bluuebunny/crossref_metadata_2025_split huggingface dataset:
Toxicity to aquatic organisms of off-target deposition of endosulfan applied by aircraft
Authors: Ernst W. R. , Jonah P. , Doe K. , Julien G. , Hennigar P. 
Published: March 2010

Abstract
Aerial drift from pesticide spray applications can result in contamination of nontarget environments such as aquatic systems. In this study, the off-target deposit of aerially applied endosulfan was collected on flat plate samplers and in containers of water placed at various distances downwind of the treated area. The water contaminated by that deposit was subsequently used to conduct 24-h lethal bioassays in a nearby temporary laboratory, using threespine stickleback (Gasterosteus aculeatus), water boatmen (Sigara alternata), caddisfly larvae (Limnephilus spp.), bivalve molluscs (Pisidium spp.), bloodworms (Chironomiidae spp.), and water fleas (Daphnia magna). Three different spray events were sampled, all of which occurred at times when meteorological conditions were within regulatory constraints. Chemical analysis of deposit collectors and exposed water indicated that deposit decreased in an exponential manner with distance downwind and ranged from 82 mg/m3 and 1.7 mg/L for plates and waters within the target site to 0.051 mg/m3 and 0.004 mg/L for plates and waters at 200 m downwind. After 24-h exposure to spray-drift contaminated water, no mortalities that could be attributed to the pesticide were observed for bivalve molluscs, bloodworms, or water fleas, even within the treated area. Water boatmen, caddisfly larvae, and threespine stickleback, on the other hand, suffered levels of mortality that varied directly with distance downwind from the treated area. The distances at which 50% mortality was measured in water boatmen and caddisfly larvae tests were 50 m and 10 m, respectively. Threespine stickleback were the most sensitive species tested, having a mortality of up to 90% at a distance of 200 m downwind. These results demonstrate the extreme risk to aquatic organisms from drift deposit of aerially applied endosulfan and indicate the need for similar assessments of other popular pesticides.
Behavioral responses of lake whitefish (coregonus clupeaformis) to cadmium during preference-avoidance testing
Authors: Mcnicol R. E. , Scherer E. 
Published: March 2010

Abstract
The behavioral responses of lake whitefish (Coregonus clupeaformis) to contact with cadmium solutions (0.2-256 μg/L) were monitored in a countercurrent-type preference-avoidance trough. A total of 27 parameters derived from 5 elements of locomotor behavior or spatial selection (including the percent-time measure) were computed and compared, and their sensitivity of response assessed. At over half of the concentrations, responses at any one concentration were dichotomous among individuals; whereas most fish showed “avoidance,” a significant number displayed “preference” when measured as the time spent on the treated side of the trough. Several of the behavioral measures displayed bimodal dose-response relationships, with a derivative of the time-spent criterion being the most sensitive indicator of response. Whitefish reacted significantly to concentrations &lt;1 and &gt;8 μg/L, but showed little response to those in between. They detected and responded to water containing cadmium at concentrations as low as 0.2 μg/L, the maximum allowable under Canadian water quality guidelines.
Adsorption of phenol and substituted phenols by iron oxides
Authors: McBride M. B. , Kung King-Hsi 
Published: March 2010

Abstract
The ability of Fe oxides to adsorb phenol and various substituted phenols from dilute aqueous solution and from the vapor state was investigated, utilizing Fourier transform infrared (FTIR) spectroscopy to evaluate the type of surface complex formed. Adsorption from solution at pH 5.5 was weak (undetectable in the case of the unsubstituted phenol). There was some indication that quantity of adsorption was inversely related to the pKa of the p-substituted phenols, with the most acidic phenols adsorbing the most strongly from solution. The FTIR spectra revealed that adsorption on goethite and amorphous Fe oxide from the vapor state tended to perturb vibrational bands sensitive to the phenolic OH group, an indication of bonding between surface Fe3+ and the phenolic ligand. Depending on level of adsorption, both physically and chemically adsorbed phenols could be detected by FTIR with chemisorption being more in evidence on amorphous Fe oxide. Phenol that was 2,6-methyl-disubstituted failed to interact strongly with the goethite surface, suggesting that steric hindrance from groups adjacent to the phenolic group prevented inner-sphere coordination of the phenols to surface Fe atoms. This steric effect was not evident for low levels of adsorption on amorphous Fe oxide, suggesting an important role of site geometry in limiting chemisorption. The strength of the Fe3+-phenolic coordination bond was correlated to the pKa of the phenol, with more acidic phenols forming weaker CO bonds. The quantity of water present determined whether the phenols adsorbed at barely detectable or much higher levels, suggesting a competition between H2O and phenols for ligand positions of surface Fe.
The biodegradation of methylene chloride in soils
Authors: Davis John W. , Madsen Steve S. 
Published: March 2010

Abstract
The aerobic biodegradation of methylene chloride was observed in a variety of surface soils including a sand, a sandy loam and a sandy clay loam, as well as a subsurface clay soil. Degradation was found to occur over concentrations ranging from approximately 0.1 ppm to 5.0 ppm. Degradation at higher concentrations was facilitated by the presence of an exogenous organic carbon source. No products other than carbon dioxide were detected in the biologically active microcosms. The time required for 50% disappearance of the parent compound varied over 100-fold, ranging from 1.3 to 191.4 d. Preexposure of the soil to methylene chloride resulted in faster rates of degradation upon subsequent exposures. Methylene chloride degradation was also observed under anaerobic conditions in the sandy loam soil. In contrast to observations under aerobic conditions, a significant lag or acclimation period preceded biodegradation under anoxic conditions, and no loss of the parent compound was observed during the first 70 d. However, following the lag period, the rate of degradation was approximately 10-fold higher under anaerobic conditions.
Early postnatal exposure to PCBs: Sperm function in rats
Authors: Sager D. , Girard D. , Nelson D. 
Published: March 2010

Abstract
Our previous studies have found that early exposure to polychlorinated biphenyls (PCBs) through milk of the dam can affect fertility when male offspring reach adulthood. A significant proportion of ovulated eggs in normal females mated to PCB-exposed males do not implant. This effect does not appear to be related to reduced weight gain of pups during PCB exposure. In this study, dams with litters were given peanut oil or a PCB mixture (Aroclor 1254) in oil at doses of 8, 16, 32 and 64 μg/g (PCBI, II, III, IV) on days 1,3,5,7 and 9 of lactation. At 120 d of age the male offspring were mated to normal females. Oviducts/uteri of sperm-positive females were flushed and eggs examined at the expected pronuclear, two- to four-cell and blastocyst stages of development. We observed either a significant decrease or a decline in number and percent of normal fertilized eggs and eggs at the two- to four-cell and blastocyst stages in females mated to male offspring of PCBII, III and IV. Neither reduced ventral prostate weights nor an increased incidence of a right kidney abnormality were correlated with reduced fertility. Caudal sperm reserves, sperm production, epididymal sperm morphology and FSH levels were not affected; testosterone levels were not reduced as compared to those of controls. With one exception, epididymal sperm motility parameters were not significantly different. It appears that early postnatal exposure to PCBs affects ability of sperm to fertilize eggs but not production, morphology or motility of epididymal sperm.
Effects of exposure to carbofuran-sprayed vegetation on the behavior, cholinesterase activity and growth of mallard ducklings (anas platyrhynchos)
Authors: Martin Pamela A. , Solomon Keith R. , Forsyth Douglas J. , Boermans Herman J. , Westcott Neil D. 
Published: March 2010

Abstract
Mallard (Anas platyrhynchos) ducklings were led for distances of 50, 150 and 300 m through plots of upland vegetation that had been sprayed with a flowable formulation of carbofuran at rates of 0, 132 and 264 g active ingredient/ha. Duckling behavior was observed and quantified immediately after exposure by using an approach-response apparatus. Brain and plasma cholinesterase (ChE) activities were determined for a subsample of ducklings from each treatment group; the remaining ducklings were monitored for growth effects. No mortality occurred during field exposure, but toxic signs were observed in ducklings moving &lt; 150 m at both spray rates. At &gt; 150 m, 17 and 100% of the ducklings had difficulty keeping pace due to anti-ChE toxicosis in the low and high spray plots, respectively. Duckling approach-response behavior became significantly slower with increasing spray rate and exposure distance (p = 0.0001). Inhibition of brain ChE activity was directly related to both spray rate and exposure distance; ducklings receiving maximum carbofuran exposure had 29% of the mean ChE activities of controls. Plasma ChE activity was inversely related to spray rate but was not affected by exposure distance and did not correlate well with brain ChE activity (R2 = 0.36). Subsequent growth rates were not affected in a dose-related manner.
Acute toxicity of four anticholinesterase insecticides to American kestrels, eastern screech-owls and Northern Bobwhites
Authors: Wiemeyer Stanley N. , Sparling Donald W. 
Published: March 2010

Abstract
American kestrels (Falco sparverius), eastern screech-owls (Otus asio), and northern bobwhites (Colinus virginianus) were given single acute oral doses of four widely diverse anticholinesterase pesticides: EPN, fenthion, carbofuran, and monocrotophos. LD50s, based on birds that died within 5 d of dosage, were computed for each chemical in each species. Sex differences in the sensitivity of northern bobwhites in reproductive condition were examined. American kestrels were highly sensitive to all chemicals tested (LD50s 0.6–4.0 mg/kg). Eastern screech-owls were highly tolerant to EPN (LD50 274 mg/kg) but sensitive to the remaining chemicals (LD50s 1.5–3.9 mg/kg). Northern bobwhites were highly sensitive to monocrotophos (LD50 0.8 mg/kg) and less sensitive to the remaining chemicals (LD50s 4.6–31 mg/kg). Female bobwhites (LD50 3.1 mg/kg) were more sensitive to fenthion than males (LD50 7.0 mg/kg). Mean percent depression of brain cholinesterase (ChE) of birds that died on the day of dosing exceeded 65% for all chemicals in all species. The response of one species to a given pesticide should not be used to predict the sensitivity of other species to the same pesticide. The need for research on several topics is discussed.
The role of acid-volatile sulfide in determining cadmium bioavailability and toxicity in freshwater sediments
Authors: Carlson Anthony R. , Phipps Gary L. , Mattson Vincent R. , Kosian Patricia A. , Cotter Anne M. 
Published: March 2010

Abstract
The objective of this study was to determine if the acid-volatile sulfide (AVS) content of freshwater sediments was important in limiting the bioavailability and toxicity of cadmium. Five different concentrations of cadmium were spiked into sediments with three different AVS concentrations, and 10-d exposures with the oligochaete Lumbriculus variegatus and the snail Helisoma sp. were conducted. Concurrent water-only cadmium exposures were also conducted. When the cadmium-to-AVS ratios were ≤1, toxicity was not observed. At ratios ≤1, mean whole-body cadmium residue concentrations of organisms were approximately equal to or less than the maximum residues obtained in survivors of the cadmium exposures in water only. These results corroborated the results of a previous experiment conducted with saltwater sediments and indicate that metal/AVS relationships could be used to establish numeric sediment quality criteria for use in the protection of aquatic life.
The lethal and sublethal responses of gammarus pulex to stress: Sensitivity and sources of variation in an in situ bioassay
Authors: Crane Mark , Maltby Lorraine 
Published: March 2010

Abstract
The feeding rate and mortality of the freshwater amphipod Gammarus pulex L., a common benthic detritivore, were measured during four trials of an in situ bioassay. The Gammarus pulex were deployed in a factorial experiment designed to assess the effects of water quality (three stations), test population (two sources), and test operator (two laboratories). Stations were selected above and below a domestic sewage treatment works, a sewage treatment works processing domestic and industrial waste, a quarry, and a pulp mill. Feeding rate appeared to have potential as an indicator of water quality, but the source of the test population and the laboratory performing the measurements both significantly influenced the results.
Predicting chemical reactivity by computer
Authors: Karickhoff Samuel W. , Mcdaniel Valeta K. , Melton Clyde , Vellino Andre N. , Nute Donald E. , Carreira Lionel A. 
Published: March 2010

Abstract
Mathematical models for predicting the fate of pollutants in the environment require reactivity parameter values —that is, the physical and chemical constants that govern reactivity. Although empirical structure-activity relationships have been developed that allow estimation of some constants, such relationships generally hold only within limited families of chemicals. Computer programs are under development that predict chemical reactivity strictly from molecular structure for a broad range of molecular structures. A prototype computer system called SPARC (SPARC Performs Automated Reasoning in Chemistry) uses computational algorithms based on fundamental chemical structure theory to estimate a variety of reactivity parameters (e.g., equilibrium/rate constants, UV-visible absorption spectra, etc.). This capability crosses chemical family boundaries to cover a broad range of organic compounds. SPARC does not do “first principles” computation, but seeks to analyze chemical structure relative to a specific reactivity query in much the same manner in which an expert chemist would do so. Molecular structures are broken into functional units with known intrinsic reactivity. This intrinsic behavior is modified for a specific molecule in question with mechanistic perturbation models. To date, computational procedures have been developed for UV-visible light absorption spectra, ionization pKa, hydrolysis rate constants, and numerous physical properties. This paper describes the logic of the approach to chemistry prediction and provides an overview of the computational procedures. Additional papers are in preparation describing in detail the chemical models and specific applications.
The effect of temperature on cadmium kinetics and oxygen consumption in soil arthropods
Authors: Janssen Martien P.M. , Bergema Walter F. 
Published: March 2010

Abstract
Soil arthropod species differ considerably in cadmium concentration and the way their burdens vary seasonally. The seasonal variation is often explained by variation in temperature and metabolic activity. To estimate the distribution of cadmium over the soil community and its annual fluxes through the different species, temperature responses of cadmium kinetics have to be taken into account.
We examined the effect of temperature on consumption, number of fecal pellets, oxygen consumption, and cadmium kinetics in two common soil arthropod species, Platynothrus peltifer and Orchesella cincta. Accumulation and elimination of cadmium was analyzed by fitting a one-compartment model. Oxygen consumption was higher for Orchesella cincta than for Platynothrus peltifer. Consumption and number of fecal pellets increased considerably between 10 and 20°C. Oxygen consumption increased exponentially in both species.
Cadmium kinetics of the species showed a different response to temperature. In Orchesella cincta, assimilation and excretion increased with temperature; in Platynothrus peltifer, assimilation increased with temperature whereas no effect was found for excretion. As a result, the equilibrium concentration remained constant in Orchesella cincta, whereas in Platynothrus peltifer it increased between 10 and 20°C.
The results indicate that the effects of temperature on cadmium kinetics differ among soil arthropod species and that it is difficult to extrapolate results from one species to the whole soil arthropod community. Species equipped to store cadmium internally seem to respond in a more pronounced way to increased temperature than do species equipped to rapidly excrete cadmium. Because oxygen consumption and cadmium kinetics are not directly related, temperature responses of cadmium kinetics should be taken into account in calculating fluxes of metals through soil arthropod populations.
Lead concentrations in wing bones of the mottled duck
Authors: Merchant Mark E. , Shukla Shyam S. , Akers Hugh A. 
Published: March 2010

Abstract
Wing samples from mottled ducks (Anas fulvigula) were collected from federal, state, and private hunting areas in Texas, Louisiana, and Florida during the 1987–1988 waterfowl season. The upper wing bone (humerus) was analyzed for lead content to determine long-term exposure of each bird to lead. Comparisons were made between mean lead concentrations found in males and females, in adults and immatures, and between mottled ducks from different areas. In general, males and adult ducks were found to contain greater lead concentrations than females and immature ducks, respectively. Of the six areas considered, Anahuac National Wildlife Refuge, Texas, was observed to have the greatest (88.9 ppm dry weight basis) and private areas in St. Bernard Parish, Louisiana, found to have the lowest (27.9 ppm) concentrations of lead. The results from this study were found to be comparable to those obtained from a similar study performed during the 1972–1973 waterfowl season.
Population-, community- and ecosystem-level responses of aquatic mesocosms to pulsed doses of a pyrethroid insecticide
Authors: Fairchild James F. , La Point Thomas W. , Zajicek James L. , Nelson Marcia K. , Dwyer F. James , Lovely Phillip A. 
Published: March 2010

Abstract
Population-, community-, and ecosystem-level responses to pulsed dosing of a pyrethroid insecticide were studied in experimental aquatic mesocosms. Twelve mesocosms (0.1 ha, 700 m3 volume) were dosed with technical-grade esfenvalerate dissolved in acetone (subsurface injection of 0-, 0.25-, 0.67-, or 1.71-μg/L nominal concentrations in triplicated mesocosms) on six dates at two-week intervals. We monitored dissipation rate of esfenvalerate; survival, growth, and reproduction of bluegill (Lepomis macrochirus); dynamics of benthos and zooplankton; biomass and productivity of phytoplankton; macrophyte biomass; diurnal oxygen pulse; and water quality over a five-month interval. Esfenvalerate dissipated rapidly from the water column (half-life, 10 h). Zooplankton and benthic macroinvertebrates decreased at 0.25 μg/L. Changes in invertebrate fauna due to esfenvalerate were partly obscured by indirect effects and seasonal dynamics. Bluegill survival, biomass, adult male survival, and reproductive success were negatively correlated with measured esfenvalerate concentrations. Although direct mortality of fish and invertebrates may be predictable from laboratory single-species tests, indirect responses of fish, zooplankton, and phytoplankton are predictable only with prior knowledge of factors controlling ecosystem structure and function.
Lethal and sublethal toxicity of benzene derivatives to the fathead minnow, using a short-term test
Authors: Marchini Silvia , Tosato Maria L. , Norberg-King Teresa J. , Hammermeister Dean E. , Hoglund Marilynn D. 
Published: March 2010

Abstract
The lethal and sublethal effects of six monosubstituted derivatives of benzene (MBs) were measured by using the 7-d test with fathead minnow larvae. The LC50s for larvae were compared to those derived from the acute test. The larvae were more sensitive than juvenile fish, yet the toxicity order of MBs was the same for both life stages, that is, butylphenylether &gt; benzophenone &gt; toluene = benzene &gt; nitrobenzene &gt; aniline. The slopes of the concentration–mortality curves indicate a peculiar behavior for aniline.
The no-observed-effect concentrations (NOECs) and the lowest-observed-effect concentrations (LOECs) for survival and growth, obtained from hypothesis test statistics, are reported together with the inhibition concentrations (ICs) for growth and biomass, calculated with a point estimation technique. The performance of the two different statistical approaches in providing adequate data for toxicity assessment is evaluated. Growth was a more or equally sensitive end point than survival, and for three chemicals biomass was more sensitive than growth.
The results of the 7-d test are compared with those of the early life stage (ELS) test. The short-term test gave the same estimates of chronic toxicity as the ELS test for benzophenone, toluene, and benzene. The toxicity of aniline was underestimated, especially with respect to growth effects.
Effects of elevated selenium concentrations on bluegills (lepomis macrochirus) in outdoor experimental streams
Authors: Hermanutz Roger O. , Allen Kathleen N. , Roush Thomas H. , Hedtke Steven F. 
Published: March 2010

Abstract
Replicated outdoor experimental streams were exposed to control water and 10 and 30 μg/L selenium (introduced as sodium selenite) to evaluate whether standard laboratory test results accurately predict the effects of selenium on fish in freshwater ecosystems and to evaluate effects found in field studies as reported in the literature. Effects on the survival, growth, and reproduction of bluegill sunfish and the early life stage of their progeny were the end points measured in a 356-d study. Adult bluegills exposed to 10 μg/L had survival reductions (p ≤ 0.05) during the final 98-d period, and those exposed to 30 μg/L experienced complete mortality. Adult growth was reduced at 10 μg/L during an intermediate period (p ≤ 0.05). Exposures of adults at both 30 and 10. μg/L for 40 weeks before spawning resulted in reduced embryo and larval survival and produced larvae with a high incidence of edema, lordosis, and internal hemorrhaging (not all were statistically significant at p ≤ 0.05). This study confirms that standard laboratory tests, which expose fish only through the water pathway, have underestimated the toxicity of selenium, and that 10 μg/L of selenium in the water of a natural ecosystem may adversely affect bluegills, as concluded by other investigators in several field studies.