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United States Environmental Protection Agency: Staff Publications

2018

Articles 1 - 7 of 7

Full-Text Articles in Environmental Health and Protection

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 …

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Preface: Workshop On Pesticide Exposure Assessment Paradigm For Non-Apis Bees, Richard Bireley, Shannon Borges, Karina Cham, David Epstein, Kristina Garber, Connie Hart, Wayne Hou, Alessio Ippolito, Jens Pistorius, Veronique Poulsen, Keith Sappington, Thomas Steeger Dec 2018

Preface: Workshop On Pesticide Exposure Assessment Paradigm For Non-Apis Bees, Richard Bireley, Shannon Borges, Karina Cham, David Epstein, Kristina Garber, Connie Hart, Wayne Hou, Alessio Ippolito, Jens Pistorius, Veronique Poulsen, Keith Sappington, Thomas Steeger

United States Environmental Protection Agency: Staff Publications

Since the mid-2000s, increased annual losses of honey bee (Apis mellifera L., Hymenoptera: Apidae) colonies and declines in some species of non-Apis bees have been reported (Biesmeijer et al. 2006, NRC 2007). These losses, particularly with respect to honey bees, have been associated with multiple factors including pesticides, pathogens (viruses, fungi, bacteria), pests (primarily the parasitic mite Varroa destructor Anderson and Trueman [Arachnida: Parasitiformes: Varroidae]), poor nutrition, and bee management practices acting in combination (vanEngelsdorp et al. 2008, 2009; Ratnieks et al. 2010). Because of the role that bees play in providing pollination services to natural and agricultural-based ecosystems, …

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The Effects Of Continuous Diazinon Exposure On Growth And Reproduction In Japanese Medaka Using A Modified Medaka Extended One Generation Reproduction Test (Meogrt), Kevin Flynn, Doug Lothenbach, Frank Whiteman, Dean Hammermeister, Joe Swintek, Matthew Etterson, Rodney Johnson Jul 2018

The Effects Of Continuous Diazinon Exposure On Growth And Reproduction In Japanese Medaka Using A Modified Medaka Extended One Generation Reproduction Test (Meogrt), Kevin Flynn, Doug Lothenbach, Frank Whiteman, Dean Hammermeister, Joe Swintek, Matthew Etterson, Rodney Johnson

United States Environmental Protection Agency: Staff Publications

The Medaka Extended One Generation Reproduction Test (MEOGRT) is a Tier 2 test within U.S. Environmental Protection Agency's (USEPA) Endocrine Disruptor Screening Program (EDSP), designed to characterize the potential adverse effects to fish of exposure to chemical that can cause disruption of the endocrine system. The MEOGRT focuses primarily on adverse effects to reproduction while collecting information regarding effects on growth, survival, and endocrine-related endpoints. However, the risk assessment process for fish, as mandated by legislation such as the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) or the Toxic Substances Control Act (TSCA), could benefit from a more detailed assessment …

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Coupling Toxicokinetic–Toxicodynamic And Population Models For Assessing Aquatic Ecological Risks To Time-Varying Pesticide Exposures, Glen Thursby, Keith Sappington, Matthew Etterson Jul 2018

Coupling Toxicokinetic–Toxicodynamic And Population Models For Assessing Aquatic Ecological Risks To Time-Varying Pesticide Exposures, Glen Thursby, Keith Sappington, Matthew Etterson

United States Environmental Protection Agency: Staff Publications

Population modeling evaluations of pesticide exposure time series were compared with aspects of a currently used risk assessment process. The US Environmental Protection Agency’s Office of Pesticide Programs models daily aquatic 30-yr pesticide exposure distributions in its risk assessments, but does not routinely make full use of the information in such time series.We used mysid shrimp Americamysis bahia toxicity and demographic data to demonstrate the value of a toxicokinetic– toxicodynamic model coupled with a series of matrix population models in risk assessment refinements. This species is a small epibenthic marine crustacean routinely used in regulatory toxicity tests. We demonstrate how …

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Sensitivity Analyses For Simulating Pesticide Impacts On Honey Bee Colonies, A. Carmen Kuan, Gloria Degrandi-Hoffman, Robert J. Curry, Kristina V. Garber, Andrew R. Kanarek, Marcia N. Snyder, Kurt L. Wolfe, S. Thomas Purucker Mar 2018

Sensitivity Analyses For Simulating Pesticide Impacts On Honey Bee Colonies, A. Carmen Kuan, Gloria Degrandi-Hoffman, Robert J. Curry, Kristina V. Garber, Andrew R. Kanarek, Marcia N. Snyder, Kurt L. Wolfe, S. Thomas Purucker

United States Environmental Protection Agency: Staff Publications

We employ Monte Carlo simulation and sensitivity analysis techniques to describe the population dynamics of pesticide exposure to a honey bee colony using the VarroaPop+Pesticide model. Simulations are performed of hive population trajectories with and without pesticide exposure to determine the effects of weather, queen strength, foraging activity, colony resources, and Varroa populations on colony growth and survival. The daily resolution of the model allows us to conditionally identify sensitivity metrics. Simulations indicate queen strength and forager lifespan are consistent, critical inputs for colony dynamics in both the control and exposed conditions. Adult contact toxicity, application rate and nectar load …

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Reproductive Success And Contaminant Associations In Tree Swallows (Tachycineta Bicolor) Used To Assess A Beneficial Use Impairment In U.S. And Binational Great Lakes’ Areas Of Concern, Christine M. Custer, Thomas W. Custer, Matthew A. Etterson, Paul M. Dummer, Diana Goldberg, J. Christian Franson Mar 2018

Reproductive Success And Contaminant Associations In Tree Swallows (Tachycineta Bicolor) Used To Assess A Beneficial Use Impairment In U.S. And Binational Great Lakes’ Areas Of Concern, Christine M. Custer, Thomas W. Custer, Matthew A. Etterson, Paul M. Dummer, Diana Goldberg, J. Christian Franson

United States Environmental Protection Agency: Staff Publications

During 2010-2014, tree swallow (Tachycineta bicolor) reproductive success was monitored at 68 sites across all 5 Great Lakes, including 58 sites located within Great Lakes Areas of Concern (AOCs) and 10 non-AOCs. Sample eggs were collected from tree swallow clutches and analyzed for contaminants including polychlorinated biphenyls (PCBs), dioxins and furans, polybrominated diphenyl ethers, and 34 other organic compounds. Contaminant data were available for 360 of the clutches monitored. Markov chain multistate modeling was used to assess the importance of 5 ecological variables and 11 of the dominant contaminants in explaining the pattern of egg and nestling failure …

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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 …

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