Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
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Concentrations of selected herbicides, herbicide metabolites, and nutrients in outflow from selected midwestern reservoirs, April 1992 through September 1993
This data set consists of digital aquifer boundaries for the High Plains aquifer in the central United States. The High Plains aquifer extends from south of 32 degrees to almost 45 degrees north latitude and from 96 degrees 30 minutes to almost 104 degrees west longitude. The area covers 174,000 square miles and is present in Texas, Oklahoma, New Mexico, Kansas, Colorado, Nebraska, Wyoming, and So
Authors
E.A. Scribner, D. A. Goolsby, E.M. Thurman, M. T. Meyer, W.A. Battaglin
Occurrence of alachlor and its sulfonated metabolite in rivers and reservoirs of the midwestern United States: The importance of sulfonation in the transport of chloroacetanilide herbicides
Alachlor and its metabolite, 2-[(2',6'-diethylphenyl)- (methoxymethyl)amino]-2-oxoethanesulfonate (ESA), were identified in 76 reservoirs in the midwestern United States using immunoassay, liquid chromatography, and gas chromatography/mass spectrometry. The median concentration of ESA (0.48 ??g/L) exceeded the median concentration of alachlor (
Authors
E.M. Thurman, D. A. Goolsby, D.S. Aga, M.L. Pomes, M. T. Meyer
Identification of a new sulfonic acid metabolite of metolachlor in soil
An ethanesulfonic acid metabolite of metolachlor (metolachlor ESA) was identified in soil-sample extracts by negative-ion, fast-atom bombardment mass spectrometry (FAB-MS) and FAB tandem mass spectrometry (FAB-MS/MS). Production fragments from MS/MS analysis of the deprotonated molecular ion of metolachlor ESA in the soil extract can be reconciled with the structure of the synthesized standard. Th
Authors
D.S. Aga, E.M. Thurman, M.E. Yockel, L.R. Zimmerman, T.D. Williams
Herbicide metabolites in surface water and groundwater: Introduction and overview
Several future research topics for herbicide metabolites in surface and ground water are outlined in this chapter. They are herbicide usage, chemical analysis of metabolites, and fate and transport of metabolites in surface and ground water. These three ideas follow the themes in this book, which are the summary of a symposium of the American Chemical Society on herbicide metabolites in surface an
Authors
E.M. Thurman, M. T. Meyer
Assimilation of trace elements ingested by the mussel Mytilus edulis: Effects of algal food abundance
Pulse-chase feeding and multi-labeled radiotracer techniques were employed to measure the assimilation of 6 trace elements (110mAg, 241Am, 109Cd, 57Co, 75Se and 65Zn) from ingested diatoms in the mussel Mytilus edulis feeding at different rates (0.1, 0.49 and 1.5 mg dry wt h-1). Uniformly radiolabeled diatoms Thalassiosira pseudonana were fed to mussels for 0.5 h, and the behavior of the radiotrac
Authors
W.-X. Wang, N.S. Fisher, S. N. Luoma
Eolian transport, saline lake basins, and groundwater solutes
Eolian processes associated with saline lakes are shown to be important in determining solute concentration in groundwater in arid and semiarid areas. Steady state mass balance analyses of chloride in the groundwater at Double Lakes, a saline lake basin in the southern High Plains of Texas, United States, suggest that approximately 4.5 × 105 kg of chloride is removed from the relatively small (4.7
Authors
Warren W. Wood, Ward E. Sanford
Comment on "Horizontal aquifer movement in a theis-theim confined system" by Donald C. Helm
In a recent paper, Helm [1994] presents an analysis of horizontal aquifer movement induced by groundwater withdrawal from a confined aquifer in which fluid and grains are incompressible. The analysis considers the aquifer in isolation (ignoring overlying and underlying strata) and assumes that the aquifer deforms purely in the horizontal direction (with no vertical movement). Helm's solution for g
Authors
Paul A. Hsieh, Richard L. Cooley
Simulation of aerobic and anaerobic biodegradation processes at a crude oil spill site
A two-dimensional, multispecies reactive solute transport model with sequential aerobic and anaerobic degradation processes was developed and tested. The model was used to study the field-scale solute transport and degradation processes at the Bemidji, Minnesota, crude oil spill site. The simulations included the biodegradation of volatile and nonvolatile fractions of dissolved organic carbon by a
Authors
Hedeff I. Essaid, Barbara A. Bekins, E. Michael Godsy, Ean Warren, Mary Jo Baedecker, Isabelle M. Cozzarelli
Concentrations and mass transport of pesticides and organic contaminants in the Mississippi River and some of its tributaries, 1987-89 and 1991-92
No abstract available.
Authors
Wilfred E. Pereira, J. A. Moody, F. D. Hostettler, C.E. Rostad, T.J. Leiker
Near field receiving water monitoring of trace metals in clams (Macoma balthica) and sediments near the Palo Alto and San Jose/Sunnyvale water quality control plants in South San Francisco Bay; June 1993 through October 1994
No abstract available.
Authors
S. N. Luoma, D.J. Cain, C. L. Brown, Michelle I. Hornberger, R. M. Bouse-Schaenemann
Modeling hexavalent chromium reduction in groundwater in field-scale transport and laboratory batch experiments
A plausible and consistent model is developed to obtain a quantitative description of the gradual disappearance of hexavalent chromium (Cr(VI)) from groundwater in a small-scale field tracer test and in batch kinetic experiments using aquifer sediments under similar chemical conditions. The data exhibit three distinct timescales. Fast reduction occurs in well-stirred batch reactors in times much l
Authors
J.C. Friedly, J.A. Davis, D.B. Kent
An empirical model of the phytoplankton chlorophyll : carbon ratio-the conversion factor between productivity and growth rate
We present an empirical model that describes the ratio of phytoplankton chlorophyll a to carbon, Chl: C, as a function of temperature, daily irradiance, and nutrient-limited growth rate. Our model is based on 219 published measurements of algal cultures exposed to light-limited or nutrient-limited growth conditions. We illustrate an approach for using this estimator of Chl: C to calculate phytopla
Authors
James E. Cloern, Christian Grenz, Lisa Vidergar-Lucas