bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of pesticide spraying on chick growth, behavior, and parental care in tree swallows (Tachycineta bicolor) nesting in an apple orchard in Ontario, Canada
Authors: Bishop Christine A , Ng Peggy , Mineau Pierre , Quinn James S , Struger John 
Published: March 2010

AbstractThe objective of this study was to investigate the consequences of the use of cholinesterase (ChE)-inhibiting insecticides in an apple orchard on behavior and growth of tree swallows (Tachycineta bicolor). In a sprayed apple orchard and two nonsprayed sites in southern Ontario, Canada, in 1996 through 1997, hunger signaling and growth of chicks, feeding activities of adults, and aerial invertebrate abundance were studied before and after insecticide spray events. In the orchard, persistent and significant increases occurred in hunger signaling by tree swallow chicks after organophosphorus (OP) insecticide spray events in both years and, after a second OP insecticide spray in 1996, significant decreases occurred in the number of feeding trips by parent birds. These trends did not occur in the control sites. After spray events in the orchard, the trends in feeding sorties of adult birds during chick-rearing did not coincide with known experimental responses in tree swallows subjected to reduced food resources. However, trends were consistent with those predicted to occur in adult passerines exposed to ChE-inhibiting insecticides. In contrast, the increased hunger signaling by chicks may reflect chronically low food resources available in the orchard but does not indicate ChE depression. Few differences were found among sites in the size and type of aerial invertebrates caught in traps. Very low densities of invertebrates occurred in the orchard relative to the other locations but the abundance did not vary significantly with insecticide events. Despite changes in avian behaviors associated with insecticide sprays, differences in masses of chicks among sites and after spray events were not related to insecticide use in the orchard. Because first-year survival of tree swallow chicks is correlated with their mass at fledging, this suggests a need to maintain relatively natural habitats with abundant food resources near sprayed agricultural areas.
Physiological effects of chronic copper exposure to rainbow trout (Oncorhynchus mykiss) in hard and soft water: Evaluation of chronic indicators
Authors: Taylor Lisa N , McGeer James C , Wood Chris M , McDonald D Gordon 
Published: March 2010

AbstractEffects of chronic copper exposure on a suite of indicators were examined: acute toxicity, acclimation, growth, sprint performance, whole-body electrolytes, tissue residues, and gill copper binding characteristics. Juvenile rainbow trout were exposed for 30 d to waterborne copper in hard water (hardness = 120 mg/L as CaCO3, pH = 8.0, Cu = 20 and 60 μg/L) and soft water (hardness = 20 mg/L as CaCO3, pH = 7.2, Cu = 1 and 2 μg/L). Significant acclimation to the metal occurred only in fish exposed to 60 μg/L, as seen by an approx. twofold increase in 96-h LC50 (153 vs 91 μg Cu/L). Chronic copper exposure had little or no effect on survival, growth, or swimming performance in either water hardness, nor was there any initial whole-body electrolyte loss (Na+ and Cl−). The present data suggest that the availability of food (3% wet body weight/day, distributed as three 1% meals) prevented growth inhibition and initial ion losses that usually result from Cu exposure. Elevated metal burdens in the gills and livers of exposed fish were measures of chronic copper exposure but not of effect. Initial gill binding experiments revealed the necessity of using radiolabeled Cu (64Cu) to detect newly accumulated Cu against gill background levels. Using this method, we verified the presence of saturable Cu-binding sites in the gills of juvenile rainbow trout and were able to make estimates of copper-binding affinity (log Kgill=Cu) and capacity (Bmax). Furthermore, we showed that both chronic exposure to Cu and to low water calcium had important effects on the Cu-binding characteristics of the gills.
Three lines of evidence in a sediment toxicity evaluation for hexachlorobutadiene
Authors: Fuchsman Phyllis C , Sferra James C , Barber Timothy R 
Published: March 2010

AbstractThree approaches were used in a site-specific sediment toxicity evaluation for hexachlorobutadiene (HCBD), a chemical not previously tested for toxicity in sediment. The results of a sediment dilution study, spiked sediment toxicity tests, and a probabilistic model based on equilibrium partitioning theory were used to estimate ecological effects thresholds for HCBD in sediments of a Gulf Coast estuary. Twenty-nine sediment samples, including 11 undiluted samples and six dilution series, were tested for toxicity under estuarine conditions (10%0 salinity) using Hyalella azteca and Leptocheirus plumulosus. Site sediment was used as diluent, and all samples were assayed for a range of organic and inorganic chemicals. A logistic relationship was observed between HCBD concentrations and organism response, and nonlinear regression explained approximately 90% of the observed variation in amphipod survival as a function of HCBD. Spiked sediment toxicity test results generally agreed with the results of the dilution study, demonstrating the causality of the observed concentration–response relationship. Effects thresholds were estimated as HCBD concentrations corresponding to 80% amphipod survival. The most conservative effects thresholds from the spiked sediment and dilution studies were 0.63 mg/kg normalized to 1% total organic carbon (mg/kg1%OC) for H. azteca and 1.4 mg/kg1%OC for L. plumulosus. Aquatic LC50s for 10 species and a measured acute–chronic ratio from the published literature were used to predict a distribution of sediment effects thresholds for HCBD, with 10th and 90th percentile values of 2.6 and 45 mg/kg1%OC, respectively. The predicted and observed sediment effects thresholds thus agreed relatively well, although the H. azteca and L. plumulosus test results from this study seem to be somewhat more conservative than the majority of published aquatic toxicity test results.
Predictability of the toxicity of a multiple mixture of dissimilarly acting chemicals toVibrio fischeri
Authors: Backhaus Thomas , Altenburger Rolf , Boedeker Wolfgang , Faust Michael , Scholze Martin , Grimme L Horst 
Published: March 2010

AbstractA promising tool for the risk assessment of chemical mixtures is the prediction of their toxicities from the effects of the individual components. For that purpose, concentration addition is uniformly regarded as valid for mixtures of similarly acting chemicals. Whether this concept or the competing notion of independent action is more appropriate for mixtures of dissimilarly acting chemicals is still in dispute. Therefore, the presented study analyzed and compared the predictive capabilities of both concepts for a multiple mixture designed of strictly dissimilarly acting compounds. Experimental investigations were conducted using a long-term bioluminescence inhibition assay with Vibrio fischeri. Results show an excellent predictive power of independent action, while concentration addition overestimates the mixture toxicity. Thus, the precise prediction of mixture toxicities depends on a valid assessment of the similarity/dissimilarity of the mixture components. However, concentration addition underestimates the EC50 of the mixture only by a factor of less than three. As the similarity of components is often unknown for mixtures found in the environment, it is concluded that concentration addition may give a realistic worst case estimation of mixture toxicities for risk assessment procedures.
Priority setting for existing chemicals: Automated data selection routine
Authors: van Haelst Anniek G , Hansen Bjorn G 
Published: March 2010

Abstract
One of the four steps within Council Regulation 793/93/EEC on the evaluation and control of existing chemicals is the priority setting step. The priority setting step is concerned with selecting high-priority substances from a large number of substances, initially starting with 2,474 high-production-volume chemicals. In order to be able to efficiently carry out the priority setting step, an automated priority setting method was developed, the so-called European Union risk ranking method (EURAM). The EURAM produces rankings among the high-production-volume chemicals appearing in the International Uniform ChemicaL Information Database (IUCLID). As part of a publication series, this paper deals with the data selection criteria used in EURAM and furthermore with data validation of the selected data. To validate the selected data in EURAM, comparisons are made with validated data of priority chemicals for which European Union risk assessment reports have been completed or with data of priority chemicals from the Screening Information Data Set initial assessment reports of the Organization for Economic Cooperation and Development. Regression analysis between the selected data in EURAM and the data selected by expert judgment in the assessment procedure resulted in good correlation for physicochemical properties and aquatic toxicity data. In addition, the type of biodegradation (i.e., readily biodegradable, inherently biodegradable, or nonbiodegradable) selected by EURAM also was in agreement with the type of biodegradation selected by expert judgment in the risk assessment procedure. Hence, the good correlation between the automated data selection procedure of EURAM and the data selection by expert judgment indicates that the data selection criteria of EURAM, which are developed in order to select data for priority purposes among high-production-volume chemicals in IUCLID, seem to perform well.
Quantification of in vivo biotransformation of the anionic surfactant C12-2-linear alkylbenzene sulfonate in fathead minnows
Authors: Tolls Johannes , Lehmann Michael P , Sijm Dick THM. 
Published: March 2010

AbstractLinear alkylbenzene sulfonate (LAS) is a major surfactant in household detergents and enters the environment via the wastewater. Aquatic organisms are thus exposed to LAS and can bioaccumulate this compound. Even though the extent of bio-accumulation is determined by the organisms' capability of metabolizing LAS, little is known about metabolism of LAS in small aquatic organisms. In the present investigation, we present a novel approach to quantify in vivo biotransformation. Fish (fathead minnows [Pimephales promelas]) were exposed to the LAS constituent 2-n-(p-sulfophenyl)-dodecane (C12-2-LAS). The parent surfactant and its biotransformation product 3-n-(p-sulfophenyl)-butyric acid (C4-3-SPC) were determined in fish tissue. On the average, the concentration of C4-3-SPC in fish was 70 to 80% of that of C12-2-LAS. The first-order one-compartment model of bioconcentration was extended to include biotransformation as an explicit process. Analysis of the C4-3-SPC/C12-2-LASconcentration ratio in fish allowed estimating a rate constant for in vivo biotransformation of C12-2-LAS in fathead minnows. With the estimates of the biotransformation rate constant (kBT,LAS) ranging between 0.31 and 0.72/d, biotransformation contributes to more than 40% of the elimination of C12-2-LAS in fathead minnows. This indicates that biotransformation is a significant process in reducing the bioaccumulation potential of LAS. Moreover, the present investigation demonstrates that the combination of measurements of parent compound and metabolite with an extended bioaccumulation model is a viable approach for quantification of biotransformation in small aquatic test animals.
Spiking hydrophobic organic compounds into soil and sediment: A review and critique of adopted procedures
Authors: Northcott Grant L , Jones Kevin C 
Published: March 2010

Abstract
Studies on the fate and effects of organic pollutants in soil and sediment are often carried out under laboratory conditions and often require the study compound to be introduced, or spiked, into the test substrate. The procedures adopted to spike relatively large amounts of hydrophobic organic compounds into soil and sediment can introduce interferences into experiments that have the potential to dominate the process(es) under investigation. This review identifies and discusses key factors of spiking procedures that can introduce significant interferences to experiments. These include soil or sediment drying and rewetting, effects of carrier solvents, and the homogeneity of spike distribution. The persistence of solvents, and therefore their contribution to soil and sediment organic carbon, is discussed with reference to potential effects on the partitioning behavior of spiked compounds. We have summarized the spiking procedures used in 64 published articles and have evaluated the information supplied by authors. From this analysis, we conclude that, in general, authors should report more detailed information regarding the procedural aspects of compound spiking. We conclude that standard operating procedures need to be validated and recommended for spiking organic compounds into soil and sediment by recommended organizations. As an aid to this process, we recommend a number of practices to observe when spiking organic compounds into soil and sediment.
Biodegradability properties of sulfonamides in activated sludge
Authors: Ingerslev Flemming , Halling-Sørensen Bent 
Published: March 2010

Abstract
Twelve different sulfonamides were selected for a biodegradation study using a respirometric screening test and an activated sludge simulation test. A simple bacterial growth inhibition test was applied to show that the sulfonamides did not affect the bacteria at the concentration levels used. None of the compounds were degraded in the screening test, leading to the conclusion that sulfonamides cannot be classified as readily biodegradable. In the simulation test, primary degradation of mixtures of four compounds at concentration levels of 250 to 500 μg/L were tested and analyzed using high-performance liquid chromatography. Biodegradation occurred after lag phases of 7 to 10 d at 20°C when nonadapted sludge was applied. Test compounds were degraded within a few days. At 6°C, degradation lag phases and degradation rates were three to four times longer. Degradation curves fit well to the logistic growth model, indicating growth of specific degraders in the test system. Sulfonamide adapted bacterial cultures were able to degrade either the same compounds as previously added or four other sulfonamides in a rapid and uniform way (t1/2 from 0.2 to 3 d). This finding shows that if capable of degrading one sulfonamide substance, these bacteria may also degrade many other sulfonamides. In practice, this implies that because the biodegradation rate is found to be identical for several sulfonamides in the sludge, the compounds may be assessed as a group by studying only a few compounds in applications such as environmental fate assessments. The mechanism for inducement of sulfonamide adaptation to the bacteria was not revealed in this study.
Influence of zwitterionic pH buffers on the bioavailability and toxicity of copper to the alga Amphidinium carterae
Authors: Vasconcelos M Teresa SD , Almeida Cristina MR , Lage Olga M , Sansonetty Filipe 
Published: March 2010

Abstract
The culture and testing of algae frequently requires stabilization of pH levels to maintain the availability of trace metals. In this work we evaluated the influence of 25 × 10−3 M N-[2-hydroxyethyl]piperazine-N′-[2-hydroxypropanesulfonic acid] (HEPPSO) and piperazine-N,N′-bis[2-hydroxypropanesulfonic acid] (POPSO) pH buffers, at pH 8.0, on the biological response of Amphidinium carterae Hulburt. Growth rate, copper uptake, mean cell size, mean cell complexity, and fluoresce in labeling of algae cultures were studied in enriched solutions of artificial seawater (ESAWs) containing a range of total copper(II) concentrations between 23 × 10−9 M (level before copper addition) and 15 × 10−6 M. The ESAW (without a pH buffer, initial pH = 8.0) was used as the control medium. Initial free copper (Cufree) was between 53 × 10−15 and 72 × 10−10 M, which represents ranges of concentrations typical of unimpacted and polluted surface seawater. These ranges were achieved using ehtylenediaminetetraacetic acid (EDTA) alone and in combination with the two buffers. Biological data endpoints were interpreted based on the cellular copper (Cucelluar, in fmol/cell) and on the estimated initial inorganic copper (Cuinorg = Cufree plus that bound with inorganic ligands) in the medium. At innocuous Cuinorg, up to 10 × 10−9 M (Cufree ≤ 4 × 10−11 M), the Cucellular was independent of the presence of the buffer and very little dependent of Cuinorg. For Cuinorg up to 0.40 × 10−9 M, the Cucellular was approximately constant (0.1-0.2 fmol/cell) and when Cuinorg ranged between 1.1 × 10−9 M and 10 × 10−9 M the Cucellular was three times higher but also constant. The POPSO enhanced copper uptake and toxicity. The HEPPSO reduced uptake and toxicity of copper because of its enhanced binding capacity compared to POPSO. Both HEPPSO and POPSO altered copper effects on mean cell size, mean cell complexity and fluorescein labeling of A. carterae, but the inherent mechanisms differed between the two buffers. This present work demonstrated that the chemical binding affinity of HEPPSO and POPSO differed and that it resulted in altered uptake and effects of copper on algae. These observations have important implications in culture and testing of algae that require metals as micronutrients yet are sensitive to metals at concentrations that exceed basic metabolic needs.
Soil and plant diet exposure routes and toxicokinetics of lindane in a terrestrial isopod
Authors: Sousa José Paulo , Loureiro Susana , Pieper Silvia , Frost Mathias , Kratz Werner , Nogueira António JA , Soares Amadeu MVM. 
Published: March 2010

AbstractIn most studies dealing with effects of toxic substances in saprotrophic isopods, animals are exposed to the test substance through contaminated food. Because these animals can be in a close contact with the soil surface, the substrate, as an exposure pathway, should not be neglected. Here the authors analyze the toxicokinetic behavior of lindane (γ-hexachlorocyclohexane [γ-HCH]) in the isopod species Porcellionides pruinosus, comparing two exposure routes: food and two soil types (artificial Organisation for Economic Cooperation and Development [OECD] soil and a natural agricultural soil). In the feeding experiment, a strong decrease of γ-HCH concentration over time was observed on the food material, with the animals showing a broader range in chemical assimilation efficiency values (averaging 17.7% and ranging from 10 to 40%). The γ-HCH bioaccumulation results indicate that when animals incubated under both soil types reached a steady state, they displayed much higher body burdens (1,359.60 pg/animal on OECD soil and 1,085.30 pg/animal on natural soil) than those exposed to contaminated food (43.75 pg/animal). Kinetic models also revealed much lower assimilation and elimination rates in the food experiment (20.66 pg/d and 0.10 pg/d) than in both soil experiments (238.60 pg/d and 350.54 pg/d for the assimilation rate and 0.19 pg/d and 0.32 pg/d for the elimination rate). Differences in results between exposure routes are discussed according to equilibrium-partitioning theory and the enhanced relevance of the substrate exposure route is analyzed under future prospects on chemical toxicity testing using isopods.
Ecotoxicological and analytical assessment of effects of bioremediation on hydrocarbon-containing soils
Authors: Saterbak Ann , Toy Robin J , McMain Bruce J , Williams M Patty , Dorn Philip B 
Published: March 2010

AbstractEcotoxicological assessments of contaminated soils require an understanding of the impact of chemicals on the terrestrial ecosystem. Eight hydrocarbon-containing field soils were evaluated using physical-chemical, hydrocarbon, and ecotoxicological assays during 11 to 13 months of laboratory bioremediation. Ecotoxicity tests included earthworm (Eisenia fetida) 14-d survival and reproduction assays and seed germination and root length assays using corn, lettuce, mustard, and wheat seeds. During bioremediation, freon-extractable total petroleum hydrocarbon decreased by 26 to 84%, depending on the soil. In most soils, earthworm survival increased to or remained at 100% following bioremediation. Earthworm reproduction increased or remained the same relative to control soils. Lettuce and mustard seed germination increased following bioremediation except in two soils with high salt concentrations. Corn and wheat germination was high on most soils and did not change following bioremediation. Root length responses varied among seeds and soils, increasing in some soils and remaining unchanged in others. The responses of organisms to hydrocarbon-containing field soils directionally improved with bioremediation.
Dietary absorption efficiencies and toxicokinetics of polychlorinated biphenyls in ring doves following exposure to aroclor® mixtures
Authors: Drouillard Ken G , Norstrom Ross J 
Published: March 2010

AbstractRing doves (Streptotpelia risoria) were fed a meal of pellets spiked with an Aroclor® mixture. Feces were collected from birds after fasting 31 h postexposure and dietary absorption efficiencies (AbE) of polychlorinated biphenyls (PCBs) were determined by mass balance. Polychlorinated biphenyl AbEs ranged from 0.86 to 0.97 for individual congeners and were similar to the lipid AbE of 0.90. The AbEs exhibited a declining trend with increasing chemical hydrophobicity. The toxicokinetics of PCBs and dietary lipids in blood plasma were also followed in the exposed birds for 25 h after feeding the contaminated meal. Despite decreasing trends in net AbEs with increasing chemical hydrophobicity, all PCBs exhibited similar blood toxicokinetics as observed for dietary lipids. The PCB plasma uptake rate constants exhibited a positive correlation with chemical hydrophobicity such that the most hydrophobic congener PCB 180 approached the plasma uptake rate constant measured for dietary lipids. Trends in assimilation kinetics of PCBs in blood were not consistent with the general prediction that solubility limitations of chemicals in the unstirred water layer (UWL) contribute to declines in net AbEs for highly hydrophobic chemicals. The data are consistent with a micelle-mediated diffusion model, which indicates that dietary lipids and hydrophobic contaminants can cross the UWL and enter intestinal tissues at equivalent rates; however, solubility limitations of highly hydrophobic chemicals in mixed micelles may contribute to decline in net AbEs.
Effects of contaminated sediment on the epidermis of mummichog, Fundulus heteroclitus
Authors: Mézin Laurent C , Hale Robert C 
Published: March 2010

Abstract
Secretion of mucus by epidermal goblet cells protects fish against many biological, physical, and chemical insults encountered in the environment. This study monitored changes in hemoglobin concentration in epidermal mucus and in the density, diameter, and mucus quality of epidermal goblet cells in the mummichog, Fundulus heteroclitus, following exposure to creosote-contaminated sediment from the Elizabeth River, Virginia, USA. Fish were exposed for 13 d in flow-through aquaria to either uncontaminated (US) or contaminated (CS) sediments and were sampled periodically. The condition index was lower and the mortality rate and the occurrence of epidermal lesions were higher in CS-exposed fish than in US-exposed fish. Hemoglobin contents in epidermal mucus from the former group were significantly higher than from the latter. Significant reductions in both size and density of goblet cells in CS-exposed fish suggested a mucus secretion rate exceeding its production rate. Significant changes in mucin types between treatments did not occur until day 13 and are not believed to be directly related to the creosote present in the contaminated sediment. These results all indicate that exposure to creosote-contaminated sediment had a profound and deleterious effect on fish health.