bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition of brain and plasma cholinesterase activity in zebra finches orally dosed with fenitrothion
Authors: Holmes Stephen B. , Boag Peter T. 
Published: March 2010

Abstract
Zebra finches (Poephila guttata) were given single oral doses of fenitrothion insecticide dissolved in soya bean oil. Brain and plasma cholinesterase (ChE) activities were measured periodically up to 10 d postexposure. Dosage rates of 1.04, 3.80 and 11.36 mg active ingredient/kg body weight resulted in maximum brain ChE inhibitions of 50, 70 and 75%, and maximum plasma ChE inhibitions of 78, 82 and 89%, respectively. Recovery of ChE activity in vivo followed an exponential pattern, with plasma ChE activity recovering more rapidly than brain ChE activity. At dosage rates of 1.04 and 3.80 mg/kg, plasma ChE activity recovered to normal in 1 to 2 d. Brain ChE activity was inhibited up to 10 d after dosing at 1.04 mg/kg. There was some mortality of exposed birds at the two higher dosage rates. Birds that died exhibited brain ChE inhibitions ranging from 3 to 84%.
Effect of sediment test variables on selenium toxicity to Daphnia magna
Authors: Stemmer B.L. , Burton G.A. , Leibfritz-Frederick S. 
Published: March 2010

Abstract
The effects of three test method variables (spiking method, sediment storage and sediment: water ratio) on solid-phase sediment toxicity of selenite-spiked sediments were investigated using Daphnia magna 48-h acute exposures. Spiking methods compared stirring and shaking of selenite with sediments followed by toxicity testing from 4 to 72 h. The two methods produced similar LC50 values; however, significant toxicity changes occurred over time. The effect of mixing spiked sediments from 0.5 to 48 h showed decreased toxicity after 24 and 48 h of shaking. Storage of selenite-spiked sediments at 4 and 25°C revealed significant differences in LC50 values between storage temperatures and with time of storage. Toxicity tended to decrease faster in sediments stored at 25°C. Sediment: water comparisons varied the volume of sediment and water used in test beakers and the sediment surface area. In general, only extreme sediment: water ratios affected survival. Varying the sediment surface area while maintaining a constant 1:4 ratio did not alter survival. An increased surface area and a decreased sediment: water ratio (1:8) decreased survival.
An in situ study on the distribution, biotransformation and flux of polycyclic aromatic hydrocarbons (pahs) in an aquatic food chain (seston-Mytilus edulis L.-Somateria mollissima L.) from the baltic: An ecotoxicological perspective
Authors: Broman Dag , Näuf Carina , Lundbergh Ivar , Zebühr Yngve 
Published: March 2010

Abstract
This in situ study is focusing on the distribution, biotransformation and flux of 19 polycyclic aromatic hydrocarbons (PAH19) in the food chain seston-blue mussel (Mytilus edulis L.)-common eider duck (Somateria mollissiima L.) as well as the distribution in the gallbladder, liver, adipose tissue and egg of the duck. All samples were collected within the open northern Baltic proper coastal areas. Analyses were carried out by gas chromatography/mass spectrometry with electron impact (GC-MSEI) and negative ion chemical ionization (GC-MSNICI). With a multivariate statistical method (SIMCA) a significant change in the PAH composition through the food chain was found. This change probably depends on an increasing metabolic activity with increasing trophic level, due to a selective biotransformation capacity for different PAHs. Decreasing PAH concentrations with increasing trophic level were found. The PAH concentrations in the different eider duck organs were: gallbladder &gt; adipose tissue ≥ liver. The theoretical inhalation of air-dispersed PAHs was of no significance compared to the exposure from food. The relatively high theoretical PAH flux through the food chain did not result in increasing concentrations with increasing trophic level, which indicates that PAHs are biotransformed quite fast. However, many intermediate metabolites of PAHs have a mutagenic and carcinogenic potential, which makes it important to observe these compounds when assessing ecotoxicological risks.
Influence of digestive processes on the absorption and fate of quinoline ingested by rainbow trout (Oncorhynchus mykiss)
Authors: Dauble Dennis D. , Curtis Lawrence R. 
Published: March 2010

AbstractRainbow trout were fed pelleted food containing [14C]-quinoline to assess the relationship of digestive processes to xenobiotic pharmacokinetics. The pH of material in the stomach of rainbow trout ranged from 2.7 to 5.2 and was highly correlated (r = 0.89) with the size of the food bolus remaining. At 2 h after feeding, 67% of the quinoline was estimated to be un-ionized and available for absorption across gastric epithelium. Quinoline was &gt;99% un-ionized in the alkaline environment of the intestine; however, relative concentrations in the intestine were about 8% of those measured in the stomach. Gastric absorption was consistent with known serum profiles and excretion patterns of dietary quinoline. Rates of gallbladder emptying appeared to exceed rates of hepatic bile secretion until about 8 h after a single feeding. Time since feeding influenced both the amount and concentration of quinoline-derived radioactivity in the bile. Consecutive feedings enhanced the movement of the food bolus and associated radioactivity from the upper and midgut regions, but had no effect on disposition of quinoline.
Effects of carbofuran, chlorpyrifos and deltamethrin on hatchability, deformity, chick size and incubation time of Japanese quail (Coturnix japonica) eggs
Authors: Martin Pamela A. 
Published: March 2010

Abstract
Japanese quail (Coturnix japonica) eggs were immersed in aqueous emulsions of carbofuran, chlorpyrifos and deltamethrin at three potential field concentrations and at three stages of incubation. No effects of pesticide exposure on hatchability were detected. There were no significant effects of carbofuran on rate of hatchling deformity, incubation time, chick mass or tarsus length. Eggs treated immediately prior to incubation with chlorpyrifos at two times the recommended field application level had a significantly greater rate of hatchling deformity (e.g., foot malformations and scoliosis) and a longer incubation period than controls. Eggs exposed to two times field application rates of deltamethrin at the preincubation stage had significantly longer incubation periods and eggs exposed to this rate of deltamethrin on incubation day 14 produced significantly lighter chicks than controls. Overall, effects were small and the three insecticides did not represent a significant hazard to quail embryos at conditions up to two times field levels of application.
Runoff-induced metals in Lakes Bay, New Jersey
Authors: Parrish Camille S. , Uchrin Christopher G. 
Published: March 2010

Abstract
Lakes Bay, an estuarine embayment located near Atlantic City, New Jersey, currently supports commercial shellfishing; however, the surrounding basin is a prime location for development. Synpotic surveys were conducted during the summer of 1986 to determine background conditions and the response to stormwater runoff inputs of three metals; copper, lead and cadmium. Background (dry weather) conditions of all three metals were found to be not significantly different than those reported for world natural waters. Significant amounts of lead and copper were found to be input to the system through a major storm water sewer that discharges to a lagoon. Sediment analysis showed that considerable sedimentation occurs in this lagoon, thus localizing the effect of this input to the system. A local stormwater retention basin was not found to be a significant source of metals. Cadmium levels were not found to be significantly different between dry and wet weather conditions. The high salinity of the system required extensive sample extraction procedures prior to analysis by atomic absorption spectrophotometry to minimize matrix interferences.
Photochemical degradation rates of tetraphenylborate and diphenylboric acid sensitized by dissolved organic matter in stream water
Authors: Mills Gary L. , Schwind Donna 
Published: March 2010

Abstract
The photochemical degradation of tetraphenylborate (TPB) and diphenylboric acid (DPBA) was studied in stream water and humic acid solutions. The rates of indirect photolysis of TPB and DPBA were similar and directly proportional to the concentration of stream water dissolved organic matter (DOM) and humic acid for values &lt; 10 mg/L. Direct photolysis of both organoborates was nondetectable during a 2-h irradiation period. Indirect photolysis rates varied only slightly from pH 6.0 to 9.0, but increased markedly below pH 6.0. Removal of dissolved oxygen increased reaction rates by a factor of two, indicating that the reaction mechanism does not involve singlet oxygen oxygenation.
Humic acids reduce the photo-induced toxicity of anthracene to fish and daphnia
Authors: Oris James T. , Hall A. Tilghman , Tylka Jacqueline D. 
Published: March 2010

Abstract
The effects of dissolved humic materials (DHM) on the photo-induced toxicity of anthracene to fathead minnows (Pimephales promelas) and daphnia (Daphnia magna) were studied in a laboratory system under simulated sunlight. In the fathead minnow toxicity tests, four concentrations of anthracene (0, 6.6, 13.1 and 19.1 μ g/L) and five concentrations of DHM (0, 0.5, 1.0, 3.0 and 6.0 mg C/L) were achieved. In the daphnia toxicity tests, four concentrations of anthracene (0, 5.58, 10.49 and 21.03 μ g/L) and four concentrations of DHM (0, 0.8, 2.7 and 6.9 mg C/L) were achieved. DHM significantly reduced acute photo-induced toxicity in both organisms. Median lethal times (LT50) were directly related to DHM concentration and inversely related to water anthracene concentration across the tested ranges of each variable. The presence of DHM also reduced anthracene bioaccumulation, and LT50 values for both fish and daphnia were inversely related to body anthracene concentration. Findings presented in this study demonstrate that the photo-induced toxicity of anthracene is primarily a fugacity-dependent phenomenon, that selective attenuation of the active wavelengths of solar ultraviolet radiation by DHM also results in a decreased level of acute toxicity and that a common mode of acute photo-induced toxicity between fish and daphnia exists.
Multi-steady-state toxicant fate and effect in laboratory aquatic ecosystems
Authors: Burnett Kelly M. , Liss William J. 
Published: March 2010

Abstract
The influence of competition, exploitation and level of energy input on toxicant fate and effect in simple aquatic laboratory ecosystems was studied. Twenty-four systems composed of populations of guppies (Poecilia reticulata), snails (family Planorbidae) and various taxa of algae were maintained in 40-liter flow-through glass aquaria. Guppies and snails were competitors for a common food resource. Ecosystems were established in which guppies and snails were sympatric and allopatric. The systems were exposed to three levels of guppy exploitation and received two levels of energy input. System dynamic and near steady-state behavior were documented through monthly measurements of population biomasses. Biomasses of interacting populations were displayed on phase planes. Shifts in system structure followed chronic exposure to a sublethal concentration of dieldrin. System responses to the toxicant ranged from increased population biomass to population extinction and were influenced by level of exploitation, energy input rate and species competition. Toxicant concentrations were determined in adult female fish. Both toxicant effect and fate were influenced by system organization and environment. Quite different conclusions concerning toxicant performance in these systems could have been drawn if observation had been restricted to only one set of organizational and environmental conditions.
Henry's law constants for selected pesticides, PAHs and PCBs
Authors: Fendinger Nicholas J. , Glotfelty Dwight E. 
Published: March 2010

Abstract
Henry's law constants (HLCs) were determined for 12 pesticides, 9 polynuclear aromatic hydrocarbons (PAHs) and 2 polychlorinated biphenyl (PCB) congeners using a wetted-wall column (WWC) technique. The WWC equilibrates an organic solute between a thin film of water and a concurrent flow of air in a vertical column. Air and water collected from the WWC were either solvent extracted or trapped on solid phase sorbents and were analyzed by gas chromatographic methods. HLCs were calculated from analyte concentrations in air and water collected from the WWC. Results of the HLCs determined by the WWC are compared with calculated values and determinations made by other investigators using purge bottle and static equilibration techniques.
Effects of acidification on minor and trace metal chemistry in little rock lake, wisconsin
Authors: Brezonik Patrick L. , Mach Carl E. , Downing Gregg , Richardson Nancy , Brigham Mark 
Published: March 2010

Abstract
Little Rock Lake is a low-alkalinity (25 μeq/L, pH 6.1) seepage lake in north-central Wisconsin. The two main basins of the lake were separated by a polyvinyl barrier in 1984, and acidification of the north basin with H2SO4 began in spring 1985; the south basin is being maintained as a reference. The effects of acidification on dissolved concentrations of Al, Fe, Mn, Cd, Cu, Ni, Pb and Zn have been studied at three scales at Little Rock Lake: (A) laboratory-scale experiments with well-mixed sediments; (b) large (4- to 5-m dia) in situ enclosures maintained at pH 4.5 to 6.0; and (c) the lake itself. In general, qualitative agreement is good between the three approaches, but some differences have been observed, especially for Al and Fe. The most significant trace metal response observed in acidifying the north basin from pH 6.1 to 5.1 has been a large increase in dissolved Mn, apparently as a result of hindered oxidation of Mn2+ at lower pH. Dissolved Al and Fe also increased at pH 5.1 but not at 5.6. Water column levels of Cd, Cu, Pb and Zn have not increased at pH 5.1 in the lake, but results of lab and enclosure studies suggest that increased concentrations of Cd and Zn will occur when the lake is acidified to pH 4.6. Sediment cores and surface sediments from both basins of the lake have been collected and analyzed for Al, Fe, Mn, Cd, Cu, Hg, Ni, Pb and Zn. Similar concentrations of most metals were found in surface sediments from both basins of the lake. Near-surface sediments were enriched in Hg and Pb relative to deeper sediment layers; the enrichment is presumed to be caused by increased atmospheric inputs during the past century, not diagenetic activity. No consistent differences in the Hg content of zooplankton, periphyton and benthic invertebrates were found at pH 5.6 and 5.1 in the acidified basin compared with the pH 6.1 reference basin.
Factors affecting mercury accumulation in fish in the upper michigan peninsula
Authors: Grieb Thomas M. , Bowie George L. , Driscoll Charles T. , Gloss Steven P. , Schofield Carl L. , Porcella Donald B. 
Published: March 2010

Abstract
Fish were sampled from 35 drainage and seepage lakes in the upper Michigan peninsula and Wisconsin in conjunction with Phase II of the U.S. Environmental Protection Agency's Eastern Lake Survey to explore the relationship between physicochemical characteristics of lakes and mercury concentrations in fish tissue. The lakes were selected using a stratified random design weighted for low pH to assess acidification effects on mercury bioaccumulation. Muscle tissue from yellow perch (Perca flavescens), northern pike (Esox lucius), white sucker (Catostomus commersoni) and largemouth bass (Micropterus salmoides) was analyzed for total and methylmercury. Differences in mercury concentrations were found between species, and methylmercury accounted for 99% of total mercury. Relationships were examined between tissue concentrations of mercury in yellow perch and lake physicochemical variables including pH, acid neutralizing capacity (ANC), calcium, conductivity, aluminum, total phosphorus, dissolved organic carbon, color, sulfate, lake area, lake depth, watershed area, Secchi depth and elevation. Mercury concentrations were negatively correlated with pH and ANC for both seepage and drainage lakes, but correlations with other water-quality characteristics varied with lake type. Dissolved organic carbon had a negative correlation with fish mercury accumulation in seepage lakes, but not in drainage lakes. Mercury concentrations had a positive correlation with age, weight and length in yellow perch.
Human health risks from methylmercury in fish
Authors: Clarkson Thomas William 
Published: March 2010

Abstract
Human health risks from methylmercury in fish are evaluated in terms of dose-response relationships for both adult and prenatal human exposures. Specifically, information has become available from three independent epidemiological studies indicating that methylmercury levels in the mother during pregnancy predict the probability of adverse effects in her offspring. The mercury levels in the mother are measured as concentration in head hair which in turn is an excellent predictor of blood concentration. The adverse effects in the offspring take the form of psychomotor retardation. These dose-response relations along with a one-compartment kinetic model for methylmercury accumulation in humans will be used to estimate minimum toxic daily intakes; these are, for nonpregnant adults, 4,300 ng Hg/kg body weight/d and about 600 to 1,100 ng Hg/kg/d for pregnant adults. These values assume continuous exposure until the individual has attained steady state balance with respect to the body burden of methylmercury. This will take up to one year in most cases.
Hydrolysis of chlorostilbene oxide II. Modeling of hydrolysis in aquifer samples and in sediment-water systems
Authors: Metwally Mohammed El-Sayed , Lee Wolfe N. 
Published: March 2010

Abstract
The disappearance kinetics of 4-chlorostilbene oxide (CSO) were determined in aquifer samples and in sediment-water systems to derive kinetic expressions that describe heterogeneous effects. Disappearance rate constants were determined in heterolytic systems and compared with those obtained in distilled water to delineate the effect of solids on the kinetics of hydrolysis. In both neutral and acid hydrolysis studies, the sorption-desorption rates of CSO were faster than the hydrolysis rates in either the aqueous or sediment-sorbed phases. Both dissolved and sorbed CSO hydrolyzed at either neutral or acidic pHs. Above pH 5, where neutral hydrolysis dominates, the hydrolysis rate constant of CSO in sterile sediment-water systems was the same as in distilled water. This suggests that sorption neither retards nor promotes the neutral hydrolysis pathway. At pHs below 5, where acid hydrolysis dominates, the pseudo-first-order hydrolysis rate constant was lower for the sorbed fraction than the rate constant in distilled water at the same pH. This indicates that hydrolysis rate constant in the sorbed phase is slower than that in the bulk aqueous phase.
Kinetics of hydrolysis were studied in raw sediment samples and samples sterilized by heat or with formalin to distinguish between abiotic and biotic hydrolysis processes. Above pH 5, the hydrolysis rate constants were larger in nonsterile systems when compared with the rate constants in the sterile systems, suggesting that both biotic and abiotic pathways contribute to the disappearance of CSO. Below pH 5, the hydrolysis rate constants were, within experimental error, the same in the sterile and nonsterile systems. In aquifer samples, the average disappearance rate constant of CSO was 0.85 (±0.11) × 10−4 min−1, which is about the same as the rate constant in distilled water. These results suggest that there is no heterolytic enhancement of the neutral hydrolysis rate constant by the aquifer materials.
Photochemical transformation of pyrene vapor deposited on eleven subfractions of a high-carbon coal stack ash
Authors: Miller Vernon R. , Wehry E. L. , Mamantov Gleb 
Published: March 2010

Abstract
A high-carbon coal stack ash has been separated by particle size and then by composition, into strongly magnetic, weakly magnetic, “nonmagnetic” mineral, heavy carbon and light carbon fractions. Eleven of these fractions have been characterized by bulk iron and carbon analyses and BET surface area determinations. The photochemical transformation of pyrene, deposited from the vapor phase onto these eleven ash fractions, has been studied. Appreciable phototransformation of adsorbed pyrene was observed for only three fractions; in those fractions, the bulk percentage of carbon (0.4–0.7%) and the specific surface area (0.50–0.68 m2/g) were both very low. For all fractions having bulk carbon percentages ≥ 4% and specific surface areas ≥ 2.85 m2/g, no detectable phototransformation of adsorbed pyrene was observed. There was no discernible correlation of photochemical reactivity of adsorbed pyrene with the iron content of the ash fractions. In general, the specific surface area of the fractions increased with increased carbon content; two different forms of carbon having different surface areas were observed.
Toxicity of parathion to captive european starlings (Sturnus vulgaris) — absence of seasonal effects
Authors: Rattner Barnett A. , Grue Christian E. 
Published: March 2010

Abstract
The effects of season on the toxicity of the prototypic organophosphorus insecticide parathion was evaluated using adult European starlings (Sturnus vulgaris) housed in outdoor pens. Groups of birds received oral doses of parathion in the fall, winter, spring and summer. Median lethal dosage, and brain and plasma cholinesterase inhibition, were found to be quite similar among seasons. Parathion may have been more toxic during hot weather (winter vs. summer LD50 estimate: 160 vs. 118 mg/kg; p &lt; 0.1). In view of previous reports in which ambient temperature extremes and harsh weather have enhanced organophosphorus insecticide toxicity to birds, it is concluded that circannual toxicity studies should include measures of sensitivity (acute oral exposure) and vulnerability (dietary exposure) to better predict responses of free-ranging birds.
Effect of sediment spatial variance and collection method on cladoceran toxicity and indigenous microbial activity determinations
Authors: Stemmer B. L. , Burton G. A. , Sasson-Brickson G. 
Published: March 2010

Abstract
Quantitative assessments of sediment quality frequently are based on data derived from sediments collected by grab sampling. Often only one sediment or one composited sediment is collected at a sample site, thereby preventing any determination of spatial variance. The significance of spatial variance and collection method on cladoceran toxicity and indigenous microbial activities was determined at a creosote contaminated site in the Little Scioto River in Marion County, Ohio. Replicate sediments were collected on two occasions from a horizontal sample grid (110 m2 and 1.4 m2) using an Ekman dredge and hand core. Sediment particle size fractions did not vary significantly between replicate grab samples. Survival of Daphnia magna and Ceriodaphnia dubia in 48-h solid phase exposures varied, however, from 0 to 100% horizontally and vertically at the test site. Percent survival and β-glucosidase activity decreased in sediment sections below a 4 to 5 cm depth. Dredged sediments produced less toxicity to the daphnids than did core collected samples. The coefficient of variance was high (&gt;40%) for both survival and hydrolase activities (alkaline phosphatase, β-galactosidase and β-glucosidase) between horizontal sediment replicates collected by either dredge or core. Subsample variance, however, was small (&lt;20%). These results highlight the important role that sediment heterogeneity and collection method have on sediment quality assessments.