bluuebunny/crossref_metadata_2025 huggingface dataset:
A framework for ecological risk assessment at the EPA
Authors: Norton Susan B. , Rodier Donald J. , van der Schalie William H. , Wood William P. , Slimak Michael W. , Gentile John H.
Published: March 2010

Ecological risk assessments evaluate the likelihood of adverse ecological effects caused by stressors related to human activities such as draining of wetlands or release of chemicals. The term stressor is used to describe any chemical, physical, or biological entity that can induce adverse effects on ecological components (i.e., individuals, populations, communities, or ecosystems). In this review article, a historical perspective on ecological risk assessment activities at the U.S. Environmental Protection Agency (EPA) is followed by a discussion of the EPA's “Framework Report,” which describes the basic elements for conducting an ecological risk assessment. The “Framework Report” is neither a procedural guide nor a regulatory requirement within the EPA. Rather, it is intended to foster a consistent approach to ecological risk assessments within the Agency, identify key issues, and define terminology.
A european perspective on ecological risk assessment, illustrated by pesticide registration procedures in the united kingdom
Authors: Greig-Smith Peter W.
Published: March 2010

This paper reviews some of the principles and critical issues for ecological risk assessment applied to the effects of chemical contaminants, using pesticide registration in the United Kingdom as an example. This subject is topical in Europe due to initiatives for harmonization of registration procedures in the European Community, and recent advances in technical aspects of risk assessment. A distinction is drawn between contamination arising from deliberate, planned releases and accidental releases. In both cases, the emphasis is on the development of consistent yet flexible decision-making procedures in which uncertainty is recognized and a role for expert judgment preserved. This approach allows for risk assessment tailored to the characteristics of particular chemicals and to the purposes of the assessment. A set of 10 issues that are important in the design and operation of decision-making procedures is discussed. An outline is given of the way in which these procedures have been incorporated into a new scheme for the assessment of the environmental effects of plant protection products by the European and Mediterranean Plant Protection Organization (EPPO) and the Council of Europe. Criteria for deciding the acceptability of proposed chemical uses are described. Finally, some likely future developments for ecological risk assessment procedures in this field are discussed.
Of measured risks: The environmental impacts of the Prudhoe Bay, alaska, oil field
Authors: Maki Alan W.
Published: March 2010

The 20th anniversary of the filing of the Trans-Alaska Pipeline System (TAPS) Environmental Impact Statement (EIS) affords an opportunity to assess retrospectively the environmental impacts of the resultant North Slope oil fields, now the largest single source of U.S. domestic oil production. As the oil field expanded, particularly to near-shore areas such as the Endicott Development, additional EIS documents were prepared to assess impacts not included in the original TAPS EIS. In the ensuing years, numerous agency-monitored and industry-sponsored environmental monitoring studies, estimated to average $4 million per year, have been conducted in and around the oil field, making the Alaskan North Slope one of the most studied environments in North America.

In this paper, the EIS requirement of the National Environmental Policy Act (NEPA) is examined as a predictive environmental risk assessment. A tabulated summary of the predicted environmental impacts from the original TAPS and offshore Endicott Development EIS documents is compared with the extensive amount of resultant monitoring data. These data confirm localized impacts to air and water quality; however, regulated discharges remain well below criteria established for the protection of human health and the environment. As predicted, some unavoidable habitat losses to resident and migratory wildlife have occurred within the oil field and pipeline corridors. Approximately 2% of the land surface in developed portions of the oil field was actually altered. However, careful monitoring of wildlife populations demonstrates that no species has experienced a measurable decline, and most continue to utilize oil field habitat for breeding, nesting, and summer forage. As habitat does not appear to be limiting the growth of North Slope caribou herds, the Central Arctic Herd has been able to accommodate the incremental habitat loss due to the oil field and has shown a sevenfold increase in numbers since the oil field development began in the early 1970s. Offshore monitoring data for the gravel causeways verify the predicted small, localized effects on water circulation and show the possibility is low that fish are experiencing resulting significant negative effects.

The challenge faced in the EIS process is not how to ensure zero impact, as this is not a realistic goal, but instead it is how to predict impacts and describe mitigation measures accurately to ensure that the resultant ecological responses remain within a normal range of ecosystem oscillations that can be used to describe sustainable development. This review demonstrates that in the EIS process, a well-designed program using the best available field data can indeed provide a relatively accurate prediction of subsequent impacts.
Toxicokinetics in aquatic systems: Model comparisons and use in hazard assessment
Authors: Landrum Peter F. , Lydy Michael J. , Lee Henry
Published: March 2010

Toxicokinetic models are not constrained by assumptions of equilibrium as are thermodynamic (equilibrium-partitioning) models and are more accurate predictors of toxicant accumulation for non-steady-state exposures and multiple uptake routes. Toxicokinetic models – compartment-based models, physiological-based models, and energetics-based models – are reviewed and the different mathematical formalisms compared. Additionally, the residue-based toxicity approach is reviewed. Coupling toxicokinetic models with tissue concentrations at which toxicity occurs offers a direct link between exposure and hazard. Basing hazard on tissue rather than environmental concentrations avoids the errors associated with accommodating multiple sources, pulsed exposures, and non-steady-state accumulation.
Determination of PCDDs, PCDFs, and PCBs in California peregrine falcons (Falco peregrinus) and their eggs
Authors: Jarman Walter M. , Burns Stephanie A. , Chang Ruth R. , Stephens Robert D. , Norstrom Ross J. , Simon Mary , Linthicum Janet
Published: March 2010

Levels of organochlorine compounds; polychlorinated biphenyls (PCBs), including non-ortho congeners; polychlorinated dibenzo-p-dioxins (PCDDs); and polychlorinated dibenzofurans (PCDFs) were determined in seven California peregrine falcon eggs (Falco peregrinus) collected from five sites between the years 1983 to 1988; one immature falcon was analyzed for PCDDs and PCDFs only. All of the identified PCDDs and PCDFs were 2,3,7,8-substituted. The major PCDD and PCDF congeners identified in the eggs were 1,2,3,7,8-pentachlorodibenzo-p-dioxin (1,2,3,7,8-PnCDD) at a geometric mean (mean) value of 11 ng/kg, 1,2,3,6,7,8-hexachlorodibenzo-p-dioxin (1,2,3,6,7,8-HxCDD) at a mean value of 11 ng/kg, 2,3,7,8-tetrachlorodibenzofuran (TCDF) at a mean value of 6.2 ng/kg, and 2,3,4,7,8-pentachlorodibenzofuran (2,3,4,7,8-PnCDF) at a level of 6.5 ng/kg. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) was present at a mean value of 5.7 ng/kg. Values of p,p′-DDE in the eggs ranged from 7,100 to 26,000 μg/kg, with a mean value of 12,000 μg/kg. ΣEPCB levels ranged from 1,400 to 13,000 μg/kg, with a mean value of 4,800 μg/kg. The mean values of the non-ortho congeners 3,4,4′-trichlorobiphenyl (PCB 37); 3,3′,4,4′-tetrachlorobiphenyl (PCB 77); 3,3′4,4′5-pentachlorobiphenyl (PCB 126); and 3,3′4,4′,5,5′-hexachlorobiphenyl (PCB 169) were 0.18, 0.93, 1.0, and 0.14 μg/kg, respectively. TCDD equivalents (TEQs) were calculated for the mean values of PCDDs, PCDFs, and non-ortho-PCBs in the eggs. Total TEQs in the eggs was 120 ng/kg; PCB 126 accounted for 83% of the TEQs.
Allozyme genotype in mosquitofish, Gambusia holbrooki, during mercury exposure: Temporal stability, concentration effects and field verification
Authors: Heagler M. G. , Newman M. C. , Mulvey M. , Dixon P. M.
Published: March 2010

Genotype frequencies at nine enzyme loci were examined in a population of mosquitofish, Gambusia holbrooki, during acute inorganic mercury exposure at three concentrations. Genotype at one locus, glucose phosphate isomerase-2 (Gpi-2), was correlated with time to death (TTD) at the low (0.83 mg/L) mercury concentration, but genotypes at none of the nine loci were related to TTD at the medium (1.07 mg/L) or the high (1.13 mg/L) mercury concentration. A survey of mosquitofish from a mercury-contaminated canal was undertaken to determine if the results of laboratory exposures could be used to predict accurately the genetic profile of mercury-contaminated field populations. Mosquitofish collected from the contaminated canal had a significantly lower frequency of the Gpi-238 allele than mosquitofish collected from the adjacent noncontaminated river. The Gpi-2 allozymes may be useful as an indicator of pollutant stress if used in conjunction with a thorough understanding of the structure and history of the population.
Bioavailability of sediment-sorbed chlorinated ethers
Authors: Meyer Charles L. , Dorn Philip B. , Suedel Burton C. , Rodgers John H.
Published: March 2010

The equilibrium partitioning approach for developing numerical sediment-quality criteria was tested in the laboratory using a mixture of chlorinated ethers/alcohols sorbed to sediments. The sorption behavior of the principal component of the mixture, tetrachloropropyl ether (TCPE), was determined on sediments with organic carbon contents ranging from 0.3 to 5.2%. Sorption was found to be a strong function of organic carbon with a log(Koc) of 2.9. Predictions of log(Koc) using Kow correlations and molecular connectivity indexes ranged from 2.9 to 3.3. Toxicity tests were then conducted on sediments spiked with the chlorinated ether mixture using the amphipod Hyalella azteca, the midge Chironomus tentans, and the water flea Daphnia magna. Sediment toxicity was highly dependent on the sediment organic carbon content, but there were differences in toxicity that could not be explained by differences in organic carbon. Interstitial water concentrations of total chloroether did not compare with effects between different sediments for either of the two sediment-dwelling organisms, with LC50 values ranging from 1.6 to 10.5 mg dissolved chloroether per liter for Hyalella azteca and 1.5 to 9.3 mg dissolved chloroether per liter for Chironomus tentans. The effect of other sediment properties on the sensitivity of these two organisms may account for this difference. For Daphnia magna, there was a much closer correlation between interstitial water concentrations and effects, with the aqueous LC50 having a range of only 0.9 to 2.0 mg/L.
Extraction efficiencies of hydrocarbons from Niagara river water
Authors: Maguire R. James , Tkacz Richard J. , Batchelor Suzanne P.
Published: March 2010

Significant concentrations of C12 to C26  n-alkanes, fluoranthene and pyrene were found in dichloromethane extracts of filtered Niagara River water at pH 12 after the water had been thoroughly extracted at pH 1. Over 40 sampling days, the total concentration of n alkanes, fluoranthene, and pyrene in the basic extracts was roughly 60% of the total in the acidic extracts plus suspended solids combined. Spike recovery experiments with 31 n-alkanes and polynuclear aromatic hydrocarbons demonstrated that the phenomenon (a) did not occur in distilled water, (b) occurred in Niagara River water, regardless of whether the initial extraction of filtered water was performed at acidic or neutral pH, and (c) was not simply the result of incomplete extraction at acidic or neutral pH. These findings support earlier studies that suggested that concentrations of lipophilic organic chemicals in Niagara River water may be underestimated when determined by the usual technique of extraction at neutral pH.
Juvenile freshwater mussel (bivalvia: unionidae) responses to acute toxicity testing with copper
Authors: Jacobson Peter J. , Cherry Donald S. , Farris Jerry L. , Neves Richard J.
Published: March 2010

The sensitivities of newly metamorphosed juveniles of Villosa iris and Anodonta grandis to copper were determined using 24-h static bioassays. Two methods of assessing postexposure response were compared: direct visual examination and the use of vital staining with neutral red. Both species responded to copper exposures, exhibiting valve closure at concentrations as low as 24 μg Cu per liter for Villosa iris and 17 μg Cu per liter for Anodonta grandis. EC50 values of 27 μg Cu per liter (Villosa iris) and 33 μg Cu per liter (Anodonta grandis) were calculated on the basis of the valve closure response. Use of vital staining with neutral red provided an EC50 of 29 μg Cu per liter for Villosa iris. The amber coloration of Anodonta grandis valves prevented determination of an EC50 using the vital staining. LC50 values of 83 μg Cu per liter (Villosa iris) and 44 μg Cu per liter (Anodonta grandis) were calculated from the results of vital staining. Neutral red was found to be effective in assessing postexposure mortality and sublethal responses after acute exposures to copper.
Effects of acidification on metal accumulation by aquatic plants and invertebrates. 2. Wetlands, ponds and small lakes
Authors: Albers Peter H. , Camardese Michael B.
Published: March 2010

Compared were concentrations of Al, Cd, Ca, Cu, Fe, Pb, Mg, Mn, Hg, Ni, P, and Zn in water, plants, and aquatic invertebrates of wetlands, ponds, and small lakes in Maryland and Maine. The accumulation of metals by aquatic plants and insects and the concentration of metals in water were not greatly affected by pH. None of the metal concentrations in water significantly correlated with metals in insects. Plant metal concentrations poorly correlated with metal concentrations in water. Concentrations of metals exceeded acceptable dietary levels more frequently in plants than in invertebrates. Concerns about metal toxicity in birds that feed on invertebrates and plants from acidified waters seem to be unwarranted. Positive correlations among pH, Ca in water, Ca in insects, and Ca in plants imply that acidification can reduce the Ca content of aquatic biota. Aquatic insects were low in Ca, but crayfishes and snails, which are adversely affected by low pH, were very high. A concern for waterfowl is Ca deprivation from decreased Ca availability in low-pH wetlands, ponds, and small lakes.
Dissipation of glyphosate and aminomethylphosphonic acid in water and sediments of boreal forest ponds
Authors: Goldsborough L. Gordon , Brown Dennis J.
Published: March 2010

Three small ponds in the boreal forest of southern Manitoba were treated with an aerial application of 2.1 kg/ha glyphosate. Two of the ponds had been treated the preceding year with 0.9 kg/ha glyphosate, whereas the third was previously untreated. Foliage samples of plants bordering the ponds were collected immediately after treatment, and water and sediment samples were collected over a period of 265 d after treatment. Samples were analyzed for glyphosate and its first metabolite, aminomethylphosphonic acid (AMPA). We found that glyphosate dissipated rapidly from the surface waters of all ponds (dissipation half-lives of 3.5-11.2 d). AMPA residues were detected in water samples during the first 14 d after treatment, suggesting that herbicide degradation was occurring in the water column. However, not all applied herbicide was accountable in residues in the water. Glyphosate and AMPA increased in sediment samples to day 36, suggesting that sediment adsorption was a major sink for the herbicide. Glyphosate dissipation from the water column was biphasic, with a rapid initial phase followed by a slower phase. We hypothesize this was due to herbicide sorption and partitioning between suspended particulate matter and bottom sediments. As was found after the first pond treatment, glyphosate dissipation was slower in chemically alkaline ponds than in a more dilute pond, suggesting that herbicide complexation with ions in solution may be a significant factor affecting the rate of dissipation in standing water.
EPA's approach to environmental research in the 90s
Authors: Bretthauer Erich W.
Published: March 2010

In the past four years the U.S. Environmental Protection Agency (EPA) has changed its approach to dealing with environmental problems, which resulted in placing much more emphasis on science. Whenever possible the Agency concentrates on addressing the highest environmental risks, stresses pollution prevention, prefers voluntary programs to regulatory approaches, and makes more use of the marketplace to achieve environmental goals. To meet the need for more technical information to support this approach, the EPA changed its planning process, increased its ecological research program, developed the Environmental Monitoring and Assessment Program (EMAP), increased its emphasis on reproductive and developmental toxicology and neurotoxicology, and restructured its approaches to risk assessment. The Agency also significantly increased its relationships with academia and the private sector in implementing its research program.
Biotransformation and mineralization of alkylbenzenes under denitrifying conditions
Authors: Hutchins Stephen R.
Published: March 2010

Batch microcosm tests were performed with nonacclimated and acclimated aquifer material from Traverse City (MI) to assess the extent of biodegradation of radiolabeled benzene, toluene, ethylbenzene, and xylenes (BTEX), either as single substrates or in a mixture, by indigenous microorganisms under denitrifying conditions. For single substrate studies, the rates and extent of biodegradation of toluene and m-xylene in the acclimated aquifer material were generally similar to those observed in the nonacclimated material. Benzene was recalcitrant in both cases o-Xylene was recalcitrant in the nonacclimated aquifer material, but degradation occurred after toluene addition. In the acclimated aquifer material, o-xylene degradation commenced without addition of toluene. Mineralization accounted for 36 to 54% of the total alkylbenzene removal Under mixed substrate conditions, solution concentrations of radiolabeled benzene decreased when nitrate was present, but not in the absence of an added electron acceptor. Mineralization did not occur, and no degradation products could be identified. Benzene removal was linked to alkylbenzene degradation, however, solution concentrations of benzene increased with subsequent toluene additions. It appears that benzene is not being degraded in these denitrifying microcosms, but merely sorbed or sequestered with the potential for subsequent release. Microbial activity, in this case the biodegradation of alkylbenzenes, enhanced this sorption beyond that observed for the initial aquifer material.
Congener-specific biotransformation and bioaccumulation of PCDDs and PCDFs from fly ash in fish
Authors: Sijm Dick T. H. M. , Opperhuizen Antoon , Wever Han
Published: March 2010

Biotransformation may be responsible for the lack of bioaccumulation of a number of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Goldfish (Carassius auratus) that were exposed to PCDDs and PCDFs, and piperonylbutoxide (PBO) in water, bio-concentrated significantly more congeners than goldfish exposed to PCDDs and PCDFs only. Mono-oxygenase activity, which is responsible for the oxidation of specific PCDD and PCDF congeners in untreated fish, was inhibited by fish treated with PBO. In the PBO-treated group and in the control group, congeners with all lateral positions substituted were found. Congeners that lack chlorine substitution on one or more of the lateral (2,3,7,8) positions and congeners that have all lateral positions chlorinated were found only in PBO-treated fish. Congeners that have at least one free lateral position were therefore assumed to be biotransformed. There was no relationship between the octanol/water partition coefficient and biotransformation of the PCDDs and PCDFs. No limitation of uptake for higher chlorinated PCDD and PCDF congeners was found.
Toward a standard Daphnia juvenile production test
Authors: Sims I.R. , Watson S. , Holmes D.
Published: March 2010

The Daphnia 21-d juvenile production test was ring tested in 1985. The results showed maximum variability, that is, the effective concentration ranged from less than the lowest concentration to greater than the highest concentration. At a workshop on this subject in 1989 several contributory factors to this variability were identified. This paper describes two experiments designed to investigate these factors, specifically the species of algae supplied as food, the ration, the age of algal culture used to feed the daphnids, and the influence that daphnid medium renewal frequency had on fecundity. The results show that, at comparable feeding rates (as milligrams of carbon per liter of culture medium or milligrams C per daphnid), a diet of Selenastrum resulted in higher fecundity than one of Chlorella or Scenedesmus. However, the use of either species of algae at rations between 0.5 and 1.0 mg C per liter (equivalent to 0.1-0.2 mg C per daphnid) would meet the revised Organization for Economic Cooperation and Development (OECD) test acceptability criterion for mean control fecundity of ≥60 juveniles. Furthermore, animals experiencing renewal of their medium three times each week produced significantly more juveniles than animals whose medium was renewed less often. The age of the algal culture used as food did not influence fecundity.
Turbidity as a method of preparing sperm dilutions in the echinoid sperm/egg bioassay
Authors: Hall Timothy J. , Haley Richard K. , Battan Kelley J.
Published: March 2010

The use of a turbidimeter for preparing sperm dilutions used in the echinoid sperm/egg bioassay was evaluated. Regression analyses of the relationship between sperm density and turbidity for the sea urchins Strongylocentrotus purpuratus and Strongylocentrotus droebachiensis and the sand dollar Dendraster excentncus indicated that although there were slope differences for each species, each coefficient of determination was highly significant (p ≤ 0.001). For Dendraster excentncus, triplicate hemacytometer counts over a range of turbidities as well as repeated preparations of a single sperm turbidity indicated similar variability for each. The use of the turbidimeter has time-saving advantages over conventional hemacytometer methods without sacrificing precision. Sperm dilutions can be prepared rapidly (1-2 min), minimizing sea water sperm preactivation before test initiation, and may therefore contribute to increased test precision.
Wetland risk assessment
Authors: Pascoe Gary A.
Published: March 2010

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

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

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

A 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

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

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 >80% when exposed for 10 d to all particle size regimes exammed Subsequent exposures of H azteca to field collected sediments resulted in >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 >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 <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

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 < 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

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

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 < 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 < 0.05 and r = 0.661, p < 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 < 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

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

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

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 > viscera without liver and kidney > gills > skin, fins, bones, and head excluding gills, brain, and eyes > kidney ≈ epidermal mucus > brain > eyes > 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

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 > 0.05) between treated and untreated areas. However, juvenile/adult female ratios on untreated areas were significantly higher (p < 0.05) than those on treated areas. Mice on treated areas consumed less lepidopteran prey than did mice on untreated areas (p < 0.05), but the total amount of food consumed per mouse did not differ significantly between treated and untreated areas (p > 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 > 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

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.
Problems induced by the use of acetone as a solvent to dose chlorpyrifos in a microecosystem
Authors: Kersting Kees
Published: March 2010

Recycling aquatic microecosystems consisting of three subsystems with a total volume of 7.5 L were used to study the effects of the insecticide chlorpyrifos. The poorly soluble chlorpyrifos was dosed dissolved in 0.5 ml of acetone. Acetone was found to be responsible for some of the observed effects. It caused a decrease of the pH by approximately two units. The decrease started 2 weeks after the introduction, and recovery to the pretreatment level took several months.