Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
GeoHEALTH-USGS Newsletter
GeoHEALTH-USGS Newsletter
The GeoHEALTH–USGS Newsletter—published since 2004—provides information on USGS science activities pertinent to safeguarding the health of fish, wildlife, domesticated animals, and people from environmental exposures to contaminants and pathogens.
Featured Science Activities
Featured Science Activities
Learn about our Featured Science Activities through our pages that highlight studies, publications, and results.
Filter Total Items: 4097
Particulate organic matter in the San Francisco Bay estuary, California: Chemical indicators of its origin and assimilation into the benthic food web Particulate organic matter in the San Francisco Bay estuary, California: Chemical indicators of its origin and assimilation into the benthic food web
No abstract available.
Authors
J. E. Cloern, E. A. Canuel, S.M. Wienke
Agricultural chemical interchange between ground water and surface water, Cedar River basin, Iowa and Minnesota: A study description Agricultural chemical interchange between ground water and surface water, Cedar River basin, Iowa and Minnesota: A study description
A review of the data collected in the Cedar River basin, Iowa and Minnesota, indicates that atrazine is consistently detected in the main-stem river at concentrations greater than 0.10 microgram per liter even during periods of extended base flow. The primary source of atrazine in the river during these periods of base flow is not known. This study is designed to determine how atrazine...
Authors
P. J. Squillace, M. J. Liszewski, E.M. Thurman
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
Deep-living microbes mount a relentless attack on rock Deep-living microbes mount a relentless attack on rock
No abstract available.
Authors
T. Appenzeller
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
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
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
Solute transport with multiple equilibrium-controlled or kinetically controlled chemical reactions Solute transport with multiple equilibrium-controlled or kinetically controlled chemical reactions
A new approach is applied to the problem of modeling solute transport accompanied by many chemical reactions. The approach, based on concepts of the concentration space and its stoichiometric subspaces, uses elements of the subspaces as primary dependent variables. It is shown that the resulting model equations are compact in form, isolate the chemical reaction expressions from flow...
Authors
John C. Friedly, Jacob Rubin
Discussion of "The modeling process and model validation" by Chin-Fu Tsang Discussion of "The modeling process and model validation" by Chin-Fu Tsang
No abstract available.
Authors
Leonard F. Konikow