Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
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Analysis of environmental data with censored observations
The potential threats to humans and to terrestrial and aquatic ecosystems from environmental contamination could depend on the sum of the concentrations of different chemicals. However, direct summation of environmental data is not generally feasible because it is common for some chemical concentrations to be recorded as being below the analytical reporting limit. This creates special problems in
Authors
S. Liu, J.-C. Lu, D.W. Kolpin, W.Q. Meeker
Concentration and transport of chlordane and nonachlor associated with suspended sediment in the Mississippi River, May 1988 to June 1990
Technical chlordane, a formerly widely used organochlorine pesticide, has become widespread in the environment. The distribution of technical chlordane in riverine environments may be due in part to resuspension and aqueous transport of contaminated bed sediment. To test this hypothesis, the Mississippi River was sampled for suspended sediment five times over a two- year period, at up to 17 sites
Authors
C.E. Rostad
Marine bacterial degradation of brominated methanes
Brominated methanes are ozone-depleting compounds whose natural sources include marine algae such as kelp. Brominated methane degradation by bacteria was investigated to address whether bacterial processes might effect net emission of these compounds to the atmosphere. Bacteria in seawater collected from California kelp beds degraded CH2Br2 but not CHBr3. Specific inhibitors showed that methanotro
Authors
K.D. Goodwin, M.E. Lidstrom, R.S. Oremland
Groundwater record of halocarbon transport by the Danube River
Groundwater dating studies have supported the concept that aquifers with low coefficients of dispersion may contain coherent records of past conditions in recharge areas. Groundwater records can provide unique information about natural or anthropogenic changes in the atmosphere and hydrosphere where long-term monitoring data are not available. Here we describe a 40-year record of halocarbon contam
Authors
J.K. Böhlke, K. Revesz, E. Busenberg, J. Deak, E. Deseo, M. Stute
The urban atmosphere as a non-point source for the transport of MTBE and other volatile organic compounds (VOCS) to shallow groundwater
Infiltration and dispersion (including molecular diffusion) can transport volatile organic compounds (VOCs) from urban air into shallow groundwater. The gasoline additive methyl-tert-butyl ether (MTBE) is of special interest because of its (1) current levels in some urban air, (2) strong partitioning from air into water, (3) resistance to degradation, (4) use as an octane-booster since the 1970s,
Authors
J. F. Pankow, N.R. Thomson, Richard L. Johnson, A. L. Baehr, J.S. Zogorski
Bacterial oxidation of methyl bromide in fumigated agricultural soils
The oxidation of [14C]methyl bromide ([14C]MeBr) to 14CO2 was measured in field experiments with soils collected from two strawberry plots fumigated with mixtures of MeBr and chloropicrin (CCl3NO2). Although these fumigants are considered potent biocides, we found that the highest rates of MeBr oxidation occurred 1 to 2 days after injection when the fields were tarped, rather than before or severa
Authors
L.G. Miller, T.L. Connell, J.R. Guidetti, R.S. Oremland
Effects of exchanged cation and layer charge on the sorption of water and EGME vapors on montmorillonite clays
The effects of exchanged cation and layer charge on the sorption of water and ethylene glycol monoethyl ether (EGME) vapors on montmorillonite have been studied on SAz-1 and SWy-1 source clays, each exchanged respectively with Ca, Na, K, Cs and tetramethylammonium (TMA) cations. The corresponding lattice expansions were also determined, and the corresponding N2 adsorption data were provided for co
Authors
Cary T. Chiou, David W. Rutherford
Practical considerations for measuring hydrogen concentrations in groundwater
Several practical considerations for measuring concentrations of dissolved molecular hydrogen (H2) in groundwater including 1 sampling methods 2 pumping methods and (3) effects of well casing materials were evaluated. Three different sampling methodologies (a downhole sampler, a gas- stripping method, and a diffusion sampler) were compared. The downhole sampler and gas-stripping methods gave simil
Authors
F. H. Chapelle, D. A. Vroblesky, J.C. Woodward, D. R. Lovley
Logistic model of nitrate in streams of the upper-midwestern United States
Nitrate in surface water can have adverse effects on aquatic life and, in drinking-water supplies, can be a risk to human health. As part of a regional study, nitrates as N (NO3-N) was analyzed in water samples collected from streams throughout 10 Midwestern states during synoptic surveys in 1989, 1990, and 1994. Data from the period immediately following crop planting at 124 sites were analyzed d
Authors
D. K. Mueller, B. C. Ruddy, W.A. Battaglin
A theoretically based determination of bowen-ratio fetch requirements
Determination of fetch requirements for accurate Bowen-ratio measurements of latent- and sensible-heat fluxes is more involved than for eddy-correlation measurements because Bowen-ratio sensors are located at two heights, rather than just one. A simple solution to the diffusion equation is used to derive an expression for Bowen-ratio fetch requirements, downwind of a step change in surface fluxes.
Authors
D.I. Stannard
Near field receiving water monitoring of trace metals in Clams (Macoma balthica) and sediments near the Palo Alto and San Jose/Sunnyvale Water Quality Control Plants in South San Francisco Bay: 1996
No abstract available.
Authors
S. N. Luoma, D.J. Cain, C. Brown, M. Hornberger, R. Bouse
In situ ecosystem effects of trace contaminants in San Francisco Bay Estuary - The necessary link to establishing water quality standards II
No abstract available.
Authors
Francis Parcheso, C. L. Brown, J.K. Thompson, S.L. Luoma