bluuebunny/crossref_metadata_2025_split huggingface dataset:
Toxicity of retene to early life stages of two freshwater fish species
Authors: Billiard Sonya M , Querbach Kirsten , Hodson Peter V 
Published: March 2010

AbstractLarval zebrafish (Danio rerio) were exposed for 14 d to graded nominal concentrations of waterborne retene (7-isopropyl-1-methylphenanthrene) from 5 to 336 h postfertilization. Reduced growth, yolk sac edema, and mortality were observed before swim up at nominal concentrations of 320 μg/L and higher in a concentration-dependent manner. Similarly, exposures of rainbow trout (Oncorhynchus mykiss) to retene (32–320 μg/L) for 42 d from the eyed egg stage to hatch and from hatch to the onset of swim up behavior caused exposure-related increases in blue sac disease posthatch. Symptoms included increased activity of cytochrome P4501A (CYP1A) enzymes, yolk sac edema, subcutaneous hemorrhaging, reduced growth, and craniofacial malformations. Chronic exposure to retene resulted in mortality before swim up. Blue sac symptoms were observed in fish exposed to nominal concentrations as low as 32 μg/L, the lowest concentration tested, and fin erosion and opercular sloughing were evident in 100% of retene-exposed swim up larvae. No symptoms were observed in control fish or in fish exposed to acetone, the solvent carrier. The observed pathology resembles the toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin toxicity to developing stages of fish, and our results suggest that chronic exposure to polycyclic aromatic hydrocarbons may be responsible for recruitment failure associated with pulp mill effluents and oil spills.
Effect of burrowing by the crab helice crassa on chemistry of intertidal muddy sedimentsa
Authors: Williamson R Bruce , Wilcock Robert J , Wise Bridget E , Pickmere Stuart E 
Published: March 2010

Abstract
The chemical environment was measured in vertical and horizontal profiles of cores taken from intertidal sediments that are extensively burrowed by the mud crab Helice crassa. The crab burrows folded the thin (2–5 mm) oxic layer into the sediment, and the burrows appeared to have a strong influence on the concentrations of acid volatile sulfide (AVS), acid-extractable FeII (probably FeCO3 and FeS), FeIII (probably predominantly hydrous ferric oxide FeOOH), and MnII, III, IV and a modest effect on FeS2 but no effect on total organic carbon, total organic nitrogen, or acid-extractable zinc concentrations. The oxic layer was thinner in the burrows than on the sediment surface and showed some minor differences in solid-state chemistry, with higher FeOOH and lower FeS2 concentrations in the burrow walls. Acid volatile sulfide, FeCO3, and FeS2 were found in the oxic layers, presumably because of deposits from crab excavations of deeper anoxic sediments. The chemistry of the bioturbated profile was highly variable, not only because of existing burrows but also because of infilled abandoned burrows. The colors of the sediment profile were strongly related to the concentrations of FeII, AVS, FeIII, Mn, and FeS2. The implications of the observed sediment chemistry to the fate and bioavailability of contaminants is discussed.
Chlordane poisoning of birds in New Jersey, USA
Authors: Stansley William , Roscoe Douglas E 
Published: March 2010

Abstract
During a 16-month period in 1996–97, we documented chlordane poisoning in six species of songbirds and four species of raptors in New Jersey. Noteworthy among these cases are recurring mass mortalities of birds at suburban roosts. At one roost we recovered a total of 425 dead or sick birds comprised of 307 common grackles (Quiscalus quiscula), 104 European starlings (Sturnus vulgaris), and 14 American robins (Turdus migratorius) over a 3-week period in July 1997. Sick birds displayed signs consistent with cyclodiene poisoning, including convulsions, opisthotonos, and excessive vocalization. Brain metabolite residues indicative of chlordane poisoning were found in all 23 specimens analyzed. We believe this to be the largest chlordane poisoning incident reported in the United States. Chlordane poisoning was also diagnosed in nine Cooper's hawks (Accipiter cooperi), a statelisted endangered species. The timing of the Cooper's hawk mortalities coincides closely with the July peak in songbird mortalities, suggesting that the hawks might be feeding on birds debilitated by chlordane. The results of this and other studies suggest that chlordane poisoning of birds may be more common than is currently recognized.
Binding of glyphosate by open-chain polyammonium cations
Authors: Abate Lorenzo , Stefano Concetta De , Foti Claudia , Sammartano Silvio 
Published: March 2010

Abstract
Interaction of glyphosate (N-(phosphonomethyl)-glycine) with six polyamines (ethylendiamine, cadaverine, putrescine, triethylenetetramine, spermine, and tetraethylenepentamine) was studied potentiometrically. Several species of different stoichiometry are formed in the various systems, according to the general formation reaction (where A = amine and glp = glyphosate). The complex species formed are always with r = 1 … (n + 2) (n = maximum degree of protonation of amines). The stability of various complexes is a linear function of charges involved in the formation reaction, and can be expressed as logKij = 0.9(±0.2)ζ (where ζ = i[3 - j]). From the temperature dependence of formation constants, ΔH° (and TΔS°) values have been obtained. Formation percentages of mixed glyphosate—polyammonium cation complexes are relevant also in low concentration conditions, and this means that these species may play a significant role in the speciation of natural fluids containing the reactants.
Estimation of mercury-sulfide speciation in sediment pore waters using octanol—water partitioning and implications for availability to methylating bacteria
Authors: Benoit Janina M. , Mason Robert P , Gilmour Cynthia C 
Published: March 2010

Abstract
The octanol—water partioning of inorganic mercury decreased with increasing sulfide, supporting a model that predicts decreased fractions of neutral Hg—S species with increasing sulfide. These results help explain the decreased availability of Hg to methylating bacteria under sulfidic conditions, and the inverse relationship between sulfide and methylmercury observed in sediments.
Hydroxyatrazine in soils and sediments
Authors: Lerch, Robert N , Thurman, E Michael , Blanchard Paul E 
Published: March 2010

Abstract
Hydroxyatrazine (HA) is the major metabolite of atrazine in most surface soils. Knowledge of HA sorption to soils, and its pattern of stream water contamination suggest that it is persistent in the environment. Soils with different atrazine use histories were collected from four sites, and sediments were collected from an agricultural watershed. Samples were exhaustively extracted with a mixed—mode extractant, and HA was quantitated using high performance liquid chromatography with UV detection. Atrazine, deethylatrazine (DEA), and deisopropylatrazine (DIA) were also measured in all samples. Concentrations of HA were considerably greater than concentrations of atrazine, DEA, and DIA in all soils and sediments studied. Soil concentrations of HA ranged from 14 to 640 μg/kg with a median concentration of 84 μg/kg. Sediment concentrations of HA ranged from 11 to 96 μg/kg, with a median concentration of 14 μg/kg. Correlations of HA and atrazine concentrations to soil properties indicated that HA levels in soils were controlled by sorption of atrazine. Because atrazine hydrolysis is known to be enhanced by sorption and pH extremes, soils with high organic matter (OM) and clay content and low pH will result in greater atrazine sorption and subsequent hydrolysis. Significant correlation of HA concentrations to OM, pH, and cation exchange capacity of sediments indicated that mixed—mode sorption (i.e., binding by cation exchange and hydrophobic interactions) was the mechanism controlling HA levels in sediment. The presence of HA in soils and stream sediments at the levels observed support existing hypotheses regarding its transport in surface runoff. These results also indicated that persistence of HA in terrestrial and aquatic ecosystems is an additional risk factor associated with atrazine usage.
Cometabolic mineralization of benzo[a]pyrene caused by hydrocarbon additions to soil
Authors: Kanaly Robert A , Bartha Richard 
Published: March 2010

Abstract
The mineralization of [7-14C]benzo[a]pyrene (BaP) in soil was investigated in response to additions of individual hydrocarbons, defined hydrocarbon mixtures, crude oil, and crude oil fractions. Neither substantial BaP mineralization nor enrichment of BaP degraders occurred in BaP—spiked soil in the absence of a suitable hydrocarbon supplement. Crude oil, the saturated and aromatic class components of crude oil, the distillates heating oil, jet fuel, and diesel fuel supported up to 60% mineralization of 80 μg [7-14C]BaP per gram of soil in 40 d. Neither single hydrocarbons nor defined hydrocarbon mixtures containing normal and branched alkanes, alicyclics, and aromatics supported comparable BaP mineralization. Evolution of 14CO2 occurred after lag periods characteristic to specific petroleum products and their concentrations. Time required for microbial proliferation, hydrocarbon toxicity, and competitive inhibition might have contributed to these lag periods, but the complete inhibition of BaP mineralization by dieselfuel vapors pointed to a dominant role of competitive inhibition. A lack of radiocarbon incorporation into soil biomass from [7-14C]BaP indicated that at least the initial steps of BaP biodegradation in soil were cometabolic in nature. Suitable hydrocarbon mixtures not only supported BaP mineralization by serving as primary substrates, but also enhanced BaP bioavailability by dissolving this hydrophobic solid.
Movement and fate of residual mineral oil contaminants in bioremediated soil
Authors: Angehrn Daniel , Schluep Mathias , Gälli René , Zeyer Josef 
Published: March 2010

Abstract
After the bioremediation of soils contaminated with mineral oil products, residual contaminants (designated as total solvent extractable material [TSEM]) remain therein. Since limited information is available about the movement and fate of these residual contaminants in the environment, the potential environmental hazards are difficult to assess. The aim of this study was to identify and quantify the relevant transport and transformation processes of the residual contaminants in bioremediated soil such as volatilization, leaching, and further biodegradation and to conduct a mass flow analysis for the TSEM in bioremediated soil for the first year after application as top soil. The results indicate that after 1 year, the major portion (93%) of the TSEM can be recovered in the top soil and 7% of the TSEM was lost. The majority of the total losses (&gt;98%) was due to transformation processes (biodegradation and aging effects), while small amounts escaped into the atmosphere (0.08%), plant uptake was negligible, (&lt;0.001%) and leaching, identified as the major transport process, accounted for only small effects (1.7%).
Comparative toxicity of ammonium and nitrate compounds to pacific treefrog and african clawed frog tadpoles
Authors: Schuytema Gerald S , Nebeker Alan V 
Published: March 2010

AbstractThe effects of ammonium nitrate, ammonium chloride, ammonium sulfate, and sodium nitrate on survival and growth of Pacific treefrog (Pseudacris regilla [Baird and Girard]) and African clawed frog (Xenopus laevis [Daudin]) tadpoles were determined in static—renewal tests. The 10-d ammonium nitrate and ammonium sulfate LC50s for P. regilla were 55.2 and 89.7 mg/L NH4-N, respectively. The 10-d LC50s for X. laevis for the three ammonium compounds ranged from 45 to 64 μg/L NH4- N. The 10-d sodium nitrate LC50s were 266.2 mg/L NO3-N for P. regilla and 1,236.2 mg/L NO3-N for X. laevis. The lowest observed adverse effect level (LOAEL) of ammonium compound based on reduced length or weight was 24.6 mg/L NH4-N for P. regilla and 99.5 mg/L NH4-N for X. laevis. The lowest sodium nitrate LOAELs based on reduced length or weight were &lt;30.1 mg/L NO3-N for P. regilla and 126.3 mg/L NO3-N for X. laevis. Calculated un—ionized NH3 comprised 0.3 to 1.0% of measured NH4-N concentrations. Potential harm to amphibians could occur if sensitive life stages were impacted by NH4-N and NO3-N in agricultural runoff or drainage for a sufficiently long period.
Evaluation of the annual killifish Nothobranchius guentheri as a tool for rapid acute toxicity screening
Authors: Shedd, Tommy R , Widder Mark W , Toussaint Margaret W , Sunkel Mark C , Hull Eugene 
Published: March 2010

AbstractThis study evaluated the use of Nothobranchius guentheri as a novel organism for rapid acute toxicity screening. A major advantage of the species is that there is no need to maintain a continuous culture to have organisms immediately available for testing. Rather, the embryos are viable under long—term storage conditions and can be hatched within a few hours. The tests require only 24 h with standard laboratory equipment. Sensitivity levels for 11 representative toxicants were comparable to those reported for five of the standard U.S. Environmental Protection Agency test species requiring continuous culture.
Sex—specific vitellogenin production in immature rainbow trout
Authors: Carlson David B , Williams David E 
Published: March 2010

Abstract
Vitellogenin (Vg) was measured in sexually immature rainbow trout (Oncorhynchus mykiss) exposed to 17β-estradiol (E2) in the diet. Mixed—sex populations of trout aged 3, 6, 12, or 18 months were maintained separately and fed E2 at 0.05 or 2.5 mg/kg for 7 d. Females fed E2 at 0.05 mg/kg consistently produced three- to fourfold greater amounts of Vg than similarly aged males. Age- and sex—matched fish fed E2 at 2.5 mg/kg produced equivalent amounts of Vg. Sex differences in Vg production were apparent only at a dose of E2 (0.05 mg/kg) that results in submaximal Vg induction. Our results document the importance of considering the sex of juvenile fish when using Vg production as a marker of xenoestrogen exposure.
An index of effluent aquatic toxicity designed by partial least squares regression, using acute and chronic tests and expert judgements
Authors: Vindimian ÉRIC , Garric Jeanne , Flammarion Patrick , Thybaud Éric , Babut Marc 
Published: March 2010

Abstract
The evaluation of the ecotoxicity of effluents requires a battery of biological tests on several species. In order to derive a summary parameter from such a battery, a single endpoint was calculated for all the tests: the EC10, obtained by nonlinear regression, with bootstrap evaluation of the confidence intervals. Principal component analysis was used to characterize and visualize the correlation between the tests. The table of the toxicity of the effluents was then submitted to a panel of experts, who classified the effluents according to the test results. Partial least squares (PLS) regression was used to fit the average value of the experts’ judgements to the toxicity data, using a simple equation. Furthermore, PLS regression on partial data sets and other considerations resulted in an optimum battery, with two chronic tests and one acute test. The index is intended to be used for the classification of effluents based on their toxicity to aquatic species.
Reactions of resorcinol and its chlorinated derivatives with monochloramine: Identification of intermediates and products
Authors: Heasley Victor L , Alexander Michael B , Deboard Ryan H , Hanley John C , McKee Tawnya C , Wadley Brian D , Shellhamer Dale F 
Published: March 2010

Abstract
An investigation of the reaction of resorcinol (compound 1) and its chlorinated derivatives 4-chlororesorcinol (compound 4), 4,6-dichlororesorcinol (compound 5), and 2,4,6-trichlororesorcinol (compound 2) with monochloramine (NH2Cl) in ether and aqueous solution (pH 7) is reported. NH2Cl reacted with compounds 1, 2, 4, and 5 to give the pentachloro intermediate, 2,2,4,4,6-pentachloro-5-cyclohexen-1,3-dione (compound 3), which underwent ring opening with H2O and loss of CO2 in the presence of NH2Cl to produce the following: 1,1,3,5,5-pentachloro-3-penten-2-one (compound 6), 1,1,1,3,5,5-hexachloro-3-penten-2-one (compound 7), and 1,1,3,5,5,5-hexachloro-3-penten-2-one (compound 8). Compound 6 reacted further with NH2Cl to give compounds 7 and 8; in the presence of NH2Cl, compound 7 rearranged to compound 8. Mechanisms for the preceding reactions are analyzed in detail. Another aspect of the investigation involved a determination of the amounts of chloroform, CHCl3, which is produced from compound 3 with NH2Cl (4%) and with NaOCl (50%). The low production of CHCl3 from compound 3 and NH2Cl is discussed in connection with the probable reactions of compounds 7 and 8 with NH2Cl and H2O.
Influence of dissolved organic matter on the toxicity of copper to Ceriodaphnia dubia: Effect of complexation kinetics
Authors: Kim Sang Don , Ma Huizhong , Allen Herbert E , Cha Daniel K 
Published: March 2010

Abstract
The reaction kinetics of copper interaction with dissolved organic matter (DOM) in water were studied in order to determine the effect of equilibration period on the toxicity of copper to aquatic organisms. The changes in physical and chemical forms of the copper during four reaction times were examined in four completely mixed reactors in series; the bioavailability of the copper as a function of these new forms was then determined with a flow-through bioassay system, using Ceriodaphnia dubia as a test organism. This study showed that the toxicity of copper to C. dubia decreased with increasing copper-DOM reaction time, which demonstrated that the copper reaction rate with dissolved organic components in the test water was slow. The toxicity of copper to C. dubia was closely related to the measured free-copper concentration (Cu2+) rather than to the total copper concentrations, a fact that supports the free ion activity model. We found that the LC50 of copper for C. dubia increased (i.e., toxicity decreased) linearly with increasing total available binding sites. Although a similar trend was observed in both natural DOM and commercial humic acid, our results indicated that for a given copper-organic carbon ratio, copper binds more strongly to humic acid than to the natural DOM. This difference may be attributed to the greater copper binding affinity of humic acid (greater than that of other metal-binding organic fractions present in DOM, i.e., fulvic acid).
Concentration, distribution, and bioavailability of mercury and methylmercury in sediments of Baltimore Harbor and Chesapeake Bay, Maryland, USA
Authors: Mason Robert P , Lawrence Angie L 
Published: March 2010

Abstract
For the Chesapeake Bay, sediments in regions such as Baltimore Harbor have total mercury (Hg) concentrations that exceed environmental effects guidelines. However, fish concentrations do not appear elevated. Indeed, the factors controlling the transfer of sedimentary Hg, especially as monomethylmercury (MMHg), the most bioaccumulative form of Hg, to these aquatic organisms are poorly understood. To examine this, we have investigated the distribution and bioavailability of Hg and MMHg to benthic organisms in Baltimore Harbor and the Chesapeake Bay, in Maryland, USA. The results discussed here show that sediment concentration for both total Hg and MMHg covaries with sediment organic content and that this parameter is a better predictor, for surface sediments, of concentration than iron content, acid volatile sulfide (AVS), or other factors. Furthermore, correlations between inorganic Hg and MMHg in benthic biota with sediment levels suggest that variation in the bioaccumulation factor (SBAF) for invertebrates is best explained in terms of sediment organic content. Thus, the results from this study emphasize the importance of organic matter in regions removed from point source input in controlling both the concentration and bioavailability of MMHg to organisms. Because of the exponential nature of the SBAF/organic content relationship, there is a nonlinear organism response to MMHg in sediments that must be considered in any estimation of the toxic effect of sediment MMHg. Also, as a result of the decoupling between total Hg and MMHg concentration and bioavailability in surface sediments, any remediation evaluation of bioavailability and/or toxicity that is based only on total Hg concentration is unlikely to provide a reliable prediction.
Biodegradation rates of separated diesel components
Authors: Olson Jennifer Jean , Mills Gary L , Herbert Bruce Eric , Morris Pamela J 
Published: March 2010

Abstract
Three hydrocarbon classes (n-alkanes, branched and cyclic alkanes, and aromatics) were separated from diesel fuel and used as hydrocarbon treatments during a 35-d batch culture experiment in which biodegradation rates of the individual classes were quantified and compared with the biodegradation rate of a treatment consisting of a composite of the three fractions. Triplicate batch cultures of each hydrocarbon treatment were sampled on experimental days 0, 3, 7, 15, and 35. The microbial inoculum used in this study was a crude oil-degrading culture isolated from a contaminated soil. As the experiment proceeded, microbial populations were estimated by total heterotrophic plate counts. Hydrocarbon concentrations were quantified by GC with flame ionization detection, and specific compound identification was confirmed by GC-MS. The composite treatment was separated into aliphatic and aromatic fractions before hydrocarbon analysis. After 35 d, the relative biodegradation for each hydrocarbon class was as follows: n-alkanes &gt; aliphatic fraction of composite solution &gt; aromatics &gt; branched and cyclic alkanes &gt; aromatic fraction of composite solution. In the composite treatment, biodegradation of both aromatic and aliphatic fractions was observed during the 35-d study period and thus did not follow a clear pattern of sequential degradation. However, the biodegradation rate for the aromatic fraction was significantly slower than the aliphatic fraction.
Effects of polychlorinated biphenyl 126 on green frog (Rana clamitans) and leopard frog (Rana pipiens) hatching success, development, and metamorphosis
Authors: Rosenshield Michele Laura , Jofré Mariana Beatriz , Karasov William Henry 
Published: March 2010

AbstractAlthough increasing evidence links planar chlorinated hydrocarbons, such as polychlorinated biphenyls (PCBs), to decreases in survival and reproduction of fish, mammals, and birds near Green Bay, Wisconsin, and the Great Lakes, USA, relatively little is known of their bioaccumulation or of their possible effects in amphibians. We exposed embryos and larvae of two ranid species commonly occurring in the Green Bay ecosystem, the green frog (Rana clamitans) and the leopard frog (Rana pipiens), to PCB 126, a model coplanar PCB compound. Nominal concentrations ranged from 0.005 to 50 μg/L, and exposure lasted through metamorphosis. Tissue concentrations of PCB 126 in tadpoles that did not metamorphose by the end of the experiment ranged from 1.2 to 9,600 ng/g wet mass. No significant mortality of embryos occurred before hatching; however, survival of larvae was significantly reduced at the highest concentration for both species. Few deformities were observed, but the incidence of edema was significantly higher in tadpoles exposed to 50 μg/L. Swimming speed and growth of tadpoles was also significantly reduced in this treatment. The percent of tadpoles that reached metamorphosis was significantly lower in green frogs at the highest concentration, and no leopard frogs survived past day 47 of the experiment in this treatment. At high concentrations, PCB 126 affected both ranid species; however, sublethal effects were not apparent for the parameters we measured at concentrations that occur in water in the Green Bay ecosystem.