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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: 3784

Ultrastructural changes in the hepatocytes of juvenile rainbow trout and mature brown trout exposed to copper or zinc Ultrastructural changes in the hepatocytes of juvenile rainbow trout and mature brown trout exposed to copper or zinc

Morphological changes in hepatocytes of mature brown trout (Salmo trutta Linnaeus) and juvenile rainbow trout (Salmo gairdneri Richardson), accompanying chronic exposures to copper and zinc, were examined by transmission electron microscopy. At a concentration of copper not inhibitory to the final stages of gonadal development or spawning of brown trout, structural alterations included...
Authors
H.V. Leland

Clay mineral formation and transformation in rocks and soils Clay mineral formation and transformation in rocks and soils

Three mechanisms for clay mineral formation (inheritance, neoformation, and transformation) operating in three geological environments (weathering, sedimentary, and diagenetic-hydrothermal) yield nine possibilities for the origin of clay minerals in nature. Several of these possibilities are discussed in terms of the rock cycle. The mineralogy of clays neoformed in the weathering...
Authors
D. D. Eberl

Simulation of solute transport in a mountain pool-and-riffle stream with a kinetic mass transfer model for sorption Simulation of solute transport in a mountain pool-and-riffle stream with a kinetic mass transfer model for sorption

In natural channels there are often long periods of low flow during which solutes have repeated opportunity for contact with relatively immobile bed materials. Such conditions can exist in very small pool-and-riffle mountain streams. If a solute can sorb onto bed materials, then both hydrodynamic and chemical processes control solute transport. A simulation of these processes is...
Authors
Kenneth E. Bencala

Terpenoid marker compounds derived from biogenic precursors in volcanic ash from Mount St. Helens, Washington Terpenoid marker compounds derived from biogenic precursors in volcanic ash from Mount St. Helens, Washington

A volcanic-ash sample obtained after the 1980 eruption of Mount St. Helens, Washington, was analyzed for cyclic terpenoid organic compounds and polycyclic aromatic hydrocarbons using capillary gas chromatography-mass spectrometry-computer techniques. Various tricyclic diterpenoid acids and hydrocarbons were identified including dehydroabietic acid, dehydroabietin, dehydroabietane...
Authors
W. E. Pereira, Colleen E. Rostad

Gas-film coefficients for streams Gas-film coefficients for streams

Equations for predicting the gas-film coefficient for the volatilization of organic solutes from streams are developed. The film coefficient is a function of windspeed and water temperature. The dependence of the coefficient on windspeed is determined from published information on the evaporation of water from a canal. The dependence of the coefficient on temperature is determined from...
Authors
R. E. Rathbun, D. Y. Tai

Variable tolerance to copper in two species from San Francisco Bay Variable tolerance to copper in two species from San Francisco Bay

In static toxicity experiments, tolerance to soluble Cu of the bivalve, Macoma balthica, and the copepod, Acartia clausi, varied substantially among populations sampled within San Francisco Bay. Intraspecific tolerance differed ten-fold or more for both species over relatively small distances, suggesting geographical isolation of populations is not a prerequisite for the development of
Authors
Samuel N. Luoma, D.J. Cain, K. Ho, A. Hutchinson

Nonequilibrium models for predicting forms of precipitated manganese oxides Nonequilibrium models for predicting forms of precipitated manganese oxides

Manganese oxides precipitated by bubbling air through 0.01 molar solutions of MnCl2, Mn(NO3)2, MnSO4, or Mn(ClO4)2 at a constantly maintained pH of 8.5 to 9.5 at temperatures of 25°C or higher consisted mainly of hausmannite, Mn3O4. At temperatures near 0°C, but with other conditions the same, the product is feitknechtite, βMnOOH, except that if the initial solution is MnSO4 and the...
Authors
J.D. Hem, Carol J. Lind

Simulation of solute transport in a mountain pool-and-riffle stream: A transient storage model Simulation of solute transport in a mountain pool-and-riffle stream: A transient storage model

The physical characteristics of mountain streams differ from the uniform and conceptually well- defined open channels for which the analysis of solute transport has been oriented in the past and is now well understood. These physical conditions significantly influence solute transport behavior, as demonstrated by a transient storage model simulation of solute transport in a very small (0...
Authors
Kenneth E. Bencala, Roy A. Walters

Complexation of copper by aquatic humic substances from different environments Complexation of copper by aquatic humic substances from different environments

The copper-complexing properties of aquatic humic substances isolated from eighteen different environments were characterized by potentiometric titration, using a cupric ion selective electrode. Potentiometric data were analyzed using FITEQL, a computer program for the determination of chemical equilibrium constants from experimental data. All the aquatic humic substances could be...
Authors
Diane M. McKnight, Gerald L. Feder, E. Michael Thurman, Robert L. Wershaw
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