Decontamination of Drinking Water Infrastructure ...

EPA Pesticide Factsheets

Technical Brief This study examines the effectiveness of decontaminating corroded iron and cement-mortar coupons that have been contaminated with spores of Bacillus atrophaeus subsp. globigii (B. globigii), which is often used as a surrogate for pathogenic B. anthracis (anthrax) in disinfection studies. Bacillus spores are persistent on common drinking water material surfaces like corroded iron, requiring physical or chemical methods to decontaminate the infrastructure. In the United States, free chlorine and monochloramine are the primary chemical disinfectants used by the drinking water industry to inactivate microorganisms. Flushing is also a common, easily implemented practice in drinking water distribution systems, although large volumes of contaminated water needing treatment could be generated. Identifying readily available alternative disinfectant formulations for infrastructure decontamination could give water utilities options for responding to specific types of contamination events. In addition to presenting data on flushing alone, which demonstrated the persistence of spores on water infrastructure in the absence of high levels of disinfectants, data on acidified nitrite, chlorine dioxide, free chlorine, monochloramine, ozone, peracetic acid, and followed by flushing are provided.

Relative survival of four serotypes of Salmonella enterica in low-water activity whey protein powder held at 36 and 70°C at various water activity levels

USDA-ARS?s Scientific Manuscript database

Salmonella enterica is the leading cause of health burdens in the United States. Although the pathogen is not able to grow at aw levels below 0.94, it can survive in low-moisture foods for long periods of time. Temperature, aw, substrate and serotype affect its persistence. The aim of this study was...

A New Approach to Monitoring Coastal Marshes for Persistent Flooding

NASA Astrophysics Data System (ADS)

Kalcic, M. T.; Underwood, L. W.; Fletcher, R. M.

2012-12-01

Many areas in coastal Louisiana are below sea level and protected from flooding by a system of natural and man-made levees. Flooding is common when the levees are overtopped by storm surge or rising rivers. Many levees in this region are further stressed by erosion and subsidence. The floodwaters can become constricted by levees and trapped, causing prolonged inundation. Vegetative communities in coastal regions, from fresh swamp forest to saline marsh, can be negatively affected by inundation and changes in salinity. As saltwater persists, it can have a toxic effect upon marsh vegetation causing die off and conversion to open water types, destroying valuable species habitats. The length of time the water persists and the average annual salinity are important variables in modeling habitat switching (cover type change). Marsh type habitat switching affects fish, shellfish, and wildlife inhabitants, and can affect the regional ecosystem and economy. There are numerous restoration and revitalization projects underway in the coastal region, and their effects on the entire ecosystem need to be understood. For these reasons, monitoring persistent saltwater intrusion and inundation is important. For this study, persistent flooding in Louisiana coastal marshes was mapped using MODIS (Moderate Resolution Imaging Spectroradiometer) time series of a Normalized Difference Water Index (NDWI). The time series data were derived for 2000 through 2009, including flooding due to Hurricane Rita in 2005 and Hurricane Ike in 2008. Using the NDWI, duration and extent of flooding can be inferred. The Time Series Product Tool (TSPT), developed at NASA SSC, is a suite of software developed in MATLAB® that enables improved-quality time series images to be computed using advanced temporal processing techniques. This software has been used to compute time series for monitoring temporal changes in environmental phenomena, (e.g. NDVI times series from MODIS), and was modified and used to compute the NDWI indices and also the Normalized Difference Soil Index (NDSI). Coastwide Reference Monitoring System (CRMS) water levels from various hydrologic monitoring stations and aerial photography were used to optimize thresholds for MODIS-derived time series of NDWI and to validate resulting flood maps. In most of the profiles produced for post-hurricane assessment, the increase in the NDWI index (from storm surge) is accompanied by a decrease in the vegetation index (NDVI) and then a period of declining water. The NDSI index represents non-green or dead vegetation and increases after the hurricane's destruction of the marsh vegetation. Behavior of these indices over time is indicative of which areas remain flooded, which areas recover to their former levels of vegetative vigor, and which areas are stressed or in transition. Tracking these indices over time shows the recovery rate of vegetation and the relative behavior to inundation persistence. The results from this study demonstrated that identification of persistent marsh flooding, utilizing the tools developed in this study, provided an approximate 70-80 percent accuracy rate when compared to the actual days flooded at the CRMS stations.

A New Approach to Monitoring Coastal Marshes for Persistent Flooding

NASA Technical Reports Server (NTRS)

Kalcic, M. T.; Undersood, Lauren W.; Fletcher, Rose

2012-01-01

Many areas in coastal Louisiana are below sea level and protected from flooding by a system of natural and man-made levees. Flooding is common when the levees are overtopped by storm surge or rising rivers. Many levees in this region are further stressed by erosion and subsidence. The floodwaters can become constricted by levees and trapped, causing prolonged inundation. Vegetative communities in coastal regions, from fresh swamp forest to saline marsh, can be negatively affected by inundation and changes in salinity. As saltwater persists, it can have a toxic effect upon marsh vegetation causing die off and conversion to open water types, destroying valuable species habitats. The length of time the water persists and the average annual salinity are important variables in modeling habitat switching (cover type change). Marsh type habitat switching affects fish, shellfish, and wildlife inhabitants, and can affect the regional ecosystem and economy. There are numerous restoration and revitalization projects underway in the coastal region, and their effects on the entire ecosystem need to be understood. For these reasons, monitoring persistent saltwater intrusion and inundation is important. For this study, persistent flooding in Louisiana coastal marshes was mapped using MODIS (Moderate Resolution Imaging Spectroradiometer) time series of a Normalized Difference Water Index (NDWI). The time series data were derived for 2000 through 2009, including flooding due to Hurricane Rita in 2005 and Hurricane Ike in 2008. Using the NDWI, duration and extent of flooding can be inferred. The Time Series Product Tool (TSPT), developed at NASA SSC, is a suite of software developed in MATLAB(R) that enables improved-quality time series images to be computed using advanced temporal processing techniques. This software has been used to compute time series for monitoring temporal changes in environmental phenomena, (e.g. NDVI times series from MODIS), and was modified and used to compute the NDWI indices and also the Normalized Difference Soil Index (NDSI). Coastwide Reference Monitoring System (CRMS) water levels from various hydrologic monitoring stations and aerial photography were used to optimize thresholds for MODIS-derived time series of NDWI and to validate resulting flood maps. In most of the profiles produced for post-hurricane assessment, the increase in the NDWI index (from storm surge) is accompanied by a decrease in the vegetation index (NDVI) and then a period of declining water. The NDSI index represents non-green or dead vegetation and increases after the hurricane s destruction of the marsh vegetation. Behavior of these indices over time is indicative of which areas remain flooded, which areas recover to their former levels of vegetative vigor, and which areas are stressed or in transition. Tracking these indices over time shows the recovery rate of vegetation and the relative behavior to inundation persistence. The results from this study demonstrated that identification of persistent marsh flooding, utilizing the tools developed in this study, provided an approximate 70-80 percent accuracy rate when compared to the actual days flooded at the CRMS stations.

The fate of pharmaceuticals and personal care products (PPCPs), endocrine disrupting contaminants (EDCs), metabolites and illicit drugs in a WWTW and environmental waters.

PubMed

Archer, Edward; Petrie, Bruce; Kasprzyk-Hordern, Barbara; Wolfaardt, Gideon M

2017-05-01

A large number of emerging contaminants (ECs) are known to persist in surface waters, and create pressure on wastewater treatment works (WWTW) for their effective removal. Although a large database for the levels of these pollutants in water systems exist globally, there is still a lack in the correlation of the levels of these pollutants with possible long-term adverse health effects in wildlife and humans, such as endocrine disruption. The current study detected a total of 55 ECs in WWTW influent surface water, 41 ECs in effluent, and 40 ECs in environmental waters located upstream and downstream of the plant. A list of ECs persisted through the WWTW process, with 28% of all detected ECs removed by less than 50%, and 18% of all ECs were removed by less than 25%. Negative mass balances of some pharmaceuticals and metabolites were observed within the WWTW, suggesting possible back-transformation of ECs during wastewater treatment. Three parental illicit drug compounds were detected within the influent of the WWTW, with concentrations ranging between 27.6 and 147.0 ng L -1 for cocaine, 35.6-120.6 ng L -1 for mephedrone, and 270.9-450.2 ng L -1 for methamphetamine. The related environmental risks are also discussed for some ECs, with particular reference to their ability to disrupt endocrine systems. The current study propose the potential of the pharmaceuticals carbamazepine, naproxen, diclofenac and ibuprofen to be regarded as priority ECs for environmental monitoring due to their regular detection and persistence in environmental waters and their possible contribution towards adverse health effects in humans and wildlife. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Persistent water level changes in a well near Parkfield, California, due to local and distant earthquakes

NASA Astrophysics Data System (ADS)

Roeloffs, Evelyn A.

1998-01-01

Coseismic water level rises in the 30-m deep Bourdieu Valley (BV) well near Parkfield, California, have occurred in response to three local and five distant earthquakes. Coseismic changes in static strain cannot explain these water level rises because (1) the well is insensitive to strain at tidal periods; (2) for the distant earthquakes, the expected coseismic static strain is extremely small; and (3) the water level response is of the incorrect sign for the local earthquakes. These water level changes must therefore be caused by seismic waves, but unlike seismic water level oscillations, they are monotonic, persist for days or weeks, and seem to be caused by waves with periods of several seconds rather than long-period surface waves. Other investigators have reported a similar phenomenon in Japan. Certain wells consistently exhibit this type of coseismic water level change, which is always in the same direction, regardless of the earthquake's azimuth or focal mechanism, and approximately proportional to the inverse square of hypocentral distance. To date, the coseismic water level rises in the B V well have never exceeded the seasonal water level maximum, although their sizes are relatively well correlated with earthquake magnitude and distance. The frequency independence of the well's response to barometric pressure in the frequency band 0.1 to 0.7 cpd implies that the aquifer is fairly well confined. High aquifer compressibility, probably due to a gas phase in the pore space, is the most likely reason why the well does not respond to Earth tides. The phase and amplitude relationships between the seasonal water level and precipitation cycles constrain the horizontal hydraulic diffusivity to within a factor of 4.5, bounding hypothetical earthquake-induced changes in aquifer hydraulic properties. Moreover, changes of hydraulic conductivity and/or diffusivity throughout the aquifer would not be expected to change the water level in the same direction at every time of the year. The first 2.5 days of a typical coseismic water level rise could be caused by a small coseismic discharge decrease at a point several tens of meters from the well. Alternatively, the entire coseismic water level signal could represent diffusion of an abrupt coseismic pore pressure increase within several meters of the well, produced by a mechanism akin to that of liquefaction. The coseismic water level changes in the BV well resemble, and may share a mechanism with, coseismic water level, stream discharge, and groundwater temperature changes at other locations where preearthquake changes have also been reported. No preearthquake changes have been observed at the BV well site, however.

Persistent water level changes in a well near Parkfield, California, due to local and distant earthquakes

USGS Publications Warehouse

Roeloffs, E.A.

1998-01-01

Coseismic water level rises in the 30-m deep Bourdieu Valley (BV) well near Parkfield, California, have occurred in response to three local and five distant earthquakes. Coseismic changes in static strain cannot explain these water level rises because (1) the well is insensitive to strain at tidal periods; (2) for the distant earthquakes, the expected coseismic static strain is extremely small; and (3) the water level response is of the incorrect sign for the local earthquakes. These water level changes must therefore be caused by seismic waves, but unlike seismic water level oscillations, they are monotonic, persist for days or weeks, and seem to be caused by waves with periods of several seconds rather than long-period surface waves. Other investigators have reported a similar phenomenon in Japan. Certain wells consistently exhibit this type of coseismic water level change, which is always in the same direction, regardless of the earthquake's azimuth or focal mechanism, and approximately proportional to the inverse square of hypocentral distance. To date, the coseismic water level rises in the BV well have never exceeded the seasonal water level maximum, although their sizes are relatively well correlated with earthquake magnitude and distance. The frequency independence of the well's response to barometric pressure in the frequency band 0.1 to 0.7 cpd implies that the aquifer is fairly well confined. High aquifer compressibility, probably due to a gas phase in the pore space, is the most likely reason why the well does not respond to Earth tides. The phase and amplitude relationships between the seasonal water level and precipitation cycles constrain the horizontal hydraulic diffusivity to within a factor of 4.5, bounding hypothetical earthquake-induced changes in aquifer hydraulic properties. Moreover, changes of hydraulic conductivity and/or diffusivity throughout the aquifer would not be expected to change the water level in the same direction at every time of the year. The first 2.5 days of a typical coseismic water level rise could be caused by a small coseismic discharge decrease at a point several tens of meters from the well. Alternatively, the entire coseismic water level signal could represent diffusion of an abrupt coseismic pore pressure increase within several meters of the well, produced by a mechanism akin to that of liquefaction. The coseismic water level changes in the BV well resemble, and may share a mechanism with, coseismic water level, stream discharge, and groundwater temperature changes at other locations where preearthquake changes have also been reported. No preearthquake changes have been observed at the BV well site, however.

Decontamination of biological agents from drinking water infrastructure: a literature review and summary.

PubMed

Szabo, Jeff; Minamyer, Scott

2014-11-01

This report summarizes the current state of knowledge on the persistence of biological agents on drinking water infrastructure (such as pipes) along with information on decontamination should persistence occur. Decontamination options for drinking water infrastructure have been explored for some biological agents, but data gaps remain. Data on bacterial spore persistence on common water infrastructure materials such as iron and cement-mortar lined iron show that spores can be persistent for weeks after contamination. Decontamination data show that common disinfectants such as free chlorine have limited effectiveness. Decontamination results with germinant and alternate disinfectants such as chlorine dioxide are more promising. Persistence and decontamination data were collected on vegetative bacteria, such as coliforms, Legionella and Salmonella. Vegetative bacteria are less persistent than spores and more susceptible to disinfection, but the surfaces and water quality conditions in many studies were only marginally related to drinking water systems. However, results of real-world case studies on accidental contamination of water systems with E. coli and Salmonella contamination show that flushing and chlorination can help return a water system to service. Some viral persistence data were found, but decontamination data were lacking. Future research suggestions focus on expanding the available biological persistence data to other common infrastructure materials. Further exploration of non-traditional drinking water disinfectants is recommended for future studies. Published by Elsevier Ltd.

Geographical distribution of persistent organochlorines in air, water and sediments from Asia and Oceania, and their implications for global redistribution from lower latitudes.

PubMed

Iwata, H; Tanabe, S; Sakai, N; Nishimura, A; Tatsukawa, R

1994-01-01

Persistent organochlorines in air, river water and sediment samples were analysed from eastern and southern Asia (India, Thailand, Vietnam, Malaysia, Indonesia) and Oceania (Papua New Guinea and Solomon Islands) to elucidate their geographical distribution in tropical environment. The concentrations of organochlorines in these abiotic samples collected from Taiwan, Japan and Australia were also monitored for comparison. Atmospheric and hydrospheric concentrations of HCHs (hexachlorocyclohexanes) and DDTs (DDT and its metabolites) in the tropical developing countries were apparently higher than those observed in the developed nations, suggesting extensive usage of these chemicals in the lower latitudes. CHLs (chlordane compounds) and PCBs (polychlorinated biphenyls) were also occasionally observed at higher levels in the tropics, implying that their usage area is also expanding southward. Distribution patterns of organochlorines in sediments showed smaller spatial variations on global terms, indicating that the chemicals released in the tropical environment are dispersed rapidly through air and water and retained less in sediments. The ratios of organochlorine concentrations in sediment and water phases were positively correlated with the latitude of sampling, suggesting that persistent and semivolatile compounds discharged in the tropics tend to be redistributed on a global scale.

Spinacia oleracea L. Leaf Stomata Harboring Cryptosporidium parvum Oocysts: a Potential Threat to Food Safety ▿ †

PubMed Central

Macarisin, Dumitru; Bauchan, Gary; Fayer, Ronald

2010-01-01

Cryptosporidium parvum is a cosmopolitan microscopic protozoan parasite that causes severe diarrheal disease (cryptosporidiosis) in mammals, including humans and livestock. There is growing evidence of Cryptosporidium persistence in fresh produce that may result in food-borne infection, including sporadic cases as well as outbreaks. However, drinking and recreational waters are still considered the major sources of Cryptosporidium infection in humans, which has resulted in prioritization of studies of parasite etiology in aquatic environments, while the mechanisms of transmission and parasite persistence on edible plants remain poorly understood. Using laser scanning confocal microscopy together with fluorescein-labeled monoclonal antibodies, C. parvum oocysts were found to strongly adhere to spinach plants after contact with contaminated water, to infiltrate through the stomatal openings in spinach leaves, and to persist at the mesophyll level. These findings and the fact that this pathogenic parasite resists washing and disinfection raise concerns regarding food safety. PMID:19933348

Decontamination of radiological agents from drinking water infrastructure: a literature review and summary.

PubMed

Szabo, Jeff; Minamyer, Scott

2014-11-01

This report summarizes the current state of knowledge on the persistence of radiological agents on drinking water infrastructure (such as pipes) along with information on decontamination should persistence occur. Decontamination options for drinking water infrastructure have been explored for some important radiological agents (cesium, strontium and cobalt), but important data gaps remain. Although some targeted experiments have been published on cesium, strontium and cobalt persistence on drinking water infrastructure, most of the data comes from nuclear clean-up sites. Furthermore, the studies focused on drinking water systems use non-radioactive surrogates. Non-radioactive cobalt was shown to be persistent on iron due to oxidation with free chlorine in drinking water and precipitation on the iron surface. Decontamination with acidification was an effective removal method. Strontium persistence on iron was transient in tap water, but adherence to cement-mortar has been demonstrated and should be further explored. Cesium persistence on iron water infrastructure was observed when flow was stagnant, but not with water flow present. Future research suggestions focus on expanding the available cesium, strontium and cobalt persistence data to other common infrastructure materials, specifically cement-mortar. Further exploration chelating agents and low pH treatment is recommended for future decontamination studies. Published by Elsevier Ltd.

Microbial sewage contamination associated with Superstorm Sandy flooding in New York City

NASA Astrophysics Data System (ADS)

O'Mullan, G.; Dueker, M.; Sahajpal, R.; Juhl, A. R.

2013-05-01

The lower Hudson River Estuary commonly experiences degraded water quality following precipitation events due to the influence of combined sewer overflows. During Super-storm Sandy large scale flooding occurred in many waterfront areas of New York City, including neighborhoods bordering the Gowanus Canal and Newtown Creek Superfund sites known to frequently contain high levels of sewage associated bacteria. Water, sediment, and surface swab samples were collected from Newtown Creek and Gowanus Canal flood impacted streets and basements in the days following the storm, along with samples from the local waterways. Samples were enumerated for the sewage indicating bacterium, Enterococcus, and DNA was extracted and amplified for 16S ribosomal rRNA gene sequence analysis. Waterways were found to have relatively low levels of sewage contamination in the days following the storm. In contrast, much higher levels of Enterococci were detected in basement and storm debris samples and these bacteria were found to persist for many weeks in laboratory incubations. These data suggest that substantial sewage contamination occurred in some flood impacted New York City neighborhoods and that the environmental persistence of flood water associated microbes requires additional study and management attention.

Persistent Distress after Water Contamination.

PubMed

Schade, Charles P; Gupta, Rahul; Jha, Ayan; Wright, Nasandra

2016-01-01

A chemical spill contaminated the public water supply of Charleston, West Virginia in January 2014 for at least a week. Psychological distress is common after disasters. We surveyed the exposed population to assess psychological distress during and three months after the incident. We inquired about stressors that might predict distress, adequacy of communication from public officials, and use of the water supply and perceptions of its safety three months after the incident. Twenty six percent of interviewees had persistent symptoms of distress. Female sex, negative household experiences during the episode (especially having someone sick), and poor perception of communication increased odds of persistent distress. Households of respondents without persistent distress were significantly more likely to report drinking tap water (RR=1.95) than those with persistent distress. Distress in Charleston area residents persisted and may have resulted in continuing mistrust of the water supply.

Widespread groundwater-level offsets caused by the Mw 5.8 Mineral, Virginia, earthquake of 23 August 2011

USGS Publications Warehouse

Roeloffs, Evelyn A.; Nelms, David L.; Sheets, Rodney A.

2015-01-01

Groundwater levels were offset in bedrock observation wells, measured by the U.S. Geological Survey or others, as far as 553 km from the Mw 5.8 Mineral, Virginia (USA), earthquake on 23 August 2011. Water levels dropped as much as 0.47 m in 34 wells and rose as much as 0.15 m in 12 others. In some wells, which are as much as 213 m deep, the water levels recovered from these deviations in hours to days, but in others the water-level offset may have persisted. The groundwater-level offsets occurred in locations where the earthquake was at least weakly felt, and the maximum water-level excursion increased with felt intensity, independent of epicentral distance. Coseismic static strain from the earthquake was too small and localized to have contributed significantly to the groundwater-level offsets. The relation with intensity is consistent with ground motion from seismic waves leading to the water-level offsets. Examination of the hydrographs indicates that short-period ground motion most likely affected the permeability of the bedrock aquifers monitored by the wells.

Decontamination of chemical agents from drinking water infrastructure: a literature review and summary.

PubMed

Szabo, Jeff; Minamyer, Scott

2014-11-01

This report summarizes the current state of knowledge on the persistence of chemical contamination on drinking water infrastructure (such as pipes) along with information on decontamination should persistence occur. Decontamination options for drinking water infrastructure have been explored for some chemical contaminants, but important data gaps remain. In general, data on chemical persistence on drinking water infrastructure is available for inorganics such as arsenic and mercury, as well as select organics such as petroleum products, pesticides and rodenticides. Data specific to chemical warfare agents and pharmaceuticals was not found and data on toxins is scant. Future research suggestions focus on expanding the available chemical persistence data to other common drinking water infrastructure materials. Decontaminating agents that successfully removed persistent contamination from one infrastructure material should be used in further studies. Methods for sampling or extracting chemical agents from water infrastructure surfaces are needed. Published by Elsevier Ltd.

Concentrations and possible sources of nitrate in water from the Silurian-Devonian aquifer, Cedar Falls, Iowa

USGS Publications Warehouse

Schaap, Bryan D.

1999-01-01

Nitrogen fertilizer sales in Iowa have been higher in recent years than during the mid- 1970’s. This suggests that nitrate concentrations in water from well 9 may persist at present levels or could increase in future years if fertilizer use increases and if higher nitrate concentrations are directly related to higher nitrogen fertilizer use.

A Molecular MST Approach to Investigate Fecal Indicator Bacteria in Bioaerosols, Bathing Water, Seaweed Wrack, and Sand at Recreational Beaches

NASA Astrophysics Data System (ADS)

Thoren, K. M.; Sinigalliano, C. D.

2016-02-01

Despite numerous cases of beach bacteria affecting millions of people worldwide, the persistence of the bacteria populations in coastal areas is still not well understood. The purpose of this study was to test the levels of persistence of Fecal Indicating Bacteria (FIB) of enterococci, Escherichia coli, and Human-source Bacteroidales, within the intertidal "swash zone" and the deeper waist zone in which people commonly bathe and play. In addition, the study sought to determine if these bacterial contaminants may also be found in aerosols at the beach. Measuring solar insolation in relation to bacterial persistence in seaweed wrack was used to determine if sunlight plays a role in modifying concentrations of FIB at the beach. Light intensity measured by a solar photometer and air quality measured by aerosol plate counts and qPCR Microbial Source Tracking (MST) was compared to varying locations where the beach samples were collected. Results from water samples demonstrate that bacteria measured using plate counts and qPCR were indeed higher within the swash zone than in the waist zone. This is in contrast with the way that the EPA currently measures and determines the public safety of beach waters. They commonly measure the waist zone, but disregard the swash zone. Results from beach bio-aerosol samples showed a wide variety of fungi and bacteria in the beach air, and qPCR MST analysis of these bio-aerosols showed the presence of FIBs such as enterococci on several of the aerosol collection plates. This emphasizes the need to collect samples from the entire beach instead of just measuring at an isolated area, and that exposure to microbial contaminants may include bathing water, beach sand, seaweed wrack, and bio-aerosols. Thus, the data reveals a potential way to identify harmful levels of bacteria and dangerous levels of poor air quality at recreational beaches. These results expound the need for broader assessment of potential beach contamination, not only the swimming water, but also the beach air, shoreline, and also varying depths of water, which can be extremely beneficial to reduce people's risk from microbial contamination exposure.

Separated by sand, fused by dropping water: habitat barriers and fluctuating water levels steer the evolution of rock-dwelling cichlid populations in Lake Tanganyika.

PubMed

Koblmüller, Stephan; Salzburger, Walter; Obermüller, Beate; Eigner, Eva; Sturmbauer, Christian; Sefc, Kristina M

2011-06-01

The conditions of phenotypic and genetic population differentiation allow inferences about the evolution, preservation and loss of biological diversity. In Lake Tanganyika, water level fluctuations are assumed to have had a major impact on the evolution of stenotopic littoral species, though this hypothesis has not been specifically examined so far. The present study investigates whether subtly differentiated colour patterns of adjacent Tropheus moorii populations are maintained in isolation or in the face of continuous gene flow, and whether the presumed influence of water level fluctuations on lacustrine cichlids can be demonstrated in the small-scale population structure of the strictly stenotopic, littoral Tropheus. Distinct population differentiation was found even across short geographic distances and minor habitat barriers. Population splitting chronology and demographic histories comply with our expectation of old and rather stable populations on steeper sloping shore, and more recently established populations in a shallower region. Moreover, population expansions seem to coincide with lake level rises in the wake of Late Pleistocene megadroughts ~100 KYA. The imprint of hydrologic events on current population structure in the absence of ongoing gene flow suggests that phenotypic differentiation among proximate Tropheus populations evolves and persists in genetic isolation. Sporadic gene flow is effected by lake level fluctuations following climate changes and controlled by the persistence of habitat barriers during lake level changes. Since similar demographic patterns were previously reported for Lake Malawi cichlids, our data furthermore strengthen the hypothesis that major climatic events synchronized facets of cichlid evolution across the East African Great Lakes. © 2011 Blackwell Publishing Ltd.

Persistence of 2,6-Dichlorobenzonitrile in aquatic environments

USGS Publications Warehouse

Van Valin, C.C.

1966-01-01

In two experiments 2,6-dichlorobenzonitrile was added to aquatic systems, and the residue levels were followed for about 6 months. A granular formulation applied to a farm pond at 0.6 p.p.m. produced highest residues in water and fish about 2 weeks following treatment whereas vegetation and soil samples had the highest levels within 1 or 2 days. Residues were still measurable after 188 days. In ponds treated with a wettable powder formulation at 10, 20, and 40 p.p.m., residues in water and fish were highest within 3 days after treatment. The concentration in water 11 days after treatment was about 2% of the three-day level. Fish whole-body residues dropped nearly as fast but were still measurable at 112 days.

Sequential UV- and chlorine-based disinfection to mitigate Escherichia coli in drinking water biofilms.

PubMed

Murphy, H M; Payne, S J; Gagnon, G A

2008-04-01

This study was designed to examine the potential downstream benefits of sequential disinfection to control the persistence of Escherichia coli under conditions relevant to drinking water distribution systems. Eight annular reactors (four polycarbonate and four cast iron) were setup in parallel to address various factors that could influence biofilm growth in distribution systems. Eight reactors were treated with chlorine, chlorine dioxide and monochloramine alone or in combination with UV to examine the effects on Escherichia coli growth and persistence in both the effluent and biofilm. In general, UV-treated systems in combination with chlorine or chlorine dioxide and monochloramine achieved greater log reductions in both effluent and biofilm than systems treated with chlorine-based disinfectants alone. However, during UV-low chlorine disinfection, E. coli was found to persist at low levels, suggesting that the UV treatment had instigated an adaptive mutation. During UV-chlorine-dioxide treatment, the E. coli that was initially below the detection limit reappeared during a low level of disinfection (0.2 mg/L) in the cast iron systems. Chloramine was shown to be effective in disinfecting suspended E. coli in the effluent but was unable to reduce biofilm counts to below the detection limit. Issues such as repair mechanism of E. coli and nitrification could help explain some of these aberrations. Improved understanding of the ability of chlorine-based disinfectant in combination with UV to provide sufficient disinfection will ultimately effect in improved management and safety of drinking water.

Perfluorooctanoic acid (PFOA), an emerging drinking water contaminant: a critical review of recent literature.

PubMed

Post, Gloria B; Cohn, Perry D; Cooper, Keith R

2012-07-01

Perfluorooctanoic acid (PFOA) is an anthropogenic contaminant that differs in several ways from most other well-studied organic chemicals found in drinking water. PFOA is extremely resistant to environmental degradation processes and thus persists indefinitely. Unlike most other persistent and bioaccumulative organic pollutants, PFOA is water-soluble, does not bind well to soil or sediments, and bioaccumulates in serum rather than in fat. It has been detected in finished drinking water and drinking water sources impacted by releases from industrial facilities and waste water treatment plants, as well as in waters with no known point sources. However, the overall occurrence and population exposure from drinking water is not known. PFOA persists in humans with a half-life of several years and is found in the serum of almost all U.S. residents and in populations worldwide. Exposure sources include food, food packaging, consumer products, house dust, and drinking water. Continued exposure to even relatively low concentrations in drinking water can substantially increase total human exposure, with a serum:drinking water ratio of about 100:1. For example, ongoing exposures to drinking water concentrations of 10 ng/L, 40 ng/L, 100 ng/L, or 400 ng/L are expected to increase mean serum levels by about 25%, 100%, 250%, and 1000%, respectively, from the general population background serum level of about 4 ng/mL. Infants are potentially a sensitive subpopulation for PFOA's developmental effects, and their exposure through breast milk from mothers who use contaminated drinking water and/or from formula prepared with contaminated drinking water is higher than in adults exposed to the same drinking water concentration. Numerous health endpoints are associated with human PFOA exposure in the general population, communities with contaminated drinking water, and workers. As is the case for most such epidemiology studies, causality for these effects is not proven. Unlike most other well-studied drinking water contaminants, the human dose-response curve for several effects appears to be steepest at the lower exposure levels, including the general population range, with no apparent threshold for some endpoints. There is concordance in animals and humans for some effects, while humans and animals appear to react differently for other effects such as lipid metabolism. PFOA was classified as "likely to be carcinogenic in humans" by the USEPA Science Advisory Board. In animal studies, developmental effects have been identified as more sensitive endpoints for toxicity than carcinogenicity or the long-established hepatic effects. Notably, exposure to an environmentally relevant drinking water concentration caused adverse effects on mammary gland development in mice. This paper reviews current information relevant to the assessment of PFOA as an emerging drinking water contaminant. This information suggests that continued human exposure to even relatively low concentrations of PFOA in drinking water results in elevated body burdens that may increase the risk of health effects. Copyright © 2012 Elsevier Inc. All rights reserved.

Contribution of precursor compounds to the release of per- and polyfluoroalkyl substances (PFASs) from waste water treatment plants (WWTPs).

PubMed

Eriksson, Ulrika; Haglund, Peter; Kärrman, Anna

2017-11-01

Per- and polyfluoroalkyl substances (PFASs) are ubiquitous in sludge and water from waste water treatment plants, as a result of their incorporation in everyday products and industrial processes. In this study, we measured several classes of persistent PFASs, precursors, transformation intermediates, and newly identified PFASs in influent and effluent sewage water and sludge from three municipal waste water treatment plants in Sweden, sampled in 2015. For sludge, samples from 2012 and 2014 were analyzed as well. Levels of precursors in sludge exceeded those of perfluoroalkyl acids and sulfonic acids (PFCAs and PFSAs), in 2015 the sum of polyfluoroalkyl phosphoric acid esters (PAPs) were 15-20ng/g dry weight, the sum of fluorotelomer sulfonic acids (FTSAs) was 0.8-1.3ng/g, and the sum of perfluorooctane sulfonamides and ethanols ranged from non-detected to 3.2ng/g. Persistent PFSAs and PFCAs were detected at 1.9-3.9ng/g and 2.4-7.3ng/g dry weight, respectively. The influence of precursor compounds was further demonstrated by an observed substantial increase for a majority of the persistent PFCAs and PFSAs in water after waste water treatment. Perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), and perfluorooctane sulfonic acid (PFOS) had a net mass increase in all WWTPs, with mean values of 83%, 28%, 37% and 58%, respectively. The load of precursors and intermediates in influent water and sludge combined with net mass increase support the hypothesis that degradation of precursor compounds is a significant contributor to PFAS contamination in the environment. Copyright © 2017. Published by Elsevier B.V.

Hydrologic conditions in Florida during Water Year 2008

USGS Publications Warehouse

Verdi, Richard J.; Holt, Sandra L.; Irvin, Ronald B.; Fulcher, David L.

2010-01-01

Record-high and record-low hydrologic conditions occurred during water year 2008 (October 1, 2007-September 30, 2008). Record-low levels were caused by a continuation of the 2007 water year drought conditions into the 2008 water year and persisting until summer rainfall. The gage at the Santa Fe River near Fort White site recorded record-low monthly mean discharges in October and November 2007. The previous records for this site were set in 1956 and 2002, respectively. Record-high conditions in northeast and northwest Florida were caused by the rainfall and runoff associated with Tropical Storm Fay. For example, St. Mary's River near Macclenny recorded a new record-high monthly mean discharge in August 2008. The previous record for this site was set in 1945. Lake Okeechobee in south Florida reached new minimum monthly mean lake levels since monitoring began in 1912 from October to March during the 2008 water year. Some wells throughout northwest and south Florida registered period-of-record lowest daily maximum water levels.

Salmonella survival during thermal dehydration of fresh garlic and storage of dehydrated garlic products.

PubMed

Zhang, Hongmei; Qi, Yan; Wang, Lei; Zhang, Shaokang; Deng, Xiangyu

2017-12-18

Salmonella survival was characterized and modeled during thermal dehydration of fresh garlic and storage of dehydrated garlic products. In our experiments that simulated commercial dehydration processing at 80±5°C, moderate level of Salmonella contamination (4-5logCFU/g) on fresh garlic was reduced below the enumeration limit (1.7logCFU/g) after 4.5h of dehydration and not detectable by culture enrichment after 7h. With high level of contamination (7-8logCFU/g), the Salmonella population persisted at 3.6logCFU/g after 8h of processing. By increasing the dehydration temperature to 90±5°C, the moderate and high levels of initial Salmonella load on fresh garlic dropped below the enumeration limit after 1.5 and 3.75h of processing and became undetectable by culture enrichment after 2.5 and 6h, respectively. During the storage of dried garlic products, Salmonella was not able to grow under all tested combinations of temperature (25 and 35°C) and water activity (0.56-0.98) levels, suggesting active inhibition. Storage temperature played a primary role in determining Salmonella survival on dehydrated garlic flakes. Under a typical storage condition at 25°C and ambient relative humidity, Salmonella could persist over months with the population gradually declining (4.3 log reduction over 88days). Granular size of dehydrated garlic had an impact on Salmonella survival, with better survival of the pathogen observed in bigger granules. At the early stage of dehydrated garlic storage (until 7days), rising water activity appeared to initially promote but then inhibited Salmonella survival, resulting in a water activity threshold at 0.73 where Salmonella displayed strongest persistence. However, this phenomenon was less apparent during extended storage (after 14days). Copyright © 2017 Elsevier B.V. All rights reserved.

Persistence of poultry associated Salmonella spp. on spinach plants

USDA-ARS?s Scientific Manuscript database

Introduction: Pre-harvest spinach contamination can occur via irrigation water and can influence the persistence of Salmonella on spinach leaves. Salmonella persistence on spinach plants should be evaluated as nearby poultry farms can be a critical source of contaminated water run-off. Purpose: The...

Parsing apart the persisters: Etiological mechanisms and criminal offense patterns of moderate- and high-level persistent offenders.

PubMed

Amemiya, Jamie; Vanderhei, Susan; Monahan, Kathryn C

2017-08-01

Longitudinal investigations that have applied Moffitt's dual taxonomic framework to criminal offending have provided support for the existence of adolescent-limited and life-course persistent antisocial individuals, but have also identified additional trajectories. For instance, rather than a single persistent trajectory, studies have found both high-level and moderate-level persistent offenders. To inform theory and progress our understanding of chronic antisocial behavior, the present study used a sample of serious adolescent offenders (N =1,088) followed from middle adolescence to early adulthood (14-25 years), and examined how moderate-level persistent offenders differed from low-rate, desisting, and high-level persistent offenders. Results indicated that moderate-level persisters' etiology and criminal offense patterns were most similar to high-level persisters, but there were notable differences. Specifically, increasing levels of contextual adversity characterized both moderate-level and high-level persisting trajectories, but moderate-level persisters reported consistently lower levels of environmental risk. While both high- and moderate-level persisters committed more drug-related offenses in early adulthood compared to adolescence, moderate-level persisters engaged in lower levels of antisocial behavior across all types of criminal offenses. Taken cumulatively, the findings of this study suggest that sociocontextual interventions may be powerful in reducing both moderate- and high-level persistence in crime.

Removal of Escherichia coli and Enterococcus faecalis after Hand Washing with Antimicrobial and Nonantimicrobial Soap and Persistence of These Bacteria in Rinsates.

PubMed

Pérez-Garza, J; García, S; Heredia, N

2017-10-01

Food handlers are important sources of contamination in the agricultural environment. This study was conducted (i) to evaluate the activity of antimicrobial soaps against Escherichia coli and Enterococcus faecalis using a hand washing model with soiled hands and (ii) to determine the survival and persistence of these bacteria in rinsates. Sterilized agricultural soil from tomato and pepper farms was inoculated with E. coli or E. faecalis at 10 3 or 10 6 CFU/g. Decontaminated hands were placed in contact with contaminated soil for 2 min and were then washed with soaps with or without antimicrobial compounds (citric extracts, chloroxylenol, triclosan, or chlorhexidine gluconate). As the control, hands were washed with sterile distilled water. The levels of bacteria remaining on the hands and recovered from the rinsates were determined using a membrane filtration method and selective media. Antimicrobial soaps removed levels of E. coli similar to those removed by distilled water and nonantimicrobial soap on hands contaminated with E. coli at 10 3 CFU/g. However, when hands were contaminated with E. coli at 10 6 CFU/g, more E. coli was removed with the chlorhexidine gluconate soap. When hands were contaminated with E. faecalis at 10 3 CFU/g, bacteria were removed more effectively with soaps containing chloroxylenol or chlorhexidine gluconate. When hands were contaminated with E. faecalis at 10 6 CFU/g, all of the antimicrobial soaps were more effective for removing the bacteria than were distilled water and nonantimicrobial soap. E. coli grew in all of the hand washing rinsates except that containing triclosan, whereas E. faecalis from the 10 6 CFU/g treatments grew in rinsates containing chlorhexidine gluconate and in the distilled water rinsates. Washing with antimicrobial soap was more effective for reducing bacteria on soiled hands than was washing with water or nonantimicrobial soap. However, persistence or growth of bacteria in these rinsates poses health risks.

Degradation of Kresoxim-Methyl in Water: Impact of Varying pH, Temperature, Light and Atmospheric CO2 Level.

PubMed

Khandelwal, Ashish; Gupta, Suman; Gajbhiye, Vijay T; Varghese, Eldho

2016-01-01

In the present investigation, persistence of kresoxim-methyl (a broad spectrum strobilurin fungicide) was studied in water. Results revealed that kresoxim-methyl readily form acid metabolite. Therefore, residues of kresoxim-methyl were quantified on the basis of parent molecule alone and sum total of kresoxim-methyl and its acid metabolite. In water, influence of various abiotic factors like pH, temperature, light and atmospheric carbon dioxide level on dissipation of kresoxim-methyl was studied. The half life value for kresoxim-methyl and total residue varied from 1 to 26.1 and 6.1 to 94.0 days under different conditions. Statistical analysis revealed the significant effect of abiotic factors on the dissipation of kresoxim-methyl from water.

Tracking persistent pharmaceutical residues from municipal sewage to drinking water

NASA Astrophysics Data System (ADS)

Heberer, Thomas

2002-09-01

In urban areas such as Berlin (Germany) with high municipal sewage water discharges and low surface water flows there is a potential risk of drinking water contamination by polar organic compounds when groundwater recharge is used in drinking water production. Thus, some pharmaceutically active compounds (PhACs) are not eliminated completely in the municipal sewage treatment plants (STPs) and they are discharged as contaminants into the receiving waters. In terms of several monitoring studies carried out in Berlin between 1996 and 2000, PhACs such as clofibric acid, diclofenac, ibuprofen, propyphenazone, primidone and carbamazepine were detected at individual concentrations up to the μg/l-level in influent and effluent samples from STPs and in all surface water samples collected downstream from the STPs. Under recharge conditions, several compounds were also found at individual concentrations up to 7.3 μg/l in samples collected from groundwater aquifers near to contaminated water courses. A few of the PhACs were also identified at the ng/l-level in Berlin tap water samples.

Trichomonas gallinae Persistence in Four Water Treatments.

PubMed

Purple, Kathryn E; Humm, Jacob M; Kirby, R Brian; Saidak, Christina G; Gerhold, Richard

2015-07-01

Trichomonas gallinae is a protozoan parasite commonly found in columbids, passerines, and several raptor species. Although T. gallinae is thought to spread between individuals and across species through shared water sources, little research has been conducted regarding the persistence of T. gallinae in the environment. To determine the persistence of T. gallinae in various communal water sources, we inoculated 1 × 10(6) trichomonads into 500 mL samples of distilled water, quarry water, bird bath water, and rain barrel water in two replicates. Aliquots of 0.5 mL were collected from each source at -1, 0, 15, 30, and 60 min; aliquots were incubated at 37 C and examined for trichomonads by light microscopy for five consecutive days. Live trichomonads were observed in all samples and at all sampling times except prior to inoculation (-1 min). The pH of water sources ranged from an average of 5.9 to 7.4 postsampling. Our findings indicate that T. gallinae can persist for up to 60 min in various water treatments and thus be infectious for birds drinking T. gallinae-contaminated water.

Benthic foraminifera as indicators of pollution in high latitude marine environments

NASA Astrophysics Data System (ADS)

Dijkstra, N.; Junttila, J.; Husum, K.; Carroll, J.; Klitgaard-Kristensen, D.; Hald, M.

2012-04-01

An increasing number of studies demonstrate the potential of benthic foraminifera to characterize ecological status. However, the use of benthic foraminifera as bio-indicators has previously not been tested in high latitudes. This research contributes to the development of foraminifera as a bio-monitoring technique for the Arctic region, as industrial activities in this region will increase in the coming years. Surface sediments (0-1 cm) from sites close to gas fields in the SW Barents Sea were studied. In addition, to elucidate the range from less to very affected, surface sediments from the harbor of the town of Hammerfest (70° N) were studied. At least 300 living benthic foraminifera from the size fraction 100 µm-1 mm were counted and identified at species level. Pollution levels (heavy metals and persistent organic pollutants) and sediment properties (grainsize and TOC) were also analyzed. Pollution levels at the sea floor in the SW Barents Sea are of background to good level (level I-II) according to the definitions by the Water Framework Directorate (WFD). Benthic foraminiferal assemblages are influenced by natural environmental parameters such as water mass properties, water depth, nutrient availability, bottom current strength, and grain size. Surface sediments from the Hammerfest harbor are of moderate environmental status (WFD level II-III) based on heavy metal concentrations and of bad environmental status (WFD IV-V) based on persistent organic pollutant concentrations. Opportunistic benthic foraminifera are dominating the assemblages. The most polluted areas in the harbor are barren for foraminifera or have high amounts of deformed shells. In both environments the foraminiferal diversity of the samples, does not correspond to expected environmental status based on the pollution levels of the sediments. Environmental status classes, based on benthic foraminifera instead of macrofauna, would allow rapid analyses of the environmental impact of pollution.

Surviving at high elevations: an inter- and intra-specific analysis in a mountain bird community.

PubMed

Bastianelli, G; Tavecchia, G; Meléndez, L; Seoane, J; Obeso, J R; Laiolo, P

2017-06-01

Elevation represents an important selection agent on self-maintenance traits and correlated life histories in birds, but no study has analysed whether life-history variation along this environmental cline is consistent among and within species. In a sympatric community of passerines, we analysed how the average adult survival of 25 open-habitat species varied with their elevational distribution and how adult survival varied with elevation at the intra-specific level. For such purpose, we estimated intra-specific variation in adult survival in two mountainous species, the Water pipit (Anthus spinoletta) and the Northern wheatear (Oenanthe oenanthe) in NW Spain, by means of capture-recapture analyses. At the inter-specific level, high-elevation species showed higher survival values than low elevation ones, likely because a greater allocation to self-maintenance permits species to persist in alpine environments. At the intra-specific level, the magnitude of survival variation was lower by far. Nevertheless, Water pipit survival slightly decreased at high elevations, while the proportion of transient birds increased. In contrast, no such relationships were found in the Northern wheatear. Intra-specific analyses suggest that living at high elevation may be costly, such as for the Water pipit in our case study. Therefore, it seems that a species can persist with viable populations in uplands, where extrinsic mortality is high, by increasing the investment in self-maintenance and prospecting behaviours.

Screening for Stockholm Convention persistent organic pollutants in the Bosna River (Bosnia and Herzogovina).

PubMed

Harman, Christopher; Grung, Merete; Djedjibegovic, Jasmina; Marjanovic, Aleksandra; Sober, Miroslav; Sinanovic, Kemo; Fjeld, Eirik; Rognerud, Sigurd; Ranneklev, Sissel Brit; Larssen, Thorjørn

2013-02-01

The Stockholm Convention, which aspires to manage persistent organic pollutants (POPs) at the international level, was recently ratified in Bosnia and Herzegovina (BiH). Despite this fact, there is in general a paucity of data regarding the levels of POPs in the environment in BiH. In the present study, screening for POPs was conducted in one of the country's major rivers, the Bosna. A two-pronged approach was applied using passive samplers to detect the freely dissolved and bioavailable concentrations in the water phase and sediment analysis to provide an integrated measure of historical contamination. At several places along the river, the concentrations of polycyclic aromatic hydrocarbons (PAH) were high and exhibited potential for both chronic and acute effects to biota. River water also showed elevated concentrations of PAH, up to 480 ng L(-1) near the city of Doboj, and diagnostic ratios suggested combustion sources for the contamination present in both types of sample. The levels of the other contaminants measured-polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers--were generally low in the water phase. However, PCBs and some OCPs were present in river sediments at levels which breach the international criteria and thus suggest potential for ecological damage. Additionally, the levels of heptachlor breached these criteria in many of the sites investigated. This study presents the first screening data for some of these Stockholm Convention relevant compounds in BiH and reveals both low concentrations of some chemical groups, but significant point sources and historic contamination for others.

The effect of balneotherapy on C-reactive protein, serum cholesterol, triglyceride, total antioxidant status and HSP-60 levels.

PubMed

Oláh, Mihály; Koncz, Agnes; Fehér, Judit; Kálmánczhey, Judit; Oláh, Csaba; Balogh, Sándor; Nagy, György; Bender, Tamás

2010-05-01

An increasing body of evidence substantiating the effectiveness of balneotherapy has accumulated during recent decades. In the present study, 42 ambulatory patients (23 males and 19 females, mean age 59.5 years) with degenerative musculoskeletal disease were randomised into one of two groups-bathing in tap water or in mineral water at the same temperature-and subjected to 30-min balneotherapy sessions on 15 occasions. Study parameters comprised serum levels of sensitised C-reactive protein (CRP), plasma lipids, heat shock protein (HSP-60) and total antioxidant status (TAS). In both groups, CRP levels followed a decreasing tendency, which still persisted 3 months later. At 3 months after balneotherapy, serum cholesterol levels were still decreasing in patients who had used medicinal water, but exhibited a trend towards an increase in the control group. Triglyceride levels followed a decreasing trend in both patient groups. TAS showed a declining tendency in both groups. No changes of HSP-60 levels were observed in either group. Balneotherapy with the thermal water from Hajdúszoboszló spa had a more pronounced physiological effect compared to that seen in the control group treated with tap water in a 3 month period.

The Microcosm Mediates the Persistence of Shiga Toxin-Producing Escherichia coli in Freshwater Ecosystems

PubMed Central

Mauro, Steven A.; Opalko, Hannah; Lindsay, Kyle; Colon, Michael P.

2013-01-01

Water is a major route for infection of humans by exotoxin-producing bacteria, including Shiga toxin-producing Escherichia coli (STEC). While STEC has the potential to be present in nearly every type of water source, its distribution is sporadic, and an understanding of factors that govern its emergence and persistence within water is lacking. In this study, we examined the influence of microbe content on STEC persistence in freshwater. We found that depletion of microbes in the water leads to a considerable increase in the persistence of STEC, an effect that can be mitigated by adding grazing protists to the water. STEC strains appear to be more resistant to the impact of grazing protists than E. coli strains that lack the Shiga toxin (stx) gene. Our results demonstrate that the microcosm can dramatically influence the persistence of STEC in aquatic ecosystems and that the overall impact by microbes on STEC strains is fundamentally different from that of non-STEC strains of bacteria. Overall, these results provide insight into why STEC and possibly other exotoxin-producing bacterial pathogens display such variability in abundance, distribution, and persistence in aquatic ecosystems. PMID:23747699

Microcystin in aquatic food webs of the Baltic and Chesapeake Bay regions

NASA Astrophysics Data System (ADS)

Bukaveckas, Paul A.; Lesutienė, Jūratė; Gasiūnaitė, Zita R.; Ložys, Linas; Olenina, Irina; Pilkaitytė, Renata; Pūtys, Žilvinas; Tassone, Spencer; Wood, Joseph

2017-05-01

We undertook a comparative study of the James River Estuary, a sub-estuary of Chesapeake Bay, and the Curonian Lagoon, a sub-estuary of the Baltic Sea, to better understand the factors that determine the presence and persistence of algal toxins in food webs. Over a 2-year period, we measured microcystin concentrations in water, sediment and biota (fish and shellfish) at both sites. Across both food webs we found highest levels of microcystin among consumers of suspended particulate matter, including planktivorous fishes and filter-feeding shellfish, and lower levels of toxin among piscivores, scavengers and benthic omnivores. Despite similar levels of microcystin in the water column at the two sites, we observed higher toxin levels in fish and sediments of the Curonian Lagoon. We attribute this difference to the legacy of prior toxic cyanobacteria blooms in the Curonian Lagoon and hydrologic factors that result in a predominance of autochthonously-derived organic matter in the sediments at this site. Our results suggest that a consideration of species-specific differences in feeding habits, and organic matter sources supporting food webs are important to understanding the accumulation and persistence of algal toxins in food webs and should therefore be considered in assessment of risks to aquatic biota and human health.

Comparative Persistence of Subgroups of F-Specific RNA Phages in River Water

PubMed Central

Yang, Yongheng

2013-01-01

F-specific (F+) RNA phages are widely used as indicators for the presence of fecal contamination and/or enteric viruses in water, and identifying subgroups of F+ RNA phages provides an approach for microbial source tracking. Different survival characteristics of the F+ RNA phage subgroups result in a misinterpretation of their original proportion in water, thus giving misleading information when they are used for microbial source tracking. This study investigated the comparative persistence of subgroups of F+ RNA phages in river water under different conditions. Results suggested that temperature and pH are the major factors affecting the persistence of F+ RNA phages in river water, and organic substances promote phage survival. The comparative persistence patterns of subgroups of F+ RNA phages varied and may bias extrapolation of their initial proportions in surface water. Thus, the characteristics of water should be taken into consideration and the results should be carefully interpreted when F+ RNA phages are used for microbial source tracking. PMID:23686274

Control of postharvest diseases of fruit by heat and fungicides: efficacy, residue levels, and residue persistence. A review.

PubMed

Schirra, Mario; D'Aquino, Salvatore; Cabras, Paolo; Angioni, Alberto

2011-08-24

Extensive research has been done in recent years to reduce the heavy dependence on chemical fungicides to control postharvest diseases and disorders of horticultural crops. Alternative strategies were based on improved cultural practices, biological control, plant-defense promoters, and physical treatments such as UV illumination, radiofrequency treatment, heat therapy, and storage technologies. Among these, postharvest heat treatments such as hot water dips, short hot water rinsing and brushing, and hot air conditioning have reduced rot development and enhanced fruit resistance to chilling injury in sensitive cultivars while retaining fruit quality during cold storage and shelf life. Additive or synergistic increases in effectiveness were observed by integrating heat therapy with various chemical compounds, thus leading to significant reductions in the application of active ingredients to protect produce from decay. This paper highlights the knowledge on this topic with emphasis on heat therapy effects and factors affecting the uptake, persistence, and performance of fungicide residues when they are applied in combination with hot water.

Gradients of microhabitat and crappie (Pomoxis spp.) distributions in reservoir coves

USGS Publications Warehouse

Kaczka, Levi J.; Miranda, Leandro E.

2013-01-01

Embayments are among the most widespread littoral habitats found in Mississippi flood-control reservoirs. These macrohabitats represent commonly used nursery zones for age-0 crappies, Pomoxis spp., despite barren and eroded shorelines formed over 60–70 years of annual water level fluctuations. We tested if embayments displayed microhabitat gradients linked to the effect of water level fluctuations on riparian vegetation and if these gradients were paralleled by gradients in age-0 crappie distribution. Habitat composition changed longitudinally along the embayments with the most pronounced gradient representing a shift from nonvegetated mudflats near the mouth of embayments to herbaceous material upstream. The degree of habitat change depended on the water level. Similarly, catch rates of crappies increased upstream toward the rear of embayments, differing among water levels and reservoirs, but the longitudinal pattern persisted. Our results indicate that habitat composition gradients occur in embayments of northwest Mississippi flood-control reservoirs and that these gradients may influence a similar gradient in age-0 crappie distribution. While the biotic interactions behind the gradients may be less clear, we speculate that water level is the main factor influencing the observed gradients in habitat composition and fish. Management to benefit age-0 crappies may involve habitat improvement along embayment shorelines and water level regimes that foster growth of herbaceous plants.

Comparative persistence of human sewage-specific enterococcal bacteriophages in freshwater and seawater.

PubMed

Booncharoen, Namfon; Mongkolsuk, Skorn; Sirikanchana, Kwanrawee

2018-07-01

Enterococcus faecalis bacteria have been recently reported for their ability to host bacteriophages that are specifically from human sewage, suggesting their application to track human fecal contamination in water resources. However, little is known about the survivability of sewage-specific enterococcal bacteriophages in various water matrices under ambient and storage conditions. In this study, bacteriophages that were derived from the Thailand-isolated E. faecalis strains AIM06 and SR14 exhibited morphologies consistent with the Siphoviridae, Podoviridae, and Myoviridae families. Four representative bacteriophages were separately spiked into environmental water samples (n = 7) comprising freshwater and seawater with low- and high-pollution (LF, HF, LS, and HS, respectively) levels, defined according to Thailand Water Quality Standards. All bacteriophages decayed fastest in HS or HF samples at 30 °C, reaching a 5-log 10 reduction in 2.2 to 9.8 days, and slowest in LS samples, requiring 8.8 to 23.5 days. The decay rates were 5 to 53 times lower at a storage temperature of 5 °C. HF samples could be stored for as little as 2.5 days to prevent the decay of 50% of the phages. Myoviridae phages decayed faster than Siphoviridae phages and Podoviridae phages in most water matrices at 30 °C. Moreover, the decay rates were 1.8 to 92 times slower in filtered samples, emphasizing a strong role for water constituents, i.e., suspended solids and natural microorganisms, in phage persistence. This study emphasized that differential enterococcal bacteriophage persistence should be considered when planning the monitoring and interpreting of fecal sources by microbial source tracking.

Attaining the canopy in dry and moist tropical forests: strong differences in tree growth trajectories reflect variation in growing conditions.

PubMed

Brienen, Roel J W; Zuidema, Pieter A; Martínez-Ramos, Miguel

2010-06-01

Availability of light and water differs between tropical moist and dry forests, with typically higher understorey light levels and lower water availability in the latter. Therefore, growth trajectories of juvenile trees--those that have not attained the canopy--are likely governed by temporal fluctuations in light availability in moist forests (suppressions and releases), and by spatial heterogeneity in water availability in dry forests. In this study, we compared juvenile growth trajectories of Cedrela odorata in a dry (Mexico) and a moist forest (Bolivia) using tree rings. We tested the following specific hypotheses: (1) moist forest juveniles show more and longer suppressions, and more and stronger releases; (2) moist forest juveniles exhibit wider variation in canopy accession pattern, i.e. the typical growth trajectory to the canopy; (3) growth variation among dry forest juveniles persists over longer time due to spatial heterogeneity in water availability. As expected, the proportion of suppressed juveniles was higher in moist than in dry forest (72 vs. 17%). Moist forest suppressions also lasted longer (9 vs. 5 years). The proportion of juveniles that experienced releases in moist forest (76%) was higher than in dry forest (41%), and releases in moist forests were much stronger. Trees in the moist forest also had a wider variation in canopy accession patterns compared to the dry forest. Our results also showed that growth variation among juvenile trees persisted over substantially longer periods of time in dry forest (>64 years) compared to moist forest (12 years), most probably because of larger persistent spatial variation in water availability. Our results suggest that periodic increases in light availability are more important for attaining the canopy in moist forests, and that spatial heterogeneity in water availability governs long-term tree growth in dry forests.

Organochlorine compounds in ice melt water from Italian Alpine rivers.

PubMed

Villa, Sara; Negrelli, Christian; Finizio, Antonio; Flora, Onelio; Vighi, Marco

2006-01-01

Organochlorine chemicals (OCs) (dichlorodiphenyltrichloroethanes, hexachlorocyclohexanes, and hexachlorobenzene) were measured in ice melt water from five glaciers in the Italian Alps. Even though the data collected may not be sufficient for a precise description of persistent organic pollutant release patterns from glacier melting, they have, however, highlighted the potential for surface water contamination. Concentrations were of the same order of magnitude in all glacial streams, indicating comparable contamination levels in different glaciers of the alpine region. OC levels in nonglacial springs sampled in the same areas are usually lower. Even if differences during the melting season (from spring to autumn) have been identified, a regular seasonal pattern in OC concentrations was not observed. Risk for the aquatic environment is excluded through direct water exposure, but it is likely to occur through biomagnification and secondary poisoning exposure.

Calculating the Diffusive Flux of Persistent Organic Pollutants between Sediments and the Water Column on the Palos Verdes Shelf Superfund Site using Polymeric Passive Samplers

EPA Science Inventory

Passive samplers were used to determine water concentrations of persistent organic pollutants (POPs) in the surface sediments and near-bottom water of a marine Superfund site on the Palos Verdes Shelf, California, USA. Measured concentrations in the porewater and water column at...

Seasonal persistence of marine-derived nutrients in south-central Alaskan salmon streams

USGS Publications Warehouse

Rinella, Daniel J.; Wipfi, Mark S.; Walker, Coowe M.; Stricker, Craig A.; Heintz, Ron A.

2013-01-01

Spawning salmon deliver annual pulses of marine-derived nutrients (MDN) to riverine ecosystems around the Pacific Rim, leading to increased growth and condition in aquatic and riparian biota. The influence of pulsed resources may last for extended periods of time when recipient food webs have effective storage mechanisms, yet few studies have tracked the seasonal persistence of MDN. With this as our goal, we sampled stream water chemistry and selected stream and riparian biota spring through fall at 18 stations (in six watersheds) that vary widely in spawner abundance and at nine stations (in three watersheds) where salmon runs were blocked by waterfalls. We then developed regression models that related dissolved nutrient concentrations and biochemical measures of MDN assimilation to localized spawner density across these 27 stations. Stream water ammonium-N and orthophosphate-P concentrations increased with spawner density during the summer salmon runs, but responses did not persist into the following fall. The effect of spawner density on δ15N in generalist macroinvertebrates and three independent MDN metrics (δ15N, δ34S, and ω3:ω6 fatty acids) in juvenile Dolly Varden (Salvelinus malma) was positive and similar during each season, indicating that MDN levels in biota increased with spawner abundance and were maintained for at least nine months after inputs. Delta 15N in a riparian plant, horsetail (Equisetum fluviatile), and scraper macroinvertebrates did not vary with spawner density in any season, suggesting a lack of MDN assimilation by these lower trophic levels. Our results demonstrate the ready assimilation of MDN by generalist consumers and the persistence of this pulsed subsidy in these organisms through the winter and into the next growing season.

Environmental signatures and effects of an oil and gas wastewater spill in the Williston Basin, North Dakota.

PubMed

Cozzarelli, I M; Skalak, K J; Kent, D B; Engle, M A; Benthem, A; Mumford, A C; Haase, K; Farag, A; Harper, D; Nagel, S C; Iwanowicz, L R; Orem, W H; Akob, D M; Jaeschke, J B; Galloway, J; Kohler, M; Stoliker, D L; Jolly, G D

2017-02-01

Wastewaters from oil and gas development pose largely unknown risks to environmental resources. In January 2015, 11.4ML (million liters) of wastewater (300g/L TDS) from oil production in the Williston Basin was reported to have leaked from a pipeline, spilling into Blacktail Creek, North Dakota. Geochemical and biological samples were collected in February and June 2015 to identify geochemical signatures of spilled wastewaters as well as biological responses along a 44-km river reach. February water samples had elevated chloride (1030mg/L) and bromide (7.8mg/L) downstream from the spill, compared to upstream levels (11mg/L and <0.4mg/L, respectively). Lithium (0.25mg/L), boron (1.75mg/L) and strontium (7.1mg/L) were present downstream at 5-10 times upstream concentrations. Light hydrocarbon measurements indicated a persistent thermogenic source of methane in the stream. Semi-volatile hydrocarbons indicative of oil were not detected in filtered samples but low levels, including tetramethylbenzenes and di-methylnaphthalenes, were detected in unfiltered water samples downstream from the spill. Labile sediment-bound barium and strontium concentrations (June 2015) were higher downstream from the Spill Site. Radium activities in sediment downstream from the Spill Site were up to 15 times the upstream activities and, combined with Sr isotope ratios, suggest contributions from the pipeline fluid and support the conclusion that elevated concentrations in Blacktail Creek water are from the leaking pipeline. Results from June 2015 demonstrate the persistence of wastewater effects in Blacktail Creek several months after remediation efforts started. Aquatic health effects were observed in June 2015; fish bioassays showed only 2.5% survival at 7.1km downstream from the spill compared to 89% at the upstream reference site. Additional potential biological impacts were indicated by estrogenic inhibition in downstream waters. Our findings demonstrate that environmental signatures from wastewater spills are persistent and create the potential for long-term environmental health effects. Published by Elsevier B.V.

Hydrogeology and water quality of areas with persistent ground- water contamination near Blackfoot, Bingham County, Idaho

USGS Publications Warehouse

Parliman, D.J.

1987-01-01

The Groveland-Collins area near Blackfoot, Idaho, has a history of either periodic or persistent localized groundwater contamination. Water users in the area report offensive smell, metallic taste, rust deposits, and bacteria in water supplies. During 1984 and 1985, data were collected to define regional and local geologic, hydrologic, and groundwater quality conditions, and to identify factors that may have affected local groundwater quality. Infiltration or leakage of irrigation water is the major source of groundwater recharge, and water levels may fluctuate 15 ft or more during the irrigation season. Groundwater movement is generally northwestward. Groundwater contains predominantly calcium, magnesium, and bicarbonate ions and characteristically has more than 200 mg/L hardness. Groundwater near the Groveland-Collins area may be contaminated from one or more sources, including infiltration of sewage effluent, gasoline or liquid fertilizer spillage, or land application of food processing wastewater. Subsurface basalt ridges impede lateral movement of water in localized areas. Groundwater pools temporarily behind these ridges and anomalously high water levels result. Maximum concentrations or values of constituents that indicate contamination were 1,450 microsiemens/cm specific conductance, 630 mg/L bicarbonate (as HCO3), 11 mg/L nitrite plus nitrate (as nitrogen), 7.3 mg/L ammonia (as nitrogen), 5.9 mg/L organic nitrogen, 4.4 mg/L dissolved organic carbon, 7,000 micrograms/L dissolved iron, 5 ,100 microgram/L dissolved manganese, and 320 microgram/L dissolved zinc. Dissolved oxygen concentrations ranged from 8.9 mg/L in uncontaminated areas to 0 mg/L in areas where food processing wastewater is applied to the land surface. Stable-isotope may be useful in differentiating between contamination from potato-processing wastewater and whey in areas where both are applied to the land surface. Development of a ground-water model to evaluate effects of land applications of organic wastewater and organic solute loading rates on subsurface water quality is not feasible at this time.

Level I water-quality inventory and monitoring, Richmond National Battlefield Park, Virginia

USGS Publications Warehouse

Moberg, Roger M.; Rice, Karen C.

2002-01-01

The U.S. Geological Survey conducted a Level I Water-Quality Inventory and Monitoring (WAQIM) data-collection effort for Richmond National Battlefield Park (Richmond NBP) from August 2001 through April 2002. The primary objective of the WAQIM program was to provide the National Park Service (NPS) and Richmond NBP with at least a nominal inventory of its natural resources and to provide those data in a data-management system consistent with park management needs. Water-quality inventory data (physical, chemical, and biological) were collected from "key" water bodies within the boundaries of Richmond NBP. The key water bodies are those waters within park boundaries that are essential to the central cultural, historical or natural resources management themes of the parks or provide habitats to threatened or endangered plants and animals. Data were collected during the fall, winter, spring, and summer over a range of hydrologic conditions. Because of the drought conditions that persisted during the study period, variations in flow between seasons were less pronounced than during normal hydrologic conditions.

Some physiological consequences of handling stress in the juvenile coho salmon (Oncorhynchus kisutch) and steelhead trout (Salmo gairdneri)

USGS Publications Warehouse

Wedemeyer, Gary

1972-01-01

The stress of handling juvenile coho salmon (Oncorhynchus kisutch) and steelhead trout (Salmo gairdneri) in soft water and in water with added salts was evaluated using blood and tissue chemistry fluctuations as indices of metabolic and endocrine function. Changes in plasma glucose, chloride, calcium, and cholesterol levels indicated that significant osmoregulatory and metabolic dysfunctions can occur and persist for about 24 hr after handling in soft water. Pituitary activation, as judged by lack of interrenal ascorbate depletion, did not occur. Increasing the ambient NaCl and Ca++ levels to about 100 milliosmols and 75–120 ppm, respectively, partially or completely alleviated the hyperglycemia and hypochloremia indicating that the stress of handling had been reduced.

Decay of Bacteroidales genetic markers in relation to traditional fecal indicators for water quality modeling of drinking water sources.

PubMed

Sokolova, Ekaterina; Aström, Johan; Pettersson, Thomas J R; Bergstedt, Olof; Hermansson, Malte

2012-01-17

The implementation of microbial fecal source tracking (MST) methods in drinking water management is limited by the lack of knowledge on the transport and decay of host-specific genetic markers in water sources. To address these limitations, the decay and transport of human (BacH) and ruminant (BacR) fecal Bacteroidales 16S rRNA genetic markers in a drinking water source (Lake Rådasjön in Sweden) were simulated using a microbiological model coupled to a three-dimensional hydrodynamic model. The microbiological model was calibrated using data from outdoor microcosm trials performed in March, August, and November 2010 to determine the decay of BacH and BacR markers in relation to traditional fecal indicators. The microcosm trials indicated that the persistence of BacH and BacR in the microcosms was not significantly different from the persistence of traditional fecal indicators. The modeling of BacH and BacR transport within the lake illustrated that the highest levels of genetic markers at the raw water intakes were associated with human fecal sources (on-site sewers and emergency sewer overflow). This novel modeling approach improves the interpretation of MST data, especially when fecal pollution from the same host group is released into the water source from different sites in the catchment.

Effects of Irrigation, Drought, and Ground-Water Withdrawals on Ground-Water Levels in the Southern Lihue Basin, Kauai, Hawaii

USGS Publications Warehouse

Izuka, Scot K.

2006-01-01

A numerical ground-water-flow model was used to investigate the effects of irrigation on ground-water levels in the southern Lihue Basin, Kauai, Hawaii, and the relation between declining ground-water levels observed in the basin in the 1990s and early 2000s and concurrent drought, irrigation reduction, and changes in ground-water withdrawal. Results of steady-state model simulations indicate that changing from pre-development to 1981 irrigation and ground-water-withdrawal conditions could, given enough time for steady state to be achieved, raise ground-water levels in some areas of the southern Lihue Basin by as much as 200 feet, and that changing from 1981 to 1998 irrigation and ground-water-withdrawal conditions could lower ground-water levels in some areas by as much as 100 feet. Transient simulations combining drought, irrigation reduction, and changes in ground-water withdrawal show trends that correspond with those observed in measured water levels. Results of this study indicate that irrigation reduction was the primary cause of the observed decline in ground-water-levels. In contrast, ground-water withdrawal had a long-duration but small-magnitude effect, and drought had a widespread, high-magnitude but short-duration effect. Inasmuch as irrigation in the future is unlikely to return to the same levels as during the period of peak sugarcane agriculture, the decline in ground-water levels resulting from the reduction and ultimate end of sugarcane irrigation can be considered permanent. Assuming that irrigation does not return to the southern Lihue Basin and that, on average, normal rainfall persists and ground-water withdrawal remains at 1998 rates, model projections indicate that average ground-water levels in the Kilohana-Puhi area will continue to recover from the drought of 1998-2002 and eventually rise to within about 4 feet of the pre-drought conditions. Long-term climate trends, increases in ground-water withdrawal, or other factors not simulated in the model could also affect ground-water levels in the southern Lihue Basin in the future.

Relation of drainage problems to high ground-water levels, Coconut Grove area, Oahu, Hawaii

USGS Publications Warehouse

Swain, L.A.; Huxel, C.J.

1971-01-01

Purpose and Scope In 1969, hydrologic data-collection sites were established in and around the Coconut Grove area for the purpose of measuring directly the relationship between rainfall, runoff, ground-water levels, the level of water in Kawainui Swamp and the canals, and tidal fluctuations. The primary objective was to identify the causes of the occurrence and persistence of flooding and to gain data on which to base recommendations for remedial action. The scope of the study included establishing and operating flow and stage-recording gages on the Swamp, Kawainui Canal, and the inner canal; periodic and repeated measurements of ground-water level in test borings throughout the residential area; collection and analysis of soil and construction borings made for engineering purposes; the assembly and analysis of all available data relating surface and subsurface flow conditions, and the development of conclusions as to the causes and means to alleviate the flooding. This report summarizes the information collected from October 1969 to June 1971, includes analysis of the data, and discusses the probable causes of flooding.

The deep-sea as a final global sink of semivolatile persistent organic pollutants? Part I: PCBs in surface and deep-sea dwelling fish of the north and south Atlantic and the Monterey Bay Canyon (California).

PubMed

Froescheis, O; Looser, R; Cailliet, G M; Jarman, W M; Ballschmiter, K

2000-03-01

The understanding of the global environmental multiphase distribution of persistent organic pollutants (POPs) as a result of the physico-chemical properties of the respective compounds is well established. We have analysed the results of a vertical transport of POPs from upper water layers (0-200 m) to the deepwater region (> 800 m) in terms of the contamination of the biophase in both water layers. The contents of persistent organochlorine compounds like polychlorinated biphenyls (PCBs) in fish living in the upper water layers of the North Atlantic and the South Atlantic, and at the continental shelf of California (Marine Sanctuary Monterey Bay and its deep-sea Canyon) are compared to the levels in deep-sea or bottom dwelling fish within the same geographic area. The deep-sea biota show significantly higher burdens as compared to surface-living species of the same region. There are also indications for recycling processes of POPs--in this case the PCBs--in the biophase of the abyss as well. It can be concluded that the bio- and geo phase of the deep-sea may act similarly as the upper horizons of forest and grasslands on the continents as an ultimate global sink for POPs in the marine environment.

Aquatic insects as Bioindicators of land Use Change in the Grand Traverse Bay Area of Michigan

Treesearch

Robert A. Haack; Toby R. Petrice; Sheridan K. Haack; David Hyndman; David Long; Bryan Pijanowski

2000-01-01

In 1996, the US-Canadian International Joint Commission identified five key stresses impacting the Great Lakes Basin Ecosystem: nutrient inputs (e.g., phosphorous and nitrogen), persistent toxic substances, physical alterations (e.g., sedimentation, infiltration, runoff, water levels), human activities and values (as manifested in land-use change, populations growth,...

Examining Influence of Fog and Stratus Clouds on Bishop Pine Water Budgets, Channel Islands, CA

NASA Astrophysics Data System (ADS)

Fischer, D. T.; Still, C. J.; Williams, A. P.

2004-12-01

We present the first results from a project whose goal is to advance our basic understanding of the role that fog and persistent stratus clouds play in ecological processes in the California Channel Islands. Our work is focused on a population of Bishop Pines (Pinus muricata) on Santa Cruz Island (SCI), the largest, most topographically complex and most biologically diverse island along the California coast. This is the southernmost population (except for an outlier stand near San Vicente, Baja California), and tree growth appears to be water-limited in such a marginal habitat. We hypothesize that persistent fog and low stratus clouds enhance the water balance of these trees via direct water inputs (fog drip and foliar absorption) and reduced solar heating. To assess these possible effects, we have established weather stations and fog and rain collectors throughout the largest Bishop pine stand on SCI. Initial analysis of weather data shows dramatic differences in solar loading over short distances. We present data on the isotopic content (oxygen-18 and hydrogen-2) of water samples collected from winter 2003 to summer 2004. The samples we collected include fogwater, rainfall, water vapor, soil water, leaf and xylem water, and stream water. We also collected and analyzed leaf biomass and soil organic matter samples at periodic intervals for carbon-13 content. These latter data are evaluated in light of extensive leaf-level ecophysiological data collected in the field and as part of a parallel greenhouse study.

Bacteria in beach sands: an emerging challenge in protecting coastal water quality and bather health

PubMed Central

Gast, Rebecca J.

2011-01-01

To protect bather health at recreational beaches, fecal indicator bacterial standards are used to monitor water quality, and waters exceeding the standards are subsequently closed to bathers. However beachgoers are also in contact with beach sands, the sanitary quality of which is not included within beach monitoring programs. In fact, sands and sediments provide habitat where fecal bacterial populations may persist, and in some cases grow, in the coastal zone. Specific pathogens are less well studied in beach sands and sediments, but there is a body of evidence that they too may persist in these environments. This paper reviews the current state of knowledge regarding the abundance and distribution of fecal indicator bacteria and pathogens in beach sands of diverse climatological regions, and at beaches subjected to varied levels of anthropogenic impact. In all regions fecal indicator bacteria are nearly ubiquitous in beach sands, and similar relationships emerge between fecal indicator abundance in dry sand, submerged sands, and water. Taken together, these studies contextualize a potential public health issue and identify research questions that must be addressed in order to support future policy decisions. PMID:21162561

Persistence behavior of metamifop and its metabolite in rice ecosystem.

PubMed

Barik, Suhrid Ranjan; Ganguly, Pritam; Patra, Sandip; Dutta, Swaraj Kumar; Goon, Arnab; Bhattacharyya, Anjan

2018-02-01

A field experiment was conducted to determine the persistence of metamifop in transplanted rice crop for two seasons. Metamifop 10% EC was applied at two doses: 100 g a.i. ha -1 and 200 g a.i. ha -1 at 2-3 leaf stage of Echinochloa crusgalli. The residues of metamifop along with its major metabolite, N-(2-fluorophenyl)-2-hydroxy-N-methylpropionamide (HFMPA), were estimated in rice plant, field water and soil using Liquid Chromatography Mass Spectrometry. Limit of detection and limit of quantification of the method for both the compounds were set at 0.003 μg g -1 and 0.010 μg g -1 respectively. Metamifop showed less persistence in field water and rice plant as compared to soil samples. Presence of HFMPA was recorded in rice plant and soil. Both the compounds were found below level of quantification in harvest samples of straw, grains, husk and soil. A safe waiting period of 52 d was suggested for harvesting of rice when metamifop was applied at 100 g a.i. ha -1 (recommended dose). Copyright © 2017 Elsevier Ltd. All rights reserved.

Concentration of organic contaminants in fish and their biological effects in a wastewater-dominated urban stream

USGS Publications Warehouse

Lozano, Nuria; Rice, Clifford P.; Pagano, James; Zintek, Larry; Barber, Larry B.; Murphy, Elizabeth W.; Nettesheim, Todd G.; Minarik, Thomas A.; Schoenfuss, Heiko L.

2012-01-01

Data are presented on the concentrations of alkylphenol and alkylphenol ethoxylates (APEs) and persistent organic compounds in largemouth bass collected from a waste-water dominated stream in downtown Chicago. The fish residue concentrations of APEs are compared to concentrations of the APEs in the water that were collected at weekly intervals over two months bracketing the fall (2006) and a spring (2007) fish collection. The concentrations of APEs were significantly higher in the spring-collected fish (5.42 μg/g) versus the fall (0.99 μg/g) tand these differences were shared by differences in the water concentrations (spring — 11.47 versus fall — 3.44 μg/L). The differences in water concentration were negatively correlated with water temperatures observed over the two sampling times. Fish residue concentrations of persistent organic compounds (PCBs, PBDEs, toxaphene, and many legacy pesticides including the DDT family) did not vary from fall to spring. Some of these residue concentrations were comparable to the highest NPE (nonylphenol ethoxylate) homologue concentrations, e.g. NP1EO was 3.5 μg/g in the bass for the spring, the PBDE-congener 47 and p,p′-DDE averaged 1.0 μg/g and 0.5 μg/g, respectively, over both seasons. All the other persistent single-analyte concentrations were lower. Biological endpoints for endocrine effects measured in the same fish showed that there was an apparent positive correlation for physiological effects based on increased vitellogenin levels in males versus concentration of NPEs; however there were no observable histological differences in fall versus spring fish samples.

Perchlorate: Health Effects and Technologies for Its Removal from Water Resources

PubMed Central

Srinivasan, Asha; Viraraghavan, Thiruvenkatachari

2009-01-01

Perchlorate has been found in drinking water and surface waters in the United States and Canada. It is primarily associated with release from defense and military operations. Natural sources include certain fertilizers and potash ores. Although it is a strong oxidant, perchlorate is very persistent in the environment. At high concentrations perchlorate can affect the thyroid gland by inhibiting the uptake of iodine. A maximum contaminant level has not been set, while a guidance value of 6 ppb has been suggested by Health Canada. Perchlorate is measured in environmental samples primarily by ion chromatography. It can be removed from water by anion exchange or membrane filtration. Biological and chemical processes are also effective in removing this species from water. PMID:19440526

Differences in biofilm formation of produce and poultry Salmonella enterica isolates and their persistence on spinach plants

USDA-ARS?s Scientific Manuscript database

Repeat irrigation of spinach plants with water containing Salmonella was used to determine Salmonella persistence on spinach leaves. Spinach plants were irrigated four times (biweekly) with water containing ca. 2.1 log CFU Salmonella per 100 ml water (the maximum generic E. coli MPN recommended by...

Use of a storm water retention system for conservation of regionally endangered fishes

USGS Publications Warehouse

Schaeffer, Jeffrey S.; Bland, James K.; Janssen, John

2012-01-01

Maintaining aquatic biodiversity in urban or suburban areas can be problematic because urban landscapes can be nearly devoid of aquatic habitats other than engineered basins for storm water management. These areas are usually of questionable value for fish, but we examined a case study in which five regionally imperiled fish species were reintroduced into an artificial storm water detention pond and subsequently thrived. Although not a formal experiment, postintroduction survey data suggested that three of the five species maintained high population densities for 10 years after initial stocking, and two persisted in lower numbers. Success was likely due to a combination of unique design features and prior habitat preparation that resulted in clear water conditions that supported dense vegetation. Stocked fish persisted despite occasional bouts of low dissolved oxygen and increased chloride levels resulting from road salt application within the watershed. Transplanted fish served as a source population for both research and further reintroduction experiments. We suggest that, for some fish species, habitat preservation has a middle ground between natural habitats and completely artificial environments that require constant husbandry and that storm water systems could be used to create engineered sanctuaries within the human landscape that have many potential benefits for both humans and fish.

A water availability gradient reveals the deficit level required to affect traits in potted juvenile Eucalyptus globulus

PubMed Central

Potts, Brad M.; Hovenden, Mark J.; Brodribb, Timothy J.; Davies, Noel W.; Rodemann, Thomas; McAdam, Scott A. M.; O’Reilly-Wapstra, Julianne M.

2017-01-01

Background and aims Drought leading to soil water deficit can have severe impacts on plants. Water deficit may lead to plant water stress and affect growth and chemical traits. Plant secondary metabolite (PSM) responses to water deficit vary between compounds and studies, with inconsistent reports of changes to PSM concentrations even within a single species. This disparity may result from experimental water deficit variation among studies, and so multiple water deficit treatments are used to fully assess PSM responses in a single species. Methods Juvenile Eucalyptus globulus were grown for 8 weeks at one of ten water deficit levels based on evapotranspiration from control plants (100 %). Treatments ranged from 90 % of control evapotranspiration (mild water deficit) to 0 % of control evapotranspiration (severe water deficit) in 10 % steps. Plant biomass, foliar abscisic acid (ABA) levels, Ψleaf, leaf C/N, selected terpenes and phenolics were quantified to assess responses to each level of water deficit relative to a control. Key Results Withholding ≥30 % water resulted in higher foliar ABA levels and withholding ≥40 % water reduced leaf water content. Ψleaf became more negative when ≥60 % water was withheld. Plant biomass was lower when ≥80 % water was withheld, and no water for 8 weeks (0 % water) resulted in plant death. The total oil concentration was lower and C/N was higher in dead and desiccated juvenile E. globulus leaves (0 % water). Concentrations of individual phenolic and terpene compounds, along with condensed tannin and total phenolic concentrations, remained stable regardless of water deficit or plant stress level. Conclusions These juvenile E. globulus became stressed with a moderate reduction in available water, and yet the persistent concentrations of most PSMs in highly stressed or dead plants suggests no PSM re-metabolization and continued ecological roles of foliar PSMs during drought. PMID:28073772

Current status of persistent organic pesticides residues in air, water, and soil, and their possible effect on neighboring countries: a comprehensive review of India.

PubMed

Yadav, Ishwar Chandra; Devi, Ningombam Linthoingambi; Syed, Jabir Hussain; Cheng, Zhineng; Li, Jun; Zhang, Gan; Jones, Kevin C

2015-04-01

Though the use of pesticides has offered significant economic benefits by enhancing the production and yield of food and fibers and the prevention of vector-borne diseases, evidence suggests that their use has adversely affected the health of human populations and the environment. Pesticides have been widely distributed and their traces can be detected in all areas of the environment (air, water and soil). Despite the ban of DDT and HCH in India, they are still in use, both in domestic and agricultural settings. In this comprehensive review, we discuss the production and consumption of persistent organic pesticides, their maximum residual limit (MRL) and the presence of persistent organic pesticides in multicomponent environmental samples (air, water and soil) from India. In order to highlight the global distribution of persistent organic pesticides and their impact on neighboring countries and regions, the role of persistent organic pesticides in Indian region is reviewed. Based on a review of research papers and modeling simulations, it can be concluded that India is one of the major contributors of global persistent organic pesticide distribution. This review also considers the health impacts of persistent organic pesticides, the regulatory measures for persistent organic pesticides, and the status of India's commitment towards the elimination of persistent organic pesticides. Copyright © 2014 Elsevier B.V. All rights reserved.

Improving regional climate and hydrological forecasting following the record setting flooding across the Lake Ontario - St. Lawrence River system

NASA Astrophysics Data System (ADS)

Gronewold, A.; Seglenieks, F.; Bruxer, J.; Fortin, V.; Noel, J.

2017-12-01

In the spring of 2017, water levels across Lake Ontario and the upper St. Lawrence River exceeded record high levels, leading to widespread flooding, damage to property, and controversy over regional dam operating protocols. Only a few years earlier, water levels on Lakes Superior, Michigan, and Huron (upstream of Lake Ontario) had dropped to record low levels leading to speculation that either anthropogenic controls or climate change were leading to chronic water loss from the Great Lakes. The contrast between low water level conditions across Earth's largest lake system from the late 1990s through 2013, and the rapid rise prior to the flooding in early 2017, underscores the challenges of quantifying and forecasting hydrologic impacts of rising regional air and water temperatures (and associated changes in lake evaporation) and persistent increases in long-term precipitation. Here, we assess the hydrologic conditions leading to the recent record flooding across the Lake Ontario - St. Lawrence River system, with a particular emphasis on understanding the extent to which those conditions were consistent with observed and anticipated changes in historical and future climate, and the extent to which those conditions could have been anticipated through improvements in seasonal climate outlooks and hydrological forecasts.

Extensive Liquid Meltwater Storage in Firn Within the Greenland Ice Sheet

NASA Technical Reports Server (NTRS)

Forster, Richard R.; Box, Jason E.; vandenBroeke, Michael R.; Miege, Clement; Burgess, Evan W.; vanAngelen, Jan H.; Lenaerts, Jan T. M.; Koenig, Lora S.; Paden, John; Lewis, Cameron;

Combination of Heat Shock and Enhanced Thermal Regime to Control the Growth of a Persistent Legionella pneumophila Strain

PubMed Central

Bédard, Emilie; Boppe, Inès; Kouamé, Serge; Martin, Philippe; Pinsonneault, Linda; Valiquette, Louis; Racine, Jules; Prévost, Michèle

2016-01-01

Following nosocomial cases of Legionella pneumophila, the investigation of a hot water system revealed that 81.5% of sampled taps were positive for L. pneumophila, despite the presence of protective levels of copper in the water. A significant reduction of L. pneumophila counts was observed by culture after heat shock disinfection. The following corrective measures were implemented to control L. pneumophila: increasing the hot water temperature (55 to 60 °C), flushing taps weekly with hot water, removing excess lengths of piping and maintaining a water temperature of 55 °C throughout the system. A gradual reduction in L. pneumophila counts was observed using the culture method and qPCR in the 18 months after implementation of the corrective measures. However, low level contamination was retained in areas with hydraulic deficiencies, highlighting the importance of maintaining a good thermal regime at all points within the system to control the population of L. pneumophila. PMID:27092528

Alkylphenols and alkylphenol ethoxylates, PBDEs, PCBs and chlorinated pesticides in largemouth bass from North Shore Channel of the Chicago River, Illinois

USDA-ARS?s Scientific Manuscript database

Fall 2006 and Spring 2007 samples of fish, water and effluent (Chicago Northside Water Reclamation Plant) were collected and analyzed for several persistent and semi-persistent chemicals that are believed to be significantly loading into the North Branch of the Chicago River from the Northside Water...

Disinfection of human enteric viruses in water by copper and silver in combination with low levels of chlorine.

PubMed Central

Abad, F X; Pintó, R M; Diez, J M; Bosch, A

1994-01-01

The efficacy of copper and silver ions, in combination with low levels of free chlorine (FC), was evaluated for the disinfection of hepatitis A virus (HAV), human rotavirus (HRV), human adenovirus, and poliovirus (PV) in water. HAV and HRV showed little inactivation in all conditions. PV showed more than a 4 log10 titer reduction in the presence of copper and silver combined with 0.5 mg of FC per liter or in the presence of 1 mg of FC per liter alone. Human adenovirus persisted longer than PV with the same treatments, although it persisted significantly less than HRV or HAV. The addition of 700 micrograms of copper and 70 micrograms of silver per liter did not enhance the inactivation rates after the exposure to 0.5 or 0.2 mg of FC per liter, although on some occasions it produced a level of inactivation similar to that induced by a higher dose of FC alone. Virus aggregates were observed in the presence of copper and silver ions, although not in the presence of FC alone. Our data indicate that the use of copper and silver ions in water systems may not provide a reliable alternative to high levels of FC for the disinfection of viral pathogens. Gene probe-based procedures were not adequate to monitor the presence of infectious HAV after disinfection. PV does not appear to be an adequate model viral strain to be used in disinfection studies. Bacteroides fragilis bacteriophages were consistently more resistant to disinfection than PV, suggesting that they would be more suitable indicators, although they survived significantly less than HAV or HRV. Images PMID:8074518

Viral persistence in surface and drinking water: Suitability of PCR pre-treatment with intercalating dyes.

PubMed

Prevost, B; Goulet, M; Lucas, F S; Joyeux, M; Moulin, L; Wurtzer, S

2016-03-15

After many outbreaks of enteric virus associated with consumption of drinking water, the study of enteric viruses in water has increased significantly in recent years. In order to better understand the dynamics of enteric viruses in environmental water and the associated viral risk, it is necessary to estimate viral persistence in different conditions. In this study, two representative models of human enteric viruses, adenovirus 41 (AdV 41) and coxsackievirus B2 (CV-B2), were used to evaluate the persistence of enteric viruses in environmental water. The persistence of infectious particles, encapsidated genomes and free nucleic acids of AdV 41 and CV-B2 was evaluated in drinking water and surface water at different temperatures (4 °C, 20 °C and 37 °C). The infectivity of AdV 41 and CV-B2 persisted for at least 25 days, whatever the water temperature, and for more than 70 days at 4 °C and 20 °C, in both drinking and surface water. Encapsidated genomes persisted beyond 70 days, whatever the water temperature. Free nucleic acids (i.e. without capsid) also were able to persist for at least 16 days in drinking and surface water. The usefulness of a detection method based on an intercalating dye pre-treatment, which specifically targets preserved particles, was investigated for the discrimination of free and encapsidated genomes and it was compared to virus infectivity. Further, the resistance of AdV 41 and CV-B2 against two major disinfection treatments applied in drinking water plants (UV and chlorination) was evaluated. Even after the application of UV rays and chlorine at high doses (400 mJ/cm(2) and 10 mg.min/L, respectively), viral genomes were still detected with molecular biology methods. Although the intercalating dye pre-treatment had little use for the detection of the effects of UV treatment, it was useful in the case of treatment by chlorination and less than 1 log10 difference in the results was found as compared to the infectivity measurements. Finally, for the first time, the suitability of intercalating dye pre-treatment for the estimation of the quality of the water produced by treatment plants was demonstrated using samples from four drinking-water plants and two rivers. Although 55% (27/49) of drinking water samples were positive for enteric viruses using molecular detection, none of the samples were positive when the intercalating dye pre-treatment method was used. This could indicate that the viruses that were detected are not infectious. Copyright © 2016 Elsevier Ltd. All rights reserved.

Persistence and distribution of 4-nonylphenol following repeated application to littoral enclosures

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

Heinis, L.J.; Liber, K.; Tunell, R.L.

1999-03-01

The persistence and distribution of 4-nonylphenol (NP) were monitored for 440 d, following application to 18 littoral enclosures situated in a 2-ha mesotrophic pond near Duluth, Minnesota. Application was accomplished by subsurface, gravity-fed injection over a 20-d period, with a 2-d frequency, to achieve nominal aqueous concentrations of 0, 3, 30, 100, and 300 {micro}g/L. Mean maximum concentrations in the water over the 20-d application period ranged from 75.7 to 81.0% of nominal for the three highest treatment levels and was 181% of nominal at the lowest treatment level. Water was the major compartment, on a mass balance basis, formore » NP until 2 to 4 d after the application period, with a mean time to 50% dissipation (DT50) of 0.74 d and a mean time to 95% dissipation (DT95) of 13.8 d. 4-Nonylphenol partitioned to enclosure wall material, macrophytes, and sediment within 2 d of initial application. Macrophytes accumulated maximum NP concentrations of 11.5 and 139 mg/kg 1 to 2 d after the application period at the 30- and 300-{micro}g/L treatment levels, respectively. Mean DT50 and DT95 estimates of NP persistence in/on the macrophytes were 10.3 and 189 d, respectively. Sediment from the 30- and 300-{micro}g/L treatments accumulated maximum dry weight NP concentrations of 2.74 and 27.4 mg/kg, respectively within 20 to 48 d of the first application. The mean sediment porewater NP concentration was 18.6 {micro}g/L for the period 2 to 34 d after application 1 at the 300-{micro}g/L treatment. The sediment was the primary sink for NP 440 d after the initial application with a concentration of 1.97 mg/kg at the 300-{micro}g/L treatment. Mean sediment DT50 and DT95 values were 66.0 and 401 d, respectively, indicating a long-term persistence of NP. Ecocores collected 1 d after the final NP application did not show significant decreases in sediment NP concentration during a 55-d incubation period, corroborating the NP persistence observed in the littoral enclosures.« less

Basalt weathering rates on Earth and the duration of liquid water on the plains of Gusev Crater, Mars

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

Steefel, Carl; Hausrath, E.M.; Navarre-Sitchler, A.K.

2008-03-15

Where Martian rocks have been exposed to liquid water, chemistry versus depth profiles could elucidate both Martian climate history and potential for life. The persistence of primary minerals in weathered profiles constrains the exposure time to liquid water: on Earth, mineral persistence times range from {approx}10 ka (olivine) to {approx}250 ka (glass) to {approx}1Ma (pyroxene) to {approx}5Ma (plagioclase). Such persistence times suggest mineral persistence minima on Mars. However, Martian solutions may have been more acidic than on Earth. Relative mineral weathering rates observed for basalt in Svalbard (Norway) and Costa Rica demonstrate that laboratory pH trends can be used tomore » estimate exposure to liquid water both qualitatively (mineral absence or presence) and quantitatively (using reactive transport models). Qualitatively, if the Martian solution pH > {approx}2, glass should persist longer than olivine; therefore, persistence of glass may be a pH-indicator. With evidence for the pH of weathering, the reactive transport code CrunchFlow can quantitatively calculate the minimum duration of exposure to liquid water consistent with a chemical profile. For the profile measured on the surface of Humphrey in Gusev Crater, the minimum exposure time is 22 ka. If correct, this estimate is consistent with short-term, episodic alteration accompanied by ongoing surface erosion. More of these depth profiles should be measured to illuminate the weathering history of Mars.« less

Water level and strain changes preceding and following the August 4, 1985 Kettleman Hills, California, earthquake

USGS Publications Warehouse

Roeloffs, E.; Quilty, E.

1997-01-01

Two of the four wells monitored near Parkfield, California, during 1985 showed water level rises beginning three days before the M4 6.1 Kettleman Hills earthquake. In one of these wells, the 3.0 cm rise was nearly unique in five years of water level data. However, in the other well, which showed a 3.8 cm rise, many other changes of comparable size have been observed. Both wells that did not display pre-earthquake rises tap partially confined aquifers that cannot sustain pressure changes due to tectonic strain having periods longer than several days. We evaluate the effect of partial aquifer confinement on the ability of these four wells to display water level changes in response to aquifer strain. Although the vertical hydraulic diffusivities cannot be determined uniquely, we can find a value of diffusivity for each site that is consistent with the site's tidal and barometric responses as well as with the rate of partial recovery of the coseismic water level drops. Furthermore, the diffusivity for one well is high enough to explain why the preseismic rise could not have been detected there. For the fourth well, the diffusivity is high enough to have reduced the size of the preseismic signal as much as 50%, although it should still have been detectable. Imperfect confinement cannot explain the persistent water level changes in the two partially confined aquifers, but it does show that they were not due to volume strain. The pre-earthquake water level rises may have been precursors to the Kettleman Hills earthquake. If so, they probably were not caused by accelerating slip over the part of the fault plane that ruptured in that earthquake because they are of opposite sign to the observed coseismic water level drops.

Key scientific issues in developing drinking water guidelines for perfluoroalkyl acids: Contaminants of emerging concern.

PubMed

Post, Gloria B; Gleason, Jessie A; Cooper, Keith R

2017-12-01

Perfluoroalkyl acids (PFAAs), a group of synthetic organic chemicals with industrial and commercial uses, are of current concern because of increasing awareness of their presence in drinking water and their potential to cause adverse health effects. PFAAs are distinctive among persistent, bioaccumulative, and toxic (PBT) contaminants because they are water soluble and do not break down in the environment. This commentary discusses scientific and risk assessment issues that impact the development of drinking water guidelines for PFAAs, including choice of toxicological endpoints, uncertainty factors, and exposure assumptions used as their basis. In experimental animals, PFAAs cause toxicity to the liver, the immune, endocrine, and male reproductive systems, and the developing fetus and neonate. Low-dose effects include persistent delays in mammary gland development (perfluorooctanoic acid; PFOA) and suppression of immune response (perfluorooctane sulfonate; PFOS). In humans, even general population level exposures to some PFAAs are associated with health effects such as increased serum lipids and liver enzymes, decreased vaccine response, and decreased birth weight. Ongoing exposures to even relatively low drinking water concentrations of long-chain PFAAs substantially increase human body burdens, which remain elevated for many years after exposure ends. Notably, infants are a sensitive subpopulation for PFAA's developmental effects and receive higher exposures than adults from the same drinking water source. This information, as well as emerging data from future studies, should be considered in the development of health-protective and scientifically sound guidelines for PFAAs in drinking water.

Key scientific issues in developing drinking water guidelines for perfluoroalkyl acids: Contaminants of emerging concern

PubMed Central

Gleason, Jessie A.; Cooper, Keith R.

2017-01-01

Perfluoroalkyl acids (PFAAs), a group of synthetic organic chemicals with industrial and commercial uses, are of current concern because of increasing awareness of their presence in drinking water and their potential to cause adverse health effects. PFAAs are distinctive among persistent, bioaccumulative, and toxic (PBT) contaminants because they are water soluble and do not break down in the environment. This commentary discusses scientific and risk assessment issues that impact the development of drinking water guidelines for PFAAs, including choice of toxicological endpoints, uncertainty factors, and exposure assumptions used as their basis. In experimental animals, PFAAs cause toxicity to the liver, the immune, endocrine, and male reproductive systems, and the developing fetus and neonate. Low-dose effects include persistent delays in mammary gland development (perfluorooctanoic acid; PFOA) and suppression of immune response (perfluorooctane sulfonate; PFOS). In humans, even general population level exposures to some PFAAs are associated with health effects such as increased serum lipids and liver enzymes, decreased vaccine response, and decreased birth weight. Ongoing exposures to even relatively low drinking water concentrations of long-chain PFAAs substantially increase human body burdens, which remain elevated for many years after exposure ends. Notably, infants are a sensitive subpopulation for PFAA’s developmental effects and receive higher exposures than adults from the same drinking water source. This information, as well as emerging data from future studies, should be considered in the development of health-protective and scientifically sound guidelines for PFAAs in drinking water. PMID:29261653

Holocene climate variability and anthropogenic impacts from Lago Paixban, a perennial wetland in Peten, Guatemala

USGS Publications Warehouse

Wahl, David B.; Hansen, Richard D.; Byrne, Roger; Anderson, Lysanna; Schreiner, T.

2016-01-01

Analyses of an ~ 6 m sediment core from Lago Paixban in Peten, Guatemala, document the complex evolution of a perennial wetland over the last 10,300 years. The basal sediment is comprised of alluvial/colluvial fill deposited in the early Holocene. The absence of pollen and gastropods in the basal sediments suggests intermittently dry conditions until ~ 9000 cal yr. BP (henceforth BP) when the basin began to hold water perennially. Lowland tropical forest taxa dominated the local vegetation at this time. A distinct band of carbonate dating to ~ 8200 BP suggests regionally dry conditions, possibly associated with the 8.2 ka event. Wetter conditions during the Holocene Thermal Maximum are indicated by evidence of a raised water level and an open water lake. The timing of this interval coincides with strengthening of the Central American Monsoon. An abrupt change at 5500 BP involved the development of a sawgrass marsh and onset of peat deposition. The lowest recorded water levels date to 5500–4500 BP. Pollen, isotope, geochemical, and sedimentological data indicate that the coring site was near the edge of the marsh during this period. A rise in the water table after 4500 BP persisted until around 3500 BP. Clay marl deposition from 3500 to 210 BP corresponds to the period of Maya settlement. An increase in δ13C, the presence of Zea pollen, and a reduction in the percentage of forest taxa pollen indicate agricultural activity at this time. In contrast to several nearby paleoenvironmental studies, proxy evidence from Lago Paixban indicates human presence through the Classic/Postclassic period transition (~ 1000 BP) and persisting until the arrival of Europeans. Cessation of human activity around 210 BP resulted in local afforestation and the re-establishment of the current sawgrass marsh at Lago Paixban.

Holocene climate variability and anthropogenic impacts from Lago Paixban, a perennial wetland in Peten, Guatemala

NASA Astrophysics Data System (ADS)

Wahl, David; Hansen, Richard D.; Byrne, Roger; Anderson, Lysanna; Schreiner, Thomas

2016-03-01

Analyses of an 6 m sediment core from Lago Paixban in Peten, Guatemala, document the complex evolution of a perennial wetland over the last 10,300 years. The basal sediment is comprised of alluvial/colluvial fill deposited in the early Holocene. The absence of pollen and gastropods in the basal sediments suggests intermittently dry conditions until 9000 cal yr. BP (henceforth BP) when the basin began to hold water perennially. Lowland tropical forest taxa dominated the local vegetation at this time. A distinct band of carbonate dating to 8200 BP suggests regionally dry conditions, possibly associated with the 8.2 ka event. Wetter conditions during the Holocene Thermal Maximum are indicated by evidence of a raised water level and an open water lake. The timing of this interval coincides with strengthening of the Central American Monsoon. An abrupt change at 5500 BP involved the development of a sawgrass marsh and onset of peat deposition. The lowest recorded water levels date to 5500-4500 BP. Pollen, isotope, geochemical, and sedimentological data indicate that the coring site was near the edge of the marsh during this period. A rise in the water table after 4500 BP persisted until around 3500 BP. Clay marl deposition from 3500 to 210 BP corresponds to the period of Maya settlement. An increase in δ13C, the presence of Zea pollen, and a reduction in the percentage of forest taxa pollen indicate agricultural activity at this time. In contrast to several nearby paleoenvironmental studies, proxy evidence from Lago Paixban indicates human presence through the Classic/Postclassic period transition ( 1000 BP) and persisting until the arrival of Europeans. Cessation of human activity around 210 BP resulted in local afforestation and the re-establishment of the current sawgrass marsh at Lago Paixban.

Microbial water quality before and after the repair of a failing onsite wastewater treatment system adjacent to coastal waters

USGS Publications Warehouse

Conn, K.E.; Habteselassie, M.Y.; Denene, Blackwood A.; Noble, R.T.

2012-01-01

Aims: The objective was to assess the impacts of repairing a failing onsite wastewater treatment system (OWTS, i.e., septic system) as related to coastal microbial water quality. Methods and Results: Wastewater, groundwater and surface water were monitored for environmental parameters, faecal indicator bacteria (total coliforms, Escherichia coli, enterococci) and the viral tracer MS2 before and after repairing a failing OWTS. MS2 results using plaque enumeration and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) often agreed, but inhibition limited the qRT-PCR assay sensitivity. Prerepair, MS2 persisted in groundwater and was detected in the nearby creek; postrepair, it was not detected. In groundwater, total coliform concentrations were lower and E.??coli was not detected, while enterococci concentrations were similar to prerepair levels. E.??coli and enterococci surface water concentrations were elevated both before and after the repair. Conclusions: Repairing the failing OWTS improved groundwater microbial water quality, although persistence of bacteria in surface water suggests that the OWTS was not the singular faecal contributor to adjacent coastal waters. A suite of tracers is needed to fully assess OWTS performance in treating microbial contaminants and related impacts on receiving waters. Molecular methods like qRT-PCR have potential but require optimization. Significance and Impact of Study: This is the first before and after study of a failing OWTS and provides guidance on selection of microbial tracers and methods. ?? 2011 The Authors. Journal of Applied Microbiology ?? 2011 The Society for Applied Microbiology.

Investigation of acidity and other water-quality characteristics of Upper Oyster Creek, Ocean County, New Jersey

USGS Publications Warehouse

Fusillo, Thomas V.; Schornick, J.C.; Koester, H.E.; Harriman, D.A.

1980-01-01

Water-quality data collected in the upper Oyster Creek drainage basin, Ocean County, N.J., indicate that the stream has excellent water quality except for a persistently low pH. The mean concentrations of the major inorganic ions were all less than 6.0 milligrams per liter. Mean concentrations of total nitrogen and total phosphorus were 0.15 mg/L and 0.01 mg/L, respectively. Dissolved oxygen averaged 8.7 mg/L and 81% saturation. Low pH levels are typical of streams draining cedar swamps. In Oyster Creek, the pH tended to decrease downstream due to chemical and biological processes. The pH levels in swamps were one-half unit or more lower than the pH levels in the adjacent stream. Sharp declines in stream pH were noted during runoff periods as the result of the mixing of poorly-buffered stream water with more highly acidic water from surrounding swamp areas. The quality of ground water within the study area was similar to the quality of streamflow, except for higher iron and ammonia-nitrogen concentrations and a higher pH range of 4.9 to 6.5. Precipitation represented a major source of many chemical constituents in the ground- and surface-waters of the Oyster Creek basin. (USGS)

Attaining the canopy in dry and moist tropical forests: strong differences in tree growth trajectories reflect variation in growing conditions

PubMed Central

Zuidema, Pieter A.; Martínez-Ramos, Miguel

2009-01-01

Availability of light and water differs between tropical moist and dry forests, with typically higher understorey light levels and lower water availability in the latter. Therefore, growth trajectories of juvenile trees—those that have not attained the canopy—are likely governed by temporal fluctuations in light availability in moist forests (suppressions and releases), and by spatial heterogeneity in water availability in dry forests. In this study, we compared juvenile growth trajectories of Cedrela odorata in a dry (Mexico) and a moist forest (Bolivia) using tree rings. We tested the following specific hypotheses: (1) moist forest juveniles show more and longer suppressions, and more and stronger releases; (2) moist forest juveniles exhibit wider variation in canopy accession pattern, i.e. the typical growth trajectory to the canopy; (3) growth variation among dry forest juveniles persists over longer time due to spatial heterogeneity in water availability. As expected, the proportion of suppressed juveniles was higher in moist than in dry forest (72 vs. 17%). Moist forest suppressions also lasted longer (9 vs. 5 years). The proportion of juveniles that experienced releases in moist forest (76%) was higher than in dry forest (41%), and releases in moist forests were much stronger. Trees in the moist forest also had a wider variation in canopy accession patterns compared to the dry forest. Our results also showed that growth variation among juvenile trees persisted over substantially longer periods of time in dry forest (>64 years) compared to moist forest (12 years), most probably because of larger persistent spatial variation in water availability. Our results suggest that periodic increases in light availability are more important for attaining the canopy in moist forests, and that spatial heterogeneity in water availability governs long-term tree growth in dry forests. Electronic supplementary material The online version of this article (doi:10.1007/s00442-009-1540-5) contains supplementary material, which is available to authorized users. PMID:20033820

Relationship between Enterococcal Levels and Sediment Biofilms at Recreational Beaches in South Florida

PubMed Central

Piggot, Alan M.; Johnson, Sara; Phillips, Matthew C.; Solo-Gabriele, Helena M.

2012-01-01

Enterococci, recommended at the U.S. federal level for monitoring water quality at marine recreational beaches, have been found to reside and grow within beach sands. However, the environmental and ecological factors affecting enterococcal persistence remain poorly understood, making it difficult to determine levels of fecal pollution and assess human health risks. Here we document the presence of enterococci associated with beach sediment biofilms at eight south Florida recreational beaches. Enterococcal levels were highest in supratidal sands, where they displayed a nonlinear, unimodal relationship with extracellular polymeric secretions (EPS), the primary component of biofilms. Enterococcal levels peaked at intermediate levels of EPS, suggesting that biofilms may promote the survival of enterococci but also inhibit enterococci as the biofilm develops within beach sands. Analysis of bacterial community profiles determined by terminal restriction fragment length polymorphisms showed the bacterial communities of supratidal sediments to be significantly different from intertidal and subtidal communities; however, no differences were observed in bacterial community compositions associated with different EPS concentrations. Our results suggest that supratidal sands are a microbiologically unique environment favorable for the incorporation and persistence of enterococci within beach sediment biofilms. PMID:22706061

TOOL FOR MONITORING HYDROPHILIC CONTAMINANTS IN WATER: POLAR ORGANIC CHEMICAL INTEGRATIVE SAMPLER (POCIS)

EPA Science Inventory

Global emissions of persistent bioconcentratable organic chemicals have resulted in a wide range of adverse ecological effects. Consequently, industry was led to develop less persistent, more water soluble, polar or hydrophilic organic compounds (HpOCs), which generally have low ...

Ubiquity and persistance of Escherichia coli in a midwestern coastal stream

USGS Publications Warehouse

Byappanahalli, Muruleedhara N.; Fowler, Melanie; Shively, Dawn; Whitman, Richard

2003-01-01

Dunes Creek, a small Lake Michigan coastal stream that drains sandy aquifers and wetlands of Indiana Dunes, has chronically elevated Escherichia coli levels along the bathing beach near its outfall. This study sought to understand the sources ofE. coli in Dunes Creek's central branch. A systematic survey of random and fixed sampling points of water and sediment was conducted over 3 years. E. coliconcentrations in Dunes Creek and beach water were significantly correlated. Weekly monitoring at 14 stations during 1999 and 2000 indicated chronic loading of E. coli throughout the stream. Significant correlations between E. coli numbers in stream water and stream sediment, submerged sediment and margin, and margin and 1 m from shore were found. Median E. coli counts were highest in stream sediments, followed by bank sediments, sediments along spring margins, stream water, and isolated pools; in forest soils, E. coli counts were more variable and relatively lower. Sediment moisture was significantly correlated with E. colicounts. Direct fecal input inadequately explains the widespread and consistent occurrence of E. coli in the Dunes Creek watershed; long-term survival or multiplication or both seem likely. The authors conclude that (i) E. coli is ubiquitous and persistent throughout the Dunes Creek basin, (ii) E. coli occurrence and distribution in riparian sediments help account for the continuous loading of the bacteria in Dunes Creek, and (iii) ditching of the stream, increased drainage, and subsequent loss of wetlands may account for the chronically high E. coli levels observed.

Predicting regime shifts in flow of the Colorado River

USGS Publications Warehouse

Gangopadhyay, Subhrendu; McCabe, Gregory J.

2010-01-01

The effects of continued global warming on water resources are a concern for water managers and stake holders. In the western United States, where the combined climatic demand and consumptive use of water is equal to or greater than the natural supply of water for some locations, there is growing concern regarding the sustainability of future water supplies. In addition to the adverse effects of warming on water supply, another issue for water managers is accounting for, and managing, the effects of natural climatic variability, particularly persistently dry and wet periods. Analyses of paleo-reconstructions of Upper Colorado River basin (UCRB) flow demonstrate that severe sustained droughts, and persistent pluvial periods, are a recurring characteristic of hydroclimate in the Colorado River basin. Shifts between persistently dry and wet regimes (e.g., decadal to multi-decadal variability (D2M)) have important implications for water supply and water management. In this study paleo-reconstructions of UCRB flow are used to compute the risks of shifts between persistently wet and dry regimes given the length of time in a specific regime. Results indicate that low frequency variability of hydro-climatic conditions and the statistics that describe this low frequency variability can be useful to water managers by providing information about the risk of shifting from one hydrologic regime to another. To manage water resources in the future water managers will have to understand the joint hydrologic effects of natural climate variability and global warming. These joint effects may produce future hydrologic conditions that are unprecedented in both the instrumental and paleoclimatic records.

Estimating persistence of brominated and chlorinated organic pollutants in air, water, soil, and sediments with the QSPR-based classification scheme.

PubMed

Puzyn, T; Haranczyk, M; Suzuki, N; Sakurai, T

2011-02-01

We have estimated degradation half-lives of both brominated and chlorinated dibenzo-p-dioxins (PBDDs and PCDDs), furans (PBDFs and PCDFs), biphenyls (PBBs and PCBs), naphthalenes (PBNs and PCNs), diphenyl ethers (PBDEs and PCDEs) as well as selected unsubstituted polycyclic aromatic hydrocarbons (PAHs) in air, surface water, surface soil, and sediments (in total of 1,431 compounds in four compartments). Next, we compared the persistence between chloro- (relatively well-studied) and bromo- (less studied) analogs. The predictions have been performed based on the quantitative structure-property relationship (QSPR) scheme with use of k-nearest neighbors (kNN) classifier and the semi-quantitative system of persistence classes. The classification models utilized principal components derived from the principal component analysis of a set of 24 constitutional and quantum mechanical descriptors as input variables. Accuracies of classification (based on an external validation) were 86, 85, 87, and 75% for air, surface water, surface soil, and sediments, respectively. The persistence of all chlorinated species increased with increasing halogenation degree. In the case of brominated organic pollutants (Br-OPs), the trend was the same for air and sediments. However, we noticed that the opposite trend for persistence in surface water and soil. The results suggest that, due to high photoreactivity of C-Br chemical bonds, photolytic processes occurring in surface water and soil are able to play significant role in transforming and removing Br-OPs from these compartments. This contribution is the first attempt of classifying together Br-OPs and Cl-OPs according to their persistence, in particular, environmental compartments.

Uptake and Accumulation of Pharmaceuticals in Overhead- and Surface-Irrigated Greenhouse Lettuce.

PubMed

Bhalsod, Gemini D; Chuang, Ya-Hui; Jeon, Sangho; Gui, Wenjun; Li, Hui; Ryser, Elliot T; Guber, Andrey K; Zhang, Wei

2018-01-31

Understanding the uptake and accumulation of pharmaceuticals in vegetables under typical irrigation practices is critical to risk assessment of crop irrigation with reclaimed water. This study investigated the pharmaceutical residues in greenhouse lettuce under overhead and soil-surface irrigations using pharmaceutical-contaminated water. Compared to soil-surface irrigation, overhead irrigation substantially increased the pharmaceutical residues in lettuce shoots. The increased residue levels persisted even after washing for trimethoprim, monensin sodium, and tylosin, indicating their strong sorption to the shoots. The postwashing concentrations in fresh shoots varied from 0.05 ± 0.04 μg/kg for sulfadiazine to 345 ± 139 μg/kg for carbamazepine. Root concentration factors ranged from 0.04 ± 0.14 for tylosin to 19.2 ± 15.7 for sulfamethoxazole. Translocation factors in surface-irrigated lettuce were low for sulfamethoxalzole, trimethoprim, monensin sodium, and tylosin (0.07-0.15), but high for caffeine (4.28 ± 3.01) and carbamazepine (8.15 ± 2.87). Carbamazepine was persistent in soil and hyperaccumulated in shoots.

Toward implementation of a national ground water monitoring network

USGS Publications Warehouse

Schreiber, Robert P.; Cunningham, William L.; Copeland, Rick; Frederick, Kevin D.

2008-01-01

The Federal Advisory Committee on Water Information's (ACWI) Subcommittee on Ground Water (SOGW) has been working steadily to develop and encourage implementation of a nationwide, long-term ground-water quantity and quality monitoring framework. Significant progress includes the planned submission this fall of a draft framework document to the full committee. The document will include recommendations for implementation of the network and continued acknowledgment at the federal and state level of ACWI's potential role in national monitoring toward an improved assessment of the nation's water reserves. The SOGW mission includes addressing several issues regarding network design, as well as developing plans for concept testing, evaluation of costs and benefits, and encouraging the movement from pilot-test results to full-scale implementation within a reasonable time period. With the recent attention to water resource sustainability driven by severe droughts, concerns over global warming effects, and persistent water supply problems, the SOGW mission is now even more critical.

Hydrogeochemical Processes Causing Persistent Low pH in Lakes within a Reclaimed Lignite Mine, East Texas

NASA Astrophysics Data System (ADS)

Paul, J. C.; Schwab, P.; Knappett, P.; Deng, Y.

2017-12-01

Surface water pH values ranging from 2.5 to 2.6 have been reported in three lakes at a reclaimed lignite mine located in the Wilcox Formation of East Texas (the site). Traditional neutralization processes using alkaline chemicals to neutralize the surface water were found to be temporary solutions at the site. Low pH conditions usually are caused by oxidation of pyritic materials in the original tailings, but that was not always apparent based on previous studies at this site. The objective of this study is to determine factors contributing to acid seepage to aid in developing pre- and post-mining strategies to mitigate persistent acidity in surface waters at this and other sites. Mineralogy, hydrogeology, and hydrogeochemical reactions were evaluated. A network of 30 wells was used to monitor the water table and chemistry of the shallow, unconfined aquifer surrounding the lakes. Pressure transducers were deployed in 18 of these wells and each of the lakes to measure high frequency water levels over approximately one year. These water levels were contoured to visualize changing hydraulic head over time and determine the correlation in time between ground water flow directions and local rainfall events. Boreholes at 15 of the monitoring wells were continuously cored, and samples were taken at selected depth intervals based on pH measurements. XRD, SEM, and TEM were used to determine the mineralogy of select soil samples. Ion chromatography was used to determine sulfate concentration, and ICP-MS was used to determine solute concentrations from water and digested soil samples. Framboidal and microcrystalline pyrite were identified in the vadose zone in silt and clay-sized fractions; these minerals have high surface area that is conducive to rapid oxidation and acidification as ground water permeates from the vadose into the saturated zone. Morphology in addition to quantity of weatherable pyrite plays a significant role in acidification. Computer models were used to evaluate the effect of dissolving and precipitating solid phases on water chemistry along identified subsurface flow pathways with a focus on metal sulfides and iron oxides as influential to acid mine seepage into the affected lakes.

Persistence of F-Specific RNA Coliphages in Surface Waters from a Produce Production Region along the Central Coast of California.

PubMed

Ravva, Subbarao V; Sarreal, Chester Z

2016-01-01

F+ RNA coliphages (FRNA) are used to source-track fecal contamination and as surrogates for enteric pathogen persistence in the environment. However, the environmental persistence of FRNA is not clearly understood and necessitates the evaluation of the survival of prototype and environmental isolates of FRNA representing all four genogroups in surface waters from the central coast of California. Water temperature played a significant role in persistence-all prototype and environmental strains survived significantly longer at 10 °C compared to 25 °C. Similarly, the availability of host bacterium was found to be critical in FRNA survival. In the absence of E. coli F(amp), all prototypes of FRNA disappeared rapidly with a D-value (days for one log reduction) of <1.2 d from water samples incubated at 25 °C; the longest surviving prototype was SP. However, in the presence of the host, the order of persistence at 25 °C was QB>MS2>SP>GA and at 10 °C it was QB = MS2>GA>SP. Significant differences in survival were observed between prototypes and environmental isolates of FRNA. While most environmental isolates disappeared rapidly at 25 °C and in the absence of the host, members of genogroups GIII and GI persisted longer with the host compared to members of GII and GIV. Consequentially, FRNA based source tracking methods can be used to detect phages from recent fecal contamination along with those that persist longer in the environment as a result of cooler temperatures and increased host presence.

The Politics of Pipes: The Persistence of Small Water Networks in Post-Privatization Manila

NASA Astrophysics Data System (ADS)

Cheng, Deborah

This project examines the politics of water provision in low-income areas of large, developing cities. In the last two decades, water privatization has become a global paradigm, emerging as a potential means for addressing the urban water crisis. In Manila, the site of the world's largest water privatization project, service to low-income areas has improved significantly in the post-privatization era. But whereas expansion of a water utility typically involves the replacement of informal providers, the experience in Manila demonstrates that the rapid connection of low-income areas actually hinges, in part, on the selective inclusion and exclusion of these smaller actors. Based on an ethnography of the private utilities and community-based providers, I use the persistence of small water networks as a lens for exploring the limits of water privatization in Manila. I focus on what I call micro-networks---community-built infrastructure that extends the formal, private utilities into low-income neighborhoods that the utilities do not wish to serve directly. In such a setup, the utility provides water only as far as the community boundary; beyond that, the micro-network operator constructs internal infrastructure, monitors for leakage and theft, and collects bills. But while these communities may gain access to safer water, they are also subject to higher costs and heightened disciplinary measures. By tracing the ways in which the utilities selectively use micro-networks to manage sub-populations, I show how the utilities make low-income spaces more governable. Delegating localized water management to micro-network operators depoliticizes the utilities' roles, shifting the sociopolitical difficulties of water provision to community organizations, while allowing the utilities to claim that these areas are served. This research leads to three related arguments. First, the persistence of small water networks highlights lingering inequities in access to water, for micro-network consumers are subject to disparities in cost, materials, and personal freedoms. Though Manila's water privatization project has resulted in significant improvements to the centralized system, its success must be tempered by the inequalities that remain. Second, the two utilities are largely able to shape both the geographies of water access and the production of knowledge. For this reason, the utilities typically use micro-networks where cost recovery may be difficult---such as in areas with uncertain land tenure or where higher levels of nonpayment are perceived---while including these areas in their aggregate coverage statistics. Third, the presence of multiple providers of water and other basic services blurs the boundaries between public, private, and community. But that blurriness serves to consolidate the private utilities' power, while increasing the opacity by which citizens navigate processes related to urban water provision. The persistence of micro-networks thus allows us to understand the ways in which low-income spaces are made more governable. By focusing on this peri-urban frontier, this project asserts that differentiation and discipline serve simultaneously as tools of governance and as points of contestation. What emerges is a waterscape consisting not of one type of privatization---where service and access are uniformly provided---but multiple, coexisting, and differentiated privatizations.

Impact of climate change on persistent turbidity in the water supply system of a Metropolitan Area

NASA Astrophysics Data System (ADS)

Chung, S. W.; Park, H. S.; Lim, K. J.; Kang, B.

2016-12-01

Persistent turbidity, a long-term resuspension of fine particles in aquatic system, is one of the major water quality concerns for the sustainable management of water supply systems in metropolitan areas. Turbid water has undesirable aesthetic and recreational appeal and may have harmful effect on ecosystem health, in addition to increasing water treatment costs in drinking water supply systems. These concerns have been more intensified as the strength and frequency of rainfall events increase by climate change in the Asian monsoon climate region, including Korea. The aim of this study was to assess the impact of potential climate change on the persistent turbidity of the Han River systems that supplies drinking water to approximately 25 million consumers dwelling in the Seoul Metropolitan areas. A comprehensive numerical and statistical modeling suit has been developed and applied to the systems for the projection of future climate, responding hydrological and soil erosion processes in the watershed, and sediment transport processes in the rivers and reservoirs systems. The down-scaled 100 years of climatic data from General Circulation Model (HadGEM2-AO) based on the IPCC's greenhouse-gas emissions scenario RCP4.5 were used for the forcing data of the watershed and river-reservoir models. As the results, an extreme flood event that may incur significant persistent turbidity was projected to be occurred five times in the future. The threshold of a flood event that is classified as an extreme event was based on the historical flood event that occurred on July of 2006 when turbid water had persisted within the Soyang Reservoir and discharged to the downstream of the Han River systems over the year until May of the following year. A two-dimensional river and reservoir model simulated the transport and dynamics of suspended sediments in Soyang Reservoir, and routed the discharged turbid water to the downstream of Paldang Reservoir, in which most of the drinking water offtake facilities are located. The statistical features of the extreme flood events, their impact on the persistent turbidity on the downstream rivers and reservoirs, and consequently on the water supply system of the Seoul Metropolitan areas will be presented in the special session.

Environmental levels, toxicity and human exposure to tributyltin (TBT)-contaminated marine environment. a review. b_antizar@hotmail.com.

PubMed

Antizar-Ladislao, Blanca

2008-02-01

Tributyltin (TBT) is a toxic chemical used for various industrial purposes such as slime control in paper mills, disinfection of circulating industrial cooling waters, antifouling agents, and the preservation of wood. Due to its widespread use as an antifouling agent in boat paints, TBT is a common contaminant of marine and freshwater ecosystems exceeding acute and chronic toxicity levels. TBT is the most significant pesticide in marine and freshwaters in Europe and consequently its environmental level, fate, toxicity and human exposure are of current concern. Thus, the European Union has decided to specifically include TBT compounds in its list of priority compounds in water in order to control its fate in natural systems, due to their toxic, persistent, bioaccumulative and endocrine disruptive characteristics. Additionally, the International Maritime Organization has called for a global treaty that bans the application of TBT-based paints starting 1 of January 2003, and total prohibition by 1 of January 2008. This paper reviews the state of the science regarding TBT, with special attention paid to the environmental levels, toxicity, and human exposure. TBT compounds have been detected in a number of environmental samples. In humans, organotin compounds have been detected in blood and in the liver. As for other persistent organic pollutants, dietary intake is most probably the main route of exposure to TBT compounds for the general population. However, data concerning TBT levels in foodstuffs are scarce. It is concluded that investigations on experimental toxicity, dietary intake, potential human health effects and development of new sustainable technologies to remove TBT compounds are clearly necessary.

Bioaccumulation and enantiomeric profiling of organochlorine pesticides and persistent organic pollutants in the killer whale (Orcinus orca) from British and Irish waters.

PubMed

McHugh, Brendan; Law, Robin J; Allchin, Colin R; Rogan, Emer; Murphy, Sinead; Foley, M Barry; Glynn, Denise; McGovern, Evin

2007-11-01

Concentrations and enantiomeric profiles for a range of organochlorine compounds are reported in blubber samples from a number of individual killer whales (Orcinus orca) from British and Irish waters. Elevated contaminant levels and enriched isotopic ratios were determined in one individual whale sampled in the Scottish Western Isles compared to the others suggesting marine mammal based dietary influences. The potential application of isotopic ratios to model contaminant uptake, enantioselective enrichment and accumulation is demonstrated. Data are presented which provide information on enantioselective enrichment factors (EFs) for o,p'-DDT, alpha-HCH and toxaphene congeners CHB26 and CHB 50. This dataset further improves the current database on reported levels of a number of contaminants and provides additional background information on potential metabolic processes in killer whales from British and Irish waters.

Environmental signatures and effects of an oil and gas wastewater spill in the Williston Basin, North Dakota

USGS Publications Warehouse

Cozzarelli, Isabelle M.; Skalak, Katherine; Kent, D.B.; Engle, Mark A.; Benthem, Adam J.; Mumford, Adam; Haase, Karl B.; Farag, Aïda M.; Harper, David; Nagel, S. C.; Iwanowicz, Luke R.; Orem, William H.; Akob, Denise M.; Jaeschke, Jeanne B.; Galloway, Joel M.; Kohler, Matthias; Stoliker, Deborah L.; Jolly, Glenn D.

2017-01-01

Wastewaters from oil and gas development pose largely unknown risks to environmental resources. In January 2015, 11.4 M L (million liters) of wastewater (300 g/L TDS) from oil production in the Williston Basin was reported to have leaked from a pipeline, spilling into Blacktail Creek, North Dakota. Geochemical and biological samples were collected in February and June 2015 to identify geochemical signatures of spilled wastewaters as well as biological responses along a 44-km river reach. February water samples had elevated chloride (1030 mg/L) and bromide (7.8 mg/L) downstream from the spill, compared to upstream levels (11 mg/L and < 0.4 mg/L, respectively). Lithium (0.25 mg/L), boron (1.75 mg/L) and strontium (7.1 mg/L) were present downstream at 5–10 times upstream concentrations. Light hydrocarbon measurements indicated a persistent thermogenic source of methane in the stream. Semi-volatile hydrocarbons indicative of oil were not detected in filtered samples but low levels, including tetramethylbenzenes and di-methylnaphthalenes, were detected in unfiltered water samples downstream from the spill. Labile sediment-bound barium and strontium concentrations (June 2015) were higher downstream from the Spill Site. Radium activities in sediment downstream from the Spill Site were up to 15 times the upstream activities and, combined with Sr isotope ratios, suggest contributions from the pipeline fluid and support the conclusion that elevated concentrations in Blacktail Creek water are from the leaking pipeline. Results from June 2015 demonstrate the persistence of wastewater effects in Blacktail Creek several months after remediation efforts started. Aquatic health effects were observed in June 2015; fish bioassays showed only 2.5% survival at 7.1 km downstream from the spill compared to 89% at the upstream reference site. Additional potential biological impacts were indicated by estrogenic inhibition in downstream waters. Our findings demonstrate that environmental signatures from wastewater spills are persistent and create the potential for long-term environmental health effects.

Skin Testing With Water Buffalo's Milk in Children With Cow's Milk Allergy.

PubMed

Sheehan, William J; Gardynski, Andrea; Phipatanakul, Wanda

2009-09-01

BACKGROUND: Cow's milk allergy is the most common food allergy in young children. In areas outside the United States, milk from other mammals has been studied as a possible and desirable alternative for children with cow's milk allergy. OBJECTIVES: We chose to further investigate water buffalo's milk as an alternative for cow's milk allergic children in the United States. METHODS: Children with cow's milk allergy were skin prick tested with water buffalo's milk. Additionally, subjects were followed clinically for 1 year after the test to determine how many of the subjects had persistent cow's milk allergy. RESULTS: In total, 30 children, age 8 months to 8 years, were skin prick tested to water buffalo's milk with 73% (22/30) having a positive test. All children with a negative water buffalo's milk skin test also had a negative cow's milk skin test. In follow-up, most (7 of 8) of the children with a negative skin prick test (SPT) to water buffalo's milk were found to have outgrown their cow's milk allergy. In comparison, all of the subjects with a positive skin test to water buffalo's milk had persistent cow's milk allergy. After adjusting for this, we determined that 96% (22/23) of the children with persistent cow's milk allergy were positive on skin testing to water buffalo's milk. CONCLUSIONS: In this population, the vast majority of children with persistent cow's milk allergy were positive on skin prick testing to water buffalo's milk. These results indicate that water buffalo's milk is unlikely to be a successful alternative for children with cow's milk allergy.

Handwashing and Ebola virus disease outbreaks: A randomized comparison of soap, hand sanitizer, and 0.05% chlorine solutions on the inactivation and removal of model organisms Phi6 and E. coli from hands and persistence in rinse water.

PubMed

Wolfe, Marlene K; Gallandat, Karin; Daniels, Kyle; Desmarais, Anne Marie; Scheinman, Pamela; Lantagne, Daniele

2017-01-01

To prevent Ebola transmission, frequent handwashing is recommended in Ebola Treatment Units and communities. However, little is known about which handwashing protocol is most efficacious. We evaluated six handwashing protocols (soap and water, alcohol-based hand sanitizer (ABHS), and 0.05% sodium dichloroisocyanurate, high-test hypochlorite, and stabilized and non-stabilized sodium hypochlorite solutions) for 1) efficacy of handwashing on the removal and inactivation of non-pathogenic model organisms and, 2) persistence of organisms in rinse water. Model organisms E. coli and bacteriophage Phi6 were used to evaluate handwashing with and without organic load added to simulate bodily fluids. Hands were inoculated with test organisms, washed, and rinsed using a glove juice method to retrieve remaining organisms. Impact was estimated by comparing the log reduction in organisms after handwashing to the log reduction without handwashing. Rinse water was collected to test for persistence of organisms. Handwashing resulted in a 1.94-3.01 log reduction in E. coli concentration without, and 2.18-3.34 with, soil load; and a 2.44-3.06 log reduction in Phi6 without, and 2.71-3.69 with, soil load. HTH performed most consistently well, with significantly greater log reductions than other handwashing protocols in three models. However, the magnitude of handwashing efficacy differences was small, suggesting protocols are similarly efficacious. Rinse water demonstrated a 0.28-4.77 log reduction in remaining E. coli without, and 0.21-4.49 with, soil load and a 1.26-2.02 log reduction in Phi6 without, and 1.30-2.20 with, soil load. Chlorine resulted in significantly less persistence of E. coli in both conditions and Phi6 without soil load in rinse water (p<0.001). Thus, chlorine-based methods may offer a benefit of reducing persistence in rinse water. We recommend responders use the most practical handwashing method to ensure hand hygiene in Ebola contexts, considering the potential benefit of chlorine-based methods in rinse water persistence.

Biodegradation of disinfection byproducts as a potential removal process during aquifer storage recovery

USGS Publications Warehouse

Landmeyer, J.E.; Bradley, P.M.; Thomas, J.M.

2000-01-01

The biodegradation potential of two drinking water disinfection byproducts was investigated using aquifer materials obtained from approximately 100 and 200 meters below land surface in an aerobic aquifer system undergoing aquifer storage recovery of treated surface water. No significant biodegradation of a model trihalomethane compound, chloroform, was observed in aquifer microcosms under aerobic or anaerobic conditions. In contrast, between 16 and 27 percent mineralization of a radiolabeled model haloacetic acid compound, chloroacetic acid, was observed. These results indicate that although the potential for biodegradation of chloroacetic acid exists in deep aquifer systems, chloroform entrained within these aquifers or formed in situ will tend to persist. These results have important implications for water managers planning to meet anticipated lowered permissible levels of tri-halomethanes in drinking water.The biodegradation potential of two drinking water disinfection byproducts was investigated using aquifer materials obtained from approximately 100 and 200 meters below land surface in an aerobic aquifer system undergoing aquifer storage recovery of treated surface water. No significant biodegradation of a model trihalomethane compound, chloroform, was observed in aquifer microcosms under aerobic or anaerobic conditions. In contrast, between 16 and 27 percent mineralization of a radiolabeled model haloacetic acid compound, chloroacetic acid, was observed. These results indicate that although the potential for biodegradation of chloroacetic acid exists in deep aquifer systems, chloroform entrained within these aquifers or formed in situ will tend to persist. These results have important implications for water managers planning to meet anticipated lowered permissible levels of trihalomethanes in drinking water.Aquifer-storage-recovery injection water often contains disinfection byproducts. Results are presented from a study in which two model disinfection byproducts, chloroform and chloroacetic acid, were used to examine biodegradation by indigenous microorganisms. The recharge system studied was near Las Vegas, NV, where the aquifers are recharged artificially during the winter months. Microcosms were constructed using aquifer material recovered from two layers. Results showed that no significant biodegradation of chloroform occurred under aerobic or anaerobic conditions, but chloroacetic acid was biodegraded under both aerobic and anaerobic conditions.

Analysis of water-level fluctuations of Lakes Winona and Winnemissett-- two landlocked lakes in a karst terrane in Volusia County, Florida

USGS Publications Warehouse

Hughes, G.H.

1979-01-01

The water levels of Lakes Winona and Winnemissett in Volusia County, Fla., correlate reasonably well during dry spells but only poorly during wet spells. Disparities develop mostly at times when the lake levels rise abruptly owing to rainstorms passing over the lake basins. The lack of correlation is attributed to the uneven distribution of the storm rainfall, even though the average annual rainfall at National Weather Service gages in the general area of the lakes is about the same. Analyses of the monthly rainfall data show that the rainfall variability between gages is sufficient to account for most of the disparity between monthly changes in the levels of the two lakes. The total annual rainfall at times may differ between rainfall gages by as much as 15 to 20 inches. Such differences tend to balance over the long term but may persist in the same direction for two or more years, causing apparent anomalies in lake-level fluctuations. (Woodard-USGS)

Flow and habitat effects on juvenile fish abundance in natural and altered flow regimes

USGS Publications Warehouse

Freeman, Mary C.; Bowen, Z.H.; Bovee, K.D.; Irwin, E.R.

2001-01-01

Conserving biological resources native to large river systems increasingly depends on how flow-regulated segments of these rivers are managed. Improving management will require a better understanding of linkages between river biota and temporal variability of flow and instream habitat. However, few studies have quantified responses of native fish populations to multiyear (>2 yr) patterns of hydrologic or habitat variability in flow-regulated systems. To provide these data, we quantified young-of-year (YOY) fish abundance during four years in relation to hydrologic and habitat variability in two segments of the Tallapoosa River in the southeastern United States. One segment had an unregulated flow regime, whereas the other was flow-regulated by a peak-load generating hydropower dam. We sampled fishes annually and explored how continuously recorded flow data and physical habitat simulation models (PHABSIM) for spring (April-June) and summer (July-August) preceding each sample explained fish abundances. Patterns of YOY abundance in relation to habitat availability (median area) and habitat persistence (longest period with habitat area continuously above the long-term median area) differed between unregulated and flow-regulated sites. At the unregulated site, YOY abundances were most frequently correlated with availability of shallow-slow habitat in summer (10 species) and persistence of shallow-slow and shallow-fast habitat in spring (nine species). Additionally, abundances were negatively correlated with 1-h maximum flow in summer (five species). At the flow-regulated site, YOY abundances were more frequently correlated with persistence of shallow-water habitats (four species in spring; six species in summer) than with habitat availability or magnitude of flow extremes. The associations of YOY with habitat persistence at the flow-regulated site corresponded to the effects of flow regulation on habitat patterns. Flow regulation reduced median flows during spring and summer, which resulted in median availability of shallow-water habitats comparable to the unregulated site. However, habitat persistence was severely reduced by flow fluctuations resulting from pulsed water releases for peak-load power generation. Habitat persistence, comparable to levels in the unregulated site, only occurred during summer when low rainfall or other factors occasionally curtailed power generation. As a consequence, summer-spawning species numerically dominated the fish assemblage at the flow-regulated site; five of six spring-spawning species occurring at both study sites were significantly less abundant at the flow-regulated site. Persistence of native fishes in flow-regulated systems depends, in part, on the seasonal occurrence of stable habitat conditions that facilitate reproduction and YOY survival.

The wettability of selected organic soils in Poland

NASA Astrophysics Data System (ADS)

Całka, A.; Hajnos, M.

2009-04-01

The wettability was measured in the laboratory by means of two methods: Water Drop Penetration Time (WDPT) test and Thin Column Wicking (TCW) method. WDPT is fast and simple method and was used to investigate potential water repellency of analyzed samples. TCW is an indirect method and was used to determine contact angles and surface free energy components. The measurement was performed in horizontal teflon chambers for thin-layer chromatography, adapted for tubes 10 cm long. The experiment was carried out on muck soils (samples were taken from two levels of soil profile: 0-20 cm and 20-40 cm) and peat soils. There were two types of peats: low-moor peats and high moor peats. Samples of low-moor peats were taken from level 25-75 cm (alder peat) and 75-125cm (sedge peat) and 25-75 cm (peloid peat). Samples of high moor peats from level 25-175 cm (sphagnum peat) and 175-225 cm (sphagnum peat with Eriophorum). There was found no variability in persistence of potential water repellency but there were differences in values of contact angles of individual soil samples. Both muck and peat samples are extremely water repellent soils. Water droplets persisted on the surface of soils for more than 24 hours. Contact angles and surface free energy components for all samples were differentiated. Ranges of water contact angles for organic soils are from 27,54o to 96,50o. The highest values of contact angles were for sphagnum peats, and the lowest for muck soil from 20-40 cm level. It means, that there are differences in wettability between these samples. Muck soil is the best wettable and sphagnum peats is the worst wettable soil. If the content of organic compounds in the soil exceeds 40% (like in peats), the tested material displays only dispersion-type interactions. Therefore for peat soils, the technique of thin column wicking could only be used to determine the dispersive component γiLW. For muck soils it was also determined electron-acceptor (Lewis acid) γ+ and electron-donor (Lewis base) γ- surface free energy components. The authors gratefully acknowledge the Ministry of Science and Higher Education for financial support of this work (grant No. N N310 149335).

Radiochemical determination of strontium-90 and cesium-137 in waters of the Pacific Ocean and its neighboring seas

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

Borisenko, G.S.; Kandinskii, P.A.; Gedeonov, L.I.

1987-03-01

Depending on the salinity of the water, two versions of strontium-90 and cesium-137 concentration from water samples are presented. Cesium-137 was concentrated by precipitating sparingly soluble mixed hexacyanoferrates (II), and strontium-90 by precipitating carbonates together with calcium. A scheme has been given for radiochemical analysis of the concentrates. Strontium-90 and cesium-137 contents in the waters of the Pacific Ocean and its neighboring seas have been determined by the radiochemical method described. The levels of radionuclide content in the water and atmospheric precipitations have been shown to be inter-related. Strontium-90 and cesium-137 contents in the surface water of the northwestern Pacificmore » were found to be much lower in 1980 than in the early seventies. The area of technogenic radioactive pollution was found to persist in the region of the Columbia mouth into the Pacific Ocean.« less

Climate change and prairie pothole wetlands: mitigating water-level and hydroperiod effects through upland management

USGS Publications Warehouse

Renton, David A.; Mushet, David M.; DeKeyser, Edward S.

2015-01-01

Prairie pothole wetlands offer crucial habitat for North America’s waterfowl populations. The wetlands also support an abundance of other species and provide ecological services valued by society. The hydrology of prairie pothole wetlands is dependent on atmospheric interactions. Therefore, changes to the region’s climate can have profound effects on wetland hydrology. The relevant literature related to climate change and upland management effects on prairie pothole wetland water levels and hydroperiods was reviewed. Climate change is widely expected to affect water levels and hydroperiods of prairie pothole wetlands, as well as the biota and ecological services that the wetlands support. In general, hydrologic model projections that incorporate future climate change scenarios forecast lower water levels in prairie pothole wetlands and longer periods spent in a dry condition, despite potential increases in precipitation. However, the extreme natural variability in climate and hydrology of prairie pothole wetlands necessitates caution when interpreting model results. Recent changes in weather patterns throughout much of the Prairie Pothole Region have been in increased precipitation that results in increased water inputs to wetlands above losses associated with warmer temperatures. However, observed precipitation increases are within the range of natural climate variability and therefore, may not persist. Identifying management techniques with the potential to affect water inputs to prairie pothole wetlands would provide increased options for managers when dealing with the uncertainties associated with a changing climate. Several grassland management techniques (for example, grazing and burning) have the potential to affect water levels and hydroperiods of prairie pothole by affecting infiltration, evapotranspiration, and snow deposition.

Monitoring duration and extent of storm-surge and flooding in Western Coastal Louisiana marshes with Envisat ASAR data

USGS Publications Warehouse

Ramsey, E.; Lu, Z.; Suzuoki, Y.; Rangoonwala, A.; Werle, D.

2011-01-01

Inundation maps of coastal marshes in western Louisiana were created with multitemporal Envisat Advanced Synthetic Aperture (ASAR) scenes collected before and during the three months after Hurricane Rita landfall in September 2005. Corroborated by inland water-levels, 7 days after landfall, 48% of coastal estuarine and palustrine marshes remained inundated by storm-surge waters. Forty-five days after landfall, storm-surge inundated 20% of those marshes. The end of the storm-surge flooding was marked by an abrupt decrease in water levels following the passage of a storm front and persistent offshore winds. A complementary dramatic decrease in flood extent was confirmed by an ASAR-derived inundation map. In nonimpounded marshes at elevations <;80 cm, storm-surge waters rapidly receded while slower recession was dominantly associated with impounded marshes at elevations >;80 cm during the first month after Rita landfall. After this initial period, drainage from marshes-especially impounded marshes-was hastened by the onset of offshore winds. Following the abrupt drops in inland water levels and flood extent, rainfall events coinciding with increased water levels were recorded as inundation re-expansion. This postsurge flooding decreased until only isolated impounded and palustrine marshes remained inundated. Changing flood extents were correlated to inland water levels and largely occurred within the same marsh regions. Trends related to incremental threshold increases used in the ASAR change-detection analyses seemed related to the preceding hydraulic and hydrologic events, and VV and HH threshold differences supported their relationship to the overall wetland hydraulic condition.

Persistence and internalization of Salmonella on/in organic spinach sprout: exploring the contamination route

USDA-ARS?s Scientific Manuscript database

Purpose: The effects of contamination route, including seed and water, on the persistence and internalization of Salmonella in organic spinach cultivars- Lazio, Space, Emilia and Waitiki were studied. Methods: Seeds (1g) were contaminated with S. Newport using 10 ml of S. Newport-water suspension ov...

Passive Sampling to Measure Baseline Dissolved Persistent Organic Pollutant Concentrations in the Water Column of the Palos Verdes Shelf Superfund Site

EPA Science Inventory

Passive sampling was used to deduce water concentrations of persistent organic pollutants (POPs) in the vicinity of a marine Superfund site on the Palos Verdes Shelf, California, USA. Pre-calibrated solid phase microextraction (SPME) fibers and polyethylene (PE) strips that were...

Mountains in the third millennium - a decade of droughts and water scarcity?

NASA Astrophysics Data System (ADS)

de Jong, C.; Shaban, A.; Belete, T.

2012-04-01

Droughts and water scarcity have touched the Alps, Mediterranean and East African mountain chains more intensively since the beginning of the third millennium and pose a major challenge for water management. The year 2011 has been no exception, with the lowest river levels on record over the past 50 years even for alpine rivers. Although considerable climate fluctuations and persistent droughts have occurred in the past, it is quite remarkable that the five hottest summers over the past 500 years in Europe and the Alps have all been concentrated after 2002, falling far outside their normal historical distribution. In most mountain chains drought phenomena are persistent over large areas and over a variety of scales. The hydrological consequences, such as decreased rain- and snowfall, drying of springs, decreased river and groundwater discharge, lowering of lake levels and excessive evaporation etc. are considerable. Seasonality has been considerably affected, with the summer extending well into the spring and autumn. Mountain-fed rivers have experienced unusually low discharge over the last 10 years, with a decreasing trend both in summer and winter discharge. These hydrological changes have multiple impacts on availability of drinking water and the energy sector, decreasing hydroelectric production and availability of cooling water for the nuclear industry and negatively effecting river navigation, irrigation agriculture as well as winter tourism in mountains. Despite these naturally-induced shortcomings, adaptation has not always been rational. In some cases, maladaptation has led to overexploitation of water resources during drought conditions, exasperating water scarcity. For example, for the tourism sector in the Alps, water demand for drinking water and artificial snow making lies far above the available resources during the winter season for numerous resorts. This has long term environmental and socio-economic impacts such as destruction of wetlands, desiccation of streams and drinking water conflicts. However, Environmental Impact Assessments still lack consideration of climate change. Data availability and measurements are so sparse in these environments that proper interdisciplinary modelling has still to be developed and most predictions are based on conceptual model approaches. Nevertheless, there is increasing necessity to adapt swiftly and rationally to droughts and increased climate irregularities in mountains. Some countries and regions have already adopted adaptation plans and strategies at the national level but they rarely consider mountain regions. Others have left it up to spontaneous adaptation at the local level. Even at the European level, there are few activities and policies yet dealing with adaptation to climate change under consideration of a combination of droughts, water scarcity or energy issues apart from the EU Strategy for Climate Change Adaptation planned for 2013. Under such conditions, it is essential to carry out scientific observations and modelling as well as develop innovative indicators, for example via climate change witnesses identified amongst the local stakeholders as well as local and regional think tanks.

Have Chinese water pricing reforms reduced urban residential water demand?

NASA Astrophysics Data System (ADS)

Zhang, B.; Fang, K. H.; Baerenklau, K. A.

2017-06-01

China continues to deal with severe levels of water scarcity and water pollution. To help address this situation, the Chinese central government initiated urban water pricing reforms in 2002 that emphasized the adoption of increasing block rate (IBR) price structures in place of existing uniform rate structures. By combining urban water use records with microlevel data from the Chinese Urban Household Survey, this research investigates the effectiveness of this national policy reform. Specifically, we compare household water consumption in 28 cities that adopted IBR pricing structures during 2002-2009, with that of 110 cities that had not yet done so. Based on difference-in-differences models, our results show that the policy reform reduced annual residential water demand by 3-4% in the short run and 5% in the longer run. These relatively modest reductions are consistent with the generous nature of the IBR pricing structures that Chinese cities have typically chosen to implement. Our results imply that more efforts are needed to address China's persistent urban water scarcity challenges.

Total Fluid and Water Consumption and the Joint Effect of Exposure to Disinfection By-Products on Risk of Bladder Cancer

PubMed Central

Michaud, Dominique S.; Kogevinas, Manolis; Cantor, Kenneth P.; Villanueva, Cristina M.; Garcia-Closas, Monteserrat; Rothman, Nathaniel; Malats, Nuria; Real, Francisco X.; Serra, Consol; Garcia-Closas, Reina; Tardon, Adonina; Carrato, Alfredo; Dosemeci, Mustafa; Silverman, Debra T.

2007-01-01

Background Findings on water and total fluid intake and bladder cancer are inconsistent; this may, in part, be due to different levels of carcinogens in drinking water. High levels of arsenic and chlorinated by-products in drinking water have been associated with elevated bladder cancer risk in most studies. A pooled analysis based on six case–control studies observed a positive association between tap water and bladder cancer but none for nontap fluid intake, suggesting that contaminants in tap water may be responsible for the excess risk. Objectives We examined the association between total fluid and water consumption and bladder cancer risk, as well as the interaction between water intake and trihalomethane (THM) exposure, in a large case–control study in Spain. Methods A total of 397 bladder cancer cases and 664 matched controls were available for this analysis. Odds ratios (OR) were estimated using unconditional logistic regression, controlling for potential confounders. Results Total fluid intake was associated with a decrease in bladder cancer risk [OR = 0.62; 95% confidence interval (CI), 0.40–0.95 for highest vs. lowest quintile comparison]. A significant inverse association was observed for water intake (for > 1,399 vs. < 400 mL/day, OR = 0.47; 95% CI, 0.33–0.66; p for trend < 0.0001), but not for other individual beverages. The inverse association between water intake and bladder cancer persisted within each level of THM exposure; we found no statistical interaction (p for interaction = 0.13). Conclusion Findings from this study suggest that water intake is inversely associated with bladder cancer risk, regardless of THM exposure level. PMID:18007986

Microplastics in the marine environment.

PubMed

Andrady, Anthony L

2011-08-01

This review discusses the mechanisms of generation and potential impacts of microplastics in the ocean environment. Weathering degradation of plastics on the beaches results in their surface embrittlement and microcracking, yielding microparticles that are carried into water by wind or wave action. Unlike inorganic fines present in sea water, microplastics concentrate persistent organic pollutants (POPs) by partition. The relevant distribution coefficients for common POPs are several orders of magnitude in favour of the plastic medium. Consequently, the microparticles laden with high levels of POPs can be ingested by marine biota. Bioavailability and the efficiency of transfer of the ingested POPs across trophic levels are not known and the potential damage posed by these to the marine ecosystem has yet to be quantified and modelled. Given the increasing levels of plastic pollution of the oceans it is important to better understand the impact of microplastics in the ocean food web. Copyright © 2011 Elsevier Ltd. All rights reserved.

Column Testing and 1D Reactive Transport Modeling to Evaluate Uranium Plume Persistence Processes

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

Johnson, Raymond H.; Morrison, Stan; Morris, Sarah

Motivation for Study: Natural flushing of contaminants at various U.S. Department of Energy Office of Legacy Management sites is not proceeding as quickly as predicted (plume persistence) Objectives: Help determine natural flushing rates using column tests. Use 1D reactive transport modeling to better understand the major processes that are creating plume persistence Approach: Core samples from under a former mill tailings area Tailings have been removed. Column leaching using lab-prepared water similar to nearby Gunnison River water. 1D reactive transport modeling to evaluate processes

Persistence of human norovirus in reconstituted pesticides--pesticide application as a possible source of viruses in fresh produce chains.

PubMed

Verhaelen, Katharina; Bouwknegt, Martijn; Rutjes, Saskia A; de Roda Husman, Ana Maria

2013-01-01

The consumption of fresh produce is frequently associated with outbreaks of human norovirus (hNoV) disease. To prevent the contamination of fresh produce with hNoV, knowledge of the possible introduction sources of the viruses, such as water, is needed to be able to implement appropriate and efficient preventive measures. Contaminated water used to reconstitute pesticides could be a relevant source of infectious hNoV, determined by the initial level of virus contamination and the persistence of these viruses in reconstituted pesticides. We studied the persistence of hNoV GI.4, hNoV GII.4 and murine norovirus (MNV-1), the only culturable norovirus, in eight different pesticides after 0 and 2h. Virus concentrations were determined by reverse transcriptase PCR, and infectivity of MNV-1 was determined by endpoint dilutions followed by maximum likelihood estimations. MNV-1 was found to remain infectious in seven of the eight tested pesticides at the highest concentration applied in practice. In the presence of the insecticide Vertimec, MNV-1 infectivity decreased rapidly with a 1.9 log(10)-unit reduction at timepoint T(0). Also, the concentration of NoV GI.4 RNA decreased considerably with a 1.7 log(10)-unit reduction; whereas the detected PCR fragment of hNoV GII.4 remained stable. Assuming a similar persistence of infectious MNV-1 and hNoV we can conclude that water containing hNoV used to dilute pesticides may be an important source of infectious hNoV in fresh produce chains. The application of pesticides may therefore not only be a chemical hazard, but also a microbiological hazard for public health. The inclusion of antiviral substances in reconstituted pesticides may be appropriate to reduce the virological health risk posed by the application of pesticides. Copyright © 2012 Elsevier B.V. All rights reserved.

Hydrologic modeling to screen potential environmental management methods for malaria vector control in Niger

NASA Astrophysics Data System (ADS)

Gianotti, Rebecca L.; Bomblies, Arne; Eltahir, Elfatih A. B.

2009-08-01

This paper describes the first use of Hydrology-Entomology and Malaria Transmission Simulator (HYDREMATS), a physically based distributed hydrology model, to investigate environmental management methods for malaria vector control in the Sahelian village of Banizoumbou, Niger. The investigation showed that leveling of topographic depressions where temporary breeding habitats form during the rainy season, by altering pool basin microtopography, could reduce the pool persistence time to less than the time needed for establishment of mosquito breeding, approximately 7 days. Undertaking soil surface plowing can also reduce pool persistence time by increasing the infiltration rate through an existing pool basin. Reduction of the pool persistence time to less than the rainfall interstorm period increases the frequency of pool drying events, removing habitat for subadult mosquitoes. Both management approaches could potentially be considered within a given context. This investigation demonstrates that management methods that modify the hydrologic environment have significant potential to contribute to malaria vector control in water-limited, Sahelian Africa.

Persistent organic pollutants (POPs) in killer whales (Orcinus orca) from the Crozet Archipelago, southern Indian Ocean.

PubMed

Noël, Marie; Barrett-Lennard, Lance; Guinet, Christophe; Dangerfield, Neil; Ross, Peter S

2009-10-01

Persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and dibenzofurans (PCDFs), are ubiquitous environmental contaminants of which significant concentrations are reported in upper trophic level animals. In 1998, we collected blubber biopsy samples (n=11) from killer whales (Orcinus orca) inhabiting the coastal waters around Possession Island, Crozet Archipelago, southern Indian Ocean, for contaminant analyses. Despite inhabiting an isolated region far removed from industrial activities, these killer whales can presently be considered among the most PCB-contaminated cetaceans in the southern hemisphere, with concentrations ranging from 4.4 to 20.5mg/kg lipid weight (lw). PCDD levels ranged from below the detection limit (5 ng/kg) to 77.1 ng/kg lw and PCDF levels from below the detection limit (7 ng/kg) to 36.1 ng/kg lw. Over 70% of our study animals had PCB concentrations which exceeded a 1.3mg/kg PCB threshold established for endocrine disruption and immunotoxicity in free-ranging harbour seals, suggesting that organic contaminants cannot be ruled out as an additional threat to this declining population.

Persistent organic pesticide residues in sediments of Vasai Creek near Mumbai: Assessment of sources and potential ecological risk.

PubMed

Singare, Pravin U

2015-11-15

Thirteen persistent organic pesticides were investigated in the sediments of Vasai Creek near Mumbai to evaluate their pollution levels and potential risks. It was observed that ΣOCPs level was in the range of 597-1538ng/g dw, with an average value of 1115.25ng/g dw. The level of ΣOPPs was in the range of 492-1034ng/g dw, with an average value of 798.15ng/g dw. The values o,p'-DDT/p,p'-DDT ratio gives an indication of use of technical DDT as the prime source of DDT, while the α/γ-BHC ratio indicate that BHCs in study area might have been received from fresh lindane. The results of an ecological risk assessment showed that sediment bound organic pesticides are of more ecotoxicological concern as they might create adverse ecological risk to the marine breeding habitats. These pesticides residues may get remobilize and released to overlying waters creating adverse effects on terrestrial and aquatic organisms. Copyright © 2015 Elsevier Ltd. All rights reserved.

Perchlorate as an emerging contaminant in soil, water and food.

PubMed

Kumarathilaka, Prasanna; Oze, Christopher; Indraratne, S P; Vithanage, Meththika

2016-05-01

Perchlorate ( [Formula: see text] ) is a strong oxidizer and has gained significant attention due to its reactivity, occurrence, and persistence in surface water, groundwater, soil and food. Stable isotope techniques (i.e., ((18)O/(16)O and (17)O/(16)O) and (37)Cl/(35)Cl) facilitate the differentiation of naturally occurring perchlorate from anthropogenic perchlorate. At high enough concentrations, perchlorate can inhibit proper function of the thyroid gland. Dietary reference dose (RfD) for perchlorate exposure from both food and water is set at 0.7 μg kg(-1) body weight/day which translates to a drinking water level of 24.5 μg L(-1). Chromatographic techniques (i.e., ion chromatography and liquid chromatography mass spectrometry) can be successfully used to detect trace level of perchlorate in environmental samples. Perchlorate can be effectively removed by wide variety of remediation techniques such as bio-reduction, chemical reduction, adsorption, membrane filtration, ion exchange and electro-reduction. Bio-reduction is appropriate for large scale treatment plants whereas ion exchange is suitable for removing trace level of perchlorate in aqueous medium. The environmental occurrence of perchlorate, toxicity, analytical techniques, removal technologies are presented. Copyright © 2016 Elsevier Ltd. All rights reserved.

Flooding Frequency Alters Vegetation in Isolated Wetlands

USGS Publications Warehouse

Haag, Kim H.; Lee, Terrie M.

2006-01-01

Many isolated wetlands in central Florida occur as small, shallow depressions scattered throughout the karst topography of the region. In these wetlands, the water table approaches land surface seasonally, and water levels and flooding frequency are largely determined by differences between precipitation and evapotranspiration. Because much of the region is flat with little topographic relief, small changes in wetland water levels can cause large changes in wetland surface area. Persistent changes in wetland flooding frequencies, as a result of changes in rainfall or human activity, can cause a substantial change in the vegetation of thousands of acres of land. Understanding the effect that flooding frequency has on wetland vegetation is important to assessing the overall ecological status of wetlands. Wetland bathymetric mapping, when combined with water-level data and vegetation assessments, can enable scientists to determine the frequency of flooding at different elevations in a wetland and describe the effects of flooding frequency on wetland vegetation at those elevations. Five cypress swamps and five marshes were studied by the U.S. Geological Survey (USGS) during 2000-2004, as part of an interdisciplinary study of isolated wetlands in central Florida (Haag and others, 2005). Partial results from two of these marshes are described in this report.

Paleoenvironmental records of water level and climatic changes from the middle to late Holocene at a Lake Erie coastal wetland, Ontario, Canada

NASA Astrophysics Data System (ADS)

Finkelstein, Sarah A.; Davis, Anthony M.

2006-01-01

Pollen and diatom assemblages, and peat stratigraphies, from a coastal wetland on the northern shore of Lake Erie were used to analyze water level and climatic changes since the middle Holocene and their effects on wetland plant communities. Peat deposition began 4700 cal yr B.P. during the Nipissing II transgression, which was driven by isostatic rebound. At that time, a diatom-rich wild rice marsh existed at the site. Water level dropped at the end of the Nipissing rise at least 2 m within 200 yr, leading to the development of shallower-water plant communities and an environment too dry for most diatoms to persist. The sharp decline in water level was probably driven primarily by outlet incision, but climate likely played some role. The paleoecological records provide evidence for post-Nipissing century-scale transgressions occurring around 2300, 1160, 700 and 450 cal yr B.P. The chronology for these transgressions correlates with other studies from the region and implies climatic forcing. Peat inception in shallow sloughs across part of the study area around 700 cal yr B.P. coincides with the Little Ice Age. These records, considered alongside others from the region, suggest that the Little Ice Age may have resulted in a wetter climate across the eastern Great Lakes region.

Integration of Pseudomonas aeruginosa and Legionella pneumophila in drinking water biofilms grown on domestic plumbing materials.

PubMed

Moritz, Miriam M; Flemming, Hans-Curt; Wingender, Jost

2010-06-01

Drinking water biofilms were grown on coupons of plumbing materials, including ethylene-propylene-diene-monomer (EPDM) rubber, silane cross-linked polyethylene (PE-X b), electron-ray cross-linked PE (PE-X c) and copper under constant flow-through of cold tap water. After 14 days, the biofilms were spiked with Pseudomonas aeruginosa, Legionella pneumophila and Enterobacter nimipressuralis (10(6) cells/mL each). The test bacteria were environmental isolates from contamination events in drinking water systems. After static incubation for 24 h, water flow was resumed and continued for 4 weeks. Total cell count and heterotrophic plate count (HPC) of biofilms were monitored, and P. aeruginosa, L. pneumophila and E. nimipressuralis were quantified, using standard culture-based methods or culture-independent fluorescence in situ hybridization (FISH). After 14 days total cell counts and HPC values were highest on EPDM followed by the plastic materials and copper. P. aeruginosa and L. pneumophila became incorporated into drinking water biofilms and were capable to persist in biofilms on EPDM and PE-X materials for several weeks, while copper biofilms were colonized only by L. pneumophila in low culturable numbers. E. nimipressuralis was not detected in any of the biofilms. Application of the FISH method often yielded orders of magnitude higher levels of P. aeruginosa and L. pneumophila than culture methods. These observations indicate that drinking water biofilms grown under cold water conditions on domestic plumbing materials, especially EPDM and PE-X in the present study, can be a reservoir for P. aeruginosa and L. pneumophila that persist in these habitats mostly in a viable but non-culturable state.

Death receptor and mitochondria-mediated hepatocyte apoptosis underlies liver dysfunction in rats exposed to organic pollutants from drinking water

PubMed Central

Yang, Guanghong; Zhou, Zhiwei; Cen, Yanli; Gui, Xiaolin; Zeng, Qibing; Ao, Yunxia; Li, Qian; Wang, Shiran; Li, Jun; Zhang, Aihua

2015-01-01

Persistent organic pollutants in drinking water impose a substantial risk to the health of human beings, but the evidence for liver toxic effect and the underlying mechanism is scarce. This study aimed to examine the liver toxicity and elucidate the molecular mechanism of organic pollutants in drinking water in normal human liver cell line L02 cells and rats. The data showed that organic extraction from drinking water remarkably impaired rat liver function, evident from the increase in the serum level of alanine aminotransferase, aspartate aminotransferase, and cholinesterase, and decrease in the serum level of total protein and albumin. Organic extraction dose-dependently induced apoptotic cell death in rat liver and L02 cells. Administration of rats with organic extraction promoted death receptor signaling pathway through the increase in gene and protein expression level of Fas and FasL. Treatment of rats with organic extraction also induced mitochondria-mediated apoptosis via increasing the expression level of proapoptotic protein, Bax, but decreasing the expression level of antiapoptotic protein, Bcl-2, resulting in an upregulation of cytochrome c and activation of caspase cascade at both transcriptional and post-transcriptional levels. Moreover, organic extraction enhanced rat liver glutathione S-transferases activity and reactive oxygen species generation, and upregulated aryl hydrocarbon receptor and glutathione S-transferase A1 at both transcriptional and translational levels. Collectively, the results indicate that organic extraction from drinking water impairs liver function, with the involvement of death receptor and mitochondria-mediated apoptosis in rats. The results provide evidence and molecular mechanisms for organic pollutants in drinking water-induced liver dysfunction, which may help prevent and treat organic extraction-induced liver injury. PMID:26316710

Death receptor and mitochondria-mediated hepatocyte apoptosis underlies liver dysfunction in rats exposed to organic pollutants from drinking water.

PubMed

Yang, Guanghong; Zhou, Zhiwei; Cen, Yanli; Gui, Xiaolin; Zeng, Qibing; Ao, Yunxia; Li, Qian; Wang, Shiran; Li, Jun; Zhang, Aihua

2015-01-01

Persistent organic pollutants in drinking water impose a substantial risk to the health of human beings, but the evidence for liver toxic effect and the underlying mechanism is scarce. This study aimed to examine the liver toxicity and elucidate the molecular mechanism of organic pollutants in drinking water in normal human liver cell line L02 cells and rats. The data showed that organic extraction from drinking water remarkably impaired rat liver function, evident from the increase in the serum level of alanine aminotransferase, aspartate aminotransferase, and cholinesterase, and decrease in the serum level of total protein and albumin. Organic extraction dose-dependently induced apoptotic cell death in rat liver and L02 cells. Administration of rats with organic extraction promoted death receptor signaling pathway through the increase in gene and protein expression level of Fas and FasL. Treatment of rats with organic extraction also induced mitochondria-mediated apoptosis via increasing the expression level of proapoptotic protein, Bax, but decreasing the expression level of antiapoptotic protein, Bcl-2, resulting in an upregulation of cytochrome c and activation of caspase cascade at both transcriptional and post-transcriptional levels. Moreover, organic extraction enhanced rat liver glutathione S-transferases activity and reactive oxygen species generation, and upregulated aryl hydrocarbon receptor and glutathione S-transferase A1 at both transcriptional and translational levels. Collectively, the results indicate that organic extraction from drinking water impairs liver function, with the involvement of death receptor and mitochondria-mediated apoptosis in rats. The results provide evidence and molecular mechanisms for organic pollutants in drinking water-induced liver dysfunction, which may help prevent and treat organic extraction-induced liver injury.

Assessment of the climate change impacts on fecal coliform contamination in a tidal estuarine system.

PubMed

Liu, Wen-Cheng; Chan, Wen-Ting

2015-12-01

Climate change is one of the key factors affecting the future microbiological water quality in rivers and tidal estuaries. A coupled 3D hydrodynamic and fecal coliform transport model was developed and applied to the Danshuei River estuarine system for predicting the influences of climate change on microbiological water quality. The hydrodynamic and fecal coliform model was validated using observational salinity and fecal coliform distributions. According to the analyses of the statistical error, predictions of the salinity and the fecal coliform concentration from the model simulation quantitatively agreed with the observed data. The validated model was then applied to predict the fecal coliform contamination as a result of climate change, including the change of freshwater discharge and the sea level rise. We found that the reduction of freshwater discharge under climate change scenarios resulted in an increase in the fecal coliform concentration. The sea level rise would decrease fecal coliform distributions because both the water level and the water volume increased. A reduction in freshwater discharge has a negative impact on the fecal coliform concentration, whereas a rising sea level has a positive influence on the fecal coliform contamination. An appropriate strategy for the effective microbiological management in tidal estuaries is required to reveal the persistent trends of climate in the future.

Risk Levels of Toxic Cyanobacteria in Portuguese Recreational Freshwaters

PubMed Central

Menezes, Carina; Dias, Elsa

2017-01-01

Portuguese freshwater reservoirs are important socio-economic resources, namely for recreational use. National legislation concerning bathing waters does not include mandatory levels or guidelines for cyanobacteria and cyanotoxins. This is an issue of concern since cyanotoxin-based evidence is insufficient to change the law, and the collection of scientific evidence has been hampered by the lack of regulatory levels for cyanotoxins in bathing waters. In this work, we evaluate the profile of cyanobacteria and microcystins (MC) in eight freshwater reservoirs from the center of Portugal, used for bathing/recreation, in order to determine the risk levels concerning toxic cyanobacteria occurrence. Three of the reservoirs did not pose a risk of MC contamination. However, two reservoirs presented a high risk in 7% of the samples according to the World Health Organization (WHO) guidelines for MC in bathing waters (above 20 µg/L). In the remaining three reservoirs, the risk concerning microcystins occurrence was low. However, they exhibited recurrent blooms and persistent contamination with MC up to 4 µg/L. Thus, the risk of exposure to MC and potential acute and/or chronic health outcomes should not be disregarded in these reservoirs. These results contribute to characterize the cyanobacterial blooms profile and to map the risk of toxic cyanobacteria and microcystins occurrence in Portuguese inland waters. PMID:29057822

Developmental Deltamethrin Exposure Causes Persistent Changes in Dopaminergic Gene Expression, Neurochemistry, and Locomotor Activity in Zebrafish.

PubMed

Kung, Tiffany S; Richardson, Jason R; Cooper, Keith R; White, Lori A

2015-08-01

Pyrethroids are commonly used insecticides that are considered to pose little risk to human health. However, there is an increasing concern that children are more susceptible to the adverse effects of pesticides. We used the zebrafish model to test the hypothesis that developmental exposure to low doses of the pyrethroid deltamethrin results in persistent alterations in dopaminergic gene expression, neurochemistry, and locomotor activity. Zebrafish embryos were treated with deltamethrin (0.25-0.50 μg/l), at concentrations below the LOAEL, during the embryonic period [3-72 h postfertilization (hpf)], after which transferred to fresh water until the larval stage (2-weeks postfertilization). Deltamethrin exposure resulted in decreased transcript levels of the D1 dopamine (DA) receptor (drd1) and increased levels of tyrosine hydroxylase at 72 hpf. The reduction in drd1 transcripts persisted to the larval stage and was associated with decreased D2 dopamine receptor transcripts. Larval fish, exposed developmentally to deltamethrin, had increased levels of homovanillic acid, a DA metabolite. Since the DA system is involved in locomotor activity, we measured the swim activity of larval fish following a transition to darkness. Developmental exposure to deltamethrin significantly increased larval swim activity which was attenuated by concomitant knockdown of the DA transporter. Acute exposure to methylphenidate, a DA transporter inhibitor, increased swim activity in control larva, while reducing swim activity in larva developmentally exposed to deltamethrin. Developmental exposure to deltamethrin causes locomotor deficits in larval zebrafish, which is likely mediated by dopaminergic dysfunction. This highlights the need to understand the persistent effects of low-dose neurotoxicant exposure during development. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Developmental Deltamethrin Exposure Causes Persistent Changes in Dopaminergic Gene Expression, Neurochemistry, and Locomotor Activity in Zebrafish

PubMed Central

Kung, Tiffany S.; Richardson, Jason R.; Cooper, Keith R.; White, Lori A.

2015-01-01

Pyrethroids are commonly used insecticides that are considered to pose little risk to human health. However, there is an increasing concern that children are more susceptible to the adverse effects of pesticides. We used the zebrafish model to test the hypothesis that developmental exposure to low doses of the pyrethroid deltamethrin results in persistent alterations in dopaminergic gene expression, neurochemistry, and locomotor activity. Zebrafish embryos were treated with deltamethrin (0.25–0.50 μg/l), at concentrations below the LOAEL, during the embryonic period [3–72 h postfertilization (hpf)], after which transferred to fresh water until the larval stage (2-weeks postfertilization). Deltamethrin exposure resulted in decreased transcript levels of the D1 dopamine (DA) receptor (drd1) and increased levels of tyrosine hydroxylase at 72 hpf. The reduction in drd1 transcripts persisted to the larval stage and was associated with decreased D2 dopamine receptor transcripts. Larval fish, exposed developmentally to deltamethrin, had increased levels of homovanillic acid, a DA metabolite. Since the DA system is involved in locomotor activity, we measured the swim activity of larval fish following a transition to darkness. Developmental exposure to deltamethrin significantly increased larval swim activity which was attenuated by concomitant knockdown of the DA transporter. Acute exposure to methylphenidate, a DA transporter inhibitor, increased swim activity in control larva, while reducing swim activity in larva developmentally exposed to deltamethrin. Developmental exposure to deltamethrin causes locomotor deficits in larval zebrafish, which is likely mediated by dopaminergic dysfunction. This highlights the need to understand the persistent effects of low-dose neurotoxicant exposure during development. PMID:25912032

Dichlorobenzene in ground water: Evidence for long-term persistence

USGS Publications Warehouse

Barber, L.B.

1988-01-01

Hydrologic and geochemical evidence were used to establish the long-term persistence of dichlorobenzene in ground water that has been contaminated from 50 years of rapid-infiltration sewage disposal. An extensive plume of dichlorobenzene extends more than 3,500 meters downgradient from the disposal beds, with concentrations of the combined isomers ranging from less than 0.01 to over 1.0 ??g/l. Based on estimates of maximum ground-water flow velocities, a minimum age of 20 years was established for the farthest downgradient zone of dichlorobenzene contamination. Branched-chained, alkylbenzenesulfonic acid surfactants, that were introduced into the ground water prior to 1966, occur along with dichlorobenzene in the downgradient part of the plume, further establish residence of the compounds in the aquifer for at least 20 years. Although dichlorobenzene can be biologically degraded under aerobic conditions, its persistence at this field site is attributed to the dynamics of the ground-water system. Denitrifying conditions, resulting from the degradation of organic compounds in the aquifer near the disposal beds, appear to have enhanced the persistence of dichlorobenzene, which is not degraded by anaerobic bacteria. Biological degradation of dichlorobenzene in the aerobic part of the plume downgradient from the source is probably limited by the paucity of a suitable organic-carbon substrate and the low concentrations of dissolved oxygen in the contaminated ground water.

Survival of spumavirus, a primate retrovirus, in laboratory media and water.

PubMed

Lotlikar, Madhavi S; Lipson, Steven M

2002-06-04

The persistence of a previously characterized spumavirus strain (strain SV-522) was investigated utilizing various laboratory media and waters, including Eagle's minimal essential medium (EMEM) plus 0% fetal bovine serum (EMEM-0%), EMEM-2%, EMEM-10%, Chlamydia transport medium (CTM), phosphate-buffered saline, distilled, estuarine, and marine water, human serum, and the germicides, ethyl alcohol (70%) and sodium hypochlorite (10%). Experiments were performed at 4 degrees C and/or 23 degrees C. Infectivity endpoints were determined in stock aliquots upon initiation of testing and then after 3, 5, 7, and 10 days. The virus was reisolated from all diluents after 5 days at 23 degrees C and in EMEM-10% after 7 days. The virus was detected in CTM, EMEM-2%, EMEM-10%, and estuarine and marine waters after 7 days at 4 degrees C. Differences in the persistence of the virus may be ascribed to temperature and organic load. Water ionic strengths (e.g., estuarine vs. marine water) had no effect on modifying persistence of viral particles. Infectivity of spumavirus was undetectable after 30 s in 70% ethanol or 10% sodium hypochlorite. After 30 min at 23 degrees C, spumavirus infectivity in normal but not heat-inactivated human serum increased by almost 100-fold. Persistence of infectivity of primate spumavirus after 7 days in media and waters, and the agent's infectious potential in the human host, emphasize a need for cautious recognition during the manipulation of primate cells/organs and in the handling of primates themselves.

Recent decline in crop water productivity in the United States: a call to grow "more crop per drop"

NASA Astrophysics Data System (ADS)

Marshall, M. T.; Tu, K. P.; Thenkabail, P.; Brown, J. F.

2016-12-01

Irrigation for agriculture accounts for approximately 80 to 90% of U.S. consumptive water use. Recent declines in freshwater supply for irrigated agriculture in the western U.S. is particularly alarming, because climate change, water withdrawals from growing and competing sectors, and water pollution, are projected to put further strain on this vital sector. Innovative water management strategies are being proposed to combat this eminent water crisis and include: developing water markets, improving crop water productivity (CWP: "more crop per drop"), and coordinating the use of surface and groundwater supplies. The increase in CWP through crop type or variety selection is particularly lucrative, because it aims to increase the marketable yield of a crop, while reducing the cost of consumptive water use. Here we estimated CWP from 2000-2015 for the Contiguous United States over the primary growing season (mid May - late October) using a recently developed and validated light-use efficiency model for estimating crop yield and the transpiration component of the Priestley-Taylor Jet Propulsion Laboratory evapotranspiration model. The models were parameterized with daily DAYMET 1 km meteorological and 7-day EROS Moderate Resolution Imaging Spectroradiometer 250 m vegetation data. An analysis will be performed on CWP and its components to characterize the magnitude, direction, and persistence of trends. CWP estimates and trends will be overlaid with the U.S. Department of Agriculture's Cropland Data Layer to rank major crops by water use versus marketable yield and to characterize intervention hotspots, respectively. County-level data on surface and ground water withdrawals for irrigated agriculture available through the U.S. Geological Survey will be used to further scrutinize emerging patterns. It is anticipated that over much of the irrigated areas of the western U.S. that persistent and decreasing trends in CWP for major water users (e.g. alfalfa) due to temperature-driven increases in atmospheric moisture demand or potential evapotranspiration will correspond to a decrease (increase) in surface (ground) water use for irrigation.

Scaling Analysis of Tide Gauge Data from the Atlantic, Gulf of Mexico, and Pacific Coasts of the United States

NASA Astrophysics Data System (ADS)

Barton, C. C.; Smigelski, J. R.; Tebbens, S. F.

2008-12-01

Most coastal regions are subject to inundation due to many periodic and non-periodic inputs including for example: diurnal and semi diurnal tides, storms, tsunamis, and global sea level change. Tide guage data provide a frequently sampled long term record of fluctuations in water level. A power-spectral-density analysis of tidal gauge data is used to quantify persistence (degree of internal correlation over various time intervals) in terms of the scaling exponent β and to identify temporal changes in persistence. The stations are located at different proximity to the open ocean, including bays, harbors, and channels. The datasets are from the NOAA CO-OPS Verified Hourly Station Datum. The length of the data sets ranges from 3 years to 101 years. The hourly data sets are decimated to one record every four hours. All data sets analyzed show three distinct regions of persistence with two inflection points at approximately one day and five days. For times less than one day, the scaling exponent ranges between 0 < β < 2.6. For the time interval 1 to 5 days, the scaling exponent ranges between 1.1 < β < 2.1. For times greater than 5 days, the scaling exponent ranges between 0.4 < β < 0.9. Persistence generally decreases as period increases but is stable between the inflection points. At Duck, NC, long term persistence in the tide gauge signal is 0.6 as compared to 0.9 for the biweekly shoreline position signal over twenty years, suggesting a strong correlation between the two and the possibility of using tide gauge data to quantify nearby shoreline mobility over similar time intervals.

Hurricane effects on a shallow lake ecosystem and its response to a controlled manipulation of water level.

PubMed

Havens, K E; Jin, K R; Rodusky, A J; Sharfstein, B; Brady, M A; East, T L; Iricanin, N; James, R T; Harwell, M C; Steinman, A D

2001-04-04

In order to reverse the damage to aquatic plant communities caused by multiple years of high water levels in Lake Okeechobee, Florida (U.S.), the Governing Board of the South Florida Water Management District (SFWMD) authorized a "managed recession" to substantially lower the surface elevation of the lake in spring 2000. The operation was intended to achieve lower water levels for at least 8 weeks during the summer growing season, and was predicted to result in a large-scale recovery of submerged vascular plants. We treated this operation as a whole ecosystem experiment, and assessed ecological responses using data from an existing network of water quality and submerged plant monitoring sites. As a result of large-scale discharges of water from the lake, coupled with losses to evaporation and to water supply deliveries to agriculture and other regional users, the lake surface elevation receded by approximately 1 m between April and June. Water depths in shoreline areas that historically supported submerged plant communities declined from near 1.5 m to below 0.5 m. Low water levels persisted for the entire summer. Despite shallow depths, the initial response (in June 2000) of submerged plants was very limited and water remained highly turbid (due at first to abiotic seston and later to phytoplankton blooms). Turbidity decreased in July and the biomass of plants increased. However, submerged plant biomass did not exceed levels observed during summer 1999 (when water depths were greater) until August. Furthermore, a vascular plant-dominated assemblage (Vallisneria, Potamogeton, and Hydrilla) that occurred in 1999 was replaced with a community of nearly 98% Chara spp. (a macro-alga) in 2000. Hence, the lake"s submerged plant community appeared to revert to an earlier successional stage despite what appeared to be better conditions for growth. To explain this unexpected response, we evaluated the impacts that Hurricane Irene may have had on the lake in the previous autumn. In mid-October 1999, this category 1 hurricane passed just to the south of the lake, with wind velocities over the lake surface reaching 90 km h(-1) at their peak. Output from a three-dimensional hydrodynamic/sediment transport model indicates that during the storm, current velocities in surface waters of the lake increased from near 5 cm s(-1) to as high as 100 cm s(-1). These strong velocities were associated with large-scale uplifting and horizontal transport of fine- grained sediments from the lake bottom. Water quality data collected after the storm confirmed that the hurricane resulted in lake-wide nutrient and suspended solids concentrations far in excess of those previously documented for a 10-year data set. These conditions persisted through the winter months and may have negatively impacted plants that remained in the lake at the end of the 1999 growing season. The results demonstrate that in shallow lakes, unpredictable external forces, such as hurricanes, can play a major role in ecosystem dynamics. In regions where these events are common (e.g., the tropics and subtropics), consideration should be given to how they might affect long-term lake management programs.

Inflow of shelf waters into the Mississippi Sound and Mobile Bay estuaries in October 2015

NASA Astrophysics Data System (ADS)

Cambazoglu, Mustafa Kemal; Soto, Inia M.; Howden, Stephan D.; Dzwonkowski, Brian; Fitzpatrick, Patrick J.; Arnone, Robert A.; Jacobs, Gregg A.; Lau, Yee H.

2017-07-01

The exchange of coastal waters between the Mississippi Sound (MSS), Mobile Bay, and Mississippi Bight is an important pathway for oil and pollutants into coastal ecosystems. This study investigated an event of strong and persistent inflow of shelf waters into MSS and Mobile Bay during October 2015 by combining in situ measurements, satellite ocean color data, and ocean model predictions. Navy Coastal Ocean Model predicted high-salinity shelf waters continuously flowing into the estuarine system and forecasted low-salinity waters trapped inside the estuaries which did not flush out until the passage of tropical cyclone Patricia's remnants in late October. The October 2015 chlorophyll-a anomaly was significantly low inside and outside the MSS for the 2003 to 2015 time series. Similar low-chlorophyll-a anomalies were only seen in 2003. The October 2015 mean in situ salinities were up to 8 psu higher than mean from 2007 to 2015, and some estuarine stations showed persistent salinities above 30 psu for almost a month in agreement with model predictions. October 2015 was associated with low fall seasonal discharge, typical of fall season, and wind which was persistently out of the east to southeast [45-180]°. These persistent wind conditions were linked to the observed anomalous conditions.

The Impact of Wind Development on County-Level Income and Employment: A Review of Methods and an Empirical Analysis (Fact Sheet). Wind And Water Power Program (WWPP).

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

Brown, Jason P.; Pender, John; Wiser, Ryan

2012-09-02

The economic development potential from wind power installations has been a driver of public and policy support for the industry at the local and state levels for many years. The possibility for economic development has been particularly salient in rural areas of the country where new investment, earnings growth, and employment opportunities have, in many cases, otherwise trended downward for some time. Despite frequent mention of the economic development potential of wind power projects, however, questions persist on the magnitude, distribution, and durability of these impacts. Of particular concern for rural communities is whether new investment in wind power projectsmore » stimulates long-term local economic growth and employment. Questions about the economic development and employment impacts of wind power also persist at the national level. However, such debates tend to be more concerned with potential economic losses associated with displacement of other energy sources or land uses and the macroeconomic effects of policy support for renewable energy and changes in electricity rates that might result from wind energy deployment. The present analysis focuses solely on county-level impacts.« less

Agricultural Groundwater Demands in the Conterminous United States

NASA Astrophysics Data System (ADS)

Ho, M. W.; Parthasarathy, V.; Etienne, E.; Russo, T. A.; Devineni, N.; Lall, U.

2016-12-01

In the conterminous United States (CONUS), over 40% of water consumed for irrigation, livestock and domestic water is sourced from groundwater. The late 20th century and 21st century saw an expansion in irrigated agriculture across the CONUS that was accompanied by increased pumping of groundwater. Groundwater is typically used to mitigate impacts of drought on surface water supplies enabling water demands to be met as well as to augment sparse surface water resources in arid regions or where surface water availability is highly variable temporally and/or spatially. A Demand Sensitive Drought Index (DSDI) is used to examine the impacts of agricultural water needs on groundwater in the CONUS. The DSDI accounts for agricultural water deficits driven by low precipitation, high agricultural water demand, or a combination of both. Changes in groundwater levels relative to agricultural water deficits are characterized relative to precipitation during the growing season and winter precipitation. In several key irrigated agricultural regions in the CONUS, long-term trends in groundwater levels appear to reflect prolonged periods of surface water deficits resulting from land use and associated unsustainable water demands. These areas are subsequent unable to recover from persistent states of agricultural drought. Conversely, reductions in agricultural water demands for crops do not necessarily lead to immediate recovery of groundwater levels due to the demand for groundwater in other sectors. Calls to establish or reform groundwater policies have recently been made in an effort to achieve holistic groundwater management strategies that consider the human demands on both surface water and groundwater. There is a need for relevant groundwater policies to ensure that water demands are adequately managed across sectors without unsustainably depleting groundwater resources and to ensure efficient economic activity.

Persistence of F-Specific RNA Coliphages in Surface Waters from a Produce Production Region along the Central Coast of California

PubMed Central

Ravva, Subbarao V.; Sarreal, Chester Z.

2016-01-01

F+ RNA coliphages (FRNA) are used to source-track fecal contamination and as surrogates for enteric pathogen persistence in the environment. However, the environmental persistence of FRNA is not clearly understood and necessitates the evaluation of the survival of prototype and environmental isolates of FRNA representing all four genogroups in surface waters from the central coast of California. Water temperature played a significant role in persistence–all prototype and environmental strains survived significantly longer at 10°C compared to 25°C. Similarly, the availability of host bacterium was found to be critical in FRNA survival. In the absence of E. coli Famp, all prototypes of FRNA disappeared rapidly with a D-value (days for one log reduction) of <1.2 d from water samples incubated at 25°C; the longest surviving prototype was SP. However, in the presence of the host, the order of persistence at 25°C was QB>MS2>SP>GA and at 10°C it was QB = MS2>GA>SP. Significant differences in survival were observed between prototypes and environmental isolates of FRNA. While most environmental isolates disappeared rapidly at 25°C and in the absence of the host, members of genogroups GIII and GI persisted longer with the host compared to members of GII and GIV. Consequentially, FRNA based source tracking methods can be used to detect phages from recent fecal contamination along with those that persist longer in the environment as a result of cooler temperatures and increased host presence. PMID:26784030

A TOXICITY IDENTIFICATION EVALUATION OF SILTY MARINE HARBOR SEDIMENTS TO CHARACTERIZE PERSISTENT AND NON-PERSISTENT CONSTITUENTS

EPA Science Inventory

Sediment toxicity in silty marine harbor sediments is frequently dominated by ammonia or sulfide, leaving the adverse effects of persistent toxic substances unnoticed. To investigate the latter, we subjected interstitial water from three contaminated silty sediments to toxicity i...

Mind the Gap: Persistent and Mobile Organic Compounds-Water Contaminants That Slip Through.

PubMed

Reemtsma, Thorsten; Berger, Urs; Arp, Hans Peter H; Gallard, Hervé; Knepper, Thomas P; Neumann, Michael; Quintana, José Benito; Voogt, Pim de

2016-10-04

The discharge of persistent and mobile organic chemicals (PMOCs) into the aquatic environment is a threat to the quality of our water resources. PMOCs are highly polar (mobile in water) and can pass through wastewater treatment plants, subsurface environments and potentially also drinking water treatment processes. While a few such compounds are known, we infer that their number is actually much larger. This Feature highlights the issue of PMOCs from an environmental perspective and assesses the gaps that appear to exist in terms of analysis, monitoring, water treatment and regulation. On this basis we elaborate strategies on how to narrow these gaps with the intention to better protect our water resources.

Physical climate response to a reduction of anthropogenic climate forcing

NASA Astrophysics Data System (ADS)

Myneni, R. B.; Samanta, A.; Anderson, B. T.; Ganguly, S.; Knyazikhin, Y.; Nemani, R. R.

2009-12-01

Recent research indicates that the warming of the climate system resulting from increased greenhouse gas (GHG) emissions over the next century will persist for many centuries after the cessation of these emissions, due principally to the persistence of elevated atmospheric carbon dioxide (CO2) concentrations and their attendant radiative forcing. However, it is unknown whether the responses of other components of the climate system—including those related to Greenland and Antarctic ice cover, the Atlantic thermohaline circulation, the West African monsoon, and ecosystems and human welfare—would be reversed even if atmospheric CO2 concentrations were to recover to 1990 levels. Here, using a simple set of experiments employing a current-generation numerical climate model, we show that many physical characteristics of the climate system, including global temperatures, precipitation, soil moisture and sea ice, recover as CO2 concentrations decrease. In contrast, stratospheric water vapor, especially in the high latitudes, exhibits non-linear hysteresis. In these regions, increases in water vapor, which initially result from increased CO2 concentrations, remain present even as CO2 concentrations recover. This result has implications for the sensitivity of the global climate system, the evolution and recovery of stratospheric ozone, and the persistence of weather patterns in the high latitudes. Our work also demonstrates that further identification of threshold behavior in response to human-induced global climate change requires an examination of the full Earth system, including cryosphere, biosphere, and chemistry.

Using reanalysis and drought indices to study portfolio-level climate risk in the industry sector

NASA Astrophysics Data System (ADS)

Bonnafous, L.

2017-12-01

Water-related hazards including flooding due to extreme rainfall, persistent drought and pollution, either due to industrial operations themselves, or to the failure of infrastructure have emerged as a potential risk for industrial operations. Most companies have risk management plans at each operational location to address these risks to a certain design level. The residual risk may or may not be managed, and is typically not quantified at a portfolio scale, i.e. across many sites. Given that climate is the driver of many of these extreme events, and there is evidence of quasi-periodic climate regimes at inter-annual and decadal timescales, it is possible that a portfolio is subject to persistent, multi-year exceedances of the design level. It is thus likely that there is correlation in the climate-induced portfolio water risk across its operational sites as multiple sites may experience a hazard beyond the design level in a given year. Therefore, a need exists for water risk indexes that allow for an exploration of the possible space and/or time clustering in exposure across many sites contained in a portfolio. Focusing on extreme daily rainfall amounts and monthly to yearly drought, and using examples from major mining companies, we illustrate how such indexes can be developed using reanalysis products as well as gridded datasets of drought indices based on climate data records. For the examples of mining companies provided, we note that the actual exposure is substantially higher than would be expected in the absence of space and time correlation of risk as is often tacitly assumed within the industry. We also find evidence for the increasing exposure to climate-induced risk, and for decadal variability in exposure. The relative vulnerability of different portfolios to multiple extreme events in a given year is also demonstrated.

Temporal and spatial changes in persistent organic pollutants in Vietnamese coastal waters detected from plastic resin pellets.

PubMed

Le, Dung Quang; Takada, Hideshige; Yamashita, Rei; Mizukawa, Kaoruko; Hosoda, Junki; Tuyet, Dao Anh

2016-08-15

Plastic resin pellets collected at Minh Chau island and Ba Lat estuary between 2007 and 2014 in Vietnam were analyzed for dichloro-diphenyl-trichloroethanes (DDTs), polychlorinated biphenyls (PCBs) and hexachlorocyclohexanes (HCHs). The study was carried out as part of the International Pellet Watch program for monitoring the global distribution of persistent organic pollutants (POPs). Higher levels of DDTs compared to PCBs indicated agricultural inputs rather than industrial discharges in the region. Most POP concentrations on both beaches decreased over the period, with the exception of HCH isomers. Though the concentration of DDTs showed a drastic decline on both beaches between 2007/2008 and 2014, DDTs accounted for 60-80% of total DDTs, suggesting that there is still a fresh input of these chemicals in the region. This study strongly recommends further investigations to track temporal and spatial patterns of POP levels in the marine environment using plastic resin pellets. Copyright © 2016 Elsevier Ltd. All rights reserved.

Detection of conveyance changes in St. Clair River using historical water-level and flow data with inverse one-dimensional hydrodynamic modeling

USGS Publications Warehouse

Holtschlag, David J.; Hoard, C.J.

2009-01-01

St. Clair River is a connecting channel that transports water from Lake Huron to the St. Clair River Delta and Lake St. Clair. A negative trend has been detected in differences between water levels on Lake Huron and Lake St. Clair. This trend may indicate a combination of flow and conveyance changes within St. Clair River. To identify where conveyance change may be taking place, eight water-level gaging stations along St. Clair River were selected to delimit seven reaches. Positive trends in water-level fall were detected in two reaches, and negative trends were detected in two other reaches. The presence of both positive and negative trends in water-level fall indicates that changes in conveyance are likely occurring among some reaches because all reaches transmit essentially the same flow. Annual water-level fall in reaches and reach lengths was used to compute conveyance ratios for all pairs of reaches by use of water-level data from 1962 to 2007. Positive and negative trends in conveyance ratios indicate that relative conveyance is changing among some reaches. Inverse one-dimensional (1-D) hydrodynamic modeling was used to estimate a partial annual series of effective channel-roughness parameters in reaches forming the St. Clair River for 21 years when flow measurements were sufficient to support parameter estimation. Monotonic, persistent but non-monotonic, and irregular changes in estimated effective channel roughness with time were interpreted as systematic changes in conveyances in five reaches. Time-varying parameter estimates were used to simulate flow throughout the St. Clair River and compute changes in conveyance with time. Based on the partial annual series of parameters, conveyance in the St. Clair River increased about 10 percent from 1962 to 2002. Conveyance decreased, however, about 4.1 percent from 2003 to 2007, so that conveyance was about 5.9 percent higher in 2007 than in 1962.

Chornobyl 30 years later: Radiation, pregnancies, and developmental anomalies in Rivne, Ukraine.

PubMed

Wertelecki, Wladimir; Chambers, Christina D; Yevtushok, Lyubov; Zymak-Zakutnya, Natalya; Sosyniuk, Zoriana; Lapchenko, Serhiy; Ievtushok, Bogdana; Akhmedzhanova, Diana; Komov, Oleksandr

2017-01-01

In the 30 years since the Chornobyl nuclear power plant disaster, there is evidence of persistent levels of incorporated ionizing radiation in adults, children and pregnant women in the surrounding area. Measured levels of Cesium-137 vary by region, and may be influenced by dietary and water sources as well as proximity to nuclear power plants. Since 2000, comprehensive, population-based birth defects monitoring has been performed in selected regions of Ukraine to evaluate trends and to generate hypotheses regarding potential causes of unexplained variations in defect rates. Significantly higher rates of microcephaly, neural tube defects, and microphthalmia have been identified in selected regions of Ukraine collectively known as Polissia compared to adjacent regions collectively termed non-Polissia, and these significantly higher rates were evident particularly in the years 2000-2009. The Polissia regions have also demonstrated higher mean whole body counts of Cesium-137 compared to values in individuals residing in other non-Polissia regions. The potential causal relationship between persistent ionizing radiation pollution and selected congenital anomaly rates supports the need for a more thorough, targeted investigation of the sources of persistent ionizing radiation and the biological plausibility of a potential teratogenic effect. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Fate and Transport of Organic Contaminants in Coastal Marsh Sediments Resulting from the 2010 Gulf Oil Spill

NASA Astrophysics Data System (ADS)

Natter, M.; Keevan, J.; Lee, M.; Keimowitz, A.; Savrda, C.; Son, A.; Okeke, B.; Wang, Y.

2011-12-01

The devastating explosion and subsequent sinking of the oil platform Deepwater Horizon at the British Petroleum Macondo-1 well in the Northern Gulf of Mexico on April 20, 2010, released approximately 4.9 million barrels of crude oil into the Gulf before the well was capped on July 15, 2010. Although most light compounds of oil may be easily degraded by natural microbes on the short term, saturated heavy oil (e.g., asphaltenes, resins, polycyclic aromatics, etc.) and those adsorbed by sediments could persist in the environment for decades. The long-term effects of high levels of persistent oil compounds on biogeochemical evolution and ecosystems of salt marshes remain unclear. This research investigates the spatial range and changes in levels of oil and their biogeochemical impacts. A total of ten marsh sampling sites that varied from pristine, non-effected marshes (e.g., Weeks Bay and Wolf Bay, Alabama) to heavily oiled wetlands (e.g., Bay Jimmy and Bayou Dulac, Louisiana) were utilized for this study. Sediment cores, bulk sediments, surface water samples, degraded oil, oiled dead marsh grass, and live marsh grass were collected from these sites in an attempt to study the source, distribution, and evolution of organic compounds and oil present in sediments and pore-waters. Geochemical analyses show alarmingly high organic carbon loads in pore-waters and sediments at heavily contaminated sites months after the influx of oil ceased. Very high levels (10-28%) of total organic carbon (TOC) within the heavily oiled sediments (down to 30 cm) are clearly distinguished from those found in pristine wetland sediments (generally < 5%). TOC levels are elevated in the deeper sediments while being depleated in the uppermost ones at certain locations. The TOC contents in uppermost sediments may be reduced by microbial degradation, water mixing, and the use of oil dispersants. Furthermore, dissolved organic carbon (DOC) levels of pore-waters extracted from oiled sediments, ranging up to hundreds of mg/kg, are on the order of one to two magnitudes higher than those at pristine and slightly contaminated sites. These DOC levels also interestingly increase with depth, possibly indicating saltwater-freshwater mixing near the sediment surface or freshwater recharge from rainfall. The spatial changes in DOC indicate that seawater and oil invaded along the deeper portion of the marsh sediments due to their higher density with respect to freshwater. TOC and DOC data clearly indicate that not all the spilled oil rose to the water surface and washed on-shore. Plumes of partially degraded oil could be spreading at various levels of the water column and feeding the underlying sediments. Geochemical biomarkers and stable isotopes (carbon and nitrogen) analyses of wetland plants, oiled sediments, and initial crude oils are underway to trace the sources of oil and the extent of oil degradation in impacted wetlands.

Handwashing and Ebola virus disease outbreaks: A randomized comparison of soap, hand sanitizer, and 0.05% chlorine solutions on the inactivation and removal of model organisms Phi6 and E. coli from hands and persistence in rinse water

PubMed Central

Gallandat, Karin; Daniels, Kyle; Desmarais, Anne Marie; Scheinman, Pamela; Lantagne, Daniele

2017-01-01

To prevent Ebola transmission, frequent handwashing is recommended in Ebola Treatment Units and communities. However, little is known about which handwashing protocol is most efficacious. We evaluated six handwashing protocols (soap and water, alcohol-based hand sanitizer (ABHS), and 0.05% sodium dichloroisocyanurate, high-test hypochlorite, and stabilized and non-stabilized sodium hypochlorite solutions) for 1) efficacy of handwashing on the removal and inactivation of non-pathogenic model organisms and, 2) persistence of organisms in rinse water. Model organisms E. coli and bacteriophage Phi6 were used to evaluate handwashing with and without organic load added to simulate bodily fluids. Hands were inoculated with test organisms, washed, and rinsed using a glove juice method to retrieve remaining organisms. Impact was estimated by comparing the log reduction in organisms after handwashing to the log reduction without handwashing. Rinse water was collected to test for persistence of organisms. Handwashing resulted in a 1.94–3.01 log reduction in E. coli concentration without, and 2.18–3.34 with, soil load; and a 2.44–3.06 log reduction in Phi6 without, and 2.71–3.69 with, soil load. HTH performed most consistently well, with significantly greater log reductions than other handwashing protocols in three models. However, the magnitude of handwashing efficacy differences was small, suggesting protocols are similarly efficacious. Rinse water demonstrated a 0.28–4.77 log reduction in remaining E. coli without, and 0.21–4.49 with, soil load and a 1.26–2.02 log reduction in Phi6 without, and 1.30–2.20 with, soil load. Chlorine resulted in significantly less persistence of E. coli in both conditions and Phi6 without soil load in rinse water (p<0.001). Thus, chlorine-based methods may offer a benefit of reducing persistence in rinse water. We recommend responders use the most practical handwashing method to ensure hand hygiene in Ebola contexts, considering the potential benefit of chlorine-based methods in rinse water persistence. PMID:28231311

Emergence and fate of cyclic volatile polydimethylsiloxanes (D4, D5) in municipal waste streams: release mechanisms, partitioning and persistence in air, water, soil and sediments.

PubMed

Surita, Sharon C; Tansel, Berrin

2014-01-15

Siloxane use in consumer products (i.e., fabrics, paper, concrete, wood, adhesive surfaces) has significantly increased in recent years due to their excellent water repelling and antimicrobial characteristics. The objectives of this study were to evaluate the release mechanisms of two siloxane compounds, octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5), which have been detected both at landfills and wastewater treatment plants, estimate persistence times in different media, and project release quantities over time in relation to their increasing use. Analyses were conducted based on fate and transport mechanisms after siloxanes enter waste streams. Due to their high volatility, the majority of D4 and D5 end up in the biogas during decomposition. D5 is about ten times more likely to partition into the solid phase (i.e., soil, biosolids). D5 concentrations in the wastewater influent and biogas are about 16 times and 18 times higher respectively, in comparison to the detected levels of D4. © 2013 Elsevier B.V. All rights reserved.

Ethanol affects hepatitis C pathogenesis: humanized SCID Alb-uPA mouse model.

PubMed

Osna, Natalia A; Kharbanda, Kusum K; Sun, Yimin; Simpson, Ronda L; Poluektova, Larisa E; Ganesan, Murali; Wisecarver, James L; Mercer, David F

2014-07-18

Alcohol consumption exacerbates the course of hepatitis C viral (HCV) infection, worsens outcomes and contributes to the development of chronic infection that exhibits low anti-viral treatment efficiency. The lack of suitable in vivo models makes HCV-ethanol studies very difficult. Here, we examine whether chimeric SCID Alb-uPA mice transplanted with human hepatocytes and infected with HCV develop worsening pathology when fed ethanol. After 5 weeks of feeding, such mice fed chow+water (control) or chow+20% ethanol in water (EtOH) diets mice developed oxidative stress, decreased proteasome activity and increased steatosis. Importantly, HCV(+) mice in the control group cleared HCV RNA after 5 weeks, while the infection persisted in EtOH-fed mice at the same or even higher levels compared with pre-feeding HCV RNA. We conclude that in chimeric SCID Alb-uPA mice, EtOH exposure causes the complex biochemical and histological changes typical for alcoholic liver injury. In addition, ethanol feeding delays the clearance of HCV RNA thereby generating persistent infection and promoting liver injury. Overall, this model is appropriate for conducting HCV-ethanol studies. Published by Elsevier Inc.

Presence and Persistence of Salmonella in Water: The Impact on Microbial Quality of Water and Food Safety.

PubMed

Liu, Huanli; Whitehouse, Chris A; Li, Baoguang

2018-01-01

Salmonella ranks high among the pathogens causing foodborne disease outbreaks. According to the Centers for Disease Control and Prevention, Salmonella contributed to about 53.4% of all foodborne disease outbreaks from 2006 to 2017, and approximately 32.7% of these foodborne Salmonella outbreaks were associated with consumption of produce. Trace-back investigations have suggested that irrigation water may be a source of Salmonella contamination of produce and a vehicle for transmission. Presence and persistence of Salmonella have been reported in surface waters such as rivers, lakes, and ponds, while ground water in general offers better microbial quality for irrigation. To date, culture methods are still the gold standard for detection, isolation and identification of Salmonella in foods and water. In addition to culture, other methods for the detection of Salmonella in water include most probable number, immunoassay, and PCR. The U.S. Food and Drug Administration (FDA) issued the Produce Safety Rule (PSR) in January 2013 based on the Food Safety Modernization Act (FSMA), which calls for more efforts toward enhancing and improving approaches for the prevention of foodborne outbreaks. In the PSR, agricultural water is defined as water used for in a way that is intended to, or likely to, contact covered produce, such as spray, wash, or irrigation. In summary, Salmonella is frequently present in surface water, an important source of water for irrigation. An increasing evidence indicates irrigation water as a source (or a vehicle) for transmission of Salmonella . This pathogen can survive in aquatic environments by a number of mechanisms, including entry into the viable but nonculturable (VBNC) state and/or residing within free-living protozoa. As such, assurance of microbial quality of irrigation water is critical to curtail the produce-related foodborne outbreaks and thus enhance the food safety. In this review, we will discuss the presence and persistence of Salmonella in water and the mechanisms Salmonella uses to persist in the aquatic environment, particularly irrigation water, to better understand the impact on the microbial quality of water and food safety due to the presence of Salmonella in the water environment.

Presence and Persistence of Salmonella in Water: The Impact on Microbial Quality of Water and Food Safety

PubMed Central

Liu, Huanli; Whitehouse, Chris A.; Li, Baoguang

2018-01-01

Salmonella ranks high among the pathogens causing foodborne disease outbreaks. According to the Centers for Disease Control and Prevention, Salmonella contributed to about 53.4% of all foodborne disease outbreaks from 2006 to 2017, and approximately 32.7% of these foodborne Salmonella outbreaks were associated with consumption of produce. Trace-back investigations have suggested that irrigation water may be a source of Salmonella contamination of produce and a vehicle for transmission. Presence and persistence of Salmonella have been reported in surface waters such as rivers, lakes, and ponds, while ground water in general offers better microbial quality for irrigation. To date, culture methods are still the gold standard for detection, isolation and identification of Salmonella in foods and water. In addition to culture, other methods for the detection of Salmonella in water include most probable number, immunoassay, and PCR. The U.S. Food and Drug Administration (FDA) issued the Produce Safety Rule (PSR) in January 2013 based on the Food Safety Modernization Act (FSMA), which calls for more efforts toward enhancing and improving approaches for the prevention of foodborne outbreaks. In the PSR, agricultural water is defined as water used for in a way that is intended to, or likely to, contact covered produce, such as spray, wash, or irrigation. In summary, Salmonella is frequently present in surface water, an important source of water for irrigation. An increasing evidence indicates irrigation water as a source (or a vehicle) for transmission of Salmonella. This pathogen can survive in aquatic environments by a number of mechanisms, including entry into the viable but nonculturable (VBNC) state and/or residing within free-living protozoa. As such, assurance of microbial quality of irrigation water is critical to curtail the produce-related foodborne outbreaks and thus enhance the food safety. In this review, we will discuss the presence and persistence of Salmonella in water and the mechanisms Salmonella uses to persist in the aquatic environment, particularly irrigation water, to better understand the impact on the microbial quality of water and food safety due to the presence of Salmonella in the water environment. PMID:29900166

Tracing groundwater with low-level detections of halogenated VOCs in a fractured carbonate-rock aquifer, Leetown Science Center, West Virginia, USA

USGS Publications Warehouse

Plummer, Niel; Sibrell, Philip L.; Casile, Gerolamo C.; Busenberg, Eurybiades; Hunt, Andrew G.; Schlosser, Peter

2013-01-01

Measurements of low-level concentrations of halogenated volatile organic compounds (VOCs) and estimates of groundwater age interpreted from 3H/3He and SF6 data have led to an improved understanding of groundwater flow, water sources, and transit times in a karstic, fractured, carbonate-rock aquifer at the Leetown Science Center (LSC), West Virginia. The sum of the concentrations of a set of 16 predominant halogenated VOCs (TDVOC) determined by gas chromatography with electron-capture detector (GC–ECD) exceeded that possible for air–water equilibrium in 34 of the 47 samples (median TDVOC of 24,800 pg kg−1), indicating that nearly all the water sampled in the vicinity of the LSC has been affected by addition of halogenated VOCs from non-atmospheric source(s). Leakage from a landfill that was closed and sealed nearly 20 a prior to sampling was recognized and traced to areas east of the LSC using low-level detection of tetrachloroethene (PCE), methyl chloride (MeCl), methyl chloroform (MC), dichlorodifluoromethane (CFC-12), and cis-1,2-dichloroethene (cis-1,2-DCE). Chloroform (CHLF) was the predominant VOC in water from domestic wells surrounding the LSC, and was elevated in groundwater in and near the Fish Health Laboratory at the LSC, where a leak of chlorinated water occurred prior to 2006. The low-level concentrations of halogenated VOCs did not exceed human or aquatic-life health criteria, and were useful in providing an awareness of the intrinsic susceptibility of the fractured karstic groundwater system at the LSC to non-atmospheric anthropogenic inputs. The 3H/3He groundwater ages of spring discharge from the carbonate rocks showed transient behavior, with ages averaging about 2 a in 2004 following a wet climatic period (2003–2004), and ages in the range of 4–7 a in periods of more average precipitation (2008–2009). The SF6 and CFC-12 data indicate older water (model ages of 10s of years or more) in the low-permeability shale of the Martinsburg Formation located to the west of the LSC. A two-a record of specific conductance, water temperature, and discharge recorded at 30-min intervals demonstrated an approximately 3-month lag in discharge at Gray Spring. The low groundwater ages of waters from the carbonate rocks support rapid advective transport of contaminants from the LSC vicinity, yet the nearly ubiquitous occurrence of low-level concentrations of halogenated VOCs at the LSC suggests the presence of long-term persistent sources, such as seepage from the closed and sealed landfill, infiltration of VOCs that may persist locally in the epikarst, exchange with low-permeability zones in fractured rock, and upward leakage of older water that may contain elevated concentrations of halogenated VOCs from earlier land use activities.

Coupled soil respiration and transpiration dynamics from tree-scale to catchment scale in dry Rocky Mountain pine forests and the role of snowpack

NASA Astrophysics Data System (ADS)

Berryman, E.; Barnard, H. R.; Brooks, P. D.; Adams, H.; Burns, M. A.; Wilson, W.; Stielstra, C. M.

2013-12-01

A current ecohydrological challenge is quantifying the exact nature of carbon (C) and water couplings across landscapes. An emerging framework of understanding places plant physiological processes as a central control over soil respiration, the largest source of CO2 to the atmosphere. In dry montane forests, spatial and temporal variability in forest physiological processes are governed by hydrological patterns. Critical feedbacks involving respiration, moisture supply and tree physiology are poorly understood and must be quantified at the landscape level to better predict carbon cycle implications of regional drought under future climate change. We present data from an experiment designed to capture landscape variability in key coupled hydrological and C processes in forests of Colorado's Front Range. Sites encompass three catchments within the Boulder Creek watershed, range from 1480 m to 3021 m above sea level and are co-located with the DOE Niwot Ridge Ameriflux site and the Boulder Creek Critical Zone Observatory. Key hydrological measurements (soil moisture, transpiration) are coupled with soil respiration measurements within each catchment at different landscape positions. This three-dimensional study design also allows for the examination of the role of water subsidies from uplands to lowlands in controlling respiration. Initial findings from 2012 reveal a moisture threshold response of the sensitivity of soil respiration to temperature. This threshold may derive from tree physiological responses to variation in moisture availability, which in turn is controlled by the persistence of snowpack. Using data collected in 2013, first, we determine whether respiration moisture thresholds represent triggers for transpiration at the individual tree level. Next, using stable isotope ratios of soil respiration and xylem and soil water, we compare the depths of respiration to depths of water uptake to assign tree vs. understory sources of respiration. This will help determine whether tree root-zone respiration exhibits a similar moisture threshold. Lastly, we examine whether moisture thresholds to temperature sensitivity are consistent across a range of snowpack persistence. Findings are compared to data collected from sites in Arizona and New Mexico to better establish the role of winter precipitation in governing growing season respiration rates. The outcome of this study will contribute to a better understanding of linkages among water, tree physiology, and soil respiration with the ultimate goal of scaling plot-level respiration fluxes to entire catchments.

Growth and persistence of pathogens on granular activated carbon filters.

PubMed Central

Camper, A K; LeChevallier, M W; Broadaway, S C; McFeters, G A

1985-01-01

Three enteric pathogens Yersinia enterocolitica O:8, Salmonella typhimurium, and enterotoxigenic Escherichia coli, were examined for their ability to colonize granular activated carbon (GAC) in pure cultures and in the presence of autochthonous river water organisms. All three organisms readily colonized sterile GAC and maintained populations of ca. 10(5) to 10(7) CFU g-1 for 14 days when suspended in sterile river water. Exposure of pathogen biofilms on GAC to unsterile river water resulted in a gradual decline in pathogens on the carbon (0.08 to 0.14 log day-1). When pathogens were introduced to sterile GAC in the presence of heterotrophic plate count organisms, they attached at levels similar to those in the pure cultures and then decreased (0.10 to 0.22 log day-1). When added with heterotrophic plate count bacteria to GAC supporting a mature biofilm of native river water bacteria, they attached at a lower level (1.0 X 10(4) to 4.6 X 10(4) CFU g-1) and decreased at a more rapid rate (0.11 to 0.70 log day-1). PMID:3911903

A persistent organic pollutant related with unusual high frequency of hermaphroditism in the neotropical anuran Physalaemus cuvieri Fitzinger, 1826.

PubMed

Moresco, Rafaela M; Margarido, Vladimir P; de Oliveira, Classius

2014-07-01

Representing a reflection of anthropic activity, the level of xenobiotic compounds in aquatic ecosystems has increased in recent years, bringing severe damage to the environment. The present work reports the occurrence of malformation in gonads of Physalaemus cuvieri individuals from a population of Atlantic Forest in Southern Brazil. Twenty male specimens were collected, which had their testicles removed, immersed in Karnovsky fixative solution, included in historesin for 2 μm cuts and stained with Hematoxylin-eosin. Four specimens showed intersexual gonads condition along with the presence of sperm and oocytes. In order to test a possible contamination of water, 2L were collected from the water body to check organochlorine, organophosphate and carbamate compounds. The analysis of water showed the presence of agrotoxic Dieldrin in a concentration of 0.05 μg/L, representing a concentration above the recommended reference. This agrotoxic, in addition to acting as endocrine disrupter and commercially prohibited, has quite persistent residual effects, and may be responsible for the high frequency of P. cuvieri with intersexual gonads, which in the long term can represent a risk for this population due to the potential impact on its effective reproductive ability. Copyright © 2014 Elsevier Inc. All rights reserved.

Predicting the response of the Amazon rainforest to persistent drought conditions under current and future climates: a major challenge for global land surface models

NASA Astrophysics Data System (ADS)

Joetzjer, E.; Delire, C.; Douville, H.; Ciais, P.; Decharme, B.; Fisher, R.; Christoffersen, B.; Calvet, J. C.; da Costa, A. C. L.; Ferreira, L. V.; Meir, P.

2014-08-01

While a majority of Global Climate Models project dryer and longer dry seasons over the Amazon under higher CO2 levels, large uncertainties surround the response of vegetation to persistent droughts in both present-day and future climates. We propose a detailed evaluation of the ability of the ISBACC Land Surface Model to capture drought effects on both water and carbon budgets, comparing fluxes and stocks at two recent ThroughFall Exclusion (TFE) experiments performed in the Amazon. We also explore the model sensitivity to different Water Stress Function (WSF) and to an idealized increase in CO2 concentration and/or temperature. In spite of a reasonable soil moisture simulation, ISBACC struggles to correctly simulate the vegetation response to TFE whose amplitude and timing is highly sensitive to the WSF. Under higher CO2 concentration, the increased Water Use Efficiency (WUE) mitigates the ISBACC's sensitivity to drought. While one of the proposed WSF formulation improves the response of most ISBACC fluxes, except respiration, a parameterization of drought-induced tree mortality is missing for an accurate estimate of the vegetation response. Also, a better mechanistic understanding of the forest responses to drought under a warmer climate and higher CO2 concentration is clearly needed.

The Interconnectedness of Water and Health: Translating Science Into Public Health-driven Policy

NASA Astrophysics Data System (ADS)

Lichtveld, M.

2017-12-01

Louisiana and other U.S. Gulf Coast communities' unique vulnerability stems from three interconnected stressors they face: historic health disparities, persistent environmental stressors, and a geography prone to both natural and technological disasters. The health of the ecosystem is inextricably linked to that of humans. Specifically, water presents both a central asset and an intransigent environmental health threat. Waterborne illnesses associated with infectious organisms, chemical contaminants, coastal erosion, natural and technological disasters such as hurricanes and oil spills, as well as climate change-associated sea level rise and dead zones, all can negatively impact human health. Existing water-related policies at the federal, state, and local levels have failed to effectively protect the health of communities and their environment to date. For example, despite the existence of the Clean Water Act and the Safe Drinking Water Act, oil spills and drinking water contamination continue to pose significant threats to communities' health and wellbeing. This presentation will examine water-related threats to Gulf Coast communities and their ecosystem. Emphasis will be placed on key examples of policy failure and the impact such failures. A public health-driven framework will demonstrate how science can inform evidence- based policy and in turn prevention-driven public health practice.

Evaluation of a new pressure ulcer preventive dressing containing ceramide 2 with low frictional outer layer.

PubMed

Nakagami, Gojiro; Sanada, Hiromi; Konya, Chizuko; Kitagawa, Atsuko; Tadaka, Etsuko; Matsuyama, Yutaka

2007-09-01

This paper is a report of an evaluation of the effectiveness of a newly developed dressing for preventing persistent erythema and pressure ulcer development and improving the water-holding capacity without increasing the skin pH in bedridden older patients. Shear forces and skin dryness play important roles in persistent erythema and pressure ulcer development. To eliminate these risks, we developed a dressing to reduce shear forces and improve the water-holding capacity. However, the effects of this dressing in clinical settings remain unknown. An experimental bilateral comparison study was conducted at a hospital in Japan in 2004 with 37 bedridden older patients at risk of pressure ulcer development. The dressing was randomly applied to the right or left greater trochanter for 3 weeks. No dressing was applied to the opposite side as a control. The skin was monitored weekly during the 3-week application for persistent erythema and pressure ulcer development. Skin hydration and pH were also assessed during the intervention and for 1 week after dressing removal. The incidence of persistent erythema was significantly lower in the intervention area than the control area [P = 0.007, RR 0.18 (95% CI: 0.05-0.73) and NNT 4.11 (2.50-11.63) ]. No pressure ulcers occurred in either the intervention or control area. Skin hydration increased significantly during dressing application and remained high after removal (P < 0.001) relative to the control area. Skin pH decreased significantly during the application (P < 0.001) but returned to control levels after removal (P = 0.38). This safe and effective dressing can be used for patients with highly prominent bones and dry skin to prevent pressure ulcers.

A Persistence Model for African American Male Urban Community College Students.

ERIC Educational Resources Information Center

Mason, Harold P.

1998-01-01

Studies Kennedy-King College's low level of persistence among African-American "nontraditional" male students, and the resulting high rate of departure before completing specified goals. Proposes a model of persistence to develop modes of action, program enhancements, and activities within the college to increase persistence level. (24…

Relations between groundwater levels and anthropogenic and meteorological stressors at selected sites in east-central Florida, 1995-2007

USGS Publications Warehouse

Murray, Louis C.

2010-01-01

Multivariate linear regression analyses were used to define the relations of water levels in the Upper Floridan aquifer (UFA) and surficial aquifer system (SAS) to anthropogenic and meteorological stressors between 1995 and 2007 at two monitoring well sites (Charlotte Street and Lake Oliver) in east-central Florida. Anthropogenic stressors of interest included municipal and agricultural groundwater withdrawals, and application of reclaimed-water to rapid-infiltration basins (source of aquifer recharge). Meteorological stressors included precipitation and potential evapotranspiration. Overall, anthropogenic and meteorological stressors accounted for about 40 to 89 percent of the variance in UFA and SAS groundwater levels and water-level changes. While mean monthly water levels were better correlated with monthly stressor values, changes in UFA and SAS water levels were better correlated with changes in stressor values. Water levels and water-level changes were influenced by system persistence as the moving-averaged values of both stressor types, which accounted for the influence of the previous month(s) conditions, consistently yielded higher adjusted coefficients of determination (R2 adj) values than did single monthly values. While monthly water-level changes tend to be influenced equally with both stressors across the hydrologically averaged 13-year period, changes were more influenced by one stressor or the other seasonally and during extended wet and dry periods. Seasonally, UFA water-level changes tended to be more influenced by anthropogenic stressors than by meteorological stressors, while changes in SAS water levels tended to be more influenced by meteorological stressors. During extended dry periods (12 months or greater), changes in UFA water levels at Charlotte Street were more affected by anthropogenic stressors than by meteorological stressors, while changes in SAS levels were more affected by meteorological stressors. At Lake Oliver, changes in both UFA and SAS water levels were better correlated with meteorological stressors for all but the wet period between April 1995 and April 1996. Interestingly, changes in both UFA and SAS water levels at Charlotte Street were also better correlated with anthropogenic stressors during a similar wet period between April 1995 and June 1996 when substantive reductions in groundwater withdrawals resulted in appreciable recovery of both UFA and SAS water levels. The regional effects of anthropogenic stressors had limited influence on water-level changes at Charlotte Street and virtually no influence on changes at Lake Oliver. When regressed against the 2.2 Mgal/d (million gallons per day) of municipal withdrawals located within 2 miles of the Charlotte Street site, water-level changes were influenced solely by precipitation and potential evapotranspiration. At a radius of 2.5 miles, however, where cumulative withdrawals totaled about 9.5 Mgal/d, water-level changes were equally influenced by both anthropogenic and meteorological stressors. Withdrawals located at distances of greater than 3 miles from this site had no appreciable effect on relations between water-level changes and these stressors. At Lake Oliver, changes in UFA water levels were equally influenced by both stressors regardless of distance, while changes in SAS levels were more influenced by meteorological stressors at all distances.

Ganga water pollution: A potential health threat to inhabitants of Ganga basin.

PubMed

Dwivedi, Sanjay; Mishra, Seema; Tripathi, Rudra Deo

2018-05-18

The water quality of Ganga, the largest river in Indian sub-continent and life line to hundreds of million people, has severely deteriorated. Studies have indicated the presence of high level of carcinogenic elements in Ganga water. We performed extensive review of sources and level of organic, inorganic pollution and microbial contamination in Ganga water to evaluate changes in the level of various pollutants in the recent decade in comparison to the past and potential health risk for the population through consumption of toxicant tainted fishes in Ganga basin. A systematic search through databases, specific websites and reports of pollution regulatory agencies was conducted. The state wise level of contamination was tabulated along the Ganga river. We have discussed the major sources of various pollutants with particular focus on metal/metalloid and pesticide residues. Bioaccumulation of toxicants in fishes of Ganga water and potential health hazards to humans through consumption of tainted fishes was evaluated. The level of pesticides in Ganga water registered a drastic reduction in the last decade (i.e. after the establishment of National Ganga River Basin Authority (NGRBA) in 2009), still the levels of some organochlorines are beyond the permissible limits for drinking water. Conversely the inorganic pollutants, particularly carcinogenic elements have increased several folds. Microbial contamination has also significantly increased. Hazard quotient and hazard index indicated significant health risk due to metal/metalloid exposure through consumption of tainted fishes from Ganga. Target cancer risk assessment showed high carcinogenic risk from As, Cr, Ni and Pb as well as residues of DDT and HCHs. Current data analysis showed that Ganga water quality is deteriorating day by day and at several places even in upper stretch of Ganga the water is not suitable for domestic uses. Although there is positive impact of ban on persistent pesticides with decreasing trend of pesticide residues in Ganga water, the increasing trend of trace and toxic elements is alarming and the prolong exposure to polluted Ganga water and/or consumption of Ganga water fishes may cause serious illness including cancer. Copyright © 2018 Elsevier Ltd. All rights reserved.

The drinking water disparities framework: on the origins and persistence of inequities in exposure.

PubMed

Balazs, Carolina L; Ray, Isha

2014-04-01

With this article, we develop the Drinking Water Disparities Framework to explain environmental injustice in the context of drinking water in the United States. The framework builds on the social epidemiology and environmental justice literatures, and is populated with 5 years of field data (2005-2010) from California's San Joaquin Valley. We trace the mechanisms through which natural, built, and sociopolitical factors work through state, county, community, and household actors to constrain access to safe water and to financial resources for communities. These constraints and regulatory failures produce social disparities in exposure to drinking water contaminants. Water system and household coping capacities lead, at best, to partial protection against exposure. This composite burden explains the origins and persistence of social disparities in exposure to drinking water contaminants.

Temporal Variation of Chemical Persistence in a Swedish Lake Assessed by Benchmarking.

PubMed

Zou, Hongyan; Radke, Michael; Kierkegaard, Amelie; McLachlan, Michael S

2015-08-18

Chemical benchmarking was used to investigate the temporal variation of the persistence of chemical contaminants in a Swedish lake. The chemicals studied included 12 pharmaceuticals, an artificial sweetener, and an X-ray contrast agent. Measurements were conducted in late spring, late autumn, and winter. The transformation half-life in the lake could be quantified for 7 of the chemicals. It ranged from several days to hundreds of days. For 5 of the chemicals (bezafibrate, climbazole, diclofenac, furosemide, and hydrochlorothiazide), the measured persistence was lower in late spring than in late autumn. This may have been caused by lower temperatures and/or less irradiation during late autumn. The seasonality in chemical persistence contributed to changes in chemical concentrations in the lake during the year. The impact of seasonality of persistence was compared with the impact of other important variables determining concentrations in the lake: chemical inputs and water flow/dilution. The strongest seasonal variability in chemical concentration in lake water was observed for hydrochlorothiazide (over a factor of 10), and this was attributable to the seasonality in its persistence.

Long-term persistence of a single Legionella pneumophila strain possessing the mip gene in a municipal shower despite repeated cycles of chlorination.

PubMed

Cooper, I R; White, J; Mahenthiralingam, E; Hanlon, G W

2008-10-01

The ability of Legionella pneumophila to colonise domestic water systems is a primary cause of outbreaks of Legionnaire's disease in humans. World Health Organization guidelines recommend that drinking water is chlorinated to between 0.2 and 1mg/L [Chlorine in drinking-water. Guidelines for drinking-water quality, 2nd edn. Geneva: World Health Organization; 1996], but L. pneumophila is repeatedly isolated from chlorinated water systems, indicating that this treatment is not effective at preventing colonisation. Current UK guidelines recommend a one-off treatment of 20-50mg/L of free chlorine to remove the bacteria. In this study we report on the persistence of L. pneumophila serogroup 1 in a domestic shower system despite repeated cycles of chlorination at 50mg/L for 1h exposure time, over the course of two and a half years. Persisting isolates were subjected to in-vitro phenotypic analyses and polymerase chain reaction analysis for the toxin-encoding mip gene. Random amplified polymorphic DNA typing was also performed to determine whether the isolates recovered on different occasions were the same strain. We found that seven isolates of L. pneumophila recovered over a two-and-a-half year period are the same genetically defined strain, indicating that the bacteria can persist despite repeated cycles of chlorination after each successive isolation.

Trends of improved water and sanitation coverage around the globe between 1990 and 2010: inequality among countries and performance of official development assistance

PubMed Central

Cha, Seungman; Mankadi, Paul Mansiangi; Elhag, Mousab Siddig; Lee, Yongjoo; Jin, Yan

2017-01-01

ABSTRACT Background: As the Millennium Development Goals ended, and were replaced by the Sustainable Development Goals, efforts have been made to evaluate the achievements and performance of official development assistance (ODA) in the health sector. In this study, we explore trends in the expansion of water and sanitation coverage in developing countries and the performance of ODA. Design: We explored inequality across developing countries by income level, and investigated how ODA for water and sanitation was committed by country, region, and income level. Changes in inequality were tested via slope changes by investigating the interaction of year and income level with a likelihood ratio test. A random effects model was applied according to the results of the Hausman test. Results: The slope of the linear trend between economic level and sanitation coverage has declined over time. However, a random effects model suggested that the change in slope across years was not significant (e.g. for the slope change between 2000 and 2010: likelihood ratio χ2 = 2.49, probability > χ2 = 0.1146). A similar pro-rich pattern across developing countries and a non-significant change in the slope associated with different economic levels were demonstrated for water coverage. Our analysis shows that the inequality of water and sanitation coverage among countries across the world has not been addressed effectively during the past decade. Our findings demonstrate that the countries with the least coverage persistently received far less ODA per capita than did countries with much more extensive water and sanitation coverage, suggesting that ODA for water and sanitation is poorly targeted. Conclusion: The most deprived countries should receive more attention for water and sanitation improvements from the world health community. A strong political commitment to ODA targeting the countries with the least coverage is needed at the global level. PMID:28604256

The Economic Costs of a Shrinking Lake Mead: a Spatial Hedonic Analysis

NASA Astrophysics Data System (ADS)

Singh, A.; Saphores, J. D.

2017-12-01

Persistent arid conditions and population growth in the Southwest have taken a toll on the Colorado River. This has led to substantial drawdowns of many water reservoirs around the Southwest, and especially of Lake Mead, which is Las Vegas' main source of drinking water. Due to its importance, Lake Mead has received a great deal of media attention about its "bathtub ring" and the exposure of rock that used to be underwater. Drops in water levels have caused some local marinas to close, thereby affecting the aesthetic and recreational value of Lake Mead, which is located in the country's largest National Recreation Area (NRA), and surrounded by protected land. Although a rich literature analyzes how water quality impacts real estate values, relatively few studies have examined how dropping water levels are capitalized in surrounding residential properties. In this context, the goal of this study is to quantify how Lake Mead's water level changes are reflected in changes in local property values, an important source of tax income for any community. Since Lake Mead is the primary attraction within its recreation area, we are also concerned with how this recreation area, which is a few miles southeast of Las Vegas, is capitalized in real estate values of the Las Vegas metropolitan area as few valuation studies have examined how proximity to national parks influences residential property value. We estimate spatial hedonic and geographically weighted regression models of single family residences to delineate the value of proximity to the Lake Mead NRA and to understand how this value changed with Lake Mead's water levels. Our explanatory variables include common structural characteristics, fixed effects to account for unobserved locally constant characteristics, and specific variables such as distance to the Las Vegas strip and to downtown casinos. Because the sharpest declines in Lake Mead water levels happened in 2010 (NASA, 2010) and winter 2016 saw an unexpected increases in water levels, we analyze home sales and variations in water levels from 2010 to the mid 2017.

Decadal-scale ecosystem memory reveals interactive effects of drought and insect defoliation on boreal forest productivity

NASA Astrophysics Data System (ADS)

Itter, M.; D'Orangeville, L.; Dawson, A.; Kneeshaw, D.; Finley, A. O.

2017-12-01

Drought and insect defoliation have lasting impacts on the dynamics of the boreal forest. Impacts are expected to worsen under global climate change as hotter, drier conditions forecast for much of the boreal increase the frequency and severity of drought and defoliation events. Contemporary ecological theory predicts physiological feedbacks in tree responses to drought and defoliation amplify impacts potentially causing large-scale productivity losses and forest mortality. Quantifying the interactive impacts of drought and insect defoliation on regional forest health is difficult given delayed and persistent responses to disturbance events. We developed a Bayesian hierarchical model to estimate forest growth responses to interactions between drought and insect defoliation by species and size class. Delayed and persistent responses to past drought and defoliation were quantified using empirical memory functions allowing for improved detection of interactions. The model was applied to tree-ring data from stands in Western (Alberta) and Eastern (Québec) regions of the Canadian boreal forest with different species compositions, disturbance regimes, and regional climates. Western stands experience chronic water deficit and forest tent caterpillar (FTC) defoliation; Eastern stands experience irregular water deficit and spruce budworm (SBW) defoliation. Ecosystem memory to past water deficit peaked in the year previous to growth and decayed to zero within 5 (West) to 8 (East) years; memory to past defoliation ranged from 8 (West) to 12 (East) years. The drier regional climate and faster FTC defoliation dynamics (compared to SBW) likely contribute to shorter ecosystem memory in the West. Drought and defoliation had the largest negative impact on large-diameter, host tree growth. Surprisingly, a positive interaction was observed between drought and defoliation for large-diameter, non-host trees likely due to reduced stand-level competition for water. Results highlight the temporal persistence of drought and defoliation stress on boreal forest growth dynamics and provide an empirical estimate of their interactive effects with explicit uncertainty.

Persistent challenging behaviour in people with an intellectual disability.

PubMed

Totsika, Vasiliki; Hastings, Richard P

2009-09-01

The aim of the present review is to summarize recent research findings on the persistence of challenging behaviours in adults and children with an intellectual disability. Studies varied in their definition and measurement of persistence or change in challenging behaviours. Persistence levels tended to be high in adults and challenging behaviours were stable over time, especially in individuals with autism. Moderate to high stability levels were evident in children, although there was a tendency for decreases in mean scores for behaviour problems over time. A substantial proportion of people with an intellectual disability experience persistent and stable challenging behaviours across their lives. Our knowledge of the factors that drive these high levels of persistence remains limited.

Water resources during drought conditions and postfire water quality in the upper Rio Hondo Basin, Lincoln County, New Mexico, 2010-13

USGS Publications Warehouse

Sherson, Lauren R.; Rice, Steven E.

2015-07-16

Changes in climate and increased groundwater and surface-water use are likely to affect the availability of water in the upper Rio Hondo Basin. Increased drought probably will increase the potential for wildfires, which can affect downstream water quality and increase flood potential. Climate-research predicted decreases in winter precipitation may have an adverse effect on the amount of groundwater recharge that occurs in the upper Rio Hondo Basin, given the predominance of winter precipitation recharge as indicated by the stable isotope results. Decreases in surface-water supplies because of persistent drought conditions and reductions in the quality of water because of the effects of wildfire may lead to a larger reliance on groundwater reserves in the upper Rio Hondo Basin. Decreasing water levels because of increasing groundwater withdrawal could reduce base flows in the Rio Bonito and Rio Ruidoso. Well organized and scientifically supported regional water-resources management will be necessary for dealing with the likely scenario of increases in demand coupled with decreases in supply in the upper Rio Hondo Basin.

An integrated evaluation of the persistence and effects of 4-nonylphenol in an experimental littoral ecosystem

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

Liber, K.; Knuth, M.L.; Stay, F.S.

1999-03-01

A comprehensive littoral enclosure study was conducted to assess the persistence and distribution of 4-nonylphenol (NP) in a littoral ecosystem, and to evaluate the compound`s effects on resident aquatic biota. Enclosures with a mean ({+-} SD) surface area and volume of 31.4 {+-} 3.3 m{sup 2} and 32.0 {+-} 6.4 m{sup 3}, respectively, received eleven applications at 48-h intervals with one of four different rates of NP. This created a 20-d application period which was followed by a three to fourteen month observation period, depending on the endpoint measured. Mean {+-} SD NP concentrations in the water column measured 2more » h after each application averaged 5 {+-} 4, 23 {+-} 11, 76 {+-} 21, and 243 {+-} 41 {micro}g/L at nominal treatments of 3, 30, 100, and 300 {micro}g/L, respectively. Persistence in the water column was relatively short, with a dissipation half-life estimated at {le} 1.2 d. Persistence of NP in sediment and on macrophytes was substantially longer, with estimated half-lives of 28 to 104 d and 8 to 13 d, respectively. Zooplankton was the most sensitive group of organisms evaluated, with significant reductions in population abundances of some copepod taxa observed at the 23 {+-} 11-{micro}g/L treatment. Fish survival was affected at 243 {+-} 41 {micro}g/L. The most sensitive benthic macroinvertebrate taxon, Pisidium (Bivalvia) was affected at 76 {+-} 21 {micro}g/L, but most taxa were only affected at the 243 {+-} 41-{micro}g/L treatment. None of the assessed populations were affected at the 5 {+-} 4-{micro}g/L treatment. Macrophytes and periphyton were not adversely affected by any of the treatments. Overall community composition, assessed at the family level or higher, was not affected at or below the 23 {+-} 11-{micro}g/L treatment, but did exhibit substantial changes at the 243 {+-} 41-{micro}g/L treatment. Some minor changes were observed at the 76 {+-} 21-{micro}g/L treatment. The maximum acceptable toxicant concentration in the water column, based on protection of the most sensitive taxa in the test system, was estimated at {approximately} 10 {micro}g/L. Details on NP persistence and distribution within the enclosures, and detailed effects on zooplankton, benthic macroinvertebrates, and fish are described in four separate papers immediately following this overview.« less

The challenge of integration in the implementation of Zimbabwe’s new water policy: case study of the catchment level institutions surrounding the Pungwe-Mutare water supply project

NASA Astrophysics Data System (ADS)

Tapela, Barbara Nompumelelo

Integrated water resources management (IWRM) is viewed by policy makers and practitioners as facilitating the achievement of a balance between water resource use and resource protection, and the resolution of water-related conflicts. The IWRM approach has found particular use in the new water policies of Southern African countries such as Zimbabwe, where water scarcity, after the land question, is perceived to be a major threat to political, economic, social, military and environmental security. Ultimately, IWRM is seen as providing a framework towards ensuring broader security at the local, national, regional and global levels. However, the pilot phase implementation of the new water policy in the various regional countries has revealed that although the legal and institutional frameworks have been put in place, the implementation of the IWRM approach has tended to be problematic (J. Latham, 2001; GTZ, 2000; Leestemaker, 2000; Savenige and van der Zaag, 2000; Sithole, 2000). This paper adopts a case study approach and empirically examines the institutional challenges of implementing the IWRM approach in the post-pilot phase of Zimbabwe's new water policy. The focus is mainly on the institutional arrangements surrounding the Pungwe-Mutare Water Supply Project located within the Save Catchment Area in Eastern Zimbabwe. The major findings of the study are that, while there persist some problems associated with the traditional management approach, there have also emerged new challenges to IWRM. These mainly relate to the transaction costs of the water sector reforms, institutional resilience, stakeholder participation, and the achievement of the desired outcomes. There have also been problems emanating from unexpected political developments at the local and national levels, particularly with regard to the government's ;fast track; land resettlement programme. The paper concludes that there is a need for a more rigorous effort towards integrating the management of water resources by the catchment level institutions.

Salt stress-induced transcription of σB- and CtsR-regulated genes in persistent and non-persistent Listeria monocytogenes strains from food processing plants.

PubMed

Ringus, Daina L; Ivy, Reid A; Wiedmann, Martin; Boor, Kathryn J

2012-03-01

Listeria monocytogenes is a foodborne pathogen that can persist in food processing environments. Six persistent and six non-persistent strains from fish processing plants and one persistent strain from a meat plant were selected to determine if expression of genes in the regulons of two stress response regulators, σ(B) and CtsR, under salt stress conditions is associated with the ability of L. monocytogenes to persist in food processing environments. Subtype data were also used to categorize the strains into genetic lineages I or II. Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) was used to measure transcript levels for two σ(B)-regulated genes, inlA and gadD3, and two CtsR-regulated genes, lmo1138 and clpB, before and after (t=10 min) salt shock (i.e., exposure of exponential phase cells to BHI+6% NaCl for 10 min at 37°C). Exposure to salt stress induced higher transcript levels relative to levels under non-stress conditions for all four stress and virulence genes across all wildtype strains tested. Analysis of variance (ANOVA) of induction data revealed that transcript levels for one gene (clpB) were induced at significantly higher levels in non-persistent strains compared to persistent strains (p=0.020; two-way ANOVA). Significantly higher transcript levels of gadD3 (p=0.024; two-way ANOVA) and clpB (p=0.053; two-way ANOVA) were observed after salt shock in lineage I strains compared to lineage II strains. No clear association between stress gene transcript levels and persistence was detected. Our data are consistent with an emerging model that proposes that establishment of L. monocytogenes persistence in a specific environment occurs as a random, stochastic event, rather than as a consequence of specific bacterial strain characteristics.

Can water-level management reduce malaria mosquito abundance around large dams in sub-Saharan Africa?

PubMed Central

Wilson, G. Glenn; Ryder, Darren; Tekie, Habte; Petros, Beyene

2018-01-01

Background Water level management has been suggested as a potential tool to reduce malaria around large reservoirs. However, no field-based test has been conducted to assess the effect of water level management on mosquito larval abundance in African settings. The objective of the present study is to evaluate the effects of water level drawdown rates on mosquito larval abundance. Methods Twelve experimental dams were constructed on the foreshore of the Koka Dam in Ethiopia. These were grouped into four daily water drawdown treatments, each with three replicates: no water-level drawdown (Group 1; Control), 10 mm.d-1 (Group 2), 15 mm.d-1 (Group 3) and 20 mm.d-1 (Group 4). Larval sampling was conducted weekly for a period of 6 weeks each in the main malaria transmission season (October to November 2013) and subsequent dry season (February to March 2014). Larval densities were compared among treatments over time using repeated measures Analysis of Variance (ANOVA). Results A total of 284 Anopheles mosquito larvae were collected from the experimental dams during the study period. Most (63.4%; n = 180) were collected during the main malaria transmission season while the remaining (36.6%; n = 104) were collected during the dry season. Larvae comprised four Anopheles species, dominated by Anopheles arabiensis (48.1% of total larval samples; n = 136) and An. pharoensis (33.2%; n = 94). Mean larval density was highest in control treatment dams with stable water levels throughout the study, and decreased significantly (P < 0.05) with increasing water drawdown rates in both seasons. During the main transmission season, anopheline larval density was generally lower by 30%, 70% and 84% in Groups 2, Group 3 and Group 4, respectively, compared with the control dams (Group 1). In the dry season, larval density was reduced by 45%, 70% and 84% in Groups 2, Group 3 and Group 4, respectively, when compared to the control dams. Conclusion Increased water drawdown rates were associated with lower mosquito larval abundance. Water level management could thus serve as a potential control measure for malaria vectors around reservoirs by regulating the persistence of shallow shoreline breeding habitats. Dam operators and water resource managers should consider incorporating water level management as a malaria control mechanism into routine dam operations to manage the risk of malaria transmission to human populations around reservoirs. PMID:29672560

Coupling of phytoplankton uptake and air-water exchange of persistent organic pollutants

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

Dachs, J.; Eisenreich, S.J.; Baker, J.E.

1999-10-15

A dynamic model that couples air-water exchange and phytoplankton uptake of persistent organic pollutants has been developed and then applied to PCB data from a small experimental lake. A sensitivity analysis of the model, taking into account the influence of physical environmental conditions such as temperature, wind speed, and mixing depth as well as plankton-related parameters such as biomass and growth rate was carried out for a number of PCBs with different physical-chemical properties. The results indicate that air-water exchange dynamics are influenced not only by physical parameters but also by phytoplankton biomass and growth rate. New phytoplankton production resultsmore » in substantially longer times to reach equilibrium. Phytoplankton uptake-induced depletion of the dissolved phase concentration maintains air and water phases out of equilibrium. Furthermore, PCBs in phytoplankton also take longer times to reach equilibrium with the dissolved water phase when the latter is supported by diffusive air-water exchange. However, both model analysis and model application to the Experimental Lakes Area of northwestern Ontario (Canada) suggest that the gas phase supports the concentrations of persistent organic pollutants, such as PCBs, in atmospherically driven aquatic environments.« less

Hindcast storm events in the Bering Sea for the St. Lawrence Island and Unalakleet Regions, Alaska

USGS Publications Warehouse

Erikson, Li H.; McCall, Robert T.; van Rooijen, Arnold; Norris, Benjamin

2015-01-01

This study provides viable estimates of historical storm-induced water levels in the coastal communities of Gambell and Savoonga situated on St. Lawrence Island in the Bering Sea, as well as Unalakleet located at the head of Norton Sound on the western coast of Alaska. Gambell, Savoonga, and Unalakleet are small Native Villages that are regularly impacted by coastal storms but where little quantitative information about these storms exists. The closest continuous water-level gauge is at Nome, located more than 200 kilometers from both St. Lawrence Island and Unalakleet. In this study, storms are identified and quantified using historical atmospheric and sea-ice data and then used as boundary conditions for a suite of numerical models. The work includes storm-surge (temporary rise in water levels due to persistent strong winds and low atmospheric pressures) modeling in the Bering Strait region, as well as modeling of wave runup along specified sections of the coast in Gambell and Unalakleet. Modeled historical water levels are used to develop return periods of storm surge and storm surge plus wave runup at key locations in each community. It is anticipated that the results will fill some of the data void regarding coastal flood data in western Alaska and be used for production of coastal vulnerability maps and community planning efforts.

Spatio-temporal distribution of perchlorate and its toxicity in Hydrilla verticillata.

PubMed

Vijaya Nadaraja, Anupama; Pushpangadhan Saraswathy, Divya; Cheruvathery Ravindran, Sayana; Mariya, Anie; Godwin Russel, Jasmin; Selvanesan, Pradeep; Pereira, Benno; Bhaskaran, Krishnakumar

2017-10-01

The spatio-temporal distribution of perchlorate in water sources around an ammonium perchlorate production unit and its toxicity response on a dominant aquatic plant, Hydrilla verticillata are reported in this study. Samples (n=453) from ground water (open well) and surface water sources within 5km from the production unit over a period of 12 months (2014, June - 2015, May) were screened for ClO 4 - . During the period, ClO 4 - concentration in ground water samples close to the production unit increased to >40,000μg/L, and ClO 4 - was detected at 1740μg/L in well water 1.6km away from the production unit. A community pond in the area also showed an increase in ClO 4 - level up to 29,000μg/L. In all water sources, ClO 4 - level was maximum during the rainy season (July, monsoon). A natural degradation of ClO 4 - was not observed in the area as evident from its persistent level and spreading to more areas. H. verticillata, the dominant vegetation in the pond exhibited severe toxic response like massive decay and loss of photosynthetic pigments such as chlorophyll and carotene due to ClO 4 - exposure. The plant accumulated ClO 4 - up to 60 ± 0.8mg/kg wet weight with a Bio-Concentration Factor 2.06±0.005. This is the first report on spatio-temporal distribution of ClO 4 - at higher levels in a natural environment and its toxicity response to plants under natural condition. Copyright © 2017 Elsevier Inc. All rights reserved.

Patients with Long-Term Oral Carriage Harbor High-Persister Mutants of Candida albicans▿

PubMed Central

LaFleur, Michael D.; Qi, Qingguo; Lewis, Kim

2010-01-01

Fungal biofilms produce a small number of persister cells which can tolerate high concentrations of fungicidal agents. Persisters form upon attachment to a surface, an important step in the pathogenesis of Candida strains. The periodic application of antimicrobial agents may select for strains with increased levels of persister cells. In order to test this possibility, 150 isolates of Candida albicans and C. glabrata were obtained from cancer patients who were at high risk for the development of oral candidiasis and who had been treated with topical chlorhexidine once a day. Persister levels were measured by exposing biofilms growing in the wells of microtiter plates to high concentrations of amphotericin B and plating for survivors. The persister levels of the isolates varied from 0.2 to 9%, and strains isolated from patients with long-term carriage had high levels of persisters. High-persister strains were isolated from every patient with Candida carriage of more than 8 consecutive weeks but from no patients with transient carriage. All of the high-persister isolates had an amphotericin B MIC that was the same as that for the wild type, indicating that these strains were drug-tolerant rather than drug-resistant mutants. Biofilms of the majority of high-persister strains also showed an increased tolerance to chlorhexidine and had the same MIC for this antimicrobial as the wild type. This study suggests that persister cells are clinically relevant, and antimicrobial therapy selects for high-persister strains in vivo. The drug tolerance of persisters may be a critical but overlooked component responsible for antimicrobial drug failure and relapsing infections. PMID:19841146

Persistence of F-specific RNA phages in surface waters from a produce production region along the central coast of California

USDA-ARS?s Scientific Manuscript database

F+ RNA coliphages (FRNA) are used to source-track fecal contamination and as surrogates for enteric pathogen persistence in the environment. However, the environmental persistence of FRNA is not clearly understood and thus we evaluated the survival of prototype and environmental isolates of FRNA rep...

Household Effectiveness vs. Laboratory Efficacy of Point-of-use Chlorination

PubMed Central

Levy, Karen; Anderson, Larissa; Robb, Katharine A.; Cevallos, William; Trueba, Gabriel; Eisenberg, Joseph N.S.

2014-01-01

Treatment of water at the household level offers a promising approach to combat the global burden of diarrheal diseases. In particular, chlorination of drinking water has been a widely promoted strategy due to persistence of residual chlorine after initial treatment. However, the degree to which chlorination can reduce microbial levels in a controlled setting (efficacy) or in a household setting (effectiveness) can vary as a function of chlorine characteristics, source water characteristics, and household conditions. To gain more understanding of these factors, we carried out an observational study within households in rural communities of northern coastal Ecuador. We found that the efficacy of chlorine treatment under controlled conditions was significantly better than its effectiveness when evaluated both by ability to meet microbiological safety standards and by log reductions. Water treated with chlorine achieved levels of microbial contamination considered safe for human consumption after 24 hours of storage in the household only 39 – 51% of the time, depending on chlorine treatment regimen. Chlorine treatment would not be considered protective against diarrheal disease according to WHO log reduction standards. Factors that explain the observed compromised effectiveness include: source water turbidity, source water baseline contamination levels, and in-home contamination. Water in 38% of the households that had low turbidity source water (< 10 NTU) met the safe water standard as compared with only 17% of the households that had high turbidity source water (> 10 NTU). A 10 MPN/100mL increase in baseline E. coli levels was associated with a 2.2% increase in failure to meet the E. colistandard. Higher mean microbial contamination levels in 54% of household samples in comparison to their matched controls, which is likely the result of in-home contamination during storage. Container characteristics (size of the container mouth) did not influence chlorine effectiveness. We found no significant differences between chlorine treatment regimens in ability to meet the safe water standards or in overall log reductions, although chlorine dosage did modify the effect of source conditions. These results underscore the importance of measuring both source water and household conditions to determine appropriate chlorine levels, as well as to evaluate the appropriateness of chlorine treatment and other point-of-use water quality improvement interventions. PMID:24561887

Household effectiveness vs. laboratory efficacy of point-of-use chlorination.

PubMed

Levy, Karen; Anderson, Larissa; Robb, Katharine A; Cevallos, William; Trueba, Gabriel; Eisenberg, Joseph N S

2014-05-01

Treatment of water at the household level offers a promising approach to combat the global burden of diarrheal diseases. In particular, chlorination of drinking water has been a widely promoted strategy due to persistence of residual chlorine after initial treatment. However, the degree to which chlorination can reduce microbial levels in a controlled setting (efficacy) or in a household setting (effectiveness) can vary as a function of chlorine characteristics, source water characteristics, and household conditions. To gain more understanding of these factors, we carried out an observational study within households in rural communities of northern coastal Ecuador. We found that the efficacy of chlorine treatment under controlled conditions was significantly better than its household effectiveness when evaluated both by ability to meet microbiological safety standards and by log reductions. Water treated with chlorine achieved levels of microbial contamination considered safe for human consumption after 24 h of storage in the household only 39-51% of the time, depending on chlorine treatment regimen. Chlorine treatment would not be considered protective against diarrheal disease according to WHO log reduction standards. Factors that explain the observed compromised effectiveness include: source water turbidity, source water baseline contamination levels, and in-home contamination. Water in 38% of the households that had low turbidity source water (<10 NTU) met the safe water standard as compared with only 17% of the households that had high turbidity source water (>10 NTU). A 10 MPN/100 mL increase in baseline Escherichia coli levels was associated with a 2.2% increase in failure to meet the E. coli standard. Higher mean microbial contamination levels were seen in 54% of household samples in comparison to their matched controls, which is likely the result of in-home contamination during storage. Container characteristics (size of the container mouth) did not influence chlorine effectiveness. We found no significant differences between chlorine treatment regimens in ability to meet the safe water standards or in overall log reductions, although chlorine dosage did modify the effect of source conditions. These results underscore the importance of measuring both source water and household conditions to determine appropriate chlorine levels, as well as to evaluate the appropriateness of chlorine treatment and other point-of-use water quality improvement interventions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Blood pressure hyperreactivity: an early cardiovascular risk in normotensive men exposed to low-to-moderate inorganic arsenic in drinking water.

PubMed

Kunrath, Julie; Gurzau, Eugen; Gurzau, Anca; Goessler, Walter; Gelmann, Elyssa R; Thach, Thu-Trang; McCarty, Kathleen M; Yeckel, Catherine W

2013-02-01

Essential hypertension is associated with chronic exposure to high levels of inorganic arsenic in drinking water. However, early signs of risk for developing hypertension remain unclear in people exposed to chronic low-to-moderate inorganic arsenic. We evaluated cardiovascular stress reactivity and recovery in healthy, normotensive, middle-aged men living in an arsenic-endemic region of Romania. Unexposed (n = 16) and exposed (n = 19) participants were sampled from communities based on WHO limits for inorganic arsenic in drinking water (<10 μg/l). Water sources and urine samples were collected and analyzed for inorganic arsenic and its metabolites. Functional evaluation of blood pressure included clinical, anticipatory, cold pressor test, and recovery measurements. Blood pressure hyperreactivity was defined as a combined stress-induced change in SBP (> 20 mmHg) and DBP (>15 mmHg). Drinking water inorganic arsenic averaged 40.2 ± 30.4 and 1.0 ± 0.2 μg/l for the exposed and unexposed groups, respectively (P < 0.001). Compared to the unexposed group, the exposed group expressed a greater probability of blood pressure hyperreactivity to both anticipatory stress (47.4 vs. 12.5%; P = 0.035) and cold stress (73.7 vs. 37.5%; P = 0.044). Moreover, the exposed group exhibited attenuated blood pressure recovery from stress and a greater probability of persistent hypertensive responses (47.4 vs. 12.5%; P = 0.035). Inorganic arsenic exposure increased stress-induced blood pressure hyperreactivity and poor blood pressure recovery, including persistent hypertensive responses in otherwise healthy, clinically normotensive men. Drinking water containing even low-to-moderate inorganic arsenic may act as a sympathetic nervous system trigger for hypertension risk.

Blood pressure hyperreactivity: an early cardiovascular risk in normotensive men exposed to low-to-moderate inorganic arsenic in drinking water

PubMed Central

Kunrath, Julie; Gurzau, Eugen; Gurzau, Anca; Goessler, Walter; Gelmann, Elyssa R.; Thach, Thu-Trang; Mccarty, Kathleen M.; Yeckel, Catherine W.

2012-01-01

Essential hypertension is associated with chronic exposure to high levels of inorganic arsenic in drinking water. However, early signs of risk for developing hypertension remain unclear in people exposed to chronic low-to-moderate inorganic arsenic. Objective We evaluated cardiovascular stress reactivity and recovery in healthy, normotensive, middle-aged men living in an arsenic-endemic region of Romania. Methods Unexposed (n=16) and exposed (n=19) participants were sampled from communities based on WHO limits for inorganic arsenic in drinking water (<10 μg/l). Water sources and urine samples were collected and analyzed for inorganic arsenic and its metabolites. Functional evaluation of blood pressure included clinical, anticipatory, cold pressor test, and recovery measurements. Results Blood pressure hyperreactivity was defined as a combined stress-induced change in SBP (>20 mmHg) and DBP (>15 mmHg). Drinking water inorganic arsenic averaged 40.2±30.4 and 1.0±0.2 μg/l for the exposed and unexposed groups, respectively (P<0.001). Compared to the unexposed group, the exposed group expressed a greater probability of blood pressure hyperreactivity to both anticipatory stress (47.4 vs. 12.5%; P=0.035) and cold stress (73.7 vs. 37.5%; P=0.044). Moreover, the exposed group exhibited attenuated blood pressure recovery from stress and a greater probability of persistent hypertensive responses (47.4 vs. 12.5%; P=0.035). Conclusions Inorganic arsenic exposure increased stress-induced blood pressure hyperreactivity and poor blood pressure recovery, including persistent hypertensive responses in otherwise healthy, clinically normotensive men. Drinking water containing even low-to-moderate inorganic arsenic may act as a sympathetic nervous system trigger for hypertension risk. PMID:23203141

Highly pathogenic influenza A(H5N1) virus survival in complex artificial aquatic biotopes.

PubMed

Horm, Viseth Srey; Gutiérrez, Ramona A; Nicholls, John M; Buchy, Philippe

2012-01-01

Very little is known regarding the persistence of Highly Pathogenic Avian Influenza (HPAI) H5N1 viruses in aquatic environments in tropical countries, although environmental materials have been suggested to play a role as reservoirs and sources of transmission for H5N1 viruses. The survival of HPAI H5N1 viruses in experimental aquatic biotopes (water, mud, aquatic flora and fauna) relevant to field conditions in Cambodia was investigated. Artificial aquatic biotopes, including simple ones containing only mud and water, and complex biotopes involving the presence of aquatic flora and fauna, were set up. They were experimentally contaminated with H5N1 virus. The persistence of HPAI H5N1 virus (local avian and human isolates) was determined by virus isolation in embryonated chicken eggs and by real-time reverse-polymerase chain reaction. Persistence of infectious virus did not exceed 4 days, and was only identified in rain water. No infectious virus particles were detected in pond and lake water or mud even when high inoculum doses were used. However, viral RNA persisted up to 20 days in rain water and 7 days in pond or lake water. Viral RNA was also detected in mud samples, up to 14 days post-contamination in several cases. Infectious virus and viral RNA was detected in few cases in the aquatic fauna and flora, especially in bivalves and labyrinth fish, although these organisms seemed to be mostly passive carriers of the virus rather than host allowing virus replication. Although several factors for the survival and persistence of HPAI viruses in the environment are still to be elucidated, and are particularly hard to control in laboratory conditions, our results, along with previous data, support the idea that environmental surveillance is of major relevance for avian influenza control programs.

Highly Pathogenic Influenza A(H5N1) Virus Survival in Complex Artificial Aquatic Biotopes

PubMed Central

Horm, Viseth Srey; Gutiérrez, Ramona A.; Nicholls, John M.; Buchy, Philippe

2012-01-01

Background Very little is known regarding the persistence of Highly Pathogenic Avian Influenza (HPAI) H5N1 viruses in aquatic environments in tropical countries, although environmental materials have been suggested to play a role as reservoirs and sources of transmission for H5N1 viruses. Methodology/Principal Findings The survival of HPAI H5N1 viruses in experimental aquatic biotopes (water, mud, aquatic flora and fauna) relevant to field conditions in Cambodia was investigated. Artificial aquatic biotopes, including simple ones containing only mud and water, and complex biotopes involving the presence of aquatic flora and fauna, were set up. They were experimentally contaminated with H5N1 virus. The persistence of HPAI H5N1 virus (local avian and human isolates) was determined by virus isolation in embryonated chicken eggs and by real-time reverse-polymerase chain reaction. Persistence of infectious virus did not exceed 4 days, and was only identified in rain water. No infectious virus particles were detected in pond and lake water or mud even when high inoculum doses were used. However, viral RNA persisted up to 20 days in rain water and 7 days in pond or lake water. Viral RNA was also detected in mud samples, up to 14 days post-contamination in several cases. Infectious virus and viral RNA was detected in few cases in the aquatic fauna and flora, especially in bivalves and labyrinth fish, although these organisms seemed to be mostly passive carriers of the virus rather than host allowing virus replication. Conclusions/Significance Although several factors for the survival and persistence of HPAI viruses in the environment are still to be elucidated, and are particularly hard to control in laboratory conditions, our results, along with previous data, support the idea that environmental surveillance is of major relevance for avian influenza control programs. PMID:22514622

The Drinking Water Disparities Framework: On the Origins and Persistence of Inequities in Exposure

PubMed Central

Balazs, Carolina L.; Ray, Isha

2014-01-01

With this article, we develop the Drinking Water Disparities Framework to explain environmental injustice in the context of drinking water in the United States. The framework builds on the social epidemiology and environmental justice literatures, and is populated with 5 years of field data (2005–2010) from California’s San Joaquin Valley. We trace the mechanisms through which natural, built, and sociopolitical factors work through state, county, community, and household actors to constrain access to safe water and to financial resources for communities. These constraints and regulatory failures produce social disparities in exposure to drinking water contaminants. Water system and household coping capacities lead, at best, to partial protection against exposure. This composite burden explains the origins and persistence of social disparities in exposure to drinking water contaminants. PMID:24524500

Persistent episodic acidification of streams linked to acid rain effects on soil

USGS Publications Warehouse

Lawrence, G.B.

2002-01-01

Episodic acidification of streams, identified in the late 1980s as one of the most significant environmental problems caused by acidic deposition, had not been evaluated since the early 1990s despite decreasing levels of acidic deposition over the past decade. This analysis indicates that episodic acidification of streams in upland regions in the northeastern United States persists, and is likely to be much more widespread than chronic acidification. Depletion of exchangeable Ca in the mineral soil has decreased the neutralization capacity of soils and increased the role of the surface organic horizon in the neutralization of acidic soil water during episodes. Increased accumulation of N and S in the forest floor from decades of acidic deposition will delay the recovery of soil base status, and therefore, the elimination of acidic episodes, which is anticipated from decreasing emissions.

Is there foul play in the leaf pocket? The metagenome of floating fern Azolla reveals endophytes that do not fix N2 but may denitrify.

PubMed

Dijkhuizen, Laura W; Brouwer, Paul; Bolhuis, Henk; Reichart, Gert-Jan; Koppers, Nils; Huettel, Bruno; Bolger, Anthony M; Li, Fay-Wei; Cheng, Shifeng; Liu, Xin; Wong, Gane Ka-Shu; Pryer, Kathleen; Weber, Andreas; Bräutigam, Andrea; Schluepmann, Henriette

2018-01-01

Dinitrogen fixation by Nostoc azollae residing in specialized leaf pockets supports prolific growth of the floating fern Azolla filiculoides. To evaluate contributions by further microorganisms, the A. filiculoides microbiome and nitrogen metabolism in bacteria persistently associated with Azolla ferns were characterized. A metagenomic approach was taken complemented by detection of N 2 O released and nitrogen isotope determinations of fern biomass. Ribosomal RNA genes in sequenced DNA of natural ferns, their enriched leaf pockets and water filtrate from the surrounding ditch established that bacteria of A. filiculoides differed entirely from surrounding water and revealed species of the order Rhizobiales. Analyses of seven cultivated Azolla species confirmed persistent association with Rhizobiales. Two distinct nearly full-length Rhizobiales genomes were identified in leaf-pocket-enriched samples from ditch grown A. filiculoides. Their annotation revealed genes for denitrification but not N 2 -fixation. 15 N 2 incorporation was active in ferns with N. azollae but not in ferns without. N 2 O was not detectably released from surface-sterilized ferns with the Rhizobiales. N 2 -fixing N. azollae, we conclude, dominated the microbiome of Azolla ferns. The persistent but less abundant heterotrophic Rhizobiales bacteria possibly contributed to lowering O 2 levels in leaf pockets but did not release detectable amounts of the strong greenhouse gas N 2 O. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Combining satellite remote sensing and surveys to understand persistent yield variation--- a case study in North China Plain

NASA Astrophysics Data System (ADS)

Zhao, Y.; Lobell, D. B.; Chen, X.

2015-12-01

A large gap between maize yields on average farmers' fields and the highest yields achieved by either experiment or farmers is typical throughout the developing world, including in the North China Plain (NCP). This maize yield gap as identified by previous studies indicates large opportunities for raising yield by improving agronomy. Quzhou county is typical of the winter-wheat summer-maize system in NCP where the average plot size is as small as 0.25 hectares. To analyze this cropping system amidst the challenge of substantial heterogeneity, we identified fields that were either persistently higher or lower yielding according to the remote sensing yield estimates, and then conducted detailed field surveys. We found irrigation facility to be a major constraint to yield both in terms of irrigation water quality and farmers' access to wells. In total, improving the access to unsalty water would be associated with a 0.32t/ha (4.2%) increase in multi-year average yield. In addition, farmers' method of choosing cultivar, which likely relates to their overall knowledge level, significantly explained yield variation. In particular, those choosing cultivars according to technician advice, personal experiences and high yielding neighbors' advice had on average higher yield than farmers that either followed seed sellers' advice or collectively purchased seeds. Overall, the study presents a generalizable methodology of assessing yield gap as well as its persistent factors using a combination of satellite and survey data.

Toxicopathological Effects of the Sunscreen UV Filter, Oxybenzone (Benzophenone-3), on Coral Planulae and Cultured Primary Cells and Its Environmental Contamination in Hawaii and the U.S. Virgin Islands.

PubMed

Downs, C A; Kramarsky-Winter, Esti; Segal, Roee; Fauth, John; Knutson, Sean; Bronstein, Omri; Ciner, Frederic R; Jeger, Rina; Lichtenfeld, Yona; Woodley, Cheryl M; Pennington, Paul; Cadenas, Kelli; Kushmaro, Ariel; Loya, Yossi

2016-02-01

Toxicity persistence to the nontarget amphipod Hyalella curvispina in runoff events following chlorpyrifos applications to soy experimental plots was compared in conventional and no-till management. Two application scenarios were compared: an early-season application with the soil almost bare and a late-season application after the foliage had attained complete soil cover. H. curvispina was exposed to chlorpyrifos using two different test systems: a short-term (48 h) runoff water exposure and a long-term (10 days) soil exposure. Both commonly used crop management practices for soybean production resulted in runoff toxicity following pesticide applications and represent a toxicity risk for adjacent inland waters. Toxicity persistence was longer after the earlier than the late season application, likely because of higher volatilization and photodecomposition losses from the soy canopy than from the soil. For the early-season application, toxicity persisted longer in the no-till plots than in the conventional tillage plots. Suspended matter was higher in the conventional treatment. Chlorpyrifos sorption to suspended matter likely contributed to the shorter persistence. For the late-season application, toxicity persisted longer in the conventional treatment. The causes remain conjectural. The soil organic carbon content was higher in the no-till treatment. Sorption to organic matter might have contributed to the shorter chlorpyrifos toxicity persistence in no-till management. Late applications are more frequent and prevail longer throughout the soy growing season. Overall, the no-till management practice seems preferably because shorter toxicity persistence in runoff represents a lower environmental risk for the adjacent inland waters.

Survival of bactericidal antibiotic treatment by tolerant persister cells of Klebsiella pneumoniae.

PubMed

Li, Ying; Zhang, Luhua; Zhou, Yingshun; Zhang, Zhikun; Zhang, Xinzhuo

2018-03-01

Persister cells, a subpopulation of tolerant cells within the bacterial culture, are commonly thought to be responsible for antibiotic therapy failure and infection recurrence. Klebsiella pneumoniae is a notorious human pathogen for its increasing resistance to antibiotics and wide involvement in severe infections. In this study, we aimed to investigate the persister subpopulation of K. pneumoniae. The presence of persisters in K. pneumoniae was determined by treatment with high concentrations of antibiotics, used alone or in combination. The effect of low level of antibiotics on persister formation was investigated by pre-exposure of cells to antibiotics with low concentrations followed by higher doses. The dependence of persister levels on growth phase was determined by measuring the survival ability of cells along the growth stages upon exposure to a high concentration of antibiotic. Analysis on persister type was carried out by persister elimination assays.Results/Key findings. We show that K. pneumoniae produces high levels of tolerant persister cells to survive treatment by a variety of high concentrations of bactericidal antibiotics and persister formation is prevalent among K. pneumoniae clinical strains. Besides, we find that persister cells can be induced by low concentrations of antibiotics. Finally, we provide evidence that persister formation is growth phase-dependent and Type II persisters dominate the persister subpopulation during the entire exponential phase of K. pneumoniae. Our study describes the formation of tolerant persister cells that allow survival of treatment by high concentrations of antibiotics in K. pneumoniae.

Effect of turbidity on chlorination efficiency and bacterial persistence in drinking water.

PubMed Central

LeChevallier, M W; Evans, T M; Seidler, R J

1981-01-01

To define interrelationships between elevated turbidities and the efficiency of chlorination in drinking water, experiments were performed to measure bacterial survival, chlorine demand, and interference with microbiological determinations. Experiments were conducted on the surface water supplies for communities which practice chlorination as the only treatment. Therefore, the conclusions of this study apply only to such systems. Results indicated that disinfection efficiency (log10 of the decrease in coliform numbers) was negatively correlated with turbidity and was influenced by season, chlorine demand of the samples, and the initial coliform level. Total organic carbon was found to be associated with turbidity and was shown to interfere with maintenance of a free chlorine residual by creating a chlorine demand. Interference with coliform detection in turbid waters could be demonstrated by the recovery of typical coliforms from apparently negative filters. The incidence of coliform masking in the membrane filter technique was found to increase as the turbidity of the chlorinated samples increased. the magnitude of coliform masking in the membrane filter technique increased from less than 1 coliform per 100 ml in water samples of less than 5 nephelometric turbidity units to greater than 1 coliform per 100 ml in water samples of greater than 5 nephelometric turbidity units. Statistical models were developed to predict the impact of turbidity on drinking water quality. The results justify maximum contaminant levels for turbidity in water entering a distribution system as stated in the National Primary Drinking Water Regulations of the Safe Drinking Water Act. Images PMID:7259162

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

Bougamont, M.; Christoffersen, P.; Price, S. F.

Ongoing, centennial-scale flow variability within the Ross ice streams of West Antarctica suggests that the present-day positive mass balance in this region may reverse in the future. Here we use a three-dimensional ice sheet model to simulate ice flow in this region over 250 years. The flow responds to changing basal properties, as a subglacial till layer interacts with water transported in an active subglacial hydrological system. We show that a persistent weak bed beneath the tributaries of the dormant Kamb Ice Stream is a source of internal ice flow instability, which reorganizes all ice streams in this region, leadingmore » to a reduced (positive) mass balance within decades and a net loss of ice within two centuries. This hitherto unaccounted for flow variability could raise sea level by 5 mm this century. Furthermore, better constraints on future sea level change from this region will require improved estimates of geothermal heat flux and subglacial water transport.« less

New disinfection and sterilization methods.

PubMed Central

Rutala, W. A.; Weber, D. J.

2001-01-01

New disinfection methods include a persistent antimicrobial coating that can be applied to inanimate and animate objects (Surfacine), a high-level disinfectant with reduced exposure time (ortho-phthalaldehyde), and an antimicrobial agent that can be applied to animate and inanimate objects (superoxidized water). New sterilization methods include a chemical sterilization process for endoscopes that integrates cleaning (Endoclens), a rapid (4-hour) readout biological indicator for ethylene oxide sterilization (Attest), and a hydrogen peroxide plasma sterilizer that has a shorter cycle time and improved efficacy (Sterrad 50). PMID:11294738

Cumulative and Synergistic Effects of Physical, Biological, and Acoustic Signals on Marine Mammal Habitat Use

DTIC Science & Technology

2013-10-28

apl.washington.edu Award Number: N00014-08-1-0394 Physical Oceanography Component Soundscapes Under Sea Ice: Can we listen for open water? LONG-TERM GOALS...as “ soundscapes ”, and graphically represented by comparing two or more features of the sound field, such as SPL levels at different frequencies or...spectral slopes between selected frequencies (Figure 1). Soundscapes are persistent on the time scale of hours to days, but can change rapidly if

Survival of prototype strains of somatic coliphage families in environmental waters and when exposed to UV low-pressure monochromatic radiation or heat.

PubMed

Lee, Hee Suk; Sobsey, Mark D

2011-06-01

The potential use of specific somatic coliphage taxonomic groups as viral indicators based on their persistence and prevalence in water was investigated. Representative type strains of the 4 major somatic coliphage taxonomic groups were seeded into reagent water and an ambient surface water source of drinking water and the survival of the added phages was measured over 90 days at temperatures of 23-25 and 4 °C. Microviridae (type strain PhiX174), Siphoviridae (type strain Lambda), and Myoviridae (type strain T4) viruses were the most persistent in water at the temperatures tested. The Microviridae (type strain PhiX174) and the Siphoviridae (type strain Lambda) were the most resistant viruses to UV radiation and the Myoviridae (type strain T4) and the Microviridae (type strain PhiX174) were the most resistant viruses to heat. Based on their greater persistence in water over time and their relative resistance to heat and/or UV radiation, the Myoviridae (type strain T4), the Microviridae (type strain PhiX174), and the Siphoviridae (type strain Lambda) were the preferred candidate somatic coliphages as fecal indicator viruses in water, with the Microviridae (type strain PhiX174) the most resistant to these conditions overall. Copyright © 2011 Elsevier Ltd. All rights reserved.

Contrasting sea-ice and open-water boundary layers during melt and freeze-up seasons: Some result from the Arctic Clouds in Summer Experiment.

NASA Astrophysics Data System (ADS)

Tjernström, Michael; Sotiropoulou, Georgia; Sedlar, Joseph; Achtert, Peggy; Brooks, Barbara; Brooks, Ian; Persson, Ola; Prytherch, John; Salsbury, Dominic; Shupe, Matthew; Johnston, Paul; Wolfe, Dan

2016-04-01

With more open water present in the Arctic summer, an understanding of atmospheric processes over open-water and sea-ice surfaces as summer turns into autumn and ice starts forming becomes increasingly important. The Arctic Clouds in Summer Experiment (ACSE) was conducted in a mix of open water and sea ice in the eastern Arctic along the Siberian shelf during late summer and early autumn 2014, providing detailed observations of the seasonal transition, from melt to freeze. Measurements were taken over both ice-free and ice-covered surfaces, offering an insight to the role of the surface state in shaping the lower troposphere and the boundary-layer conditions as summer turned into autumn. During summer, strong surface inversions persisted over sea ice, while well-mixed boundary layers capped by elevated inversions were frequent over open-water. The former were often associated with advection of warm air from adjacent open-water or land surfaces, whereas the latter were due to a positive buoyancy flux from the warm ocean surface. Fog and stratus clouds often persisted over the ice, whereas low-level liquid-water clouds developed over open water. These differences largely disappeared in autumn, when mixed-phase clouds capped by elevated inversions dominated in both ice-free and ice-covered conditions. Low-level-jets occurred ~20-25% of the time in both seasons. The observations indicate that these jets were typically initiated at air-mass boundaries or along the ice edge in autumn, while in summer they appeared to be inertial oscillations initiated by partial frictional decoupling as warm air was advected in over the sea ice. The start of the autumn season was related to an abrupt change in atmospheric conditions, rather than to the gradual change in solar radiation. The autumn onset appeared as a rapid cooling of the whole atmosphere and the freeze up followed as the warm surface lost heat to the atmosphere. While the surface type had a pronounced impact on boundary-layer structure in summer, the surface was often warmer than the atmosphere in autumn, regardless of surface type. Hence the autumn boundary-layer structure was more dependent on synoptic scale meteorology.

Evaluation of exposure to lead from drinking water in large buildings.

PubMed

Deshommes, Elise; Andrews, Robert C; Gagnon, Graham; McCluskey, Tim; McIlwain, Brad; Doré, Evelyne; Nour, Shokoufeh; Prévost, Michèle

2016-08-01

Lead results from 78,971 water samples collected in four Canadian provinces from elementary schools, daycares, and other large buildings using regulatory and investigative sampling protocols were analyzed to provide lead concentration distributions. Maximum concentrations reached 13,200 and 3890 μg/L following long and short stagnation periods respectively. High lead levels were persistent in some large buildings, reflected by high median values considering all taps, or specific to a few taps in the building. Simulations using the Integrated Uptake Biokinetic (IEUBK) model and lead concentrations after 30 min of stagnation in the dataset showed that, for most buildings, exposure to lead at the tap does not increase children's blood lead levels (BLLs). However, buildings or taps with extreme concentrations represent a significant health risk to young children attending school or daycare, as the estimated BLL far exceeded the 5 μg/dL threshold. Ingestion of water from specific taps could lead to acute exposure. Finally, for a few taps, the total daily lead intake reached the former World Health Organization (WHO) tolerable level for adults, suggesting potential health risks. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mud Banks along the southwest coast of India are not too muddy for plankton.

PubMed

Jyothibabu, R; Balachandran, K K; Jagadeesan, L; Karnan, C; Arunpandi, N; Naqvi, S W A; Pandiyarajan, R S

2018-02-07

Considering Alappuzha Mud Bank in the southern Kerala coast as a typical case of biologically productive Mud Banks that form along the southwest coast of India during the Southwest Monsoon (June - September), the present study addresses several pertinent missing links between the physical environment in Mud Banks and their influence on plankton stock. This study showed that very strong coastal upwelling prevails in the entire study domain during the Southwest Monsoon, which manifests itself in the form of significantly cool, hypoxic and nitrate-rich waters surfacing near the coast. The upwelled water persisting throughout the Southwest Monsoon period was found to have fuelled the exceptionally high phytoplankton stock in the entire study area, including the Mud Bank region. Having accepted that Mud Banks are special because of the calm sea surface conditions and relatively high turbidity level in the water column around them, the present study showed that except at points close to the sea bottom, turbidity level in the Alappuzha Mud Bank was below the critical level to inhibit the plankton stock. The suspended sediments that form in the Mud Bank occasionally could be attributed to the disturbance of the bottom fluid muddy layer and their vertical spurts.

A water risk index for portfolio exposure to climatic extremes: conceptualization and an application to the mining industry

NASA Astrophysics Data System (ADS)

Bonnafous, Luc; Lall, Upmanu; Siegel, Jason

2017-04-01

Corporations, industries and non-governmental organizations have become increasingly concerned with growing water risks in many parts of the world. Most of the focus has been on water scarcity and competition for the resource between agriculture, urban users, ecology and industry. However, water risks are multi-dimensional. Water-related hazards include flooding due to extreme rainfall, persistent drought and pollution, either due to industrial operations themselves, or to the failure of infrastructure. Most companies have risk management plans at each operational location to address these risks to a certain design level. The residual risk may or may not be managed, and is typically not quantified at a portfolio scale, i.e. across many sites. Given that climate is the driver of many of these extreme events, and there is evidence of quasi-periodic climate regimes at inter-annual and decadal timescales, it is possible that a portfolio is subject to persistent, multi-year exceedances of the design level. In other words, for a multi-national corporation, it is possible that there is correlation in the climate-induced portfolio water risk across its operational sites as multiple sites may experience a hazard beyond the design level in a given year. Therefore, from an investor's perspective, a need exists for a water risk index that allows for an exploration of the possible space and/or time clustering in exposure across many sites contained in a portfolio. This paper represents a first attempt to develop an index for financial exposure of a geographically diversified, global portfolio to the time-varying risk of climatic extremes using long daily global rainfall datasets derived from climate re-analysis models. Focusing on extreme daily rainfall amounts and using examples from major mining companies, we illustrate how the index can be developed. We discuss how companies can use it to explore their corporate exposure, and what they may need to disclose to investors and regulators to promote transparency as to risk exposure and mitigation efforts. For the examples of mining companies provided, we note that the actual exposure is substantially higher than would be expected in the absence of space and time correlation of risk as is usually tacitly assumed. We also find evidence for the increasing exposure to climate-induced risk, and for decadal variability in exposure. The relative vulnerability of different portfolios to multiple extreme events in a given year is also demonstrated.

Breast oedema following free flap breast reconstruction.

PubMed

Greenhowe, Jennifer; Stephen, Christopher; McClymont, Liusaidh; Munnoch, D Alex

2017-08-01

Breast oedema causes significant morbidity and is historically difficult to quantify. The aim of this study was to identify changes in breast tissue water content from pre-operative levels in the native breast to post-operative levels in mastectomy skin flaps and free flaps in the reconstructed breast. One hundred patients undergoing unilateral mastectomy and immediate free flap breast reconstruction were examined pre-operatively and at three post-operative appointments. A validated moisture meter was used to record dermal water percentages of each breast quadrant and areola in both breasts pre-operatively, then four quadrants of both breasts plus the unaffected areola and free flap at each post-operative review. Native skin of the reconstructed breast showed significant, persistent increase in MWC from 45.6% ± 0.5% to 72.8% ± 0.9% at 1st follow up (p < 0.001), decreasing only to 67.6% ± 0.8% by 3rd follow up. There was a marked difference (p < 0.001) in the mean water content (MWC) of the initial free flap (39.7% ± 0.6%) compared to 61.8% ± 1.7% at 1st follow up, then 55.1% ± 1.4% at 2nd and 53.7% ± 1.3% at 3rd follow ups. The unaffected breast showed a small but significant increase in MWC of all quadrants at subsequent follow up (greatest difference 3.1% at 1st follow up). This patient group demonstrates significant, persistent oedema of the reconstructed breast, which can be monitored using a non-invasive moisture meter. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Pesticides in Ground Water of the Maryland Coastal Plain

USGS Publications Warehouse

Denver, Judith M.; Ator, Scott W.

2006-01-01

Selected pesticides are detectable at low levels (generally less than 0.1 microgram per liter) in unconfined ground water in many parts of the Maryland Coastal Plain. Samples were recently collected (2001-04) from 47 wells in the Coastal Plain and analyzed for selected pesticides and degradate compounds (products of pesticide degradation). Most pesticide degradation occurs in the soil zone before infiltration to the water table, and degradates of selected pesticides were commonly detected in ground water, often at higher concentrations than their respective parent compounds. Pesticides and their degradates often occur in ground water in mixtures of multiple compounds, reflecting similar patterns in usage. All measured concentrations in ground water were below established standards for drinking water, and nearly all were below other health-based guidelines. Although drinking-water standards and guidelines are typically much higher than observed concentrations in ground water, they do not exist for many detected compounds (particularly degradates), or for mixtures of multiple compounds. The distribution of observed pesticide compounds reflects known usage patterns, as well as chemical properties and environmental factors that affect the fate and transport of these compounds in the environment. Many commonly used pesticides, such as glyphosate, pendimethalin, and 2,4-D were not detected in ground water, likely because they were sorbed onto organic matter or degraded in the soil zone. Others that are more soluble and (or) persistent, like atrazine, metolachlor, and several of their degradates, were commonly detected in ground water where they have been used. Atrazine, for example, an herbicide used primarily on corn, was most commonly detected in ground water on the Eastern Shore (where agriculture is common), particularly where soils are well drained. Conversely, dieldrin, an insecticide previously used heavily for termite control, was detected only on the Western Shore, where urban land is more common. Use of dieldrin was suspended in 1987, but this compound is relatively persistent in the environment, and several decades are typically required for ground water to move completely through the surficial aquifer. U.S. Department of the Interior U.S. Geological Survey USGS Fact Sheet FS 2006-3119 2006 Location of the Maryland Coastal Plain.

Water-level representation by men and women as a function of rod-and-frame test proficiency and visual and postural information.

PubMed

Robert, M; Ohlmann, T

1994-01-01

In the water-level task, it has been repeatedly shown that, compared with men, women more often fail to represent the surface of a liquid as horizontal regardless of the tilt of the container. An attempt was made to reduce this robust gender gap through the manipulation of relevant upright references conveyed both by the position of the stimuli and the posture of the subject. It was reasoned that bringing the women to focus on such gravitational references through postural adjustment might help their performance equal that of men, thus shedding some light on the nature of the difficulty they experience in the standard setting. A lesser effect was anticipated among men. However, the results showed that, even after controlling for proficiency in the correlated visuospatial situation of the rod-and-frame test, the performance of men always surpassed that of women. Irrespective of gender, water-level representation on vertical sheets was unaffected by the subject's posture, whereas it improved when horizontal sheets were coupled with the most unstable posture. Whereas the persistence of the yet-unaccounted-for gender difference was underscored, the contributions of visual and postural cues issued at arm and full-body levels were discussed.

Measles virus induces persistent infection by autoregulation of viral replication.

PubMed

Doi, Tomomitsu; Kwon, Hyun-Jeong; Honda, Tomoyuki; Sato, Hiroki; Yoneda, Misako; Kai, Chieko

2016-11-24

Natural infection with measles virus (MV) establishes lifelong immunity. Persistent infection with MV is likely involved in this phenomenon, as non-replicating protein antigens never induce such long-term immunity. Although MV establishes stable persistent infection in vitro and possibly in vivo, the mechanism by which this occurs is largely unknown. Here, we demonstrate that MV changes the infection mode from lytic to non-lytic and evades the innate immune response to establish persistent infection without viral genome mutation. We found that, in the persistent phase, the viral RNA level declined with the termination of interferon production and cell death. Our analysis of viral protein dynamics shows that during the establishment of persistent infection, the nucleoprotein level was sustained while the phosphoprotein and large protein levels declined. The ectopic expression of nucleoprotein suppressed viral replication, indicating that viral replication is self-regulated by nucleoprotein accumulation during persistent infection. The persistently infected cells were able to produce interferon in response to poly I:C stimulation, suggesting that MV does not interfere with host interferon responses in persistent infection. Our results may provide mechanistic insight into the persistent infection of this cytopathic RNA virus that induces lifelong immunity.

Bacterial repopulation of drinking water pipe walls after chlorination.

PubMed

Mathieu, Laurence; Francius, Grégory; El Zein, Racha; Angel, Edith; Block, Jean-Claude

2016-09-01

The short-term kinetics of bacterial repopulation were evaluated after chlorination of high-density polyethylene (HDPE) colonized with drinking water biofilms and compared with bare HDPE surfaces. The effect of chlorination was partial as a residual biofilm persisted and was time-limited as repopulation occurred immediately after water resupply. The total number of bacteria reached the same levels on both the bare and chlorinated biofilm-fouled HDPE after a seven-day exposure to drinking water. Due to the presence of a residual biofilm, the hydrophobicity of chlorinated biofilm-fouled surface exhibited much lower adhesion forces (2.1 nN) compared to bare surfaces (8.9 nN). This could explain the rapid repopulation after chlorination, with a twofold faster bacterial accumulation rate on the bare HDPE surface. γ-Proteobacteria dominated the early stages of repopulation of both surfaces and a shift in the dominance occurred over the colonization time. Such observations define a timescale for cleaning frequency in industrial environments and guidelines for a rinsing procedure using drinking water.

Concentrations of Glyphosate, Its Degradation Product, Aminomethylphosphonic Acid, and Glufosinate in Ground- and Surface-Water, Rainfall, and Soil Samples Collected in the United States, 2001-06

USGS Publications Warehouse

Scribner, Elisabeth A.; Battaglin, William A.; Gilliom, Robert J.; Meyer, Michael T.

2007-01-01

The U.S. Geological Survey conducted a number of studies from 2001 through 2006 to investigate and document the occurrence, fate, and transport of glyphosate, its degradation product, aminomethylphosphonic acid (AMPA), and glufosinate in 2,135 ground- and surface-water samples, 14 rainfall samples, and 193 soil samples. Analytical methods were developed to detect and measure glyphosate, AMPA, and glufosinate in water, rainfall, and soil. Results show that AMPA was detected more frequently and occurred at similar or higher concentrations than the parent compound, glyphosate, whereas glufosinate was seldom found in the environment. Glyphosate and AMPA were detected more frequently in surface water than in ground water. Trace levels of glyphosate and AMPA may persist in the soil from year to year. The methods and data described in this report are useful to researchers and regulators interested in the occurrence, fate, and transport of glyphosate and AMPA in the environment.

Demography of the ecosystem engineer Crassostrea gigas, related to vertical reef accretion and reef persistence

NASA Astrophysics Data System (ADS)

Walles, Brenda; Mann, Roger; Ysebaert, Tom; Troost, Karin; Herman, Peter M. J.; Smaal, Aad C.

2015-03-01

Marine species characterized as structure building, autogenic ecosystem engineers are recognized worldwide as potential tools for coastal adaptation efforts in the face of sea level rise. Successful employment of ecosystem engineers in coastal protection largely depends on long-term persistence of their structure, which is in turn dependent on the population dynamics of the individual species. Oysters, such as the Pacific oyster (Crassostrea gigas), are recognized as ecosystem engineers with potential for use in coastal protection. Persistence of oyster reefs is strongly determined by recruitment and shell production (growth), processes facilitated by gregarious settlement on extant shell substrate. Although the Pacific oyster has been introduced world-wide, and has formed dense reefs in the receiving coastal waters, the population biology of live oysters and the quantitative mechanisms maintaining these reefs has rarely been studied, hence the aim of the present work. This study had two objectives: (1) to describe the demographics of extant C. gigas reefs, and (2) to estimate vertical reef accretion rates and carbonate production in these oyster reefs. Three long-living oyster reefs (>30 years old), which have not been exploited since their first occurrence, were examined in the Oosterschelde estuary in the Netherlands. A positive reef accretion rate (7.0-16.9 mm year-1 shell material) was observed, consistent with self-maintenance and persistent structure. We provide a framework to predict reef accretion and population persistence under varying recruitment, growth and mortality scenarios.

Non-persistent pesticides removal in constructed wetlands

NASA Astrophysics Data System (ADS)

Tu, Yue; Jiang, Lei; Li, Haixiang

2018-03-01

The heavy use of non-persistent pesticides, resulting in the accumulation of environment and destroy the aquatic environment. This paper presents the research status of using CWs to treat non-persistent pesticides in water. The removal mechanisms are mainly physical deposition, chemical hydrolysis and plant absorption. Analysis of the factors that affect the removal effect are mainly the nature of pesticides, HRT, plants. Some scholars have proposed that secondary products of non-persistent pesticides may be more harmful to the environment, However, the relevant reports are scarce.

Persistent toxic substances: sources, fates and effects.

PubMed

Wong, Ming H; Armour, Margaret-Ann; Naidu, Ravi; Man, Ming

2012-01-01

Persistent toxic substances (PTS) include the Stockholm persistent organic pollutants, like dichlorodiphenyltrichloroethane, polychlorinated biphenyls, dioxin/furan, etc., and organometallic compounds, like organomercury, organotin, and organolead, which all share the same characteristics of being persistent, toxic, bioaccumulative, and able to travel long distances through different media. The adverse health effects of some of the emerging chemicals like pentabromodiphenyl ether, bisphenol A, and di(2-ethylhexyl)phthalate, which are widely used in daily appliances (e.g., TVs, computers, mobile phones, plastic baby bottles), have become a public health concern due to more evidence now available showing their adverse effects like disturbance of the endocrine system and cancer. This article is an attempt to review the current status of PTS in our environment, citing case studies in China and North America, and whether our existing drinking water treatment and wastewater treatment processes are adequate in removing them from water. Some management issues of these emerging chemicals of concern are also discussed.

Incidence of somatic and F+ coliphage in Great Lake Basin recreational waters.

PubMed

Wanjugi, Pauline; Sivaganesan, Mano; Korajkic, Asja; McMinn, Brian; Kelty, Catherine A; Rhodes, Eric; Cyterski, Mike; Zepp, Richard; Oshima, Kevin; Stachler, Elyse; Kinzelman, Julie; Kurdas, Stephan R; Citriglia, Mark; Hsu, Fu-Chih; Shanks, Orin C

2018-04-25

There is a growing interest for the use of coliphage as an alternative indicator to assess fecal pollution in recreational waters. Coliphage are a group of viruses that infect Escherichia coli and are considered as potential surrogates to infer the likely presence of enteric viral pathogens. We report the use of a dead-end hollow fiber ultrafiltration single agar layer method to enumerate F+ and somatic coliphage from surface waters collected from three Great Lake areas. At each location, three sites (two beaches; one river) were sampled five days a week over the 2015 beach season (n = 609 total samples). In addition, culturable E. coli and enterococci concentrations, as well as 16 water quality and recreational area parameters were assessed such as rainfall, turbidity, dissolved oxygen, pH, and ultra violet absorbance. Overall, somatic coliphage levels ranged from non-detectable to 4.39 log 10 plaque forming units per liter and were consistently higher compared to F+ (non-detectable to 3.15 log 10  PFU/L), regardless of sampling site. Coliphage concentrations weakly correlated with cultivated fecal indicator bacteria levels (E. coli and enterococci) at 75% of beach sites tested in study (r = 0.28 to 0.40). In addition, ultraviolet light absorption and water temperature were closely associated with coliphage concentrations, but not fecal indicator bacteria levels suggesting different persistence trends in Great Lake waters between indicator types (bacteria versus virus). Finally, implications for coliphage water quality management and future research directions are discussed. Copyright © 2018. Published by Elsevier Ltd.

Antibiotics in the surface water of the Yangtze Estuary: occurrence, distribution and risk assessment.

PubMed

Yan, Caixia; Yang, Yi; Zhou, Junliang; Liu, Min; Nie, Minghua; Shi, Hao; Gu, Lijun

2013-04-01

The occurrence and distribution of five groups of antibiotics were investigated in the surface water of Yangtze Estuary over four seasons. Of the 20 antibiotics, only sulfamerazine was not detected at all sampling sites, indicating widespread occurrence of antibiotic residues in the study area. Detection frequencies and concentrations of antibiotics were generally higher in January, indicating that low flow conditions and low temperature might enhance the persistence of antibiotics in water. Antibiotic levels varied with location, with the highest concentrations being observed around river discharge and sewage outfall. Furthermore, a positive correlation between total antibiotic and DOC concentrations revealed the significant role played by DOC. Risk assessment based on single compound exposure showed that sulfapyridine and sulfamethoxazole could cause medium risk to daphnid in the Yangtze Estuary. Copyright © 2012 Elsevier Ltd. All rights reserved.

Predicting the response of the Amazon rainforest to persistent drought conditions under current and future climates: a major challenge for global land surface models

NASA Astrophysics Data System (ADS)

Joetzjer, E.; Delire, C.; Douville, H.; Ciais, P.; Decharme, B.; Fisher, R.; Christoffersen, B.; Calvet, J. C.; da Costa, A. C. L.; Ferreira, L. V.; Meir, P.

2014-12-01

While a majority of global climate models project drier and longer dry seasons over the Amazon under higher CO2 levels, large uncertainties surround the response of vegetation to persistent droughts in both present-day and future climates. We propose a detailed evaluation of the ability of the ISBACC (Interaction Soil-Biosphere-Atmosphere Carbon Cycle) land surface model to capture drought effects on both water and carbon budgets, comparing fluxes and stocks at two recent throughfall exclusion (TFE) experiments performed in the Amazon. We also explore the model sensitivity to different water stress functions (WSFs) and to an idealized increase in CO2 concentration and/or temperature. In spite of a reasonable soil moisture simulation, ISBACC struggles to correctly simulate the vegetation response to TFE whose amplitude and timing is highly sensitive to the WSF. Under higher CO2 concentrations, the increased water-use efficiency (WUE) mitigates the sensitivity of ISBACC to drought. While one of the proposed WSF formulations improves the response of most ISBACC fluxes, except respiration, a parameterization of drought-induced tree mortality is missing for an accurate estimate of the vegetation response. Also, a better mechanistic understanding of the forest responses to drought under a warmer climate and higher CO2 concentration is clearly needed.

Alterations of cytochrome P450 and the occurrence of persistent organic pollutants in tilapia caged in the reservoirs of the Iguaçu River.

PubMed

Yamamoto, F Y; Diamante, G D; Santana, M S; Santos, D R; Bombardeli, R; Martins, C C; Oliveira Ribeiro, C A; Schlenk, D

2018-05-15

Environmental chemicals originating from human activities, such as persistent organic pollutants (POPs), may interfere with the endocrine system of aquatic organisms. The effect of these chemicals on biota and human populations is of high public concern but remains poorly understood, especially in aquatic environments of South America. The aim of this study was to investigate the bioavailability of POPs and the related effects in caged male tilapia (Oreochromis niloticus) in four cascading reservoirs of the Iguaçu River, Southern Brazil. POPs including organochlorine pesticides (OCPs), polychlorinated biphenyl (PCBs), and polybrominated diphenyl ethers (PBDEs) were determined in the reservoir water and tissue samples of tilapia after two months of exposure. The PCB levels in water (14.7 ng L -1 ) were 14 times higher than the limits permitted by the Brazilian legislation in the Salto Santiago (SS) reservoir. Similarly, concentrations of aldrin and its metabolites (6.05 ng L -1 ) detected in the water sample of the Salto Osório (SO) reservoir were also above the permitted limits. RT-qPCR analysis revealed different transcript levels of cytochrome P450 enzymes (CYP1A and CYP3A) in the liver among the four groups, with induced activity in tilapia from the SS reservoir. Quantification of the CYP3A mRNA expression and catalytic activity showed higher values for fish caged at the SS reservoir. The fish from this site also had a higher number of eosinophils observed in the testes. Although overt measurements of endocrine disruption were not observed in caged fish, alteration of CYP enzymes with co-occurrence of organochlorine contaminants in water may suggest bioavailability of contaminants from agricultural sources to biota. Additional studies with feral or caged animals for a longer duration may be necessary to evaluate the risks of the waterways to humans and wildlife. Copyright © 2018 Elsevier Ltd. All rights reserved.

Ranking REACH registered neutral, ionizable and ionic organic chemicals based on their aquatic persistency and mobility.

PubMed

Arp, H P H; Brown, T N; Berger, U; Hale, S E

2017-07-19

The contaminants that have the greatest chances of appearing in drinking water are those that are mobile enough in the aquatic environment to enter drinking water sources and persistent enough to survive treatment processes. Herein a screening procedure to rank neutral, ionizable and ionic organic compounds for being persistent and mobile organic compounds (PMOCs) is presented and applied to the list of industrial substances registered under the EU REACH legislation as of December 2014. This comprised 5155 identifiable, unique organic structures. The minimum cut-off criteria considered for PMOC classification herein are a freshwater half-life >40 days, which is consistent with the REACH definition of freshwater persistency, and a log D oc < 4.5 between pH 4-10 (where D oc is the organic carbon-water distribution coefficient). Experimental data were given the highest priority, followed by data from an array of available quantitative structure-activity relationships (QSARs), and as a third resort, an original Iterative Fragment Selection (IFS) QSAR. In total, 52% of the unique REACH structures made the minimum criteria to be considered a PMOC, and 21% achieved the highest PMOC ranking (half-life > 40 days, log D oc < 1.0 between pH 4-10). Only 9% of neutral substances received the highest PMOC ranking, compared to 30% of ionizable compounds and 44% of ionic compounds. Predicted hydrolysis products for all REACH parents (contributing 5043 additional structures) were found to have higher PMOC rankings than their parents, due to increased mobility but not persistence. The fewest experimental data available were for ionic compounds; therefore, their ranking is more uncertain than neutral and ionizable compounds. The most sensitive parameter for the PMOC ranking was freshwater persistency, which was also the parameter that QSARs performed the most poorly at predicting. Several prioritized drinking water contaminants in the EU and USA, and other contaminants of concern, were identified as PMOCs. This identification and ranking procedure for PMOCs can be part of a strategy to better identify contaminants that pose a threat to drinking water sources.

Response of coliform populations in streambed sediment and water column to changes in nutrient concentrations in water.

PubMed

Shelton, D R; Pachepsky, Y A; Kiefer, L A; Blaustein, R A; McCarty, G W; Dao, T H

2014-08-01

As sediments increasingly become recognized as reservoirs of indicator and pathogen microorganisms, an understanding of the persistence of indicator organisms becomes important for assessment and predictions of microbial water quality. The objective of this work was to observe the response of water column and sediment coliform populations to the change in nutrient concentrations in the water column. Survival experiments were conducted in flow-through chambers containing sandy sediments. Bovine feces were collected fresh and introduced into sediment. Sixteen days later, the same fecal material was autoclaved and diluted to provide three levels - 1×, 0.5×, and 0.1× of nutrient concentrations - spike in water column. Total coliforms, Escherichia coli, and total aerobic heterotrophic bacterial concentrations were monitored in water and sediment. Bacteria responded to the nutrient spike with initial growth both in the water column and in sediment. The response of bacterial concentrations in water column was nonlinear, with no significant changes at 0.1 and .5× spikes, but a substantial change at 1× spike. Bacteria in sediment responded to the spikes at all added nutrient levels. Coliform inactivation rates both in sediment and in water after the initial growth occurred, were not significantly different from the inactivation rates before spike. These results indicate that introduction of nutrients into the water column results in nonlinear response of E. coli concentrations both in water and in sediments, followed by the inactivation with the same rate as before introduction of nutrients. Published by Elsevier Ltd.

Diluting the founder effect: cryptic invasions expand a marine invader's range

PubMed Central

Roman, Joe

2006-01-01

Most invasion histories include an estimated arrival time, followed by range expansion. Yet, such linear progression may not tell the entire story. The European green crab (Carcinus maenas) was first recorded in the US in 1817, followed by an episodic expansion of range to the north. Its population has recently exploded in the Canadian Maritimes. Although it has been suggested that this northern expansion is the result of warming sea temperatures or cold-water adaptation, Canadian populations have higher genetic diversity than southern populations, indicating that multiple introductions have occurred in the Maritimes since the 1980s. These new genetic lineages, probably from the northern end of the green crab's native range in Europe, persist in areas that were once thought to be too cold for the original southern invasion front. It is well established that ballast water can contain a wide array of nonindigenous species. Ballast discharge can also deliver genetic variation on a level comparable to that of native populations. Such gene flow not only increases the likelihood of persistence of invasive species, but it can also rapidly expand the range of long-established nonindigenous species. PMID:16959635

Arsenic exposure and its impact on health in Chile.

PubMed

Ferreccio, Catterina; Sancha, Ana María

2006-06-01

The problem of arsenic in Chile was reviewed. In Chile, the population is exposed to arsenic naturally via drinking-water and by air pollution resulted from mining activities. The sources of arsenic were identified to estimate the exposure of population to arsenic through air, water, and food. Health effects, particularly early effects, observed in children and adults, such as vascular diseases (premature cardiac infarct), respiratory illnesses (bronchiectasis), and skin lesions have been described. Chronic effects, such as lung and bladder cancers, were reported 20 years after peak exposure and persisted 27 years after mitigation measures for removing arsenic from drinking surface water were initiated. Although the effects of arsenic are similar in different ethnic and cultural groups (e.g. Japanese, Chinese, Indian, Bangladeshi, American, and Taiwanese), variations could be explained by age at exposure, the dose received, smoking, and nutrition. Since health effects were observed at arsenic levels of 50 microg/L in drinking-water, it is advised that Chile follows the World Health Organization's recommendation of 10 microg/L. The Chilean experience in removal of arsenic suggests that it is feasible to reach this level using the conventional coagulation process.

Relation between Enterococcus concentrations and turbidity in fresh and saline recreational waters, coastal Horry County, South Carolina, 2003–04

USGS Publications Warehouse

Landmeyer, James E.; Garigen, Thomas J.

2016-06-24

The positive relation observed between turbidity and Enterococcus concentrations in surface water at the water-quality data collection station located in the channel that drains a freshwater swamp may be attributed to bacterial survival in the abundant channel bed sediments that characterized this more naturalized area. Surface-water bed sediments collected near each water-quality data collection station and the surf zone were incubated in static microcosms in the laboratory and analyzed for Enterococcus concentrations over time. Enterococcus concentrations continued to persist in bed sediments collected in the channel that drains the swamp even after almost 4 months of incubation. Conversely, enterococci were not observed to persist in bed sediments characterized by high specific conductance. Although it is currently (2016) unknown whether this persistence of enterococci demonstrates growth or viability, the data indicate that enterococci can exist in channel bed-sediment environments outside of a host for a long time. This observation confirms previous reports that challenge the use of Enterococcus concentrations as an indicator of the recent introduction of fecal-related material and the associated acute risk to other pathogens.

Methane evasion and oxidation in the Big Cypress National Preserve—a low relief carbonate wetland

NASA Astrophysics Data System (ADS)

Ward, N. D.; Bianchi, T. S.; Cohen, M. J.; Martin, J. B.; Quintero, C.; Brown, A.; Osborne, T.; Sawakuchi, H. O.

2016-12-01

The Big Cypress National Preserve is a low relief carbonate wetland characterized by unique basin patterning known as "cypress domes." Here we examine the concentration and stable isotopic composition of methane in pore waters, surface waters, and bubbles from the sediment across horizontal gradients in four domes during three sampling campaigns. The proportion of methane oxidized in surface waters was estimated based on isotopic differences between surface water and pore waters/bubbles. Rates of methane evasion from surface waters, soils, and cypress knees to the atmosphere were also measured. Surface water CH4 concentrations ranged from 170 to 4,533 ppm with the highest levels generally being observed during wet periods. Pore water CH4 concentrations ranged from 748 to 75,213 ppm. The concentration of methane in bubbles ranged from 6.5 to 71%. The stable isotopic composition of CH4 ranged from -69.2 to -43.8‰ for all samples and was generally more enriched in surface waters compared to bubbles and porewaters, particularly in the two domes that were persistently inundated throughout the year. Based on these isotopic values, the average percentage of surface water CH4 that was oxidized was 37 ± 16% (maximum of 67%) and 19 ± 4% (maximum of 47%) in the two domes that are persistently inundated versus the two domes that are not inundated during the dry season, respectively. The average rate of CH4 evasion was 3.6 ± 1.6 mmol m-2 d-1 via diffusion, 7.6 ± 4.7 mmol m-2 d-1 via ebullition, 10.9 ± 11.4 mmol m-2 d-1­ from soil surfaces, and 34.3 ± 27.4 mmol m-2 d-1 from cypress knees. These results indicate that CH4 is produced in great quantities in inundated sediments, particularly in the center of the cypress domes. Diffusive fluxes from surface waters are suppressed by microbial oxidation in the water column, whereas ebullition from sediments and evasion through cypress knees, and likely other vascular vegetation, are the primary pathways for CH4 outgassing.

PERCHLORATE CROP INTERACTIONS VIA CONTAMINATED IRRIGATION WATER

EPA Science Inventory

Perchlorate has contaminated water and sods at several locations in the United States. Perchlorate is water soluble, exceedingly mobile in aqueous systems, and can persist for many decades under typical ground- and surface water conditions. Perchlorate is of concern because of un...

Persistence of Undergraduate Women in STEM Fields

ERIC Educational Resources Information Center

Pedone, Maggie Helene

2016-01-01

The underrepresentation of women in science, technology, engineering, and mathematics (STEM) is a complex problem that continues to persist at the postsecondary level, particularly in computer science and engineering fields. This dissertation explored the pre-college and college level factors that influenced undergraduate women's persistence in…

Persistence of environmental DNA in freshwater ecosystems.

PubMed

Dejean, Tony; Valentini, Alice; Duparc, Antoine; Pellier-Cuit, Stéphanie; Pompanon, François; Taberlet, Pierre; Miaud, Claude

2011-01-01

The precise knowledge of species distribution is a key step in conservation biology. However, species detection can be extremely difficult in many environments, specific life stages and in populations at very low density. The aim of this study was to improve the knowledge on DNA persistence in water in order to confirm the presence of the focus species in freshwater ecosystems. Aquatic vertebrates (fish: Siberian sturgeon and amphibian: Bullfrog tadpoles) were used as target species. In control conditions (tanks) and in the field (ponds), the DNA detectability decreases with time after the removal of the species source of DNA. DNA was detectable for less than one month in both conditions. The density of individuals also influences the dynamics of DNA detectability in water samples. The dynamics of detectability reflects the persistence of DNA fragments in freshwater ecosystems. The short time persistence of detectable amounts of DNA opens perspectives in conservation biology, by allowing access to the presence or absence of species e.g. rare, secretive, potentially invasive, or at low density. This knowledge of DNA persistence will greatly influence planning of biodiversity inventories and biosecurity surveys.

Persistence of two Trichomonas gallinae isolates in chlorinated and distilled water with or without organic material.

PubMed

Gerhold, Richard W; Maestas, Lauren P; Harnage, Philip M

2013-09-01

Trichomonas gallinae is a protozoan parasite commonly found in columbids, passerines, and raptors. In passerines and columbids, trichomonosis causes significant morbidity and mortality associated with contaminated bird feeders and waters. However, there has been little work on the persistence of T. gallinae in water to determine if artificial waters are a likely source of infection for naive birds. To examine drinking water as a source of T. gallinae transmission, we inoculated 1 x 10(6) trichomonads into containers with 500 ml of either distilled or chlorinated water. In addition, we inoculated the same number of trichomonads in distilled or chlorinated water contaminated with 15 g organic matter. Aliquots of 0.5 ml were collected from each container at 0, 0.5, 1, 5, 10, or 20 min; inoculated into a Trichomonas culture packet; and incubated at 37 C for 6 days. Survival was best in the presence of organic matter, with either distilled or chlorinated water. Uncontaminated chlorinated water did not allow survival at any sampling period.

Water-Bearing Rocks in Noctis Labyrinthus

NASA Image and Video Library

2014-07-30

Many of the depressions in Noctis Labyrinthus contain water-bearing minerals, suggesting that water was available and persistent in this region during the Late Hesperian to Amazonian epochs on Mars, as seen by NASA Mars Reconnaissance Orbiter.

Evaluating the environmental fate of pharmaceuticals using a level III model based on poly-parameter linear free energy relationships.

PubMed

Zukowska, Barbara; Breivik, Knut; Wania, Frank

2006-04-15

We recently proposed how to expand the applicability of multimedia models towards polar organic chemicals by expressing environmental phase partitioning with the help of poly-parameter linear free energy relationships (PP-LFERs). Here we elaborate on this approach by applying it to three pharmaceutical substances. A PP-LFER-based version of a Level III fugacity model calculates overall persistence, concentrations and intermedia fluxes of polar and non-polar organic chemicals between air, water, soil and sediments at steady-state. Illustrative modeling results for the pharmaceuticals within a defined coastal region are presented and discussed. The model results are highly sensitive to the degradation rate in water and the equilibrium partitioning between organic carbon and water, suggesting that an accurate description of this particular partitioning equilibrium is essential in order to obtain reliable predictions of environmental fate. The PP-LFER based modeling approach furthermore illustrates that the greatest mobility in aqueous phases may be experienced by pharmaceuticals that combines a small molecular size with strong H-acceptor properties.

Bacteriophages as indicators of faecal pollution and enteric virus removal.

PubMed

McMinn, B R; Ashbolt, N J; Korajkic, A

2017-07-01

Bacteriophages are an attractive alternative to faecal indicator bacteria (FIB), particularly as surrogates of enteric virus fate and transport, due to their closer morphological and biological properties. Based on a review of published data, we summarize densities of coliphages (F+ and somatic), Bacteroides spp. and enterococci bacteriophages (phages) in individual human waste, raw wastewater, ambient fresh and marine waters and removal through wastewater treatment processes utilizing traditional treatments. We also provide comparisons with FIB and enteric viruses whenever possible. Lastly, we examine fate and transport characteristics in the aquatic environment and provide an overview of the environmental factors affecting their survival. In summary, concentrations of bacteriophages in various sources were consistently lower than FIB, but more reflective of infectious enteric virus levels. Overall, our investigation indicates that bacteriophages may be adequate viral surrogates, especially in built systems, such as wastewater treatment plants. Bacteriophage are alternative fecal indicators that may be better surrogates for viral pathogens than fecal indicator bacteria (FIB). This report offers a summary of the existing literature concerning the utility of bacteriophage as indicators of viral presence (fecal sources and surface waters) and persistence (in built infrastructure and aquatic environments). Our findings indicate that bacteriophage levels in all matrices examined are consistently lower than FIB, but similar to viral pathogens. Furthermore, in built infrastructure (e.g. wastewater treatment systems) bacteriophage closely mimic viral pathogen persistence suggesting they may be adequate sentinels of enteric virus removal. © 2017 The Society for Applied Microbiology.

75 FR 75761 - Water Quality Standards for the State of Florida's Lakes and Flowing Waters

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-06

... widespread, persistent, and growing problem. Nitrogen/phosphorus pollution in fresh water systems can... Florida's regulated drinking water systems and a 10 mg/L criteria for nitrate in Class I waters. FDEP..., kidney, and central nervous system problems. 44 45 \\44\\ USEPA. 2009. National Primary Drinking Water...

PERSISTENCE OF WASTEWATER COMPOUNDS DURING DRINKING WATER TREATMENT: REMOVAL AND POTENTIAL EXPOSURE

EPA Science Inventory

The amount of water available for human consumption is becoming limited in some communities. Water reuse or recycling has become one method of overcoming this problem. Whether this takes the form of direct water reuse (toilet-to-tap), ground water recharging, or discharging eff...

Effect of climatic conditions on the development of soil water repellency in soils treated with the wastewater of the olive oil production

NASA Astrophysics Data System (ADS)

Schaumann, Gabriele E.; Peikert, Benjamin; Tamimi, Nesreen; Steinmetz, Zacharias; Fischer, Jonas; Bibus, Daniel; Marei Sawalha, Amer; Dag, Arnon

2014-05-01

The disposal of untreated wastewater on soil can induce severe water repellency. The final degree of water repellency may strongly depend on the environmental conditions prevailing during and after disposal. Also unpolluted soil can develop severe water repellency upon exposure to extreme heat or draught events. The induced water repellency can be either persistent or of transient nature. However, the underlying mechanisms are not yet completely understood. The objective of this study was to investigate how climatic conditions determine the development and persistence of water repellency following wastewater disposal. Our hypothesis was that amphiphilic organic wastewater compounds physically sorb onto surfaces, which renders them hydrophobic. Depending on temperature and moisture, those compounds are degraded, chemically incorporated into SOM, or irreversibly sorbed to soil particles during the time after the first waste water-soil contact. According to our hypothesis, biological communities favor degradation and transformation of OM of waste water into SOM under moist soil conditions. This would reduce the initial hydrophobization. In contrast, drying irreversibly renders soil hydrophobic and phytotoxic due to immobilization of OMW OM in the soil. To test these hypotheses, we investigated effects of olive mil wastewater (OMW), the effluent originating from olive oil production, directly applied to soil. In Israel and Palastine, olive oil production generates large amounts of OMW within a short period of time between November and January. As sewage facilities do not accept OMW, it is often disposed onto soil, which leads to severe soil and groundwater pollution. If the above mentioned hypotheses match, pollution and hydrophobization might be minimized if the wastewater is discharged at the right time of the year. In order to test this, we conducted field (2-3 years) and laboratory (60 days) experiments in Israel (Gilat, arid climate) and in the West Bank (Bait Reema, Mediterranean climate) to assess the effect of climatic conditions during OMW application on the development of water repellency as a function of time. In the field experiments, OMW was applied to the soil in winter, spring, and summer, the latter with and without subsequent irrigation to keep the field moist for at least 6 weeks after OMW application. Most effects were strongest for the summer scenario without additional irrigation (field and lab) where the field effect persisted for at least 6 months. In contrast, summer application on moist soil only resulted in a slight and temporarily enhanced water repellency. Spring application induced a clearly less severe water repellency than summer application under dry conditions. Water repellency in the field developed more dramatically and with higher persistence in Gilat, which can be explained by its coarser soil texture but also by the more arid conditions. Repellency developed gradually during the hot summer time following OMW application in spring and summer plots and in the summer scenario of the lab incubation experiments, suggesting a contribution of abiotic processes inducing repellency. The results clearly show that extreme heat and/or drought may induce persistent water repellency and that abiotic and physicochemical mechanisms including drought-induced, irreversible sorption of amphiphilic substances to soil particles are capable to render water repellency persistent.

Rate of disappearance of gas bubble trauma signs in juvenile salmonids

USGS Publications Warehouse

Hans, K.M.; Mesa, M.G.; Maule, A.G.

1999-01-01

To assess the rate of disappearance of gas bubble trauma (GBT) signs in juvenile salmonids, we exposed spring chinook salmon Oncorhynchus tshawytscha and steelhead O. mykiss to water containing high levels of dissolved gas supersaturation (DGS) for a time period sufficient to induce signs of GBT, reduced the DGS to minimal levels, and then sampled fish through time to document changes in severity of GBT. Because of the tendency of GBT signs to dissipate at different rates, we conducted trials focusing on emboli (bubbles) in the gill filaments and lateral line and separate trials that focused on bubbles in the external surfaces (fins, eyes, and opercula). Bubbles in gill filaments dissipated almost completely within 2 h after transfer of fish to water of nearly normal DGS (104%), whereas bubbles in the lateral line dissipated to negligible levels within 5 h. Bubbles on external surfaces were more persistent through time than they were in gill filaments and the lateral line. Although typically dissipating to low levels within 48 h, external bubbles sometimes remained for 4 d. Assuming a direct relation exists between easily observable signs and direct mortality, our results suggest that fish can recover quickly from the potentially lethal effects of DGS once they move from water with high DGS to water of almost normal gas saturation. These results should be of fundamental importance to fishery managers interpreting the results of monitoring for the severity and prevalence of GBT in juvenile salmonids in the Columbia River system and perhaps elsewhere.

Bacterial persistence by RNA endonucleases

PubMed Central

Maisonneuve, Etienne; Shakespeare, Lana J.; Jørgensen, Mikkel Girke; Gerdes, Kenn

2011-01-01

Bacteria form persisters, individual cells that are highly tolerant to different types of antibiotics. Persister cells are genetically identical to nontolerant kin but have entered a dormant state in which they are recalcitrant to the killing activity of the antibiotics. The molecular mechanisms underlying bacterial persistence are unknown. Here, we show that the ubiquitous Lon (Long Form Filament) protease and mRNA endonucleases (mRNases) encoded by toxin-antitoxin (TA) loci are required for persistence in Escherichia coli. Successive deletion of the 10 mRNase-encoding TA loci of E. coli progressively reduced the level of persisters, showing that persistence is a phenotype common to TA loci. In all cases tested, the antitoxins, which control the activities of the mRNases, are Lon substrates. Consistently, cells lacking lon generated a highly reduced level of persisters. Moreover, Lon overproduction dramatically increased the levels of persisters in wild-type cells but not in cells lacking the 10 mRNases. These results support a simple model according to which mRNases encoded by TA loci are activated in a small fraction of growing cells by Lon-mediated degradation of the antitoxins. Activation of the mRNases, in turn, inhibits global cellular translation, and thereby induces dormancy and persistence. Many pathogenic bacteria known to enter dormant states have a plethora of TA genes. Therefore, in the future, the discoveries described here may lead to a mechanistic understanding of the persistence phenomenon in pathogenic bacteria. PMID:21788497

Function of child anger and sadness in response to a blocked goal.

PubMed

Tan, Lin; Smith, Cynthia L

2018-06-01

Drawing from the functional theory of emotion, anger is proposed to serve adaptive functions such as motivating children to persist in overcoming difficulties to achieve their goals, whereas sadness helps children to shift attention away from goals that they determine cannot be attained. Despite the theorized importance of anger to persistence, it does not always relate to persistence in expected ways empirically; the role that sadness might play in how anger relates to persistence is often not considered even though children often experience both anger and sadness when goals are blocked. We hypothesized that how anger relates to persistence would depend on the level of sadness that children felt and, thus, tested sadness as a moderator of the relation of anger to persistence. We expected that the relation of anger to persistence would be stronger when sadness is lower. Child anger, sadness, and persistence were observed in a locked-box frustration task when children were 4 or 5 years old (N = 116). Although higher levels of child anger were associated with more persistence, the association between anger and persistence was stronger when sadness was lower than when sadness was higher. The findings indicate that children's ability to use the motivational aspects of anger to promote persistence may depend on the levels of sadness felt. Copyright © 2018 Elsevier Inc. All rights reserved.

Reducing SCADA System Nuisance Alarms in the Water Industry in Northern Ireland.

PubMed

O'Donoghue, Nigel; Phillips, Debra H; Nicell, Ciaran

2015-08-01

The advancement of telemetry control for the water industry has increased the difficulty of managing large volumes of nuisance alarms (i.e., alarms that do not require a response). The aim of this study was to identify and reduce the number of nuisance alarms that occur for Northern Ireland (NI) Water by carrying out alarm duration analysis to determine the appropriate length of persistence (an advanced alarm management tool) that could be applied. All data were extracted from TelemWeb (NI Water's telemetry monitoring system) and analyzed in Excel. Over a 6-week period, an average of 40 000 alarms occurred per week. The alarm duration analysis, which has never been implemented before by NI Water, found that an average of 57% of NI Water alarms had a duration of <5 minutes. Applying 5-minute persistence, therefore, could prevent an average 26 816 nuisance alarms per week. Most of these alarms were from wastewater assets.

A Mathematical View of Water Table Fluctuations in a Shallow Aquifer in Brazil.

PubMed

Neto, Dagmar C; Chang, Hung K; van Genuchten, Martinus Th

2016-01-01

Detailed monitoring of the groundwater table can provide important data about both short- and long-term aquifer processes, including information useful for estimating recharge and facilitating groundwater modeling and remediation efforts. In this paper, we presents results of 4 years (2002 to 2005) of monitoring groundwater water levels in the Rio Claro Aquifer using observation wells drilled at the Rio Claro campus of São Paulo State University in Brazil. The data were used to follow natural periodic fluctuations in the water table, specifically those resulting from earth tides and seasonal recharge cycles. Statistical analyses included methods of time-series analysis using Fourier analysis, cross-correlation, and R/S analysis. Relationships could be established between rainfall and well recovery, as well as the persistence and degree of autocorrelation of the water table variations. We further used numerical solutions of the Richards equation to obtain estimates of the recharge rate and seasonable groundwater fluctuations. Seasonable soil moisture transit times through the vadose zone obtained with the numerical solution were very close to those obtained with the cross-correlation analysis. We also employed a little-used deep drainage boundary condition to obtain estimates of seasonable water table fluctuations, which were found to be consistent with observed transient groundwater levels during the period of study. © 2015, National Ground Water Association.

Generic Protocol for the Verification of Ballast Water Treatment Technology. Version 5.1

DTIC Science & Technology

2010-09-01

the Protocol ..................................................................................... 2 1.4 Verification Testing Process ...Volumes, Containers and Processing .................................................................38 Table 10. Recommendation for Water...or persistent distortion of a measurement process that causes errors in one direction. Challenge Water: Water supplied to a treatment system under

PERCHLORATE-CROP INTERACTIONS FROM CONTAMINATED IRRIGATION WATER AND FERTILIZER APPLICATIONS

EPA Science Inventory

Perchlorate has contaminated water and soils at several locations in the United States. Perchlorate is water soluble, exceedingly mobile in aqueous systems, and can persist for many decades under typical ground and surface water conditions. Perchlorate is of concern because of un...

Atlantic ocean surface waters buffer declining atmospheric concentrations of persistent organic pollutants.

PubMed

Nizzetto, Luca; Lohmann, Rainer; Gioia, Rosalinda; Dachs, Jordi; Jones, Kevin C

2010-09-15

Decreasing environmental concentrations of some persistent organic pollutants (POPs) have been observed at local or regional scales in continental areas after the implementation of international measures to curb primary emissions. A decline in primary atmospheric emissions can result in re-emissions of pollutants from the environmental capacitors (or secondary sources) such as soils and oceans. This may be part of the reason why concentrations of some POPs such as polychlorinated biphenyls (PCBs) have not declined significantly in the open oceanic areas, although re-emission of POPs from open ocean water has barely been documented. In contrast, results from this study show that several polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) have undergone a marked decline (2-3 orders of magnitude for some homologues) over a major portion of the remote oligotrophic Atlantic Ocean. The decline appears to be faster than that observed over continental areas, implicating an important role of oceanic geochemical controls on levels and cycling of some POPs. For several lower chlorinated PCDD/Fs, we observed re-emission from surface water back to the atmosphere. An assessment of the effectiveness of the main sink processes highlights the role of degradation in surface waters as potentially key to explaining the different behavior between PCDD/Fs and PCBs and controlling their overall residence time in the ocean/atmosphere system. This study provides experimental evidence that the ocean has a buffering capacity - dependent on individual chemicals - which moderates the rate at which the system will respond to an underlying change in continental emissions.

Intermolecular network analysis of the liquid and vapor interfaces of pentane and water: microsolvation does not trend with interfacial properties.

PubMed

Ghadar, Yasaman; Clark, Aurora E

2014-06-28

Liquid:vapor and liquid:liquid interfaces exhibit complex organizational structure and dynamics at the molecular level. In the case of water and organic solvents, the hydrophobicity of the organic, its conformational flexibility, and compressibility, all influence interfacial properties. This work compares the interfacial tension, width, molecular conformations and orientations at the vapor and aqueous liquid interfaces of two solvents, n-pentane and neopentane, whose varying molecular shapes can lead to significantly different interfacial behavior. Particular emphasis has been dedicated toward understanding how the hydrogen bond network of water responds to the pentane relative to the vapor interface and the sensitivity of the network to the individual pentane isomer and system temperature. Interfacial microsolvation of the immiscible solvents has been examined using graph theoretical methods that quantify the structure and dynamics of microsolvated species (both H2O in C5H12 and C5H12 in H2O). At room temperature, interfacial water at the pentane phase boundary is found to have markedly different organization and dynamics than at the vapor interface (as indicated by the hydrogen bond distributions and hydrogen bond persistence in solution). While the mesoscale interfacial properties (e.g. interfacial tension) are sensitive to the specific pentane isomer, the distribution and persistence of microsolvated species at the interface is nearly identical for both systems, irrespective of temperature (between 273 K and 298 K). This has important implications for understanding how properties defined by the interfacial organization are related to the underlying solvation reactions that drive formation of the phase boundary.

Filling Gaps in Biogeochemical Understanding of Wildfire Effects on Watersheds and Water Quality

NASA Astrophysics Data System (ADS)

Rhoades, Charles; Covino, Timothy; Chow, Alex

2017-04-01

Large, high-severity wildfires alter the biogeochemical conditions that determine how watersheds retain and release nutrients and influence stream water quality. These effects are commonly expected to abate within a few years, but recent studies show that post-fire watershed changes can have persistent, but poorly-understood biogeochemical consequences. Owing to the increased frequency and extent of high-severity wildfires predicted for western North America, and the growing awareness of the links between wildfire and clean water supply, there is a need to address these knowledge gaps. For the past 15 years we have tracked stream nutrients, chemistry, temperature, and sediment after the 2002 Hayman Fire, the largest wildfire in Colorado history. Our earlier work showed that headwater catchments that experienced extensive, high-severity forest fires had elevated stream nitrate, temperature, and turbidity for five post-fire years. Recent sampling, conducted 13 and 14 years after the fire, found that turbidity had largely returned to pretreatment levels, but that stream nitrate remained an order of magnitude above pre-fire levels in catchments with extensive high-severity wildfire. Stream temperature and total dissolved nitrogen concentration also remained higher in those catchments compared to unburned streams. Decreased plant demand is the mechanism commonly credited for post-fire nutrient losses, though our current work is evaluating the implications of soil and stream nutrient uptake and supply on persistent nitrogen (N) export from severely-burned catchments. For example, we have measured higher total soil N and higher net N mineralization in severely-burned portions of the Hayman Fire compared to moderately or unburned areas, indicating that higher soil N supply may contribute to N losses from upland soils. Conversely, using a nutrient tracer approach we found reduced N uptake in burned streams, which suggests a switch from the N-limited conditions typical of pristine catchments. Low stream dissolved organic carbon (DOC) in severely-burned catchments suggests greater carbon limitation on in-stream biological activity. This is the likely result of organic matter losses during the wildfire compounded by low allochthonous inputs from uplands or riparian zones. We also find that catchments with severely-burned headwater reaches and sparse riparian vegetation have high stream nitrate. Our findings regarding soil N supply and in-stream N retention coupled with the persistent N losses from burned headwaters and exposed riparian zones help prioritize restoration efforts aimed at mitigating long-term water quality effects of severe wildfires.

LINKING EFFECTS OF PERSISTENT BIOACCUMULATIVE TOXICANTS TO CHEMICAL EXPOSURES IN AQUATIC ECOSYSTEMS

EPA Science Inventory

The critical step in characterization of ecological risks associated with exposures of fish and wildlife to persistent bioaccumulative toxicants (PBTs) is linking chemical residue based toxicological data to concentrations of PBTs in sediments, water, and biota. This is necessary...

Integrated systems analysis of persistent polar pollutants in the water cycle.

PubMed

van der Voet, E; Nikolic, I; Huppes, G; Kleijn, R

2004-01-01

Persistent polar pollutants (P3) are difficult to degrade in standard waste water treatment plants. As a result, they end up in the effluent and are emitted to the surface water. In some areas, this problem is aggravated through "closed loop recycling", causing concentrations of P3 in surface water to build up over time. This could cause violation of (future) EU regulations. In the P-THREE project, various alternative waste water treatment techniques are investigated regarding their effectiveness in eliminating these substances, especially membrane bioreactor treatment and advanced oxidation processes, MBR and AOP. The integrated systems analysis which is the subject of this paper assesses these techniques in a broader systems context: (1) the life-cycle of the P3, (2) the life cycle of the WWTPs, and (3) the WWTP life cycle costs.

Cumulative Inequality and Racial Disparities in Health: Private Insurance Coverage and Black/White Differences in Functional Limitations

PubMed Central

Taylor, Miles G.

2014-01-01

Objectives. To test different forms of private insurance coverage as mediators for racial disparities in onset, persistent level, and acceleration of functional limitations among Medicare age-eligible Americans. Method. Data come from 7 waves of the Health and Retirement Study (1996–2008). Onset and progression latent growth models were used to estimate racial differences in onset, level, and growth of functional limitations among a sample of 5,755 people aged 65 and older in 1996. Employer-provided insurance, spousal insurance, and market insurance were next added to the model to test how differences in private insurance mediated the racial gap in physical limitations. Results. In baseline models, African Americans had larger persistent level of limitations over time. Although employer-provided, spousal provided, and market insurances were directly associated with lower persistent levels of limitation, only differences in market insurance accounted for the racial disparities in persistent level of limitations. Discussion. Results suggest private insurance is important for reducing functional limitations, but market insurance is an important mediator of the persistently larger level of limitations observed among African Americans. PMID:24569001

Water tables constrain height recovery of willow on Yellowstone's northern range.

PubMed

Bilyeu, Danielle M; Cooper, David J; Hobbs, N Thompson

2008-01-01

Excessive levels of herbivory may disturb ecosystems in ways that persist even when herbivory is moderated. These persistent changes may complicate efforts to restore ecosystems affected by herbivores. Willow (Salix spp.) communities within the northern range in Yellowstone National Park have been eliminated or degraded in many riparian areas by excessive elk (Cervus elaphus L.) browsing. Elk browsing of riparian willows appears to have diminished following the reintroduction of wolves (Canis lupis L.), but it remains uncertain whether reduced herbivory will restore willow communities. The direct effects of elk browsing on willows have been accompanied by indirect effects from the loss of beaver (Castor canadensis Kuhl) activity, including incision of stream channels, erosion of fine sediments, and lower water tables near streams historically dammed by beaver. In areas where these changes have occurred, lowered water tables may suppress willow height even in the absence of elk browsing. We conducted a factorial field experiment to understand willow responses to browsing and to height of water tables. After four years of protection from elk browsing, willows with ambient water tables averaged only 106 cm in height, with negligible height gain in two of three study species during the last year of the experiment. Willows that were protected from browsing and had artificially elevated water tables averaged 147 cm in height and gained 19 cm in the last year of the experiment. In browsed plots, elevated water tables doubled height gain during a period of slightly reduced browsing pressure. We conclude that water availability mediates the rate of willow height gain and may determine whether willows grow tall enough to escape the browse zone of elk and gain resistance to future elk browsing. Consequently, in areas where long-term beaver absence has resulted in incised stream channels and low water tables, a reduction in elk browsing alone may not be sufficient for recovery of tall willow stands. Because tall willow stems are important elements of habitat for beaver, mitigating water table decline may be necessary in these areas to promote recovery of historical willow-beaver mutualisms.

Lunar rocks as a source of oxygen

NASA Technical Reports Server (NTRS)

Poole, H. G.

1963-01-01

A thermodynamic study of the thermal stability of conventional terrestrial minerals in a hypothetical lunar atmosphere has opened some interesting speculation. Much of the Earth's crust is composed of oxides of silicon, aluminum, magnesium, and related compounds. These crust components may be as much a product of the Earth's atmosphere as vegetation and animal life. Though inanimate and long considered imperishable, these materials are stable under conditions of an atmosphere equivalent to 34 ft of water at sea level and persist under adverse conditions of moisture and temperature to altitudes of roughly 29,000 ft above sea level. The oxygen content averages 21% ) and the oxygen partial pressure would be roughly 1/5 atm.

EPA GROUND WATER ISSUE: Ground Water Sample Preservation at ISCO Sites – Recommended Guidelines

EPA Science Inventory

In-situ chemical oxidation (ISCO) involves the introduction of a chemical oxidant into the subsurface for the purpose of transforming ground water contaminants into harmless byproducts. Due to oxidant persistence, ground water samples collected at hazardous waste sites may contai...

Persistent organic pollutants in maternal blood plasma and breast milk from Russian arctic populations.

PubMed

Klopov, V; Odland, J O; Burkow, I C

1998-10-01

Under the auspices of Arctic Monitoring and Assessment Programme (AMAP), a Russian-Norwegian co-operation project was established to assess the exposure of delivering women to persistent organic pollutants (POPs) in Arctic areas of Russia. In the period 1993-95 blood and breast milk samples were collected from 94 delivering women in Yamal and Tajmyr Autonomous Regions of Siberia. Concentrations of chlorinated pesticides and polychlorinated biphenyls (PCBs) were determined by high resolution gas chromatography with electron capture detection. The POP levels in maternal plasma among the non-indigenous women were higher than the native population, especially in total PCB, HCHs (hexachlorocyclohexanes) and the DDT-group. The dietary questionnaires showed that the non-indigenous populations consumed considerably less local food items like reindeer meat and fresh water fish. There was no correlation between local food consumption and elevated levels of pollutants. Even if the indigenous groups had lower concentrations of the most important pollutants than the non-indigenous population, they were still higher than the levels measured in the Scandinavian countries of the AMAP-study and up to levels of medical concern. The most important sources of organic pollutants for the Russian Arctic populations of Yamal and Tajmyr seems to be imported food from other areas of Russia and local use of pesticides. It must be a high priority concern to further elucidate these trends and initiate prophylactic measures for the exposed population groups.

Personality and Persistence in Education: A Longitudinal Study.

ERIC Educational Resources Information Center

Gottfredson, Denise C.

Persistence in educational pursuits is strongly related to the prestige level and income level of an occupation. Personality correlates of persistence in education were examined in the context of a causal model of attainment in an eight-year longitudinal study of a nationally representative sample of 2213 young men. Results imply that anxiety and…

An Updated Global Picture of Cigarette Smoking Persistence among Adults

PubMed Central

Troost, Jonathan P.; Barondess, David A.; Storr, Carla L.; Wells, J. Elisabeth; Al-Hamzawi, Ali Obaid; Andrade, Laura Helena; Bromet, Evelyn; Bruffaerts, Ronny; Florescu, Silvia; de Girolamo, Giovanni; de Graaf, Ron; Gureje, Oye; Haro, Josep Maria; Hu, Chiyi; Huang, Yueqin; Karam, Aimee N.; Kessler, Ronald C.; Lepine, Jean-Pierre; Matschinger, Herbert; Medina-Mora, Maria Elena; O'Neill, Siobhan; Posada-Villa, Jose; Sagar, Rajesh; Takeshima, Tadashi; Tomov, Toma; Williams, David R.; Anthony, James C.

2012-01-01

Background Cross-national variance in smoking prevalence is relatively well documented. The aim of this study is to estimate levels of smoking persistence across 21 countries with a hypothesized inverse relationship between country income level and smoking persistence. Methods Data from the World Health Organization World Mental Health Survey Initiative were used to estimate cross-national differences in smoking persistence–the proportion of adults who started to smoke and persisted in smoking by the date of the survey. Result There is large variation in smoking persistence from 25% (Nigeria) to 85% (China), with a random-effects meta-analytic summary estimate of 55% with considerable cross-national variation. (Cochran's heterogeneity Q statistic=6,845; p<0.001). Meta-regressions indicated observed differences are not attributable to differences in country income level, age distribution of smokers, or how recent the onset of smoking began within each country. Conclusion While smoking should remain an important public health issue in any country where smokers are present, this report identifies several countries with higher levels of smoking persistence (namely, China and India). PMID:23626929

Recycled iron fuels new production in the eastern equatorial Pacific Ocean.

PubMed

Rafter, Patrick A; Sigman, Daniel M; Mackey, Katherine R M

2017-10-24

Nitrate persists in eastern equatorial Pacific surface waters because phytoplankton growth fueled by nitrate (new production) is limited by iron. Nitrate isotope measurements provide a new constraint on the controls of surface nitrate concentration in this region and allow us to quantify the degree and temporal variability of nitrate consumption. Here we show that nitrate consumption in these waters cannot be fueled solely by the external supply of iron to these waters, which occurs by upwelling and dust deposition. Rather, a substantial fraction of nitrate consumption must be supported by the recycling of iron within surface waters. Given plausible iron recycling rates, seasonal variability in nitrate concentration on and off the equator can be explained by upwelling rate, with slower upwelling allowing for more cycles of iron regeneration and uptake. The efficiency of iron recycling in the equatorial Pacific implies the evolution of ecosystem-level mechanisms for retaining iron in surface ocean settings where it limits productivity.

Assessing the Occurrence, Persistence, and Fate of Natural and Synthetic Steroid Estrogens in Vernal Pools

NASA Astrophysics Data System (ADS)

Mina, O.

2015-12-01

The presence of natural and synthetic estrogens in treated wastewater used for irrigation of agricultural fields poses a potential risk to surface water ecosystems. While a large number of recent studies have investigated the occurrence, fate, and transport of estrogens in the environment, the vast majority of these studies have focused on the fate of estrogens in streams and rivers. However, no studies have been conducted assessing the occurrence, persistence, and fate of estrogens in impacted sensitive aquatic ecosystems such as vernal pools. This is of particular importance because vernal pools serve as critical breeding habitat for amphibians, which are known to be sensitive to the presence of endocrine disrupting compounds. A spray irrigation system was implemented over 50 years ago at Penn State's "Living Filter" as an alternative to discharging treated wastewater to a high quality trout stream. This system introduces all of Penn State's treated wastewater onto approximately 250 ha of agricultural and forested land at a rate of ~5 cm/ha/week. More than a dozen vernal pools are impacted by this wastewater irrigation, with some ponds adjacent to irrigation laterals receiving direct inputs of the treated wastewater. The goal of this study was to assess the impact of these weekly irrigation activities on the occurrence, persistence, and fate of estrogens (17α- and 17β-estradiol, estrone, estriol, and ethinylestradiol) in 3 vernal pools during an 8-week field study. The spring 2015 study period coincided with wood frog breeding and metamorphosis. Irrigation wastewater was collected weekly and water samples near the sediment-water interface in each vernal pool were collected daily. Real-time monitoring stations continuously recorded the temperature, pH, redox potential, DO, EC, and water level at each pool. Nearly 100% of the daily samples (n>130) collected contained estrogens, and the concentrations were several times higher compared to the wastewater. Additionally, the data suggest transformation of estrone back to 17α- and 17β-estradiol potentially due to anaerobic conditions in the vernal pools. This unique field study suggests that more research is needed to quantify the potential impact of estrogenic activity on amphibians, particularly during the critical metamorphosis period.

Beyond the swab: ecosystem sampling to understand the persistence of an amphibian pathogen.

PubMed

Mosher, Brittany A; Huyvaert, Kathryn P; Bailey, Larissa L

2018-06-02

Understanding the ecosystem-level persistence of pathogens is essential for predicting and measuring host-pathogen dynamics. However, this process is often masked, in part due to a reliance on host-based pathogen detection methods. The amphibian pathogens Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal) are pathogens of global conservation concern. Despite having free-living life stages, little is known about the distribution and persistence of these pathogens outside of their amphibian hosts. We combine historic amphibian monitoring data with contemporary host- and environment-based pathogen detection data to obtain estimates of Bd occurrence independent of amphibian host distributions. We also evaluate differences in filter- and swab-based detection probability and assess inferential differences arising from using different decision criteria used to classify samples as positive or negative. Water filtration-based detection probabilities were lower than those from swabs but were > 10%, and swab-based detection probabilities varied seasonally, declining in the early fall. The decision criterion used to classify samples as positive or negative was important; using a more liberal criterion yielded higher estimates of Bd occurrence than when a conservative criterion was used. Different covariates were important when using the liberal or conservative criterion in modeling Bd detection. We found evidence of long-term Bd persistence for several years after an amphibian host species of conservation concern, the boreal toad (Anaxyrus boreas boreas), was last detected. Our work provides evidence of long-term Bd persistence in the ecosystem, and underscores the importance of environmental samples for understanding and mitigating disease-related threats to amphibian biodiversity.

Neonicotinoid pesticides in drinking water in agricultural regions of southern Ontario, Canada.

PubMed

Sultana, Tamanna; Murray, Craig; Kleywegt, Sonya; Metcalfe, Chris D

2018-07-01

Because of the persistence and solubility of neonicotinoid insecticides (NNIs), there is concern that these compounds may contaminate sources of drinking water. The objective of this project was to evaluate the distribution of NNIs in raw and treated drinking water from selected municipalities that draw their water from the lower Great Lakes in areas of southern Ontario, Canada where there is high intensity agriculture. Sites were monitored using Polar Organic Chemical Integrative Samplers (POCIS) and by collecting grab samples at six drinking water treatment plants. Thiamethoxam, clothianidin and imidacloprid were detected in both POCIS and grab samples of raw water. The frequency of detection of NNIs was much lower in treated drinking water, but some compounds were still detected at estimated concentrations in the low ng L -1 range. Thiamethoxam was detected in one grab sample of raw drinking water at a mean concentration of 0.28 μg L -1 , which is above the guidelines for drinking water recommended in some jurisdictions, including the European Union directive on pesticide levels <0.1 μg L -1 in water intended for human consumption. Further work is required to determine whether contamination of sources of drinking water with this class of insecticides is a global problem in agricultural regions. Copyright © 2018 Elsevier Ltd. All rights reserved.

NOWCASTING AND FORECASTING BEACH BACTERIA CONCENTRATION USING THE EPA VIRTUAL BEACH SOFTWARE

EPA Science Inventory

Beaches are subject to closure when bacterial counts exceed water quality criteria. Many authorities base these decisions on sample counts, which typically require a day or more to analyze. Sometimes called the persistence model, because conditions are assumed to persist, experie...

Persistence of enteric viruses within oysters (Crassostrea virginica)

USDA-ARS?s Scientific Manuscript database

It is well known that water-borne enteric viruses are concentrated by bivalves. Why these viruses are selectively retained and remain infectious within shellfish tissues for extended periods is unknown. Our current hypothesis is that phagocytic hemocytes (blood cells) are a site of virus persiste...

Ecosystem characteristics and processes facilitating persistent macrobenthic biomass hotspots and associated benthivory in the Pacific Arctic

NASA Astrophysics Data System (ADS)

Grebmeier, Jacqueline M.; Bluhm, Bodil A.; Cooper, Lee W.; Danielson, Seth L.; Arrigo, Kevin R.; Blanchard, Arny L.; Clarke, Janet T.; Day, Robert H.; Frey, Karen E.; Gradinger, Rolf R.; Kędra, Monika; Konar, Brenda; Kuletz, Kathy J.; Lee, Sang H.; Lovvorn, James R.; Norcross, Brenda L.; Okkonen, Stephen R.

2015-08-01

The northern Bering and Chukchi Seas are areas in the Pacific Arctic characterized by high northward advection of Pacific Ocean water, with seasonal variability in sea ice cover, water mass characteristics, and benthic processes. In this review, we evaluate the biological and environmental factors that support communities of benthic prey on the continental shelves, with a focus on four macrofaunal biomass "hotspots." For the purpose of this study, we define hotspots as macrofaunal benthic communities with high biomass that support a corresponding ecological guild of benthivorous seabird and marine mammal populations. These four benthic hotspots are regions within the influence of the St. Lawrence Island Polynya (SLIP), the Chirikov Basin between St. Lawrence Island and Bering Strait (Chirikov), north of Bering Strait in the southeast Chukchi Sea (SECS), and in the northeast Chukchi Sea (NECS). Detailed benthic macrofaunal sampling indicates that these hotspot regions have been persistent over four decades of sampling due to annual reoccurrence of seasonally consistent, moderate-to-high water column production with significant export of carbon to the underlying sediments. We also evaluate the usage of the four benthic hotspot regions by benthic prey consumers to illuminate predator-prey connectivity. In the SLIP hotspot, spectacled eiders and walruses are important winter consumers of infaunal bivalves and polychaetes, along with epibenthic gastropods and crabs. In the Chirikov hotspot, gray whales have historically been the largest summer consumers of benthic macrofauna, primarily feeding on ampeliscid amphipods in the summer, but they are also foraging further northward in the SECS and NECS hotspots. Areas of concentrated walrus foraging occur in the SLIP hotspot in winter and early spring, the NECS hotspot in summer, and the SECS hotspot in fall. Bottom up forcing by hydrography and food supply to the benthos influences persistence and composition of benthic prey that then influences the distributions of benthivorous upper trophic level populations.

Use of surface water in drinking water production associated with municipal Legionnaires' disease incidence.

PubMed

Den Boer, J W; Coutinho, R A; Yzerman, E P F; van der Sande, M A B

2008-04-01

Given an observed geographical variation in Legionnaires' disease incidence in The Netherlands, the aim of the study was to test the hypothesis that the type of drinking water production was an independent determinant of the incidence of Legionnaires' disease. For the 1987-2005 period, the incidence of Legionnaires' disease in The Netherlands and the price of water as a proxy for production type was studied at the municipal level. The data on the price of water were available at the municipal level. For each of the 466 municipalities in The Netherlands a mean standardised incidence rate per 100,000 inhabitants over the 1987-2005 period was calculated, excluding patients with the most probable source of infection abroad or in hospital. Logistic regression was used to assess the relation of the price of water to the incidence rates. In order to control for diagnostic and inclusion bias, they were estimated using questionnaire data collected from all 62 medical microbiology laboratories in the country. The incidence of Legionnaires' disease varied between municipalities from 0.0 to 5.6 per 100,000 person-years. In univariate analysis high versus low water price was positively associated with a high municipal incidence rate (odds ratio (OR) 1.9; 95% CI 1.5-2.6). The association persisted (OR 5.1; 95% CI 3.2-8.0) after correction for diagnostic and inclusion bias. The price of water as a proxy for the type of water production was an independent risk factor for high municipal Legionnaires' disease incidence in The Netherlands. This can guide future prevention policies.

High-resolution mapping of global surface water and its long-term changes

NASA Astrophysics Data System (ADS)

Pekel, J. F.; Cottam, A.; Gorelick, N.; Belward, A.

2016-12-01

The location and persistence of surface water is both affected by climate and human activity and affects climate, biological diversity and human wellbeing. Global datasets documenting surface water location and seasonality have been produced but measuring long-term changes at high resolution remains a challenge.To address the dynamic nature of water, the European Commission's Joint Research Centre (JRC), working with the Google Earth Engine (GEE) team has processed each single pixel acquired by Landsat 5, 7, and 8 between 16th March 1984 to 10th October 2015 (> 3.000.000 Landsat scenes, representing > 1823 Terabytes of data).The produced dataset record months and years when water was present across 32 year, were occurrence changed and what form changes took in terms of seasonality and persistence, and document intra-annual persistence, inter-annual variability, and trends.This validated dataset shows that impacts of climate change and climate oscillations on surface water occurrence can be measured and that evidence can be gathered showing how surface water is altered by human activities.Freely available, we anticipate that this dataset will provide valuable information to those working in areas linked to security of water supply for agriculture, industry and human consumption, for assessing water-related disaster reduction and recovery and for the study of waterborne pollution and disease spread. The maps will also improve surface boundary condition setting in climate and weather models, improve carbon emissions estimates, inform regional climate change impact studies, delimit wetlands for biodiversity and determine desertification trends. Issues such as dam building (and less widespread dam removal), disappearing rivers, the geopolitics of water distribution and coastal erosion are also addressed.

Economic weights for genetic improvement of lactation persistency and milk yield.

PubMed

Togashi, K; Lin, C Y

2009-06-01

This study aimed to establish a criterion for measuring the relative weight of lactation persistency (the ratio of yield at 280 d in milk to peak yield) in restricted selection index for the improvement of net merit comprising 3-parity total yield and total lactation persistency. The restricted selection index was compared with selection based on first-lactation total milk yield (I(1)), the first-two-lactation total yield (I(2)), and first-three-lactation total yield (I(3)). Results show that genetic response in net merit due to selection on restricted selection index could be greater than, equal to, or less than that due to the unrestricted index depending upon the relative weight of lactation persistency and the restriction level imposed. When the relative weight of total lactation persistency is equal to the criterion, the restricted selection index is equal to the selection method compared (I(1), I(2), or I(3)). The restricted selection index yielded a greater response when the relative weight of total lactation persistency was above the criterion, but a lower response when it was below the criterion. The criterion varied depending upon the restriction level (c) imposed and the selection criteria compared. A curvilinear relationship (concave curve) exists between the criterion and the restricted level. The criterion increases as the restriction level deviates in either direction from 1.5. Without prior information of the economic weight of lactation persistency, the imposition of the restriction level of 1.5 on lactation persistency would maximize change in net merit. The procedure presented allows for simultaneous modification of multi-parity lactation curves.

Groundwater-level trends in the U.S. glacial aquifer system, 1964-2013

USGS Publications Warehouse

Hodgkins, Glenn A.; Dudley, Robert W.; Nielsen, Martha G.; Renard, Benjamin; Qi, Sharon L.

2017-01-01

The glacial aquifer system in the United States is a major source of water supply but previous work on historical groundwater trends across the system is lacking. Trends in annual minimum, mean, and maximum groundwater levels for 205 monitoring wells were analyzed across three regions of the system (East, Central, West Central) for four time periods: 1964-2013, 1974-2013, 1984-2013, and 1994-2013. Trends were computed separately for wells in the glacial aquifer system with low potential for human influence on groundwater levels and ones with high potential influence from activities such as groundwater pumping. Generally there were more wells with significantly increasing groundwater levels (levels closer to ground surface) than wells with significantly decreasing levels. The highest numbers of significant increases for all four time periods were with annual minimum and/or mean levels. There were many more wells with significant increases from 1964 to 2013 than from more recent periods, consistent with low precipitation in the 1960s. Overall there were low numbers of wells with significantly decreasing trends regardless of time period considered; the highest number of these were generally for annual minimum groundwater levels at wells with likely human influence. There were substantial differences in the number of wells with significant groundwater-level trends over time, depending on whether the historical time series are assumed to be independent, have short-term persistence, or have long-term persistence. Mean annual groundwater levels have significant lag-one-year autocorrelation at 26.0% of wells in the East region, 65.4% of wells in the Central region, and 100% of wells in the West Central region. Annual precipitation across the glacial aquifer system, on the other hand, has significant autocorrelation at only 5.5% of stations, about the percentage expected due to chance.

Modeling turbidity type and intensity effects on the growth and starvation mortality of age-0 yellow perch

USGS Publications Warehouse

Manning, Nathan M; Bossenbroek, Jonathan M.; Mayer, Christine M.; Bunnell, David B.; Tyson, Jeff T.; Rudstam, Lars G.; Jackson, James R.

2014-01-01

We sought to quantify the possible population-level influence of sediment plumes and algal blooms on yellow perch (Perca flavescens), a visual predator found in systems with dynamic water clarity. We used an individual-based model (IBM), which allowed us to include variance in water clarity and the distribution of individual sizes. Our IBM was built with laboratory data showing that larval yellow perch feeding rates increased slightly as sediment turbidity level increased, but that both larval and juvenile yellow perch feeding rates decreased as phytoplankton level increased. Our IBM explained a majority of the variance in yellow perch length in data from the western and central basins of Lake Erie and Oneida Lake, with R2 values ranging from 0.611 to 0.742. Starvation mortality was size dependent, as the greatest daily mortality rates in each simulation occurred within days of each other. Our model showed that turbidity-dependent consumption rates and temperature are key components in determining growth and starvation mortality of age-0 yellow perch, linking fish production to land-based processes that influence water clarity. These results suggest the timing and persistence of sediment plumes and algal blooms can drastically alter the growth potential and starvation mortality of a yellow perch cohort.

Mapping groundwater level and aquifer storage variations from InSAR measurements in the Madrid aquifer, Central Spain

NASA Astrophysics Data System (ADS)

Béjar-Pizarro, Marta; Ezquerro, Pablo; Herrera, Gerardo; Tomás, Roberto; Guardiola-Albert, Carolina; Ruiz Hernández, José M.; Fernández Merodo, José A.; Marchamalo, Miguel; Martínez, Rubén

2017-04-01

Groundwater resources are under stress in many regions of the world and the future water supply for many populations, particularly in the driest places on Earth, is threatened. Future climatic conditions and population growth are expected to intensify the problem. Understanding the factors that control groundwater storage variation is crucial to mitigate its adverse consequences. In this work, we apply satellite-based measurements of ground deformation over the Tertiary detritic aquifer of Madrid (TDAM), Central Spain, to infer the spatio-temporal evolution of water levels and estimate groundwater storage variations. Specifically, we use Persistent Scatterer Interferometry (PSI) data during the period 1992-2010 and piezometric time series on 19 well sites covering the period 1997-2010 to build groundwater level maps and quantify groundwater storage variations. Our results reveal that groundwater storage loss occurred in two different periods, 1992-1999 and 2005-2010 and was mainly concentrated in a region of ∼200 km2. The presence of more compressible materials in that region combined with a long continuous water extraction can explain this volumetric deficit. This study illustrates how the combination of PSI and piezometric data can be used to detect small aquifers affected by groundwater storage loss helping to improve their sustainable management.

Persistence of pharmaceutical compounds and other organic wastewater contaminants in a conventional drinking-water-treatment plant.

PubMed

Stackelberg, Paul E; Furlong, Edward T; Meyer, Michael T; Zaugg, Steven D; Henderson, Alden K; Reissman, Dori B

2004-08-15

In a study conducted by the US Geological Survey and the Centers for Disease Control and Prevention, 24 water samples were collected at selected locations within a drinking-water-treatment (DWT) facility and from the two streams that serve the facility to evaluate the potential for wastewater-related organic contaminants to survive a conventional treatment process and persist in potable-water supplies. Stream-water samples as well as samples of raw, settled, filtered, and finished water were collected during low-flow conditions, when the discharge of effluent from upstream municipal sewage-treatment plants accounted for 37-67% of flow in stream 1 and 10-20% of flow in stream 2. Each sample was analyzed for 106 organic wastewater-related contaminants (OWCs) that represent a diverse group of extensively used chemicals. Forty OWCs were detected in one or more samples of stream water or raw-water supplies in the treatment plant; 34 were detected in more than 10% of these samples. Several of these compounds also were frequently detected in samples of finished water; these compounds include selected prescription and non-prescription drugs and their metabolites, fragrance compounds, flame retardants and plasticizers, cosmetic compounds, and a solvent. The detection of these compounds suggests that they resist removal through conventional water-treatment processes. Other compounds that also were frequently detected in samples of stream water and raw-water supplies were not detected in samples of finished water; these include selected prescription and non-prescription drugs and their metabolites, disinfectants, detergent metabolites, and plant and animal steroids. The non-detection of these compounds indicates that their concentrations are reduced to levels less than analytical detection limits or that they are transformed to degradates through conventional DWT processes. Concentrations of OWCs detected in finished water generally were low and did not exceed Federal drinking-water standards or lifetime health advisories, although such standards or advisories have not been established for most of these compounds. Also, at least 11 and as many as 17 OWCs were detected in samples of finished water. Drinking-water criteria currently are based on the toxicity of individual compounds and not combinations of compounds. Little is known about potential human-health effects associated with chronic exposure to trace levels of multiple OWCs through routes such as drinking water. The occurrence in drinking-water supplies of many of the OWCs analyzed for during this study is unregulated and most of these compounds have not been routinely monitored for in the Nation's source- or potable-water supplies. This study provides the first documentation that many of these compounds can survive conventional water-treatment processes and occur in potable-water supplies. It thereby provides information that can be used in setting research and regulatory priorities and in designing future monitoring programs. The results of this study also indicate that improvements in water-treatment processes may benefit from consideration of the response of OWCs and other trace organic contaminants to specific physical and chemical treatments.

Persistence of pharmaceutical compounds and other organic wastewater contaminants in a conventional drinking-water-treatment plant

USGS Publications Warehouse

Stackelberg, P.E.; Furlong, E.T.; Meyer, M.T.; Zaugg, S.D.; Henderson, A.K.; Reissman, D.B.

2004-01-01

In a study conducted by the US Geological Survey and the Centers for Disease Control and Prevention, 24 water samples were collected at selected locations within a drinking-water-treatment (DWT) facility and from the two streams that serve the facility to evaluate the potential for wastewater-related organic contaminants to survive a conventional treatment process and persist in potable-water supplies. Stream-water samples as well as samples of raw, settled, filtered, and finished water were collected during low-flow conditions, when the discharge of effluent from upstream municipal sewage-treatment plants accounted for 37-67% of flow in stream 1 and 10-20% of flow in stream 2. Each sample was analyzed for 106 organic wastewater-related contaminants (OWCs) that represent a diverse group of extensively used chemicals. Forty OWCs were detected in one or more samples of stream water or raw-water supplies in the treatment plant; 34 were detected in more than 10% of these samples. Several of these compounds also were frequently detected in samples of finished water; these compounds include selected prescription and non-prescription drugs and their metabolites, fragrance compounds, flame retardants and plasticizers, cosmetic compounds, and a solvent. The detection of these compounds suggests that they resist removal through conventional water-treatment processes. Other compounds that also were frequently detected in samples of stream water and raw-water supplies were not detected in samples of finished water; these include selected prescription and non-prescription drugs and their metabolites, disinfectants, detergent metabolites, and plant and animal steroids. The non-detection of these compounds indicates that their concentrations are reduced to levels less than analytical detection limits or that they are transformed to degradates through conventional DWT processes. Concentrations of OWCs detected in finished water generally were low and did not exceed Federal drinking-water standards or lifetime health advisories, although such standards or advisories have not been established for most of these compounds. Also, at least 11 and as many as 17 OWCs were detected in samples of finished water. Drinking-water criteria currently are based on the toxicity of individual compounds and not combinations of compounds. Little is known about potential human-health effects associated with chronic exposure to trace levels of multiple OWCs through routes such as drinking water. The occurrence in drinking-water supplies of many of the OWCs analyzed for during this study is unregulated and most of these compounds have not been routinely monitored for in the Nation's source- or potable-water supplies. This study provides the first documentation that many of these compounds can survive conventional water-treatment processes and occur in potable-water supplies. It thereby provides information that can be used in setting research and regulatory priorities and in designing future monitoring programs. The results of this study also indicate that improvements in water-treatment processes may benefit from consideration of the response of OWCs and other trace organic contaminants to specific physical and chemical treatments. ?? 2004 Elsevier B.V. All rights reserved.

Relations between Preschool Attention Span-Persistence and Age 25 Educational Outcomes

PubMed Central

McClelland, Megan M.; Acock, Alan C.; Piccinin, Andrea; Rhea, Sally Ann; Stallings, Michael C.

2012-01-01

This study examined relations between children’s attention span-persistence in preschool and later school achievement and college completion. Children were drawn from the Colorado Adoption Project using adopted and non-adopted children (N = 430). Results of structural equation modeling indicated that children’s age 4 attention span-persistence significantly predicted math and reading achievement at age 21 after controlling for achievement levels at age 7, adopted status, child vocabulary skills, gender, and maternal education level. Relations between attention span-persistence and later achievement were not fully mediated by age 7 achievement levels. Logistic regressions also revealed that age 4 attention span-persistence skills significantly predicted the odds of completing college by age 25. The majority of this relationship was direct and was not significantly mediated by math or reading skills at age 7 or age 21. Specifically, children who were rated one standard deviation higher on attention span-persistence at age 4 had 48.7% greater odds of completing college by age 25. Discussion focuses on the importance of children’s early attention span-persistence for later school achievement and educational attainment. PMID:23543916

Relations between Preschool Attention Span-Persistence and Age 25 Educational Outcomes.

PubMed

McClelland, Megan M; Acock, Alan C; Piccinin, Andrea; Rhea, Sally Ann; Stallings, Michael C

2013-04-01

This study examined relations between children's attention span-persistence in preschool and later school achievement and college completion. Children were drawn from the Colorado Adoption Project using adopted and non-adopted children ( N = 430). Results of structural equation modeling indicated that children's age 4 attention span-persistence significantly predicted math and reading achievement at age 21 after controlling for achievement levels at age 7, adopted status, child vocabulary skills, gender, and maternal education level. Relations between attention span-persistence and later achievement were not fully mediated by age 7 achievement levels. Logistic regressions also revealed that age 4 attention span-persistence skills significantly predicted the odds of completing college by age 25. The majority of this relationship was direct and was not significantly mediated by math or reading skills at age 7 or age 21. Specifically, children who were rated one standard deviation higher on attention span-persistence at age 4 had 48.7% greater odds of completing college by age 25. Discussion focuses on the importance of children's early attention span-persistence for later school achievement and educational attainment.

An Investigation on the Persistence of Uranium Hydride during Storage of Simulant Nuclear Waste Packages.

PubMed

Stitt, C A; Harker, N J; Hallam, K R; Paraskevoulakos, C; Banos, A; Rennie, S; Jowsey, J; Scott, T B

2015-01-01

Synchrotron X-rays have been used to study the oxidation of uranium and uranium hydride when encapsulated in grout and stored in de-ionised water for 10 months. Periodic synchrotron X-ray tomography and X-ray powder diffraction have allowed measurement and identification of the arising corrosion products and the rates of corrosion. The oxidation rates of the uranium metal and uranium hydride were slower than empirically derived rates previously reported for each reactant in an anoxic water system, but without encapsulation in grout. This was attributed to the grout acting as a physical barrier limiting the access of oxidising species to the uranium surface. Uranium hydride was observed to persist throughout the 10 month storage period and industrial consequences of this observed persistence are discussed.

An Investigation on the Persistence of Uranium Hydride during Storage of Simulant Nuclear Waste Packages

PubMed Central

Harker, N. J.; Hallam, K. R.; Paraskevoulakos, C.; Banos, A.; Rennie, S.; Jowsey, J.

2015-01-01

Synchrotron X-rays have been used to study the oxidation of uranium and uranium hydride when encapsulated in grout and stored in de-ionised water for 10 months. Periodic synchrotron X-ray tomography and X-ray powder diffraction have allowed measurement and identification of the arising corrosion products and the rates of corrosion. The oxidation rates of the uranium metal and uranium hydride were slower than empirically derived rates previously reported for each reactant in an anoxic water system, but without encapsulation in grout. This was attributed to the grout acting as a physical barrier limiting the access of oxidising species to the uranium surface. Uranium hydride was observed to persist throughout the 10 month storage period and industrial consequences of this observed persistence are discussed. PMID:26176551

High monetary reward rates and caloric rewards decrease temporal persistence

PubMed Central

Bode, Stefan; Murawski, Carsten

2017-01-01

Temporal persistence refers to an individual's capacity to wait for future rewards, while forgoing possible alternatives. This requires a trade-off between the potential value of delayed rewards and opportunity costs, and is relevant to many real-world decisions, such as dieting. Theoretical models have previously suggested that high monetary reward rates, or positive energy balance, may result in decreased temporal persistence. In our study, 50 fasted participants engaged in a temporal persistence task, incentivised with monetary rewards. In alternating blocks of this task, rewards were delivered at delays drawn randomly from distributions with either a lower or higher maximum reward rate. During some blocks participants received either a caloric drink or water. We used survival analysis to estimate participants' probability of quitting conditional on the delay distribution and the consumed liquid. Participants had a higher probability of quitting in blocks with the higher reward rate. Furthermore, participants who consumed the caloric drink had a higher probability of quitting than those who consumed water. Our results support the predictions from the theoretical models, and importantly, suggest that both higher monetary reward rates and physiologically relevant rewards can decrease temporal persistence, which is a crucial determinant for survival in many species. PMID:28228517

High monetary reward rates and caloric rewards decrease temporal persistence.

PubMed

Fung, Bowen J; Bode, Stefan; Murawski, Carsten

2017-02-22

Temporal persistence refers to an individual's capacity to wait for future rewards, while forgoing possible alternatives. This requires a trade-off between the potential value of delayed rewards and opportunity costs, and is relevant to many real-world decisions, such as dieting. Theoretical models have previously suggested that high monetary reward rates, or positive energy balance, may result in decreased temporal persistence. In our study, 50 fasted participants engaged in a temporal persistence task, incentivised with monetary rewards. In alternating blocks of this task, rewards were delivered at delays drawn randomly from distributions with either a lower or higher maximum reward rate. During some blocks participants received either a caloric drink or water. We used survival analysis to estimate participants' probability of quitting conditional on the delay distribution and the consumed liquid. Participants had a higher probability of quitting in blocks with the higher reward rate. Furthermore, participants who consumed the caloric drink had a higher probability of quitting than those who consumed water. Our results support the predictions from the theoretical models, and importantly, suggest that both higher monetary reward rates and physiologically relevant rewards can decrease temporal persistence, which is a crucial determinant for survival in many species. © 2017 The Authors.

Far-reaching transport of Pearl River plume water by upwelling jet in the northeastern South China Sea

NASA Astrophysics Data System (ADS)

Chen, Zhaoyun; Pan, Jiayi; Jiang, Yuwu; Lin, Hui

2017-09-01

Satellite images from the Moderate Resolution Imaging Spectroradiometer (MODIS) show that there was a belt of turbid water appearing along an upwelling front near the Chinese coast of Guangdong, and indicate that the turbid water of the Pearl River plume water could be transported to a far-reaching area east of the Taiwan Bank. Numerical modeling results are consistent with the satellite observations, and reveal that a strong jet exists at the upwelling front with a speed as high as 0.8 m s- 1, which acts as a pathway for transporting the high-turbidity plume water. The dynamical analysis suggests that geostrophic equilibrium dominates in the upwelling front and plume areas, and the baroclinicity of the upwelling front resulting from the horizontal density gradient is responsible for the generation of the strong jet, which enhances the far-reaching transport of the terrigenous nutrient-rich water of the Pearl River plume. Model sensitivity analyses also confirm that this jet persists as long as the upwelling front exists, even when the wind subsides and becomes insignificant. Further idealized numerical model experiments indicate that the formation and persistence of the upwelling front jet depend on the forcing strength of the upwelling-favorable wind. The formation time of the jet varies from 15 to 158 h as the stress of the upwelling-favorable wind changes from 0.2 to 0.01 N m- 2. With the persistent transport of the nutrient-rich plume water, biophysical activities can be promoted significantly in the far-reaching destination area of the oligotrophic water.

[Mechanism of tritium persistence in porous media like clay minerals].

PubMed

Wu, Dong-Jie; Wang, Jin-Sheng; Teng, Yan-Guo; Zhang, Ke-Ni

2011-03-01

To investigate the mechanisms of tritium persistence in clay minerals, three types of clay soils (montmorillonite, kaolinite and illite) and tritiated water were used in this study to conduct the tritium sorption tests and the other related tests. Firstly, the ingredients, metal elements and heat properties of clay minerals were studied with some instrumental analysis methods, such as ICP and TG. Secondly, with a specially designed fractionation and condensation experiment, the adsorbed water, the interlayer water and the structural water in the clay minerals separated from the tritium sorption tests were fractionated for investigating the tritium distributions in the different types of adsorptive waters. Thirdly, the location and configuration of tritium adsorbed into the structure of clay minerals were studied with infrared spectrometry (IR) tests. And finally, the forces and mechanisms for driving tritium into the clay minerals were analyzed on the basis of the isotope effect of tritium and the above tests. Following conclusions have been reached: (1) The main reason for tritium persistence in clay minerals is the entrance of tritium into the adsorbed water, the interlayer water and the structural water in clay minerals. The percentage of tritium distributed in these three types of adsorptive water are in the range of 13.65% - 38.71%, 0.32% - 5.96%, 1.28% - 4.37% of the total tritium used in the corresponding test, respectively. The percentages are different for different types of clay minerals. (2) Tritium adsorbed onto clay minerals are existed in the forms of the tritiated hydroxyl radical (OT) and the tritiated water molecule (HTO). Tritium mainly exists in tritiated water molecule for adsorbed water and interlayer water, and in tritiated hydroxyl radical for structural water. (3) The forces and effects driving tritium into the clay minerals may include molecular dispersion, electric charge sorption, isotope exchange and tritium isotope effect.

Temperature-dependent persistence of human norovirus within oysters (Crassotrea virginica)

USDA-ARS?s Scientific Manuscript database

This study characterizes the persistence of human norovirus in Eastern oysters (Crassostrea virginica) held at different seawater temperatures. Oysters were contaminated with human norovirus GI.1 (Norwalk strain 8fIIa) by exposing them to virus contaminated water at 15 degrees C, and subsequently ho...

CATALYTIC DECHLORINATION OF 2-CL BP IN SEDIMENTS AND WATER-SOLVENT SYSTEMS BY FE/PD BIMETAL

EPA Science Inventory

Polychlorinated biphenyls (PCBs) are one group of persistent organic pollutants (POPs) of international concern because of global distribution, persistence, and toxicity. Removal of these compounds from the environment presents a very tough challenge because they are highly hydro...

Fate of permethrin in model outdoor ponds

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

Rawn, G.P.; Webster, G.R.; Muir, D.C.

1982-01-01

In 1979 and 1980, outdoor artificial ponds were treated with /sup 14/C-permethrin (labelled at either the cyclopropyl or methylene position) at 0.028 kg/ha (15 ug/L). Uptake of permethrin by duckweed and hydrosoil was monitored by direct combustion, TLC-autoradiography, HPLC, and liquid scintillation counting. Rapid loss of permethrin from the water coincided with the detection of five degradation products in the water at concentrations below 2.0 ug/L. The products were cis- and trans-cyclopropyl acid, phenoxybenzoic acid, and phenoxybenzyl alcohol, and an unknown non-cleaved product of permethrin. Permethrin was readily sorbed by duckweed but was not persistent. Permethrin residues in the hydrosoil,more » which was the major sink for permethrin added to the ponds, were persistent and were detected at 420 days post-treatment. Cis-permethrin was more persistent in the hydrosoil than the trans-permethrin. The results indicated that permethrin in water was short-lived at an application rate of 15 ug/L because of the rapid degradation of permethrin in the water and sorption of permethrin by the hydrosoil and vegetation. However, at one year post-treatment, permethrin residues were still detected in the hydrosoil at 1.0 ug/kg.« less

Models and observations of foam coverage and bubble content in the surf zone

NASA Astrophysics Data System (ADS)

Kirby, J. T.; Shi, F.; Holman, R. A.

2010-12-01

Optical and acoustical observations and communications are hampered in the nearshore by the presence of bubbles and foam generated by breaking waves. Bubble clouds in the water column provide a highly variable (both spatially and temporally) obstacle to direct acoustic and optical paths. Persistent foam riding on the water surface creates a primary occlusion of optical penetration into the water column. In an effort to better understand and predict the level of bubble and foam content in the surfzone, we have been pursuing the development of a detailed phase resolved model of fluid and gaseous components of the water column, using a Navier-Stokes/VOF formulation extended to include a multiphase description of polydisperse bubble populations. This sort of modeling provides a detailed description of large scale turbulent structures and associated bubble transport mechanisms under breaking wave crests. The modeling technique is too computationally intensive, however, to provide a wider-scale description of large surfzone regions. In order to approach the larger scale problem, we are developing a model for spatial and temporal distribution of foam and bubbles within the framework of a Boussinesq model. The basic numerical framework for the code is described by Shi et al (2010, this conference). Bubble effects are incorporated both in the mass and momentum balances for weakly dispersive, fully nonlinear waves, with spatial and temporal bubble distributions parameterized based on the VOF modeling and measurements and tied to the computed rate of dissipation of energy during breaking. A model of a foam layer on the water surface is specified using a shallow water formulation. Foam mass conservation includes source and sink terms representing outgassing of the water column, direct foam generation due to surface agitation, and erosion due to bubble bursting. The foam layer motion in the plane of the water surface arises due to a balance of drag forces due to wind and water column motion. Preliminary steps to calibrate and verify the resulting models will be taken based on results to be collected during the Surf Zone Optics experiment at Duck, NC in September 2010. Initial efforts will focus on an examination of breaking wave patterns and persistent foam distributions, using ARGUS imagery.

Simultaneous Determination of 13 Priority Polycyclic Aromatic Hydrocarbons in Tehran’s Tap Water and Water for Injection Samples Using Dispersive Liquid-Liquid Micro Extraction Method and Gas Chromatography-Mass Spectrometry

PubMed Central

Sadeghi, Ramezan; Kobarfard, Farzad; Yazdanpanah, Hassan; Eslamizad, Samira; Bayate, Mitra

2016-01-01

Polycyclic aromatic hydrocarbons (PAHs) are classified as persistent and carcinogenic organic pollutants. PAHs contamination has been reported in water. Many of relevant regulatory bodies such as EU and EPA have regulated the limit levels for PAHs in drinking water. In this study, 13 priority polycyclic aromatic hydrocarbons (PAHs) were determined in tap water samples of Tehran and water for injection. Dispersive liquid-liquid microextraction procedure combined with gas chromatography-mass spectrometry was used for the extraction and determination of PAHs in the samples. Under the optimized conditions, the range of extraction recoveries and relative standard deviations (RSDs) of PAHs in water using internal standard (anthracene-d10) were in the range of 71-90% and 4-16%, respectively. Limit of detection for different PAHs were between 0.03 and 0.1 ngmL-1. The concentration of PAHs in all tap water as well as water for injection samples were lower than the limit of quantification of PAHs. This is the first study addressing the occurrence of PAHs in water for injection samples in Iran using dispersive liquid-liquid micro extraction procedure combined with gas chromatography-mass spectrometry. PMID:27642318

Chihuahua: a water reuse case in the desert.

PubMed

Espino, M S; Navarro, C J; Pérez, J M

2004-01-01

Water supply for all kind of uses in Chihuahua is mainly groundwater. During the last decade this city has been damaged with a heavy hydrologic crisis because of a persistent drought. This came up with the overexploitation of groundwater aquifers; therefore a deficit between demand and offer was done. To minimize this problem the government authorities have started an integral plan of optimizing hydrologic resources which considers the treatment of wastewater and the use of reclaimed water. The secondary wastewater treatment facility of the city treats about 30,000 m3/d of a wastewater with high organic contents, and produces an effluent with low concentration of suspended solids, organic matter, fats, detergents, and metals. Reclaimed water is conveyed toward strategic sites for the irrigation of great green areas in sport clubs, educational institutions and industrial zones, besides of its utilization on some manufacturing processes, road service, and also over construction industry. The potential reuse of this water goes farther from those activities; the treatment of the secondary effluent until the required levels of the water-bearing recharge criteria are met for drinking water supply is considered as the next step to achieve through a suitable planning strategy for the best integral resource advantage.

Presence, infectivity, and stability of enteric viruses in seawater: Relationship to marine water quality in the Florida Keys

USGS Publications Warehouse

Wetz, J.J.; Lipp, E.K.; Griffin, Dale W.; Lukasik, J.; Wait, D.; Sobsey, M.D.; Scott, T.M.; Rose, J.B.

2004-01-01

Concerns about the presence of enteric viruses in the surface waters of the Florida Keys prompted analyses of virus stability and persistence in these waters. In an in vitro study we evaluated the survival of poliovirus and stability of viral RNA in filtered natural seawater (FSW), unfiltered natural seawater (USW), artificial seawater (ASW) and DI water. This study compared cell culture infectivity with direct reverse transcription-polymerase chain reaction analysis. Attenuated poliovirus was seeded in the above water types and incubated in the dark at 22 and 30??C for 60 days. At 22??C, enhanced poliovirus survival and enhanced detection of viral RNA was observed in the seeded DI water control, artificial seawater and FSW samples. Detection of viruses in unfiltered seawater decreased rapidly at both temperatures by both methods of detection, suggesting that in the natural environment detection of enteroviral RNA may indicate a recent contamination event. In addition, in situ sampling in the Florida Keys during the late winter of 2000 revealed the presence of infectious enteroviruses at two sites and no sites exceeded recommended levels of microbial water quality indicators (enterococci or fecal coliform bacteria). ?? 2003 Elsevier Ltd. All rights reserved.

Integrated fate modeling for exposure assessment of produced water on the Sable Island Bank (Scotian shelf, Canada).

PubMed

Berry, Jody A; Wells, Peter G

2004-10-01

Produced water is the largest waste discharge from the production phase of oil and gas wells. Produced water is a mixture of reservoir formation water and production chemicals from the separation process. This creates a chemical mixture that has several components of toxic concern, ranging from heavy metals to soluble hydrocarbons. Analysis of potential environmental effects from produced water in the Sable Island Bank region (NS, Canada) was conducted using an integrated modeling approach according to the ecological risk assessment framework. A hydrodynamic dispersion model was used to describe the wastewater plume. A second fugacity-based model was used to describe the likely plume partitioning in the local environmental media of water, suspended sediment, biota, and sediment. Results from the integrated modeling showed that the soluble benzene and naphthalene components reach chronic no-effect concentration levels at a distance of 1.0 m from the discharge point. The partition modeling indicated that low persistence was expected because of advection forces caused by tidal currents for the Sable Island Bank system. The exposure assessment for the two soluble hydrocarbon components suggests that the risks of adverse environmental effects from produced water on Sable Island Bank are low.

The hydrological consequences of human impact in the Lublin Region

NASA Astrophysics Data System (ADS)

Michalczyk, Zdzisław; Mięsiak-Wójcik, Katarzyna; Sposób, Joanna; Turczyński, Marek

2012-01-01

The Lublin Region is an area where local transformations in the natural environment, including the hydrosphere, occur. They result from the impact of agriculture, industry as well as water supply and sewage disposal. These activities lead to changes in the water network resulting from land improvement works, channel straightening and water runoff acceleration, as well as to the formation of local, both point and diffuse sources, of water pollution. The consequences of human impact are manifested in local transformations of the quality or quantity of water resources. As a result of intense groundwater draw-off, hydrogeological conditions are transformed, which is reflected in the persistence of depression cones of varied size and depth, noticeable in the vicinity of water intakes for Lublin, Chełm, Zamość and Kraśnik. The lowering of the first-level groundwater table also occurs as a consequence of the drainage of chalk and marl mine workings in Chełm and Rejowiec, whereas in the area of the hard coal mine both shallow and deep groundwater was transformed. It is important to indicate the consequences of human impact changes of water conditions as the hydrosphere resources should be used according to the principles of sustainable development.

Future water demand in California under a broad range of land use scenarios

NASA Astrophysics Data System (ADS)

Wilson, T. S.; Sleeter, B. M.; Cameron, D. R.

2016-12-01

California continues to be gripped by the most severe drought on record. Most general circulation models agree the state will continue to warm this century and research suggests persistent, long-term droughts may become the new normal, exacerbating an already uncertain water supply future. Population increases and agricultural intensification will likely stress existing, highly variable inter-annual water supplies even further in coming decades. Using the Land Use and Carbon Scenario Simulator (LUCAS) model, we explore a wide range of potential water demand futures from 2012 to 2062 based on 8 alternative, spatially-explicit (1 km) land use scenarios and land-use related water demand. Scenarios include low and high rates for urbanization, agricultural expansion, and agricultural contraction as well as lowest and highest rates for the combined suite of anthropogenic land uses. Land change values were sampled from county-level historical (1991-2012) land change data and county-level average water use data for urban areas (i.e. municipal and industrial) and annual and perennial cropland. We modeled 100 Monte Carlo simulations for each scenario to better characterize and capture model uncertainty and a range of potential future outcomes. Results show water demand in Mediterranean California was lowest in the low anthropogenic change scenario, dropping an average 2.7 million acre feet (MAF) by 2062. The highest water demand was seen in the high urbanization (+3.2 MAF), high agricultural expansion (+4.1 MAF), and the high anthropogenic (+4.3 MAF) scenarios. Results provide water managers and policy makers with information on diverging land use and water use futures, based on observed land change and water use trends, helping better inform land and resource management decisions.

Enterococcus in surface waters from the Des Moines River (Iowa) watershed: location, persistence and vancomycin resistance.

PubMed

Larsen, Bryan; Essmann, Michael K; Geletta, Simon; Duff, Barbara

2012-01-01

The object of this study was to quantify vancomycin-resistant enterococci in surface water from Central Iowa obtained from April 2007 to August 2007. Water from established sampling sites in four watersheds was plated on bile-esculin agar. Presumptively identified enterococci were categorized as "above the level of concern" if the sample contained ≥ 107 CFU per 100 ml. Confirmation of isolates as enterococci was based on growth at elevated temperature in high salt and on Enterococcus agar. Isolates that grew on 6 μg/ml vancomycin agar were deemed resistant. PCR analysis of resistant strains characterized vancomycin resistance genes. 77.2% of surface water samples from Central Iowa contained enterococci. Among enterococcal isolates, 10.4% grew on media containing 6 μg/ml vancomycin. PCR analysis of resistance genes showed a preponderance of VanC2/C3 in the area studied and VanB was not detected. Vancomycin-resistant Enterococcus is present in Central Iowa surface waters but resistance rarely involved VanA genotypes. Nevertheless, the potential for community-acquired infections remains a risk.

Microphysical Characteristics of Clouds During the TRMM Field Campaign

NASA Technical Reports Server (NTRS)

Stith, Jeffrey L.

2003-01-01

Further analysis of the TRMM field campaign data was conducted to examine the growth of precipitation in updraft regions of the TRMM field campaign tropical clouds and to extend the earlier results to cover the whole TRMM data set collected by the University of North Dakota (UND). The results have been submitted for publication. In this paper, composite vertical profiles of liquid water, small particle concentration, and updraft/downdraft magnitudes were presented from each of the campaigns. They exhibited similar peak values for the two TRMM regions of LBA and Kwajalein. Updrafts were found to be favored locations for precipitation embryos in the form of liquid or frozen drizzle-sized droplets. Although liquid water concentrations decreased to undetectable levels between -5 and -18 C in most glaciating updrafts, occasional traces of liquid water were found in updrafts at colder temperatures, probably due to the persistence of liquid drizzle droplets. The updraft magnitudes where the traces of liquid water were observed at cold temperatures do not appear to be stronger than updrafts without liquid water at similar temperatures, however.

Radioactive contamination of cistern waters along the Croatian coast of the Adriatic sea by 90Sr.

PubMed

Franić, Z; Lokobauer, N; Marović, G

1999-07-01

Measurements of radioactive contamination of water samples from cisterns collecting rainwater containing fission products from roofs and other surfaces have been carried out along the Croatian coast of the Adriatic sea since 1968. An exponential decline of radioactivity followed the nuclear moratorium. After the nuclear accident at Chernobyl, higher levels of 137Cs and 90Sr were detected again, with cistern waters being the only environmental samples in Croatia in which elevated 90Sr activities persisted for several years. For the pre-Chernobyl period, the observed mean residence time of 90Sr in cistern waters, estimated to be 6.2 +/- 1.9 y, was similar to that calculated for fallout. Contrary, for the post-Chernobyl time, observed 90Sr mean residence time was calculated to be considerably shorter, reflecting the tropospheric mean residence time. The annual dose for the critical adult population received from 90Sr and 137Cs by drinking cistern water was estimated to be very small, in the 1990's less than few microSv y(-1).

Effect of pH on the Transformation of a New Readymix Formulation of the Herbicides Bispyribac Sodium and Metamifop in Water.

PubMed

Saha, Suman; Majumder, Sambrita; Das, Sushovan; Das, Tapan Kumar; Bhattacharyya, Anjan; Roy, Sankhajit

2018-04-01

A laboratory experiment was conducted to investigate the effect of pH on the persistence and the dissipation of the new readymix formulation of bispyribac sodium and metamifop. The experiment was conducted in water of three different pH viz. 4.0, 7.0 and 9.2. The spiking level of both the compounds in water was 1.0 and 2.0 µg/mL. The residues were extracted by a simple, quick and reliable method and quantified by liquid chromatography tandem mass spectrometry (LC-MS/MS). The method was justified based on the recovery study, which was > 85%. The dissipation of both compounds followed first order kinetics. The half-life values ranged between 19.86-36.29 and 9.92-19.69 days for bispyribac sodium and metamifop, respectively. The pH of water has a prominent effect on degradation of both the compounds. The rate of dissipation of both the compounds was highest in water of acidic pH followed by neutral and alkaline pH.

PERCHLORATE PHYTOREMEDIATION USING HARDWOOD TREES AND VASCULAR PLANTS

EPA Science Inventory

Perchlorate has contaminated water and soils at several locations in the United States. Perchlorate is
water soluble, exceedingly mobile in aqueous systems, and can persist for many decades under typical ground and surface water conditions. Perchlorate is of concern because of...

Reactivation of Kamb Ice Stream tributaries triggers century-scale reorganization of Siple Coast ice flow in West Antarctica

DOE PAGES

Bougamont, M.; Christoffersen, P.; Price, S. F.; ...

2015-10-21

Ongoing, centennial-scale flow variability within the Ross ice streams of West Antarctica suggests that the present-day positive mass balance in this region may reverse in the future. Here we use a three-dimensional ice sheet model to simulate ice flow in this region over 250 years. The flow responds to changing basal properties, as a subglacial till layer interacts with water transported in an active subglacial hydrological system. We show that a persistent weak bed beneath the tributaries of the dormant Kamb Ice Stream is a source of internal ice flow instability, which reorganizes all ice streams in this region, leadingmore » to a reduced (positive) mass balance within decades and a net loss of ice within two centuries. This hitherto unaccounted for flow variability could raise sea level by 5 mm this century. Furthermore, better constraints on future sea level change from this region will require improved estimates of geothermal heat flux and subglacial water transport.« less

Contaminants assessment in the coral reefs of Virgin Islands National Park and Virgin Islands Coral Reef National Monument

USGS Publications Warehouse

Bargar, Timothy A.; Garrison, Virginia H.; Alvarez, David A.; Echols, Kathy

2013-01-01

Coral, fish, plankton, and detritus samples were collected from coral reefs in Virgin Islands National Park (VIIS) and Virgin Islands Coral Reef National Monument (VICR) to assess existing contamination levels. Passive water sampling using polar organic chemical integrative samplers (POCIS) and semi-permeable membrane devices found a few emerging pollutants of concern (DEET and galaxolide) and polynuclear aromatic hydrocarbons. Very little persistent organic chemical contamination was detected in the tissue or detritus samples. Detected contaminants were at concentrations below those reported to be harmful to aquatic organisms. Extracts from the POCIS were subjected to the yeast estrogen screen (YES) to assess potential estrogenicity of the contaminant mixture. Results of the YES (estrogen equivalency of 0.17–0.31 ng/L 17-β-estradiol) indicated a low estrogenicity likelihood for contaminants extracted from water. Findings point to low levels of polar and non-polar organic contaminants in the bays sampled within VICR and VIIS.

The Tropopause Inversion Layer: New Observations, New Theories

NASA Astrophysics Data System (ADS)

Tandon, N.; Randel, W. J.; Pan, L.; Son, S.; Polvani, L. M.

2009-12-01

There is now great interest in the tropopause inversion inversion layer (TIL), a 1-2 km region just above the tropopause where there is a spike in static stability. Radio occultation data from the COSMIC GPS mission are providing an unprecedented level of spatial and temporal resolution with which to analyze the TIL. We start by showing the agreement between GPS data and radiosondes. We then examine the causes and consequences of the TIL. Observations from the ACE satellite and fixed dynamical heating calculations suggest strong roles for water vapor and ozone in the formation and modulation of the TIL. This agrees with observations showing a large TIL in the polar winter, where water vapor levels are persistently high. It is also clear that TIL strength is related to vorticity, but observations and models have important differences that need to be reconciled. These dynamical considerations dovetail with observations showing high TIL variability in the storm-track regions. Finally there is evidence from ozonesonde data that the TIL may be coupled to transport across the tropopause.

Pesticides in the nation's rivers, 1975-1980, and implications for future monitoring

USGS Publications Warehouse

Gilliom, Robert J.; Alexander, Richard B.; Smith, Richard A.

1985-01-01

Water samples were taken four times per year and bed-sediment samples two times per year during 1975-80 at 160 to 180 stations on major rivers of the United States. Samples were analyzed for 18 insecticides and 4 herbicides, which together accounted for about one-third of the total amount of all pesticides applied to major crops during 1975-80. Fewer than 10 percent of almost 3,000 water samples and fewer than 20 percent of almost 1,000 bed-sediment samples contained reportable concentrations of any of the compounds. The patterns of detection result from a combination of widely variable detection capabilities, chemical properties, and use. Most detections in water samples were of relatively persistent yet soluble compounds: atrazine (4.8 percent of samples), diazinon (1.2), and lindane (1.1). Most detections in bed-sediment samples were of the hydrophobic and persistent insecticides: DDE (17 percent of samples), DDD (12), dieldrin (12), chlordane (9.9), and DDT (8.5). Only for atrazine in water, and for DDE, DDD, DDT, and chlordane in bed sediments, were geographic patterns of detection correlated (pH<0.10) with use on farms. Detections of organochlorine insecticides in both water and bed sediments appear to have erratically but gradually decreased during 1975-80. For the 1975-79 period, more stations had downtrends than had uptrends in bed-sediment levels of organochlorines. No clear trends were evident in concentrations of organophosphate insecticides or herbicides in either water or bed sediments. Findings suggest that future pesticide monitoring efforts must be responsive to changes in pesticides used and to geographic patterns of use. Different types of monitoring approaches are necesssary for chemicals having different chemical and physical properties. Before an effective dynamic monitoring effort can be designed, however, selected case studies are needed to characterize and refine sampling and analytical capabilities for different types of chemicals, river environments, and sample types.

Nanosized solvent superstructures in ultramolecular aqueous dilutions: twenty years' research using water proton NMR relaxation.

PubMed

Demangeat, Jean-Louis

2013-04-01

proton nuclear magnetic resonance (NMR) relaxation times T1, T2, T1/T2 are sensitive to motion and organization of water molecules. Especially, increase in T1/T2 reflects a higher degree of structuring. My purpose was to look at physical changes in water in ultrahigh aqueous dilutions. Samples were prepared by iterative centesimal (c) dilution with vigorous agitation, ranging between 3c and 24c (Avogadro limit 12c). Solutes were silica-lactose, histamine, manganese-lactose. Solvents were water, NaCl 0.15 M or LiCl 0.15 M. Solvents underwent strictly similar, simultaneous dilution/agitation, for each level of dilution, as controls. NMR relaxation was studied within 0.02-20 MHz. No changes were observed in controls. Increasing T1 and T1/T2 were found in dilutions, which persisted beyond 9c (manganese-lactose), 10c (histamine) and 12c (silica-lactose). For silica-lactose in LiCl, continuous decrease in T2 with increase in T1/T2 within the 12c-24c range indicated growing structuring of water despite absence of the initial solute. All changes vanished after heating/cooling. These findings were interpreted in terms of nanosized (>4-nm) supramolecular structures involving water, nanobubbles and ions, if any. Additional study of low dilutions of silica-lactose revealed increased T2 and decreased T1/T2 compared to solvent, within the 10(-3)-10(-6) range, reflecting transient solvent destructuring. This could explain findings at high dilution. Proton NMR relaxation demonstrated modifications of the solvent throughout the low to ultramolecular range of dilution. The findings suggested the existence of superstructures that originate stereospecifically around the solute after an initial destructuring of the solvent, developing more upon dilution and persisting beyond 12c. Copyright © 2013 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

Hatching, growth, ion accumulation, and skeletal ossification of brook trout (Salvelinus fontinalis) alevins in acidic soft waters

USGS Publications Warehouse

Steingraeber, M.T.; Gingerich, W.H.

1991-01-01

Brook trout eyed eggs and subsequent alevins were exposed to pH 5.0, 6.5, and 7.0 in soft reconstituted water and to pH 8.2 in hard well water for up to 72 d. Hatching was delayed and hatching success reduced (p K+ > Cl- during yolk absorption and early exogenous feeding. Whole-body monovalent ion concentrations were reduced for short periods during yolk absorption in alevins exposed to pH 6.5 and throughout most of the experiment for those exposed to pH 5.0. Whole-body Mg2+ concentrations were not affected by treatment pH and remained near their median hatch level throughout the exposure. The whole-body concentration of Ca2+ was reduced in fish exposed to pH 5.0, particularly near the end of the experiment. Calcium accumulation in fish was influenced by the interaction of pH and time at pH 5.0 but not at the other pH levels. Alevins exposed to pH 5.0 experienced delayed ossification of skeletal structures associated with feeding, respiration, and locomotion that usually persisted for up to 10 d. The detection of skeletal abnormalities early in life might aid in identifying fish populations at risk in acidified waters.

Endosulfan leaching from Typic Argiudolls in soybean tillage areas and groundwater pollution implications.

PubMed

Grondona, Sebastián I; Gonzalez, Mariana; Martínez, Daniel E; Massone, Héctor E; Miglioranza, Karina S B

2014-06-15

Endosulfan has been recently added to Persistent Organic Pollutants (POPs) list and due to its extensive and massive use and environmental persistence constitutes a potential hazard to groundwater resources. Undisturbed soil columns were used to evaluate endosulfan leaching in two series of Typic Argiudolls considering natural and agricultural land use. Columns were spiked with 10μgL(-1) of technical endosulfan and eluted under saturated flow with five pore volumes of distilled water. Alfa and beta isomer residues were detected in the upper soil level, with decreasing values through the profile, being influenced by soil texture and land use. The endosulfan sulfate metabolite was mainly found in the upper level linked to high dehydrogenase activity. Results from leachates (total endosulfan 27-87ngL(-1)) showed higher α-isomer mobility, and suggest alkaline hydrolysis of both endosulfan isomers. The agricultural use modified the physico-chemical properties and structure of soils leading to vertical migration of endosulfan isomers under saturated conditions. Intact column test provided information close to field data showing its utility for the assessment of groundwater pollution by endosulfan. Copyright © 2014 Elsevier B.V. All rights reserved.

The coverage and frequency of mass drug administration required to eliminate persistent transmission of soil-transmitted helminths

PubMed Central

Anderson, Roy; Truscott, James; Hollingsworth, T. Deirdre

2014-01-01

A combination of methods, including mathematical model construction, demographic plus epidemiological data analysis and parameter estimation, are used to examine whether mass drug administration (MDA) alone can eliminate the transmission of soil-transmitted helminths (STHs). Numerical analyses suggest that in all but low transmission settings (as defined by the magnitude of the basic reproductive number, R0), the treatment of pre-school-aged children (pre-SAC) and school-aged children (SAC) is unlikely to drive transmission to a level where the parasites cannot persist. High levels of coverage (defined as the fraction of an age group effectively treated) are required in pre-SAC, SAC and adults, if MDA is to drive the parasite below the breakpoint under which transmission is eliminated. Long-term solutions to controlling helminth infections lie in concomitantly improving the quality of the water supply, sanitation and hygiene (WASH). MDA, however, is a very cost-effective tool in long-term control given that most drugs are donated free by the pharmaceutical industry for poor regions of the world. WASH interventions, by lowering the basic reproductive number, can facilitate the ability of MDA to interrupt transmission. PMID:24821921

The coverage and frequency of mass drug administration required to eliminate persistent transmission of soil-transmitted helminths.

PubMed

Anderson, Roy; Truscott, James; Hollingsworth, T Deirdre

2014-01-01

A combination of methods, including mathematical model construction, demographic plus epidemiological data analysis and parameter estimation, are used to examine whether mass drug administration (MDA) alone can eliminate the transmission of soil-transmitted helminths (STHs). Numerical analyses suggest that in all but low transmission settings (as defined by the magnitude of the basic reproductive number, R0), the treatment of pre-school-aged children (pre-SAC) and school-aged children (SAC) is unlikely to drive transmission to a level where the parasites cannot persist. High levels of coverage (defined as the fraction of an age group effectively treated) are required in pre-SAC, SAC and adults, if MDA is to drive the parasite below the breakpoint under which transmission is eliminated. Long-term solutions to controlling helminth infections lie in concomitantly improving the quality of the water supply, sanitation and hygiene (WASH). MDA, however, is a very cost-effective tool in long-term control given that most drugs are donated free by the pharmaceutical industry for poor regions of the world. WASH interventions, by lowering the basic reproductive number, can facilitate the ability of MDA to interrupt transmission.

Role of water channel AQP-CD in water retention in SIADH and cirrhotic rats.

PubMed

Fujita, N; Ishikawa, S E; Sasaki, S; Fujisawa, G; Fushimi, K; Marumo, F; Saito, T

1995-12-01

We determined whether aquaporin of collecting duct (AQP-CD) is involved in pathogenesis of water retention in rats with experimental models of syndrome of inappropriate secretion of antidiuretic hormone (SIADH) and liver cirrhosis. SIADH rats were made by administering 1-desamino-8-D-arginine vasopressin (DDAVP) subcutaneously and providing them with a liquid diet. Serum Na levels decreased to < 120 meq/l on day 2, and hyponatremia persisted throughout the rest of observation period. Six hours after the DDAVP infusion, the expression of AQP-CD mRNA significantly increased by 198%, followed by > 144% increases in its expression during the 14-day observation period. On day 7, the increased expression of AQP-CD mRNA was abolished after the administration of an antidiuretic, nonpeptide arginine vasopressin (AVP) antagonist, OPC-31260, which was closely related to a marked diuresis and a prompt normalization of serum Na levels in SIADH rats. Rats were made cirrhotic by injecting a mixture of carbon tetrachloride and olive oil subcutaneously for 3 mo. The expression of AQP-CD mRNA was increased by 164% in the decompensated cirrhotic rats. The blockade of AVP action by OPC-31260 significantly diminished its expression. These results indicate that water channel AQP-CD plays an important role in water retention in pathological states of SIADH and liver cirrhosis.

Occurrence of pharmaceutical contaminants and screening of treatment alternatives for southeastern Louisiana.

PubMed

Boyd, G R; Grimm, D A

2001-12-01

Recent studies conducted in Germany, Switzerland, Denmark, Brazil, Canada, the United States, and elsewhere indicate that low-level concentrations of pharmaceuticals and personal-care products (PPCPs) and their metabolites may be widespread contaminants in our aquatic environment. The persistence of pharmaceutical contaminants has been attributed to (1) human consumption of drugs and subsequent discharges from sewage treatment plants, and (2) veterinary use of drugs and nonpoint discharges from agricultural runoff. Contamination of water resources by these compounds, particularly endocrine disrupting chemicals (EDCs), is emerging as an international environmental concern. The long-term effects of continuous, low-level exposure to PPCPs is not well understood. Preliminary data for raw water samples collected from the Mississippi River and Lake Pontchartrain, Louisiana, are summarized. Three PPCP compounds (clofibric acid, naproxen, and estrone) were analyzed using solid-phase extraction, derivatization, and GC/MS. Batch experiments also were conducted to determine equilibrium capacity of activated carbon for clofibric acid. Preliminary results indicate the occurrence of the selected PPCP contaminants in raw water samples at or near method-detection limits. For batch equilibrium experiments, preliminary results indicate that activated carbon potentially can be used to remove clofibric acid from water. More research is needed to develop rapid and reliable methods for PPCP analysis and to determine the effectiveness of treatment processes for removal of PPCP contaminants in water.

Stochastic Modeling of the Persistence of HIV: Early Population Dynamics

DTIC Science & Technology

2013-05-10

fluid, Brownian motion is named after the botanist Robert Brown. In the late nineteenth century, he observed that pollen floating in water appeared...to move about in a random manner. When he replaced the pollen with inorganic material, he noticed that the motion persisted. Upon plotting the motion

Spatial and Temporal Trends of Persistent Organic Chemicals with Emphasis on Brominated Flame Retardants

EPA Science Inventory

Rapid growth in chemical and agrochemical industries during the past century have resulted in the release of large numbers of persistent organic chemicals (POCs) into the environment. Since POCs are prevalent in air, water, soil and tissue of organisms throughout the world and r...

Maternal educational level and the risk of persistent post-partum glucose metabolism disorders in women with gestational diabetes mellitus.

PubMed

Gante, Inês; Ferreira, Ana Carina; Pestana, Gonçalo; Pires, Daniela; Amaral, Njila; Dores, Jorge; do Céu Almeida, Maria; Sandoval, José Luis

2018-03-01

Gestational diabetes mellitus (GDM) occurs in 5-15% of pregnancies, and lower maternal educational attainment has been associated with higher risk of GDM. We aimed to determine if maternal education level is associated with persistent post-partum glucose metabolism disorders in women with GDM. Retrospective cohort study of women with GDM followed in 25 Portuguese health institutions between 2008 and 2012. Educational attainment was categorised into four levels. Prevalence of post-partum glucose metabolism disorders (type 2 diabetes mellitus, increased fasting plasma glucose or impaired glucose tolerance) was compared and adjusted odds ratios calculated controlling for confounders using logistic regression. We included 4490 women diagnosed with GDM. Educational level ranged as follows: 6.8% (n = 307) were at level 1 (≤ 6th grade), 34.6% (n = 1554) at level 2 (6-9th grade), 30.4% (n = 1364) at level 3 (10-12th grade) and 28.2% (n = 1265) at level 4 (≥ university degree). At 6 weeks post-partum re-evaluation, 10.9% (n = 491) had persistent glucose metabolism disorders. Educational levels 1 and 2 had a higher probability of persistent post-partum glucose metabolism disorders when compared to level 4 (OR = 2.37 [1.69;3.32], p < 0.001 and OR = 1.39 [1.09;1.76], p = 0.008, for level 1 and 2, respectively), an association that persisted in multivariable logistic regression adjusting for confounders (level 1 OR = 2.25 [1.53;3.33], p < 0.001; level 2 OR = 1.43 [1.09;1.89], p = 0.01). Persistent post-partum glucose metabolism disorders are frequent in women with GDM and associated with lower maternal educational level. Interventions aimed at this risk group may contribute towards a decrease in prevalence of post-partum glucose metabolism disorders.

Sorption and degradation of wastewater-associated non-steroidal anti-inflammatory drugs and antibiotics in soils.

PubMed

Lin, Kunde; Gan, Jay

2011-04-01

Presence of pharmaceuticals at trace levels in recycled water is an emerging issue impacting the beneficial reuse of treated wastewater, including practices such as irrigation and groundwater recharge in arid and semi-arid regions. To assess the environmental risks of irrigation with recycled water containing such micropollutants, in this study we evaluated sorption and degradation of five pharmaceuticals that are antibiotic and anti-inflammatory drugs in two soils collected from arid regions. Naproxen and trimethoprim showed moderate to strong sorption, while the sorption of diclofenac, ibuprofen and sulfamethoxazole was negligible in both soils. Under aerobic conditions, the studied compounds were susceptible to microbial degradation with half-lives varying from 4.8 to 69.3d. Apart from sulfamethoxazole, the other compounds were relatively persistent under anaerobic conditions as indicated by a negligible loss over 84d of incubation or half-lives >50d. The degradation of the selected pharmaceuticals was influenced by microbial activities, oxygen status in the soil, soil type and compound characteristics. The poor sorption and relative persistence of diclofenac and ibuprofen under anaerobic conditions suggest that the two chemicals may pose a high leaching risk when using recycled for irrigation or groundwater replenishment. Copyright © 2010 Elsevier Ltd. All rights reserved.

Risk factors for persistent cervical intraepithelial neoplasia grades 1 and 2: managed by watchful waiting.

PubMed

Ho, Gloria Y F; Einstein, Mark H; Romney, Seymour L; Kadish, Anna S; Abadi, Maria; Mikhail, Magdy; Basu, Jayasri; Thysen, Benjamin; Reimers, Laura; Palan, Prabhudas R; Trim, Shelly; Soroudi, Nafisseh; Burk, Robert D

2011-10-01

: This study examines risk factors for persistent cervical intraepithelial neoplasia (CIN) and examines whether human papillomavirus (HPV) testing predicts persistent lesions. : Women with histologically diagnosed CIN 1 or CIN 2 (n = 206) were followed up every 3 months without treatment. Human papillomavirus genotyping, plasma levels of ascorbic acid, and red blood cell folate levels were obtained. Cervical biopsy at 12 months determined the presence of CIN. Relative risk (RR) was estimated by log-linked binomial regression models. : At 12 months, 70% of CIN 1 versus 54% of CIN 2 lesions spontaneously regressed (p < .001). Levels of folate or ascorbic acid were not associated with persistent CIN at 12 months. Compared with HPV-negative women, those with multiple HPV types (RRs ranged from 1.68 to 2.17 at each follow-up visit) or high-risk types (RRs range = 1.74-2.09) were at increased risk for persistent CIN; women with HPV-16/18 had the highest risk (RRs range = 1.91-2.21). Persistent infection with a high-risk type was also associated with persistent CIN (RRs range = 1.50-2.35). Typing for high-risk HPVs at 6 months only had a sensitivity of 46% in predicting persistence of any lesions at 12 months. : Spontaneous regression of CIN 1 and 2 occurs frequently within 12 months. Human papillomavirus infection is the major risk factor for persistent CIN. However, HPV testing cannot reliably predict persistence of any lesion.

Acidification of lake water due to drought

NASA Astrophysics Data System (ADS)

Mosley, L. M.; Zammit, B.; Jolley, A. M.; Barnett, L.

2014-04-01

Droughts are predicted to increase in many river systems due to increased demand on water resources and climate variability. A severe drought in the Murray-Darling Basin of Australia from 2007 to 2009 resulted in unprecedented declines in water levels in the Lower Lakes (Ramsar-listed ecosystem of international importance) at the end of the river system. The receding water exposed large areas (>200 km2) of sediments on the lake margins. The pyrite (FeS2) in these sediments oxidised and generated high concentrations of acidity. Upon rewetting of the exposed sediments, by rainfall or lake refill, surface water acidification (pH 2-3) occurred in several locations (total area of 21.7 km2). High concentrations of dissolved metals (Al, As, Co, Cr, Cu, Fe, Mn, Ni, Zn), which greatly exceeded aquatic ecosystem protection guidelines, were mobilised in the acidic conditions. In many areas neutralisation of the surface water acidity occurred naturally during lake refill, but aerial limestone dosing was required in two areas to assist in restoring alkalinity. However acidity persists in the submerged lake sediment and groundwater several years after surface water neutralisation. The surface water acidification proved costly to manage and improved water management in the Murray-Darling Basin is required to prevent similar events occurring in the future.

Evaluation of Listeria monocytogenes survival and infectivity in non-traditional agricultural waters

USDA-ARS?s Scientific Manuscript database

Introduction: Listeria monocytogenes (Lm) is an enteric bacterium that can be found in environmental reservoirs. Restricted water availability for agriculture has increased interest in surface and reuse water sources which could potentially transmit Lm. Purpose: Persistence and infectivity of Lm re...

Emerging Contaminants in US Drinking Water: Do you know where your water's been?

EPA Science Inventory

The drinking water and wastewater cycles are integrally linked. Chemicals that are present in household wastewater may be sufficiently mobile and persistent to survive on-site or municipal wastewater treatment and post-discharge environmental processes. Such compounds have the ...

Spatial and seasonal distribution of selected antibiotics in surface waters of the Pearl Rivers, China.

PubMed

Yang, Ji-Feng; Ying, Guang-Guo; Zhao, Jian-Liang; Tao, Ran; Su, Hao-Chang; Liu, You-Sheng

2011-01-01

The distribution and occurrence of 15 antibiotics in surface water of the Pearl River System (Liuxi River, Shijing River and Zhujiang River) and effluents of four wastewater treatment plants (WWTPs) were investigated in two sampling events representing wet season and dry season by using rapid resolution liquid chromatography-electrospray tandem mass spectrometry (RRLC-MS/MS) in positive ionization mode. Only eight antibiotics (sulfadiazine, sulfapyridine, sulfamethazine, sulfamethoxazole, trimethoprim, roxithromycin, erythromycin-H₂O and norfloxacin) were detected in the water samples of the three rivers and the effluents. The detection frequencies and levels of antibiotics in the dry season were higher than those in the wet season. This could be attributed to the dilution effects in the wet season and relatively lower temperature in the dry season under which antibiotics could persist for a longer period. The levels of the detected antibiotics in different sites are generally in a decreasing order as follows: Shijing River ≥WWTP effluent ≥Zhujiang River ≥ Liuxi River. Risk assessment based on the calculated risk quotients showed that only erythromycin-H₂O and roxithromycin detected in the Pearl Rivers might have adverse effects on aquatic organisms.

How to spy on your neighbor's water consumption from space

NASA Astrophysics Data System (ADS)

Neely, W.; Borsa, A. A.; Burney, J. A.

2017-12-01

Dependence on groundwater has increased in the agricultural production regions of California's Central Valley due to recent and persistent droughts. To protect the long-term reliability of groundwater resources in California, the state passed the Sustainable Groundwater Management Act (SGMA) in September 2014. In situ observation of subsurface reservoir levels is ideal for monitoring aquifer health at a water district scale, but is limited by the low density of monitoring wells and temporal gaps between measurements. An alternative to well measurements relies on the fact that groundwater extraction may lead to surface subsidence due to the compaction of the aquifer at depth. Such surface displacements can be resolved using geodetic techniques. We present an integrative approach using Interferometric Synthetic Aperture Radar (InSAR) and continuous Global Positioning System (cGPS) station observations to characterize surface deformation related to extensive pumping at a farm-level resolution every 12-24 days. We demonstrate our technique in the southern Central Valley where we observe subsidence upwards of 25 cm/yr from late 2014 to early 2017. Our methods offer an inexpensive supplement to in situ measurements that allows for the detection and deterrence of water mismanagement.

Plant Pathogen-Induced Water-Soaking Promotes Salmonella enterica Growth on Tomato Leaves

PubMed Central

Potnis, Neha; Colee, James; Jones, Jeffrey B.

2015-01-01

Plant pathogen infection is a critical factor for the persistence of Salmonella enterica on plants. We investigated the mechanisms responsible for the persistence of S. enterica on diseased tomato plants by using four diverse bacterial spot Xanthomonas species that differ in disease severities. Xanthomonas euvesicatoria and X. gardneri infection fostered S. enterica growth, while X. perforans infection did not induce growth but supported the persistence of S. enterica. X. vesicatoria-infected leaves harbored S. enterica populations similar to those on healthy leaves. Growth of S. enterica was associated with extensive water-soaking and necrosis in X. euvesicatoria- and X. gardneri-infected plants. The contribution of water-soaking to the growth of S. enterica was corroborated by an increased growth of populations on water-saturated leaves in the absence of a plant pathogen. S. enterica aggregates were observed with bacterial spot lesions caused by either X. euvesicatoria or X. vesicatoria; however, more S. enterica aggregates formed on X. euvesicatoria-infected leaves as a result of larger lesion sizes per leaf area and extensive water-soaking. Sparsely distributed lesions caused by X. vesicatoria infection do not support the overall growth of S. enterica or aggregates in areas without lesions or water-soaking; S. enterica was observed as single cells and not aggregates. Thus, pathogen-induced water-soaking and necrosis allow S. enterica to replicate and proliferate on tomato leaves. The finding that the pathogen-induced virulence phenotype affects the fate of S. enterica populations in diseased plants suggests that targeting of plant pathogen disease is important in controlling S. enterica populations on plants. PMID:26386057

Litter quality and its response to water level drawdown in boreal peatlands at plant species and community level

NASA Astrophysics Data System (ADS)

Straková, Petra; Anttila, Jani; Spetz, Peter; Kitunen, Veikko; Tapanila, Tarja; Laiho, Raija

2010-05-01

There is increasing evidence that changes in the species composition and structure of plant communities induced by global change will have much more impact on plant-mediated carbon cycling than any phenotypic responses. These impacts are largely mediated by shifts in litter quality. There are few documentations of these changes so far, due to the relatively long time scale required for their direct observation. Here, we examine the changes in litter inputs induced by persistent water-level drawdown in boreal peatland sites. Peatlands contain a major proportion of the terrestrial carbon pool, and it is thus important to be able to predict their behaviour and role in the global C cycle under different global change factors. We studied the effects of short-term (ca. 4 years) and long-term (ca. 40 years) persistent water level (WL) drawdown on the quantity and chemical quality of above-ground plant litter inputs at three sites: bog, oligotrophic fen and mesotrophic fen. The parameters used to characterize litter quality included various extractable substances, cellulose, holocellulose, composition of hemicellulose (neutral sugars, uronic acids), lignin, CuO oxidation phenolic products, and concentrations of C, nitrogen (N), phosphorus (P), potassium, magnesium, manganese and calcium. Four different groups of litter were clearly distinct based on their chemical quality: foliar litters, graminoids, mosses and woody litters. The pristine conditions were characterized by Sphagnum moss and graminoid litter. Following short-term WL drawdown, changes in the quality and quantity of litter inputs were small. Following long-term WL drawdown, total litter inputs dramatically increased, due to increased tree litter inputs, and the litter type composition greatly changed. These changes resulted in annual inputs of 1901-2010 kg•ha-1 C, 22-24 kg•ha-1 N, 1.5-2.2 kg•ha-1 P, 967-1235 kg•ha-1 lignin and lignin-like compounds and 254-300 kg•ha-1 water solubles after long-term WL drawdown, compared to respective values of 394-658, 5.6-9.3, 0.22-24.4, 161-293 and 44-81 for the pristine conditions. The direct effects of WL drawdown on litter quality were overruled by the indirect effects via changes in vegetation composition. The short-term (reflecting transient conditions) and long-term (reflecting longer-lasting situation of already adapted ecosystem) effects were very different. Our results imply that the long-term effects will strongly affect the soil properties and C cycle of peatlands.

Survival and persistence of fecal host-specific Bacteroidales cells and their DNA assessed by PMA-qPCR

NASA Astrophysics Data System (ADS)

Bae, S.; Bombardelli, F.; Wuertz, S.

2008-12-01

Understanding and managing microbial pollutions in water is one of the foremost challenges of establishing effective managements and remediation strategies to impaired water bodies polluted by uncharacterized fecal sources. Quantitative microbial source tracking (MST) approaches using fecal Bacteroidales and quantitative PCR (qPCR) assays to measure gene copies of host-specific 16S rRNA genetic markers are promising because they can allow for identifying and quantifying fecal loadings from a particular animal host and understanding the fate and transport of host-specific Bacteroidales over a range of conditions in water bodies. Similar to the case of traditional fecal indicator bacteria, a relatively long persistence of target DNA may hamper applied MST studies, if genetic markers cannot be linked to recent fecal pollution in water. We report a successful approach to removing the qPCR signal derived from free DNA and dead host-specific Bacteroidales cells by selectively binding the DNA and consequently inhibiting PCR amplification using light- activated propidium monoazide (PMA). Optimal PMA-qPCR conditions were determined as 100 µM of PMA concentration and a 10-min light exposure time at different solids concentrations in order to mimic a range of water samples. Under these conditions, PMA-qPCR resulted in the selective exclusion of DNA from heat- treated cells of non-culturable Bacteroidales in human feces and wastewater influent and effluent samples. Also, the persistence of feces-derived host-specific Bacteroidales DNA and their cells (determined by universal, human-, cow- and dog-specific Bacteroidales qPCR assays) in seawater was investigated in microcosms at environmental conditions. The average T99 (two log reduction) value for host-specific viable Bacteroidales cells was 28 h, whereas that for total host-specific Bacteroidales DNA was 177 h. Natural sunlight did not have a strong influence on the fate of fecal Bacteroidales cells and their DNA, presumably because the presence of oxygen significantly affected the viability and persistence of these obligate anaerobes. In conclusion, measuring Bacteroidales DNA in viable cells is recommended in applied MST studies because extracellular Bacteroidales DNA persists longer in the environment. The methods and results presented are helpful to improve the accuracy of MST applications, to develop a model of fate and transport of host-specific Bacteroidales, and to implement management practices to protect water quality.

Contrasting conditions of surface water balance in wet years and dry years as a possible land surface-atmosphere feedback mechanism in the West African Sahel

NASA Technical Reports Server (NTRS)

Lare, A. R.; Nicholson, S. E.

1994-01-01

The climate of West Africa, in particular the Sahel, is characterized by multiyear persistence of anomalously wet or dry conditions. Its Southern Hemisphere counterpart, the Kalahari, lacks the persistence that is evident in the Sahel even though both regions are subject to similar large-scale forcing. It has been suggested that land surface-atmosphere feedback contributes to this persistence and to the severity of drought. In this study, surface energy and water balance are quantified for nine stations along a latitudinal transect that extends from the Sahara to the Guinea coast. In the wetter regions of West Africa, the difference between wet and dry years is primarily reflected in the magnitude of runoff. For the Sahel and drier locations, evapotranspiration and soil moisture are more sensitive to rainfall anomalies. The increase in evapotranspiration, and hence latent heating, over the Sahel in wet years alters the thermal structure and gradients of the overlying atmosphere and thus the strength of the African easterly jet (AEJ) at 700 mb. The difference between dry and wet Augusts corresponds to a decrease in magnitude of the AEJ at 15 deg N on the order of 2.6 m/s, which is consistent with previous studies of observed winds. Spatial patterns were also developed for surface water balance parameters for both West Africa and southern Africa. Over southern Africa, the patterns are not as spatially homogeneous as those over West Africa and are lower in magnitude, thus supporting the suggestion that the persistence of rainfall anomalies in the Sahel might be due, at least in part, to land-atmosphere feedback, and that the absence of such persistence in the Kalahari is a consequence of less significant changes in surface water and energy balance.

Energy conversion modeling of the intrinsic persistent luminescence of solids via energy transfer paths between transition levels.

PubMed

Huang, Bolong; Sun, Mingzi

2017-04-05

An energy conversion model has been established for the intrinsic persistent luminescence in solids related to the native point defect levels, formations, and transitions. In this study, we showed how the recombination of charge carriers between different defect levels along the zero phonon line (ZPL) can lead to energy conversions supporting the intrinsic persistent phosphorescence in solids. This suggests that the key driving force for this optical phenomenon is the pair of electrons hopping between different charged defects with negative-U eff . Such a negative correlation energy will provide a sustainable energy source for electron-holes to further recombine in a new cycle with a specific quantum yield. This will help us to understand the intrinsic persistent luminescence with respect to native point defect levels as well as the correlations of electronics and energetics.

Granular activated carbon to remove agrichemicals from water

USDA-ARS?s Scientific Manuscript database

Many growers capture and reuse irrigation water in ponds or flood irrigation tanks. Agrichemical residues can potentially build up over time and affect future crops irrigated with residue-laden water. One key chemical of concern is paclobutrazol, which is very persistent, with a half-life of around ...

Pollutant emissions and environmental assessment of ethyl 3-ethoxybutyrate, a potential renewable fuel

DOE PAGES

Storey, John M. E.; Bunce, Michael P.; Clarke, Edwina M.; ...

2016-06-14

Renewable and bio-based transportation fuel sources can lower the life-cycle greenhouse gas emissions from vehicles. Here, we present an initial assessment of ethyl 3-ethoxybutyrate (EEB) as a biofuel in terms of its performance as a fuel oxygenate and its persistence in the environment. EEB can be produced from ethanol and poly-3-hydroxybutyrate, a bacterial storage polymer that can be produced from non-food biomass and other organic feedstocks. The physicochemical properties of EEB and fuel-relevant properties of EEB-gasoline blends were measured, emissions of criteria pollutants from EEB as a gasoline additive in a production vehicle were evaluated, and fate and persistence ofmore » EEB in the environment were estimated. EEB solubility in water was 25.8 g/L, its K ow was 1.8, and its Henry's Law constant was 1.04 x 10 -5 atm-m 3/mole. The anti-knock index values for 5% and 20% v/v EEB-gasoline blends were 91.6 and 91.9, respectively. Reductions in fuel economy were consistent with the level of oxygenation, and criteria emissions were met by the vehicle operated over the urban dynamometer driving cycle (FTP 75). Predicted environmental persistence ranged from 15 d to 30 d which indicates that EEB is not likely to be a persistent organic pollutant. Combined, these results suggest a high potential for the use of EEB as a renewable fuel source.« less

Pollutant emissions and environmental assessment of ethyl 3-ethoxybutyrate, a potential renewable fuel

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

Storey, John M. E.; Bunce, Michael P.; Clarke, Edwina M.

Renewable and bio-based transportation fuel sources can lower the life-cycle greenhouse gas emissions from vehicles. Here, we present an initial assessment of ethyl 3-ethoxybutyrate (EEB) as a biofuel in terms of its performance as a fuel oxygenate and its persistence in the environment. EEB can be produced from ethanol and poly-3-hydroxybutyrate, a bacterial storage polymer that can be produced from non-food biomass and other organic feedstocks. The physicochemical properties of EEB and fuel-relevant properties of EEB-gasoline blends were measured, emissions of criteria pollutants from EEB as a gasoline additive in a production vehicle were evaluated, and fate and persistence ofmore » EEB in the environment were estimated. EEB solubility in water was 25.8 g/L, its K ow was 1.8, and its Henry's Law constant was 1.04 x 10 -5 atm-m 3/mole. The anti-knock index values for 5% and 20% v/v EEB-gasoline blends were 91.6 and 91.9, respectively. Reductions in fuel economy were consistent with the level of oxygenation, and criteria emissions were met by the vehicle operated over the urban dynamometer driving cycle (FTP 75). Predicted environmental persistence ranged from 15 d to 30 d which indicates that EEB is not likely to be a persistent organic pollutant. Combined, these results suggest a high potential for the use of EEB as a renewable fuel source.« less

Spatial heterogeneity in human activities favors the persistence of wolves in agroecosystems.

PubMed

Ahmadi, Mohsen; López-Bao, José Vicente; Kaboli, Mohammad

2014-01-01

As human populations expand, there is increasing demand and pressure for land. Under this scenario, behavioural flexibility and adaptation become important processes leading to the persistence of large carnivores in human-dominated landscapes such as agroecosystems. A growing interest has recently emerged on the outcome of the coexistence between wolves and humans in these systems. It has been suggested that spatial heterogeneity in human activities would be a major environmental factor modulating vulnerability and persistence of this contentious species in agroecosystems. Here, we combined information from 35 den sites detected between 2011 and 2012 in agroecosystems of western Iran (Hamedan province), a set of environmental variables measured at landscape and fine spatial scales, and generalized linear models to identify patterns of den site selection by wolves in a highly-modified agroecosystem. On a landscape level, wolves selected a mixture of rangelands with scattered dry-farms on hillsides (showing a low human use) to locate their dens, avoiding areas with high densities of settlements and primary roads. On a fine spatial scale, wolves primarily excavated dens into the sides of elevated steep-slope hills with availability of water bodies in the vicinity of den sites, and wolves were relegated to dig in places with coarse-soil particles. Our results suggest that vulnerability of wolves in human-dominated landscapes could be compensated by the existence of spatial heterogeneity in human activities. Such heterogeneity would favor wolf persistence in agroecosystems favoring a land sharing model of coexistence between wolves and people.

Pollutant emissions and environmental assessment of ethyl 3-ethoxybutyrate, a potential renewable fuel.

PubMed

Storey, John M E; Bunce, Michael P; Clarke, Edwina M; Edmonds, Jennifer W; Findlay, Robert H; Ritchie, Stephen M C; Eyers, Laurent; McMurry, Zackery A; Smoot, James C

2016-09-01

Renewable and bio-based transportation fuel sources can lower the life-cycle greenhouse gas emissions from vehicles. We present an initial assessment of ethyl 3-ethoxybutyrate (EEB) as a biofuel in terms of its performance as a fuel oxygenate and its persistence in the environment. EEB can be produced from ethanol and poly-3-hydroxybutyrate, a bacterial storage polymer that can be produced from non-food biomass and other organic feedstocks. Physicochemical properties of EEB and fuel-relevant properties of EEB-gasoline blends were measured, emissions of criteria pollutants from EEB as a gasoline additive in a production vehicle were evaluated, and fate and persistence of EEB in the environment were estimated. EEB solubility in water was 25.8 g/L, its Kow was 1.8, and its Henry's Law constant was 1.04 × 10(-5) atm-m(3)/mole. The anti-knock index values for 5 and 20 % v/v EEB-gasoline blends were 91.6 and 91.9, respectively. Reductions in fuel economy were consistent with the level of oxygenation, and criteria emissions were met by the vehicle operated over the urban dynamometer driving cycle (FTP 75). Predicted environmental persistence ranged from 15 to 30 days which indicates that EEB is not likely to be a persistent organic pollutant. In combination, these results suggest a high potential for the use of EEB as a renewable fuel source.

Spatial Heterogeneity in Human Activities Favors the Persistence of Wolves in Agroecosystems

PubMed Central

Ahmadi, Mohsen; López-Bao, José Vicente; Kaboli, Mohammad

2014-01-01

As human populations expand, there is increasing demand and pressure for land. Under this scenario, behavioural flexibility and adaptation become important processes leading to the persistence of large carnivores in human-dominated landscapes such as agroecosystems. A growing interest has recently emerged on the outcome of the coexistence between wolves and humans in these systems. It has been suggested that spatial heterogeneity in human activities would be a major environmental factor modulating vulnerability and persistence of this contentious species in agroecosystems. Here, we combined information from 35 den sites detected between 2011 and 2012 in agroecosystems of western Iran (Hamedan province), a set of environmental variables measured at landscape and fine spatial scales, and generalized linear models to identify patterns of den site selection by wolves in a highly-modified agroecosystem. On a landscape level, wolves selected a mixture of rangelands with scattered dry-farms on hillsides (showing a low human use) to locate their dens, avoiding areas with high densities of settlements and primary roads. On a fine spatial scale, wolves primarily excavated dens into the sides of elevated steep-slope hills with availability of water bodies in the vicinity of den sites, and wolves were relegated to dig in places with coarse-soil particles. Our results suggest that vulnerability of wolves in human-dominated landscapes could be compensated by the existence of spatial heterogeneity in human activities. Such heterogeneity would favor wolf persistence in agroecosystems favoring a land sharing model of coexistence between wolves and people. PMID:25251567

Evidence for high salinity of Early Cretaceous sea water from the Chesapeake Bay crater.

PubMed

Sanford, Ward E; Doughten, Michael W; Coplen, Tyler B; Hunt, Andrew G; Bullen, Thomas D

2013-11-14

High-salinity groundwater more than 1,000 metres deep in the Atlantic coastal plain of the USA has been documented in several locations, most recently within the 35-million-year-old Chesapeake Bay impact crater. Suggestions for the origin of increased salinity in the crater have included evaporite dissolution, osmosis and evaporation from heating associated with the bolide impact. Here we present chemical, isotopic and physical evidence that together indicate that groundwater in the Chesapeake crater is remnant Early Cretaceous North Atlantic (ECNA) sea water. We find that the sea water is probably 100-145 million years old and that it has an average salinity of about 70 per mil, which is twice that of modern sea water and consistent with the nearly closed ECNA basin. Previous evidence for temperature and salinity levels of ancient oceans have been estimated indirectly from geochemical, isotopic and palaeontological analyses of solid materials in deep sediment cores. In contrast, our study identifies ancient sea water in situ and provides a direct estimate of its age and salinity. Moreover, we suggest that it is likely that remnants of ECNA sea water persist in deep sediments at many locations along the Atlantic margin.

Experimentally derived salinity tolerance of hatchling Burmese pythons (Python molurus bivittatus) from the Everglades, Florida (USA)

USGS Publications Warehouse

Hart, Kristen M.; Schofield, Pamela J.; Gregoire, Denise R.

2012-01-01

In a laboratory setting, we tested the ability of 24 non-native, wild-caught hatchling Burmese pythons (Python molurus bivittatus) collected in the Florida Everglades to survive when given water containing salt to drink. After a one-month acclimation period in the laboratory, we grouped snakes into three treatments, giving them access to water that was fresh (salinity of 0, control), brackish (salinity of 10), or full-strength sea water (salinity of 35). Hatchlings survived about one month at the highest marine salinity and about five months at the brackish-water salinity; no control animals perished during the experiment. These results are indicative of a "worst-case scenario", as in the laboratory we denied access to alternate fresh-water sources that may be accessible in the wild (e.g., through rainfall). Therefore, our results may underestimate the potential of hatchling pythons to persist in saline habitats in the wild. Because of the effect of different salinity regimes on survival, predictions of ultimate geographic expansion by non-native Burmese pythons that consider salt water as barriers to dispersal for pythons may warrant re-evaluation, especially under global climate change and associated sea-level-rise scenarios.

Experimentally derived salinity tolerance of hatchling Burmese pythons (Python molurus bivittatus) from the Everglades, Florida (USA)

USGS Publications Warehouse

Hart, K.M.; Schofield, P.J.; Gregoire, D.R.

2012-01-01

In a laboratory setting, we tested the ability of 24 non-native, wild-caught hatchling Burmese pythons (Python molurus bivittatus) collected in the Florida Everglades to survive when given water containing salt to drink. After a one-month acclimation period in the laboratory, we grouped snakes into three treatments, giving them access to water that was fresh (salinity of 0, control), brackish (salinity of 10), or full-strength sea water (salinity of 35). Hatchlings survived about one month at the highest marine salinity and about five months at the brackish-water salinity; no control animals perished during the experiment. These results are indicative of a "worst-case scenario", as in the laboratory we denied access to alternate fresh-water sources that may be accessible in the wild (e.g., through rainfall). Therefore, our results may underestimate the potential of hatchling pythons to persist in saline habitats in the wild. Because of the effect of different salinity regimes on survival, predictions of ultimate geographic expansion by non-native Burmese pythons that consider salt water as barriers to dispersal for pythons may warrant re-evaluation, especially under global climate change and associated sea-level-rise scenarios. ?? 2011.

Predicting Undergraduates' Persistence in Science, Technology, Engineering, and Math Fields

NASA Astrophysics Data System (ADS)

Koch, Amanda Joy

A national shortage of workers in Science, Technology, Engineering, and Math (STEM) occupations has led to efforts to identify why people leave these fields. Lower persistence rates in STEM for females than for males have also led to examinations of features that cause females to leave STEM fields. The current study examines individual- and school-level features that influence undergraduate students' decisions to leave STEM majors, focusing on potential explanations for why females are more likely than males to leave. Persistence in STEM was examined in three samples: (a) persistence through the second year of college in a sample of high school seniors interested in STEM majors; (b) persistence through the fourth year of college in a sample of second year undergraduate STEM majors; and (c) persistence through the second, third, and fourth years of college in a sample of high school seniors interested in STEM majors. Differences between persistence in male-dominated and non-male-dominated STEM majors were also examined. In all samples, gender differences were found for most individual-level predictors, with males tending to score higher than females on measures such as SAT-Math, self-rated STEM ability, and high school extracurricular activities and awards in STEM. On the other hand, females earned better high school grades and had stronger relative non-STEM ability and achievement than males. Bivariate analyses indicated that those who persisted in STEM majors typically had higher scores than those who did not persist for SAT-Math, high school achievement, STEM course taking, undergraduate STEM grades, self-rated STEM ability, interest in STEM, extracurricular activities and awards in STEM, degree goals, and socioeconomic status. Multivariate analyses identified SAT-Math as one of the best predictors of persistence in high school samples, and undergraduate STEM GPA was one of the best predictors in the samples of second year undergraduates. In several samples, a significant cross-level interaction was found between gender and undergraduate females' college-level proportional representation in STEM; however, the effects were inconsistent across samples. Even when controlling for various individual- and school-level predictors, gender effects tended to remain significant, with females in most samples leaving STEM majors at higher rates than males.

Persistence and elimination of human norovirus in food and on food contact surfaces: a critical review

USDA-ARS?s Scientific Manuscript database

This critical review addresses the persistence of human norovirus (NoV) in water, shellfish, processed meats, soils and organic wastes; on berries, herbs, vegetables, fruits and salads; and on food contact surfaces. The review focuses on studies using NoV; information from studies involving only su...

Persistent effects of a severe drought on Amazonian forest canopy.

PubMed

Saatchi, Sassan; Asefi-Najafabady, Salvi; Malhi, Yadvinder; Aragão, Luiz E O C; Anderson, Liana O; Myneni, Ranga B; Nemani, Ramakrishna

2013-01-08

Recent Amazonian droughts have drawn attention to the vulnerability of tropical forests to climate perturbations. Satellite and in situ observations have shown an increase in fire occurrence during drought years and tree mortality following severe droughts, but to date there has been no assessment of long-term impacts of these droughts across landscapes in Amazonia. Here, we use satellite microwave observations of rainfall and canopy backscatter to show that more than 70 million hectares of forest in western Amazonia experienced a strong water deficit during the dry season of 2005 and a closely corresponding decline in canopy structure and moisture. Remarkably, and despite the gradual recovery in total rainfall in subsequent years, the decrease in canopy backscatter persisted until the next major drought, in 2010. The decline in backscatter is attributed to changes in structure and water content associated with the forest upper canopy. The persistence of low backscatter supports the slow recovery (>4 y) of forest canopy structure after the severe drought in 2005. The result suggests that the occurrence of droughts in Amazonia at 5-10 y frequency may lead to persistent alteration of the forest canopy.

Groundwater, Vegetation, and Atmosphere: Comparative Riparian Evapotranspiration, Restoration, and Water Salvage

Treesearch

J. R. Cleverly; C. N. Dahm; J. R. Thibault; D. McDonnell; J. E. Allred Coonrod

2006-01-01

As water shortages persist throughout the Western U.S., a great deal of money and effort is directed toward decreasing riparian water loss, thereby enabling continued water use by irrigators, industry, and municipalities. This study focuses upon long-term measurement of evapotranspiration (ET) by native and non-native riparian species along the Middle Rio Grande (MRG)...

Reductive Dehalogenation of Organic Contaminants in Soils and Ground Water

EPA Pesticide Factsheets

Reductive dehalogenation is a process which may prove to be of paramount importance in dealing with a particularly persistent class of contaminants often found in soil and ground water at superfund sites.

Experimental evidence of nitrogen control on pCO(2) in phosphorus-enriched humic and clear coastal lagoon waters.

PubMed

Peixoto, Roberta B; Marotta, Humberto; Enrich-Prast, Alex

2013-01-01

Natural and human-induced controls on carbon dioxide (CO(2)) in tropical waters may be very dynamic (over time and among or within ecosystems) considering the potential role of warmer temperatures intensifying metabolic responses and playing a direct role on the balance between photosynthesis and respiration. The high magnitude of biological processes at low latitudes following eutrophication by nitrogen (N) and phosphorus (P) inputs into coastal lagoons waters may be a relevant component of the carbon cycle, showing controls on partial pressure of CO(2) (pCO(2)) that are still poorly understood. Here we assessed the strength of N control on pCO(2) in P-enriched humic and clear coastal lagoons waters, using four experimental treatments in microcosms: control (no additional nutrients) and three levels of N additions coupled to P enrichments. In humic coastal lagoons waters, a persistent CO(2) supersaturation was reported in controls and all nutrient-enriched treatments, ranging from 24- to 4-fold the atmospheric equilibrium value. However, both humic and clear coastal lagoons waters only showed significant decreases in pCO(2) in relation to the controlled microcosms in the two treatments with higher N addition levels. Additionally, clear coastal lagoons water microcosms showed a shift from CO(2) sources to CO(2) sinks, in relation to the atmosphere. Only in the two more N-enriched treatments did pCO(2) substantially decrease, from 650 µatm in controls and less N-enriched treatments to 10 µatm in more N-enriched microcosms. Humic substrates and N inputs can modulate pCO(2) even in P-enriched coastal lagoons waters, thereby being important drivers on CO(2) outgassing from inland waters.

Experimental evidence of nitrogen control on pCO2 in phosphorus-enriched humic and clear coastal lagoon waters

PubMed Central

Peixoto, Roberta B.; Marotta, Humberto; Enrich-Prast, Alex

2013-01-01

Natural and human-induced controls on carbon dioxide (CO2) in tropical waters may be very dynamic (over time and among or within ecosystems) considering the potential role of warmer temperatures intensifying metabolic responses and playing a direct role on the balance between photosynthesis and respiration. The high magnitude of biological processes at low latitudes following eutrophication by nitrogen (N) and phosphorus (P) inputs into coastal lagoons waters may be a relevant component of the carbon cycle, showing controls on partial pressure of CO2 (pCO2) that are still poorly understood. Here we assessed the strength of N control on pCO2 in P-enriched humic and clear coastal lagoons waters, using four experimental treatments in microcosms: control (no additional nutrients) and three levels of N additions coupled to P enrichments. In humic coastal lagoons waters, a persistent CO2 supersaturation was reported in controls and all nutrient-enriched treatments, ranging from 24- to 4-fold the atmospheric equilibrium value. However, both humic and clear coastal lagoons waters only showed significant decreases in pCO2 in relation to the controlled microcosms in the two treatments with higher N addition levels. Additionally, clear coastal lagoons water microcosms showed a shift from CO2 sources to CO2 sinks, in relation to the atmosphere. Only in the two more N-enriched treatments did pCO2 substantially decrease, from 650 µatm in controls and less N-enriched treatments to 10 µatm in more N-enriched microcosms. Humic substrates and N inputs can modulate pCO2 even in P-enriched coastal lagoons waters, thereby being important drivers on CO2 outgassing from inland waters. PMID:23390422

Occurrence and distribution of pesticide compounds in surface water of the Santa Ana basin, California, 1998-2001

USGS Publications Warehouse

Kent, Robert; Belitz, Kenneth; Altmann, Andrea J.; Wright, Michael T.; Mendez, Gregory O.

2005-01-01

A study of the occurrence and distribution of pesticide compounds in surface water of the highly urbanized Santa Ana Basin, California, was done as part of the U.S. Geological Survey's National Water-Quality Assessment Program (NAWQA). One-hundred and forty-eight samples were collected from 23 sites, and analyzed for pesticide compounds during the study period from November 1998 to September 2001. Sixty-six different pesticide compounds were detected at varying frequencies and concentrations, and one or more pesticides were detected in 92 percent of the samples. All pesticide concentrations were below maximum levels permitted in drinking water. However, two compounds-diazinon and diuron-exceeded nonenforceable drinking water health-advisory levels in at least one stream sample, and five compounds exceeded guidelines to protect aquatic life-carbaryl, chlorpyrifos, diazinon, lindane, and malathion. Twenty-two pesticide compounds were detected in at least 25 percent of the samples collected from any one fixed site. These are identified as 'major' pesticide compounds and are emphasized in this report. The degree to which pesticides were used in the basin, as well as their physical-chemical properties, are important explanatory factors in stream pesticide occurrence, and most pesticides probably enter streams with urban runoff. Stormflow substantially increases urban runoff, and storm effects on stream pesticide concentrations sometimes persist for several days or weeks after the storm. Water sources other than urban runoff also deliver pesticide compounds to surface water in the basin. For example, atrazine may enter streams in gaining reaches where ground water carries high loads as a result of historical use in the basin. Also, the data suggest that lindane, and perhaps bromacil, are present in treated wastewater, the predominant source of water to streams in the Santa Ana Basin.

Cumulative inequality and racial disparities in health: private insurance coverage and black/white differences in functional limitations.

PubMed

Kail, Ben Lennox; Taylor, Miles G

2014-09-01

To test different forms of private insurance coverage as mediators for racial disparities in onset, persistent level, and acceleration of functional limitations among Medicare age-eligible Americans. Data come from 7 waves of the Health and Retirement Study (1996-2008). Onset and progression latent growth models were used to estimate racial differences in onset, level, and growth of functional limitations among a sample of 5,755 people aged 65 and older in 1996. Employer-provided insurance, spousal insurance, and market insurance were next added to the model to test how differences in private insurance mediated the racial gap in physical limitations. In baseline models, African Americans had larger persistent level of limitations over time. Although employer-provided, spousal provided, and market insurances were directly associated with lower persistent levels of limitation, only differences in market insurance accounted for the racial disparities in persistent level of limitations. Results suggest private insurance is important for reducing functional limitations, but market insurance is an important mediator of the persistently larger level of limitations observed among African Americans. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Market Anatomy of a Drought: Modeling Barge and Corn Market Adaptation to Reduced Rainfall and Low Mississippi River Water Levels During the 2012 Midwestern U.S. Drought

NASA Astrophysics Data System (ADS)

Foster, B.; Characklis, G. W.; Thurman, W. N.

2015-12-01

In mid 2012, a severe drought swept across the Midwest, the heartland of corn production in the U.S. When the drought persisted into late Fall, corn markets were affected in two distinct ways: (1) reduced rainfall led to projected and actual corn yields that were lower than expected and (2) navigation restrictions, a result of low water levels on the Mississippi River, disrupted barge transportation, the most common and inexpensive mode for moving corn to many markets. Both (1) and (2) led to significant financial losses, but due to the complexity of the economic system and the coincidence of two different market impacts, the size of the role that low water levels played wass unclear. This is important, as losses related to low water levels are used to justify substantial investments in dredging activities on the Mississippi River. An "engineering" model of the system, suggests that low water levels should drive large increases in barge and corn prices, while some econometric models suggest that water levels explain very little of the changes in barge rates and corn prices. Employing a model that integrates both the engineering and economic elements of the system indicates that corn prices and barge rates during the drought display spatial and temporal behavior that is difficult to explain using either the engineering or econometric models alone. This integrated model accounts for geographic and temporal variations in drought impacts and identifies unique market responses to four different sets of conditions over the drought's length. Results illustrate that corn and barge price responses during the drought were a product of comingled, but distinct, reactions to both supply changes and navigation disruptions. Results also provide a more structured description of how the economic system that governs corn allocation interacts with the Mississippi River system during drought. As both public and private parties discuss potential managerial or infrastructural methods for keeping shipping channels open during drought, the results of this work should help them to decide how different interventions might benefit or hurt barge operators and/or corn sellers.

Monitoring Coastal Marshes for Persistent Flooding and Salinity Stress

NASA Technical Reports Server (NTRS)

Kalcic, Maria

2010-01-01

Our objective is to provide NASA remote sensing products that provide inundation and salinity information on an ecosystem level to support habitat switching models. Project born out of need by the Coastal Restoration Monitoring System (CRMS), joint effort by Louisiana Department of Natural Resources and the U.S. Geological Survey, for information on persistence of flooding by storm surge and other flood waters. The results of the this work support the habitat-switching modules in the Coastal Louisiana Ecosystem Assessment and Restoration (CLEAR) model, which provides scientific evaluation for restoration management. CLEAR is a collaborative effort between the Louisiana Board of Regents, the Louisiana Department of Natural Resources (LDNR), the U.S. Geological Survey (USGS), and the U.S. Army Corps of Engineers (USACE). Anticipated results will use: a) Resolution enhanced time series data combining spatial resolution of Landsat with temporal resolution of MODIS for inundation estimates. b) Potential salinity products from radar and multispectral modeling. c) Combined inundation and salinity inputs to habitat switching module to produce habitat switching maps (shown at left)

Impact of prolonged storm activity on the Ecological Status of intertidal benthic habitats within oyster (Crassostrea gigas) trestle cultivation sites.

PubMed

O'Carroll, Jack P J; Quinn, Christina; Forde, James; Patterson, Adrian; O'Beirn, Francis X; Kennedy, Robert

2016-09-15

The Ecological Status (ES; sensu the Water Framework Directive) of intertidal benthic communities within six oyster trestle cultivation sites was found to be negatively impacted along the access routes to trestles in a 2013 study. All cultivation sites occur within Natura 2000 sites. The current study revisited four of the 2013 cultivation sites in February 2014 one month after the storm activity of winter 2013/14 to test if the compaction effect along access routes persisted after the storms. Three levels of the fixed factor treatment were sampled; immediately below the trestles, along the access route and 300m away from any anthropogenic activity. The compaction effect at the Access treatment persisted in spite of the major storm activity. The current study showed the IQI to be effective for assessing the impacts of aquaculture and highlights the IQI as a tool for monitoring Conservation Status of intertidal communities under the Habitats Directive. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fluoroacetate content of some species of the toxic Australian plant genus, Gastrolobium, and its environmental persistence.

PubMed

Twigg, L E; King, D R; Bowen, L H; Wright, G R; Eason, C T

1996-01-01

Gas chromatography confirmed the relatively high concentrations of fluoroacetate found in toxic Gastrolobiums, a genus of indigenous Australian plants. Fluoroacetate concentration in these plants ranged from 0.1 to 3875 micrograms/g (ppm) dry weight, with young leaves and flowers containing the highest concentrations. However, there was considerable intrastand variation between individual plants of at least two species with coefficients of variation ranging from 94% to 129%. Despite the high concentrations of fluoroacetate in many species, only one of nine soil samples collected from beneath these plants contained fluoroacetate. None of the 16 water samples collected from nearby streams and catchment dams contained fluoroacetate. This suggests that fluoroacetate does not persist in this environment. Fluoroacetate was also found in the genus Nemcia, and very low levels of fluoroacetate (ng/g) were detected in the foodstuffs, tea and guar gum. The latter indicates that other plant species may produce biologically insignificant amounts of fluoroacetate.

THE PERSISTENCE OF MYCOBACTERIUM AVIUM IN A DRINKING WATER SYSTEM AFTER THE ADDITION OF FILTRATION

EPA Science Inventory

Drinking water is increasingly recognized as a major source of pathogenic nontuberculous mycobacteria (NTM) associated with human infection. Our goal was to determine if the prevalence of NTM would decrease after the addition of filtration treatment to an unfiltered surface water...

Impact of Oxidant Residuals on Ground Water Samples at ISCO Sites: Recommended Guidelines for Sample Preservation

EPA Science Inventory

In-situ chemical oxidation (ISCO) involves the introduction of a chemical oxidant into the subsurface for the purpose of transforming ground water contaminants into less toxic or harmless byproducts. Due to oxidant persistence, ground water samples collected at hazardous waste si...

Irrigated agriculture with limited water supply:Tools for understanding and managing irrigation and crop water use efficiencies

USDA-ARS?s Scientific Manuscript database

Water availability for irrigated agriculture is declining in both China and the United States due to increased use for power generation, municipalities, industries and environmental protection. Persistent droughts have exacerbated the situation, leading to increases in irrigated area as farmers atte...

Ground Water Sampling at ISCO Sites - Residual Oxidant Impact on Sample Quality and Sample Preservation Guideline

EPA Science Inventory

In-situ chemical oxidation (ISCO) involves the delivery of a chemical oxidant into the subsurface where oxidative reactions transform ground water contaminants into less toxic or harmless byproducts. Due to oxidant persistence, ground water samples collected at hazardous waste si...

Warming combined with more extreme precipitation regimes modifies the water sources used by trees

DOE PAGES

Grossiord, Charlotte; Sevanto, Sanna; Dawson, Todd E.; ...

2016-09-09

The persistence of vegetation under climate change will depend on a plant's capacity to exploit water resources. In addition, we analyzed water source dynamics in piñon pine and juniper trees subjected to precipitation reduction, atmospheric warming, and to both simultaneously.

Preferential colonization and release of Legionella pneumophila from mature drinking water biofilms grown on copper versus unplasticized polyvinylchloride coupons

EPA Science Inventory

Legionella persistence and amplification in premise drinking water systems is a known contributor to legionellosis outbreaks, especially in the presence of suitable eukaryotic hosts. Here we examined Legionella pneumophila behavior within drinking water biofilms grown on copper ...

Multi-scale Landscape Factors Influencing Stream Water Quality in the State of Oregon

EPA Science Inventory

Enterococci bacteria are used to indicate the presence of human and/or animal fecal materials in surface water. In addition to human influences on the quality of surface water, a cattle grazing is a widespread and persistent ecological stressor in the Western United States. Cattl...

Warming combined with more extreme precipitation regimes modifies the water sources used by trees

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

Grossiord, Charlotte; Sevanto, Sanna; Dawson, Todd E.

The persistence of vegetation under climate change will depend on a plant's capacity to exploit water resources. In addition, we analyzed water source dynamics in piñon pine and juniper trees subjected to precipitation reduction, atmospheric warming, and to both simultaneously.

Multimatrix measurement of persistent organic pollutants in Mar Chiquita, a continental saline shallow lake.

PubMed

Ballesteros, M L; Miglioranza, K S B; Gonzalez, M; Fillmann, G; Wunderlin, D A; Bistoni, M A

2014-08-15

RAMSAR sites are determined by specific characteristics of the environment in terms of ecological productivity as well services for human development, but they are also one of the most threatened ecosystems. Thus, the objective of this work was to evaluate the dynamic of Persistent Organic Pollutants (POPs) in different biotic and abiotic matrixes of the RAMSAR site (wetlands with international importance), Mar Chiquita Lake. Sampling was performed according to land use (agricultural, urban, and industrial) at two stations: Laguna del Plata and Campo Mare. POPs were analyzed in superficial water (Sw), suspended particulate material (SPM), bottom sediment (Bs) and fish tissues (Odontesthes bonariensis). Organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) were analyzed by GC-ECD. HCHs, Endosulfans, DDTs, PCBs and PBDEs were found in all matrixes at both stations. The high persistence and transport processes are responsible for the occurrence of HCHs, DDTs and PCBs in Bs, SPM and fish tissues, even many years after their prohibition. PBDEs showed lower levels according to the scarcity of punctual sources in the area. Endosulfan showed variable amounts in agreement with application periods since this pesticide was used until a few years ago in this area. Finally, PCB levels overpassed the acceptable daily intake for human consumption being a risk for human health Thus, the present report confirms the occurrence of POPs in Mar Chiquita lake, alerting on the contribution of agricultural and urban pollutants in a RAMSAR site. Current results also raise concerns on biomagnification processes through the food web. Copyright © 2014 Elsevier B.V. All rights reserved.

Extracellular fluid volume expansion and third space sequestration at the site of small bowel anastomoses.

PubMed

Chan, S T; Kapadia, C R; Johnson, A W; Radcliffe, A G; Dudley, H A

1983-01-01

Intestinal surgery is usually associated with the parenteral administration of sodium and water, sometimes in amounts considerably in excess of excretory capacity. We have studied the effect of this situation on the water content of the gut at and 5 cm from a single-layer end-to-end anastomosis in the rabbit. Water content was measured by desiccation. One group of animals (group 1) did not receive intravenous therapy. The second group (group 2) received 5 ml kg-1 h-1 of Hartmann's solution during the operative period and thereafter to a total volume of 200 ml by 48 h. In group 1 there was a 5-10 per cent increase in tissue weight both at the anastomotic site and at 5 cm (P less than 0.01, Mann-Whitney U test) on the first 3 days. Thereafter, water content at the anastomosis persisted, but resolved in normal gut. In group 2 a further 5 per cent increase in weight over group 1 occurred (P less than 0.01), persistent at the anastomotic site over 5 days, though resolving elsewhere after 2 days. Extracellular fluid volume expansion exaggerates an anatomical third space present in the region of an anastomosis. At the suture line, oedema so induced is persistent and could be deleterious.

Rainfall runoff modelling of the Upper Ganga and Brahmaputra basins using PERSiST.

PubMed

Futter, M N; Whitehead, P G; Sarkar, S; Rodda, H; Crossman, J

2015-06-01

There are ongoing discussions about the appropriate level of complexity and sources of uncertainty in rainfall runoff models. Simulations for operational hydrology, flood forecasting or nutrient transport all warrant different levels of complexity in the modelling approach. More complex model structures are appropriate for simulations of land-cover dependent nutrient transport while more parsimonious model structures may be adequate for runoff simulation. The appropriate level of complexity is also dependent on data availability. Here, we use PERSiST; a simple, semi-distributed dynamic rainfall-runoff modelling toolkit to simulate flows in the Upper Ganges and Brahmaputra rivers. We present two sets of simulations driven by single time series of daily precipitation and temperature using simple (A) and complex (B) model structures based on uniform and hydrochemically relevant land covers respectively. Models were compared based on ensembles of Bayesian Information Criterion (BIC) statistics. Equifinality was observed for parameters but not for model structures. Model performance was better for the more complex (B) structural representations than for parsimonious model structures. The results show that structural uncertainty is more important than parameter uncertainty. The ensembles of BIC statistics suggested that neither structural representation was preferable in a statistical sense. Simulations presented here confirm that relatively simple models with limited data requirements can be used to credibly simulate flows and water balance components needed for nutrient flux modelling in large, data-poor basins.

Contact-dependent growth inhibition induces high levels of antibiotic-tolerant persister cells in clonal bacterial populations.

PubMed

Ghosh, Anirban; Baltekin, Özden; Wäneskog, Marcus; Elkhalifa, Dina; Hammarlöf, Disa L; Elf, Johan; Koskiniemi, Sanna

2018-05-02

Bacterial populations can use bet-hedging strategies to cope with rapidly changing environments. One example is non-growing cells in clonal bacterial populations that are able to persist antibiotic treatment. Previous studies suggest that persisters arise in bacterial populations either stochastically through variation in levels of global signalling molecules between individual cells, or in response to various stresses. Here, we show that toxins used in contact-dependent growth inhibition (CDI) create persisters upon direct contact with cells lacking sufficient levels of CdiI immunity protein, which would otherwise bind to and neutralize toxin activity. CDI-mediated persisters form through a feedforward cycle where the toxic activity of the CdiA toxin increases cellular (p)ppGpp levels, which results in Lon-mediated degradation of the immunity protein and more free toxin. Thus, CDI systems mediate a population density-dependent bet-hedging strategy, where the fraction of non-growing cells is increased only when there are many cells of the same genotype. This may be one of the mechanisms of how CDI systems increase the fitness of their hosts. © 2018 The Authors.

Unscrambling Egg Allergy: The Diagnostic Value of Specific IgE Concentrations and Skin Prick Tests for Ovomucoid and Egg White in the Management of Children with Hen's Egg Allergy.

PubMed

Marriage, D E; Erlewyn-Lajeunesse, M; Unsworth, D J; Henderson, A J

2012-01-01

Resolution of egg allergy occurs in the majority of egg allergic children. Positive specific IgE antibodies to ovomucoid (OVM) have been suggested to be of greater predictive value for persistent egg allergy than specific IgE to egg white. The performance of OVM-specific IgE antibody levels in a cohort of children referred for a routine egg challenge was compared with egg white specific IgE levels in predicting a positive egg challenge. 24/47 subjects had persistent egg allergy. Receiver operating characteristic analysis showed that OVM-specific IgE testing was the most useful test for the diagnosis of persistent egg allergy. The optimal decision points for the prediction of persistent egg allergy were >0.35 kUA/L for specific IgE levels to both EW and OVM, and ≥3 mm for SPT. Children with specific IgE levels suggestive of persistent egg allergy need not be subject to an egg provocation challenge, reducing both costs and risks to the child.

Distribution of the Luminous Bacterium Beneckea harveyi in a Semitropical Estuarine Environment

PubMed Central

O'Brien, Catherine H.; Sizemore, Ronald K.

1979-01-01

Bioluminescent bacteria were found in the water column, sediment, shrimp, and gastrointestinal tract of marine fishes from the semitropical estuarine environment of the East Lagoon, Galveston Island, Tex. Populations in the water column decreased during cold weather while sedimentary populations persisted. The highest percentages of luminous organisms were isolated from the gastrointestinal tract of marine fishes, where they persisted during 5 days of starvation. The presence of chitin temporarily increased intestinal populations. All isolates were Beneckea harveyi, whose natural habitat appears to be the gut of fishes and whose free-living reservoir appears to be marine sediments. PMID:16345465

The occurrence of pharmaceuticals, personal care products, endocrine disruptors and illicit drugs in surface water in South Wales, UK.

PubMed

Kasprzyk-Hordern, Barbara; Dinsdale, Richard M; Guwy, Alan J

2008-07-01

The presence and fate of 56 pharmaceuticals, personal care products, endocrine disruptors and illicit drugs (PPCPs) were investigated in the South Wales region of the UK. Two contrasting rivers: River Taff and River Ely were chosen for this investigation and were monitored for a period of 10 months. The impact of the factors affecting the levels of concentration of PPCPs and illicit drugs in surface water such as surrounding area, proximity to wastewater effluent and weather conditions, mainly rainfall was also investigated. Most PPCPs were frequently found in river water at concentrations reaching single microgL(-1) and their levels depended mainly on the extent of water dilution resulting from rainfall. Discharge of treated wastewater effluent into the river course was found to be the main cause of water contamination with PPCPs. The most frequently detected PPCPs represent the group of pharmaceuticals dispensed at the highest levels in the Welsh community. These were antibacterial drugs (trimethoprim, erythromycin-H(2)O and amoxicillin), anti-inflammatories/analgesics (paracetamol, tramadol, codeine, naproxen, ibuprofen and diclofenac) and antiepileptic drugs (carbamazepine and gabapentin). Only four PPCPs out of 56 (simvastatin, pravastatin, digoxin and digoxigenin) were not quantified over the course of the study. Several PPCPs were found to be both ubiquitous and persistent in the aqueous environment (e.g. erythromycin-H(2)O, codeine, carbamazepine, gabapentin and valsartan). The calculated average daily loads of PPCPs indicated that in total almost 6 kg of studied PPCPs are discharged daily into the studied rivers. The illicit drugs studied were found in rivers at low levels of ng L(-1). Average daily loads of amphetamine, cocaine and its main metabolite benzoylecgonine were as follows: 8, 1.2 and 39 gday(-1), respectively. Their frequent occurrence in surface water is primarily associated with their high illegal usage and is strongly associated with the discharge of insufficiently treated wastewater effluent.

Children's Blood Lead Seasonality in Flint, Michigan (USA), and Soil-Sourced Lead Hazard Risks.

PubMed

Laidlaw, Mark A S; Filippelli, Gabriel M; Sadler, Richard C; Gonzales, Christopher R; Ball, Andrew S; Mielke, Howard W

2016-03-25

In Flint; MI; USA; a public health crisis resulted from the switching of the water supply from Lake Huron to a more corrosive source from the Flint River in April 2014; which caused lead to leach from water lines. Between 2010 and 2015; Flint area children's average blood lead patterns display consistent peaks in the third quarter of the year. The third quarter blood lead peaks displayed a declining trend between 2010 and 2013; then rose abruptly between the third quarters of 2013 from 3.6% blood lead levels ≥5 µg/dL to a peak of about 7% in the third quarter of 2014; an increase of approximately 50%. The percentage of blood lead level ≥5 µg/dL in the first quarter of 2015 then dropped to 2.3%; which was the same percentage as the first quarter of 2014 (prior to the Flint River water source change). The Flint quarterly blood lead level peak then rose to about 6% blood lead levels ≥ 5 µg/dL in the third quarter of 2015; and then declined to about 2.5% in the fourth quarter of 2015. Soil lead data collected by Edible Flint food collaborative reveal generally higher soil lead values in the metropolitan center for Flint; with lower values in the outskirts of the city. The questions that are not being asked is why did children's blood lead levels display a seasonal blood lead pattern before the introduction of the new water supply in Flint; and what are the implications of these seasonal blood lead patterns? Based upon previous findings in Detroit and other North American cities we infer that resuspension to the air of lead in the form of dust from lead contaminated soils in Flint appears to be a persistent contribution to lead exposure of Flint children even before the change in the water supply from Lake Huron to the Flint River.

Exertional rhabdomyolysis in a collegiate american football player after preventive cold-water immersion: a case report.

PubMed

Kahanov, Leamor; Eberman, Lindsey E; Wasik, Mitchell; Alvey, Thurman

2012-01-01

To describe a case of exertional rhabdomyolysis in a collegiate American football player after preventive coldwater immersion. A healthy man (19 years old) participated in full-contact football practice followed by conditioning (2.5 hours). After practice, he entered a coach-mandated postpractice cold-water immersion and had no signs of heat illness before developing leg cramps, for which he presented to the athletic training staff. After 10 minutes of repeated stretching, massage, and replacement of electrolyte-filled fluids, he was transported to the emergency room. Laboratory tests indicated a creatine kinase (CK) level of 2545 IU/L (normal range, 45-260 IU/L), CK-myoglobin fraction of 8.5 ng/mL (normal < 6.7 ng/mL), and CK-myoglobin relative index of 30% (normal range, 25%-30%). Myoglobin was measured at 499 ng/mL (normal = 80 ng/mL). The attending physician treated the athlete with intravenous fluids. Exercise-associated muscle cramps, dehydration, exertional rhabdomyolysis. The patient was treated with rest and rehydration. One week after the incident, he began biking and swimming. Eighteen days later, the patient continued to demonstrate elevated CK levels (527 IU/L) but described no other symptoms and was allowed to return to football practice as tolerated. Two months after the incident, his CK level remained high (1900 IU/L). The athlete demonstrated no signs of heat illness upon entering the cold-water immersion but experienced severe leg cramping after immersion, resulting in a diagnosis of exertional rhabdomyolysis. Previously described cases have not linked cold-water immersion with the pathogenesis of rhabdomyolysis. In this football player, CK levels appeared to be a poor indicator of rhabdomyolysis. Our patient demonstrated no other signs of the illness weeks after the incident, yet his elevated CK levels persisted. Cold-water immersion immediately after exercise should be monitored by the athletic training staff and may not be appropriate to prevent muscle damage, given the lack of supporting evidence.

Children’s Blood Lead Seasonality in Flint, Michigan (USA), and Soil-Sourced Lead Hazard Risks

PubMed Central

Laidlaw, Mark A.S.; Filippelli, Gabriel M.; Sadler, Richard C.; Gonzales, Christopher R.; Ball, Andrew S.; Mielke, Howard W.

2016-01-01

In Flint; MI; USA; a public health crisis resulted from the switching of the water supply from Lake Huron to a more corrosive source from the Flint River in April 2014; which caused lead to leach from water lines. Between 2010 and 2015; Flint area children’s average blood lead patterns display consistent peaks in the third quarter of the year. The third quarter blood lead peaks displayed a declining trend between 2010 and 2013; then rose abruptly between the third quarters of 2013 from 3.6% blood lead levels ≥5 µg/dL to a peak of about 7% in the third quarter of 2014; an increase of approximately 50%. The percentage of blood lead level ≥5 µg/dL in the first quarter of 2015 then dropped to 2.3%; which was the same percentage as the first quarter of 2014 (prior to the Flint River water source change). The Flint quarterly blood lead level peak then rose to about 6% blood lead levels ≥ 5 µg/dL in the third quarter of 2015; and then declined to about 2.5% in the fourth quarter of 2015. Soil lead data collected by Edible Flint food collaborative reveal generally higher soil lead values in the metropolitan center for Flint; with lower values in the outskirts of the city. The questions that are not being asked is why did children’s blood lead levels display a seasonal blood lead pattern before the introduction of the new water supply in Flint; and what are the implications of these seasonal blood lead patterns? Based upon previous findings in Detroit and other North American cities we infer that resuspension to the air of lead in the form of dust from lead contaminated soils in Flint appears to be a persistent contribution to lead exposure of Flint children even before the change in the water supply from Lake Huron to the Flint River. PMID:27023578

Risk factors for persistent gestational trophoblastic neoplasia.

PubMed

Kuyumcuoglu, Umur; Guzel, Ali Irfan; Erdemoglu, Mahmut; Celik, Yusuf

2011-01-01

This retrospective study evaluated the risk factors for persistent gestational trophoblastic disease (GTN) and determined their odds ratios. This study included 100 cases with GTN admitted to our clinic. Possible risk factors recorded were age, gravidity, parity, size of the neoplasia, and beta-human chorionic gonadotropin levels (beta-hCG) before and after the procedure. Statistical analyses consisted of the independent sample t-test and logistic regression using the statistical package SPSS ver. 15.0 for Windows (SPSS, Chicago, IL, USA). Twenty of the cases had persistent GTN, and the differences between these and the others cases were evaluated. The size of the neoplasia and histopathological type of GTN had no statistical relationship with persistence, whereas age, gravidity, and beta-hCG levels were significant risk factors for persistent GTN (p < 0.05). The odds ratios (95% confidence interval (CI)) for age, gravidity, and pre- and post-evacuation beta-hCG levels determined using logistic regression were 4.678 (0.97-22.44), 7.315 (1.16-46.16), 2.637 (1.41-4.94), and 2.339 (1.52-3.60), respectively. Patient age, gravidity, and beta-hCG levels were risk factors for persistent GTN, whereas the size of the neoplasia and histopathological type of GTN were not significant risk factors.

Directional analysis of CO2 persistence at a rural site.

PubMed

Pérez, Isidro A; Sánchez, M Luisa; García, M Ángeles; Paredes, Vanessa

2011-09-01

Conditional probability was used to establish persistence of CO(2) concentrations at a rural site. Measurements extended over three years and were performed with a CO(2) continuous monitor and a sodar. Concentrations in the usual range at this site were proposed as the truncation level to calculate conditional probability, allowing us to determine the extent of CO(2) sequences. Extension of episodes may be inferred from these values. Persistence of wind directions revealed two groups of sectors, one with a persistence of about 16 h and another of about 9 h. Cumulative distribution of CO(2) was calculated in each wind sector and three groups, associated with different concentration origins, were established. One group was linked to transport and local sources, another to the rural environment, and a third to transport of clean air masses. Daily evolution of concentrations revealed major differences during the night and monthly analysis allowed us to associate group 1 with the vegetation cycle and group 3 with wind speed from December to April. Persistence of concentrations was obtained, and group 3 values were lower for concentrations above the truncation level, whereas persistence of groups 1 and 2 was similar. However, group 3 persistence was, in general, between group 1 and 2 persistence for concentrations below the truncation level. Copyright © 2011 Elsevier B.V. All rights reserved.

Hydrologic response across a snow persistence gradient on the west and east slopes of the Rocky Mountains in Colorado

NASA Astrophysics Data System (ADS)

Richard, G. A.; Hammond, J. C.; Kampf, S. K.; Moore, C. D.; Eurich, A.

2017-12-01

Snowpack trend analyses and modeling studies suggest that lower elevation snowpacks in mountain regions are most sensitive to drought and warming temperatures, however, in Colorado, most snow monitoring occurs in the high elevations where snow lasts throughout the winter and most streamflow monitoring occurs at lower elevations. The lack of combined snow and streamflow monitoring in watersheds along the transition from intermittent to persistent snow creates a gap in our understanding of snowmelt and runoff within the intermittent-persistent snow transition. Expanded hydrologic monitoring that spans the gradient of snow conditions in Colorado can help improve streamflow prediction and inform land and water managers. This study established hydrologic monitoring watersheds in intermittent, transitional, and persistent snow zones on the east slope and west slope of the Rocky Mountains in Colorado, and uses this monitoring network to improve understanding of how snow accumulation and melt affect soil moisture and streamflow generation under different snow conditions. We monitored six small watersheds (three west slope, three east slope) (0.8 to 3.9 km2) that drain intermittent, transitional, and persistent snow zones. At each site, we measured: streamflow, snow depth, soil moisture, precipitation, air temperature, and snow water equivalent (SWE). In our first season of monitoring, the west slope persistent and transitional sites had more mid-winter melt and infiltration, shorter snowpack duration, and lower peak SWE than the east slope sites. Snow cover remained at the east slope persistent site into June, whereas much of the snow at the persistent site on the west slope had already melted by early June. The difference in soil water input likely has consequences for streamflow response that we will continue to examine in future years. At the west slope intermittent site, the stream did not flow during the entire first year of monitoring, while at the east slope intermittent site, the streams flowed intermittently during winter and spring, likely a result of different subsurface geology. With our ongoing watershed monitoring across a broad range of snow conditions in Colorado, we continue to learn about the factors that increase or decrease streamflow in the headwater streams that supply the state's major rivers.

Persistence of Avian Influenza Virus (H5N1) in Feathers Detached from Bodies of Infected Domestic Ducks ▿

PubMed Central

Yamamoto, Yu; Nakamura, Kikuyasu; Yamada, Manabu; Mase, Masaji

2010-01-01

Asian lineage highly pathogenic avian influenza virus (H5N1) continues to cause mortality in poultry and wild bird populations at a panzootic scale. However, little is known about its persistence in contaminated tissues derived from infected birds. We investigated avian influenza virus (H5N1) persistence in feathers detached from bodies of infected ducks to evaluate their potential risk for environmental contamination. Four-week-old domestic ducks were inoculated with different clades of avian influenza virus (H5N1). Feathers, drinking water, and feces were collected on day 3 postinoculation and stored at 4°C or 20°C. Viral persistence in samples was investigated for 360 days by virus isolation and reverse transcription-PCR. Infectious viruses persisted for the longest period in feathers, compared with drinking water and feces, at both 4°C and 20°C. Viral infectivity persisted in the feathers for 160 days at 4°C and for 15 days at 20°C. Viral titers of 104.3 50% egg infectious doses/ml or greater were detected for 120 days in feathers stored at 4°C. Viral RNA in feathers was more stable than the infectivity. These results indicate that feathers detached from domestic ducks infected with highly pathogenic avian influenza virus (H5N1) can be a source of environmental contamination and may function as fomites with high viral loads in the environment. PMID:20581177

Increasing persistency in lay and stabilising egg quality in longer laying cycles. What are the challenges?

PubMed Central

Bain, M. M.; Nys, Y.; Dunn, I.C.

2016-01-01

Abstract In the past 50 years, selection starting initially at the breed level and then using quantitative genetics coupled with a sophisticated breeding pyramid, has resulted in a very productive hybrid for a variety of traits associated with egg production.One major trait currently being developed further is persistency of lay and the concept of the “long life” layer. Persistency in lay however cannot be achieved without due consideration of how to sustain egg quality and the health and welfare of the birds in longer laying cycles. These multiple goals require knowledge and consideration of the bird’s physiology, nutritional requirements, which vary depending on age and management system, reproductive status and choice of the selection criteria applied.The recent advent of molecular genetics offers considerable hope that these multiple elements can be balanced for the good of all in the industry including the hens.The “long life” layer, which will be capable of producing 500 eggs in a laying cycle of 100 weeks, is therefore on the horizon, bringing with it the benefits of a more efficient utilisation of diminishing resources, including land, water, raw materials for feed as well as a reduction in waste, and an overall reduced carbon footprint. PMID:26982003

Increasing persistency in lay and stabilising egg quality in longer laying cycles. What are the challenges?

PubMed

Bain, M M; Nys, Y; Dunn, I C

2016-06-01

In the past 50 years, selection starting initially at the breed level and then using quantitative genetics coupled with a sophisticated breeding pyramid, has resulted in a very productive hybrid for a variety of traits associated with egg production. One major trait currently being developed further is persistency of lay and the concept of the "long life" layer. Persistency in lay however cannot be achieved without due consideration of how to sustain egg quality and the health and welfare of the birds in longer laying cycles. These multiple goals require knowledge and consideration of the bird's physiology, nutritional requirements, which vary depending on age and management system, reproductive status and choice of the selection criteria applied. The recent advent of molecular genetics offers considerable hope that these multiple elements can be balanced for the good of all in the industry including the hens. The "long life" layer, which will be capable of producing 500 eggs in a laying cycle of 100 weeks, is therefore on the horizon, bringing with it the benefits of a more efficient utilisation of diminishing resources, including land, water, raw materials for feed as well as a reduction in waste, and an overall reduced carbon footprint.

Evaluation of immune response following one dose of an AS03A-adjuvanted H1N1 2009 pandemic influenza vaccine in Japanese adults 65 years of age or older.

PubMed

Ikematsu, Hideyuki; Tenjinbaru, Kazuyoshi; Li, Ping; Madan, Anu; Vaughn, David

2012-08-01

This study assessed the immunogenicity, long-term persistence of immune response and safety of a single dose of an A/California/07/2009 H1N1 pandemic influenza vaccine adjuvanted with AS03 (α-tocopherol and squalene based oil-in-water emulsion Adjuvant System) in subjects ≥ 65 y of age (NCT01114620). At Day 21, the HI immune response met all three European guidance criteria [seroconversion rate (SCR): 60.0%; seroprotection rate (SPR): 64.0%; geometric mean fold rise (GMFR): 10.2] and the US guidance criterion for SCR. At month 6, the HI immune response against the A/California/07/2009 H1N1 strain persisted but at levels lower than that observed at Day 21 (SCR: 38.8%; SPR: 42.9%; HI antibody geometric mean titer: 27.6); the European regulatory guidance criteria for SCR and GMFR were still met. Overall, the vaccine was well-tolerated. In this open-label, single group study, 50 subjects received one dose of the 3.75 µg hemagglutinin (HA) AS03-adjuvanted H1N1 2009 vaccine. Immunogenicity assessments were made before vaccination, 21 days and six months after vaccination using hemagglutination inhibition (HI) and microneutralization assays. Immunogenicity end points were based on US and European regulatory criteria. A single dose of the 3.75 µg HA AS03-adjuvanted H1N1 2009 pandemic vaccine induced immune responses against the vaccine strain that met the European regulatory guidance criteria at day 21 in the elderly Japanese population; the immune response persisted at lower levels at month 6. No safety concerns were identified. These results suggest that two vaccine doses might be useful for the elderly population to improve antibody induction and persistence.

Effects of chlorpyrifos in freshwater model ecosystems: the influence of experimental conditions on ecotoxicological thresholds.

PubMed

van Wijngaarden, René P A; Brock, Theo C M; Douglas, Mark T

2005-10-01

Three experiments were conducted to determine the impact of the insecticide chlorpyrifos (single applications of 0.01 to 10 microg AI litre(-1)) in plankton-dominated nutrient-rich microcosms. The microcosms (water volume approximately 14 litres) were established in the laboratory under temperature, light regimes and nutrient levels that simulated cool 'temperate' and warm 'Mediterranean' environmental conditions. The fate of chlorpyrifos in the water column was monitored and the effects on zooplankton, phytoplankton and community metabolism were followed for 4 or 5 weeks. The mean half-life (t1/2) of chlorpyrifos in the water of the test systems was 45 h under 'temperate' conditions and about 30 h under 'Mediterranean' environmental conditions. Microcrustaceans (cladocerans and copepod nauplii) were amongst the most sensitive organisms. All three experiments yielded community NOEC (no observed effect concentrations) of 0.1 microg AI litre(-1), similar to those derived from more complex outdoor studies. Above this threshold level, responses and effect chains, and time spans for recovery, differed between the experiments. For example, algal blooms as an indirect effect from the impact of exposure on grazing organisms were only observed under the 'Mediterranean' experimental conditions. The relatively simple indoor test system seems to be sufficient to provide estimates of safe threshold levels for the acute insecticidal effects of low-persistence compounds such as chlorpyrifos. The robustness of the community NOEC indicates that this threshold level is likely to be representative for many freshwater systems. Copyright (c) 2005 Society of Chemical Industry.

Cyanobacterial flora from polluted industrial effluents.

PubMed

Parikh, Amit; Shah, Vishal; Madamwar, Datta

2006-05-01

Effluents originating from pesticides, agro-chemicals, textile dyes and dyestuffs industries are always associated with high turbidity, colour, nutrient load, and heavy metals, toxic and persistent compounds. But even with such an anthropogenic nature, these effluents contain dynamic cyanobacterial communities. Documentation of cyanobacterial cultures along the water channels of effluents discharged by above mentioned industries along the west coast of India and their relationship with water quality is reported in this study. Intensity of pollution was evaluated by physico-chemical analysis of water. Higher load of solids, carbon and nutrients were found to be persistent throughout the analysis. Sediment and water samples were found to be colored in nature. Cyanobacterial community structure was found to be influenced by the anthropogenic pollution. 40 different cyanobacterial species were recorded from 14 genera of 5 families and an elevated occurrence of Phormidium, Oscillatoria and Chroococcus genera was observed in all the sampling sites.

Rapid Water Transport by Long-Lasting Modon Eddy Pairs in the Southern Midlatitude Oceans

NASA Astrophysics Data System (ADS)

Hughes, Chris W.; Miller, Peter I.

2017-12-01

Water in the ocean is generally carried with the mean flow, mixed by eddies, or transported westward by coherent eddies at speeds close to the long baroclinic Rossby wave speed. Modons (dipole eddy pairs) are a theoretically predicted exception to this behavior, which can carry water to the east or west at speeds much larger than the Rossby wave speed, leading to unusual transports of heat, nutrients, and carbon. We provide the first observational evidence of such rapidly moving modons propagating over large distances. These modons are found in the midlatitude oceans around Australia, with one also seen in the South Atlantic west of the Agulhas region. They can travel at more than 10 times the Rossby wave speed of 1-2 cm s-1 and typically persist for about 6 months carrying their unusual water mass properties with them, before splitting into individual vortices, which can persist for many months longer.

Assimilation of CryoSat-2 altimetry to a hydrodynamic model of the Brahmaputra river

NASA Astrophysics Data System (ADS)

Schneider, Raphael; Nygaard Godiksen, Peter; Ridler, Marc-Etienne; Madsen, Henrik; Bauer-Gottwein, Peter

2016-04-01

Remote sensing provides valuable data for parameterization and updating of hydrological models, for example water level measurements of inland water bodies from satellite radar altimeters. Satellite altimetry data from repeat-orbit missions such as Envisat, ERS or Jason has been used in many studies, also synthetic wide-swath altimetry data as expected from the SWOT mission. This study is one of the first hydrologic applications of altimetry data from a drifting orbit satellite mission, namely CryoSat-2. CryoSat-2 is equipped with the SIRAL instrument, a new type of radar altimeter similar to SRAL on Sentinel-3. CryoSat-2 SARIn level 2 data is used to improve a 1D hydrodynamic model of the Brahmaputra river basin in South Asia set up in the DHI MIKE 11 software. CryoSat-2 water levels were extracted over river masks derived from Landsat imagery. After discharge calibration, simulated water levels were fitted to the CryoSat-2 data along the Assam valley by adapting cross section shapes and datums. The resulting hydrodynamic model shows accurate spatio-temporal representation of water levels, which is a prerequisite for real-time model updating by assimilation of CryoSat-2 altimetry or multi-mission data in general. For this task, a data assimilation framework has been developed and linked with the MIKE 11 model. It is a flexible framework that can assimilate water level data which are arbitrarily distributed in time and space. Different types of error models, data assimilation methods, etc. can easily be used and tested. Furthermore, it is not only possible to update the water level of the hydrodynamic model, but also the states of the rainfall-runoff models providing the forcing of the hydrodynamic model. The setup has been used to assimilate CryoSat-2 observations over the Assam valley for the years 2010 to 2013. Different data assimilation methods and localizations were tested, together with different model error representations. Furthermore, the impact of different filtering and clustering methods and error descriptions of the CryoSat-2 observations was evaluated. Performance improvement in terms of discharge and water level forecast due to the assimilation of satellite altimetry data was then evaluated. The model forecasts were also compared to climatology and persistence forecasts. Using ensemble based filters, the evaluation was done not only based on performance criteria for the central forecast such as root-mean-square error (RMSE) and Nash-Sutcliffe model efficiency (NSE), but also based on sharpness, reliability and continuous ranked probability score (CRPS) of the ensemble of probabilistic forecasts.

Factors Mediating Environmental Biofilm Formation by Legionella pneumophila.

PubMed

Abu Khweek, Arwa; Amer, Amal O

2018-01-01

Legionella pneumophila ( L. pneumophila ) is an opportunistic waterborne pathogen and the causative agent for Legionnaires' disease, which is transmitted to humans via inhalation of contaminated water droplets. The bacterium is able to colonize a variety of man-made water systems such as cooling towers, spas, and dental lines and is widely distributed in multiple niches, including several species of protozoa In addition to survival in planktonic phase, L. pneumophila is able to survive and persist within multi-species biofilms that cover surfaces within water systems. Biofilm formation by L. pneumophila is advantageous for the pathogen as it leads to persistence, spread, resistance to treatments and an increase in virulence of this bacterium. Furthermore, Legionellosis outbreaks have been associated with the presence of L. pneumophila in biofilms, even after the extensive chemical and physical treatments. In the microbial consortium-containing L. pneumophila among other organisms, several factors either positively or negatively regulate the presence and persistence of L. pneumophila in this bacterial community. Biofilm-forming L. pneumophila is of a major importance to public health and have impact on the medical and industrial sectors. Indeed, prevention and removal protocols of L. pneumophila as well as diagnosis and hospitalization of patients infected with this bacteria cost governments billions of dollars. Therefore, understanding the biological and environmental factors that contribute to persistence and physiological adaptation in biofilms can be detrimental to eradicate and prevent the transmission of L. pneumophila . In this review, we focus on various factors that contribute to persistence of L. pneumophila within the biofilm consortium, the advantages that the bacteria gain from surviving in biofilms, genes and gene regulation during biofilm formation and finally challenges related to biofilm resistance to biocides and anti-Legionella treatments.

Low Contribution of PbO 2 -Coated Lead Service Lines to Water Lead Contamination at the Tap

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

Triantafyllidou, Simoni; Schock, Michael R.; DeSantis, Michael K.

2015-02-24

To determine if residential water sampling corroborates the expectation that formation of stable PbO2 coatings on lead service lines (LSLs) provides an effective lead release control strategy, lead profile sampling was evaluated for eight home kitchen taps in three U.S. cities with observed PbO2-coated LSLs (Newport, Rhode Island; Cincinnati and Oakwood, Ohio). After various water standing times, these LSLs typically released similar or lower peak lead levels (1 to 18 μg/L) than the lead levels from the respective kitchen faucets (1 to 130 μg/L), and frequently 50–80% lower than the lead levels typically reported from Pb(II)-coated LSLs in comparable publishedmore » sampling studies. Prolonged stagnation (10–101 h) at the Cincinnati sites produced varying results. One site showed minimal (0–4 μg/L) increase in lead release from the PbO2-coated LSL, and persistence of free chlorine residual. However, the other site showed up to a 3-fold increase proportional to standing time, with essentially full depletion of the chlorine residual. Overall, lead release was consistently much lower than that reported in studies of Pb(II)-coated LSL scales, suggesting that natural formation of PbO2 in LSLs is an effective lead “corrosion” control strategy.« less

The status of pesticide pollution in surface waters (rivers and lakes) of Greece. Part I. Review on occurrence and levels.

PubMed

Konstantinou, Ioannis K; Hela, Dimitra G; Albanis, Triantafyllos A

2006-06-01

This review evaluates and summarizes the results of long-term research projects, monitoring programs and published papers concerning the pollution of surface waters (rivers and lakes) of Greece by pesticides. Pesticide classes mostly detected involve herbicides used extensively in corn, cotton and rice production, organophosphorus insecticides as well as the banned organochlorines insecticides due to their persistence in the aquatic environment. The compounds most frequently detected were atrazine, simazine, alachlor, metolachlor and trifluralin of the herbicides, diazinon, parathion methyl of the insecticides and lindane, endosulfan and aldrin of the organochlorine pesticides. Rivers were found to be more polluted than lakes. The detected concentrations of most pesticides follow a seasonal variation, with maximum values occurring during the late spring and summer period followed by a decrease during winter. Nationwide, in many cases the reported concentrations ranged in low ppb levels. However, elevated concentrations were recorded in areas of high pesticide use and intense agricultural practices. Generally, similar trends and levels of pesticides were found in Greek rivers compared to pesticide contamination in other European rivers. Monitoring of the Greek water resources for pesticide residues must continue, especially in agricultural regions, because the nationwide patterns of pesticide use are constantly changing. Moreover, emphasis should be placed on degradation products not sufficiently studied so far.

Harm avoidance and persistence are associated with somatoform disorder psychopathology: A study in Taiwan.

PubMed

Huang, Wei-Lieh; Chen, Tzu-Ting; Chen, I-Ming; Chang, Li-Ren; Lin, Yu-Hsuan; Liao, Shih-Cheng; Gau, Susan Shur-Fen

2016-05-15

Whether personality features affect the development of somatoform disorders and their psychopathologies is an important issue. Aim of this study was to resolve this issue by comparing indicators of psychopathology and personality features in subjects with somatoform disorders and healthy controls. This study recruited 148 subjects with somatoform disorders and 146 healthy controls. The severity of psychopathology was measured with the Patient Health Questionnaire-15 (PHQ-15), Health Anxiety Questionnaire (HAQ), Beck Depression Inventory-II (BDI-II), and Beck Anxiety Inventory (BAI). The Tridimensional Personality Questionnaire (TPQ) was used to assess personality features. Demographic data, psychopathology indicators, and TPQ scores were compared between groups. Correlation and multivariate linear regression analysis were used to identify the personality dimensions or demographic variables associated with psychopathology. The somatoform group had lower novelty seeking (NS) and reward dependence (RD) and higher harm avoidance (HA) and severity of psychopathologies. Multiple regression analysis revealed that fatigability, persistence, gender, and education level were predictive of PHQ-15; HA, educational level, persistence, and dependence were predictive of HAQ; HA, persistence, education level, and NS were predictive of BDII-II; and fatigability, education level, persistence, and anticipatory worry were predictive of BAI. The development of somatoform disorders was associated with fatigability, age, residence location, education level, and attachment. The limitations include heterogeneity of the diagnosis, the high proportion of undifferentiated somatoform disorder, and the cross-sectional study design. HA/fatigability, persistence, and education level are associated with each type of psychopathology. Fatigability is a powerful predictor of somatoform disorder development. Copyright © 2016. Published by Elsevier B.V.

Water quality of the Little Arkansas River and Equus Beds Aquifer before and concurrent with large-scale artificial recharge, south-central Kansas, 1995-2012

USGS Publications Warehouse

Tappa, Daniel J.; Lanning-Rush, Jennifer L.; Klager, Brian J.; Hansen, Cristi V.; Ziegler, Andrew C.

2015-01-01

Recharge activities at Phase I recharge wells have not resulted in substantial effects on groundwater quality in the area, likely because the total amount of water recharged is relatively small (1 billion gallons) compared to aquifer storage volume (greater than 990 billion gallons in winter 2012). The eastward movement of the Burrton chloride plume is likely being slowed by a line of recharge locations associated with Phase I; however, chloride concentrations in deep groundwater still advanced to less than one half mile from the central part of the study area. Water-quality constituents of concern (major ions, nutrients, trace elements, triazine herbicides, and fecal indicator bacteria) have not increased substantially and are likely more affected by climatological (natural recharge by precipitation) and natural (geochemical oxidation/reduction, metabolic and decay rates) processes than artificial recharge. Arsenic remains a water-quality constituent of concern because of natural and continued persistence of concentrations exceeding the Federal maximum contaminant level of 10 micrograms per liter, especially in the deeper parts of theEquus Beds aquifer.

Brine Spills Associated with Unconventional Oil Development in North Dakota.

PubMed

Lauer, Nancy E; Harkness, Jennifer S; Vengosh, Avner

2016-05-17

The rapid rise of unconventional oil production during the past decade in the Bakken region of North Dakota raises concerns related to water contamination associated with the accidental release of oil and gas wastewater to the environment. Here, we characterize the major and trace element chemistry and isotopic ratios ((87)Sr/(86)Sr, δ(18)O, δ(2)H) of surface waters (n = 29) in areas impacted by oil and gas wastewater spills in the Bakken region of North Dakota. We establish geochemical and isotopic tracers that can identify Bakken brine spills in the environment. In addition to elevated concentrations of dissolved salts (Na, Cl, Br), spill waters also consisted of elevated concentrations of other contaminants (Se, V, Pb, NH4) compared to background waters, and soil and sediment in spill sites had elevated total radium activities ((228)Ra + (226)Ra) relative to background, indicating accumulation of Ra in impacted soil and sediment. We observed that inorganic contamination associated with brine spills in North Dakota is remarkably persistent, with elevated levels of contaminants observed in spills sites up to 4 years following the spill events.

Treatment of 2,4-D, mecoprop, and dicamba using membrane bioreactor technology.

PubMed

Ghoshdastidar, Avik J; Tong, Anthony Z

2013-08-01

Phenoxyacetic and benzoic acid herbicides are widely used agricultural, commercial, and domestic pesticides. As a result of high water solubility, mobility, and persistence, 2,4-dichlorophenoxyacetic acid (2,4-D), methylchlorophenoxypropionic acid (mecoprop), and 3,6-dichloro-2-methoxybenzoic acid (dicamba) have been detected in surface and waste waters across Canada. As current municipal wastewater treatment plants do not specifically address chronic, trace levels of contaminants like pesticides, an urgent need exists for an efficient, environmentally friendly means of breaking down these toxic herbicides. A commercially available herbicide mix, WeedEx, containing 2,4-D, mecoprop, and dicamba, was subjected to treatment using membrane bioreactor (MBR) technology. The three herbicides, in simulated wastewater with a chemical oxygen demand of 745 mg/L, were introduced to the MBR at concentrations ranging from 300 μg/L to 3.5 mg/L. Herbicides and biodegradation products were extracted from MBR effluent using solid-phase extraction followed by detection using high-performance liquid chromatography coupled with mass spectrometry. 2,4-D was reduced by more than 99.0 % within 12 days. Mecoprop and dicamba were more persistent and reduced by 69.0 and 75.4 %, respectively, after 112 days of treatment. Half-lives of 2,4-D, mecoprop and dicamba during the treatment were determined to be 1.9, 10.5, and 28.3 days, respectively. Important water quality parameters of the effluent such as dissolved oxygen, pH, ammonia, chemical oxygen demand, etc. were measured daily. MBR was demonstrated to be an environmentally friendly, compact, and efficient method for the treatment of toxic phenoxyacetic and benzoic acid herbicides.

Chlorophyll catalyse the photo-transformation of carcinogenic benzo[a]pyrene in water

PubMed Central

Luo, Lijuan; Lai, Xueying; Chen, Baowei; Lin, Li; Fang, Ling; Tam, Nora F. Y.; Luan, Tiangang

2015-01-01

Algal blooms cause great damage to water quality and aquaculture. However, this study showed that dead algal cells and chlorophyll could accelerate the photo-transformation of benzo[a]pyrene (BaP), a ubiquitous and persistent pollutant with potently mutagenic and carcinogenic toxicities, under visible light irradiation. Chlorophyll was found to be the major active substance in dead algal cells, and generated a high level of singlet oxygen to catalyse the photo-transformation of BaP. According to various BaP metabolites formed, the degradation mechanism was proposed as that chlorophyll in dead algal cells photo-oxidized BaP to quinones via photocatalytic generation of singlet oxygen. The results provided a good insight into the role of chlorophyll in the photo-transformation of organic contaminants and could be a possible remediation strategy of organic pollutants in natural environment. PMID:26239357

A study of DNA damage in buccal cells of consumers of well- and/or tap-water using the comet assay: Assessment of occupational exposure to genotoxicants.

PubMed

Vazquez Boucard, Celia; Lee-Cruz, Larisa; Mercier, Laurence; Ramírez Orozco, Martín; Serrano Pinto, Vania; Anguiano, Gerardo; Cazares, Linette; Díaz, Daniel

2017-10-01

Because of concerns that natural aquifers in the region of Todos Santos (Baja California Sur, Mexico) might be contaminated by organochlorine pesticides and heavy metals, a case-control study was conducted among consumers and non-consumers of well- and/or tap-water to determine risks to human health. This study was based on a genotoxic evaluation of buccal cells using the Comet assay technique. Levels of DNA damage in the consumers group were significantly higher than those of the control group. However, occupational exposure to genotoxicants showed to be the critical factor rather than water consumption. Taking into account the professions of well- and/or tap-water consumers, agricultural workers exposed directly (those who fumigated) or indirectly (those not involved in fumigating) to agrochemicals showed greater genetic damage than controls. This difference persisted even when age, and whether the person smoked or consumed alcoholic drinks were considered. These factors were not associated with the level of genetic damage observed. Chemical analyses of organochlorine pesticides and heavy metals were carried out to evaluate the water quality of wells, faucets, and surface water of canals consumed by the population and/or used for irrigation. High concentrations of α and β endosulfan were detected in water of surface canals. Although our inventory of agrochemicals employed in the region showed the use of products considered carcinogenic and/or mutagenic, they were not detected by the analytical techniques used. Heavy metals (arsenic, mercury, and lead) were detected in water of some wells used for irrigation and human consumption. Environ. Mol. Mutagen. 58:619-627, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Summary of Hydrologic Conditions in Georgia, 2008

USGS Publications Warehouse

Knaak, Andrew E.; Joiner, John K.; Peck, Michael F.

2009-01-01

The United States Geological Survey (USGS) Georgia Water Science Center (WSC) maintains a long-term hydrologic monitoring network of more than 290 real-time streamgages, more than 170 groundwater wells, and 10 lake and reservoir monitoring stations. One of the many benefits of data collected from this monitoring network is that analysis of the data provides an overview of the hydrologic conditions of rivers, creeks, reservoirs, and aquifers in Georgia. Hydrologic conditions are determined by statistical analysis of data collected during the current water year (WY) and comparison of the results to historical data collected at long-term stations. During the drought that persisted through 2008, the USGS succeeded in verifying and documenting numerous historic low-flow statistics at many streamgages and current water levels in aquifers, lakes, and reservoirs in Georgia. Streamflow data from the 2008 WY indicate that this drought is one of the most severe on record when compared to drought periods of 1950-1957, 1985-1989, and 1999-2002.

The investigation of atmospheric deposition distribution of organochlorine pesticides (OCPs) in Turkey

NASA Astrophysics Data System (ADS)

Cindoruk, S. Sıddık; Tasdemir, Yücel

2014-04-01

Atmospheric deposition is a significant pollution source leading to contamination of remote and clean sites, surface waters and soils. Since persistent organic pollutants (POPs) stay in atmosphere without any degradation, they can be transported and deposited to clean surfaces. Organochlorine pesticides are an important group of POPs which have toxic and harmful effects to living organisms and environment. Therefore, atmospheric deposition levels and characteristics are of importance to determine the pollution quantity of water and soil surfaces in terms of POPs. This study reports the distribution quantities of atmospheric deposition including bulk, dry, wet and air-water exchange of particle and gas phase OCPs as a result of 1-year sampling campaign. Atmospheric deposition distribution showed that the main mechanism for OCPs deposition is wet processes with percentage of 69 of total deposition. OCP compounds' deposition varied according to atmospheric concentration and deposition mechanism. HCH compounds were dominant pesticide species for all deposition mechanisms. HCH deposition constituted the 65% of Σ10OCPs.

Seaweeds and plastic debris can influence the survival of faecal indicator organisms in beach environments.

PubMed

Quilliam, Richard S; Jamieson, Julie; Oliver, David M

2014-07-15

The revised Bathing Water Directive (rBWD) introduces more stringent standards for microbial water quality and promotes more pro-active management of the beach environment through the production of a bathing water profile (BWP). The aim of this study was to determine whether living seaweeds in the littoral zone are colonised by faecal indicator organisms (FIOs), and to quantify the survival dynamics of waterborne Escherichia coli in microcosms containing senescing seaweeds. Living seaweed (Fucus spiralis) was not associated with FIO colonisation, although could be providing a protected environment in the underlying sand. Senescing seaweeds enhanced waterborne E. coli survival compared to plastic debris, with the brown seaweed Laminaria saccharina facilitating greater E. coli persistence than either Chondrus crispus or Ulva lactuca. This has important implications for FIO survival on bathing beaches as the majority of beach-cast biomass is composed of brown seaweeds, which could support significant levels of FIOs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Survival of infectious Poliovirus-1 in river water compared to the persistence of somatic coliphages, thermotolerant coliforms and Poliovirus-1 genome.

PubMed

Skraber, S; Gassilloud, B; Schwartzbrod, L; Gantzer, C

2004-07-01

The microbiological quality of water is currently assessed by search for fecal bacteria indicators. There is, however, a body of knowledge demonstrating that bacterial indicators are less resistant to environmental factors than human pathogenic viruses and therefore underestimate the viral risk. As river water is often used as a resource for drinking water production, it is particularly important to obtain a valid estimation of the health hazard, including specific viral risk. This work was conducted to compare the survival of infectious Poliovirus-1 used as a pathogenic virus model to the persistence of, on the one hand, thermotolerant coliforms commonly used as indicators and on the other hand, to somatic coliphages and Poliovirus-1 genome considered as potential indicators. We studied the behavior of infectious Poliovirus-1 and the three (potential) indicators of viral contamination in river water at three different temperatures (4 degrees C,18 degrees C and 25 degrees C). This experiment was performed twice with river water sampled at two different periods, once in winter and once in summer. Our results showed that the survival of thermotolerant coliforms can be 1.5-fold lower than infectious Poliovirus-1. In contrast, under all our experimental conditions, somatic coliphages and Poliovirus-1 genome persisted longer than infectious Poliovirus-1, surviving, respectively, 2-6-fold and about 2-fold longer than infectious Poliovirus-1. According to our results exclusively based on survival capacity, somatic coliphages and viral genome, unlike thermotolerant coliforms appear to be better indicators of viral contamination in river water. Moreover, the disappearance of viral genome is well-correlated to that one of infectious virus irrespective of the conditions tested.

Plant pathogen-induced water-soaking promotes Salmonella enterica growth on tomato leaves.

PubMed

Potnis, Neha; Colee, James; Jones, Jeffrey B; Barak, Jeri D

2015-12-01

Plant pathogen infection is a critical factor for the persistence of Salmonella enterica on plants. We investigated the mechanisms responsible for the persistence of S. enterica on diseased tomato plants by using four diverse bacterial spot Xanthomonas species that differ in disease severities. Xanthomonas euvesicatoria and X. gardneri infection fostered S. enterica growth, while X. perforans infection did not induce growth but supported the persistence of S. enterica. X. vesicatoria-infected leaves harbored S. enterica populations similar to those on healthy leaves. Growth of S. enterica was associated with extensive water-soaking and necrosis in X. euvesicatoria- and X. gardneri-infected plants. The contribution of water-soaking to the growth of S. enterica was corroborated by an increased growth of populations on water-saturated leaves in the absence of a plant pathogen. S. enterica aggregates were observed with bacterial spot lesions caused by either X. euvesicatoria or X. vesicatoria; however, more S. enterica aggregates formed on X. euvesicatoria-infected leaves as a result of larger lesion sizes per leaf area and extensive water-soaking. Sparsely distributed lesions caused by X. vesicatoria infection do not support the overall growth of S. enterica or aggregates in areas without lesions or water-soaking; S. enterica was observed as single cells and not aggregates. Thus, pathogen-induced water-soaking and necrosis allow S. enterica to replicate and proliferate on tomato leaves. The finding that the pathogen-induced virulence phenotype affects the fate of S. enterica populations in diseased plants suggests that targeting of plant pathogen disease is important in controlling S. enterica populations on plants. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Work factors as predictors of persistent fatigue: a prospective study of nurses' aides.

PubMed

Eriksen, W

2006-06-01

To identify work factors that predict persistent fatigue in nurses' aides. The sample comprised 5547 Norwegian nurses' aides, not on leave when they completed a mailed questionnaire in 1999. Of these, 4645 (83.7%) completed a second questionnaire 15 months later. The outcome measure was the occurrence of persistent fatigue, defined as having felt "usually fatigued" or "always fatigued" in daytime during the previous 14 days. In respondents without persistent fatigue at baseline, medium and high work demands, heavy smoking, being single, and having long term health problems were associated with increased risk of persistent fatigue at follow up. Medium and high rewards for well done work, medium levels of leadership fairness, and regular physical exercise were associated with reduced risk of persistent fatigue at follow up. In respondents with persistent fatigue at baseline, medium and high levels of positive challenges at work, high support from immediate superior, medium feedback about quality of one's work, and changes of work or work tasks that resulted in less heavy work or lower work pace were associated with increased odds of recovery (no persistent fatigue at follow up). Working in a nursing home and being intensely bothered by long term health problems were associated with reduced odds of recovery. High demands and lack of rewards at work may cause persistent fatigue in nurses' aides. Reduction of demands, adequate feedback, and mental stimulation in the form of support and positive challenges may facilitate recovery in those who have persistent fatigue. Leaders in the health services may be in a position to regulate factors that influence the level of fatigue in nurses' aides.

Delayed Noradrenergic Activation in the Dorsal Hippocampus Promotes the Long-Term Persistence of Extinguished Fear

PubMed Central

Chai, Ning; Liu, Jian-Feng; Xue, Yan-Xue; Yang, Chang; Yan, Wei; Wang, Hui-Min; Luo, Yi-Xiao; Shi, Hai-Shui; Wang, Ji-Shi; Bao, Yan-Ping; Meng, Shi-Qiu; Ding, Zeng-Bo; Wang, Xue-Yi; Lu, Lin

2014-01-01

Fear extinction has been extensively studied, but little is known about the molecular processes that underlie the persistence of extinction long-term memory (LTM). We found that microinfusion of norepinephrine (NE) into the CA1 area of the dorsal hippocampus during the early phase (0 h) after extinction enhanced extinction LTM at 2 and 14 days after extinction. Intra-CA1 infusion of NE during the late phase (12 h) after extinction selectively promoted extinction LTM at 14 days after extinction that was blocked by the β-receptor antagonist propranolol, protein kinase A (PKA) inhibitor Rp-cAMPS, and protein synthesis inhibitors anisomycin and emetine. The phosphorylation levels of PKA, cyclic adenosine monophosphate response element-binding protein (CREB), GluR1, and the membrane GluR1 level were increased by NE during the late phase after extinction that was also blocked by propranolol and Rp-cAMPS. These results suggest that the enhancement of extinction LTM persistence induced by NE requires the activation of the β-receptor/PKA/CREB signaling pathway and membrane GluR1 trafficking. Moreover, extinction increased the phosphorylation levels of Erk1/2, CREB, and GluR1, and the membrane GluR1 level during the late phase, and anisomycin/emetine alone disrupted the persistence of extinction LTM, indicating that the persistence of extinction LTM requires late-phase protein synthesis in the CA1. Propranolol and Rp-cAMPS did not completely disrupt the persistence of extinction LTM, suggesting that another β-receptor/PKA-independent mechanism underlies the persistence of extinction LTM. Altogether, our results showed that enhancing hippocampal noradrenergic activity during the late phase after extinction selectively promotes the persistence of extinction LTM. PMID:24553734

Persistence of microbial communities including Pseudomonas aeruginosa in a hospital environment: a potential health hazard

PubMed Central

2014-01-01

Background The persistence of microbial communities and how they change in indoor environments is of immense interest to public health. Moreover, hospital acquired infections are significant contributors to morbidity and mortality. Evidence suggests that, in hospital environments agent transfer between surfaces causes healthcare associated infections in humans, and that surfaces are an important transmission route and may act as a reservoir for some of the pathogens. This study aimed to evaluate the diversity of microorganisms that persist on noncritical equipment and surfaces in a main hospital in Portugal, and are able to grow in selective media for Pseudomonas, and relate them with the presence of Pseudomonas aeruginosa. Results During 2 years, a total of 290 environmental samples were analyzed, in 3 different wards. The percentage of equipment in each ward that showed low contamination level varied between 22% and 38%, and more than 50% of the equipment sampled was highly contaminated. P. aeruginosa was repeatedly isolated from sinks (10 times), from the taps’ biofilm (16 times), and from the showers and bedside tables (two times). Two ERIC clones were isolated more than once. The contamination level of the different taps analyzed showed correlation with the contamination level of the hand gels support, soaps and sinks. Ten different bacteria genera were frequently isolated in the selective media for Pseudomonas. Organisms usually associated with nosocomial infections as Stenotrophomonas maltophilia, Enterococcus feacalis, Serratia nematodiphila were also repeatedly isolated on the same equipment. Conclusions The environment may act as a reservoir for at least some of the pathogens implicated in nosocomial infections. The bacterial contamination level was related to the presence of humidity on the surfaces, and tap water (biofilm) was a point of dispersion of bacterial species, including potentially pathogenic organisms. The materials of the equipment sampled could not be related to the microbial contamination level. The presence of a disinfectant in the isolation medium suggests that the number of microorganism in the environment could be higher and shows the diversity of disinfectant resistant species. The statistical analysis suggests that the presence of bacteria could increase the risk of transmission by hand manipulation. PMID:24885173

Climate change and avian influenza

PubMed Central

Slingenbergh, J.; Xiao, X.

2009-01-01

Summary This paper discusses impacts of climate change on the ecology of avian influenza viruses (AI viruses), which presumably co-evolved with migratory water birds, with virus also persisting outside the host in subarctic water bodies. Climate change would almost certainly alter bird migration, influence the AI virus transmission cycle and directly affect virus survival outside the host. The joint, net effects of these changes are rather unpredictable, but it is likely that AI virus circulation in water bird populations will continue with endless adaptation and evolution. In domestic poultry, too little is known about the direct effect of environmental factors on highly pathogenic avian influenza transmission and persistence to allow inference about the possible effect of climate change. However, possible indirect links through changes in the distribution of duck-crop farming are discussed. PMID:18819672

HITTING THE BULL'S-EYE IN GROUNDWATER SAMPLING

EPA Science Inventory

Many of the commonly-used groundwater sampling techniques and procedures have resulted from methods developed for water supply investigations. These methods have persisted, even though the monitoring goals may have changed from water supply development to contaminant source and ...

DENSE NONAQUEOUS PHASE LIQUIDS -- A WORKSHOP SUMMARY

EPA Science Inventory

site characterization, and, therefore, DNAPL remediation, can be expected. Dense nonaqueous phase liquids (DNAPLs) in the subsurface are long-term sources of ground-water contamination, and may persist for centuries before dissolving completely in adjacent ground water. In respo...

Improved inland water levels from SAR altimetry using novel empirical and physical retrackers

NASA Astrophysics Data System (ADS)

Villadsen, Heidi; Deng, Xiaoli; Andersen, Ole B.; Stenseng, Lars; Nielsen, Karina; Knudsen, Per

2016-06-01

Satellite altimetry has proven a valuable resource of information on river and lake levels where in situ data are sparse or non-existent. In this study several new methods for obtaining stable inland water levels from CryoSat-2 Synthetic Aperture Radar (SAR) altimetry are presented and evaluated. In addition, the possible benefits from combining physical and empirical retrackers are investigated. The retracking methods evaluated in this paper include the physical SAR Altimetry MOde Studies and Applications (SAMOSA3) model, a traditional subwaveform threshold retracker, the proposed Multiple Waveform Persistent Peak (MWaPP) retracker, and a method combining the physical and empirical retrackers. Using a physical SAR waveform retracker over inland water has not been attempted before but shows great promise in this study. The evaluation is performed for two medium-sized lakes (Lake Vänern in Sweden and Lake Okeechobee in Florida), and in the Amazon River in Brazil. Comparing with in situ data shows that using the SAMOSA3 retracker generally provides the lowest root-mean-squared-errors (RMSE), closely followed by the MWaPP retracker. For the empirical retrackers, the RMSE values obtained when comparing with in situ data in Lake Vänern and Lake Okeechobee are in the order of 2-5 cm for well-behaved waveforms. Combining the physical and empirical retrackers did not offer significantly improved mean track standard deviations or RMSEs. Based on these studies, it is suggested that future SAR derived water levels are obtained using the SAMOSA3 retracker whenever information about other physical properties apart from range is desired. Otherwise we suggest using the empirical MWaPP retracker described in this paper, which is both easy to implement, computationally efficient, and gives a height estimate for even the most contaminated waveforms.

Can mercury in fish be reduced by water level management? Evaluating the effects of water level fluctuation on mercury accumulation in yellow perch (Perca flavescens)

USGS Publications Warehouse

Larson, James H.; Maki, Ryan P.; Knights, Brent C.; Gray, Brian R.

2014-01-01

Mercury (Hg) contamination of fisheries is a major concern for resource managers of many temperate lakes. Anthropogenic Hg contamination is largely derived from atmospheric deposition within a lake’s watershed, but its incorporation into the food web is facilitated by bacterial activity in sediments. Temporal variation in Hg content of fish (young-of-year yellow perch) in the regulated lakes of the Rainy–Namakan complex (on the border of the United States and Canada) has been linked to water level (WL) fluctuations, presumably through variation in sediment inundation. As a result, Hg contamination of fish has been linked to international regulations of WL fluctuation. Here we assess the relationship between WL fluctuations and fish Hg content using a 10-year dataset covering six lakes. Within-year WL rise did not appear in strongly supported models of fish Hg, but year-to-year variation in maximum water levels (∆maxWL) was positively associated with fish Hg content. This WL effect varied in magnitude among lakes: In Crane Lake, a 1 m increase in ∆maxWL from the previous year was associated with a 108 ng increase in fish Hg content (per gram wet weight), while the same WL change in Kabetogama was associated with only a 5 ng increase in fish Hg content. In half the lakes sampled here, effect sizes could not be distinguished from zero. Given the persistent and wide-ranging extent of Hg contamination and the large number of regulated waterways, future research is needed to identify the conditions in which WL fluctuations influence fish Hg content.

Occurrence of neonicotinoid insecticides in finished drinking water and fate during drinking water treatment

USGS Publications Warehouse

Klarich, Kathryn L.; Pflug, Nicholas C.; DeWald, Eden M.; Hladik, Michelle L.; Kolpin, Dana W.; Cwiertny, David M.; LeFevre, Gergory H.

2017-01-01

Neonicotinoid insecticides are widespread in surface waters across the agriculturally-intensive Midwestern US. We report for the first time the presence of three neonicotinoids in finished drinking water and demonstrate their general persistence during conventional water treatment. Periodic tap water grab samples were collected at the University of Iowa over seven weeks in 2016 (May-July) after maize/soy planting. Clothianidin, imidacloprid, and thiamethoxam were ubiquitously detected in finished water samples and ranged from 0.24-57.3 ng/L. Samples collected along the University of Iowa treatment train indicate no apparent removal of clothianidin and imidacloprid, with modest thiamethoxam removal (~50%). In contrast, the concentrations of all neonicotinoids were substantially lower in the Iowa City treatment facility finished water using granular activated carbon (GAC) filtration. Batch experiments investigated potential losses. Thiamethoxam losses are due to base-catalyzed hydrolysis at high pH conditions during lime softening. GAC rapidly and nearly completely removed all three neonicotinoids. Clothianidin is susceptible to reaction with free chlorine and may undergo at least partial transformation during chlorination. Our work provides new insights into the persistence of neonicotinoids and their potential for transformation during water treatment and distribution, while also identifying GAC as an effective management tool to lower neonicotinoid concentrations in finished drinking water.

THE PERSISTENCE OF NONTUBERCULOUS MYCOBACTERIA INI A DRINKING WATER DISTRIBUTION SYSTEM AFTER THE ADDITION OF FILTRATION TREATMENT

EPA Science Inventory

There is evidence that drinking water may be a source of pathogenic nontuberculous mycobacteria (NTM) infections in humans. One method by which NTM are believed to enter drinking water distribution systems is by their intracellular colonization of protozoa. Our goal was to determ...

THE PERSISTENCE OF MYCOBACTERIUM AVIUM IN A DRINKING WATER DISTRIBUTION SYSTEM AFTER THE ADDITION OF FILTRATION TREATMENT

EPA Science Inventory

There is evidence that drinking water may be a source of pathogenic nontuberculous mycobacteria (NTM) infections in humans. One method by which NTM are believed to enter drinking water distribution systems is by their intracellular location within protozoa. Our goal was to determ...

Influence of solar radiation and biotic interactions on bacterial and eukaryotic communities associated with sewage decomposition in ambient water

EPA Science Inventory

Sewage and ambient water both consist of a highly complex array of bacteria and eukaryotic microbes. When these communities are mixed, the persistence of sewage-derived pathogens in environmental waters can represent a significant public health concern. Solar radiation and biot...

Influence of Solar Radiation and Biotic Interactions on Bacterial and Eukaryotic Communities Associated with Sewage Decomposition in Ambient Water - Poster

EPA Science Inventory

Sewage and ambient water both consist of a highly complex array of bacteria and eukaryotic microbes. When these communities are mixed, the persistence of sewage-derived pathogens in environmental waters can represent a significant public health concern. Solar radiation and biotic...

The persistence of Mycobacterium avium in a drinking water system, what is the risk to human health?

EPA Science Inventory

Drinking water is believed to be a major source of human exposure to nontuberculous mycobacteria (NTM) such as Mycobacterium avium. We monitored the prevalence of M. avium in a drinking water system during the addition of filtration treatment. Our goal was to determine if the pre...

Evaluation of the persistence of micropollutants through pure-oxygen activated sludge nitrification and denitrification

USGS Publications Warehouse

Levine, A.D.; Meyer, M.T.; Kish, G.

2006-01-01

The persistence of pharmaceuticals, hormones, and household and industrial chemicals through a pure-oxygen activated sludge, nitrification, denitrification wastewater treatment facility was evaluated. Of the 125 micropollutants that were tested in this study, 55 compounds were detected in the untreated wastewater, and 27 compounds were detected in the disinfected effluent. The persistent compounds included surfactants, fire-retardant chemicals, pesticides, fragrance compounds, hormones, and one pharmaceutical. Physical-chemical properties of micropollutants that affected partitioning onto wastewater solids included vapor pressure and octanol-water partition coefficients.

The persistence of the water budget myth and its relationship to sustainability

USGS Publications Warehouse

Devlin, J.F.; Sophocleous, M.

2005-01-01

Sustainability and sustainable pumping are two different concepts that are often used interchangeably. The latter term refers to a pumping rate that can be maintained indefinitely without mining an aquifer, whereas the former term is broader and concerns such issues as ecology and water quality, among others, in addition to sustainable pumping. Another important difference between the two concepts is that recharge can be very important to consider when assessing sustainability, but is not necessary to estimate sustainable pumping rates. Confusion over this distinction is made worse by the Water Budget Myth, which comprises the mistaken yet persistent ideas that (1) sustainable pumping rates cannot exceed virgin recharge rates in aquifers, and (2) that virgin recharge rates must therefore be known to estimate sustainable pumping rates. Analysis of the water balance equation shows the special circumstances that must apply for the Water Budget Myth to be true. However, due to the effects recharge is likely to have on water quality, ecology, socioeconomic factors, and, under certain circumstances, its requirement for numerical modeling, it remains important in assessments of sustainability. ?? Springer-Verlag 2004.

Distribution and seasonal dynamics of arsenic in a shallow lake in northwestern New Jersey, USA

USGS Publications Warehouse

Barringer, J.L.; Szabo, Z.; Wilson, T.P.; Bonin, J.L.; Kratzer, T.; Cenno, K.; Romagna, T.; Alebus, M.; Hirst, B.

2011-01-01

Elevated concentrations of arsenic (As) occurred during warm months in water from the outlet of Lake Mohawk in northwestern New Jersey. The shallow manmade lake is surrounded by residential development and used for recreation. Eutrophic conditions are addressed by alum and copper sulfate applications and aerators operating in the summer. In September 2005, arsenite was dominant in hypoxic to anoxic bottom water. Filterable As concentrations were about 1.6-2 times higher than those in the upper water column (23-25 ??g/L, mostly arsenate). Hypoxic/anoxic and near-neutral bottom conditions formed during the summer, but became more oxic and alkaline as winter approached. Acid-leachable As concentrations in lake-bed sediments ranged up to 694 mg/kg in highly organic material from the tops of sediment cores but were <15 mg/kg in geologic substrate. During warm months, reduced As from the sediment diffuses into the water column and is oxidized; mixing by aerators, wind, and boat traffic spreads arsenate and metals, some in particulate form, throughout the water column. Similar levels of As in sediments of lakes treated with arsenic pesticides indicate that most of the As in Lake Mohawk probably derives from past use of arsenical pesticides, although records of applications are lacking. The annual loss of As at the lake outlet is only about 0.01% of the As calculated to be in the sediments, indicating that elevated levels of As in the lake will persist for decades. ?? 2010 US Government.

Day/night regulation of aquaporins during the CAM cycle in Mesembryanthemum crystallinum.

PubMed

Vera-Estrella, Rosario; Barkla, Bronwyn J; Amezcua-Romero, Julio C; Pantoja, Omar

2012-03-01

Mesembryanthemum crystallinum exhibits induction of Crassulacean acid metabolism (CAM) after a threshold stage of development, by exposure to long days with high light intensities or by water and salt stress. During the CAM cycle, fluctuations in carbon partitioning within the cell lead to transient drops in osmotic potential, which are likely stabilized/balanced by passive movement of water via aquaporins (AQPs). Protoplast swelling assays were used to detect changes in water permeability during the day/night cycle of CAM. To assess the role of AQPs during the same period, we followed transcript accumulation and protein abundance of four plasma membrane intrinsic proteins (PIPs) and one tonoplast intrinsic protein (TIP). CAM plants showed a persistent rhythm of specific AQP protein abundance changes throughout the day/night cycle, including changes in amount of McPIP2;1, McTIP1;2, McPIP1;4 and McPIP1;5, while the abundance of McPIP1;2 was unchanged. These protein changes did not appear to be coordinated with transcript levels for any of the AQPs analysed; however, they did occur in parrallel to alterations in water permeability, as well as variations in cell osmolarity, pinitol, glucose, fructose and phosphoenolpyruvate carboxylase (PEPc) levels measured throughout the day/night CAM cycle. Results suggest a role for AQPs in maintaining water balance during CAM and highlight the complexity of protein expression during the CAM cycle. © 2011 Blackwell Publishing Ltd.

The persistent microbicidal effect in water exposed to the corona discharge.

PubMed

Julák, Jaroslav; Scholtz, Vladimír; Kotúčová, Soňa; Janoušková, Olga

2012-07-01

This article describes and particularly explains a new phenomenon of persistent microbicidal effect of water previously exposed to the low-temperature plasma, which cannot be attributed to the acidification only. The direct microbicidal action of plasma is well documented, being mediated by number of reactive particles with a short lifetime. However, we observed the microbicidal effect also in exposed water stored for a month, where it must be mediated by stable particles. In water and in phosphate-buffered saline, the formation of NO(x) and corresponding acids, H(2)O(2) and O(3) was confirmed after exposition to the low-temperature plasma generated in air by DC negative glow corona and positive streamer discharge. The time course of acidification, H(2)O(2) and O(3) formation were deremined. Except uncertain traces of HCN, SIFT-MS analysis of exposed liquids reveals no additional reactive compounds. The microbicidal effect persists almost unchanged during 4 weeks of storage, although O(3) completely and H(2)O(2) almost disappears. Staphylococcus epidermidis and Escherichia coli were inactivated within 10 min of incubation in exposed liquids, Candida albicans needs at least 1 h. The solutions prepared by artificial mixing of reactive compounds mimic the action of exposed water, but in lesser extent. The acid milieu is the main cause of the microbicidal effect, but the possibility of still unidentified additional compound remains open. Copyright © 2011 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Simulation of fluid flow and energy transport processes associated with high-level radioactive waste disposal in unsaturated alluvium

USGS Publications Warehouse

Pollock, David W.

1986-01-01

Many parts of the Great Basin have thick zones of unsaturated alluvium which might be suitable for disposing of high-level radioactive wastes. A mathematical model accounting for the coupled transport of energy, water (vapor and liquid), and dry air was used to analyze one-dimensional, vertical transport above and below an areally extensive repository. Numerical simulations were conducted for a hypothetical repository containing spent nuclear fuel and located 100 m below land surface. Initial steady state downward water fluxes of zero (hydrostatic) and 0.0003 m yr−1were considered in an attempt to bracket the likely range in natural water flux. Predicted temperatures within the repository peaked after approximately 50 years and declined slowly thereafter in response to the decreasing intensity of the radioactive heat source. The alluvium near the repository experienced a cycle of drying and rewetting in both cases. The extent of the dry zone was strongly controlled by the mobility of liquid water near the repository under natural conditions. In the case of initial hydrostatic conditions, the dry zone extended approximately 10 m above and 15 m below the repository. For the case of a natural flux of 0.0003 m yr−1 the relative permeability of water near the repository was initially more than 30 times the value under hydrostatic conditions, consequently the dry zone extended only about 2 m above and 5 m below the repository. In both cases a significant perturbation in liquid saturation levels persisted for several hundred years. This analysis illustrates the extreme sensitivity of model predictions to initial conditions and parameters, such as relative permeability and moisture characteristic curves, that are often poorly known.

The relation between amyotrophic lateral sclerosis and inorganic selenium in drinking water: a population-based case-control study

PubMed Central

2010-01-01

Background A community in northern Italy was previously reported to have an excess incidence of amyotrophic lateral sclerosis among residents exposed to high levels of inorganic selenium in their drinking water. Methods To assess the extent to which such association persisted in the decade following its initial observation, we conducted a population-based case-control study encompassing forty-one newly-diagnosed cases of amyotrophic lateral sclerosis and eighty-two age- and sex-matched controls. We measured long-term intake of inorganic selenium along with other potentially neurotoxic trace elements. Results We found that consumption of drinking water containing ≥ 1 μg/l of inorganic selenium was associated with a relative risk for amyotrophic lateral sclerosis of 5.4 (95% confidence interval 1.1-26) after adjustment for confounding factors. Greater amounts of cumulative inorganic selenium intake were associated with progressively increasing effects, with a relative risk of 2.1 (95% confidence interval 0.5-9.1) for intermediate levels of cumulative intake and 6.4 (95% confidence interval 1.3-31) for high intake. Conclusion Based on these results, coupled with other epidemiologic data and with findings from animal studies that show specific toxicity of the trace element on motor neurons, we hypothesize that dietary intake of inorganic selenium through drinking water increases the risk for amyotrophic lateral sclerosis. PMID:21134276

Presence and survival of culturable Campylobacter spp. and Escherichia coli in a temperate urban estuary.

PubMed

Schang, Christelle; Lintern, Anna; Cook, Perran L M; Osborne, Catherine; McKinley, Anand; Schmidt, Jonathon; Coleman, Rhys; Rooney, Graham; Henry, Rebekah; Deletic, Ana; McCarthy, David

2016-11-01

Urban estuaries throughout the world typically contain elevated levels of faecal contamination, the extent of which is generally assessed using faecal indicator organisms (FIO) such as Escherichia coli. This study assesses whether the bacterial FIO, E. coli is a suitable surrogate for Campylobacter spp., in estuaries. The presence and survival dynamics of culturable E. coli and Campylobacter spp. are compared in the water column, bank sediments and bed sediments of the Yarra River estuary (located in Melbourne, Australia). The presence of E. coli did not necessarily indicate detectable levels of Campylobacter spp. in the water column, bed and bank sediments, but the inactivation rates of the two bacteria were similar in the water column. A key finding of the study is that E. coli and Campylobacter spp. can survive for up to 14days in the water column and up to 21days in the bed and bank sediments of the estuary. Preliminary data presented in this study also suggests that the inactivation rates of the two bacteria may be similar in bed and bank sediments. This undermines previous hypotheses that Campylobacter spp. cannot survive outside of its host and indicates that public health risks can persist in aquatic systems for up to three weeks after the initial contamination event. Copyright © 2016. Published by Elsevier B.V.

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

Salt Plug Formation Caused by Decreased River Discharge in a Multi-channel Estuary

PubMed Central

Shaha, Dinesh Chandra; Cho, Yang-Ki

2016-01-01

Freshwater input to estuaries may be greatly altered by the river barrages required to meet human needs for drinking water and irrigation and prevent salt water intrusion. Prior studies have examined the salt plugs associated with evaporation and salt outwelling from tidal salt flats in single-channel estuaries. In this work, we discovered a new type of salt plug formation in the multi-channel Pasur River Estuary (PRE) caused by decreasing river discharges resulting from an upstream barrage. The formation of a salt plug in response to changes in river discharge was investigated using a conductivity-temperature-depth (CTD) recorder during spring and neap tides in the dry and wet seasons in 2014. An exportation of saline water from the Shibsa River Estuary (SRE) to the PRE through the Chunkhuri Channel occurred during the dry season, and a salt plug was created and persisted from December to June near Chalna in the PRE. A discharge-induced, relatively high water level in the PRE during the wet season exerted hydrostatic pressure towards the SRE from the PRE and thereby prevented the intrusion of salt water from the SRE to the PRE. PMID:27255892

Emerging contaminants in surface waters in China—a short review

NASA Astrophysics Data System (ADS)

Yang, Guang; Fan, Maohong; Zhang, Guangming

2014-07-01

Emerging contaminants (ECs) have drawn attention to many countries due to their persistent input and potential threat to human health and the environment. This article reviews the current contamination sources and their status for surface waters in China. The contamination levels of ECs in surface waters are in the range ng L-1 to μg L-1 in China, apparently about the same as the situation in other countries. ECs enter surface water via runoff, drainage, rainfall, and wastewater treatment effluent. The frequency of occurrence of ECs increased rapidly from 2006 to 2011; a significant reason is the production and consumption of pharmaceuticals and personal care products. As for the distribution of EC pollution in China, the frequency of occurrence of ECs in eastern regions is higher than in western regions. A majority of EC studies have focused on surface waters of the Haihe River and Pearl River watersheds due to their highly developed industries and intense human activity. Legislative and administrative regulation of ECs is lacking in China. To remove ECs, a number of technologies, such as absorption by activated carbon, membrane filtration technology, and advanced oxidation processes, have been researched.

Alteration of host-pathogen interactions in the wake of climate change - Increasing risk for shellfish associated infections?

PubMed

Hernroth, Bodil E; Baden, Susanne P

2018-02-01

The potential for climate-related spread of infectious diseases through marine systems has been highlighted in several reports. With this review we want to draw attention to less recognized mechanisms behind vector-borne transmission pathways to humans. We have focused on how the immune systems of edible marine shellfish, the blue mussels and Norway lobsters, are affected by climate related environmental stressors. Future ocean acidification (OA) and warming due to climate change constitute a gradually increasing persistent stress with negative trade-off for many organisms. In addition, the stress of recurrent hypoxia, inducing high levels of bioavailable manganese (Mn) is likely to increase in line with climate change. We summarized that OA, hypoxia and elevated levels of Mn did have an overall negative effect on immunity, in some cases also with synergistic effects. On the other hand, moderate increase in temperature seems to have a stimulating effect on antimicrobial activity and may in a future warming scenario counteract the negative effects. However, rising sea surface temperature and climate events causing high land run-off promote the abundance of naturally occurring pathogenic Vibrio and will in addition, bring enteric pathogens which are circulating in society into coastal waters. Moreover, the observed impairments of the immune defense enhance the persistence and occurrence of pathogens in shellfish. This may increase the risk for direct transmission of pathogens to consumers. It is thus essential that in the wake of climate change, sanitary control of coastal waters and seafood must recognize and adapt to the expected alteration of host-pathogen interactions. Copyright © 2017 Elsevier Inc. All rights reserved.

Biomagnification of persistent organic pollutants along a high-altitude aquatic food chain in the Tibetan Plateau: Processes and mechanisms.

PubMed

Ren, Jiao; Wang, Xiaoping; Wang, Chuanfei; Gong, Ping; Wang, Xiruo; Yao, Tandong

2017-01-01

Biomagnification of some persistent organic pollutants (POPs) has been found in marine and freshwater food chains; however, due to the relatively short food chains in high-altitude alpine lakes, whether trophic transfer would result in the biomagnification of POPs is not clear. The transfer of various POPs, including organochlorine pesticides and polychlorinated biphenyls (PCBs), along the aquatic food chain in Nam Co Lake (4700 m), in the central Tibetan Plateau, was studied. The POPs levels in the water, sediment and biota [plankton, invertebrates and fish (Gymnocypris namensis)] of Nam Co were generally low, with concentrations comparable to those reported for the remote Arctic. The composition profiles of POPs in the fish were different from that in the water, but similar to their food. DDEs, DDDs, PCB 138, 153 and 180 displayed significant positive correlations with trophic levels, with trophic magnification factors (TMFs) ranged between 1.5 and 4.2, implying these chemicals can undergo final biomagnification along food chain. A fugacity-based dynamic bioaccumulation model was applied to the fish with localized parameters, by which the simulated concentrations were comparable to the measured data. Modeling results showed that most compounds underwent net gill loss and net gut uptake; only when the net result of the combined gut and gill fluxes would be positive, bioaccumulation could eventually occur. The net accumulation flux increased with fish age, which was caused by the continuous increase of gut uptake by aged fish. Due to the oligotrophic condition, efficient food absorption is likely the key factor that influences the gut POPs uptake. Long residence times with half-lives up to two decades were found for the higher chlorinated PCBs in Gymnocypris namensis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Periodic monitoring of persistent organic pollutants and molecular damage in Cyprinus carpio from Büyük Menderes River.

PubMed

Çağdaş, Beste; Kocagöz, Rasih; Onat, İlgen; Perçin, Fatih; Özaydın, Okan; Orhan, Hilmi

2017-02-01

Concentrations of persistent organic pollutants (POPs) were quantified in river water and sediment, as well as in the liver and muscle tissues of Cyprinus carpio that were sampled four times in a year at three stations in the Büyük Menderes River (BMR). Potential biomarkers of possible cellular molecular damage, namely lipid peroxidation (LPO) degradation products, protein carbonyls (PCO) and DNA repair product 8-hydroxy-2'-deoxyguanosine (8-OHdG), were analysed. All the targeted pollutants were measurable both in biotic and abiotic samples. Interestingly, the results suggested that there was recent organochlorine pesticide (OCP) input into the river water in the first two sampling periods in all stations in contrast to prohibition, while input of polychlorinated biphenyls (PCBs) and polybrominated diphenylethers (PBDEs) was not detected. Liver POP concentrations were higher than in muscle, as expected, and were found to decrease from the first to the fourth sampling period in all stations, except PBDEs. Levels of LPO degradation products in the liver and in muscle tissues decreased from the first to the fourth sampling period. This suggests that these markers reflect the lipid damage in respective tissues due to the tissue burden of targeted POPs. Protein carbonyls were the highest in the first sampling period, followed by a dramatic decrease in the second, and then a gradual increase towards the fourth sampling period in all stations. 8-OHdG levels were lower in Sarayköy station in the first sampling period. Among the measured biomarkers, only several LPO degradation products were significantly correlated with OCPs and PCBs in liver tissue.

A Water Grid for the UK

NASA Astrophysics Data System (ADS)

Leathard, A.; Fowler, H. J.; Kilsby, C. G.

2009-04-01

Anthropogenically aggravated climate change associated with intensive expansion of the global economy has increased the demand for water whilst simultaneously altering natural variability in its distribution, straining water resources unsustainably and inequitably in many parts of the world, increasing drought risk, and encouraging decision-makers to reconsider the security of water supply. Indeed, in the absence of additional resource development, contemporary planning forecasts imply increased water stress across much of the United Kingdom. The regulatory authorities of the UK currently promote increased efficiency of water delivery and consumption combined with a portfolio of financial instruments as a means of reducing water stress, maintaining present levels of consumer service without significant further exploitation of the environment. Despite an increasingly sophisticated understanding of climate change and its effects, significant uncertainty remains in the quantification of its impacts on the water sector, and questions persist as to the effectiveness of such demand management measures compared to that of more traditional infrastructure improvements. Faced with possible futures provided for by detrimentally over-stressed resources, what opportunities remain for future strategic development in the UK? Is there a single national strategy that is both politically and socially acceptable? This ongoing study aims to evolve robust national adaptation strategies by quantifying the projected impacts of climate change across mainland UK using multi-model and perturbed-physics ensembles of projected future climate, encapsulating uncertainties in a scenario-driven integrated water resources model incorporating socio-economic elements.

Definition and preoperative predictors of persistently elevated prostate-specific antigen after radical prostatectomy: results from the Shared Equal Access Regional Cancer Hospital (SEARCH) database.

PubMed

Moreira, Daniel M; Presti, Joseph C; Aronson, William J; Terris, Martha K; Kane, Christopher J; Amling, Christopher L; Freedland, Stephen J

2010-06-01

To define a level of persistently elevated prostate-specific antigen (PSA) after radical prostatectomy (RP) that equates with high-risk for disease progression, and to identify preoperative predictors of PSA persistence among men from the Shared Equal Access Regional Cancer Hospital (SEARCH) database. A total of 901 men treated with RP between 2001 and 2008 were separated into groups based upon PSA nadir within 6 months after RP. We explored the association between nadir groups and time to biochemical recurrence (BCR) using multivariate Cox proportional hazards and determined the preoperative predictors of PSA persistence using logistic regression. Relative to men with undetectable PSA levels, those with a PSA nadir of 0.03 (hazard ratio [HR] 3.88, P < 0.001), 0.04 (HR 4.87, P < 0.001), 0.05-0.09 (HR 12.69, P < 0.001), 0.1-0.19 (HR 13.17, P < 0.001), and 0.2 ng/mL (HR 13.23, P < 0.001) were at increased risk of BCR while men with a nadir of 0.01 (HR 1.36, P = 0.400) and 0.02 (HR 1.64, P = 0.180) were not. Using the PSA persistence definition of a PSA nadir > or = 0.03 ng/mL, 230 men (26%) had persistence. The independent preoperative predictors of PSA persistence were higher body mass index (BMI, P = 0.002), pathological Gleason score (relative to 2-6: 4 + 3-10, P = 0.001) and preoperative PSA level (P < 0.001). Men with a PSA nadir > or = 0.03 ng/mL after RP were at higher risk for BCR. Using a PSA persistence definition of a PSA nadir > or = 0.03 ng/mL, persistence was predicted by known factors associated with aggressive disease (tumour grade, PSA level and BMI). Validation of the present definition in different populations using later end-points remains necessary to assess its prognostic usefulness.

Putting the past behind us: Social stress-induced urinary retention can be overcome.

PubMed

Weiss, Dana A; Butler, Stephan J; Fesi, Joanna; Long, Christopher J; Valentino, Rita J; Canning, Douglas A; Zderic, Stephen A

2015-08-01

To study the pathophysiology of dysfunctional voiding, we have previously developed a model of stress-induced voiding dysfunction. We have shown that cyclosporine A (CsA), an inhibitor of the Ca(2+)-calmodulin complex, can prevent social stress-induced urinary retention. However, treatment with cyclosporine has not had an effect on the increase in the stress peptide corticotrophin-releasing factor (CRF) in Barrington's nucleus, which is involved in the micturition pathway. We now investigate whether cyclosporine administered after stress can reverse the abnormal voiding phenotype, and whether it has effects on the bladder wall itself, or on the stress response within Barrington's nucleus. Six-week old Swiss-Webster mice were exposed to aggressor males for 1 h a day, followed by 23 h of barrier separation. In a long-term trial, 1 month of stress was followed by single-cage housing for 6 months. In a separate CsA reversal trial, mice either received CsA in drinking water or had plain drinking water during 1 month of single-cage housing during recovery. Bladder contractile function was examined on a Guth myograph. Nuclear translocation of myocyte enhancing factor (MEF)-2 and NFAT (nuclear factor of activated T cells) in the bladder was assessed using electrophoretic mobility shift assays (EMSAs). The expression of CRF was determined in Barrington's nucleus using in situ hybridization. Voiding dysfunction persisted for up to 6 months after stress exposure while mice recovered in single-cage housing. In the CsA reversal trial, voiding patterns improved when they received CsA in water during single-cage housing following stress, whereas those that underwent single-cage housing alone had persistent abnormal voiding (Fig. A). There was no difference between CRF levels in Barrington's nucleus between reversal groups (p = 0.42) (Fig. B), possibly indicating a direct effect on the bladder rather than a persistent stress effect. There were no differences in the contractility of bladder wall muscle. CsA decreased the nuclear translocation of MEF-2 and NFAT induced by stress (Fig. C,D). CsA reverses stress-induced urinary retention, but does not change the stress-induced CRF increase in Barrington's nucleus. Furthermore, bladder smooth muscle contractility is unchanged by CsA; however, there are changes in the levels of the downstream transcription factors MEF-2 and NFAT. We suspect that additional CsA responsive neural changes play a pivotal role in the abnormal voiding phenotype following social stress. Copyright © 2015 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Climate Factors Contributing to Streamflow Inputs and Extreme Water-level Deviations from Long-term Averages for Lakes Superior and Michigan-Huron

NASA Astrophysics Data System (ADS)

Anderson, M. T.; Stamm, J. F.

2014-12-01

The Great Lakes are a highly valued freshwater resource of the United States and Canada. The Lakes are the focus of a science-based restoration program, known as the Great Lakes Restoration Initiative (GLRI). Physical and chemical factors, such as inflows and nutrient loads to the Great Lakes can affect ecosystem function, contribute to the spread of invasive species and increase the occurrence of harmful algal blooms. Since about 1999, water levels in Lakes Superior and Michigan-Huron have been at or below the long-term average (1918 to present). Analyses of streamflow trends for the period 1960 to 2012 in watersheds draining into Lakes Superior and Michigan-Huron showed a long-term decline in average inflows, which helps to explain the persistently below-average lake levels. Recent climatic conditions of October 2013 to August 2014 have contributed to a rapid rise in lake levels, most notably in Lake Superior. Lake Superior recently reached an elevation of 602.56 feet above sea level in August 2014, which is the highest level in 17 years. Coincident with this recovery was the development of a large algal bloom in Lake Erie in August of 2014 that shut down the Toledo, Ohio municipal water supply. These anomalous, extreme deviations from long-term average lake levels will be examined to better understand the forcing factors that contributed to changes in inflow volumes and lake-levels. Particular focus will be given to the climatology of years when changes in lake levels are most pronounced, such as; the measured lake-level declines during 1964-1965 and 1998-2000; and lake-level rises during 1973-1974, 1987-1989, and 2013-2014. The climatology of years with periods of algal blooms will also be examined such as, 2003, 2008, 2011 and 2014.

Erosion of continental margins in the Western Mediterranean due to sea-level stagnancy during the Messinian Salinity Crisis

NASA Astrophysics Data System (ADS)

Just, Janna; Hübscher, Christian; Betzler, Christian; Lüdmann, Thomas; Reicherter, Klaus

2011-02-01

High-resolution multi-channel seismic data from continental slopes with minor sediment input off southwest Mallorca Island, the Bay of Oran (Algeria) and the Alboran Ridge reveal evidence that the Messinian erosional surface is terraced at an almost constant depth interval between 320 and 380 m below present-day sea level. It is proposed that these several hundred- to 2,000-m-wide terraces were eroded contemporaneously and essentially at the same depth. Present-day differences in these depths result from subsidence or uplift in the individual realms. The terraces are thought to have evolved during one or multiple periods of sea-level stagnancy in the Western Mediterranean Basin. According to several published scenarios, a single or multiple periods of relative sea-level stillstand occurred during the Messinian desiccation event, generally known as the Messinian Salinity Crisis. Some authors suggest that the stagnancy started during the refilling phase of the Mediterranean basins. When the rising sea level reached the height of the Sicily Sill, the water spilled over this swell into the eastern basin. The stagnancy persisted until sea level in the eastern basin caught up with the western Mediterranean water level. Other authors assigned periods of sea-level stagnancy to drawdown phases, when inflowing waters from the Atlantic kept the western sea level constant at the depth of the Sicily Sill. Our findings corroborate all those Messinian sea-level reconstructions, forwarding that a single or multiple sea-level stagnancies at the depth of the Sicily Sill lasted long enough to significantly erode the upper slope. Our data also have implications for the ongoing debate of the palaeo-depth of the Sicily Sill. Since the Mallorcan plateau experienced the least vertical movement, the observed terrace depth of 380 m there is inferred to be close to the Messinian depth of this swell.

Acute and persistent effects of pre- and posthatching thermal environments on growth and metabolism in the red-eared slider turtle, Trachemys scripta elegans.

PubMed

Ligon, Day B; Peterson, Charles C; Lovern, Matthew B

2012-04-01

Many ectotherms possess the capacity to survive a wide range of thermal conditions. Long-term exposure to temperature can induce acclimational and/or organizational effects, and the developmental stage at which temperature exposure occurs may affect the type, degree, and persistence of these effects. We incubated red-eared slider turtle embryos at three different constant temperatures (T(inc); 26.5, 28.5, 30.5°C), then divided the resulting hatchlings between two water temperatures (T(water); 25, 30°C). We calculated growth rates to assess the short- and long-term effects of thermal experience on this metabolically costly process. We also measured resting metabolic rate (RMR) at three body temperatures (T(body;) 26.5, 28.5, 30.5°C) shortly after hatching and 6 months posthatching to characterize the degree and persistence of acclimation to T(inc) and T(water) . Hatchling RMRs were affected by T(body) and T(inc) , and fit a pattern consistent with positive but incomplete metabolic compensation to T(inc) . Average growth rates over the first 11 weeks posthatching were strongly affected by T(water) but only marginally influenced by T(inc) , and only at T(water) = 30°C. Six-month RMRs exhibited strong acclimation to T(water) consistent with positive metabolic compensation. However, within each T(water) treatment, RMR fit patterns indicative of inverse metabolic compensation to T(inc) , opposite of the pattern observed in hatchlings. Average growth rates calculated over 6 months continued to show a strong effect of T(water) , and the previously weak effect of T(inc) observed within the 30°C T(water) treatment became more pronounced. Our results suggest that metabolic compensation was reversible regardless of the life stage during which exposure occurred, and therefore is more appropriately considered acclimational than organizational. © 2012 WILEY PERIODICALS, INC.

Modest Amounts of Voluntary Exercise Reduce Pain- and Stress-Related Outcomes in a Rat Model of Persistent Hind Limb Inflammation.

PubMed

Pitcher, Mark H; Tarum, Farid; Rauf, Imran Z; Low, Lucie A; Bushnell, Catherine

2017-06-01

Aerobic exercise improves outcomes in a variety of chronic health conditions, yet the support for exercise-induced effects on chronic pain in humans is mixed. Although many rodent studies have examined the effects of exercise on persistent hypersensitivity, the most used forced exercise paradigms that are known to be highly stressful. Because stress can also produce analgesic effects, we studied how voluntary exercise, known to reduce stress in healthy subjects, alters hypersensitivity, stress, and swelling in a rat model of persistent hind paw inflammation. Our data indicate that voluntary exercise rapidly and effectively reduces hypersensitivity as well as stress-related outcomes without altering swelling. Moreover, the level of exercise is unrelated to the analgesic and stress-reducing effects, suggesting that even modest amounts of exercise may impart significant benefit in persistent inflammatory pain states. Modest levels of voluntary exercise reduce pain- and stress-related outcomes in a rat model of persistent inflammatory pain, independently of the amount of exercise. As such, consistent, self-regulated activity levels may be more relevant to health improvement in persistent pain states than standardized exercise goals. Published by Elsevier Inc.

The impact of major earthquakes and subsequent sewage discharges on the microbial quality of water and sediments in an urban river.

PubMed

Devane, Megan L; Moriarty, Elaine M; Wood, David; Webster-Brown, Jenny; Gilpin, Brent J

2014-07-01

A series of large earthquakes struck the city of Christchurch, New Zealand in 2010-2011. Major damage sustained by the sewerage infrastructure required direct discharge of up to 38,000 m(3)/day of raw sewage into the Avon River of Christchurch for approximately six months. This allowed evaluation of the relationship between concentrations of indicator microorganisms (Escherichia coli, Clostridium perfringens and F-RNA phage) and pathogens (Campylobacter, Giardia and Cryptosporidium) in recreational water and sediment both during and post-cessation of sewage discharges. Giardia was the pathogen found most frequently in river water and sediment, although Campylobacter was found at higher levels in water samples. E. coli levels in water above 550 CFU/100 mL were associated with increased likelihood of detection of Campylobacter, Giardia and Cryptosporidium, supporting the use of E. coli as a reliable indicator for public health risk. The strength of the correlation of microbial indicators with pathogen detection in water decreased in the following order: E. coli>F-RNA phage>C. perfringens. All the microorganisms assayed in this study could be recovered from sediments. C. perfringens was observed to accumulate in sediments, which may have confounded its usefulness as an indicator of fresh sewage discharge. F-RNA phage, however, did not appear to accumulate in sediment and in conjunction with E. coli, may have potential as an indicator of recent human sewage discharge in freshwater. There is evidence to support the low-level persistence of Cryptosporidium and Giardia, but not Campylobacter, in river sediments after cessation of sewage discharges. In the event of disturbances of the sediment, it is highly probable that there could be re-mobilisation of microorganisms beyond the sediment-water exchange processes occurring under base flow conditions. Re-suspension events do, therefore, increase the potential risk to human health for those who participate in recreational and work-related activities in the river environment. Copyright © 2014 Elsevier B.V. All rights reserved.

Near-coastal ocean variability off southern Tamaulipas - northern Veracruz, western Gulf of Mexico, during spring-summer 2013

NASA Astrophysics Data System (ADS)

Rivas, David

2016-04-01

Six months of observations from a near-coastal mooring deployed off southern Tamaulipas-northern Veracruz coast (western Gulf of Mexico) during spring-summer 2013 provides velocity, temperature, salinity, sea level, and dissolved oxygen series in a region which ocean dynamics is still poorly understood. As shown in a preceding analysis of this region's winter circulation for winter 2012-2013, coastal trapped motions associated with the regional invasion of synoptic cold fronts modulate the local variability; this pattern remains in the spring 2013, when even more intense events of alongshore flow (>50 cm/s) are observed. This intensified flow is associated with a significant decrease in the dissolved oxygen, most probably related to an influence of hypoxic waters coming from the northern Gulf. In late spring-mid summer, the wind pattern corresponds to persistent southeasterly winds that favor the occurrence of a local upwelling, which maintains a local thermal reduction (>3 degrees Celsius) and is associated with a persistent northward flow (>30 cm/s). The late summer was characterized by a significant tropical-cyclone activity, when a depression, a storm, and a hurricane affected the western Gulf. These tropical systems caused an intense precipitation and hence an important intensification of the local riverine discharge, and the winds enhanced the mixing of such riverine waters, via mostly kinetic stirring and Ekman pumping.

Cyclic volatile methylsiloxanes in fish from the Baltic Sea.

PubMed

Kierkegaard, Amelie; Bignert, Anders; McLachlan, Michael S

2013-10-01

Laboratory studies suggest that the cyclic volatile methylsiloxanes (cVMS) octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6) will persist in the aquatic environment and bioaccumulate in fish. Here these cVMS were measured in herring collected in the Swedish waters of the Baltic Sea and the North Sea and in grey seals from the Baltic Proper. D4, D5, and D6 were present in herring muscle at concentrations around 10, 200, and 40ngg(-1) lipid weight, respectively. The ratio of these concentrations was similar to the relative magnitude of estimated emissions to water, suggesting that the efficiency of overall transfer through the environment and food web was similar (within a factor 2-3) for the three chemicals. The concentrations of D5 and D6 were similar in herring caught in the highly populated Baltic Proper and in the less populated Bothnian Sea and Bothnian Bay. The D4 concentrations were lower at the most remote northern station, suggesting that D4 is less persistent than D5 and D6. Herring from the North Sea had lower levels of all three chemicals. The concentrations of D4, D5 and D6 in grey seal blubber were lower than the lipid normalized concentrations in herring, indicating that they do not biomagnify in grey seals. Copyright © 2012 Elsevier Ltd. All rights reserved.

Determinants of persistent underweight among children, aged 6-35 months, after huge economic development and improvements in health services in Oman.

PubMed

Alasfoor, Deena; Traissac, Pierre; Gartner, Agnès; Delpeuch, Francis

2007-09-01

Over the last decades, health indicators have witnessed major improvements in the Sultanate of Oman. This study was aimed at factors associated with underweight among children in four regions of Oman, as, in 1998, underweight was prevalent among 17.9% of children aged less than five years. A case-control study was conducted in 2002: 190 cases were 6-35-month old children with weight-for-age < -2 z-scores. Controls were individually matched by village of residence, sex, and age. The questionnaire included anthropometry of children, child-feeding practices, morbidity, anthropometry of mothers, parity, birth-spacing, and socioeconomic characteristics. Conditional logistic regression was used for analyses. Birth-weight of < 2,500 g was strongly associated with underweight and also were height of mother, low level of education of mother, bad quality of water in households, diarrhoea of children in the last two weeks, and regular use of infant formula. Factors, such as birth-weight, height of mother, supply of safe water in household, and care for mothers and children were the determinants of persistent underweight after huge economic development and improvements in health services. Further research is also needed to investigate further specific determinants of low birth-weight in the Omani context and try to disentangle emaciation and determinants of linear growth retardation.

The influence of global climate change on the environmental fate of persistent organic pollutants: A review with emphasis on the Northern Hemisphere and the Arctic as a receptor

NASA Astrophysics Data System (ADS)

Ma, Jianmin; Hung, Hayley; Macdonald, Robie W.

2016-11-01

Following worldwide bans and restrictions on the use of many persistent organic pollutants (POPs) from the late 1970s, their regional and global distributions have become governed increasingly by phase partitioning between environmental reservoirs, such as air, water, soil, vegetation and ice, where POPs accumulated during the original applications. Presently, further transport occurs within the atmospheric and aquatic reservoirs. Increasing temperatures provide thermodynamic forcing to drive these chemicals out of reservoirs, like soil, vegetation, water and ice, and into the atmosphere where they can be transported rapidly by winds and then recycled among environmental media to reach locations where lower temperatures prevail (e.g., polar regions and high elevations). Global climate change, widely considered as global warming, is also manifested by changes in hydrological systems and in the cryosphere; with the latter now exhibiting widespread loss of ice cover on the Arctic Ocean and thawing of permafrost. All of these changes alter the cycling and fate of POPs. There is abundant evidence from observations and modeling showing that climate variation has an effect on POPs levels in biotic and abiotic environments. This article reviews recent progress in research on the effects of climate change on POPs with the intention of promoting awareness of the importance of interactions between climate and POPs in the geophysical and ecological systems.

Case study of odor and indoor air quality assessment in the dewatering building at the Stickney Water Reclamation Plant.

PubMed

Sharma, Manju; O'Connell, Susan; Garelli, Brett; Sattayatewa, Chakkrid; Moschandreas, Demetrios; Pagilla, Krishna

2012-01-01

Indoor air quality (IAQ) and odors were determined using sampling/monitoring, measurement, and modeling methods in a large dewatering building at a very large water reclamation plant. The ultimate goal was to determine control strategies to reduce the sensory impacts on the workforce and achieve odor reduction within the building. Study approaches included: (1) investigation of air mixing by using CO(2) as an indicator, (2) measurement of airflow capacity of ventilation fans, (3) measurement of odors and odorants, (4) development of statistical and IAQ models, and (5) recommendation of control strategies. The results showed that air quality in the building complies with occupational safety and health guidelines; however, nuisance odors that can increase stress and productivity loss still persist. Excess roof fan capacity induced odor dispersion to the upper levels. Lack of a local air exhaust system of sufficient capacity and optimum design was found to be the contributor to occasional less than adequate indoor air quality and odors. Overall, air ventilation rate in the building has less effect on persistence of odors in the building. Odor/odorant emission rates from centrifuge drops were approximately 100 times higher than those from the open conveyors. Based on measurements and modeling, the key control strategies recommended include increasing local air exhaust system capacity and relocation of exhaust hoods closer to the centrifuge drops.

Estrogenic alkylphenols in fish tissues, sediments, and waters from the U.K. Tyne and Tees estuaries

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

Lye, C.M.; Frid, C.L.J.; Gill, M.E.

1999-04-01

Nonylphenols and related compounds are common products of biodegradation of a large group of nonionic surfactants, the nonylphenol polyethoxylates. Many of these compounds are known to be environmentally persistent and to elicit estrogenic response in both mammals and fish. In this study, nonylphenol (NP), nonylphenol monoethoxylate (NP1EO), and octylphenol (OP) were found in tissues of mature male flounder, Platichthys flesus, and in tissues of juvenile flounder. These fish also showed detectable levels of the yolk protein vitellogenin in their plasma, indicative of estrogenic exposure. The compounds were also found in discharges from a major sewage treatment works and in sedimentsmore » from two estuaries in north-east England; the highest levels from the highly industrialized Tees and lower levels from the industrialized/urbanized Tyne estuary. The implications of these findings for fish populations are discussed.« less

Ultra-trace determination of Persistent Organic Pollutants in Arctic ice using stir bar sorptive extraction and gas chromatography coupled to mass spectrometry.

PubMed

Lacorte, S; Quintana, J; Tauler, R; Ventura, F; Tovar-Sánchez, A; Duarte, C M

2009-12-04

This study presents the optimization and application of an analytical method based on the use of stir bar sorptive extraction (SBSE) gas chromatography coupled to mass spectrometry (GC-MS) for the ultra-trace analysis of POPs (Persistent Organic Pollutants) in Arctic ice. In a first step, the mass-spectrometry conditions were optimized to quantify 48 compounds (polycyclic aromatic hydrocarbons, brominated diphenyl ethers, chlorinated biphenyls, and organochlorinated pesticides) at the low pg/L level. In a second step, the performance of this analytical method was evaluated to determine POPs in Arctic cores collected during an oceanographic campaign. Using a calibration range from 1 to 1800 pg/L and by adjusting acquisition parameters, limits of detection at the 0.1-99 and 102-891 pg/L for organohalogenated compounds and polycyclic aromatic hydrocarbons, respectively, were obtained by extracting 200 mL of unfiltered ice water. alpha-hexachlorocyclohexane, DDTs, chlorinated biphenyl congeners 28, 101 and 118 and brominated diphenyl ethers congeners 47 and 99 were detected in ice cores at levels between 0.5 to 258 pg/L. We emphasise the advantages and disadvantages of in situ SBSE in comparison with traditional extraction techniques used to analyze POPs in ice.

Contaminants of Emerging Concern During De Facto Water Reuse

EPA Science Inventory

Our drinking water and wastewater cycles are integrally linked. Chemicals that are present in household wastewater may be sufficiently mobile and persistent to survive both on-site or municipal wastewater treatment and post-discharge environmental processes. Thus, such contamin...

Consent Decree D.G. Yuengling and Son, Inc. Clean Water Act Settlement

EPA Pesticide Factsheets

Yuengling owns and operates two beer breweries (the New Brewery and the Old Brewery) in Pottsville, Pennsylvania, which have been in significant non-compliance with the Clean Water Act because of persistent violations of application industrial wastewater.

VISUALIZING THE RELATIONSHIP OF PBTS IN WATER AND SEDIMENT TO RESIDUES IN FISH

EPA Science Inventory

Bioaccumulation of persistent bioaccumulative toxicants (PBTs) in aquatic organisms results from uptake of the chemicals through several different exposure routes associated with water, sediment, and biota. This paper presents an approach for depicting and interpreting bioaccumul...

Rescaled range analysis of streamflow records in the São Francisco River Basin, Brazil

NASA Astrophysics Data System (ADS)

Araujo, Marcelo Vitor Oliveira; Celeste, Alcigeimes B.

2018-01-01

Hydrological time series are sometimes found to have a distinctive behavior known as long-term persistence, in which subsequent values depend on each other even under very large time scales. This implies multiyear consecutive droughts or floods. Typical models used to generate synthetic hydrological scenarios, widely used in the planning and management of water resources, fail to preserve this kind of persistence in the generated data and therefore may have a major impact on projects whose design lives span for long periods of time. This study deals with the evaluation of long-term persistence in streamflow records by means of the rescaled range analysis proposed by British engineer Harold E. Hurst, who first observed the phenomenon in the mid-twentieth century. In this paper, Hurst's procedure is enhanced by a strategy based on statistical hypothesis testing. The case study comprises the six main hydroelectric power plants located in the São Francisco River Basin, part of the Brazilian National Grid. Historical time series of inflows to the major reservoirs of the system are investigated and 5/6 sites show significant persistence, with values for the so-called Hurst exponent near or greater than 0.7, i.e., around 40% above the value 0.5 that represents a white noise process, suggesting that decision makers should take long-term persistence into consideration when conducting water resources planning and management studies in the region.

Exertional Rhabdomyolysis in a Collegiate American Football Player After Preventive Cold-Water Immersion: A Case Report

PubMed Central

Kahanov, Leamor; Eberman, Lindsey E.; Wasik, Mitchell; Alvey, Thurman

2012-01-01

Objective: To describe a case of exertional rhabdomyolysis in a collegiate American football player after preventive cold-water immersion. Background: A healthy man (19 years old) participated in full-contact football practice followed by conditioning (2.5 hours). After practice, he entered a coach-mandated post-practice cold-water immersion and had no signs of heat illness before developing leg cramps, for which he presented to the athletic training staff. After 10 minutes of repeated stretching, massage, and replacement of electrolyte-filled fluids, he was transported to the emergency room. Laboratory tests indicated a creatine kinase (CK) level of 2545 IU/L (normal range, 45–260 IU/L), CK-myoglobin fraction of 8.5 ng/mL (normal < 6.7 ng/mL), and CK-myoglobin relative index of 30% (normal range, 25%– 30%). Myoglobin was measured at 499 ng/mL (normal = 80 ng/mL). The attending physician treated the athlete with intravenous fluids. Differential Diagnosis: Exercise-associated muscle cramps, dehydration, exertional rhabdomyolysis. Treatment: The patient was treated with rest and rehydration. One week after the incident, he began biking and swimming. Eighteen days later, the patient continued to demonstrate elevated CK levels (527 IU/L) but described no other symptoms and was allowed to return to football practice as tolerated. Two months after the incident, his CK level remained high (1900 IU/L). Uniqueness: The athlete demonstrated no signs of heat illness upon entering the cold-water immersion but experienced severe leg cramping after immersion, resulting in a diagnosis of exertional rhabdomyolysis. Previously described cases have not linked cold-water immersion with the pathogenesis of rhabdomyolysis. Conclusions: In this football player, CK levels appeared to be a poor indicator of rhabdomyolysis. Our patient demonstrated no other signs of the illness weeks after the incident, yet his elevated CK levels persisted. Cold-water immersion immediately after exercise should be monitored by the athletic training staff and may not be appropriate to prevent muscle damage, given the lack of supporting evidence. PMID:22488291

Herbicide Persistence in Seawater Simulation Experiments

PubMed Central

Mercurio, Philip; Mueller, Jochen F.; Eaglesham, Geoff; Flores, Florita; Negri, Andrew P.

2015-01-01

Herbicides are detected year-round in marine waters, including those of the World Heritage listed Great Barrier Reef (GBR). The few previous studies that have investigated herbicide persistence in seawater generally reported half-lives in the order of months, and several studies were too short to detect significant degradation. Here we investigated the persistence of eight herbicides commonly detected in the GBR or its catchments in standard OECD simulation flask experiments, but with the aim to mimic natural conditions similar to those found on the GBR (i.e., relatively low herbicide concentrations, typical temperatures, light and microbial communities). Very little degradation was recorded over the standard 60 d period (Experiment 1) so a second experiment was extended to 365 d. Half-lives of PSII herbicides ametryn, atrazine, diuron, hexazinone and tebuthiuron were consistently greater than a year, indicating high persistence. The detection of atrazine and diuron metabolites and longer persistence in mercuric chloride-treated seawater confirmed that biodegradation contributed to the breakdown of herbicides. The shortest half-life recorded was 88 d for growth-regulating herbicide 2,4-D at 31°C in the dark, while the fatty acid-inhibitor metolachlor exhibited a minimum half-life of 281 d. The presence of moderate light and elevated temperatures affected the persistence of most of the herbicides; however, the scale and direction of the differences were not predictable and were likely due to changes in microbial community composition. The persistence estimates here represent some of the first appropriate data for application in risk assessments for herbicide exposure in tropical marine systems. The long persistence of herbicides identified in the present study helps explain detection of herbicides in nearshore waters of the GBR year round. Little degradation of these herbicides would be expected during the wet season with runoff and associated flood plumes transporting a high proportion of the original herbicide from rivers into the GBR lagoon. PMID:26313296

Herbicide Persistence in Seawater Simulation Experiments.

PubMed

Mercurio, Philip; Mueller, Jochen F; Eaglesham, Geoff; Flores, Florita; Negri, Andrew P

2015-01-01

Herbicides are detected year-round in marine waters, including those of the World Heritage listed Great Barrier Reef (GBR). The few previous studies that have investigated herbicide persistence in seawater generally reported half-lives in the order of months, and several studies were too short to detect significant degradation. Here we investigated the persistence of eight herbicides commonly detected in the GBR or its catchments in standard OECD simulation flask experiments, but with the aim to mimic natural conditions similar to those found on the GBR (i.e., relatively low herbicide concentrations, typical temperatures, light and microbial communities). Very little degradation was recorded over the standard 60 d period (Experiment 1) so a second experiment was extended to 365 d. Half-lives of PSII herbicides ametryn, atrazine, diuron, hexazinone and tebuthiuron were consistently greater than a year, indicating high persistence. The detection of atrazine and diuron metabolites and longer persistence in mercuric chloride-treated seawater confirmed that biodegradation contributed to the breakdown of herbicides. The shortest half-life recorded was 88 d for growth-regulating herbicide 2,4-D at 31°C in the dark, while the fatty acid-inhibitor metolachlor exhibited a minimum half-life of 281 d. The presence of moderate light and elevated temperatures affected the persistence of most of the herbicides; however, the scale and direction of the differences were not predictable and were likely due to changes in microbial community composition. The persistence estimates here represent some of the first appropriate data for application in risk assessments for herbicide exposure in tropical marine systems. The long persistence of herbicides identified in the present study helps explain detection of herbicides in nearshore waters of the GBR year round. Little degradation of these herbicides would be expected during the wet season with runoff and associated flood plumes transporting a high proportion of the original herbicide from rivers into the GBR lagoon.

Environmental Containment Property Estimation Using QSARs in an Expert System

DTIC Science & Technology

1991-10-15

economical method to estimate aqueous solubility, octanol/ water partition coefficients, vapor pressures, organic carbon, normalized soil sorption...PROPERTY ESTIMATION USING QSARs IN AN EXPERT SYSTEM William J. Doucette Mark S. Holt Doug J. Denne Joan E. McLean Utah State University Utah Water ...persistence of a chemical are aqueous solubility, octanol/ water partition coefficient, soil/ water sorption coefficient, Henry’s Law constant

Resetting the bar: Establishing baselines for persistent contaminants after Hurricane Sandy in the coastal environments of New Jersey and New York, USA

USGS Publications Warehouse

Reilly, Timothy J.; Focazio, Michael J.; Simmons, Dale L.

2016-01-01

In the immediate aftermath of natural disasters, public health officials and other first responders engage in many activities to protect the public and ecosystems in the affected area. These activities include critical tasks designed to minimize adverse consequences resulting from chemical and microbial contaminant exposures, such as acute disease incidence and transmission. However, once these urgent priorities have been met and situations requiring immediate attention have been stabilized, questions regarding the potential longer term threats to humans and ecosystems associated with persistent contaminant exposures remain. Research conducted to address these questions is frequently challenged by the lack of available baseline contaminant information collected before the event for comparison and perspective. In addition, deployments of field crews and collection of environmental samples typically occur days, weeks, or months after the event. Consequently, during and in the aftermath of disasters, public health agencies commonly advise the public to disinfect water, avoid contact with disturbed infrastructure (such as sewer lines), and (or) refrain from use of recreational waters, with the general focus on acute health threats; however, the persisting effects of such releases on local recreational waters, fisheries, and other estuarine habitats are often undetermined.

Urogenital schistosomiasis transmission on Unguja Island, Zanzibar: characterisation of persistent hot-spots.

PubMed

Pennance, Tom; Person, Bobbie; Muhsin, Mtumweni Ali; Khamis, Alipo Naim; Muhsin, Juma; Khamis, Iddi Simba; Mohammed, Khalfan Abdallah; Kabole, Fatma; Rollinson, David; Knopp, Stefanie

2016-12-16

Elimination of urogenital schistosomiasis transmission is a priority for the Zanzibar Ministry of Health. Preventative chemotherapy together with additional control interventions have successfully alleviated much of the disease burden. However, a persistently high Schistosoma haematobium prevalence is found in certain areas. Our aim was to characterise and evaluate these persistent "hot-spots" of transmission and reinfection in comparison with low-prevalence areas, to support the intervention planning for schistosomiasis elimination in Zanzibar. Prevalences of S. haematobium were annually determined by a single urine filtration in schoolchildren from 45 administrative areas (shehias) in Unguja in 2012, 2013 and 2014. Coverage data for biannual treatment with praziquantel were available from ministerial databases and internal surveys. Among the 45 shehias, five hot-spot (≥ 15 % prevalence) and two low-prevalence (≤ 5 %) shehias were identified and surveyed in mid-2014. Human-water contact sites (HWCSs) and the presence of S. haematobium-infected and uninfected Bulinus globosus, as well as safe water sources (SWSs) and their reliability in terms of water availability were determined and mapped. We found no major difference in the treatment coverage between persistent hot-spot and low-prevalence shehias. On average, there were considerably more HWCSs containing B. globosus in hot-spot than in low-prevalence shehias (n = 8 vs n = 2) and also more HWCSs containing infected B. globosus (n = 2 vs n = 0). There was no striking difference in the average abundance of SWSs in hot-spot and low-prevalence shehias (n = 45 vs n = 38) and also no difference when considering SWSs with a constant water supply (average: 62 % vs 62 %). The average number of taps with a constant water supply, however, was lower in hot-spot shehias (n = 7 vs n = 14). Average distances from schools to the nearest HWCS were considerably shorter in hot-spot shehias (n = 229 m vs n = 722 m). The number of HWCSs, their infestation with B. globosus and their distance to schools seem to play a major role for a persistently high S. haematobium prevalence in children. In addition to treatment, increasing access to reliably working taps, targeted snail control at HWCSs near schools and enhanced behaviour change measures are needed to reduce prevalences in hot-spot areas and to finally reach elimination. ISRCTN48837681 .

Survival and persistence of nonspore-forming biothreat agents in water.

PubMed

Gilbert, S E; Rose, L J

2012-09-01

To determine whether nonspore-forming biothreat agents can survive and persist in potable water that does not contain a disinfectant.  Autoclaved, de-chlorinated Atlanta municipal water was inoculated with eight isolates of bacterial biothreat agents (10⁶ CFU ml⁻¹). The inoculated water samples were incubated at 5, 8 (Francisella tularensis only) or 25°C and assayed for viability by culture and by the presence of metabolic activity as measured by esterase activity (ScanRDI, AES Chemunex). Viability as determined by culture varied from 1 to 30 days, depending upon the organism and the temperature of the water. All organisms were determined viable as measured by esterase activity for the entire 30 days, regardless of the incubation temperature.  Francisella tularensis was culturable for at least 21 days if held at 8°C. The remaining nonspore-forming bacterial biothreat agents were found to be metabolically active for at least 30 days in water held at 5 or 25°C.  The data can assist public health officials to determine the safety of drinking water after contamination with a biothreat agent. No claim to US Government works. Letters in Applied Microbiology © 2012 The Society for Applied Microbiology.

Bioavailability of iodine and hardness (magnesium and calcium salt) in drinking water in the etiology of endemic goitre in Sundarban delta of West Bengal (India).

PubMed

Chandra, Amar K; Tripathy, Smritiratan; Debnath, Arijit; Ghosh, Dishari

2007-04-01

Endemic goitre has been reported from the ecologically diverse Sundarban delta of West Bengal (India). To study the etiological factors for the persistence of endemic goitre, bioavailability of iodine and hardness of water used for drinking in the region were evaluated because these common environmental factors are inversely and directly related with goitre prevalence in several geographical regions. For the present study from 19 Community Development Blocks of Sundarban delta, 19 areas were selected at random. From each area at least 8 drinking water samples were collected and analyzed for iodine and the hardness (calcium and magnesium salt content). Iodine content in the drinking water samples was found in the range from 21 to 119 mg/L and total hardness of drinking water was found to range from 50 to 480 ppm. Presence of magnesium salt was found higher than the calcium salts in most of the samples. These findings suggest that the entire delta region is environmentally iodine sufficient but water is relatively hard and thus possibility of hardness of water for the persistence of endemic goitre may not be ruled out.

Persistent effects of a severe drought on Amazonian forest canopy

PubMed Central

Saatchi, Sassan; Asefi-Najafabady, Salvi; Malhi, Yadvinder; Aragão, Luiz E. O. C.; Anderson, Liana O.; Myneni, Ranga B.; Nemani, Ramakrishna

2013-01-01

Recent Amazonian droughts have drawn attention to the vulnerability of tropical forests to climate perturbations. Satellite and in situ observations have shown an increase in fire occurrence during drought years and tree mortality following severe droughts, but to date there has been no assessment of long-term impacts of these droughts across landscapes in Amazonia. Here, we use satellite microwave observations of rainfall and canopy backscatter to show that more than 70 million hectares of forest in western Amazonia experienced a strong water deficit during the dry season of 2005 and a closely corresponding decline in canopy structure and moisture. Remarkably, and despite the gradual recovery in total rainfall in subsequent years, the decrease in canopy backscatter persisted until the next major drought, in 2010. The decline in backscatter is attributed to changes in structure and water content associated with the forest upper canopy. The persistence of low backscatter supports the slow recovery (>4 y) of forest canopy structure after the severe drought in 2005. The result suggests that the occurrence of droughts in Amazonia at 5–10 y frequency may lead to persistent alteration of the forest canopy. PMID:23267086

Effects of low and high salinity regimes on seasonal gametogenesis of the ribbed mussel Geukensia granosissima in coastal Louisiana, USA

USGS Publications Warehouse

Honig, Aaron; LaPeyre, Megan K.; Supan, John

2014-01-01

Benthic intertidal bivalves play an essential role in estuarine ecosystems by contributing to habitat provision, water filtration, and host vegetation productivity. As such, ecosystem level changes that impact population distributions and persistence of local bivalve populations may have large ecosystem level consequences, making it important to better understand the population ecology of native bivalves. In order to determine potential impacts of shifting salinity and temperature regimes along the northern Gulf of Mexico, the seasonal timing of gametogenesis in the Gulf estuarine ribbed mussel, Geukensia granossisima, was examined across a salinity gradient in southeastern Louisiana, from July 2011 through October 2012. Ten mussels were randomly sampled monthly from low (~ 5) and high (~25) salinity marsh sites in southeastern Louisiana, and histologically processed to determine the seasonal progression of gametogenesis. Peak ripeness occurred at both sites between April and September, was positively correlated with temperature, and coincided with seasonal shifts in salinity. Mussels located in lower salinity waters demonstrated a shorter period of gametogenesis, and lower rates of ripeness indicating that changes in salinity regimes may impact long-term population dynamics.

Factors Associated With Persistent Increase in Level of Alanine Aminotransferase in Patients With Chronic Hepatitis B Receiving Oral Antiviral Therapy.

PubMed

Jacobson, Ira M; Washington, Mary K; Buti, Maria; Thompson, Alexander; Afdhal, Nezam; Flisiak, Robert; Akarca, Ulus Salih; Tchernev, Konstantin G; Flaherty, John F; Aguilar Schall, Raul; Myers, Robert P; Subramanian, G Mani; McHutchison, John G; Younossi, Zobair; Marcellin, Patrick; Patel, Keyur

2017-07-01

Despite complete suppression of viral DNA with antiviral agents, in some patients with chronic hepatitis B (CHB), serum levels of alanine aminotransferase (ALT) do not normalize. We investigated factors associated with persistent increases in ALT level in patients with CHB given long-term tenofovir disoproxil fumarate. We analyzed data from 471 hepatitis B e antigen (HBeAg)-positive and HBeAg-negative patients with CHB participating in 2 phase 3 trials. We identified patients with an increased level of ALT (above the upper limit of normal range) after 5 years (240 weeks) of tenofovir disoproxil fumarate therapy. We analyzed findings from liver biopsy specimens collected from 467 patients (99%) at baseline and 339 patients (72%) at year 5 of treatment; biopsy specimens were evaluated by an independent pathologist. We performed stepwise, forward, multivariate regression analyses of specified baseline characteristics and on-treatment response parameters to identify factors associated with persistent increases in ALT level. Of the 471 patients, 87 (18%) still had an increased ALT level at year 5 of treatment. Factors associated significantly with a persistent increase in ALT level were a steatosis score of 5% or greater (grade 1 or more) at baseline (odds ratio [OR], 2.236; 95% confidence interval [CI], 1.031-4.852; P = .042) and at year 5 (OR, 3.392; 95% CI, 1.560 ≥ 7.375; P = .002), HBeAg seropositivity at baseline (OR, 3.297; 95% CI, 1.653-6.576; P < .001), and age 40 years or older (OR, 2.099; 95% CI, 1.014-4.342; P = .046). Of the 42 HBeAg-positive patients with steatosis at baseline, 21 (50%) had an increased ALT level at year 5 of treatment. Patients with persistent increases in ALT level were more likely to have an increase in steatosis at year 5 than those with a normal ALT level. HBeAg seropositivity and hepatic steatosis contribute to persistent increases in ALT level in patients with CHB receiving suppressive antiviral treatment. ClinicalTrials.gov registration numbers: NCT00117676 and NCT00116805. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

Confirmation of putative stormwater impact on water quality at a Florida beach by microbial source tracking methods and structure of indicator organism populations.

PubMed

Brownell, M J; Harwood, V J; Kurz, R C; McQuaig, S M; Lukasik, J; Scott, T M

2007-08-01

The effect of a stormwater conveyance system on indicator bacteria levels at a Florida beach was assessed using microbial source tracking methods, and by investigating indicator bacteria population structure in water and sediments. During a rain event, regulatory standards for both fecal coliforms and Enterococcus spp. were exceeded, contrasting with significantly lower levels under dry conditions. Indicator bacteria levels were high in sediments under all conditions. The involvement of human sewage in the contamination was investigated using polymerase chain reaction (PCR) assays for the esp gene of Enterococcus faecium and for the conserved T antigen of human polyomaviruses, all of which were negative. BOX-PCR subtyping of Escherichia coli and Enterococcus showed higher population diversity during the rain event; and higher population similarity during dry conditions, suggesting that without fresh inputs, only a subset of the population survives the selective pressure of the secondary habitat. These data indicate that high indicator bacteria levels were attributable to a stormwater system that acted as a reservoir and conduit, flushing high levels of indicator bacteria to the beach during a rain event. Such environmental reservoirs of indicator bacteria further complicate the already questionable relationship between indicator organisms and human pathogens, and call for a better understanding of the ecology, fate and persistence of indicator bacteria.

Water-level changes induced by local and distant earthquakes at Long Valley caldera, California

USGS Publications Warehouse

Roeloffs, Evelyn A.; Sneed, Michelle; Galloway, Devin L.; Sorey, Michael L.; Farrar, Christopher D.; Howle, James F.; Hughes, J.

2003-01-01

Distant as well as local earthquakes have induced groundwater-level changes persisting for days to weeks at Long Valley caldera, California. Four wells open to formations as deep as 300 m have responded to 16 earthquakes, and responses to two earthquakes in the 3-km-deep Long Valley Exploratory Well (LVEW) show that these changes are not limited to weathered or unconsolidated near-surface rocks. All five wells exhibit water-level variations in response to earth tides, indicating they can be used as low-resolution strainmeters. Earthquakes induce gradual water-level changes that increase in amplitude for as long as 30 days, then return more slowly to pre-earthquake levels. The gradual water-level changes are always drops at wells LKT, LVEW, and CH-10B, and always rises at well CW-3. At a dilatometer just outside the caldera, earthquake-induced strain responses consist of either a step followed by a contractional strain-rate increase, or a transient contractional signal that reaches a maximum in about seven days and then returns toward the pre-earthquake value. The sizes of the gradual water-level changes generally increase with earthquake magnitude and decrease with hypocentral distance. Local earthquakes in Long Valley produce coseismic water-level steps; otherwise the responses to local earthquakes and distant earthquakes are indistinguishable. In particular, water-level and strain changes in Long Valley following the 1992 M7.3 Landers earthquake, 450 km distant, closely resemble those initiated by a M4.9 local earthquake on November 22, 1997, during a seismic swarm with features indicative of fluid involvement. At the LKT well, many of the response time histories are identical for 20 days after each earthquake, and can be matched by a theoretical solution giving the pore pressure as a function of time due to diffusion of a nearby, instantaneous, pressure drop. Such pressure drops could be produced by accelerated inflation of the resurgent dome by amounts too small to be detected by the two-color electronic distance-measuring network. Opening-mode displacement in the south moat, inferred to have followed a M4.9 earthquake on November 22, 1997, could also create extensional strain on the dome and lead to water-level changes similar to those following dome inflation. Contractional strain that could account for earthquake-induced water-level rises at the CW-3 well is inconsistent with geodetic observations. We instead attribute these water-level rises to diffusion of elevated fluid pressure localized in the south moat thermal aquifer. For hydraulic diffusivities appropriate to the upper few hundred meters at Long Valley, an influx of material at temperatures of 300°C can thermally generate pressure of 6 m of water or more, an order of magnitude larger than needed to account for the CW-3 water-level rises. If magma or hot aqueous fluid rises to within 1 km of the surface in the eastern part of the south moat, then hydraulic diffusivities are high enough to allow fluid pressure to propagate to CW-3 on the time scale observed. The data indicate that seismic waves from large distant earthquakes can stimulate upward movement of fluid in the hydrothermal system at Long Valley.

Persistently high psychological well-being predicts better HDL cholesterol and triglyceride levels: findings from the midlife in the U.S. (MIDUS) longitudinal study.

PubMed

Radler, Barry T; Rigotti, Attilio; Ryff, Carol D

2018-01-03

Psychological correlates of blood lipid levels have been previously evaluated mostly in cross sectional studies. However, prospectively measured psychological factors might also predict favorable blood lipid profiles, thereby indicating a healthy mind/body interplay that is associated with less disease, better health and longer lives. This paper examined whether longitudinal profiles of psychological well-being over 9-10 years are predictors of blood lipid profiles. Using the MIDUS (Midlife in the U.S.) biological subsample (n = 1054, aged 34 to 84, 55% female), cross-time trajectories of well-being were linked with three lipid outcomes (i.e., HDL cholesterol, triglycerides, and LDL cholesterol), measured for the first time at the 2nd wave of the study. Most adults showed largely stable profiles of well-being, albeit at different levels. Some showed persistently high well-being over time, while others revealed persistently low or moderate well-being. After adjusting for the effect of demographics, health behaviors, medications, and insulin resistance, adults with persistently high levels of environmental mastery and self-acceptance-two components of psychological well-being-had significantly higher levels of HDL as well as significantly lower levels of triglycerides compared to adults with persistently low levels of well-being. Converging with prior findings, no association was found between well-being and LDL cholesterol. Over 9-10 years, persistently high levels of psychological well-being measures predicted high HDL cholesterol and low triglycerides. These findings add longitudinal evidence to the growing body of research showing that positive psychological factors are linked with better lipoprotein profiles. A better blood lipid profile, particularly higher HDL-C, may be key in mediating how psychological well-being positively impacts health and length of life. Additional research is required to further validate this hypothesis as well as to establish potential underlying mechanisms.

Obg and Membrane Depolarization Are Part of a Microbial Bet-Hedging Strategy that Leads to Antibiotic Tolerance.

PubMed

Verstraeten, Natalie; Knapen, Wouter Joris; Kint, Cyrielle Ines; Liebens, Veerle; Van den Bergh, Bram; Dewachter, Liselot; Michiels, Joran Elie; Fu, Qiang; David, Charlotte Claudia; Fierro, Ana Carolina; Marchal, Kathleen; Beirlant, Jan; Versées, Wim; Hofkens, Johan; Jansen, Maarten; Fauvart, Maarten; Michiels, Jan

2015-07-02

Within bacterial populations, a small fraction of persister cells is transiently capable of surviving exposure to lethal doses of antibiotics. As a bet-hedging strategy, persistence levels are determined both by stochastic induction and by environmental stimuli called responsive diversification. Little is known about the mechanisms that link the low frequency of persisters to environmental signals. Our results support a central role for the conserved GTPase Obg in determining persistence in Escherichia coli in response to nutrient starvation. Obg-mediated persistence requires the stringent response alarmone (p)ppGpp and proceeds through transcriptional control of the hokB-sokB type I toxin-antitoxin module. In individual cells, increased Obg levels induce HokB expression, which in turn results in a collapse of the membrane potential, leading to dormancy. Obg also controls persistence in Pseudomonas aeruginosa and thus constitutes a conserved regulator of antibiotic tolerance. Combined, our findings signify an important step toward unraveling shared genetic mechanisms underlying persistence. Copyright © 2015 Elsevier Inc. All rights reserved.

Persistent homology and non-Gaussianity

NASA Astrophysics Data System (ADS)

Cole, Alex; Shiu, Gary

2018-03-01

In this paper, we introduce the topological persistence diagram as a statistic for Cosmic Microwave Background (CMB) temperature anisotropy maps. A central concept in 'Topological Data Analysis' (TDA), the idea of persistence is to represent a data set by a family of topological spaces. One then examines how long topological features 'persist' as the family of spaces is traversed. We compute persistence diagrams for simulated CMB temperature anisotropy maps featuring various levels of primordial non-Gaussianity of local type. Postponing the analysis of observational effects, we show that persistence diagrams are more sensitive to local non-Gaussianity than previous topological statistics including the genus and Betti number curves, and can constrain Δ fNLloc= 35.8 at the 68% confidence level on the simulation set, compared to Δ fNLloc= 60.6 for the Betti number curves. Given the resolution of our simulations, we expect applying persistence diagrams to observational data will give constraints competitive with those of the Minkowski Functionals. This is the first in a series of papers where we plan to apply TDA to different shapes of non-Gaussianity in the CMB and Large Scale Structure.

Quantitative Campylobacter spp., antibiotic resistance genes, and veterinary antibiotics in surface and ground water following manure application: Influence of tile drainage control.

PubMed

Frey, Steven K; Topp, Edward; Khan, Izhar U H; Ball, Bonnie R; Edwards, Mark; Gottschall, Natalie; Sunohara, Mark; Lapen, David R

2015-11-01

This work investigated chlortetracycline, tylosin, and tetracycline (plus transformation products), and DNA-based quantitative Campylobacter spp. and Campylobacter tetracycline antibiotic resistant genes (tet(O)) in tile drainage, groundwater, and soil before and following a liquid swine manure (LSM) application on clay loam plots under controlled (CD) and free (FD) tile drainage. Chlortetracycline/tetracycline was strongly bound to manure solids while tylosin dominated in the liquid portion of manure. The chlortetracycline transformation product isochlortetracycline was the most persistent analyte in water. Rhodamine WT (RWT) tracer was mixed with manure and monitored in tile and groundwater. RWT and veterinary antibiotic (VA) concentrations were strongly correlated in water which supported the use of RWT as a surrogate tracer. While CD reduced tile discharge and eliminated application-induced VA movement (via tile) to surface water, total VA mass loading to surface water was not affected by CD. At both CD and FD test plots, the biggest 'flush' of VA mass and highest VA concentrations occurred in response to precipitation received 2d after application, which strongly influenced the flow abatement capacity of CD on account of highly elevated water levels in field initiating overflow drainage for CD systems (when water level <0.3m below surface). VA concentrations in tile and groundwater became very low within 10d following application. Both Campylobacter spp. and Campylobacter tet(O) genes were present in groundwater and soil prior to application, and increased thereafter. Unlike the VA compounds, Campylobacter spp. and Campylobacter tet(O) gene loadings in tile drainage were reduced by CD, in relation to FD. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

Sorbent Nanotechnologies for Water Cleaning

NASA Astrophysics Data System (ADS)

Ahmed, Snober

Despite decades of regulatory efforts to mitigate water pollution, many chemicals, particularly heavy metals, still present risks to human health. In addition to direct exposure, certain metals such as mercury threaten public health due to its persistence, bioaccumulation and bioamplification throughout the food chain. A number of U.S. Federal and State regulations have been established to reduce the levels of mercury in water. Activated carbon (AC) has been widely explored for the removal of mercury. However, AC suffers from many limitations inherent to its chemical properties, and it becomes increasingly challenging to meet current and future regulations by simply modifying AC to enhance its performance. Recently, the performance of nanosorbents have been studied in order to removal pollutants. Nanosorbents utilize the ultra-high reactive surface of nanoparticles for rapid, effective and even permanent sequestration of heavy metals from water and air, thus showed promising results as compared to AC. The goal of this thesis research is to develop nanomaterial-based sorbents for the removal of mercury from water. It describes the development of a new solid-support assisted growth of selenium nanoparticles, their use for water remediation, and the development of a new nanoselenium-based sorbent sponge for fast and efficient mercury removal. The nanoselenium sorbent not only shows irreversible interaction with mercury but also exhibits remarkable properties by overcoming the limitations of AC. The nanoselenium sponge was shown to remove mercury to undetectable levels within one minute. This new sponge technology would have an impact on inspiring new stringent regulations and lowering costs to help industries meet regulatory requirements, which will ultimately help improve air and water quality, aquatic life and public health.

Spatial patterns of soil nutrients and groundwater levels within the Debre Mawi watershed of the Ethiopian highlands

NASA Astrophysics Data System (ADS)

Guzman, Christian; Tilahun, Seifu; Dagnew, Dessalegn; Zegeye, Assefe; Tebebu, Tigist; Yitaferu, Birru; Steenhuis, Tammo

2015-04-01

Persistent patterns of erosion have emerged in the Ethiopian highlands leading to soil and water conservation practices being implemented throughout the countryside. A common concern is the loss of soil fertility and loss of soil water. This study investigates the spatial patterns of soil nutrients and water table depths in a small sub-watershed in the northwestern Ethiopian highlands. NPK, a particularly important group of nutrients for inorganic fertilizer considerations, did not follow a consistent trend as a group along and across slope and land use transects. Whereas nitrogen content was greatest in the upslope regions (~0.1% TN), available phosphorus had comparably similar content in the different slope regions throughout the watershed (~2.7 mg/kg). The exchangeable cations (K, Ca, Mg) did increase in content in a downslope direction (in most cases though, they were highest in the middle region) but not consistently later in the season. On average, calcium (40 cmol/kg), magnesium (5 cmol/kg), and potassium (0.5 cmol/kg) were orders of magnitudes different in content. The perched water table in different areas of the watershed showed a very distinct trend. The lower part of the sub-watershed had shallower levels of water table depths (less than 10 cm from the surface) than did the upper parts of the sub-watershed (usually greater than 120 cm from the surface). The middle part of the sub-watershed had water table depths located at 40 to 70 cm below the surface. These results show how the landscape slope position and land use may be important for planning where and when soil nutrients and water would be expected to be appropriately "conserved" or stored.

Giardiasis

DTIC Science & Technology

2011-06-01

5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Naval Medical Research Detachment, Lima , Peru, 8. PERFORMING ORGANIZATION...outbreaks of giardiasis have been linked to un- filtered water from shallow wells, persistent contamination of communal drinking water sources, and...The key to the prevention of giardiasis transmission lies in preventing fecal contamination of food and water, and preventing direct transmission

Persistence of uranium groundwater plumes: contrasting mechanisms at two DOE sites in the groundwater-river interaction zone.

PubMed

Zachara, John M; Long, Philip E; Bargar, John; Davis, James A; Fox, Patricia; Fredrickson, Jim K; Freshley, Mark D; Konopka, Allan E; Liu, Chongxuan; McKinley, James P; Rockhold, Mark L; Williams, Kenneth H; Yabusaki, Steve B

2013-04-01

We examine subsurface uranium (U) plumes at two U.S. Department of Energy sites that are located near large river systems and are influenced by groundwater-river hydrologic interaction. Following surface excavation of contaminated materials, both sites were projected to naturally flush remnant uranium contamination to levels below regulatory limits (e.g., 30 μg/L or 0.126 μmol/L; U.S. EPA drinking water standard), with 10 years projected for the Hanford 300 Area (Columbia River) and 12 years for the Rifle site (Colorado River). The rate of observed uranium decrease was much lower than expected at both sites. While uncertainty remains, a comparison of current understanding suggests that the two sites have common, but also different mechanisms controlling plume persistence. At the Hanford 300 A, the persistent source is adsorbed U(VI) in the vadose zone that is released to the aquifer during spring water table excursions. The release of U(VI) from the vadose zone and its transport within the oxic, coarse-textured aquifer sediments is dominated by kinetically-limited surface complexation. Modeling implies that annual plume discharge volumes to the Columbia River are small (

Persistence of uranium groundwater plumes: Contrasting mechanisms at two DOE sites in the groundwater-river interaction zone

NASA Astrophysics Data System (ADS)

Zachara, John M.; Long, Philip E.; Bargar, John; Davis, James A.; Fox, Patricia; Fredrickson, Jim K.; Freshley, Mark D.; Konopka, Allan E.; Liu, Chongxuan; McKinley, James P.; Rockhold, Mark L.; Williams, Kenneth H.; Yabusaki, Steve B.

2013-04-01

We examine subsurface uranium (U) plumes at two U.S. Department of Energy sites that are located near large river systems and are influenced by groundwater-river hydrologic interaction. Following surface excavation of contaminated materials, both sites were projected to naturally flush remnant uranium contamination to levels below regulatory limits (e.g., 30 μg/L or 0.126 μmol/L; U.S. EPA drinking water standard), with 10 years projected for the Hanford 300 Area (Columbia River) and 12 years for the Rifle site (Colorado River). The rate of observed uranium decrease was much lower than expected at both sites. While uncertainty remains, a comparison of current understanding suggests that the two sites have common, but also different mechanisms controlling plume persistence. At the Hanford 300 A, the persistent source is adsorbed U(VI) in the vadose zone that is released to the aquifer during spring water table excursions. The release of U(VI) from the vadose zone and its transport within the oxic, coarse-textured aquifer sediments is dominated by kinetically-limited surface complexation. Modeling implies that annual plume discharge volumes to the Columbia River are small (< one pore volume). At the Rifle site, slow oxidation of naturally reduced, contaminant U(IV) in the saturated zone and a continuous influx of U(VI) from natural, up-gradient sources influence plume persistence. Rate-limited mass transfer and surface complexation also control U(VI) migration velocity in the sub-oxic Rifle groundwater. Flux of U(VI) from the vadose zone at the Rifle site may be locally important, but it is not the dominant process that sustains the plume. A wide range in microbiologic functional diversity exists at both sites. Strains of Geobacter and other metal reducing bacteria are present at low natural abundance that are capable of enzymatic U(VI) reduction in localized zones of accumulated detrital organic carbon or after organic carbon amendment. Major differences between the sites include the geochemical nature of residual, contaminant U; the rates of current kinetic processes (both biotic and abiotic) influencing U(VI) solid-liquid distribution; the presence of detrital organic matter and the resulting spatial heterogeneity in microbially-driven redox properties; and the magnitude of groundwater hydrologic dynamics controlled by river-stage fluctuations, geologic structures, and aquifer hydraulic properties. The comparative analysis of these sites provides important guidance to the characterization, understanding, modeling, and remediation of groundwater contaminant plumes influenced by surface water interaction that are common world-wide.

Extensive Floods in United Kingdom

NASA Technical Reports Server (NTRS)

2002-01-01

Rain continues to fall in the United Kingdom, bringing more water to an already water-logged landscape. Some rivers there are experiencing their worst flooding in more than 50 years. Of particular note, Britain's River Ouse reached its highest levels on record since 1625. Thousands of people have been evacuated from their homes since October 30, when a large low-pressure system brought torrential rains and hurricane-force winds, placing regions around more than 40 rivers across the country on flood alert. Since then, the rains have persisted, keeping water levels high and causing additional rivers to overrun their banks. In all, at least 12 people have been killed and more than 5,000 properties flooded. Some officials estimate damages could reach 500 million pounds (roughly $715 million). These Landsat 7 scenes show a comparison of the region surrounding Exeter, England, before and after the floods. The top image was acquired September 28 and the bottom image was acquired October 30, 2000. Note the extensive flooding along the River Exe in the bottom image (blue pixels). The light bluish-white pixels in the top image are clouds, and the black splotches on the landscape are the clouds' shadows. The reddish-brown shapes are agricultural fields. Image by Robert Simmon and Brian Montgomery, NASA GSFC. Data provided by Ron Beck, USGS EROS Data Center.

Microbial Diversity in a Hypersaline Sulfate Lake: A Terrestrial Analog of Ancient Mars

PubMed Central

Pontefract, Alexandra; Zhu, Ting F.; Walker, Virginia K.; Hepburn, Holli; Lui, Clarissa; Zuber, Maria T.; Ruvkun, Gary; Carr, Christopher E.

2017-01-01

Life can persist under severe osmotic stress and low water activity in hypersaline environments. On Mars, evidence for the past presence of saline bodies of water is prevalent and resulted in the widespread deposition of sulfate and chloride salts. Here we investigate Spotted Lake (British Columbia, Canada), a hypersaline lake with extreme (>3 M) levels of sulfate salts as an exemplar of the conditions thought to be associated with ancient Mars. We provide the first characterization of microbial structure in Spotted Lake sediments through metagenomic sequencing, and report a bacteria-dominated community with abundant Proteobacteria, Firmicutes, and Bacteroidetes, as well as diverse extremophiles. Microbial abundance and functional comparisons reveal similarities to Ace Lake, a meromictic Antarctic lake with anoxic and sulfidic bottom waters. Our analysis suggests that hypersaline-associated species occupy niches characterized foremost by differential abundance of Archaea, uncharacterized Bacteria, and Cyanobacteria. Potential biosignatures in this environment are discussed, specifically the likelihood of a strong sulfur isotopic fractionation record within the sediments due to the presence of sulfate reducing bacteria. With its high sulfate levels and seasonal freeze-thaw cycles, Spotted Lake is an analog for ancient paleolakes on Mars in which sulfate salt deposits may have offered periodically habitable environments, and could have concentrated and preserved organic materials or their biomarkers over geologic time. PMID:29018418

Microbial Diversity in a Hypersaline Sulfate Lake: A Terrestrial Analog of Ancient Mars.

PubMed

Pontefract, Alexandra; Zhu, Ting F; Walker, Virginia K; Hepburn, Holli; Lui, Clarissa; Zuber, Maria T; Ruvkun, Gary; Carr, Christopher E

2017-01-01

Life can persist under severe osmotic stress and low water activity in hypersaline environments. On Mars, evidence for the past presence of saline bodies of water is prevalent and resulted in the widespread deposition of sulfate and chloride salts. Here we investigate Spotted Lake (British Columbia, Canada), a hypersaline lake with extreme (>3 M) levels of sulfate salts as an exemplar of the conditions thought to be associated with ancient Mars. We provide the first characterization of microbial structure in Spotted Lake sediments through metagenomic sequencing, and report a bacteria-dominated community with abundant Proteobacteria, Firmicutes, and Bacteroidetes, as well as diverse extremophiles. Microbial abundance and functional comparisons reveal similarities to Ace Lake, a meromictic Antarctic lake with anoxic and sulfidic bottom waters. Our analysis suggests that hypersaline-associated species occupy niches characterized foremost by differential abundance of Archaea, uncharacterized Bacteria, and Cyanobacteria. Potential biosignatures in this environment are discussed, specifically the likelihood of a strong sulfur isotopic fractionation record within the sediments due to the presence of sulfate reducing bacteria. With its high sulfate levels and seasonal freeze-thaw cycles, Spotted Lake is an analog for ancient paleolakes on Mars in which sulfate salt deposits may have offered periodically habitable environments, and could have concentrated and preserved organic materials or their biomarkers over geologic time.

The persistence and character of stranded oil on coarse-sediment beaches.

PubMed

Owens, Edward H; Taylor, Elliott; Humphrey, Blair

2008-01-01

Small amounts of oil that can persist for decades in the intertidal zone of coarse-sediment beaches have been documented in a few well-studied cases. Oil that survives attenuation over the short-term (weeks to months) will persist until there is a change in the environmental conditions, as might occur where there is a seasonal storm-wave climate or as a beach undergoes long-term (erosional) changes. Oil residues can persist on the beach surface as tar mats, asphalt-like pavements, or as veneers on sediment particles or hard surfaces. Subsurface oil residues can persist in similar forms or as fill or partial fill of the pore spaces between coarse-sediment particles. Oil penetrates until it reaches fine-grained sediment, the water table, bedrock, or other penetration-limiting layers. Amounts of persistent oil are very small fractions of the volumes that were originally stranded and these protected residues can continue to biodegrade as they become thinner and more discontinuous.

Tsivat Basin conduit system persists through two surges, Bering Piedmont Glacier, Alaska

USGS Publications Warehouse

Fleisher, P.J.; Cadwell, D.H.; Muller, E.H.

1998-01-01

The 1993-1995 surge of Bering Glacier, Alaska, occurred in two distinct phases. Phase 1 of the surge began on the eastern sector in July, 1993 and ended in July, 1994 after a powerful outburst of subglacial meltwater into Tsivat Lake basin on the north side of Weeping Peat Island. Within days, jokulhlaup discharge built a 1.5 km2 delta of ice blocks (25-30 m) buried in outwash. By late October 1994, discharge temporarily shifted to a vent on Weeping Peat Island, where a second smaller outburst dissected the island and built two new sandar. During phase 2, which began in spring 1995 and ended within five months, continuous discharge issued from several vents along the ice front on Weeping Peat Island before returining to the Tsivat Basin. Surge related changes include a five- to six-fold increase in meltwater turbidity; the redirection of supercooled water in two ice-contact lakes; and an increase in the rate of glaciolacustrine sedimentation. US Geological Survey aerial photos by Austin Post show large ice blocks in braided channels indicating excessive subglacial discharge in a similar position adjacent to Weeping Peat Island during the 1966-1967 surge. During the subsequent three decades of retreat, the location of ice-marginal, subglacial discharge vents remained aligned on a linear trend that describes the position of a persistent subglacial conduit system. The presence of a major conduit system, possibly stabilized by subglacial bedrock topography, is suggested by: 1) high-level subglacial meltwater venting along the northern side of Weeping Peat Island during the 1966-1967 surge, 2) persistent low-level discharge between surges, and 3) the recurrence of localizing meltwater outbursts associated with both phases of the 1993-1005 surge.

Hydrogeology and simulation of regional ground-water-level declines in Monroe County, Michigan

USGS Publications Warehouse

Reeves, Howard W.; Wright, Kirsten V.; Nicholas, J.R.

2004-01-01

Observed ground-water-level declines from 1991 to 2003 in northern Monroe County, Michigan, are consistent with increased ground-water demands in the region. In 1991, the estimated ground-water use in the county was 20 million gallons per day, and 80 percent of this total was from quarry dewatering. In 2001, the estimated ground-water use in the county was 30 million gallons per day, and 75 percent of this total was from quarry dewatering. Prior to approximately 1990, the ground-water demands were met by capturing natural discharge from the area and by inducing leakage through glacial deposits that cover the bedrock aquifer. Increased ground-water demand after 1990 led to declines in ground-water level as the system moves toward a new steady-state. Much of the available natural discharge from the bedrock aquifer had been captured by the 1991 conditions, and the response to additional withdrawals resulted in the observed widespread decline in water levels. The causes of the observed declines were explored through the use of a regional ground-water-flow model. The model area includes portions of Lenawee, Monroe, Washtenaw, and Wayne Counties in Michigan, and portions of Fulton, Henry, and Lucas Counties in Ohio. Factors, including lowered water-table elevations because of below average precipitation during the time period (1991 - 2001) and reduction in water supply to the bedrock aquifer because of land-use changes, were found to affect the regional system, but these factors did not explain the regional decline. Potential ground-water capture for the bedrock aquifer in Monroe County is limited by the low hydraulic conductivity of the overlying glacial deposits and shales and the presence of dense saline water within the bedrock as it dips into the Michigan Basin to the west and north of the county. Hydrogeologic features of the bedrock and the overlying glacial deposits were included in the model design. An important step of characterizing the bedrock aquifer was the determination of inputs and outputs of water—leakage from glacial deposits and flows across model boundaries. The imposed demands on the groundwater system create additional discharge from the bedrock aquifer, and this discharge is documented by records and estimates of water use including: residential and industrial use, irrigation, and quarry dewatering. Hydrologic characterization of Monroe County and surrounding areas was used to determine the model boundaries and inputs within the ground-water model. MODFLOW-2000 was the computer model used to simulate ground-water flow. Predevelopment, 1991, and 2001 conditions were simulated with the model. The predevelopment model did not include modern water use and was compared to information from early settlement of the county. The 1991 steady-state model included modern demands on the ground-water system and was based on a significant amount of data collected for this and previous studies. The predevelopment and 1991 simulations were used to calibrate the numerical model. The simulation of 2001 conditions was based on recent data and explored the potential ground-water levels if the current conditions persist. Model results indicate that the ground-water level will stabilize in the county near current levels if the demands imposed during 2001 are held constant.

Persistence and extirpation in invaded landscapes: patch characteristics and connectivity determine effects of non-native predatory fish on native salamanders

USGS Publications Warehouse

Pilliod, David S.; Arkle, Robert S.; Maxell, Bryce A.

2012-01-01

Studies have demonstrated negative effects of non-native, predatory fishes on native amphibians, yet it is still unclear why some amphibian populations persist, while others are extirpated, following fish invasion. We examined this question by developing habitat-based occupancy models for the long-toed salamander (Ambystoma macrodactylum) and nonnative fish using survey data from 1,749 water bodies across 470 catchments in the Northern Rocky Mountains, USA. We first modeled the habitat associations of salamanders at 468 fishless water bodies in 154 catchments where non-native fish were historically, and are currently, absent from the entire catchment. Wethen applied this habitat model to the complete data set to predict the probability of salamander occupancy in each water body, removing any effect of fish presence. Finally, we compared field-observed occurrences of salamanders and fish to modeled probability of salamander occupancy. Suitability models indicated that fish and salamanders had similar habitat preferences, possibly resulting in extirpations of salamander populations from entire catchments where suitable habitats were limiting. Salamanders coexisted with non-native fish in some catchments by using marginal quality, isolated (no inlet or outlet) habitats that remained fishless. They rarely coexisted with fish within individual water bodies and only where habitat quality was highest. Connectivity of water bodies via streams resulted in increased probability of fish invasion and consequently reduced probability of salamander occupancy.These results could be used to identify and prioritize catchments and water bodies where control measures would be most effective at restoring amphibian populations. Our approach could be useful as a framework for improved investigations into questions of persistence and extirpation of native species when non-native species have already become established.

Algae-mediated removal of selected pharmaceutical and personal care products (PPCPs) from Lake Mead water.

PubMed

Bai, Xuelian; Acharya, Kumud

2017-03-01

The persistence and fate of pharmaceutical and personal care products (PPCPs) in the Lake Mead ecosystem are particularly important considering the potential ecological risks and human health impacts. This study evaluated the removal of five common PPCPs (i.e., trimethoprim, sulfamethoxazole, carbamazepine, ciprofloxacin, and triclosan) from Lake Mead water mediated by the green alga Nannochloris sp. The results from the incubation studies showed that trimethoprim and carbamazepine were highly resistant to uptake in the algal cultural medium and were measured at approximately 90%-100% of the applied dose after 14days of incubation. Sulfamethoxazole was found relatively persistent, with >60% of the applied dose remaining in the water after 14days, and its removal was mainly caused by algae-mediated photolysis. However, ciprofloxacin and triclosan dissipated significantly and nearly 100% of the compounds were removed from the water after 7days of incubation under 24h of light. Ciprofloxacin and triclosan were highly susceptible to light, and their estimated half-lives were 12.7hours for ciprofloxacin and 31.2hours for triclosan. Algae-mediated sorption contributed to 11% of the removal of trimethoprim and sulfamethoxazole, 13% of the removal of carbamazepine, and 27% of the removal of triclosan from the lake water. This research showed that 1) trimethoprim, sulfamethoxazole, and carbamazepine are quite persistent in aquatic environments and may potentially affect human health via drinking water intake; 2) photolysis is the dominant pathway to remove ciprofloxacin from aquatic ecosystems, which indicates that ciprofloxacin may have lower ecological risks compared with other PPCPs; and 3) triclosan can undergo photolysis as well as algae-mediated uptake and it may potentially affect the food web because of its high toxicity to aquatic species. Copyright © 2017 Elsevier B.V. All rights reserved.

Combined impact of ocean acidification and corrosive waters in a river-influenced coastal upwelling area off Central Chile

NASA Astrophysics Data System (ADS)

Vargas, C.; De La Hoz, M.; San Martin, V.; Contreras, P.; Navarro, J. M.; Lagos, N. A.; Lardies, M.; Manríquez, P. H.; Torres, R.

2012-12-01

Elevated CO2 in the atmosphere promotes a cascade of physical and chemical changes affecting all levels of biological organization, and the evidence from local to global scales has shown that such anthropogenic climate change has triggered significant responses in the Earth's biota. The increased concentration of CO2 is likely to cause a corresponding increase in ocean acidification (OA). In addition, economically valuable shellfish species predominantly inhabit coastal regions both in natural stocks and/or in managed stocks and farming areas. Many coastal ecosystems may experience seawater pCO2 levels significantly higher than expected from equilibrium with the atmosphere, which in this case are strongly linked to biological processes and/or the impact of two important processes; river plumes and coastal upwelling events, which indeed interplay in a very dynamic way on continental shelves, resulting in both source or sink of CO2 to the atmosphere. Coastal ecosystems receive persistent acid inputs as a result of freshwater discharges from river basins into the coastal domain. In this context, since shellfish resources and shellfish aquaculture activities predominantly occur in nearshore areas, it is expected that shellfish species inhabiting river-influenced benthic ecosystems will be exposed persistently to acidic conditions that are suboptimal for its development. In a wider ecological context, little is also known about the potential impacts of acid waters on the performance of larvae and juveniles of almost all the marine species inhabiting this benthic ecosystem in Eastern Southern Pacific Ocean. We present here the main results of a research study aimed to investigate the environmental conditions to which economically valuable calcifiers shellfish species are exposed in a river-influenced continental shelf off Central Chile. By using isotopic measurements in the dissolved inorganic carbon (DIC) pool (d13C-DIC) we showed the effect of the remineralization of organic matter due to natural or anthropogenically stimulated respiration processes within river basin may impact the coastal ocean. Furthermore, the upwelling of corrosive subsurface waters might also undersaturate coastal waters with respect to aragonite. In addition, by using a mesocosm system to simulate different pH and CO2 levels we have evaluate under controlled conditions the effect of ocean acidification on the larval stage of an economically-important gastropod species (Concholepas concholepas). In this presentation, we show some preliminary results using multi-source data from different research projects dealing with the carbon cycle and OA processes along Chilean coast. Funded by Project RIVOM (Fondecyt 1095069), Project TOA-SPACE (Fondecyt 1090624), and Project Anillo ACT132 (CONICYT).

Collegiate Athletics: An Investigation into Athletic Persistence of Freshman Student-Athletes Participating in NCAA Division-III Varsity Athletic Programs

ERIC Educational Resources Information Center

Sombito, Lester Jamili

2015-01-01

Understanding of the persistence of student-athletes in athletics at the D-III level is complex. This research study investigated the issue of student-athlete retention by focusing on Division III (D-III) student-athlete persistence in athletics by asking the following research question, "To what extent do freshman student-athletes persist in…

Persistence factors among engineering students at the Polytechnic University of Puerto Rico: Student perceptions and curricular implications

NASA Astrophysics Data System (ADS)

Gonzalez Juarbe, Juan M.

Various persistence studies demonstrate that there is a direct correlation between college or university academic program completion and the amount of students' involvement in the college or university on a social, academic, and institutional level. These studies suggest that, over the course of time, the greater the level of involvement the greater the probability of increased persistence towards program completion. Student persistence among Hispanic engineering students was researched at the Polytechnic University of Puerto Rico during the period of January 2002 to April 2003. Persistence factors lead students to either one of the following behaviors: (1) to re-enroll, (2) to switch to another educational program, or (3) to depart from the institution. Increased student persistence is the result of recurring decisions to re-enroll each trimester. Decreased student persistence is the outcome associated with a decision to either depart or switch to another educational vocation. Early departure at the institution is linked to perceptions formed day-to-day as the student experiences the educational environment. These perceptions inspire behavioral outcomes to either persist or depart the education process. Desirable behavioral outcomes are closely related with educational commitments leading to increased persistence. Likewise, undesirable behavioral outcomes are those resulting in decreased persistence. Satisfactory student experiences in successfully achieving social, academic, and institutional responsibilities set the course towards increased persistence. In the research undertaken, student and faculty educational experiences were analyzed and documented. This was accomplished by the use of a combined quantitative and qualitative research methodology. The volunteer participants in this study included: six full time professors, eight part time professors, eighty-one students at a job fair, and seven individual student participants. Personal data on the participants was kept confidential. A questionnaire based on persistence variable indicators was developed and used as a data collection instrument for a statistical quantitative analysis. Eighty-one students responded to questionnaire items using a Likert scale ranging from one representing disagreement to five representing agreement. This was followed by a qualitative analysis to increase the scope and depth of the quantitative phase. The qualitative analysis involved discussions with full time professors, part time professors, students, and student graduates. Persistence indicators were then classified into social, academic, and institutional classifications to develop a graphic model of student persistence and a persistence interaction formula indicator. Student persistence levels are proportionally correlated to student contentment with educational outcomes.

Environmental reservoirs and mechanisms of persistence of Vibrio cholerae

PubMed Central

Lutz, Carla; Erken, Martina; Noorian, Parisa; Sun, Shuyang; McDougald, Diane

2013-01-01

It is now well accepted that Vibrio cholerae, the causative agent of the water-borne disease cholera, is acquired from environmental sources where it persists between outbreaks of the disease. Recent advances in molecular technology have demonstrated that this bacterium can be detected in areas where it has not previously been isolated, indicating a much broader, global distribution of this bacterium outside of endemic regions. The environmental persistence of V. cholerae in the aquatic environment can be attributed to multiple intra- and interspecific strategies such as responsive gene regulation and biofilm formation on biotic and abiotic surfaces, as well as interactions with a multitude of other organisms. This review will discuss some of the mechanisms that enable the persistence of this bacterium in the environment. In particular, we will discuss how V. cholerae can survive stressors such as starvation, temperature, and salinity fluctuations as well as how the organism persists under constant predation by heterotrophic protists. PMID:24379807

Disease progression in Chinese chronic hepatitis C patients with persistently normal alanine aminotransaminase levels.

PubMed

Hui, C-K; Zhang, H-Y; Shek, T; Yao, H; Yueng, Y-H; Leung, K-W; Lai, S-T; Lai, J-Y; Leung, N; Lau, G K

2007-06-01

Although chronic hepatitis C virus-infected patients with persistently normal alanine aminotransaminase levels usually have mild liver disease, disease progression can still occur. However, it is uncertain which group of patients is at risk of disease progression. To examine the severity of liver disease on liver biopsy in Chinese patients with persistently normal alanine aminotransaminase levels, and their disease progression over time. Eighty-two patients with persistently normal alanine aminotransaminase levels were followed up longitudinally. The median time of follow-up was 8.1 years. Forty-seven of the 82 patients (57.3%) had a second liver biopsy. At the time of analysis, six of the 82 patients (7.3%) developed decompensated liver cirrhosis. Patients with an initial fibrosis stage F2 or F3 [6/23 (26.1%) vs. 0/59 (0%), P < 0.0001] or inflammatory grade A2 or A3 [5/40 (12.5%) vs. 1/42 (2.4%), P = 0.04] were more likely to develop decompensated liver cirrhosis. On multivariate analysis, initial fibrosis stage F2 or F3 was independently associated with progression to decompensated liver cirrhosis (relative risk 2.3, 95% confidence interval 0.03-2.5, P = 0.02). Chinese chronic hepatitis C virus patients with persistently normal alanine aminotransaminase levels with moderate to severe fibrosis at initial evaluation are more likely to develop decompensated liver cirrhosis.

Stress hysteresis as the cause of persistent holes in particulate suspensions

NASA Astrophysics Data System (ADS)

Deegan, Robert D.

2010-03-01

Concentrated particulate suspensions under vibrations can support stable, localized, vertically oriented free surfaces. The most robust of these structures are persistent holes: deep and stable depressions of the interface. Using a reduced model of the hydrodynamics we show that a rheology with hysteresis can lead to motion opposite to the time-averaged applied force. Moreover, we show experimentally that particulate suspensions of cornstarch in water exhibits hysteresis in the shear-rate response to an applied sinusoidal stress. The results of our model and our experiments suggest that hysteresis accounts for the outward force needed to support persistent holes.

Selenium status and fungi in the protein-losing enteropathy of persistent diarrhea.

PubMed

Dwipoerwantoro, Pramita G; Lukito, Widjaja; Aulia, Diana; Arnaud, Josiane; Roussel, Anne-Marie

2017-06-01

A vicious cycle of infection, malabsorption, and malnutrition has been implicated in the perpetuation of diarrheal disease. This study examined whether persistent diarrhea is associated with changes in selenium status and stool alpha-1 antitrypsin (AAT) concentration. This cross-sectional study included 30 children aged 1-12 years with persistent diarrhea who were hospitalized in Cipto Mangunkusumo Hospital and Fatmawati Hospital, Jakarta, and 30 apparently healthy children who were matched by age and sex and lived in a rural area of Jakarta. Clinical examinations, blood routine tests, erythrocyte glutathione peroxidase (GPX) activity and plasma selenium levels as well as AAT in fresh stool samples were performed in all the subjects. Of 30 children with persistent diarrhea, 17 had moderate malnutrition and 13 had severe malnutrition. The mean plasma selenium was significantly lower in children with persistent diarrhea than in children without diarrhea (86.0 μg/L [95% CI: 76.1-95.9] vs 110 μg/L [95% CI: 104-116, p<0.0001). The mean stool AAT concentration was significantly higher in children with persistent diarrhea than in those without diarrhea (115 mg/dL [95% CI: 38.5-191] vs 16 mg/dL [95% CI: 4.0-13.5, p<0.0001]). Selenium correlated with AAT (p=0.05). Fecal fungi were persistently present. Although selenium status in both groups was optimal for the obtained plasma GPX activity, children with persistent diarrhea exhibited lower plasma selenium levels. This study suggests that the decrease in the plasma selenium level may be the consequence of protein loss and that fungi may be involved.

Mechanisms of racial inequalities in prevalence of diarrhoea in South Africa.

PubMed

Choi, Susanne Y P

2003-09-01

Decades of apartheid policies have resulted in marked racial inequalities in health in South Africa. The black:white rate ratio of diarrhoea among children aged less than five years, one of the five most common causes of infant and child deaths, stood at 6.5 in 1998. Using data from the 1998 South African Demographic and Health Survey, this paper examines the mechanisms of this racial disparity. The research confirms the presence of persistent racial inequalities in access to safe drinking-water and sanitation and in maternal education and household wealth, with the black population constituting the most disadvantaged group. While the living environment and access to safe drinking-water explain the excessive risk of diarrhoea among the black population compared to the coloured and Indian populations, the excessive risk of diarrhoea among the black population compared to the white population cannot be explained by disparities in the living environment, hygiene levels, and socioeconomic factors.

Internalization of fresh produce by foodborne pathogens.

PubMed

Erickson, Marilyn C

2012-01-01

Recent studies addressing the internalization of fresh produce by foodborne pathogens arose in response to the growing number of recent and high profile outbreaks involving fresh produce. Because chemical sanitizing agents used during harvest and minimal processing are unlikely to reach enteric pathogens residing within plant tissue, it is imperative that paths for pathogen entry be recognized and minimized. Using both microscopy and microbial enumeration tools, enteric pathogens have been shown to enter plant tissues through both natural apertures (stomata, lateral junctions of roots, flowers) and damaged (wounds, cut surfaces) tissue. In studies revealing preharvest internalization via plant roots or leaf stomata, experimental conditions have primarily involved exposure of plants to high pathogen concentrations (≥ 6 log g⁻¹ soil or 6 log ml⁻¹ water), but those pathogens internalized appear to have short-term persistence. Postharvest internalization of pathogens via cut surfaces may be minimized by maintaining effective levels of sanitizing agents in waters during harvesting and minimal processing.

Body size mediates social and environmental effects on nest building behaviour in a fish with paternal care.

PubMed

Lehtonen, Topi K; Lindström, Kai; Wong, Bob B M

2015-07-01

Body size, social setting, and the physical environment can all influence reproductive behaviours, but their interactions are not well understood. Here, we investigated how male body size, male-male competition, and water turbidity influence nest-building behaviour in the sand goby (Pomatoschistus minutus), a marine fish with exclusive paternal care. We found that environmental and social factors affected the nest characteristics of small and large males differently. In particular, association between male size and the level of nest elaboration (i.e. the amount of sand piled on top of the nest) was positive only under clear water conditions. Similarly, male size and nest entrance size were positively associated only in the absence of competition. Such interactions may, in turn, help to explain the persistence of variation in reproductive behaviours, which-due to their importance in offspring survival-are otherwise expected to be under strong balancing selection.

Source and persistence of pesticides in a semi-confined chalk aquifer of southeast England.

PubMed

Lapworth, D J; Gooddy, D C

2006-12-01

Pesticide contamination in groundwater is an increasing problem that poses a significant long-term threat to water quality. Following the detection of elevated concentrations of diuron in boreholes in a semi-confined chalk aquifer from southeast England, a sampling programme was undertaken. Between 2003 and 2004 diuron was observed in 90% of groundwaters analysed. In 60% of groundwater samples metabolites of diuron were more prevalent than the parent compound. Longer-term (1989-2005) monitoring shows that pollution of the aquifer by atrazine, simazine, and more recently diuron, shows a positive correlation with periods of high groundwater levels. Results from groundwater residence time indicators suggest that the highest diuron concentrations are associated with waters containing the greatest proportion of recent recharge. There is some evidence to indicate that diuron occurrence can be spatially related to areas of urban and industrial development and is probably correlated with amenity usage.

Significance and Clinical Management of Persistent Low-Level Viremia and Very-Low-Level Viremia in HIV-1-Infected Patients

PubMed Central

Kelly, Sean; Li, Jonathan Z.; Harrigan, P. Richard; Taiwo, Babafemi

2014-01-01

A goal of HIV therapy is to sustain suppression of the plasma viral load below the detection limits of clinical assays. However, widely followed treatment guidelines diverge in their interpretation and recommended management of persistent viremia of low magnitude, reflecting the limited evidence base for this common clinical finding. Here, we review the incidence, risk factors, and potential consequences of low-level HIV viremia (LLV; defined in this review as a viremia level of 50 to 500 copies/ml) and very-low-level viremia (VLLV; defined as a viremia level of <50 copies/ml detected by clinical assays that have quantification cutoffs of <50 copies/ml). Using this framework, we discuss practical issues related to the diagnosis and management of patients experiencing persistent LLV and VLLV. Compared to viral suppression at <50 or 40 copies/ml, persistent LLV is associated with increased risk of antiretroviral drug resistance and overt virologic failure. Higher immune activation and HIV transmission may be additional undesirable consequences in this population. It is uncertain whether LLV of <200 copies/ml confers independent risks, as this level of viremia may reflect assay-dependent artifacts or biologically meaningful events during suppression. Resistance genotyping should be considered in patients with persistent LLV when feasible, and treatment should be modified if resistance is detected. There is a dearth of clinical evidence to guide management when genotyping is not feasible. Increased availability of genotypic assays for samples with viral loads of <400 copies/ml is needed. PMID:24733471

Voluntary activation of the sympathetic nervous system and attenuation of the innate immune response in humans.

PubMed

Kox, Matthijs; van Eijk, Lucas T; Zwaag, Jelle; van den Wildenberg, Joanne; Sweep, Fred C G J; van der Hoeven, Johannes G; Pickkers, Peter

2014-05-20

Excessive or persistent proinflammatory cytokine production plays a central role in autoimmune diseases. Acute activation of the sympathetic nervous system attenuates the innate immune response. However, both the autonomic nervous system and innate immune system are regarded as systems that cannot be voluntarily influenced. Herein, we evaluated the effects of a training program on the autonomic nervous system and innate immune response. Healthy volunteers were randomized to either the intervention (n = 12) or control group (n = 12). Subjects in the intervention group were trained for 10 d in meditation (third eye meditation), breathing techniques (i.a., cyclic hyperventilation followed by breath retention), and exposure to cold (i.a., immersions in ice cold water). The control group was not trained. Subsequently, all subjects underwent experimental endotoxemia (i.v. administration of 2 ng/kg Escherichia coli endotoxin). In the intervention group, practicing the learned techniques resulted in intermittent respiratory alkalosis and hypoxia resulting in profoundly increased plasma epinephrine levels. In the intervention group, plasma levels of the anti-inflammatory cytokine IL-10 increased more rapidly after endotoxin administration, correlated strongly with preceding epinephrine levels, and were higher. Levels of proinflammatory mediators TNF-α, IL-6, and IL-8 were lower in the intervention group and correlated negatively with IL-10 levels. Finally, flu-like symptoms were lower in the intervention group. In conclusion, we demonstrate that voluntary activation of the sympathetic nervous system results in epinephrine release and subsequent suppression of the innate immune response in humans in vivo. These results could have important implications for the treatment of conditions associated with excessive or persistent inflammation, such as autoimmune diseases.

Assessment of the contamination of drinking water supply wells by pesticides from surface water resources using a finite element reactive transport model and global sensitivity analysis techniques

NASA Astrophysics Data System (ADS)

Malaguerra, Flavio; Albrechtsen, Hans-Jørgen; Binning, Philip John

2013-01-01

SummaryA reactive transport model is employed to evaluate the potential for contamination of drinking water wells by surface water pollution. The model considers various geologic settings, includes sorption and degradation processes and is tested by comparison with data from a tracer experiment where fluorescein dye injected in a river is monitored at nearby drinking water wells. Three compounds were considered: an older pesticide MCPP (Mecoprop) which is mobile and relatively persistent, glyphosate (Roundup), a newer biodegradable and strongly sorbing pesticide, and its degradation product AMPA. Global sensitivity analysis using the Morris method is employed to identify the dominant model parameters. Results show that the characteristics of clay aquitards (degree of fracturing and thickness), pollutant properties and well depths are crucial factors when evaluating the risk of drinking water well contamination from surface water. This study suggests that it is unlikely that glyphosate in streams can pose a threat to drinking water wells, while MCPP in surface water can represent a risk: MCPP concentration at the drinking water well can be up to 7% of surface water concentration in confined aquifers and up to 10% in unconfined aquifers. Thus, the presence of confining clay aquitards may not prevent contamination of drinking water wells by persistent compounds in surface water. Results are consistent with data on pesticide occurrence in Denmark where pesticides are found at higher concentrations at shallow depths and close to streams.

Response of crayfish to hyporheic water availability and excess sedimentation

USGS Publications Warehouse

Dyer, Joseph J.; Worthington, Thomas A.; Brewer, Shannon K.

2015-01-01

Crayfish in many headwater streams regularly cope with seasonal drought. However, it is unclear how landscape changes affect the long-term persistence of crayfish populations. We designed two laboratory experiments to investigate the acute effects of common landscape stressors on crayfish: water withdrawal and sedimentation. The first experiment tested the interaction among water withdrawals (four 24-h water reductions of 0, 15, 30, or 45 cm) and two substrate treatments (pebble and cobble) on the burrowing depth of crayfish. The second experiment evaluated the effects of excess fine sediment (three treatments of 0, 45, and 90% sediment) and substrate type (cobble and pebble) on crayfish burrowing depth. Crayfish were able to burrow deeper into the simulated hyporheic zone in cobble substrate when compared to pebble. Crayfish subjected to greater water withdrawals in the pebble treatment were not able to reach the simulated hyporheic zone. Excess fine sediment reduced the depth that crayfish burrowed, regardless of substrate type. Results from this study suggest excess fine sediment may reduce crayfish persistence, particularly when seeking refuge during prolonged dry conditions.

Coliphages and gastrointestinal illness in recreational waters: pooled analysis of six coastal beach cohorts

EPA Science Inventory

BACKGROUND: Coliphages have been proposed as indicators of fecal contamination in recreational waters because they better mimic the persistence of pathogenic viruses in the environment and wastewater treatment than fecal indicator bacteria. We estimated the association between co...

Effect of Season on the Persistence of Bacterial Pathogens in Runoff from Agricultural Plots

EPA Science Inventory

Runoff from agricultural fields undergoing manure applications may carry a variety of chemical and microbial contaminants that compromise water quality and increase the possibility of human exposure to pathogenic microorganisms when recreational waters are impacted. A series of r...

40 CFR 257.24 - Detection monitoring program.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Disposal Units Ground-Water Monitoring and Corrective Action § 257.24 Detection monitoring program. (a... unit; (ii) The mobility, stability, and persistence of waste constituents or their reaction products in... constituents, and reaction products in the ground water; and (iv) The concentration or values and coefficients...

A Water Grid for the UK

NASA Astrophysics Data System (ADS)

Leathard, A.; Fowler, H. J.; Kilsby, C. G.

2009-12-01

Anthropogenically aggravated climate change associated with intensive expansion of the global economy has increased the demand for water whilst simultaneously altering natural variability in its distribution, straining water resources unsustainably and inequitably in many parts of the world, increasing drought risk, and encouraging decision-makers to reconsider the security of water supply. Indeed, in the absence of additional resource development, contemporary planning forecasts imply increased water stress across much of the United Kingdom. Until recently the regulatory authorities of the UK promoted increased efficiency of water delivery and consumption combined with a portfolio of financial instruments as a means of reducing water stress, maintaining present levels of consumer service without significant further exploitation of the environment. However, despite an increasingly sophisticated understanding of climate change and its effects, significant uncertainty remains in the quantification of its impacts on the water sector, and questions persist as to the effectiveness of such demand management measures compared to that of more traditional infrastructure improvements. Faced with possible futures provided for by detrimentally over-stressed resources, what opportunities remain for future strategic development in the UK? Is there a single national strategy that is both politically and socially acceptable? Do the benefits of national water infrastructure projects outweigh their costs? This ongoing study aims to evolve robust national adaptation strategies by quantifying the projected impacts of climate change across mainland UK using multi-model and perturbed-physics ensembles of projected future climate, encapsulating uncertainties in a scenario-driven integrated water resources model incorporating socio-economic elements.

Persistently declining oxygen levels in the interior waters of the eastern subarctic Pacific

NASA Astrophysics Data System (ADS)

Whitney, Frank A.; Freeland, Howard J.; Robert, Marie

2007-10-01

Fifty years of measurements at Ocean Station Papa (OSP, 50°N, 145°W) show trends in the interior waters of the subarctic Pacific that are both impacted by short term (few years to bi-decadal) atmospheric or ocean circulation oscillations and by persistent climate trends. Between 1956 and 2006, waters below the ocean mixed layer to a depth of at least 1000 m have been warming and losing oxygen. On density surfaces found in the depth range 100-400 m ( σθ = 26.3-27.0), the ocean is warming at 0.005-0.012 °C y -1, whereas oxygen is declining at 0.39-0.70 μmol kg -1 y -1 or at an integrated rate of 123 mmol m -2 y -1 (decrease of 22% over 50 years). During this time, the hypoxic boundary (defined as 60 μmol O 2 kg -1) has shoaled from ∼400 to 300 m. In the Alaska Gyre, the 26.2 isopycnal occasionally ventilates, whereas at OSP 26.0 σθ has not been seen at the ocean surface since 1971 as the upper ocean continues to stratify. To interpret the 50 year record at OSP, the isopycnal transport of oxygenated waters within the interior of the subarctic Pacific is assessed by using a slightly modified “NO” parameter [Broecker, W., 1974. “NO” a conservative water-mass tracer. Earth and Planetary Science Letters 23, 100-107]. The highest nitrate-oxygen signature in interior waters of the North Pacific is found in the Bering Sea Gyre, Western Subarctic Gyre and East Kamchatka Current region as a consequence of winter mixing to the ∼26.6 isopycnal. By mixing with low NO waters found in the subtropics and Okhotsk Sea, this signature is diluted as waters flow eastward across the Pacific. Evidence of low NO waters flowing north from California is seen along the coasts of British Columbia and SE Alaska. Oxygen in the subsurface waters of the Alaskan Gyre was supplied ∼60% by subarctic and 40% by subtropical waters during WOCE surveys, whereas such estimates are shown to periodically vary by 20% at OSP. Other features discernable in the OSP data include periods of increased ventilation of deeper isopycnals on an ∼18 year cycle and strong, short term (few month) variability caused by passing mesoscale eddies. The potential impacts of declining oxygen on coastal ecosystems are discussed.

Developing and implementing the use of predictive models for estimating water quality at Great Lakes beaches

USGS Publications Warehouse

Francy, Donna S.; Brady, Amie M.G.; Carvin, Rebecca B.; Corsi, Steven R.; Fuller, Lori M.; Harrison, John H.; Hayhurst, Brett A.; Lant, Jeremiah; Nevers, Meredith B.; Terrio, Paul J.; Zimmerman, Tammy M.

2013-01-01

Predictive models have been used at beaches to improve the timeliness and accuracy of recreational water-quality assessments over the most common current approach to water-quality monitoring, which relies on culturing fecal-indicator bacteria such as Escherichia coli (E. coli.). Beach-specific predictive models use environmental and water-quality variables that are easily and quickly measured as surrogates to estimate concentrations of fecal-indicator bacteria or to provide the probability that a State recreational water-quality standard will be exceeded. When predictive models are used for beach closure or advisory decisions, they are referred to as “nowcasts.” During the recreational seasons of 2010-12, the U.S. Geological Survey (USGS), in cooperation with 23 local and State agencies, worked to improve existing nowcasts at 4 beaches, validate predictive models at another 38 beaches, and collect data for predictive-model development at 7 beaches throughout the Great Lakes. This report summarizes efforts to collect data and develop predictive models by multiple agencies and to compile existing information on the beaches and beach-monitoring programs into one comprehensive report. Local agencies measured E. coli concentrations and variables expected to affect E. coli concentrations such as wave height, turbidity, water temperature, and numbers of birds at the time of sampling. In addition to these field measurements, equipment was installed by the USGS or local agencies at or near several beaches to collect water-quality and metrological measurements in near real time, including nearshore buoys, weather stations, and tributary staff gages and monitors. The USGS worked with local agencies to retrieve data from existing sources either manually or by use of tools designed specifically to compile and process data for predictive-model development. Predictive models were developed by use of linear regression and (or) partial least squares techniques for 42 beaches that had at least 2 years of data (2010-11 and sometimes earlier) and for 1 beach that had 1 year of data. For most models, software designed for model development by the U.S. Environmental Protection Agency (Virtual Beach) was used. The selected model for each beach was based on a combination of explanatory variables including, most commonly, turbidity, day of the year, change in lake level over 24 hours, wave height, wind direction and speed, and antecedent rainfall for various time periods. Forty-two predictive models were validated against data collected during an independent year (2012) and compared to the current method for assessing recreational water quality-using the previous day’s E. coli concentration (persistence model). Goals for good predictive-model performance were responses that were at least 5 percent greater than the persistence model and overall correct responses greater than or equal to 80 percent, sensitivities (percentage of exceedances of the bathing-water standard that were correctly predicted by the model) greater than or equal to 50 percent, and specificities (percentage of nonexceedances correctly predicted by the model) greater than or equal to 85 percent. Out of 42 predictive models, 24 models yielded over-all correct responses that were at least 5 percent greater than the use of the persistence model. Predictive-model responses met the performance goals more often than the persistence-model responses in terms of overall correctness (28 versus 17 models, respectively), sensitivity (17 versus 4 models), and specificity (34 versus 25 models). Gaining knowledge of each beach and the factors that affect E. coli concentrations is important for developing good predictive models. Collection of additional years of data with a wide range of environmental conditions may also help to improve future model performance. The USGS will continue to work with local agencies in 2013 and beyond to develop and validate predictive models at beaches and improve existing nowcasts, restructuring monitoring activities to accommodate future uncertainties in funding and resources.

Unraveling energy conversion modeling in the intrinsic persistent upconverted luminescence of solids: a study of native point defects in antiferromagnetic Er2O3.

PubMed

Huang, Bolong

2016-05-11

We investigated the mechanism of the intrinsic persistent luminescence of Er2O3 in the A-type lattice based on first-principles calculations. We found that the native point defects were engaged in mutual subtle interactions in the form of chemical reactions between different charge states. The release of energy related to lattice distortion facilitates the conversion of energy for electrons to be transported between the valence band and the trap levels or even between the deep trap levels so as to generate persistent luminescence. The defect transitions that take place along the zero-phonon line release energy to enable optical transitions, with the exact amount of negative effective correlation energy determined by the lattice distortions. Our calculations on the thermodynamic transition levels confirm that both the visible and NIR experimentally observed intrinsic persistent luminescence (phosphor or afterglow) are related to the thermodynamic transition levels of oxygen-related defects, and the thermodynamic transition levels within different charge states for these defects are independent of the chemical potentials of the given species. Lattice distortion defects such as anion Frenkel (a-Fr) pair defects play an important role in transporting O-related defects between different lattice sites. To obtain red persistent luminescence that matches the biological therapeutic window, it is suggested to increase the electron transition levels between high-coordinated O vacancies and related metastable a-Fr defects; a close-packed core-shell structure is required to quench low-coordinated O-related defects so as to reduce the green band luminescence. We further established a conversed chain reaction (CCR) model to interpret the energy conversion process of persistent luminescence in terms of the inter-reactions of native point defects between different charge states. It is advantageous to use the study of defect levels combined with formation energies to suggest limits to doping energy and explain photostimulated luminescence in terms of native point defects.

Persistent α-Fetoprotein Elevation in Healthy Adults and Mutational Analysis of α-Fetoprotein Promoter, Enhancer, and Silencer Regions.

PubMed

Jeon, Yejoo; Choi, Yun Suk; Jang, Eun Sun; Kim, Jin Wook; Jeong, Sook-Hyang

2017-01-15

α-Fetoprotein (AFP) is normally <10 ng/mL in adults without malignancy or liver regeneration. However, hereditary or nonhereditary persistence of AFP in healthy adults may be encountered in clinical practice. This study describes four cases of persistent AFP elevation in healthy adults and investigates mutations in key transcription regulatory regions of the AFP gene as potential drivers of AFP overexpression. Four healthy adults with persistently elevated AFP levels (12.1 to 186.1 ng/mL) for >1 year, and 20 controls with low AFP levels (<0.61 to 2.9 ng/mL) were included in the study. AFP levels were collected from the families of two of the patients. We sequenced five regions that are critical for AFP expression: a promoter, two enhancers, and two silencers. One of the two cases in which family information was represented is the first case of hereditary persistence of AFP in South Korea. Mutations related to AFP overexpression were not found in the transcription regulatory regions among the four patients. Persistent AFP elevation is a heterogeneous condition with or without a hereditary pattern and may be caused by factors outside of transcription regulatory region changes. Further research on the mechanism of AFP elevation is needed.

Persistent α-Fetoprotein Elevation in Healthy Adults and Mutational Analysis of α-Fetoprotein Promoter, Enhancer, and Silencer Regions

PubMed Central

Jeon, Yejoo; Choi, Yun Suk; Jang, Eun Sun; Kim, Jin Wook; Jeong, Sook-Hyang

2017-01-01

Background/Aims α-Fetoprotein (AFP) is normally <10 ng/mL in adults without malignancy or liver regeneration. However, hereditary or nonhereditary persistence of AFP in healthy adults may be encountered in clinical practice. This study describes four cases of persistent AFP elevation in healthy adults and investigates mutations in key transcription regulatory regions of the AFP gene as potential drivers of AFP overexpression. Methods Four healthy adults with persistently elevated AFP levels (12.1 to 186.1 ng/mL) for >1 year, and 20 controls with low AFP levels (<0.61 to 2.9 ng/mL) were included in the study. AFP levels were collected from the families of two of the patients. We sequenced five regions that are critical for AFP expression: a promoter, two enhancers, and two silencers. Results One of the two cases in which family information was represented is the first case of hereditary persistence of AFP in South Korea. Mutations related to AFP overexpression were not found in the transcription regulatory regions among the four patients. Conclusions Persistent AFP elevation is a heterogeneous condition with or without a hereditary pattern and may be caused by factors outside of transcription regulatory region changes. Further research on the mechanism of AFP elevation is needed. PMID:27609486

Factors Affecting M-Learners' Course Satisfaction and Learning Persistence

ERIC Educational Resources Information Center

Joo, Young Ju; Joung, Sunyoung; Lim, Eugene; Kim, Hae Jin

2014-01-01

This study investigated whether college students' self-efficacy, level of learning strategy use, academic burnout, and school support predict course satisfaction and learning persistence. To this end, self-efficacy, level of learning strategy use, academic burnout, and school support were used as prediction variables, and course satisfaction and…

Assessment of mitochondrial DNA damage in little brown bats (Myotis lucifugus) collected near a mercury-contaminated river

USGS Publications Warehouse

Karouna-Renier, Natalie K.; White, Carl; Perkins, Christopher R.; Schmerfeld, John J.; Yates, David

2014-01-01

Historical discharges of Hg into the South River near the town of Waynesboro, VA, USA, have resulted in persistently elevated Hg concentrations in sediment, surface water, ground water, soil, and wildlife downstream of the discharge site. In the present study, we examined mercury (Hg) levels in in little brown bats (Myotis lucifugus) from this location and assessed the utility of a non-destructively collected tissue sample (wing punch) for determining mitochondrial DNA (mtDNA) damage in Hg exposed bats. Bats captured 1 and 3 km from the South River, exhibited significantly higher levels of total Hg (THg) in blood and fur than those from the reference location. We compared levels of mtDNA damage using real-time quantitative PCR (qPCR) analysis of two distinct regions of mtDNA. Genotoxicity is among the many known toxic effects of Hg, resulting from direct interactions with DNA or from oxidative damage. Because it lacks many of the protective protein structures and repair mechanisms associated with nuclear DNA, mtDNA is more sensitive to the effects of genotoxic chemicals and therefore may be a useful biomarker in chronically exposed organisms. Significantly higher levels of damage were observed in both regions of mtDNA in bats captured 3 km from the river than in controls. However, levels of mtDNA damage exhibited weak correlations with fur and blood THg levels, suggesting that other factors may play a role in the site-specific differences.

Long-Term Persistence of Cell-Mediated and Humoral Responses to A(H1N1)pdm09 Influenza Virus Vaccines and the Role of the AS03 Adjuvant System in Adults during Two Randomized Controlled Trials

PubMed Central

Clément, Frédéric; Willekens, Julie; Dewé, Walthère; Walravens, Karl; Vaughn, David W.; Leroux-Roels, Geert

2017-01-01

ABSTRACT We investigated the role of AS03A (here AS03), an α-tocopherol oil-in-water emulsion-based adjuvant system, on the long-term persistence of humoral and cell-mediated immune responses to A(H1N1)pdm09 influenza vaccines. In two studies, a total of 261 healthy adults (≤60 years old) were randomized to receive two doses of AS03-adjuvanted vaccine containing 3.75 μg of hemagglutinin (HA) or nonadjuvanted vaccine containing 15 μg of hemagglutinin (in study A) or 3.75 μg of hemagglutinin (in study B) 21 days apart. Hemagglutination inhibition (HI) antibody, memory B-cell, and CD4+/CD8+ T-cell responses were characterized up to 1 year following dose 1. We also assessed the effects of age and seasonal influenza vaccination history. AS03-adjuvanted (3.75 μg HA) vaccine and nonadjuvanted vaccine at 15 μg but not at 3.75 μg HA elicited HI antibody responses persisting at levels that continued to meet European licensure criteria through month 12. At month 12, the geometric mean titer for AS03-adjuvanted vaccine was similar to that for nonadjuvanted (15-μg) vaccine in study A (1:86 and 1:88, respectively) and higher than that for nonadjuvanted (3.75-μg) vaccine in study B (1:77 and 1:35, respectively). A(H1N1)pdm09-specific CD4+ T-cell and B-cell responses were stronger in AS03-adjuvanted groups and persisted only in these groups for 12 months at levels exceeding prevaccination frequencies. Advancing age and a seasonal vaccination history tended to reduce HI antibody and memory B-cell responses and, albeit less consistently, CD4+ T-cell responses. Thus, AS03 seemed to enhance the persistence of humoral and cell-mediated responses to A(H1N1)pdm09 vaccine, allowing for antigen sparing and mitigating potential negative effects of age and previous seasonal vaccination. (These studies have been registered at ClinicalTrials.gov under registration no. NCT00968539 and NCT00989287.) PMID:28446441

Long-Term Persistence of Cell-Mediated and Humoral Responses to A(H1N1)pdm09 Influenza Virus Vaccines and the Role of the AS03 Adjuvant System in Adults during Two Randomized Controlled Trials.

PubMed

van der Most, Robbert G; Clément, Frédéric; Willekens, Julie; Dewé, Walthère; Walravens, Karl; Vaughn, David W; Leroux-Roels, Geert

2017-06-01

We investigated the role of AS03 A (here AS03), an α-tocopherol oil-in-water emulsion-based adjuvant system, on the long-term persistence of humoral and cell-mediated immune responses to A(H1N1)pdm09 influenza vaccines. In two studies, a total of 261 healthy adults (≤60 years old) were randomized to receive two doses of AS03-adjuvanted vaccine containing 3.75 μg of hemagglutinin (HA) or nonadjuvanted vaccine containing 15 μg of hemagglutinin (in study A) or 3.75 μg of hemagglutinin (in study B) 21 days apart. Hemagglutination inhibition (HI) antibody, memory B-cell, and CD4 + /CD8 + T-cell responses were characterized up to 1 year following dose 1. We also assessed the effects of age and seasonal influenza vaccination history. AS03-adjuvanted (3.75 μg HA) vaccine and nonadjuvanted vaccine at 15 μg but not at 3.75 μg HA elicited HI antibody responses persisting at levels that continued to meet European licensure criteria through month 12. At month 12, the geometric mean titer for AS03-adjuvanted vaccine was similar to that for nonadjuvanted (15-μg) vaccine in study A (1:86 and 1:88, respectively) and higher than that for nonadjuvanted (3.75-μg) vaccine in study B (1:77 and 1:35, respectively). A(H1N1)pdm09-specific CD4 + T-cell and B-cell responses were stronger in AS03-adjuvanted groups and persisted only in these groups for 12 months at levels exceeding prevaccination frequencies. Advancing age and a seasonal vaccination history tended to reduce HI antibody and memory B-cell responses and, albeit less consistently, CD4 + T-cell responses. Thus, AS03 seemed to enhance the persistence of humoral and cell-mediated responses to A(H1N1)pdm09 vaccine, allowing for antigen sparing and mitigating potential negative effects of age and previous seasonal vaccination. (These studies have been registered at ClinicalTrials.gov under registration no. NCT00968539 and NCT00989287.). Copyright © 2017 van der Most et al.

Neurotoxic, inflammatory, and mucosecretory responses in the nasal airways of mice repeatedly exposed to the macrocyclic trichothecene mycotoxin roridin A: dose-response and persistence of injury.

PubMed

Corps, Kara N; Islam, Zahidul; Pestka, James J; Harkema, Jack R

2010-04-01

Macrocyclic trichothecene mycotoxins encountered in water-damaged buildings have been suggested to contribute to illnesses of the upper respiratory tract. Here, the authors characterized the adverse effects of repeated exposures to roridin A (RA), a representative macrocyclic trichothecene, on the nasal airways of mice and assessed the persistence of these effects. Young, adult, female C57BL/6 mice were exposed to single daily, intranasal, instillations of RA (0.4, 2, 10, or 50 microg/kg body weight [bw]) in saline (50 microl) or saline alone (controls) over 3 weeks or 250 microg/kg RA over 2 weeks. Histopathologic, immunohistochemical, and morphometric analyses of nasal airways conducted 24 hr after the last instillation revealed that the lowest-effect level was 10 microg/kg bw. RA exposure induced a dose-dependent, neutrophilic rhinitis with mucus hypersecretion, atrophy and exfoliation of nasal transitional and respiratory epithelium, olfactory epithelial atrophy and loss of olfactory sensory neurons (OSNs). In a second study, the persistence of lesions in mice instilled with 250 microg/kg bw RA was assessed. Nasal inflammation and excess luminal mucus were resolved after 3 weeks, but OSN loss was still evident in olfactory epithelium (OE). These results suggest that nasal inflammation, mucus hypersecretion, and olfactory neurotoxicity could be important adverse health effects associated with short-term, repeated, airborne exposures to macrocyclic trichothecenes.

Oceanography of Glacier Bay, Alaska: Implications for biological patterns in a glacial fjord estuary

USGS Publications Warehouse

Etherington, L.L.; Hooge, P.N.; Hooge, Elizabeth Ross; Hill, D.F.

2007-01-01

Alaska, U.S.A, is one of the few remaining locations in the world that has fjords that contain temperate idewater glaciers. Studying such estuarine systems provides vital information on how deglaciation affects oceanographic onditions of fjords and surrounding coastal waters. The oceanographic system of Glacier Bay, Alaska, is of particular interest ue to the rapid deglaciation of the Bay and the resulting changes in the estuarine environment, the relatively high oncentrations of marine mammals, seabirds, fishes, and invertebrates, and the Bay’s status as a national park, where ommercial fisheries are being phased out. We describe the first comprehensive broad-scale analysis of physical and iological oceanographic conditions within Glacier Bay based on CTD measurements at 24 stations from 1993 to 2002. easonal patterns of near-surface salinity, temperature, stratification, turbidity, and euphotic depth suggest that freshwater nput was highest in summer, emphasizing the critical role of glacier and snowmelt to this system. Strong and persistent tratification of surface waters driven by freshwater input occurred from spring through fall. After accounting for seasonal nd spatial variation, several of the external physical factors (i.e., air temperature, precipitation, day length) explained a large mount of variation in the physical properties of the surface waters. Spatial patterns of phytoplankton biomass varied hroughout the year and were related to stratification levels, euphotic depth, and day length. We observed hydrographic atterns indicative of strong competing forces influencing water column stability within Glacier Bay: high levels of freshwater ischarge promoted stratification in the upper fjord, while strong tidal currents over the Bay’s shallow entrance sill enhanced ertical mixing. Where these two processes met in the central deep basins there were optimal conditions of intermediate tratification, higher light levels, and potential nutrient renewal. These conditions were associated with high and sustained hlorophylla levels observed from spring through fall in these zones of the Bay and provide a framework for understanding he abundance patterns of higher trophic levels within this estuarine system.

[Galectin-3 in Patients With Paroxysmal and Persistent Atrial Fibrillation and Metabolic Syndrome].

PubMed

A, V A; Zaslavskaya, E L; Soboleva, A V; Baranova, E I; Listopad, O V; Nifontov, S E; Nrady, A O; Shlyakhto, E V

2016-06-01

To evaluate serum galectin 3 and to determine the potential clinical value of this parameter in patients with atrial fibrillation - AF (paroxysmal and persistent) and metabolic syndrome (MS). We examined 100 patients with MS (50 with paroxysmal or persistent AF and 50 without arrhythmia) and 50 healthy persons. Serum galectin 3 measured by ELISA method, ECHO cardiography was performed to all examined persons. Galectin 3 in patients with MS and AF was higher, than in patients with MS without arrhythmia and much more higher than galectin 3 in healthy persons 0,72 (0,44;1,36), 0,44 (0,42;1,22) and 0,32 (0,28;0,42) ng/ml (<0,01). In patients with persistent AF levels of galectin 3 is higher than in patients with paroxysmal AF. Positive correlation between the levels of galectin 3 and duration arrhythmia was revealed (r=0,301; p<0,01). Higher level of galectin 3 was revealed in patients with frequent paroxysms of AF and ineffective antiarrhythmic therapy. Marker of myocardial fibrosis serum galectin 3 in patients with atrial fibrillation and metabolic syndrome is higher than in patients with the metabolic syndrome, without this arrhythmia and higher than in healthy controls. In patients with persistent AF level of galectin 3 was higher than in patients with paroxysmal AF.

Strengthen the collaboration between the River Basin Management Organization of China and International Environmental Specimen Bank Group.

PubMed

Tan, Lingzhi; Liu, Hui; Shu, Jinxiang; Xia, Fan

2015-02-01

Several types of emerging organic contaminants were investigated in many recent researches, such as persistent toxic substance (PTS), persistent organic pollutants (POPs), endocrine disrupters (EDs), and volatile organic compounds (VOCs). But the Chinese country standard detection methods of emerging organic pollutants were not developed with the dramatic increasing of the organic substances production. Hence, it is necessary to obtain the latest informations about the long-term storage of representative environmental specimens, which could provide scientific basis for environmental management and environmental decision-making of the water resources protection and management organization. As the significant water resource conservation organization, the Water Environment Monitoring Center of Yangtze River Basin is experienced in water environmental monitoring and records many useful water resources and environment informations. It is also our responsibility to monitor all the pollutants in water environment of the Yangtze River valley, especially the emerging organic contaminants. Meanwhile, the International Environmental Specimen Bank (IESB) accumulates lots environmental organic pollution specimens and plays a significant role in environmental monitoring. Thus, the collaboration between the two parties will be greatly helpful for each further researches and monitoring work of organic contaminants in Yangtze River Basin.

Degradation of terbuthylazine, difenoconazole and pendimethalin pesticides by selected fungi cultures.

PubMed

Pinto, A P; Serrano, C; Pires, T; Mestrinho, E; Dias, L; Teixeira, D Martins; Caldeira, A T

2012-10-01

Contamination of waters by xenobiotic compounds such as pesticides presents a serious environmental problem with substantial levels of pesticides now contaminating European water resources. The aim of this work was to evaluate the ability of the fungi Fusarium oxysporum, Aspergillus oryzae, Lentinula edodes, Penicillium brevicompactum and Lecanicillium saksenae, for the biodegradation of the pesticides terbuthylazine, difenoconazole and pendimethalin in batch liquid cultures. These pesticides are common soil and water contaminants and terbuthylazine is considered the most persistent triazine herbicide in surface environments. P. brevicompactum and L. saksenae were achieved by enrichment, isolation and screening of fungi capable to metabolize the pesticides studied. The isolates were obtained from two pesticide-primed materials (soil and biomixture). Despite the relatively high persistence of terbuthylazine, the results obtained in this work showed that the fungi species studied have a high capability of biotransformation of this xenobiotic, comparatively the results obtained in other similar studies. The highest removal percentage of terbuthylazine from liquid medium was achieved with A. oryzae (~80%), although the major biodegradation has been reached with P. brevicompactum. The higher ability of P. brevicompactum to metabolize terbuthylazine was presumably acquired through chronic exposure to contamination with the herbicide. L. saksenae could remove 99.5% of the available pendimethalin in batch liquid cultures. L. edodes proved to be a fungus with a high potential for biodegradation of pesticides, especially difenoconazole and pendimethalin. Furthermore, the metabolite desethyl-terbuthylazine was detected in L. edodes liquid culture medium, indicating terbuthylazine biodegradation by this fungus. The fungi strains investigated could prove to be valuable as active pesticide-degrading microorganisms, increasing the efficiency of biopurification systems containing wastewaters contaminated with the xenobiotics studied or compounds with similar intrinsic characteristics. Copyright © 2012 Elsevier B.V. All rights reserved.

Mechanistic Processes Controlling Persistent Changes of Forest Canopy Structure After 2005 Amazon Drought

NASA Astrophysics Data System (ADS)

Shi, Mingjie; Liu, Junjie; Zhao, Maosheng; Yu, Yifan; Saatchi, Sassan

2017-12-01

The long-term impact of Amazonian drought on canopy structure has been observed in ground and remote sensing measurements. However, it is still unclear whether it is caused by biotic (e.g., plant structure damage) or environmental (e.g., water deficiency) factors. We used the Community Land Model version 4.5 (CLM4.5) and radar backscatter observations from SeaWinds Scatterometer on board QuikSCAT (QSCAT) satellite to investigate the relative role of biotic and environmental factors in controlling the forest canopy disturbance and recovery processes after the 2005 Amazonian drought. We validated the CLM4.5 simulation of the drought impact and the recovery of leaf carbon (C) pool, an indicator of canopy structure, over southwestern Amazonia with QSCAT backscatter observations, which are sensitive to canopy structure change. We found that the leaf C pool simulated by CLM4.5 recovered to the 2000-2009 mean level (343 g C m-2) in 3 years after a sharp decrease in 2005, consistent with the QSCAT observed slow recovery. Through sensitivity experiments, we found that the slow C recovery was primarily due to biotic factors represented by the canopy damage and reduction of plant C pools. The recovery of soil water and the coupling between water and C pools, which is an environmental factor, only contributes 24% to the leaf C recovery. The results showed (1) the strength of scatterometer backscatter measurements in capturing canopy damage over tropical forests and in validating C cycle models and (2) the biotic factors play the dominant role in regulating the drought induced disturbance and persistent canopy changes in CLM4.5.