Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
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Approach for environmental baseline water sampling
Samples collected during the exploration phase of mining represent baseline conditions at the site. As such, they can be very important in forecasting potential environmental impacts should mining proceed, and can become measurements against which future changes are compared. Constituents in stream water draining mined and mineralized areas tend to be geochemically, spatially, and temporally varia
Authors
K. S. Smith
Simulating adsorption of U(VI) under transient groundwater flow and hydrochemistry: Physical versus chemical nonequilibrium model
Coupled intragrain diffusional mass transfer and nonlinear surface complexation processes play an important role in the transport behavior of U(VI) in contaminated aquifers. Two alternative model approaches for simulating these coupled processes were analyzed and compared: (1) the physical nonequilibrium approach that explicitly accounts for aqueous speciation and instantaneous surface complexatio
Authors
J. Greskowiak, M.B. Hay, H. Prommer, C. Liu, V.E.A. Post, R. Ma, J.A. Davis, C. Zheng, J.M. Zachara
Methane oxidation in a crude oil contaminated aquifer: Delineation of aerobic reactions at the plume fringes
High resolution direct-push profiling over short vertical distances was used to investigate CH4 attenuation in a petroleum contaminated aquifer near Bemidji, Minnesota. The contaminant plume was delineated using dissolved gases, redox sensitive components, major ions, carbon isotope ratios in CH4 and CO2, and the presence of methanotrophic bacteria. Sharp redox gradients were observed near the wat
Authors
R.T. Amos, Barbara A. Bekins, Geoffrey N. Delin, Isabelle M. Cozzarelli, D.W. Blowes, J. D. Kirshtein
Occurrence of azoxystrobin, propiconazole, and selected other fungicides in US streams, 2005-2006
Fungicides are used to prevent foliar diseases on a wide range of vegetable, field, fruit, and ornamental crops. They are generally more effective as protective rather than curative treatments, and hence tend to be applied before infections take place. Less than 1% of US soybeans were treated with a fungicide in 2002 but by 2006, 4% were treated. Like other pesticides, fungicides can move-off of f
Authors
William A. Battaglin, Mark W. Sandstrom, Kathryn Kuivila, Dana W. Kolpin, Michael T. Meyer
Sulfur in the South Florida ecosystem: Distribution, sources, biogeochemistry, impacts, and management for restoration
Sulfur is broadly recognized as a water quality issue of significance for the freshwater Florida Everglades. Roughly 60% of the remnant Everglades has surface water sulfate concentrations above 1 mg l-1, a restoration performance measure based on present sulfate levels in unenriched areas. Highly enriched marshes in the northern Everglades have average sulfate levels of 60 mg l-1. Sulfate loading
Authors
William H. Orem, C. Gilmour, D. Axelrad, David P. Krabbenhoft, D. Scheidt, P. Kalla, P. McCormick, M. Gabriel, George Aiken
Global patterns of phytoplankton dynamics in coastal ecosystems
Scientific Committee on Ocean Research Working Group 137 Meeting; Hangzhou, China, 17-21 October 2010; Phytoplankton biomass and community structure have undergone dramatic changes in coastal ecosystems over the past several decades in response to climate variability and human disturbance. These changes have short- and long-term impacts on global carbon and nutrient cycling, food web structure and
Authors
H. Paerl, Kedong Yin, J. Cloern, James E. Cloern
A distribution-based parameterization for improved tomographic imaging of solute plumes
Difference geophysical tomography (e.g. radar, resistivity and seismic) is used increasingly for imaging fluid flow and mass transport associated with natural and engineered hydrologic phenomena, including tracer experiments, in situ remediation and aquifer storage and recovery. Tomographic data are collected over time, inverted and differenced against a background image to produce ‘snapshots’ rev
Authors
Adam Pidlisecky, K. Singha, F. D. Day-Lewis
Metallothionein-like multinuclear clusters of mercury(II) and sulfur in peat
Strong mercury(II)–sulfur (Hg-SR) bonds in natural organic matter, which influence mercury bioavailability, are difficult to characterize. We report evidence for two new Hg-SR structures using X-ray absorption spectroscopy in peats from the Florida Everglades with added Hg. The first, observed at a mole ratio of organic reduced S to Hg (Sred/Hg) between 220 and 1140, is a Hg4Sx type of cluster wit
Authors
K. L. Nagy, A. Manceau, J. D. Gasper, J. N. Ryan, G. R. Aiken
Toxicity of methylmercury injected into eggs when dissolved in water versus corn oil
In a previous study, the embryotoxicity of methylmercury dissolved in corn oil was compared among 26 species of birds. Corn oil is not soluble in the water‐based matrix that constitutes the albumen of an egg. To determine whether the use of corn oil limited the usefulness of this earlier study, a comparison was made of the embryotoxicity of methylmercury dissolved in corn oil versus water. Mallard
Authors
Gary H. Heinz, Daivd J. Hoffman, Jon D. Klimstra, Katherine R. Stebbins, Shannon L. Kondrad
Dissolved organic matter in the Florida everglades: Implications for ecosystem restoration
Dissolved organic matter (DOM) in the Florida Everglades controls a number of environmental processes important for ecosystem function including the absorption of light, mineral dissolution/precipitation, transport of hydrophobic compounds (e.g., pesticides), and the transport and reactivity of metals, such as mercury. Proposed attempts to return the Everglades to more natural flow conditions will
Authors
G. R. Aiken, C.C. Gilmour, D. P. Krabbenhoft, W. Orem
Ammonium in thermal waters of Yellowstone National Park: Processes affecting speciation and isotope fractionation
Dissolved inorganic nitrogen, largely in reduced form (NH4(T)≈NH4(aq)++NH3(aq)o), has been documented in thermal waters throughout Yellowstone National Park, with concentrations ranging from a few micromolar along the Firehole River to millimolar concentrations at Washburn Hot Springs. Indirect evidence from rock nitrogen analyses and previous work on organic compounds associated with Washburn Hot
Authors
J.M. Holloway, D. Kirk Nordstrom, J.K. Böhlke, R. Blaine McCleskey, J. W. Ball
Comparative mobility of sulfonamides and bromide tracer in three soils
In animal agriculture, sulfonamides are one of the routinely used groups of antimicrobials for therapeutic and sub-therapeutic purposes. It is observed that, the animals when administered the antimicrobials, often do not completely metabolize them; and excrete the partially metabolized forms into the environment. Due to the continued use of antimicrobials and disposal of untreated waste, widesprea
Authors
S.T. Kurwadkar, C.D. Adams, Michael T. Meyer, Dana W. Kolpin