bluuebunny/crossref_metadata_2025_split huggingface dataset:
Toxicity of silver to steelhead and rainbow trout, fathead minnows and Daphnia Magna
Authors: Nebeker Alan V. , McAuliffe Chris K. , Mshar Roger , Stevens Donald G. 
Published: March 2010

Abstract
Rainbow (Salmo gairdneri) and steelhead (Salmogairdneri) trout and fathead minnows (Pimephales promelas) were exposed to silver for 96 h in replicated flow-through tests. Rainbow trout, fathead minnows and Daphnia magna were exposed to silver in replicated static acute tests. Steelhead trout embryo-larval stages were tested in a flow-through system for 60 d, and D. magna were exposed through complete life cycles in replicated static-renewal tests. All silver concentrations were measured values. No differences were seen between flow-through and static LC50 values. Rainbow trout 96-h flow-through LC50 values were 8.6 and 9.7 μg/L silver; static values were 10.9 and 8.5 μg/L. The 96-h LC50 for steelhead trout in the flow-through test was 9.2 μg/L. Fathead minnow 96-h flow-through LC50 values were 5.6 and 7.4 μg/L silver; static values were 9.4 and 9.7 μg/L. The absence of food in static tests with D. magna caused silver to be about 10 times more toxic; the 48-h static mean EC50 value for D. magna without food was 0.9 μg/L, compared to 12.5 μg/L in the test with food. The early-life-stage test with steelhead trout, from newly fertilized eggs to post-swimup juveniles, showed complete mortality at 1.3 μg/L and significant reduction in fish survival at 0.5 μg/L silver. Mean weight and length at end of test were greatly reduced at 1.1 μg/L, and were significantly different from controls at 0.1 μg/L. The mean 21-d EC50 value for the D. magna test with food was 3.5 μg/L. The 21-d lowest significant (α = 0.05) effect on survival occurred at 4.1 μg/L. The mean silver concentration at which there was a significant decrease in total Daphnia young/female/day after 21 d, compared to the control was 10.5 μg/L silver.
Evaluation and development of static shake-flask biodegradation test systems
Authors: Blum James E. , Stevenson Cathy A. , Stainken Dennis M. 
Published: March 2010

Abstract
Several biodegradation flask systems were evaluated to assess the effects of flask shape and volume and length of incubation on the recovery of 14CO2. During a 6-h incubation period, it was demonstrated that the recovery of 14 CO2 decreased as the volume of the flask (50 ml to 2 L) and the length of the diffusion path increased. Increasing the incubation time improved the performance of flasks, which were relatively inefficient at 6 h. Selected flask systems were further assessed, measuring the extent of CO2 evolution from nonradiolabeled linear alkylate sulfonate and glucose by a mixed inoculum.
Use of microcosms to study transport, transformation and fate of organics in aquatic systems
Authors: Rodgers John H. , Dickson Kenneth L. , Saleh Farida Y. , Staples Charles A. 
Published: March 2010

Abstract
Assessing the hazards of chemicals in aquatic ecosystems requires methods for examining where a potential toxicant is likely to be in place, time, form and concentration. Currently there is considerable interest in the use of microcosms as predictors of transport, transformation and fate of potentially toxic organics in aquatic systems. Generic microcosms of varying complexity can serve as useful tools for studying partitioning and kinetics of organic chemicals. Microcosms facilitate determination of mass balances and recovery of transformation products for further study. In this study, extensively characterized generic microcosms were used to examine the fates of naphthalene and lindane, and to compare observed compartmentalization and processing to predictions by two fate models, the Exposure Analysis Modeling System (EXAMS) and Simplified Lake and Stream Analysis (SLSA). Inputs to the fate models consisted of microcosm characteristics and laboratory-determined rate coefficients for the two chemicals. Both fate models demonstrated good capabilities for predicting aqueous phase concentrations of naphthalene and lindane. However, EXAMS and SLSA predicted sediment naphthalene and lindane concentrations that exceeded observed concentrations by up to two orders of magnitude. This lack of agreement for sediments may be attributed to model inputs or model constructs. Sediments deserve further attention, since many organic chemicals of environmental concern have relatively large sediment-water partition coefficients and are not biodegraded at an appreciable rate. Both the questions of depth distribution of chemicals through time and sediment microbial degradation rates need further study, since the understanding of them may enhance model development. Depending upon the question or the hypothesis addressed, microcosm construction may range from simple to complex with one to several compartments. Through careful microcosm design, processes controlling the fate of a particular chemical in nature may be isolated and examined in detail. Fates of a variety of chemicals can be compared and contrasted efficiently in replicate microcosms. As simplified systems, microcosms are accurate predictors only for those processes and equilibrium phenomena that are sufficiently understood to scale to natural systems. Microcosms can provide feedback information for theoretical model testing and validation.
Fate of methyl parathion in aquatic channel microcosms
Authors: Holm H. W. , Kollig H. P. , Payne W. R. , Proctor L. M. 
Published: March 2010

Abstract
The fate of methyl parathion and the development of biological communities were examined as a function of inorganic nutrient enrichment, inorganic nutrients plus glycerol and presence of sediments in two eight-compartment, continuous-flow channel microcosms. First-order degradation rates of methyl parathion were related to the different nutrient treatments, with higher rates associated with the organically enriched environments. A stable state was generally established in each compartment after 6 weeks of development. Aufwuchs biomass dominated the systems and observed differences (α = 0.10) in nutrient concentrations were reflected by differences (α = 0.05) in some aufwuchs structural parameters and in community function. Inclusion of sediments had no significant effect on any of the parameters measured.
Potential terrestrial fate and effects on soil biota of a coal liquefaction product spill
Authors: Strayer Richard F. , Edwards Nelson T. , Walton Barbara T. , Charles-Shannon Velma 
Published: March 2010

Abstract
Contaminated soil samples collected from the site of a coal liquefaction product spill were used to study potential fates and effects of this synthetic fuel. Simulated weathering in the laboratory caused significant changes in residual oil composition. Soil column leachates contained high phenol levels that decreased exponentially over time. Toxicity tests demonstrated that the oil-contaminated soil was phytotoxic and caused embryotoxic and teratogenic effects on eggs of the cricket Acheta domesticus.
Toxicity of creosote-contaminated sediment to field- and laboratory-colonized estuarine benthic communities
Authors: Tagatz Marlin E. , Plaia Gayle R. , Deans Christine H. , Lores Emile M. 
Published: March 2010

Abstract
Macrobenthic animal communities that colonized uncontaminated and creosote-contaminated sand (177, 844 and 4,420 μg/g, nominal) during 8 weeks were compared to assess effects of marine-grade creosote on community structure. Aquaria were colonized in the laboratory by planktonic larvae entrained in continuously supplied unfiltered seawater and in the field by animals that occurred naturally. Individuals and species in aquaria that contained 844 and 4,420 μg creosote/g sand were significantly fewer (α = 0.05) than those in the control. Abundance of animals in field-colonized communities contaminated with 177 μg/g creosote, but not in laboratory-colonized communities, also was less than that in the control. The lowest creosote concentration at either site that affected numbers of individuals or species was 844 μg/g for mollusks and 177 μg/g for echinoderms, annelids and arthropods. The Shannon-Weaver index of diversity, Simpson's index of dominance and the Bray-Curtis dissimilarity index differences were greater with each increase in creosote concentration. Rarefaction indices of diversity indicated that the distribution of individuals within species was about the same for laboratory and field assemblages of animals. Initial measured concentrations of creosote in sand (midrange concentration) decreased by 30% in the laboratory and by 42% in the field at the end of the 8-week test.
Fate and speciation of silver in publicly owned treatment works
Authors: Lytle Paul E. 
Published: March 2010

Abstract
The fate and speciation of silver in three categories of publicly owned treatment works and their receiving waters were studied. The plants included those that treated (a) municipal sewage and commercial photoprocessing effluents, (b) municipal sewage and nonphotographic silver effluents and (c) municipal sewage with no known silver effluents. Specific objectives were to determine if the source of silver affects silver removal and how secondary treatment affects the speciation of silver.
The average removal efficiency for total silver at the six treatment plants studied was 75%. The two plants receiving silver from photoprocessing operations achieved 95% removal. The two plants receiving silver from industrial sources achieved 83% removal. The plants with no known silver contributors achieved 48% removal. There was no significant increase in silver in any of the sediments downstream of the treatment plant discharges.
The highest influent free silver ion concentrations were associated with the treatment plants that had no known photoprocessing or industrial silver sources. The concentrations of silver ion in the effluents from all treatment plants ranged from 0.001 to 0.07 μg/L. Downstream silver ion concentrations were always ≤ 0.05 μg/L. With the chronic toxicity value to freshwater aquatic life for silver ion being stated as 0.12 μg/L, the relatively small quantities of silver ion and total silver that were discharged should have little, if any, impact on receiving water quality.
The influence of speciation on the toxicity of silver to fathead minnow (Pimephales promelas)
Authors: Leblanc Gerald A , Mastone Joseph D , Paradice Arthur P , Wilson Brenda F , Jr Haines B Lockhart , Robillard Kenneth A 
Published: March 2010

Abstract
Silver sulfide, silver thiosulfate complex and silver chloride complexes were tested and compared with free silver ion for their toxic effects in 96 h flow through acute toxicity tests using fathead minnows (Pimephales promelas). Thirty day fathead minnow embryo larval tests were conducted with silver sulfide and silver thiosulfate complex. Extensive chemical analyses were performed to quantify actual exposures. Compared with free silver ion, silver chloride complexes were about 300 times less toxic acutely silver sulfide was at least 15,000 times less toxic acutely and silver thiosulfate complex was more than 17,500 times less toxic acutely. The estimated maximum acceptable toxicant concentrations (MATCs) determined from the embryo larval tests with silver sulfide and silver thiosulfate complex were greater than 11 mg/L (as total silver) and greater than 16 but less than 35 mg/L (as total silver), respectively. The MATC previously reported for free silver ion from tests with rainbow trout (Salmo gairdneri) was greater than 0 00009 but less than 0 00017 mg/L. These differences in acute toxicities and the differences of five orders of magnitude in the MATC values are attributed to the influence of chemical speciation on the effects of silver in the aquatic environment. Thus, the speciation of silver is an essential factor in its potential to affect fish and, presumably, other aquatic life, and therefore should be considered in environmental risk assessment.
Relative toxicities of chemicals to the earthworm Eisenia foetida
Authors: Roberts Brian L. , Wyman Dorough H. 
Published: March 2010

Abstract
In the present study, 90 chemicals were tested against Eisenia foetida for the purpose of using this organism as the marker species to indicate the relative toxicities of chemicals to earthworms and other soil invertebrates. The worms were exposed to deposits of the chemicals on filter paper for 48 h and the mortality was recorded; concentrations were expressed in μg/cm2. Based on the resulting LC50 values, the chemicals were classified as supertoxic (&lt; 1.0 μg/cm2), extremely toxic (1–10 μg/cm2), very toxic (10–100 μg/cm2), moderately toxic (100–1,000 μg/cm2) or relatively nontoxic (&gt; 1,000 μg/cm2). Of the chemicals tested (pesticides, solvents, metals, drugs, carcinogens, etc.), only carbofuran and eserine salicylate, both carbamates, were supertoxic. The remaining chemicals were distributed about equally among the other toxicity categories. The most surprising results were that the phenolic hydrolytic products of parathion, carbaryl, 2,4-D and 2,4,5-T were as toxic, or more toxic, than the parent material, with all of these compounds falling within the extremely toxic and very toxic classifications. Several chemicals, considered only moderately or relatively nontoxic to mammals, were extremely or very toxic to earthworms; among these compounds were carbaryl, malathion, cypermethrin and benomyl. The results of this study further demonstrate the unpredictability of chemical toxicity to different animal species, a fact which complicates the assessment of environmental risk to one or more species based on data attained with another.
The effect of naphthalene on oxygen consumption and hemoglobin concentration in Chironomus attenuatus and on oxygen consumption and life cycle of Tanytarsus dissimilis
Authors: Darville Roy G. , Wilhm Jerry L. 
Published: March 2010

Abstract
The effects of naphthalene on the physiology and life cycle of two species of benthic macroinvertebrates, Chironomus attenuatus and Tanytarsus dissimilis (Diptera: Chironomidae), were determined. The acute effects measured were survival, oxygen consumption, hemoglobin concentration and total body glycogen content. A flow-through system was used to determine chronic effects on life cycle and reproduction parameters.
Both species had LC50 values of approximately 13 mg/L. After exposure to naphthalene for 1 h, the oxygen consumption of both species decreased. Tanytarsus was more sensitive than Chironomus, which is consistent with the life histories of the two species. The decrease in oxygen uptake was due to inhibition of the electron transport chain or interference with functioning of the nervous system.
Hemoglobin concentrations in Chironomus were not good indicators of naphthalene stress. Although hemoglobin in Chironomus decreased after 4 h of exposure, the decrease was not significant. The decrease could not be accounted for by alteration of hemoglobin structure or by inhibition of synthesis.
Life cycle exposures at naphthalene concentrations of less than 0.5 mg/L resulted in minimal effects. Egg hatching and adult emergence were the best indicators of chronic exposure. Pupation times and numbers of eggs were not significantly changed.
Effects of freshwater exposure to arsenic trioxide on the parr-smolt transformation of coho salmon (Oncorhynchus kisutch)
Authors: Nichols John W. , Wedemeyer Gary A. , Mayer Foster L. , Dickhoff Walton W. , Gregory Stan V. , Yasutake William T. , Smith Stanley D. 
Published: March 2010

Abstract
The effects of chronic (6 months) exposure to arsenic trioxide in fresh water on the Parr-smolt transformation of coho salmon (Oncorhynchus kisutch) were evaluated. Exposure to 300 μg As/L (as As2O3) appeared to delay the onset of the normal increase in plasma thyroxine concentration and cause a transient reduction of gill Na+,K+-ATPase activity. Fish exposed to 300 μg As/L also migrated to the sea less successfully than did nonexposed smolts, but there were no effects on the survival and growth of smolts held in 28‰ salt water for 6 months.
A quantitative correlation of the LC50 values of esters in pimephales promelas using physicochemical and topological parameters
Authors: Basak S. C. , Gieschen D. P. , Magnuson V. R. 
Published: March 2010

Abstract
In recent years much emphasis has been given to the development of easily calculated molecular descriptors that can adequately predict the pharmacological and toxic action of bioactive molecules. In this article a quantitative structure-activity relationship (QSAR) study of industrially important esters was carried out using hydrophobicity (log P, octanol-water), molecular connectivity indices (lX, lXv), Wiener number (W) and information-theoretic topological indices defined on the total molecular graph. Information-theoretic topological indices studied include information content (IC), structural information content (SIC) and complementary information content (CIC), as well as information indices derived from the distance matrix of the hydrogen-suppressed chemical graph (IWD, I WD). The topological index lXv, an electronic parameter, was found to be the single best descriptor for predicting the LC50 values of esters in Pimephales promelas. However, a multiparametric relationship including a lipophilic (log P), an electronic (lXv) and a steric (CIC) parameter resulted in the most significant correlation, suggesting multiconditionality in the mode of toxic action of these esters.
Fate of 3,3′-dichlorobenzidine in soil: Persistence and binding
Authors: Boyd Stephen A. , Kao Chun Wei , Suflita Joseph M. 
Published: March 2010

Abstract
The fate of the carcinogen 3,3′-dichlorobenzidine (DCB) in soil was evaluated with regard to persistence and binding. A Brookston clay loam soil was amended with 4 or 40 ppm 14C-DCB and incubated under aerobic conditions for 32 weeks or under anaerobic conditions for 1 year. Mineralization occurred very slowly in aerobic soil and did not occur in anaerobic soil. Total 14C radioactivity in soil remained essentially constant during the incubations, demonstrating that volatile losses of DCB or DCB decomposition products did not occur in our incubation system. DCB was shown to bind strongly to soil. After 32 weeks of incubation, approximately 90% of the applied radioactivity remained in soil after extraction with ethyl acetate and methanol. The loss of solvent-extractable DCB occurred mostly in the first several weeks of incubation and was accompanied by an increase in alkali-extractable DCB. These data strongly suggest the formation of covalent linkages between DCB and soil humic components as the primary fate of DCB in the Brookston soil. The significance of humus-bound DCB residues as potential sources of future contamination is essentially unknown.
Photolytic oxidative demethylation of aqueous dimethylsiloxanols
Authors: Buch R. R. , Lane T. H. , Annelin R. B. , Frye C. L. 
Published: March 2010

Abstract
Dimethylsilanediol and other water-soluble dimethysiloxanols undergo aqueous photolytic oxidative demethylation with tropospheric ultraviolet radiation in the presence of suitable chromophores, such as nitrogen oxides, to give silicic acid and carbon dioxide. The “biosuitability” of the resulting silicic acid was demonstrated by monitoring the growth of diatoms (Navicula pelliculosa) in the irradiated aqueous media. Thus, a plausible route for the further degradation of such water soluble hydrolysis products of poly(dimethyl-siloxane) to naturally occurring materials was conclusively demonstrated. Furthermore, di- and monomethyl silanol species were shown not to be utilized by the diatom colony, even when present as completely water soluble components.
Transport and fate of diethyl phthalate in aquatic ecosystems
Authors: Lewis David L. , Holm Harvey W. , Kollig Heinz P. , Hall Tom L. 
Published: March 2010

Abstract
Sorption, alkaline hydrolysis, photolysis and microbial transformation of diethyl phthalate (DEP) were studied in a large laboratory aquatic ecosystem composed of a series of reactor tanks. Microbial transformation accounted for 95 to 99% of the rapid loss of DEP from water. First-order rate coefficients for the loss of DEP, except in reactor tanks depleted of inorganic nutrients, were statistically constant among diverse chemical and microbial environments, suggesting a constant transformation rate per unit of colonized surface area. The diversities of reactor tank environments were substantiated by large ranges in the dissolved organic carbon, nitrogen, phosphorus, chlorophyll, ATP and biomass measurements. Microbial transformation of DEP resulted specifically from bacterial activity, most of which was associated with aquatic microbial growth (aufwuchs) attached to submerged surfaces or suspended in streamers or mats.
Time variable model of the fate of DDE and lindane in a quarry
Authors: Di Toro Dominic M. , Paquin Paul R. 
Published: March 2010

Abstract
A time variable model has been used to analyze a field scale experiment in which a flooded limestone quarry was dosed with equal quantities of Lindane and DDE. The water column and sediment chemical concentrations were monitored for one year after the initial dosing. The markedly different physical-chemical characteristics of the test chemicals provided an interesting contrast for model application.
A simplified time variable model of partitioning chemicals is cast in the form of analytical solutions for the total, dissolved and particulate concentrations of chemical in completely mixed, interactive, water column and sediment compartments. The model formulation incorporates chemical decay and transport mechanisms of particulate and diffusive exchange between water column and sediment. The Lindane and DDE model calibrations based on data from the first year after dosing are presented. A preliminary verification of the model, obtained by projecting DDE levels in the water and sediment five years after initial dosing, when the quarry was revisited, is also shown. The model results underscore the significance of chemical partitioning on chemical fate and highlight the importance and utility of a modeling framework which incorporates realistic mechanisms of water column and sediment interaction.
A seven-day life cycle cladoceran toxicity test
Authors: Mount D. I. , Norberg T. J. 
Published: March 2010

Abstract
A three-brood life cycle test for Ceriodaphnia reticulata, using renewal techniques, that can be completed in 7 d is described. The test is convenient when samples to be tested are limited in volume or when time is especially important, such as in on-site effluent testing. The cladoceran C. reticulata is easily cultured and is not bothered by handling; control survival in tests has not been a problem.
Comparison of physical and chemical characteristics of shale oil fuels and analogous petroleum products
Authors: Ghassemi Masood , Panahloo Arshia , Quinlivan Sandra 
Published: March 2010

Abstract
The available data on the physical and chemical characteristics of crude and hydrotreated shale oil and for shale-derived naphtha, jet fuel, diesel fuel and residual fuel are reviewed and compared with similar data for analogous petroleum products. The databases for shale oil and petroleum are very diverse and have been generated by numerous investigators using a range of analytical procedures and test samples of various origins, including different raw material sources, processing scales and operating conditions. For both petroleum and shale oil, the detailed compositional data primarily relate to lighter “cuts.” Similar data for heavier cuts generally have not been obtained because of the very complex and variable nature of these products and the questionable utility of the results from the standpoint of refinery applications, and because properties of the individual compounds (especially from the standpoint of biological activity) may not be directly additive. Based on the data reviewed and the consideration of raw material chemistry and nature of the refining operation, it appears that the differences between shale oil and petroleum products are generally a matter of degree rather than kind, with the degree of similarity increasing with the extent of refining.