bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of petrochemical sludge concentrations on changes in mutagenic activity during soil bioremediation process
Authors: Morelli Irma Susana , Vecchioli Graciela Isabel , Del Panno María Teresa , Painceira María Teresa 
Published: March 2010

Abstract
The present study was performed to assess the effect of the petrochemical sludge application rate on the mutagenic activity (Ames test) of soil and the persistence of mutagenic activity during laboratory soil bioremediation process. Sludge-soil systems were prepared at four different sludge application rates (1.25, 2.5, 5, and 10% w/w). Unamended soil was used as a control. Immediately following sludge application, in the absence or presence of S9, a linear correlation between sludge application rates and mutagenicity was found but differed significantly (p &lt; 0.05) from the control system only at higher application rates (5 and 10% w/w). The direct mutagenicity of all systems decreases during the bioremediation process, and after a year of treatment only the 10% system induced a mutagenic response that was significantly different from the control system. On the other hand, an initial increase of the indirect mutagenicity was observed at all application rates. The time required for observing this increase was inversely proportional to the initial sludge concentration. After a year of treatment, the indirect mutagenicity of all sludge-amended soils was not significantly different but was significantly different from the unamended soils. The persistence of the direct mutagenic activity of the sludge-amended soils was related to the sludge concentration, whereas the indirect mutagenic persistence was related to the relationship between easily degradable hydrocarbons and polynuclear aromatic hydrocarbons concentration and independent from the initial application rate.
The effect of 2,5,2′,5′-tetrachlorobiphenyl on growth and death of the cyanobacterium Anabaena flos-aquae
Authors: Lee Dae-Young , Rhee G-Yull 
Published: March 2010

Abstract
The effect of 2,5,2′,5′-tetrachlorobiphenyl (TcBP) on cell death was investigated in the cyanobacterium Anabaena flosaquae (Lyngb.) Bréb grown in a P-limited, semicontinuous culture under N2-fixing conditions during a 17-d period. The TcBP was supplied daily to yield final concentrations of 1, 10, and 100 ppb (or ng/ml). At 1 and 10 ppb, the population size of live cells (sum of live vegetative cells and live heterocysts) was not different from that of the TcBP-free controls (p &gt; 0.1, t test) and remained constant both in its absolute value (9.6 × 105 cells/ml) and as a percentage of the total population (98.6%). However, at 100 ppb, the population size of live cells declined significantly after the 11th day (8.2 × 105 cells/ml, or 96.6% of total population; p &lt; 0.01, t test). The decrease in viable cells was mostly found in vegetative cells. Bioconcentration factor in the cell ([pg TcBP/g dry wt cells]/[pg TcBP/ml]) was 1.23 × 105.
Assessment of the estrogenicity and toxicity of a domestic wastewater effluent flowing through a constructed wetland system using biomarkers in male fathead minnows (Pimephales promelasrafinesque, 1820)
Authors: Hemming Jon M , Waller William T , Chow Marjorie C , Denslow Nancy D , Venables Barney 
Published: March 2010

AbstractThe toxicity and estrogenicity of a final treated municipal effluent was examined while flowing through a constructed wetland in north-central Texas, USA. Fish data were collected, and a baseline wetland characterization was performed to assess wetland treatment potential for these effluent properties. Vitellogenin (VTG), gonadosomatic index (GSI), hepatosomatic index (HSI), and secondary sexual characteristics were biomarkers used in fish models to assess aqueous estrogenicity. Biological indicators used to assess overall fish health included hematocrit and condition factor. Estrogenic nature of final sewage treatment works effluent was screened, concurrent with a three-week fish exposure, via gas chromatography/mass spectrometry for target estrogenic compounds, including 17β-estradiol, ethynylestradiol, bisphenol A, nonylphenolic compounds, phthalates, and DDT. The VTG in Pimephales promelas was measured after exposure at four sites in a treatment wetland and was significantly elevated (p &lt; 0.0001) in fish exposed at the inflow site. The GSIs were significantly less (α = 0.001) at the inflow site. At wetland sites closest to the inflow, secondary sexual characteristics, tubercle numbers, and fatpad thickness were less (α = 0.0001) than in laboratory controls. The HSIs and density of male breeding stripes were not significantly different from those of laboratory controls. However, elevated HSIs were found at the inflow site. Hematocrit and condition factors were both less (α = 0.001) in effluent-exposed fish at wetland sites closer to the inflow than in control fish or fish further downstream.
Toxicokinetics of waterborne bisphenol a in landlocked salmon (Salmo salar m. Sebago) eggs at various temperatures
Authors: Honkanen Jani O , Heinonen Jari , Kukkonen Jussi V.K. 
Published: March 2010

Abstract
Eye-pigmented eggs of landlocked salmon were exposed to waterbone [14C]-labeled bisphenol A at four temperatures (2, 6, 8, and 12°C). Both in accumulation and depuration experiments, the eggs were exposed to a bisphenol A concentration of 1 μg/L for 196 h. In the depuration experiment, the exposed eggs were placed into clean water for 96 h. At each sampling time, the eggs were dissected into three parts (eggshell, embryo, and yolk sac), and all of these parts were weighed and analyzed separately in a liquid scintillation counter. The results show that waterborne bisphenol A accumulates in developing salmon eggs. Accumulation of bisphenol A showed a clear trend both in whole eggs and in dissected parts: the higher the temperature, the higher the uptake rate constant and the concentration of bisphenol A. Steady state was reached only in the embryos at the lowest temperature; in other cases, accumulation was linear. Depuration was significant only in the embryos at 2 and 6°C. As the accumulation and the depuration results show, the elimination of bisphenol A was evidently more significant at lower temperatures.
Juvenile amphibians do not avoid potentially lethal levels of urea on soil substrate
Authors: Hatch Audrey C , Belden Lisa K , Scheessele Erin , Blaustein Andrew R 
Published: March 2010

Abstract
We examined the effects of a forest fertilizer (urea) on newly metamorphosed terrestrial amphibians (Western toads, Bufo boreas; Cascades frogs, Rana cascadae; long-toed salamanders, Ambystoma macrodactylum; and roughskin newts, Taricha granulosa). We examined avoidance behavior of Western toads and Cascades frogs on both paper towel and soil substrates dosed with urea (control and 100 kg N/ha and an additional treatment of 50 kg N/ha for Western toads on soil substrate) and avoidance behavior of long-toed salamanders on soil substrate dosed with urea. We further examined the survival and feeding behavior of all four species exposed to urea on soil substrate (100 kg N/ha) for 5 d. Juvenile Western toads and Cascades frogs avoided paper towels dosed with urea but did not avoid urea-dosed soil substrate. However, Western toads and Cascades frogs both suffered significant mortality when exposed to urea on a soil substrate for 5 d. Furthermore, after adjusting for weight, we found that urea-exposed juvenile Western toads and Cascades frogs consumed significantly fewer prey items (crickets) compared with nonexposed control animals. Long-toed salamanders did not discriminate against soil substrate dosed with urea, and neither long-toed salamanders nor roughskin newts died or reduced prey consumption as a result of urea exposure. Juvenile amphibians may not be able to detect and avoid harmful levels of urea fertilizer on a natural substrate. Furthermore, anthropogenic stressors such as urea fertilizer can significantly reduce the survival and prey consumption of juvenile amphibians. These effects are important to consider in light of possible threats to the conservation status of many amphibian species.
Metal–colloid partitioning in artificial interstitial waters of marine sediments: Influences of salinity, pH, and colloidal organic carbon concentration
Authors: Cantwell Mark G. , Burgess Robert M 
Published: March 2010

Abstract
For decades, heavy metals have been deposited into marine sediments as a result of anthropogenic activities. Depending on their bioavailability, these metals may represent a risk to benthic organisms. Dissolved interstitial water metal concentrations have been shown to be better predictors of bioavailability than sediment metal concentrations. In order to improve our understanding of metals bioavailability in sediments, it is essential to fully comprehend metal speciation. Colloidal organic carbon is ubiquitous in marine interstitial water and readily forms complexes with numerous dissolved metals, greatly reducing their bioavailability. Methods were applied to isolate dissolved and colloidal cadmium, copper, nickel, lead, and zinc from interstitial waters using centrifugation and stirred cell ultrafiltration. Influences of salinity, pH, and colloidal carbon concentration on partitioning behavior were investigated. In the pH study, colloidal-dissolved partitioning of each metal (Kp) was observed to increase as pH rose. Conversely, in the salinity experiment, metal Kps declined as salinity increased. For the metal–organic colloid study, linear isotherms were calculated for each of the metals, resulting in log Kcocs ranging from 5.90 for zinc to 7.50 for copper. Kp values calculated from metal-spiked field sediments were in good agreement with those measured in the salinity study. These results provide insight into the behavior of metals associated with colloidal organic carbon in marine sediments under the conditions occurring in estuarine systems.
Hydrocarbon humps in the marine environment: Synthesis, toxicity, and aqueous solubility of monoaromatic compounds
Authors: Smith Emma , Wraige Emma , Donkin Peter , Rowland Steven 
Published: March 2010

Abstract
A recent study has shown that some monoaromatic hydrocarbon constituents of the so-called unresolved complex mixtures (UCMs) or gas chromatographic humps, which are widespread in the marine environment, are toxic to the mussel Mytilus edulis. Here we describe the synthesis and toxicological assessment of 6-cyclohexyltetralin, 7-cyclohexyl-1-methyltetralin, and 7-cyclohexyl-1-n-propyltetralin, which contain structural features consistent with some monoaromatic UCM hydrocarbons. The compounds were all toxic to M. edulis when measured in the assay used previously to determine the toxicity of a monoaromatic UCM. The aqueous solubilities of the hydrocarbons in fresh and seawater at different temperatures were determined and found to range from about 10 to 110 μg/L (10–60 μg/L in seawater at 15°C). Further studies of the aromatic UCM composition of a wide range of oils and oil residues are required to determine whether such alkylated compounds as 7-cyclohexyl-1-methyltetralin and 7-cyclohexyl-1-n-propyltetralin or their analogues are widespread in oils. If these aromatic compounds prove to be important in UCMs, toxicity experiments should be conducted with other biological end points and monitoring studies of pollutant hydrocarbons should probably include measurement of aromatic UCM hydrocarbons.
A novel toxicity fingerprinting method for pollutant identification with lux-marked biosensors
Authors: Turner Nigel L , Horsburgh Alison , Paton Graeme I , Killham Ken , Meharg Andrew , Primrose Sandy , Strachan Norval J C 
Published: March 2010

Abstract
At present, monitoring and identification of environmental pollutants in freshwater is performed predominantly by laboratory-based chemical analysis. Such an approach is often time-consuming and expensive and requires prior knowledge of the pollutants present for most practical purposes, because chemical identification techniques are generally specific to individual pollutants or pollutant classes [3]. In addition, total pollutant load does not always accurately reflect environmental toxicity because pollutant bioavailability is dependent upon water chemistry. For these reasons, a movement is increasing toward the use of biological techniques for the monitoring of environmental pollution by industry and regulators alike [2].
Impact of vinclozolin on reproductive behavior and endocrinology in Japanese quail (Coturnix coturnix japonica)
Authors: McGary Sabrina , Henry Paula F P , Ottinger Mary Ann 
Published: March 2010

AbstractThe impact of endocrine-disrupting chemicals (EDCs) has been demonstrated in mammalian models, but less research is available for avian species. The effects of vinclozolin (VIN), an antiandrogenic fungicide, on sexual differentiation and maturation were investigated in Japanese quail (Coturnix coturnix japonica). On day 4 of incubation, embryos were exposed to no treatment, oil, or 25, 50, or 100 ppm of VIN. Endpoints measured included adult male reproductive behavior, hypothalamic gonadotropin-releasing hormone I (GnRH-I) content in hatchlings and adults, plasma steroid levels in hatchlings and adults, proctodeal gland growth during maturation, and relative testicular weight at seven weeks of age. Results showed that exposure to VIN significantly (p &lt; 0.05) altered GnRH-I in male hatchlings, whereas GnRH-I levels in females remained unaffected. Although steroid levels were unaltered by any VIN treatment, the display of male reproductive behavior seemed delayed, with the number of mounts and the number of cloacal contacts being significantly (p &lt; 0.05) lower in the VIN-treated males. This could have an extreme negative impact on wild avian species that are routinely exposed to similar EDCs.
A comparison of biomarker responses in the earthworm Aporrectodea caliginosa to the organophosphorus insecticides diazinon and chlorpyrifos
Authors: Booth Lynn H , O'Halloran Kathryn 
Published: March 2010

Abstract
Three biomarkers in Aporrectodea caliginosa Savigny were evaluated for their ability to detect exposure to organophosphorus insecticides, and these physiological responses were related to effects on growth and life-table parameters. Adult and juvenile earthworms were exposed to a laboratory-simulated field rate (low concentration) and a higher sublethal concentration of diazinon and chlorpyrifos. After a four-week exposure, juveniles were evaluated for cholinesterase activity, glutathione S-transferase activity, and growth, and adults were evaluated for the lysosomal neutral red retention assay (NRRA) and growth. Cholinesterase activity and the NRRA were more sensitive than growth in each age group for detecting exposure to the pesticides. Life-table parameters were evaluated in earthworms exposed as juveniles and as adults. Maturation was less sensitive to pesticides than was cocoon production. Growth and cocoon production in earthworms exposed as juveniles appeared to be more sensitive to organophosphorus insecticides than earthworms exposed as adults. Life-table responses in juveniles may, therefore, be more predictive of long-term impacts of organophosphorus insecticide applications on populations than responses in adults. Biomarker responses occurred at similar or lower concentrations than those causing an adverse effect on cocoon production and cocoon viability, indicating their usefulness in risk assessment for predicting ecologically relevant assessment end points.
Environmental quality standards: Endpoints or triggers for a tiered ecological effect assessment approach?
Authors: Sijm Dick , de Bruijn Jack , Crommentuijn Trudie , van Leeuwen Kees 
Published: March 2010

AbstractThe recently derived Dutch Environmental Quality Standards (EQS) for water, soil, and sediment for approximately 170 substances have been evaluated. Three methods have been used to derive the Dutch EQS. Independent of how the EQS were derived, they are given equal weight in Dutch environmental policy. Scientifically, the three methods may deserve different weights. For example, for soil and sediment, the least reliable method had to be applied to derive most of the EQS. Ecological effects in these compartments may be either overestimated or underestimated. A multitiered approach is proposed, which is relevant for all parties involved, including other countries, and which may help improve ecological effect assessment.
Structure–specificity relationships for haloalkane dehalogenases
Authors: Damborský Jiří , Rorije Emiel , Jesenská Andrea , Nagata Yuji , Klopman Gilles , Peijnenburg Willie J G M 
Published: March 2010

Abstract
A structural analysis of the substrate specificity of hydrolytic dehalogenases originating from three different bacterial isolates has been performed using the multiple computer-automated structure evaluation methodology. This methodology identifies structural fragments in substrate molecules that either activate or deactivate biological processes. The analysis presented in this contribution is based on newly measured dehalogenation data combined with data from the literature (91 substrates). The enzymes under study represent different specificity classes of haloalkane dehalogenases (haloalkane dehalogenase from Xanthobacter autotrophicus GJ10, Rhodococcus erythropolis Y2, and Sphingomonas paucimobilis UT26). Three sets of structural rules have been identified to explain their substrate specificity and to predict activity for untested substrates. Predictions of activity and inactivity based on the structural rules from this analysis were provided for those compounds that were not yet tested experimentally. Predictions were also made for the compounds with available experimental data not used for the model construction (i.e., the external validation set). Correct predictions were obtained for 28 of 30 compounds in the validation set. Incorrect predictions were noted for two substrates outside the chemical domain of the set of compounds for which the structural rules were generated. A mechanistic interpretation of the structural rules generated provided a fundamental understanding of the structure–specificity relationships for the family of haloalkane dehalogenases.
Factors affecting the occurrence and enantiomeric degradation of hexachlorocyclohexane isomers in northern and temperate aquatic systems
Authors: Law Sheryl A , Diamond Miriam L , Helm Paul A , Jantunen Liisa M , Alaee Mehran 
Published: March 2010

Abstract
Concentrations of α- and γ-hexachlorocyclohexane (HCH), α/γ-HCH ratios, and enantiomer ratios (ER) of α-HCH were measured in lakes in the arctic, subarctic, Great Lakes, Canada, and temperate regions, and temperate and arctic wetlands and streams. The highest concentrations of α-HCH were found in cold, large, and oligotrophic lakes such as those in the arctic, subarctic, and the upper Great Lakes, which is attributed to greater inputs from atmospheric deposition and slower loss rates relative to warmer, temperate lakes. High α/γ-HCH ratios in northern systems indicate aged HCH that has undergone long-range transport to high latitude areas, whereas low ratios in the lower Great Lakes and small temperate systems indicate recent γ-HCH usage and residual α-HCH concentrations. Enantioselective degradation (ERs ranged from 0.31 to 0.7) was greatest in small, high arctic lakes and streams and in large lakes in the subarctic in which α-HCH concentrations and contact time between chemical and sediments are highest and nutrient concentrations are lowest. Low ERs were found in wetlands and streams in which contact between chemical and sediments was greatest. Conversely, minimal enantioselective degradation occurred in temperate small lakes and wetlands (ERs ranging from 0.77 to 1.06), despite the warmer temperatures, greater microbial populations, and nutrient availability. The results suggest that enantioselective degradation is optimized by maximal contact between chemical and sediment substrates in nutrientpoor waters in which, it is hypothesized, oligotrophic bacteria may act as biofilms.
Aryl hydrocarbon receptor-mediated and estrogenic activities of oxygenated polycyclic aromatic hydrocarbons and azaarenes originally identified in extracts of river sediments
Authors: Machala Miroslav , Ciganek Miroslav , Bláha Luděk , Minksová Kateřina , Vondráčk Jan 
Published: March 2010

Abstract
Reproductive dysfunction in wildlife populations can be a result of environmental contaminants binding to aryl hydrocarbon receptor (AhR) or estrogenic receptors. Signaling by both types of receptors can be affected by polycyclic aromatic hydrocarbons (PAHs), which are potential endocrine disruptors. However, our knowledge regarding the effects of oxygenated (oxy)-PAHs and azaarenes on AhR-mediated and estrogenic activities is incomplete. In the present study, we have identified 9-fluorenone, anthrone, anthraquinone, benzanthrone, benz[α]anthracene-7,12-dione, benz[c]acridine, and dibenz[a, h]acridine as prevalent oxy-PAHs and azaarenes found in river sediments. Their concentrations in sediment samples ranged from 2.1 to 165.2 ng g−1 for oxy-PAHs and up to 27.3 ng g−1 for azaarenes. Their relative AhR-inducing and estrogenic potencies were quantified in vitro using two cell lines that were stably transfected with a luciferase reporter gene system and expressed as induction equivalency factors (IEFs). The only oxy-PAHs with detectable levels of in vitro AhR-mediated activity were benzanthrone and benz[a]anthracene-7,12-dione. However, their IEFs were approximately three to four orders of magnitude lower than those of benzo[a]pyrene. On the other hand, azaarenes showed a strong AhR-mediated activity, with dibenzo[a, h]acridine being a far more potent inducer of activity than benzo[a]pyrene. Benzanthrone, benz[a]anthracene-7,12-dione, anthraquinone, and benz[a]acridine were weak inducers of in vitro estrogenic activity, with IEFs similar to that of benzo[a]pyrene. Based on concentrations and relative potencies, our results suggest that dibenzo[a, h]acridine can significantly contribute to the overall AhR-mediated activity in river sediments, whereas the remaining compounds do not. No studied compound was found to contribute significantly to estrogen receptor–mediated activity in vitro.
Chlorodifluoroacetic acid fate and toxicity to the macrophytes Lemna gibba, Myriophyllum spicatum, and Myriophyllum sibiricum in aquatic microcosms
Authors: Hanson Mark L , Sibley Paul K , Mabury Scott A , Muir Derek C , Solomon Keith R 
Published: March 2010

Abstract
Chlorodifluoroacetic acid (CDFA) is a novel haloacetic acid (HAA) and has been recently documented in aquatic systems. It is a suspected degradation product of the refrigerants 1,1,2-trichloro-1,1-difluoroethane (CFC-113) and 1-chloro-1,1-difluoroethane (HCFC-142b). Haloacetic acids can be phytotoxic, putatively acting through inhibition of the citric acid cycle. Replicate (n = 3) 12,000-L model aquatic ecosystems (microcosms) were dosed once at 0.5, 1, 5, and 20 mg/L of neutralized CDFA. Three microcosms served as controls. Each microcosm was stocked with eight individual apical shoots of both Myriophyllum spicatum and Myriophyllum sibiricum and sampled at regular intervals over a 42-d exposure period. The plants were assessed for the somatic endpoints of plant length, root growth, node number, and wet and dry mass and the biochemical endpoints of chlorophyll-a/b and carotenoid content as well as citric acid levels. The duckweed Lemna gibba was also introduced into these systems and monitored over a period of 14 d for wet/dry mass, plant/frond number, chlorophyll content, and growth rate. Concentrations of CDFA remained constant in the water column over the course of the fate investigation (241 d), indicating that this compound undergoes little, if any, degradation in aquatic systems. Results showed few statistically significant differences from controls for all three plant species with exposure to CDFA but no biologically relevant impacts. Overall, CDFA does not appear to pose any risk to these aquatic macrophytes at current environmental concentrations.