bluuebunny/crossref_metadata_2025_split huggingface dataset:
Carbofuran disposition in the rat after aerosol inhalation
Authors: Ferguson Paul W. , Jewell Sarah A. , Krieger Robert I. , Raabe Otto G. 
Published: March 2010

Abstract[14C-]Carbonyl carbofuran toxicity, metabolism and pharmacokinetics in male Sprague-Dawley rats were studied after 4.1 μm (50 min, 0.2 and 1.2 μg/L) and 1.5 μm (70 min, 0.2 μg/L) aerodynamic diameter monodisperse aerosol exposures. Regional carbofuran deposition for each particle size was similar to human and rodent models for insoluble aerosols. Total carbofuran deposition was greater than expected in the rodent model but similar to that in human models.3-Hydroxycarbofuran/carbofuran ratios in gastrointestinal tract and liver (1.3, 3 × greater after 4.1 μm) provided additional deposition indices. Rapid in vitro solubility t1/2 (17 min) for 4.1 μm particles and minimal differences in plasma carbamate (% total 14C/animal) after varied particle size exposure indicated primary clearance by dissolution, irrespective of deposition site. Carbofuran (1.2 μg/L, 4.1μm) inhibited red blood cell acetylcholinesterase (55% at 10 min postexposure with recovery by 2 h). Eight-hour 14C metabolic fate in 14CO2 (31–38%), urine (9–12%), feces (2–5.5%) and carcass (44–58%) were similar for each particle size. Carbamate pharmacokinetics measured for 2 h postexposure to 4.1 μm particles described monoexponential elimination. Plasma half-lives for carbofuran (36 min) and 3-hydroxycarbofuran (62 min) were similar to those previously determined after oral and i.v. exposures.
Use of aquatic toxicology and quantitative chemistry to estimate environmental deactivation of marine-grade creosote in seawater
Authors: Borthwick Patrick W. , Patrick James M. 
Published: March 2010

Abstract
The acute toxicity of marine-grade creosote, expressed as the 96-h LC50, is 0.018 mg/L for mysids (Mysidopsis bahia Molenock), 0.24 mg/L for pink shrimp (Penaeus duorarum Burken-road) and 0.72 mg/L for sheepshead minnows (Cyprinodon variegatus, Lacépède). The 96-h EC50 (shell deposition) for Eastern oysters (Crassostrea virginica Gmelin) is 0.71 mg/L. Mysid bioassays and chemical analyses estimate the half-life (≤ 1 week) for marine-grade creosote in seawater.
Effect on Daphnia pulex (de geer) of daily pulse exposures to copper or cadmium
Authors: Ingersoll Christopher G. , Winner Robert W. 
Published: March 2010

Abstract
The most recent U.S. EPA water quality criteria indicate that chronic exposures to pulses of the LC50 concentration of a metal will cause no damage to freshwater animals as long as the average daily concentration does not exceed the chronic, no-observable-effect concentration. We have tested this concept by exposing Daphnia pulex to such pulses of copper and cadmium. The exposures to cadmium for periods of up to 70d, caused no adverse effects. However, 70-d exposures to daily pulses of copper resulted in significant reductions in survival, growth and reproduction. Although the two-number criterion has not been tested for other chemicals, it is probable that the success of this approach in protecting freshwater animals from chronic exposures to chemicals will be as variable among other chemicals as we have shown it to be between copper and cadmium.
Seasonal patterns of sedimentary hydrocarbons in the raritan bay-lower new york bay
Authors: Stainken Dennis M. , Gray Multer H. , Mirecki June 
Published: March 2010

Abstract
Surface sediments from 24 stations in the Raritan Bay-lower New York Bay were analyzed seasonally for size-grade distributions, percent volatiles and extractable hydrocarbons. Seasonal means of size-grade fractions were not statistically different, although much inter- and intrastation variability occurred. Greater silt-clay content tended to occur at the head of the bay (especially in winter) and decreased down the bay. During fall and winter, the occurrence of silt-clay fractions tended to increase throughout the bay.
Extractable hydrocarbons exhibited significant seasonal differences (p &lt; 0.05). Extractable hydrocarbon ranges were 1–1,273 μg/g dry sediment, with seasonal means of 160–327 μg/g dry sediment, depending on the bay region. Hydrocarbon content and percent volatiles generally increased with increased silt-clay content. Best correlations of hydrocarbons with silt-clay occurred in summer and fall. Throughout the seasons, hydrocarbon material appeared to move down the bay, with lowest values in fall-winter and the highest in spring-summer.
An In Situ assessment of the acute toxicity of urban runoff to benthic macroinvertebrates
Authors: Medeiros Carmen , Leblanc Ronald , Coler Robert A. 
Published: March 2010

Abstract
Colonized Hester-Dendy substrates were deployed for 96 h in an urban river reach, storm drain channel and a control site to assess the toxicity of urban runoff. The mean macroinver-tebrate diversity during rain events was reduced from 1.7 at the control station to 1.0 at both urban stations. Snowmelt exerted the same effect on river substrate diversity, but only reduced channel values from 2.0 to 1.4. During periods of no runoff, however, mean channel and control diversities remained the same (1.5), while river values dropped to 0.8. Similarly, substrate population densities during rain were, respectively, two and seven times more limiting for the storm drain channel and river reach stations. The same trend was evident in heavy metals uptake, indicating that dry weather toxicity in urban river reaches originates from the sediments. Runoff, then, serves to reduce toxicity during input, but increases it over the long run.
Patterns of toxicological effects in ecosystems: A modeling study
Authors: O'Neill R. V. , Bartell S. M. , Gardner R. H. 
Published: March 2010

Abstract
Differences in patterns of response in a pelagic ecosystem due to seasonal exposure and differential sensitivities of populations and trophic levels to chemical stress were examined with a simulation model. Simulations of constant 7-d exposures initiated at different times of year demonstrated that stresses imposed during the spring reduced average producer and consumer biomass. Stresses imposed later in the year reduced grazer biomass and permitted increased phytoplankton production. Simulated exposures to phenol, naphthalene and four heavy metals predicted different effects when toxic sensitivities of populations and trophic levels were ignored. Risks of increased blue-green algae production or decreased game fish production were estimated from repeated simulations that extrapolated uncertainties associated with individual toxic effects parameters. Estimates of risk that included population-specific toxicities were two or three times greater than risks estimated from trophic level toxicities alone.
A comprehensive prebiological screen for ecotoxicologic effects
Authors: Gillett James W. 
Published: March 2010

Abstract
Simple properties of chemicals—the octanol-water partition coefficient (Kow), Henry's Law constant (Hc) and biodegradability half-life (t1/2) — provide a means of evaluating ecotoxicologic testing requirements prior to direct screening using various organisms. Based on potential for exposure, arrays of properties portending ecotoxicologic concern are suggested for bioaccumulation and chronic effects, multispecies-multimedia involvement, inhalation toxicology and abiotic atmospheric effects.
Relative sensitivity ofChironomus tentanslife stages to copper
Authors: Nebeker Alan V. , Cairns Michael A. , Wise Claudia M. 
Published: March 2010

AbstractThe four larval instars of the midge Chironomus tentans Fabricius were exposed to copper to determine their relative sensitivities. The impact of copper on adult emergence and effect of exposure time on LC50 values were also determined. First-instar larvae appeared to be the most sensitive to acute exposure, with a 96-h LC50 of 298 μg/L copper, followed by second-instar (LC50 = 773 μg/L), third-instar (LC50 = 1,446 μg/L) and fourth-instar (LC50 = 1,690 μg/L) larvae, at a water hardness of 71 to 84 mg/L. Adults emerged successfully from fourth-instar larvae and pupae that survived 20-d copper exposures of up to 235 μg/L; the 20-day EC50 was 77.5 μg/L.Methods for continuous culture of C. tentans in a flow-through rearing facility using Cerophyl, a commercially available powdered grass product, as food and substrate are presented.
Sampling and analytical procedures for evaluation of airborne chlordane levels in family quarters
Authors: Thomas Thomas C. , Nishioka Yoshimi A. 
Published: March 2010

Abstract
A sampling and analysis protocol was developed for determining trace levels of chlordane in the interior of family housing units. Chlordane, when applied as a termiticide through sub-slab injection, found its way into family quarters through heating ducts. In this study, methods were developed to sample and analyze for trace levels of this airborne chlordane. Commercially available Chromosorb 102 sampling tubes were evaluated and found to be extremely useful. Trace levels of chlordane collected on these commercial sampling tubes can be stored before analysis for up to 131 d after sampling, with no measurable loss of chlordane. Chlordane collection efficiency and recovery from Chromosorb 102 sampling tubes was found to be excellent.
Bioenergetic alterations correlated with growth, fecundity and body burden of cadmium for mysids (Mysidopsis bahia)
Authors: Carr Robert Scott , Williams John W. , Saksa Frank I. , Buhl Rosanna L. , Neff Jerry M. 
Published: March 2010

Abstract
Reduced growth and reproductive potential are common sublethal stress responses. Bioenergetic alterations as evidenced by scope for growth or O:N ratio measurements are also sensitive sublethal stress responses for certain animals. The O:N ratio, which is the ratio of oxygen consumed to nitrogen excreted in atomic equivalents, reflects the relative utilization of protein in energy metabolism. The purpose of the present study was to determine whether concentration-dependent alterations in the O:N ratio for mysids (Mysidopsis bahia) could be detected at various times during a life-cycle toxicity test and to assess the utility of this index for diagnosing bioenergetic responses that result in reduced growth and reproductive inhibition.
Juvenile M. bahia were exposed to cadmium (CdCl2) in a continuous-flow proportional diluter system. The exposure concentrations were monitored routinely throughout the test and varied less than ±10% from the nominal concentrations. The O:N ratio measurements were made at 4, 10 and 18 d of exposure. Dry weights and cadmium body burdens of individual mysids were made at day 18 and day 33, the termination of the test.
Significant alterations in the O:N ratio were evident by 4 d and indicated a shift toward lipid utilization with increasing cadmium concentration. Growth was significantly reduced in the lowest concentration (4 ppb) at 18 d and a linear concentration-dependent increase in the cadmium body burden was observed at the termination of the test. These results suggest that alterations in the O:N ratio are a sensitive and early diagnostic index for detecting sublethal stress responses. We feel that this approach could be used in place of the standard life-cycle toxicity test for determining the concentration of a toxicant at which no effect on growth and reproductive processes will occur.
Computation of total molecular surface area from gas phase ion mobility data and its correlation with aqueous solubilities of hydrocarbons
Authors: Lande S. S. , Hagen D. F. , Seaver A. E. 
Published: March 2010

Abstract
Gas phase ion mobility data of molecular ions were utilized to estimate the total molecular surface area (TSA) of neutral molecules. Assumptions are made in the first approximation that ions/molecules can be represented as equivalent hard spheres and that the radii of the neutral molecule and its gas phase molecular ion are equal. TSA values derived from experimental ion mobilities measured by plasma chromatography compared reasonably (±5%) with TSA data derived from computer-simulated molecular models for the polynuclear aromatic hydrocarbons, butylbenzene isomers and linear alkanes. The known relationship between logarithms of aqueous solubility and TSA for the solute was examined utilizing TSA values derived from ion mobility data. Correlation coefficients exceeded 0.95 for aromatic hydrocarbons and for linear alkanes of fewer than 12 carbons but not for longer alkane chains.
Movement of pesticides in soil columns as affected by anhydrous ammonia
Authors: Smith Sammie , Willis Guye H. 
Published: March 2010

Abstract
A soil column study was conducted to characterize the movement of permethrin [3-phenoxybenzyl(1RS)-cis, trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate], fenvalerate [(RS)-α-cyano-3-phenoxybenzyl(RS)-2-(4-chlorophenyl)-3-methylbutyrate], toxaphene (chlorinated camphene), trifluralin (α,α,α -trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) and metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one] in soil as affected by fertilizer anhydrous NH3 application at 0, 50 and 150 kg N/ha. The soil columns were leached with three pore volumes of water and segmented. Under the saturated flow conditions used in the study, the insecticides were essentially immobile in the columns receiving no anhydrous NH3. About 5% permethrin was found 5 to 10 cm below the zone of application and about 9% fenvalerate and 16% toxaphene were found 5 to 20 cm below the zone of application in the soil columns receiving the highest level of anhydrous NH3. No appreciable amounts (&lt;0.5%) of the insecticides occurred in the column leachates. There was no apparent enhancement of the mobility of the herbicides trifluralin and metribuzin due to anhydrous NH3 application. Extensive disappearance of trifluralin occurred at all anhydrous NH3 levels, and the disappearance of metribuzin increased with increasing anhydrous NH3 application. The observed enhanced leaching of the insecticides appears to support the hypothesis that soil humic substances, solubilized by NH3, can serve as pesticide carriers.
Chemistry and aquatic toxicity of raw oil shale leachates from piceance basin, Colorado
Authors: Meyer Joseph S. , Sanchez Deborah A. , Bergman Harold L. , McWhorter David B. , Brookman John A. 
Published: March 2010

AbstractLeachates were collected during the period of 1981 to 1983 from several depths in two surface piles of raw, mined oil shale in the Piceance Basin of northwest Colorado. Although both piles were subject to similar climatic conditions, the composition of major inorganic ions in the leachates differed considerably because of different shale compositions. Acute toxicity to Daphnia magna and fathead minnows (Pimephales promelas) occurred when leachate conductivity exceeded 7,000 to 8,000 μmhos/cm and total dissolved solids exceeded 6 to 7 g/L (0.6 to 0.7% salt). D. magna were more sensitive than fathead minnows in acute toxicity tests, and D. magna 48-h LC50 values were as low as 13% of full-strength leachate. The lowest no observed effect concentration determined in D. magna 21-d chronic toxicity tests was 0.9% of full-strength leachate. Because of interactions among the major ions, the contributions to toxicity by trace elements and organic compounds in the oil shale leachates could not be differentiated from contributions by MgSO4, the major toxicant. This study demonstrated that toxic mechanisms occurring within complex chemical mixtures cannot always be identified on the basis of single-compound toxicity values, and that reconstituted mixtures of principal chemical components are useful in identifying toxicants and their interactions with other mixture constituents.
Fate of three phosphate ester flame retardants in small ponds
Authors: Muir D. C. G. , Lint D. , Grift N. P. 
Published: March 2010

Abstract
The fate of 14C-labeled t-butylphenyldiphenyl phosphate (tBPDP), 2-ethylhexyl diphenyl phosphate (EHDP) and tri(m-cresyl) phosphate (mTCP) was studied for up to 360 d following addition of each compound to artificial ponds (5 m3 volume) to give initial water concentrations of about 50 μg/L. Concentrations of each phosphate ester decreased rapidly, with half-lives of about 0.5 d for each compound. Concentrations of intact esters in bottom sediments decreased more slowly, with half-lives of 39 d for tBPDP and mTCP and 79 d for EHDP. A series of unidentified 14C-labeled nonpolar oxidation products, as well as diaryl phosphates, was isolated by TLC analysis of extracts of water and sediment. Concentrations of 197 ng/m3 tBPDP and 32 ng/m3 EHDP were detected in air (5 cm height) above the ponds during the first 18 h after the addition of the esters to the water. Volatilization losses during the experiment were estimated to represent less than 10% of the amounts added to the water initially. Maximum concentrations in fathead minnows (Pimephales promelas), ranging from 7.3 μg/g for mTCP to 10 μg/g for tBPDP, were observed 8 h after application. Chironomid larvae collected from bottom sediments accumulated concentrations that were 11- to 37-fold greater than levels of each compound present in sediment. After 360 d, most of the remaining 14C was present in bottom sediment, representing 24 to 30% of the amount originally added.
A multidisciplinary approach to the assessment of ocean sewage sludge disposal
Authors: Fava James A. , McCulloch Wayne L. , Gift James J. , Reisinger H. James , Storms Stephen E. , Maciorowski Anthony F. , Edinger John E. , Buchak Edward 
Published: March 2010

Abstract
This article presents a multidisciplinary approach to assess the hazards of ocean sewage sludge dumping. It combines physical and chemical sludge characteristics, estimated safe chronic levels and bioaccumulation potential with estimated environmental exposure (concentration and time) information. The hazard assessment was used to evaluate sewage sludges from 12 water pollution control plants operated by the New York City Department of Environmental Protection. Using a mathematical dispersion model, the worst-case minimum dilution after 4 h was predicted to be 11,500:1. Of the three marine species tested, mysid shrimp were found to be the most sensitive. Using an application factor of 0.05, estimated chronic safe levels were estimated, the values do not exceed the limiting permissible concentrations, after allowing for initial dilution. Also, the concentrations of the chemicals in the liquid sewage sludge phase were below ambient water quality criteria. The results suggest that the ocean disposal of sewage sludge does not appear to present the environmental hazard originally perceived.
Microbial transformation rates of AZO and triphenylmethane dyes
Authors: Michaels Glenda B. , Lewis David L. 
Published: March 2010

Abstract
Using field-collected and laboratory cultures, bacterial transformation rates for one azo and two triphenylmethane dyes were studied as a means of assessing the potential degradation of these compounds in aquatic environments. Transformation was measured as loss of color by spectrophotometry, and first- and second-order transformation rate coefficients were determined. Second- order coefficients (kb) were based on total colony-forming units (CFU) of bacteria in batch cultures. Percentages of total bacteria that transformed the dyes were determined by isolating bacterial colonies from field-collected samples and testing the isolates for the capacity to transform the dyes in dilute nutrient medium. The azo dye, Acid Orange 6, was not transformed under the aerobic conditions of these studies. Basic Violet 1 was transformed and k1 values ranged from -0.003 to -0.023 h−1, with a mean (kb) of 3.5 × 10−14L CFU−1 h−1. Basic Violet 3 also was transformed and k1 values ranged from -0.002 to -0.012 h−1, with a mean kb of 2.8 × 10−14 L CFU−1 h−1. The percentage of transformer bacteria for Basic Violet 1 ranged from 6 to 28%, with a mean of 13.5%, and the range for Basic Violet 3 was 0 to 24%, with a mean of 8.32%. Therefore, the triphenylmethane dyes were transformed at similar rates, and similar fractions of the total bacterial populations were involved in the transformation.
Organochlorine contaminants in passeriformes and other avian prey of the peregrine falcon in the western united states
Authors: Deweese L. R. , McEwen L. C. , Hensler G. L. , Petersen B. E. 
Published: March 2010

Abstract
About 1,150 individuals of 38 species of Passeriformes and other small birds were collected in 1980 at 36 locations in eight western U.S. states for organochlorine (OC) chemical analysis. The bird carcasses (less beak, tarsi, gastrointestinal tract, and feathers) were combined by species and location (4 to 15 specimens per sample) into 124 composited samples for analysis. Also analyzed were 77 single specimens of four species, to assess variation in residue concentrations in individual birds. The chemicals detected (greater than 0.05 ppm) were the following (in order of frequency): DDE, polychlorinated biphenyls (PCBs), hexachlorocyclohexane (HCH), heptachlor epoxide, oxychlordane, dieldrin and toxaphene. DDE accounted for 72% of total OC concentrations (ppm DDE/ppm total OCs) overall and PCBs accounted for 3%. DDE mean (geometric) residues were highest in tree swallows (Tachycineta bicolor Vieillot), 12.0 ppm; killdeer (Charadrius vociferus L.), 5.9 ppm; and Brewer's blackbirds (Euphagus cyanocephalus Wagler), 2.7 ppm. Eight migratory species showed mean DDE residues 13 times higher than those in four resident species (1.3 vs. 0.1 ppm, p &lt; 0.05), but PCB residues were similar (0.03 vs. 0.02 ppm). Insectivorous species showed higher DDE, PCB and total OC residues than did either omnivores or granivores (p &lt; 0.05). Males of some species showed higher residues of DDE, PCBs and total OCs than did females (p &lt; 0.05). DDE residues, but not PCBs, in killdeer, Brewer's blackbirds and violet-green swallows (Tachycineta thalassina Swainson) were significantly related (0.01 &lt; p &lt; 0.08) to latitude and longitude of origin.
Concentrations of DDE in the carcass fat of some individual tree swallows and killdeer would be in the lethal range if 15 to 20% of the stored DDE were rapidly mobilized to the brain. Samples of 13 species contained DDE concentrations (greater than 3 ppm) considered sufficient to inhibit the normal reproduction of avian predators feeding on them. The evidence suggests that potentially harmful OC concentrations are present in certain western migrants and pose an even greater hazard to avian predators such as the peregrine falcon (Falco peregrinus Tunstall).
Assessment of the safety of dioctyl adipate in freshwater environments
Authors: Felder J.D. , Adams W.J. , Saeger V.W. 
Published: March 2010

Abstract
A safety assessment of dioctyl adipate (DOA) in freshwater environments was conducted. DOA is relatively insoluble in water and is likely to partition to sediment and biota in the aquatic environment. Biodegradation was found to be rapid and extensive under conditions simulating sewage systems and the natural environment. Measured environmental concentrations of DOA averaged less than 0.5 μg/L in natural surface waters. DOA was not acutely toxic to algae and fish at or above its water solubility of 0.78 ± 0.16 mg/L. It was acutely and chronically toxic to Daphnia magna at 480 to 850 and 24 to 52 μg/L, respectively. A bioconcentration study with bluegill showed that DOA is not an accumulative or persistent chemical in this species. The mean 28-d bioconcentration factor was 27. A comparison of the mean environmental water concentrations of DOA with laboratory chronic toxicity values for D. magna showed a safety margin of approximately three orders of magnitude. The conclusion drawn from this environmental safety assessment is that, under present use and disposal patterns, DOA presents a small hazard to the freshwater aquatic environment.