Publications
Dive into our publications and explore the science from the Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology).
Filter Total Items: 3787
Comment on "environmental fate and effects of ethylene oxide"
No abstract available.
Authors
R. E. Rathbun, D. Y. Tai, R.L. Berglund, R.A. Conway, G.T. Waggy, M.H. Spiegel
Interactions of solutes and streambed sediment: 2. A dynamic analysis of coupled hydrologic and chemical processes that determine solute transport
Solute transport in streams is determined by the interaction of physical and chemical processes. Data from an injection experiment for chloride and several cations indicate significant influence of solutestreambed processes on transport in a mountain stream. These data are interpreted in terms of transient storage processes for all tracers and sorption processes for the cations. Process parameter
Authors
Kenneth E. Bencala
Effect of anisotropy and groundwater system geometry on seepage through lakebeds. 1. Analog and dimensional analysis
Distribution of seepage through lakebeds is controlled partly by geometric configuration of the lake and of the groundwater system interacting with the lake. To evaluate the effect of these factors, conductive-paper electric-analog models were used to analyze a number of lake and groundwater settings having different geometric configurations. Most settings analyzed are of lakes that do not penetra
Authors
H.O. Pfannkuch, T. C. Winter
The ecological effect of acid conditions and precipitation of hydrous metal oxides in a Rocky Mountain stream
Periphyton and benthic invertebrates assemblages were studied at the confluence of two Rocky Mountain streams, Deer Creek and the Snake River near Montezuma, Colorado. Upstream from the confluence the Snake River is acidic and enriched in dissolved trace metals, while Deer Creek is a typical Rocky Mountain stream. In the Snake River, downstream from the confluence, the pH increases and hydrous met
Authors
Diane M. McKnight, G. L. Feder
Effect of anisotropy and groundwater system geometry on seepage through lakebeds. 2. Numerical simulation analysis
The interaction of lakes and groundwater is controlled partly by the geologic framework through which the water flows. Two interrelated geometric factors of the groundwater system that affect flow are overall geometry of the system, and anisotropy of the porous media within the system. Numerical simulation analysis was made for variations in the coefficient of anisotropy for each of several lake a
Authors
T. C. Winter, H.O. Pfannkuch
Effects of copper on composition species of periphyton in a Sierra Nevada, California, stream
An oligotrophic stream was continuously dosed for 1 yr at 2.5, 5 and 10 mu g l-1 CuT; c12, 25 and 50 ng l-1 Cu2+. The numerically most abundant taxa were Bacillariophyceae (Achnanthes minutissima, Cocconeis placentula, Cymbella microcephala, C. sinuata, Fragilaria construens, F. crotonensis, Navicula spp., Synedra acus and S. rumpens), and the Cyanophyta Lyngbya spp., a co-dominant during spring a
Authors
H.V. Leland, J.L. Carter
Development and evaluation of a gas chromatographic method for the determination of triazine herbicides in natural water samples
A multi-residue method is described for the determination o triazine herbicides in natural water samples. The technique uses solvent extraction followed by gas chromatographic separation and detection employing nitrogen-selective devices. Seven compounds can be determined simultaneously at a nominal detection limit of 0.1 μg/L in a 1-litre sample. Three different natural water samples were used fo
Authors
T.R. Steinheimer, M.G. Brooks
Comparison of sediments and organisms in identifying sources of biologically available trace metal contamination
Sediments and an indicator organism (Macoma balthica, a deposit-feeding bivalve) were used to assess the relative importance of secondary sewage, urban runoff, a landfill containing metal-enriched ash wastes and a yacht harbor in contributing to Ag, Cu and Zn enrichment in South San Francisco Bay. Spatial gradients in sediments and organisms showed Cu and Ag enrichment originated from sewage disch
Authors
E.A. Thomson, Samuel N. Luoma, C.E. Johansson, D.J. Cain
Subsurface injection of treated sewage into a saline-water aquifer at St. Petersburg, Florida - Water-quality changes and potential for recovery of injected sewage
The city of St. Petersburg is testing subsurface injection of treated sewage into the Floridan aquifer as a means of eliminating discharge of sewage to surface waters and as a means of storing treated sewage for future nonpotable reuse. The injection zone at the test site at the start of injection contained saline water with chloride concentrations ranging from 14,000 to 20,000 milligrams per lite
Authors
J.J. Hickey, G. G. Ehrlich
Complexation of trace metals by adsorbed natural organic matter
The adsorption behavior and solution speciation of Cu(II) and Cd(II) were studied in model systems containing colloidal alumina particles and dissolved natural organic matter. At equilibrium a significant fraction of the alumina surface was covered by adsorbed organic matter. Cu(II) was partitioned primarily between the surface-bound organic matter and dissolved Cu-organic complexes in the aqueous
Authors
J.A. Davis
Bonded-phase extraction column isolation of organic compounds in groundwater at a hazardous waste site
A procedure for isolation of hazardous organic compounds from water for gas chromatography/mass spectrometry analysis Is presented and applied to creosote- and pentachlorophenol-contaminated groundwater resulting from wood-treatment processes. This simple procedure involved passing a 50-100-mL sample through a bonded-phase extraction column, eluting the trapped organic compounds from the column wi
Authors
C.E. Rostad, W. E. Pereira, S.M. Ratcliff
Origin and distribution of carbon dioxide in the unsaturated zone of the southern High Plains of Texas
Partial pressures of CO2, O2, N2, and Ar were monitored at two locations in the Ogallala aquifer system on the Southern High Plains of Texas. Samples were collected monthly during parts of 1980–1981 from nine depths ranging from 0.6 to 36 meters below land surface. PCO2 was observed to be greater at depth than in the active soil zone and thus appears to contradict the normal process in which CO2 i
Authors
Warren W. Wood, Michael J. Petraitis