Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 3787
Denitrification in nitrate-contaminated groundwater: Occurrence in steep vertical geochemical gradients
A relatively narrow vertical zone (5–6 m thick) of NO3− containing groundwater was identified using multilevel sampling devices in a sand and gravel aquifer on Cape Cod, MA, USA. The aquifer has been chronically contaminated by surface disposal of treated sewage 0.3 km upgradient from the study area. The NO3− zone was anoxic and contained high concentrations of N2O (16.5 μM), suggesting that it wa
Authors
R. L. Smith, B.L. Howes, J.H. Duff
Herbicides in surface waters of the midwestern United States: The effect of spring flush
Approximately three-fourths of all preemergent herbicides used in the United States are applied to row crops over a 12-state area, called the "corn belt" (I). The application of these compounds may cause widespread degradation of water quality (2). Because herbicides are water soluble, there is the potential for leaching into groundwater and surface water (3, 4), as well as aerial transport and Oc
Authors
E.M. Thurman, D. A. Goolsby, M. T. Meyer, D.W. Kolpin
Formation and transport of deethylatrazine in the soil and vadose zone
Atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) and two degradation products were monitored at seven depths in the soil and vadose zone throughout the growing season in two experimental plots in which corn (Zea mays L.) was grown. The soils in these plots were a Kimo silty clay loam (clayey over loamy, montmorillonitic, mesic, Fluvaquentic Hapludoll) and a Eudora silt loam (course, si
Authors
C.D. Adams, E.M. Thurman
Large-scale distribution of metal contamination in the fine-grained sediments of the Clark Fork River, Montana, U.S.A.
Historic discharges from the mining and smelting complex at the head-waters of the Clark Fork River have resulted in elevated Ag, Cd, Cu, Pb and Zn concentrations in the <60 μm fraction of both bed and flood-plain sediments of the river. Processes affecting the trends in longitudinal distributions of these metals were investigated by repeated sampling over a 380 km river reach between August 1986
Authors
E.V. Axtmann, S. N. Luoma
Balloon and core sampling for determining bulk density of alluvial desert soil
Samples were collected from major strata in the upper 5 m of an alluvial soil profile in the Amargosa Desert of southern Nevada to compare rubber-balloon and drive-core bulk-density measurement methods. For strate where the fine soil was <82% sand and <15% clay, differences between total and fine-soil bulk-density values determined by the two methods were typically <10 and 15%, respectively, even
Authors
Brian J. Andraski
The chemistry of iron, aluminum, and dissolved organic material in three acidic, metal-enriched, mountain streams, as controlled by watershed and in-stream processes
Several studies were conducted in three acidic, metal-enriched, mountain streams, and the results are discussed together in this paper to provide a synthesis of watershed and in-stream processes controlling Fe, Al, and DOC (dissolved organic carbon) concentrations. One of the streams, the Snake River, is naturally acidic; the other two, Peru Creek and St. Kevin Gulch, receive acid mine drainage. A
Authors
Diane M. McKnight, Kenneth E. Bencala
Comment on "Temperature dependence of the aqueous solubilities of highly chlorinated dibenzo-p-dioxins"
No abstract available.
Authors
Cary T. Chiou, Milton Manes
Stoichiometry of mineral reactions from mass balance computations for acid mine waters, Iron Mountain, California
No abstract available.
Authors
Charles N. Alpers, D. Kirk Nordstrom
Use of tree-ring chemistry to document historical ground-water contamination events
The annual growth rings of tulip trees (Liriodendron tulipifera L.) appear to preserve a chemical record of ground-water contamination at a landfill in Maryland. Zones of elevated iron and chlorine concentrations in growth rings from trees immediately downgradient from the landfill are closely correlated temporally with activities in the landfill expected to generate iron and chloride contaminatio
Authors
Don A. Vroblesky, Thomas M. Yanosky
Solute transport with multisegment, equilibrium-controlled reactions: A feed forward simulation method
The feed forward method (FF method) is one of the ways of formulating operational equations which simulate transport of solutes influenced by equilibrium-controlled reaction networks. The FF method provides increased solution efficiency by adapting its formulations to some of the network's fundamental features. In this study the FF method is further developed by adapting and testing it for a varie
Authors
Jacob Rubin
Hazardous wastes from large-scale metal extraction. A case study
No abstract available
Authors
Johnnie N. Moore, Samuel N. Luoma