bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mutagenicity of chlorine-substituted furanones and their inactivation by reaction with nucleophiles
Authors: Ishiguro Yasuhisa , Dence Carlton W. , Lalonde Robert T. , Santodonato Joseph 
Published: March 2010

Abstract
The reported high mutagenic potency of 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone against Salmonella typhimurium (TA100) was confirmed in the determined value of 6,300 net revertants/nmol. Partial inactivation of the furanone by Arochlor 1254-induced rat liver homogenate fraction (S9) was observed. Inactivation by the nucleophiles hydroxide ion, SO2, S2O2/3−, pyrrolidine and glutathione, all in aqueous solutions, was determined and the results compared. Mutagenic reduction was observed for all of the nucleophiles but was most pronounced for glutathione. Inactivation by hydroxide ion was most sensitive in the pH range of 9 to 11, was associated with chloride ion formation and paralleled irreversible ultraviolet spectral change resulting in the loss of the 227 nm absorption maximum and the appearance of a new maximum at 255 nm. Neutral aqueous solutions of the furanone and glutathione were marked by two UV maxima, at 250 and 270 nm, and lacked the aldehydic 1H-NMR signal, which was observed in the spectrum of the neutral solution of the furanone alone and was attributed to the presence of its acyclic tautomeric form. Several other furanones were prepared. Their Ames mutagenicities and those of chlorine-substituted intermediates obtained in the synthesis of the furanone were determined and compared, and then related to the reported mutagenicities of some 2-chloropropenals.
Fate of dyes in aquatic systems: I. Solubility and partitioning of some hydrophobic dyes and related compounds
Authors: Baughman George L. , Perenich Theresa A. 
Published: March 2010

Abstract
Solubilities and vapor pressures from the literature are combined with calculated octanol/water partition coefficients, Kow, to assess the expected environmental behavior of about 50 dyes. Most of the older disperse dyes (those that have been in use for decades) have solubilities on the order of 10−7 to 10−6 m. This solubility suggests the potential for a 30- to 150-fold concentration enhancement in sediments and bioconcentration of about 1,000 times in the absence of metabolism. The data also indicate that solubilities computed from Kow (estimated by the substituent method) may be significantly overestimated and that the product of subcooled liquid solubility and estimated Kow for disperse dyes is 10 to 100 times smaller than reported for most other compounds.
Henry's law constants calculated from solubility and vapor pressure show that the disperse and vat dyes will be entirely gas-phase-controlled in their rate of volatilization from water and that this process will be extremely slow. No definitive conclusions can be drawn about the behavior of more recently developed disperse dyes. The available physical constants are compiled along with structures, Color Index number, CAS number and names for 80 compounds.
Effects of monocrotophos and fenthion on discrimination acquisition and reversal in northern bobwhite (colinus virginianus)
Authors: Kreitzer J. F. , Fleming W. J. 
Published: March 2010

Abstract
Adult male northern bobwhite (Colinus virginianus) were fed diets containing organo-phosphorus pesticides, and the birds' discrimination acquisition and reversal performance was evaluated. The birds received the pesticide-laced diets continually, beginning 2 d before behavioral testing and ending after the birds completed the test series consisting of an acquisition and 10 reversals. Bobwhites fed a diet containing 0.18 ppm monocrotophos made 118% more errors (p ± 0.05) than did controls during reversals but not during acquisition. The behavior of bobwhites fed diets containing 0.02 and 0.06 ppm monocrotophos was not different from that of controls. Acquisition performance of bobwhites fed a diet containing 7 ppm fenthion was not different (p &gt; 0.05) from that of controls; however, bobwhites fed the fenthion diet made 48% fewer errors (p ± 0.05) in the reversals. When retested after 18 (monocrotophos) and 73 (fenthion) d on clean diets, no residual behavioral effects were detected. Brain cholinesterase activity was inhibited in all treatment groups.
Effects of fumigation with hydrogen fluoride on the loading of [14C]sucrose into the phloem of soybean leaves
Authors: Madkour Samia , Weinstein Leonard H. 
Published: March 2010

Abstract
The effect of gaseous hydrogen fluoride (HF) on the loading of [14C]sucrose into phloem was studied because this response was a possible target site for F inhibition of translocation of photoassimilate in intact soybean plants. The active loading of [14C]sucrose into the minor veins of soybean leaf discs was inhibited by continuously exposing the plants to HF at nominal concentrations of 1, 3 and 5 μg F m−3 for 8 to 11 d under both controlled-environment and field conditions. The data suggest that phloem loading at atmospheric levels of HF greater than approximately 1 μg m−3 was inhibited less in the plants grown and fumigated in the field than in the laboratory.
Biodegradation of NTA and m-cresol in coastal environments
Authors: Palumbo Anthony V. , Pfaender Frederick K. , Paerl H. W. 
Published: March 2010

Abstract
The biodegradation of m-cresol and nitrilotriacetic acid (NTA) by nonadapted natural populations of aerobic heterotrophic bacteria was examined in a coastal environment near Beaufort, North Carolina, over an 18-month period and in synoptic samples from the Mississippi River, its plume and adjacent coastal waters. The uptake kinetics of radiolabeled m-cresol and NTA were measured at a freshwater site, an estuarine site and a high-salinity offshore site. Uptake of both compounds was greatest in the summer, and half-saturation constants and maximum uptake velocities were greater for NTA than for m-cresol. m-Cresol uptake was greatest in the freshwater environment, and NTA uptake was greatest in the estuary where bacterial numbers and activity were also highest. The uptake of both compounds was lowest in the offshore environment where biological activity was lowest. It appears from the spatial patterns in the Newport River estuary and in areas off the Mississippi that m-cresol biodegradation is substantially reduced at increasing salinity but that NTA uptake is not. Only at extremely low concentrations (less than 1 to 10 μg L−1) and only during the warmer portions of the year is biodegradation of m-cresol in freshwater and estuarine environments important in determining its fate. At higher concentrations and in the marine environment, biodegradation by nonadapted populations is slow and other processes, such as adaptation, dilution and mixing, may be more significant in determining the fate of both compounds.
Characterization of agricultural nonpoint pollution: Pesticide migration in a West Tennessee watershed
Authors: Klaine S. J. , Hinman M. L. , Winkelmann D. A. , Sauser K. R. , Martin J. R. , Moore L. W. 
Published: March 2010

Abstract
Pesticide migration from agricultural fields may stress receiving stream ecosystems as well as contaminate ground water. Research was conducted on an 18-ha single-field watershed in west Tennessee to characterize the fate of atrazine during a 12-month period after pesticide application. Rainfall runoff and soil cores were sampled and analyzed for atrazine residues. Total loss of atrazine by runoff accounted for approximately 1.5% of the total atrazine applied. Concentrations as high as 0.25 mg/L were detected in the field discharge. By the fourth storm event after pesticide application, the atrazine concentration was below detection limits (0.1 μg/L). Atrazine loss in the upper 10 cm of soil followed a first-order decay trend, with only 1.88% of the initial concentration remaining 238 d after pesticide application. The mean half-life for atrazine in the upper 10 cm was approximately 21.5 d. Atrazine was detected in the 10- to 20-cm soil level after the first rainfall. Atrazine was not detected below 20 cm at any sampling date during the 238 d of the study.
Screening and biomonitoring of industrial effluents using phytotoxicity tests
Authors: Wang Wuncheng , Williams Judson M. 
Published: March 2010

Abstract
The use of phytotoxicity (higher plant) tests as a part of ecotoxicology is relatively underdeveloped. The objective of this study was to evaluate phytotoxicity tests for screening and biomonitoring complex effluent samples. Mortality tests using common duckweed and seed germination tests were conducted using eight effluent samples collected from three industrial sources. Duckweed plants were found to be extremely sensitive to two effluents, with nearly 100% mortality occurring. Duckweed plants in some samples showed lesions (breakup of colony structure) and loss of green pigments (chlorosis); others showed localized dead tissues (necrosis). Six kinds of seeds were tested: cabbage, cucumber, millet, Japanese millet, rice and wheat. Cabbage and millet seeds were the most sensitive. The germination of these seeds was 100% inhibited in some samples. The results suggest that phytotoxicity tests with higher plants have potential for use in the biomonitoring of industrial effluents because of their simplicity, sensitivity and cost-effectiveness.
Sorption behavior of tributyltin on estuarine and freshwater sediments
Authors: Unger Michael A. , MacIntyre William G. , Huggett Robert J. 
Published: March 2010

Abstract
Equilibrium sorption of tributyltin chloride (TBT) was measured on selected estuarine and freshwater sediments. Isotherms from 24-h equilibrations were linear, with sorption coefficients between 1.1 × 102 and 8.2 × 103 L/kg. The similarity of sorption and desorption coefficients for these sorbates showed that TBT sorption is reversible. Sorption coefficients decreased with increasing salinity and varied by a factor of 2 over the salinity range 0 to 34%. Desorption kinetics indicated an initial fast rate followed by a slower rate of desorption, similar to published data for metal ions and hydrophobic organic molecules on sediments. Water and sediment concentrations of TBT at locations in the Chesapeake Bay system were used to calculate apparent sorption coefficients, which generally agreed with laboratory-measured sorption coefficients. Exceptionally high apparent sorption coefficients were found near areas of high vessel activity and may be due to TBT paint chips in the sediment.
Biodehalogenation: Active site versus enzymatic and whole cell rates with cytochromes P-450
Authors: Castro C. E. , Yokoyama W. , Belser N. O. 
Published: March 2010

Abstract
The products stoichiometry and kinetics of the reduction of trichloronitromethane (chloropicrin), bromotrichloromethane, carbon tetrachloride, ethylene dibromide and 1,2-dibromo-3-chloropropane by iron(II) deuteroporphyrinlX, rat liver P-450PB and P-450 cam were compared with the reactions of reduced liver microsomes and the whole-cell model Pseudomonas putida (PpG-786). The polyhalomethanes in all cases undergo quantitative reductive hydrogenolysis The vicinal halides are Quantitatively converted by all P-450 components to the corresponding olefins
In contrast to the steric retardation of the rates exhibited by P-450 cam, the rate constants for the mammalian enzyme were the same as those obtained for the heme in homogeneous solution. Microsomal reactions followed the same general reactivity patterns but on a much compressed scale. The whole-cell conversions are apparently controlled in part by permeation; thus the microbial dehalogenation processes proceed at much slower rates than the actual chemistry that occurs at the active site. The results establish that the reductase capacities of widely divergent P-450 cytochromes are consistent with the chemistry and mechanisms established for hemes in homogeneous solutions. Both microorganisms and mammals have the capacity to dehalogenate these substances.
Interpretation of confidence intervals for median effective dose estimates
Authors: Kaiser Mark S. 
Published: March 2010

Abstract
Philosophical considerations in the interpretation of probability can confuse the meaning of interval estimates. Most techniques for calculating interval estimates for the median effective dose (LC50) have been developed under a Neyman-Pearson probability structure, which requires interpretation in terms of asymptotic mathematics. Fiducial probability, designed to allow the inductive use of a single experiment, fails to resolve this major difficulty in interpretation. In the evaluation of LC50 estimators, care should be exercised to ensure correct identification of random variables, consistent partitioning of sources of variability and proper choice of criteria for comparing estimators. Despite the difficulties raised by these issues, the calculation of interval estimates in short-term toxicity testing remains an important benchmark in assessing the potentially harmful effects of chemical compounds in the environment.
Effect of food availability on the acute toxicity of four chemicals to mysidopsis bahia (mysidacea) in static exposures
Authors: Cripe Geraldine M. , Ingley-guezou Anne , Goodman Larry R. , Forester Jerrold 
Published: March 2010

Abstract
The effect of nutritionally deficient Artemia nauplii on the growth of the mysid, Mysidopsis bahia, were evaluated in static systems. When Artemia nauplii with or without highly unsaturated fatty acid 20:5 ω 3 were fed to 24‒h‒old M. bahia there was no difference in growth of mysids on either ration after 96 h of feeding. A study comparing amount of available food in static systems necessary for good survival and growth indicated that rations of 5, 10 or 30 Artemia per mysid per day (A/m/d) were different from 50, 70, 90 and 110 A/m/d as measured by dry weight. Static acute 96‒h tests were conducted with ≤24‒h‒old Mysidopsis bahia using either carbophenothion, cypermethrin, malathion, or 4‒(tert‒octyl)phenol. For each chemical, two replicate tests were conducted simultaneously with each of three rations of food provided. The rations chosen were 10 A/m/d, providing survival with minimal growth, a midpoint ration (60 A/m/d), and 110 A/m/d, clearly in excess of that necessary for good survival and growth. Only LC50s obtained in tests using 10 A/m/d were significantly different from other test results. These tests indicate that lack of food does adversely affect results of mysid static tests. In addition, excess food has the potential to reduce dissolved oxygen to nearly unacceptable concentrations.
Aquatic toxicology of the pyrethroid insecticides: Neurotoxicology of pyrethroids: Single or multiple mechanisms of action?
Authors: Clark Marshall J. , Brooks Matthew W. 
Published: March 2010

Abstract
It has been almost 25 years since the classic studies first described the pyrethroid mode of action on voltage—dependent sodium channels. In the interval that followed, this electrophysiological approach has been enlarged upon using a variety of preparations with essentially the same result. Thus, there is little disagreement that pyrethroids have an action at or near the sodium channel in the nerve. Recently, a number of additional mechanisms have been suggested, including the perturbation of the voltage—dependent calcium channels. Using a functional bioassay that consists of a calcium—dependent, potassium—stimulated pulsed release of norepinephrine from rat brain synaptosomes, Type II pyrethroids caused a substantial enhancement of norepinephrine release that was not apparent when Type I pyrethroids were used. The ED50 dose of deltamethrin that resulted in half—maximal enhanced norepinephrine release (i.e., 2.9 × 10−9 M) correlated well with the ED50 dose of deltamethrin that resulted in half—maximal enhanced 45Ca uptake (i.e., 2.4 × 10−9 M). Norepinephrine release was only partially blocked by tetrodotoxin and a calcium channel antagonist, D595. Deltamethrin enhanced norepinephrine release in the presence of tetrodotoxin but was unable to enhance release in the presence of D595. These results are supportive of a highly sensitive action of Type II pyrethroids at presynaptic nerve terminals in the central nervous system and of the involvement of voltage—dependent calcium channels.
Dorsal gill incision: A simple method for obtaining blood samples in small fish
Authors: Watson Carl F. , Baer Kevin N. , Benson William H. 
Published: March 2010

Abstract
Hematological parameters may provide valuable diagnostic information in assessing the sublethal toxicological effects of waterborne contaminants in fish. However, because of size limitations, the use of hematological evaluations in small fish has been restricted. In addition, only a few techniques have been reported in the literature for obtaining blood from small fish. The present investigation was undertaken to evaluate a simple and rapid technique, dorsal gill incision, for collecting blood samples from small fish. Blood samples were obtained from bluegill sunfish, Lepomis macrochirus, by caudal peduncle transection and dorsal gill incision. Analysis of the coefficients of variation in whole blood parameters indicated that the variability in samples was reduced with the dorsal gill incision technique. Plasma aspartate aminotransferase and creatine kinase levels in caudal peduncle transection samples were significantly elevated (p &lt; 0.05) above the levels obtained by dorsal gill incision. Dorsal gill incision is proposed as an easy and rapid alternative to currently available methods for blood sampling in small fish.
Comparisons of single-species, microcosm and field responses to a complex effluent
Authors: Pontasch Kurt W. , Niederlehner B. R. , Cairns John 
Published: March 2010

Abstract
Short-term, single-species toxicity tests are used to identify, regulate and monitor the discharge of problem effluents into receiving ecosystems. The ability of single-species tests to protect entire ecosystems has been questioned, and microcosm tests have been proposed as additional tools for reducing uncertainty in environmental risk assessment. We compared responses to a complex effluent in microcosms of indigenous macroinvertebrates and protozoans with responses observed in acute tests with Daphnia magna, Ceriodaphnia dubia and Pimephales promelas and in chronic survival and reproductive tests with C. dubia. The predictive utility of these various tests was then evaluated in relation to observed effects in the receiving stream. The acute LC50s (percent effluent) from the acute tests were 63.1 for P. promelas, 18.8 to 31.3 for D. magna and 54.7 for C. dubia. Results from 7-d chronic tests indicated that C. dubia survival was significantly (p ≤ 0.05) affected at 30% effluent and that reproduction was affected at concentrations ≥3% effluent. In the protozoan microcosms, community composition was significantly (p ≤ 0.05) changed at 1.0%, while protozoan species richness was significantly reduced at 3.0% effluent. In the macroinvertebrate microcosms, mayflies were the only macroinvertebrates adversely affected by the effluent. Four mayfly taxa showed significant (p ≤ 0.05) reductions in density in the 1.0% treatment and four others were significantly reduced at 10.0%; however, some chironomids had significant increases in density at 0.1% and above. Microcosm responses corresponded well with observed effects in the field. The microcosms correctly predicted which indigenous organisms would be lost and which would be stimulated at various ambient concentrations of the effluent.
Development and evaluation of a novel marine sediment pore water toxicity test with the polychaete dinophilus gyrociliatus
Authors: Carr Robert Scott , Williams John W. , Fragata Carlos T. B. 
Published: March 2010

Abstract
As a candidate for future use in the National Status and Trends Program, a novel marine sediment pore water toxicity test procedure was developed and evaluated. The test procedure involves obtaining sediment pore water with a pressurized squeeze-extraction device, and then conducting a life-cycle toxicity test with the polychaete Dinophilus gyrociliatus. Recent studies have demonstrated that for certain nonpolar organic contaminants, the key route of exposure is from the interstitial (pore) water. Sediment samples were collected from 15 different stations in the San Francisco Bay area with varying amounts of contamination. The results from the San Francisco study and other studies conducted during the development of this test procedure are reported.
Interaction of humic acid with selected trace metals: Influence on bioaccumulation in daphnids
Authors: Stackhouse R. Allan , Benson William H. 
Published: March 2010

Abstract
The influence of humic acid (HA) on the bioaccumulation of Cd, Cr VI and two forms of Cr III was evaluated using a common freshwater cladoceran, Daphnia magna. HA (0.5, 5 and 50 mg/L) had a much greater influence on the bioaccumulation of Cd and Cr III than of Cr VI. At only one time point (96 h) did the 50 mg/L HA significantly decrease the bioaccumulation of Cr VI. The remaining concentrations of HA (0.5 and 5 mg/L) had no influence on Cr VI bioaccumulation. However, with both forms of Cr III, 50 mg/L HA significantly decreased bioaccumulation, while 0.5 and 5 mg/L HA concentrations either decreased or had no influence on bioaccumulation. The results of the Cd-HA interaction were much more variable than those obtained with Cr VI or Cr III. The bioaccumulation of Cd was increased, decreased or not influenced by HA, depending on the concentration of HA and the exposure period examined.
Octanol/water partition coefficients and bioconcentration factors of chloronitrobenzenes in rainbow trout (salmo gairdneri)
Authors: Niimi A. J. , Lee H. B. , Kissoon G. P. 
Published: March 2010

Abstract
The relationship between octanol/water partition coefficient (Kow) and bioconcentration factor (BCF) of 14 monochloro- to pentachloronitrobenzenes were examined in rainbow trout through waterborne and dietary exposure studies. The results indicated BCF was not significantly correlated with Kow for this chemical group. The role of chemical half-lives and chemical absorption efficiencies are examined as factors that could explain why the BCF of some chemical groups are lower than predicted.
Variability associated with identification of toxics in national pollutant discharge elimination system (npdes) effluent toxicity tests
Authors: Dorn P. B. , Rodgers J. H. 
Published: March 2010

Abstract
Effluent toxicity testing is a routine National Pollutant Discharge Elimination System (NPDES) permit monitoring requirement for many municipal and industrial dischargers. Effluent toxicity compliance limits are being set in an increasing effort to limit discharge of toxics into U.S. water bodies. To that end, hazard assessment principles are being applied to limit discharged toxicity based on instream effects as judged by effluent toxicity, fate and exposure. Uncertainty arises in complying with effluent toxicity limits because of a number of factors, including an unacceptably toxic effluent, error in conducting a specified test, test organism health, statistical variability and interferences in the test solution that mask the toxic effect.
Three factors that may influence compliance with toxicity limits and/or identification of toxics are discussed. These factors indicate the need for additional consideration before setting permit limits, determining requirements for toxicity reduction and possibly implementing additional effluent treatment.
Comparisons between reference toxicant data and control mortality showed that reference toxicant data provide an additional control for determining whether effluent toxicity test results are valid and that they can be used to test regulatory compliance. Statistical sampling theory was explored to determine compliance with an effluent toxicity requirement of 80% survival in 100% effluent. Third, several test species were used to determine the causative toxic agents in order to correctly identify toxicity and to separate true toxic effects from interferences in exposures to receiving water.