Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 4094
Source water controls on the character and origin of dissolved organic matter in streams of the Yukon River basin, Alaska
Climate warming and permafrost degradation at high latitudes will likely impact watershed hydrology, and consequently, alter the concentration and character of dissolved organic carbon (DOC) in northern rivers. We examined seasonal variation of DOC chemistry in 16 streams of the Yukon River basin, Alaska. Our primary objective was to evaluate the relationship between source water (shallow versus d
Authors
Jonathan A. O'Donnell, George R. Aiken, Evan S. Kane, Jeremy B. Jones
Multiple well-shutdown tests and site-scale flow simulation in fractured rocks
A new method was developed for conducting aquifer tests in fractured-rock flow systems that have a pump-and-treat (P&T) operation for containing and removing groundwater contaminants. The method involves temporary shutdown of individual pumps in wells of the P&T system. Conducting aquifer tests in this manner has several advantages, including (1) no additional contaminated water is withdrawn, and
Authors
Claire R. Tiedeman, Pierre J. Lacombe, Daniel J. Goode
Invertebrate mercury bioaccumulation in permanent, seasonal, and flooded rice wetlands within California's Central Valley
We examined methylmercury (MeHg) bioavailability in four of the most predominant wetland habitats in California's Central Valley agricultural region during the spring and summer: white rice, wild rice, permanent wetlands, and shallowly-flooded fallow fields. We sampled MeHg and total mercury (THg) concentrations in two aquatic macroinvertebrate taxa at the inlets, centers, and outlets of four repl
Authors
Joshua T. Ackerman, A. Keith Miles, Collin A. Eagles-Smith
Ecological distribution and population physiology defined by proteomics in a natural microbial community
An important challenge in microbial ecology is developing methods that simultaneously examine the physiology of organisms at the molecular level and their ecosystem level interactions in complex natural systems. We integrated extensive proteomic, geochemical, and biological information from 28 microbial communities collected from an acid mine drainage environment and representing a range of biofil
Authors
Ryan S. Mueller, Vincent J. Denef, Linda H. Kalnejais, K. Blake Suttle, Brian C. Thomas, Paul Wilmes, Richard L. Smith, D. Kirk Nordstrom, R. Blaine McCleskey, Menesh B. Shah, Nathan C. VerBekmoes, Robert L. Hettich, Jillian F. Banfield
Mercury concentrations in fish from a Sierra Nevada foothill reservoir located downstream from historic gold-mining operations
This study examined mercury concentrations in whole fish from Camp Far West Reservoir, an 830-ha reservoir in northern California, USA, located downstream from lands mined for gold during and following the Gold Rush of 1848–1864. Total mercury (reported as dry weight concentrations) was highest in spotted bass (mean, 0.93 μg/g; range, 0.16–4.41 μg/g) and lower in bluegill (mean, 0.45 μg/g; range,
Authors
Michael K. Saiki, Barbara A. Martin, Thomas W. May, Charles N. Alpers
Estimating natural background groundwater chemistry, Questa molybdenum mine, New Mexico
This 2 1/2 day field trip will present an overview of a U.S. Geological Survey (USGS) project whose objective was to estimate pre-mining groundwater chemistry at the Questa molybdenum mine, New Mexico. Because of intense debate among stakeholders regarding pre-mining groundwater chemistry standards, the New Mexico Environment Department and Chevron Mining Inc. (formerly Molycorp) agreed that the U
Authors
Phillip L. Verplanck, D. Kirk Nordstrom, Geoffrey S. Plumlee, Bruce M. Walker
Three-dimensional benchmark for variable-density flow and transport simulation: matching semi-analytic stability modes for steady unstable convection in an inclined porous box
This benchmark for three-dimensional (3D) numerical simulators of variable-density groundwater flow and solute or energy transport consists of matching simulation results with the semi-analytical solution for the transition from one steady-state convective mode to another in a porous box. Previous experimental and analytical studies of natural convective flow in an inclined porous layer have shown
Authors
Clifford I. Voss, Craig T. Simmons, Neville I. Robinson
Predictive modeling of transient storage and nutrient uptake: Implications for stream restoration
This study examined two key aspects of reactive transport modeling for stream restoration purposes: the accuracy of the nutrient spiraling and transient storage models for quantifying reach-scale nutrient uptake, and the ability to quantify transport parameters using measurements and scaling techniques in order to improve upon traditional conservative tracer fitting methods. Nitrate (NO3–) uptake
Authors
Ben L. O'Connor, Miki Hondzo, Judson W. Harvey
Cytochrome P4501A biomarker indication of oil exposure in harlequin ducks up to 20 years after the Exxon Valdez oil spill
Hydrocarbon-inducible cytochrome P4501A (CYP1A) expression was measured, as ethoxyresorufin-O-deethylase (EROD) activity, in livers of wintering harlequin ducks (Histrionicus histrionicus) captured in areas of Prince William Sound, Alaska, USA, oiled by the 1989 Exxon Valdez spill and in birds from nearby unoiled areas, during 2005 to 2009 (up to 20 years following the spill). The present work rep
Authors
Daniel Esler, Kimberly A. Trust, Brenda E. Ballachey, Samuel A. Iverson, Tyler L. Lewis, Daniel Rizzolo, Daniel M. Mulcahy, A. Keith Miles, Bruce R. Woodin, John J. Stegeman, John D. Henderson, Barry W. Wilson
Novel silver tubing method for quantitative introduction of water into high temperature conversion systems for stable hydrogen and oxygen isotopic measurements
A new method to seal water in silver tubes for use in a TC/EA reduction unit using a semi-automated sealing apparatus can yield reproducibilities (1 standard deviation) of δ2H and &delta18O measurements of 1.0 ‰ and 0.06 ‰, respectively. These silver tubes containing reference waters may be preferred for calibration of H- and O-bearing materials analyzed with a TC/EA reduction unit. The new sealin
Authors
Haiping Qi, Manfred Groning, Tyler B. Coplen, Bryan Buck, Stanley J. Mroczkowski, Willi A. Brand, Heike Geilmann, Matthias Gehre
Isotope reference materials
Measurement of the same isotopically homogeneous sample by any laboratory worldwide should yield the same isotopic composition within analytical uncertainty. International distribution of light element isotopic reference materials by the International Atomic Energy Agency and the U.S. National Institute of Standards and Technology enable laboratories to achieve this goal.
Authors
Tyler B. Coplen
Mapping brucellosis increases relative to elk density using hierarchical Bayesian models
The relationship between host density and parasite transmission is central to the effectiveness of many disease management strategies. Few studies, however, have empirically estimated this relationship particularly in large mammals. We applied hierarchical Bayesian methods to a 19-year dataset of over 6400 brucellosis tests of adult female elk (Cervus elaphus) in northwestern Wyoming. Management c
Authors
Paul C. Cross, Dennis M. Heisey, Brandon M. Scurlock, William H. Edwards, Angela Brennan, Michael R. Ebinger