bluuebunny/crossref_metadata_2025 huggingface dataset:
Environmental loads from water-sprinkled softwood timber: 2. Influence of tree species and water characteristics on wastewater discharges
Authors: Borga Peter , Elowson Torbjörn , Liukko Kari
Published: March 2010

The concentration patterns of a number of compounds in the inlet water and wastewater from sprinkling of timber from Scotch pine and Norway spruce have been studied. The timber was separated with respect to species and sprinkled with water from a eutrophic or an oligotrophic receiving water for 18 weeks. Organic and inorganic compounds including dissolved organic carbon (DOC), distillable phenols, resin acids, bacterial phospholipid fatty acids, organic and inorganic phosphorus, nitrogen and sulphur, and a number of metal ions were monitored in the inlet water and wastewater. The toxicity of the wastewater was estimated during the first 2 weeks using a Microtox® test and appeared to decline in parallel with DOC. Most compounds showed both an environmental net load and an absorption by the timber, the loads being smaller and the absorption larger when using eutrophic water. At both sites the loads were generally largest during the first 2 weeks and larger in magnitude at the oligotrophic site and in the spruce wastewater. The initial growth of the bacterial biomass in the pile system was slower at the oligotrophic site, and the results indicated that a rapid growth of the bacterial biomass reduces the initial environmental loads and that this process is associated with the nutrient status of the receiving water.
Occurrence, sources, and fate of trichloroacetic acid in swiss waters
Authors: Müller Stephan R. , Zweifel Hans-Rudolf , Kinnison David J. , Jacobsen Jens A. , Meier Markus A. , Ulrich Markus M. , Schwarzenbach René P.
Published: March 2010

The occurrence, sources, and fate of trichloroacetic acid (TCA) has been investigated in surface waters, ground waters, drinking waters, wastewaters, and rainwater in Switzerland. The concentrations found in surface waters varied between less than 27 ng/L (limit of quantification) and 340 ng/L, whereas the concentrations in ground water were always below 27 ng/L. It was found that the main sources of TCA in surface waters were the effluents of wastewater treatment plants (average concentration, 430 ng/L; range, 40-1060 ng/L). The average TCA concentration in rainwater was 300 ng/L range, (<27-900 ng/L). A dynamic mathematical model revealed that TCA is not significantly degraded in a lake (half-life >230 d). A detailed mass balance in the catchment area of a small lake (Greifensee) and a very rough mass balance over Switzerland indicate that rain is the major source of TCA in Switzerland (>90%), but they also show that about 60 to 80% of the TCA deposited by rain is eliminated, most probably in the soil.
Triphenyltin and its degradation products in foliage and soils from sprayed pecan orchards and in fish from adjacent ponds
Authors: Kannan Kurunthachalam , Lee Richard F.
Published: March 2010

Triphenyltin (TPT) is a fungicide used on a variety of crops throughout the world. In this study, pecan orchards in central Georgia (USA) previously sprayed with commercial TPT hydroxide mixtures were found to have TPT concentrations of 8.5 to 37 μg/g dry weight in foliage and 1.2 to 12 μg/g dry weight in soil. Total phenyltin concentrations (monophenyltin [MPT] + diphenyltin [DPT] + TPT) in foliage and soils immediately after application were up to 72 and 26 μg/g dry weight, respectively. Besides TPT, DPT and MPT were present in the leaves and soils, with MPT generally the predominant compound. The proportion of MPT to TPT in pecan leaves increased with time after spraying, which was indicative of photolytic degradation of TPT. Microbial degradation of radiolableled TPT in soil or sediment samples was slow, with only 5% degraded during a 14-d incubation period. Triphenyltin was absent from the subsurface soils (2 to 15 cm depth) even though it had been sprayed eight to 10 times a year at a rate of 850 g/ha for the past 10 years. In an orchard where the last spraying was carried out approx. 2 years ago, TPT was absent, but MPT was present at approximately the same concentration as recently sprayed orchards. Fish (blue gill, largemouth bass, and channel catfish) from a pond near a recently sprayed pecan orchard had TPT as well as DPT and MPT. The predominate phenyltin in all fish was MPT, with 22 μg/g wet weight in the liver of catfish. Radiolabeled TPT was only slowly metabolized by the fathead minnow, with 2% of the TPT metabolized to DPT after 6 d of exposure via water. Photodegradation appears to be the major factor affecting the fate of TPT in soils.
Toxicity of sediment-associated pyrene and phenanthrene to Limnodrilus hoffmeisteri (oligochaeta: Tubificidae)
Authors: Lotufo Guilherme R. , Fleeger John W.
Published: March 2010

Acute and sublethal toxicities of sediment-spiked pyrene and phenanthrene to Limnodrilus hoffmeisteri Cleparéde were investigated. Phenanthrene was acutely toxic at high sediment concentrations (10-d median lethal concentration of 297.5 μg g−1; 252.2-348.3, 95% confidence interval [CI]). Pyrene was not acutely toxic, even at concentrations as high as 841 μg g−1. A significant impact of pyrene and phenanthrene on the feeding activity of L. hoffmeisteri was demonstrated through daily collection of egested fecal material during 5- and 10-d experiments. A short (5-d) exposure detected toxic effects more efficiently than a 10-d exposure, yielding IC25 values (estimated concentration causing a 25% reduction of measured endpoint in relation to the control[s]) of 58.9 μg g−1 (32.1-89.4, 95% CI) for pyrene and 28.4 μg g−1 (10.0-41.3, 95% CI) for phenanthrene. Effects on burrowing behavior and reproduction were assessed in a 28-d sediment exposure. Low burrowing avoidance (<25%) was detected in high phenanthrene concentrations (143-612 μg g−1) but was not detected with pyrene. Offspring production was significantly reduced in dosed sediments yielding IC25 values of 59.1 μg g−1 (38.3-112.5, 95% CI) for pyrene and 40.5 μg g−1 (12.1-165.5, 95% CI) for phenanthrene. Decreases in egestion rates in the presence of nonpolar contaminants should be quantified when investigating the effects of bioturbation by deposit feeders on the flux of contaminants from sediment into the water column.
Comparison of nonplanar and coplanar PCB congener partitioning in seawater and bioaccumulation in blue mussels (Mytilus edulis)
Authors: Bergen Barbara J. , Nelson William G. , Pruell Richard J.
Published: March 2010

The partitioning of 18 nonplanar and three coplanar (International Union of Pure and Applied Chemistry [IUPAC] numbers 77, 126, and 169) polychlorinated biphenyl (PCB) congeners was quantified in New Bedford Harbor, Massachusetts, USA. Concurrently, bioaccumulation of these congeners was measured in blue mussels deployed for 7 and 28 d in New Bedford Harbor, and bioconcentration factors (BCFs) were calculated for each congener. The PCB concentrations measured in the dissolved and particulate fractions of seawater samples were used to calculate partition coefficients (Kp) for each congener. These values were correlated with reported octanol/water partition coefficients (Kow). No significant differences (p > 0.05) were observed in the relationships between Kp and Kow for the coplanar congeners relative to the nonplanar congeners. Coplanar congeners reached steady state faster than the nonplanar congeners; however, after 28 d a similar relationship was observed between BCF and Kow in coplanar and nonplanar congeners. These data indicate that coplanar PCBs partition in seawater and accumulate in mussels similarly to nonplanar PCBs with the same number of chlorines.
A bleached-kraft mill effluent fraction causing induction of a fish mixed-function oxygenase enzyme
Authors: Burnison B. Kent , Hodson Peter V. , Nuttley Donna J. , Efler Sue
Published: March 2010

Pulp mill effluents contain a myriad of chemicals that have the potential to cause deleterious effects on aquatic biota in receiving waters. Some of these chemicals evoke an acute lethal response of exposed biota while others evoke sublethal responses. One such sublethal response is the induction of mixed-function oxygenases (MFO) in fish, specifically the CYP1A1 enzyme ethoxyresorufin-o-deethylase (EROD). We followed the partitioning of the inducing chemicals in pulp mill effluent fractions by Toxicity Identification Evaluation (TIE), or bioassay-driven chemical analysis. This procedure was eventually modified to a more direct technique involving centrifugation, filtration, cleanup procedures, and C18 solid-phase adsorption. The extracts from the fractionation of two pulp mill effluents after secondary treatment were tested for EROD-inducing activity in a 4-d rainbow trout bioassay. The methanol extracts of particulates/colloids showed significant inducing capacity in Mill A effluent but not in Mill B effluent. The C18 methanol extracts induced activity from both effluents, with extracts from Mill A causing the greatest response. The particulate/colloidal extract (Mill A) was used as the source material for chemicals which caused EROD induction. The fraction was purified by solid-phase extraction techniques and reverse-phase high-performance liquid chromatography. The majority of the EROD activity was found in the moderately nonpolar region of the chromatogram (Kow = 4.6 to 5.1).
Survival and cover-seeking response of northern bobwhites and mourning doves dosed with aldicarb
Authors: Hawkes Anthony W. , Brewer Larry W. , Hooper Michael J. , Kendall Ronald J. , Hobson James F.
Published: March 2010

Survival and cover-seeking responses of wild northern bobwhites (Colinus virginianus) and mourning doves (Zenaida macroura) dosed with aldicarb were investigated. Acute toxicity range-finding tests were conducted to establish optimum dose levels for subsequent dose–release activities. Estimated median lethal dose values derived for doves and bobwhites were 0.82 and 1.48 mg/kg body weight, respectively. Wild mourning doves and northern bobwhites were orally administered aldicarb or a vehicle blank and monitored for 7 d posttreatment to determine survival and cover-seeking response. Doves receiving the highest aldicarb concentration (1.07 mg/kg bodyweight) had a significantly lower survival rate than did controls. However, when mortalities attributable to acute toxicity were removed from the analysis, there were no differences in daily survival rates among treatment groups. All bobwhite treatment groups had lower survival rates than controls. When acute mortalities were removed from the survival analysis, the 1.36-mg/kg bodyweight treatment group still had a significantly lower survival rate than controls. Postdose observations of behavior indicate that mourning doves and northern bobwhites receiving a lethal dose of aldicarb are limited in their cover-seeking ability due to the rapid onset of physical impairment associated with this compound.
Development of a plant bioassay to assess toxicity of chemical stressors to emergent macrophytes
Authors: Powell Rebecca L. , Kimerle Richard A. , Moser E. Michelle
Published: March 2010

A static renewal bioassay has been proposed to evaluate the effects of chemical stressors on the growth of emergent macrophytes. Bioassay methods were developed using Oryza sativa L. (domestic rice) as the test species and boron as the test compound. After culturing O. sativa in a natural sediment for 2 weeks, the plants were continuously exposed to various concentrations of boron dissolved in the dilution water. At the end of the exposure period the plants were evaluated. Endpoints included visual observations, dry weight, residue, and chlorophyll concentration in the leaf tissue. Dose–response relationships were established for each endpoint; however, dry weight appears to be the least sensitive endpoint. Exposure duration also significantly influenced toxic values. The bioassay procedure was then used to screen several other emergent macrophytes for toxicity to boron. Visual observations and residue indicated treatment differences for each of these species; however, dry weight and chlorophyll concentration did not confirm the differences. Oryza sativa plants exposed to water naturally contaminated with boron accumulated similar concentrations of boron in their leaf tissue as plants exposed to laboratory-prepared solutions of boron. Based on the data presented here, this bioassay appears to be useful in evaluating the potential toxicity of chemical stressors to emergent macrophytes.
Evaluating the environmental fate of a variety of types of chemicals using the EQC model
Authors: Mackay Donald , Di Guardo Antonio , Paterson Sally , Cowan Christina E.
Published: March 2010

The multimedia equilibrium criterion model, which can be used to evaluate the environmental fate of a variety of chemicals, is described. The model treats chemicals that fall into three categories. In the first the chemicals may partition into all environmental media, in the second they are involatile, and in the third they are insoluble in water. The structure of the model, the process equations, and the required input data for each chemical type are described. By undertaking a sequence of level I, II, and III calculations, increasing information is obtained about the chemical's partitioning, its susceptibility to transformation and transport, and the environmental process and the chemical characteristics that most influence chemical fate. Output data, consisting of tables and charts, give a complete picture of the chemical's fate in an evaluative or generic environment. The model is illustrated by applying it to two chemicals, pyrene, which is a chemical of the first type, and lead, which is of a second type. The role of this model as a tool for assessing the fate of new and existing chemicals is discussed.
Bioconcentration and metabolism of [14C]3-chloro-P-toluidine hydrochloride by Bluegill Sunfish
Authors: Spanggord Ronald J. , Gordon G. Ross , Schocken Mark J. , Starr Robert I.
Published: March 2010

Bluegill sunfish (Lepomis macrochirus) were continuously exposed to 0.1 μg/ml of uniformly radiolabeled [14C]3-chloro-p-toluidine hydrochloride (CPTH) for 28 d, after which the fish were transferred to flowing untreated water for a 28-d depuration period. At periodic intervals during the treatment and depuration periods, samples of water and fish were analyzed for [14C] residues to determine the degree of CPTH absorption. Samples of bluegill that were exposed to the radiolabeled chemical for 28 d were analyzed to determine the distribution of the radiolabel and to isolate and identify possible metabolites. The steady-state concentrations in the bluegill tissues were reached by day 7 of exposure to the radiolabeled compound, with mean concentrations in the edible, nonedible, and whole-body tissues determined to be 2.9, 12.0, and 7.5 μg/g of tissue, respectively. Bioconcentration factors of 33×, 150×, and 88× were calculated for the three types of tissues. About 64% of the accumulated radiolabeled CPTH and metabolites were eliminated from the fish on day 28 of depuration. The distribution of radioactivity was found to be similar in all tissue groups. One metabolite was confirmed as N-acetyl-3-chloro-p-toluidine, with two metabolites suggested to be 4-acetamido-2-chlorobenzoic acid and 4-amino-2-chlorobenzoic acid. The N-acetylated breakdown product has been previously reported to occur in both mammals and birds; thus, the metabolism of CPTH in fish may parallel that observed in these other species. Although the effects of biomagnification cannot be fully assessed at this time, we can conclude that when bluegill sunfish are continuously exposed to sublethal levels of CPTH, bioconcentration will not occur to an appreciable extent, and that residues will be rapidly excreted upon removal of the fish from the CPTH source. Furthermore, published information pertaining to various aquatic organisms indicates that bioaccumulation will not be a problem if the bioconcentration factor is below 100.
Aerobic biodegradation of [14C]3-chloro-P-toluidine hydrochloride in a loam soil
Authors: Spanggord Ronald J. , Gordon G. Ross , Starr Robert I. , Elias Donald J.
Published: March 2010

Degradation of the pesticide 3-chloro-p-toluidine hydrochloride (CPTH) occurred in a loam soil when applied at concentrations of 3.5 and 35 μg/g. The compound degraded according to pseudo-first-order kinetics, with a calculated rate constant of 2.74 × 10−2 h−1, at a soil temperature of 22°C; this rate constant yielded a half-life of 25 h. The loss of radiolabeled CPTH from soil was suggested to be controlled by both irreversible binding to the soil colloids and microbial transformation. Mineralization of the radiolabeled CPTH was interpreted as involving two zero-order kinetic rates; an initial rate of carbon dioxide release was estimated to be 0.33% d−1 (half-life of 152 d), followed by a slower rate of 0.07% d−1, which resulted in a half-life of 718 d. Approximately 13% of the radiolabeled CPTH that was applied to soil at 3.5 μg/g was mineralized to [14C] carbon dioxide during the 99-d incubation period. A primary metabolite was identified as N-acetyl-3-chloro-p-toluidine (ACPTH); this metabolite reached a maximum concentration at the 1-d sampling period, and degraded with a pseudo-first-order rate constant of 2.67 × 10−2 h−1; the half-life for ACPTH was calculated to be 26 h. When CPTH was applied to soil at 35 μg/g, the compound was also mineralized in soil by a similar metabolic pathway to that observed at the lower concentration. However, the rate of mineralization was slower, which suggests that elevated soil concentrations of CPTH may affect the viability of certain microorganisms.
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

The 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

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

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

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

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

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

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

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

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

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

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

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” (>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

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

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

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 < kaolinite < illite < montmorillonite ≈ humic acids < 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.
Regulation of microbial phenanthrene mineralization in sediment samples by sorbent-sorbate contact time, inocula and gamma irradiation-induced sterilization artifacts
Authors: Sandoli Robert L. , Ghiorse William C. , Madsen Eugene L.
Published: March 2010

Time-dependent diffusion and/or sorption reactions were proposed as a mechanism for protecting polycyclic aromatic hydrocarbons (PAHs) in surface and subsurface sediments from a coal tar waste-contaminated field site. 14C-labeled phenanthrene was aged in both subsurface sand and organic matter-rich seep sediments that had previously been sterilized by gamma irradiation. After aging periods ranging from 0 to 28 d, the sediments were dispensed to replicate vials and inoculated with site-derived phenanthrene-degrading microorganisms (with and without previous enrichment on phenanthrene), and cumulative 14CO2 production was measured. When pure culture and mixed inocula originated from the seep sediments, phenanthrene mineralization from sand sediment samples was retarded with longer aging periods. However, when a mixed inoculum originating from the sand sediments was tested, aging of the phenanthrene had only a slight or no effect on its rate or extent of mineralization. Thus, the susceptibility of phenanthrene to biodegradation varied with the source of the microbial inocula. When gamma-irradiated seep sediments were the sorbent, all mineralization of 14C phenanthrene was eliminated. Several hypotheses were tested for explaining this sorbent-dependent inhibition of phenanthrene metabolism. Gamma radiation-induced changes in the sorptive properties of the seep sediment seemed to be the cause.
Quantitative structure-activity relationships for polychlorinated hydroxybiphenyl estrogen receptor binding affinity: An Assessment of conformer flexibility
Authors: Bradbury Steven P. , Ankley Gerald T. , Mekenyan Ovanes G.
Published: March 2010

A diverse group of xenobiotics has a high binding affinity to the estrogen receptor (ER), suggesting that it can accommodate large variability in ligand structure. Relationships between xenobiotic structure, binding affinity, and estrogenic response have been suggested to be dependent on the conformational structures of the ligands. To explore the influence of conformational flexibility on ER binding affinity, a quantitative structure—activity relationship (QSAR) study was undertaken with estradiol, diethylstilbestrol, and a set of polychlorinated hydroxybiphenyls (PCHBs) of environmental concern. Although the low-energy minima of the PCHB congeners suggested that interconversions among conformers were likely, the electronic parameters associated with the conformer geometries for a specific PCHB congener could vary significantly. The results of the QSAR analysis suggested that among the PCHBs studied, the most polarizable conformers (lower absolute volume polarizability values) were most closely associated with ER binding affinity. Across the set of “polarizable” conformers, which did not include the low-energy gas-phase conformers, the electron donating properties of the hydroxy moiety and the aromatic component of the estradiol A ring analogue in the PCHBs were found to be correlated with higher ER binding affinity.
The body ion loss biomarker. 1. Interactions between trace metals and low pH in reconstituted coal mine-polluted water
Authors: Grippo Richard S. , Dunson William A.
Published: March 2010

Net body ion loss of brook charr (Salvelinus fontinalis) was evaluated as a biomarker of the potential toxicity of coal mine-polluted water. Fish were exposed in reconstituted coal mine-polluted water prepared in a continuously flowing system with a mixture of 16 water chemistry variables adjusted to match stream concentrations measured in moderately and severely mine-impacted streams. Changes in net body cation (Na+, K+, and Ca2+) loss rates from the fish were determined. Metal/pH interactions were tested by exposing fish to (1) a mixture of all six potentially toxic metals (Al, Fe, Zn, Mn, Ni, and Cd or Pb), (2) individual metals, (3) no metals (low pH effect), or (4) time control. At severe levels (pH ≈ 3.34) all metal treatments caused a net whole-body sodium loss rate similar to that observed for pH alone. Body potassium rates were essentially unchanged from that of the control; a significant calcium influx observed under control conditions was eliminated by most acid and metal exposures. At less severe pollution levels (pH ≈ 3.95) some metals (Ni2+, Mn2+, and Zn2+) blocked the net loss of body sodium induced by acidity. We conclude that net body sodium loss rate is a sensitive, reproducible, and acute indicator of acid and trace metal pollution and may be a useful biomarker for determining the presence and degree of impact of coal mine-polluted water on fish.
A survey of estrogenic activity in United Kingdom inland waters
Authors: Harries Jule E. , Sheahan David A. , Matthiessen Peter , Neall Paula , Rycroft Richard , Tylor Tina , Jobling Susan , Routledge Edwin J. , Sumpter John P.
Published: March 2010

Vitellogenin, a yolk-precursor protein normally found only in the blood plasma of sexually mature female teleosts and other egg-laying vertebrates, was used as an indicator of exposure of male rainbow trout (Oncorhynchus mykiss) to exogenous estrogens. Vitellogenin concentrations were measured using a specific radioimmunoassay for trout. Cages containing adult male trout were placed at the points of discharge and at varying distances downstream of treated sewage effluent outfalls into the River Lea (UK) during the summer and winter months of 1992. After 3 weeks exposure at the majority of sites, fish held up to 15 km downstream of inputs showed an increase in plasma vitellogenin concentration, with statistically significant elevations up to 4.5 km downstream. A repeat survey in November 1992 below Harpenden sewage treatment works showed that the only two stations to give a significant response were 3 m and 1.6 km downstream of the outfall. This reduced effect compared to the first survey is thought to be due to dilution of both the influent sewage to the treatment works and of the river water itself by increased rainfall, the overall increase in dilution being approx. 36%. Trout were also placed in 15 raw water storage reservoirs in southeast England during the summer of 1993 for an exposure period of 6 weeks. No biologically significant increases in plasma vitellogenin concentration were observed in any of the reservoirs.