bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biological and chemical factors of importance in the bioaccumulation and trophic transfer of persistent organochlorine contaminants in arctic marine food webs
Authors: Borgå Katrine , Fisk Aaron T. , Hoekstra Paul F. , Muir Derek C. G. 
Published: November 2004

Abstract
Recent studies of arctic marine food webs have provided detailed insights regarding the biological and chemical factors that influence the bioaccumulation and trophic transfer of persistent organochlorine (OC) contaminants in aquatic systems. The present paper summarizes the recent literature with an emphasis on identifying important ecological factors for explaining variability of OC concentrations among organisms. The Arctic ecosystem has a number of unique attributes, including long food chains, reduced diversity of species, similar food webs across the entire region, and limited influence from pollution point sources. Lipid content, body size, age, gender, reproduction, habitat use, migration, biotransformation, seasonal changes in habitat conditions, feeding ecology, and trophic position have all been demonstrated to influence OC concentrations and bioaccumulation in arctic marine biota. The relative importance of each factor varies among OCs and organisms. Diet or trophic level is the dominant factor influencing OC concentrations and dynamics in seabirds and marine mammals, although biotransformation can significantly influence nonrecalcitrant OCs, such as hexachlorocyclohexane isomers. Dietary accumulation of OCs is also an important route of exposure for arctic fish and zooplankton, and biomagnification of OCs may also occur among these organisms. To date, only limited attempts have been made to model trophic transfer of OCs in the arctic marine food web. Although models developed to assess OC dynamics in aquatic food webs have included some biological variables (e.g., lipid content, feeding rate, diet composition, and growth rate), selection of processes included in these models as well as their mathematical solutions and parameterization all introduce simplification. This reduces biological validity of the models and may be particularly problematic in a highly seasonal environment, such as the Arctic Ocean.
Probabilistic uncertainty analysis of the European Union System for the evaluation of substances multimedia regional distribution model
Authors: Matthies Michael , Berding Volker , Beyer Andreas 
Published: November 2004

Abstract
The European Union System for the Evaluation of Substances (EUSES) is a computerized model system to facilitate and harmonize health and environmental risk assessment of previously notified and new substances. For calculation of regional background exposure, a multimedia distribution model is used. In the present study, the uncertainty of this regional model is analyzed. Environmental parameters were collected for North Rhine Westphalia (Germany), which resembles the standard region of EUSES. Probability distribution functions of various types (uniform, triangular, normal, log normal) depending on data availability were derived for environmental input parameters, including geometric parameters. Generic log-normal distribution functions with fixed standard deviations were chosen for solubility in air, water, and n-octanol as well as for degradation half-lives. Monte Carlo simulations were carried out for 10 reference substances having different properties. Contribution of environmental parameter uncertainty to total output uncertainties is higher than that of substance parameters. Range of output uncertainty, defined as the ratio of the logarithms of the 90th and 10th percentiles of the cumulative probability distribution function, shows an increase from air and water to soil. The highest-occurring range is 1.4 orders of magnitude, which means that total uncertainty of the regional model is relatively low and, usually, is lower than the range of measured values. The median of output probability distributions lies above the point estimate. Influence of input parameters was estimated as their rank correlation coefficients to output uncertainty. Substance and environmental parameters contribute differently to output variance depending on individual substance properties and environmental compartment. Hence, the present study underlines the need to perform uncertainty analyses instead of either using a set of simple rules or just looking at certain parameters.
Application of the narcosis target lipid model to algal toxicity and deriving predicted-no-effect concentrations
Authors: McGrath Joy A. , Parkerton Thomas F. , Di Toro Dominic M. 
Published: November 2004

Abstract
The narcosis target lipid model (TLM) was developed to predict the toxicity of chemicals to aquatic organisms that act via narcosis. It is based on the hypothesis that target lipid is the site of toxic action within the organism, that octanol is the appropriate surrogate, and that target lipid has the same physical-chemical properties in all organisms. Here the TLM is extended to available freshwater green algal toxicity data to support a narcosis toxic mode-of-action (TMoA) effect assessment. For each species, significant linear relationships were observed between log(median effective concentration [EC50]) and log(Kow) of the test chemicals. The slope of the log-log relationship statistically was similar to the universal narcosis slope of −0.945 that was derived from an earlier analysis of the TLM to nonalgal species. Critical target lipid body burdens (CTLBB), CL* were estimated for each algal species from the intercepts of the regressions and found to be within the range (43–398 μmol/g octanol) reported previously, indicating that algae exhibit a similar sensitivity distribution relative to other aquatic species. The TLM is used to derive the predicted-no-effect concentrations (PNECs) using the hazardous concentration to 5% species (HC5) statistical extrapolation procedure. This calculation requires an analysis of the variability of the universal slope, the CL*, and the acute-to-chronic ratio. The PNECs derived using this procedure were consistent with chronic-no-effect concentrations reported for narcotic chemicals. This is in contrast to PNECs derived from limited chemical-specific toxicity data and default application factors. It is concluded that coupling the TLM to the HC5 extrapolation procedure allows optimal use of available toxicity data for deriving environmental quality criteria with a narcotic TMoA.
Comparison of time-integrated pesticide concentrations determined from field-deployed passive samplers with daily river-water extractions
Authors: Hyne Ross V. , Pablo Fleur , Aistrope Melissa , Leonard Alex W. , Ahmad Nazir 
Published: November 2004

Abstract
The rate of release of three performance reference compounds (PRCs) from passive samplers when deployed in rivers with variable flow and temperature were compared with their release from passive samplers in a laboratory continuous-flow system. The passive samplers used in the current study were constructed from low-density polyethylene bags containing trimethylpentane solvent (TRIMPS). The half-lives for release from the TRIMPS of the PRCs tributylphosphate, endosulfan sulfate, and chlorpyrifosethyl were 7.3, 20.8, and &gt;75 d, respectively, when deployed in rivers, compared with half-lives of 10.4, 26.5, and approximately 73 d in a laboratory flow system. The mean pesticide concentrations taken up by TRIMPS deployed for periods from 7 to 22 d in rivers adjacent to cotton fields were determined during two studies in the austral summer of 2000/2001 and 2001/2002. During the studies, mean total endosulfan and chlorpyrifos-ethyl concentrations were also determined from daily river-water extractions. Regression equations established in previous laboratory studies related the concentration factors into TRIMPS to the time of deployment for a number of pesticides, including endosulfan and chlorpyrifos-ethyl. The laboratory-derived calibration factors were used to determine the mean pesticide concentrations for each deployment period, and these were compared with the cumulative mean concentrations calculated from the daily extractions. The pesticide concentrations determined using the TRIMPS were within twofold of the cumulated mean of the daily river-water extractions of endosulfan and chlorpyrifos-ethyl for deployment periods of 7 to 22 d when the mean river-water concentrations were &gt;0.005 μg/L.
Aging reduces the bioavailability of even a weakly sorbed pesticide (carbaryl) in soil
Authors: Ahmad Riaz , Kookana Rai S. , Megharaj Mallavarapu , Alston Angus M. 
Published: November 2004

Abstract
We investigated bioavailability and biodegradation of carbaryl (1-naphthyl methylcarbamate) in a soil with a long history of pesticide contamination from a storage facility located at Mamoon Kanjan, Pakistan. Carbaryl is weakly sorbed and generally considered to be easily degradable in soil. Extraction studies revealed that 49% of the total carbaryl in soil (88.0 mg kg−1) was not water-extractable and also not bioavailable, as demonstrated by inoculation of the contaminated soil with a carbaryl-degrading, mixed bacterial culture. Inoculation of the contaminated soil with the carbaryl-degrading culture showed that the bacteria were capable of degrading only the available (i.e., water-extractable) fraction of the pesticide. When the soil was pulverized in a ball mill to enhance the release of residue, an additional 19% of the carbaryl became bioavailable. A significant proportion of residue (≈33%) remained unavailable. The long (&gt;12 years) contact time between the pesticide and soil (i.e., aging), allowing possible sequestration into soil nanopores and the organic matter matrices, is suggested to have rendered the pesticide unavailable for microbial degradation. High concentration (88.0 mg kg−1) in soil facilitated its persistence and sequestration. Results from the present study demonstrate that even a weakly sorbed and easily degradable pesticide, carbaryl, is effectively sequestrated in soil with time, rendering it partly inaccessible to microorganisms and affecting the bioavailability of the compound.
Plant uptake and translocation of highly weathered, soil-bound technical chlordane residues: Data from field and rhizotron studies
Authors: Mattina MaryJane Incorvia , Eitzer Brian D. , Iannucci-Berger William , Lee Wen-Yee , White Jason C. 
Published: November 2004

Abstract
It has been observed that plants are susceptible to uptake from soil and in planta transport of technical chlordane, in spite of its hydrophobicity and sequestration within the soil matrix due to weathering. Field and rhizotron studies were conducted with Cucurbitaceae planted in highly weathered, chlordane-contaminated soil to investigate details of soil-to-plant contaminant uptake. In the field-work, Cucurbita pepo L. (zucchini) was grown in soil at four levels of chlordane contamination: Clean (&lt;limits of quantitation, 5 ng/g), low (average, 370 ng/g), medium (average, 1,951 ng/g), and high (average, 4,572 ng/g). The analysis of plant tissues (root, stem, leaf, and fruit) resulted in the detection of chlordane consistently at the highest concentration in the root tissue at each level of soil contamination. As the soil chlordane concentration increased, the average chlordane concentration in the root tissue increased as follows: Clean, 370 ng/g; low, 8,130 ng/g; medium, 21,800 ng/g; high, 29,400 ng/g. Further analysis of the field-grown plants showed distinct differences in both the proportional distribution of chlordane among the plant tissues and the pattern of the chlordane residues in each tissue type. These differences are attributed to plant uptake from soil versus uptake from air. In the rhizotron studies, uptake of chlordane residues by C. pepo L. was compared with that of another Cucurbitaceae, Cucumis sativus L. (cucumber). Xylem sap from the rhizotron-grown plants was collected and analyzed for chlordane, in addition to determination of chlordane residues in soil, roots, and aerial plant tissue. Component fractions and enantiomer fractions of both chiral and achiral chlordanes were followed through soil, root, xylem sap, and aerial tissue compartments. They indicate that the xenobiotic residues translocate enantioselectively from the soil matrix into and through the plant environment with genera-specific patterns. The determination of chlordanes at ng/g concentration explicitly for the first time in the xylem sap of plants grown in contaminated soil confirms the presence of a soil-sequestered and highly hydrophobic organic contaminant within the aqueous plant environment.
Toxicity of storm-water runoff after dormant spray application in a French prune orchard, Glenn County, California, USA: Temporal patterns and the effect of ground covers
Authors: Werner Ingeborg , Zalom Frank G. , Oliver Michael N. , Deanovic Linda A. , Kimball Tom S. , Henderson John D. , Wilson Barry W. , Krueger William , Wallender Wes W. 
Published: November 2004

Abstract
Organophosphorous (OP) insecticides, especially diazinon, have been detected routinely in surface waters of the Sacramento and San Joaquin River watersheds, coincident with rainfall events following their application to dormant orchards during the winter months. Preventive best management practices (BMP) aim at reducing off-site movement of pesticides into surface waters. Two proposed BMPs are: The use of more hydrophobic pyrethroid insecticides believed to adsorb strongly to organic matter and soil and the use of various types of ground cover vegetation to increase the soil's capacity for water infiltration. To measure the effectiveness of these BMPs, storm water runoff was collected in a California prune orchard (Glenn County, CA, USA) during several rainstorms in the winter of 2001, after the organophosphate diazinon and the pyrethroid esfenvalerate were applied to different orchard sections. We tested and compared acute toxicity of orchard runoff from diazinon- and esfenvalerate-sprayed sections to two species of fish (Pimephales promelas, Onchorhynchus mykiss) and three aquatic invertebrates (Ceriodaphnia dubia, Simocephalus vetelus, Chironomus riparius), and determined the mitigating effect of three ground cover crops on toxicity and insecticide loading in diazinon-sprayed orchard rows. Runoff from the esfenvalerate-sprayed orchard section was less toxic to waterflea than runoff from the diazinon-sprayed section. However, runoff from the orchard section sprayed with esfenvalerate was highly toxic to fish larvae. Samples collected from both sections one month later were not toxic to fish, but remained highly toxic to invertebrates. The ground cover crops reduced total pesticide loading in runoff by approximately 50%. No differences were found between the types of vegetation used as ground covers.
Wastewater treatment polymers identified as the toxic component of a diamond mine effluent
Authors: de Rosemond Simone J. C. , Liber Karsten 
Published: November 2004

Abstract
The Ekati™ Diamond Mine, located approximately 300 km northeast of Yellowknife in Canada's Northwest Territories, uses mechanical crushing and washing processes to extract diamonds from kimberlite ore. The processing plant's effluent contains kimberlite ore particles (≤0.5 mm), wastewater, and two wastewater treatment polymers, a cationic polydiallydimethylammonium chloride (DADMAC) polymer and an anionic sodium acrylate polyacrylamide (PAM) polymer. A series of acute (48-h) and chronic (7-d) toxicity tests determined the processed kimberlite effluent (PKE) was chronically, but not acutely, toxic to Ceriodaphnia dubia. Reproduction of C. dubia was inhibited significantly at concentrations as low as 12.5% PKE. Toxicity identification evaluations (TIE) were initiated to identify the toxic component of PKE. Ethylenediaminetetraacetic acid (EDTA), sodium thiosulfate, aeration, and solid phase extraction with C-18 manipulations failed to reduce PKE toxicity. Toxicity was reduced significantly by pH adjustments to pH 3 or 11 followed by filtration. Toxicity testing with C. dubia determined that the cationic DADMAC polymer had a 48-h median lethal concentration (LC50) of 0.32 mg/L and 7-d median effective concentration (EC50) of 0.014 mg/L. The anionic PAM polymer had a 48-h LC50 of 218 mg/L. A weight-of-evidence approach, using the data obtained from the TIE, the polymer toxicity experiments, the estimated concentration of the cationic polymer in the kimberlite effluent, and the behavior of kimberlite minerals in pH-adjusted solutions provided sufficient evidence to identify the cationic DADMAC polymer as the toxic component of the diamond mine PKE.
Pollution-induced community tolerance of soil microbes in response to a zinc gradient
Authors: Davis Miles R. H. , Zhao Fang-Jie , McGrath Steve P. 
Published: November 2004

Abstract
The long-term accumulation of Zn in soils provides the microbial community time to adapt to this heavy metal. To assess the effects of long-term exposure to Zn on the metabolic diversity and tolerance to Zn of soil microbial community, the pollution-induced community tolerance (PICT) method, based on the Biolog microtitre plate system, was used. It especially is useful to study gradients of pollutants for detecting PICT. Such a Zn gradient was found by selecting soils at increasing distances from galvanized electricity pylons at two sites where Zn accumulation had occurred over a period of decades. Soil metabolic profiles showed a humpbacked response to increasing soil Zn concentrations, indicating that accumulation of Zn up to 2,000 mg/kg did not decrease the metabolic biodiversity in the culturable fraction of the microbial community. This fraction of the microbial community showed significant PICT, because the effective concentration that reduces the metabolic biodiversity by 50% (EC50), values for Zn added to the Biolog wells increased by up to two orders of magnitude with increasing soil-Zn concentration along the transects. Significant PICT was detectable at soil Zn concentrations above approximately 300 mg/kg. The EC50 values correlated more closely with soil total Zn than with soil pore water Zn. The results suggest that, although long-term exposure to Zn imposes stress on soil microbes, resulting in an increased tolerance, detectable PICT does not necessarily lead to a decrease in metabolic diversity.
Partial life-cycle toxicity and bioconcentration modeling of perfluorooctanesulfonate in the northern leopard frog (Rana pipiens)
Authors: Ankley Gerald T. , Kuehl Douglas W. , Kahl Michael D. , Jensen Kathleen M. , Butterworth Brian C. , Nichols John W. 
Published: November 2004

Abstract
A number of recent monitoring studies have demonstrated elevated concentrations of perfluorooctanesulfonate (PFOS) in humans and wildlife throughout the world. Although no longer manufactured in the United States, the global distribution and relative persistence of PFOS indicates a need to understand its potential ecological effects. Presently, little is known concerning toxicity of PFOS in chronic exposures with aquatic species. Therefore, we evaluated the effects of PFOS on survival and development of the northern leopard frog (Rana pipiens) from early embryogenesis through complete metamorphosis. Exposures were conducted via water at measured PFOS concentrations ranging from 0.03 to 10 mg/L. Animals exposed to 10 mg/L began dying within approximately two weeks of test initiation. Survival was not affected by PFOS at lower concentrations; however, time to metamorphosis was delayed and growth reduced in the 3-mg/L treatment group. Tadpoles readily accumulated PFOS directly from water. Using a one-compartment bioaccumulation model, growth was shown to have a modest impact on steady-state PFOS concentrations. Variability in observed growth rates and the possible contribution of a size-dependent decrease in PFOS elimination rate contributed uncertainty to modeling efforts. Nevertheless, fitted uptake and elimination rate constants were comparable to those determined in earlier studies with juvenile rainbow trout. Overall, our studies suggest that R. pipiens is not exceptionally sensitive to PFOS in terms of either direct toxicity or bioconcentration potential of the chemical.
Influence of leaching medium and drying time between successive leaching periods on the emission of chromium, copper, and boron from treated wood
Authors: García-Valcárcel Ana I. , Bravo Isabel , Jiménez Cristina , Tadeo José Luis 
Published: November 2004

Abstract
Laboratory studies were conducted to determine leaching of Cu, Cr, and B from pine sapwood treated with Cr-Cu-B (CCB) preservative in different leaching media (ultrapure water [UPW], rainwater [RW], and soil water [SW]). Losses of metals from CCB-treated wood, expressed in percentage of initial content, were always highest for B (11.2–63.5%) and lowest for Cr (0.02–0.36%) in any of the leaching media assayed. Losses of B and Cr from treated wood were not affected by the leaching medium; however, losses of Cu were 1.5 to 2.5 times higher in SW than in UPW and RW. The influence of drying time between successive leaching periods on release of metals also was determined. Treated wood was submitted to wetting-drying cycles of 24 h/d, 18 h/d, and 6 h/d in contact with the leaching medium over a total contact time of 276 h. For an equivalent contact period of CCB-treated wood with either UPW or RW, leaching of B was from 1.1 to 1.9 times higher for continual wetting than under intermittent wetting conditions. Leaching of Cu was not affected by the wetting-drying periods when wood was in contact with RW, but it was 1.2 to 1.5 times higher for continual wetting with UPW. In general, leaching of Cr was not affected by the wetting-drying cycles when in contact with UPW or RW. However, when CCB-treated wood was in contact with SW under discontinuous wetting of 6 h/d, Cu and Cr emissions were approximately 1.2 and 2.5 times higher, respectively, than with continuous wetting. This study shows that the type of leaching medium and the drying time between successive wetting periods must be considered when evaluating metal losses from CCB-treated wood during service life.
Responses of nontarget lepidoptera to foray 48B® Bacillus thuringiensis var. kurstaki on Vancouver Island, British Columbia, Canada
Authors: Boulton Timothy J. 
Published: November 2004

Abstract
Impacts of a gypsy moth (Lymantria dispar) eradication program on native, nontarget Lepidoptera were assessed in 1999, on southeastern Vancouver Island (BC, Canada). The microbial insecticide Bacillus thuringiensis var. kurstaki (Btk) was applied aerially over two areas totalling 12,805 ha on May 8, May 19, and June 8, 1999, at a dosage of 50 billion international units in 4.0 L/ha. Lepidoptera were collected from two host plant species: Garry oak (Quercus garryana) and common snowberry (Symphoricarpos albus). Lepidopteran larvae were collected from common snowberry foliage at 24 urban parks and from Garry oak foliage at 28 oak-dominated habitats, representing 12 and 14 replicates, respectively, of two treatments: unsprayed (reference) and sprayed (treatment). Prespray data were collected from March 25 to May 6 for S. albus, and from April 26 to May 6 for Q. garryana. Postspray data were collected from May 10 through June 15 for S. albus and from May 10 to July 6 for Q. garryana. The 15 most abundant lepidopteran species were analyzed statistically. However, the majority of species were collected infrequently, and, therefore were pooled for statistical analysis. After the Btk spray applications, 11 of the individual species and groups of uncommon species were found to be significantly less abundant in the treatment sites than in the reference sites. The effects of sample date were statistically significant on almost all groups of Lepidoptera analyzed, both before and after Btk spray applications, indicating temporal variation in lepidopteran abundance. Significant variation in diversity of members of the Lepidoptera, as a result of Btk spray application, was not detected on S. albus or Q. garryana. However, results showed significant variation in lepidoptera richness and abundance on both host plant species.