bluuebunny/crossref_metadata_2025_split huggingface dataset:
Life history and spatial distribution of the enchytraeid worm Cognettia sphagnetorum (Oligochaeta) in metal-polluted soil: Below-ground sink-source population dynamics?
Authors: Salminen Janne , Haimi Jari 
Published: March 2010

Abstract
We studied the life history, metal-avoidance behavior, spatial distribution, and population growth of enchytraeid worms (Cognettia sphagnetorum [Oligochaeta]) originating from two sites: one uncontaminated, and another patchily polluted by heavy metals. Effects of patchy soil contamination on populations were studied in microcosms. In uncontaminated soil, worms from the polluted site had lower viability and reduced growth rate as juveniles but higher growth rate as adults compared to worms from the unpolluted site. They were also smaller in size at fragmentation (reproduction). Worms from the polluted site reached a larger population size than worms from the unpolluted site. Hence, worms from the polluted site seemed to allocate more energy to reproduction, because such a strategy can be highly adaptive when living in a less-polluted patch (the source) in, on average, a highly polluted environment. The C. sphagnetorum actively avoided Cu-contaminated soil, with the response being stronger in individuals from the contaminated site. When an unpolluted patch (the source) was surrounded by a toxic environment (the sink), worms were found in the sink, either because intraspecific competition overrode the avoidance behavior or because of random walk migration. As a result, total population size in these microcosms were as high as those in totally uncontaminated microcosms. Our results indicate that avoidance behavior and increased allocation to reproduction, together with the observed dispersal pattern, can be an adaptive strategy for C. sphagnetorum in the presence of small, less-polluted patches in, on average, a hostile environment. Hence, sink–source population regulation can explain spatial distribution and survival of C. sphagnetorum in patchily polluted field soils. When such population dynamics occur, this pattern should be taken into account when population densities in the field are monitored for ecological risk-assessment procedures concerning toxicants.
Chemical and biological availability of sediment-sorbed benzo[a]pyrene and hexachlorobiphenyl
Authors: Schuler Lance J , Lydy Michael J 
Published: March 2010

Abstract
This study examined the chemical and biological availability of two nonpolar organic compounds, benzo[a]pyrene (BaP) and hexachlorobiphenyl (HCBP), from a spiked sediment that was aged for varying amounts of time. Chemical availability was evaluated using four different solvent combinations to extract chemicals from the sediment. The extractability of BaP and HCBP from sediment using traditional solvents was then compared to the transfer efficiency (TE) of a benthic invertebrate (Lumbriculus variegatus) to relate chemical extractability to bioavailability in the organisms. Results indicated that water was the solvent that best approximated bioavailability for BaP, whereas comparisons for HCBP were inappropriate, because TE values exceeded 100%. The inability to obtain a reasonable TE estimate for HCBP was most likely due to the fact that the oligochaetes received a major portion of their uptake from interstitial water instead of ingestion of sediment particles, which invalidated an important assumption of the TE model. Overall, the results of this study indicate that exhaustive chemical extractions may be an inaccurate representation of the bioavailable fractions for some contaminants.
Multigeneration zinc acclimation and tolerance inDaphnia magna: Implications for water-quality guidelines and ecological risk assessment
Authors: Muyssen Brita T A , Janssen Colin R 
Published: March 2010

AbstractDevelopment of zinc tolerance is described for the cladoceran Daphnia magna Straus. Zinc tolerance (i.e., toxicity and deficiency) was monitored during successive generations of D. magna acclimated to different zinc concentrations. Survival, reproduction, carapax length measurements, and cellular energy allocation assessments were used as test endpoints. Special attention was paid to the consequences of zinc deficiency. The zinc acclimation concentration clearly influenced the overall fitness of the organism. After several generations of acclimation, an optimal concentration curve was observed, with an optimum zinc concentration between 300 and 450 μg/L. Zinc deficiency resulted in a lower zinc tolerance, a higher coefficient of variation for brood size, and an increased pH sensitivity. These results clearly indicate that (background) zinc concentrations present in test and culture media have to be considered in the evaluation of toxicity test results, especially when the toxicity data are used for water-quality guideline derivation and/or ecological risk assessment. Culture and test media containing very little or no zinc do not provide a basis for useful ecotoxicological data.
Comparison of different life-cycle impact assessment methods for aquatic ecotoxicity
Authors: Schulze Carsten , Jödicke Almut , Scheringer Martin , Margni Manuele , Jolliet Olivier , Hungerbühler Konrad , Matthies Michael 
Published: March 2010

Abstract
Human and ecotoxicity impact categories are problematic to quantify within life-cycle impact assessment (LCIA) because their local scope makes them difficult to aggregate with the traditional global-impact categories used in life-cycle assessment (LCA). For being able to assess local impacts such as toxicity, LCIA developers increasingly include fate modeling into LCA. This article follows this development by comparing different LCIA methods for aquatic ecotoxicology and by investigating the importance of fate within LCIA, the necessity of considering freshwater and seawater compartments separately, and the key degradation and intermedia transfer processes involved. The methods are compared by assessing an example study of domestic clothes washing in former West Germany. Four LCIA methods are selected and applied to four substances emitted during the washing process. The conclusion is that the consideration of environmental fate does matter and that aquatic ecotoxic impacts can differ significantly for the same substance in freshwater and in marine ecosystems. The way (bio)degradation, photolysis, volatilization, and transfer from agricultural soils are considered plays an important role as do the system boundaries chosen. This means that the LCIA methodology should remain flexible so that appropriate methods can be chosen for different applications. Fate models being developed in the environmental risk assessment of chemicals can contribute to the further improvement of LCIA methods.
Substances with estrogenic activity in effluents of sewage treatment plants in southwestern Germany. 2. Biological analysis
Authors: Körner Wolfgang , Spengler Peter , Bolz Ulrike , Schuller Winfried , Hanf Volker , Metzger Jörg W 
Published: March 2010

Abstract
The proliferation test with human estrogen receptor-positive MCF-7 breast cancer cells (E-Screen assay) was applied for quantitative determination of total estrogenic activity in 24-h composite effluent samples from 16 municipal and two industrial sewage treatment plants (STPs) in the state of Baden-Württemberg, southwestern Germany. The estrogenic efficacy relative to the positive control, 17β-estradiol, was between 26 and 74% (median, 48%) for the 16 municipal STPs. Estradiol equivalent concentrations (EEQs) were between 0.2 and 7.8 ng/L (median, 1.6 ng/L) and, thereby, were lower than those found in a pilot study, which revealed EEQs of greater than 10 ng/L in the effluents of two other STPs. The EEQs in 14 of the 16 effluent samples were very similar (0.9–3.3 ng/L), indicating a rather constant input of estrogenic substances via STPs into rivers. Additional activated charcoal filtration turned out to be very efficient in further eliminating estrogenic activity from effluents. The EEQs of the E-Screen assay and those calculated from the results of extensive chemical analysis using the estradiol equivalency factors determined for 13 natural and synthetic estrogenic substances were comparable for most of the effluent samples. 17β-Estradiol, 17α-ethinylestradiol, and, to a lesser extent, estrone contributed to 90% or more of the EEQ value.
Prediction of biodegradation from the atom-type electrotopological state indices
Authors: Huuskonen Jarmo 
Published: March 2010

AbstractA group contribution method based on atom-type electrotopological state indices for predicting the biodegradation of a diverse set of 241 organic chemicals is presented. Multiple linear regression and artificial neural networks were used to build the models using a training set of 172 compounds, for which the approximate time for ultimate biodegradation was estimated from the results of a survey of an expert panel. Derived models were validated by using a leave-25%-out method and against two test sets of 12 and 57 chemicals not included in the training set. The squared correlation coefficient (r2) for a linear model with 15 structural parameters was 0.76 for the training set and 0.68 for the test set of 12 molecules. The model predicted correctly the biodegradation of 48 chemicals in the test set of 57 molecules, for which biodegradability was presented as rapid or slow. The use of artificial neural networks gave better prediction for both test sets when the same set of parameters was tested as inputs in neural network simulations. The predictions of rapidly biodegradable chemicals were more accurate than the predictions of slowly bio-degradable chemicals for both the regression and neural network models.
Characterization of estrogenic compounds in water samples collected from United Kingdom estuaries
Authors: Thomas Kevin V , Hurst Mark R , Matthiessen Peter , Waldock Mike J 
Published: March 2010

Abstract
This report describes the identification of important estrogenic compounds in surface and sediment pore-water samples collected from the Tyne and Tees estuaries (United Kingdom) through the application of toxicity identification evaluation (TIE) procedures. The Tyne and Tees estuaries represent estuaries that have been historically impacted by industrial activities and continue to receive treated domestic sewage and industrial effluent. In 1998, Dabholm Gut on the Tees received a mixture of treated and untreated effluent, while Howdon sewage treatment works (STW) discharged primary treated effluents. An estrogenically active water sample collected from Howdon STW on the Tyne was shown to contain 17β-estradiol, androsterone, and an unknown estrogenic compound(s). Most of the activity contained in a sample collected from the Dabholm Gut combined discharges on the Tees was also due to 17β-estradiol with additional activity from nonylphenol and (tentatively) bis(2-ethylhexyl)phthalate. The only sediment pore-water sample to demonstrate estrogenic activity was collected from Dabholm Gut.
Degradation of a stilbene-type fluorescent whitening agent with hypochlorite: Identification of the degradation products by capillary electrophoresis
Authors: Blanco Marcelo , Jiménez Lidia , Valverde Ismael 
Published: March 2010

Abstract
The E,E-(4,4′-bis[2-sulfostyryl]biphenyl) (DSBP) is a fluorescent whitening agent widely used by the textile and detergent industries to whiten fabrics. Hypochlorite used to bleach fabrics oxidizes DSBP slowly at room temperature and in a higher rate at 60°C. The ions of metals such as Fe, Cu, and Mn accelerate the process considerably. At ambient temperature, the oxidation results from cleavage of the stilbene bonds and involves the formation of various intermediates that evolve to end products. The intermediates form within minutes to hours and the end products within months. At 60°C or in presence of the previously mentioned transition metals, intermediates form within minutes and the end products within days. The end products of the oxidation are 4-sulfobenzaldehyde and 4,4′-bisaldehyde biphenyl; in the presence of excess of hypochlorite, however, the process yields their corresponding oxidized derivatives 4-sulfobenzoic acid and 4,4′- biphenyldicarboxylic acid. Despite the chlorinating ability of hypochlorite, the major degradation products formed contain no chlorine.
Compositional and chiral profiles of weathered chlordane residues in soil
Authors: Eitzer Brian D , Mattina Maryjane Incorvia , Iannucci-Berger William 
Published: March 2010

Abstract
The fate of chlordane and other persistent organic pollutants in the environment is of international concern. The behavior of persistent organic pollutants under both abiotic and biotic conditions must be determined for the comprehensive elucidation of their cycling through the biosphere. Standard analytical methods such as gas chromatography with electron capture detection are adequate for studies of cycling under abiotic conditions. Since two of the main components of technical chlordane, cis-chlordane and trans-chlordane, are optically active, chiral gas chromatography can be used to study the impact of biotic influences on chlordane's fate. We report here the use of chiral gas chromatography interfaced with ion trap mass spectrometry as part of an analytically rigorous method for the simultaneous determination of the compositional and chiral profiles of weathered soil residues of technical chlordane. Using the method described, several patterns in the long-term weathering of technical chlordane in soil are observed.
A test system to evaluate the susceptibility of Oregon, USA, native stream invertebrates to triclopyr and carbaryl
Authors: Peterson Jennifer L , Jepson Paul C , Jenkins Jeffrey J 
Published: March 2010

AbstractThe susceptibility of six indigenous macroinvertebrate species representative of U.S. Pacific Northwest streams (Ameletus sp., Brachycentrus americanus, Calineuria californica, Cinygma sp., Lepidostoma unicolor, Psychoglypha sp. early and late instar) to formulated triclopyr ester (herbicide) and carbaryl (insecticide) was determined using laboratory bioassays. Acute toxicity was expressed as the lethal concentration to 50% (LC50) and 1% (LC1) of the test population based on a 96-h exposure duration. Carbaryl was found to be 1,000 times more toxic than triclopyr for all the organisms tested. The LC1 values (7.5, 28.8, 9.0, 3.0, 9.5, 14.8, 33.8 μg/L, respectively, for carbaryl and 1.8, 3.9, 4.0, 4.2, 29.0, 16.1 mg/L, respectively, for triclopyr) were used in the calculation of hazardous concentration to 5% of the stream macroinvertebrate community (HC5) based on the lower 95% confidence limit (HC5/95). The hazardous concentration (HC5/95) for triclopyr was 0.11 mg/L and for carbaryl ranged from 0.43 to 0.66 μg/L, respectively. Triclopyr and carbaryl symptomology were analyzed for two organisms, C. californica and Cinygma sp. Carbaryl symptomology included knockdown and moribund states with severity and time of appearance being a function of dose. In triclopyr poisoning, death occurred suddenly with little or no symptomology. Time to 50% mortality (LT50) values were consistently higher for C. californica than for Cinygma sp. exposed to both chemicals at similar concentrations.
Effect of varying pesticide exposure duration and concentration on the toxicity of carbaryl to two field-collected stream invertebrates, Calineuria californica (Plecoptera: Perlidae) and Cinygma sp. (Ephemeroptera: Heptageniidae)
Authors: Peterson Jennifer L , Jepson Paul C. , Jenkins Jeffrey J 
Published: March 2010

Abstract
The effect of exposure duration on the toxicity of a forest insecticide (carbaryl) was assessed under environmentally realistic exposure regimes against two stream invertebrates indigenous to the United States Pacific Northwest, Calineuria californica (Plecoptera: Perlidae) and Cinygma sp. (Ephemeroptera: Heptageniidae). Laboratory bioassays were conducted to evaluate the relationship between pulsed exposures of 15, 30, and 60 min and toxicity for a range of chemical concentrations (10.2–1,730 μg/L). For Cinygma sp., the 50% lethal concentration (LC50) values were calculated as 848 μg/L (15 min), 220 μg/L (30 min), and 165 μg/L (60 min). The C. californica consistently had lower mortality at a given concentration compared with Cinygma sp. Fifteen- and 30-min exposures did not elicit 50% mortality with C. californica, and it had a 60-min LC50 of 1,139 μg/L. Time to 50% mortality over 96 h after a 15-, 30-, or 60-min exposure, with the rest of the test period in freshwater (PLT50), was a function of exposure duration and concentration. Analysis of symptomology throughout the test period for C. californica gave evidence of recovery from the knockdown and moribund states, but this was not the case for Cinygma sp. The pulse duration resulting in 50% mortality was calculated as 43 min for Cinygma sp. exposed at 204 μg/L and 16 min at 408 μg/L. A three-dimensional probit plane model [Y = — 10.86 + 4.83(In C) + 3.0(In T)], where Y is probit mortality, C is concentration in μg/L and T is time in hours, was used to explain the interaction between concentration (μg/L) and duration of exposure (hours) for Cinygma sp.
Genetic diversity of the major histocompatibility complex of cotton rats (Sigmodon hispidus) inhabiting an oil refinery complex
Authors: Pfau Russell S , McBee Karen , Van Den Bussche Ronald A 
Published: March 2010

Abstract
We examined genetic diversity of an immune-response gene within the major histocompatibility complex in cotton rats (Sigmodon hispidus) inhabiting an oil refinery complex. Genetic diversity of MHC-DQA exon-2 was examined within and among contaminated and noncontaminated reference grids. The level of gene diversity within contaminated grids (0.748) was lower than within reference grids (0.818), but the difference was not statistically significant (p &gt; 0.5). Analysis of molecular variance, pairwise FST values, and hierarchical clustering failed to reveal population genetic structure related to contamination. Results of this study indicate either that the level of contaminant-induced selection is insignificant at this major histocompatibility complex (MHC) locus or that gene flow from surrounding areas has obliterated the effects of selection.
A comparison of the effect of new and established insecticides on nontarget invertebrates of winter wheat fields
Authors: Moreby Stephen J , Southway Sue , Barker Alison , Holland John M 
Published: March 2010

Abstract
Six insecticides, a carbamate (pirimicarb), four pyrethroid/mixtures (tao-fluvalinate, zeta-cypermethrin, deltamethrin, and pirimcarb+deltamethrin), and an organophosphate (dimethoate), registered for use within cereals, were field-tested for toxicity to beneficial nontarget invertebrate groups important as food for farmland birds. Compared to the control and the other compounds, pirimicarb was the least toxic for most invertebrate groups examined. The pyrethroids and pyrethroid mixture significantly reduced numbers of many of the nontarget groups compared to the control and pirimicarb. Tao-fluvalinate was the least toxic pyrethroid tested when compared to the other compounds. Toxicity was further tested on larvae of graminivorous sawflies, an important chick-food group, using field-sprayed plants in laboratory and semifield trials. None of the pyrethroid and carbamate compounds and mixtures was as toxic as the organophosphate, but all were more toxic than the control. The semifield experiments provided a useful way of determining potential insecticide impact on this nontarget group where field populations are often too low for field trials to have statistically conclusive results.
Arsenic biotransformation by the brown macroalga Fucus serratus
Authors: Geiszinger Anita , Goessler Walter , Pedersen Søren N , Francesconi Kevin A 
Published: March 2010

Abstract
The brown alga Fucus serratus was maintained in aquaria with added arsenate (0, 20, 50, and 100 μg As/L, four individuals per treatment) for up to 19 weeks. Biotransformation of arsenic by Fucus was monitored by high-performance liquid chromatography/inductively coupled plasma mass spectrometry and liquid chromatography/electrospray mass spectrometry analysis of aqueous extracts of algal frond tips removed periodically throughout the experiment. Major arsenic species monitored were arsenate, arsenite, methylarsonate, dimethylarsinate, and the four arsenosugars 1 to 4 found naturally in Fucus. Algae accumulated arsenate readily and transformed it into several arsenic compounds depending on the exposure concentration. At 100 μg As/L, the major metabolite was arsenite with smaller quantities of methylarsonate and dimethylarsinate, but only traces of arsenosugars were formed. In contrast, the 20–μg-As/L group accumulated only small quantities of arsenite and methylarsonate, while dimethylarsinate and arsenosugars were major arsenic metabolites. At 50 μg As/L exposure, algae had significant quantities of all arsenic metabolites monitored. Arsenate was toxic to the algae at 100 μg As/L, but had no obvious detrimental effect at 20 μg As/L. The data are consistent with a process of arsenate detoxification by reduction and alkylation; at higher exposures, however, the alkylation processes become saturated, leading to an accumulation of arsenite and subsequent toxicity.
Polychlorinated biphenyl contamination and minisatellite DNA mutation rates of tree swallows
Authors: Stapleton Mary , Dunn Peter O , McCarty John , Secord Anne , Whittingham Linda A 
Published: March 2010

Abstract
The evidence that exposure to polychlorinated biphenyls (PCBs) leads to mutations is equivocal and controversial. Using multilocus DNA fingerprinting, we compared the mutation rate of tree swallows (Tachycineta bicolor) nesting at sites with high and low levels of contamination with PCBs. The upper Hudson River, USA, is highly contaminated with PCBs as a result of releases from two capacitor manufacturing plants in Hudson Falls and Fort Edward, New York, USA. Tree swallows nesting nearby have some of the highest known concentrations of PCBs in their tissues of any contemporary bird population (up to 114,000 ng PCB/g tissue). We found no difference in mutation rates between sites in New York with high PCB contamination and reference sites in Wisconsin, USA, and Ontario and Alberta, Canada, with known or presumably low levels of contamination. Thus, the mechanism behind altered reproductive behavior of tree swallows along the upper Hudson River is most likely physiological impairment, such as endocrine disruption, rather than mutation.
Effects of water hardness and dissolved organic material on bioavailability of selected organic chemicals
Authors: Akkanen Jarkko , Kukkonen Jussi V K 
Published: March 2010

AbstractThe influence of water hardness and dissolved organic matter (DOM) on bioavailability of organic chemicals to Daphnia magna was studied by using benzo[a]pyrene (BaP), pyrene, atrazine, and 3,3′,4,4′-tetrachlorobiphenyl (TCB) as model compounds. Two types of DOM were used, namely Lake Kontiolampi, Joeusuu, Finland water (KL) and Nordic reference fulvic acid (NoFA) dissolved in artificial freshwater. Binding of the four contaminants by KL, DOM decreased with increasing water hardness. Furthermore, increasing hardness reduced the binding of BaP and pyrene to NoFA. The binding of atrazine and TCB by NoFA was low and was not significantly affected by water hardness. In the DOM-free samples, the bioconcentration of the four contaminants in D. magna usually was not affected by water hardness. In the presence of DOM, the bioconcentration factors (BCFs) were lower (except for atrazine) than in the DOM-free controls. In the presence of both types of DOM, increasing water hardness resulted in higher BCFs for BaP. The bioconcentration of pyrene and TCB increased with increasing water hardness in the presence of KL DOM. In conclusion, the effects of DOM and water hardness on bioavailability of hydrophobic chemicals depend on the type of chemical and on the properties of DOM.