 ml), standard protocol failed to detect coliphage in any of them. An easy, rapid and accurate modified technique has thereby been implemented for coliphage assessment from water samples. Coliform free water does not always signify pathogen free potable water and it is demonstrated that coliphage is a more reliable 'biomarker' to ascertain contamination level in potable water. Copyright © 2014 Elsevier B.V. All rights reserved.

Determination of patulin in apple and derived products by UHPLC-MS/MS. Study of matrix effects with atmospheric pressure ionisation sources.

PubMed

Beltrán, Eduardo; Ibáñez, María; Sancho, Juan Vicente; Hernández, Félix

2014-01-01

Sensitive and reliable analytical methodology has been developed for the measurement of patulin in regulated foodstuffs by using ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) with triple quadrupole analyser. Solid samples were extracted with ethyl acetate, while liquid samples were directly injected into the chromatographic system after dilution and filtration without any clean-up step. Chromatographic separation was achieved in less than 4min. Electrospray (ESI) and atmospheric pressure chemical ionisation (APCI) sources were evaluated, in order to assess matrix effects. The use of ESI source caused strong signal suppression in samples; however, matrix effect was negligible using APCI, allowing quantification with calibration standards prepared in solvent. The method was validated in four different apple matrices (juice, fruit, puree and compote) at two concentrations at the low μgkg(-1) level. Average recoveries (n=5) ranged from 71% to 108%, with RSDs lower than 14%. Copyright © 2013 Elsevier Ltd. All rights reserved.

Markers of inflammation in alveolar cells exposed to fine particulate matter from prescribed fires and urban air.

PubMed

Myatt, Theodore A; Vincent, Michael S; Kobzik, Lester; Naeher, Luke P; MacIntosh, David L; Suh, Helen

2011-10-01

To assess the effect of fine particulate matter (PM(2.5)) from different particle sources on tumor necrosis factor- (TNF-) α, we measured TNF production from rat alveolar macrophages (AM) and human dendritic cells (DC) exposed to PM(2.5) from different sources. Fire-related PM(2.5) samples, rural ambient, and urban indoor and outdoor samples were collected in the Southeast United States. Tumor necrosis factor release was measured from rat AM and human DC following incubation with PM(2.5). Tumor necrosis factor release in AMs was greatest for fire-related PM(2.5) compared with other samples (TNF: P value = 0.005; mortality: P value = 0.005). Tumor necrosis factor releases from the DCs and AMs exposed to fire-associated PM(2.5) were strongly correlated (r = 0.87, P value < 0.0001). Particulate matter exposure produces TNF release consistent with pulmonary inflammation in rat AMs and human DCs, with the response in rat AMs differing by particle source.

Area estimation using multiyear designs and partial crop identification

NASA Technical Reports Server (NTRS)

Sielken, R. L., Jr.

1984-01-01

Statistical procedures were developed for large area assessments using both satellite and conventional data. Crop acreages, other ground cover indices, and measures of change were the principal characteristics of interest. These characteristics are capable of being estimated from samples collected possibly from several sources at varying times, with different levels of identification. Multiyear analysis techniques were extended to include partially identified samples; the best current year sampling design corresponding to a given sampling history was determined; weights reflecting the precision or confidence in each observation were identified and utilized, and the variation in estimates incorporating partially identified samples were quantified.

Genetic characterization of Arcobacter isolates from various sources.

PubMed

Shah, A H; Saleha, A A; Zunita, Z; Cheah, Y K; Murugaiyah, M; Korejo, N A

2012-12-07

Arcobacter is getting more attention due to its detection from wide host-range and foods of animal origin. The objective of this study was to determine the prevalence of Arcobacter spp. in various sources at farm level and beef retailed in markets in Malaysia and to assess the genetic relatedness among them. A total of 273 samples from dairy cattle including cattle (n=120), floor (n=30), water (n=18) and milk (n=105) as well as 148 beef samples collected from retail markets were studied. The overall prevalence of Arcobacter in various sources was 15% (63/421). However, source-wise detection rate of Arcobacter spp. was recorded as 26.66% (8/30) in floor, 26.3% (39/148) in beef, 11.11% (2/18) in water, 7.6% (8/105) in milk and 6.66% (8/120) in cattle. Arcobacter butzleri was the frequently isolated species however, a total of 75%, 66.7%, 53.8%, 50% and 12.5%% samples from floor, milk, beef, water and cattle, respectively, were carrying more than one species simultaneously. One (12.5%) cattle and beef sample (2.5%) found to be carrying one Arcobacter spp., A. skirrowii, only. Typing of Arcobacter isolates was done though pulsed field gel electrophoresis (PFGE) after digested with Eag1 restriction endonuclease (RE). Digestion of genomic DNA of Arcobacter from various sources yielded 12 major clusters (≥ 50% similarity) which included 29 different band patterns. A number of closely related A. butzleri isolates were found from beef samples which indicate cross contamination of common type of Arcobacter. Fecal shedding of Arcobacter by healthy animals can contaminate water and milk which may act as source of infection in humans. Copyright © 2012 Elsevier B.V. All rights reserved.

Microplastic analysis in the South Funen Archipelago, Baltic Sea, implementing manta trawling and bulk sampling.

PubMed

Tamminga, Matthias; Hengstmann, Elena; Fischer, Elke Kerstin

2018-03-01

Microplastic contamination in surface waters of the South Funen Archipelago in Denmark was assessed. Therefore, ten manta trawls were conducted in June 2015. Moreover, 31 low-volume bulk samples were taken to evaluate, whether consistent results in comparison to the net-based approach can be obtained. Microplastic contamination in the South Funen Archipelago (0.07 ± 0.02 particles/m3) is slightly below values reported before. The sheltered position of the study area, low population pressure on adjacent islands and the absence of any major potential point sources were identified as major factors explaining the low concentration of microplastics. Within the Archipelago, harbors or marinas and the associated vessel traffic are the most probable sources of microplastics. The concentration of microplastics in low-volume bulk samples is not comparable to manta trawl results. This is mainly due to insufficient representativeness of the bulk sample volumes.

Testing portable luminescence reader signals against late Pleistocene to modern OSL ages of coastal and desert dunefield sand in Israel

NASA Astrophysics Data System (ADS)

Roskin, Joel; Sivan, Dorit; Bookman, Revital; Porat, Naomi; López, Gloria I.

2017-04-01

Rapid assessment of luminescence signals of poly-mineral samples by a pulsed-photon portable OSL reader (PPSL) is useful for interpreting sedimentary sections during fieldwork, and can assist with targeted field sampling for later full OSL dating and prioritize laboratory work. This study investigates PPSL signal intensities in order to assess its usefulness in obtaining relative OSL ages from linear regressions created by interpolating newly generated PPSL values of samples with existing OSL ages from two extensive Nilotic-sourced dunefields. Eighteen OSL-dated sand samples from two quartz-dominated sand systems in Israel were studied:(1) the Mediterranean littoral-sourced coastal dunefields that formed since the middle Holocene; and (2) the inland north-western Negev desert dunefield that rapidly formed between the Last Glacial Maximum and the Holocene. Samples from three coastal dune profiles were also measured. Results show that the PPSL signals differ by several orders of magnitude between modern and late Pleistocene sediments. The coastal and desert sand have different OSL age - PPSL signal ratios. Coastal sand show better correlations between PPSL values and OSL ages. However, using regression curves for each dunefield to interpolate ages is less useful than expected as samples with different ages exhibit similar PPSL signals. The coastal dune profiles yielded low luminescence signal values depicting a modern profile chronology. This study demonstrates that a rapid assessment of the relative OSL ages across different and extensive dunefields is useful and may be achieved. However, the OSL ages obtained by linear regression are only a very rough age estimate. The reasons for not obtaining more reliable ages need to be better understood, as several variables can affect the PPSL signal such as mineral provenance, intrinsic grain properties, micro-dosimetry and moisture content.

The Use and Interpretation of Sodium Concentrations in Casual (Spot) Urine Collections for Population Surveillance and Partitioning of Dietary Iodine Intake Sources

PubMed Central

Conkle, Joel; van der Haar, Frits

2016-01-01

In 2013, the World Health Organization (WHO) called for joint surveillance of population salt and iodine intakes using urinary analysis. 24-h urine collection is considered the gold standard for salt intake assessment, but there is an emerging consensus that casual urine sampling can provide comparable information for population-level surveillance. Our review covers the use of the urinary sodium concentration (UNaC) and the urinary iodine concentration (UIC) from casual urine samples to estimate salt intakes and to partition the sources of iodine intakes. We reviewed literature on 24-h urinary sodium excretion (UNaE) and UNaC and documented the use of UNaC for national salt intake monitoring. We combined information from our review of urinary sodium with evidence on urinary iodine to assess the appropriateness of partitioning methods currently being adapted for cross-sectional survey analyses. At least nine countries are using casual urine collection for surveillance of population salt intakes; all these countries used single samples. Time trend analyses indicate that single UNaC can be used for monitoring changes in mean salt intakes. However; single UNaC suffers the same limitation as single UNaE; i.e., an estimate of the proportion excess salt intake can be biased due to high individual variability. There is evidence, albeit limited, that repeat UNaC sampling has good agreement at the population level with repeat UNaE collections; thus permitting an unbiased estimate of the proportion of excess salt intake. High variability of UIC and UNaC in single urine samples may also bias the estimates of dietary iodine intake sources. Our review concludes that repeated collection, in a sub-sample of individuals, of casual UNaC data would provide an immediate practical approach for routine monitoring of salt intake, because it overcomes the bias in estimates of excess salt intake. Thus we recommend more survey research to expand the evidence-base on predicted-UNaE from repeat casual UNaC sampling. We also conclude that the methodology for partitioning the sources of iodine intake based on the combination of UIC and UNaC measurements in casual urine samples can be improved by repeat collections of casual data; which helps to reduce regression dilution bias. We recommend more survey research to determine the effect of regression dilution bias and circadian rhythms on the partitioning of dietary iodine intake sources. PMID:28025546

Promoting Health for All Kansans Through Mass Media: Lessons Learned From a Pilot Assessment of Student Ebola Perceptions.

PubMed

Chesser, Amy K; Keene Woods, Nikki; Mattar, Jennifer; Craig, Timothy

2016-08-01

We aimed to assess student knowledge of Ebola virus disease (EVD) and opinions about media coverage of EVD. We conducted a pilot study with a cross-sectional survey and a convenience sample. Sixty-five college students participated in the survey and reported a low level of basic knowledge of EVD, high health literacy levels, and Internet and health professionals as sources for health information. This pilot study was an important first step to understanding students' knowledge of Ebola, common sources of health information, and health literacy levels. Results from this study highlight the need to improve health communication training and further evaluate the quality of health information dissemination via all communication sources. (Disaster Med Public Health Preparedness. 2016;10:641-643).

Fine-grained suspended sediment source identification for the Kharaa River basin, northern Mongolia

NASA Astrophysics Data System (ADS)

Rode, Michael; Theuring, Philipp; Collins, Adrian L.

2015-04-01

Fine sediment inputs into river systems can be a major source of nutrients and heavy metals and have a strong impact on the water quality and ecosystem functions of rivers and lakes, including those in semiarid regions. However, little is known to date about the spatial distribution of sediment sources in most large scale river basins in Central Asia. Accordingly, a sediment source fingerprinting technique was used to assess the spatial sources of fine-grained (<10 microns) sediment in the 15 000 km2 Kharaa River basin in northern Mongolia. Five field sampling campaigns in late summer 2009, and spring and late summer in both 2010 and 2011, were conducted directly after high water flows, to collect an overall total of 900 sediment samples. The work used a statistical approach for sediment source discrimination with geochemical composite fingerprints based on a new Genetic Algorithm (GA)-driven Discriminant Function Analysis, the Kruskal-Wallis H-test and Principal Component Analysis. The composite fingerprints were subsequently used for numerical mass balance modelling with uncertainty analysis. The contributions of the individual sub-catchment spatial sediment sources varied from 6.4% (the headwater sub-catchment of Sugnugur Gol) to 36.2% (the Kharaa II sub-catchment in the middle reaches of the study basin) with the pattern generally showing higher contributions from the sub-catchments in the middle, rather than the upstream, portions of the study area. The importance of riverbank erosion was shown to increase from upstream to midstream tributaries. The source tracing procedure provides results in reasonable accordance with previous findings in the study region and demonstrates the general applicability and associated uncertainties of an approach for fine-grained sediment source investigation in large scale semi-arid catchments. The combined application of source fingerprinting and catchment modelling approaches can be used to assess whether tracing estimates are credible and in combination such approaches provide a basis for making sediment source apportionment more compelling to catchment stakeholders and managers.

Air quality assessment and the use of specific markers to apportion pollutants to source

NASA Astrophysics Data System (ADS)

Douce, David Stewart

The contributions of specific polluting sources to both indoor and outdoor atmospheric pollution are difficult to determine, as solid and gaseous products from different combustion sources are often similar. Sometimes, however, a marker compound can be identified that is unique to a pollution source (or at least not present in most other local combustion sources) and which will allow assessment of the contribution of that source to total atmospheric pollution.The aim of this study was to identify suitable marker compounds and methods for the apportionment (assessment of percentage contribution) of specific sources to atmospheric pollution. The sources selected were diesel exhaust emissions in outdoor, and environmental tobacco smoke (ETS) in indoor environments. Studies with controlled (laboratory) atmospheres would be followed by field studies using these methods and markers to produce apportionments for these sources to air pollution in selected environments. Initial analysis of such polluting sources was therefore the qualitative analysis of volatile compounds and particulate associated material, both organic and inorganic. Volatile organic compounds were adsorbed onto various resins, while particulate material was sampled onto various filter paper types. Organics were determined by GC-AED and GC-MS, and elements by ICP-MS.1-Nitropyrene was identified as a suitable marker for diesel particulate emissions (<5um). A large volume air sample from Sheffield city centre using 1-nitropyrene as a marker suggested that 63% of atmospheric particulate material (<5um) might be of diesel origin. However the concentration of 1-nitropyrene is low in atmospheric samples, and in the volumes used in routine sampling the amount of 1-nitropyrene was below the limit of detection on the instrument used. In an alternative approach the aliphatic alkane tetracosane (C24) was used as a diesel marker for urban air, with a 1-nitropyrene:tetracosane ratio derived from the average results from laboratory experiments with a diesel engine running at various speeds and loads. This approach yielded apportionment values ranging from 5-85% for the diesel contribution to particulate material (<5mum) in the urban air of Sheffield. No volatile marker compound was found for diesel apportionment.The contribution of ETS to atmospheric pollution has previously been estimated from the measurement of respirable suspended particulates (RSP), which was superseded by total UV absorbance and total fluorescence of a methanol extract. More recent work has suggested the use of solanesol or scopoletin as marker compounds. This thesis shows that the non specific methods overestimated the particulate contribution of ETS in some atmospheres, and that solanesol is a better marker compound than scopoletin. Preliminary studies from a small number of smokers homes and offices, with solanesol as a marker compound for particulate ETS, indicated that ETS contributions to total particulate material (<5mum) ranged from 6 to 49% in homes and 11 to 28% in offices.Pyrrole was used as a marker for ETS contribution to volatile organic pollution, and studies with controlled atmospheres with a smoking machine allowed calculation of the ratios of pyrrole to other volatile organic compounds (VOC's) in ETS. Samples from the field study were used to produce apportionment percentage levels of benzene, toluene, o-xylene and p+m-xylene associated with ETS.In addition the use of tree bark as a atmospheric sink for airborne particulates was investigated. Six nitrated polycyclic aromatic hydrocarbons associated with diesel emissions were quantified in bark extracts and levels of these were found to be highest during winter months.

Microbial risk assessment of drinking water based on hydrodynamic modelling of pathogen concentrations in source water.

PubMed

Sokolova, Ekaterina; Petterson, Susan R; Dienus, Olaf; Nyström, Fredrik; Lindgren, Per-Eric; Pettersson, Thomas J R

2015-09-01

Norovirus contamination of drinking water sources is an important cause of waterborne disease outbreaks. Knowledge on pathogen concentrations in source water is needed to assess the ability of a drinking water treatment plant (DWTP) to provide safe drinking water. However, pathogen enumeration in source water samples is often not sufficient to describe the source water quality. In this study, the norovirus concentrations were characterised at the contamination source, i.e. in sewage discharges. Then, the transport of norovirus within the water source (the river Göta älv in Sweden) under different loading conditions was simulated using a hydrodynamic model. Based on the estimated concentrations in source water, the required reduction of norovirus at the DWTP was calculated using quantitative microbial risk assessment (QMRA). The required reduction was compared with the estimated treatment performance at the DWTP. The average estimated concentration in source water varied between 4.8×10(2) and 7.5×10(3) genome equivalents L(-1); and the average required reduction by treatment was between 7.6 and 8.8 Log10. The treatment performance at the DWTP was estimated to be adequate to deal with all tested loading conditions, but was heavily dependent on chlorine disinfection, with the risk of poor reduction by conventional treatment and slow sand filtration. To our knowledge, this is the first article to employ discharge-based QMRA, combined with hydrodynamic modelling, in the context of drinking water. Copyright © 2015 Elsevier B.V. All rights reserved.

[Mutagenicity study of water samples from a waterworks taking Yangtze River as its water source in Jiangsu Province].

PubMed

Xiao, Sanhua; Luo, Lan; Qiao, Qian; Lü, Xuemin; Wang, Yanhui; Feng, Lin; Tang, Fei; Wang, Haiyong; Bie, Nana; Wang, Yuehong

2017-05-01

To understand the occurrence and change of mutagencity of water samples in the process of drinking water treatment and distribution in a waterworks taking Yangtze River as its water source in Jiangsu Province. Large volume of inlet water, finished water and tap water samples were extracted by XAD-2 resin. Mutagencities were assessed by Ames test and a mutation ratio( MR) of 2 or greater was judged as a positive result. Compared with the samples with S9, samples without S9 presented more positive results( P = 0. 005). That water treatment elevated MR values( P = 0. 007) while the pipe transport made MR values down( P = 0. 038) was observed in samples without S9. The tap water showed weaker mutagenicities than the raw water in samples with S9( P = 0. 008). Compared to the raw water samples, the finished water samples showed more positive results(-S9) and lower MR values( + S9, P =0. 002). Significant mutagenicities of water samples from the Yangtze Riverand its processed water were presented, and frame shit and direct mutagens deserved special concern.

Polycyclic Aromatic Hydrocarbons in Residential Dust: Sources of Variability

PubMed Central

Metayer, Catherine; Petreas, Myrto; Does, Monique; Buffler, Patricia A.; Rappaport, Stephen M.

2013-01-01

Background: There is interest in using residential dust to estimate human exposure to environmental contaminants. Objectives: We aimed to characterize the sources of variability for polycyclic aromatic hydrocarbons (PAHs) in residential dust and provide guidance for investigators who plan to use residential dust to assess exposure to PAHs. Methods: We collected repeat dust samples from 293 households in the Northern California Childhood Leukemia Study during two sampling rounds (from 2001 through 2007 and during 2010) using household vacuum cleaners, and measured 12 PAHs using gas chromatography–mass spectrometry. We used a random- and a mixed-effects model for each PAH to apportion observed variance into four components and to identify sources of variability. Results: Median concentrations for individual PAHs ranged from 10 to 190 ng/g of dust. For each PAH, total variance was apportioned into regional variability (1–9%), intraregional between-household variability (24–48%), within-household variability over time (41–57%), and within-sample analytical variability (2–33%). Regional differences in PAH dust levels were associated with estimated ambient air concentrations of PAH. Intraregional differences between households were associated with the residential construction date and the smoking habits of residents. For some PAHs, a decreasing time trend explained a modest fraction of the within-household variability; however, most of the within-household variability was unaccounted for by our mixed-effects models. Within-household differences between sampling rounds were largest when the interval between dust sample collections was at least 6 years in duration. Conclusions: Our findings indicate that it may be feasible to use residential dust for retrospective assessment of PAH exposures in studies of health effects. PMID:23461863

Surma eye cosmetic in Afghanistan: a potential source of lead toxicity in children.

PubMed

McMichael, J R; Stoff, B K

2018-02-01

Surma is a traditional eye cosmetic used as an eyeliner for infants in Afghanistan, as well as in many other countries in Asia, the Middle East, and Africa. Surma has been reported to contain lead and to be a potential source of lead toxicity in children, which can lead to permanent damage to multiple organ systems. To our knowledge, assessment for lead in surma found in Afghanistan has not been performed. We determined the quantitative lead content of a convenience sample of 10 surma products acquired in Afghanistan. Analysis revealed that 70% of surma samples contained high levels of lead (range 35-83%). The remaining samples contained low levels of lead (range 0.04-0.17%). The majority of surma samples contained very high levels of lead, a troubling finding that could potentially correlate with lead toxicity in Afghan children. Making available lead-free surma alternatives and providing health education, for both healthcare professionals and the general population, in locations where surma use is prevalent and for those involved in care of refugees and immigrants from Afghanistan, may be strategies to prevent lead poisoning in children. What is Known: • Surma is a traditional cosmetic used as an eyeliner for infants in Afghanistan as well as in many countries in Asia, the Middle East, and Africa. • Surma has been reported to contain lead and to be a source of lead toxicity in children. What is New: • Assessment for lead content in surma found in Afghanistan has not been performed. • In this convenience sample of 10 surma products acquired in Afghanistan, 70% contained very high levels of lead.

The importance of quality control in validating concentrations of contaminants of emerging concern in source and treated drinking water samples.

PubMed

Batt, Angela L; Furlong, Edward T; Mash, Heath E; Glassmeyer, Susan T; Kolpin, Dana W

2017-02-01

A national-scale survey of 247 contaminants of emerging concern (CECs), including organic and inorganic chemical compounds, and microbial contaminants, was conducted in source and treated drinking water samples from 25 treatment plants across the United States. Multiple methods were used to determine these CECs, including six analytical methods to measure 174 pharmaceuticals, personal care products, and pesticides. A three-component quality assurance/quality control (QA/QC) program was designed for the subset of 174 CECs which allowed us to assess and compare performances of the methods used. The three components included: 1) a common field QA/QC protocol and sample design, 2) individual investigator-developed method-specific QA/QC protocols, and 3) a suite of 46 method comparison analytes that were determined in two or more analytical methods. Overall method performance for the 174 organic chemical CECs was assessed by comparing spiked recoveries in reagent, source, and treated water over a two-year period. In addition to the 247 CECs reported in the larger drinking water study, another 48 pharmaceutical compounds measured did not consistently meet predetermined quality standards. Methodologies that did not seem suitable for these analytes are overviewed. The need to exclude analytes based on method performance demonstrates the importance of additional QA/QC protocols. Published by Elsevier B.V.

Quality assessment of MEG-to-MRI coregistrations

NASA Astrophysics Data System (ADS)

Sonntag, Hermann; Haueisen, Jens; Maess, Burkhard

2018-04-01

For high precision in source reconstruction of magnetoencephalography (MEG) or electroencephalography data, high accuracy of the coregistration of sources and sensors is mandatory. Usually, the source space is derived from magnetic resonance imaging (MRI). In most cases, however, no quality assessment is reported for sensor-to-MRI coregistrations. If any, typically root mean squares (RMS) of point residuals are provided. It has been shown, however, that RMS of residuals do not correlate with coregistration errors. We suggest using target registration error (TRE) as criterion for the quality of sensor-to-MRI coregistrations. TRE measures the effect of uncertainty in coregistrations at all points of interest. In total, 5544 data sets with sensor-to-head and 128 head-to-MRI coregistrations, from a single MEG laboratory, were analyzed. An adaptive Metropolis algorithm was used to estimate the optimal coregistration and to sample the coregistration parameters (rotation and translation). We found an average TRE between 1.3 and 2.3 mm at the head surface. Further, we observed a mean absolute difference in coregistration parameters between the Metropolis and iterative closest point algorithm of (1.9 +/- 15){\\hspace{0pt}}\\circ and (1.1 +/- 9) m. A paired sample t-test indicated a significant improvement in goal function minimization by using the Metropolis algorithm. The sampled parameters allowed computation of TRE on the entire grid of the MRI volume. Hence, we recommend the Metropolis algorithm for head-to-MRI coregistrations.

A geostatistical approach for quantification of contaminant mass discharge uncertainty using multilevel sampler measurements

NASA Astrophysics Data System (ADS)

Li, K. Betty; Goovaerts, Pierre; Abriola, Linda M.

2007-06-01

Contaminant mass discharge across a control plane downstream of a dense nonaqueous phase liquid (DNAPL) source zone has great potential to serve as a metric for the assessment of the effectiveness of source zone treatment technologies and for the development of risk-based source-plume remediation strategies. However, too often the uncertainty of mass discharge estimated in the field is not accounted for in the analysis. In this paper, a geostatistical approach is proposed to estimate mass discharge and to quantify its associated uncertainty using multilevel transect measurements of contaminant concentration (C) and hydraulic conductivity (K). The approach adapts the p-field simulation algorithm to propagate and upscale the uncertainty of mass discharge from the local uncertainty models of C and K. Application of this methodology to numerically simulated transects shows that, with a regular sampling pattern, geostatistics can provide an accurate model of uncertainty for the transects that are associated with low levels of source mass removal (i.e., transects that have a large percentage of contaminated area). For high levels of mass removal (i.e., transects with a few hot spots and large areas of near-zero concentration), a total sampling area equivalent to 6˜7% of the transect is required to achieve accurate uncertainty modeling. A comparison of the results for different measurement supports indicates that samples taken with longer screen lengths may lead to less accurate models of mass discharge uncertainty. The quantification of mass discharge uncertainty, in the form of a probability distribution, will facilitate risk assessment associated with various remediation strategies.

Association of Fecal Indicator Bacteria with Human Viruses and Microbial Source Tracking Markers at Coastal Beaches Impacted by Nonpoint Source Pollution

PubMed Central

McQuaig, Shannon; Griffith, John

2012-01-01

Water quality was assessed at two marine beaches in California by measuring the concentrations of culturable fecal indicator bacteria (FIB) and by library-independent microbial source tracking (MST) methods targeting markers of human-associated microbes (human polyomavirus [HPyV] PCR and quantitative PCR, Methanobrevibacter smithii PCR, and Bacteroides sp. strain HF183 PCR) and a human pathogen (adenovirus by nested PCR). FIB levels periodically exceeded regulatory thresholds at Doheny and Avalon Beaches for enterococci (28.5% and 31.7% of samples, respectively) and fecal coliforms (20% and 5.8%, respectively). Adenoviruses were detected at four of five sites at Doheny Beach and were correlated with detection of HPyVs and human Bacteroides HF183; however, adenoviruses were not detected at Avalon Beach. The most frequently detected human source marker at both beaches was Bacteroides HF183, which was detected in 27% of samples. Correlations between FIBs and human markers were much more frequent at Doheny Beach than at Avalon Beach; e.g., adenovirus was correlated with HPyVs and HF183. Human sewage markers and adenoviruses were routinely detected in samples meeting FIB regulatory standards. The toolbox approach of FIB measurement coupled with analysis of several MST markers targeting human pathogens used here demonstrated that human sewage is at least partly responsible for the degradation of water quality, particularly at Doheny Beach, and resulted in a more definitive assessment of recreational water quality and human health risk than reliance on FIB concentrations alone could have provided. PMID:22773625

Assessment of nonpoint source chemical loading potential to watersheds containing uranium waste dumps and human health hazards associated with uranium exploration and mining, Red, White, and Fry Canyons, southeastern Utah, 2007

USGS Publications Warehouse

Beisner, Kimberly R.; Marston, Thomas M.; Naftz, David L.; Snyder, Terry; Freeman, Michael L.

2010-01-01

During May, June, and July 2007, 58 solid-phase samples were collected from abandoned uranium mine waste dumps, background sites, and adjacent streambeds in Red, White, and Fry Canyons in southeastern Utah. The objectives of this sampling program were to (1) assess the nonpoint-source chemical loading potential to ephemeral and perennial drainage basins from uranium waste dumps and (2) assess potential effects on human health due to recreational activities on and around uranium waste dumps on Bureau of Land Management property. Uranium waste-dump samples were collected using solid-phase sampling protocols. After collection, solid-phase samples were homogenized and extracted in the laboratory using a leaching procedure. Filtered (0.45 micron) water samples were obtained from the field leaching procedure and were analyzed for major and trace elements at the Inductively Coupled Plasma-Mass Spectrometry Metals Analysis Laboratory at the University of Utah. A subset of the solid-phase samples also were digested with strong acids and analyzed for major ions and trace elements at the U.S. Geological Survey Geologic Division Laboratory in Denver, Colorado. For the initial ranking of chemical loading potential for uranium waste dumps, results of leachate analyses were compared with existing aquatic-life and drinking-water-quality standards. To assess potential effects on human health, solid-phase digestion values for uranium were compared to soil screening levels (SSL) computed using the computer model RESRAD 6.5 for a probable concentration of radium. One or more chemical constituents exceeded aquatic life and drinking-water-quality standards in approximately 64 percent (29/45) of the leachate samples extracted from uranium waste dumps. Most of the uranium waste dump sites with elevated trace-element concentrations in leachates were located in Red Canyon. Approximately 69 percent (31/45) of the strong acid digestible soil concentration values were greater than a calculated SSL. Uranium waste dump sites with elevated leachate and total digestible concentrations may need to be further investigated to determine the most appropriate remediation method.

Contamination of tomatoes with coliforms and Escherichia coli on farms and in markets of northwest Nigeria.

PubMed

Shenge, Kenneth C; Whong, Clement M Z; Yakubu, Lydia L; Omolehin, Raphael A; Erbaugh, J Mark; Miller, Sally A; LeJeune, Jeffrey T

2015-01-01

Although recent reports indicated that produce contamination with foodborne pathogens is widespread in Nigeria, the sources and magnitude of microbial contamination of fruits and vegetables on farms and in markets have not been thoroughly identified. To ascertain possible pathways of contamination, the frequency and magnitude of coliform and Escherichia coli contamination of tomatoes produced in northwest Nigeria was assessed on farms and in markets. Eight hundred twenty-six tomato fruit samples and 36 irrigation water samples were collected and assessed for fecal indicator organisms. In addition, the awareness and use of food safety practices by tomato farmers and marketers were determined. Median concentration of coliforms on all field- and market-sourced tomato fruit samples, as well as in irrigation water sources, in Kaduna, Kano, and Katsina states exceeded 1,000 most probable number (MPN) per g. Median E. coli counts from 73 (17%) of 420 field samples and 231 (57%) of 406 market tomato fruit samples exceeded 100 MPN/g. Median E. coli concentrations on tomato fruits were higher (P < 0.01) in the rainy season (2.45 Log MPN/g), when irrigation was not practiced than in the dry (1.10 Log MPN/g) and early dry (0.92 Log MPN/g) seasons. Eighteen (50%) of 36 irrigation water samples had E. coli counts higher than 126 MPN/100 ml. Median E. coli contamination on market tomato fruit samples (2.66 Log MPN/g) were higher (P < 0.001) than those from tomatoes collected on farms (0.92 Log MPN/g). Farmers and marketers were generally unaware of the relationship between food safety practices and microbial contamination on fresh produce. Good agricultural practices pertaining to food safety on farms and in local markets were seldom used. Adoption of food safety practices on-farm, during transport, and during marketing could improve the microbial quality of tomatoes available to the public in this region of the world.

Urine and toenail cadmium levels in pregnant women: A reliability study.

PubMed

White, Alexandra J; O'Brien, Katie M; Jackson, Brian P; Karagas, Margaret R

2018-05-29

Cadmium, as measured in human tissue, has been associated with numerous health outcomes. However, few studies have evaluated the reliability of cadmium measurements across different biologic samples. We evaluated toenail cadmium levels over time and compared toenail cadmium to urinary cadmium. We also evaluated the relationship between biomarker concentrations and cigarette smoking, a known source of cadmium exposure. Cadmium was assessed in urine and toenail samples collected from 1338 pregnant women participating in the New Hampshire Birth Cohort Study. Each participant was asked to provide a urine and a toenail sample at enrollment (between 24 and 28 weeks gestation) and another toenail sample 2-8 weeks postpartum. Cadmium concentrations were determined using inductively-coupled plasma mass spectrometry. Spearman correlations were assessed for cadmium in the toenails across the two-time points and comparing toenail and urine levels. Smoking status was evaluated as a predictor of cadmium levels. Toenail cadmium assessed during pregnancy and postpartum were modestly correlated (R = 0.3, p < 0.0001). However, urine and toenail cadmium levels were unrelated (R = -0.03, p = 0.46). Both toenail and urinary cadmium levels were associated with women's smoking status. Our findings suggest that both toenail and urinary cadmium concentrations reflect the major source of exposure - cigarette smoking. Toenail cadmium concentrations are modestly reproducible pre- and postpartum; but do not appear to be related to urinary cadmium and thus likely represent different windows and chronicity of exposure among pregnant women. Published by Elsevier Ltd.

A review of accuracy assessment for object-based image analysis: From per-pixel to per-polygon approaches

NASA Astrophysics Data System (ADS)

Ye, Su; Pontius, Robert Gilmore; Rakshit, Rahul

2018-07-01

Object-based image analysis (OBIA) has gained widespread popularity for creating maps from remotely sensed data. Researchers routinely claim that OBIA procedures outperform pixel-based procedures; however, it is not immediately obvious how to evaluate the degree to which an OBIA map compares to reference information in a manner that accounts for the fact that the OBIA map consists of objects that vary in size and shape. Our study reviews 209 journal articles concerning OBIA published between 2003 and 2017. We focus on the three stages of accuracy assessment: (1) sampling design, (2) response design and (3) accuracy analysis. First, we report the literature's overall characteristics concerning OBIA accuracy assessment. Simple random sampling was the most used method among probability sampling strategies, slightly more than stratified sampling. Office interpreted remotely sensed data was the dominant reference source. The literature reported accuracies ranging from 42% to 96%, with an average of 85%. A third of the articles failed to give sufficient information concerning accuracy methodology such as sampling scheme and sample size. We found few studies that focused specifically on the accuracy of the segmentation. Second, we identify a recent increase of OBIA articles in using per-polygon approaches compared to per-pixel approaches for accuracy assessment. We clarify the impacts of the per-pixel versus the per-polygon approaches respectively on sampling, response design and accuracy analysis. Our review defines the technical and methodological needs in the current per-polygon approaches, such as polygon-based sampling, analysis of mixed polygons, matching of mapped with reference polygons and assessment of segmentation accuracy. Our review summarizes and discusses the current issues in object-based accuracy assessment to provide guidance for improved accuracy assessments for OBIA.

Sources of groundwater and characteristics of surface-water recharge at Bell, White, and Suwannee Springs, Florida, 2012–13

USGS Publications Warehouse

Stamm, John F.; McBride, W. Scott

2016-12-21

Discharge from springs in Florida is sourced from aquifers, such as the Upper Floridan aquifer, which is overlain by an upper confining unit that locally can have properties of an aquifer. Water levels in aquifers are affected by several factors, such as precipitation, recharge, and groundwater withdrawals, which in turn can affect discharge from springs. Therefore, identifying groundwater sources and recharge characteristics can be important in assessing how these factors might affect flows and water levels in springs and can be informative in broader applications such as groundwater modeling. Recharge characteristics include the residence time of water at the surface, apparent age of recharge, and recharge water temperature.The groundwater sources and recharge characteristics of three springs that discharge from the banks of the Suwannee River in northern Florida were assessed for this study: Bell Springs, White Springs, and Suwannee Springs. Sources of groundwater were also assessed for a 150-foot-deep well finished within the Upper Floridan aquifer, hereafter referred to as the UFA well. Water samples were collected for geochemical analyses in November 2012 and October 2013 from the three springs and the UFA well. Samples were analyzed for a suite of major ions, dissolved gases, and isotopes of sulfur, strontium, oxygen, and hydrogen. Daily means of water level and specific conductance at White Springs were continuously recorded from October 2012 through December 2013 by the Suwannee River Water Management District. Suwannee River stage at White Springs was computed on the basis of stage at a U.S. Geological Survey streamgage about 2.4 miles upstream. Water levels in two wells, located about 2.5 miles northwest and 13 miles southeast of White Springs, were also used in the analyses.Major ion concentrations were used to differentiate water from the springs and Upper Floridan aquifer into three groups: Bell Springs, UFA well, and White and Suwannee Springs. When considered together, evidence from water-level, specific conductance, major-ion concentration, and isotope data indicated that groundwater at Bell Springs and the UFA well was a mixture of surface water and groundwater from the upper confining unit, and that groundwater at White and Suwannee Springs was a mixture of surface water, groundwater from the upper confining unit, and groundwater from the Upper Floridan aquifer. Higher concentrations of magnesium in groundwater samples at the UFA well than in samples at Bell Springs might indicate less mixing with surface water at the UFA well than at Bell Springs. Characteristics of surface-water recharge, such as residence time at the surface, apparent age, and recharge water temperature, were estimated on the basis of isotopic ratios, and dissolved concentrations of gases such as argon, tritium, and sulfur hexafluoride. Oxygen and deuterium isotopic ratios were consistent with rapid recharge by rainwater for samples collected in 2012, and longer residence time at the surface (ponding) for samples collected in 2013. Apparent ages of groundwater samples, computed on the basis of tritium activity and sulfur hexafluoride concentration, indicated groundwater recharge occurred after the late 1980s; however, the estimated apparent ages likely represent the average of ages of multiple sources. Recharge since the 1980s is consistent with groundwater from shallow sources, such as the upper confining unit and Upper Floridan aquifer. Recharge water temperature computed for the three springs and UFA well averaged 20.1 degrees Celsius, which is similar to the mean annual air temperature of 20.6 degrees Celsius at a nearby weather station for 1960–2014.

Microbiological, chemical and physical quality of drinking water for commercial turkeys: a cross-sectional study.

PubMed

Di Martino, G; Piccirillo, A; Giacomelli, M; Comin, D; Gallina, A; Capello, K; Buniolo, F; Montesissa, C; Bonfanti, L

2018-04-17

Drinking water for poultry is not subject to particular microbiological, chemical and physical requirements, thereby representing a potential transmission route for pathogenic microorganisms and contaminants and/or becoming unsuitable for water-administered medications. This study assessed the microbiological, chemical and physical drinking water quality of 28 turkey farms in North-Eastern Italy: 14 supplied with tap water (TW) and 14 with well water (WW). Water salinity, hardness, pH, ammonia, sulphate, phosphate, nitrate, chromium, copper and iron levels were also assessed. Moreover, total bacterial count at 22°C, presence and enumeration of Enterococcus spp. and E. coli, presence of Salmonella spp. and Campylobacter spp. were quantified. A water sample was collected in winter and in summer at 3 sampling sites: the water source (A), the beginning (B) and the end (C) of the nipple line (168 samples in total). Chemical and physical quality of both TW and WW sources was mostly within the limits of TW for humans. However, high levels of hardness and iron were evidenced in both sources. In WW vs. TW, sulphate and salinity levels were significantly higher, whilst pH and nitrate levels were significantly lower. At site A, microbiological quality of WW and TW was mostly within the limit of TW for humans. However, both sources had a significantly lower microbiological quality at sites B and C. Salmonella enterica subsp. enterica serotype Kentucky was isolated only twice from WW. Campylobacter spp. were rarely isolated (3.6% of farms); however, Campylobacter spp. farm-level prevalence by real-time PCR was up to 43% for both water sources. Winter posed at higher risk than summer for Campylobacter spp. presence in water, whereas no significant associations were found with water source, site, recirculation system, and turkey age. Low salinity and high hardness were significant risk factors for C. coli and C. jejuni presence, respectively. These results show the need of improving sanitization of drinking water pipelines for commercial turkeys.

Cluster analysis and quality assessment of logged water at an irrigation project, eastern Saudi Arabia.

PubMed

Hussain, Mahbub; Ahmed, Syed Munaf; Abderrahman, Walid

2008-01-01

A multivariate statistical technique, cluster analysis, was used to assess the logged surface water quality at an irrigation project at Al-Fadhley, Eastern Province, Saudi Arabia. The principal idea behind using the technique was to utilize all available hydrochemical variables in the quality assessment including trace elements and other ions which are not considered in conventional techniques for water quality assessments like Stiff and Piper diagrams. Furthermore, the area belongs to an irrigation project where water contamination associated with the use of fertilizers, insecticides and pesticides is expected. This quality assessment study was carried out on a total of 34 surface/logged water samples. To gain a greater insight in terms of the seasonal variation of water quality, 17 samples were collected from both summer and winter seasons. The collected samples were analyzed for a total of 23 water quality parameters including pH, TDS, conductivity, alkalinity, sulfate, chloride, bicarbonate, nitrate, phosphate, bromide, fluoride, calcium, magnesium, sodium, potassium, arsenic, boron, copper, cobalt, iron, lithium, manganese, molybdenum, nickel, selenium, mercury and zinc. Cluster analysis in both Q and R modes was used. Q-mode analysis resulted in three distinct water types for both the summer and winter seasons. Q-mode analysis also showed the spatial as well as temporal variation in water quality. R-mode cluster analysis led to the conclusion that there are two major sources of contamination for the surface/shallow groundwater in the area: fertilizers, micronutrients, pesticides, and insecticides used in agricultural activities, and non-point natural sources.

An adaptive Bayesian inference algorithm to estimate the parameters of a hazardous atmospheric release

NASA Astrophysics Data System (ADS)

Rajaona, Harizo; Septier, François; Armand, Patrick; Delignon, Yves; Olry, Christophe; Albergel, Armand; Moussafir, Jacques

2015-12-01

In the eventuality of an accidental or intentional atmospheric release, the reconstruction of the source term using measurements from a set of sensors is an important and challenging inverse problem. A rapid and accurate estimation of the source allows faster and more efficient action for first-response teams, in addition to providing better damage assessment. This paper presents a Bayesian probabilistic approach to estimate the location and the temporal emission profile of a pointwise source. The release rate is evaluated analytically by using a Gaussian assumption on its prior distribution, and is enhanced with a positivity constraint to improve the estimation. The source location is obtained by the means of an advanced iterative Monte-Carlo technique called Adaptive Multiple Importance Sampling (AMIS), which uses a recycling process at each iteration to accelerate its convergence. The proposed methodology is tested using synthetic and real concentration data in the framework of the Fusion Field Trials 2007 (FFT-07) experiment. The quality of the obtained results is comparable to those coming from the Markov Chain Monte Carlo (MCMC) algorithm, a popular Bayesian method used for source estimation. Moreover, the adaptive processing of the AMIS provides a better sampling efficiency by reusing all the generated samples.

Organic compounds in Elm Fork Trinity River water used for public supply near Carrollton, Texas, 2002-05

USGS Publications Warehouse

Ging, Patricia B.; Delzer, Gregory C.; Hamilton, Pixie A.

2009-01-01

Organic compounds studied in this U.S. Geological Survey (USGS) assessment generally are man-made, including pesticides, solvents, gasoline hydrocarbons, personal-care and domestic-use products, refrigerants, and propellants. A total of 103 of 277 compounds were detected at least once among the 30 samples of source water for a community water system on the Elm Fork Trinity River near Carrollton, Texas, collected approximately monthly during 2002-05. The diversity of compounds detected indicates a variety of different sources and uses (including wastewater discharge, industrial, agricultural, domestic, and others) and different pathways (including overland runoff and groundwater discharge) to drinking-water supplies. Nine compounds were detected year-round in source-water samples, including chloroform, methyl tert-butyl ether (MTBE), and selected herbicide compounds commonly used in the Trinity River Basin and in other urban areas across the United States. About 90 percent of the 42 compounds detected most frequently in source water (in at least 20 percent of the samples) also were detected most frequently in finished water (after treatment but before distribution). Concentrations for all detected compounds in source and finished water generally were less than 0.1 microgram per liter and always less than human-health benchmarks, which are available for about one-half of the detected compounds.

Sources of self-efficacy for physical activity.

PubMed

Warner, Lisa M; Schüz, Benjamin; Wolff, Julia K; Parschau, Linda; Wurm, Susanne; Schwarzer, Ralf

2014-11-01

The effects of self-efficacy beliefs on physical activity are well documented, but much less is known about the origins of self-efficacy beliefs. This article proposes scales to assess the sources of self-efficacy for physical activity aims and to comparatively test their predictive power for physical activity via self-efficacy over time to detect the principal sources of self-efficacy beliefs for physical activity. A study of 1,406 German adults aged 16-90 years was conducted to construct scales to assess the sources of self-efficacy for physical activity (Study 1). In Study 2, the scales' predictive validity for self-efficacy and physical activity was tested in a sample of 310 older German adults. Short, reliable and valid instruments to measure six sources of self-efficacy for physical activity were developed that enable researchers to comparatively test the predictive value of the sources of self-efficacy. The results suggest that mastery experience, self-persuasion, and reduction in negative affective states are the most important predictors of self-efficacy for physical activity in community-dwelling older adults. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Anthropogenic Organic Compounds in Ground Water and Finished Water of Community Water Systems near Dayton, Ohio, 2002-04

USGS Publications Warehouse

Thomas, Mary Ann

2007-01-01

Source water for 15 community-water-system (CWS) wells in the vicinity of Dayton, Ohio, was sampled to evaluate the occurrence of 258 anthropogenic compounds (AOCs). At least one AOC was detected in 12 of the 15 samples. Most samples contained a mixture of compounds (average of four compounds per sample). The compounds that were detected in more than 30 percent of the samples included three volatile organic compounds (VOCs) (trichloroethene, chloroform, and 1,1,1-trichloroethane) and four pesticides or pesticide breakdown products (prometon, simazine, atrazine, and deethylatrazine). In general, VOCs were detected at higher concentrations than pesticides were; among the VOCs, the maximum detected concentration was 4.8 ?g/L (for trichloroethene), whereas among the pesticides, the maximum detected concentration was 0.041 ?g/L (for atrazine). During a later phase of the study, samples of source water from five CWS wells were compared to samples of finished water associated with each well. In general, VOC detections were higher in finished water than in source water, primarily due to the occurrence of trihalomethanes, which are compounds that can form during the treatment process. In contrast, pesticide detections were relatively similar between source- and finished-water samples. To assess the human-health relevance of the data, concentrations of AOCs were compared to their respective human-health benchmarks. For pesticides, the maximum detected concentrations were at least 2 orders of magnitude less than the benchmark values. However, three VOCs - trichloroethene, carbon tetrachloride, and tetrachloromethane - were detected at concentrations that approach human-health benchmarks and therefore may warrant inclusion in a low-concentration, trends monitoring program.

Host Specificity and Source of Enterocytozoon bieneusi Genotypes in a Drinking Source Watershed

PubMed Central

Guo, Yaqiong; Alderisio, Kerri A.; Yang, Wenli; Cama, Vitaliano; Xiao, Lihua

2014-01-01

To assess the host specificity of Enterocytozoon bieneusi and to track the sources of E. bieneusi contamination, we genotyped E. bieneusi in wildlife and stormwater from the watershed of New York City's source water, using ribosomal internal transcribed spacer (ITS)-based PCR and sequence analyses. A total of 255 specimens from 23 species of wild mammals and 67 samples from stormwater were analyzed. Seventy-four (29.0%) of the wildlife specimens and 39 (58.2%) of the stormwater samples from streams were PCR positive. Altogether, 20 E. bieneusi genotypes were found, including 8 known genotypes and 12 new ones. Sixteen and five of the genotypes were seen in animals and stormwater from the watershed, respectively, with WL4 being the most common genotype in both animals (35 samples) and stormwater (23 samples). The 20 E. bieneusi genotypes belonged to five genogroups (groups 1, 3, 4, and 7 and an outlier), with only 23/113 (20.4%) E. bieneusi-positive samples belonging to zoonotic genogroup 1 and 3/20 genotypes ever being detected in humans. The two genogroups previously considered host specific, groups 3 and 4, were both detected in multiple groups of mammals. Thus, with the exception of the type IV, Peru11, and D genotypes, which were detected in only 7, 5, and 2 animals, respectively, most E. bieneusi strains in most wildlife samples and all stormwater samples in the watershed had no known public health significance, as these types have not previously been detected in humans. The role of different species of wild mammals in the contribution of E. bieneusi contamination in stormwater was supported by determinations of host-adapted Cryptosporidium species/genotypes in the same water samples. Data from this study indicate that the host specificity of E. bieneusi group 3 is broader than originally thought, and wildlife is the main source of E. bieneusi in stormwater in the watershed. PMID:24141128

Toxicity characterization of urban stormwater with bioanalytical tools.

PubMed

Tang, Janet Y M; Aryal, Rupak; Deletic, Ana; Gernjak, Wolfgang; Glenn, Eva; McCarthy, David; Escher, Beate I

2013-10-01

Stormwater harvesting has become an attractive alternative strategy to address the rising demand for urban water supply due to limited water sources and population growth. Nevertheless, urban stormwater is also a major source of surface water pollution. Runoff from different urban catchments with source contributions from anthropogenic activities and various land uses causes variable contaminant profiles, thus posing a challenging task for environmental monitoring and risk assessment. A thorough understanding of raw stormwater quality is essential to develop appropriate treatment facilities for potential indirect potable reuse of stormwater. While some of the key chemical components have previously been characterized, only scarce data are available on stormwater toxicity. We benchmarked stormwater samples from urban, residential and industrial sites across various Australian capital cities against samples from the entire water cycle, from sewage to drinking water. Six biological endpoints, targeting groups of chemicals with modes of toxic action of particular relevance for human and environmental health, were investigated: non-specific toxicity (Microtox and combined algae test), the specific modes of action of phytotoxicity (combined algae test), dioxin-like activity (AhR-CAFLUX), and estrogenicity (E-SCREEN), as well as reactive toxicity encompassing genotoxicity (umuC) and oxidative stress (AREc32). Non-specific toxicity was highly variable across sites. The baseline toxicity equivalent concentrations of the most polluted samples were similar to secondary treated effluent from wastewater treatment plants. Phytotoxicity results correlated well with the measured herbicide concentrations at all sites. High estrogenicity was found in two sampling events and could be related to sewage overflow. Genotoxicity, dioxin-like activity, and oxidative stress response were evident in only three of the samples where the stormwater drain was beside a heavy traffic road, confirming that road runoff is the potential source of contaminants, while the bioanalytical equivalent concentrations (BEQ) of these samples were similar to those of raw sewage. This study demonstrates the benefit of bioanalytical tools for screening-level stormwater quality assessment, forming the basis for the evaluation of future stormwater treatment and reuse schemes. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sources and occurrence of chloroform and other trihalomethanes in drinking-water supply wells in the United States, 1986-2001

USGS Publications Warehouse

Ivahnenko, Tamara; Zogorski, J.S.

2006-01-01

Chloroform and three other trihalomethanes (THMs)--bromodichloromethane, dibromochloromethane, and bromoform--are disinfection by-products commonly produced during the chlorination of water and wastewater. Samples of untreated ground water from drinking-water supply wells (1,096 public and 2,400 domestic wells) were analyzed for THMs and other volatile organic compounds (VOCs) during 1986-2001, or compiled, as part of the U.S. Geological Survey's National Water-Quality Assessment Program. This report provides a summary of potential sources of THMs and of the occurrence and geographical distribution of THMs in samples from public and domestic wells. Evidence for an anthropogenic source of THMs and implications for future research also are presented. Potential sources of THMs to both public and domestic wells include the discharge of chlorinated drinking water and wastewater that may be intentional or inadvertent. Intentional discharge includes the use of municipally supplied chlorinated water to irrigate lawns, golf courses, parks, gardens, and other areas; the use of septic systems; or the regulated discharge of chlorinated wastewater to surface waters or ground-water recharge facilities. Inadvertent discharge includes leakage of chlorinated water from swimming pools, spas, or distribution systems for drinking water or wastewater sewers. Statistical analyses indicate that population density, the percentage of urban land, and the number of Resource Conservation and Recovery Act hazardous-waste facilities near sampled wells are significantly associated with the probability of detection of chloroform, especially for public wells. Domestic wells may have several other sources of THMs, including the practice of well disinfection through shock chlorination, laundry wastewater containing bleach, and septic system effluent. Chloroform was the most frequently detected VOC in samples from drinking-water supply wells (public and domestic wells) in the United States. Although chloroform was detected frequently in samples from public and domestic wells and the other THMs were detected in some samples, no concentrations in samples from either well type exceeded the U.S. Environmental Protection Agency's Maximum Contaminant Level of 80 micrograms per liter for total THMs. Chloroform was detected in public well samples almost twice as frequently (11 percent) as in domestic well samples (5 percent). The other three THMs also were detected more frequently in public well samples than in domestic well samples. This detection pattern may be attributed to public wells having a higher pumping capacity than domestic wells. The higher capacity wells create a larger capture zone that potentially intercepts more urban and other land uses and associated point and nonpoint sources of contamination than the smaller capacity domestic wells. THM detection frequencies in domestic well samples show a pattern of decreasing frequency with increasing bromide content, that is in the order: chloroform > bromodichloromethane >= dibromochloromethane >= bromoform. This same pattern has been documented in studies of water chlorination, indicating that an important source of chloroform and other THMs in drinking-water supply wells may be the recycling of chlorinated water and wastewater. Mixtures of THMs commonly occur in public well samples, and the most frequently occurring are combinations of the brominated THMs. These THMs have limited industrial production, few natural sources, and small or no reported direct releases to the environment. Therefore, industrial, commercial, or natural sources are not likely sources of the brominated THMs in public and domestic well samples. The THM detection frequency pattern, the co-occurrence of brominated THMs, and other lines of evidence indicate that the recycling of water with a history of chlorination is an important source of these compounds in samples from drinking-water supply wells.

Health risk assessment of drinking arsenic-containing groundwater in Hasilpur, Pakistan: effect of sampling area, depth, and source.

PubMed

Tabassum, Riaz Ahmad; Shahid, Muhammad; Dumat, Camille; Niazi, Nabeel Khan; Khalid, Sana; Shah, Noor Samad; Imran, Muhammad; Khalid, Samina

2018-02-10

Currently, several news channels and research publications have highlighted the dilemma of arsenic (As)-contaminated groundwater in Pakistan. However, there is lack of data regarding groundwater As content of various areas in Pakistan. The present study evaluated As contamination and associated health risks in previously unexplored groundwater of Hasilpur-Pakistan. Total of 61 groundwater samples were collected from different areas (rural and urban), sources (electric pump, hand pump, and tubewell) and depths (35-430 ft or 11-131 m). The water samples were analyzed for As level and other parameters such as pH, electrical conductivity, total dissolved solids, cations, and anions. It was found that 41% (25 out of 61) water samples contained As (≥ 5 μg/L). Out of 25 As-contaminated water samples, 13 water samples exceeded the permissible level of WHO (10 μg/L). High As contents have been found in tubewell samples and at high sampling depths (> 300 ft). The major As-contaminated groundwater in Hasilpur is found in urban areas. Furthermore, health risk and cancer risk due to As contamination were also assessed with respect to average daily dose (ADD), hazard quotient (HQ), and carcinogenic risk (CR). The values of HQ and CR of As in Hasilpur were up to 58 and 0.00231, respectively. Multivariate analysis revealed a positive correlation between groundwater As contents, pH, and depth in Hasilpur. The current study proposed the proper monitoring and management of well water in Hasilpur to minimize the As-associated health hazards.

Completeness of Reporting of Patient-Relevant Clinical Trial Outcomes: Comparison of Unpublished Clinical Study Reports with Publicly Available Data

PubMed Central

Wieseler, Beate; Wolfram, Natalia; McGauran, Natalie; Kerekes, Michaela F.; Vervölgyi, Volker; Kohlepp, Petra; Kamphuis, Marloes; Grouven, Ulrich

2013-01-01

Background Access to unpublished clinical study reports (CSRs) is currently being discussed as a means to allow unbiased evaluation of clinical research. The Institute for Quality and Efficiency in Health Care (IQWiG) routinely requests CSRs from manufacturers for its drug assessments. Our objective was to determine the information gain from CSRs compared to publicly available sources (journal publications and registry reports) for patient-relevant outcomes included in IQWiG health technology assessments (HTAs) of drugs. Methods and Findings We used a sample of 101 trials with full CSRs received for 16 HTAs of drugs completed by IQWiG between 15 January 2006 and 14 February 2011, and analyzed the CSRs and the publicly available sources of these trials. For each document type we assessed the completeness of information on all patient-relevant outcomes included in the HTAs (benefit outcomes, e.g., mortality, symptoms, and health-related quality of life; harm outcomes, e.g., adverse events). We dichotomized the outcomes as “completely reported” or “incompletely reported.” For each document type, we calculated the proportion of outcomes with complete information per outcome category and overall. We analyzed 101 trials with CSRs; 86 had at least one publicly available source, 65 at least one journal publication, and 50 a registry report. The trials included 1,080 patient-relevant outcomes. The CSRs provided complete information on a considerably higher proportion of outcomes (86%) than the combined publicly available sources (39%). With the exception of health-related quality of life (57%), CSRs provided complete information on 78% to 100% of the various benefit outcomes (combined publicly available sources: 20% to 53%). CSRs also provided considerably more information on harms. The differences in completeness of information for patient-relevant outcomes between CSRs and journal publications or registry reports (or a combination of both) were statistically significant for all types of outcomes. The main limitation of our study is that our sample is not representative because only CSRs provided voluntarily by pharmaceutical companies upon request could be assessed. In addition, the sample covered only a limited number of therapeutic areas and was restricted to randomized controlled trials investigating drugs. Conclusions In contrast to CSRs, publicly available sources provide insufficient information on patient-relevant outcomes of clinical trials. CSRs should therefore be made publicly available. Please see later in the article for the Editors' Summary PMID:24115912

The influence of DNA degradation in formalin-fixed, paraffin-embedded (FFPE) tissue on locus-specific methylation assessment by MS-HRM.

PubMed

Daugaard, Iben; Kjeldsen, Tina E; Hager, Henrik; Hansen, Lise Lotte; Wojdacz, Tomasz K

2015-12-01

Readily accessible formalin-fixed paraffin embedded (FFPE) tissues are a highly valuable source of genetic material for molecular analyses in both research and in vitro diagnostics but frequently genetic material in those samples is highly degraded. With locus-specific methylation changes being widely investigated for use as biomarkers in various aspects of clinical disease management, we aimed to evaluate to what extent standard laboratory procedures can approximate the quality of the DNA extracted from FFPE samples prior to methylation analyses. DNA quality in 107 FFPE non-small cell lung cancer (NSCLC) samples was evaluated using spectrophotometry and gel electrophoresis. Subsequently, the quality assessment results were correlated with the results of locus specific methylation assessment with methylation sensitive high resolution melting (MS-HRM). The correlation of template quality with PCR amplification performance and HRM based methylation detection indicated a significant influence of DNA quality on PCR amplification but not on methylation assessment. In conclusion, standard laboratory procedures fairly well approximate DNA degradation of FFPE samples and DNA degradation does not seem to considerably affect locus-specific methylation assessment by MS-HRM. Copyright © 2015 Elsevier Inc. All rights reserved.

Heavy metals in soils of Hechuan County in the upper Yangtze (SW China): Comparative pollution assessment using multiple indices with high-spatial-resolution sampling.

PubMed

Ni, Maofei; Mao, Rong; Jia, Zhongmin; Dong, Ruozhu; Li, Siyue

2018-02-01

In order to assess heavy metals (HMs) in soils of the upper Yangtze Basin, a very high-spatial-resolution sampling (582 soil samples) was conducted from Hechuan County, an important agricultural practice area in the Southwest China. Multiple indices including geoaccumulation index (I geo ), enrichment factor (EF), sediment pollution index (SPI) and risk index (RI), as well as multivariate statistics were employed for pollution assessment and source identification of HMs in soils. Our results demonstrated that the averages of eight HMs decreased in the following order: Zn (82.8 ± 15.9) > Cr (71.6 ± 12.2) > Ni (32.1 ± 9.89) > Pb (27.6 ± 13.8) > Cu (25.9 ± 11.8) > As (5.48 ± 3.42) > Cd (0.30 ± 0.077) > Hg (0.082 ± 0.092). Averages of HMs except Cd were lower than threshold value of Environmental Quality Standard for Soils, while 43% of total samples had Cd concentration exceeding the national standard, 1% of samples for Hg and 5% samples for Ni, moreover, Cd and Hg averages were much higher than their background levels. I geo and EF indicated that their levels decreased as follows: Cd > Hg > Zn > Pb > Ni > Cu > Cr > As, with moderate enrichments of Cd and Hg. RI indicated that 61.7% of all samples showed moderate risk, while 6.5% of samples with greater than considerable risk due to human activities should be paid more attention. Multivariate analysis showed lithogenic source of Cu, Cr, Ni and Zn, while Cd and Hg were largely contributed by anthropogenic activities such as agricultural practices. Our study would be helpful for improving soil environmental quality in SW, China, as well as supplying modern approaches for other areas with soil HM pollution. Copyright © 2017 Elsevier Inc. All rights reserved.

AN ASSESSMENT OF DIOXIN LEVELS IN PROCESSED ...

EPA Pesticide Factsheets

The presence of dioxin-like compounds in ball clay was discovered in 1996 as a result of an investigation to determine the sources of elevated levels of dioxin found in two chicken fat samples from a national survey of poultry. The investigation indicated that soybean meal added to chicken feed was the source of dioxin contamination. Further investigation showed that the dioxin contamination came from the mixing of a natural clay known as

Assessment of heavy metal pollution in surface soils and plant material in the post-industrial city of Katowice, Poland.

PubMed

Steindor, Karolina A; Franiel, Izabella J; Bierza, Wojciech M; Pawlak, Beata; Palowski, Bernard F

2016-01-01

This investigation was undertaken to assess the level of environment pollution by biological monitoring. The leaves and bark of popular ornamental trees Acer pseudoplatanus L. and Acer platanoides L. and soil from the sampling sites were used to perform heavy metals pollution monitoring in urban areas with different pollution sources, as well to investigate the suitability of the leaves and bark as bioindicators of Pb, Zn, Cd and Cu pollution. Plant samples were collected at nine locations classified into three pollution groups based on metal content in the soils. The chosen pollution indices were used to assess the level of contamination according to background values. Soils in the Katowice area are found to be relatively heavily contaminated with Pb, Zn and Cd. Both of the maple tree species did not statistically differ in terms of the investigated elements' concentration in leaves or bark. Only bark samples reflected the pollution level, showing differences between the sampling points, and therefore are recommended for biomonitoring purposes.

Viable Legionella Pneumophila Not Detectable by Culture on Agar Media

DTIC Science & Technology

1987-09-01

iom’microorganisms released to the enirnmet becomesa primary factors in risk assessment. Cul- prime consideration in risk assessment. The ability to ture methods have...detection of microorganisms in the not always be culturable. We surveyed environment. In this sense, LegioneIla pnesanopliila, the environmental ...samples collected from agent of Legionnaires’ pneumonia and related illnesses, poses a microbiological dilemma for environmental morn- * sources

Locating People Diagnosed With HIV for Public Health Action: Utility of HIV Case Surveillance and Other Data Sources.

PubMed

Padilla, Mabel; Mattson, Christine L; Scheer, Susan; Udeagu, Chi-Chi N; Buskin, Susan E; Hughes, Alison J; Jaenicke, Thomas; Wohl, Amy Rock; Prejean, Joseph; Wei, Stanley C

Human immunodeficiency virus (HIV) case surveillance and other health care databases are increasingly being used for public health action, which has the potential to optimize the health outcomes of people living with HIV (PLWH). However, often PLWH cannot be located based on the contact information available in these data sources. We assessed the accuracy of contact information for PLWH in HIV case surveillance and additional data sources and whether time since diagnosis was associated with accurate contact information in HIV case surveillance and successful contact. The Case Surveillance-Based Sampling (CSBS) project was a pilot HIV surveillance system that selected a random population-based sample of people diagnosed with HIV from HIV case surveillance registries in 5 state and metropolitan areas. From November 2012 through June 2014, CSBS staff members attempted to locate and interview 1800 sampled people and used 22 data sources to search for contact information. Among 1063 contacted PLWH, HIV case surveillance data provided accurate telephone number, address, or HIV care facility information for 239 (22%), 412 (39%), and 827 (78%) sampled people, respectively. CSBS staff members used additional data sources, such as support services and commercial people-search databases, to locate and contact PLWH with insufficient contact information in HIV case surveillance. PLWH diagnosed <1 year ago were more likely to have accurate contact information in HIV case surveillance than were PLWH diagnosed ≥1 year ago ( P = .002), and the benefit from using additional data sources was greater for PLWH with more longstanding HIV infection ( P < .001). When HIV case surveillance cannot provide accurate contact information, health departments can prioritize searching additional data sources, especially for people with more longstanding HIV infection.

Source apportionment and health risk assessment of potentially toxic elements in road dust from urban industrial areas of Ahvaz megacity, Iran.

PubMed

Najmeddin, Ali; Keshavarzi, Behnam; Moore, Farid; Lahijanzadeh, Ahmadreza

2017-10-28

This study investigates the occurrence and spatial distribution of potentially toxic elements (PTEs) (Hg, Cd, Cu, Mo, Pb, Zn, Ni, Co, Cr, Al, Fe, Mn, V and Sb) in 67 road dust samples collected from urban industrial areas in Ahvaz megacity, southwest of Iran. Geochemical methods, multivariate statistics, geostatistics and health risk assessment model were adopted to study the spatial pollution pattern and to identify the priority pollutants, regions of concern and sources of the studied PTEs. Also, receptor positive matrix factorization model was employed to assess pollution sources. Compared to the local background, the median enrichment factor values revealed the following order: Sb > Pb > Hg > Zn > Cu > V > Fe > Mo > Cd > Mn > Cr ≈ Co ≈ Al ≈ Ni. Statistical results show that a significant difference exists between concentrations of Mo, Cu, Pb, Zn, Fe, Sb, V and Hg in different regions (univariate analysis, Kruskal-Wallis test p < 0.05), indicating the existence of highly contaminated spots. Integrated source identification coupled with positive matrix factorization model revealed that traffic-related emissions (43.5%) and steel industries (26.4%) were first two sources of PTEs in road dust, followed by natural sources (22.6%) and pipe and oil processing companies (7.5%). The arithmetic mean of pollution load index (PLI) values for high traffic sector (1.92) is greater than industrial (1.80) and residential areas (1.25). Also, the results show that ecological risk values for Hg and Pb in 41.8 and 9% of total dust samples are higher than 80, indicating their considerable or higher potential ecological risk. The health risk assessment model showed that ingestion of dust particles contributed more than 83% of the overall non-carcinogenic risk. For both residential and industrial scenarios, Hg and Pb had the highest risk values, whereas Mo has the lowest value.

Brief assessment of cognition in schizophrenia: normative data in an English-speaking ethnic Chinese sample.

PubMed

Eng, Goi Khia; Lam, Max; Bong, Yioe Ling; Subramaniam, Mythily; Bautista, Dianne; Rapisarda, Attilio; Kraus, Michael; Lee, Jimmy; Collinson, Simon Lowes; Chong, Siow Ann; Keefe, Richard S E

2013-12-01

There is a dearth of non-Western normative data for neuropsychological batteries designed to measure cognitive deficits in schizophrenia. Here, we provide normative data for English-speaking ethnic Chinese on the widely used Brief Assessment of Cognition in Schizophrenia acquired from 595 healthy community participants between ages 14 and 55. Means and standard deviations of subtests and composite scores were stratified by age group and sex. We also explored linear regression approaches to generate continuous norms adjusted for age, sex, and education. Notable differences in subtest performances were found against a Western comparison sample. Normative data established in the current sample are essential for clinical and research purposes as it serves as a reference source of cognition for ethnic Chinese.

The assessment of data sources for influenza virologic surveillance in New York State.

PubMed

Escuyer, Kay L; Waters, Christine L; Gowie, Donna L; Maxted, Angie M; Farrell, Gregory M; Fuschino, Meghan E; St George, Kirsten

2017-03-01

Following the 2013 USA release of the Influenza Virologic Surveillance Right Size Roadmap, the New York State Department of Health (NYSDOH) embarked on an evaluation of data sources for influenza virologic surveillance. To assess NYS data sources, additional to data generated by the state public health laboratory (PHL), which could enhance influenza surveillance at the state and national level. Potential sources of laboratory test data for influenza were analyzed for quantity and quality. Computer models, designed to assess sample sizes and the confidence of data for statistical representation of influenza activity, were used to compare PHL test data to results from clinical and commercial laboratories, reported between June 8, 2013 and May 31, 2014. Sample sizes tested for influenza at the state PHL were sufficient for situational awareness surveillance with optimal confidence levels, only during peak weeks of the influenza season. Influenza data pooled from NYS PHLs and clinical laboratories generated optimal confidence levels for situational awareness throughout the influenza season. For novel influenza virus detection in NYS, combined real-time (rt) RT-PCR data from state and regional PHLs achieved ≥85% confidence during peak influenza activity, and ≥95% confidence for most of low season and all of off-season. In NYS, combined data from clinical, commercial, and public health laboratories generated optimal influenza surveillance for situational awareness throughout the season. Statistical confidence for novel virus detection, which is reliant on only PHL data, was achieved for most of the year. © 2016 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

Evaluation of volatile organic compound (VOC) blank data and application of study reporting levels to groundwater data collected for the California GAMA Priority Basin Project, May 2004 through September 2010

USGS Publications Warehouse

Fram, Miranda S.; Olsen, Lisa D.; Belitz, Kenneth

2012-01-01

Volatile organic compounds (VOCs) were analyzed in quality-control samples collected for the California Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project. From May 2004 through September 2010, a total of 2,026 groundwater samples, 211 field blanks, and 109 source-solution blanks were collected and analyzed for concentrations of 85 VOCs. Results from analyses of these field and source-solution blanks and of 2,411 laboratory instrument blanks during the same time period were used to assess the quality of data for the 2,026 groundwater samples. Eighteen VOCs were detected in field blanks or source-solution blanks: acetone, benzene, bromodichloromethane, 2-butanone, carbon disulfide, chloroform, 1,1-dichloroethene, dichloromethane, ethylbenzene, tetrachloroethene, styrene, tetrahydrofuran, toluene, trichloroethene, trichlorofluoromethane, 1,2,4-trimethylbenzene, m- and p-xylenes, and o-xylene. The objective of the evaluation of the VOC-blank data was to determine if study reporting levels (SRLs) were needed for any of the VOCs detected in blanks to ensure the quality of the data from groundwater samples. An SRL is equivalent to a raised reporting level that is used in place of the reporting level used by the analyzing laboratory [long‑term method detection level (LT-MDL) or laboratory reporting level (LRL)] to reduce the probability of reporting false-positive detections. Evaluation of VOC-blank data was done in three stages: (1) identification of a set of representative quality‑control field blanks (QCFBs) to be used for calculation of SRLs and identification of VOCs amenable to the SRL approach, (2) evaluation of potential sources of contamination to blanks and groundwater samples by VOCs detected in field blanks, and (3) selection of appropriate SRLs from among four potential SRLs for VOCs detected in field blanks and application of those SRLs to the groundwater data. An important conclusion from this study is that to ensure the quality of the data from groundwater samples, it was necessary to apply different methods of determining SRLs from field blank data to different VOCs, rather than use the same method for all VOCs. Four potential SRL values were defined by using three approaches: two values were defined by using a binomial probability method based on one-sided, nonparametric upper confidence limits, one was defined as equal to the maximum concentration detected in the field blanks, and one was defined as equal to the maximum laboratory method detection level used during the period when samples were collected for the project. The differences in detection frequencies and concentrations among different types of blanks (laboratory instrument blanks, source-solution blanks, and field blanks collected with three different sampling equipment configurations) and groundwater samples were used to infer the sources and mechanisms of contamination for each VOC detection in field blanks. Other chemical data for the groundwater samples (oxidation-reduction state, co-occurrence of VOCs, groundwater age) and ancillary information about the well sites (land use, presence of known sources of contamination) were used to evaluate whether the patterns of detections of VOCs in groundwater samples before and after application of potential SRLs were plausible. On this basis, the appropriate SRL was selected for each VOC that was determined to require an SRL. The SRLs for ethylbenzene [0.06 microgram per liter (μg/L)], m- and p-xylenes (0.33 μg/L), o-xylene (0.12 μg/L), toluene (0.69 μg/L), and 1,2,4-trimethylbenzene (0.56 μg/L) corresponded to the highest concentrations detected in the QCFBs and were selected because they resulted in the most censoring of groundwater data. Comparisons of hydrocarbon ratios in groundwater samples and blanks and comparisons between detection frequencies of the five hydrocarbons in groundwater samples and different types of blanks suggested three dominant sources of contamination that affected groundwater samples and blanks: (1) ethylbenzene, m- and p-xylenes, o-xylene, and toluene from fuel or exhaust components sorbed onto sampling lines, (2) toluene from vials and the source blank water, and (3) 1,2,4-trimethylbenzene from materials used for collection of samples for radon-222 analysis.

Micronutrient Intake among Children in Puerto Rico: Dietary and Multivitamin-Multimineral Supplement Sources.

PubMed

Lopez-Cepero, Andrea; Torres, Roxana; Elias, Augusto; Rosal, Milagros C; Palacios, Cristina

2015-12-01

Micronutrients are critical for healthy growth and development of children. Micronutrient intake from dietary sources is inadequate among some children and may be improved by use of multivitamin and multimineral (MVMM) supplements. To assess micronutrient intake from dietary and MVMM supplement sources among 12-year-old children in Puerto Rico. A representative sample of 732 children enrolled in an oral health study in Puerto Rico, who completed dietary and MVMM assessments through one 24-h recall, were included in this analysis. Micronutrient intake sources were described and compared to the Dietary Reference Intakes (DRIs) using the Estimated Average Requirement when available (used Adequate Intake for vitamin K and pantothenic acid). Micronutrient profiles of MVMM users and non-users were compared using t-tests. Mean intakes of vitamins A, D, E, and K, pantothenic acid, calcium, and magnesium from food and beverage sources were below the DRIs. From food and beverage sources, MVMM users had higher intakes of riboflavin and folate compared to non-users (p < 0.05). When MVMM supplements were taken into account, users had higher intakes of all nutrients except vitamin K. With the help of MVMM, users increased intake of vitamins E, A, D, and pantothenic acid to IOM-recommended levels but calcium, magnesium, and vitamin K remained below guidelines. Micronutrient intake from diet was below the IOM-recommended levels in the total sample. MVMM use improved intake of selected micronutrients and facilitated meeting recommendations for some nutrients. Public health measures to improve micronutrient intake among children in Puerto Rico are needed.

Fecal Contamination of Drinking-Water in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis

PubMed Central

Bain, Robert; Cronk, Ryan; Wright, Jim; Yang, Hong; Slaymaker, Tom; Bartram, Jamie

2014-01-01

Background Access to safe drinking-water is a fundamental requirement for good health and is also a human right. Global access to safe drinking-water is monitored by WHO and UNICEF using as an indicator “use of an improved source,” which does not account for water quality measurements. Our objectives were to determine whether water from “improved” sources is less likely to contain fecal contamination than “unimproved” sources and to assess the extent to which contamination varies by source type and setting. Methods and Findings Studies in Chinese, English, French, Portuguese, and Spanish were identified from online databases, including PubMed and Web of Science, and grey literature. Studies in low- and middle-income countries published between 1990 and August 2013 that assessed drinking-water for the presence of Escherichia coli or thermotolerant coliforms (TTC) were included provided they associated results with a particular source type. In total 319 studies were included, reporting on 96,737 water samples. The odds of contamination within a given study were considerably lower for “improved” sources than “unimproved” sources (odds ratio [OR] = 0.15 [0.10–0.21], I2 = 80.3% [72.9–85.6]). However over a quarter of samples from improved sources contained fecal contamination in 38% of 191 studies. Water sources in low-income countries (OR = 2.37 [1.52–3.71]; p<0.001) and rural areas (OR = 2.37 [1.47–3.81] p<0.001) were more likely to be contaminated. Studies rarely reported stored water quality or sanitary risks and few achieved robust random selection. Safety may be overestimated due to infrequent water sampling and deterioration in quality prior to consumption. Conclusion Access to an “improved source” provides a measure of sanitary protection but does not ensure water is free of fecal contamination nor is it consistent between source types or settings. International estimates therefore greatly overstate use of safe drinking-water and do not fully reflect disparities in access. An enhanced monitoring strategy would combine indicators of sanitary protection with measures of water quality. Please see later in the article for the Editors' Summary PMID:24800926

Assessment of Chlamydia psittaci Shedding and Environmental Contamination as Potential Sources of Worker Exposure throughout the Mule Duck Breeding Process

PubMed Central

Hulin, V.; Bernard, P.; Vorimore, F.; Aaziz, R.; Cléva, D.; Robineau, J.; Durand, B.; Angelis, L.

2015-01-01

Chlamydia psittaci is an obligate intracellular bacterium responsible for avian chlamydiosis, otherwise known as psittacosis, a zoonotic disease that may lead to severe atypical pneumonia. This study was conducted on seven mule duck flocks harboring asymptomatic birds to explore the circulation and persistence of C. psittaci during the entire breeding process and assess the potential sources of worker exposure. Cloacal swabs and air samples were taken on each occasion requiring humans to handle the birds. In parallel, environmental samples, including dust, water, and soil, were collected. Specific real-time PCR analyses revealed the presence of C. psittaci in all flocks but with three different shedding patterns involving ducks about the age of 4, 8, and 12 weeks with heavy, moderate, and low excretion levels, respectively. Air samples were only positive in flocks harboring heavy shedders. Dust in flocks with heavy or moderate shedders carried chlamydial loads strongly associated with the loads detected in avian and soil samples. Environmental contamination, significantly correlated with shedding dynamics, was considered to be the most probable source of exposure. The high prevalence of bacteriophage Chp1 in all flocks, mostly jointly present with chlamydia, suggests an important factor in C. psittaci persistence, thus creating a greater risk for humans. A survey conducted in these flocks regarding farming practices and activities showed that disinfection seems to be the most promising practice for reducing C. psittaci prevalence in ducks and that the place and the duration of action during operations seem to be potential risk factors. Strict adherence to good practices is strongly recommended. PMID:26712548

Assessing the microbiological performance and potential cost of boiling drinking water in urban Zambia.

PubMed

Psutka, Rebecca; Peletz, Rachel; Michelo, Sandford; Kelly, Paul; Clasen, Thomas

2011-07-15

Boiling is the most common method of disinfecting water in the home and the benchmark against which other point-of-use water treatment is measured. In a six-week study in peri-urban Zambia, we assessed the microbiological effectiveness and potential cost of boiling among 49 households without a water connection who reported "always" or "almost always" boiling their water before drinking it. Source and household drinking water samples were compared weekly for thermotolerant coliforms (TTC), an indicator of fecal contamination. Demographics, costs, and other information were collected through surveys and structured observations. Drinking water samples taken at the household (geometric mean 7.2 TTC/100 mL, 95% CI, 5.4-9.7) were actually worse in microbiological quality than source water (geometric mean 4.0 TTC/100 mL, 95% CI, 3.1-5.1) (p < 0.001), although both are relatively low levels of contamination. Only 60% of drinking water samples were reported to have actually been boiled at the time of collection from the home, suggesting over-reporting and inconsistent compliance. However, these samples were of no higher microbiological quality. Evidence suggests that water quality deteriorated after boiling due to lack of residual protection and unsafe storage and handling. The potential cost of fuel or electricity for boiling was estimated at 5% and 7% of income, respectively. In this setting where microbiological water quality was relatively good at the source, safe-storage practices that minimize recontamination may be more effective in managing the risk of disease from drinking water at a fraction of the cost of boiling.

(I Can’t Get No) Saturation: A simulation and guidelines for sample sizes in qualitative research

PubMed Central

2017-01-01

I explore the sample size in qualitative research that is required to reach theoretical saturation. I conceptualize a population as consisting of sub-populations that contain different types of information sources that hold a number of codes. Theoretical saturation is reached after all the codes in the population have been observed once in the sample. I delineate three different scenarios to sample information sources: “random chance,” which is based on probability sampling, “minimal information,” which yields at least one new code per sampling step, and “maximum information,” which yields the largest number of new codes per sampling step. Next, I use simulations to assess the minimum sample size for each scenario for systematically varying hypothetical populations. I show that theoretical saturation is more dependent on the mean probability of observing codes than on the number of codes in a population. Moreover, the minimal and maximal information scenarios are significantly more efficient than random chance, but yield fewer repetitions per code to validate the findings. I formulate guidelines for purposive sampling and recommend that researchers follow a minimum information scenario. PMID:28746358

Historical trends in occurrence and atmospheric inputs of halogenated volatile organic compounds in untreated ground water used as a source of drinking water

USGS Publications Warehouse

Shapiro, S.D.; Busenberg, E.; Focazio, M.J.; Plummer, Niel

2004-01-01

Analyses of samples of untreated ground water from 413 community-, non-community- (such as restaurants), and domestic-supply wells throughout the US were used to determine the frequency of detection of halogenated volatile organic compounds (VOCs) in drinking-water sources. The VOC data were compiled from archived chromatograms of samples analyzed originally for chlorofluorocarbons (CFCs) by purge-and-trap gas chromatography with an electron-capture detector (GC-ECD). Concentrations of the VOCs could not be ascertained because standards were not routinely analyzed for VOCs other than trichloromonofluoromethane (CFC-11), dichlorodifluoromethane (CFC-12) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113). Nevertheless, the peak areas associated with the elution times of other VOCs on the chromatograms can be classified qualitatively to assess concentrations at a detection limit on the order of parts per quadrillion. Three or more VOCs were detected in 100% (percent) of the chromatograms, and 77.2% of the samples contained 10 or more VOCs. The maximum number of VOCs detected in any sample was 24. Modeled ground-water residence times, determined from concentrations of CFC-12, were used to assess historical trends in the cumulative occurrence of all VOCs detected in this analysis, as well as the occurrence of individual VOCs, such as CFC-11, carbon tetrachloride (CCl4), chloroform and tetrachloroethene (PCE). The detection frequency for all of the VOCs detected has remained relatively constant from approximately 1940 to 2000; however, the magnitude of the peak areas on the chromatograms for the VOCs in the water samples has increased from 1940 to 2000. For CFC-11, CCl4, chloroform and PCE, small peaks decrease from 1940 to 2000, and large peaks increase from 1940 to 2000. The increase in peak areas on the chromatograms from analyses of more recently recharged water is consistent with reported increases in atmospheric concentrations of the VOCs. Approximately 44% and 6.7% of the CCl4 and PCE detections, respectively, in pre-1940 water, and 68% and 62% of the CCl4 and PCE detections, respectively, in water recharged in 2000 exceed solubility equilibrium with average atmospheric concentrations. These exceedences can be attributed to local atmospheric enrichment or direct contaminant input to ground-water flow systems. The detection of VOCs at concentrations indicative of atmospheric sources in 100% of the samples indicates that untreated drinking water from ground-water sources in the US recharged within the past 60 years has been affected by anthropogenic activity. Additional inputs from a variety of sources such as spills, underground injections and leaking landfills or storage tanks increasingly are providing additional sources of contamination to ground water used as drinking-water sources. ?? 2003 Elsevier B.V. All rights reserved.

A BASIS FOR MODIFYING THE TANK 12 COMPOSITE SAMPLING DESIGN

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

Shine, G.

The SRR sampling campaign to obtain residual solids material from the Savannah River Site (SRS) Tank Farm Tank 12 primary vessel resulted in obtaining appreciable material in all 6 planned source samples from the mound strata but only in 5 of the 6 planned source samples from the floor stratum. Consequently, the design of the compositing scheme presented in the Tank 12 Sampling and Analysis Plan, Pavletich (2014a), must be revised. Analytical Development of SRNL statistically evaluated the sampling uncertainty associated with using various compositing arrays and splitting one or more samples for compositing. The variance of the simple meanmore » of composite sample concentrations is a reasonable standard to investigate the impact of the following sampling options. Composite Sample Design Option (a). Assign only 1 source sample from the floor stratum and 1 source sample from each of the mound strata to each of the composite samples. Each source sample contributes material to only 1 composite sample. Two source samples from the floor stratum would not be used. Composite Sample Design Option (b). Assign 2 source samples from the floor stratum and 1 source sample from each of the mound strata to each composite sample. This infers that one source sample from the floor must be used twice, with 2 composite samples sharing material from this particular source sample. All five source samples from the floor would be used. Composite Sample Design Option (c). Assign 3 source samples from the floor stratum and 1 source sample from each of the mound strata to each composite sample. This infers that several of the source samples from the floor stratum must be assigned to more than one composite sample. All 5 source samples from the floor would be used. Using fewer than 12 source samples will increase the sampling variability over that of the Basic Composite Sample Design, Pavletich (2013). Considering the impact to the variance of the simple mean of the composite sample concentrations, the recommendation is to construct each sample composite using four or five source samples. Although the variance using 5 source samples per composite sample (Composite Sample Design Option (c)) was slightly less than the variance using 4 source samples per composite sample (Composite Sample Design Option (b)), there is no practical difference between those variances. This does not consider that the measurement error variance, which is the same for all composite sample design options considered in this report, will further dilute any differences. Composite Sample Design Option (a) had the largest variance for the mean concentration in the three composite samples and should be avoided. These results are consistent with Pavletich (2014b) which utilizes a low elevation and a high elevation mound source sample and two floor source samples for each composite sample. Utilizing the four source samples per composite design, Pavletich (2014b) utilizes aliquots of Floor Sample 4 for two composite samples.« less

Multivariate analysis and geochemical approach for assessment of metal pollution state in sediment cores.

PubMed

Jamshidi-Zanjani, Ahmad; Saeedi, Mohsen

2017-07-01

Vertical distribution of metals (Cu, Zn, Cr, Fe, Mn, Pb, Ni, Cd, and Li) in four sediment core samples (C 1 , C 2 , C 3 , and C 4 ) from Anzali international wetland located southwest of the Caspian Sea was examined. Background concentration of each metal was calculated according to different statistical approaches. The results of multivariate statistical analysis showed that Fe and Mn might have significant role in the fate of Ni and Zn in sediment core samples. Different sediment quality indexes were utilized to assess metal pollution in sediment cores. Moreover, a new sediment quality index named aggregative toxicity index (ATI) based on sediment quality guidelines (SQGs) was developed to assess the degree of metal toxicity in an aggregative manner. The increasing pattern of metal pollution and their toxicity degree in upper layers of core samples indicated increasing effects of anthropogenic sources in the study area.

Sources and preparation of data for assessing trends in concentrations of pesticides in streams of the United States, 1992-2006

USGS Publications Warehouse

Martin, Jeffrey D.

2009-01-01

This report provides a water-quality data set of 44 commonly used pesticides and 8 pesticide degradates suitable for a national assessment of trends in pesticide concentrations in streams of the United States. Water-quality samples collected from January 1992 through August 2006 at stream-water sites of the U.S. Geological Survey National Water-Quality Assessment Program and the National Stream Quality Accounting Network Program were compiled, reviewed, selected, and prepared for trend analysis as described in this report. Samples analyzed at the U.S. Geological Survey National Water Quality Laboratory by a gas chromatography/mass spectrometry analytical method were the most extensive in time and space and were selected for national trend analysis. The selection criteria described in the report produced a trend data set of 16,869 pesticide samples at 201 stream and river sites.

Factors associated with sources, transport, and fate of volatile organic compounds and their mixtures in aquifers of the United States

USGS Publications Warehouse

Squillace, P.J.; Moran, M.J.

2007-01-01

Factors associated with sources, transport, and fate of volatile organic compounds (VOCs) in groundwater from aquifers throughout the United States were evaluated using statistical methods. Samples were collected from 1631 wells throughout the conterminous United States between 1996 and 2002 as part of the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey. Water samples from wells completed in aquifers used to supply drinking water were analyzed for more than 50 VOCs. Wells were primarily rural domestic water supplies (1184), followed by public water supplies (216); the remaining wells (231) supplied a variety of uses. The median well depth was 50 meters. Age-date information shows that about 60% of the samples had a fraction of water recharged after 1953. Chloroform, toluene, 1,2,4-trimethylbenzene, and perchloroethene were some of the frequently detected VOCs. Concentrations generally were less than 1 ??g/L. Source factors include, in order of importance, general land-use activity, septic/sewer density, and sites where large concentrations of VOCs are potentially released, such as leaking underground storage tanks. About 10% of all samples had VOC mixtures that were associated with concentrated sources; 20% were associated with dispersed sources. Important transport factors included well/screen depth, precipitation/groundwater recharge, air temperature, and various soil characteristics. Dissolved oxygen was strongly associated with VOCs and represents the fate of many VOCs in groundwater. Well type (domestic or public water supply) was also an important explanatory factor. Results of multiple analyses show the importance of (1) accounting for both dispersed and concentrated sources of VOCs, (2) measuring dissolved oxygen when sampling wells to help explain the fate of VOCs, and (3) limiting the type of wells sampled in monitoring networks to avoid unnecessary variance in the data, or controlling for this variance during data analysis.

Assessment of physico-chemical quality of borehole and spring water sources supplied to Robe Town, Oromia region, Ethiopia

NASA Astrophysics Data System (ADS)

Shigut, Dagim Abera; Liknew, Geremew; Irge, Dejene Disasa; Ahmad, Tanweer

2017-03-01

The study was carried out to find the physico-chemical water quality of borehole and spring water supplied to Robe Town. For this study, a total of six water samples were collected from three borehole and three spring water sources. The analyses for 14 physico-chemical parameters, pH, turbidity, electrical conductivity, total dissolved solids, total suspended solids total hardness cations (Ca2+, Mg2+), anions (NO2 -, NO3 -, SO4 2- and PO4 3-) and heavy metals (Fe and Mn), were done in the laboratory by adopting standard procedures suggested by the American Public Health Association (APHA). Descriptive statistics were used to describe data, while Pearson correlation was used to determine the influences of the physico-chemical variables. The single factor analysis of variance ( t test) was used to determine possible differences between the borehole and spring water, while means plots were used for further structure detection. From the total samples analyzed, most of the samples comply with the water quality guidelines of Ethiopian limit, WHO and U.SEPA. The pH of the water samples from borehole groundwater source was found to be slightly acidic and bove the maximum permissible limit (MPL). High concentration of Fe and Mn that exceeds the MPL set by WHO was found in the three boreholes. The spring water sources were found to be better for drinking than borehole water sources.

Assessment of water quality index of bore well water samples from some selected locations of South Gujarat, India.

PubMed

Tripathi, S; Patel, H M; Srivastava, P K; Bafna, A M

2013-10-01

The present study calculates the water quality index (WQI) of some selected sites from South Gujarat (India) and assesses the impact of industries, agriculture and human activities. Chemical parameters were monitored for the calculation of WQI of some selected bore well samples. The results revealed that the WQI of the some bore well samples exceeded acceptable levels due to the dumping of wastes from municipal, industrial and domestic sources and agricultural runoff as well. Inverse Distance Weighting (IDW) was implemented for interpolation of each water quality parameter (pH, EC, alkalinity, total hardness, chloride, nitrate and sulphate) for the entire sampled area. The bore water is unsuitable for drinking and if the present state of affairs continues for long, it may soon become an ecologically dead bore.

Wikipedia as an evidence source for nursing and healthcare students.

PubMed

Haigh, Carol A

2011-02-01

Where students once were confined to the University library, they are now at liberty to wander through cyber-space at will. There is evidence to suggest that student have been very quick to exploit the opportunities that the Internet can offer them. Students frequently cited search engines such as Google and Web 2.0 information sharing sites such as Wikipedia as the first places they look when seeking information for an assignment. Although a number of disciplines have accepted that Wikipedia can be viewed as an accurate and legitimate evidence source nurse educators tend to view Wikipedia with a degree of suspicion. The purpose of this paper is to carry out an exploratory study of health and health related content on a sample of Wikipedia site with the overall intention of assessing the quality of their source and supporting information. A 10% sample of health related Wikipedia entries were evaluated, with a total of 2598 references assessed. In total 1473 (56%) of the references citied on the Wikipedia pages reviewed could be argued to come from clearly identifiable reputable sources. This translates to a mean number of reputable sources of M=29 per Wikipedia entry. The quality of the evidence taken obtained from the 2500 plus references from over 50 Wikipedia pages was of sufficiently sound quality to suggest that, for health related entries, Wikipedia is appropriate for use by nursing students. Copyright © 2010 Elsevier Ltd. All rights reserved.

ADHD knowledge, perceptions, and information sources: perspectives from a community sample of adolescents and their parents.

PubMed

Bussing, Regina; Zima, Bonnie T; Mason, Dana M; Meyer, Johanna M; White, Kimberly; Garvan, Cynthia W

2012-12-01

The chronic illness model advocates for psychoeducation within a collaborative care model to enhance outcomes. To inform psychoeducational approaches for ADHD, this study describes parent and adolescent knowledge, perceptions, and information sources and explores how these vary by sociodemographic characteristics, ADHD risk, and past child mental health service use. Parents and adolescents were assessed 7.7 years after initial school district screening for ADHD risk. The study sample included 374 adolescents (56% high and 44% low ADHD risk) aged, on average, 15.4 (standard deviation = 1.8) years, and 36% were African American. Survey questions assessed ADHD knowledge, perceptions, and cues to action and elicited used and preferred information sources. Multiple logistic regression was used to determine potential independent predictors of ADHD knowledge. McNemar tests compared information source utilization against preference. Despite relatively high self-rated ADHD familiarity, misperceptions among parents and adolescents were common, including a sugar etiology (25% and 27%, respectively) and medication overuse (85% and 67%, respectively). African American respondents expressed less ADHD awareness and greater belief in sugar etiology than Caucasians. Parents used a wide range of ADHD information sources, whereas adolescents relied on social network members and teachers/school. However, parents and adolescents expressed similar strong preferences for the Internet (49% and 51%, respectively) and doctor (40% and 27%, respectively) as ADHD information sources. Culturally appropriate psychoeducational strategies are needed that combine doctor-provided ADHD information with reputable Internet sources. Despite time limitations during patient visits, both parents and teens place high priority on receiving information from their doctor. Copyright © 2012 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Assessment of In Situ Time Resolved Shock Experiments at Synchrotron Light Sources*

NASA Astrophysics Data System (ADS)

Belak, J.; Ilavsky, J.; Hessler, J. P.

2005-07-01

Prior to fielding in situ time resolved experiments of shock wave loading at the Advanced Photon Source, we have performed feasibility experiments assessing a single photon bunch. Using single and poly-crystal Al, Ti, V and Cu shock to incipient spallation on the gas gun, samples were prepared from slices normal to the spall plane of thickness 100-500 microns. In addition, single crystal Al of thickness 500 microns was shocked to incipient spallation and soft recovered using the LLNL e-gun mini-flyer system. The e-gun mini-flyer impacts the sample target producing a 10's ns flat-top shock transient. Here, we present results for imaging, small-angle scattering (SAS), and diffraction. In particular, there is little SAS away from the spall plane and significant SAS at the spall plane, demonstrating the presence of sub-micron voids. * Use of the Advanced Photon Source was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. W-31-109-Eng-38 and work performed under the auspices of the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory under Contract W-7405-Eng-48.

Trace elements and common ions in southeastern Idaho snow: Regional air pollutant tracers for source area emissions

USGS Publications Warehouse

Abbott, M.; Einerson, J.; Schuster, P.; Susong, D.; Taylor, Howard E.; ,

2004-01-01

Snow sampling and analysis methods which produce accurate and ultra-low measurements of trace elements and common ion concentration in southeastern Idaho snow, were developed. Snow samples were collected over two winters to assess trace elements and common ion concentrations in air pollutant fallout across the southeastern Idaho. The area apportionment of apportionment of fallout concentrations measured at downwind location were investigated using pattern recognition and multivariate statistical technical techniques. Results show a high level of contribution from phosphates processing facilities located outside Pocatello in the southern portion of the Eastern Snake River Plain, and no obvious source area profiles other than at Pocatello.

Water-quality assessment of the largely urban blue river basin, Metropolitan Kansas City, USA, 1998 to 2007

USGS Publications Warehouse

Wilkison, D.H.; Armstrong, D.J.; Hampton, S.A.

2009-01-01

From 1998 through 2007, over 750 surface-water or bed-sediment samples in the Blue River Basin - a largely urban basin in metropolitan Kansas City - were analyzed for more than 100 anthropogenic compounds. Compounds analyzed included nutrients, fecal-indicator bacteria, suspended sediment, pharmaceuticals and personal care products. Non-point source runoff, hydrologic alterations, and numerous waste-water discharge points resulted in the routine detection of complex mixtures of anthropogenic compounds in samples from basin stream sites. Temporal and spatial variations in concentrations and loads of nutrients, pharmaceuticals, and organic wastewater compounds were observed, primarily related to a site's proximity to point-source discharges and stream-flow dynamics. ?? 2009 ASCE.

Concentration, composition and sources of PAHs in the coastal sediments of the exclusive economic zone (EEZ) of Qatar, Arabian Gulf.

PubMed

Soliman, Y S; Al Ansari, E M S; Wade, T L

2014-08-30

Surface sediments were collected from sixteen locations in order to assess levels and sources of polycyclic aromatic hydrocarbons (PAHs) in sediments of Qatar exclusive economic zone (EEZ). Samples were analyzed for 16 parent PAHs, 18 alkyl homologs and for dibenzothiophenes. Total PAHs concentration (∑PAHs) ranged from 2.6 ng g(-1) to 1025 ng g(-1). The highest PAHs concentrations were in sediments in and adjacent to harbors. Alkylated PAHs predominated most of the sampling locations reaching up to 80% in offshore locations. Parent PAHs and parent high molecular weight PAHs dominated location adjacent to industrial activities and urban areas. The origin of PAHs sources to the sediments was elucidated using ternary plot, indices, and molecular ratios of specific compounds such as (Ant/Phe+Ant), (Flt/Flt+Pyr). PAHs inputs to most coastal sites consisted of mixture of petroleum and combustion derived sources. However, inputs to the offshore sediments were mainly of petroleum origin. Copyright © 2014 Elsevier Ltd. All rights reserved.

Identifying potential sources of Sudan I contamination in Capsicum fruits over its growth period.

PubMed

Wu, Naiying; Gao, Wei; Zhou, Li; Lian, Yunhe; Li, Fengfei; Han, Wenjie

2015-04-15

Sudan dyes in spices are often assumed to arise from cross-contamination or malicious addition. Here, experiments were carried out to identify the potential source of Sudan I-IV in Capsicum fruits through investigation of their contents in native Capsicum tissues, soils and associated agronomic materials. Sudan II-IV was not detected in any of the tested samples. Sudan I was found in almost all samples except for the mulching film. Sudan I concentrations decreased from stems to leaves and then to fruits or roots. Sudan I levels in soils were significantly elevated by vegetation treatment. These results exclude the possibility of soil as the main source for Sudan I contamination in Capsicum fruits. Further study found out pesticide and fertilizer constitutes the major source of Sudan I contamination. This work represents a preliminary step for a detailed Sudan I assessment to support Capsicum management and protection in the studied region. Copyright © 2014 Elsevier Ltd. All rights reserved.

Floodplains as a source of fine sediment in grazed landscapes: Tracing the source of suspended sediment in the headwaters of an intensively managed agricultural landscape

NASA Astrophysics Data System (ADS)

Yu, Mingjing; Rhoads, Bruce L.

2018-05-01

The flux of fine sediment within agricultural watersheds is an important factor determining the environmental quality of streams and rivers. Despite this importance, the contributions of sediment sources to suspended sediment loads within intensively managed agricultural watersheds remain poorly understood. This study assesses the provenance of fine suspended sediment in the headwater portion of a river flowing through an agricultural landscape in Illinois. Sediment source samples were collected from five sources: croplands, forested floodplains, grasslands, upper grazed floodplains, and lower grazed floodplains. Event-based and aggregated suspended sediment samples were collected from the stream at the watershed outlet. Quantitative geochemical fingerprinting techniques and a mixing model were employed to estimate the relative contributions of sediment from the five sources to the suspended sediment loads. To account for possible effects of small sample sizes, the analysis was repeated with only two sources: grazed floodplains and croplands/grasslands/forested floodplains. Results based on mean values of tracers indicate that the vast majority of suspended sediment within the stream (>95%) is derived from erosion of channel banks and the soil surface within areas of grazed floodplains. Uncertainty analysis based on Monte Carlo simulations indicates that mean values of tracer properties, which do not account for sampling variability in these properties, probably overestimate contributions from the two major sources. Nevertheless, this analysis still supports the conclusion that floodplain erosion accounts for the largest percentage of instream sediment (≈55-75%). Although grazing occurs over only a small portion of the total watershed area, grazed floodplains, which lie in close proximity to the stream channel, are an important source of sediment in this headwater steam system. Efforts to reduce fluxes of fine sediment in this intensively managed landscape should focus on eroding floodplain surfaces and channel banks within heavily grazed reaches of the stream.

In Search of the Largest Possible Tsunami: An Example Following the 2011 Japan Tsunami

NASA Astrophysics Data System (ADS)

Geist, E. L.; Parsons, T.

2012-12-01

Many tsunami hazard assessments focus on estimating the largest possible tsunami: i.e., the worst-case scenario. This is typically performed by examining historic and prehistoric tsunami data or by estimating the largest source that can produce a tsunami. We demonstrate that worst-case assessments derived from tsunami and tsunami-source catalogs are greatly affected by sampling bias. Both tsunami and tsunami sources are well represented by a Pareto distribution. It is intuitive to assume that there is some limiting size (i.e., runup or seismic moment) for which a Pareto distribution is truncated or tapered. Likelihood methods are used to determine whether a limiting size can be determined from existing catalogs. Results from synthetic catalogs indicate that several observations near the limiting size are needed for accurate parameter estimation. Accordingly, the catalog length needed to empirically determine the limiting size is dependent on the difference between the limiting size and the observation threshold, with larger catalog lengths needed for larger limiting-threshold size differences. Most, if not all, tsunami catalogs and regional tsunami source catalogs are of insufficient length to determine the upper bound on tsunami runup. As an example, estimates of the empirical tsunami runup distribution are obtained from the Miyako tide gauge station in Japan, which recorded the 2011 Tohoku-oki tsunami as the largest tsunami among 51 other events. Parameter estimation using a tapered Pareto distribution is made both with and without the Tohoku-oki event. The catalog without the 2011 event appears to have a low limiting tsunami runup. However, this is an artifact of undersampling. Including the 2011 event, the catalog conforms more to a pure Pareto distribution with no confidence in estimating a limiting runup. Estimating the size distribution of regional tsunami sources is subject to the same sampling bias. Physical attenuation mechanisms such as wave breaking likely limit the maximum tsunami runup at a particular site. However, historic and prehistoric data alone cannot determine the upper bound on tsunami runup. Because of problems endemic to sampling Pareto distributions of tsunamis and their sources, we recommend that tsunami hazard assessment be based on a specific design probability of exceedance following a pure Pareto distribution, rather than attempting to determine the worst-case scenario.

What measurements tell us about air composition and emissions in three US oil and gas fields

NASA Astrophysics Data System (ADS)

Petron, G.; Miller, B. R.; Montzka, S. A.; Dlugokencky, E. J.; Kofler, J.; Sweeney, C.; Karion, A.; Frost, G. J.; Helmig, D.; Hueber, J.; Schnell, R. C.; Conley, S. A.; Tans, P. P.

2013-12-01

In 2012 and 2013, the NOAA Global Monitoring Division and several collaborators conducted intensive airborne and ground campaigns in three US oil and gas plays to study emissions of methane and surface ozone precursors. In this presentation we will focus on the multiple species analysis in discrete air samples collected with the NOAA Mobile Laboratory (ML) and the light aircraft in the Uinta Basin (Utah), Denver Julesburg Basin (Colorado) and Barnett Shale (Texas). Hydrocarbon ratios in samples collected with the ML downwind of specific sources show significantly more variability than the aircraft samples. These surface samples provide some useful information about the composition of various sources in each region. Ratios of the non-methane hydrocarbons on the ground and higher in the boundary layer show some differences between the plays, which could be explained by the different composition of the raw gas being produced or by different mixes of sources contributions. Understanding the speciation of atmospheric emissions is critical to identify emission vectors and to assess their potential air quality and climate impacts. Our measurement results will be compared with data from other studies, including emission inventories.

Volatile element chemistry of selected lunar, meteoritic, and terrestrial samples

NASA Technical Reports Server (NTRS)

Simoneit, B. R.; Christiansen, P. C.; Burlingame, A. L.

1973-01-01

Using vacuum pyrolysis and high resolution mass spectrometry, a study is made of the gas release patterns of representative lunar samples, meteorites, terrestrial samples, and synthetic samples doped with various sources of carbon and nitrogen. The pyrolytic gas evolution patterns were intercorrelated, allowing an assessment of the possible sources of the volatilizable material in the lunar samples to be made. Lightly surface adsorbed species and more strongly chemisorbed species are released from ambient to 300 C and from 300 to 500 C, respectively. The low-temperature volatiles (less than 500 C) derived from various chondrites correlate well with the gas evolution patterns of volatile-rich samples, as for example 74220 and 61221. Solar wind entrapped species and molecules derived from reactions probably in the grain surfaces are evolved from about 500 to 700 C, respectively. Solar wind implanted C, N, and S species are generated from 750 to 1150 C, probably by reaction with the mineral matrix during the annealing process. Possible indigenous and/or refractory carbide, nitride, and sulfide C, N, and S are released in the region from 1200 C to fusion.

The development of radioactive sample surrogates for training and exercises

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

Martha Finck; Bevin Brush; Dick Jansen

2012-03-01

The development of radioactive sample surrogates for training and exercises Source term information is required for to reconstruct a device used in a dispersed radiological dispersal device. Simulating a radioactive environment to train and exercise sampling and sample characterization methods with suitable sample materials is a continued challenge. The Idaho National Laboratory has developed and permitted a Radioactive Response Training Range (RRTR), an 800 acre test range that is approved for open air dispersal of activated KBr, for training first responders in the entry and exit from radioactively contaminated areas, and testing protocols for environmental sampling and field characterization. Membersmore » from the Department of Defense, Law Enforcement, and the Department of Energy participated in the first contamination exercise that was conducted at the RRTR in the July 2011. The range was contaminated using a short lived radioactive Br-82 isotope (activated KBr). Soil samples contaminated with KBr (dispersed as a solution) and glass particles containing activated potassium bromide that emulated dispersed radioactive materials (such as ceramic-based sealed source materials) were collected to assess environmental sampling and characterization techniques. This presentation summarizes the performance of a radioactive materials surrogate for use as a training aide for nuclear forensics.« less

Molecular assays for targeting human and bovine enteric viruses in coastal waters and their application for library-independent source tracking

USGS Publications Warehouse

Fong, T.-T.; Griffin, Dale W.; Lipp, E.K.

2005-01-01

Rapid population growth and urban development along waterways and coastal areas have led to decreasing water quality. To examine the effects of upstream anthropogenic activities on microbiological water quality, methods for source-specific testing are required. In this study, molecular assays targeting human enteroviruses (HEV), bovine enteroviruses (BEV), and human adenoviruses (HAdV) were developed and used to identify major sources of fecal contamination in the lower Altamaha River, Georgia. Two-liter grab samples were collected monthly from five tidally influenced stations between July and December 2002. Samples were analyzed by reverse transcription- and nested-PCR. PCR results were confirmed by dot blot hybridization. Eleven and 17 of the 30 surface water samples tested positive for HAdV and HEV, respectively. Two-thirds of the samples tested positive for either HEV or HAdV, and the viruses occurred simultaneously in 26% of samples. BEV were detected in 11 of 30 surface water samples. Binary logistic regression analysis showed that the presence of both human and bovine enteric viruses was not significantly related to either fecal coliform or total coliform levels. The presence of these viruses was directly related to dissolved oxygen and streamflow but inversely related to water temperature, rainfall in the 30 days preceding sampling, and chlorophyll-?? concentrations. The stringent host specificity of enteric viruses makes them good library-independent indicators for identification of water pollution sources. Viral pathogen detection by PCR is a highly sensitive and easy-to-use tool for rapid assessment of water quality and fecal contamination when public health risk characterization is not necessary. Copyright ?? 2005, American Society for Microbiology. All Rights Reserved.

Environmental assessment of a wood-waste-fired industrial watertube boiler. Volume 1. Technical results. Final report, March 1981-March 1984

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

Castaldini, C.; Waterland, L.R.

1987-03-01

The two-volume report gives results from field tests of a wood-waste-fired industrial watertube boiler. Two series of tests were performed: one firing dry (11% moisture) wood waste, and the other firing green (34% moisture) wood waste. Emission measurements included: continuous monitoring of flue-gas emissions; source-assessment sampling system (SASS) sampling of the flue gas with subsequent laboratory analysis of samples to give total flue-gas organics in two boiling-point ranges, compound category information within these ranges, specific quantitation of the semi-volatile organic priority pollutants, and flue-gas concentrations of 73 trace elements; Method 5 sampling for particulate; controlled condensation system sampling for SO/submore » 2/ and SO/sub 3/; and grab sampling of boiler mechanical collector hopper ash for inorganic composition determinations. Total organic emissions decreased from 60-135 mg/dscm firing dry wood to 2-65 mg/dscm firing green wood, in parallel with corresponding boiler CO emissions.« less

Environmental assessment of a wood-waste-fired industrial watertube boiler. Volume 2. Data supplement. Final report, March 1981-March 1984

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

Castaldini, C.; Waterland, L.R.

1987-03-01

The two-volume report gives results from field tests of a wood-waste-fired industrial watertube boiler. Two series of tests were performed: one firing dry (11% moisture) wood waste, and the other firing green (34% moisture) wood waste. Emission measurements included: continuous monitoring of flue-gas emissions; source-assessment sampling system (SASS) sampling of the flue-gas with subsequent laboratory analysis of samples to give total flue-gas organics in two boiling-point ranges, compound category information within these ranges, specific quantitation of the semi-volatile organic priority pollutants, and flue gas concentrations of 73 trace elements; Method 5 sampling for particulate; controlled condensation system sampling for SO/submore » 2/ and SO/sub 3/; and grab sampling of boiler mechanical collector hopper ash for inorganic and organic composition determinations. Total organic emissions decreased from 60-135 mg/dscm firing dry wood to 2-65 mg/dscm firing green wood, in parallel with corresponding boiler CO emissions.« less

Assessment of airborne heavy metal pollution in soil and lichen in the Meric-Ergene Basin, Turkey.

PubMed

Hanedar, Asude

2015-01-01

In the present study, accumulations of airborne heavy metals in lichen and soil samples were determined on the basis of pollutant source groups by conducting Zinc (Zn), Lead (Pb), Iron (Fe), Copper (Cu), Chromium (Cr), Cadmium (Cd), Arsenic (As), Cobalt (Co) and Manganese (Mn) analyses on a total of 48 samples collected in the periods of May 2014 and August 2014 from 12 sampling points in a heavily industrialized area, a mixed industrial and residential area, an agricultural area and a background area in the Meric-Ergene Basin, and pH and total organic carbon determination was carried out on soil samples. With the obtained data, heavy metal levels were statistically assessed in detail by being associated with each other and with their probable sources; the accumulations found in soil and lichen samples were compared and spatial variances were set forth. Based on the results, it was observed that heavy metal pollution is at high levels particularly in industrialized areas, and that the differences between the cleanest and most polluted levels determined from soil samples for As, Cr, Cd and Pb reach 10 folds. The highest levels of all heavy metals were determined in both the soil and lichen samples collected from the areas in the south-east part of the region, where industrial activities and particularly leather and chemical industries are concentrated. With the comparison of the indication properties of soil and lichen, it was determined that significant and comparable results can be observed in both matrices.

Greater nutrition knowledge is associated with lower 1-year postpartum weight retention in low-income women.

PubMed

Nuss, Henry; Freeland-Graves, Jeanne; Clarke, Kristine; Klohe-Lehman, Deborah; Milani, Tracey J

2007-10-01

The purpose of this study was to assess nutrition knowledge during early and late postpartum in a sample of low-income and minority women, and to determine if that knowledge had any relationship to weight retention at 1-year postpartum. A questionnaire was developed and validated in a sample of 151 low-income new mothers. This instrument was then administered to a separate sample of mothers (n=140) of similar demographics to assess nutrition knowledge at 0 to 1 days and 12 months postpartum. In addition, a survey of nutrition information sources was administered at both time points. Nutrition knowledge was compared with 12-month postpartum weight retention and demographic variables. Women who retained less than 5% of weight gained during pregnancy had greater knowledge of nutrition at 0 months (53% vs 49%, P<0.05) and 12 months (55% vs 51%, P<0.05) than those who retained 5% or more of weight gained during pregnancy. Whites had higher nutrition knowledge scores than non-Hispanic blacks and Hispanics. Women who lactated 6 months or more had more knowledge than those who lactated less than 6 months. Higher knowledge test scores were observed among women who used the Internet and books/magazines as their source for information. These results indicate that assessment of nutrition knowledge in early postpartum can identify women at risk for significant weight retention.

A Review of the Validity and Reliability of Alcohol Retail Sales Data for Monitoring Population Levels of Alcohol Consumption: A Scottish Perspective

PubMed Central

Robinson, Mark; Thorpe, Rachel; Beeston, Clare; McCartney, Gerry

2013-01-01

Aims: To assess the validity and reliability of using alcohol retail sales data to measure and monitor population levels of alcohol consumption. Methods: Potential sources of bias that could lead to under- or overestimation of population alcohol consumption based on alcohol retail sales data were identified and, where possible, quantified. This enabled an assessment of the potential impact of each bias on alcohol consumption estimates in Scotland. Results: Overall, considering all the possible sources of overestimation and underestimation, and taking into account the potential for sampling variability to impact on the results, the range of uncertainty of consumption during 2010 was from an overestimate of 0.3 l to an underestimate of 2.4 l of pure alcohol per adult. This excludes the impacts of alcohol stockpiling and alcohol sold through outlets not included in the sampling frame. On balance, there is therefore far greater scope for alcohol retail sales data to be underestimating per adult alcohol consumption in Scotland than there is for overestimation. Conclusion: Alcohol retail sales data offer a robust source of data for monitoring per adult alcohol consumption in Scotland. Consideration of the sources of bias and a comprehensive understanding of data collection methods are essential for using sales data to monitor trends in alcohol consumption. PMID:22926649

Use of mass spectrometry coupled with a solids insertion probe to prescreen soil samples for environmental samples

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

Check, C.E.; Bach, S.B.H.

1995-12-31

The contamination of air, water, and soils by a myriad of sources generates a large sample Currently, sample volume for hazardous constituent analyses is approximately half a million samples per year. The total analytical costs associated with this are astronomical. The analysis of these samples is vital in terms of assessing the types of contamination present and to what degree a site has been contaminated. The results of these analyses are very important for making an informed, knowledgeable decision as to the need for remediation and what type of remediation processes should be initiated based on site suitability vs non-actionmore » for the various sample sites. With an ever growing environmental consciousness in today`s society, the assessment and subsequent remediation of a site needs to be accomplished promptly despite the time constraints traditional methods place on such actions. In order to facilitate a rapid assessment, it is desirable to utilize instrumentation and equipment which afford the most information about a site allowing for optimization in environmental assessment while maintaining a realistic time schedule for the resulting remediation process. Because there are various types of environmental samples that can be taken at a site, different combinations of instrumentation and methods are required for assessing the level and type of contamination present whether it is in air, water, or soils. This study is limited to analyzing soil-like media that would normally fall under EPA Method 8270 which is used to analyze solid waste matrices, soils, and groundwater for semi-volatile organic compounds.« less

Gender and ethnic differences in young adolescents' sources of cigarettes.

PubMed

Robinson, L A; Klesges, R C; Zbikowski, S M

1998-01-01

To identify the sources used by young adolescents to obtain cigarettes. In early 1994 a survey assessing usual sources of cigarettes and characteristics of the respondents was administered in homeroom classes. A large urban, predominantly African American school system. A population-based sample of 6967 seventh graders averaging 13 years of age. Reports of usual sources of cigarettes. At this age level, young smokers were more likely to get cigarettes from friends (31.2%) than buy them in stores (14.3%). However, the odds of purchasing varied for different groups of children. Regular smokers were much more likely (48.3%) to have purchased cigarettes than experimental smokers (9.6%), p < 0.001. Girls were less likely to have bought their cigarettes than boys (p < 0.001), and black smokers were less likely to have purchased cigarettes than white children (p < 0.001). Results suggested that family members who smoke may constitute a more important source of tobacco products than previously recognised, particularly for young girls. In this middle-school sample, peers provided the major point of cigarette distribution. However, even at this age, direct purchase was not uncommon. Sources of cigarettes varied significantly with gender, ethnicity, and smoking rate.

SPECIATION OF ARSENIC IN TARGET FOODS AND COMPOSITE DIET SAMPLES

EPA Science Inventory

For the general population, food may surpass drinking water as the major source of ingestion of total elemental arsenic. Accurate assessments of inorganic arsenic intake via food are needed to understand the relative contributions of drinking water and foods to human exposures t...

MOLECULAR DETECTION OF CRYPTOSPORIDIUM OOCYSTS IN WATER: THE CHALLENGE AND PROMISE

EPA Science Inventory

Because of the presence of host-adapted Cryptosporidium species and genotypes, molecular tools can help assess the source and hazardous potential of Cryptosporidium oocysts in water. The development and use of molecular tools in the analysis of environmental samples have gone tho...

Field-deployed Metabolomics for Assessing Waters Impacted by Point and Non-Point Sources of Contamination

EPA Science Inventory

Metabolomics is becoming well-established for studying chemical contaminant-induced alterations to normal biological function. For example, the literature contains a wealth of laboratory-based studies involving analysis of samples from organisms exposed to individual chemical tox...

Field-deployed Metabolomics for Assessing Surface Waters Impacted by Point and Non-Point Sources of Contamination

EPA Science Inventory

Metabolomics has become well-established for studying chemical contaminant-induced alterations to normal biological function. For example, the literature contains a wealth of laboratory-based studies involving analysis of samples from organisms exposed to individual chemical toxi...

Baseline ecological risk assessment of the Calcasieu Estuary, Louisiana: 3. An evaluation of the risks to benthic invertebrates associated with exposure to contaminated sediments

USGS Publications Warehouse

MacDonald, Donald D.; Ingersoll, Christopher G.; Kemble, Nile E.; Smorong, Dawn E.; Sinclair, Jesse A.; Lindskoog, Rebekka; Gaston, Gary; Sanger, Denise; Carr, R. Scott; Biedenbach, James; Gouguet, Ron; Kern, John; Shortelle, Ann; Field, L. Jay; Meyer, John

2011-01-01

The sediments in the Calcasieu Estuary are contaminated with a wide variety of chemicals of potential concern (COPCs), including heavy metals, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, phthalates, chlorinated benzenes, and polychlorinated dibenzo-p-dioxins and dibenzofurans. The sources of these COPCs include both point and non-point source discharges. As part of a baseline ecological risk assessment, the risks to benthic invertebrates posed by exposure to sediment-associated COPCs were assessed using five lines of evidence, including whole-sediment chemistry, pore-water chemistry, whole-sediment toxicity, pore-water toxicity, and benthic invertebrate community structure. The results of this assessment indicated that exposure to whole sediments and/or pore water from the Calcasieu Estuary generally posed low risks to benthic invertebrate communities (i.e., risks were classified as low for 68% of the sampling locations investigated). However, incremental risks to benthic invertebrates (i.e., compared with those associated with exposure to conditions in reference areas) were indicated for 32% of the sampling locations within the estuary. Of the three areas of concern (AOCs) investigated, the risks to benthic invertebrates were highest in the Bayou d'Inde AOC; risks were generally lower in the Upper Calcasieu River AOC and Middle Calcasieu River AOC. The areas showing the highest risks to sediment-dwelling organisms were generally located in the vicinity of point source discharges of COPCs. These results provided risk managers with the information required to make decisions regarding the need for remedial actions at the site.

Healthcare Databases in Thailand and Japan: Potential Sources for Health Technology Assessment Research.

PubMed

Saokaew, Surasak; Sugimoto, Takashi; Kamae, Isao; Pratoomsoot, Chayanin; Chaiyakunapruk, Nathorn

2015-01-01

Health technology assessment (HTA) has been continuously used for value-based healthcare decisions over the last decade. Healthcare databases represent an important source of information for HTA, which has seen a surge in use in Western countries. Although HTA agencies have been established in Asia-Pacific region, application and understanding of healthcare databases for HTA is rather limited. Thus, we reviewed existing databases to assess their potential for HTA in Thailand where HTA has been used officially and Japan where HTA is going to be officially introduced. Existing healthcare databases in Thailand and Japan were compiled and reviewed. Databases' characteristics e.g. name of database, host, scope/objective, time/sample size, design, data collection method, population/sample, and variables were described. Databases were assessed for its potential HTA use in terms of safety/efficacy/effectiveness, social/ethical, organization/professional, economic, and epidemiological domains. Request route for each database was also provided. Forty databases- 20 from Thailand and 20 from Japan-were included. These comprised of national censuses, surveys, registries, administrative data, and claimed databases. All databases were potentially used for epidemiological studies. In addition, data on mortality, morbidity, disability, adverse events, quality of life, service/technology utilization, length of stay, and economics were also found in some databases. However, access to patient-level data was limited since information about the databases was not available on public sources. Our findings have shown that existing databases provided valuable information for HTA research with limitation on accessibility. Mutual dialogue on healthcare database development and usage for HTA among Asia-Pacific region is needed.

Healthcare Databases in Thailand and Japan: Potential Sources for Health Technology Assessment Research

PubMed Central

Saokaew, Surasak; Sugimoto, Takashi; Kamae, Isao; Pratoomsoot, Chayanin; Chaiyakunapruk, Nathorn

2015-01-01

Background Health technology assessment (HTA) has been continuously used for value-based healthcare decisions over the last decade. Healthcare databases represent an important source of information for HTA, which has seen a surge in use in Western countries. Although HTA agencies have been established in Asia-Pacific region, application and understanding of healthcare databases for HTA is rather limited. Thus, we reviewed existing databases to assess their potential for HTA in Thailand where HTA has been used officially and Japan where HTA is going to be officially introduced. Method Existing healthcare databases in Thailand and Japan were compiled and reviewed. Databases’ characteristics e.g. name of database, host, scope/objective, time/sample size, design, data collection method, population/sample, and variables were described. Databases were assessed for its potential HTA use in terms of safety/efficacy/effectiveness, social/ethical, organization/professional, economic, and epidemiological domains. Request route for each database was also provided. Results Forty databases– 20 from Thailand and 20 from Japan—were included. These comprised of national censuses, surveys, registries, administrative data, and claimed databases. All databases were potentially used for epidemiological studies. In addition, data on mortality, morbidity, disability, adverse events, quality of life, service/technology utilization, length of stay, and economics were also found in some databases. However, access to patient-level data was limited since information about the databases was not available on public sources. Conclusion Our findings have shown that existing databases provided valuable information for HTA research with limitation on accessibility. Mutual dialogue on healthcare database development and usage for HTA among Asia-Pacific region is needed. PMID:26560127

Ochratoxin A Concentrations in a Variety of Grain-Based and Non-Grain-Based Foods on the Canadian Retail Market from 2009 to 2014.

PubMed

Kolakowski, Beata; O'Rourke, Sarah M; Bietlot, Henri P; Kurz, Karl; Aweryn, Barbara

2016-12-01

The extent of ochratoxin A (OTA) contamination of domestically produced foods sold across Canada was determined from 2009 to 2014 with sampling and testing occurring each fiscal year. Cereal-based, fruit-based, and soy-based food samples (n = 6,857) were analyzed. Almost half of the samples (3,200; 47%) did not contain detectable concentrations of OTA. The remaining 3,657 samples contained OTA at 0.040 to 631 ng/g. Wheat, oats, milled products of other grains (such as rye and buckwheat), and to a lesser extent corn products and their derived foods were the most significant potential sources of OTA exposure for the Canadian population. Wine, grape juice, soy products, beer, dairy-based infant formula, and licorice candy were not significant contributors to OTA consumption. Spices had the highest OTA concentrations; but because so little is ingested, these foods are not considered to be a significant source of OTA. In contrast, infant formulas and cereals can be important dietary sources of OTA. Infant cereals containing oats and infant formulas containing soy had detectable concentrations of OTA, some of which exceeded the proposed Canadian guidelines. The prevalence and concentrations of OTA in major crops (wheat, corn, and oats) varied widely across years. Because these foods were purchased at retail stores, no information was available on the OTA concentrations in the raw materials, the storage conditions before purchase of the samples, or the origin of the ingredients (may include blends of raw materials from different years and/or different geographical regions of Canada); therefore, impact of these factors could not be assessed. Overall, 2.3% of the samples exceeded the proposed Canadian OTA regulatory limits and 2.7% exceeded the current European Union (EU) OTA regulatory limits. These results are consistent with a Health Canada exposure assessment published in 2010, despite the inclusion of a wider range of products and confirm the safety of foods widely available across Canada.

Drawing and Writing in Digital Science Notebooks: Sources of Formative Assessment Data

NASA Astrophysics Data System (ADS)

Shelton, Angi; Smith, Andrew; Wiebe, Eric; Behrle, Courtney; Sirkin, Ruth; Lester, James

2016-06-01

Formative assessment strategies are used to direct instruction by establishing where learners' understanding is, how it is developing, informing teachers and students alike as to how they might get to their next set of goals of conceptual understanding. For the science classroom, one rich source of formative assessment data about scientific thinking and practice is in notebooks used during inquiry-oriented activities. In this study, the goal was to better understand how student knowledge was distributed between student drawings and writings about magnetism in notebooks, and how these findings might inform formative assessment strategies. Here, drawing and writing samples were extracted and evaluated from our digital science notebook, with embedded content and laboratories. Three drawings and five writing samples from 309 participants were analyzed using a common ten-dimensional rubric. Descriptive and inferential statistics revealed that fourth-grade student understanding of magnetism was distributed unevenly between writing and drawing. Case studies were then presented for two exemplar students. Based on the rubric we developed, students were able to articulate more of their knowledge through the drawing activities than through written word, but the combination of the two mediums provided the richest understanding of student conceptions and how they changed over the course of their investigations.

Risk Assessment Approach for the Hanford Site River Corridor Closure Project

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

Thomson, J.E.; Weiss, S.G.; Sands, J.P.

2007-07-01

The river corridor portion of the U.S. Department of Energy's (DOE) Hanford Site includes the 100 Area and 300 Area, which border the Columbia River and cover 565 km{sup 2} (218 mi{sup 2}). The River Corridor Closure (RCC) Project scope of work includes 486 contaminated facilities, 4 of 9 deactivated plutonium production reactors, and 370 waste disposal sites. DOE's cleanup actions in the river corridor were initiated in 1994 under the Comprehensive Environmental Response, Compensation, and Liability Act of 1981 (42 U.S.C. 9601, et seq.) (CERCLA) and included source and groundwater operable units (OUs). DOE's RCC Project, awarded to Washingtonmore » Closure Hanford (WCH) in 2005, focuses on source OUs and has allowed cleanup actions to continue in the 100 and 300 Areas with completion by 2013. The regulatory authorization for cleanup actions at source OUs in the river corridor consists primarily of interim action records of decision (RODs), which were supported by qualitative risk assessments and limited field investigations. A key to establishing final cleanup decisions and proceeding toward final CERCLA closeout is completion of quantitative baseline risk assessment activities. Baseline risk assessment is necessary to determine whether cleanup actions are protective of human health and the environment and to identify any course corrections needed to ensure that current and future cleanup actions are protective. Because cleanup actions are ongoing under interim action RODs, it is desirable to establish the final cleanup decision bases as early as possible to minimize the impacts of any identified course corrections to the cleanup approach. Risk assessment is being performed by WCH as the River Corridor Baseline Risk Assessment (RCBRA). The RCBRA uses a multi-step process that summarizes existing data; uses the data quality objectives process to identify both data gaps and unresolved issues through public workshops; and solicits input from regulators, trustees, and stakeholders. Sampling and analysis plans are then developed to document quality requirements and identify field sample collection approaches. After required data are collected, the risks to human health and the environment are assessed. Sampling of upland, riparian, and near-shore environments for the 100/300 Area Component was performed in 2005 and 2006. The 100/300 Area Component includes former operational/reactor areas. The results of these efforts will be incorporated into a mid-2007 draft risk assessment report for the 100/300 Area Component of the RCBRA. Adapting methodology developed from the 100/300 Area Component, the Inter-Areas risk assessment will be conducted for the riparian and near-shore environments. The Inter-Areas Component includes shoreline areas between former operational areas addressed in the 100/300 Area Component. The Inter-Areas risk assessment will supplement results from the 100/300 Area Component to provide a more complete analysis of residual risks in the river corridor. Plans for the final element of the RCBRA, the Columbia River Component, are being developed by DOE and currently is not part of the RCC Project. The Columbia River Component includes the reach of the Columbia River located adjacent to the Hanford Site and reaches downstream to an undetermined boundary. Recommendations for final cleanup decisions at source units within the river corridor, based in part on the risk assessment results, will be presented for future public review in a River Corridor Source Unit Proposed Plan. To form an integrated cleanup approach for the river corridor, the RCBRA results for the source units require integration with risk assessment results from groundwater cleanup actions managed by other contractors. WCH's risk assessment task includes development of an integration strategy for activities leading up to the final regulatory decisions for all OUs in the river corridor. (authors)« less

Mixed species radioiodine air sampling readout and dose assessment system

DOEpatents

Distenfeld, Carl H.; Klemish, Jr., Joseph R.

1978-01-01

This invention provides a simple, reliable, inexpensive and portable means and method for determining the thyroid dose rate of mixed airborne species of solid and gaseous radioiodine without requiring highly skilled personnel, such as health physicists or electronics technicians. To this end, this invention provides a means and method for sampling a gas from a source of a mixed species of solid and gaseous radioiodine for collection of the mixed species and readout and assessment of the emissions therefrom by cylindrically, concentrically and annularly molding the respective species around a cylindrical passage for receiving a conventional probe-type Geiger-Mueller radiation detector.

Comparing wastewater chemicals, indicator bacteria concentrations, and bacterial pathogen genes as fecal pollution indicators

USGS Publications Warehouse

Haack, S.K.; Duris, J.W.; Fogarty, L.R.; Kolpin, D.W.; Focazio, M.J.; Furlong, E.T.; Meyer, M.T.

2009-01-01

The objective of this study was to compare fecal indicator bacteria (FIB) (fecal coliforms, Escherichia coli [EC], and enterococci [ENT]) concentrations with a wide array of typical organic wastewater chemicals and selected bacterial genes as indicators of fecal pollution in water samples collected at or near 18 surface water drinking water intakes. Genes tested included esp (indicating human-pathogenic ENT) and nine genes associated with various animal sources of shiga-toxin-producing EC (STEC). Fecal pollution was indicated by genes and/or chemicals for 14 of the 18 tested samples, with little relation to FIB standards. Of 13 samples with <50 EC 100 mL-1, human pharmaceuticals or chemical indicators of wastewater treatment plant effluent occurred in six, veterinary antibiotics were detected in three, and stx1 or stx2 genes (indicating varying animal sources of STEC) were detected in eight. Only the EC eaeA gene was positively correlated with FIB concentrations. Human-source fecal pollution was indicated by the esp gene and the human pharmaceutical carbamazepine in one of the nine samples that met all FIB recreational water quality standards. Escherichia coli rfbO157 and stx2c genes, which are typically associated with cattle sources and are of potential human health significance, were detected in one sample in the absence of tested chemicals. Chemical and gene-based indicators of fecal contamination may be present even when FIB standards are met, and some may, unlike FIB, indicate potential sources. Application of multiple water quality indicators with variable environmental persistence and fate may yield greater confidence in fecal pollution assessment and may inform remediation decisions. Copyright ?? 2009 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

Mercury deposition in snow near an industrial emission source in the western U.S. and comparison to ISC3 model predictions

USGS Publications Warehouse

Abbott, M.L.; Susong, D.D.; Krabbenhoft, D.P.; Rood, A.S.

2002-01-01

Mercury (total and methyl) was evaluated in snow samples collected near a major mercury emission source on the Idaho National Engineering and Environmental Laboratory (INEEL) in southeastern Idaho and 160 km downwind in Teton Range in western Wyoming. The sampling was done to assess near-field (<12 km) deposition rates around the source, compare them to those measured in a relatively remote, pristine downwind location, and to use the measurements to develop improved, site-specific model input parameters for precipitation scavenging coefficient and the fraction of Hg emissions deposited locally. Measured snow water concentrations (ng L-1) were converted to deposition (ug m-2) using the sample location snow water equivalent. The deposition was then compared to that predicted using the ISC3 air dispersion/deposition model which was run with a range of particle and vapor scavenging coefficient input values. Accepted model statistical performance measures (fractional bias and normalized mean square error) were calculated for the different modeling runs, and the best model performance was selected. Measured concentrations close to the source (average = 5.3 ng L-1) were about twice those measured in the Teton Range (average = 2.7 ng L-1) which were within the expected range of values for remote background areas. For most of the sampling locations, the ISC3 model predicted within a factor of two of the observed deposition. The best modeling performance was obtained using a scavenging coefficient value for 0.25 ??m diameter particulate and the assumption that all of the mercury is reactive Hg(II) and subject to local deposition. A 0.1 ??m particle assumption provided conservative overprediction of the data, while a vapor assumption resulted in highly variable predictions. Partitioning a fraction of the Hg emissions to elemental Hg(0) (a U.S. EPA default assumption for combustion facility risk assessments) would have underpredicted the observed fallout.

Using portable X-ray fluorescence spectrometry and GIS to assess environmental risk and identify sources of trace metals in soils of peri-urban areas in the Yangtze Delta region, China.

PubMed

Ran, Jing; Wang, Dejian; Wang, Can; Zhang, Gang; Yao, Lipeng

2014-08-01

Portable X-ray fluorescence (PXRF) spectrometry may be very suitable for a fast and effective environmental assessment and source identification of trace metals in soils. In this study, topsoils (0-10 cm) at 139 sites were in situ scanned for total trace metals (Cr, Cu, Ni, Pb and Zn) and arsenic concentrations by PXRF in a typical town in Yangtze Delta region of Jiangsu province, China. To validate the utility of PXRF, 53 samples were collected from the scanning sites for the determination of selected trace metals using conventional methods. Based on trace metal concentrations detected by in situ PXRF, the contamination extent and sources of trace metals were studied via geo-accumulation index, multivariate analysis and geostatistics. The trace metal concentrations determined by PXRF were similar to those obtained via conventional chemical analysis. The median concentration of As, Cr, Cu, Ni, Pb and Zn in soils were 10.8, 56.4, 41.5, 43.5, 33.5, and 77.7 mg kg(-1), respectively. The distribution patterns of Cr, Cu, Ni, Pb, and Zn were mostly affected by anthropogenic sources, while As was mainly derived from lithogenic sources. Overall, PXRF has been successfully applied to contamination assessment and source identification of trace metals in soils.

Framework for regional synthesis of water-quality data for the glacial aquifer system in the United States

USGS Publications Warehouse

Warner, Kelly L.; Arnold, Terri L.

2005-01-01

The glacial aquifer system is the largest principal aquifer in aerial extent and ground-water use for public supply in the United States. A principal aquifer is defined as a regionally extensive aquifer or aquifer system that has the potential to be used as a source of potable water (U.S. Geological Survey, 2003). Multiple aquifers often are grouped into large, extensive aquifer systems such as the glacial aquifer system. The glacial aquifer system is considered here to include all unconsolidated aquifers above bedrock north of the line of continental glaciation throughout the country (fig. 1). Total withdrawals from the glacial aquifer system were 3,560 million gallons per day in 2000, which constitutes almost 5 percent of total withdrawals from all aquifers in the United States (Maupin and Barber, 2005). Approximately 41 million people relied on the glacial aquifer for public supply and domestic use in 2000. The U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program began assessing the glacial aquifer system in 1991. The assessment of water-quality data on a regional scale, such as the glacial aquifer system, is coincident with the regional framework established by the Regional Aquifer-System Analysis Program (RASA) (Sun and others, 1997). From 1978 to 1995, the RASA Program systematically evaluated 25 of the Nation's most important groundwater systems including studies in the glacial aquifer system in the northeast, Midwest, and northern Midwest United States. The NAWQA Program is building on the work of the RASA Program to study the water quality of 16 of the most important ground-water systems (Lapham and others, 2005). Over 1,700 water-quality samples have been collected by the NAWQA Program from 1991 to 2004 to assess the glacial aquifer system. This large data set is unique in that the samples have been collected using a consistent sampling protocol, and multiple nested samples. The nested samples address the recently recharged shallow ground water, deeper water from principal aquifers often used for domestic supply, and source water used for public supplies within the glacial aquifer system. Information concerning the NAWQA Program including study unit boundaries is shown in figure 1 (Lapham and others, 2005). A framework for comparison of water quality across the glacial aquifer system has been developed based on two primary characteristics: intrinsic susceptibility and vulnerability. Intrinsic susceptibility, which is a measure of the ease at which water enters and moves through aquifer material, is a characteristic of the aquifer and overlying material and of the hydrologic conditions. Intrinsic susceptibility is independent of the chemical characteristics of the contaminant and its sources. In this way, intrinsic susceptibility assessments do not target specific natural or anthropogenic sources of contamination but instead consider only the physical factors affecting the flow of water to, and through the ground-water resource (Focazio and others, 2002). On a regional scale, intrinsic susceptibility is represented by the spatial distribution of fine- or coarse-grained material at the land surface, and the physical setting of the aquifer system. Vulnerability, which is a function of both intrinsic susceptibility and the proximity and characteristics of contaminant sources, includes consideration of features related to anthropogenic sources of contaminants, such as the character of the upgradient land use (for example, urban, agricultural, undeveloped, and others); as well as features related to natural sources of contaminants, such as the mineralogy of the aquifer material or the geochemical conditions within the aquifer system. The framework helps categorize this large region into areas of similar hydrogeologic characteristics for which water quality can be compared. The purpose of this report is to describe this framework and how it will be used for regional synthesis of water-quality da

Escherichia coli sampling reliability at a frequently closed Chicago beach: monitoring and management implications

USGS Publications Warehouse

Whitman, Richard L.; Nevers, Meredith B.

2004-01-01

Monitoring beaches for recreational water quality is becoming more common, but few sampling designs or policy approaches have evaluated the efficacy of monitoring programs. The authors intensively sampled water for E. coli (N=1770) at 63rd Street Beach, Chicago for 6 months in 2000 in order to (1) characterize spatial-temporal trends, (2) determine between and within transect variation, and (3) estimate sample size requirements and determine sampling reliability.E. coli counts were highly variable within and between sampling sites but spatially and diurnally autocorrelated. Variation in counts decreased with water depth and time of day. Required number of samples was high for 70% precision around the critical closure level (i.e., 6 within or 24 between transect replicates). Since spatial replication may be cost prohibitive, composite sampling is an alternative once sources of error have been well defined. The results suggest that beach monitoring programs may be requiring too few samples to fulfill management objectives desired. As the recreational water quality national database is developed, it is important that sampling strategies are empirically derived from a thorough understanding of the sources of variation and the reliability of collected data. Greater monitoring efficacy will yield better policy decisions, risk assessments, programmatic goals, and future usefulness of the information.

Sources and transport pathways of micropollutants into surface waters - an overview

NASA Astrophysics Data System (ADS)

Stamm, Christian

2017-04-01

Micropollutants reach water bodies from a large range of sources through different transport pathways. They consist of hundreds or thousands of compounds rendering exposure assessment an analytical challenge. Prominent examples of micropollutants are wastewater-born pharmaceuticals and hormones or plant protection products originating from diffuse agricultural sources. This presentation reviews the possible origin of micropollutants and their transport pathways. It demonstrates that considering municipal wastewater and agriculture may fall short of comprising all relevant source-pathway combination in a given watershed by providing examples from industry, animal production, or leaching to groundwater. The diversity of source-pathway leads on the one hand to a large number of possible chemicals to be considered including parent compounds of end products, their transformation products, legacy compounds but also intermediates used during industrial synthesis processes. On the other hand, it leads to a wide range of temporal dynamics by which these compounds reach streams and rivers. This combination makes a comprehensive exposure assessment for micropollutants a real scientific challenge. An outlook into new development in sampling and analytics will suggest possible solution for this challenge.

Water Quality, Sanitation, and Hygiene Conditions in Schools and Households in Dolakha and Ramechhap Districts, Nepal: Results from A Cross-Sectional Survey.

PubMed

Shrestha, Akina; Sharma, Subodh; Gerold, Jana; Erismann, Séverine; Sagar, Sanjay; Koju, Rajendra; Schindler, Christian; Odermatt, Peter; Utzinger, Jürg; Cissé, Guéladio

2017-01-18

This study assessed drinking water quality, sanitation, and hygiene (WASH) conditions among 708 schoolchildren and 562 households in Dolakha and Ramechhap districts of Nepal. Cross-sectional surveys were carried out in March and June 2015. A Delagua water quality testing kit was employed on 634 water samples obtained from 16 purposively selected schools, 40 community water sources, and 562 households to examine water quality. A flame atomic absorption spectrophotometer was used to test lead and arsenic content of the same samples. Additionally, a questionnaire survey was conducted to obtain WASH predictors. A total of 75% of school drinking water source samples and 76.9% point-of-use samples (water bottles) at schools, 39.5% water source samples in the community, and 27.4% point-of-use samples at household levels were contaminated with thermo-tolerant coliforms. The values of water samples for pH (6.8-7.6), free and total residual chlorine (0.1-0.5 mg/L), mean lead concentration (0.01 mg/L), and mean arsenic concentration (0.05 mg/L) were within national drinking water quality standards. The presence of domestic animals roaming inside schoolchildren's homes was significantly associated with drinking water contamination (adjusted odds ratio: 1.64; 95% confidence interval: 1.08-2.50; p = 0.02). Our findings call for an improvement of WASH conditions at the unit of school, households, and communities.

Water Quality, Sanitation, and Hygiene Conditions in Schools and Households in Dolakha and Ramechhap Districts, Nepal: Results from A Cross-Sectional Survey

PubMed Central

Shrestha, Akina; Sharma, Subodh; Gerold, Jana; Erismann, Séverine; Sagar, Sanjay; Koju, Rajendra; Schindler, Christian; Odermatt, Peter; Utzinger, Jürg; Cissé, Guéladio

2017-01-01

This study assessed drinking water quality, sanitation, and hygiene (WASH) conditions among 708 schoolchildren and 562 households in Dolakha and Ramechhap districts of Nepal. Cross-sectional surveys were carried out in March and June 2015. A Delagua water quality testing kit was employed on 634 water samples obtained from 16 purposively selected schools, 40 community water sources, and 562 households to examine water quality. A flame atomic absorption spectrophotometer was used to test lead and arsenic content of the same samples. Additionally, a questionnaire survey was conducted to obtain WASH predictors. A total of 75% of school drinking water source samples and 76.9% point-of-use samples (water bottles) at schools, 39.5% water source samples in the community, and 27.4% point-of-use samples at household levels were contaminated with thermo-tolerant coliforms. The values of water samples for pH (6.8–7.6), free and total residual chlorine (0.1–0.5 mg/L), mean lead concentration (0.01 mg/L), and mean arsenic concentration (0.05 mg/L) were within national drinking water quality standards. The presence of domestic animals roaming inside schoolchildren’s homes was significantly associated with drinking water contamination (adjusted odds ratio: 1.64; 95% confidence interval: 1.08–2.50; p = 0.02). Our findings call for an improvement of WASH conditions at the unit of school, households, and communities. PMID:28106779

Investigation of spatial and historical variations of air pollution around an industrial region using trace and macro elements in tree components.

PubMed

Odabasi, Mustafa; Tolunay, Doganay; Kara, Melik; Ozgunerge Falay, Ezgi; Tuna, Gizem; Altiok, Hasan; Dumanoglu, Yetkin; Bayram, Abdurrahman; Elbir, Tolga

2016-04-15

Several trace and macro elements (n=48) were measured in pine needle, branch, bark, tree ring, litter, and soil samples collected at 27 sites (21 industrial, 6 background) to investigate their spatial and historical variation in Aliaga industrial region in Turkey. Concentrations generally decreased with distance from the sources and the lowest ones were measured at background sites far from major sources. Spatial distribution of anthropogenic trace elements indicated that their major sources in the region are the iron-steel plants, ship-breaking activities and the petroleum refinery. Patterns of 40 elements that were detected in most of the samples were also evaluated to assess their suitability for investigation of historical variations. Observed increasing trends of several trace and macro elements (As, Cr, Fe, Mo, Ni, V, Cu, Pb, Sb, Sn, and Hg) in the tree-ring samples were representative for the variations in anthropogenic emissions and resulting atmospheric concentrations in Aliaga region. It was shown that lanthanides (La, Ce, Pr, Nd, Sm, Gd, Dy, Er, Yb) could also be used for the investigation of historical variations due to specific industrial emissions (i.e., petroleum refining). Results of the present study showed that tree components, litter, and soil could be used to determine the spatial variations of atmospheric pollution in a region while tree rings could be used to assess the historical variations. Copyright © 2016 Elsevier B.V. All rights reserved.

Geochemical characteristics and reservoir continuity of Silurian Acacus in Ghadames Basin, Southern Tunisia

NASA Astrophysics Data System (ADS)

Mahmoudi, S.; Mohamed, A. Belhaj; Saidi, M.; Rezgui, F.

2017-11-01

The present work is dealing with the study of lateral and vertical continuity of the multi-layers Acacus reservoir (Ghadames Basin-Southern Tunisia) using the distribution of hydrocarbon fraction. For this purpose, oil-oil and source rock-oil correlations as well as the composition of the light fractions and a number of saturate and aromatic biomarkers parameters, including C35/C34 hopanes and DBT/P, have been investigated. Based on the ratios of light fraction and their fingerprints, the Acacus reservoir from Well1 and Well2 have found to be laterally non-connected although the hydrocarbons they contain have the same source rock. Moreover, the two oil samples from two different Acacus reservoir layers crossed by Well3-A3 and A9, display a similar hydrocarbons distribution, suggesting vertical reservoir continuity. On the other hand, the biomarker distributions of the oils samples and source rocks assess a Silurian ;Hot shale; that is the source rock feeding the Acacus reservoir. The biomarker distribution is characterized by high tricyclic terpanes contents compared to hopanes for the Silurian source rock and the two crude oils. This result is also confirmed by the dendrogram that precludes the Devonian source rocks as a source rock in the study area.

In vitro assessment of estrogenic bioactivity in complex environmental effluents**

EPA Science Inventory

Environmental effluents contain a diversity of chemicals, can originate from a variety of sources, and have been found to contain estrogenic and/or androgenic activity. In this study, samples were collected from targeted sites or as runoff from an agriculture field that was spray...

In vitro assessment of estrogenic bioactivity in complex environmental effluents

EPA Science Inventory

Environmental effluents contain a diversity of chemicals, can originate from a variety of sources, and have been found to contain estrogenic and/or androgenic activity. In this study, samples were collected from targeted sites or as runoff from an agriculture field that was spray...

A Twin Study of Objectively Assessed Personality in Childhood.

ERIC Educational Resources Information Center

Plomin, Robert; Foch, Terryl T.

1980-01-01

Obtained objective measures of activity, fidgeting, vigilance, selective attention, and aggression for a sample of 87 twin pairs in late childhood. Little evidence for genetic influence on behavior was found. Between-family environmental sources of variance were far more important than within-family factors. (Author/RH)

Advanced Tools Webinar Series Presents: Regulatory Issues and Case Studies of Advanced Tools

EPA Science Inventory

U.S. EPA has released A Guide for Assessing Biodegradation and Source Identification of Organic Ground Water Contaminants using Compound Specific Isotope Analysis (CSIA) [EPA 600/R-08/148 | December 2008 | www.epa.gov/ada]. The Guide provides recommendations for sample collecti...

HOLISTIC APPROACH FOR ASSESSING THE PRESENCE ...

EPA Pesticide Factsheets

As an integral part of our continuing research in environmental quality assessment approaches, we have developed a variety of passive integrative sampling devices widely applicable for use in defining the presence and potential impacts of a broad array of contaminants. The semipermeable membrane device (SPMD) has gained widespread use for sampling hydrophobic chemicals from water and air, the polar organic chemical integrative sampler (POCIS) is applicable for sequestering waterborne hydrophilic organic chemicals, the stabilized liquid membrane device (SLMD) is used to integratively sample waterborne ionic metals, and the passive integrative mercury sampler (PIMS) is applicable for sampling vapor phase or dissolved neutral mercury species. This suite of integrative samplers forms the basis for a new passive sampling approach for assessing the presence and potential toxicological significance of a broad spectrum of environmental contaminants. In a proof-of-concept study, three of our four passive integrative samplers were used to assess the presence o,f a wide variety of contaminants in , the waters of a constructed wetland, and to determine the effectiveness of the constructed wetland in removing contaminants. The wetland is used for fmal polishing of secondary- treatment municipal wastewater and the effluent is used as a source of water for a state wildlife area. Numerous contaminants, including organochlorine pesticides (OCs), polycyclic aromatic hydrocarbons

Lead Contamination and Source Characterization in Soils Around a Lead-Zinc Smelting Plant in a Near-Urban Environment in Baoji, China.

PubMed

Deng, Wenbo; Li, Xuxiang; An, Zhisheng; Yang, Liu

2016-11-01

Economic reforms in China since 1978 have promoted nationwide socioeconomic advancement but led to a considerable amount of environmental pollution. The distribution and sources of Pb in a typical peri-urban industrial part of Baoji, China, were assessed by determining the Pb contents and isotopic compositions in 52 topsoil samples from the study area. The topsoil samples were polluted averagely with 40.88 mg Pb kg -1 , was 1.86 times higher than the Pb content of local background soil (22.04 mg kg -1 ). Pb isotopic compositions were determined by analyzing samples prepared using total digestion and acid extraction methods. Radiogenic isotopes contributed more to the Pb concentrations in the acid extracts than in the total digests. This was shown by the 207/206 Pb and 208/206 Pb ratios, which were 0.845-0.88 and 2.088-2.128, respectively, in the acid extracts and 0.841-0.875 and 2.086-2.125, respectively, in the total digests. This indicates that anthropogenic sources of Pb could be identified more sensitively in acid extracts than in total digests. The Pb isotope ratios showed that burning coal and smelting ore are the predominant anthropogenic sources of Pb in the study area, i.e., a lead-zinc smelter and a coking plant are major sources of Pb in the study area.

Assessment of arsenic, fluoride, bacteria, and other contaminants in drinking water sources for rural communities of Kasur and other districts in Punjab, Pakistan.

PubMed

Arshad, Nasima; Imran, Saiqa

2017-01-01

High levels of arsenic contamination in drinking water of two villages, Badarpur and Ibrahimabad of district Kasur, central Punjab, Pakistan is reported first time in present studies. Groundwater quality situation was found to be impaired when samples of different rural areas of district Kasur were monitored according to Pakistan Standards and Quality Control Authority (PSQCA) for all significant water quality constituents and analyzed for trace elements, physico-chemical, and microbiological parameters. Out of 35water sources, 97 % were found unsafe and only 3 % of the sources were within safe limits. High concentrations of arsenic, fluoride, and bacteria were found in 91, 74, and 77 % sources of drinking water, respectively. Very high concentrations of arsenic ranging 58-3800 μg/L were found in the water samples obtained from Badarpur and Ibrahimabad. A decrease in water contamination was observed with increase in source depth. The health issues like arsenicosis and skeletal/dental flourosis were observed in the residents of the monitored areas. Drinking water quality conditions of some rural areas of northen and southern districts of Punjab was also analyzed and compared with Kasur district. High levels of nitrates were found in the samples of Islamabad and Rawalpindi, while high levels of arsenic, iron, fluoride, and TDS were found in Bahawalpur district. Graphical abstract ᅟ.

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).

Organic Compounds in Running Gutter Brook Water Used for Public Supply near Hatfield, Massachusetts, 2003-05

USGS Publications Warehouse

Brown, Craig J.; Trombley, Thomas J.

2009-01-01

The 258 organic compounds studied in this U.S. Geological Survey (USGS) assessment generally are man-made, including pesticides, solvents, gasoline hydrocarbons, personal-care and domestic-use products, and pavement and combustion-derived compounds. Of these 258 compounds, 26 (about 10 percent) were detected at least once among the 31 samples collected approximately monthly during 2003-05 at the intake of a flowthrough reservoir on Running Gutter Brook in Massachusetts, one of several community water systems on tributaries of the Connecticut River. About 81 percent of the watershed is forested, 14 percent is agricultural land, and 5 percent is urban land. In most source-water samples collected at Running Gutter Brook, fewer compounds were detected and their concentrations were low (less than 0.1 micrograms per liter) when compared with compounds detected at other stream sites across the country that drain watersheds that have a larger percentage of agricultural and urban areas. The relatively few compounds detected at low concentrations reflect the largely undeveloped land use at Running Gutter Brook. Despite the absence of wastewater discharge points on the stream, however, the compounds that were detected could indicate different sources and uses (point sources, precipitation, domestic, and agricultural) and different pathways to drinking-water supplies (overland runoff, groundwater discharge, leaking of treated water from distribution lines, and formation during treatment). Six of the 10 compounds detected most commonly (in at least 20 percent of the samples) in source water also were detected commonly in finished water (after treatment but prior to distribution). Concentrations in source and finished water generally were below 0.1 micrograms per liter and always less than humanhealth benchmarks, which are available for about one-half of the compounds detected. On the basis of this screening-level assessment, adverse effects to human health are expected to be negligible (subject to limitations of available humanhealth benchmarks).

Water-quality assessment of the Kentucky River basin, Kentucky; results of investigations of surface-water quality, 1987-90

USGS Publications Warehouse

Haag, K.H.; Garcia, Rene; Jarrett, G.L.; Porter, S.D.

1995-01-01

The U.S. Geological Survey investigated the water quality of the Kentucky River Basin in Kentucky as part of the National Water-Quality Assessment program. Data collected during 1987-90 were used to describe the spatial and temporal variability of water-quality constituents including metals and trace elements, nutrients, sediments, pesticides, dissolved oxygen, and fecal-coliform bacteria. Oil-production activities were the source of barium, bromide, chloride, magnesium, and sodium in several watersheds. High concentrations of aluminum, iron, and zinc were related to surface mining in the Eastern Coal Field Region. High concentrations of lead and zinc occurred in streambed sediments in urban areas, whereas concentrations of arsenic, strontium, and uranium were associated with natural geologic sources. Concentrations of phosphorus were significantly correlated with urban and agricultural land use. The high phosphorus content of Bluegrass Region soils was an important source of phosphorus in streams. At many sites in urban areas, most of the stream nitrogen load was attributable to wastewater-treatment-plant effluent. Average suspended-sediment concentrations were positively correlated with discharge. There was a downward trend in suspended-sediment concentrations downstream in the Kentucky River main stem during the study. The most frequently detected herbicides in water samples were atrazine, 2,4-D, alachlor, metolachlor, and dicamba. Diazinon, malathion, and parathion were the most frequently detected organophosphate insecticides in water samples. Detectable concentrations of aldrin, chlordane, DDT, DDE, dieldrin, endrin, endosulfan, heptachlor, and lindane were found in streambed-sediment samples. Dissolved-oxygen concentrations were sometimes below the minimum concentration needed to sustain aquatic life. At some sites, high concentrations of fecal-indicator bacteria were found and water samples did not meet sanitary water-quality criteria.

Crushing of Subglacial Lake Sediment as a Source of Bio-utilisable Gases.

NASA Astrophysics Data System (ADS)

Gill Olivas, B.; Telling, J.; Michaud, A. B.; Skidmore, M. L.; Priscu, J. C.; Tranter, M.

2017-12-01

Recent research has shown microbial ecosystems exist under glaciers and ice sheets. The sources of energy to support these ecosystems are still not fully understood, particularly beneath the Antarctic Ice Sheet, where direct access to the atmosphere and in-washed organic matter and oxidising agents does not occur. Hence, sub-ice sheet energy sources are restricted to those in subglacial environments, except for ice-margin environments. This study focuses on sediments from Subglacial Lake Whillans (SLW), the first subglacial lake to be directly and cleanly sampled. Sediment from three depths in a shallow core extracted from SLW were used to assess the possible energy contributions from mechanochemical reactions to this subglacial ecosystem. To do this, the samples were crushed under an anoxic atmosphere using a ball mill. The sediments were then transferred into serum bottles under anoxic conditions. They were wetted and the headspace gas was subsequently sampled and analysed during a 40 day incubation. Results show the release of substantial amounts of hydrogen, which could potentially serve as an abiotic source of energy to microbes, in particular, methanogenic archaea. Significant amounts of short chain hydrocarbons (including methane and ethylene), possibly from the reactivation of ancient organic carbon, were also observed. Crushed samples showed a significant concentration of hydrogen peroxide produced on contact with water, as well as significant amounts of Si radicals, showing comminution of these sediments unlocks the potential for a wide range of redox conditions and reactions to develop within glacially eroded sediment under ice. This in turn provides a previously overlooked source of nutrients and energy for microbes to utilise.

Hydrological, water-quality, and ecological data for streams in Independence, Missouri, June 2005 through September 2013

USGS Publications Warehouse

Niesen, Shelley L.; Christensen, Eric D.

2015-01-01

Water-quality, hydrological, and ecological data collected from June 2005 through September 2013 from the Little Blue River and smaller streams within the City of Independence, Missouri, are presented in this report. These data were collected as a part of an ongoing cooperative study between the U.S. Geological Survey and the City of Independence Water Pollution Control Department to characterize the water quality and ecological condition of Independence streams. The quantities, sources of selected constituents, and processes affecting water quality and aquatic life were evaluated to determine the resulting ecological condition of streams within Independence. Data collected for this study fulfill the municipal separate sewer system permit requirements for the City of Independence and can be used to provide a baseline with which city managers can determine the effectiveness of current (2014) and future best management practices within Independence. Continuous streamflow and water-quality data, collected during base flow and stormflow, included physical and chemical properties, inorganic constituents, common organic micro-constituents, pesticides in streambed sediment and surface water, fecal indicator bacteria and microbial source tracking data, and suspended sediment. Dissolved oxygen, pH, specific conductance, water temperature, and turbidity data were measured continuously at seven sites within Independence. Base-flow and stormflow samples were collected at eight gaged and two ungaged sites. Fecal sources samples were collected for reference for microbial source tracking, and sewage influent samples were collected as additional source samples. Dry-weather screening was done on 11 basins within Independence to identify potential contaminant sources to the streams. Benthic macroinvertebrate community surveys and habitat assessments were done on 10 stream sites and 2 comparison sites outside the city. Sampling and laboratory procedures and quality-assurance and quality-control methods used in data collection for this study are described in this report.

Quantifying tap-to-household water quality deterioration in urban communities in Vellore, India: The impact of spatial assumptions.

PubMed

Alarcon Falconi, Tania M; Kulinkina, Alexandra V; Mohan, Venkata Raghava; Francis, Mark R; Kattula, Deepthi; Sarkar, Rajiv; Ward, Honorine; Kang, Gagandeep; Balraj, Vinohar; Naumova, Elena N

2017-01-01

Municipal water sources in India have been found to be highly contaminated, with further water quality deterioration occurring during household storage. Quantifying water quality deterioration requires knowledge about the exact source tap and length of water storage at the household, which is not usually known. This study presents a methodology to link source and household stored water, and explores the effects of spatial assumptions on the association between tap-to-household water quality deterioration and enteric infections in two semi-urban slums of Vellore, India. To determine a possible water source for each household sample, we paired household and tap samples collected on the same day using three spatial approaches implemented in GIS: minimum Euclidean distance; minimum network distance; and inverse network-distance weighted average. Logistic and Poisson regression models were used to determine associations between water quality deterioration and household-level characteristics, and between diarrheal cases and water quality deterioration. On average, 60% of households had higher fecal coliform concentrations in household samples than at source taps. Only the weighted average approach detected a higher risk of water quality deterioration for households that do not purify water and that have animals in the home (RR=1.50 [1.03, 2.18], p=0.033); and showed that households with water quality deterioration were more likely to report diarrheal cases (OR=3.08 [1.21, 8.18], p=0.02). Studies to assess contamination between source and household are rare due to methodological challenges and high costs associated with collecting paired samples. Our study demonstrated it is possible to derive useful spatial links between samples post hoc; and that the pairing approach affects the conclusions related to associations between enteric infections and water quality deterioration. Copyright © 2016 Elsevier GmbH. All rights reserved.

Year-round Source Contributions of Fossil Fuel and Biomass Combustion to Elemental Carbon on the North Slope Alaska Utilizing Radiocarbon Analysis

NASA Astrophysics Data System (ADS)

Barrett, T. E.; Gustafsson, O.; Winiger, P.; Moffett, C.; Back, J.; Sheesley, R. J.

2015-12-01

It is well documented that the Arctic has undergone rapid warming at an alarming rate over the past century. Black carbon (BC) affects the radiative balance of the Arctic directly and indirectly through the absorption of incoming solar radiation and by providing a source of cloud and ice condensation nuclei. Among atmospheric aerosols, BC is the most efficient absorber of light in the visible spectrum. The solar absorbing efficiency of BC is amplified when it is internally mixed with sulfates. Furthermore, BC plumes that are fossil fuel dominated have been shown to be approximately 100% more efficient warming agents than biomass burning dominated plumes. The renewal of offshore oil and gas exploration in the Arctic, specifically in the Chukchi Sea, will introduce new BC sources to the region. This study focuses on the quantification of fossil fuel and biomass combustion sources to atmospheric elemental carbon (EC) during a year-long sampling campaign in the North Slope Alaska. Samples were collected at the Department of Energy Atmospheric Radiation Measurement (ARM) climate research facility in Barrow, AK, USA. Particulate matter (PM10) samples collected from July 2012 to June 2013 were analyzed for EC and sulfate concentrations combined with radiocarbon (14C) analysis of the EC fraction. Radiocarbon analysis distinguishes fossil fuel and biomass burning contributions based on large differences in end members between fossil and contemporary carbon. To perform isotope analysis on EC, it must be separated from the organic carbon fraction of the sample. Separation was achieved by trapping evolved CO2 produced during EC combustion in a cryo-trap utilizing liquid nitrogen. Radiocarbon results show an average fossil contribution of 85% to atmospheric EC, with individual samples ranging from 47% to 95%. Source apportionment results will be combined with back trajectory (BT) analysis to assess geographic source region impacts on the EC burden in the western Arctic.

Urban stormwater harvesting and reuse: a probe into the chemical, toxicology and microbiological contaminants in water quality.

PubMed

Chong, Meng Nan; Sidhu, Jatinder; Aryal, Rupak; Tang, Janet; Gernjak, Wolfgang; Escher, Beate; Toze, Simon

2013-08-01

Stormwater is one of the last major untapped urban water resources that can be exploited as an alternative water source in Australia. The information in the current Australian Guidelines for Water Recycling relating to stormwater harvesting and reuse only emphasises on a limited number of stormwater quality parameters. In order to supply stormwater as a source for higher value end-uses, a more comprehensive assessment on the potential public health risks has to be undertaken. Owing to the stochastic variations in rainfall, catchment hydrology and also the types of non-point pollution sources that can provide contaminants relating to different anthropogenic activities and catchment land uses, the characterisation of public health risks in stormwater is complex, tedious and not always possible through the conventional detection and analytical methods. In this study, a holistic approach was undertaken to assess the potential public health risks in urban stormwater samples from a medium-density residential catchment. A combined chemical-toxicological assessment was used to characterise the potential health risks arising from chemical contaminants, while a combination of standard culture methods and quantitative polymerase chain reaction (qPCR) methods was used for detection and quantification of faecal indicator bacteria (FIB) and pathogens in urban stormwater. Results showed that the concentration of chemical contaminants and associated toxicity were relatively low when benchmarked against other alternative water sources such as recycled wastewater. However, the concentrations of heavy metals particularly cadmium and lead have exceeded the Australian guideline values, indicating potential public health risks. Also, high numbers of FIB were detected in urban stormwater samples obtained from wet weather events. In addition, qPCR detection of human-related pathogens suggested there are frequent sewage ingressions into the urban stormwater runoff during wet weather events. Further water quality monitoring study will be conducted at different contrasting urban catchments in order to undertake a more comprehensive public health risk assessment for urban stormwater.

Measuring Sexual and Gender Minority Populations in Health Surveillance.

PubMed

Patterson, Joanne G; Jabson, Jennifer M; Bowen, Deborah J

2017-04-01

Sexual and gender minorities (SGMs) are underrepresented and information about SGMs is difficult to locate in national health surveillance data, and this limits identification and resolution of SGM health disparities. It is also not known how measures of sexual orientation and transgender-inclusive gender identity in health surveillance compare with best practice recommendations. This article reviews and summarizes the publicly available, English language, large-scale, rigorously sampled, national, international, and regional data sources that include sexual orientation or transgender-inclusive gender identity and compares measures with best practice guidelines. A systematic review was undertaken of national, international, state, and regional health surveillance data sources. Data sources that measured sexual orientation or transgender-inclusive gender identity and met seven inclusion criteria were included. Forty-three publicly accessible national, international, and regional data sources included measures of sexual orientation and transgender-inclusive gender identity and health. For each data source, sampling design, sample characteristics, study years, survey questions, contact persons, and data access links are provided. Few data sources met best practice recommendations for SGM measurement: 14% measured all three dimensions of sexual orientation (identity, behavior, attraction) as recommended by the Sexual Minority Assessment Research Team. No data sources measured transgender-inclusive gender identity according to the Gender Identity in U.S. Surveillance-recommended two-step method of measuring sex assigned at birth and current gender identity. This article provides a much needed detailed summary of extant health surveillance data sources that can be used to inform research about health risks and disparities among SGM populations. Future recommendations are for more rigorous measurement and oversampling to advance what is known about SGM health disparities and guide development of interventions to reduce disparities.

Measuring Sexual and Gender Minority Populations in Health Surveillance

PubMed Central

Jabson, Jennifer M.; Bowen, Deborah J.

2017-01-01

Abstract Purpose: Sexual and gender minorities (SGMs) are underrepresented and information about SGMs is difficult to locate in national health surveillance data, and this limits identification and resolution of SGM health disparities. It is also not known how measures of sexual orientation and transgender-inclusive gender identity in health surveillance compare with best practice recommendations. This article reviews and summarizes the publicly available, English language, large-scale, rigorously sampled, national, international, and regional data sources that include sexual orientation or transgender-inclusive gender identity and compares measures with best practice guidelines. Methods: A systematic review was undertaken of national, international, state, and regional health surveillance data sources. Data sources that measured sexual orientation or transgender-inclusive gender identity and met seven inclusion criteria were included. Results: Forty-three publicly accessible national, international, and regional data sources included measures of sexual orientation and transgender-inclusive gender identity and health. For each data source, sampling design, sample characteristics, study years, survey questions, contact persons, and data access links are provided. Few data sources met best practice recommendations for SGM measurement: 14% measured all three dimensions of sexual orientation (identity, behavior, attraction) as recommended by the Sexual Minority Assessment Research Team. No data sources measured transgender-inclusive gender identity according to the Gender Identity in U.S. Surveillance-recommended two-step method of measuring sex assigned at birth and current gender identity. Conclusions: This article provides a much needed detailed summary of extant health surveillance data sources that can be used to inform research about health risks and disparities among SGM populations. Future recommendations are for more rigorous measurement and oversampling to advance what is known about SGM health disparities and guide development of interventions to reduce disparities. PMID:28287877

Floodplains as a source of fine sediment in grazed landscapes: tracing the source of suspended sediment in the headwaters of an intensively managed agricultural landscape

NASA Astrophysics Data System (ADS)

Yu, M.; Rhoads, B. L.; Stumpf, A.

2017-12-01

The flux of fine sediment within agricultural watersheds is an important factor determining the environmental quality of streams and rivers. Despite this importance, the contributions of sediment sources to suspended sediment loads within intensively managed agricultural watersheds remain poorly understood. This study assesses the provenance of fine suspended sediment in the headwater portion of a river flowing through an agricultural landscape in Illinois. Sediment source samples were collected from five potential sources: streambanks, forested floodplain, grassland, and grazed floodplains. Event-based and aggregated suspended sediment samples were collected from the stream at the watershed outlet. Quantitative geochemical fingerprinting techniques and a mixing model were employed to estimate the relative contributions of sediment from five potential sources to the suspended sediment loads. Organic matter content, trace elements, and fallout radionuclides were used as potential tracers. Principal Component analysis was employed to complement the results and Monte Carlo random sampling routine was used to test the uncertainty in estimated contributions of sources to in-stream sediment loads. Results indicate that the majority of suspended sediment is derived from streambanks and grazed floodplains. Erosion of the floodplain both by surface runoff and by streambank erosion from lateral channel migration contributes to the production of fine sediment within the stream system. These results suggest that human activities, in this case grazing, have converted portions of floodplains, normally net depositional environments, into sources of fine sediments. Efforts to reduce fluxes of fine sediment in this intensively managed landscape should focus on degraded floodplain surfaces and eroding channel banks within heavily grazed reaches of the stream.

Groundwater arsenic in Chimaltenango, Guatemala.

PubMed

Lotter, Jason T; Lacey, Steven E; Lopez, Ramon; Socoy Set, Genaro; Khodadoust, Amid P; Erdal, Serap

2014-09-01

In the Municipality of Chimaltenango, Guatemala, we sampled groundwater for total inorganic arsenic. In total, 42 samples were collected from 27 (43.5%) of the 62 wells in the municipality, with sites chosen to achieve spatial representation throughout the municipality. Samples were collected from household faucets used for drinking water, and sent to the USA for analysis. The only site found to have a concentration above the 10 μg/L World Health Organization provisional guideline for arsenic in drinking water was Cerro Alto, where the average concentration was 47.5 μg/L. A health risk assessment based on the arsenic levels found in Cerro Alto showed an increase in noncarcinogenic and carcinogenic risks for residents as a result of consuming groundwater as their primary drinking water source. Using data from the US Geological Survey and our global positioning system data of the sample locations, we found Cerro Alto to be the only site sampled within the tertiary volcanic rock layer, a known source of naturally occurring arsenic. Recommendations were made to reduce the levels of arsenic found in the community's drinking water so that the health risks can be managed.

PFAAs in Fish and Other Seafood Products from Icelandic Waters

PubMed Central

Halldorsson, Thorhallur I.; Gunnlaugsdottir, Helga

2014-01-01

Perfluorinatedalkyl acids (PFAAs) are of growing concern due to possible health effects on humans. Exposure assessments indicate that fish consumption is one of the major sources of perfluorooctane sulfonate (PFOS) exposure to humans, one of the major PFASs, whereas concerns of overestimation of this exposure source have been raised. Therefore, PFAAs concentrations in fish from the North Atlantic (Icelandic fishing grounds) in the flesh of different fish species were investigated along with more detailed analyses of tissue concentrations in cod (Gadus morhua) and lumpfish (Cyclopterus lumpus). Further, fish feed was investigated as a possible source of PFAAs in aquaculture by examining fish meal as feed ingredient. No PFAAs were detected in the edible part of all fish samples, except for PFOS in pollock (Pollachius virens, 0,05 ng/g wet weight). PFOS was the only PFAA detected in the fish meal samples with the exception of PFOSA in blue whiting (Micromesistius poutassou) meal (0,45 ng/g dry weight (d.w.)), where the PFOS concentration was 1,3–13 ng/g d.w. in the capelin (Mallotus villosus) and mackerel (Scomber scombrus) meal samples. The conclusions of the study are that fish commonly consumed from the Icelandic fishing grounds are unlikely to be an important source of PFAAs exposure. PMID:24782899

Into the deep: Evaluation of SourceTracker for assessment of faecal contamination of coastal waters.

PubMed

Henry, Rebekah; Schang, Christelle; Coutts, Scott; Kolotelo, Peter; Prosser, Toby; Crosbie, Nick; Grant, Trish; Cottam, Darren; O'Brien, Peter; Deletic, Ana; McCarthy, David

2016-04-15

Faecal contamination of recreational waters is an increasing global health concern. Tracing the source of the contaminant is a vital step towards mitigation and disease prevention. Total 16S rRNA amplicon data for a specific environment (faeces, water, soil) and computational tools such as the Markov-Chain Monte Carlo based SourceTracker can be applied to microbial source tracking (MST) and attribution studies. The current study applied artificial and in-laboratory derived bacterial communities to define the potential and limitations associated with the use of SourceTracker, prior to its application for faecal source tracking at three recreational beaches near Port Phillip Bay (Victoria, Australia). The results demonstrated that at minimum multiple model runs of the SourceTracker modelling tool (i.e. technical replicates) were required to identify potential false positive predictions. The calculation of relative standard deviations (RSDs) for each attributed source improved overall predictive confidence in the results. In general, default parameter settings provided high sensitivity, specificity, accuracy and precision. Application of SourceTracker to recreational beach samples identified treated effluent as major source of human-derived faecal contamination, present in 69% of samples. Site-specific sources, such as raw sewage, stormwater and bacterial populations associated with the Yarra River estuary were also identified. Rainfall and associated sand resuspension at each location correlated with observed human faecal indicators. The results of the optimised SourceTracker analysis suggests that local sources of contamination have the greatest effect on recreational coastal water quality. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cancer diagnosis by infrared spectroscopy: methodological aspects

NASA Astrophysics Data System (ADS)

Jackson, Michael; Kim, Keith; Tetteh, John; Mansfield, James R.; Dolenko, Brion; Somorjai, Raymond L.; Orr, F. W.; Watson, Peter H.; Mantsch, Henry H.

1998-04-01

IR spectroscopy is proving to be a powerful tool for the study and diagnosis of cancer. The application of IR spectroscopy to the analysis of cultured tumor cells and grading of breast cancer sections is outlined. Potential sources of error in spectral interpretation due to variations in sample histology and artifacts associated with sample storage and preparation are discussed. The application of statistical techniques to assess differences between spectra and to non-subjectively classify spectra is demonstrated.

Preliminary results from exploratory sampling of wells for the California oil, gas, and groundwater program, 2014–15

USGS Publications Warehouse

McMahon, Peter B.; Kulongoski, Justin T.; Wright, Michael T.; Land, Michael T.; Landon, Matthew K.; Cozzarelli, Isabelle M.; Vengosh, Avner; Aiken, George R.

2016-08-03

This report evaluates the utility of the chemical, isotopic, and groundwater-age tracers for assessing sources of salinity, methane, and petroleum hydrocarbons in groundwater overlying or near several California oil fields. Tracers of dissolved organic carbon inoil-field-formation water are also discussed. Tracer data for samples collected from 51 water wells and 4 oil wells are examined.

Attention and Working Memory as Predictors of Intelligence

ERIC Educational Resources Information Center

Schweizer, Karl; Moosbrugger, Helfried

2004-01-01

The paper reports on an investigation of attention and working memory as sources of intelligence. The investigation was concentrated on the relatedness of attention and working memory as predictors of intelligence and on the structure underlying the prediction. In a sample of 120 participants, intelligence was assessed by the Advanced Progressive…

In Vitro Assays for Assessment of Androgenic and Estrogenic Activity of Defined Mixtures and Complex Environmental Samples

EPA Science Inventory

Point sources of endocrine active compounds to aquatic environments such as waste water treatment plants, pulp and paper mills, and animal feeding operations invariably contain complex mixtures of chemicals. The current study investigates the use of targeted in vitro assays des...

In vitro assays for assessment of androgenic and estrogenic activity of defined mixtures and complex environment samples

EPA Science Inventory

Point sources of potentially endocrine active compounds to aquatic environments such as waste water treatment plants, pulp and paper mills, and animal feeding operations invariably contain complex mixtures of chemicals. The current study investigates the use of targeted in vitro ...

In vitro assays for assessment of androgenic and estrogenic activity in defined mixtures and complex environmental samples

EPA Science Inventory

Eflluents from sources such as waste water treatment plants and animal feeding operations invariably contain complex mixtures of chemicals. Recent research on effluent from cattle feeding operations in the US have linked morphological alterations in fish with in vitro androgenic ...

Communication Problems of Learning Disabled Children.

ERIC Educational Resources Information Center

Bryan, Tanis

The presentation reviews the empirical data concerning the existence and types of language problems experienced by learning disabled (LD) and reading disabled (RD) children. An introductory section provides criteria for classification as LD in research samples and a discussion of research data sources in the field of language assessment. Section…

From Research to Practice: Teacher and Pediatrician Awareness of Phenotypic Traits in Neurogenetic Syndromes

ERIC Educational Resources Information Center

Lee, Tammy H.; Blasey, Christine M.; Dyer-Friedman, Jennifer; Glaser, Bronwyn; Reiss, Allan L.; Eliez, Stephan

2005-01-01

Pediatricians' and teachers' knowledge of physical, cognitive, and behavioral features associated with three genetic syndromes were assessed and the effectiveness of information sources about these syndromes evaluated. The surveyed sample included 53 pediatricians and 69 teachers from Northern and Central California. Respondents demonstrated…

Oral bioaccessibility testing and read-across hazard assessment of nickel compounds.

PubMed

Henderson, Rayetta G; Cappellini, Danielle; Seilkop, Steven K; Bates, Hudson K; Oller, Adriana R

2012-06-01

In vitro metal ion bioaccessibility, as a measure of bioavailability, can be used to read-across toxicity information from data-rich, source substances to data-poor, target substances. To meet the data requirements for oral systemic toxicity endpoints under the REACH Regulation in Europe, 12 nickel substances underwent bioaccessibility testing in stomach and intestinal fluids. A read-across paradigm was developed based on the correlation between gastric bioaccessibility and in vivo acute oral toxicity. The oral LD₅₀ values were well predicted by nickel release (R² = 0.91). Samples releasing <48% available nickel (mgNi released/mg available Ni × 100) are predicted to have an LD₅₀ > 2000 mg/kg; while samples releasing > 76% available nickel are expected to have an LD₅₀ between 300 and 2000 mg/kg. The hazard classifications (European Regulation on Classification, Labelling and Packaging of Chemical Substances and Mixtures) for all oral systemic endpoints were evaluated based on read-across from three source nickel compounds (sulfate, subsulfide, oxide). Samples releasing < 48% available nickel were read-across from nickel oxides and subsulfide. Samples releasing > 76% Ni were read-across from nickel sulfate. This assessment suggests that nickel chloride and dihydroxide should be less stringently classified and nickel sulfamate should receive a more stringent classification for oral systemic endpoints than currently assigned. Copyright © 2012 Elsevier Inc. All rights reserved.

Origin and spatial distribution of metals in moss samples in Albania: A hotspot of heavy metal contamination in Europe.

PubMed

Lazo, Pranvera; Steinnes, Eiliv; Qarri, Flora; Allajbeu, Shaniko; Kane, Sonila; Stafilov, Trajce; Frontasyeva, Marina V; Harmens, Harry

2018-01-01

This study presents the spatial distribution of 37 elements in 48 moss samples collected over the whole territory of Albania and provides information on sources and factors controlling the concentrations of elements in the moss. High variations of trace metals indicate that the concentrations of elements are affected by different factors. Relations between the elements in moss, geochemical interpretation of the data, and secondary effects such as redox conditions generated from local soil and/or long distance atmospheric transport of the pollutants are discussed. Zr normalized data, and the ratios of different elements are calculated to assess the origin of elements present in the current moss samples with respect to different geogenic and anthropogenic inputs. Factor analysis (FA) is used to identify the most probable sources of the elements. Four dominant factors are identified, i.e. natural contamination; dust emission from local mining operations; atmospheric transport of contaminants from local and long distance sources; and contributions from air borne marine salts. Mineral particle dust from local emission sources is classified as the most important factor affecting the atmospheric deposition of elements accumulated in the current moss samples. The open slag dumps of mining operation in Albania is probably the main factor contributing to high contents of Cr, Ni, Fe, Ti and Al in the moss. Enrichment factors (EF) were calculated to clarify whether the elements in the present moss samples mainly originate from atmospheric deposition and/or local substrate materials. Copyright © 2017 Elsevier Ltd. All rights reserved.

Quantitative PCR measurements of Escherichia coli including shiga toxin-producing E. coli (STEC) in animal feces and environmental waters.

PubMed

Ahmed, W; Gyawali, P; Toze, S

2015-03-03

Quantitative PCR (qPCR) assays were used to determine the concentrations of E. coli including shiga toxin-producing E. coli (STEC) associated virulence genes (eaeA, stx1, stx2, and hlyA) in ten animal species (fecal sources) and environmental water samples in Southeast Queensland, Australia. The mean Log10 concentrations and standard deviations of E. coli 23S rRNA across fecal sources ranged from 1.3 ± 0.1 (horse) to 6.3 ± 0.4 (cattle wastewater) gene copies at a test concentration of 10 ng of DNA. The differences in mean concentrations of E. coli 23S rRNA gene copies among fecal source samples were significantly different from each other (P < 0.0001). Among the virulence genes, stx2 (25%, 95% CI, 17-33%) was most prevalent among fecal sources, followed by eaeA (19%, 95% CI, 12-27%), stx1 (11%, 95% CI, 5%-17%) and hlyA (8%, 95% CI, 3-13%). The Log10 concentrations of STEC virulence genes in cattle wastewater samples ranged from 3.8 to 5.0 gene copies at a test concentration of 10 ng of DNA. Of the 18 environmental water samples tested, three (17%) were positive for eaeA and two (11%) samples were also positive for the stx2 virulence genes. The data presented in this study will aid in the estimation of quantitative microbial risk assessment (QMRA) from fecal pollution of domestic and wild animals in drinking/recreational water catchments.

Dismantling of the PETRA glove box: tritium contamination and inventory assessment

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

Wagner, R.

2015-03-15

The PETRA facility is the first installation in which experiments with tritium were carried out at the Tritium Laboratory Karlsruhe. After completion of two main experimental programs, the decommissioning of PETRA was initiated with the aim to reuse the glove box and its main still valuable components. A decommissioning plan was engaged to: -) identify the source of tritium release in the glove box, -) clarify the status of the main components, -) assess residual tritium inventories, and -) de-tritiate the components to be disposed of as waste. Several analytical techniques - calorimetry on small solid samples, wipe test followedmore » by liquid scintillation counting for surface contamination assessment, gas chromatography on gaseous samples - were deployed and cross-checked to assess the remaining tritium inventories and initiate the decommissioning process. The methodology and the main outcomes of the numerous different tritium measurements are presented and discussed. (authors)« less

Monitoring well utility in a heterogeneous DNAPL source zone area: Insights from proximal multilevel sampler wells and sampling capture-zone modelling

NASA Astrophysics Data System (ADS)

McMillan, Lindsay A.; Rivett, Michael O.; Wealthall, Gary P.; Zeeb, Peter; Dumble, Peter

2018-03-01

Groundwater-quality assessment at contaminated sites often involves the use of short-screen (1.5 to 3 m) monitoring wells. However, even over these intervals considerable variation may occur in contaminant concentrations in groundwater adjacent to the well screen. This is especially true in heterogeneous dense non-aqueous phase liquid (DNAPL) source zones, where cm-scale contamination variability may call into question the effectiveness of monitoring wells to deliver representative data. The utility of monitoring wells in such settings is evaluated by reference to high-resolution multilevel sampler (MLS) wells located proximally to short-screen wells, together with sampling capture-zone modelling to explore controls upon well sample provenance and sensitivity to monitoring protocols. Field data are analysed from the highly instrumented SABRE research site that contained an old trichloroethene source zone within a shallow alluvial aquifer at a UK industrial facility. With increased purging, monitoring-well samples tend to a flow-weighted average concentration but may exhibit sensitivity to the implemented protocol and degree of purging. Formation heterogeneity adjacent to the well-screen particularly, alongside pump-intake position and water level, influence this sensitivity. Purging of low volumes is vulnerable to poor reproducibility arising from concentration variability predicted over the initial 1 to 2 screen volumes purged. Marked heterogeneity may also result in limited long-term sample concentration stabilization. Development of bespoke monitoring protocols, that consider screen volumes purged, alongside water-quality indicator parameter stabilization, is recommended to validate and reduce uncertainty when interpreting monitoring-well data within source zone areas. Generalised recommendations on monitoring well based protocols are also developed. A key monitoring well utility is their proportionately greater sample draw from permeable horizons constituting a significant contaminant flux pathway and hence representative fraction of source mass flux. Acquisition of complementary, high-resolution, site monitoring data, however, vitally underpins optimal interpretation of monitoring-well datasets and appropriate advancement of a site conceptual model and remedial implementation.

Chemical mixtures and environmental effects: a pilot study to assess ecological exposure and effects in streams

USGS Publications Warehouse

Buxton, Herbert T.; Reilly, Timothy J.; Kuivila, Kathryn; Kolpin, Dana W.; Bradley, Paul M.; Villeneuve, Daniel L.; Mills, Marc A.

2015-01-01

Assessment and management of the risks of exposure to complex chemical mixtures in streams are priorities for human and environmental health organizations around the world. The current lack of information on the composition and variability of environmental mixtures and a limited understanding of their combined effects are fundamental obstacles to timely identification and prevention of adverse human and ecological effects of exposure. This report describes the design of a field-based study of the composition and biological activity of chemical mixtures in U.S. stream waters affected by a wide range of human activities and contaminant sources. The study is a collaborative effort by the U.S. Geological Survey and the U.S. Environmental Protection Agency. Scientists sampled 38 streams spanning 24 States and Puerto Rico. Thirty-four of the sites were located in watersheds impacted by multiple contaminant sources, including industrial and municipal wastewater discharges, crop and animal agricultural runoff, urban runoff, and other point and nonpoint contaminant sources. The remaining four sites were minimally development reference watersheds. All samples underwent comprehensive chemical and biological characterization, including sensitive and specific direct analysis for over 700 dissolved organic and inorganic chemicals and field parameters, identification of unknown contaminants (environmental diagnostics), and a variety of bioassays to evaluate biological activity and toxicity.

Assessment of Impacts Produced by Anthropogenic Sources in a Little City near an Important Industrial Area (Modugno, Southern Italy)

PubMed Central

de Gennaro, Gianluigi; Marzocca, Annalisa; Trizio, Livia; Tutino, Maria

2013-01-01

An annual monitoring campaign of VOCs, consisting of twelve sampling periods, was carried out from June 2008 to June 2009 in Modugno, a city located in the Apulia region (Southern Italy), in order to assess the urban air quality, identify the main emission sources, and quantify the cancer and no-cancer risk attributable to inhalation exposures. Monitoring, carried out by using the Radiello diffusive samplers, was conducted in eleven sampling sites throughout the city taking into account the traffic density and the architecture of the city. From the study of the data, it was found that, among all considered VOCs, benzene, toluene, ethylbenzene, and xylenes (BTEX) are the pollutants at higher concentration. The analysis of VOC concentrations, the study of the topography of the city, and the use of different diagnostic ratios between the BTEX species showed that the vehicular traffic emissions were the predominant source of VOCs in the urban area of Modugno. Despite that the annual concentration of benzene is lower than the regulatory limit, the estimation of cancer risk showed that the global lifetime cancer risk attributed to the investigated VOC exposure was not negligible and therefore should be taken into account in future regulatory approaches. PMID:23476120

Comparative Assessment of Heavy Metals in Drinking Water Sources in Two Small-Scale Mining Communities in Northern Ghana.

PubMed

Cobbina, Samuel J; Duwiejuah, Abudu B; Quansah, Reginald; Obiri, Samuel; Bakobie, Noel

2015-08-28

The study assessed levels of heavy metals in drinking water sources in two small-scale mining communities (Nangodi and Tinga) in northern Ghana. Seventy-two (72) water samples were collected from boreholes, hand dug wells, dug-out, and a stream in the two mining communities. The levels of mercury (Hg), arsenic (As), lead (Pb), zinc (Zn), and cadmium (Cd) were determined using an atomic absorption spectrophotometer (AAS). Mean levels (mg/l) of heavy metals in water samples from Nangodi and Tinga communities were 0.038 and 0.064 (Hg), 0.031 and 0.002 (As), 0.250 and 0.031 (Pb), 0.034 and 0.002 (Zn), and 0.534 and 0.023 (Cd), respectively, for each community. Generally, levels of Hg, As, Pb, Zn, and Cd in water from Nangodi exceeded the World Health Organisation (WHO) stipulated limits of 0.010 for Hg, As, and Pb, 3.0 for Zn and 0.003 for Cd for drinking water, and levels of Hg, Pb, and Cd recorded in Tinga, exceeded the stipulated WHO limits. Ingestion of water, containing elevated levels of Hg, As, and Cd by residents in these mining communities may pose significant health risks. Continuous monitoring of the quality of drinking water sources in these two communities is recommended.

Comparative Assessment of Heavy Metals in Drinking Water Sources in Two Small-Scale Mining Communities in Northern Ghana

PubMed Central

Cobbina, Samuel J.; Duwiejuah, Abudu B.; Quansah, Reginald; Obiri, Samuel; Bakobie, Noel

2015-01-01

The study assessed levels of heavy metals in drinking water sources in two small-scale mining communities (Nangodi and Tinga) in northern Ghana. Seventy-two (72) water samples were collected from boreholes, hand dug wells, dug-out, and a stream in the two mining communities. The levels of mercury (Hg), arsenic (As), lead (Pb), zinc (Zn), and cadmium (Cd) were determined using an atomic absorption spectrophotometer (AAS). Mean levels (mg/l) of heavy metals in water samples from Nangodi and Tinga communities were 0.038 and 0.064 (Hg), 0.031 and 0.002 (As), 0.250 and 0.031 (Pb), 0.034 and 0.002 (Zn), and 0.534 and 0.023 (Cd), respectively, for each community. Generally, levels of Hg, As, Pb, Zn, and Cd in water from Nangodi exceeded the World Health Organisation (WHO) stipulated limits of 0.010 for Hg, As, and Pb, 3.0 for Zn and 0.003 for Cd for drinking water, and levels of Hg, Pb, and Cd recorded in Tinga, exceeded the stipulated WHO limits. Ingestion of water, containing elevated levels of Hg, As, and Cd by residents in these mining communities may pose significant health risks. Continuous monitoring of the quality of drinking water sources in these two communities is recommended. PMID:26343702

Towards multi-level biomonitoring of nematodes to assess risk of nitrogen and phosphorus pollution in Jinchuan Wetland of Northeast China.

PubMed

Wang, Yunbiao; Qiao, Jie; He, Chunguang; Wang, Zhongqiang; Luo, Wenbo; Sheng, Lianxi

2015-12-01

Cultivation for agricultural production often poses threats to nearby wetlands ecosystems in fertile landscapes. In this study, nematode ecological indexes were assessed through the main soil properties of the wetlands, farmlands, and edges of wetlands and farmlands in Jinchuan Wetland by the random sampling. Behavior and reproduction in Caenorhabditis elegans (C. elegans) exposed to the sampled waters were also examined. Stress proteins Hsp70 and Hsp90 were measured both in the living field samples of C. elegans and the lab-tested C. elegans. Our results suggested that disturbance to wetland ecosystems by nitrogen and phosphorus reduced nematode richness and proportions of bacterivore nematodes. Bacterivore nematode diversity and plant-parasitic ecological index were proven to be sensitive indicators of the ecological health of wetlands. Nematode Hsp70 were useful biosensors to monitor and assess the levels of nitrogen and phosphorus pollutions in wetlands. Furthermore, multi-level soil faunal assessments by canonical correspondence analysis showed that Jinchuan Wetland is threatened with non-point source pollution from nearby farmlands.

Water quality in the Withers Swash Basin, with emphasis on enteric bacteria, Myrtle Beach, South Carolina, 1991-93

USGS Publications Warehouse

Guimaraes, W.B.

1995-01-01

Water samples were collected in 1991-93 from Withers Swash and its two tributaries (the Mainstem and KOA Branches) in Myrtle Beach, S.C., and analyzed for physical properties, organic and inorganic constituents, and fecal coliform and streptococcus bacteria. Samples were collected during wet- and dry-weather conditions to assess the water quality of the streams before and after storm runoff. Water samples were analyzed for over 200 separate physical, chemical, and biological constituents. Concentrations of 11 constituents violated State criteria for shellfish harvesting waters, and State Human Health Criteria. The 11 constituents included concentrations of dissolved oxygen, arsenic, lead, cadmium, mercury, chlordane, dieldrin, 1,1,1-trichloroethane, 1,1-dichloroethylene, trichloroethylene, and fecal coliform bacteria. Water samples were examined for the presence of enteric bacteria (fecal coliform and fecal streptococcus) at 46 sites throughout the Withers Swash Basin and 5 sites on the beach and in the Atlantic Ocean. Water samples were collected just upstream from all confluences in order to determine sources of bacterial contamination. Temporally and spatially high concentrations of enteric bacteria were detected throughout the Withers Swash Basin; however, these sporadic bacteria concentrations made it difficult to determine a single source of the contamination. These enteric bacteria concentrations are probably derived from a number of sources in the basin including septic tanks, garbage containers, and the feces of waterfowl and domestic animals.

Forensic source differentiation of petrogenic, pyrogenic, and biogenic hydrocarbons in Canadian oil sands environmental samples.

PubMed

Wang, Zhendi; Yang, C; Parrott, J L; Frank, R A; Yang, Z; Brown, C E; Hollebone, B P; Landriault, M; Fieldhouse, B; Liu, Y; Zhang, G; Hewitt, L M

2014-04-30

To facilitate monitoring efforts, a forensic chemical fingerprinting methodology has been applied to characterize and differentiate pyrogenic (combustion derived) and biogenic (organism derived) hydrocarbons from petrogenic (petroleum derived) hydrocarbons in environmental samples from the Canadian oil sands region. Between 2009 and 2012, hundreds of oil sands environmental samples including water (snowmelt water, river water, and tailings pond water) and sediments (from river beds and tailings ponds) have been analyzed. These samples were taken from sites where assessments of wild fish health, invertebrate communities, toxicology and detailed chemistry are being conducted as part of the Canada-Alberta Joint Oil Sands Monitoring Plan (JOSMP). This study describes the distribution patterns and potential sources of PAHs from these integrated JOSMP study sites, and findings will be linked to responses in laboratory bioassays and in wild organisms collected from these same sites. It was determined that hydrocarbons in Athabasca River sediments and waters were most likely from four sources: (1) petrogenic heavy oil sands bitumen; (2) biogenic compounds; (3) petrogenic hydrocarbons of other lighter fuel oils; and (4) pyrogenic PAHs. PAHs and biomarkers detected in snowmelt water samples collected near mining operations imply that these materials are derived from oil sands particulates (from open pit mines, stacks and coke piles). Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

Determination and Distribution of Polycyclic Aromatic Hydrocarbons in Rivers, Sediments and Wastewater Effluents in Vhembe District, South Africa

PubMed Central

Edokpayi, Joshua N.; Odiyo, John O.; Popoola, Oluwaseun E.; Msagati, Titus A. M.

2016-01-01

Polycyclic aromatic hydrocarbons are very toxic and persistent environmental contaminants. This study was undertaken to assess the concentrations and possible sources of 16 PAHs (Polycyclic aromatic hydrocarbons) classified by the United State Environmental Protection Agency as priority pollutants in water and sediments of the Mvudi and Nzhelele Rivers. Effluents from Thohoyandou wastewater treatment plant and Siloam waste stabilization ponds were also investigated. Diagnostic ratios were used to evaluate the possible sources of PAHs. PAHs in the water samples were extracted using 1:1 dichloromethane and n-hexane mixtures, while those in the sediment samples were extracted with 1:1 acetone and dichloromethane using an ultrasonication method. The extracts were purified using an SPE technique and reconstituted in n-hexane before analyses with a gas chromatograph time of flight—mass spectrometer. The results obtained indicate the prevalence of high molecular weight PAHs in all the samples. PAHs concentrations in water and sediment samples from all the sampling sites were in the range of 13.174–26.382 mg/L and 27.10–55.93 mg/kg, respectively. Combustion of biomass was identified as the major possible source of PAHs. Effluents from wastewater treatment facilities were also considered as major anthropogenic contributions to the levels of PAHs found in both river water and sediments. Mvudi and Nzhelele Rivers show moderate to high contamination level of PAHs. PMID:27043597

Pornography Consumption, Perceptions of Pornography as Sexual Information, and Condom Use.

PubMed

Wright, Paul J; Sun, Chyng; Steffen, Nicola

2018-04-10

Pornography use is becoming more commonplace and may be a modality by which individuals receive sex education. This survey study assessed pornography consumption, perceptions of pornography as a source of sexual information, and condom use in a heterosexual sample of 200 sexually active German adults who were not in monogamous relationships. At the bivariate, overall sample level, there was only a modest association between consuming pornography and a decreased frequency of condom use. However, consistent with the sexual script acquisition, activation, application model ( 3 AM) of sexual media socialization, this association was moderated by differential perceptions of pornography as a source of sexual information. Interaction decomposition revealed that there was no association between pornography consumption and condom use among participants who disagreed that pornography is a source of sexual information. Conversely, pornography consumption was associated with a lower frequency of condom use among participants who agreed that pornography is a source of sexual information. As the perception that pornography is a source of sexual information strengthened, the relationship between pornography consumption and less frequent condom use increased. Gender did not moderate these associations. These findings point toward the importance of fostering a critical reading of pornography through media literacy education.

Occurrence and temporal variability of methyl tert-butyl ether (MTBE) and other volatile organic compounds in select sources of drinking water : results of the focused survey

USGS Publications Warehouse

Delzer, Gregory C.; Ivahnenko, Tamara

2003-01-01

The large-scale use of the gasoline oxygenate methyl tert-butyl ether (MTBE), and its high solubility, low soil adsorption, and low biodegradability, has resulted in its detection in ground water and surface water in many places throughout the United States. Studies by numerous researchers, as well as many State and local environmental agencies, have discovered high levels of MTBE in soils and ground water at leaking underground gasoline-storage-tank sites and frequent occurrence of low to intermediate levels of MTBE in reservoirs used for both public water supply and recreational boating.In response to these findings, the American Water Works Association Research Foundation sponsored an investigation of MTBE and other volatile organic compounds (VOCs) in the Nation's sources of drinking water. The goal of the investigation was to provide additional information on the frequency of occurrence, concentration, and temporal variability of MTBE and other VOCs in source water used by community water systems (CWSs). The investigation was completed in two stages: (1) reviews of available literature and (2) the collection of new data. Two surveys were associated with the collection of new data. The first, termed the Random Survey, employed a statistically stratified design for sampling source water from 954 randomly selected CWSs. The second, which is the focus of this report, is termed the Focused Survey, which included samples collected from 134 CWS source waters, including ground water, reservoirs, lakes, rivers, and streams, that were suspected or known to contain MTBE. The general intent of the Focused Survey was to compare results with the Random Survey and provide an improved understanding of the occurrence, concentration, temporal variability, and anthropogenic factors associated with frequently detected VOCs. Each sample collected was analyzed for 66 VOCs, including MTBE and three other ether gasoline oxygenates (hereafter termed gasoline oxygenates). As part of the Focused Survey, 451 source-water samples and 744 field quality-control (QC) samples were collected from 78 ground-water, 39 reservoir and (or) lake, and 17 river and (or) stream source waters at fixed intervals for a period of 1 year.Using a common assessment level of 0.2 μg/L (micrograms per liter) (2.0 μg/L for methyl ethyl ketone), 37 of the 66 VOCs analyzed were detected in both surveys. However, VOCs, especially MTBE and other gasoline oxygenates, were detected more frequently in the Focused Survey than in the Random Survey. MTBE was detected in 55.5 percent of the CWSs sampled in the Focused Survey and in 8.7 percent of those sampled in the Random Survey. Little difference in occurrence, however, was observed for trihalomethanes (THMs), which were detected in 16.4 and 14.8 percent of Focused Survey and Random Survey CWSs, respectively. This may indicate a pervasive occurrence of THMs in several source-water types, regardless of CWS size or geographic location.Using data at or above the method detection limit to assess temporal variability and anthropogenic factors associated with frequent detection of select VOCs, concentrations in the Focused Survey in ground-water, reservoir, and river source waters were typically less than 1 μg/L. Also, at a 95-percent confidence interval, no statistically significant differences were observed in comparing concentrations in the first and second ground-water sample. A weak seasonal pattern was observed in samples collected from reservoirs and lakes where gasoline oxygenates and other gasoline compounds were detected more frequently during spring and summer, presumedly a result of increased use of motorized watercraft during these seasons. In contrast, seasonal patterns were not observed in samples collected from rivers and streams. The lack of seasonal differences in river and stream source waters sampled may indicate a common and continuous source of contamination.The most frequently detected VOC (MTBE) and the two most frequently occurring subgroups of VOCs (gasoline oxygenates and THMs) detected in CWS source waters were further characterized to evaluate some anthropogenic factors that may better explain their frequent occurrence. Gasoline oxygenates were detected in 73.9 percent of all CWSs sampled. The concentration of gasoline oxygenates was slightly correlated with watercraft use on reservoirs inside MTBE high-use areas (r2=0.3783) but not outside of these areas (r2=0.0242). In general, the concentration of gasoline oxygenates increased as watercraft use increased. THMs were detected in 47.8 percent of the CWSs supplied by surface water. The frequent occurrence of THMs in reservoir source waters was determined to be an artifact of disinfection and the recycling of chlorinated water to these reservoirs. All CWSs with frequent occurrence of THMs served by a reservoir indicated that chlorine was added to waters for various reasons and that the chlorinated water was then released back to,or upstream of, the reservoir or lake that was sampled.

Study design and percent recoveries of anthropogenic organic compounds with and without the addition of ascorbic acid to preserve water samples containing free chlorine, 2004-06

USGS Publications Warehouse

Valder, Joshua F.; Delzer, Gregory C.; Price, Curtis V.; Sandstrom, Mark W.

2008-01-01

The National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS) began implementing Source Water-Quality Assessments (SWQAs) in 2002 that focus on characterizing the quality of source water and finished water of aquifers and major rivers used by some of the larger community water systems in the United States. As used for SWQA studies, source water is the raw (ambient) water collected at the supply well prior to water treatment (for ground water) or the raw (ambient) water collected from the river near the intake (for surface water). Finished water is the water that is treated, which typically involves, in part, the addition of chlorine or other disinfection chemicals to remove pathogens, and is ready to be delivered to consumers. Finished water is collected before the water enters the distribution system. This report describes the study design and percent recoveries of anthropogenic organic compounds (AOCs) with and without the addition of ascorbic acid to preserve water samples containing free chlorine. The percent recoveries were determined by using analytical results from a laboratory study conducted in 2004 by the USGS's National Water Quality Laboratory (NWQL) and from data collected during 2004-06 for a field study currently (2008) being conducted by the USGS's NAWQA Program. The laboratory study was designed to determine if preserving samples with ascorbic acid (quenching samples) adversely affects analytical performance under controlled conditions. During the laboratory study, eight samples of reagent water were spiked for each of five analytical schedules evaluated. Percent recoveries from these samples were then compared in two ways: (1) four quenched reagent spiked samples analyzed on day 0 were compared with four quenched reagent spiked samples analyzed on day 7 or 14, and (2) the combined eight quenched reagent spiked samples analyzed on day 0, 7, or 14 were compared with eight laboratory reagent spikes (LRSs). Percent recoveries from the quenched reagent spiked samples that were analyzed at two different times (day 0 and day 7 or 14) can be used to determine the stability of the quenched samples held for an amount of time representative of the normal amount of time between sample collection and analysis. The comparison between the quenched reagent spiked samples and the LRSs can be used to determine if quenching samples adversely affects the analytical performance under controlled conditions. The field study began in 2004 and is continuing today (February 2008) to characterize the effect of quenching on field-matrix spike recoveries and to better understand the potential oxidation and transformation of 277 AOCs. Three types of samples were collected from 11 NAWQA Study Units across the Nation: (1) quenched finished-water samples (not spiked), (2) quenched finished-water spiked samples, and (3) nonquenched finished-water spiked samples. Percent recoveries of AOCs in quenched and nonquenched finished-water spiked samples collected during 2004-06 are presented. Comparisons of percent recoveries between quenched and nonquenched spiked samples can be used to show how quenching affects finished-water samples. A maximum of 6 surface-water and 7 ground-water quenched finished-water spiked samples paired with nonquenched finished-water spiked samples were analyzed. Analytical results for the field study are presented in two ways: (1) by surface-water supplies or ground-water supplies, and (2) by use (or source) group category for surface-water and ground-water supplies. Graphical representations of percent recoveries for the quenched and nonquenched finished-water spiked samples also are presented.

A comprehensive analysis of the content of heavy rare-earth elements and platinum in snow samples to assess the ecological hazard of air pollution in urban areas

NASA Astrophysics Data System (ADS)

Vinokurov, S. F.; Tarasova, N. P.; Trunova, A. N.; Sychkova, V. A.

2017-07-01

Snow samples from the territory of the Setun River Valley Wildlife Sanctuary are analyzed for the content of rare-earth elements, heavy metals, and other hazardous elements by the inductively coupled plasma mass-spectrometry method. The changes in the concentrations of rare-earth elements, Pt, Pd, and indicator ratios of elements in the solid fractions of snow are revealed. A trend toward a decrease in the content of several elements northeastward of the Moscow Ring Road (MRR) is established. The level of seasonal atmospheric contamination of the area under study is assessed, and a possible source is identified.

The Fukushima releases: an inverse modelling approach to assess the source term by using gamma dose rate observations

NASA Astrophysics Data System (ADS)

Saunier, Olivier; Mathieu, Anne; Didier, Damien; Tombette, Marilyne; Quélo, Denis; Winiarek, Victor; Bocquet, Marc

2013-04-01

The Chernobyl nuclear accident and more recently the Fukushima accident highlighted that the largest source of error on consequences assessment is the source term estimation including the time evolution of the release rate and its distribution between radioisotopes. Inverse modelling methods have proved to be efficient to assess the source term due to accidental situation (Gudiksen, 1989, Krysta and Bocquet, 2007, Stohl et al 2011, Winiarek et al 2012). These methods combine environmental measurements and atmospheric dispersion models. They have been recently applied to the Fukushima accident. Most existing approaches are designed to use air sampling measurements (Winiarek et al, 2012) and some of them use also deposition measurements (Stohl et al, 2012, Winiarek et al, 2013). During the Fukushima accident, such measurements are far less numerous and not as well distributed within Japan than the dose rate measurements. To efficiently document the evolution of the contamination, gamma dose rate measurements were numerous, well distributed within Japan and they offered a high temporal frequency. However, dose rate data are not as easy to use as air sampling measurements and until now they were not used in inverse modelling approach. Indeed, dose rate data results from all the gamma emitters present in the ground and in the atmosphere in the vicinity of the receptor. They do not allow one to determine the isotopic composition or to distinguish the plume contribution from wet deposition. The presented approach proposes a way to use dose rate measurement in inverse modeling approach without the need of a-priori information on emissions. The method proved to be efficient and reliable when applied on the Fukushima accident. The emissions for the 8 main isotopes Xe-133, Cs-134, Cs-136, Cs-137, Ba-137m, I-131, I-132 and Te-132 have been assessed. The Daiichi power plant events (such as ventings, explosions…) known to have caused atmospheric releases are well identified in the retrieved source term, except for unit 3 explosion where no measurement was available. The comparisons between the simulations of atmospheric dispersion and deposition of the retrieved source term show a good agreement with environmental observations. Moreover, an important outcome of this study is that the method proved to be perfectly suited to crisis management and should contribute to improve our response in case of a nuclear accident.

Pathways of heavy metals contamination and associated human health risk in Ajay River basin, India.

PubMed

Singh, Umesh Kumar; Kumar, Balwant

2017-05-01

The sources of heavy metals and their loads in the Ajay River were investigated based on the seasonal and spatial variations. To identify variation and pathways of heavy metals, seventy-six water samples were estimated for 2 years at nineteen sampling sites. The multifaceted data were applied to evaluate statistical relation between variables and arithmetic calculation of the indices. Fickling plot suggested that the acidic pollutants do not affect the water quality because all samples lie within the neutral pH range. Further, OC showed significant relation with Fe, Mn, Ni and Co. Compositional analysis identified weathering of rocks, mobility of soil and sediment, atmospheric deposition and numerous anthropogenic inputs as major sources of heavy metals. The mean values of heavy metal pollution index (HPI) and pollution index (PI) were found above the critical index and strong loadings respectively due to higher values of Cd, Pb and Fe. Similarly, assessment of human risk revealed that the high load of Cd, Pb and Fe in water body could harm the population. Majority of the samples showed high concentration of heavy metals as compared to regulatory standard and background values, which suggests that the water is highly contaminated through numerous geogenic and anthropogenic sources. Copyright © 2017 Elsevier Ltd. All rights reserved.

Passive soil gas technique for investigating soil and groundwater plume emanating from volatile organic hydrocarbon at Bazian oil refinery site.

PubMed

Hamamin, Dara Faeq

2018-05-01

The current work is an attempt to illustrate the importance of using passive soil gas as an innovative investigation technique in the assessment of soil and groundwater pollutions that emanates from volatile hydrocarbon activities in newly emerging countries. Bazian Oil Refinery as one of the largest refinery in Iraqi Kurdistan Region produces 40,000 barrels a day and provides a wide range of petroleum products for daily consumption. The types and scale of different process that happen in this industrial site have led to concerns with regard to its impact on both the soil and groundwater the vicinity of the factory. The researcher conducted a combined sampling design with a dual-phased extraction procedure for soil vapor and groundwater samples in order to assess the susceptibility of the subsurface to pollution with hydrocarbon. The aims were to characterize potential source(s), map the areal extent of the site which is at risk to be affected with the identified9 hydrocarbon compounds and vapor. A collection kit from Beacon Environmental Service was used to collect a total number of 50 passive soil vapors in the first step of work. To extrapolate results, five shallow boring for soils and six for water sampling were carefully observed. The selection of the sampling points was based on the results revealed by the PSG survey that showed significant quantities of analyzed organic hydrocarbon for a follow-up investigation. The matrices were analyzed by ALS Laboratory to target more than 40 VOCs and SVOCs. The plan was to make the mass to concentration tie-in for the selected analyzed compounds (Benzene, Toluene, and Total Petroleum Hydrocarbons) from the PSG in mass (nanograms) with both the soil and water samples in concentration. The results revealed that the PSG technique is unique in identifying the source and extent of soil and groundwater pollutions plume. Copyright © 2017 Elsevier B.V. All rights reserved.

Trace Metals in Saharan Dust: The Use of in Vitro Bioaccessibility Extractions To Assess Potential Health Risks in a Dustier World: Chapter 3

USGS Publications Warehouse

Morman, Suzette A.; Garrison, Virginia H.; Plumlee, Geoffrey S.

2013-01-01

Exposure to fine particulate matter (PM) is acknowledged as a risk factor for human morbidity and mortality. Epidemiology and toxicology studies have focused on anthropogenic sources of PM and few consider contributions produced by natural processes (geogenic), or PM produced from natural sources as a result of human activities (geoanthropogenic PM). The focus of this study was to elucidate relationships between human/ecosystem health and dusts produced by a system transitioning from a dominantly natural to a geoanthropogenic PM source. As part of a larger study investigating the relationship between atmospheric transportation of African dust, human health, and coral reef declines, we examined dust samples sourced in Mali, Africa, collected using high-volume samplers from three sites (Mali, Tobago and U.S. Virgin Islands). Inhalation and ingestion exposure pathways were explored by filter extractions using simulated lung and gastric fluids. Bioaccessibility varied by metal and extraction fluid. Although too few samples were analyzed for robust statistics, concentrations for several metals decreased slightly while bioaccessibility increased at downwind sites.

Coastal Online Analysis and Synthesis Tool 2.0 (COAST)

NASA Technical Reports Server (NTRS)

Brown, Richard B.; Navard, Andrew R.; Nguyen, Beth T.

2009-01-01

The Coastal Online Assessment and Synthesis Tool (COAST) 3D geobrowser has been developed to integrate disparate coastal datasets from NASA and other sources into a desktop tool that provides new data visualization and analysis capabilities for coastal researchers, managers, and residents. It is built upon the widely used NASA-developed open source World Wind geobrowser from NASA Ames (Patrick Hogan et al.) .Net and C# version is used for development. It is leveraged off of World Wind community shared code samples and COAST 2.0 enhancement direction is based on Coastal science community feedback and needs assessment (GOMA). The main objective is to empower the user to bring more user-meaningful data into multi-layered, multi-temporal spatial context.

Inter-species and intra-annual variations of moss nitrogen utilization: Implications for nitrogen deposition assessment.

PubMed

Dong, Yu-Ping; Liu, Xue-Yan; Sun, Xin-Chao; Song, Wei; Zheng, Xu-Dong; Li, Rui; Liu, Cong-Qiang

2017-11-01

Moss nitrogen (N) concentrations and natural 15 N abundance (δ 15 N values) have been widely employed to evaluate annual levels and major sources of atmospheric N deposition. However, different moss species and one-off sampling were often used among extant studies, it remains unclear whether moss N parameters differ with species and different samplings, which prevented more accurate assessment of N deposition via moss survey. Here concentrations, isotopic ratios of bulk carbon (C) and bulk N in natural epilithic mosses (Bryum argenteum, Eurohypnum leptothallum, Haplocladium microphyllum and Hypnum plumaeforme) were measured monthly from August 2006 to August 2007 at Guiyang, SW China. The H. plumaeforme had significantly (P < 0.05) lower bulk N concentrations and higher δ 13 C values than other species. Moss N concentrations were significantly (P < 0.05) lower in warmer months than in cooler months, while moss δ 13 C values exhibited an opposite pattern. The variance component analyses showed that different species contributed more variations of moss N concentrations and δ 13 C values than different samplings. Differently, δ 15 N values did not differ significantly between moss species, and its variance mainly reflected variations of assimilated N sources, with ammonium as the dominant contributor. These results unambiguously reveal the influence of inter-species and intra-annual variations of moss N utilization on N deposition assessment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Intraoperative visualization and assessment of electromagnetic tracking error

NASA Astrophysics Data System (ADS)

Harish, Vinyas; Ungi, Tamas; Lasso, Andras; MacDonald, Andrew; Nanji, Sulaiman; Fichtinger, Gabor

2015-03-01

Electromagnetic tracking allows for increased flexibility in designing image-guided interventions, however it is well understood that electromagnetic tracking is prone to error. Visualization and assessment of the tracking error should take place in the operating room with minimal interference with the clinical procedure. The goal was to achieve this ideal in an open-source software implementation in a plug and play manner, without requiring programming from the user. We use optical tracking as a ground truth. An electromagnetic sensor and optical markers are mounted onto a stylus device, pivot calibrated for both trackers. Electromagnetic tracking error is defined as difference of tool tip position between electromagnetic and optical readings. Multiple measurements are interpolated into the thin-plate B-spline transform visualized in real time using 3D Slicer. All tracked devices are used in a plug and play manner through the open-source SlicerIGT and PLUS extensions of the 3D Slicer platform. Tracking error was measured multiple times to assess reproducibility of the method, both with and without placing ferromagnetic objects in the workspace. Results from exhaustive grid sampling and freehand sampling were similar, indicating that a quick freehand sampling is sufficient to detect unexpected or excessive field distortion in the operating room. The software is available as a plug-in for the 3D Slicer platforms. Results demonstrate potential for visualizing electromagnetic tracking error in real time for intraoperative environments in feasibility clinical trials in image-guided interventions.

Post-earthquake outbreak of rotavirus gastroenteritis in Kashmir (India): an epidemiological analysis.

PubMed

Karmakar, Somenath; Rathore, Abhilakh Singh; Kadri, Syed Manzoor; Dutt, Som; Khare, Shashi; Lal, Shiv

2008-10-01

An earthquake struck Kashmir on 8 October 2005. A central team of public health specialists was sent to Kashmir to assess the public health measures required following the earthquake, and to assist in institution of public health measures. Epidemiological and environmental investigation in Tangdar block (Kupwara district) and Uri Tehsil (Baramula district). Visits to villages affected by the earthquake, rehabilitation camps and health care, examination of cases with acute diarrhoeal disease (ADD), environmental observations, collection of clinical samples from ADD cases and environmental samples from drinking water sources, and laboratory methods. In total, 1783 cases of ADD were reported between 14 October and 17 December 2005 in Tangdar (population 65000). The overall attack rate was 20% in children under 4 years of age. Twelve cases of ADD with loose motions without blood were studied, and 11 rectal swabs and one stool sample were processed. No bacterial enteropathogens could be isolated, but three of the 12 samples yielded rotavirus antigen on enzyme-linked immunosorbent assay. Twelve of 13 (92.3%) water samples, collected from various stream or tap water (source: spring/stream) sources, were unsatisfactory (P=0.001) using the H(2)S strip method compared with other sources (well/mineral water). All eight water sources in Tangdar block were unsatisfactory, indicated by blackening of H(2)S filter paper strips. Following the earthquake, drinking stream water or tap water without boiling or chlorination may have led to a common source water-borne outbreak of rotavirus gastroenteritis. Other contributing factors were: overcrowding; poor sanitation; open-air defaecation; poor hygiene; and living in makeshift camps near streams. Person-to-person transmission may also have contributed to perpetuation of the outbreak. Following the establishment of medical camps and information, education and communication regarding the need to drink boiled water and follow safer hygienic practices, the outbreak was brought under control. The earthquake in Kashmir in 2005 led to widespread contamination of drinking water sources such as stream and tap water (source: stream or spring). This appears to have led to a common source outbreak of rotavirus between October and December 2005, leading to ADD, amongst infants and small children, transmitted by the faecal-oral route and perpetuated by person-to-person transmission.

Sediment source fingerprinting as an aid to catchment management: A review of the current state of knowledge and a methodological decision-tree for end-users

USGS Publications Warehouse

Collins, A.L; Pulley, S.; Foster, I.D.L; Gellis, Allen; Porto, P.; Horowitz, A.J.

2017-01-01

The growing awareness of the environmental significance of fine-grained sediment fluxes through catchment systems continues to underscore the need for reliable information on the principal sources of this material. Source estimates are difficult to obtain using traditional monitoring techniques, but sediment source fingerprinting or tracing procedures, have emerged as a potentially valuable alternative. Despite the rapidly increasing numbers of studies reporting the use of sediment source fingerprinting, several key challenges and uncertainties continue to hamper consensus among the international scientific community on key components of the existing methodological procedures. Accordingly, this contribution reviews and presents recent developments for several key aspects of fingerprinting, namely: sediment source classification, catchment source and target sediment sampling, tracer selection, grain size issues, tracer conservatism, source apportionment modelling, and assessment of source predictions using artificial mixtures. Finally, a decision-tree representing the current state of knowledge is presented, to guide end-users in applying the fingerprinting approach.

Metal sources and exposures in the homes of young children living near a mining-impacted Superfund site.

PubMed

Zota, Ami R; Schaider, Laurel A; Ettinger, Adrienne S; Wright, Robert O; Shine, James P; Spengler, John D

2011-01-01

Children living near hazardous waste sites may be exposed to environmental contaminants, yet few studies have conducted multi-media exposure assessments, including residential environments where children spend most of their time. We sampled yard soil, house dust, and particulate matter with aerodynamic diameter <2.5 in 59 homes of young children near an abandoned mining area and analyzed samples for lead (Pb), zinc (Zn), cadmium (Cd), arsenic (As), and manganese (Mn). In over half of the homes, dust concentrations of Pb, Zn, Cd, and As were higher than those in soil. Proximity to mine waste (chat) piles and the presence of chat in the driveway significantly predicted dust metals levels. Homes with both chat sources had Pb, Zn, Cd, and As dust levels two to three times higher than homes with no known chat sources after controlling for other sources. In contrast, Mn concentrations in dust were consistently lower than in soil and were not associated with chat sources. Mn dust concentrations were predicted by soil concentrations and occupant density. These findings suggest that nearby outdoor sources of metal contaminants from mine waste may migrate indoors. Populations farther away from the mining site may also be exposed if secondary uses of chat are in close proximity to the home.

Investigating the sources of sediment in a Canadian agricultural watershed using a colour-based fingerprinting technique

NASA Astrophysics Data System (ADS)

Barthod, Louise; Lobb, David; Owens, Philip; Martinez-Carreras, Nuria; Koiter, Alexander; Petticrew, Ellen; McCullough, Gregory

2014-05-01

The development of beneficial management practises to minimize adverse impacts of agriculture on soil and water quality requires information on the sources of sediment at the watershed scale. Sediment fingerprinting allows for the determination of sediment sources and apportionment of their contribution within a watershed, using unique physical, radiochemical or biogeochemical properties, or fingerprints, of the potential sediment sources. The use of sediment colour as a fingerprint is an emerging technique that can provide a rapid and inexpensive means of investigating sediment sources. This technique is currently being utilized to determine sediment sources within the South Tobacco Creek Watershed, an agricultural watershed located in the Canadian prairies (south-central Manitoba). Suspended sediment and potential source (topsoil, channel bank and shale bedrock material) samples were collected between 2009 and 2011 at six locations along the main stem of the creek. Sample colour was quantified from diffuse reflectance spectrometry measurements over the visible wavelength range using a spectroradiometer (ASD Field Spec Pro, 400-2500 nm). Sixteen colour coefficients were derived from several colour space models (CIE XYZ, CIE xyY, CIE Lab, CIE Luv, CIE Lch, Landsat RGB, Redness Index). The individual discrimination power of the colour coefficients, after passing several prerequisite tests (e.g., linearly additive behaviour), was assessed using discriminant function analysis. A stepwise discriminant analysis, based on the Wilk's lambda criterion, was then performed in order to determine the best-suited colour coefficient fingerprints which maximized the discrimination between the potential sources. The selected fingerprints classified the source samples in the correct category 86% of the time. The misclassification is due to intra-source variability and source overlap which can lead to higher uncertainty in sediment source apportionment. The selected fingerprints were then included in a Bayesian mixing model using Monte-Carlo simulation (Stable Isotope Analysis in R, SIAR) in order to apportion the contribution of the different sources to the sediment collected at each location. A switch in the dominant sediment source between the headwaters and the outlet of the watershed is observed. Sediment is enriched with shale bedrock and depleted of topsoil sources as the stream crosses and down-cuts through the Manitoba Escarpment. The switch in sources highlights the importance of the sampling location in relation to the scale and geomorphic connectivity of the watershed. Although the results include considerable uncertainty, they are consistent with the findings from a classical fingerprinting approach undertaken in the same watershed (i.e., geochemical and radionuclide fingerprints), and confirm the potential of sediment colour parameters as suitable fingerprints.

Assessment of On-site sanitation system on local groundwater regime in an alluvial aquifer

NASA Astrophysics Data System (ADS)

Quamar, Rafat; Jangam, C.; Veligeti, J.; Chintalapudi, P.; Janipella, R.

2017-12-01

The present study is an attempt to study the impact of the On-site sanitation system on the groundwater sources in its vicinity. The study has been undertaken in the Agra city of Yamuna sub-basin. In this context, sampling sites (3 nos) namely Pandav Nagar, Ayodhya Kunj and Laxmi Nagar were selected for sampling. The groundwater samples were analyzed for major cations, anions and faecal coliform. Critical parameters namely chloride, nitrate and Faecal coliform were considered to assess the impact of the On-site sanitation systems. The analytical results shown that except for chloride, most of the samples exceeded the Bureau of Indian Standard limits for drinking water for all the other analyzed parameters, i.e., nitrate and faecal coliform in the first two sites. In Laxmi Nagar, except for faecal coliform, all the samples are below the BIS limits. In all the three sites, faecal coliform was found in majority of the samples. A comparison of present study indicates that the contamination of groundwater in alluvial setting is less as compared to hard rock where On-site sanitation systems have been implemented.

Biogeochemical snapshot of an urban water system: The Anacostia River, Washington DC

NASA Astrophysics Data System (ADS)

Macavoy, S.; Ewers, E.; Bushaw-Newton, K.

2007-12-01

Highly urbanized and contaminated with PAHs, heavy metals, and sewage, the Anacostia River flows through Maryland and Washington, DC into the tidal Potomac River. Efforts have been underway to assess the river's ecological integrity and to determine the extent of anthropogenic influences. This study examines the nutrients, bacterial biomarkers, organic material, and carbon, nitrogen and sulfur sources in the Anacostia. High biological oxygen demand and low nitrogen (0.33-0.56 mg /L)/phosphorus (0.014 - 0.021 mg/L) concentrations were observed in three areas of the river. Bacterial activity based on carbon source utilization was higher in sediment samples than in water column samples. While bacterial abundances were decreased in downstream areas of sediment; abundances increased in downstream areas in the water column. Downstream sites had higher nutrient concentrations and dissolved organic carbon (up to 13.7 mg/L). Odd-chain length and branched fatty acids (FAs) in the sediments indicated bacterial sources, but long chain FAs indicative of terrestrial primary production were also abundant in some sediments. Also dominant among methyl esters and ketones in some sediment and water column samples was methyl isobutyl ketone, a common industrial solvent and combustion by-product. Sediment carbon stable isotope analyses show a mix of autochthonous and allochthonous derived materials, but most carbon was derived from terrestrial sources (-23.3 to -31.7°). Sediment nitrogen stable isotopes ranged from -5.4 to. 5.6, showing nitrate uptake by plants and also recycling of nitrogen within the river. Sulfur sources were generally between 3 and -5, reflecting local sulfate sources and anaerobic sulfate reduction.

Inferring the source of evaporated waters using stable H and O isotopes

NASA Astrophysics Data System (ADS)

Bowen, G. J.; Putman, A.; Brooks, J. R.; Bowling, D. R.; Oerter, E.; Good, S. P.

2017-12-01

Stable isotope ratios of H and O are widely used identify the source of water, e.g., in aquifers, river runoff, soils, plant xylem, and plant-based beverages. In situations where the sampled water is partially evaporated, its isotope values will have evolved along an evaporation line (EL) in δ2H/δ18O space, and back-correction along the EL to its intersection with a meteoric water line (MWL) has been used to estimate the source water's isotope ratios. Several challenges and potential pitfalls exist with traditional approaches to this problem, including potential for bias from a commonly used regression-based approach for EL slope estimation and incomplete estimation of uncertainty in most studies. We suggest the value of a model-based approach to EL estimation, and introduce a mathematical framework that eliminates the need to explicitly estimate the EL-MWL intersection, simplifying analysis and facilitating more rigorous uncertainty estimation. We apply this analysis framework to data from 1,000 lakes sampled in EPA's 2007 National Lakes Assessment. We find that data for most lakes is consistent with a water source similar to annual runoff, estimated from monthly precipitation and evaporation within the lake basin. Strong evidence for both summer- and winter-biased sources exists, however, with winter bias pervasive in most snow-prone regions. The new analytical framework should improve the rigor of source-water inference from evaporated samples in ecohydrology and related sciences, and our initial results from U.S. lakes suggest that previous interpretations of lakes as unbiased isotope integrators may only be valid in certain climate regimes.

Lead Concentration Levels in Water Samples Collected in Alameda County, CA

NASA Astrophysics Data System (ADS)

Sethy, D.; Hoang, R.; Yu, I.; Hernandez, N.; Fang, K.; Zhang, W.; Li, J.; Munui, K. N.; Sot, R.; Luong, K.; Bonzo, R.; Sankar, R.; Chiu, D.; Rodriguez, V. A.

2016-12-01

The recent health crisis in Flint, Michigan has attracted an amount of interest in other public utilities' water supplies and infrastructure with regards to concerns over the presence of lead. In an effort to begin assessing the potential for a health crisis similar to that experienced in Flynt, during 2016 our team measured lead concentration levels in water samples by collected in Alameda County. More than 12 sites were selected from which samples were collected. These sites included parks, schools, and private residences. At each site 500mL samples were collected and prepared for later analysis. Samples were subjected to an analytical chemistry technique designed to isolate and concentrate lead to detectable levels of 1 part per billion (ppb). All 8 samples yielded detectable levels of lead; all samples were also well below the EPA regulatory 15 ppb. Two samples collected in West Oakland parks were found to have the highest and lowest levels: DeFremery (4 ppb) and Raimondi (1ppb), respectively. Though preliminary in nature, results from this study suggest that further investigations should be undertaken to assess possible lead contamination associated with drinking water sources in Alameda County.

Fitting distributions to microbial contamination data collected with an unequal probability sampling design.

PubMed

Williams, M S; Ebel, E D; Cao, Y

2013-01-01

The fitting of statistical distributions to microbial sampling data is a common application in quantitative microbiology and risk assessment applications. An underlying assumption of most fitting techniques is that data are collected with simple random sampling, which is often times not the case. This study develops a weighted maximum likelihood estimation framework that is appropriate for microbiological samples that are collected with unequal probabilities of selection. A weighted maximum likelihood estimation framework is proposed for microbiological samples that are collected with unequal probabilities of selection. Two examples, based on the collection of food samples during processing, are provided to demonstrate the method and highlight the magnitude of biases in the maximum likelihood estimator when data are inappropriately treated as a simple random sample. Failure to properly weight samples to account for how data are collected can introduce substantial biases into inferences drawn from the data. The proposed methodology will reduce or eliminate an important source of bias in inferences drawn from the analysis of microbial data. This will also make comparisons between studies and the combination of results from different studies more reliable, which is important for risk assessment applications. © 2012 No claim to US Government works.

Soil-transmitted helminth eggs assessment in wastewater in an urban area in India.

PubMed

Grego, Sonia; Barani, Viswa; Hegarty-Craver, Meghan; Raj, Antony; Perumal, Prasanna; Berg, Adrian B; Archer, Colleen

2018-02-01

Water quality and sanitation are inextricably linked to prevalence and control of soil-transmitted helminth infections, a public health concern in resource-limited settings. India bears a large burden of disease associated with poor sanitation. Transformative onsite sanitation technologies are being developed that feature elimination of pathogens including helminth eggs in wastewater treatment. We are conducting third-party testing of multiple sanitation technology systems in Coimbatore (Tamil Nadu) India. To ensure stringent testing of the pathogen removal ability of sanitation technologies, the presence of helminth eggs in wastewater across the town of Coimbatore was assessed. Wastewater samples from existing test sites as well as desludging trucks servicing residential and non-residential septic tanks, were collected. The AmBic methodology (based on washing, sieving, sedimenting and floating) was used for helminth egg isolation. We tested 29 different source samples and found a 52% prevalence of potentially infective helminth eggs. Identification and enumeration of helminth species is reported against the septage source (private residential vs. shared toilet facility) and total solids content. Trichuris egg counts were higher than those of hookworm and Ascaris from desludging trucks, whereas hookworm egg counts were higher in fresh wastewater samples. Surprisingly, no correlation between soil transmitted helminth eggs and total solids was observed.

VizieR Online Data Catalog: ChaMP. I. First X-ray source catalog (Kim+, 2004)

NASA Astrophysics Data System (ADS)

Kim, D.-W.; Cameron, R. A.; Drake, J. J.; Evans, N. R.; Freeman, P.; Gaetz, T. J.; Ghosh, H.; Green, P. J.; Harnden, F. R. Jr; Karovska, M.; Kashyap, V.; Maksym, P. W.; Ratzlaff, P. W.; Schlegel, E. M.; Silverman, J. D.; Tananbaum, H. D.; Vikhlinin, A. A.; Wilkes, B. J.; Grimes, J. P.

2004-01-01

The Chandra Multiwavelength Project (ChaMP) is a wide-area (~14deg2 < survey of serendipitous Chandra X-ray sources, aiming to establish fair statistical samples covering a wide range of characteristics (such as absorbed active galactic nuclei, high-z clusters of galaxies) at flux levels (fX~10-15 to 10-14erg/s/cm2) ) intermediate between the Chandra deep surveys and previous missions. We present the first ChaMP catalog, which consists of 991 near on-axis, bright X-ray sources obtained from the initial sample of 62 observations. The data have been uniformly reduced and analyzed with techniques specifically developed for the ChaMP and then validated by visual examination. To assess source reliability and positional uncertainty, we perform a series of simulations and also use Chandra data to complement the simulation study. The false source detection rate is found to be as good as or better than expected for a given limiting threshold. On the other hand, the chance of missing a real source is rather complex, depending on the source counts, off-axis distance (or PSF), and background rate. The positional error (95% confidence level) is usually less than 1" for a bright source, regardless of its off-axis distance, while it can be as large as 4" for a weak source (~20counts) at a large off-axis distance (Doff-axis>8'). We have also developed new methods to find spatially extended or temporary variable sources, and those sources are listed in the catalog. (5 data files).

Characteristics of randomized trials published in Latin America and the Caribbean according to funding source.

PubMed

Reveiz, Ludovic; Sangalang, Stephanie; Glujovsky, Demian; Pinzon, Carlos E; Asenjo Lobos, Claudia; Cortes, Marcela; Cañón, Martin; Bardach, Ariel; Bonfill, Xavier

2013-01-01

Few studies have assessed the nature and quality of randomized controlled trials (RCTs) in Latin America and the Caribbean (LAC). The aims of this systematic review are to evaluate the characteristics (including the risk of bias assessment) of RCT conducted in LAC according to funding source. A review of RCTs published in 2010 in which the author's affiliation was from LAC was performed in PubMed and LILACS. Two reviewers independently extracted data and assessed the risk of bias. The primary outcomes were risk of bias assessment and funding source. A total of 1,695 references were found in PubMed and LILACS databases, of which 526 were RCTs (N = 73.513 participants). English was the dominant publication language (93%) and most of the RCTs were published in non-LAC journals (84.2%). Only five of the 19 identified countries accounted for nearly 95% of all RCTs conducted in the region (Brazil 70.9%, Mexico 10.1%, Argentina 5.9%, Colombia 3.8%, and Chile 3.4%). Few RCTs covered priority areas related with Millennium Development Goals like maternal health (6.7%) or high priority infectious diseases (3.8%). Regarding children, 3.6% and 0.4% RCT evaluated nutrition and diarrhea interventions respectively but none pneumonia. As a comparison, aesthetic and sport related interventions account for 4.6% of all trials. A random sample of RCTs (n = 358) was assessed for funding source: exclusively public (33.8%); private (e.g. pharmaceutical company) (15.3%); other (e.g. mixed, NGO) (15.1%); no funding (35.8%). Overall assessments for risk of bias showed no statistically significant differences between RCTs and type of funding source. Statistically significant differences favoring private and others type of funding was found when assessing trial registration and conflict of interest reporting. Findings of this study could be used to provide more direction for future research to facilitate innovation, improve health outcomes or address priority health problems.

Characteristics of Randomized Trials Published in Latin America and the Caribbean According to Funding Source

PubMed Central

Reveiz, Ludovic; Sangalang, Stephanie; Glujovsky, Demian; Pinzon, Carlos E.; Asenjo Lobos, Claudia; Cortes, Marcela; Cañón, Martin; Bardach, Ariel; Bonfill, Xavier

2013-01-01

Introduction Few studies have assessed the nature and quality of randomized controlled trials (RCTs) in Latin America and the Caribbean (LAC). Methods and Findings The aims of this systematic review are to evaluate the characteristics (including the risk of bias assessment) of RCT conducted in LAC according to funding source. A review of RCTs published in 2010 in which the author's affiliation was from LAC was performed in PubMed and LILACS. Two reviewers independently extracted data and assessed the risk of bias. The primary outcomes were risk of bias assessment and funding source. A total of 1,695 references were found in PubMed and LILACS databases, of which 526 were RCTs (N = 73.513 participants). English was the dominant publication language (93%) and most of the RCTs were published in non-LAC journals (84.2%). Only five of the 19 identified countries accounted for nearly 95% of all RCTs conducted in the region (Brazil 70.9%, Mexico 10.1%, Argentina 5.9%, Colombia 3.8%, and Chile 3.4%). Few RCTs covered priority areas related with Millennium Development Goals like maternal health (6.7%) or high priority infectious diseases (3.8%). Regarding children, 3.6% and 0.4% RCT evaluated nutrition and diarrhea interventions respectively but none pneumonia. As a comparison, aesthetic and sport related interventions account for 4.6% of all trials. A random sample of RCTs (n = 358) was assessed for funding source: exclusively public (33.8%); private (e.g. pharmaceutical company) (15.3%); other (e.g. mixed, NGO) (15.1%); no funding (35.8%). Overall assessments for risk of bias showed no statistically significant differences between RCTs and type of funding source. Statistically significant differences favoring private and others type of funding was found when assessing trial registration and conflict of interest reporting. Conclusion Findings of this study could be used to provide more direction for future research to facilitate innovation, improve health outcomes or address priority health problems. PMID:23418566

Carbon Isotopes of Methane in the Atlantic Realm: Links Between Background Station Data and Emission Source Regions

NASA Astrophysics Data System (ADS)

Lowry, D.; Fisher, R. E.; Lanoisellé, M.; Nisbet, E. G.

2011-12-01

Large networks of cavity ring-down spectroscopy (CRDS) instruments to measure mixing ratios of greenhouse gases are currently being developed in wealthier populated regions. However, many major natural source regions are remote from wealthy nations, and there are often great logistical obstacles to setting up and maintaining continuous monitoring of these sources. Thus flux assessments in many regions of the world rely on a few unequally spaced 'background' stations, plus satellite interpolation. This limited network can be supplemented to great effect by methane isotope data to identify emissions from different sources and their region of emission. Ideally both carbon and hydrogen isotope signatures are needed for maximum separation of source groups. However the more complex analytical procedure and larger sample requirements for D/H measurement mean that resources are currently better utilized for high-precision carbon isotope (δ13C) measurement of methane. In particular, NOAA maintains an invaluable isotopic measurement network. Since 2008 the greenhouse gas group at Royal Holloway and partners have been measuring methane in and around the Atlantic region, currently measuring mixing ratios by CRDS at Barra (Scotland), Ascension, and E. Falklands. In addition, regular flask sampling for δ13C of CH4 is underway at these sites, plus Cape Point, South Africa, and Ny-Alesund, Spitzbergen, supplemented by collection at Sable Island, Canada, and sampling campaigns on-board the British Antarctic Survey ship, RRS James Clark Ross, between 50°S and 80°N. Methane mixing ratio and δ13C, when combined with back trajectory analysis, help to identify sources over which the air masses have passed. While the South Atlantic shows little N-S variation in δ13C (predominantly -47.2 to -46.8%) it is punctuated by emission plumes from sources in South America and Africa, and although infrequently sampled, they can in some instances be compared with the isotopic characteristics from source studies and monthly emission maps from satellite products. North Atlantic sites have a seasonal cycle (up to 0.7 to 0.8%) that increases polewards, reaching -48% in Arctic summer. Emissions contributing to this seasonal cycle and inter-annual anomalies in the cycle are wetlands (-70 to -55%, but generally more 13C-depleted with increasing latitude) and biomass burning (-30 to -25%). Added to these, and mostly with isotopic signatures between those of the two main natural sources, are anthropogenic fossil fuel (gas, coal), landfill, ruminant and vehicle emissions. The δ13C of the source mix that dominated the North Atlantic from 8 to 53°N in late September 2010 was -56.5%. This is lower than expected if anthropogenic emissions were dominant (eg. London -52 to -49%), but corresponds to the period when maximum influence of high latitude wetland (around -68%) is expected. Methane in air leaving the Eastern seaboard of Canada (Sable Island) allows regional contributions to the Atlantic mix to be assessed. These samples indicate a δ13C source mix of -52 ±2% for air leaving the NE USA and -60 ±2% for air leaving Southern Canada during summer 2010. Further north a wetland emission signal (-70 to -66%) has predominated during recent summers.

[Sources and potential risk of heavy metals in roadside soils of Xi' an City].

PubMed

Chen, Jing-hui; Lu, Xin-wei; Zhai, Meng

2011-07-01

Based on the X-Ray fluorescence spectroscopic measurement of heavy metals concentration in roadside soil samples from Xi' an City, and by the methods of principal component analysis, cluster analysis, and correlation analysis, this paper approached the possible sources of heavy metals in the roadside soils of the City. In the meantime, potential ecological risk index was used to assess the ecological risk of the heavy metals. In the roadside soils, the mean concentrations of Co, Cr, Cu, Mn, Ni, Pb, and Zn were higher than those of the Shaanxi soil background values. The As, Mn and Ni in roadside soils mainly came from natural source and transportation source, the Cu, Pb, and Zn mainly came from transportation source, and the Co and Cr mainly came from industry source. These heavy metals in the roadside soils belonged to medium pollution, and had medium potential ecological risk.

Using sediment particle size distribution to evaluate sediment sources in the Tobacco Creek Watershed

NASA Astrophysics Data System (ADS)

Liu, Cenwei; Lobb, David; Li, Sheng; Owens, Philip; Kuzyk, ZouZou

2014-05-01

Lake Winnipeg has recently brought attention to the deteriorated water quality due to in part to nutrient and sediment input from agricultural land. Improving water quality in Lake Winnipeg requires the knowledge of the sediment sources within this ecosystem. There are a variety of environmental fingerprinting techniques have been successfully used in the assessment of sediment sources. In this study, we used particle size distribution to evaluate spatial and temporal variations of suspended sediment and potential sediment sources collected in the Tobacco Creek Watershed in Manitoba, Canada. The particle size distribution of suspended sediment can reflect the origin of sediment and processes during sediment transport, deposition and remobilization within the watershed. The objectives of this study were to quantify visually observed spatial and temporal changes in sediment particles, and to assess the sediment source using a rapid and cost-effective fingerprinting technique based on particle size distribution. The suspended sediment was collected by sediment traps twice a year during rainfall and snowmelt periods from 2009 to 2012. The potential sediment sources included the top soil of cultivated field, riparian area and entire profile from stream banks. Suspended sediment and soil samples were pre-wet with RO water and sieved through 600 μm sieve before analyzing. Particle size distribution of all samples was determined using a Malvern Mastersizer 2000S laser diffraction with the measurement range up to 600μm. Comparison of the results for different fractions of sediment showed significant difference in particle size distribution of suspended sediment between snowmelt and rainfall events. An important difference of particle size distribution also found between the cultivated soil and forest soil. This difference can be explained by different land uses which provided a distinct fingerprint of sediment. An overall improvement in water quality can be achieved by managing sediment according to the identified sediment sources in the watershed.

Photo-acoustic excitation and detection of guided ultrasonic waves in bone samples covered by a soft coating layer

NASA Astrophysics Data System (ADS)

Zhao, Zuomin; Moilanen, Petro; Karppinen, Pasi; Määttä, Mikko; Karppinen, Timo; Hæggström, Edward; Timonen, Jussi; Myllylä, Risto

2012-12-01

Photo-acoustic (PA) excitation was combined with skeletal quantitative ultrasound (QUS) for multi-mode ultrasonic assessment of human long bones. This approach permits tailoring of the ultrasonic excitation and detection so as to efficiently detect the fundamental flexural guided wave (FFGW) through a coating of soft tissue. FFGW is a clinically relevant indicator of cortical thickness. An OPO laser with tunable optical wavelength, was used to excite a photo-acoustic source in the shaft of a porcine femur. Ultrasonic signals were detected by a piezoelectric transducer, scanning along the long axis of the bone, 20-50 mm away from the source. Five femurs were measured without and with a soft coating. The coating was made of an aqueous gelatin-intralipid suspension that optically and acoustically mimicked real soft tissue. An even coating thickness was ensured by using a specific mold. The optical wave length of the source (1250 nm) was tuned to maximize the amplitude of FFGW excitation at 50 kHz frequency. The experimentally determined FFGW phase velocity in the uncoated samples was consistent with that of the fundamental antisymmetric Lamb mode (A0). Using appropriate signal processing, FFGW was also identified in the coated bone samples, this time with a phase velocity consistent with that theoretically predicted for the first mode of a fluid-solid bilayer waveguide (BL1). Our results suggest that photo-acoustic quantitative ultrasound enables assessment of the thickness-sensitive FFGW in bone through a layer of soft tissue. Photo-acoustic characterization of the cortical bone thickness may thus become possible.

Caffeine in an Urbanized Estuary: Past and Present Influence of Wastewater Effluents in Boston Harbor, MA, USA

EPA Science Inventory

Caffeine has been identified by previous research as a potential tracer of sanitary wastewater. To further assess the utility of caffeine as a tracer of wastewater sources, samples from 25 sites throughout Boston Harbor were collected and analyzed for caffeine by LC-MS/MS. Caff...

DEVELOPMENT OF VIRAL INTERNAL CONTROLS FOR THE ASSESSMENT OF INHIBITOR REMOVAL FROM ENVIRONMENTAL WATER SAMPLES.

EPA Science Inventory

The presence of human enteric viruses in drinking water is of public health concern. It is therefore important to be able to reliably detect these viruses in contaminating water sources. Cell culture methods are time consuming and also not all enteric viruses can currently be p...

Positive Affect as a Source of Resilience for Women in Chronic Pain.

ERIC Educational Resources Information Center

Zautra, Alex J.; Johnson, Lisa M.; Davis, Mary C.

2005-01-01

A sample of 124 women with osteoarthritis or fibromyalgia, or both, completed initial assessments for demographic data, health status, and personality traits and 10-12 weekly interviews regarding pain, stress, negative affect, and positive affect. Multilevel modeling analyses indicated that weekly elevations of pain and stress predicted increases…

Dioxin congener patterns in commercial catfish from the United States and the indication of mineral clays as the potential source

USDA-ARS?s Scientific Manuscript database

Since 1991 the U.S. Department of Agriculture (USDA) has conducted annual surveys of pesticide residues in foods under the Agricultural Marketing Service’s Pesticide Data Program (PDP). To assess chemical residues in domestically marketed catfish products, 1479 catfish samples were collected during ...

AN ASSESSMENT OF DIOXIN LEVELS IN PROCESSED BALL CLAY FROM THE U.S.

EPA Science Inventory

The presence of dioxin-like compounds in ball clay was discovered in 1996 as a result of an investigation to determine the sources of elevated levels of dioxin found in two chicken fat samples from a national survey of poultry. The investigation indicated that soybean meal added...

Co-Occurring ODD and GAD Symptom Groups: Source-Specific Syndromes and Cross-Informant Comorbidity

ERIC Educational Resources Information Center

Drabick, Deborah A. G.; Gadow, Kenneth D.; Loney, Jan

2008-01-01

Despite important clinical and nosological implications, the comorbidity of oppositional defiant disorder (ODD) and generalized anxiety disorder (GAD) has received little attention. A clinic-based sample of 243 boys (ages 6-10 years), their parents, and teachers participated in an evaluation that involved assessments of behavioral, academic, and…

Mercury, trace elements and organic constituents in atmospheric fine particulate matter, Shenandoah National Park, Virginia, USA: A combined approach to sampling and analysis

USGS Publications Warehouse

Kolker, A.; Engle, M.A.; Orem, W.H.; Bunnell, J.E.; Lerch, H.E.; Krabbenhoft, D.P.; Olson, M.L.; McCord, J.D.

2008-01-01

Compliance with U.S. air quality regulatory standards for atmospheric fine particulate matter (PM2.5) is based on meeting average 24 hour (35 ?? m-3) and yearly (15 ??g m-3) mass-per-unit-volume limits, regardless of PM2.5 composition. Whereas this presents a workable regulatory framework, information on particle composition is needed to assess the fate and transport of PM2.5 and determine potential environmental/human health impacts. To address these important non-regulatory issues an integrated approach is generally used that includes (1) field sampling of atmospheric particulate matter on filter media, using a size-limiting cyclone, or with no particle-size limitation; and (2) chemical extraction of exposed filters and analysis of separate particulate-bound fractions for total mercury, trace elements and organic constituents, utilising different USGS laboratories optimised for quantitative analysis of these substances. This combination of sampling and analysis allowed for a more detailed interpretation of PM2.5 sources and potential effects, compared to measurements of PM2.5 abundance alone. Results obtained using this combined approach are presented for a 2006 air sampling campaign in Shenandoah National Park (Virginia, USA) to assess sources of atmospheric contaminants and their potential impact on air quality in the Park. PM2.5 was collected at two sampling sites (Big Meadows and Pinnacles) separated by 13.6 km. At both sites, element concentrations in PM2.5 were low, consistent with remote or rural locations. However, element/Zr crustal abundance enrichment factors greater than 10, indicating anthropogenic input, were found for Hg, Se, S, Sb, Cd, Pb, Mo, Zn and Cu, listed in decreasing order of enrichment. Principal component analysis showed that four element associations accounted for 84% of the PM 2.5 trace element variation; these associations are interpreted to represent: (1) crustal sources (Al, REE); (2) coal combustion (Se, Sb), (3) metal production and/or mobile sources (Mo, Cd, Pb, Cu, Zn) and (4) a transient marine source (Sr, Mg). Concentrations of Hg in PM2.5 at background levels in the single pg m-3 were shown by collection and analysis of PM2.5 on filters and by an automated speciation analyser set up at the Big Meadows air quality site. The speciation unit revealed periodic elevation of reactive gaseous mercury (RGM) that co-occurred with peaks in SO2, indicating an anthropogenic source. GC/MS total ion current chromatograms for the two sites were quite similar indicating that organic signatures were regional in extent and/or that the same compounds were present locally at each site. Calculated carbon preference index values for n-alkanes indicated that plant waxes rather than anthropogenic sources, were the dominant alkane source. Polycyclic aromatic hydrocarbons (PAHs) were detected, with a predominance of non-alkylated, and higher molecular weight PAHs in this fraction, suggestive of a combustion source (fossil fuel or forest fires). ?? 2008 The Authors. Journal compilation ?? 2008 International Association of Geoanalysts.

Vulnerability Assessment of Groundwater Resources by Nutrient Source Apportionment to Individual Groundwater Wells: A Case Study in North Carolina

NASA Astrophysics Data System (ADS)

Ayub, R.; Obenour, D. R.; Keyworth, A. J.; Genereux, D. P.; Mahinthakumar, K.

2016-12-01

Groundwater contamination by nutrients (nitrogen and phosphorus) is a major concern in water table aquifers that underlie agricultural areas in the mid-Atlantic Coastal Plain of the United States. High nutrient concentrations leaching into shallow groundwater can lead to human health problems and eutrophication of receiving surface waters. Liquid manure from concentrated animal feeding operations (CAFOs) stored in open-air lagoons and applied to spray fields can be a significant source of nutrients to groundwater, along with septic waste. In this study, we developed a model-based methodology for source apportionment and vulnerability assessment using sparse groundwater quality sampling measurements for Duplin County, North Carolina (NC), obtained by the NC Department of Environmental Quality (NC DEQ). This model provides information relevant to management by estimating the nutrient transport through the aquifer from different sources and addressing the uncertainty of nutrient contaminant propagation. First, the zones of influence (dependent on nutrient pathways) for individual groundwater monitoring wells were identified using a two-dimensional vertically averaged groundwater flow and transport model incorporating geologic uncertainty for the surficial aquifer system. A multiple linear regression approach is then applied to estimate the contribution weights for different nutrient source types using the nutrient measurements from monitoring wells and the potential sources within each zone of influence. Using the source contribution weights and their uncertainty, a probabilistic vulnerability assessment of the study area due to nutrient contamination is performed. Knowledge of the contribution of different nutrient sources to contamination at receptor locations (e.g., private wells, municipal wells, stream beds etc.) will be helpful in planning and implementation of appropriate mitigation measures.

MPN estimation of qPCR target sequence recoveries from whole cell calibrator samples.

PubMed

Sivaganesan, Mano; Siefring, Shawn; Varma, Manju; Haugland, Richard A

2011-12-01

DNA extracts from enumerated target organism cells (calibrator samples) have been used for estimating Enterococcus cell equivalent densities in surface waters by a comparative cycle threshold (Ct) qPCR analysis method. To compare surface water Enterococcus density estimates from different studies by this approach, either a consistent source of calibrator cells must be used or the estimates must account for any differences in target sequence recoveries from different sources of calibrator cells. In this report we describe two methods for estimating target sequence recoveries from whole cell calibrator samples based on qPCR analyses of their serially diluted DNA extracts and most probable number (MPN) calculation. The first method employed a traditional MPN calculation approach. The second method employed a Bayesian hierarchical statistical modeling approach and a Monte Carlo Markov Chain (MCMC) simulation method to account for the uncertainty in these estimates associated with different individual samples of the cell preparations, different dilutions of the DNA extracts and different qPCR analytical runs. The two methods were applied to estimate mean target sequence recoveries per cell from two different lots of a commercially available source of enumerated Enterococcus cell preparations. The mean target sequence recovery estimates (and standard errors) per cell from Lot A and B cell preparations by the Bayesian method were 22.73 (3.4) and 11.76 (2.4), respectively, when the data were adjusted for potential false positive results. Means were similar for the traditional MPN approach which cannot comparably assess uncertainty in the estimates. Cell numbers and estimates of recoverable target sequences in calibrator samples prepared from the two cell sources were also used to estimate cell equivalent and target sequence quantities recovered from surface water samples in a comparative Ct method. Our results illustrate the utility of the Bayesian method in accounting for uncertainty, the high degree of precision attainable by the MPN approach and the need to account for the differences in target sequence recoveries from different calibrator sample cell sources when they are used in the comparative Ct method. Published by Elsevier B.V.

Bacteriological quality of drinking water from source to household in Ibadan, Nigeria.

PubMed

Oloruntoba, E O; Sridhar, M K C

2007-06-01

The bacteriological quality of drinking water from well, spring, borehole, and tap sources and that stored in containers by urban households in Ibadan was assessed during wet and dry seasons. The MPN technique was used to detect and enumerate the number of coliforms in water samples. Results showed that majority of households relied on wells, which were found to be the most contaminated of all the sources. At the household level, water quality significantly deteriorated after collection and storage as a result of poor handling. Furthermore, there was significant seasonal variation in E. coli count at source (P=0.013) and household (P=0.001). The study concludes that there is a need to improve the microbial quality of drinking water at source and the household level through hygiene education, and provision of simple, acceptable, low-cost treatment methods.

[Subjective and objective indicators of job stress and burnout in a residential home for the elderly].

PubMed

Fiabane, Elena; Dordoni, Paola; Argentero, Piergiorgio

2016-01-01

Elderly care workers have a higher risk than other professionals of developing burnout. Despite literature has highlighted the methodological advantage resulting from an integration of subjective and objective measures of stressors, only few studies have investigated job stress and burnout in the Italian elderly care context using this kind of assessment. The aims of this study were: (a) to investigate the level of stress and burnout and their organizational sources in a sample of eldercare workers by means of subjective and objective tools, and b) to compare the stress and burnout levels between health care staff and nursing aides employed in a residential home for the, elderly. The sample of the study included the totality of the elderly workers employed in a residential home for the elderly (N=49; response rate: 100%). The Maslach Burnout Inventory-GS and the Areas of Worklife Scale were used for the subjective assessment of burnout and organizational riskfactors. A check list of objective indicators was used for the objective assessment of job stress. Results from the self-report questionnaires showed high levels of exhaustion and a perception of high workload and unfairness for, the total sample. Objective parameters ofjob stress risk were biomechanical overload, dealing with suffering people and the risk of work-related violence. Nursing aides had greater risk of burnout and reported a greater number of objective sources of stress, compared to health care workers. This exploratory study supports the use of both subjective and objective method for the assessment of job stress risk as the most comprehensive approach for the implementation of preventive and corrective interventions.

A holistic passive integrative sampling approach for assessing the presence and potential impacts of waterborne environmental contaminants

USGS Publications Warehouse

Petty, J.D.; Huckins, J.N.; Alvarez, D.A.; Brumbaugh, W. G.; Cranor, W.L.; Gale, R.W.; Rastall, A.C.; Jones-Lepp, T. L.; Leiker, T.J.; Rostad, C. E.; Furlong, E.T.

2004-01-01

As an integral part of our continuing research in environmental quality assessment approaches, we have developed a variety of passive integrative sampling devices widely applicable for use in defining the presence and potential impacts of a broad array of contaminants. The semipermeable membrane device has gained widespread use for sampling hydrophobic chemicals from water and air, the polar organic chemical integrative sampler is applicable for sequestering waterborne hydrophilic organic chemicals, the stabilized liquid membrane device is used to integratively sample waterborne ionic metals, and the passive integrative mercury sampler is applicable for sampling vapor phase or dissolved neutral mercury species. This suite of integrative samplers forms the basis for a new passive sampling approach for assessing the presence and potential toxicological significance of a broad spectrum of environmental contaminants. In a proof-of-concept study, three of our four passive integrative samplers were used to assess the presence of a wide variety of contaminants in the waters of a constructed wetland, and to determine the effectiveness of the constructed wetland in removing contaminants. The wetland is used for final polishing of secondary-treatment municipal wastewater and the effluent is used as a source of water for a state wildlife area. Numerous contaminants, including organochlorine pesticides, polycyclic aromatic hydrocarbons, organophosphate pesticides, and pharmaceutical chemicals (e.g., ibuprofen, oxindole, etc.) were detected in the wastewater. Herein we summarize the results of the analysis of the field-deployed samplers and demonstrate the utility of this holistic approach.

Levels and risk assessment of hydrocarbons and organochlorines in aerosols from a North African coastal city (Bizerte, Tunisia).

PubMed

Barhoumi, Badreddine; Castro-Jiménez, Javier; Guigue, Catherine; Goutx, Madeleine; Sempéré, Richard; Derouiche, Abdelkader; Achour, Amani; Touil, Soufiane; Driss, Mohamed Ridha; Tedetti, Marc

2018-05-09

The aim of this study was to assess, for the first time, the concentrations, sources, dry deposition and human health risks of polycyclic aromatic hydrocarbons (PAHs), aliphatic hydrocarbons (AHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in total suspended particle (TSP) samples collected in Bizerte city, Tunisia (North Africa), during one year (March 2015-January 2016). Concentrations of PAHs, AHs, PCBs and OCPs ranged 0.5-17.8 ng m -3 , 6.7-126.5 ng m -3 , 0.3-11 pg m -3 and 0.2-3.6 pg m -3 , respectively, with higher levels of all contaminants measured in winter. A combined analysis revealed AHs originating from both biogenic and petrogenic sources, while diesel vehicle emissions were identified as dominant sources for PAHs. PCB potential sources included electronic, iron, cement, lubricant factories located within or outside Bizerte city. The dominant OCP congeners were p,p'-DDT and p,p'-DDE, reflecting a current or past use in agriculture. Health risk assessment showed that the lifetime excess cancer risk from exposure to airborne BaP was negligible in Bizerte, except in winter, where a potential risk to the local population may occur. Copyright © 2018 Elsevier Ltd. All rights reserved.

Provision of safe domestic water for the promotion and protection of public health: a case study of the city of Beirut, Lebanon.

PubMed

Korfali, Samira Ibrahim; Jurdi, Mey

2009-04-01

Securing adequate safe drinking water and proper sanitation is a major challenge facing the developing world. The "Water for Life Decade" emphasizes the importance of upgrading national water quality and sanitation services. This study assessed the domestic water profile in the city of Beirut. Samples were collected from three types of household water sources (municipality, private wells, and vended water bottles) and assessed for their physiochemical and microbiological profile. At the same time, a cross-sectional survey assessing water consumption patterns and the prevalence of water-borne diseases was conducted. The results showed a deficient water quality profile in all three water sources. The measured physiochemical and bacteriological parameters reflected the high frequency of water-borne diseases. Action to secure a safe domestic water supply is essential. The plan should guarantee the protection of water sources, ensure sufficient treatment of domestic water and upgrade the national program for potable water quality control. Periodic quality monitoring and legislating the chaotic water-vending sector are indispensable. Additionally, the deterioration of private well sources by sea and wastewater infiltration necessitates the enforcement of legislation associated with the use and management of private wells. Consumer awareness and active contributions to promote and protect public health are important.

Comprehensive risk assessment and source identification of selected heavy metals (Cu, Cd, Pb, Zn, Hg, As) in tidal saltmarsh sediments of Shuangtai Estuary, China.

PubMed

Liu, Chang-Fa; Li, Bing; Wang, Yi-Ting; Liu, Yuan; Cai, Heng-Jiang; Wei, Hai-Feng; Wu, Jia-Wen; Li, Jin

2017-10-06

Heavy metals do not degrade and can remain in the environment for a long time. In this study, we analyzed the effects of Cu, Cd, Pb, Zn, Hg, and As, on environmental quality, pollutant enrichment, ecological hazard, and source identification of elements in sediments using data collected from samples taken from Shuangtai tidal wetland. The comprehensive pollution indices were used to assess environmental quality; fuzzy similarity analysis and geoaccumulation index were used to analyze pollution accumulation; correlation matrix, principal component analysis, and clustering analysis were used to analyze pollution source; environmental risk index and ecological risk index were used to assess ecological risk. The results showed that the environmental quality was either clean or almost clean. Pollutant enrichment analysis showed that the four sub-regions had similar pollution-causing metals to the background values of the soil element of the Liao River Plain, which were ranked according to their similarity. Source identification showed that all the elements were correlated. Ecological hazard analysis showed that the environmental risk index in the study area was less than zero, posing a low ecological risk. Ecological risk of the six elements was as follows: As > Cd > Hg > Cu > Pb > Zn.

A study of formaldehyde sources in air

NASA Astrophysics Data System (ADS)

Shen, Haiwei

Formaldehyde (CH2O) is a central component of photooxidation chemistry. The atmospheric sources of CH2O involve a complex mixture of biogenic and anthropogenic volatile organic compounds (VOCs). This study explores the geographical and altitudinal variations of CH2O production from its precursors over the Eastern U.S. and assesses the contributions from biogenic and anthropogenic VOC emissions to atmospheric CH2O. Measurements of airborne CH2O and hydrocarbons over North America and model results were used to evaluate CH2O production from its precursors. Source attribution results from a photochemical box model indicate 95% of the CH2O arose in various proportions from a mixture of methane, isoprene, methyl hydroperoxide, methanol, and a peroxyacetyl group. Methane on average contributed 32% at altitudes below 2 km to CH2O production, 43% in 2-6 km, and 52% in 6-12 km. It was the predominant CH 2O source in 1-12 km. Isoprene served as a major source of CH2 O (range 0-72%, average 17%) over the southeastern U.S. region within 0-1-km layer. Methyl hydroperoxide was one of the predominant contributors over the ocean and averaged from 6 to 33% in all layers. Production from the peroxyacetyl group and methanol were 7-17% and 10-14% on average in the layers in 0-12 km, respectively. A compound specific radiocarbon analysis technique was developed for atmospheric CH2O to examine its biogenic and anthropogenic carbon fraction. The method used filter collection, a preparative capillary gas chromatography isolation technique, and AMS detection. Ambient samples were collected on the roof of the CACS building at the Bay Campus of the University of RI, Narragansett, RI. The 14CH2O data, 48-hour back trajectories, and VOC observations from the RI Department of Environmental Management were used to assess the relative contributions of biogenic and fossil precursors to CH2O. The results show a large fraction of fossil/industrial carbon in collected CH2O samples and imply the precursors of CH 2O were dominated by fossil/industrial sources even during summer when biogenic sources are expected at their highest. It is suggested that pollutants from upwind coastal cities carried by the southwest sea breeze strongly influenced the site during our limited summer sample collection.

Soft x-ray imaging with incoherent sources

NASA Astrophysics Data System (ADS)

Wachulak, P.; Torrisi, A.; Ayele, M.; Bartnik, A.; Czwartos, J.; Wegrzyński, Ł.; Fok, T.; Parkman, T.; Vondrová, Š.; Turnová, J.; Odstrcil, M.; Fiedorowicz, H.

2017-05-01

In this work we present experimental, compact desk-top SXR microscope, the EUV microscope which is at this stage a technology demonstrator, and finally, the SXR contact microscope. The systems are based on laser-plasma EUV and SXR sources, employing a double stream gas puff target. The EUV and SXR full field microscopes, operating at 13.8 nm and 2.88 nm wavelengths, respectively, are capable of imaging nanostructures with a sub-50 nm spatial resolution with relatively short (seconds) exposure times. The SXR contact microscope operates in the "water-window" spectral range, to produce an imprint of the internal structure of the sample in a thin layer of SXR light sensitive photoresist. Applications of such desk-top EUV and SXR microscopes for studies of variety of different samples - test objects for resolution assessment and other objects such as carbon membranes, DNA plasmid samples, organic and inorganic thin layers, diatoms, algae and carcinoma cells, are also presented. Details about the sources, the microscopes as well as the imaging results for various objects will be presented and discussed. The development of such compact imaging systems may be important to the new research related to biological, material science and nanotechnology applications.

Chemicals and microbes in bioaerosols from reaction tanks of six wastewater treatment plants: survival factors, generation sources, and mechanisms.

PubMed

Wang, Yanjie; Lan, Huachun; Li, Lin; Yang, Kaixiong; Qu, Jiuhui; Liu, Junxin

2018-06-19

Sampling was conducted from biochemical reaction tanks of six municipal wastewater treatment plants in the Yangtze River and Zhujiang deltas and the Jing-Jin-Ji region to assess their morphology, level, and composition. Morphological observations suggested that particles were scattered amorphously with C, O, and Si as the major elements. Bioaerosols are composed of spatially varying levels of microorganisms and chemicals. As the sampling height increased, the level of the components in the bioaerosols decreased. Wastewater in the biochemical reaction tanks was identified as an important source of bioaerosols using SourceTracker analysis. The aerosolization of film drops produced by bursting of bubbles was the main reason for the generation of bioaerosols. Increasing the aeration rate of water may promote bioaerosol generation. Relative humidity, temperature, wind speed, and solar illumination influenced the survival of bioaerosols. Large particle sedimentation and wind diffusion significantly decreased the atmospheric aerosol concentration. When the sampling point height increased from 0.1 m to 3.0 m, the concentrations of the microorganisms and total suspended particles decreased by 23.71% and 38.74%, respectively. Considerable attention should be paid to the control of total suspended particles and microorganisms in bioaerosols.

Antibiotics in the coastal environment of the Hailing Bay region, South China Sea: Spatial distribution, source analysis and ecological risks.

PubMed

Chen, Hui; Liu, Shan; Xu, Xiang-Rong; Zhou, Guang-Jie; Liu, Shuang-Shuang; Yue, Wei-Zhong; Sun, Kai-Feng; Ying, Guang-Guo

2015-06-15

In this study, the occurrence and spatial distribution of 38 antibiotics in surface water and sediment samples of the Hailing Bay region, South China Sea, were investigated. Twenty-one, 16 and 15 of 38 antibiotics were detected with the concentrations ranging from <0.08 (clarithromycin) to 15,163ng/L (oxytetracycline), 2.12 (methacycline) to 1318ng/L (erythromycin-H2O), <1.95 (ciprofloxacin) to 184ng/g (chlortetracycline) in the seawater, discharged effluent and sediment samples, respectively. The concentrations of antibiotics in the water phase were correlated positively with chemical oxygen demand and nitrate. The source analysis indicated that untreated domestic sewage was the primary source of antibiotics in the study region. Fluoroquinolones showed strong sorption capacity onto sediments due to their high pseudo-partitioning coefficients. Risk assessment indicated that oxytetracycline, norfloxacin and erythromycin-H2O posed high risks to aquatic organisms. Copyright © 2015 Elsevier Ltd. All rights reserved.

Global sensitivity analysis in wind energy assessment

NASA Astrophysics Data System (ADS)

Tsvetkova, O.; Ouarda, T. B.

2012-12-01

Wind energy is one of the most promising renewable energy sources. Nevertheless, it is not yet a common source of energy, although there is enough wind potential to supply world's energy demand. One of the most prominent obstacles on the way of employing wind energy is the uncertainty associated with wind energy assessment. Global sensitivity analysis (SA) studies how the variation of input parameters in an abstract model effects the variation of the variable of interest or the output variable. It also provides ways to calculate explicit measures of importance of input variables (first order and total effect sensitivity indices) in regard to influence on the variation of the output variable. Two methods of determining the above mentioned indices were applied and compared: the brute force method and the best practice estimation procedure In this study a methodology for conducting global SA of wind energy assessment at a planning stage is proposed. Three sampling strategies which are a part of SA procedure were compared: sampling based on Sobol' sequences (SBSS), Latin hypercube sampling (LHS) and pseudo-random sampling (PRS). A case study of Masdar City, a showcase of sustainable living in the UAE, is used to exemplify application of the proposed methodology. Sources of uncertainty in wind energy assessment are very diverse. In the case study the following were identified as uncertain input parameters: the Weibull shape parameter, the Weibull scale parameter, availability of a wind turbine, lifetime of a turbine, air density, electrical losses, blade losses, ineffective time losses. Ineffective time losses are defined as losses during the time when the actual wind speed is lower than the cut-in speed or higher than the cut-out speed. The output variable in the case study is the lifetime energy production. Most influential factors for lifetime energy production are identified with the ranking of the total effect sensitivity indices. The results of the present research show that the brute force method is best for wind assessment purpose, SBSS outperforms other sampling strategies in the majority of cases. The results indicate that the Weibull scale parameter, turbine lifetime and Weibull shape parameter are the three most influential variables in the case study setting. The following conclusions can be drawn from these results: 1) SBSS should be recommended for use in Monte Carlo experiments, 2) The brute force method should be recommended for conducting sensitivity analysis in wind resource assessment, and 3) Little variation in the Weibull scale causes significant variation in energy production. The presence of the two distribution parameters in the top three influential variables (the Weibull shape and scale) emphasizes the importance of accuracy of (a) choosing the distribution to model wind regime at a site and (b) estimating probability distribution parameters. This can be labeled as the most important conclusion of this research because it opens a field for further research, which the authors see could change the wind energy field tremendously.

Calibrated simulations of Z opacity experiments that reproduce the experimentally measured plasma conditions

DOE PAGES

Nagayama, T.; Bailey, J. E.; Loisel, G.; ...

2016-02-05

Recently, frequency-resolved iron opacity measurements at electron temperatures of 170–200 eV and electron densities of (0.7 – 4.0) × 10 22 cm –3 revealed a 30–400% disagreement with the calculated opacities [J. E. Bailey et al., Nature (London) 517, 56 (2015)]. The discrepancies have a high impact on astrophysics, atomic physics, and high-energy density physics, and it is important to verify our understanding of the experimental platform with simulations. Reliable simulations are challenging because the temporal and spatial evolution of the source radiation and of the sample plasma are both complex and incompletely diagnosed. In this article, we describe simulationsmore » that reproduce the measured temperature and density in recent iron opacity experiments performed at the Sandia National Laboratories Z facility. The time-dependent spectral irradiance at the sample is estimated using the measured time- and space-dependent source radiation distribution, in situ source-to-sample distance measurements, and a three-dimensional (3D) view-factor code. The inferred spectral irradiance is used to drive 1D sample radiation hydrodynamics simulations. The images recorded by slit-imaged space-resolved spectrometers are modeled by solving radiation transport of the source radiation through the sample. We find that the same drive radiation time history successfully reproduces the measured plasma conditions for eight different opacity experiments. These results provide a quantitative physical explanation for the observed dependence of both temperature and density on the sample configuration. Simulated spectral images for the experiments without the FeMg sample show quantitative agreement with the measured spectral images. The agreement in spectral profile, spatial profile, and brightness provides further confidence in our understanding of the backlight-radiation time history and image formation. Furthermore, these simulations bridge the static-uniform picture of the data interpretation and the dynamic-gradient reality of the experiments, and they will allow us to quantitatively assess the impact of effects neglected in the data interpretation.« less

Genetic Relatedness Among Shiga Toxin-Producing Escherichia coli Isolated Along the Animal Food Supply Chain and in Gastroenteritis Cases in Qatar Using Multilocus Sequence Typing.

PubMed

Palanisamy, Srikanth; Chang, YuChen; Scaria, Joy; Penha Filho, Rafael Antonio Casarin; Peters, Kenlyn E; Doiphode, Sanjay H; Sultan, Ali; Mohammed, Hussni O

2017-06-01

Pathogenic Escherichia coli has been listed among the most important bacteria associated with foodborne illnesses around the world. We investigated the genetic relatedness among Shiga toxin-producing E. coli (STEC) isolated along the animal food supply chain and from humans diagnosed with gastroenteritis in Qatar. Samples were collected from different sources along the food supply chain and from patients admitted to the hospital with complaints of gastroenteritis. All samples were screened for the presence of E. coli O157:H7 and non-O157 STEC using a combination of bacterial enrichment and molecular detection techniques. A proportional sampling approach was used to select positive samples from each source for further multilocus sequence typing (MLST) analysis. Seven housekeeping genes described for STEC were amplified by polymerase chain reaction, sequenced, and analyzed by MLST. Isolates were characterized by allele composition, sequence type (ST) and assessed for epidemiologic relationship within and among different sources. Nei's genetic distance was calculated at the allele level between sample pools in each site downstream. E. coli O157:H7 occurred at a higher rate in slaughterhouse and retail samples than at the farm or in humans in our sampling. The ST171, an ST common to enterotoxigenic E. coli and atypical enteropathogenic E. coli, was the most common ST (15%) in the food supply chain. None of the genetic distances among the different sources was statistically significant. Enterohemorrhagic E. coli pathogenic strains are present along the supply chain at different levels and with varying relatedness. Clinical isolates were the most diverse, as expected, considering the polyclonal diversity in the human microbiota. The high occurrence of these food adulterants among the farm products suggests that implementation of sanitary measures at that level might reduce the risk of human exposure.

Design and evaluation of a field study on the contamination of selected volatile organic compounds and wastewater-indicator compounds in blanks and groundwater samples

USGS Publications Warehouse

Thiros, Susan A.; Bender, David A.; Mueller, David K.; Rose, Donna L.; Olsen, Lisa D.; Martin, Jeffrey D.; Bernard, Bruce; Zogorski, John S.

2011-01-01

The Field Contamination Study (FCS) was designed to determine the field processes that tend to result in clean field blanks and to identify potential sources of contamination to blanks collected in the field from selected volatile organic compounds (VOCs) and wastewater-indicator compounds (WICs). The VOCs and WICs analyzed in the FCS were detected in blanks collected by the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Program during 1996–2008 and 2002–08, respectively. To minimize the number of variables, the study required ordering of supplies just before sampling, storage of supplies and equipment in clean areas, and use of adequate amounts of purge-and-trap volatile-grade methanol and volatile pesticide-grade blank water (VPBW) to clean sampling equipment and to collect field blanks.Blanks and groundwater samples were collected during 2008–09 at 16 sites, which were a mix of water-supply and monitoring wells, located in 9 States. Five different sample types were collected for the FCS at each site: (1) a source-solution blank collected at the USGS National Water Quality Laboratory (NWQL) using laboratory-purged VPBW, (2) source-solution blanks collected in the field using laboratory-purged VPBW, (3) source-solution blanks collected in the field using field-purged VPBW, (4) a field blank collected using field-purged VPBW, and (5) a groundwater sample collected from a well. The source-solution blank and field-blank analyses were used to identify, quantify, and document extrinsic contamination and to help determine the sources and causes of data-quality problems that can affect groundwater samples.Concentrations of compounds detected in FCS analyses were quantified and results were stored in the USGS National Water Information System database after meeting rigorous identification and quantification criteria. The study also utilized information provided by laboratory analysts about evidence indicating the presence of selected compounds, using less rigorous identification criteria than is required for reporting data to the National Water Information System database. For the FCS, these data are considered adequate to indicate "evidence of presence," and were used only for diagnostic purposes. Evidence of VOCs and WICs at low concentrations near or less than the long-term method detection level can indicate a contamination problem that could affect future datasets if method detection levels were ever to be lowered.

Risk Assessment of Heavy Metals in Abandoned Mine Lands as Signifcant Contamination Problem in Romania

NASA Astrophysics Data System (ADS)

Horvath, E.; Jordan, G.; Fugedi, U.; Bartha, A.; Kuti, L.; Heltai, G.; Kalmar, J.; Waldmann, I.; Napradean, I.; Damian, G.

2009-04-01

INTRODUCTION Wide-spread environmental contamination associated with historic mining in Europe has triggered social responses to improve related environmental legislation, the environmental assessment and management methods for the mining industry. Pollution by acid mine drainage (AMD) from ore and coal mining is the outstanding and most important source of mining-induced environmental pollution. Younger et al. (2002) estimates that watercourses polluted by coal mine drainage could be in the order of 2,000 to 3,000 km, and 1,000 to 1,500 km polluted by metal mine discharges for the EU 15 Member States (Younger et al. 2002). Significance of contamination risk posed by mining is also highlighted by mine accidents such as those in Baia Mare, Romania in 2002 and in Aznalcollar, Spain in 1999 (Jordan and D'Alessandro 2004). The new EU Mine Waste Directive (Directive 2006/21/EC) requires the risk-based inventory of abandoned mines in the EU. The cost-effective implementation of the inventory is especially demanding in countries with extensive historic mining and great number of abandoned mine sites, like Romania. The problem is further complicated in areas with trans-boundary effects. The objective of this investigation to carry out the risk-based contamination assessment of a mine site with possible trans-boundary effects in Romania. Assessment follows the source-pathway-receptor chain with a special attention to heavy metal leaching from waste dumps as sources and to transport modelling along surface water pathways. STUDY AREA In this paper the Baiut mine catchment located in the Gutai Mts., Romania, close to the Hungarian border is studied. The polymetallic deposites in the Tertiary Inner-Carpathian Volcanic Arc are exposed by a series of abandoned Zn and Pb mines first operated in the 14th century. Elevation in the high relief catchment ranges from 449m to 1044m. Geology is characterised by andesites hosting the ore deposits and paleogene sediments dominating at the lower topographic elevations. Several mine adits, waste rock dumps are located along the main stream and a large tailings dump is found next to village Baiut just above the receiving floodplain. Predominant land cover is coniferous and mixed forests with agricultural lands on the downstream floodplain. METHODS Six samples at vaious depths were collected from the two major waste rock dumps in the headwater area, and the large tailings dump was also sampled for heavy metal source characterisation. 11 stream sediment samples were collected along the main surface water contamination transport pathway, and a further 11 soil samples were collected in 2 boreholes in the receptor floodplain in October 2008. Besides background stream sediment samples, samples from the exposed rock formations were also collected in order to capture natural background geochemistry in the studied mineralised area. The collected waste rock, stream sediment, soil and rock samples are analysed for total chemical composition (major elements and heavy metals) by ICP-MS spectroscopy, and XRD is used for the determination of mineralogical composition. Rock sample mineralogy is further investigated in thin-sections by petrological microscopy. According to EU legislation expectations, a special emphasis is taken on the determination of metal mobility from the waste rock dumps and various leaching tests are performed and compared including US EPA, USGS and ISO methods. A simple cathcment-based distributed sediment transport model (Jordan et al, 2005; Jordan et al. 2005, 2008) is used to decribe the pathways and quantities of particle-bound contamination. RESULTS AND CONCLUSIONS Results show that (1) sediments are an efficient means for the preliminary inventory of mine contamination as a preparation for the more detailed hydrological sampling and assessment, and (2) the risk-based contamination assessment of mining sites often located in diverse geological, hydrological and landcover environment requires careful and successive sampling design and a tiered assessment approach. Leaching tests are shown cost-efficient and informative methods for source (hazard) characterisation. REFERENCES Directive 2006/21/EC the European Parliament and of the Council on the management of waste from extractive industries and amending Directive 2004/35/EC. Commission of the European Communities, Brussels. Jordan G. and D'Alessandro M. (eds) (2004) Mining, Mining Waste and Related Environmental Issues: Problems and Solutions in the Central and Eastern European Candidate Countries. Joint Research Centre of the European Commission, Ispra. LB-NA-20868-EN-C. Jordan G., van Rompaey A., Szilassi P., Csillag G., Mannaerts C. and Woldai T. (2005) Historical land use changes and their impact on sediment fluxes in the Balaton basin (Hungary). Agriculture, Ecosystems and Environment, 108, 119-133. Jordan G., van Rompaey A., Somody A., Fügedi U., Bats M. and Farsang A. (2008) Spatial Modelling of Contamination in a Catchment Area Impacted by Mining: a Case Study for the Recsk Copper Mines, Hungary. Journal of Land Contamination and Reclamation (in press). Younger P.L., Banwart S.A., Hedin R.S. (2002) Mine water. Hydrology, pollution, remediation. Kluwer Academic Publishers, Dodrecht.

Multivariate statistical assessment of heavy metal pollution sources of groundwater around a lead and zinc plant.

PubMed

Zamani, Abbas Ali; Yaftian, Mohammad Reza; Parizanganeh, Abdolhossein

2012-12-17

The contamination of groundwater by heavy metal ions around a lead and zinc plant has been studied. As a case study groundwater contamination in Bonab Industrial Estate (Zanjan-Iran) for iron, cobalt, nickel, copper, zinc, cadmium and lead content was investigated using differential pulse polarography (DPP). Although, cobalt, copper and zinc were found correspondingly in 47.8%, 100.0%, and 100.0% of the samples, they did not contain these metals above their maximum contaminant levels (MCLs). Cadmium was detected in 65.2% of the samples and 17.4% of them were polluted by this metal. All samples contained detectable levels of lead and iron with 8.7% and 13.0% of the samples higher than their MCLs. Nickel was also found in 78.3% of the samples, out of which 8.7% were polluted. In general, the results revealed the contamination of groundwater sources in the studied zone. The higher health risks are related to lead, nickel, and cadmium ions. Multivariate statistical techniques were applied for interpreting the experimental data and giving a description for the sources. The data analysis showed correlations and similarities between investigated heavy metals and helps to classify these ion groups. Cluster analysis identified five clusters among the studied heavy metals. Cluster 1 consisted of Pb, Cu, and cluster 3 included Cd, Fe; also each of the elements Zn, Co and Ni was located in groups with single member. The same results were obtained by factor analysis. Statistical investigations revealed that anthropogenic factors and notably lead and zinc plant and pedo-geochemical pollution sources are influencing water quality in the studied area.

Multivariate statistical assessment of heavy metal pollution sources of groundwater around a lead and zinc plant

PubMed Central

2012-01-01

The contamination of groundwater by heavy metal ions around a lead and zinc plant has been studied. As a case study groundwater contamination in Bonab Industrial Estate (Zanjan-Iran) for iron, cobalt, nickel, copper, zinc, cadmium and lead content was investigated using differential pulse polarography (DPP). Although, cobalt, copper and zinc were found correspondingly in 47.8%, 100.0%, and 100.0% of the samples, they did not contain these metals above their maximum contaminant levels (MCLs). Cadmium was detected in 65.2% of the samples and 17.4% of them were polluted by this metal. All samples contained detectable levels of lead and iron with 8.7% and 13.0% of the samples higher than their MCLs. Nickel was also found in 78.3% of the samples, out of which 8.7% were polluted. In general, the results revealed the contamination of groundwater sources in the studied zone. The higher health risks are related to lead, nickel, and cadmium ions. Multivariate statistical techniques were applied for interpreting the experimental data and giving a description for the sources. The data analysis showed correlations and similarities between investigated heavy metals and helps to classify these ion groups. Cluster analysis identified five clusters among the studied heavy metals. Cluster 1 consisted of Pb, Cu, and cluster 3 included Cd, Fe; also each of the elements Zn, Co and Ni was located in groups with single member. The same results were obtained by factor analysis. Statistical investigations revealed that anthropogenic factors and notably lead and zinc plant and pedo-geochemical pollution sources are influencing water quality in the studied area. PMID:23369182

Epidemiology of Cyclospora cayetanensis and other intestinal parasites in a community in Haiti.

PubMed

Lopez, Adriana S; Bendik, Jean M; Alliance, Jean Y; Roberts, Jacquelin M; da Silva, Alexandre J; Moura, Iaci N S; Arrowood, Michael J; Eberhard, Mark L; Herwaldt, Barbara L

2003-05-01

We conducted an exploratory investigation in a community in Haiti to determine the prevalence of Cyclospora cayetanensis infection and to identify potential risk factors for C. cayetanensis infection. In 2001, two cross-sectional stool surveys and a nested case-control study were conducted. In 2002, a follow-up cross-sectional stool survey was conducted among children < or =10 years of age. Stool specimens from study participants and water samples from their wells were examined for Cyclospora and other intestinal parasites. In stools, the prevalence of infection with Cyclospora in persons of all ages decreased from 12% (20 of 167 persons) in February 2001 to 1.1% (4 of 352 persons) in April 2001, a 90.8% decrease. For children < or =10 years of age, the prevalence rates were 22.5% (16 of 71 children) in February 2001, 3.0% (4 of 135 children) in April 2001, and 2.5% (2 of 81 children) in January 2002. Use of the water from the artesian well in the northern region of the community versus the one in the south was the only risk factor associated with Cyclospora infection in multivariate analyses (odds ratio, 18.5; 95% confidence interval, 2.4 to 143.1). The water sample from one of the nine wells or water sources tested (one sample per source) in January 2001, shortly before the investigation began, was positive for Cyclospora by UV fluorescence microscopy and PCR. None of the water samples from the 46 wells or water sources tested during the investigation (one sample per source per testing period, including the artesian wells) were positive for Cyclospora. Further studies are needed to assess the role of water as a possible risk factor for Cyclospora infection in Haiti and other developing countries.

Assessment of heavy metal accumulation in two species of Tillandsia in relation to atmospheric emission sources in Argentina.

PubMed

Wannaz, Eduardo D; Carreras, Hebe A; Pérez, Carlos A; Pignata, María L

2006-05-15

The ability of Tillandsia capillaris Ruiz and Pav. f. capillaris and Tillandsia permutata A. Cast. to accumulate heavy metals was evaluated in relation to potential atmospheric emission sources in Argentina. The sampling areas (n=38) were chosen in the province of Córdoba, located in the center of Argentina, and categorized according to land use, anthropogenic activities and/or distance to potential heavy metal emission sources. In each sampling site, pools of 40-50 individuals of each species were made from plants collected along the four cardinal directions. The concentrations of V, Mn, Fe, Co, Ni, Cu, Zn, Pb and Br of these samples were measured by Total Reflection X-Ray Fluorescence (TXRF) analysis with Synchrotron Radiation. Each species was submitted to a cluster analysis in order to discriminate different groups of heavy metals as tracers of natural or anthropogenic sources. A Contamination Factor (CF) was calculated using the concentrations of the elements in each sample compared to their concentrations in the control samples. Finally, the rank coefficients of correlation between the CFs and the categorical variables characteristic of each site (land use and anthropogenic load) were analyzed. A positive correlation was found for T. capillaris between the CFs of V, Mn, Co, Ni, Cu and Zn and the urban-industrial category, whereas the CF values for Zn and Pb were positively correlated with the road category. In T. permutata there was a positive correlation between the CF of Zn and the urban-industrial category and the CF of Pb with the road category. We therefore conclude that T. capillaris is a more efficient metal accumulator in passive biomonitoring studies.

Pharmaceutical Equivalence of Distributed Generic Antiretroviral (ARV) in Asian Settings: The Cross-Sectional Surveillance Study - PEDA Study.

PubMed

Sapsirisavat, Vorapot; Vongsutilers, Vorasit; Thammajaruk, Narukjaporn; Pussadee, Kanitta; Riyaten, Prakit; Kerr, Stephen; Avihingsanon, Anchalee; Phanuphak, Praphan; Ruxrungtham, Kiat

2016-01-01

Ensuring that medicines meet quality standards is mandatory for ensuring safety and efficacy. There have been occasional reports of substandard generic medicines, especially in resource-limiting settings where policies to control quality may be less rigorous. As HIV treatment in Thailand depends mostly on affordable generic antiretrovirals (ARV), we performed quality assurance testing of several generic ARV available from different sources in Thailand and a source from Vietnam. We sampled Tenofovir 300mg, Efavirenz 600mg and Lopinavir/ritonavir 200/50mg from 10 primary hospitals randomly selected from those participating in the National AIDS Program, 2 non-government organization ARV clinics, and 3 private drug stores. Quality of ARV was analyzed by blinded investigators at the Faculty of Pharmaceutical Science, Chulalongkorn University. The analysis included an identification test for drug molecules, a chemical composition assay to quantitate the active ingredients, a uniformity of mass test and a dissolution test to assess in-vitro drug release. Comparisons were made against the standards described in the WHO international pharmacopeia. A total of 42 batches of ARV from 15 sources were sampled from January-March 2015. Among those generics, 23, 17, 1, and 1 were Thai-made, Indian-made, Vietnamese-made and Chinese-made, respectively. All sampled products, regardless of manufacturers or sources, met the International Pharmacopeia standards for composition assay, mass uniformity and dissolution. Although local regulations restrict ARV supply to hospitals and clinics, samples of ARV could be bought from private drug stores even without formal prescription. Sampled generic ARVs distributed within Thailand and 1 Vietnamese pharmacy showed consistent quality. However some products were illegally supplied without prescription, highlighting the importance of dispensing ARV for treatment or prevention in facilities where continuity along the HIV treatment and care cascade is available.

Multivariate statistical evaluation of dissolved trace elements and a water quality assessment in the middle reaches of Huaihe River, Anhui, China.

PubMed

Wang, Jie; Liu, Guijian; Liu, Houqi; Lam, Paul K S

2017-04-01

A total of 211 water samples were collected from 53 key sampling points from 5-10th July 2013 at four different depths (0m, 2m, 4m, 8m) and at different sites in the Huaihe River, Anhui, China. These points monitored for 18 parameters (water temperature, pH, TN, TP, TOC, Cu, Pb, Zn, Ni, Co, Cr, Cd, Mn, B, Fe, Al, Mg, and Ba). The spatial variability, contamination sources and health risk of trace elements as well as the river water quality were investigated. Our results were compared with national (CSEPA) and international (WHO, USEPA) drinking water guidelines, revealing that Zn, Cd and Pb were the dominant pollutants in the water body. Application of different multivariate statistical approaches, including correlation matrix and factor/principal component analysis (FA/PCA), to assess the origins of the elements in the Huaihe River, identified three source types that accounted for 79.31% of the total variance. Anthropogenic activities were considered to contribute much of the Zn, Cd, Pb, Ni, Co, and Mn via industrial waste, coal combustion, and vehicle exhaust; Ba, B, Cr and Cu were controlled by mixed anthropogenic and natural sources, and Mg, Fe and Al had natural origins from weathered rocks and crustal materials. Cluster analysis (CA) was used to classify the 53 sample points into three groups of water pollution, high pollution, moderate pollution, and low pollution, reflecting influences from tributaries, power plants and vehicle exhaust, and agricultural activities, respectively. The results of the water quality index (WQI) indicate that water in the Huaihe River is heavily polluted by trace elements, so approximately 96% of the water in the Huaihe River is unsuitable for drinking. A health risk assessment using the hazard quotient and index (HQ/HI) recommended by the USEPA suggests that Co, Cd and Pb in the river could cause non-carcinogenic harm to human health. Copyright © 2017 Elsevier B.V. All rights reserved.

Source identification of combustion-related air pollution during an episode and afterwards in winter-time in Istanbul.

PubMed

Kuzu, S Levent

2016-10-11

Conventional air pollutants (PM 10 , CO, NO x ) gradually increased from fall to winter during 2015 in Istanbul. Several air pollution episodes were observed during this period. This study was made in order to determine polycyclic aromatic hydrocarbon (PAH) levels, identify the sources of air pollution, and make toxicity assessment based on Benzo(a)pyrene equivalent concentrations. The sampling took 14 sequential days during winter. High-pressure weather conditions prevailed at the start of the sampling. The conditions were then changed to low-pressure condition towards the end of the sampling. Strong inversion was effective on the onset of the sampling. Strong inversion was effective at the onset of the sampling. A high-volume sampler was used to collect gas and particle phase samples. Total suspended particle concentrations were between 27 and 252 μg m -3 . Sixteen PAH species were investigated. Total (gas + particle) PAH concentrations were between 76.4 and 1280.3 ng m -3 , with an average of 301.4 ng m -3 . Individual PAH concentrations were between not detected (n.d.) and 99.2 ng m -3 in the gaseous phase, and between n.d. and 11.5 ng m -3 in the particle phase. Phenanthrene had the highest share among 16 PAH compounds. Benzo(a)pyrene was not detected in 8 days. On the remaining days, its concentration ranged between 5.5 and 14.8 ng m -3 with an average of 3.7 ng m -3 . Low-molecular-weight PAHs dominated gaseous phase; inversely, high-molecular-weight PAHs dominated particle phase. Possible sources were identified by diagnostic ratios. These ratios suggested that coal combustion and diesel vehicle exhaust emissions had a substantial impact on ambient air quality. Benzo(a)pyrene equivalencies were calculated for each PAH compound in order to make toxicity assessment. Total benzo(a)pyrene equivalencies ranged between 0.4 and 30.0 ng m -3 with an average of 7.2 ng m -3 .

Tradeoff between assessment and control of aquatic invasive species: A case study of sea lamprey management in the St. Marys River

USGS Publications Warehouse

Robinson, Jason M.; Wilberg, Michael J.; Adams, Jean V.; Jones, Michael L.

2016-01-01

Allocating resources between the gathering of information to guide management actions and implementing those actions presents an inherent tradeoff. This tradeoff is evident for control of the Sea Lamprey Petromyzon marinus in the St. Marys River, connecting Lakes Huron and Superior and a major source of parasitic Sea Lampreys to Lake Huron and northern Lake Michigan. Larval Sea Lampreys in the St. Marys River are controlled through the application of Bayluscide, which is applied to areas of high larval density. Bayluscide applications are guided with an annual deepwater electrofishing survey to estimate larval Sea Lamprey density at relatively fine spatial scales. We took a resampling approach to describe the effect of sampling intensity on the success of the larval Sea Lamprey management program and explicitly incorporated the economic tradeoff between assessment and control efforts to maximize numbers of larvae killed in the St. Marys River. When no tradeoff between assessment and control was incorporated, increasing assessment always led to more larvae killed for the same treatment budget. When the tradeoff was incorporated, the sampling intensity that maximized the number of larvae killed depended on the overall budget available. Increased sampling intensities maximized effectiveness under medium to large budgets (US \\$0.4 to \\$2.0 million), and intermediate sampling intensities maximized effectiveness under low budgets. Sea Lamprey control actions based on assessment information outperformed those that were implemented with no assessment under all budget scenarios.

Use of stable isotopes of nitrogen and water to identify sources of nitrogen in three urban creeks of Durham, North Carolina, 2011-12

USGS Publications Warehouse

McSwain, Kristen Bukowski; Young, Megan B.; Giorgino, Mary L.

2014-01-01

A preliminary assessment of nitrate sources was conducted in three creeks that feed nutrient impaired Falls and Jordan Lakes in the vicinity of Durham County, North Carolina, from July 2011 to June 2012. Cabin Branch, Ellerbe Creek, and Third Fork Creek were sampled monthly to determine if sources of nitrate in surface water could be identified on the basis of their stable isotopic compositions. Land use differs in the drainage basins of the investigated creeks—the predominant land use in Cabin Branch Basin is forest, and the Ellerbe and Third Fork Creek Basins are predominantly developed urban areas. Total nutrient concentrations were below 1 milligram per liter (mg/L). All measured nitrate plus nitrite concentrations were below the North Carolina standard of 10 mg/L as nitrogen with the highest concentration of 0.363 mg/L measured in Third Fork Creek. Concentrations of ammonia were generally less than 0.1 mg/L as nitrogen in all creek samples. More than 50 percent of the total nitrogen measured in the creeks was in the form of organic nitrogen. Total phosphorus and orthophosphate concentrations in all samples were generally less than 0.2 mg/L as phosphorus. The isotopic composition of surface water (δ2HH20 and δ18OH2O) is similar to that of modern-day precipitation. During July and August 2011 and May and June 2012, surface-water samples displayed a seasonal difference in isotopic composition, indicating fractionation of isotopes as a result of evaporation and, potentially, mixing with local and regional groundwater. The dominant source of nitrate to Cabin Branch, Ellerbe Creek, and Third Fork Creek was the nitrification of soil nitrogen. Two stormflow samples in Ellerbe Creek and Third Fork Creek had nitrate sources that were a mixture of the nitrification of soil nitrogen and an atmospheric source that had bypassed some soil contact through impermeable surfaces within the drainage basin. No influence of a septic or wastewater source was found in Cabin Branch. Results from this study suggest that it is possible to distinguish sources of nitrogen and biogeochemical processes on nitrate using stable isotopes of nitrogen and oxygen in small creeks of Durham County, North Carolina.

Quality and Labelling Information Moringa Oleifera Products Marketed for HIV-infected People in Zimbabwe

PubMed Central

Jani, Zvinji Tella; Maponga, Charles Chiedza; Mudzengi, Josephine; Morse, Gene D.; Nhachi, Charles Fungai Brian

2016-01-01

Labeling information and quality of marketed Moringa oleifera products were assessed. Personnel in 60 pharmacies and 11 herbal shops were interviewed about the sources, dosages, indications and counseling information of Moringa oleifera products. Content analysis of written information provided on Moringa oleifera products was also done. Three samples of Moringa from popular sources were acquired to determine heavy metal content and microbial contamination. The results were compared to specified limits in the European and Chinese pharmacopeia, World Health Organization guidelines and Bureau of Indian Standards. Moringa was available as capsules or powder in 73% of the premises. Moringa was recommended for seven different disease conditions. Four different dosage regimens were prescribed. The main references cited for the counseling information were unscientific literature (62%). The selected Moringa samples were contaminated with bacteria and fungi above the European Pharmacopeia specified limits. Escherichia coli and Salmonella species were present in all three samples. All three samples contained arsenic, nickel and cadmium above the permissible limits. Moringa oleifera with variable labeling information and poor microbial and heavy metal quality is widely available in Zimbabwe. PMID:28239441

Quality and labeling information of Moringa oleifera products marketed for HIV-infected people in Zimbabwe.

PubMed

Monera-Penduka, Tsitsi Grace; Jani, Zvinji Tella; Maponga, Charles Chiedza; Mudzengi, Josephine; Morse, Gene D; Nhachi, Charles Fungai Brian

2016-12-31

Labeling information and quality of marketed Moringa oleifera products were assessed. Personnel in 60 pharmacies and 11 herbal shops were interviewed about the sources, dosages, indications and counseling information of Moringa oleifera products. Content analysis of written information provided on Moringa oleifera products was also done. Three samples of Moringa from popular sources were acquired to determine heavy metal content and microbial contamination. The results were compared to specified limits in the European and Chinese pharmacopeia, World Health Organization guidelines and Bureau of Indian Standards. Moringa was available as capsules or powder in 73% of the premises. Moringa was recommended for seven different disease conditions. Four different dosage regimens were prescribed. The main references cited for the counseling information were unscientific literature (62%). The selected Moringa samples were contaminated with bacteria and fungi above the European Pharmacopeia specified limits. Escherichia coli and Salmonella species were present in all three samples. All three samples contained arsenic, nickel and cadmium above the permissible limits. Moringa oleifera with variable labeling information and poor microbial and heavy metal quality is widely available in Zimbabwe.

Integrating quantitative PCR and Bayesian statistics in quantifying human adenoviruses in small volumes of source water.

PubMed

Wu, Jianyong; Gronewold, Andrew D; Rodriguez, Roberto A; Stewart, Jill R; Sobsey, Mark D

2014-02-01

Rapid quantification of viral pathogens in drinking and recreational water can help reduce waterborne disease risks. For this purpose, samples in small volume (e.g. 1L) are favored because of the convenience of collection, transportation and processing. However, the results of viral analysis are often subject to uncertainty. To overcome this limitation, we propose an approach that integrates Bayesian statistics, efficient concentration methods, and quantitative PCR (qPCR) to quantify viral pathogens in water. Using this approach, we quantified human adenoviruses (HAdVs) in eighteen samples of source water collected from six drinking water treatment plants. HAdVs were found in seven samples. In the other eleven samples, HAdVs were not detected by qPCR, but might have existed based on Bayesian inference. Our integrated approach that quantifies uncertainty provides a better understanding than conventional assessments of potential risks to public health, particularly in cases when pathogens may present a threat but cannot be detected by traditional methods. © 2013 Elsevier B.V. All rights reserved.

Estimating instream constituent loads using replicate synoptic sampling, Peru Creek, Colorado

NASA Astrophysics Data System (ADS)

Runkel, Robert L.; Walton-Day, Katherine; Kimball, Briant A.; Verplanck, Philip L.; Nimick, David A.

2013-05-01

SummaryThe synoptic mass balance approach is often used to evaluate constituent mass loading in streams affected by mine drainage. Spatial profiles of constituent mass load are used to identify sources of contamination and prioritize sites for remedial action. This paper presents a field scale study in which replicate synoptic sampling campaigns are used to quantify the aggregate uncertainty in constituent load that arises from (1) laboratory analyses of constituent and tracer concentrations, (2) field sampling error, and (3) temporal variation in concentration from diel constituent cycles and/or source variation. Consideration of these factors represents an advance in the application of the synoptic mass balance approach by placing error bars on estimates of constituent load and by allowing all sources of uncertainty to be quantified in aggregate; previous applications of the approach have provided only point estimates of constituent load and considered only a subset of the possible errors. Given estimates of aggregate uncertainty, site specific data and expert judgement may be used to qualitatively assess the contributions of individual factors to uncertainty. This assessment can be used to guide the collection of additional data to reduce uncertainty. Further, error bars provided by the replicate approach can aid the investigator in the interpretation of spatial loading profiles and the subsequent identification of constituent source areas within the watershed. The replicate sampling approach is applied to Peru Creek, a stream receiving acidic, metal-rich effluent from the Pennsylvania Mine. Other sources of acidity and metals within the study reach include a wetland area adjacent to the mine and tributary inflow from Cinnamon Gulch. Analysis of data collected under low-flow conditions indicates that concentrations of Al, Cd, Cu, Fe, Mn, Pb, and Zn in Peru Creek exceed aquatic life standards. Constituent loading within the study reach is dominated by effluent from the Pennsylvania Mine, with over 50% of the Cd, Cu, Fe, Mn, and Zn loads attributable to a collapsed adit near the top of the study reach. These estimates of mass load may underestimate the effect of the Pennsylvania Mine as leakage from underground mine workings may contribute to metal loads that are currently attributed to the wetland area. This potential leakage confounds the evaluation of remedial options and additional research is needed to determine the magnitude and location of the leakage.

Estimating instream constituent loads using replicate synoptic sampling, Peru Creek, Colorado

USGS Publications Warehouse

Runkel, Robert L.; Walton-Day, Katherine; Kimball, Briant A.; Verplanck, Philip L.; Nimick, David A.

2013-01-01

The synoptic mass balance approach is often used to evaluate constituent mass loading in streams affected by mine drainage. Spatial profiles of constituent mass load are used to identify sources of contamination and prioritize sites for remedial action. This paper presents a field scale study in which replicate synoptic sampling campaigns are used to quantify the aggregate uncertainty in constituent load that arises from (1) laboratory analyses of constituent and tracer concentrations, (2) field sampling error, and (3) temporal variation in concentration from diel constituent cycles and/or source variation. Consideration of these factors represents an advance in the application of the synoptic mass balance approach by placing error bars on estimates of constituent load and by allowing all sources of uncertainty to be quantified in aggregate; previous applications of the approach have provided only point estimates of constituent load and considered only a subset of the possible errors. Given estimates of aggregate uncertainty, site specific data and expert judgement may be used to qualitatively assess the contributions of individual factors to uncertainty. This assessment can be used to guide the collection of additional data to reduce uncertainty. Further, error bars provided by the replicate approach can aid the investigator in the interpretation of spatial loading profiles and the subsequent identification of constituent source areas within the watershed.The replicate sampling approach is applied to Peru Creek, a stream receiving acidic, metal-rich effluent from the Pennsylvania Mine. Other sources of acidity and metals within the study reach include a wetland area adjacent to the mine and tributary inflow from Cinnamon Gulch. Analysis of data collected under low-flow conditions indicates that concentrations of Al, Cd, Cu, Fe, Mn, Pb, and Zn in Peru Creek exceed aquatic life standards. Constituent loading within the study reach is dominated by effluent from the Pennsylvania Mine, with over 50% of the Cd, Cu, Fe, Mn, and Zn loads attributable to a collapsed adit near the top of the study reach. These estimates of mass load may underestimate the effect of the Pennsylvania Mine as leakage from underground mine workings may contribute to metal loads that are currently attributed to the wetland area. This potential leakage confounds the evaluation of remedial options and additional research is needed to determine the magnitude and location of the leakage.

Application of Gauss's theorem to quantify localized surface emissions from airborne measurements of wind and trace gases

DOE PAGES

Conley, Stephen; Faloona, Ian; Mehrotra, Shobhit; ...

2017-09-13

Airborne estimates of greenhouse gas emissions are becoming more prevalent with the advent of rapid commercial development of trace gas instrumentation featuring increased measurement accuracy, precision, and frequency, and the swelling interest in the verification of current emission inventories. Multiple airborne studies have indicated that emission inventories may underestimate some hydrocarbon emission sources in US oil- and gas-producing basins. Consequently, a proper assessment of the accuracy of these airborne methods is crucial to interpreting the meaning of such discrepancies. We present a new method of sampling surface sources of any trace gas for which fast and precise measurements can be mademore » and apply it to methane, ethane, and carbon dioxide on spatial scales of ~1000 m, where consecutive loops are flown around a targeted source region at multiple altitudes. Using Reynolds decomposition for the scalar concentrations, along with Gauss's theorem, we show that the method accurately accounts for the smaller-scale turbulent dispersion of the local plume, which is often ignored in other average mass balance methods. With the help of large eddy simulations (LES) we further show how the circling radius can be optimized for the micrometeorological conditions encountered during any flight. Furthermore, by sampling controlled releases of methane and ethane on the ground we can ascertain that the accuracy of the method, in appropriate meteorological conditions, is often better than 10 %, with limits of detection below 5 kg h -1 for both methane and ethane. Because of the FAA-mandated minimum flight safe altitude of 150 m, placement of the aircraft is critical to preventing a large portion of the emission plume from flowing underneath the lowest aircraft sampling altitude, which is generally the leading source of uncertainty in these measurements. Finally, we show how the accuracy of the method is strongly dependent on the number of sampling loops and/or time spent sampling the source plume.« less

Application of Gauss's theorem to quantify localized surface emissions from airborne measurements of wind and trace gases

NASA Astrophysics Data System (ADS)

Conley, Stephen; Faloona, Ian; Mehrotra, Shobhit; Suard, Maxime; Lenschow, Donald H.; Sweeney, Colm; Herndon, Scott; Schwietzke, Stefan; Pétron, Gabrielle; Pifer, Justin; Kort, Eric A.; Schnell, Russell

2017-09-01

Airborne estimates of greenhouse gas emissions are becoming more prevalent with the advent of rapid commercial development of trace gas instrumentation featuring increased measurement accuracy, precision, and frequency, and the swelling interest in the verification of current emission inventories. Multiple airborne studies have indicated that emission inventories may underestimate some hydrocarbon emission sources in US oil- and gas-producing basins. Consequently, a proper assessment of the accuracy of these airborne methods is crucial to interpreting the meaning of such discrepancies. We present a new method of sampling surface sources of any trace gas for which fast and precise measurements can be made and apply it to methane, ethane, and carbon dioxide on spatial scales of ˜ 1000 m, where consecutive loops are flown around a targeted source region at multiple altitudes. Using Reynolds decomposition for the scalar concentrations, along with Gauss's theorem, we show that the method accurately accounts for the smaller-scale turbulent dispersion of the local plume, which is often ignored in other average mass balance methods. With the help of large eddy simulations (LES) we further show how the circling radius can be optimized for the micrometeorological conditions encountered during any flight. Furthermore, by sampling controlled releases of methane and ethane on the ground we can ascertain that the accuracy of the method, in appropriate meteorological conditions, is often better than 10 %, with limits of detection below 5 kg h-1 for both methane and ethane. Because of the FAA-mandated minimum flight safe altitude of 150 m, placement of the aircraft is critical to preventing a large portion of the emission plume from flowing underneath the lowest aircraft sampling altitude, which is generally the leading source of uncertainty in these measurements. Finally, we show how the accuracy of the method is strongly dependent on the number of sampling loops and/or time spent sampling the source plume.

Application of Gauss's theorem to quantify localized surface emissions from airborne measurements of wind and trace gases

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

Conley, Stephen; Faloona, Ian; Mehrotra, Shobhit

Airborne estimates of greenhouse gas emissions are becoming more prevalent with the advent of rapid commercial development of trace gas instrumentation featuring increased measurement accuracy, precision, and frequency, and the swelling interest in the verification of current emission inventories. Multiple airborne studies have indicated that emission inventories may underestimate some hydrocarbon emission sources in US oil- and gas-producing basins. Consequently, a proper assessment of the accuracy of these airborne methods is crucial to interpreting the meaning of such discrepancies. We present a new method of sampling surface sources of any trace gas for which fast and precise measurements can be mademore » and apply it to methane, ethane, and carbon dioxide on spatial scales of ~1000 m, where consecutive loops are flown around a targeted source region at multiple altitudes. Using Reynolds decomposition for the scalar concentrations, along with Gauss's theorem, we show that the method accurately accounts for the smaller-scale turbulent dispersion of the local plume, which is often ignored in other average mass balance methods. With the help of large eddy simulations (LES) we further show how the circling radius can be optimized for the micrometeorological conditions encountered during any flight. Furthermore, by sampling controlled releases of methane and ethane on the ground we can ascertain that the accuracy of the method, in appropriate meteorological conditions, is often better than 10 %, with limits of detection below 5 kg h -1 for both methane and ethane. Because of the FAA-mandated minimum flight safe altitude of 150 m, placement of the aircraft is critical to preventing a large portion of the emission plume from flowing underneath the lowest aircraft sampling altitude, which is generally the leading source of uncertainty in these measurements. Finally, we show how the accuracy of the method is strongly dependent on the number of sampling loops and/or time spent sampling the source plume.« less

Drinking water contamination by chromium and lead in industrial lands of Karachi.

PubMed

Nadeem-ul-Haq; Arain, Mubashir Aslam; Haque, Zeba; Badar, Nasira; Mughal, Noman

2009-05-01

To identify and quantify chromium and lead as contaminant in water sources of Karachi. This water assessment survey was conducted from June 2007 to February 2008 in all the 18 towns of Karachi. In total 216 water samples were collected from ground (n=108) and surface water sources (n = 108). Water samples were collected in a liter polyethylene acid resistant bottle with extreme care to prevent contamination and concentrations of heavy metals (chromium and lead). Metallic ion contents were estimated by Atomic Absorption Spectrophotometer. Statistical analysis was done by applying T-test and chi-square for continuous and categorical variables respectively at 95% confidence level; Pearson correlation was also determined between chromium and lead concentrations. A total of 187 water samples had lead concentration higher than the maximum acceptable concentration (MAC) in drinking water, established by WHO (10 PPB) and lead contaminated sources were in significantly higher proportion than chromium contaminated water samples (n = 49) [chi2 = 128; P- < 0.001]. Mean chromium concentration in ground water was (micro = 49; SE = 3.8) was significantly higher than mean chromium concentration (micro = 33, SE = 3.5) in surface water (P = 0.003). There was a significant and positive correlation between chromium and lead concentrations in ground water (P = 0.04) however Pearson correlation was not significant for surface water (P = 0.6). Industrial towns (Korangi, Landhi and SITE) had significantly higher concentration of chromium (micro = 82.4; SE = 8.9) in their ground and tap water as compared to the mean chromium concentration (micro = 33; SE = 2.2) in the water samples of rest of the towns of Karachi (P < 0.001). Chromium and Lead levels are high in almost all ground water sources, however extremely high concentrations were found in industrial areas. Presence of any one of the heavy metal contamination necessitate the need for the estimation of other heavy metals as significant positive correlation was found between chromium and lead concentration, indicating the possibility of similar contamination sources in Karachi.

Determination of sulfur in human hair using high resolution continuum source graphite furnace molecular absorption spectrometry and its correlation with total protein and albumin

NASA Astrophysics Data System (ADS)

Ozbek, Nil; Baysal, Asli

2017-04-01

Human hair is a valuable contributor for biological monitoring. It is an information storage point to assess the effects of environmental, nutritional or occupational sources on the body. Human proteins, amino acids or other compounds are among the key components to find the sources of different effects or disorders in the human body. Sulfur is a significant one of these compounds, and it has great affinity to some metals and compounds. This property of the sulfur affects the human health positively or negatively. In this manuscript, sulfur was determined in hair samples of autistic and age-match control group children via molecular absorption of CS using a high-resolution continuum source graphite furnace atomic absorption spectrometer. For this purpose, hair samples were appropriately washed and dried at 75 °C. Then samples were dissolved in microwave digestion using HNO3 for sulfur determination. Extraction was performed with HCl hydrolysation by incubation for 24 h at 110 °C for total protein and albumin determination. The validity of the method for the sulfur determination was tested using hair standard reference materials. The results were in the uncertainty limits of the certified values at 95% confidence level. Finally correlation of sulfur levels of autistic children's hair with their total protein and albumin levels were done.

Initial Results from the Survey of Organizational Research Climates (SOuRCe) in the U.S. Department of Veterans Affairs Healthcare System.

PubMed

Martinson, Brian C; Nelson, David; Hagel-Campbell, Emily; Mohr, David; Charns, Martin P; Bangerter, Ann; Thrush, Carol R; Ghilardi, Joseph R; Bloomfield, Hanna; Owen, Richard; Wells, James A

2016-01-01

In service to its core mission of improving the health and well-being of veterans, Veterans Affairs (VA) leadership is committed to supporting research best practices in the VA. Recognizing that the behavior of researchers is influenced by the organizational climates in which they work, efforts to assess the integrity of research climates and share such information with research leadership in VA may be one way to support research best practices. The Survey of Organizational Research Climate (SOuRCe) is the first validated survey instrument specifically designed to assess the organizational climate of research integrity in academic research organizations. The current study reports on an initiative to use the SOuRCe in VA facilities to characterize the organizational research climates and pilot test the effectiveness of using SOuRCe data as a reporting and feedback intervention tool. We administered the SOuRCe using a cross-sectional, online survey, with mailed follow-up to non-responders, of research-engaged employees in the research services of a random selection of 42 VA facilities (e.g., Hospitals/Stations) believed to employ 20 or more research staff. We attained a 51% participation rate, yielding more than 5,200 usable surveys. We found a general consistency in organizational research climates across a variety of sub-groups in this random sample of research services in the VA. We also observed similar SOuRCe scale score means, relative rankings of these scales and their internal reliability, in this VA-based sample as we have previously documented in more traditional academic research settings. Results also showed more substantial variability in research climate scores within than between facilities in the VA research service as reflected in meaningful subgroup differences. These findings suggest that the SOuRCe is suitable as an instrument for assessing the research integrity climates in VA and that the tool has similar patterns of results that have been observed in more traditional academic research settings. The local and specific nature of organizational climates in VA research services, as reflected in variability across sub-groups within individual facilities, has important policy implications. Global, "one-size-fits-all" type initiatives are not likely to yield as much benefit as efforts targeted to specific organizational units or sub-groups and tailored to the specific strengths and weaknesses documented in those locations.

Airframe self-noise: Four years of research. [aircraft noise reduction for commercial aircraft

NASA Technical Reports Server (NTRS)

Hardin, J. C.

1976-01-01

A critical assessment of the state of the art in airframe self-noise is presented. Full-scale data on the intensity, spectra and directivity of this noise source are evaluated in the light of the comprehensive theory developed by Ffowcs-Williams and Hawkins. Vibration of panels on commercial aircraft is identified as a possible additional source of airframe noise. The present understanding and methods for prediction of other component sources - airfoils, struts, and cavities - are discussed, and areas for further research as well as potential methods for airframe noise reduction are identified. Finally, the various experimental methods which have been developed for airframe noise research are discussed and sample results are presented.

Environmental assessment of a crude-oil heater using staged air lances for NOx reduction. Volume 1. Technical results. Final report June 1981-November 1983

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

DeRosier, R.

1984-07-01

This volume of the report gives emission results from field tests of a crude-oil process heater burning a combination of oil and refinery gas. The heater had been modified by adding a system for injecting secondary air to reduce NOx emissions. One test was conducted with the staged air system (low NOx), and the other, without (baseline). Tests included continuous monitoring of flue gas emissions and source assessment sampling system (SASS) sampling of the flue gas with subsequent laboratory analysis of the samples utilizing gas chromatography (GC), infrared spectrometry (IR), gas chromatography/mass spectroscopy (GC/MS), and low resolution mass spectrometry (SSMS)more » for trace metals. LRMS analysis suggested the presence of eight compound categories in the organic emissions during the baseline test and four in the low-NOx test.« less

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

Bence, A.E.; Burns, W.A.

A procedure has been developed that discriminates Exxon Valdez crude from other sources of hydrocarbons found in Prince Williams Sound and the Gulf of Alaska. The procedure uses polycyclic aromatic hydrocarbon (PAH) distributions, measured by gas chromatography/mass spectrometry (GC/MS), to fingerprint sample extracts. The relative abundances of alkylated phenanthrenes, dibenzothiophenes, and chrysenes are used to differentiate Exxon Valdez crude and its weathering products from other hydrocarbons. Saturate fraction distributions are used to confirm the PAH identification whenever possible. The procedure has been applied to the more than 1,500 PAH analyses of tissues reported by the Oil Spill Health Task Force,more » formed after the spill to assess subsistence food safety, and nearly 4,700 PAH analyses of biological samples in PWSOIL, the government`s damage-assessment chemistry database. These two datasets constitute the largest collection of hydrocarbon analyses of biological samples form the spill-impact zone. 70 refs., 14 figs., 8 tabs.« less

Performance of human fecal anaerobe-associated PCR-based assays in a multi-laboratory method evaluation study

USGS Publications Warehouse

Layton, Blythe A.; Cao, Yiping; Ebentier, Darcy L.; Hanley, Kaitlyn; Ballesté, Elisenda; Brandão, João; Byappanahalli, Muruleedhara N.; Converse, Reagan; Farnleitner, Andreas H.; Gentry-Shields, Jennifer; Gourmelon, Michèle; Lee, Chang Soo; Lee, Jiyoung; Lozach, Solen; Madi, Tania; Meijer, Wim G.; Noble, Rachel; Peed, Lindsay; Reischer, Georg H.; Rodrigues, Raquel; Rose, Joan B.; Schriewer, Alexander; Sinigalliano, Chris; Srinivasan, Sangeetha; Stewart, Jill; ,; Laurie, C.; Wang, Dan; Whitman, Richard; Wuertz, Stefan; Jay, Jenny; Holden, Patricia A.; Boehm, Alexandria B.; Shanks, Orin; Griffith, John F.

2013-01-01

A number of PCR-based methods for detecting human fecal material in environmental waters have been developed over the past decade, but these methods have rarely received independent comparative testing in large multi-laboratory studies. Here, we evaluated ten of these methods (BacH, BacHum-UCD, Bacteroides thetaiotaomicron (BtH), BsteriF1, gyrB, HF183 endpoint, HF183 SYBR, HF183 Taqman®, HumM2, and Methanobrevibacter smithii nifH (Mnif)) using 64 blind samples prepared in one laboratory. The blind samples contained either one or two fecal sources from human, wastewater or non-human sources. The assay results were assessed for presence/absence of the human markers and also quantitatively while varying the following: 1) classification of samples that were detected but not quantifiable (DNQ) as positive or negative; 2) reference fecal sample concentration unit of measure (such as culturable indicator bacteria, wet mass, total DNA, etc); and 3) human fecal source type (stool, sewage or septage). Assay performance using presence/absence metrics was found to depend on the classification of DNQ samples. The assays that performed best quantitatively varied based on the fecal concentration unit of measure and laboratory protocol. All methods were consistently more sensitive to human stools compared to sewage or septage in both the presence/absence and quantitative analysis. Overall, HF183 Taqman® was found to be the most effective marker of human fecal contamination in this California-based study.

Assessing contribution of DOC from sediments to a drinking-water reservoir using optical profiling

USGS Publications Warehouse

Downing, Bryan D.; Bergamaschi, Brian A.; Evans, David G.; Boss, Emmanuel

2008-01-01

Understanding the sources of dissolved organic carbon (DOC) in drinking-water reservoirs is an important management issue because DOC may form disinfection by-products, interfere with disinfection, or increase treatment costs. DOC may be derived from a host of sources-algal production of DOC in the reservoir, marginal production of DOC from mucks and vascular plants at the margins, and sediments in the reservoir. The purpose of this study was to assess if release of DOC from reservoir sediments containing ferric chloride coagulant was a significant source of DOC to the reservoir. We examined the source-specific contributions of DOC using a profiling system to measure the in situ distribution of optical properties of absorption and fluorescence at various locations in the reservoir. Vertical optical profiles were coupled with discrete water samples measured in the laboratory for DOC concentration and optical properties: absorption spectra and excitation emission matrix spectra (EEMs). Modeling the in situ optical data permitted estimation of the bulk DOC profile in the reservoir as well as separation into source-specific contributions. Analysis of the source-specific profiles and their associated optical characteristics indicated that the sedimentary source of DOC to the reservoir is significant and that this DOC is labile in the reservoir. We conclude that optical profiling is a useful technique for understanding complex biogeochemical processes in a reservoir.

The value and limitations of global air-sampling networks for improving our understanding trace gas behavior

NASA Astrophysics Data System (ADS)

Montzka, S. A.

2016-12-01

Measurements from global surface-based air sampling networks provide a fundamental understanding of how and why concentrations of long-lived trace gases are changing over time. Results from these networks are used to quantify trace-gas concentrations and their time-dependent changes on global and smaller scales, and thus provide a means to quantify emission rates, loss frequencies, and mixing processes. Substantial advances in measurement and sampling technologies and the ability of these programs to create and maintain reliable gas standards mean that spatial concentration gradients and time-dependent changes are often very reliably measured. The presence of multiple independent networks allows an assessment of this reliability. Furthermore, recent global `snap-shot' surveys (e.g., HIPPO and ATom) and ongoing atmospheric profiling programs help us assess the ability of surface-based data to describe concentration distributions throughout most of the atmosphere ( 80% of its mass). In this overview talk, I'll explore the usefulness and limitations of existing long-term, ongoing sampling network programs and their advantages and disadvantages for characterizing concentrations on global and regional scales, and how recent advances (and short-term sampling programs) help us assess the accuracy of the surface networks to provide estimates of source and sink magnitudes, and inter-annual variability in both.

Assessment of nonpoint source chemical loading potential to watersheds containing uranium waste dumps associated with uranium exploration and mining, San Rafael Swell, Utah

USGS Publications Warehouse

Freeman, Michael L.; Naftz, David L.; Snyder, Terry; Johnson, Greg

2008-01-01

During July and August of 2006, 117 solid-phase samples were collected from abandoned uranium waste dumps, geologic background sites, and adjacent streambeds in the San Rafael Swell, in southeastern Utah. The objective of this sampling program was to assess the nonpoint source chemical loading potential to ephemeral and perennial watersheds from uranium waste dumps on Bureau of Land Management property. Uranium waste dump samples were collected using solid-phase sampling protocols. After collection, solid-phase samples were homogenized and extracted in the laboratory using a field leaching procedure. Filtered (0.45 micron) water samples were obtained from the field leaching procedure and were analyzed for Ag, As, Ba, Be, Cd, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Se, U, V, and Zn at the Inductively Coupled Plasma-Mass Spectrometry Metals Analysis Laboratory at the University of Utah, Salt Lake City, Utah and for Hg at the U.S. Geological Survey National Water Quality Laboratory, Denver, Colorado. For the initial ranking of chemical loading potential of suspect uranium waste dumps, leachate analyses were compared with existing aquatic life and drinking-water-quality standards and the ratio of samples that exceeded standards to the total number of samples was determined for each element having a water-quality standard for aquatic life and drinking-water. Approximately 56 percent (48/85) of the leachate samples extracted from uranium waste dumps had one or more chemical constituents that exceeded aquatic life and drinking-water-quality standards. Most of the uranium waste dump sites with elevated trace-element concentrations in leachates were along Reds Canyon Road between Tomsich Butte and Family Butte. Twelve of the uranium waste dump sites with elevated trace-element concentrations in leachates contained three or more constituents that exceeded drinking-water-quality standards. Eighteen of the uranium waste dump sites had three or more constituents that exceeded trace-element concentrations for aquatic life water-quality standards. The proximity of the uranium waste dumps in the Tomsich Butte area near Muddy Creek, coupled with the elevated concentration of trace elements, increases the offsite impact potential to water resources. Future assessment and remediation priority of these areas may be done by using GIS-based risk-mapping techniques, such as Sensitive Catchment Integrated Mapping and Analysis Project.

A Quantitative Proteomics Approach to Clinical Research with Non-Traditional Samples

PubMed Central

Licier, Rígel; Miranda, Eric; Serrano, Horacio

2016-01-01

The proper handling of samples to be analyzed by mass spectrometry (MS) can guarantee excellent results and a greater depth of analysis when working in quantitative proteomics. This is critical when trying to assess non-traditional sources such as ear wax, saliva, vitreous humor, aqueous humor, tears, nipple aspirate fluid, breast milk/colostrum, cervical-vaginal fluid, nasal secretions, bronco-alveolar lavage fluid, and stools. We intend to provide the investigator with relevant aspects of quantitative proteomics and to recognize the most recent clinical research work conducted with atypical samples and analyzed by quantitative proteomics. Having as reference the most recent and different approaches used with non-traditional sources allows us to compare new strategies in the development of novel experimental models. On the other hand, these references help us to contribute significantly to the understanding of the proportions of proteins in different proteomes of clinical interest and may lead to potential advances in the emerging field of precision medicine. PMID:28248241

A Quantitative Proteomics Approach to Clinical Research with Non-Traditional Samples.

PubMed

Licier, Rígel; Miranda, Eric; Serrano, Horacio

2016-10-17

The proper handling of samples to be analyzed by mass spectrometry (MS) can guarantee excellent results and a greater depth of analysis when working in quantitative proteomics. This is critical when trying to assess non-traditional sources such as ear wax, saliva, vitreous humor, aqueous humor, tears, nipple aspirate fluid, breast milk/colostrum, cervical-vaginal fluid, nasal secretions, bronco-alveolar lavage fluid, and stools. We intend to provide the investigator with relevant aspects of quantitative proteomics and to recognize the most recent clinical research work conducted with atypical samples and analyzed by quantitative proteomics. Having as reference the most recent and different approaches used with non-traditional sources allows us to compare new strategies in the development of novel experimental models. On the other hand, these references help us to contribute significantly to the understanding of the proportions of proteins in different proteomes of clinical interest and may lead to potential advances in the emerging field of precision medicine.

Characterizing the isotopic composition of atmospheric ammonia emission sources using passive samplers and a combined oxidation-bacterial denitrifier approach.

PubMed

Felix, J David; Elliott, Emily M; Gish, Timothy J; McConnell, Laura L; Shaw, Stephanie L

2013-10-30

Ammonia (NH3) emissions are a substantial source of nitrogen pollution to sensitive terrestrial, aquatic, and marine ecosystems and dependable quantification of NH3 sources is of growing importance due to recently observed increases in ammonium (NH4(+)) deposition rates. While determination of the nitrogen isotopic composition of NH3 (δ(15)N-NH3) can aid in the quantification of NH3 emission sources, existing methods have precluded a comprehensive assessment of δ(15)N-NH3 values from major emission sources. We report an approach for the δ(15)N-NH4(+) analysis of low concentration NH4(+) samples that couples the bromate oxidation of NH4(+) to NO2(-) and the microbial denitrifier method for δ(15)N-NO2(-) analysis. This approach reduces the required sample mass by 50-fold relative to standard elemental analysis (EA) procedures, is capable of high throughput, and eliminates toxic chemicals used in a prior method for the analysis of low concentration samples. Using this approach, we report a comprehensive inventory of δ(15)N-NH3 values from major emission sources (including livestock operations, marine sources, vehicles, fertilized cornfields) collected using passive sampling devices. The δ(15)N-NH4(+) analysis approach developed has a standard deviation of ±0.7‰ and was used to analyze passively collected NH3 emissions with a wide range of ambient NH3 concentrations (0.2 to 165.6 µg/m(3)). The δ(15)N-NH3 values reveal that the NH3 emitted from volatilized livestock waste and fertilizer has relatively low δ(15)N values (-56 to -23‰), allowing it to be differentiated from NH3 emitted from fossil fuel sources that are characterized by relatively high δ(15)N values (-15 to +2‰). The isotopic source signatures presented in this emission inventory can be used as an additional tool in identifying NH3 emission sources and tracing their transport across localized landscapes and regions. The insight into the transport of NH3 emissions provided by isotopic investigation is an important step in devising strategies to reduce future NH3 emissions, a mounting concern for air quality scientists, epidemiologists, and policy-makers. Copyright © 2013 John Wiley & Sons, Ltd.

A guide for the utilization of Health Insurance Review and Assessment Service National Patient Samples

PubMed Central

Kim, Logyoung; Kim, Jee-Ae; Kim, Sanghyun

2014-01-01

The claims data of the Health Insurance Review and Assessment Service (HIRA) is an important source of information for healthcare service research. The claims data of HIRA is collected when healthcare service providers submit a claim to HIRA to be reimbursed for a service that they provided to patients. To improve the accessibility of healthcare service researchers to claims data of HIRA, HIRA has developed the Patient Samples which are extracted using a stratified randomized sampling method. The Patient Samples of HIRA consist of five tables: a table for general information (Table 20) containing socio-demographic information such as gender, age and medical aid, indicators for inpatient and outpatient services; a table for specific information on healthcare services provided (Table 30); a table for diagnostic information (Table 40); a table for outpatient prescriptions (Table 53) and a table for information on healthcare service providers (Table of providers). Researchers who are interested in using the Patient Sample data for research can apply via HIRA’s website (https://www.hira.or.kr). PMID:25078381

Alternative method to trace sediment sources in a subtropical rural catchment of southern Brazil by using near-infrared spectroscopy

NASA Astrophysics Data System (ADS)

Tiecher, Tales; Caner, Laurent; Gomes Minella, Jean Paolo; Henrique Ciotti, Lucas; Antônio Bender, Marcos; dos Santos Rheinheimer, Danilo

2014-05-01

Conventional fingerprinting methods based on geochemical composition still require a time-consuming and critical preliminary sample preparation. Thus, fingerprinting characteristics that can be measured in a rapid and cheap way requiring a minimal sample preparation, such as spectroscopy methods, should be used. The present study aimed to evaluate the sediment sources contribution in a rural catchment by using conventional method based on geochemical composition and on an alternative method based on near-infrared spectroscopy. This study was carried out in a rural catchment with an area of 1,19 km2 located in southern Brazil. The sediment sources evaluated were crop fields (n=20), unpaved roads (n=10) and stream channels (n=10). Thirty suspended sediment samples were collected from eight significant storm runoff events between 2009 and 2011. Sources and sediment samples were dried at 50oC and sieved at 63 µm. The total concentration of Ag, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, La, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Sb, Se, Sr, Ti, Tl, V and Zn were estimated by ICP-OES after microwave assisted digestion with concentrated HNO3 and HCl. Total organic carbon (TOC) was estimated by wet oxidation with K2Cr2O7 and H2SO4. The near-infrared spectra scan range was 4000 to 10000 cm-1 at a resolution of 2 cm-1, with 100 co added scans per spectrum. The steps used in the conventional method were: i) tracer selection based on Kruskal-Wallis test, ii) selection of the best set of tracers using discriminant analyses and finally iii) the use of a mixed linear model to calculate the sediment sources contribution. The steps used in the alternative method were i) principal component analyses to reduce the number of variables, ii) discriminant analyses to determine the tracer potential of the near-infrared spectroscopy, and finally iii) the use of past least square based on 48 mixtures of the sediment sources in various weight proportions to calculate the sediment sources contribution. Both conventional and alternative methods were capable to discriminate 100% of the sediment sources. Conventional fingerprinting method provided a sediment sources contribution of 33±19% by crop fields, 25±13% by unpaved roads and 42±19% by stream channels. The contribution of sediment sources obtained by alternative fingerprinting method using near-infrared spectroscopy was 71±22% of crop fields, 21±12% of unpaved roads and 14±19% of stream channels. No correlation was observed between source contribution assessed by the two methods. Notwithstanding, the average contribution of the unpaved roads was similar by both methods. The highest difference in the average contribution of crop fields and stream channels estimated by the two methods was due to similar organic matter content of these two sediment sources which hampers their discrimination by assessing the near-infrared spectra, where much of the bands are highly correlated with the TOC levels. Efforts should be taken to try to combine both the geochemical composition and near-infrared spectroscopy information on a single estimative of the sediment sources contribution.

Quantification and source identification of the Total Elgin gas leak, UK - North Sea, by aircraft sampling

NASA Astrophysics Data System (ADS)

Lee, J. D.; Bauguitte, S.; Wellpott, A.; Lowry, D.; Fisher, R. E.; Lewis, A. C.; Hopkins, J.; Allen, G.; O'Shea, S.; Lanoiselle, M.; France, J.; Lidster, R.; Punjabi, S.; Manning, A. J.; Ryerson, T. B.; Mobbs, S.; Gallagher, M. W.; Coe, H.; Pyle, J. A.; Nisbet, E. G.

2012-12-01

Aircraft measurement and air sampling have been used to quantify the source and magnitude of the North Sea Total Elgin wellhead platform gas leak in March/April 2012. Isotopic techniques were used to characterise the geological source formation from which the gas came. Initially on 30 March 2012 the leak was in the range 1.6 - 0.7 kg s-1, reducing to less than half that rate by 3 April 2012. Keeling plot analysis of methane in air samples showed that the gas had δ13CCH4 -43‰, implying that the gas source was not the main high-pressure high-temperature Elgin gas field (5.5 km deep, at 190oC) but more probably the overlying Hod Formation. The evidence in the air plume for release of very volatile NMHCs confirmed media reports that the gas leak was on the production platform, above the sea level. This contrasts with the early situation in the BP Deepwater Horizon event, where release was underwater and volatile NMHC species were taken up in the water column. Non-methane hydrocarbons (NMHC) and other volatile organic compounds in the plumes were determined from flask samples by offline analysis. NMHC content was dominated by light alkanes ranging from >20 ppb ethane to <1 ppb benzene and <0.1 ppb higher monoaromatics. The methodology developed in this work is widely applicable to future emissions of environmental concern in circumstances where direct access is difficult or dangerous, and permits unbiased regulatory assessment of potential impact, independent of the emitting party.

Insights into organic-aerosol sources via a novel laser-desorption/ionization mass spectrometry technique applied to one year of PM10 samples from nine sites in central Europe

NASA Astrophysics Data System (ADS)

Daellenbach, Kaspar R.; El-Haddad, Imad; Karvonen, Lassi; Vlachou, Athanasia; Corbin, Joel C.; Slowik, Jay G.; Heringa, Maarten F.; Bruns, Emily A.; Luedin, Samuel M.; Jaffrezo, Jean-Luc; Szidat, Sönke; Piazzalunga, Andrea; Gonzalez, Raquel; Fermo, Paola; Pflueger, Valentin; Vogel, Guido; Baltensperger, Urs; Prévôt, André S. H.

2018-02-01

We assess the benefits of offline laser-desorption/ionization mass spectrometry in understanding ambient particulate matter (PM) sources. The technique was optimized for measuring PM collected on quartz-fiber filters using silver nitrate as an internal standard for m/z calibration. This is the first application of this technique to samples collected at nine sites in central Europe throughout the entire year of 2013 (819 samples). Different PM sources were identified by positive matrix factorization (PMF) including also concomitant measurements (such as NOx, levoglucosan, and temperature). By comparison to reference mass spectral signatures from laboratory wood burning experiments as well as samples from a traffic tunnel, three biomass burning factors and two traffic factors were identified. The wood burning factors could be linked to the burning conditions; the factors related to inefficient burns had a larger impact on air quality in southern Alpine valleys than in northern Switzerland. The traffic factors were identified as primary tailpipe exhaust and most possibly aged/secondary traffic emissions. The latter attribution was supported by radiocarbon analyses of both the organic and elemental carbon. Besides these sources, factors related to secondary organic aerosol were also separated. The contribution of the wood burning emissions based on LDI-PMF (laser-desorption/ionization PMF) correlates well with that based on AMS-PMF (aerosol mass spectrometer PMF) analyses, while the comparison between the two techniques for other components is more complex.

Technical basis for the use of a correlated neutron source in the uranium neutron coincidence collar

DOE PAGES

Root, Margaret A.; Menlove, Howard Olsen; Lanza, Richard C.; ...

2017-01-16

Active neutron coincidence systems are commonly used by international inspectorates to verify a material balance across the various stages of the nuclear fuel cycle. The Uranium Neutron Coincidence Collar (UNCL) is one such instrument; it is used to measure the linear density of 235U (g 235U/cm of active length in assembly) in fresh light water reactor fuel in nuclear fuel fabrication facilities. The UNCL and other active neutron interrogation detectors have historically relied on americium lithium ( 241AmLi) sources to induce fission within the sample in question. Californium-252 is under consideration as a possible alternative to the traditional 241AmLi source.more » Finally, this work relied upon a combination of experiments and Monte Carlo simulations to demonstrate the technical basis for the replacement of 241AmLi sources with 252Cf sources by evaluating the statistical uncertainty in the measurements incurred by each source and assessing the penetrability of neutrons from each source for the UNCL.« less

Technical basis for the use of a correlated neutron source in the uranium neutron coincidence collar

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

Root, Margaret A.; Menlove, Howard Olsen; Lanza, Richard C.

Active neutron coincidence systems are commonly used by international inspectorates to verify a material balance across the various stages of the nuclear fuel cycle. The Uranium Neutron Coincidence Collar (UNCL) is one such instrument; it is used to measure the linear density of 235U (g 235U/cm of active length in assembly) in fresh light water reactor fuel in nuclear fuel fabrication facilities. The UNCL and other active neutron interrogation detectors have historically relied on americium lithium ( 241AmLi) sources to induce fission within the sample in question. Californium-252 is under consideration as a possible alternative to the traditional 241AmLi source.more » Finally, this work relied upon a combination of experiments and Monte Carlo simulations to demonstrate the technical basis for the replacement of 241AmLi sources with 252Cf sources by evaluating the statistical uncertainty in the measurements incurred by each source and assessing the penetrability of neutrons from each source for the UNCL.« less

Understanding human infectious Cryptosporidium risk in drinking water supply catchments.

PubMed

Swaffer, Brooke; Abbott, Hayley; King, Brendon; van der Linden, Leon; Monis, Paul

2018-07-01

Treating drinking water appropriately depends, in part, on the robustness of source water quality risk assessments, however quantifying the proportion of infectious, human pathogenic Cryptosporidium oocysts remains a significant challenge. We analysed 962 source water samples across nine locations to profile the occurrence, rate and timing of infectious, human pathogenic Cryptosporidium in surface waters entering drinking water reservoirs during rainfall-runoff conditions. At the catchment level, average infectivity over the four-year study period reached 18%; however, most locations averaged <5%. The maximum recorded infectivity fraction within a single rainfall runoff event was 65.4%, and was dominated by C. parvum. Twenty-two Cryptosporidium species and genotypes were identified using PCR-based molecular techniques; the most common being C. parvum, detected in 23% of water samples. Associations between landuse and livestock stocking characteristics with Cryptosporidium were determined using a linear mixed-effects model. The concentration of pathogens in water were significantly influenced by flow and dominance of land-use by commercial grazing properties (as opposed to lifestyle properties) in the catchment (p < 0.01). Inclusion of measured infectivity and human pathogenicity data into a quantitative microbial risk assessment (QMRA) could reduce the source water treatment requirements by up to 2.67 log removal values, depending on the catchment, and demonstrated the potential benefit of collating such data for QMRAs. Copyright © 2018 Elsevier Ltd. All rights reserved.

Performance Characteristics of qPCR Assays Targeting Human- and Ruminant-Associated Bacteroidetes for Microbial Source Tracking across Sixteen Countries on Six Continents

PubMed Central

2013-01-01

Numerous quantitative PCR assays for microbial fecal source tracking (MST) have been developed and evaluated in recent years. Widespread application has been hindered by a lack of knowledge regarding the geographical stability and hence applicability of such methods beyond the regional level. This study assessed the performance of five previously reported quantitative PCR assays targeting human-, cattle-, or ruminant-associated Bacteroidetes populations on 280 human and animal fecal samples from 16 countries across six continents. The tested cattle-associated markers were shown to be ruminant-associated. The quantitative distributions of marker concentrations in target and nontarget samples proved to be essential for the assessment of assay performance and were used to establish a new metric for quantitative source-specificity. In general, this study demonstrates that stable target populations required for marker-based MST occur around the globe. Ruminant-associated marker concentrations were strongly correlated with total intestinal Bacteroidetes populations and with each other, indicating that the detected ruminant-associated populations seem to be part of the intestinal core microbiome of ruminants worldwide. Consequently tested ruminant-targeted assays appear to be suitable quantitative MST tools beyond the regional level while the targeted human-associated populations seem to be less prevalent and stable, suggesting potential for improvements in human-targeted methods. PMID:23755882

Petroleum systems of the San Joaquin Basin Province -- geochemical characteristics of gas types: Chapter 10 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

USGS Publications Warehouse

Lillis, Paul G.; Warden, Augusta; Claypool, George E.; Magoon, Leslie B.

2008-01-01

The San Joaquin Basin Province is a petroliferous basin filled with predominantly Late Cretaceous to Pliocene-aged sediments, with organic-rich marine rocks of Late Cretaceous, Eocene, and Miocene age providing the source of most of the oil and gas. Previous geochemical studies have focused on the origin of the oil in the province, but the origin of the natural gas has received little attention. To identify and characterize natural gas types in the San Joaquin Basin, 66 gas samples were analyzed and combined with analyses of 15 gas samples from previous studies. For the purpose of this resource assessment, each gas type was assigned to the most likely petroleum system. Three general gas types are identified on the basis of bulk and stable carbon isotopic composition—thermogenic dry (TD), thermogenic wet (TW) and biogenic (B). The thermogenic gas types are further subdivided on the basis of the δ13C values of methane and ethane and nitrogen content into TD-1, TD-2, TD-Mixed, TW-1, TW-2, and TW-Mixed. Gas types TD-1 and TD-Mixed, a mixture of biogenic and TD-1 gases, are produced from gas fields in the northern San Joaquin Basin. Type TD-1 gas most likely originated from the Late Cretaceous to Paleocene Moreno Formation, a gas-prone source rock. The biogenic component of the TD-Mixed gas existed in the trap prior to the influx of thermogenic gas. For the assessment, these gas types were assigned to the Winters- Domengine Total Petroleum System, but subsequent to the assessment were reclassified as part of the Moreno-Nortonville gas system. Dry thermogenic gas produced from oil fields in the southern San Joaquin Basin (TD-2 gas) most likely originated from the oil-prone source rock of Miocene age. These samples have low wetness values due to migration fractionation or biodegradation. The thermogenic wet gas types (TW-1, TW-2, TW-Mixed) are predominantly associated gas produced from oil fields in the southern and central San Joaquin Basin. Type TW-1 gas most likely originates from source rocks within the Eocene Kreyenhagen Formation or the Eocene Tumey formation of Atwill (1935). Type TW-2 gas most likely originates from the Miocene Monterey Formation and equivalents. TW-Mixed gas is likely a mixture of biogenic and wet thermogenic gas (TW-1 or TW-2) derived from source rocks mentioned above. The thermogenic wet gas types are included in the corresponding Eocene or Miocene total petroleum systems. Type B gas is a dry, nonassociated gas produced from the Pliocene San Joaquin Formation in the central and southern San Joaquin Basin. This gas type most likely originated from Pliocene marine source rocks as a product of methanogenesis, and defines the Neogene Nonassociated Gas Total Petroleum System.

Examining the influence of urban definition when assessing relative safety of drinking-water in Nigeria.

PubMed

Christenson, Elizabeth; Bain, Robert; Wright, Jim; Aondoakaa, Stephen; Hossain, Rifat; Bartram, Jamie

2014-08-15

Reducing inequalities is a priority from a human rights perspective and in water and public health initiatives. There are periodic calls for differential national and global standards for rural and urban areas, often justified by the suggestion that, for a given water source type, safety is worse in urban areas. For instance, initially proposed post-2015 water targets included classifying urban but not rural protected dug wells as unimproved. The objectives of this study were to: (i) examine the influence of urban extent definition on water safety in Nigeria, (ii) compare the frequency of thermotolerant coliform (TTC) contamination and prevalence of sanitary risks between rural and urban water sources of a given type and (iii) investigate differences in exposure to contaminated drinking-water in rural and urban areas. We use spatially referenced data from a Nigerian national randomized sample survey of five improved water source types to assess the extent of any disparities in urban-rural safety. We combined the survey data on TTC and sanitary risk with map layers depicting urban versus rural areas according to eight urban definitions. When examining water safety separately for each improved source type, we found no significant urban-rural differences in TTC contamination and sanitary risk for groundwater sources (boreholes and protected dug wells) and inconclusive findings for piped water and stored water. However, when improved and unimproved source types were combined, TTC contamination was 1.6 to 2.3 times more likely in rural compared to urban water sources depending on the urban definition. Our results suggest that different targets for urban and rural water safety are not justified and that rural dwellers are more exposed to unsafe water than urban dwellers. Additionally, urban-rural analyses should assess multiple definitions or indicators of urban to assess robustness of findings and to characterize a gradient that disaggregates the urban-rural dichotomy. Copyright © 2014 Elsevier B.V. All rights reserved.

Assessment of potential migration of radionuclides and trace elements from the White Mesa uranium mill to the Ute Mountain Ute Reservation and surrounding areas, southeastern Utah

USGS Publications Warehouse

Naftz, David L.; Ranalli, Anthony J.; Rowland, Ryan C.; Marston, Thomas M.

2011-01-01

In 2007, the Ute Mountain Ute Tribe requested that the U.S. Environmental Protection Agency and U.S. Geological Survey conduct an independent evaluation of potential offsite migration of radionuclides and selected trace elements associated with the ore storage and milling process at an active uranium mill site near White Mesa, Utah. Specific objectives of this study were (1) to determine recharge sources and residence times of groundwater surrounding the mill site, (2) to determine the current concentrations of uranium and associated trace elements in groundwater surrounding the mill site, (3) to differentiate natural and anthropogenic contaminant sources to groundwater resources surrounding the mill site, (4) to assess the solubility and potential for offsite transport of uranium-bearing minerals in groundwater surrounding the mill site, and (5) to use stream sediment and plant material samples from areas surrounding the mill site to identify potential areas of offsite contamination and likely contaminant sources.

Contextual Information for the Potential Enhancement of Annual Radiation Protection Program Review Reports.

PubMed

Emery, Robert J; Gutiérrez, Janet M

2017-08-01

Organizations possessing sources of ionizing radiation are required to develop, document, and implement a "radiation protection program" that is commensurate with the scope and extent of permitted activities and sufficient to ensure compliance with basic radiation safety regulations. The radiation protection program must also be reviewed at least annually, assessing program content and implementation. A convenience sample assessment of web-accessible and voluntarily-submitted radiation protection program annual review reports revealed that while the reports consistently documented compliance with necessary regulatory elements, very few included any critical contextual information describing how important the ability to possess radiation sources was to the central mission of the organization. Information regarding how much radioactive material was currently possessed as compared to license limits was also missing. Summarized here are suggested contextual elements that can be considered for possible inclusion in annual radiation protection program reviews to enhance stakeholder understanding and appreciation of the importance of the ability to possess radiation sources and the importance of maintaining compliance with associated regulatory requirements.

Detection of Bovine and Porcine Adenoviruses for Tracing the Source of Fecal Contamination

PubMed Central

Maluquer de Motes, Carlos; Clemente-Casares, Pilar; Hundesa, Ayalkibet; Martín, Margarita; Girones, Rosina

2004-01-01

In this study, a molecular procedure for the detection of adenoviruses of animal origin was developed to evaluate the level of excretion of these viruses by swine and cattle and to design a test to facilitate the tracing of specific sources of environmental viral contamination. Two sets of oligonucleotides were designed, one to detect porcine adenoviruses and the other to detect bovine and ovine adenoviruses. The specificity of the assays was assessed in 31 fecal samples and 12 sewage samples that were collected monthly during a 1-year period. The data also provided information on the environmental prevalence of animal adenoviruses. Porcine adenoviruses were detected in 17 of 24 (70%) pools of swine samples studied, with most isolates being closely related to serotype 3. Bovine adenoviruses were present in 6 of 8 (75%) pools studied, with strains belonging to the genera Mastadenovirus and Atadenovirus and being similar to bovine adenoviruses of types 2, 4, and 7. These sets of primers produced negative results in nested PCR assays when human adenovirus controls and urban-sewage samples were tested. Likewise, the sets of primers previously designed for detection of human adenovirus also produced negative results with animal adenoviruses. These results indicate the importance of further studies to evaluate the usefulness of these tests to trace the source of fecal contamination in water and food and for environmental studies. PMID:15006765

Source Water Identification and Chemical Typing for Nitrogen at the Kissimmee River, Pool C, Florida--Preliminary Assessment

USGS Publications Warehouse

,

2002-01-01

As part of the South Florida Water Management District's Ground Water-Surface Water Interactions Study, a project was undertaken to identify the ages and sources of water in the area of Pool C, Kissimmee River, Florida. Twenty-two water samples were collected along two transects: at a remnant river oxbows (Site D) and in the dredged part of the channel (Site C). The samples were analyzed for concentrations of fluoride and strontium, and for isotopes of oxygen, hydrogen, and nitrogen. Selected samples were analyzed for one or more additional isotopes (carbon-14, the ratio of strontium-87 to strontium-86, tritium, and tritium-helium-3). Delta nitrogen-15 values for nitrate at Site C can be explained by soil nitrogen and fertilizer sources; at Site D soil nitrogen accounts for most values, although animal wastes may explain higher values. Some of the isotopic data seem to be contradictory: carbon-14 data apparently indicate that shallow ground water is younger at Site D than at Site C, whereas strontium-87/86 ratios lead to the opposite conclusion. More detailed analysis of major ions and nutrients for all sampling points, along with flow measurements, could allow more definitive interpretation of isotope data and provide additional insight into mixing of ground water and surface water at the sites.

Detection of bovine and porcine adenoviruses for tracing the source of fecal contamination.

PubMed

Maluquer de Motes, Carlos; Clemente-Casares, Pilar; Hundesa, Ayalkibet; Martín, Margarita; Girones, Rosina

2004-03-01

In this study, a molecular procedure for the detection of adenoviruses of animal origin was developed to evaluate the level of excretion of these viruses by swine and cattle and to design a test to facilitate the tracing of specific sources of environmental viral contamination. Two sets of oligonucleotides were designed, one to detect porcine adenoviruses and the other to detect bovine and ovine adenoviruses. The specificity of the assays was assessed in 31 fecal samples and 12 sewage samples that were collected monthly during a 1-year period. The data also provided information on the environmental prevalence of animal adenoviruses. Porcine adenoviruses were detected in 17 of 24 (70%) pools of swine samples studied, with most isolates being closely related to serotype 3. Bovine adenoviruses were present in 6 of 8 (75%) pools studied, with strains belonging to the genera Mastadenovirus and Atadenovirus and being similar to bovine adenoviruses of types 2, 4, and 7. These sets of primers produced negative results in nested PCR assays when human adenovirus controls and urban-sewage samples were tested. Likewise, the sets of primers previously designed for detection of human adenovirus also produced negative results with animal adenoviruses. These results indicate the importance of further studies to evaluate the usefulness of these tests to trace the source of fecal contamination in water and food and for environmental studies.

Atmospheric occurrence, homologue patterns and source apportionment of short- and medium-chain chlorinated paraffins in Shanghai, China: Biomonitoring with Masson pine (Pinus massoniana L.) needles.

PubMed

Wang, Xue-Tong; Zhou, Jun; Lei, Bing-Li; Zhou, Jing-Ming; Xu, Si-Yue; Hu, Bao-Ping; Wang, De-Qing; Zhang, Dong-Ping; Wu, Ming-Hong

2016-08-01

A comprehensive survey was conducted to Masson pine (Pinus massoniana L.) needles widely distributed in Shanghai in order to investigate the levels and homologue group patterns of short- and medium-chain chlorinated paraffins (SCCPs and MCCPs), to identify and quantitatively assess source contributions to the total CPs in pine needle samples. The concentration ranged from not detected (ND) to 13,600ngg(-1) with a geometric mean (GM) value of 63.7ngg(-1) for ΣSCCPs, from 12.4 to 33,500ngg(-1) with a GM value of 677ngg(-1) for ΣMCCPs, and from 14.0 to 45,700ngg(-1) with a GM value of 768ngg(-1) for total CPs. For different sampling units, the pollution levels both for SCCPs and MCCPs in pine needles were in the same orders: Pudong>suburbs>Puxi>Chongming. These significant differences in SCCPs and MCCPs among four sampling units could be associated with difference in industrial activities and to some extent also in population density. All pine needle samples (n=131) were divided into 2 groups by hierarchical cluster analysis (HCA) for SCCPs and MCCPs, the most abundant homologue groups in the bulk of pine needle samples were C11Cl5-7 and C13Cl5-7 for SCCPs, and C14Cl7-8 and C15Cl7-8 for MCCPs. Correlation analysis suggested that SCCPs and MCCPs in pine needles in the studied area may be derived from different sources. Four sources for pine needles were identified by the FA-MLR model; their relative contributions to the total CP burden in pine needles were 18.0% for F1 (attributed to commercial SCCP mixture), 42.2% for F2 (attributed to commercial MCCP mixture), 29.3% for F3 (attributed to LRAT), and 10.5% for F4 (unknown source). CP contamination of atmospheric air by point sources and long-range atmospheric transport in Shanghai should receive more attention by local government. Copyright © 2016 Elsevier B.V. All rights reserved.

National Environmental/Energy Workforce Assessment, Phase II, Post-Secondary Education Profile: Solid Waste.

ERIC Educational Resources Information Center

National Field Research Center Inc., Iowa City, IA.

Educational programs in solid waste management offered by 16 schools in 9 states were surveyed. These programs represent a sample, only, of the various programs available nationwide. Enrollment and graduate statistics are presented. Overall, 116 full-time and 124 part-time faculty were involved in the programs surveyed. Curricula and sources of…

In Vitro Assessment of Estrogenic Activity in Source and Treated Drinking Water Extracts from 25 U.S. Drinking Water Plants

EPA Science Inventory

The presence of estrogenic compounds in environmental water samples and their potential impact on fish, wildlife and human reproductive health has been of concern for some time. In vitro assays have been successfully used to screen for estrogenic activity in many types of water s...

SOURCE APPORTIONMENT OF INDOOR, OUTDOOR, AND PERSONAL PM2.5 IN SEATTLE, WASHINGTON, USING POSITIVE MATRIX FACTORIZATION

EPA Science Inventory

As part of a large exposure assessment and health effects panel study, 33 trace elements and light-absorbing carbon were measured on 24-hr particulate matter with an aero-dynamic diameter <2.5 um (PM2.5) fixed-site filter samples collected between September 26, 2000, and May 25, ...

Back to the Basics: Socio-Economic, Gender, and Regional Disparities in Canada's Educational System

ERIC Educational Resources Information Center

Edgerton, Jason D.; Peter, Tracey; Roberts, Lance W.

2008-01-01

This study reassessed the extent to which socio-economic background, gender, and region endure as sources of educational inequality in Canada. The analysis utilized the 28,000 student Canadian sample from the data set of the OECD's 2003 "Programme for International Student Assessment (PISA)". Results, consistent with previous findings,…

Task Order 2 Enhanced Preliminary Assessment, Fort Douglas, Salt Lake City, Utah

DTIC Science & Technology

1989-12-01

sourCs Prov in flo LS. AnY Toxi : nd 0 mtara 200 P, Sw~ia B Properlty IProposed A2 To Be [Excessed Blb HISTORIC AREAS RECOMMENDED SAMPLING METHODS...approximately 30 gal) located outside, in the back yard. All flammable materials such as gasoline and paints are reportedly stored here [1-2]. In

Multidimensional, Threshold Effects of Social Support in Firefighters: Is More Support Invariably Better?

ERIC Educational Resources Information Center

Varvel, Shiloh Jordan; He, Yuhong; Shannon, Jennifer K.; Tager, David; Bledman, Rashanta A.; Chaichanasakul, Adipat; Mendoza, Monique M.; Mallinckrodt, Brent

2007-01-01

This study examined the relationship between social support (Social Provisions Scale) and stress (Perceived Stress Scale) in a sample of male firefighters in a midwestern community (N=53). The authors assessed 5 types of perceived support from 2 sources: peer firefighters and supervisors. Results indicate that reassurance of worth and social…

Rural environment study for water from different sources in cluster of villages in Mehsana district of Gujarat.

PubMed

Khatri, Nitasha; Tyagi, Sanjiv; Rawtani, Deepak

2017-12-07

Water pollution and water scarcity are major environmental issues in rural and urban areas. They lead to decline in the quality of water, especially drinking water. Proper qualitative assessment of water is thus necessary to ensure that the water consumed is potable. This study aims to analyze the physicochemical parameters in different sources of water in rural areas and assess the quality of water through a classification system based on BIS and CPCB standards. The classification method has defined water quality in six categories, viz., A, B, C, D, E, and F depending on the levels of physicochemical parameters in the water samples. The proposed classification system was applied to nine villages in Kadi Taluka, Mehsana district of Gujarat. The water samples were collected from borewells, lakes, Narmada Canal, and sewerage systems and were analyzed as per APHA and IS methods. It was observed that most of the physicochemical parameters of Narmada Canal and borewell water fell under class A, thus making them most suitable for drinking. Further, a health camp conducted at Karannagar village, Mehsana revealed no incidents of any waterborne diseases. However, there were certain incidents of kidney stones and joint pain in few villages due to high levels of TDS. Toxic metal analysis in all the water sources revealed low to undetectable concentration of toxic metals such as lead, arsenic, mercury, and cadmium in all the water sources. It is also recommended that the regular treatment of the Narmada Canal water be continued to maintain its excellent quality.

Short- and medium-chain chlorinated paraffins in sediments from the middle reaches of the Yangtze River: Spatial distributions, source apportionment and risk assessment.

PubMed

Qiao, Lin; Gao, Lirong; Xia, Dan; Huang, Huiting; Zheng, Minghui

2017-01-01

Chlorinated paraffins (CPs) are easily adsorbed into sediments where they pose potential risks to the ecosystem and human health. Few studies have investigated short- and medium-chain CPs (SCCPs and MCCPs) in sediments. The aim of the present study was to comprehensively investigate contamination levels, spatial distributions, sources and risks posed by CPs in sediments from the middle reaches of the Yangtze River. The sediment samples were analyzed by two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC-TOFMS). The concentrations of SCCPs and MCCPs ranged from 4.19 to 41.6ng/g dry weight (dw) and not detected to 14.6ng/g dw, respectively. No significant correlation was found between the total organic carbon contents and CP concentrations (P>0.05). The spatial distributions showed that CP contamination levels in the sediments were related to local human activities. The dominant congener groups were C 10-11 Cl 6-7 for SCCPs, and C 14 Cl 7-8 for MCCPs. Correspondence analysis revealed that likely sources of SCCPs were the production and use of CP-42 and CP-52. Principal component analysis indicated that SCCPs and MCCPs in the sediments may come from different sources. Moreover, CPs with nine carbon atoms were quantitated for the first time in sediment samples, and the results indicated they should not be neglected in future analyses. Risk assessments indicated that CPs in the sediments did not pose a great ecological risk currently. Copyright © 2016 Elsevier B.V. All rights reserved.

Preliminary assessment of a water-quality monitoring program for total maximum daily loads in Johnson County, Kansas, January 2015 through June 2016

USGS Publications Warehouse

Rasmussen, Teresa J.; Paxson, Chelsea R.

2017-08-25

Municipalities in Johnson County in northeastern Kansas are required to implement stormwater management programs to reduce pollutant discharges, protect water quality, and comply with applicable water-quality regulations in accordance with National Pollutant Discharge Elimination System permits for stormwater discharge. To this end, municipalities collect grab samples at streams entering and leaving their jurisdiction to determine levels of excessive nutrients, sediment, and fecal bacteria to characterize pollutants and understand the factors affecting them.In 2014, the U.S. Geological Survey and the Johnson County Stormwater Management Program, with input from the Kansas Department of Health and Environment, initiated a 5-year monitoring program to satisfy minimum sampling requirements for each municipality as described by new stormwater permits issued to Johnson County municipalities. The purpose of this report is to provide a preliminary assessment of the monitoring program. The monitoring program is described, a preliminary assessment of the monitoring program design is provided using water-quality data collected during the first 2 years of the program, and the ability of the current monitoring network and sampling plan to provide data sufficient to quantify improvements in water quality resulting from implemented and planned best management practices is evaluated. The information in this initial report may be used to evaluate changes in data collection methods while data collection is still ongoing that may lead to improved data utility.Discrete water-quality samples were collected at 27 sites and analyzed for nutrients, Escherichia coli (E. coli) bacteria, total suspended solids, and suspended-sediment concentration. In addition, continuous water-quality data (water temperature, pH, dissolved oxygen, specific conductance, turbidity, and nitrate plus nitrite) were collected at one site to characterize variability and provide a basis for comparison to discrete data. Base flow samples indicated that point sources are likely affecting nutrient concentrations and E. coli bacteria densities at several sites. Concentrations of all analytes in storm runoff samples were characterized by substantial variability among sites and samples. About one-half of the sites, representing different watersheds, had storm runoff samples with nitrogen concentrations greater than 10 milligrams per liter. About one-third of the sites, representing different watersheds, had storm runoff samples with total phosphorus concentrations greater than 3 milligrams per liter. Six sites had samples with E. coli densities greater than 100,000 colonies per 100 milliliters of water. Total suspended solids concentrations of about 12,000 milligrams per liter or greater occurred in samples from three sites.Data collected for this monitoring program may be useful for some general assessment purposes but may also be limited in potential to fully inform stormwater management activities. Valuable attributes of the monitoring program design included incorporating many sites across the county for comparisons among watersheds and municipalities, using fixed-stage samplers to collect multiple samples during single events, collection of base flow samples in addition to storm samples to isolate possible point sources from stormwater sources, and use of continuous monitors to characterize variability. Limiting attributes of the monitoring program design included location of monitoring sites along municipal boundaries to satisfy permit requirements rather than using watershed-based criteria such as locations of tributaries, potential pollutant sources, and implemented management practices. Additional limiting attributes include having a large number of widespread sampling locations, which presented logistical challenges for predicting localized rainfall and collecting and analyzing samples during short timeframes associated with storms, and collecting storm samples at fixed-stage elevations only during the rising limb of storms, which does not characterize conditions over the storm hydrograph. The small number of samples collected per site resulted in a sample size too small to be representative of site conditions, including seasonal and hydrologic variability, and insufficient for meaningful statistical analysis or site-specific modeling.Several measures could be taken to improve data utility and include redesigning the monitoring network according to watershed characteristics, incorporating a nested design in which data are collected at different scales (watershed, subwatershed, and best management practices), increasing sampling frequency, and combining different methods to allow for flexibility to focus on areas and conditions of particular interest. A monitoring design that would facilitate most of these improvements would be to focus efforts on a limited number of watersheds for several years, then cycle to the next set of watersheds for several years, eventually returning to previously monitored watersheds to document changes.Redesign of the water-quality monitoring program requires considerable effort and commitment from municipalities of Johnson County. However, the long-term benefit likely is a monitoring program that results in improved stream conditions and more effective management practices and efficient expenditure of resources.

Assessing the Role of Land Use in Watershed Nitrate Export Using Triple Oxygen Isotopes

NASA Astrophysics Data System (ADS)

Bostic, J.; Nelson, D. M.; Eshleman, K. N.

2017-12-01

Quantifying the influence of land-use patterns on the amount and source(s) of nitrate (NO3) exported from watersheds is critical for understanding and mitigating the effects of nutrient pollution on downstream waterbodies. The isotopic composition of NO3 is valuable for fingerprinting of NO3 sources, including manure and atmospheric nitrate. To assess loads, sources, and potential transformations of NO3 in the Chesapeake Bay (CB) watershed, stream samples from fourteen sub-watersheds of the CB were collected semi-monthly and during multiple storm events from October 2015-September 2016 (Water Year 2016). The watersheds range in size (500 - 127,900 ha) and in dominant land-use (forest, urban, agriculture). The samples were analyzed for nitrate concentrations and isotopes (δ15N, as well as the triple oxygen isotope composition, defined as Δ17O ≅ δ17O - 0.52 x δ18O). Stream loads of nitrate were estimated using WRTDS (Weighted Regressions on Time, Discharge, and Season). NO3 deposition (dry and wet) was fairly uniform across all watersheds (2.1 - 3.0 kg NO3-N ha-1), whereas stream NO3 varied greatly (0.6 - 11.8 kg NO3-N ha-1). Stream loads of NO3 were positively related to the percent of agricultural land (r2 = 0.67, p < 0.005) and negatively related to the percent of forested land (r2 = 0.61, p < 0.005). Preliminary isotope data indicate a positive relationship between δ15NNO3 and the proportion of agricultural land (r2 = 0.48, p < 0.0001), which suggests that nitrate inputs in predominantly agricultural watersheds are manure or pools of partially denitrified fertilizer. A positive relationship between Δ17ONO3 and the percent of forested land (r2 = 0.19, p < 0.005) suggests that forests export a greater proportion of atmospheric nitrate than other systems. Full NO3 isotope data for Water Year 2016 ( 400 samples) will be presented from all watersheds to elucidate the amount and sources of NO3 exported from a variety of land-uses.

Microbial and geochemical quality of shallow well water in high-density areas in Mzuzu City in Malawi

NASA Astrophysics Data System (ADS)

Msilimba, Golden; Wanda, Elijah M. M.

In Malawi, shallow wells constitute the most important water sources for domestic purposes. However, increasing human population coupled with poor sanitation and infrastructure is undermining the quality of shallow well water. An assessment of microbial and geochemical quality of shallow well water in high-density areas of Zolozolo, Ching’ambo and Chiputula in Mzuzu City, Northern Malawi, has been carried out. The study aimed at characterising domestic water sources, identifying possible sources of water contamination and determining levels of microbial and chemical contamination. Arc-view GIS was used to map the water sources. A questionnaire survey was carried out to elicit information on characteristics of drinking water sources. Water samples were collected from quasi-randomly selected shallow wells and analysed for microbial and chemical parameters using standard methods. HCA, performed using R-programme, was used to group sampled sites according to their bio-physicochemical characteristics. Compliance of the water with MBS/WHO water quality guidelines was determined. The WQI was computed to turn multifaceted data obtained from laboratory analyses into simple information that is comprehensible and useable by the public to assess overall quality of water at a specific water points. The GW-chart was used to show hydrogeochemical water types from each sampled site. Microbial analysis revealed that water from 96.3% of shallow wells recorded faecal coliforms ranging from 129 to 920 cfu per 100 ml which were significantly higher than the Malawi Standards and WHO thresholds. In general, shallow well water is of low mineralisation (EC range 80-500 μS cm-1), with hydrogeochemical facies dominated by Ca-HCO3, which evolves to Ca-Cl water type. The shallow well water registered a WQI range of 50.16-66.04%, with a medium WQ rating. This suggested that the water obtained from the shallow wells is unsuitable for direct human consumption. It was observed that 100% of the shallow wells were at risk of pollution from onsite sanitation because of their proximity to sanitary facilities. It was strongly recommended that onsite treatment interventions have to be mobilised and initiated to protect the households from further possible consequences of using the water.

Spatial variability in airborne bacterial communities across land-use types and their relationship to the bacterial communities of potential source environments

PubMed Central

Bowers, Robert M; McLetchie, Shawna; Knight, Rob; Fierer, Noah

2011-01-01

Although bacteria are ubiquitous in the near-surface atmosphere and they can have important effects on human health, airborne bacteria have received relatively little attention and their spatial dynamics remain poorly understood. Owing to differences in meteorological conditions and the potential sources of airborne bacteria, we would expect the atmosphere over different land-use types to harbor distinct bacterial communities. To test this hypothesis, we sampled the near-surface atmosphere above three distinct land-use types (agricultural fields, suburban areas and forests) across northern Colorado, USA, sampling five sites per land-use type. Microbial abundances were stable across land-use types, with ∼105–106 bacterial cells per m3 of air, but the concentrations of biological ice nuclei, determined using a droplet freezing assay, were on average two and eight times higher in samples from agricultural areas than in the other two land-use types. Likewise, the composition of the airborne bacterial communities, assessed via bar-coded pyrosequencing, was significantly related to land-use type and these differences were likely driven by shifts in the sources of bacteria to the atmosphere across the land-uses, not local meteorological conditions. A meta-analysis of previously published data shows that atmospheric bacterial communities differ from those in potential source environments (leaf surfaces and soils), and we demonstrate that we may be able to use this information to determine the relative inputs of bacteria from these source environments to the atmosphere. This work furthers our understanding of bacterial diversity in the atmosphere, the terrestrial controls on this diversity and potential approaches for source tracking of airborne bacteria. PMID:21048802

Simultaneous Quantification of Free Cholesterol, Cholesteryl Esters, and Triglycerides without Ester Hydrolysis by UHPLC Separation and In-Source Collision Induced Dissociation Coupled MS/MS

NASA Astrophysics Data System (ADS)

Gardner, Michael S.; McWilliams, Lisa G.; Jones, Jeffrey I.; Kuklenyik, Zsuzsanna; Pirkle, James L.; Barr, John R.

2017-08-01

We demonstrate the application of in-source nitrogen collision-induced dissociation (CID) that eliminates the need for ester hydrolysis before simultaneous analysis of esterified cholesterol (EC) and triglycerides (TG) along with free cholesterol (FC) from human serum, using normal phase liquid chromatography (LC) coupled to atmospheric pressure chemical ionization (APCI) tandem mass spectrometry (MS/MS). The analysis requires only 50 μL of 1:100 dilute serum with a high-throughput, precipitation/evaporation/extraction protocol in one pot. Known representative mixtures of EC and TG species were used as calibrators with stable isotope labeled analogs as internal standards. The APCI MS source was operated with nitrogen source gas. Reproducible in-source CID was achieved with the use of optimal cone voltage (declustering potential), generating FC, EC, and TG lipid class-specific precursor fragment ions for multiple reaction monitoring (MRM). Using a representative mixture of purified FC, CE, and TG species as calibrators, the method accuracy was assessed with analysis of five inter-laboratory standardization materials, showing -10% bias for Total-C and -3% for Total-TG. Repeated duplicate analysis of a quality control pool showed intra-day and inter-day variation of 5% and 5.8% for FC, 5.2% and 8.5% for Total-C, and 4.1% and 7.7% for Total-TG. The applicability of the method was demonstrated on 32 serum samples and corresponding lipoprotein sub-fractions collected from normolipidemic, hypercholesterolemic, hypertriglyceridemic, and hyperlipidemic donors. The results show that in-source CID coupled with isotope dilution UHPLC-MS/MS is a viable high precision approach for translational research studies where samples are substantially diluted or the amounts of archived samples are limited. [Figure not available: see fulltext.

Quantification of source impact to PM using three-dimensional weighted factor model analysis on multi-site data

NASA Astrophysics Data System (ADS)

Shi, Guoliang; Peng, Xing; Huangfu, Yanqi; Wang, Wei; Xu, Jiao; Tian, Yingze; Feng, Yinchang; Ivey, Cesunica E.; Russell, Armistead G.

2017-07-01

Source apportionment technologies are used to understand the impacts of important sources of particulate matter (PM) air quality, and are widely used for both scientific studies and air quality management. Generally, receptor models apportion speciated PM data from a single sampling site. With the development of large scale monitoring networks, PM speciation are observed at multiple sites in an urban area. For these situations, the models should account for three factors, or dimensions, of the PM, including the chemical species concentrations, sampling periods and sampling site information, suggesting the potential power of a three-dimensional source apportionment approach. However, the principle of three-dimensional Parallel Factor Analysis (Ordinary PARAFAC) model does not always work well in real environmental situations for multi-site receptor datasets. In this work, a new three-way receptor model, called "multi-site three way factor analysis" model is proposed to deal with the multi-site receptor datasets. Synthetic datasets were developed and introduced into the new model to test its performance. Average absolute error (AAE, between estimated and true contributions) for extracted sources were all less than 50%. Additionally, three-dimensional ambient datasets from a Chinese mega-city, Chengdu, were analyzed using this new model to assess the application. Four factors are extracted by the multi-site WFA3 model: secondary source have the highest contributions (64.73 and 56.24 μg/m3), followed by vehicular exhaust (30.13 and 33.60 μg/m3), crustal dust (26.12 and 29.99 μg/m3) and coal combustion (10.73 and 14.83 μg/m3). The model was also compared to PMF, with general agreement, though PMF suggested a lower crustal contribution.

Ground water contamination with (238)U, (234)U, (235)U, (226)Ra and (210)Pb from past uranium mining: cove wash, Arizona.

PubMed

Dias da Cunha, Kenya Moore; Henderson, Helenes; Thomson, Bruce M; Hecht, Adam A

2014-06-01

The objectives of the study are to present a critical review of the (238)U, (234)U, (235)U, (226)Ra and (210)Pb levels in water samples from the EPA studies (U.S. EPA in Abandoned uranium mines and the Navajo Nation: Red Valley chapter screening assessment report. Region 9 Superfund Program, San Francisco, 2004, Abandoned uranium mines and the Navajo Nation: Northern aum region screening assessment report. Region 9 Superfund Program, San Francisco, 2006, Health and environmental impacts of uranium contamination, 5-year plan. Region 9 Superfund Program, San Franciso, 2008) and the dose assessment for the population due to ingestion of water containing (238)U and (234)U. The water quality data were taken from Sect. "Data analysis" of the published report, titled Abandoned Uranium Mines Project Arizona, New Mexico, Utah-Navajo Lands 1994-2000, Project Atlas. Total uranium concentration was above the maximum concentration level for drinking water (7.410-1 Bq/L) in 19 % of the water samples, while (238)U and (234)U concentrations were above in 14 and 17 % of the water samples, respectively. (226)Ra and (210)Pb concentrations in water samples were in the range of 3.7 × 10(-1) to 5.55 × 102 Bq/L and 1.11 to 4.33 × 102 Bq/L, respectively. For only two samples, the (226)Ra concentrations exceeded the MCL for total Ra for drinking water (0.185 Bq/L). However, the (210)Pb/(226)Ra ratios varied from 0.11 to 47.00, and ratios above 1.00 were observed in 71 % of the samples. Secular equilibrium of the natural uranium series was not observed in the data record for most of the water samples. Moreover, the (235)U/(total)U mass ratios ranged from 0.06 to 5.9 %, and the natural mass ratio of (235)U to (total)U (0.72 %) was observed in only 16 % of the water samples, ratios above or below the natural ratio could not be explained based on data reported by U.S. EPA. In addition, statistical evaluations showed no correlations among the distribution of the radionuclide concentrations in the majority of the water samples, indicating more than one source of contamination could contribute to the sampled sources. The effective doses due to ingestion of the minimum uranium concentrations in water samples exceed the average dose considering inhalation and ingestion of regular diet for other populations around the world (1 μSv/year). The maximum doses due to ingestion of (238)U or (234)U were above the international limit for effective dose for members of the public (1 mSv/year), except for inhabitants of two chapters. The highest effective dose was estimated for inhabitants of Cove, and it was almost 20 times the international limit for members of the public. These results indicate that ingestion of water from some of the sampled sources poses health risks.

Assessment of statistical methods used in library-based approaches to microbial source tracking.

PubMed

Ritter, Kerry J; Carruthers, Ethan; Carson, C Andrew; Ellender, R D; Harwood, Valerie J; Kingsley, Kyle; Nakatsu, Cindy; Sadowsky, Michael; Shear, Brian; West, Brian; Whitlock, John E; Wiggins, Bruce A; Wilbur, Jayson D

2003-12-01

Several commonly used statistical methods for fingerprint identification in microbial source tracking (MST) were examined to assess the effectiveness of pattern-matching algorithms to correctly identify sources. Although numerous statistical methods have been employed for source identification, no widespread consensus exists as to which is most appropriate. A large-scale comparison of several MST methods, using identical fecal sources, presented a unique opportunity to assess the utility of several popular statistical methods. These included discriminant analysis, nearest neighbour analysis, maximum similarity and average similarity, along with several measures of distance or similarity. Threshold criteria for excluding uncertain or poorly matched isolates from final analysis were also examined for their ability to reduce false positives and increase prediction success. Six independent libraries used in the study were constructed from indicator bacteria isolated from fecal materials of humans, seagulls, cows and dogs. Three of these libraries were constructed using the rep-PCR technique and three relied on antibiotic resistance analysis (ARA). Five of the libraries were constructed using Escherichia coli and one using Enterococcus spp. (ARA). Overall, the outcome of this study suggests a high degree of variability across statistical methods. Despite large differences in correct classification rates among the statistical methods, no single statistical approach emerged as superior. Thresholds failed to consistently increase rates of correct classification and improvement was often associated with substantial effective sample size reduction. Recommendations are provided to aid in selecting appropriate analyses for these types of data.

A framework for a critical assessment of the quality of epidemiological studies of driver health and accident risk.

PubMed

Elvik, Rune

2011-11-01

A large number of studies have tried to assess how various aspects of driver health influence driver involvement in accidents. The objective of this paper is to provide a framework for a critical assessment of the quality these studies from a methodological point of view. Examples are given of how various sources of bias and confounding can produce study findings that are highly misleading. Ten potential sources of error and bias in epidemiological studies of the contribution of driver health impairments to road accidents are discussed: (1) Poor description of the medical conditions whose effects are studied (measurement error). (2) Inadequate control for the effects of exposure on accident rate. (3) Sampling endogeneity with respect to assessment for fitness to drive (outcome-based sampling; self-selection bias). (4) Combined exposure to several risk factors. (5) Poor control for potentially confounding factors. (6) Failure to specify potentially moderating factors (interaction effects). (7) Failure to consider a severity gradient with respect to the effect of health impairments. (8) Failure to specify the compliance of drivers with medical treatments or treatment effectiveness. (9) No data on the population prevalence of various health conditions. (10) The use of multiple study approaches and methods making the comparison and synthesis of findings difficult. Examples are given of how all these items may influence the findings of a single study or make synthesising findings from multiple studies difficult. A checklist for assessing study quality is provided. Copyright © 2011 Elsevier Ltd. All rights reserved.

Pre-analytical Factors Influence Accuracy of Urine Spot Iodine Assessment in Epidemiological Surveys.

PubMed

Doggui, Radhouene; El Ati-Hellal, Myriam; Traissac, Pierre; El Ati, Jalila

2018-03-26

Urinary iodine concentration (UIC) is commonly used to assess iodine status of subjects in epidemiological surveys. As pre-analytical factors are an important source of measurement error and studies about this phase are scarce, our objective was to assess the influence of urine sampling conditions on UIC, i.e., whether the child ate breakfast or not, urine void rank of the day, and time span between last meal and urine collection. A nationwide, two-stage, stratified, cross-sectional study including 1560 children (6-12 years) was performed in 2012. UIC was determined by the Sandell-Kolthoff method. Pre-analytical factors were assessed from children's mothers by using a questionnaire. Association between iodine status and pre-analytical factors were adjusted for one another and socio-economic characteristics by multivariate linear and multinomial regression models (RPR: relative prevalence ratios). Skipping breakfast prior to morning urine sampling decreased UIC by 40 to 50 μg/L and the proportion of UIC < 100 μg/L was higher among children having those skipped breakfast (RPR = 3.2[1.0-10.4]). In unadjusted analyses, UIC was less among children sampled more than 5 h from their last meal. UIC decreased with rank of urine void (e.g., first vs. second, P < 0.001); also, the proportion of UIC < 100 μg/L was greater among 4th rank samples (vs. second RPR = 2.1[1.1-4.0]). Subjects' breakfast status and urine void rank should be accounted for when assessing iodine status. Providing recommendations to standardize pre-analytical factors is a key step toward improving accuracy and comparability of survey results for assessing iodine status from spot urine samples. These recommendations have to be evaluated by future research.

Assessing the condition of bayous and estuaries: Bayou Chico Gulf of Mexico demonstration study

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

Dickson, K.; Acevedo, M.; Waller, T.

1995-12-31

A demonstration study was conducted in May 1994 on Bayou Chico to assess the utility of various assessment and measurement endpoints in determining the condition of bayous and estuaries. Bayou Chico has water quality problems attributed to its low flushing rate and urban/industrial land use in its watershed. The sampling scheme assessed the within-sampling station and spatial variability of measurement endpoints. Fourteen sampling stations in Bayou Chico and 3 stations in Pensacola Bay were selected based on an intensified EMAP sampling grid. Time and space coordinated sampling was conducted for: sediment contaminants and properties, sediment toxicity, water quality, benthic infauna,more » zooplankton and phytoplankton populations. Fish and crabs were also collected and analyzed for a suite of biomarkers and organic chemical residues. Primary productivity was measured via the light bottle dark bottle oxygen method and via diurnal oxygen measurements made with continuous recording data sondes. Stream sites were evaluated for water and sediment quality, water and sediment toxicity, benthic invertebrates and fish. Watershed analyses included assessment of land use/landcover (via SPOT and TM images), soils, pollution sources (point and non-point) and hydrography. These data were coordinated via an Arc/Info GIS system for display and spatial analysis. 1994 survey data were used to parameterize environmental fate models such as SWMM (Storm Water Management Model), DYNHYD5 (WASP5 hydrodynamics model) and WASP5 (Water Quality Analysis Simulation Program) to make predictions about the dynamics and fate of chemical contaminants in Bayou Chico. This paper will present an overview, and report on the results in regards to within-site and spatial variability in Bayou Chico. Conclusions on the efficacy of the assessment and measurement endpoints in evaluating the condition (health) of Bayou Chico will be presented.« less