bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polychlorinated biphenyls in eggs and chorioallantoic membranes of American alligators (Alligator mississippiensis) from coastal South Carolina
Authors: Cobb George P , Wood Pattie D , O'Quinn Michael 
Published: March 2010

AbstractAssessing chemical exposure in threatened or endangered wildlife species presents unique analytical problems. Chorioallantoic membranes (CAMs) have been proposed as surrogate tissues for evaluation of polychlorinated biphenyl (PCB) exposure in oviparous species. Research was undertaken to determine the extent of PCB accumulation in alligators (Alligator mississippiensis) at sites along the coast of South Carolina and to evaluate the utility of CAMs as surrogate tissues for determining PCB concentrations in whole alligator eggs. Polychlorinated biphenyls were found in eggs and CAMs of alligators from both sites examined. Concentrations of PCBs were higher in CAMs (p = 0.02) and eggs (p = 0.001) from sites known to contain chlorinated hydrocarbons than from more pristine sites. Total PCBs partitioned predictably (r2 &gt; 0.59; p &lt; 0.02) between egg and CAM tissues indicating the utility of CAMs to serve as surrogate tissues when comparing total PCB concentrations in whole eggs. Tetrachloro through octachloro biphenyl homologues and total PCBs in CAMs from reference areas were correlated with concentrations of these homologues in eggs. At contaminated sites, total PCB concentrations in CAMs were correlated with total PCB concentrations in eggs.
Terrestrial wildlife risk assessment for TCDD in land-applied pulp and paper mill sludge
Authors: Meyn Ossi , Zeeman Maurice , Wise Michael J , Keane Susan E 
Published: March 2010

Abstract
A risk assessment was performed to evaluate the potential effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in land-applied pulp and paper mill sludge on terrestrial wildlife. Three representative bird and mammal species were assessed for potential individual risk of adverse effects. A dietary model was used to estimate TCDD exposures of adult birds and mammals, and a pharmacokinetic model was used to estimate exposure for avian embryos. Using the quotient method, modeled exposure levels were compared to published no-observed-adverse-effect levels (NOAELs) for birds and mammals to calculate risk. Monte Carlo analysis was used to consider the variability and uncertainty in the risk estimates. The results suggest that TCDD in land-applied pulp and paper sludge may pose significant individual risks to terrestrial wildlife under certain circumstances. Shrews were found to be most at risk due to their high consumption rate of food items that are expected to bioconcentrate the TCDD from soil at the application sites. Of all possible pathways, only dietary exposure was considered in this investigation. The analysis centered on parameter uncertainty and does not include an assessment of alternative models, although this could be a significant source of uncertainty.
Cytochrome P4501A immunoassay in freshwater turtles and exposure to PCBs and environmental pollutants
Authors: Yawetz Aminadav , Benedek-Segal Michal , Woodin Bruce 
Published: March 2010

AbstractThis is the result of a comparative study of cytochrome P4501A (CYP1A) induction in liver microsomes from three species of freshwater turtles. CYP1A induction in turtle hepatic microsomes was compared to CYP1A induction in microsomes from the alligator, Alligator mississippiensis. Treatment of two species of freshwater turtles with four consecutive intraperitoneal injections of 100 mg/kg Aroclor 1254 caused a four- to five-fold increase in P4501A in hepatic microsomes of Chrysemys picta picta and Chrysemys picta elegans. The same treatment administered to another freshwater turtle, Mauremys caspica rivulata, resulted in a very low but significant (p &lt; 0.01) induction of P4501A in hepatic microsomes. Specimens of M. caspica rivulata collected from an organic waste oxidation pond near the petrochemical industry area of the city of Ashdod exhibited normal levels of total hepatic microsomal cytochrome P450 but no detectable level of induction of cytochrome P4501A. The lack of P4501A1 induction could have resulted from two possible reasons. The first possibility is that the turtles were not exposed to residues of petrochemical waste in the pond. More likely, the apparent lack of induction resulted from the low response to CYP1A inducers found in this species. Induction of cytochrome P4501A was evaluated immunohistochemically in liver tissue of C. picta picta pretreated with Aroclor 1254 (400 mg/kg) or (124 mg/kg) 3,3′,4,4′-tetrachlorobiphenyl. The most intensive staining was exhibited by sections of liver from a 3,3′,4,4′-tetrachlorobiphenyl-treated turtle. Staining of P4501A in liver sections from Aroclor 1254-treated turtles was relatively moderate. In induced turtles, staining of the hepatocytes concentrated near the cell membranes and nuclear membranes, but stained granules were observed throughout the cytoplasm. The presence of inducible CYP1A enzymes in turtles is of importance from an evolutionary point of view and has potential ecological relevance.
Reduction of selenium oxyanions by Enterobacter cloacae strain SLD1a-1: Reduction of selenate to selenite
Authors: Losi Mark E , Frankenberger William T 
Published: March 2010

Abstract
Reduction of selenate ( SeO2−4) to selenite ( SeO2−3) by Enterobacter cloacae strain SLD1a-1 (ATCC 700258), a facultative anaerobe isolated from agricultural drainage water, was studied in microcosm experiments using washed cell suspensions. The washed cell suspension removed 92% of added SeO2−4 (at 127 μM) from solution over 10.5 h using glucose as the electron donor. A method was developed that allowed for the assessment of factors affecting only reduction of SeO2−4 to SeO2−3, the first step in the reduction of SeO2−4 to Se0 and/or Se2−. The method consisted of treating the cell suspensions with 2,4-dinitrophenol (DNP), after which SeO2−4 reduction proceeds relatively unimpeded but SeO2−3 reduction is inhibited and SeO2−3 accumulates in solution and is quantified. Optimum pH was found to be 6.5–7.0, and an electrical conductivity of 10 dS m−1 and greater inhibited the reaction. Reduction of SeO2−4 at 127 μM by SLD1a-1 was unaffected by NO3−, NO2−, SO2−4, AsO3−4, and Fe3+ at equimolar concentrations but was inhibited by NO3− and SO2−4 at levels 5 and 236 times greater, respectively, than the SeO2−4 concentration and by CrO2−4 and SO2−3 at concentrations equimolar with that of SeO2−4. It was found that the more easily an electron donor enters the glycolytic pathway, the greater its propensity to promote SeO2−4 reduction. In addition, initially growing the organism in the presence of lactose and maltose enhanced the organism's subsequent use of these electron donors in reduction of SeO2−4. Optimum temperature for the reaction was 30°C, and lowering the oxygen level enhanced SeO2−4 reduction and removal of Se from solution. Our results provide useful information for optimization of a bioreactor using E. cloacae SLD1a-1 to treat Se-contaminated water.
Role of ground water on hexachlorocyclohexane (lindane) detections in surface water in western Canada
Authors: Donald David B , Block Howard , Wood John 
Published: March 2010

Abstract
Interrelationships between surface water and groundwater dynamics of α- and γ-hexachlorocyclohexane (HCH) were investigated by determining their detection frequency and concentrations in surface water that originated primarily from surface runoff of snow and rain and in surface water that originated from ground water. In the prairie ecozone in Saskatchewan, where lindane (γ-HCH) is currently used, lindane and α-HCH were detected in about 50% of water samples taken from lakes and ponds that are recharged primarily by surface runoff (N = 43 sites). Maximum concentrations for lindane and α-HCH were 0.011 and 0.004 μg/L, respectively. Isomers of HCH were not detected in any of the eight prairie springs that were examined (N = 10 samples). These springs originate from ground water located beneath agricultural lands. In the montane ecozone of Alberta where lindane is not used for agricultural purposes, only α-HCH was detected frequently in the Waterton and Athabasca rivers. From 1976 to 1992, α-HCH was detected in 81% of water samples from the Waterton River with no significant difference in detection frequency through the year (χ2 for 12 months = 14.6, d.f. = 11, p = 0.20, N = 163 samples). The site on the Waterton River is located downstream from a series of large lakes with multiyear storage of surface water. In contrast, discharge for the Athabasca River originates primarily from surface water during summer and ground water during winter. Detection frequency for α-HCH during these seasons was 53% and 2%, respectively, with the annual pattern a normal distribution. These results indicate that HCH isomers were not detected frequently in surface waters that originate from ground water.
Use of various acute, sublethal and early life-stage tests to evaluate the toxicity of refinery effluents
Authors: Sherry James , Scott Brian , Dutka Bernard 
Published: March 2010

Abstract
The toxicities of effluents from three Ontario, Canada, refineries were assessed with microbes, plants, invertebrates, and fish. Acute toxicity was assessed by the Microtox™ test, an assay based on electron transport activity in submitochondrial particles, and Daphnia magna (water flea) and Oncorhynchus mykiss (rainbow trout, 96-h exposure) bioassays. Short-term toxic effects were measured with bioassays of growth and survival of Pimephales promelas (fathead minnow) larvae; survival and reproduction of Ceriodaphnia dubia (water flea); growth of Selenastrum capricornutum (alga); growth of Lemna minor (aquatic plant); germination of Lactuca sativa (nonaquatic plant); survival, growth, and maturation of Panagrellus redivivus (nematode); and genotoxicity in the SOS-Chromotest. Only the Microtox test and the submitochondrial particle test detected acute toxicity in the effluent samples. Reduced survival and sublethal responses were caused by some effluents, but not all effluents were toxic, and none caused a response in all of the tests applied. The results suggest that the effluent treatment systems used at Ontario refineries have largely eliminated acute toxicity to the organisms in our test battery. Although reduced survival and sublethal effects were detected in some of the effluents, the effects were minor. Some of the tests provided evidence, albeit weak, of variations in the responses of the test organisms to a temporal series of effluent samples. Not unexpectedly, there were also minor differences in the responses of the tests to effluents from the three refineries. The fathead minnow test seems to be a sensitive indicator of the sublethal toxicity of Ontario refinery effluents.
Polychlorinated biphenyls and chlorinated pesticides in southern Ontario, Canada, green frogs
Authors: Russell Ronald W , Gillan Katherine A , Haffner G Douglas 
Published: March 2010

AbstractGreen frogs were collected from seven southern Ontario, Canada, locations and analyzed for chlorinated organicchemicals to establish the relative distribution of these chemicals at specific sites. At Hillman Marsh, a wildlife reserve in an agricultural area, green frogs accumulated significantly greater amounts of highly chlorinated Polychlorinated biphenyls (PCBs) than green frogs from all other collection sites. The source of PCBs is unknown. At Ancaster, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) accumulated in green frogs to a significantly greater extent than at all other sites. This was attributed to the presence of agriculture at Ancaster and the historic use of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) in agriculture. Chemical concentrations measured in green frogs from all locations were considerably lower than reported levels in other species resulting in observable effects. Specific data relating chronic effects in amphibians to environmental exposure to DDE and PCBs is lacking. Contaminant accumulation in southern Ontario amphibians may be an important factor contributing to amphibian declines only at specific sites.
Mechanistic quantitative structure–activity relationship model for the photoinduced toxicity of polycyclic aromatic hydrocarbons: II. An empirical model for the toxicity of 16 polycyclic aromatic hydrocarbons to the duckweed Lemna gibba L. G-3
Authors: Huang Xiao-Dong , Krylov Sergey N , Ren Lisha , McConkey Brendan J , Dixon D George , Greenberg Bruce M 
Published: March 2010

Abstract
Photoinduced toxicity of polycyclic aromatic hydrocarbons (PAHs) occurs via photosensitization reactions (e.g., generation of singlet-state oxygen) and by photomodification (photooxidation and/or photolysis) of the chemicals to more toxic species. The quantitative structure–activity relationship (QSAR) described in the companion paper predicted, in theory, that photosensitization and photomodification additively contribute to toxicity. To substantiate this QSAR modeling exercise it was necessary to show that toxicity can be described by empirically derived parameters. The toxicity of 16 PAHs to the duckweed Lemna gibba was measured as inhibition of leaf production in simulated solar radiation (a light source with a spectrum similar to that of sunlight). A predictive model for toxicity was generated based on the theoretical model developed in the companion paper. The photophysical descriptors required of each PAH for modeling were efficiency of photon absorbance, relative uptake, quantum yield for triplet-state formation, and the rate of photomodification. The photomodification rates of the PAHs showed a moderate correlation to toxicity, whereas a derived photosensitization factor (PSF; based on absorbance, triplet-state quantum yield, and uptake) for each PAH showed only a weak, complex correlation to toxicity. However, summing the rate of photomodification and the PSF resulted in a strong correlation to toxicity that had predictive value. When the PSF and a derived photomodification factor (PMF; based on the photomodification rate and toxicity of the photomodified PAHs) were summed, an excellent explanatory model of toxicity was produced, substantiating the additive contributions of the two factors.
Comparative ecotoxicity of interstitial waters in littoral ecosystems using Microtox® and the rotiferBrachionus plicatilis
Authors: Del Valls T Ángel , Lubián Luis M , Forja Jesús M , Gómez-Parra Abelardo 
Published: March 2010

AbstractThe toxic effects of sediment interstitial waters collected from seven littoral sites in the Gulf of Cádiz were tested with the Microtox® assay and a 7-d Brachionus plicatilis (Rotifera) decline test. Dissolved organic carbon (DOC), nutrients (ammonia, phosphate, nitrate, nitrite, and silicate), the heavy metals (Fe, Mn, Zn, Cu, Pb, Cr, and Cd), and the linear alkylbenzensulfonate (LAS) concentrations in the interstitial water were measured. The results of assays were compared in a dose-response relationship between sites. This comparison has demonstrated a general agreement between toxicity values determined by Brachionus plicatilis and Photobacterium phosphoreum, except in the case of interstitial water toxicity from mixtures of heavy metals. Data derived from interstitial water chemistry and bioassays were assembled by multivariate statistical techniques (principal components analysis). Positive prevalence of these components in cases studied was used to establish those ranges in chemical concentrations associated with adverse effects. The interstitial water guidelines, in terms of concentrations at or below which biological effects have been shown to be minimal (mg/L), are: DOC, 12.8; phosphate, 0.28; LAS, 80.4; ammonia, 12.1; chromium, 0.0045.
Sensitivity of glochidial stages of freshwater mussels (Bivalvia: Unionidae) to copper
Authors: Jacobson Peter J , Neves Richard J , Cherry Donald S , Farris Jerry L 
Published: March 2010

Abstract
The sensitivity of glochidial stages of unionid mussels was evaluated in a series of exposures to aqueous copper. Glochidia held within marsupia of gravid Villosa iris (I. Lea, 1829) exhibited no observable effect following a 30-d copper exposure at levels up to 19.1 μg Cu/L. Similarly, transformation of encapsulated glochidia of Actinonaias pectorosa (Conrad, 1834), Pyganodon grandis (Say, 1829), and V. iris to the juvenile stage was unaffected by 12- to 20-d copper exposures of largemouth bass, Micropterus salmoides (Lacepede), at levels up to 200 μg Cu/L. In contrast, released glochidia of all species were sensitive to copper at comparatively low concentrations. The median lethal concentrations (24-h) for Lampsilis fasciola (Rafinesque, 1820) ranged from 26 to 48 μg Cu/L, from 36 to 80 μg Cu/L for V. iris, from 37 to 81 μg Cu/L for Medionidus conradicus (I. Lea, 1834), from 42 to 132 μg Cu/L for A. pectorosa, and from 46 to 347 μg Cu/L for P. grandis. Copper sensitivity varied with changes in test conditions, including length of exposure, water temperature, and water hardness. Although sensitivity of released glochidia to copper was comparable to previously reported values for juvenile mussels, the juveniles may be at greater risk given their residency in benthic sediments where toxicants such as metals may be sequestered at high levels. An evaluation of this risk is an urgent priority for further research.
Wildlife and endocrine disrupters: Requirements for hazard identification
Authors: Campbell Pamela M. , Hutchinson Thomas H 
Published: March 2010

Abstract
The increasing demands of the global economy and our growing human population exert profound effects on the ecosystem. As a species, we have an essential need for quality air, water, and soil and a diversity of living organisms, so any vision of a sustainable future must be formulated on the basis of their protection. Decisions on the most effective ways to protect ecosystems must be prioritized on the basis of science and our understanding of the most important factors that affect wildlife populations. In the case of endocrine disrupters, it is important that further research be conducted (1) to determine the status and trends of wildlife populations and the evidence for a widespread effect of endocrine disrupters, (2) to determine the extent to which species differences in the mechanisms that control reproduction and development will affect their sensitivity to endocrine disrupters, and (3) to ensure full validation and refinement of new test methods for assessing the effects of endocrine disrupters across diverse species. Premature implementation of testing and assessment methods for endocrine disrupters, without appropriate consideration of the above points, may result in assessment schemes that placate public opinion but neither alleviate the major factors affecting wildlife populations nor protect diverse species with distinctive endocrine systems.
A multivariate biological and chemical characterization of industrial effluents connected to municipal sewage treatment plants
Authors: Andrén Cecilia , Eklund Britta , Gravenfors Erik , Kukulska Zofia , Tarkpea Maria 
Published: March 2010

Abstract
Effluents from middle-sized industries, connected to municipal treatment plants in two cities in Sweden were sampled daily during 1 week and were characterized chemically and biologically. The results were evaluated mainly with multivariate statistics to find relations between chemistry and toxicity. The principal component analysis (PCA) overview of the chemical variables displayed three main clusters: nitrogen fractions, metals, and organic parameters. An overview of the biological responses showed that inhibition of nitrification was not correlated to the other biological tests. Bivariate statistics found significant correlations existing between different endpoints of Microtox®. In the partial least squares in latent structures (PLS) models created for the biological toxicity tests (Microtox, inhibition of nitrification, and algal growth test with Selenastrum capricornutum), two significant groups causing toxicity were detected, namely inorganic metals and organic pollutants detected by adsorbable organic halogens, chemical oxygen demand, and total organic carbon. When characterizing these industrial effluents, the chemical determinations and the various biological toxicity tests complement each other and none can be excluded.
Individual variation in the swimming performance of fishes: An overlooked source of variation in toxicity studies
Authors: Kolok Alan S. , Plaisance Eric P P , Abdelghani Assaf 
Published: March 2010

Abstract
A commonly used indicator of sublethal stress in fish is impaired swimming performance. Analysis of performance data usually employs a simple comparison, in which the mean of a stressed group of fish is compared to that of a control group. Although such a comparison is satisfactory in many cases, a comparison emphasizing individual variation in performance can yield valuable information unattainable by a means comparison. In this experiment, we determined critical swimming speeds of subadult male fathead minnows before and after exposure to contaminated sediments from Devil's Swamp, Louisiana, USA. The data were then analyzed using a means comparison and an individual approach to illustrate the differences in explanatory power between the two approaches.
Trophic transfer of silver to marine herbivores: A review of recent studies
Authors: Fisher Nicholas S , Wang Wen-Xiong 
Published: March 2010

Abstract
We review recent progress in understanding the trophic transfer of silver (Ag) in marine herbivores, especially mussels that have been extensively used as biomonitors of coastal contamination. A bioenergetic-based kinetic model is invaluable in predicting the trophic transfer and bioaccumulation of Ag in aquatic animals. Critical parameters that need to be quantified in predicting trophic transfer include Ag assimilation efficiency (AE) from ingested food particles, animal feeding rates, and Ag efflux rates. Silver AEs in marine herbivores are generally low (&lt; 30%). Assimilation efficiencies from ingested sediments tend to be lower than those from ingested phytoplankton. Various biological and chemical factors, including Ag distribution in phytoplankton cytoplasm, gut passage time, importance of intracellular versus extracellular digestion, and metal desorption at lowered pHs typical of invertebrate guts, all influence Ag assimilation from ingested particles. Many experimental studies show that uptake from the dissolved phase exceeds uptake via ingestion in the overall Ag bioaccumulation in aquatic animals. However, these results are probably not predictive of field situations due to their simplistic experimental conditions in which fluctuations of feeding conditions of animals and physicochemistry of Ag are not considered. In mussels, the kinetic model predicts that either the solute or particulate pathway can dominate Ag overall uptake in nature, and this is dependent on Ag partition coefficients for suspended particles and Ag AE. Silver is the only metal that varies substantially in the importance of different uptake pathways due to its very high particle reactivity and high uptake rate from the dissolved phase. Total suspended solids (TSS) loads can sharply affect Ag bioaccumulation in mussels because high TSS loads can dilute Ag concentrations in both dissolved and particulate phases. Processes affecting Ag trophic transfer and bioaccumulation are discussed.