Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 3746
Fluoride geochemistry of thermal waters in Yellowstone National Park: I. Aqueous fluoride speciation
Thermal water samples from Yellowstone National Park (YNP) have a wide range of pH (1–10), temperature, and high concentrations of fluoride (up to 50 mg/l). High fluoride concentrations are found in waters with field pH higher than 6 (except those in Crater Hills) and temperatures higher than 50 °C based on data from more than 750 water samples covering most thermal areas in YNP from 1975 to 2008.
Authors
Y. Deng, D. Kirk Nordstrom, R. Blaine McCleskey
Mercury distribution and lipid oxidation in fish muscle: Effects of washing and isoelectric protein precipitation
Nearly all the mercury (Hg) in whole muscle from whitefish (Coregonus clupeaformis) and walleye (Sander vitreus) was present as methyl mercury (MeHg). The Hg content in whole muscle from whitefish and walleye was 0.04–0.09 and 0.14–0.81 ppm, respectively. The myofibril fraction contained approximately three-fourths of the Hg in whitefish and walleye whole muscle. The sarcoplasmic protein fraction
Authors
Y. Gong, David P. Krabbenhoft, L. Ren, B. Egelandsdal, M.P. Richards
Loss of volatile hydrocarbons from an LNAPL oil source
The light nonaqueous phase liquid (LNAPL) oil pool in an aquifer that resulted from a pipeline spill near Bemidji, Minnesota, was analyzed for volatile hydrocarbons (VHCs) to determine if the composition of the oil remains constant over time. Oil samples were obtained from wells at five locations in the oil pool in an anaerobic part of the glacial outwash aquifer. Samples covering a 21-year period
Authors
Mary Jo Baedecker, Robert P. Eganhouse, Barbara A. Bekins, Geoffrey N. Delin
Tracking nonpoint source nitrogen pollution in human-impacted watersheds
Nonpoint source nitrogen (N) pollution is a leading contributor to U.S. water quality impairments. We combined watershed N mass balances and stable isotopes to investigate fate and transport of nonpoint N in forest, agricultural, and urbanized watersheds at the Baltimore Long-Term Ecological Research site. Annual N retention was 55%, 68%, and 82% for agricultural, suburban, and forest watersheds,
Authors
Sujay S. Kaushal, Peter M Groffman, Lawrence Band, Emily M. Elliott, Catherine A. Shields, Carol Kendall
The challenge of interpreting environmental tracer concentrations in fractured rock and carbonate aquifers
No abstract available.
Authors
Allen M. Shapiro
A comparison of recharge rates in aquifers of the United States based on groundwater-age data
An overview is presented of existing groundwater-age data and their implications for assessing rates and timescales of recharge in selected unconfined aquifer systems of the United States. Apparent age distributions in aquifers determined from chlorofluorocarbon, sulfur hexafluoride, tritium/helium-3, and radiocarbon measurements from 565 wells in 45 networks were used to calculate groundwater rec
Authors
P. B. McMahon, Niel Plummer, J.K. Böhlke, S.D. Shapiro, S.R. Hinkle
Rethinking hyporheic flow and transient storage to advance understanding of stream-catchment connections
Although surface water and groundwater are increasingly referred to as one resource, there remain environmental and ecosystem needs to study the 10 m to 1 km reach scale as one hydrologic system. Streams gain and lose water over a range of spatial and temporal scales. Large spatial scales (kilometers) have traditionally been recognized and studied as river-aquifer connections. Over the last 25 yea
Authors
Kenneth E. Bencala, M.N. Gooseff, Briant A. Kimball
Effects of humic substances on precipitation and aggregation of zinc sulfide nanoparticles
Nanoparticulate metal sulfides such as ZnS can influence the transport and bioavailability of pollutant metals in anaerobic environments. The aim of this work was to investigate how the composition of dissolved natural organic matter (NOM) influences the stability of zinc sulfide nanoparticles as they nucleate and aggregate in water with dissolved NOM. We compared NOM fractions that were isolated
Authors
Amrika Deonarine, Boris L.T. Lau, George R. Aiken, Joseph N. Ryan, Heileen Hsu-Kim
Effects of human-induced alteration of groundwater flow on concentrations of naturally-occurring trace elements at water-supply wells
The effects of human-induced alteration of groundwater flow patterns on concentrations of naturally-occurring trace elements were examined in five hydrologically distinct aquifer systems in the USA. Although naturally occurring, these trace elements can exceed concentrations that are considered harmful to human health. The results show that pumping-induced hydraulic gradient changes and artificial
Authors
J. D. Ayotte, Z. Szabo, M. J. Focazio, S. M. Eberts
Calibration of models using groundwater age
There have been substantial efforts recently by geochemists to determine the age of groundwater (time since water entered the system) and its uncertainty, and by hydrologists to use these data to help calibrate groundwater models. This essay discusses the calibration of models using groundwater age, with conclusions that emphasize what is practical given current limitations rather than theoretical
Authors
Ward E. Sanford
Seasonal variations in ectotherm growth rates: Quantifying growth as an intermittent non steady state compensatory process
Generally, growth rates of living organisms are considered to be at steady state, varying only under environmental forcing factors. For example, these rates may be described as a function of light for plants or organic food resources for animals and these could be regulated (or not) by temperature or other conditions. But, what are the consequences for an individual's growth (and also for the popu
Authors
J.-M. Guarini, Laurent Chauvaud, James E. Cloern, J. Clavier, J. Coston-Guarini, Y. Patry
Removal of inorganic mercury and methylmercury from surface waters following coagulation of dissolved organic matter with metal-based salts
The presence of inorganic mercury (IHg) and methylmercury (MeHg) in surface waters is a health concern worldwide. This study assessed the removal potential use of metal-based coagulants as a means to remove both dissolved IHg and MeHg from natural waters and provides information regarding the importance of Hg associations with the dissolved organic matter (DOM) fraction and metal hydroxides. Previ
Authors
Y.K. Henneberry, T.E.C. Kraus, J.A. Fleck, David P. Krabbenhoft, P.M. Bachand, W.R. Horwath