bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biological effects of polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls in bald eagle (Haliaeetus leucocephalus) chicks
Authors: Elliott  , Hart Leslie E. , Cheng Kimberly M. , Norstrom Ross J. , Lorenzen Angela , Kennedy Sean W. , Philibert Helene , Stegeman John J. , Bellward Gail D. 
Published: March 2010

Abstract
During the1992 breeding season, eggs of bald eagles (Haliaeetus leucocephalus) were collected within a gradient of exposure to chlorinated hydrocarbon pollutants, particularly from pulp mill point sources, on the southern coast of British Columbia, Canada. Twenty-five eggs were placed in a laboratory incubator, of which 18 hatched; chicks were sacrificed within 24 h. Hatching success was not significantly different between eggs taken from pulp mill sites and reference sites. A hepatic cytochrome P4501A (CYP1A) cross-reactive protein was induced nearly sixfold in chicks from near a pulp mill at Powell River compared to those from a reference site (p &lt; 0.05). Hepatic ethoxyresorufin-O-deethylase (EROD) and benzyloxyresorufin O-dealkylase (BROD) activities were also significantly elevated in chicks from nests located near pulp mills compared to reference sites (p &lt; 0.0005 and p &lt; 0.02, respectively). A hepatic CYP2B cross-reactive protein was threefold higher in chicks from pulp mill versus reference sites, but the difference was not significant. Residual yolk sacs of eggs collected near pulp mill sites contained greater concentrations of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) compared to reference areas. No significant differences in concentrations of polychlorinated biphenyls (PCBs), non-ortho congeners, and organochlorine pesticides occurred among sites. Regressions showed that the hepatic CYP1A cross-reactive protein and EROD and BROD activities were positively correlated with 2,3,7,8-TCDD, 2,3,7,8-TCDF, and toxic equivalents (TEQsWHO—Wrld Health Organization toxic equivalence factors) in yolk sacs. No significant concentration-related effects were found for morphological, physiological, or histological parameters, such as chick growth, edema, or density of thymic lymphocytes. Using hepatic CYP1A induction as a biomarker, a no-observed-effect-level (NOEL) of 100 ng/kg and a lowest-observed-effect-level (LOEL) of 210 ng/kg TEQsWHO on a whole egg (wet weight basis) are suggested for bald eagle chicks.
Gibbs free energies of formation of pcdds: Evaluation of estimation methods and application for predicting dehalogenation pathways
Authors: Huang Ching-Li , Harrison B. Keith , Madura Jeffry , Dolfing Jan 
Published: March 2010

Abstract
Gibbs free energies of formation for the ideal gas, liquid phase, and species in solution were estimated for 75 polychlorinated dibenzo-p-dioxins (PCDDs) at 298.15 K and 100,000 Pa. These values were used to calculate standard redox potentials, with H2 as the electron donor. Owing to the lack of experimental thermodynamic data for the involved chemical species, the standard-state ideal gas enthalpies of formation were evaluated by several semiempirical methods including the Modified Neglect of Diatomic Differential Overlap (MNDO), Austin Model 1 (AM1), and MNDO–Parametric Method 3 (PM3). Three different implementations of Benson's group additivity method for estimation of ideal gas enthalpies of formation were also evaluated. As a result of the evaluation, the CHETAH program based on Benson's group additive method was chosen for ideal gas enthalpy of formation calculations. Entropies, vapor pressure, and aqueous solubility were calculated by existing methods in order to complete the thermodynamic cycle. Calculated redox potentials indicate that chlorodioxins, including 2,3,7,8-tetrachlorodioxin, can serve as electron acceptors in anaerobic environments, at least from a thermodynamic perspective.
Uptake of methyl mercury by the floater mussel, Pyganodon grandis (bivalvia, unionidae), caged in a flooded wetland
Authors: Malley Diane F. , Stewart A. Robin , Hall Britt D. 
Published: March 2010

Abstract
A 6.7-ha wetland with a pond at the Experimental Lakes Area, northwestern Ontario, was experimentally flooded to determine causes of elevated waterborne methyl mercury (MeHg) associated with impoundment. Unionid mussels, Pyganodon grandis (formerly Anodonata grandis grandis) were caged in the experimental pond before and after flooding to determine their ability to monitor the elevated waterborne MeHg. Mussels were also caged in a reference wetland pond and in the lake from which they were collected (source lake). Background levels of MeHg in source lake mussel body parts were in the order mantle &lt; gill or visceral remains &lt; foot or kidney and ranged from 108 to 618 ng/g dry weight. Caging in the source lake did not alter MeHg concentration in any body part. Mussels transplanted to the ponds for 90 d showed statistically significant increases above background MeHg in the mantle and visceral remains in the preflood experimental pond (waterborne MeHg 0.09 ng/L) and in the mantle, visceral remains, foot, and kidney in the reference pond (waterborne MeHg 0.24 ng/L). The visceral remains of mussels in the reference pond contained higher levels of MeHg than did those in the preflood experimental pond. Flooding increased waterborne MeHg from 0.1 to 2.3 ng/L and resulted in an increase in MeHg and total Hg (THg) in the mantle, foot, and visceral remains of mussels in the experimental pond. Inexplicably, mussels caged in a hypoxic environment in the experimental pond lost MeHg and THg from all body parts. We concluded that not only can P. grandis monitor elevation in waterborne MeHg with flooding, but the MeHg levels in mussels also reflect small differences in background levels of natural MeHg in ponds.
A limitation of the microtox® test for toxicity measurements of nonionic surfactants
Authors: Sherrard Kim B. , Marriott Philip J. , McCormick Malcolm J. , Millington Keith 
Published: March 2010

Abstract
The Microtox® test was successfully used to measure EC50 values of nonionic polyethoxylate surfactants. However, toxicity measurements of real samples that contain surfactants above a particular concentration, termed the critical toxicity concentration (CTC) are not valid. These samples require dilution before the test is performed, and because the relationship between toxicity and concentration is not linear above the CTC, the EC50 cannot be extrapolated back to give the toxicity of the original concentrated sample and a true estimation of toxicity is therefore not possible. This phenomenon may be related to the minimum surface tension requirement of the bacteria or other physical properties of the surfactant such as the tendency to assemble at interfaces and surfaces and the tendency to form micelles.
A quantitative analysis of the dynamics of the sorption of hydrophobic organic chemicals to suspended sediments
Authors: Lick Wilbert , Rapaka Venkatrao 
Published: March 2010

Abstract
Recent long-term adsorption and desorption experiments with hexachlorobenzene and three polychlorinated biphenyl congeners have clearly demonstrated that the rates of adsorption and desorption for hydrophobic organic chemicals to natural suspended sediments can be relatively slow and therefore that the assumption of chemical equilibrium may not be valid in many realistic situations. These experiments have also led to a better understanding of the adsorption, desorption, and partitioning processes. Based on this experimental work, a theoretical model of the adsorption, desorption, and partitioning of hydrophobic organic chemicals to suspended sediments has been developed. In the present article, a description of this model is given, and results of numerical calculations using this model are compared with experimental results. In the modeling, the emphasis is on the dynamics of sorption.
The model is relatively simple, with retarded chemical diffusion within the particle/floc as the basic transport process. A complicating factor is the variations in the particle/floc size and density distributions; these distributions are dependent on local conditions and may also vary with time. In the modeling, they were chosen on the basis of measurements taken during the sorption experiments. In general, good agreement between the numerical and experimental results was obtained for all cases considered.
Homogeneous hydrolysis rate constants—Part II: Additions, corrections and halogen effects
Authors: Jeffers Peter M. , Lee Wolfe N. 
Published: March 2010

Abstract
Neutral and alkaline rate constants were measured for 14 halogenated hydrocarbons, and new or revised rate constants were determined for hexachloroethane, trichloroethene, and 1,2-dichloroethane. These results include the effects of F or Br substitution for Cl in halogenated methanes, ethanes, and ethenes. The brominated ethanes and ethenes are more reactive than the corresponding chlorinated compounds, due to lower activation energies and higher activation entropies. Fluorine substitution increases the activation energy for some of the ethanes and greatly decreases reactivity for most of the compounds studied. However, fluorodichloromethane is about as reactive as chloroform. Complex reactions were observed in alkaline solutions of vinyl chloride and 1,2-dichlorotrifluoroethane.
Leukoproliferative response of splenocytes from english sole (Pleuronectes vetulus) exposed to chemical contaminants
Authors: Arkoosh Mary R. , Clemons Ethan , Huffman Paul , Sanborn Herb R. , Casillas Edmundo , Stein John E. 
Published: March 2010

Abstract
The leukoproliferative (LP) response of splenic leukocytes from the marine benthic fish English sole (Pleuronectes vetulus) stimulated with the mitogens lipopolysaccharide (LPS), concanavalin A (Con A), and pokeweed mitogen (PWM) was examined as a biomarker of immunotoxic effects. English sole were exposed to contaminants, either by injection of an organic-solvent extract of a sediment containing polycyclic aromatic compounds (PACs) or placed for up to 5 weeks on a reference sediment containing 0.15 to 1.5% (v/v) of the PAC-contaminated sediment. English sole either injected with the contaminated extract or held on PAC-contaminated sediment had an augmented response to Con A. The LP response to LPS showed no relationship to PAC exposure in laboratory-exposed fish, while PWM showed no consistent relationship to exposure to PACs. In a field study, English sole captured from an urban area in Puget Sound, Washington, USA, contaminated with PACs and other chemical contaminants had a significantly augmented LP response to Con A and PWM in comparison to the LP response in fish from a nonurban reference site. Fish from another nonurban site also had an augmented LP response to Con A, indicating that the elevation of the Con A LP response can also result from factors other than chemical contaminant exposure. In addition, English sole from this site also had an augmented LP response to LPS, whereas fish from urban sites did not exhibit an augmented LP response to LPS. Overall, the results demonstrated that although the LP response in splenic leukocytes of English sole to Con A was linked to contaminant exposure, the LP response to Con A did not exhibit high specificity as an indicator of chemical contaminant exposure. However, the concerted use of Con A, LPS, and PWM allowed for identification of apparent chemical contaminant-induced alterations of the LP response in English sole from an urban area of Puget Sound.
The potential of an earthworm avoidance test for evaluation of hazardous waste sites
Authors: Yeardley Roger B. , Gast Laura C. , Lazorchak James M. 
Published: March 2010

Abstract
An earthworm avoidance test has potential advantages for use in evaluation of hazardous wastes sites. Because organisms often exhibit behavioral responses at lower levels of stress than those that acute toxicity tests are able to detect, avoidance tests could provide increased sensitivity to hazardous chemicals. Avoidance is an ecologically relevant endpoint that neither acute nor sublethal tests measure. Avoidance can potentially indicate sublethal stress in a short period of time, testing is easily done in a soil matrix, and an avoidance test has the potential for specialized applications for soil testing. “Dual-control” test data established that, in absence of a toxicant, worms did not congregate, but instead distributed themselves fairly randomly with respect to the two sides of the test chambers, that is, they did not display behavior that might be mistaken for avoidance. In tests with artificial soil spiked with reference toxicants and hazardous site soils, worms avoided soils containing various toxic chemicals. Avoidance behavior proved in most cases be a more sensitive indicator of chemical contamination than acute tests. Determination of avoidance was possible in 1 to 2 d, much less than the current duration of acute and sublethal earthworm tests.
The translocation of white phosphorus from hen (Gallus domesticus) to egg
Authors: Nam Sae-Im , Macmillan Denise L. , Roebuck Bill D. 
Published: March 2010

Abstract
Thousands of waterfowl deaths occurring at Eagle River Flats (ERF), Anchorage, Alaska, USA, have been attributed to the ingestion of white phosphorus (P4) particles. White phosphorus has been found in the egg of one herring gull (Larus argentatus) and in the yolks of some shorebirds at ERF. The presence of P4 in eggs suggests potential toxic consequences for avian reproduction. This study was undertaken to determine the magnitude and potential importance of P4 translocation from the hen to the egg. Egg-laying hens (Gallus domesticus) were gavaged with a single dose of 1, 3, or 5 mg P4/kg body weight or dosed with 1 mg P4/kg body weight for 5 consecutive d. Eggs of dosed hens were collected daily. White phosphorus was extracted from the yolk and the white, individually, with isooctane and analyzed by gas chromatography. White phosphorus had no significant effect on chicken weight, egg weight, or shell thickness. However, laying frequency was significantly reduced (p &lt; 0.05) in chickens receiving 1 mg P4/kg body weight for 5 d. For all treatments, P4 was detected in the yolk and not in the white. It was first detected in the yolk approx. 1 to 2 d after P4 exposure and became nondetectable 6 to 10 d after P4 exposure. The total P4 recovered from eggs of chickens treated with P4 was less than 0.01% of the administered dose.
A resource conservative procedure for comparison of dose-response relationships
Authors: Link William A. , Hill Elwood F. , Hines James E. , Henry Paula F. P. 
Published: March 2010

Abstract
The evaluation of effects of toxicants on a wildlife community can be complicated by varying responses among the community's constituent populations. Even within populations, considerable variability in dose-response relations may result from different avenues of exposure to the toxicant. Full-scale investigations of the dose-response relations among a variety of species and avenues of exposure can therefore be prohibitively expensive, whether this expense is measured by the number of experimental animals needed, by the human resources committed to the study, or by laboratory expenses. We propose an abbreviated protocol for investigations of multiple dose-response relations that is designed to limit these expenses. The protocol begins with the judicious choice of a baseline dose-response relation to be estimated by a full-scale study involving a minimum of five doses levels, with 10 subjects per dose level. This relation is then used as the basis for rapid screening of subsequent dose-response relations, which are compared to the baseline relation by testing for differences in the median effective dosages. These secondary studies can consist of as few as 14 animals exposed to the estimated median lethal concentration from the baseline study. We describe MS-DOS-compatible software available from the authors that can be used to analyze these data.
Persistent synthetic chlorinated hydrocarbons in albatross tissue samples from midway atoll
Authors: Jones Paul D. , Hannah Donald J. , Buckland Simon J. , Day Peter J. , Leathem Scott V. , Porter Lawrence J. , Auman Heidi J. , Sanderson J. Thomas , Giesy John P. , Summer Cheryl , Ludwig James P. , Colborn Theo L. 
Published: March 2010

Abstract
Anthropogenic organic contaminants have been found in even the most remote locations. To assess the global distribution and possible effects of such contaminants, we examined the tissues of two species of albatross collected from Midway Atoll in the central North Pacific Ocean. These birds have an extensive feeding range covering much of the subtropical and northern Pacific Ocean. Anthropogenic contaminants were found at relatively great concentrations in these birds. The sum of 19 polychlorinated biphenyl (PCB) congeners ranged from 177 ng/g wet weight in eggs to 2,750 ng/g wet weight in adult fat. Total toxic equivalents (TEQs) derived from polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) ranged from 17.2 to 297 pg/g wet weight in the same tissues, while the inclusion of TEQs from PCBs increased these values to 48.4 and 769 pg/g wet weight, respectively. While contaminant concentrations varied between species and tissues, the contaminant profile was relatively uniform. The profile of contaminants detected was unusual in that much of the TEQs was contributed by two pentachlorinated congeners (2,3,4,7,8-pentachlorinated dibenzofuran and 1,2,3,7,8-pentachlorinated dibenzo-p-dioxin), and the profiles of PCB congeners did not match known sources. When compared to other studies the concentrations detected in the Midway Atoll samples were near or above the thresholds known to cause adverse effects in other fish-eating bird species.
Bioavailability of hydrophobic organic compounds from nonaqueous-phase liquids: The biodegradation of naphthalene from coal tar
Authors: Ghoshal Subhasis , Luthy Richard G. 
Published: March 2010

Abstract
The literature on microbial degradation of polycyclic aromatic hydrocarbon (PAH) compounds in soils and sediments shows that microbial biotreatment rates are highly variable. Although it is believed that these disparate results are somehow attributable to the bioavailability of PAH compounds, current understanding does not allow prediction of this phenomenon. This work evaluated relationships between coal tar composition and aqueous naphthalene concentration and between the rate of naphthalene mass transfer and microbial mineralization of naphthalene. The use of a dissolution-degradation framework for identifying rate-controlling phenomena in slurry biotreatment of coal tar is discussed. Experiments were performed in slurry systems with two coal tars for which naphthalene was the principal component. In slurry systems coal tar was present either as a single 0.7-ml globule or as coated onto 250-μm-diameter microporous silica beads. Independent tests were conducted with these systems to assess the rates of naphthalene mass transfer and rates of naphthalene biomineralization. The area-dependent mass transfer coefficient of naphthalene in the coal tar-silica beads system was three orders of magnitude greater than for the single coal tar globule. A coupled, solute-mass transfer biodegradation model was used to compare initial biomineralization rates with rates of naphthalene dissolution. Analysis of the results showed that the rate of biomineralization of naphthalene in the systems containing single coal tar globules was influenced by the rate of mass transfer of naphthalene.
Evaluation of the goulden large-sample extractor for acidic compounds in natural waters
Authors: Headley John V. , Dickson Leslie C. , Swyngedouw Chris , Crosley Bob , Whitley Gerry 
Published: March 2010

Abstract
The Goulden Large-Sample Extractor has received extensive use for monitoring and surveillance surveys of natural waters impacted by pulp and paper mills and agricultural runoff water. However, there are concerns about whether this sampler, which was originally developed for extractions of hydrophobic polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and other organochlorines, is suitable for sampling polar acidic compounds. The sampler was evaluated for recovery of surrogates for resin acids, fatty acids, herbicide acids, and chlorophenols from natural waters. Performance tests conducted in this work indicated that three surrogate compounds with Kp (CDCM/CWater pH2) values from 16,700 to 1,260 were extracted from pH 2-adjusted 20-L water samples with an average recovery of 83.6%. The surrogate compounds with Kp values less than 1,000 were extracted with significantly lower recoveries. The variability ranged from 10 to 36% relative standard deviation. Recoveries and variability compared favorably with reported recoveries and variabilities for neutral pesticide surrogates. Specific performance criteria (percent recoveries ± standard deviation, number of determinations in parentheses) observed for the surrogates 2,4,6-tribromophenol, heptadecanoic acid, O-methylpodocarpic acid, dichlorophenylacetic acid, and 4-bromophenol were 89.5 ± 24.0 (17), 82.8 ± 21.7 (18), 78.4 ± 14.8 (18), 41.9 ± 8.5 (16), and 22.1 ± 8.1 (19), respectively. Low recoveries of the 4-bromophenol surrogate may be due in part to side reactions with diazomethane. As a result, 4-bromophenol is not recommended as a surrogate. These values can be used to provide guidelines for acceptable surrogate recoveries and validation of extractions of polar acidic compounds.
Growth responses of periphyton and chironomids exposed to biologically treated bleached-kraft pulp mill effluent
Authors: Dubé Monique G. , Culp Joseph M. 
Published: March 2010

Abstract
Experiments were conducted in artificial streams to determine the effects of increasing concentrations of bleached-kraft pulp mill effluent (BKME) on periphyton and chironomid (Chironomidae) growth in the Thompson River, British Columbia, Canada. Periphyton growth, as determined by increases in chlorophyll a, was significantly stimulated at all effluent concentrations tested (0.25, 0.5, 1.0, 5.0, and 10.0%). Chironomid growth (total biomass and individual weight) was also significantly stimulated at low effluent concentrations (≤1.0%). At higher concentrations (5.0 and 10.0%), chironomid growth was inhibited relative to the 1.0% treatment streams but was greater than in the controls. Increases in growth were attributed to the effects of nutrient and organic enrichment from BKME. The effluent contained high concentrations of phosphorus and appears to be an important source of carbon for benthic insects grazing on the biofilm. In high-concentration effluent streams, chironomid growth decreased despite low levels of typical pulp mill contaminants (chlorinated phenolics, resin acids, and adsorbable organic halide). This suggests that other compounds in the effluent, such as wood extractives, may be inhibiting chironomid growth. These results support findings of field monitoring studies conducted in the Thompson River, in which changes in periphyton and chironomid abundance occurred downstream of a bleached-kraft pulp mill.