bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wetland risk assessment
Authors: Pascoe Gary A. 
Published: March 2010

Abstract
Wetlands represent unique environments for assessing ecological risks. Habitats may vary from riverine to basin type and include such diverse media as surface waters, sediments, soils, and ground water, with both terrestrial and aquatic biota. Given the diversity of wetland habitats, a number of species may be expected to be fairly unique to a particular site. Wetland ecosystems may be impacted by chemical contamination or by nonchemical stressors such as temperature or suspended solids. A key to assessing ecological risks to chemically contaminated wetlands is determining the degree of contaminant bioavailability from multiple environmental media. Chemical and physical factors of the various wetland habitats must be evaluated for their role in chemical release, transformation, and availability. Approaches to assessing ecological risks may extend from simple benchmark or literature comparisons to direct measurement of exposure and toxicity through laboratory and/or field tests. To increase the utility of wetland risk assessments, the uncertainty inherent in the complex habitats and in the chemistry that governs contaminant bioavailability should be minimized. This can be most readily accomplished by applying an assessment methodology triad of ecology, chemistry, and toxicology to characterize ecological risks. Literature toxicity information and laboratory and field data are used to evaluate potential threats to individuals or species in each trophic level of the wetland food web. The ecological data are integrated with this information to assess whether the concentrations of contaminants and the observed or predicted toxicity relate to actual ecological effects. The ecological relevance of the expected or measured biological responses is of prime importance in predicting risks to the wetland ecosystem. Applications of this approach to risk assessments are presented as case studies of metals-contaminated wetlands at Milltown Reservoir, Montana, and Kesterson Reservoir, California.
Organic carbon partitioning as a basis for predicting the toxicity of chlorpyrifos in sediments
Authors: Ankley Gerald T. , Call Daniel J. , Cox Julie S. , Kahl Michael D. , Hoke Robert A. , Kosian Patricia A. 
Published: March 2010

Abstract
The objective of this study was to evaluate an organic carbon partitioning model for predicting bioavailability of the organophosphate chlorpyrifos in sediments, in support of the development of a sediment-quality criterion for the pesticide. Initial 10-d water-only toxicity tests were conducted with the midge Chironomus tentans to define the sensitivity of this species to chlorpyrifos. Two uncontaminated sediments with differing organic carbon contents (approximately 3 and 8.5%) were spiked with varying amounts of chlorpyrifos designed to result in equilibrium interstitial (pore) water concentrations that would bracket the effects concentrations observed in the water-only exposures. Ten-day toxicity tests with Chironomus tentans were conducted with the spiked sediments under conditions similar to those in the water-only exposure. Based on predicted pore-water concentrations of chlorpyrifos, results of the water-only and sediment tests were in close agreement. The water-only LC50 of chlorpyrifos to Chironomus tentans was 70 ng/L, whereas LC50 values based on predicted pore-water concentrations in the two test sediments were 40 and 70 ng/L. Total concentrations of chlorpyrifos measured in pore water from the test sediments were always at least an order of magnitude greater than predicted pore-water concentrations of the pesticide. However, upon correction for that fraction of the measured chlorpyrifos potentially bound to DOC in the pore water, measured and predicted chlorpyrifos concentrations were in much closer agreement, with the former typically about threefold greater than the latter. Overall, these results suggest that within the range of organic carbon tested in the present study, an equilibrium partitioning model based on organic carbon is appropriate for predicting the bioavailability of sediment-associated chlorpyrifos to benthic invertebrates.
Degradation of silicone polymers in soil
Authors: Lehmann R.G. , Varaprath S. , Frye C.L. 
Published: March 2010

Abstract
Silicone polymers (polydimethylsiloxanes, or PDMS) are used in numerous personal care and household products, eventually enter wastewater treatment plants, and are later applied to the land as a component of sludge. The fate of silicones in soil is largely unknown, but this study shows that in a moist (0.2 MPa = 12% moisture) Londo sandy clay loam, 200 centi-stoke (cs)14C-labeled PDMS degraded slowly over six months to yield about 3% of applied 14C as low-molecular-weight, water-soluble products. When the soil was allowed to dry in one week from 12 to 3% moisture, the degradation rate was much more rapid, and after several days at 3 % moisture about half of the applied 14C was water desorbable. HPLC-GPC of tetrahydrofuran (THF) soil extracts showed that PDMS had been degraded to low-molecular-weight molecules of the general formula HO-[Si(CH3)2O]n-H. The range of moistures in this experiment was measured in a field of Londo sandy clay loam during the summer of 1992, indicating that PDMS should be unstable in the soil environment. Further work on the identification and biological degradation of these small products is ongoing.
Exposure of fish to biologically treated bleached-kraft effluent. 1. Biochemical, physiological and pathological assessment of rocky mountain whitefish (prosopium williamsoni) and longnose sucker (catostomus catostomus)
Authors: Kloepper-Sams P.J. , Swanson S.M. , Marchant T. , Schryer R. , Owens J.W. 
Published: March 2010

AbstractA suite of biochemical, physiological, and pathological measures was used to assess possible effects of exposure to bleached-kraft mill effluent (BKME) on wild longnose sucker (Catostomus catostomus) and mountain whitefish (Prosopium williamsoni) in the Wapiti/Smoky river system, as compared to similar populations in a reference river system without BKME inputs. Individual fish body burden data (i.e., metals, polychlorinated dioxins and furans, fatty and resin acids, chlorophenolics) were examined for correlations between chemical exposure and biological response. General incidence of gross pathology and histopathology showed no relationship with exposure to BKME, and no neoplastic or preneoplastic lesions were observed in either exposed or reference fish. The few significant differences observed in longnose sucker blood parameters were not correlated with exposure to BKME and appeared to reflect, at least in part, habitat gradients. Liver somatic indexes were higher for female BKME-exposed longnose sucker, but were not significantly different in male sucker nor in mountain whitefish. Some differences in circulating sex steroid levels were observed in longnose sucker exposed to BKME (but not in mountain whitefish, the species with higher contaminant body burdens). Steroid profile differences may have been related to natural differences in duration of spawning periods in the two fish populations. Other measures of reproductive capacity (relative gonad size, fecundity, young-of-the-year) showed no reductions in exposed fish. The detoxification enzyme cytochrome P4501A was induced in both species, with greater induction in whitefish than in longnose sucker. Whitefish P4501A induction correlated well with some BKME exposure measures, but not with liver or gonad weights, pathology, reproductive capacity, or population-level parameters. Increased liver size and apparent differences in sex steroid profiles in longnose sucker did not translate to other health effects or population-level effects. Thus, exposure to this biologically treated BKME produced one consistent biochemical marker of exposure (P4501A) in the two fish species that was not associated with any discernible adverse effects on individual fish health.
Uptake of chlordane by a deposit-feeding bivalve: Does the depth of sediment contamination make a difference?
Authors: Wilcock Robert J. , Pridmore Rick D. , Northcott Grant L. , Hewitt Judi E. , Thrush Simon F. , Cummings Vonda J. 
Published: March 2010

Abstract
Intertidal sediment was treated with technical chlordane (11 ppb) and combined with untreated natural sediment in small containers to produce a range of contaminant depth profiles (viz, top 2 cm [only] treated, all except the top 2 cm treated, all treated, all untreated) Adult specimens of Macomona liliana (a tellinid bivalve) were placed in some of the containers All of the containers were immersed in seawater and exposed to an artificial semidiurnal tidal regime over 5 d Approximately 24 to 36% of the applied chlordane was lost from the sediments presumably dissolved in the recirculating seawater Losses of chlordane were generally greater when shellfish were present, possibly through transport to the sediment surface and subsequent solubilization in seawater Macomona liliana accumulated the greatest concentration of chlordane (5,728 ppb lipid) from sediments having a uniform concentration of chlordane (7 ppb at the end of the experiment), whereas those in containers with either the top 2 cm treated or all but the top 2 cm treated, accumulated 3,617 and 2 756 ppb lipid, respectively The shellfish body burden accounted for only a small proportion (≤1%) of the total chlordane in each of the containers Chlordane depth profiles were not as well defined in the sediments having Macomona liliana, as those that did not These results indicate that Macomona liliana can assimilate organochlorines bound to sediments at depths below 2 cm, most probably by ingestion Animals constantly exposed to contaminated sediment accumulated more than those able to feed alternately on contaminated and uncontaminated sediments The ability of Macomona liliana to accumulate and depurate contaminants throughout the sediment profile may in crease the chances of more sensitive species being exposed to harmful concentrations
Responses of Hyalella azteca and chironomus tentans to particle-size distribution and organic matter content of formulated and natural freshwater sediments
Authors: Suedel Burton C. , Rodgers John H. 
Published: March 2010

Abstract
The freshwater amphipod, Hyalella azteca (Saussure), and midge, Chironomus tentans (Fabricius), were exposed to formulated sediments and nontoxic field collected sediments for 10 d to determine their responses to varying sediment particle sizes (0 to 100% sand, 0 to 100% silt, 0 to 60% clay) and organic matter content (0 12 to 7 8%) of freshwater sediments In experiments with formulated sediments, H azteca survival was &gt;80% when exposed for 10 d to all particle size regimes exammed Subsequent exposures of H azteca to field collected sediments resulted in &gt;80% H azteca survival in all sediments Field collected sediments with organic matter content ranging from 0 12 to 7 8% yielded no observed effects on amphipod survival, which ranged from 84 to 100% Survival of C tentans ranged from 4 to 56% when exposed to formulated sediments for 10 d with 0% particulate organic matter content A threshold organic matter content between 0 76 and 0 91% was observed for C tentans exposed to formulated and field collected sediments Chironomus tentans survival was &gt;80% in all cases when exposed to various particle size regimes in formulated sediments containing 2 5% particulate organic matter Formulated sediments were suitable for determining H azteca and C tentans responses to particle size regimes and organic matter content of sediments, as test results using formulated and natural sediments were in agreement Except for C tentans observed intolerance of &lt;0 76 to 0 91% organic matter content of sediments, C tentans and H azteca are suitable benthic toxicity testing organisms for determining the potential toxicity of sediments with a wide range of particle size regimes and organic matter content
Avian nesting success and diversity in conventionally and organically managed apple orchards
Authors: Fluetsch Kimberly Morgan , Sparling Donald W. 
Published: March 2010

Abstract
This study examines the effects of operational use of pesticides on avian species inhabiting apple orchards in Pennsylvania Mourning dove (Zenaida macroura) and American robin (Turdus migratorius) nests were monitored in three organic and three conventional apple orchards during 1990 and 1991 In 1991 we surveyed the avian communities of these orchards by using line transects Organophosphorus (OP) (e g, azinphos methyl, phosphamidon, parathion, dimethoate), carbamate (CA) (e g, methomyl, formetanate, oxamyl), and organochlorine (endosulfan) pesticides, known to be highly toxic to birds, were sprayed individually or in mixtures as part of routine pest management as many as 19 times during peaks in breeding activity Spray card tests revealed that OP pesticides were deposited on 86% of the nests in conventional orchards Daily survival rates (DSRs) for nests of both species were higher in the organic orchards than in the conventional orchards for 1991 and for years combined ( p &lt; 0 05) Species diversity was greater in the organic orchards ( H = 2 43) than in the conventional orchards ( H = 1 79) Repeated applications of pesticides within the conventional orchards reduced the reproductive success of doves and robins and may have lowered avian species diversity compared with organic orchards
Planning and implementation of a comprehensive ecological risk assessment at the milltown reservoir-clark fork river superfund site, montana
Authors: Pascoe Gary A. , Dalsoglio Julie A. 
Published: March 2010

Abstract
The U.S. Environmental Protection Agency (EPA) initiated an innovative ecological risk assessment program at the Milltown Reservoir-Clark Fork River Sediments Superfund Site in 1989. The site is located in the Clark Fork River (CFR) basin of western Montana, and consists of 160 km (100 miles) of the CFR and an 820-acre wetland at Milltown Reservoir. The focus of the assessment was to identify chronic risks to ecological receptors from metals-contaminated sediments that have deposited in aquatic and terrestrial habitats of the site. Lack of established sediment or soil quality criteria, the extent of habitats within the watershed, and anticipated complex sediment and soil chemistry led to a unique laboratory and field-based approach for the baseline risk assessment. Study tasks evaluated aquatic, wetland, and terrestrial habitats across multiple trophic levels. The risk assessment integrated the results of these studies as a triad of chemical, toxicological, and ecological information. The comprehensive nature of the risk assessment was designed to help determine a remedial action for the wetland operable unit and set the basis for additional studies in the upper Clark Fork River watershed. As the problem formulation step in the EPA's risk assessment methodology, this article describes the background of the site, the approach and conceptual model for the risk assessment, and the planning process for implementing the various field and laboratory studies.
Effects of PCDDs, PCDFs and PCBs in common tern (sterna hirundo) breeding in estuarine and coastal colonies in the netherlands and belgium
Authors: Bosveld A.T.C. , Gradener J. , van Den Berg M. , Murk A.J. , Brouwer A. , van Kampen M. , Evers E.H.G. 
Published: March 2010

Abstract
In 1991, eggs of the common tern (Sterna hirundo) were collected at eight different locations and incubated artificially. The residual yolk sacs of the hatchlings from the highly polluted colonies, located in the main sedimentation area of the Rhine and Meuse rivers, contained on average 16 ng TEQ (toxicity equivalency) per gram lipid, which was fivefold higher than the concentrations in the reference colony. The hepatic EROD activity was induced fourfold compared to the reference colony (p &lt; 0.005). At the individual level, a significant relationship was found between log TEQ and both log EROD and log PROD (r = 0.568, p &lt; 0.05 and r = 0.661, p &lt; 0.02, respectively). Average TEQ concentration in chicks that hatched after 23 d of incubation were twice the concentration of those that hatched after 21 d (p &lt; 0.05). No concentration-related effects on morphology and physiology were found. The non-ortho- and mono-ortho-PCBs were predominant regarding the total TEQ, while the PCDDs and PCDFs contributed less than 10%. The PCB patterns were highly similar among the individual birds and among different locations. In contrast, PCDD and PCDF patterns were not similar at all locations, and two distinct patterns could be recognized and related to sediments that were deposited during different time periods.
Kinetics of alachlor and atrazine biotransformation under various electron acceptor conditions
Authors: Wilber Gregory G. , Parkin Gene F. 
Published: March 2010

Abstract
Second-order rate constants were developed for the biotransformation of the herbicides atrazine and alachlor under aerobic, nitrate-reducing, sulfate-reducing, and methanogenic conditions. Batch-reactor techniques were used, with seed cultures taken from acclimated biofilm columns. The reactors were fed acetate as a primary substrate. Pesticide biotransformation appeared to depend upon the continued presence of the primary substrate, indicating co-metabolic transformations. All four electron acceptor conditions tested resulted in some biotransformation of both pesticides. Rate constants for alachlor ranged from 6.25 × 10−5 to 1.60 × 10−4 L/mg volatile suspended solids (VSS)·h, with the highest rate constant occurring under sulfate-reducing conditions, and the lowest under methanogenic conditions. Rate constants for atrazine ranged from 1.04 × 10−5 to 3.32 × 10−5 L/mg VSS·h, although differences among the four electron acceptor conditions were not statistically significant.
Enhanced mineralization of organic compounds in nonaqueous-phase liquids
Authors: Labare Michael P. , Alexander Martin 
Published: March 2010

Abstract
Biodegradation of phenanthrene, biphenyl, or di(2 ethylhexyl) phthalate initially present in a variety of nonaqueous phase liquids (NAPLs) was slow in samples of soil and aquifer solids The NAPLs were hexadecane, dibutyl phthalate, 2,2,4,4,6,8,8-heptamethylnonane, cyclohexane, commercial oils, crude oil, creosote, and kerosene Slurrying the soil or aquifer solids markedly enhanced the rate and extent of mineralization of the test compounds initially in many of the NAPLs Both the low rate and the extent of mineralization of the three compounds initially in dibutyl phthalate in soil slurries and of di(2 ethylhexyl) phthalate in heptamethylnonane present in slurries of aquifer solids were increased by inoculation of acclimated microbial cultures Increasing the NAPL volume decreased phenanthrene biodegradation in soil, but the effect of larger NAPL volume could be alleviated by slurrying and inoculation The rate or extent of mineralization in aquifer slurries of di(2-ethylhexyl) phthalate initially in some NAPLs was increased by addition of N and P, and inoculation further enhanced the degradation
Uptake, distribution and elimination of 54Mn(II) in the brown trout (Salmo trutta)
Authors: Rouleau Claude , Tjälve Hans , Gottofrey James , Pelletier ÉMilien 
Published: March 2010

Abstract
Brown trout (Salmo trutta) were exposed to water containing 0.1 μg·L−1 (1.8 nmol·L−1) of 54Mn(II) for 1, 3, or 6 weeks. Additional trout were exposed for 3 weeks and allowed to depurate for 1 or 3 weeks. Both the uptake and the organ distribution of manganese (Mn) were determined by gamma counting and whole-body autoradiography. Steady-state concentration, Css, and biological half-life, t1/2, were calculated. The whole-body Mn concentration (1.78 μg·kg−1) reached after 6 weeks of exposure was close to Css (1.88 μg·kg−1) and t1/2 was 9.6 d. Manganese concentration in tissues followed the decreasing order liver &gt; viscera without liver and kidney &gt; gills &gt; skin, fins, bones, and head excluding gills, brain, and eyes &gt; kidney ≈ epidermal mucus &gt; brain &gt; eyes &gt; muscle. Autoradiograms indicated high Mn concentrations in the pancreatic tissue, skeleton, gastrointestinal mucosa, and olfactory system. Gills, viscera, and eyes (t1/2 = 3.7 to 8.8 d) were near steady state after 6 weeks of exposure, while the other tissues were not (t1/2 = 14.6 to 26.4 d). The depuration rate of total radioactivity was relatively rapid initially as 22% of Mn content was lost during the first week, and became slower in the following 2 weeks. Participation of Mn in enzymatic activities of liver, pancreas, and gastrointestinal mucosa may explain its high uptake in these tissues, whereas accumulation in the skeleton seems to be related to bone formation. The uptake of Mn by way of olfactory system favoured its accumulation in the brain of trout. As Mn is known to be neurotoxic, we suggest this route of uptake could be of toxicological significance for fish.
Effects of dimilin® application on white-footed mouse populations in a central appalachian forest
Authors: Seidel George E. , Whitmore Robert C. 
Published: March 2010

Abstract
Densities, food habits, and physical condition of white-footed mice (Peromyscus leucopus) were examined on 10 Dimilinr̀-treated and 10 untreated areas in 1985 and 1986. Estimates of mouse density did not differ significantly (p &gt; 0.05) between treated and untreated areas. However, juvenile/adult female ratios on untreated areas were significantly higher (p &lt; 0.05) than those on treated areas. Mice on treated areas consumed less lepidopteran prey than did mice on untreated areas (p &lt; 0.05), but the total amount of food consumed per mouse did not differ significantly between treated and untreated areas (p &gt; 0.05); mice in treated areas apparently compensated for the loss of lepidopterans by using other food sources more heavily. Body measurements, weight, and fat content of mice did not differ (p &gt; 0.05) between treated and untreated areas.
EROD induction in cultured chick embryo liver: A sensitive bioassay for dioxin-like environmental pollutants
Authors: Brunström Björn , Engwall Magnus , Hjelm Katarina , Lindqvist Lars , Zebühr Yngve 
Published: March 2010

Abstract
A technique for studying 7-ethoxyresorufin O-deethylase (EROD) induction in chick embryo liver in vitro was developed. Livers from 8-d-old embryos were cultured in rotating vials at 37°C for 48 h in a medium to which DMSO-dissolved test compounds had been added. This bioassay proved to be highly sensitive to dioxin-like compounds, and its usefulness for assessing the toxic potency of such compounds in environmental samples was demonstrated. Concentration-response curves were determined for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3,3′,4,4′,5-pentachlorobiphenyl (PCB IUPAC no. 126), 3,3′,4,4′-tetrachlorobiphenyl (PCB 77), 2,3,3′,4,4′-pentachlorobiphenyl (PCB 105), and benzo[k]fluoranthene (BkF). TCDD induced EROD in a concentration-dependent manner, having an EC50 of 5.0 × 10−12 M. The cultured embryo livers were extremely sensitive to TCDD, and about 30 fg of this compound per liver (2 × 10−13 M) was enough to significantly induce EROD. The EC50 values obtained for PCBs 126, 77, 105, and BkF were 4.4 × 10−11 M, 9.2 × 10−9 M, 1.6 × 10−8 M, and 6.2 × 10−7 M, respectively. The maximal induction levels obtained for three different preparations of polychlorinated naphthalenes (PCNs) were less than those of the other compounds tested. When the technical PCN mixture Halowax 1014 was coadministered with TCDD, the induction was lower than that caused by TCDD alone. An organic extract of fly ash from a municipal waste combustion plant was very potent. Considering its contents of polychlorinated dibenzo-p-dioxins/furans, expressed as TCDD equivalents, the EC50 obtained was close to that for TCDD.