bluuebunny/crossref_metadata_2025_split 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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.