Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
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Effect of seasonally changing tissue weight on trace metal concentrations in the bivalve Macoma balthica in San Francisco Bay
The influence of seasonal changes in the weight of soft tissues on temporal fluctuations in tissue concentrations of Cu and Zn was examined in 4 populations of the clam Macoma balthica sampled in San Francisco Bay for a period of 2 to 5 yr. Fluctuations in metal concentration expected from changes in tissue weight between sampling dates were estimated by assuming that whole body metal burden was c
Authors
Daniel J. Cain, Samuel N. Luoma
Metabolism of reduced methylated sulfur compounds in anaerobic sediments and by a pure culture of an estuarine methanogen
Addition of dimethylsulfide (DMS), dimethyldisulfide (DMDS), or methane thiol (MSH) to a diversity of anoxic aquatic sediments (e.g., fresh water, estuarine, alkaline/hypersaline) stimulated methane production. The yield of methane recovered from DMS was often 52 to 63%, although high concentrations of DMS (as well as MSH and DMDS) inhibited methanogenesis in some types of sediments. Production o
Authors
R.P. Kiene, Ronald S. Oremland, Anthony Catena, Laurence G. Miller, D.G. Capone
Variability in the fractionation of Cu, Ag, and Zn among cytosolic proteins in the bivalve Macoma balthica
Gel filtration chromatographs of cytosols from the clam Macorna balthica analysed from both field and laboratory treated specimens showed that uptake of Cu, Ag, and Zn in the metallothionein-like protein (MLP) pool follows exposure both in nature and in the laboratory. Specimens collected from San Francisco Bay over 18 mo showed strong temporal variability in the fractionation of the metals among
Authors
C. Johansson, Daniel J. Cain, Samuel N. Luoma
Water solubility enhancement of some organic pollutants and pesticides by dissolved humic and fulvic acids
No abstract available.
Authors
Cary T. Chiou, Ronald L. Malcolm, Terry I. Brinton, Daniel E. Kile
Resurgence of submersed aquatic macrophytes in the tidal Potomac River, Maryland, Virginia, and the District of Columbia
A 1978–81 survey of submersed aquatic macrophytes in the tidal Potomac River showed that there were virtually no plants in the freshwater tidal river between Chain Bridge and Quantico, Virginia, decades after the disappearance of plants in the late 1930’s. Plant populations were monitored in subsequent years (1983–85) using qualitative shoreline surveys and quantitative resampling of the original
Authors
V. Carter, N. Rybicki
Coincidence and spatial variability of geology, soils, and vegetation, Mill Run watershed, Virginia
The Mill Run watershed is a structurally‐controlled synclinal basin on the eastern limb of the Massanutten Mountain complex of northwestern Virginia. Bedrock contacts are obscured by coarse sandstone debris from exposures near basin divides. Colluvium blankets more than half the basin, masking geomorphic surfaces, affecting vegetation patterns, and contributing to the convexity of the alluvial, te
Authors
C.G. Olson, C. R. Hupp
Recovering fresh water stored in saline limestone aquifers
Numerical modeling techniques are used to examine the hydrogeologic, design, and management factors governing the recovery efficiency of subsurface fresh-water storage. The modeling approach permitted many combinations of conditions to be studied. A sensitivity analysis was used that consisted of varying certain parameters while keeping constant as many other parameters or processes as possible. T
Authors
M. L. Merritt
Chemistry of illite/smectite and end-member illite
Chemical data from three different series of diagenetic illite/smectites (I/S), analyzed statistically by two regresion techniques, indicate that the content of fixed-K per illite layer is not constant, but ranges from ∼0.55 per O10(OH)2 for illite layers in randomly interstratified I/S (R=0; > 50% smectite layers) to ∼1.0 per O10(OH)2 for illite layers formed in ordered I/S (R>0; <50% smectite la
Authors
J. Srodon, D.J. Morgan, E.V. Eslinger, D. D. Eberl, M.R. Karlinger
Measurement of nitrous oxide reductase activity in aquatic sediments
Denitrification in aquatic sediments was measured by an N2O reductase assay. Sediments consumed small added quantities of N2O over short periods (a few hours). In experiments with sediment slurries, N2O reductase activity was inhibited by O2, C2H2, heat treatment, and by high levels of nitrate (1 mM) or sulfide (10 mM). However, ambient levels of nitrate (<100 μM) did not influence activity, and m
Authors
L.G. Miller, Ronald S. Oremland, S. Paulsen
Concentration of trace elements in water samples by reductive precipitation
No abstract available.
Authors
R. K Skogerboe, W.A. Hanagan, Howard E. Taylor
Assessment of the instantaneous unit hydrograph derived from the theory of topologically random networks
An instantaneous unit hydrograph (iuh) based on the theory of topologically random networks (topological iuh) is evaluated in terms of sets of basin characteristics and hydraulic parameters. Hydrographs were computed using two linear routing methods for each of two drainage basins in the southeastern United States and are the basis of comparison for the topological iuh's. Elements in the sets of b
Authors
M.R. Karlinger, B.M. Troutman
Field determination of the three-dimensional hydraulic conductivity tensor of anisotropic media: 1. Theory
A field method is proposed for determining the three-dimensional hydraulic conductivity tensor and specific storage of an anisotropic porous or fractured medium. The method, known as cross-hole testing (to distinguish it from conventional single-hole packer tests), consists of injecting fluid into (or withdrawing fluid from) packed-off intervals in a number of boreholes and monitoring the transien
Authors
Paul A. Hsieh, Shlomo P. Neuman