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Publications

Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).

Filter Total Items: 4098

Trace metals (Cd, Cu, Ni, and Zn) and nutrients in coastal waters adjacent to San Francisco Bay, California Trace metals (Cd, Cu, Ni, and Zn) and nutrients in coastal waters adjacent to San Francisco Bay, California

Samples collected in December 1990 and July 1991 show that dissolved Cd, Cu, Ni, and Zn distributions in the Gulf of the Farallones are dominated by mixing of two end-members: (1) metal-enriched San Francisco Bay water and (2) offshore California Current water. The range of dissolved metal concentrations observed is 0.2–0.9 nmol kg−1 for Cd, 1–20 nmol kg−1 for Cu, 4–16 nmol kg−1 for Ni...
Authors
A. VanGeen, Samuel N. Luoma

Deposition of aerially applied BT in an oak forest and its prediction with the FSCBG model Deposition of aerially applied BT in an oak forest and its prediction with the FSCBG model

Data are provided from 17 single-swath aerial spray trials that were conducted over a fully leafed, 16-m tall, mixed oak forest. The distribution of cross-swath spray deposits was sampled at the top of the canopy and below the canopy. Micrometeorological conditions were measured above and within the canopy during the spray trials. The USDA Forest Service FSCBG (Forest Service-Cramer...
Authors
Dean E. Anderson, David R. Miller, Yansen Wang, William G. Yendol, Karl Mierzejewski, Michael L. McManus

Modeling biotic uptake by periphyton and transient hyporrheic storage of nitrate in a natural stream Modeling biotic uptake by periphyton and transient hyporrheic storage of nitrate in a natural stream

To a convection-dispersion hydrologic transport model we coupled a transient storage submodel (Bencala, 1984) and a biotic uptake submodel based on Michaelis-Menten kinetics (Kim et al., 1990). Our purpose was threefold: (1) to simulate nitrate retention in response to change in load in a third-order stream, (2) to differentiate biotic versus hydrologie factors in nitrate retention, and...
Authors
Brian K.A. Kim, Alan P. Jackman, Frank J. Triska

A geochemical transport model for redox-controlled movement of mineral fronts in groundwater flow systems: A case of nitrate removal by oxidation of pyrite A geochemical transport model for redox-controlled movement of mineral fronts in groundwater flow systems: A case of nitrate removal by oxidation of pyrite

A one-dimensional prototype geochemical transport model was developed in order to handle simultaneous precipitation-dissolution and oxidation-reduction reactions governed by chemical equilibria. Total aqueous component concentrations are the primary dependent variables, and a sequential iterative approach is used for the calculation. The model was verified by analytical and numerical...
Authors
Peter Engesgaard, Kenneth L. Kipp

Inductively coupled plasma-mass spectrometry as an element-specific detector for field-flow fractionation particle separation Inductively coupled plasma-mass spectrometry as an element-specific detector for field-flow fractionation particle separation

An inductively coupled plasma-mass spectrometer was used for the quantitative measurement of trace elements In specific,submicrometer size-fraction particulates, separated by sedimentation field-flow fractionation. Fractions were collected from the eluent of the field-flow fractionation centrifuge and nebulized, with a Babington-type pneumatic nebulizer, into an argon inductively coupled...
Authors
Howard E. Taylor, John R. Garbarino, Deirdre M. Murphy, Ronald Beckett

Use of chlorofluorocarbons (CCl3F and CCl2F2) as hydrologic tracers and age‐dating tools: The alluvium and terrace system of central Oklahoma Use of chlorofluorocarbons (CCl3F and CCl2F2) as hydrologic tracers and age‐dating tools: The alluvium and terrace system of central Oklahoma

The use of Chlorofluorocarbons (CFCs) as an age‐dating tool and tracer in shallow groundwaters has been investigated. New methodology for field sampling and preserving groundwaters containing parts per trillion concentrations of the CFCs, F‐1l and F‐12, is presented. Samples are analyzed by purge‐and‐trap gas chromatography with an electron capture detector. Physical and chemical...
Authors
Eurybiades Busenberg, Niel Plummer

Large-scale natural gradient tracer test in sand and gravel, Cape Cod, Massachusetts: 3. Hydraulic conductivity variability and calculated macrodispersivities Large-scale natural gradient tracer test in sand and gravel, Cape Cod, Massachusetts: 3. Hydraulic conductivity variability and calculated macrodispersivities

Hydraulic conductivity (K) variability in a sand and gravel aquifer on Cape Cod, Massachusetts, was measured and subsequently used in stochastic transport theories to estimate macrodispersivities. Nearly 1500 K measurements were obtained by borehole flowmeter tests and permeameter analyses of cores. The geometric mean for the flowmeter tests (0.11 cm/s) is similar to that estimated from...
Authors
Kathryn M. Hess, Steven H. Wolf, Michael A. Celia

Relation of nickel concentrations in tree rings to groundwater contamination Relation of nickel concentrations in tree rings to groundwater contamination

Increment cores were collected from trees growing at two sites where groundwater is contaminated by nickel. Proton-induced X ray emission spectroscopy was used to determine the nickel concentrations in selected individual rings and in parts of individual rings. Ring nickel concentrations were interpreted on the basis of recent concentrations of nickel in aquifers, historical information...
Authors
Thomas M. Yanosky, Don A. Vroblesky
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