bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structure-activity relationships for nitrogen-containing aromatic molecules
Authors: Schultz T. Wayne , Moulton Becky A. 
Published: March 2010

Abstract
Twenty-four nitrogen-containing aromatic molecules, mono- and dicyclic homologs from each of 12 different analog sets, were studied to determine their relative acute static toxicities, monitored as population growth impairment to the ciliate Tetrahymena pyriformis. Quantitative structure-activity correlations between the molecular descriptors log l-octanol/water partition coefficient (log Kow) and log toxicity are reported. Using the complete data set the descriptor does not provide an adequate model for predictability. A scatter plot of log Kow versus log toxicity suggests two parallel linear correlations: one consisting of the more complex multiple H-polar nitrogen-containing compounds and the other with the single H-polar and in-ring substituted nitrogen-containing compounds.
Pentachlorophenol toxicity to amphipods and fathead minnows at different test pH values
Authors: Spehar R. L. , Nelson H. P. , Swanson M. J. , Renoos J. W. 
Published: March 2010

Abstract
Juvenile amphipods (Gammarus pseudolimnaeus and Crangonyx pseudogracilis) and fathead minnows (Pimephales promelas) were exposed to pentachlorophenol (PCP) at pH values of 6.5, 7.5, 8.0 and 8.5 for 96 h, and early life stages of fathead minnows were exposed for 32 d at the same pH values to determine the relationship between test pH and the acute and chronic toxicity of PCP. Residue analyses were performed on fathead minnows after 32 d to determine the relationship between test pH and PCP bioaccumulation. Technical-grade PCP (88% active ingredient; Dowicide EC7) was used as the toxicant source.
Acute exposures with all three species showed that PCP toxicity was decreased with increased test pH. The slopes of this relationship were similar for the amphipods, but were different from that observed for fathead minnows. Early life stage exposures of fathead minnows showed that chronic PCP toxicity and bioaccumulation were similarly decreased when pH values were increased. The decrease in chronic PCP toxicity appeared to be due to the reduction in PCP accumulation as a direct result of the increased ionization of PCP at higher pH values, indicating that the ionized form was less toxic per unit concentration than was the un-ionized form. However, these studies suggest that chronic as well as acute toxicity may be caused by both forms of PCP when significant concentrations are present in solution.
Impact of atrazine and hexachlorobiphenyl on the structure and function of model stream ecosystems
Authors: Lynch Thomas R. , Johnson Howard E. , Adams William J. 
Published: March 2010

Abstract
Six laboratory model streams derived directly from natural stream communities were used to study the effects of atrazine and a hexachlorobiphenyl isomer on community structure and function. Two streams were treated with 2,4,5,2′,4′,5′-hexachlorobiphenyl (0.10 μ/L) dissolved in acetone, two streams received atrazine (25 μg/L) dissolved in dimethylsulfoxide and each of the two remaining streams received one of the carrier solvents at the same solvent concentration as the solute-treated streams (0.69 μl/L). The chemicals were administered to the streams for four 30-d periods, each of which was followed by a 60-d recovery period.
The results indicate that at the concentrations used, neither chemical had any significant or lasting effects on the structure of macroinvertebrate populations, periphyton standing biomass or rates of primary production and community respiration. The negative nature of the results for hexachlorobiphenyl are of special interest because in these experiments all components of the biota accumulated substantial quantities of this chemical.
Macroinvertebrate drift in the streams increased abruptly upon the injection of both solutes and their carrier solvents. This response appeared to be a reaction primarily to the solvents rather than the solutes. This effect should be investigated in more detail as it indicates that carrier solvents may alter the outcome and interpretation of test results.
Fate and metabolism of o-toluidine in the marine bivalve molluscs Mytilus edulis and Crassostrea gigas
Authors: Knezovich John P. , Crosby Donald G. 
Published: March 2010

Abstract
The in vivo fate and metabolism of a model aromatic amine (o-toluidine) were determined for mussels (Mytilus edulis) and oysters (Crassostrea gigas). o-Toluidine was found to be relatively nontoxic and was rapidly turned over in mollusc tissues. The biotransformation of o-toluidine and N-acetyl-o-toluidine was determined by the extraction and analysis of eliminated metabolites. The metabolism of [14C]o-toluidine in both bivalve species resulted in the formation of 2-nitrosotoluene, N-methyl-o-toluidine and N-formyl-o-toluidine. Small amounts of N-hydroxy-o-toluidine were detected in experiments with M. edulis. Mussels were found to be capable of N-deacetylation but oysters were not. The total extent of o-toluidine and N-acetyl-o-toluidine biotransformation in mussels from pristine waters was found to be greater than in mussels from contaminated waters.
The formation of N-oxidized metabolites is toxicologically important because this pathway constitutes the route of activation for mutagenic and carcinogenic aromatic amines. The formation of an N-formyl metabolite by these bivalves is also interesting, as this detoxication pathway has not been previously reported for marine invertebrates. The lack of carbon oxidizing pathways in these bivalves may be of limited toxicological significance because of their ability to utilize other detoxification (N-conjugation) pathways.
Airborne lead and trace elements in an indoor shooting range: A study of the DC national guard armory pistol range
Authors: Olmez Ilhan , Kotra J. P. , Lowery Sharon , Zoller William H. 
Published: March 2010

Abstract
Concentrations of airborne particulate lead in an indoor pistol range far exceeded the recently revised Occupational Safety and Health Administration target standard of 50 μg/m3, often by two or three orders of magnitude. A substantial fraction (40 to 50%) of the lead occurred on respirable-size particles (diameter ≤ 2 μm). Significantly elevated levels of Sb, Cu, As and Ba also resulted from the firing of .38 and .45 caliber pistols. The high levels of respirable, toxic elements observed indicate a potentially serious exposure for users and, in particular, the operators of such facilities.
Effects of lugworms and seagrass on kepone® (chlordecone) distribution in sediment/water laboratory systems
Authors: O'Neill Ellen J. , Monti Carol A. , Ahearn Donald G. , Pritchard Parmely H. , Bourquin Al W. 
Published: March 2010

Abstract
The influence of lugworms (Arenicola cristata Stimpson) and seagrass (Thalassia testudinum Koenig) on Kepone® (chlordecone) distribution in sediment/water systems was examined. Radiolabeled Kepone was introduced into continuous-flow sediment/water systems, and the dissolved and sorbed concentrations of Kepone were quantified. Lugworm activity decreased the Kepone concentration in the water and increased its concentration in the sediment. The presence of seagrasses did not appreciably affect the concentration of Kepone in the water. Bioturbation appeared to be the prime factor in the transport of Kepone from water to sediment.
Sorption dynamics of hydrophobic pollutants in sediment suspensions
Authors: Karickhoff Samuel W. , Morris Kenneth R. 
Published: March 2010

Abstract
Sorption of hydrophobic organic chemicals in natural sediment suspensions was found to frequently require extended time periods (days to weeks) for complete equilibration. Sorption dynamics could be described by a two-compartment model that distinguished rapid or “labile” exchange (requiring at most a few hours to achieve) from highly retarded or “nonlabile” sorption requiring days to weeks to occur. In general, one-half or less of the total sorption was labile. For highly hydrophobic chemicals and high solid concentrations, the labile fraction decreased to 0.1 or less in some systems. The kinetic exchange constant for nonlabile sorption varied inversely with the sorption equilibrium constant. That is, the more highly sorbed chemicals sorbed more slowly. For some sediments, air-drying to facilitate sample transport or storage was found to result in formation of highly stable aggregates that severely altered sorbent availability to hydrophobic chemicals. An understanding of sorption dynamics is important in describing the fate of highly sorbed pollutants in aquatic systems.
Comparison of pots versus microcosms for predicting agroecosystem effects due to waste amendment
Authors: Tolle Duane A. , Arthur Mickey F. , Chesson Jean , Van Voris Peter 
Published: March 2010

Abstract
Two laboratory test units (plastic flower pots and intact soil-core microcosms) were compared for their accuracy in predicting crop yield and element uptake in field plots. All three test units were amended with four treatment levels of unweathered, acidic fly ash (0, 100, 400 and 700 t/ha), fertilized with alfalfa meal and planted in late June with equivalent rates of Saranac alfalfa (Medicago sativa), Climax timothy (Phleum praetense) and Clintford oats (Avena sativa). Microcosms were more accurate than pots in predicting the dose-response yield curve for alfalfa/timothy grown in field plots. The hypothesis of parallelism between regression equations for alfalfa yield was rejected for pots versus field plots, but was not rejected for microcosms versus field plots. Neither of the two laboratory units accurately predicted the dose-response curves for oat grain or total oat yield. Pots were only slightly more accurate than microcosms in predicting the enrichment ratios (ERs) for alfalfa uptake of elements from field plots, based on statistical analysis of the distributions of In-ER ratios for 22 elements. The extra rooting depth of the 60-cm microcosms may provide more accurate yield data for long tap-rooted species like alfalfa, as well as permit a second year of accurate data on crop yield and element uptake.
Contaminants and bilateral asymmetry in yellow perch
Authors: Carline Robert F. , Lawai Marilyn V. 
Published: March 2010

Abstract
Several studies have shown that contaminants can induce bilateral asymmetry in fishes. In this study five bilateral meristic characters from seven populations of yellow perch (Perca flavescens) from Ohio and Wisconsin were enumerated to determine if there were any relationships among the asymmetries for each character and the body burdens of contaminants. Bilateral characters included scales on, above and below the lateral line, pectoral fin rays and gill rakers. Contaminants found in yellow perch were primarily polychlorinated biphenyls, DDT and dieldrin. All populations were asymmetrical for each bilateral character, but the degree of asymmetry was not related to contaminant levels. Unless a direct relationship between asymmetry and contaminants can be shown, we do not believe that this phenomenon will be a useful biological monitor.
Anthracene bioconcentration in rainbow trout during single-compound and complex-mixture exposures
Authors: Linder Greg , Bergman Harold L. , Meyer Joseph S. 
Published: March 2010

Abstract
Rainbow trout were exposed for 72 h to [14C]anthracene alone and [14C]anthracene in an oil shale retort water. Tissue levels of [14C]anthracene were analyzed at 24, 48 and 72 h to determine non-steady-state bioconcentration factors (BCFs), and uptake and depuration rates were calculated from anthracene disappearance in exposure waters and metabolite appearance in depuration waters. Uptake rates (14.6 to 16.9 h−1) were similar to previously reported values; however, depuration rates (0.00158 to 0.00188 h−1) were very low. Consequently, measured non-steady-state BCFs after 72 h (9,000 to 9,200) for anthracene were higher than expected, probably because fish were not fed and had low excretion rates. Measured and estimated anthracene BCFs were lower in retort water exposures than in single-compound exposures because of slower uptake and faster depuration. We attribute slower uptake during retort water exposures to either decreased bioavailability of anthracene or rate-limiting transport of contaminants from uptake sites to storage and processing sites. Induction of mixed-function oxidases may have increased depuration from fish exposed to retort water. We conclude that bioconcentration of individual compounds from complex chemical mixtures may be difficult to predict based on single-compound kinetics.
Predicting single-species toxicity in natural water systems
Authors: Connolly John P. 
Published: March 2010

Abstract
A methodology is proposed to predict single-species toxicity in natural waters by using laboratory bioassay data which relate effect to a tissue concentration of toxicant or to injury accumulation. Such relationships should be independent of test conditions and therefore be transferable from lab to field. Data for endrin and copper are presented which illustrate relationships between tissue concentrations and mortality. A mathematical model of uptake and elimination of toxicants by fish is used to relate exposure concentration to tissue concentration and then to effect. Prediction of toxicity in a laboratory test in which the exposure concentration varies in time is presented as a first step in testing the methodology. Using a dose-response relationship determined from published data for zinc toxicity to rainbow trout in a constant exposure toxicity test, the survival time under time-varying exposure is calculated and compared to observed data. The model predicted survival times that were consistent with the observed times. Whole-body residue is used as the estimate of dose.
A methodology for considering chemicals for which tissue concentration is not a useful estimate of dose is also presented. Diazinon-induced acetylcholinesterase inhibition data are used to demonstrate this methodology.
Sites of benzidine, α-naphthylamine and p-toluidine retention in soils
Authors: Graveel John G. , Sommers Lee E. , Nelson Darrell W. 
Published: March 2010

Abstract
The binding of benzidine (4,4′-diaminobiphenyl), α-naphthylamine (1-aminonaphthalene) and p-toluidine (4-methylaniline) by three soils was studied by incubating soils amended with the aromatic amines and then sequentially extracting them with 60:40 (v/v) ethylacetate: methanol (EtAc: MeOH), ammonium acetate (NH4OAc) and sodium hydroxide (NaOH) as a function of time. Essentially all of the added α-naphthylamine and p-toluidine was extracted initially with EtAc: MeOH and NH4OAc, whereas only 21% of added benzidine was extracted by these reagents. After 24 h, a significant decrease was found for amines extractable with EtAc: MeOH and NH4OAc. During 63 to 84 d after incubation, a gradual increase in the proportion of amine recovered by NaOH extraction was found. Fractionation of the NaOH extract into humic and fulvic acids indicated that benzidine and α-naphthylamine were primarily associated with the humic acid fraction, whereas p-toluidine was in the fulvic acid fraction. Simultaneous measurement of 14CO2 evolved showed that the average decomposition rate was 2, 12 and 15% for benzidine, α-naphthylamine and p-toluidine, respectively. Results indicate that binding of benzidine, α-naphthylamine and p-toluidine to soils involves both rapid, reversible equilibrium with inorganic and organic components of soil and nucleophilic addition to the phenolic components of humus. These retention mechanisms may explain why benzidine, α-naphthylamine and p-toluidine resist decomposition in soils.
Aryl hydrocarbon hydroxylase levels in herring gull embryos from different locations on the great lakes
Authors: Ellenton Jennifer A. , Brownlee Lorna J. , Hollebone Bryan R. 
Published: March 2010

Abstract
Aryl hydrocarbon hydroxylase (AHH) levels were measured in the livers of herring gull (Larus argentatus) embryos to determine if monooxygenase activity in this species could be used as a “bioeffects” monitor of environmental contamination. Herring gull eggs were collected in 1981 from five locations on the Great Lakes Basin and from one clean colony on the Atlantic coast. Microsomal protein determinations and AHH assays were conducted on livers from the embryos at 20 and 25 d of incubation. Organochlorines (DDE, DDT, tetrachlorobenzene, pentachlorobenzene, hexachlorobenzene, heptachlor epoxide, chlordane, dieldrin, mirex, photomirex, polychlorinated biphenyls and 2,3,7,8-tetrachlorodibenzo-p-dioxin) were also measured in egg homogenates from each colony. The 25-d embryos were found to be the most suitable for AHH analysis, since they had a higher baseline level and a greater response than did the 20-d embryos. Specimens from two of the Great Lakes colonies had significantly higher AHH activities than was found for the Atlantic coast colony. These levels of AHH activity closely paralleled the concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin present in eggs gathered from the colonies in 1980. Further work regarding monooxygenase levels in herring gull embryos is discussed.
Geochemical investigations of polychlorinated dibenzo-p-dioxins in the subsurface environment at an abandoned wood-treatment facility
Authors: Pereira Wilfred E. , Rostad Colleen E. , Sisak Mary E. 
Published: March 2010

Abstract
The discharge of effluents containing creosote and pentachlorophenol into two unlined surface impoundments at a wood-treatment facility in Pensacola, Florida, resulted in contamination of the underlying sand and gravel aquifer. These wastes contained significant amounts of chlorinated dioxins, such as isomers of hexa- and heptachlorodibenzo-p-dioxins and octachlorodibenzo-p-dioxin, probably derived from commercial pentachlorophenol. Geochemical investigations of pond sludge, groundwater and porous media from the unsaturated and saturated zones indicated that these geologic materials were contaminated by chlorinated dioxins. The fate and movement of these compounds in the subsurface environment were studied using the technique of GC-MS-MS. Chlorinated dioxins migrated both vertically and horizontally in the subsurface and were present at considerable distances from the source of contamination. Concentrations of chlorinated dioxins in groundwater were several orders of magnitude lower than in porous media from the unsaturated and saturated zones. Ratios of the various isomers remained relatively constant in highly contaminated areas. However, in less contaminated areas, isomer ratios changed dramatically; at certain locations, one hexachlorodibenzo-p-dioxin isomer predominated. The environmental significance of these compounds is discussed.
Effects of application procedures and irrigation on degradation and movement of aldicarb residues in soil
Authors: Wyman Jeffrey A. , Jensen John O. , Curwen David , Jones Russell L. , Marquardt Terry E. 
Published: March 2010

Abstract
Aldicarb was applied to potato plants in two locations in Wisconsin to determine the effects of application procedures and irrigation on degradation and movement of aldicarb residues, plant uptake, insect control and crop yield. Two application procedures (3.36 kg. AI/ha applied in the furrows at planting and 2.24 kg AI/ha applied as a top-dress application consisting of a surface-applied band covered with soil at plant emergence) and two irrigation regimens (medium water use based on evapotranspiration and heavy water use based on evapotranspiration plus 60%) were tested. The emergence application was effective in reducing the downward movement of aldicarb residues without significantly affecting performance as measured by insecticidal efficacy, crop residues and yield. Excess irrigation increased downward movement of aldicarb residues in soil, diminished foliar residues and resulted in decreased insect control and crop yield. Differences in soil characteristics, primarily in water-holding capacity, were important in reducing downward movement of aldicarb in soil.
Measurement of water solubilities, octanol/water partition coefficients and vapor pressures of commercial phthalate esters
Authors: Howard Philip H. , Banerjee Sujit , Robillard Kenneth H. 
Published: March 2010

Abstract
Water solubilities, octanol/water partition coefficients and vapor pressures were measured for a variety of commercial phthalate esters, several of which were mixtures. The results provide insight into the applicability of the procedures, which were developed for pure compounds, to more complex industrial products and formulations.
Organic substances in the rainfall of Lake Superior: 1983
Authors: Strachan W. M. J. 
Published: March 2010

Abstract
In 1983, sampling for organic substances in rainfall was undertaken at two, open-lake locations at opposite ends of Lake Superior — Isle Royale and Caribou Island. Triplicate samples, averaging 22 litres, were collected in each time period (approximately 6 weeks) and analysed for α-BHC, lindane, heptachlor epoxide, dieldrin, endrin, DDT residues, methoxychlor, polychlorinated biphenyls and hexachlorobenzene. α- and δ-chlordane, mirex and toxaphene were also investigated but were not found in any of the samples. Concentrations of these compounds ranged from 0.01 to 65 ng/L. The east side of the lake received considerably lower concentrations in rainfall (on average, roughly 65% less) and the levels of most of the observed substances were higher at both locations in the spring and early summer. Estimates of direct loadings to the lake were made using volume-weighted concentrations. The highest was for α-BHC at 860 kg/year and the lowest for hexachlorobenzene at 3.7 kg/year; the loading estimate for polychlorinated biphenyls was 300 kg/year.
Chronic toxicity of tebuthiuron to an alga (Selenastrum capricornutum), a cladoceran (Daphnia magna), and the fathead minnow (Pimephales promelas)
Authors: Meyerhoff Roger D. , Grothe Douglas W. , Sauter Scott , Dorulla Georgia K. 
Published: March 2010

Abstract
Chronic toxicity studies were conducted with an alga (Selenastrum capricornutum), a cladoceran (Daphnia magna) and the fathead minnow (Pimephales promelas) to determine their relative sensitivities to tebuthiuron, a soil-applied herbicide. The alga was the most sensitive of the three species. The no observed effect concentrations for the studies with the fathead minnow (9.3 mg/L) and the cladoceran (21.8 mg/L) were higher than the algistatic concentration (1.5 mg/L) for Selenastrum. These concentrations are 8 to 121 times higher than the highest transient concentration of tebuthiuron reported for a catchment pond.
Enlarged livers and hepatic microsomal mixed-function oxidase components in tumor-bearing brown bullheads from a chemically contaminated river
Authors: Fabacher David L. , Baumann Paul C. 
Published: March 2010

Abstract
Hepatic mixed-function oxidase (MFO) components in tumor-bearing brown bullheads (Ictalurus nebulosus) from a chemically contaminated river and in bullheads from two relatively uncontaminated sites were compared to determine if the components in the river bullheads were induced. Induction of MFO components could be indicative of chemical contamination of the river water and of contaminant stress in the fish. In general, biochemical hepatic microsomal MFO component levels in bullheads from the river were the same as, or lower than, those in bullheads from uncontaminated sites. However, the liver weight as a percentage of body weight was significantly greater in bullheads from the river than in those from the uncontaminated sites. Thus, a comparison of bullheads from the river and the uncontaminated sites appeared to show that relative liver weight was indicative of chemical contamination of the river water and of contaminant stress in its fish. However, biochemical hepatic microsomal components measured in this study were apparently not adequate as indicators of chemical contamination of the river water or of contaminant stress in bullheads from the river.