bluuebunny/crossref_metadata_2025_split huggingface dataset:
Methyl sulfonyl polychlorinated biphenyls and 2,2-bis(4-chlorophenyl)-1,1-dichlorethenein gray seal tissues determined by gas chromatography with electron capture detection and atomic emission detection
Authors: Janák Karel , Becker Gerhard , Colmsjö Anders , Östman Conny , Athanasiadou Maria , Valters Karlis , Bergman Åke 
Published: February 2010

Abstract
The presence of 24 methyl sulfonyl polychlorinated biphenyl (PCB) congeners (MeSO2-CBs) and 3-methyl sulfonyl 2,2-bis(4-chlorophenyl)-1,1-dichlorethene (DDE) (MeSO2-DDE), metabolites of PCB and DDE, in blubber, lung, and liver of gray seals has been determined by using atomic emission detection (AED) and electron capture detection (ECD). Selective accumulation of aryl methyl sulfones in blubber, liver, and lung tissue was also investigated. For the liver samples, a substantial and highly specific retention of PCB methyl sulfones was observed. The atomic emission technique significantly improved the determination of measured solutes compared with ECD. Atomic emission detection was also valuable for the monitoring of the prefractionation and to decrease the requirements of sample clean-up. Comparing both detection techniques showed a good correlation between the results of the AED sulfur-selective line and ECD.
Effect of mixtures of polycyclic aromatic hydrocarbons and sediments on fluoranthene biodegradation patterns
Authors: Beckles Denise M , Ward C Herb , Hughes Joseph B 
Published: February 2010

Abstract
The biodegradation of fluoranthene, alone and in mixtures with naphthalene and acenaphthene, was studied in systems with and without sediments. In sediment-free systems, fluoranthene was not degraded when present alone or in combination with acenaphthene but was degraded when combined with naphthalene. Naphthalene and acenaphthene degradation were not influenced by fluoranthene. In sediment-containing systems, fluoranthene degradation occurred only in the presence of naphthalene. After complete degradation of naphthalene, fluoranthene degradation stopped. Experiments using all three polycyclic aromatic hydrocarbons in both sediment-free and -containing systems showed results similar to those obtained using pairs.
Persistent organochlorine contaminants in ringed seals (Phoca hispida) from the Kara Sea, Russian Arctic
Authors: Nakata Haruhiko , Tanabe Shinsuke , Tatsukawa Ryo , Koyama Yasuhiro , Miyazaki Nobuyuki , Belikov Stanislav , Boltunov Andrei 
Published: February 2010

Abstract
Ringed seals collected from the KaraSea in the Russian Arctic during 1995 were analyzed for persistent organochlorines (OCs) such as DDTs, polychlorinated biphenyls (PCBs), chlordane compounds (CHLs), hexachlorocyclohexanes (HCHs), and hexachlorobenzene to understand the present status of contamination. Noticeably higher levels of DDTs and PCBs were detected in ringed seals from the Russian Arctic when the values compared with same species from the Canadian Arctic and the Norwegian Arctic. This suggests the presence of significant local sources of DDTs and PCBs in Russia or nearby areas. Concentrations of CHLs and HCHs in ringed seals were comparable with those in this species elsewhere in circumpolar regions, probably as a consequence of uniform distribution of CHLs and HCHs due to the atmospheric transport of these compounds to the Arctic region. Larga seals collected from the Sea of Okhotsk were also analyzed for OCs to compare residue levels and accumulation patterns with those in ringed seals. In larga seals, the prominent residues were DDTs and PCBs, with levels comparable or slightly lower than those in ringed seals. Lactational transfer of PCBs, DDTs, and CHLs was evident in ringed seals based on increasing concentrations with age in males but not in females. The transfer rates were estimated to be 38% for DDTs, 25% for PCBs, and 30% for CHLs of the whole body burden in the mature female. Comparison of the PCB congener pattern accumulated in seals suggested that ringed seals have an greater capacity to degrade toxic non-ortho (IUPAC 126) and mono-ortho (IUPAC 105 and 118) coplanar congeners than did Baikal seals, but a lower capacity than found in larga seals.
Sensitivity of fish embryos to weathered crude oil: Part II. Increased mortality of pink salmon (Oncorhynchus gorbuscha) embryos incubating downstream from weatheredExxon valdezcrude oil
Authors: Heintz Ron A , Short Jeffrey W , Rice Stanley D 
Published: February 2010

AbstractWe incubated pink salmon embryos under three exposure conditions, direct contact with oil-coated gravel, effluent from oil-coated gravel, and direct contact with gravel coated with very weathered oil (VWO). Embryo mortalities and polynuclear aromatic hydrocarbon (PAH) accumulation in embryo tissues during the direct-contact and effluent exposure experiments were not significantly different, indicating that PAH accumulation was mediated by aqueous transport. Mortality rates for embryos exposed initially to a total PAH concentration (TPAH) of 1.0 ppb were significantly higher than controls when the PAH were derived from VWO. The same aqueous TPAH concentration failed to increase mortality rates when the PAH were derived from less weathered oil, indicating that toxicity of effluents from the VWO was primarily associated with the larger PAH. We conclude that water quality standards for TPAH above 1.0 ppb may fail to protect fish embryos. Further, pink salmon embryos incubating in Prince William Sound after the Exxon Valdez oil spill may have accumulated lethal concentrations of PAH from interstitial water that was contaminated when it percolated through oil reservoirs located upstream from salmon redds.
Improved method for estimating bioconcentration/bioaccumulation factor from octanol/water partition coefficient
Authors: Meylan William M , Howard Philip H , Boethling Robert S , Aronson Dallas , Printup Heather , Gouchie Sybil 
Published: February 2010

Abstract
A compound's bioconcentration factor (BCF) is the most commonly used indicator of its tendency to accumulate in aquatic organisms from the surrounding medium. Because it is expensive to measure, the BCF is generally estimated from the octanol/water partition coefficient (Kow), but currently used regression equations were developed from small data sets that do not adequately represent the wide range of chemical substances now subject to review. To develop an improved method, we collected BCF data in a file that contained information on measured BCFs and other key experimental details for 694 chemicals. Log BCF was then regressed against log Kow and chemicals with significant deviations from the line of best fit were analyzed by chemical structure. The resulting algorithm classifies a substance as either nonionic or ionic, the latter group including carboxylic acids, sulfonic acids and their salts, and quaternary N compounds. Log BCF for nonionics is estimated from log Kow and a series of correction factors if applicable; different equations apply for log Kow 1.0 to 7.0 and &gt;7.0. For ionics, chemicals are categorized by log Kow and a log BCF in the range 0.5 to 1.75 is assigned. Organometallics, nonionics with long alkyl chains, and aromatic azo compounds receive special treatment. The correlation coefficient (r2 = 0.73) and mean error (0.48) for log BCF (n = 694) indicate that the new method is a significantly better fit to existing data than other methods.
Life-cycle framework for assessment of site remediation options: Case study
Authors: Page Cynthia A , Diamond Miriam L , Campbell Monica , McKenna Stephen 
Published: February 2010

AbstractAn adaptation of life-cycle assessment for contaminated site remediation activities was used to examine a lead-contaminated site remediated by excavation and disposal. The study indicated emissions and impacts associated with energy consumption (transportation of contaminated soil to hazardous and nonhazardous sites), solid waste production (contaminated soil and sludge), land use at four sites (the contaminated site, two disposal sites, and a borrow pit for clean fill), and potential toxicity from emissions and contaminants remaining on-site. These impacts were drawn from an inventory compiled mainly from proprietary consultants' reports, and related to impacts through several stressor–impact models; the process-related indicators of global warming potential, solid waste burden, and ecological and human toxicity potential; and site-related indicators of land use and residual human toxicity burden. Ecological and human toxicity potentials were estimated using the Mackay level III model for southern Ontario, Canada, adapted for metals. The life-cycle approach proved useful for identifying potential impacts occurring at local, regional, and global scales, over all activities and locations affected by the remediation.
Enhanced anaerobic biotransformation of carbon tetrachloride in the presence of reduced iron oxides
Authors: Kim Sanggoo , Picardal Flynn W 
Published: February 2010

Abstract
Rates of anaerobic transformation of carbon tetrachloride (CT) by the facultative anaerobe Shewanella putrefaciens 200 were increased by the presence of Fe(III)-containing minerals. In batch reactors with amorphous, Fe(III)-hydroxide and S. putrefaciens, CT transformation rates could be modeled by a first—order expression in which the pseudo—first-order rate constant was linearly proportional to the initial concentration of Fe(III)-oxide. Subsequent measurement of soluble and acid—extractable Fe(II) showed that increased CT transformation rates were proportional to microbially reduced, surface—bound Fe(II), rather than soluble Fe(II). In biomimetic experiments using 20 mM dithiothreitol (DTT) as a reductant, rates of transformation of CT by DTT were low in the absence of Fe(III)-oxides. However, in the presence of iron oxides, DTT was able to transform CT at elevated rates. Results again strongly suggested that surface—bound Fe(II) was primarily responsible for the reductive transformation of CT. Results suggested that the surface area of the iron mineral determines the rate of CT transformation by affecting the extent of iron reduction. Chloroform (CF) was the only transformation product identified and production of CF was nonstoichiometric. In microbial and abiotic experiments with Fe(III) oxides, the percentage of the transformed CT recovered as CF decreased even though the rate and extent of CT transformation was increased. Overall, our results have important implications for an improved understanding of possible microbial and geochemical interactions in the environmental transformation of chlorinated organic pollutants and for modeling of CT transformation rates in anaerobic, iron—bearing sediments.
Assessment of sediment contamination, acute toxicity, and population viability of the estuarine amphipodLeptocheirus plumulosusin baltimore harbor, maryland, USA
Authors: McGee Beth L , Fisher, Daniel J , Yonkos Lance T , Ziegler Gregory P , Turley Steve 
Published: February 2010

AbstractIn Chesapeake Bay, Maryland, USA, some of the most contaminated sediments are found in the highly industrialized Baltimore Harbor—Patapsco River area. As part of a comprehensive assessment of sediment quality in this system, sediment toxicity was assessed in 10-d acute tests with the estuarine amphipod Leptocheirus plumulosus. Mean amphipod survival was significantly reduced in 7 of the 25 samples tested despite the occurrence of minor experimental artifacts. The most toxic sediments were collected from Bear Creek; other areas exhibiting toxicity included the Inner Harbor and Colgate Creek. Marginal toxicity was observed in samples from Curtis Creek, Lazeretto Point, and Back River. Negative relationships were detected between survival and concentrations of select sediment—associated contaminants, whereas a very strong positive association existed between survival in laboratory exposures and density of L. plumulosus at the test sites. A weight of evidence approach, including correlation analyses, a model of polycyclic aromatic hydrocarbon bioavailability, and comparisons to benchmark sediment levels, was used to tentatively identify classes of contaminants that contributed to the observed toxicity. Analysis of results suggested that toxicity at stations in Bear Creek and Colgate Creek may have been driven by sediment—associated metals, whereas toxicity at stations in the Inner Harbor was likely due to both metal and organic contaminants. The observed relationships among toxicity test results, concentrations of sediment—associated contaminants, and abundance of L. plumulosus at the test sites suggests that acute toxicity tests with this species are indicative of adverse biological effects in the field.
Diel cycles in calcite production and dissolution in a eutrophic basin
Authors: Cicerone, Daniel S , Stewart Arthur J , Roh Yul 
Published: February 2010

Abstract
Calcite production is understood largely as a longer—term phenomenon (e.g., seasonal whitings) that can occur in hardwater lakes, and is significant ecologically because it can slow the rate of eutrophication by reducing, through adsorption, the availability of nutrients to primary producers. In this study we show that rapid changes in concentration of dissolved CO2 by photosynthesis and respiration within a eutrophic basin generated strong day—to-night cycles in calcite production and dissolution. Diel cycles in calcite production and dissolution were large enough that they could drive secondary diel cycles in the availability of metals that strongly sorb to the surfaces of calcite particles. We explored the possibility of the secondary diel cycling of metals by intensive 7-d in situ monitoring of water—quality conditions in a shallow, eutrophic spill—control basin near an industrial facility in eastern Tennessee; inspecting data from a 7-year record of water—quality parameters for this basin; analyzing physicochemical characteristics and mineralogic composition of sediments in the basin; and conducting laboratory experiments to characterize the interaction of calcite with Cd, under solid—liquid nonequilibrium conditions. We found that the basin accumulated and stored calcite. In situ monitoring showed that calcite was produced during daylight, and tended to dissolve again at night; the calcite production and dissolution processes seemed to be modulated by dissolved—phase CO2 dynamics, in concert with large diel fluctuations in pCa, pH, and PO2. Laboratory experiments showed a rapid interaction (&lt;6 h) of Cd with calcite, in response to dissolved CO2 changes. Thus, concentrations of dissolved Cd can vary over daily cycles, mediated by diel changes in calcite production and dissolution. Thermodynamic considerations suggest that other metals, such as Zn, Sr, Ni, and Ba, may demonstrate this behavior as well.
Comparison ofBrachionus calyciflorus2-d and microtox® chronic 22-h tests withDaphnia magna21-d test for the chronic toxicity assessment of chemicals
Authors: Radix Pascal , Léonard Marc , Papantoniou Christos , Roman Gilles , Saouter Erwan , Gallotti—Schmitt Sophie , Thiébaud Hervé , Vasseur Paule 
Published: February 2010

AbstractThe Daphnia magna 21-d test may be required by European authorities as a criterion for the assessment of aquatic chronic toxicity for the notification of new substances. However, this test has several drawbacks. It is labor—intensive, relatively expensive, and requires the breeding of test organisms. The Brachionous calyciflorus 2-d test and Microtoxr̀ chronic 22-h test do not suffer from these disadvantages and could be used as substitutes for the Daphnia 21-d test for screening assays. During this study, the toxicity of 25 chemicals was measured using both the Microtox chronic toxicity and B. calyciflorus 2-d tests, and the no—observed-effect concentrations (NOECs) were compared to the D. magna 21-d test. The Brachionus test was slightly less sensitive than the Daphnia test, but the correlation between the two tests was relatively good (r2 = 0.88). On average, the Microtox chronic test presented the same sensitivity as the Daphnia test, but the results did not correlate as well (r2 = 0.54). The B. calyciflorus 2-d test, and to a lesser extent the Microtox chronic 22-h test, were able to predict the chronic toxicity values of the Daphnia 21-d test. They constitute promising cost—effective tools for chronic toxicity screening.
Pyrene metabolites in the hepatopancreas and gut of the isopod porcellio scaber, a new biomarker for polycyclic aromatic hydrocarbon exposure in terrestrial ecosystems
Authors: Stroomberg, Gerard J , Knecht Joop A DE , Ariese Freek , Gestel Cornelis AM Van , Velthorst Nel H 
Published: February 2010

Abstract
The object of this study was to investigate the formation of pyrene metabolites by the isopod Porcellio scaber as a possible tool in the environmental risk assessment of polycyclic aromatic hydrocarbon (PAH) exposure in terrestrial ecosystems. The formation of pyrene metabolites was studied after either pulse exposure to a single high dose, or prolonged exposure (14 d) to a lower dosage. Exposure studies were carried out with unlabeled or radiolabeled pyrene, ion pair chromatography was used for analysis, and reference conjugates were synthesized. We also measured pyrene metabolites in field—exposed animals, to explore their use as biomarkers of PAH exposure. Analysis of the hepatopancreas and gut of single isopods revealed the formation of five products, one of which was 1-hydroxypyrene. Four of the remaining products were identified as phase II metabolites of 1- hydroxypyrene, with UV absorption and fluorescence characteristics similar to that of pyrene. One metabolite was identified as pyrene−1-glucoside, which is in accordance with high rates of glucosidation, reported for these isopods. Another conjugate was identified as pyrene−1-sulfate. None of the metabolites coeluted with a pyrene−1-glucuronide reference obtained from fish bile. A fifth metabolite detected by on—line scintillation detection did not exhibit any absorption at 340 nm, possibly because one of the aromatic rings of pyrene had lost its aromatic character. Although pyrene is not known for its toxicity, it usually co—occurs with other PAHs that are transformed into toxic products. Investigating the metabolism of pyrene can provide information with regard to the biotransformation capacity of invertebrate species and uptake and elimination kinetics. Because pyrene is one of the most predominant PAHs in the environment, analysis of its metabolites provides an extra tool for the environmental risk assessment of ecosystems with regard to PAH exposure, bioavailability, and biotransformation.
Validity and ecological relevance of an active in situ bioassay using gammarus pulex and limnephilus lunatus
Authors: Schulz Ralf , Liess Mathias 
Published: February 2010

Abstract
In situ bioassays using aquatic organisms serve as a link between laboratory and field studies. However, the ecological relevance of in situ studies had not previously been assessed by direct comparison with field data. In this study, an in situ bioassay employing Gammarus pulex L. (Crustacea: Amphipoda) and Limnephilus lunatus Curtis (Insecta: Trichoptera) was used in two agricultural tributaries and the connecting headstream. Simultaneously, the short—term insecticide contamination and the stream population dynamics of both species were monitored. During transient insecticide inputs (duration: about 1 h; peak concentrations: 6.2 mg/L fenvalerate; 0.6 μg/L parathion—ethyl), mortality of both species in the in situ bioassay was significantly higher in the contaminated tributary than in the uncontaminated control tributary (analysis of variance [ANOVA], Fisher's protected least significant difference [PLSD]; p &lt; 0.05). Limnephilus lunatus gave comparable responses in the stream; however, no mortality of G. pulex was observed in the stream. The reason for this difference is presumably that, in contrast to the bioassay, a typical avoidance behavior of G. pulex to pesticides, downstream drift, is possible in the field. During runoff events, G. pulex migrated from the potentially contaminated headstream section into the uncontaminated tributary, which can be regarded as a refuge and source for recolonization. Significantly lower coefficients of variance in the bioassay (≤0.22 compared to ≥0.55 in the field samples) allow for a better detection of adverse effects of pesticide with this method. Hence, although the bioassay is valuable for identifying insecticide input events, supplementary field studies are necessary for an ecological interpretation of the results.
Qualitative assessment of genotoxicity using random amplified polymorphic DNA: Comparison of genomic template stability with key fitness parameters inDaphnia magnaexposed to benzo[a]pyrene
Authors: Atienzar Franck A , Conradi Mercedes , Evenden Andrew J , Jha Awadhesh N , Depledge Michael H 
Published: February 2010

AbstractA method of DNA profiling using the random amplified polymorphic DNA (RAPD) was used to assess toxicant—induced DNA effects in laboratory populations of Daphnia magna exposed to varying concentrations of the genotoxic hydrocarbon benzo[a]pyrene. These effects, represented by changes in the RAPD profiles, were compared with a number of key ecological fitness parameters (age—specific survival, age—specific fecundity, net reproductive rate, and intrinsic rate of population increase). Not only was the RAPD profiling method shown to be a rapid and reproducible assay of toxicant—induced DNA effects, but the qualitative measure of genomic template stability compared favorably with the traditional indices of fitness. The RAPD profiles, however, exhibited higher sensitivity in detecting toxic effects. The significance of these findings for future ecotoxicological studies is discussed.
Bioavailability of cadmium and zinc to the common carp, CYPRINUS carpio, in complexing environments: A test for the validity of the free ion activity model
Authors: Ginneken Luc Van , Chowdhury Mohammed J , Blust Ronny 
Published: February 2010

Abstract
The uptake of cadmium and zinc by the common carp, Cyprinus carpio, was studied in chemically defined freshwater in the presence of different organic ligands (i.e., citrate, glycine, histidine, ethylenediaminetetraacetic acid, and nitrilotriacetic acid). In most cases, metal complexation decreased Cd and Zn uptake by reducing the free Cd and Zn ion activity. However, Cd and Zn uptake did not increase linearly with the free Cd and Zn ion activity in the solution. A good fit to the data was obtained when the observations were fitted to a Michaelis—Menten-like model for carrier—mediated transport of the metal ions across the biological interface. In addition, the uptake of Cd in the presence of citrate, glycine, and histidine was markedly higher than expected on the basis of the free Cd ion activity. It was concluded that cadmium complexes of these low molecular weight, hydrophilic ligands contributed to the Cd bioavailability, probably by direct uptake of these complexes. Zinc uptake in the presence of the complexing agents could be predicted on the basis of the ambient free Zn ion activity, although uptake in the presence of citrate was lower than expected on the basis of the free Zn ion activity. These results provide a challenging test for the free ion activity model.