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Full-Text Articles in Environmental Health and Protection

Integrating Lidar Data And Multi-Temporal Aerial Imagery To Map Wetland Inundation Dynamics Using Google Earth Engine, Qiusheng Wu, Charles B. Lane, Xuecao Li, Kaiguang Zhao, Yuyu Zhou, Nicholas Clinton, Ben Devries, Heather E. Golden, Megan W. Lang Dec 2019

Integrating Lidar Data And Multi-Temporal Aerial Imagery To Map Wetland Inundation Dynamics Using Google Earth Engine, Qiusheng Wu, Charles B. Lane, Xuecao Li, Kaiguang Zhao, Yuyu Zhou, Nicholas Clinton, Ben Devries, Heather E. Golden, Megan W. Lang

United States Environmental Protection Agency: Staff Publications

The Prairie Pothole Region of North America is characterized by millions of depressional wetlands, which provide critical habitats for globally significant populations of migratory waterfowl and other wildlife species. Due to their relatively small size and shallow depth, these wetlands are highly sensitive to climate variability and anthropogenic changes, exhibiting inter- and intra-annual inundation dynamics. Moderate-resolution satellite imagery (e.g., Landsat, Sentinel) alone cannot be used to effectively delineate these small depressional wetlands. By integrating fine spatial resolution Light Detection and Ranging (LiDAR) data and multi-temporal (2009–2017) aerial images, we developed a fully automated approach to delineate wetland inundation extent at …


Seasonality Of Nitrogen Balances In A Mediterranean Climate Watershed, Oregon, Us, Jiajia Lin, Jana E. Compton, Scott G. Leibowitz, George Mueller-Warrant, William Matthews, Stephen H. Schoenholtz, Daniel M. Evans, Rob A. Coulombe Dec 2018

Seasonality Of Nitrogen Balances In A Mediterranean Climate Watershed, Oregon, Us, Jiajia Lin, Jana E. Compton, Scott G. Leibowitz, George Mueller-Warrant, William Matthews, Stephen H. Schoenholtz, Daniel M. Evans, Rob A. Coulombe

United States Environmental Protection Agency: Staff Publications

We constructed a seasonal nitrogen (N) budget for the year 2008 in the Calapooia River Watershed (CRW), an agriculturally dominated tributary of the Willamette River (Oregon, U.S.) under Mediterranean climate. Synthetic fertilizer application to agricultural land (dominated by grass seed crops) was the source of 90% of total N input to the CRW. Over 70% of the stream N export occurred during the wet winter, the primary time of fertilization and precipitation, and the lowest export occurred in the dry summer. Averaging across all 58 tributary subwatersheds, 19% of annual N inputs were exported by streams, and 41% by crop …


Estimates Of Present And Future Flood Risk In The Conterminous United States, Oliver E.J. Wing, Paul D. Bates, Andrew M. Smith, Christopher C. Sampson, Kris A. Johnson, Joseph Fargione, Philip Morefield Feb 2018

Estimates Of Present And Future Flood Risk In The Conterminous United States, Oliver E.J. Wing, Paul D. Bates, Andrew M. Smith, Christopher C. Sampson, Kris A. Johnson, Joseph Fargione, Philip Morefield

United States Environmental Protection Agency: Staff Publications

Past attempts to estimate rainfall-driven flood risk across the US either have incomplete coverage, coarse resolution or use overly simplified models of the flooding process. In this paper, we use a new 30m resolution model of the entire conterminous US with a 2D representation of flood physics to produce estimates of flood hazard, which match to within 90% accuracy the skill of local models built with detailed data. These flood depths are combined with exposure datasets of commensurate resolution to calculate current and future flood risk. Our data show that the total US population exposed to serious flooding is 2.6–3.1 …


Statistical Survey Of Persistent Organic Pollutants: Risk Estimations To Humans And Wildlife Through Consumption Of Fish From U.S. Rivers, Angela L. Batt, John B. Wathen, James M. Lazorchak, Anthony R. Olsen, Thomas M. Kincaid Jan 2017

Statistical Survey Of Persistent Organic Pollutants: Risk Estimations To Humans And Wildlife Through Consumption Of Fish From U.S. Rivers, Angela L. Batt, John B. Wathen, James M. Lazorchak, Anthony R. Olsen, Thomas M. Kincaid

United States Environmental Protection Agency: Staff Publications

U.S. EPA conducted a national statistical survey of fish tissue contamination at 540 river sites (representing 82 954 river km) in 2008−2009, and analyzed samples for 50 persistent organic pollutants (POPs), including 21 PCB congeners, 8 PBDE congeners, and 21 organochlorine pesticides. The survey results were used to provide national estimates of contamination for these POPs. PCBs were the most abundant, being measured in 93.5% of samples. Summed concentrations of the 21 PCB congeners had a national weighted mean of 32.7 μg/kg and a maximum concentration of 857 μg/kg, and exceeded the human health cancer screening value of 12 μg/kg …


A Photosynthesis-Based Two-Leaf Canopy Stomatal Conductance Model For Meteorology And Air Quality Modeling With Wrf/Cmaq Px Lsm, Limei Ran, Jonathan Pleim, Conghe Song, Larry Band, John T. Walker, Francis S. Binkowski Jan 2017

A Photosynthesis-Based Two-Leaf Canopy Stomatal Conductance Model For Meteorology And Air Quality Modeling With Wrf/Cmaq Px Lsm, Limei Ran, Jonathan Pleim, Conghe Song, Larry Band, John T. Walker, Francis S. Binkowski

United States Environmental Protection Agency: Staff Publications

A coupled photosynthesis-stomatal conductance model with single-layer sunlit and shaded leaf canopy scaling is implemented and evaluated in a diagnostic box model with the Pleim-Xiu land surface model (PX LSM) and ozone deposition model components taken directly from the meteorology and air quality modeling system—WRF/CMAQ (Weather Research and Forecast model and Community Multiscale Air Quality model). The photosynthesis-based model for PX LSM (PX PSN) is evaluated at a FLUXNET site for implementation against different parameterizations and the current PX LSM approach with a simple Jarvis function (PX Jarvis). Latent heat flux (LH) from PX PSN is further evaluated at five …


Atp Binding Cassette Sub-Family Member 2 (Abcg2) And Xenobiotic Exposure During Early Mouse Embryonic Stem Cell Differentiation, Mitchell B. Rosen, Susan C. Jeffay, Harriette P. Nichols, Maria R. Hoopes, E. Sidney Hunter Iii Jan 2017

Atp Binding Cassette Sub-Family Member 2 (Abcg2) And Xenobiotic Exposure During Early Mouse Embryonic Stem Cell Differentiation, Mitchell B. Rosen, Susan C. Jeffay, Harriette P. Nichols, Maria R. Hoopes, E. Sidney Hunter Iii

United States Environmental Protection Agency: Staff Publications

Background: ATP binding cassette sub-family member 2 (ABCG2) is a welldefined efflux transporter found in a variety of tissues. The role of ABCG2 during early embryonic development, however, is not established. Previous work which compared data from the ToxCast screening program with that from in-house studies suggested an association exists between exposure to xenobiotics that regulate Abcg2 transcription and differentiation of mouse embryonic stem cells (mESC), a relationship potentially related to redox homeostasis.

Methods: mESC were grown for up to 9 days. Pharmacological inhibitors were used to assess transporter function with and without xenobiotic exposure. Proliferation and differentiation were …


Weight Of Evidence Evaluation Of A Network Of Adverse Outcome Pathways Linking Activation Of The Nicotinic Acetylcholine Receptor In Honey Bees To Colony Death, Carlie A. Lalone, Daniel L. Villeneuve, Judy Wu-Smart, Rebecca Y. Milsk, Keith Sappington, Kristina V. Garber, Justin Housenger, Gerald T. Ankley Jan 2017

Weight Of Evidence Evaluation Of A Network Of Adverse Outcome Pathways Linking Activation Of The Nicotinic Acetylcholine Receptor In Honey Bees To Colony Death, Carlie A. Lalone, Daniel L. Villeneuve, Judy Wu-Smart, Rebecca Y. Milsk, Keith Sappington, Kristina V. Garber, Justin Housenger, Gerald T. Ankley

United States Environmental Protection Agency: Staff Publications

Ongoing honey bee (Apis mellifera) colony losses are of significant international concern because of the essential role these insects play in pollinating crops. Both chemical and non-chemical stressors have been implicated as possible contributors to colony failure; however, the potential role(s) of commonly-used neonicotinoid insecticides has emerged as particularly concerning. Neonicotinoids act on the nicotinic acetylcholine receptors (nAChRs) in the central nervous system to eliminate pest insects. However, mounting evidence indicates that neonicotinoids also may adversely affect beneficial pollinators, such as the honey bee, via impairments on learning and memory, and ultimately foraging success. The specificmechanisms linking activation …


Influence Of Resource Availability On Juniperus Virginiana Expansion In A Forest–Prairie Ecotone, A. C. Ganguli, D. M. Engle, P. M. Mayer, L. F. Salo Aug 2016

Influence Of Resource Availability On Juniperus Virginiana Expansion In A Forest–Prairie Ecotone, A. C. Ganguli, D. M. Engle, P. M. Mayer, L. F. Salo

United States Environmental Protection Agency: Staff Publications

Woody plant expansion into grasslands and savannas is a global concern. Rapid expansion of Juniperus virginiana, a tree native to North America, has profound ecological consequences. We used transplanted J. virginiana seedlings to investigate the role of resource availability on J. virginiana expansion following the removal of fire, the factor historically limiting range expansion of this fire-intolerant species. We evaluated J. virginiana seedling survival and seedling growth, two important phases in woody plant expansion, relative to two below ground resource factors, plant-available soil water (soil clay content, an index of plant-available soil water) and plant-available nitrogen (PAN), and an above …


A Comparison Between 2010 And 2006 Air Quality And Meteorological Conditions, And Emissions And Boundary Conditions Used In Simulations Of The Aqmeii-2 North American Domain, Till E. Stoeckenius, Christian Hogrefe, Justin Zagunis, Timonthy M. Sturtz, Benjamin Wells, Tanarit Sakulyanontvittaya Jan 2016

A Comparison Between 2010 And 2006 Air Quality And Meteorological Conditions, And Emissions And Boundary Conditions Used In Simulations Of The Aqmeii-2 North American Domain, Till E. Stoeckenius, Christian Hogrefe, Justin Zagunis, Timonthy M. Sturtz, Benjamin Wells, Tanarit Sakulyanontvittaya

United States Environmental Protection Agency: Staff Publications

Several participants in Phase 2 of the Air Quality Model Evaluation International Initiative (AQMEII-2) who are applying coupled models to the North American domain are comparing model results for two years, 2006 and 2010, with the goal of performing dynamic model evaluation. From a modeling perspective, the differences of interest are the large reductions in domain total emissions of NOx (21%) and SO2 (37%) from 2006 to 2010 and significant differences in meteorological conditions between these two years. The emission reductions occurred mostly in the eastern U.S, with some reduction in emissions from western wildfires in 2010. Differences …


Identification Of Putative Geographically Isolated Wetlands Of The Conterminous United States, Charles R. Lane, Ellen D'Amico Jan 2016

Identification Of Putative Geographically Isolated Wetlands Of The Conterminous United States, Charles R. Lane, Ellen D'Amico

United States Environmental Protection Agency: Staff Publications

Geographically isolated wetlands (GIWs) are wetlands completely surrounded by uplands. While common throughout the United States (U.S.), there have heretofore been no nationally available, spatially explicit estimates of GIW extent, complicating efforts to understand the myriad biogeochemical, hydrological, and habitat functions of GIWs and hampering conservation and management efforts at local, state, and national scales. We used a 10-m geospatial buffer as a proxy for hydrological or ecological connectivity of National Wetlands Inventory palustrine and lacustrine wetland systems to nationally mapped and available stream, river, and lake data. We identified over 8.3 million putative GIWs across the conterminous U.S., encompassing …


Seasonality Of Coliform Bacteria Detection Rates In New Jersey Domestic Wells, Thomas B. Atherholt, Nicholas A. Procopio, Sandra M. Goodrow Jan 2016

Seasonality Of Coliform Bacteria Detection Rates In New Jersey Domestic Wells, Thomas B. Atherholt, Nicholas A. Procopio, Sandra M. Goodrow

United States Environmental Protection Agency: Staff Publications

It is important that indicators of fecal pollution are reliable. Coliform bacteria are a commonly used indicator of fecal pollution. As other investigators have reported elsewhere, we observed a seasonal pattern of coliform bacteria detections in domestic wells in New Jersey. Examination of a statewide database of 10 years of water quality data from 93,447 samples, from 78,207 wells, generated during real estate transactions, revealed that coliform bacteria were detected in a higher proportion of wells during warm weather months. Further examination of the seasonal pattern of other data, including well water pH, precipitation, ground and surface water temperatures, surface …


Alpha-Lipoic Acid Supplementation Protects Enzymes From Damage By Nitrosative And Oxidative Stress, Sylvia Hiller, Robert Dekroon, Eric D. Hamlett, Longquan Xu, Cristina Osorio, Jennifer Robinette, Witold Winnik, Stephen Simington, Nobuyo Maeda, Oscar Alzate, Xianwen Yi Jan 2016

Alpha-Lipoic Acid Supplementation Protects Enzymes From Damage By Nitrosative And Oxidative Stress, Sylvia Hiller, Robert Dekroon, Eric D. Hamlett, Longquan Xu, Cristina Osorio, Jennifer Robinette, Witold Winnik, Stephen Simington, Nobuyo Maeda, Oscar Alzate, Xianwen Yi

United States Environmental Protection Agency: Staff Publications

Background: S-nitrosylation of mitochondrial enzymes involved in energy transfer under nitrosative stress may result in ATP deficiency. We investigated whether α-lipoic acid, a powerful antioxidant, could alleviate nitrosative stress by regulating S-nitrosylation,which could result in retaining themitochondrial enzyme activity.

Methods: In this study, we have identified the S-nitrosylated forms of subunit 1 of dihydrolipoyllysine succinyltransferase (complex III), and subunit 2 of the α-ketoglutarate dehydrogenase complex by implementing a fluorescence-based differential quantitative proteomics method.

Results: We found that the activities of these two mitochondrial enzymes were partially but reversibly inhibited by S-nitrosylation in cultured endothelial cells, and that their activities …


Estimating Ozone And Secondary Pm2.5 Impacts From Hypothetical Single Source Emissions In The Central And Eastern United States, Kirk R. Baker, Robert A. Kotchenruther, Rynda C. Hudman Jan 2016

Estimating Ozone And Secondary Pm2.5 Impacts From Hypothetical Single Source Emissions In The Central And Eastern United States, Kirk R. Baker, Robert A. Kotchenruther, Rynda C. Hudman

United States Environmental Protection Agency: Staff Publications

Secondary pollutant impacts from emissions of single sources may need to be assessed to satisfy a variety of regulatory requirements including the Clean Air Act New Source Review and Prevention of Significant Deterioration programs and the National Environmental Policy Act. In this work, single source impacts on O3 and secondary PM2.5 are estimated with annual 2011 photochemical grid model simulations where new hypothetical sources are added to the central and eastern United States with varying precursor emission rates and emission release heights. Impacts from these hypothetical sources are tracked with photochemical grid model source apportionment. Single source impacts …


Temporal Trends In The Spatial Distribution Of Impervious Cover Relative To Stream Location, J. Wickham, A. Neale, M. Mehaffey, T. Jarnagin, D. Norton Jan 2016

Temporal Trends In The Spatial Distribution Of Impervious Cover Relative To Stream Location, J. Wickham, A. Neale, M. Mehaffey, T. Jarnagin, D. Norton

United States Environmental Protection Agency: Staff Publications

Use of impervious cover is transitioning from an indicator of surface water condition to one that also guides and informs watershed planning and management, including Clean Water Act (33 U.S.C. §1251 et seq.) reporting. Whether it is for understanding surface water condition or planning and management, impervious cover is most commonly expressed as summary measurement (e.g., percentage watershed in impervious cover). We use the National Land Cover Database to estimate impervious cover in the vicinity of surface waters for three time periods (2001, 2006, 2011). We also compare impervious cover in the vicinity of surface waters to watershed summary estimates …


Carbon Storage In Us Wetlands, A. M. Nahlik, M. S. Fennessy Jan 2016

Carbon Storage In Us Wetlands, A. M. Nahlik, M. S. Fennessy

United States Environmental Protection Agency: Staff Publications

Wetland soils contain some of the highest stores of soil carbon in the biosphere. However, there is little understanding of the quantity and distribution of carbon stored in our remaining wetlands or of the potential effects of human disturbance on these stocks. Here we use field data from the 2011 National Wetland Condition Assessment to provide unbiased estimates of soil carbon stocks for wetlands at regional and national scales. We find that wetlands in the conterminous United States store a total of 11.52 PgC, much of which is within soils deeper than 30 cm. Freshwater inland wetlands, in part due …


Cyanotoxins In Inland Lakes Of The United States: Occurrence And Potential Recreational Health Risks In The Epa National Lakes Assessment 2007, Keith A. Loftin, Jennifer L. Graham, Elizabeth D. Hillborn, Sarah C. Lehmann, Michael T. Meyer, Julie E. Dietze, Christopher B. Griffith Jan 2016

Cyanotoxins In Inland Lakes Of The United States: Occurrence And Potential Recreational Health Risks In The Epa National Lakes Assessment 2007, Keith A. Loftin, Jennifer L. Graham, Elizabeth D. Hillborn, Sarah C. Lehmann, Michael T. Meyer, Julie E. Dietze, Christopher B. Griffith

United States Environmental Protection Agency: Staff Publications

A large nation-wide survey of cyanotoxins (1161 lakes) in the United States (U.S.) was conducted during the EPA National Lakes Assessment 2007. Cyanotoxin data were compared with cyanobacteria abundance- and chlorophyll-based World Health Organization (WHO) thresholds and mouse toxicity data to evaluate potential recreational risks. Cylindrospermopsins, microcystins, and saxitoxins were detected (ELISA) in 4.0, 32, and 7.7% of samples with mean concentrations of 0.56, 3.0, and 0.061 mg/L, respectively (detections only). Co-occurrence of the three cyanotoxin classes was rare (0.32%) when at least one toxin was detected. Cyanobacteria were present and dominant in 98 and 76% of samples, respectively. Potential …


Water Consumption Estimates Of The Biodiesel Process In The Us, Qingshi Tu, Mingming Lu, Y. Jeffrey Yang, Don Scott Jan 2016

Water Consumption Estimates Of The Biodiesel Process In The Us, Qingshi Tu, Mingming Lu, Y. Jeffrey Yang, Don Scott

United States Environmental Protection Agency: Staff Publications

As a renewable alternative to petroleum diesel, biodiesel has been widely used in the US and the world. However, its potential impact on water resources has not been much evaluated. This study investigates water consumption from the biodiesel process, which includes three stages: soybean irrigation, soybean-to-soybean oil processing, and biodiesel manufacturing, at both national and state levels. Mass-based allocation is performed and water consumption at the three stages is obtained on the basis of million gallons per year and gallon water per gallon biodiesel (gal/gal). The normalized water consumption (water intensity) of the irrigation, oil processing, and biodiesel production stages …


Potential Aquifer Vulnerability In Regions Down-Gradient From Uranium In Situ Recovery (Isr) Sites, James A. Saunders, Bruce E. Pivetz, Nathan Voorhies, Richard T. Wilkin Jan 2016

Potential Aquifer Vulnerability In Regions Down-Gradient From Uranium In Situ Recovery (Isr) Sites, James A. Saunders, Bruce E. Pivetz, Nathan Voorhies, Richard T. Wilkin

United States Environmental Protection Agency: Staff Publications

Sandstone-hosted roll-front uranium ore deposits originate when U(VI) dissolved in groundwater is reduced and precipitated as insoluble U(IV) minerals. Groundwater redox geochemistry, aqueous complexation, and solute migration are important in leaching uranium from source rocks and transporting it in low concentrations to a chemical redox interface where it is deposited in an ore zone typically containing the uranium minerals uraninite, pitchblende, and/or coffinite; various iron sulfides; native selenium; clays; and calcite. In situ recovery (ISR) of uranium ores is a process of contacting the uranium mineral deposit with leaching and oxidizing (lixiviant) fluids via injection of the lixiviant into wells …


Regional Scale Cropland Carbon Budgets: Evaluating A Geospatial Agricultural Modeling System Using Inventory Data, Xuesong Zhang, Roberto C. Izaurralde, David H. Manowitz, Ritvik Sahajpal, Tristram O. West, Allison M. Thomson, Min Xu, Kaiguang Zhao, Stephen D. Leduc, Jimmy R. Williams Jan 2015

Regional Scale Cropland Carbon Budgets: Evaluating A Geospatial Agricultural Modeling System Using Inventory Data, Xuesong Zhang, Roberto C. Izaurralde, David H. Manowitz, Ritvik Sahajpal, Tristram O. West, Allison M. Thomson, Min Xu, Kaiguang Zhao, Stephen D. Leduc, Jimmy R. Williams

United States Environmental Protection Agency: Staff Publications

Accurate quantification and clear understanding of regional scale cropland carbon (C) cycling is critical for designing effective policies and management practices that can contribute toward stabilizing atmospheric CO2 concentrations. However, extrapolating site-scale observations to regional scales represents a major challenge confronting the agricultural modeling community. This study introduces a novel geospatial agricultural modeling system (GAMS) exploring the integration of the mechanistic Environmental Policy Integrated Climate model, spatially-resolved data, surveyed management data, and supercomputing functions for cropland C budgets estimates. This modeling system creates spatiallyexplicit modeling units at a spatial resolution consistent with remotely-sensed crop identification and assigns cropping systems …


Bringing Resilience To Wildlife Management And Biodiversity Protection, Melinda Harm Benson, Matthew E. Hopton Jan 2014

Bringing Resilience To Wildlife Management And Biodiversity Protection, Melinda Harm Benson, Matthew E. Hopton

United States Environmental Protection Agency: Staff Publications

Biological diversity can be considered both temporally (Le., evolutionary time) and/or spatially and reflects the number, variety, and variability of organisms. It includes diversity within species (Le., genetic and morphological), between species (Le., alpha and beta), and among ecosystems (Le., beta and gamma). Over the past few hundred years, human activities have increased species extinction rates by as much as 1,000 times above the background rates that were typical over Earth's history (Figure 2.1) (Millennium Ecosystem Assessment 2005; but see He and Hubbell 2011). In the United States, there are approximately 1,900 species listed as threatened or endangered, with potentially …


Molecular Detection Of Campylobacter Spp. And Fecal Indicator Bacteria During The Northern Migration Of Sandhill Cranes (Grus Canadensis) At The Central Platte River, Jingrang Lu, Hodon Ryu, Jason R. Vogel, Jorge Santo Domingo, Nicholas J. Ashbolt Jun 2013

Molecular Detection Of Campylobacter Spp. And Fecal Indicator Bacteria During The Northern Migration Of Sandhill Cranes (Grus Canadensis) At The Central Platte River, Jingrang Lu, Hodon Ryu, Jason R. Vogel, Jorge Santo Domingo, Nicholas J. Ashbolt

United States Environmental Protection Agency: Staff Publications

The risk to human health of the annual sandhill crane (Grus canadensis) migration through Nebraska, which is thought to be a major source of fecal pollution of the central Platte River, is unknown. To better understand potential risks, the presence of Campylobacter species and three fecal indicator bacterial groups (Enterococcus spp., Escherichia coli, and Bacteroidetes) was assayed by PCR from crane excreta and water samples collected during their stopover at the Platte River, Nebraska, in 2010. Genus-specific PCR assays and sequence analyses identified Campylobacter jejuni as the predominant Campylobacter species in sandhill crane excreta. Campylobacter …


Comparison Of Pcr And Quantitative Real-Time Pcr Methods For The Characterization Of Ruminant And Cattle Fecal Pollution Sources, Meredith R. Raith, Catherine A. Kelty, John F. Griffith, Alexander Schriewer, Stefan Wuertz, Sophie Mieszkin, Michele Gourmelon, Georg H. Reischer, Andreas H. Farnleitner, Jared S. Ervin, Patricia A. Holden, Darcy L. Ebentier, Jennifer A. Jay, Dan Wang, Alexandria B. Boehm, Tiong Gim Aw, Joan B. Rose, E. Balleste, W.G. Meijer, Mano Sivaganesan, Orin C. Shanks Jan 2013

Comparison Of Pcr And Quantitative Real-Time Pcr Methods For The Characterization Of Ruminant And Cattle Fecal Pollution Sources, Meredith R. Raith, Catherine A. Kelty, John F. Griffith, Alexander Schriewer, Stefan Wuertz, Sophie Mieszkin, Michele Gourmelon, Georg H. Reischer, Andreas H. Farnleitner, Jared S. Ervin, Patricia A. Holden, Darcy L. Ebentier, Jennifer A. Jay, Dan Wang, Alexandria B. Boehm, Tiong Gim Aw, Joan B. Rose, E. Balleste, W.G. Meijer, Mano Sivaganesan, Orin C. Shanks

United States Environmental Protection Agency: Staff Publications

The State of California has mandated the preparation of a guidance document on the application of fecal source identification methods for recreational water quality management. California contains the fifth highest population of cattle in the United States, making the inclusion of cow-associated methods a logical choice. Because the performance of these methods has been shown to change based on geography and/or local animal feeding practices, laboratory comparisons are needed to determine which assays are best suited for implementation. We describe the performance characterization of two end-point PCR assays (CF128 and CF193) and five real-time quantitative PCR (qPCR) assays (Rum2Bac, BacR, …


Development And Evaluation Of A Quantitative Pcr Assay Targeting Sandhill Crane (Grus Canadensis) Fecal Pollution, Hodon Ryu, Jingrang Lu, Jason Vogel, Michael Elk, Felipe Chávez-Ramírez, Nicholas Ashbolt, Jorge Santo Domingo Jan 2012

Development And Evaluation Of A Quantitative Pcr Assay Targeting Sandhill Crane (Grus Canadensis) Fecal Pollution, Hodon Ryu, Jingrang Lu, Jason Vogel, Michael Elk, Felipe Chávez-Ramírez, Nicholas Ashbolt, Jorge Santo Domingo

United States Environmental Protection Agency: Staff Publications

While the microbial water quality in the Platte River is seasonally impacted by excreta from migrating cranes, there are no methods available to study crane fecal contamination. Here we characterized microbial populations in crane feces using phylogenetic analysis of 16S rRNA gene fecal clone libraries. Using these sequences, a novel crane quantitative PCR (Crane1) assay was developed, and its applicability as a microbial source tracking (MST) assay was evaluated by determining its host specificity and detection ability in environmental waters. Bacteria from crane excreta were dominated by bacilli and proteobacteria, with a notable paucity of sequences homologous to Bacteroidetes and …


Partially Acetylated Sugarcane Bagasse For Wicking Oil From Contaminated Wetlands, Seungoon Chung, Makram T. Suidan, Albert D. Venosa Jan 2011

Partially Acetylated Sugarcane Bagasse For Wicking Oil From Contaminated Wetlands, Seungoon Chung, Makram T. Suidan, Albert D. Venosa

United States Environmental Protection Agency: Staff Publications

Sugarcane bagasse was partially acetylated to enhance its oil-wicking ability in saturated environments while holding moisture for hydrocarbon biodegradation. The water sorption capacity of raw bagasse was reduced fourfold after treatment, which indicated considerably increased hydrophobicity but not a limited capability to hold moisture for hydrocarbon biodegradation. Characterization results by Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and surface area analyzer suggested that treated bagasse exhibited enhanced hydrophobicity and surface area. Oil wicking test results indicate that treated bagasse is more effective in wicking oil from highly saturated environments than raw bagasse and suggest that application …


Time-Lapse Three-Dimensional Inversion Of Complex Conductivity Data Using An Active Time Constrained (Atc) Approach, M. Karaoulis, A. Revil, D. D. Werkema, B. J. Minsley, W. F. Woodruff, A. Kemna Jan 2011

Time-Lapse Three-Dimensional Inversion Of Complex Conductivity Data Using An Active Time Constrained (Atc) Approach, M. Karaoulis, A. Revil, D. D. Werkema, B. J. Minsley, W. F. Woodruff, A. Kemna

United States Environmental Protection Agency: Staff Publications

Induced polarization (more precisely the magnitude and phase of impedance of the subsurface) is measured using a network of electrodes located at the ground surface or in boreholes. This method yields important information related to the distribution of permeability and contaminants in the shallow subsurface. We propose a new time-lapse 3-D modelling and inversion algorithm to image the evolution of complex conductivity over time.We discretize the subsurface using hexahedron cells. Each cell is assigned a complex resistivity or conductivity value. Using the finite-element approach, we model the in-phase and out-of-phase (quadrature) electrical potentials on the 3-D grid, which are then …


Active Pharmaceutical Ingredients And Aquatic Organisms, Christian G. Daughton, Bryan W. Brooks Jan 2011

Active Pharmaceutical Ingredients And Aquatic Organisms, Christian G. Daughton, Bryan W. Brooks

United States Environmental Protection Agency: Staff Publications

The presence of active pharmaceuticals ingredients (APIs) in aquatic systems has led in recent years to a burgeoning literature examining environmental occurrence, fate, effects, risk assessment, and treatability of these compounds. The vast preponderance of studies aimed at identifying and quantifying contaminant residues in aquatic tissues have involved the conventional and legacy pollutants. Comparatively few studies have been targeted at APIs, primarily those that are lipophilic. Although APIs have received much attention as "emerging" contaminants of concern, it is important to recognize that traditional approaches to understand and predict exposure and effects of other environmental organic contaminant classes mayor may …


Ddt And Other Organohalogen Pesticides In Aquatic Organisms, Nancy Beckvar, Guilherme R. Lotufo Jan 2011

Ddt And Other Organohalogen Pesticides In Aquatic Organisms, Nancy Beckvar, Guilherme R. Lotufo

United States Environmental Protection Agency: Staff Publications

Organohalogen (OH) compounds are persistent hydrocarbon compounds containing a halogen group, often chlorine or bromine, that substitutes for hydrogen atoms in different positions in the hydrocarbon. They may occur naturally, but this chapter's focus is on synthetically produced compounds, mainly organochlorines, that were produced for use as pesticides. Nine OH compounds (aldrin, chlordane, dichlorodiphenyltrichloroethane [DDT], dieldrin, endrin, heptachlor, hexachlorobenzene, mirex, and toxaphene) are in the top 12 list of particularly toxic and persistent organic pollutants (POPs) identified by the Stockholm Convention treaty implemented in 2004 under the United Nations Environment Program (UNEP). More than 90 countries have signed on to …


National Primary Drinking Water Regulations May 2009

National Primary Drinking Water Regulations

United States Environmental Protection Agency: Staff Publications

NOTES

1 Definitions

• Maximum Contaminant Level Goal (MCLG): The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety and are non-enforceable public health goals.

• Maximum Contaminant Level (MCL): The highest level of a contaminant that is allowed in drinking water. MCLs are set as close to MCLGs as feasible using the best available treatment technology and taking cost into consideration. MCLs are enforceable standards.

• Maximum Residual Disinfectant Level Goal (MRDLG): The level of a drinking water disinfectant below which there is …


Mitigation Under Section 404 Of The Clean Water Act: Where It Comes From, What It Means, Palmer Hough, Morgan Robertson Jan 2009

Mitigation Under Section 404 Of The Clean Water Act: Where It Comes From, What It Means, Palmer Hough, Morgan Robertson

United States Environmental Protection Agency: Staff Publications

The requirement to mitigate impacts to wetlands and streams is a frequently misunderstood policy with a long and complicated history. We narrate the history of mitigation since the inception of the Clean Water Act Section 404 permit program in 1972, through struggles between the US Environmental Protection Agency and the US Army Corps of Engineers, through the emerging importance of wetland conservation on the American political landscape, and through the rise of market-based approaches to environmental policy. Mitigation, as it is understood today, was not initially foreseen as a component of the Section 404 permitting program, but was adapted from …


Fundulus As The Premier Teleost Model In Environmental Biology: Opportunities For New Insights Using Genomics, Karen G. Burnett, Lisa J. Bain, William S. Baldwin, Gloria V. Callard, Sarah Cohen, Richard T. Di Giulio, David H. Evans, Marta Gómez-Chiarri, Mark E. Hahn, Cindi A. Hoover, Sibel I. Karchner, Fumi Katoh, Deborah L. Maclatchy, William S. Marshall, Joel N. Meyer, Diane E. Nacci, Marjorie F. Oleksiak, Bernard B. Rees, Thomas D. Singer, John J. Stegeman, David W. Towle, Peter A. Van Veld, Wolfgang K. Vogelbein, Andrew Whitehead, Richard N. Winn, Douglas L. Crawford Jan 2007

Fundulus As The Premier Teleost Model In Environmental Biology: Opportunities For New Insights Using Genomics, Karen G. Burnett, Lisa J. Bain, William S. Baldwin, Gloria V. Callard, Sarah Cohen, Richard T. Di Giulio, David H. Evans, Marta Gómez-Chiarri, Mark E. Hahn, Cindi A. Hoover, Sibel I. Karchner, Fumi Katoh, Deborah L. Maclatchy, William S. Marshall, Joel N. Meyer, Diane E. Nacci, Marjorie F. Oleksiak, Bernard B. Rees, Thomas D. Singer, John J. Stegeman, David W. Towle, Peter A. Van Veld, Wolfgang K. Vogelbein, Andrew Whitehead, Richard N. Winn, Douglas L. Crawford

United States Environmental Protection Agency: Staff Publications

A strong foundation of basic and applied research documents that the estuarine fish Fundulus heteroclitus and related species are unique laboratory and field models for understanding how individuals and populations interact with their environment. In this paper we summarize an extensive body of work examining the adaptive responses of Fundulus species to environmental conditions, and describe how this research has contributed importantly to our understanding of physiology, gene regulation, toxicology, and ecological and evolutionary genetics of teleosts and other vertebrates. These explorations have reached a critical juncture at which advancement is hindered by the lack of genomic resources for these …