bluuebunny/crossref_metadata_2025_split huggingface dataset:
The mobility of [14C]3-chloro-P-toluidine hydrochloride in a loam soil profile
Authors: Irwin Katherine C. , Podoll R. Thomas , Starr Robert I. , Elias Donald J. 
Published: March 2010

AbstractThe movement of radiolabeled 3-chloro-p-toluidine hydrochloride (CPTH) in a loam soil was evaluated in a column leaching study. Twenty-five-gram portions of the soil were treated with about 30 μg/g of uniformly labeled [14C]CPTH, and then incubated (aged) for 24 h under aerobic conditions; this soil was applied to untreated soil columns, which were then leached with dilute aqueous calcium sulfate for a total leachate volume equal to or greater than 50.8 times the cross-sectional area, or about 450 to 600 ml. Results indicated that about 2% of the initial radiolabeled compound leached through the soil profile, with the mean apparent partition coefficient calculated to be 65 ml/g. The soil columns were separated into 6-cm sections and extracted with dilute aqueous calcium sulfate, followed by 80% aqueous acetonitrile. About 90% of the [14C]CPTH was sorbed to the uppermost 6 cm of soil. Following extraction, the residual soil was combusted, with these results indicating that an average 77% of the parent compound and products present in the upper 6 cm were bound to the soil colloids. Approximately 1% of the applied radiolabeled compound volatilized during the soil aging and leaching processes. The mean mass balance based upon [14C] analyses was 102%. One major metabolite was detected in leachate fractions and soil extracts, which was tentatively identified as N-acetyl-3-chloro-p -toluidine, based upon HPLC retention times. This same degradation product was previously identified and confirmed using mass spectroscopy in CPTH aerobic soil biodegradation and fish accumulation studies. The extent to which CPTH was bound to the loam soil colloids, with only minimal movement through the soil profile, suggests a low potential for mobility of this pesticide in the soil environment.
Rice field surface microlayers: Collection, composition and pesticide enrichment
Authors: Gever Joel R. , Mabury Scott A. , Crosby Donald G. 
Published: March 2010

Abstract
The thin organic film (surface microlayer) found on natural waters can concentrate hydrophobic pollutants. Enrichment factors (EFs), the ratio of pollutant concentration in microlayer to that in subsurface water, previously have been measured in relatively thick (˜50–150 μm) aqueous sections of surface. A modified sampling method, using glass plates silanized with dichlorodimethylsilane, allowed the collection of samples with virtually no dilution by subsurface water. Surface microlayers from a flooded rice field, collected onto silanized plates and analyzed by GC-MS, showed 26 fatty acids and esters of 8 to 24 C atoms, saturated and unsaturated, and methyl esters of nonanoic, hexacosanoic, and octacosanoic acids as well as cholesterol. Microlayers were collected with both silanized and unsilanized glass plates after application of carbofuran (3.27 kg/ha) and a mixture of carbofuran (3.12 kg/ha) and thiobencarb (3.04 kg/ha) to 9.8-m2 field plots. Log EF was 0.14 to 1.43 for carbofuran and 0.04 to 2.30 for thiobencarb in samples collected with unsilanized plates; log EF from silanized plates was 3.88 to 7.55 and 4.04 to 5.74 for carbofuran and thiobencarb, respectively. Log EFs in samples collected from a commercial rice field with silanized plates were 3.88 and 4.18 for carbofuran and 4.77 and 5.15 for thiobencarb, greater than predicted from their Kow. Thiobencarb irradiated (285–340 nm) in isolated microlayers was photodegraded more rapidly than by itself. The only identified photoproduct was 4-chlorobenzyl mercaptan. These observations have significance for pesticide fate, analysis, and ecotoxicology.
Effect of viscosity of nonaqueous-phase liquids (NAPLs) on biodegradation of NAPL constituents
Authors: Birman Irina , Alexander Martin 
Published: March 2010

Abstract
A study was conducted to evaluate the effect of viscosity of nonaqueous-phase liquids (NAPLs) on biodegradation of phenanthrene in soil slurries and to find means to enhance the process in viscous NAPLs. When present in kerosene, diesel fuel, fuel oil, and mixtures of the NAPLs, phenanthrene was biodegraded rapidly. Gasoline alone or in mixtures with other solvents prolonged the acclimation phase and reduced the rate of mineralization of the hydrocarbon. The rate and extent of biodegradation decreased with increasing viscosity of nontoxic NAPLs. The slow mineralization of phenanthrene initially in 150 Bright stock or crude oils was enhanced by vigorous agitation of soil slurries, addition of a nonionic surfactant and delayed inoculation, or increasing the temperature. The data suggest means for enhanced bioremediation of toxicants present in viscous NAPLs.
Use of metal chelating agents to differentiate among sources of acute aquatic toxicity
Authors: Hockett J. Russell , Mount David R. 
Published: March 2010

Abstract
Metals are common toxicants found in effluents and other environmental samples. Within Toxicity Identification Evaluation methods proposed by the U.S. Environmental Protection Agency and others, addition of ethylenediaminetetraacetic acid (EDTA) is used as an indicator of metal toxicity. Previous experiments showed that addition of sodium thiosulfate, originally included to detect toxicity due to oxidants, was also effective at reducing toxicity from some common metals. In the present study, we characterized the effectiveness of both EDTA and thiosulfate in removing the toxicity of 16 different metal ions to Ceriodaphnia dubia. Ethylenediaminetetraacetic acid addition removed toxicity associated with all cationic metals tested except for Cr3+, Fe2+, Al3+, and Ag+. Thiosulfate addition was less effective than EDTA for Zn2+, Mn2+, Pb2+, and Ni2+, but reduced toxicity of both Ag+ and selenite (Se[VI]), which EDTA did not. Results of this research can be used to categorize metal toxicity in unknown samples based on the response to additions of EDTA and thiosulfate.
Structure—activity relationships for chloro- and nitrophenol toxicity in the pollen tube growth test
Authors: Schüürmann Gerrit , Somashekar Rayasamuda K. , Kristen Udo 
Published: March 2010

Abstract
Acute toxicity of 10 chlorophenols and 10 nitrophenols with identical substitution patterns is analyzed with the pollen tube growth (PTG) test. Concentration values of 50% growth inhibition (IC50) between 0.1 and 300 mg/L indicate that the absolute sensitivity of this alternative biotest is comparable to conventional aquatic test systems. Analysis of quantitative structure–activity relationships using lipophilicity (log Kow), acidity (pKa), and quantum chemical parameters to model intrinsic acidity, solvation interactions, and nucleophilicity reveals substantial differences between the intraseries trends of log IC50. With chlorophenols, a narcotic-type relationship is derived, which, however, shows marked differences in slope and intercept when compared to reference regression equations for polar narcosis. Regression analysis of nitrophenol toxicity suggests interpretation in terms of two modes of action: oxidative uncoupling activity is associated with a pKa window from 3.8 to 8.5, and more acidic congeners with diortho- substitution show a transition from uncoupling to a narcotic mode of action with decreasing pKa and log Kow. Model calculations for phenol nucleophilicity suggest that differences in the phenol readiness for glucuronic acid conjugation as a major phase-II detoxication pathway have no direct influence on acute PTG toxicity of the compounds.
An investigation of factors limiting the reductive dechlorination of polychlorinated biphenyls
Authors: Liu Xia , Sokol Roger C. , Kwon O.-Seob , Bethoney Charlotte M. , Rhee G.-Yull 
Published: March 2010

Abstract
A study was conducted to determine whether the apparent limitation of dechlorination of Aroclor 1248 was due to bioavailability of polychlorinated biphenyls (PCBs) or an accumulation of metabolic products. After 15 weeks of laboratory incubation, sediment microorganisms from the St. Lawrence River reduced the total number of chlorines in Aroclor 1248-spiked sediments by 33%. However, dechlorination apparently leveled off with a significant number of meta- and para-chlorines still remaining, showing no further change out to 30 weeks. When these sediments were incubated an additional 18 weeks with either fresh medium or the original supernatant, no additional dechlorination was found in either treatment. Similarly, dechlorination was not inhibited in freshly spiked Aroclor 1248 sediment slurries made with the old supernatant. Addition of the nonionic surfactant Tween 20, at a concentration below the critical micelle concentration that increased PCB desorption, also failed to enhance dechlorination of the plateau sediments. The extent and final congener pattern in all treatments were nearly identical. Therefore, the termination of dechlorination at the plateau level was not due to PCB bioavailability or accumulation of inhibitory metabolic products. These results strongly suggest that the cessation of dechlorination at the plateau was due to the accumulation of daughter congeners with chlorine substitution patterns that were not amenable to further dechlorination by the present microbial consortium.
Effects of an anionic surfactant, linear alkylbenzene sulfonate, on survival, reproduction and growth of the soil-living collembolan Folsomia fimetaria
Authors: Holmstrup Martin , Krogh Paul Henning 
Published: March 2010

Abstract
Sewages sludge is widely used as a fertilizer or disposed of by land application. Sewage sludge often contains potentially toxic compounds and elements in significant concentrations. A major component is the anionic detergent, linear alkylbenzene sulfonate (LAS), which is frequently used in industrial and household detergents, and which may be found in the range 4 to 10 g kg−1 dry matter. The effects of LAS on Folsomia fimetaria L. were investigated by use of a single species test system with 30 g soil spiked with LAS. Tests with either newly hatched individuals or adults (16–19 d old) were run for 3 weeks followed by extraction in a high-gradient extracting system. Juvenile mortality increased with increasing concentrations of LAS, whereas adult mortality was unaffected at the LAS levels tested (0–1,000 mg/kg dry soil). Effective concentration, 10%, values were estimated as 163 mg/kg for growth of juveniles, 185 mg/kg for molting frequency, and 147 mg/kg for reproductive output. Rough estimates show that significant negative direct effects on populations of F. fimetaria may be expected at concentrations 8 to 20 times higher than those likely to be found in sludge-amended soils.
The role of water ventilation and sediment ingestion in the uptake of benzo[A]pyrene in gizzard shad (dorosoma cepedianum)
Authors: Kolok Alan S. , Huckins James N. , Petty Jimmie D. , Oris James T. 
Published: March 2010

Abstract
The objective of this study was to determine whether sediment ingestion or water ventilation was the primary route of uptake for benzo[a]pyrene (BaP) in the gizzard shad (Dorosoma cepedianum), a detritivorous fish. Two experiments were conducted in which fish were exposed to sediments spiked with 1 μg/g BaP. In the first experiment, fish were prevented from feeding by esophagus ligation. In the second experiment, 20 nonligated fish and 30 ligated fish were added to the aquarium. The nonligated fish roiled the water as they fed. Fish were collected 4, 8, 15, and 22 d after the experiments began. Gizzard shad metabolize BaP; therefore, the concentrations of BaP equivalents (parent BaP plus metabolite) were determined. Concentrations of BaP equivalents were significantly greater in the ligated fish in experiment 2 relative to those in experiment 1. In contrast, the concentration of BaP equivalents in the ligated fish in experiment 2 was not significantly different than that in the nonligated fish. Our results suggest that ventilation of turbid water may be a significant source of BaP for gizzard shad. Sediment ingestion, however, does not appear to significantly influence the total body concentration of BaP equivalents in gizzard shad.
The role of water ventilation and sediment ingestion on the uptake of hexachlorobenzene by gizzard shad (Dorosoma cepedianum)
Authors: Kolok Alan S. , Groetsch Kory J. , Oris James T. 
Published: March 2010

Abstract
The objective of this study was to determine whether sediment ingestion or water ventilation was the primary route for uptake of hexachlorobenzene (HCB) in the detritivorous fish, gizzard shad (Dorosoma cepedianum). Twenty nonligated and 30 esophagus-ligated fish were exposed to sediments spiked with 1 μg/g HCB for 29 d. The nonligated fish roiled the water as they fed, forcing the ligated fish to ventilate turbid water. Fish were collected 7, 14, 22, and 29 d after initiation of the experiment. Detectable levels of HCB were found in all ligated and nonligated fish, although the concentration of HCB in the ligated fish only ranged from 14 to 33% of that found in the nonligated fish. Thus, ingestion of contaminated sediments is a significant source of HCB for gizzard shad.
House sparrow preferential consumption of pesticide granules with different surface coatings
Authors: Best Louis B. , Stafford Tamara R. , Mihaich Ellen M. 
Published: March 2010

Abstract
House sparrows were given choices among granules of a single carrier type (gypsum or cellulose complex) but with different surface coatings. The three surface coatings included graphite, a black pigment, and uncoated. An outdoor aviary equipped with a video recording system was used to document bird visits to, and pecks within, a tray setup containing the granules. The house sparrows preferred uncolored gypsum granules (50% of the trips and 92% of the pecks) over granules darkened with either graphite or pigment; pigmented granules were avoided the most. Sparrow use did not differ significantly between uncoated cellulose-complex granules and those with either a 0.4 or 0.7% graphite coating. Bird visitation to the granule tray setup was influenced by weather conditions; more visits occurred on days with cooler temperatures and/or greater amounts of precipitation. Knowledge of how birds respond to granule surface coatings may be useful in developing pesticide formulations that are less attractive to birds.
Developmental effects of barium exposure in a marine bivalve (Mytilus californianus)
Authors: Spangenberg Jill V. , Cherr Gary N. 
Published: March 2010

Abstract
Previous reports indicated that barium (Ba) and/or strontium (Sr) were primarily responsible for the toxicity of a southern California produced water to developing marine embryos. To further investigate toxicity of Ba and Sr in seawater, mussel embryos (Mytilus californianus) were subjected to static exposures of barium acetate and strontium chloride from fertilization through veliger formation. Only Ba exhibited bioactivity at environmentally relevant levels. Adverse effects occurred between 200 and 900 μg/L (ppb); higher concentrations were associated with decreased toxicity and apparent precipitation of Ba salts from seawater. Nominal Ba exposure concentrations between 100 and 900 μg/L yielded measured concentrations of 100 to 550 μg/L soluble Ba when analyzed by inductively coupled argon plasma emission spectroscopy. Adverse developmental effects included abnormal shell calcification and embryo morphology. Exposure of embryos to Ba in stage-specific experiments revealed that developmental stages were differentially affected, though they exhibited similar abnormalities. Gastrulae were the most sensitive, while blastula and trochophore larvae were less so. Adverse effects in embryos exposed during the gastrula stage were not reversible despite washing and return to clean seawater. These findings are among the first to demonstrate that low concentrations of soluble Ba in seawater can be toxic and are of potential concern in the marine environment.
A two-step experimental design for a sediment bioassay using growth of the amphipod Hyalella azteca for the test end point
Authors: Kubitz Jody A. , Besser John M. , Giesy John P. 
Published: March 2010

Abstract
We designed a sediment bioassay using 25% growth inhibition of Hyalella azteca as the end point. Hyalella azteca exhibits size-specific fecundity, so growth is a surrogate of reproductive production. We investigated density effects on growth to address whether crowding could affect test interpretation; amphipods in 14,000/m2 exposures were 16 to 20% smaller than those at 7,000/m2. Using power analysis, we found that 20 to 25 samples are required to determine significance when α = 0.10 and 1 − β = 0.90. To minimize the need for laboratory resources, we designed a two-step (screening and confirmatory) bioassay, which we tested with field-collected sediments. The screening bioassay compared 11 sediments to a reference. Three sediments were “toxic” (significant growth inhibition when 1 − β = 0.66 and n = 5), five sediments were “nontoxic” (&gt;90% of reference), and three sediments were “possibly toxic” (growth inhibition was insignificant). In the confirmatory bioassay, three possibly toxic and two nontoxic samples were reevaluated. Two were toxic (1 − β = 0.91 and n = 20), and the remaining four samples were nontoxic. In summary, five sediments were toxic and six sediments were nontoxic. The two-step analysis used minimal laboratory resources but maximized statistical power, where needed, to discriminate growth effects.
Ecological restructuring in experimental aquatic mesocosms due to the application of diflubenzuron
Authors: Boyle Terence P. , Fairchild James F. , Haverland Pamela S. , Lebo Jon A. , Robinson-Wilson Everett F. 
Published: March 2010

Abstract
Diflubenzuron is a chitin-inhibiting insecticide that is registered for use in controlling a multitude of invertebrate pests. The selective mode of action of diflubenzuron provided us with a unique tool for examining the indirect responses of an experimental aquatic ecosystem following direct impacts at the primary consumer (invertebrate) trophic level. Twelve outdoor aquatic mesocosms (0.1 ha each) were randomly assigned to three treatments of diflubenzuron (four mesocosms/treatment): control, monthly (five total 10-μg/L applications), or biweekly (twice monthly; nine total 10-μg/L applications). Direct impacts on invertebrates (numbers and species composition of insects and zooplankton) and indirect impacts on fish (mortality, growth, and reproduction of bluegill sunfish and largemouth bass), phytoplankton (biomass and productivity), and water quality were measured over 16 weeks posttreatment. Both monthly and biweekly treatments of diflubenzuron decreased total numbers (fivefold reduction) and species richness (twofold reduction) and increased dominance (twofold increase) of zooplankton within 4 weeks posttreatment; Cladocerans, Copepods, and Rotifers were all sensitive. Diflubenzuron reduced species richness of emergent insects, which resulted in increased dominance by a few species; however, impacts on emergent insects were confounded by a treatment × time interaction. Direct reductions in invertebrate grazers caused indirect increases in algal biomass. Indirect effects on biomass (50% reduction) and individual weight (50% reduction) of juvenile bluegill occurred because of apparent decreases in invertebrate food resources. No statistically significant impacts were observed on adult bluegill or largemouth bass for the duration of the experiment. Results indicated that diflubenzuron had both direct and indirect impacts on the experimental aquatic ecosystems under the conditions tested.
A 7-D toxicity test for marine pollutants using the pacific mysid Mysidopsis intii. 2. Protocol evaluation
Authors: Harmon Valerie L. , Langdon Chris J. 
Published: March 2010

Abstract
The sensitivity of the Pacific coast mysid Mysidopsis intii to pollutants was compared in 7-d toxicity tests with that of the Gulf coast mysid M. bahia and the Pacific coast mysid Holmesimysis costata. Survival and growth responses of M. intii to zinc (maximum acceptable toxicant concentration [MATC] survival and growth, 152 μg/L) were as sensitive as survival of both M. bahia (MATC survival, 152 μg/L) and H. costata (MATC survival, 152 μg/L). In contrast, the 7-d test for M. intii was less sensitive (MATC growth and survival, 4.99 mg/L) than the test for H. costata (MATC survival, 1.99 mg/L) when sodium dodecyl sulfate (SDS) was used as the toxicant. Interlaboratory evaluation of the 7-d test for M. intii exposed to SDS indicated that the test was reliable. The mean test results for the group of participating laboratories were not significantly different from those of a group of three in-house tests, indicating that shipping and handling did not affect mysid sensitivity to SDS. Mysid growth was not as sensitive to SDS as survival in the interlaboratory tests. Although there were significant differences in median lethal concentration (LC50) values among participating laboratories, coefficients of variation of LC50 and MATC survival values among laboratories were 10.3 and 37%, respectively. These coefficients were comparable to those reported for interlaboratory tests with H. costata.
Microbial mineralization of organic compounds in an acidic agricultural soil: Effects of preadsorption to various soil constituents
Authors: Knaebel David B. , Vestal J. Robie , Federle Thomas W. , McAvoy Drew C. 
Published: March 2010

Abstract
This study investigated the interactions between organic chemicals and components of the soil matrix and their effects on subsequent microbial mineralization kinetics. Five 14C-labeled chemicals (anionic, cationic, and nonionic surfactants) were aseptically sorbed to montmorillonite, kaolinite, illite, sand, humic acids, and fulvic acids. Small amounts of these sorbed chemicals were dosed to an acidic, sludge-amended agricultural soil (Rossmoyne) to a final added chemical concentration of 50 ng g−1. Controls received the same final added concentration of the chemicals in water. The ratio of sorbed chemical to soil was kept low to minimize changes to the soil mineralogy, chemistry, and microbiology. Microbial mineralization of the chemicals to 14CO2 was measured over a period of 60 to 70 d, and the data were fitted to first-order and 3/2-order mineralization models. Association with the soil constituents inhibited the mineralization of the chemicals in the following rank (from least to greatest effect): controls ≈ sand &lt; kaolinite &lt; illite &lt; montmorillonite ≈ humic acids &lt; fulvic acids. These experiments demonstrated that interactions with some soil constituents (kaolinite, illite, and sand) had little effect on the microbial metabolism of these chemicals, while montmorillonite, humic acids, and especially fulvic acids significantly decreased the bioavailability of the chemicals to the microbial community. The first group of soil constituents had little influence on the mineralization kinetic parameters, whereas the latter significantly reduced at least one of the parameter estimates. The parent soil, possibly via interactions with its mineral surfaces, also had effects on the degradation of the chemicals, since soil microbial biomass and physiological activity were not correlated with any of the mineralization kinetic parameter estimates. These experiments demonstrate that the environmental form of a chemical has a significant influence on its eventual microbial metabolism and is an important parameter to consider when investigating the fate of chemicals in soil environments.