bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simulation of the aquatic fate of triclopyr butoxyethyl ester and its predicted effects on coho salmon
Authors: McCall Philip J. , Laskowski Dennis A. , Bidlack Harvey D. 
Published: March 2010

Abstract
Mathematical simulations of the dissipation of triclopyr butoxyethyl ester in a model aquatic system representing a shallow, static pond were conducted. Aqueous hydrolysis, sorption to bottom sediment, hydrolysis in sediment and photolysis were considered in predicting aqueous concentration-time profiles. Potential concentrations in Coho salmon were evaluated as part of the model based on rate constants for uptake, hydrolysis and elimination as determined in laboratory investigations conducted in another study. Predicted chemical concentrations in the fish were then related to toxicity data to estimate aqueous concentrations in the model environment required to give a toxic response. In general, the simulations showed that the ester concentration in the pond water would decline, with an approximate half-life of 6 to 24 h. Initial ester concentrations of 1.0 to 1.5 mg/L in this simulated pond environment would be required to result in chemical concentrations in fish above toxic threshold levels.
Chemical characterization and mutagenic properties of polycyclic aromatic compounds in sediment from tributaries of the great lakes
Authors: Fabacher David L. , Schmitt Christopher J. , Besser John M. , Mac Michael J. 
Published: March 2010

Abstract
Sediments from four inshore industrial sites and a reference site in the Great Lakes were extracted with solvents and characterized chemically for polycyclic aromatic compounds (PACs). An aqueous phase and a crude organic extract were obtained. The crude organic extract was further resolved into fractions A-2 (polycyclic aromatic hydrocarbons) and A-3 (nitrogen-containing polycyclic aromatic compounds), which were analyzed for PACs by gas chromatography and gas chromatography-mass spectrometry. The extracts and fractions were tested for mutagenicity in three assays: Ames, rat hepatocyte unscheduled DNA synthesis, and Chinese hamster ovary hypoxanthine-guanine phosphoribosyl transferase (CHO/HGPRT). Sediments from the industrial sites contained 27 to 363 μg/g total PACs; the reference site, less than 1 μg/g. Qualitative differences in the residue profiles among the sites were attributable to the probable sources of the PACs (petroleum versus combustion). Only one industrial site yielded measurable (0.1 μg/g or more) concentrations of individual nitrogen-containing PACs. In the Ames assay, only the highest doses of the A-2 fractions from two sites approached positive results. Conversely, the crude organic extract and A-2 and A-3 fractions from all sites induced unscheduled DNA synthesis. Crude organic extracts and the A-2 and A-3 fractions from all industrial sites gave well-defined dose-response relations in the CHO/HGPRT assay. We established the presence of chemical mutagens in sediment that could be correlated with neoplasms in fish from many of the sites; however, the mutagenicity of the sediment extracts was not completely related to the degree of contamination by PACs. We also discuss the utility of mutagenicity assays in the evaluation of complex chemical mixtures and recommend the use of a CHO/HGPRT-type assay in which cells are not required to proliferate in the presence of potential interfering chemicals.
Dissolved organic macromolecules reduce the uptake of hydrophobic organic contaminants by the gills of rainbow trout (Salmo gairdneri)
Authors: Black Marsha C. , McCarthy John F. 
Published: March 2010

Abstract
The effect of the binding of two model hydrophobic organic contaminants, benzo[a]pyrene and 2,2′,5,5′ -tetrachlorobiphenyl, to Aldrich humic acid, a commercially available source of dissolved organic macromolecules (DOM), on the uptake of these contaminants by the gills of rainbow trout (Salmo gairdneri) was examined. The efficiency with which trout gills extracted the contaminants from water (with and without DOM present) was measured using a fish metabolic chamber that separated exposure water from water that passed over the gills. Measurements of the contaminant extraction efficiency of trout gills were compared with measurements of contaminant binding to DOM. Contaminants bound to DOM did not diffuse across the gill membrane. Percentage reductions in the concentration of freely dissolved contaminant were equal to percentage reductions in the uptake of the contaminant by the gills. Thus, only the freely dissolved contaminant appears to be available for uptake by fish gills. These correlations between the concentration of freely dissolved contaminant and the fraction of the exposure concentration that is transferred across the gills provide a basis for predicting contaminant dose based on physicochemical measurements of contaminant binding to naturally occurring DOM in the aquatic environment.
A physiological study of the effects of triton surfactants on Lemna minor L.
Authors: Caux P. Y. , Weinberger P. , Carlisle D. B. 
Published: March 2010

Abstract
Adjuvants significantly contribute to many commercial herbicide/pesticide formulations and are often present at concentrations approaching those of the active ingredient. The Canadian Forest Service is currently testing alkyl aryl polyether alcohol adjuvants as “acceptable” replacement surfactants in the fenitrothion formulation used to control the spruce budworm, Choristoneura fumiferana. This study describes the toxic effects of these compounds on a common and widespread aquatic vascular plant, Lemna minor L.
The parameters monitored during the 14-d exposure included growth (biomass), frond fluorescence and chlorophyll content, conductivity of the test media and specific ion leakage. At 1 μg/ml, no response of any of the monitored parameters was observed for any of the Tritons, and 10 μg/ml resulted in no response for Triton X-114. Exposure to 10 μg/ml of the other Tritons tested, however, resulted in toxic effects such that frond development was depressed 25 to 50%. Exposure to 50 μg/ml of the lower ethoxylates, Tritons X-l5 and X-35, elicited approximately twofold greater depression of the parameters assessed than did treatments with comparable concentrations of the higher ethoxylates, Tritons X-100 and X-114. A positive correlation was obtained between the degree of phytotoxicity and the hydrophilie-lipophilic balance (HLB), and partition coefficients for the Triton surfactants.
Effects of chlorine on microbial communities in naturally derived microcosms: Population and community level responses to environmental perturbations
Authors: Pratt J. R. , Bowers N. J. , Niederlehner B. R. , Cairns J. 
Published: March 2010

Abstract
Laboratory microcosms and field enclosures were used to evaluate effects of chlorine on microbial community structure and function. Microcosms were exposed to chlorine (as sodium hypochlorite) at concentrations up to 308 μg/L total residual chlorine (TRC) for 28 d. Test systems were sampled weekly to evaluate protozoan species accrual, biomass distribution, microbial enzyme activity, and macronutrient retention. Protozoan species numbers were depressed at all sampling times at TRC concentrations ≥25 μg/L. Algal biomass (chlorophyll a) was adversely affected at 2 μg/L, and alkaline phosphatase activity was inhibited at ≥6 μg/L. Other biomass measures and macronutrient retention were affected at 25 to 308 μg/L. Oxygen production was depressed at ≥25 μg/L. Field enclosures (sediment-water mesocosms) were dosed daily with chlorine, resulting in average chlorine doses up to 261 μg/L. Protozoan species numbers were depressed at chlorine doses ≥79 μg/L, and zooplankton density was affected at 24 μg/L. Algal biomass and total biomass were adversely affected at the highest chlorine level, 261 μg/L. Nontaxonomic measures were typically less sensitive than community structure responses to chronic chlorine stress. Estimated effect levels for both experiments overlapped; however, the response of specific variables (i.e., stimulation, inhibition, no effect) to chlorine differed between the two tests. These results support the importance of experimental design and dosage regime in chronic toxicity testing.
Using stream survey data to predict directional change in fish populations following physicochemical stream perturbations
Authors: Layher William G. , Maughan O. Eugene 
Published: March 2010

Abstract
Standing stocks of fish species were graphed against 30 abiotic variables measured in Kansas streams. The resulting habitat suitability curves for each variable allowed fish biomass to be normalized to index values that could be regressed linearly against these variables. Stepwise multiple-regression techniques isolated variables that accounted for much of the biomass of individual populations. Regression models applied to an independent data set from Oklahoma produced highly significant (though low) correlations between predicted and observed standing stocks. Assigning suitability index values to Oklahoma streams from curves developed with Kansas data identified other variables as limiting, thus explaining much of the biomass variation. This analysis indicated that the habitat suitability curves approximated fish population changes along a single-variable axis. Kansas stream data has been placed in a statistical data set and provided with visual display. The system allows for rapid assessment of the effects of changes in 30 physicochemical variables on populations of about 100 fish species in Kansas streams.
Structural alterations in aquatic insect communities exposed to copper in laboratory streams
Authors: Clements William H. , Cherry Donald S. , Cairns John 
Published: March 2010

Abstract
The effects of copper on aquatic insect communities were examined using rock-filled trays colonized in the field for 30 d, transferred to laboratory streams, and dosed with CuSO4. Each stream was randomly assigned to one of three treatments: control (0 μg/L), low dose (15–32 μg/L), and high dose (135–178 μg/L). Experiments were replicated over three seasons. Exposure to copper for 96 h significantly reduced both the total number of individuals and number of taxa during each season, with greatest effects observed in summer. Owing to differences in sensitivity to copper, the percent composition of dominant orders of aquatic insects varied among treatments. The relative abundance of Ephemeroptera decreased in treated streams during each season. The response of other aquatic insects, including Diptera and Plecoptera, varied between seasons, but these groups were generally less sensitive to copper exposure. These results indicate that the artificial substrates employed in this study are amenable to experimental manipulation and will provide a unique opportunity to examine the community responses of aquatic insects to toxicants under environmentally realistic conditions.
Simple, specific analysis of organophosphorus and carbamate pesticides in sediments using column extraction and gas chromatography
Authors: Belisle Andre A. , Swineford Douglas M. 
Published: March 2010

Abstract
A simple, specific procedure was developed for the analysis of organophosphorus and carbamate pesticides in sediment. The wet soil was mixed with anhydrous sodium sulfate to bind water and the residues were column extracted in acetonermethylene chloride (1:1, v/v). Coextracted water was removed by additional sodium sulfate packed below the sample mixture. The eluate was concentrated and analyzed directly by capillary gas chromatography using phosphorus and nitrogen specific detectors. Recoveries averaged 93% for sediments extracted shortly after spiking, but decreased significantly as the samples aged.
Soil biodegradation of carbofuran and furathiocarb following soil pretreatment with these pesticides
Authors: Hendry Karen M. , Richardson Curtis J. 
Published: March 2010

Abstract
A field application level (9 μg·g−1) of carbofuran was completely hydrolyzed within 1 to 3 days in a loamy sand soil pretreated with the same level of carbofuran, while &lt;5% of the carbofuran was hydrolyzed in control soil not pretreated. The number of microbial carbofuran-hydrolyzers was substantially greater in loamy sand soil treated twice with a field application level (9 μg·g−1) of carbofuran than in untreated soil. Also, carbofuran-adapted soil showed no significant change in the number of carbofuran-hydrolyzers during the period of rapid degradation. Inorganic nitrogen, at a typical fertilization level, appeared to slightly stimulate the enhanced degradation of carbofuran in the pretreated soil. Soil pretreated with an application level hydrolyzed 65% of a residue level (8 ng·g−1) within two days, but virtually none of the remaining carbofuran was hydrolyzed thereafter. A microbial biomass carbon experiment with a sandy loam soil indicated that only 0.2% of the applied carbonyl-C could be attributed to biomass. Soil pretreated with a residue level did not show rapid degradation of the same level or a field application level, although the field application level was degraded slightly faster in this soil than in soil not pretreated. Soil pretreated with a field application level of carbofuran or furathiocarb also rapidly hydrolyzed the same level of furathiocarb, but furathiocarb is probably converted into carbofuran before hydrolysis.
Relationships among models for acute toxic effects: Applications to fluctuating concentrations
Authors: Breck James E. 
Published: March 2010

AbstractA damage-repair model for estimating mortality due to fluctuating exposures reduces to the probit plane model for short exposure times or negligible repair rates. Interpreting the probit plane as a cumulative damage model, data from constant exposures may be useful for predicting mortality due to fluctuating exposures of short duration.
Nonequilibrium sorption of organic contaminants during flow through columns of aquifer materials
Authors: Lee L. S. , Rao P. S. C. , Brusseau M. L. , Ogwada R. A. 
Published: March 2010

Abstract
Batch equilibrium and miscible displacement studies were conducted to investigate sorption and transport of trichloroethylene (TCE) and p-xylene in two sand aquifer materials low in organic carbon content. The utility of a bicontinuum (two-site) sorption model to describe the extent of sorption nonequilibrium during transport in saturated columns was evaluated. Model parameters estimated from the breakthrough curves (BTC) obtained at a high pore-water velocity (v = 24 cm/h) were used successfully to describe the BTC measured at a lower pore-water velocity (v = 6 cm/h). The assumption of local sorption equilibrium was valid at the lower velocity, and the measured BTC could be described by an equilibrium sorption model coupled to a convective-dispersive transport model. Values for column retardation factors estimated by fitting the two-site model to the BTC were comparable with those estimated from equilibrium sorption isotherms. BTC measured for displacement of binary mixtures (TCE plus p-xylene) and single-solute (TCE or p-xylene alone) were identical, suggesting that there is no competitive sorption between these two solutes. These column observations were consistent with sorption isotherm data.
Laboratory acidification of a crustacean zooplankton assemblage from a Rocky mountain subalpine lake (U.S.A.)
Authors: Bruns D. A. , Wiersma G. B. 
Published: March 2010

Abstract
A laboratory acidification experiment was conducted with a Rocky Mountain zooplankton assemblage from a subalpine lake located downwind of energy development activities and significant sources of acid precursors. The objective of the study was to assess the relative effects of lowered pH (treatment pH 4.2 and 5.2, control pH 6.8) on the survival of different crustacean zoo-plankton species under controlled conditions for extended periods (19 to 41 d). Analysis of variance (e.g., F = 4.55, p &lt; 0.05) indicated statistically significant differences between controls and treatments (acid treatments contained fewer individuals than did controls) for all four species, and significant differences among species. Newman-Keuls multiple range tests (e.g., q = 4.02, p &lt; 0.025) demonstrated the following ranking of species sensitivity (high to low) to a lowered pH of 5.2: Daphnia rosea &gt; Holopedium gibberum &gt; Diaptomus lintoni &gt; Cyclops sp. At pH 4.2, H. gibberum was significantly more tolerant than D. rosea and D. lintoni (q = 4.50, p &lt; 0.025), but no other significant differences were apparent. The results agree generally with those of other published experiments and field surveys.
Porphyria in herring gulls: A biochemical response to chemical contamination of great lakes food chains
Authors: Fox Glen A. , Norstrom Ross J. , Wigfield Donald C. , Kennedy Sean W. 
Published: March 2010

AbstractConcentrations of highly carboxylated porphyrins (HCPs) in the livers of adult herring gulls (Larus argentatus) from colonies throughout the Great Lakes were found to be markedly elevated in comparison with those in gulls from coastal areas and in seven other species of birds consuming diets uncontaminated with polyhalogenated aromatic hydrocarbons (PHAHs). The highes levels were found in gulls from lower Green Bay (Lake Michigan), Saginaw Bay (Lake Huron) ant Lake Ontario. We suggest that the high levels of HCPs reflect PHAH-induced derangement of heme biosynthesis. Determination of HCPs offers promise as a specific and sensitive biological marker of PHAH-induced toxicity and as a measure of the toxicological significance of the chemical burden in gulls, terminal members of Great Lakes food chains.
Effect of low-level continuous chlorination on Corbicula fluminea
Authors: Ramsay George G. , Tackett J. Hainey , Morris David W. 
Published: March 2010

Abstract
The time required for continuous chlorination to produce 100% mortality in adult Corbicula fluminea was determined. The total residual chlorine concentrations maintained were lower than any previously tested: 0.05, 0.10 and 0.20 mg/L.
Improvement and application of an immunoassay for screening environmental samples for dioxin contamination
Authors: Vanderlaan Martin , Stanker Larry H. , Watkins Bruce E. , Petrovic Peter , Gorbach Siegbert 
Published: March 2010

Abstract
We previously had developed monoclonal antibodies for the immunoassay of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF), and have since refined the use of these antibodies for the detection of dioxins in a wide range of contaminated samples, with the aim of developing a screening assay for dioxin contamination. The levels of PCDD and PCDF contamination in 13 different samples, including fly ash, soil, technical-grade chemicals, motor oils, polychlorinated biphenyl transformer oil and still-bottom residues, were determined by immunoassay. The contamination ranged from less than 1 to several thousand ppb PCDD and PCDF. The levels of PCDD and PCDF contamination in some samples were determined by conventional GC-MS. The monoclonal antibodies used in this study detect many of the tri-, tetra- and pentachloro congeners of PCDD and PCDF, while the GC-MS data included information on total tetra- and pentachloro congeners of PCDD and PCDF, as well as levels of specifically regulated toxic congeners. There were good correlations between the results of the immunoassay and those of conventional GC-MS analysis, in spite of the differences in the exact congeners detected by the two techniques. There were no false-negative results. Moreover, the immunoassay required substantially less sample cleanup than did GC-MS, thus offering the promise of greatly reduced costs and time for screening samples. Only the soil matrix interfered with results; the cleanup methods for this matrix still need improvement.
Utilization of microcomputer and telecommunications technologies in the development of a local environmental management and risk assessment program
Authors: Wagner Vaughn E. , Bianchi Marco A. , Heeter Carrie 
Published: March 2010

Abstract
An environmental management and risk assessment program (EMRAP) was designed and implemented by the Macomb County Health Department in 1985 to address health problems associated with hazardous materials exposures. The establishment of a toxicological resource center provides a focal point for the rapid assembly, assessment and dissemination of toxicological and biomedical information. The program utilizes a microcomputer with toxicological/biomedical software as well as a telecommunication linkage to public and private databases.
The need for first responder agencies, e.g., fire and police, to effectively manage toxic materials incidents prompted a proposed design modification of the existing EMRAP computer/telecommunication system. The result will be 24-h, 7-d accessibility to biomedical/risk analytical databases by a remote telecommunication information system.
Whole ecosystem manipulation: A productive avenue for test system research?
Authors: Perry James A. , Troelstrup Nels H. 
Published: March 2010

AbstractSingle-species, microcosm and mesocosm toxicity tests frequently have been shown to be inadequate in assessing impacts on whole ecosystems, yet effective environmental management requires attention to such impacts. Whole ecosystem manipulation provides community and ecosystem level assessment, but is expensive and logistically demanding. Thus most whole ecosystem experiments are pseudoreplicated, which gives them limited inferential capability. We present the results of two whole ecosystem experiments — dosing of stream channels with chlorine and ammonia and acidification of a lake — and review several other such experiments from the literature. Most whole ecosystem studies are complex, expensive, involve multiple investigators and have a low degree of true replication. Difficulty in replicating whole system manipulations makes quantifying cause-effect relationships difficult, but this can be partially overcome by carefully developing the inferences from an investigation. In sum, we suggest that such experiments do indeed represent a useful test system, and that they are the only acceptable way of discerning impacts at the community and ecosystem levels.
Flow-through culture techniques for neanthes arenaceodentata (annelida: Polychaeta), including influence of diet on growth and survival
Authors: Pesch Carol E. , Schauer Paul S. 
Published: March 2010

Abstract
Neanthes arenaceodentata has been used frequently in saltwater toxicity tests. A flowing‒water system is described for the laboratory culturing of this polychaete. The system features the shallow, flat trays that are commonly used to culture shellfish. Three diet studies were conducted to determine the best diet to feed laboratory cultures to promote good growth (measured by dry weight) and survival. First, all diets (including commercially prepared diets, yeasts, whole‒grain and grain by‒products, algae, and animal tissue) were evaluated singly in a 28‒d test. Then, selected diets, alone and in combination, were evaluated in two tests (34 and 70 d) that simulated our culture conditions. In the first test, a commercially prepared diet, prawn flakes, produced the best growth; however, worms fed macroalgae had better survival (84% or more versus 60% for those fed prawn flakes). In the last two experiments, a combination of a macroalga and prawn flakes produced the best growth and survival. For example, after 34 d, prawn flakes alone and prawn flakes plus a macroalga produced a similar increase in dry weight of worms (18.8 and 18.7 mg, respectively), but survival was 26% higher with the combination diet.