bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acid neutralization in laboratory sediment-water microcosms from a rocky mountain subalpine lake (USA)
Authors: Bruns D. A. , O'Rourke T. P. , Wiersma G. B. 
Published: March 2010

Abstract
A laboratory sediment–water microcosm experiment for a Rocky Mountain subalpine lake was conducted over a 35-d incubation period. Three sets of treatments were acidified to a pH of 4.3 and compared with a set of control microcosms. Treatments included additions of nitric acid, sulfuric acid and both acids combined. All treatment microcosms demonstrated rapid pH recovery to near that of the controls (e.g., 6.2) and changes in ion concentration suggested that over 90% of this recovery could be accounted for by cation exchange and microbial reduction of sulfates and nitrates. Denitrification appeared to predominate in both sets of treatments that involved nitric acid while cation exchange (mostly calcium) was more important in the sulfuric acid treatment. These results are consistent with published findings for both laboratory and field studies and demonstrate the potential importance of sediments for acid neutralization in a Rocky Mountain lake.
Arsenic uptake and transfer in a simplified estuarine food chain
Authors: Lindsay Diane M. , Sanders James G. 
Published: March 2010

Abstract
A simplified food chain of phytoplankton species, Artemia sp., and Palaemonetes pugio was used to study pathways of arsenic uptake in estuarine ecosystems. Uptake of arsenic by phytoplankton was significant; however, only small amounts of arsenic were incorporated by Artemia and no significant increases in arsenic content of P. pugio were found in those organisms exposed to arsenic-contaminated food or to elevated water concentrations.
Enhanced anaerobic biodegradation of vinyl chloride in ground water
Authors: Barrio-Lage Gladys A. , Parsons Frances Z. , Narbaitz Roberto M. , Lorenzo Pedro A. , Archer Horace E. 
Published: March 2010

Abstract
The enhanced biotransformation of vinyl chloride (VC) under anaerobic conditions was studied using static microcosms and a flow-through column packed with soil from a study site. Vinyl chloride was found to be resistant to transformation in the static microcosms in five months of incubation; however, 89% of the vinyl chloride that was dissolved in the water was transformed when the microbiota in the columns was stimulated with a mixture of nutrients. In the presence of nutrients such as methane, methanol, ammonium phosphate and phenol, the main products of biotransformation were nonchlorinated organics such as methane and ethylene. Sodium acetate, added to the water and soil, did not enhance the biotransformation of VC because acetate-utilizing bacteria were not found at the study site and none developed in soil sample after the 21 d allowed for adaptation. Four biodegradation mechanisms of vinyl chloride under anaerobic conditions were recognized in this study: (a) reductive dechlorination to ethylene; (b) mineralization to methane; (c) formation of chloromethane, probably followed by methane formation; and (d) bio-oxidation to CO2, where acetate and citrate were added. A pseudo-first-order rate constant of 1.01 × 10−3 months−1 and a t1/2 of 57.2 years were calculated for the disappearance of vinyl chloride in soil and water microcosms under anaerobic conditions, without bioenhancement.
Degradation of methomyl in chlorinated water
Authors: Miles Carl J. , Oshiro Wendy C. 
Published: March 2010

Abstract
Methomyl degrades rapidly in chlorinated water and the rate increases with decreasing pH, increasing temperature and increasing chlorine concentrations. Reaction rate with free chlorine is 1,000-fold faster than with chloramine. Methomyl forms methomyl sulfoxide and N-chloromethomyl before degrading to acetic acid, methanesulfonic acid and dichloromethylamine.
Kinetics of chloroguaiacols and other chlorinated phenolic derivatives in rainbow trout (salmo gairdneri)
Authors: Niimi A. J. , Kissoon G. P. , Lee H. B. 
Published: March 2010

Abstract
Chlorinated phenolic derivatives are important chemical constituents that are present in pulp and paper mill effluents. Subadult rainbow trout (Salmo gairdneri) were exposed to six dichloroto terachloroguaiacols, two chlorinated vanillins and trichlorosyringol through waterborne and dietary exposure. Equilibrium concentrations were attained within 2 d in waterborne exposed fish, and bioconcentration factor (BCF) values ranged from 1 to 270 among the guaiacols, less than 5 for the chlorovanillins and 125 for trichlorosyringol. Dietary exposure indicated these chemicals are poorly absorbed and have half-lives of less than several days. The kinetics of these chemicals are consistent with residue levels reported in fish collected from waters receiving mill effluents where waterborne uptake appears to be the primary mode for accumulation.
Toxicity of heavy metals in cultured hepatocytes
Authors: Denizeau Francine , Marion Michel , Chtaib Mohamed , Schmit Jean-Pierre 
Published: March 2010

Abstract
The cytotoxicity of three heavy metals that are representative environmental contaminants was investigated in primary cultures of rat hepatocytes. The cells were exposed to Cd, Ag or Hg and to mixtures comprised of Cd and either Ag or Hg at various concentrations. Incorporation of [3H]arginine ([3H]Arg) into proteins was used to monitor cytotoxic effects. In parallel, the uptake of metals by the cells was also determined. Concentration-response profiles for each individual agent show that among the metals studied Cd is the most cytotoxic. This effect is not due to preferential uptake because the amounts of Ag and Hg accumulated by the cells (at low exposure concentrations) were similar to those of Cd. When Ag was used in combination with Cd, amino acid incorporation data showed no evidence of modulated toxicity. In contrast, when Hg was added with Cd, the results suggested the possibility of interaction: The reduction in incorporated [3H]Arg was more pronounced than that expected on the basis of individual responses. Measurement of metal uptake by the cells revealed that intracellular levels of Ag were comparable whether Cd was present or not. Similarly, the amount of Cd accumulated by the hepatocytes was not significantly affected by the presence of Ag or Hg. In conclusion, the present data describe the cytotoxicity of nonessential heavy metals in hepatocytes and their concomitant accumulation by the cells. It is therefore possible to examine one phenomenon in relation to the other. The results are further discussed in the light of the bioinorganic properties of the metals investigated.
Effects of methyl parathion on red-winged blackbird (Agelaius Phoeniceus) incubation behavior and nesting success
Authors: Meyers S. Mark , Cummings John L. , Bennett Richard S. 
Published: March 2010

Abstract
Free-living female red-winged blackbirds (Agelaius phoeniceus) were captured on their nests and given oral doses of 0, 2.37 or 4.21 mg/kg methyl parathion in a propylene glycol carrier during incubation. Birds were released immediately after dosing and observed for 5 h to document behavioral effects, amount of time spent off the nest after dosing and time spent incubating. Each nest was monitored until nestlings fledged or until all nestlings died or disappeared. For each nest, the time of abandonment, hatching success and fledging success were determined. In addition, prefledging weights were obtained for all nestlings in nests at 8 d after hatch. Although methyl parathion caused ataxia, lacrimation and lethargy and significantly depressed cholinesterase activity (&gt;35%) at 4.21 mg/kg, there were no apparent adverse effects on reproduction. Females receiving 4.21 mg/kg methyl parathion were able to return to their nests, resume incubation, successfully hatch their clutch and rear their young. Nestlings of poisoned females did not have significantly different body weights at 8 d compared to controls, indicating that methyl parathion did not disrupt the females' ability to forage and deliver adequate food to nestlings. Band returns from the following year indicated that treatment birds returned and nested in nearly the same proportion as did controls and other red-winged blackbirds occupying the ponds. There was no indication that a single oral dose of methyl parathion (2.37 or 4.21 mg/kg) decreased over-winter survival.
Metal contamination in liver and muscle of northern pike (Esox lucius) and white sucker (Catostomus commersoni) and in sediments from lakes near the smelter at flin flon, manitoba
Authors: Harrison S. E. , Klaverkamp J. F. 
Published: March 2010

Abstract
Northern pike (Esox lucius Linnaeus), white sucker (Catostomus commersoni Lacépède) and sediment cores were obtained from 13 lakes located 4.5 to 84 km from the base metal smelter at Flin Flon, Manitoba, Canada. Zn, Cu, Cd, Hg, Se, Pb and As concentrations were determined in liver and muscle of fish. Depth profiles of Zn, Cu, Cd, Hg and Se concentrations were determined in sediment cores. The area receiving significant metal deposition from the smelter is smaller than previously estimated. Increases in metal concentrations in depth profiles of sediment cores appear to coincide with the onset of smelting operations at Flin Flon. Metal concentrations in fish from two lakes near the smelter dropped between 1976 and 1982, after a tall stack (250 m) was installed on the smelter. Metal concentrations in muscle were poor indicators of metal concentrations in sediments. Concentrations of Cd and Se in liver of northern pike, and concentrations of Zn, Cu, Cd and Se in liver of white sucker were greatest in the most contaminated lakes. Concentrations of Hg in fish declined with increased proximity to the smelter. Limnological variables seemed to have little influence on metal concentrations in fish.
Copper toxicity to Paratya australiensis: II. Influence of bicarbonate and ionic strength
Authors: Daly Helen R. , Campbell Ian C. , Hart Barry T. 
Published: March 2010

Abstract
The acute toxicity of copper to the Australian freshwater shrimp, Paratya australiensis, was shown to decrease in solutions of increasing alkalinity brought about by the addition of NaHCO3. This effect could not be explained merely in terms of changes in copper speciation in the solutions. Estimates of the free copper(II) ion concentration of the LC50 values were made using both copper ion selective electrodes measurements and chemical equilibrium computer calculations. Whereas there were discrepancies between the estimates obtained using these two methods, both indicated an apparent increase in tolerance of P. australiensis to the free copper(II) ion in more alkaline waters. An additional set of experiments, in which NaCl was added to test waters in place of NaHCO3, demonstrated that the increased tolerance of P. australiensis to copper in higher alkalinity waters was caused by a combination of physiological effects associated with increased ionic strength of the test waters and, to a lesser extent, changes in metal speciation in test waters. Further study of the reason for the discrepancy between estimates of copper(II) concentrations derived from ion selective electrode measurements and computer calculations is required.
Toxicity of fluoranthene in sediment to marine amphipods: A test of the equilibrium partitioning approach to sediment quality criteria
Authors: Swartz Richard C. , Schults Donald W. , Ditsworth George R. , Lamberson Janet O. , Dewitt Theodore H. 
Published: March 2010

Abstract
The toxicity of fluoranthene in sediment to the marine benthic amphipods, Rhepoxynius abronius (Barnard) and Corophium spinicorne (Stimpson) was determined in relation to the equilibrium partitioning approach to the development of sediment quality criteria. Toxicity tests were conducted with well-sorted fine sands at three levels of organic carbon (OC), 0.18, 0.31 and 0.48%. Measured interstitial water concentrations of fluoranthene less than 50 μg/L were highly correlated with predictions based on the equilibrium partitioning model. LC50s based on bulk (total) fluoranthene concentrations increased significantly with increasing sediment OC. LC50s based on fluoranthene concentrations in interstitial water were not significantly different between 0.18 and 0.48% OC or between 0.31 and 0.48% OC, but the LC50 at 0.31% OC was significantly higher than that at 0.18% OC. The regression of sediment OC on bulk fluoranthene LC50 was linear, indicating that the concentration of fluoranthene in interstitial water was constant at equitoxic conditions, as predicted by the equilibrium partitioning model. The 10-d LC50 of fluoranthene in interstitial water (23.8 μg/L) was intermediate between the U.S. Environmental Protection Agency's (U.S. EPA) acute (40 μg/L) and chronic (16 μg/L) water quality values for fluoranthene. Within the limitations of these experiments (i.e., one chemical, two species, sandy sediment with low carbon content), the results indicate that sediment quality criteria derived from the equilibrium partitioning model and water quality criteria would protect sensitive benthic invertebrates. The epibenthic, tube-dwelling Corophium was less sensitive to test sediments than the infaunal, free-burrowing Rhepoxynius, possibly because of different routes of exposure to fluoranthene. There was a close correspondence between estimates of sediment quality for fluoranthene based on distinctly different methodologies including equilibrium partitioning, apparent effects threshold, toxicity tests applied to experimentally spiked sediment and toxicity tests applied to field-collected sediment.
Equilibrium partitioning and bioaccumulation of sediment-associated contaminants by infaunal organisms
Authors: Lake James L. , Rubinstein Norman I. , Lee Henry , Lake Carol A. , Heltshe James , Pavignano Sharon 
Published: March 2010

Abstract
The utility and limits of applicability of a simple equilibrium partitioning model for predicting the maximum concentration of neutral organic compounds which can be accumulated by infaunal organisms exposed to a contaminated sediment were examined. Accumulation factors (AFs) for PCBs, the lipid normalized PCB concentration in organisms divided by the organic carbon normalized PCB concentration in sediments, were measured for PCBs in infaunal mollusks and polychaetes at field sites with a range of sediment Aroclor (A-1254) and total organic carbon (TOC) concentrations. The average AFs for A-1254 were found to be higher (x̄ = 4.94; range 3.76–7.27) at sites with lower contaminant concentrations (15.0–48.3 ng A-1254/g dry sediment) than at more contaminated sites (328–9,200 ng/g), where AFs were lower (x̄ = 2.62; range 1.14–5.04). AF data grouped on the basis of sediment A-1254 and TOC concentration differed statistically between, but not within each group. Significant differences in mean AFs were found between some species and between some PCB congeners. When all data were considered, the variability associated with AFs was lower than that found for bioaccumulation factors on a wet weight basis, indicating the utility of lipid and organic carbon normalization.
Slowly reversible sorption of aliphatic halocarbons in soils. I. Formation of residual fractions
Authors: Pignatello Joseph J. 
Published: March 2010

Abstract
This study describes the formation of slowly reversible sorbed fractions of various halogenated alkanes and alkenes in two surface soils. After the initial sorption equilibration period, the compounds were desorbed by one of two methods. The first used repetitive batch extraction with water. After 16 extractions of 24 to 72 h each, concentrations in the aqueous phase reached low values and a slow desorbing, residual fraction remained in the soil. The residual fraction in the soil was determined independently after extraction with hot acetone, whose efficacy was demonstrated. During desorption, apparent soil-water distribution coefficients increased progressively to as much as 200 times greater than equilibrium sorption coefficients, Kd, obtained separately from sorption isotherms. With increasing sorption equilibration time, the residual became greater in magnitude and less mobile. The second desorption method simulated desorption to infinite dilution over a 96 h period by using Tenax GC polymeric adsorbent beads included in the suspension as a sink for desorbed chemical. Control experiments proved the usefulness of Tenax and showed that desorption from the soil was rate limiting. All compounds studied formed slowly reversible fractions in the soils. This fraction amounted to several percent of the total sorbed from solution. The results indicate that formation of slowly reversible fractions is probably typical of nonpolar organic compounds, including those with weak sorbing tendencies.
The stage specific toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin in embryos of the japanese medaka (Oryzias latipes)
Authors: Wisk Joseph D. , Cooper Keith R. 
Published: March 2010

AbstractEmbryos of the Japanese medaka were individually exposed to varying concentrations of [3H]2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in a static, nonrenewal system. The EC50 with 95% confidence interval (C.I.) to prevent hatching was 14 (11–17) nanograms (ng) of TCDD equivalents per liter (L) of water (parts per trillion). The LC50 with 95% C.I. for survival to 3 d posthatch was 9 (6–12) ng TCDD equivalents/L. The EC50 with 95% C.I. for embryos with minor lesions and severe, life-threatening lesions were 3.5 (1.3–5.7) ng TCDD equivalents/L and 14 (12.4–15.6) ng TCDD equivalents/L, respectively. In a separate experiment that was terminated prior to the embryos hatching or dying, the EC50 for lesions was calculated to be 2.2 (1.4–3.0) ng TCDD equivalents/L. Based on the amount of TCDD equivalents recovered from dechorionated embryos, the ED50 with 95% C.I. for lesions was calculated to be 0.24 picograms of TCDD equivalents per milligram of dechorionated embryo weight (parts per billion). When the embryos were exposed to [3H]TCDD within 1 to 2 h after fertilization, no concentration dependent increase in visible lesions was observed until after the formation of the liver rudiment (day 4 of development). By exposing Japanese medaka embryos to lethal concentrations of TCDD beginning on different days of embryonic development, it was demonstrated that the sensitive period for toxicity was during liver formation on day 4 or 5 of development. The sensitive period for development was not caused by differences in TCDD absorption across the chorion. When embryos were exposed to [3H]TCDD prior to, during or after liver formation, there was no statistical difference in the dose of TCDD equivalents that crossed the chorion and entered the yolk and embryo.
Monitoring linear alkyl benzene sulfonate in the environment: 1973–1986
Authors: Rapaport R.A. , Eckhoff W.S. 
Published: March 2010

Abstract
Results from extensive monitoring from 1973 to 1986 indicate that linear alkyl benzene sulfonate (LAS) is extensively removed by sewage treatment with resulting river water concentrations in the low ppb range. Wastewater treatment plant removal efficiencies exceed those for biochemical oxygen demand (BOD); they average 98% for activated sludge, 80% for trickling filters and 27% for primary clarification. Concentrations in influent sewage (x̄ = 3.5 mg/L), effluent sewage (x̄ = 0.06–2.1 mg/L), and in river waters (&lt;0.005–0.3 mg/L) are in agreement with predicted concentrations and measurements by other investigators. Levels of LAS in soil cores analyzed shortly after sludge amendment range from &lt;3 to 47 mg/kg and are consistent with sludge loading rates and biodegradation of LAS from the previous year's sludge application. Removal of LAS occurs by biodegradation in all compartments and sorption/settling from the water column. Longer chain length, more sorptive LAS homologs are relatively enriched in sludge solids and in river sediments, thus the average LAS chain length was found to be higher in those compartments. Results obtained from long-term monitoring support the rapid removal of LAS by biodegradation in the environment.
A remote in situ apparatus for ambient toxicity testing of larval and yearling fish in river or estuarine systems
Authors: Ziegenfuss Michael C. , Hall Lenwood W. , Bushong Steven J. , Sullivan John A. , Unger Michael A. 
Published: March 2010

Abstract
A remote in situ apparatus for ambient toxicity testing of prolarval and yearling striped bass, Morone saxatilis, was designed and tested in the upper Chesapeake Bay and Potomac River during the 1989 spawning season. The apparatus' design, capabilities and significance in environmental monitoring are discussed.
Biological transformations of 1,1,1-trichloroethane in subsurface soils and ground water
Authors: Klečka Gary M. , Gonsior Stanley J. , Markham Daniel A. 
Published: March 2010

Abstract
1,1,1-Trichloroethane was readily degraded in samples from an alluvial aquifer under both methanogenic and sulfate reducing conditions. No lag period was noted prior to disappearance of the parent compound. Products detected in the reaction mixtures included 1,1-dichloroethane, chloroethane, 1,1-dichloroethene, acetic acid and carbon dioxide. No other chlorinated metabolites were detected. Biological reductive dehalogenation was responsible for the metabolism of 1,1,1-trichloroethane to 1,1-dichloroethane and to chloroethane. Abiotic transformations resulted in 1,1-dichloroethene and acetic acid. However, biological mechanisms also appeared to contribute to the formation of acetic acid, which was subsequently mineralized to carbon dioxide. Pseudofirst-order rate constants estimated for the biotransformation of 1,1,1-trichloroethane were in the range of 0.0034 day−1 to 0.015 day−1, whereas the rate constant for abiotic degradation was approximately 0.0006 day−1. Biotransformation of the compound was not observed in aquifer samples under aerobic or denitrifying conditions.
Investigation of preference-avoidance responses to an oil refinery effluent with striped bass and steelhead trout
Authors: Carr Robert Scott , Barrows Michael E. , Reichenbach Norman G. , DeGraeve G. Michael , Pollock Terry L. , Fava James A. , Glickman Andrew H. 
Published: March 2010

Abstract
Preference-avoidance tests using a modified Y-maze test apparatus were conducted with juvenile striped bass, Morone saxatilis, and steelhead (rainbow) trout, Oncorhynchus mykiss (formerly Salmo gairdneri), exposed to a refinery effluent discharged into San Francisco Bay. The test system was set up on site at the refinery, and the performance of the test system was validated using two reference materials, phenol (reference avoidant) and a mixture of amino acids (which was hoped would serve as a reference attractant). Both species of fish were tested at four effluent concentrations ranging from 0.1 to 10% with two different dilution waters, the receiving water and a known high-quality natural seawater. The results of this study indicate that juveniles of both species tended to avoid the effluent at concentrations that might be expected to occur within a short distance of the refinery outfall diffuser. At concentrations that would occur outside the zone of initial dilution, neither species of fish exhibited a preference or avoidance response to the refinery effluent.