Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 3787
Fate and transport of linear alkylbenzenesulfonate in a sewage- contaminated aquifer: A comparison of natural-gradient pulsed tracer tests
Two natural-gradient tracer tests were conducted to determine the transport and biodegradation behavior of linear alkylbenzenesulfonate (LAS) surfactant under in situ conditions in a sewage-contaminated aquifer. The tests were conducted in two biogeochemically distinct zones of the aquifer: (1) an aerobic uncontaminated zone (oxic zone) and (2) a moderately aerobic, sewage-contaminated zone (trans
Authors
C.J. Krueger, L. B. Barber, D.W. Metge, J.A. Field
Effect of contaminant concentration on aerobic microbial mineralization of DCE and VC in stream-bed sediments
Discharge of DCE and VC to an aerobic surface water system simultaneously represents a significant environmental concern and, potentially, a non-engineered opportunity for efficient contaminant bioremediation. The potential for bioremediation, however, depends on the ability of the stream-bed microbial community to efficiently and completely degrade DCE and VC over a range of contaminant concentra
Authors
P. M. Bradley, F. H. Chapelle
Microbial mineralization of VC and DCE under different terminal electron accepting conditions
Production of 14CO2 from [1,2-14C] dichloroethene (DCE) or [1,2-14C] vinyl chloride (VC) was quantified in aquifer and stream-bed sediment microcosms to evaluate the potential for microbial mineralization as a pathway for DCE and VC biodegradation under aerobic, Fe(III)-reducing, SO4-reducing, and methanogenic conditions. Mineralization of [1,2-14C] DCE and [1,2-14C] VC to 14CO2 decreased under in
Authors
P. M. Bradley, F. H. Chapelle
Herbicides in ground water of the Midwest: A regional study of shallow aquifers, 1991-94
The intensive herbicide use associated with the 'Corn Belt' marks the Midwestern United States as a region where herbicide contamination of ground water could be a problem. To better understand the regional occurrence of herbicides in shallow aquifers of the Midwest, a sampling network of 303 wells across 12 States was developed. The results documented relatively widespread, low-level concentratio
Authors
Dana W. Kolpin, J. K. Stamer, D. A. Goolsby, E.M. Thurman
Contribution of hydroxylated atrazine degradation products to the total atrazine load in midwestern streams
The contribution of hydroxylated atrazine degradation products (HADPs) to the total atrazine load (i.e., atrazine plus stable metabolites) in streams needs to be determined in order to fully assess the impact of atrazine contamination on stream ecosystems and human health. The objectives of this study were (1) to determine the contribution of HADPs to the total atrazine load in streams of nine mid
Authors
R.N. Lerch, P.E. Blanchard, E.M. Thurman
The environmental occurrence of herbicides: The importance of degradates in ground water
Numerous studies are being conducted to investigate the occurrence, fate, and effects on human health and the environment from the extensive worldwide use of herbicides to control weeds. Few studies, however, are considering the degradates of these herbicides in their investigations. Our study of herbicides in aquifers across Iowa found herbicide degradates to be prevalent in ground water, being d
Authors
D.W. Kolpin, E.M. Thurman, S. M. Linhart
Degradation of chloroacetanilide herbicides: The prevalence of sulfonic and oxanilic acid metabolites in Iowa groundwaters and surface waters
Water samples were collected from 88 municipal wells throughout Iowa during the summer and were collected monthly at 12 stream sites in eastern Iowa from March to December 1996 to study the occurrence of the sulfonic and oxanilic metabolites of acetochlor, alachlor, and metolachlor. The sulfonic and oxanilic metabolites were present in almost 75% of the groundwater samples and were generally prese
Authors
Stephen J. Kalkhoff, Dana W. Kolpin, E.M. Thurman, I. Ferrer, D. Barcelo
Investigation of anion-exchange and immunoaffinity particle-loaded membranes for the isolation of charged organic analytes from water
Anion-exchange and immunoaffinity particle loaded membranes (PLMs) were investigated as a mechanism for the isolation of charged organic analytes from water. Kinetic properties determined theoretically included dynamic capacity, pressure drop (ΔP), residence and diffusion times (Tr, Td), and total membrane porosity (εT). These properties were confirmed through experimental evaluation, and the PLM
Authors
T. R. Dombrowski, G.S. Wilson, E.M. Thurman
Evaluation of microtiter-plate enzyme-linked immunosorbent assay for the analysis of triazine and chloroacetanilide herbicides in rainfall
Triazine and chloroacetanilide concentrations in rainfall samples collected from a 23-state region of the United States were analyzed with microtiter-plate enzyme-linked immunosorbent assay (ELISA). Thirty-six percent of rainfall samples (2072 out of 5691) were confirmed using gas chro matography/mass spectrometry (GC/MS) to evaluate the operating performance of ELISA as a screening test. Comparis
Authors
M.L. Pomes, E.M. Thurman, D.S. Aga, D. A. Goolsby
Relation of usage to the occurrence of cotton and rice herbicides in three streams of the Mississippi delta
During the 1995 growing season water samples were collected from three streams in the Mississippi delta and were analyzed for selected cotton and rice herbicides and metabolites. The purpose of the study was to relate the use of these herbicides to their occurrence in streams of the delta, to describe how the geochemistry of these herbicides affects their occurrence, and to report the occurrence o
Authors
R.H. Coupe, E.M. Thurman, L.R. Zimmerman
Simulating transport of volatile organic compounds in the unsaturated zone using the computer model R-UNSAT
Subsurface spills of gasoline and other petroleum products are a common environmental problem throughout the industrialized world. The U.S. Environmental Protection Agency has estimated that 40 percent of the more than 200,000 retail service stations in the United States have had accidental releases of petroleum hydrocarbons to the subsurface (U.S. Environmental Protection Agency, 1991). Restorati
Authors
Matthew A. Lahvis, Arthur L. Baehr
Comparing nocturnal eddy covariance measurements to estimates of ecosystem respiration made by scaling chamber measurements at six coniferous boreal sites
During the growing season, nighttime ecosystem respiration emits 30–100% of the daytime net photosynthetic uptake of carbon, and therefore measurements of rates and understanding of its control by the environment are important for understanding net ecosystem exchange. Ecosystem respiration can be measured at night by eddy covariance methods, but the data may not be reliable because of low turbulen
Authors
M.B. Lavigne, M. G. Ryan, D.E. Anderson, D. D. Baldocchi, P.M. Crill, D.R. Fitzjarrald, M. L. Goulden, S.T. Gower, J.M. Massheder, J.H. McCaughey, M. Rayment, Robert G. Striegl