bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bioconcentration of polybrominated benzenes and biphenyls and related superhydrophobic chemicals in fish: Role of bioavailability and elimination into the feces
Authors: Gobas Frank A. P. C. , Clark Kathryn E. , Shiu Wan Ying , Mackay Donald 
Published: March 2010

Abstract
Bioconcentration data are reported for a series of superhydrophobic chemicals including polybrominated biphenyls, brominated benzenes, mirex and polychlorinated biphenyls in the guppy (Poecilia reticulata). The observed bioconcentration factors follow a linear relationship with the 1-octanol/water partition coefficient for chemicals with a log Kow of up to 6. For chemicals with higher Kow values, the bioconcentration factors were lower than expected from the linear relationship. This loss of linear correlation is shown to be caused by (a) a low fraction of bioavailable chemical in the water, (b) elimination of chemical into the feces, (c) an insufficient exposure time to achieve equilibrium and (d) fish growth. Procedures are presented by which the magnitudes and relative contributions of these factors to reducing the apparent bioconcentration factor from linearity can be determined.
Lead poisoning and other mortality factors in trumpeter swans
Authors: Blus Lawrence J. , Stroud Richard K. , Reiswig Barry , McEneaney Terry 
Published: March 2010

Abstract
Lead poisoning and other causes of mortality of trumpeter swans were investigated. Necropsies or Pb concentrations in livers were available for 72 trumpeter swans (Cygnus buccinator) found dead in seven western states from 1976 to 1987; data from other published and unpublished sources (1925 to 1987) also are summarized. Ingestion of lead artifacts (shotgun pellets or fishing sinkers) accounted for about 20% of the known mortality of trumpeter swans in the tri-state area of Idaho, Montana and Wyoming, where the population has been declining for several decades. In western Washington, the incidence of lead-induced mortality was higher and accounted for nearly 50% of the known mortalities. Maximum Pb concentrations (wet weight) in the livers of birds found dead and in whole blood from captured swans were 37 and 0.71 μg/g, respectively. Other elements, including Cd, Cu and Zn, were generally not elevated in blood and tissue samples. It is not certain that lead toxicosis is related to the decline of the tri-state swan population. Other causes of mortality in swans include gunshot, disease and traumatic injuries (impact).
Microbial degradation of sparingly soluble organic chemicals: Phthalate esters
Authors: Gibbons Jacqueline A. , Alexander Martin 
Published: March 2010

Abstract
Strains of Mycobacterium and Nocardia isolated because of their ability to use di(2‒ethylhexyl) phthalate (DEHP) as sole carbon source also grew on diethyl, diisooctyl, and butyl benzyl phthalates. As the two bacteria grew on DEHP, they excreted products that increased the solubility of DEHP and diisooctyl, dihexyl, and diisodecyl but not butyl benzyl or di‒n‒butyl phthalates. The solubilizer was produced by Mycobacterium sp. even when grown on a water‒soluble substrate such as acetate. Addition of the solubilizer to culture media enhanced the degradation of DEHP and diisooctyl phthalate by Mycobacterium sp. and Nocardia sp. but not butyl benzyl phthalate. The extent of DEHP degradation by Mycobacterium sp. in media amended with the solubilizer was reduced and the initiation of degradation was delayed if the solubilizer was first treated with protease. The effect of protease was not a result of its toxicity to Mycobacterium or use of the enzyme preparation for growth of the organism. The results thus show that microbial products increase the solubility of certain phthalates and enhance their degradation.
Transport of some chlorinated contaminants by the water, suspended sediments, and bed sediments in the St. Clair and Detroit rivers
Authors: Lau Y. L. , Krishnappan B. G. , Oliver B. G. 
Published: March 2010

Abstract
Measurements of water flow, sediment transport and concentrations of some chlorinated contaminants were used to calculate the transport of contaminants in the St. Clair and Detroit Rivers. The transport was distributed between the water phase, the suspended sediments, and the bed sediments. The chemicals chosen were hexachlorobenzene, octachlorostyrene and polychlorinated biphenyls. From measurements on three transects in the St. Clair River and two transects in the Detroit River, it can be concluded that the suspended sediments can often transport the largest amount of contaminants, especially near sources of industrial discharge. The amount transported in the soluble phase was of the same order of magnitude as that in the particulate phase. The transport by the bed sediments was negligible in the St. Clair River mainly because of a lack of supply of such sediments. The partitioning of several halogenated compounds between the “dissolved” and “suspended sediment” phase is also discussed.
Atrazine tolerance of algae isolated from two agricultural streams
Authors: Hersh Charles M. , Crumpton William G. 
Published: March 2010

Abstract
Based on photosynthesis (oxygen evolution) EC50s determined from short (5 min) assays, green algae (Chlorella sp. and other species of Chlorococcales) isolated at random from an atrazine‒contaminated stream (Big Spring) in midsummer exhibited similar tolerances to atrazine (range of EC50s: 42–125 μg/L) compared to algae isolated at random from a noncontaminated stream (Osage Spring) (range of EC50s: 35–162 μg/L). A laboratory strain of Chlamydomonas reinhardii known to be susceptible to atrazine responded similarly (EC50: 45 μg/L). The EC50s of these algae are similar to those previously reported for laboratory strains. In contrast, an alga (Franceia sp., Chlorococcales) isolated at random during late spring from Big Spring responded similarly to a laboratory strain of Chlamydomonas reinhardii that is resistant to atrazine (Franceia sp. EC50s: 430–774 μg/L, C. reinhardii EC50: 466 μg/L). The EC50 values of these algae are near the high end of the range of EC50s reported for green algae.
Toxicokinetics and toxicodynamics of pyrethroid insecticides in fish
Authors: Bradbury Steven P. , Coats Joel R. 
Published: March 2010

Abstract
The pyrethroid insecticides are extremely toxic to fish, with 96—h LC50 values generally below 10 μg/L and i.p. and i.v. LD50 values below 20 mg/kg. Corresponding LD50 values in mammals and birds are in the range of several hundred to several thousand milligrams per kilogram. This review examines pyrethroid toxicokinetics and toxicodynamics in fish as critical factors associated with species selectivity. Studies with permethrin, cypermethrin and fenvalerate have established that rates of metabolism and elimination in rainbow trout are significantly lower than those reported for birds and mammals. Comparatively low lethal brain pyrethroid concentrations and nonneural aspects of pyrethroid intoxication in fish suggest that variations in toxicodynamics are also crucial in evaluating pyrethroid selectivity.
Toxicity of pyrethroid insecticides to fish
Authors: Haya Katsuji 
Published: March 2010

Abstract
A selected review of the biological, chemical and environmental factors that affect the acute and chronic, lethal and sublethal toxicity of pyrethroid insecticides to fish is presented. Pyrethroid insecticides are extremely toxic to fish; for example, 96—h LC50 values are in the nmol/L range. The symptoms associated with acute lethality suggest that effects on the nervous system, respiratory surfaces and renal ion regulation are associated with the mechanism of lethal action in fish.
Qualitative structure—activity relationships indicate that the structural features required for good insecticidal activity and for lethality to fish are the same. Lethality also varies with biological (species, size) and environmental (temperature, sediment) factors. Some of these effects may be related to bioavailability and rates of pyrethroid biotransformation.
Chronic exposure studies indicate that newly hatched larvae or early juveniles are the life stages most sensitive to pyrethroids. Exposures of fish to sublethal concentrations of pyrethroids have resulted in decreased growth and impaired swimming performance. The effects on bioenergetics and energy metabolism are variable.
Acute, chronic and sublethal effects of synthetic pyrethroids on freshwater zooplankton
Authors: Day Kristin E. 
Published: March 2010

Abstract
A review of the acute, subacute and chronic effects of four synthetic pyrethroids —permethrin, cypermethrin, deltamethrin and fenvalerate —on freshwater zooplankton is presented. Acute toxicities in the laboratory were found to range from 0.12 to 5.0 μg/L for cladocerans and copepods. Lower concentrations of pyrethroids (≤0.01 μg/L) reduced reproduction and rates of filtration of food by daphnids. Similar results were observed in field experiments. Simulation of direct overspray of aquatic ecosystems resulted in subsurface concentrations of pyrethroids greater than the levels known to be toxic in the laboratory (&gt;1 μg/L). At these concentrations, populations of cladocerans were reduced. At concentrations of 0.05 μg/L or greater, rates of filtration by cladocerans were depressed. Indirect effects on communities included increases in populations of rotifers and green algae (Chlorophyta). Higher levels of contamination (&gt;10 μg/L) caused reductions in copepods, rotifers and ostracods. Levels of pyrethroids of 0.01 μg/L or less were found to have no detectable effects on zooplankton in the field.
Mobility and persistence of the herbicides atrazine, metolachlor and terbuthylazine in plainfield sand determined using field lysimeters
Authors: Bowman B. T. 
Published: March 2010

Abstract
Field lysimeters (75 × 15 cm) packed with 18 kg (dry weight) Plainfield sand were used to study the mobility and persistence of commercial formulations of the herbicides atrazine, metolachlor and terbuthylazine under two precipitation regimes: rainfall, and rainfall with supplementary watering. Leachate from the 70-cm soil cores was monitored daily for each herbicide. Pairs of soil cores for each herbicide and each moisture regime were sectioned (7 × 10 cm) after 1, 2, 4, 8, 12 and 21 weeks to obtain both mobility and persistence data. After 21 weeks under rainfall, the maximum movements of atrazine, terbuthylazine and metolachlor were, respectively, 30, 20 and 10 cm, and under supplementary watering, were, respectively, 70, 50 and 40 cm. Only a single trace of atrazine appeared in the effluent of rainfall cores. Both atrazine and terbuthylazine appeared in the effluent following a 50-mm water application on day 2. Atrazine also appeared in the effluent on several occasions after week 12 under supplementary watering.
Determination of octanol/water partition coefficients for hydrophobic organic chemicals with the “slow-stirring” method
Authors: De Bruijn Jack , Busser Frans , Seinen Willem , Hermens Joop 
Published: March 2010

Abstract
Experimental data are presented on octanol/water partition coefficients for 70 hydrophobic organic chemicals that were determined with a “slow-stirring” method. With this method, log Kow values can be obtained relatively easily, with high reproducibility and low standard deviations. For compounds with log Kow values of less than 4.5, the experimental data agree well with literature data based on the classical shake-flask method. For more hydrophobic compounds, deviations occur because of the formation of octanol emulsions in the shake-flask procedure. In general, there is reasonable agreement with literature data obtained by reversed-phase HPLC or the generator-column method, although substantial deviations do occur for some individual compounds, especially the higher-chlorinated ortho-substituted polychlorinated biphenyl (PCB) congeners. For chlorobenzenes, chloroanilines and PCBs, substituent constants (π) are calculated. With these π values, partition coefficients for these compounds can be estimated simply by calculation.
Hydrolysis of chlorostilbene oxide: I. Hydrolysis in homogeneous systems
Authors: Metwally Mohammed El-Sayed , Lee Wolfe N. 
Published: March 2010

Abstract
The hydrolysis kinetics of 4-chlorostilbene oxide (CSO) in buffered distilled water, in natural waters and in sediment-associated water are reported. The disappearance of CSO followed pseudo-first-order kinetics in buffered distilled water over the experimental pH range of 3 to 11. Below pH 5, acid-catalyzed hydrolysis dominates, with a second-order rate constant of 11.3 (±1.0) M−1 min−1. Above pH 5, hydrolysis is independent of pH, with a rate constant of 1.02 (±0.12) × 10−4 min−1 at 25°C. In natural waters, the hydrolysis rate constant of CSO had an average value of 0.59 (±0.12) × 10−4 min−1. In sediment-associated water, the observed rate constant was 1.70 (±0.05) × 10−4 min−1. Sorption of CSO to the humic materials in natural waters and biotic effects in sediment-associated water appropriately explain the differences from sterile buffer solutions. Buffer catalysis was observed, but on the other hand, a negative ionic strength effect was determined. The formation of diastereoisomers of 1-(4-chlorophenyl)-2-phenylethylene glycol as major products at both acidic and neutral pH values suggests that CSO undergoes acid-catalyzed as well as neutral hydrolysis reactions through an A-1 carbonium ion mechanism. The rate constant for hydrolysis of CSO at pH 14 is only 70% faster than the hydrolysis rate constant over the pH range of 5 to 11, which suggests that nucleophilic addition of hydroxide ion is not the main hydrolytic mechanism of CSO hydrolysis at high pH values.
Special applications of insect gut microflora in kinetic studies of microbial substrate removal rates
Authors: Lewis David L. , Said William A. 
Published: March 2010

Abstract
Because of the highly controlled environment in which they live and their unique genetic history, the gut microflora of some insects may be useful for studying some of the underlying principles that govern the kinetics of uptake and metabolism of substrates by microorganisms. In the present studies, D-glucose mineralization kinetics were investigated using facultative anaerobes from termite gut microflora to test the similarity of kinetics principles developed previously with aquatic environmental microbial samples. As with environmental samples, heterogeneous kinetics were observed in the gut microflora, with increasingly enhanced glucose removal rates at diminishing amended substrate concentrations. These results lend support to the general applicability of these kinetics principles to a diversity of mixed microbial populations having greatly dissimilar environmental histories.
Toxicity and biodegradation of phthalic acid esters under methanogenic conditions
Authors: O'Connor Owen A. , Rivera M. D. , Young L. Y. 
Published: March 2010

Abstract
Phthalate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate and di(2-ethylhexyl) phthalate were evaluated for their anaerobic biodegradability and toxicity to methanogenesis. Two anaerobic bioassays (the biochemical methane potential and the anaerobic toxicity assay) were used to monitor the stoichiometric conversion of added substrate to carbon dioxide and methane. Each phthalic acid ester was the only added carbon source (20 to 200 mg/L) prepared in prereduced defined medium using a 10% (v/v) inoculum of municipal digester sludge. Over an extended incubation period (50 to 100 d), all concentrations of phthalate and dibutyl phthalate and low concentrations (20 mg/L) of dimethyl phthalate and diethyl phthalate achieved 75 to 100% of their theoretical methane potentials. Higher concentrations (100 to 200 mg/L) of dimethyl phthalate and diethyl phthalate achieved 25 to 50% of their theoretical methane potentials. Di(2-ethylhexyl) phthalate showed little mineralization at any concentration, although biotransformation of this substrate was indicated. Acclimation for most of the compounds took several days to weeks before degradation commenced. In the anaerobic toxicity assay, only concentrations greater than 20 mg/L diethyl phthalate produced any significant suppression of methanogenesis over time. All other substrates produced little inhibition of methanogenesis during the initial period of incubation. Generally, increased incubation led to increased levels of methane production above active control levels. Thus, many of these compounds were metabolized completely under methanogenic conditions and were observed to produce little inhibition of methane production. Their fate, therefore, may be significantly influenced by their concentration and residence time in methanogenic habitats.
Airborne residues resulting from use of methyl parathion, molinate and thiobencarb on rice in the sacramento valley, California
Authors: Seiber James N. , McChesney Michael M. , Woodrow James E. 
Published: March 2010

Abstract
In connection with requirements of California's Toxic Air Contaminant Act, 24-h ambient air samples were collected using an XAD-4 resin trap technique capable of simultaneously collecting methyl parathion, methyl paraoxon, molinate and thiobencarb. Sampling was conducted on rooftops of public buildings located in four towns in two counties where methyl parathion, molinate and thiobencarb were used in significant quantities, and at a background site located in a county where no use occurred, for four intervals each week for 5 weeks during the springtime application period of 1986. Satisfactory recoveries (greater than 66%) were obtained from dynamic spiking experiments, and the precision from field replicates was consistently less than 50% relative standard deviation using a protocol designed to accommodate a large number of samples. Daily maximum average concentrations (and the range in averages for all sites over the 19 and 20 sampling days in the two-county use area) were 25.7 ng/m3 (0.2-6.2 ng/m3) for methyl parathion, 3.1 ng/m3 (&lt;0.5-0.8 ng/m3) for methyl paraoxon, 1,720 ng/m3 (60-650 ng/m3) for molinate and 250 ng/m3 (12.9-67.8 ng/m3) for thiobencarb. Concentrations correlated well with reported uses of methyl parathion and molinate in the general vicinity of the sampling sites. The likely sources of observed residue levels, based upon the method of application and pesticide physicochemical properties, were spray drift during application for methyl parathion, vapor-phase oxidation of parent thion for methyl paraoxon, and postapplication volatilization from field water for molinate and thiobencarb.
Current approaches to developing sediment quality criteria
Authors: Chapman Peter M. 
Published: March 2010

Abstract
Current approaches to developing sediment quality criteria are reviewed and separated into two major groups: those approaches that provide only chemical-by-chemical criteria and those that provide criteria for chemical mixtures also. The individual approaches include background sediment chemistry, water quality criteria, sediment/water equilibrium partitioning, sediment bioas-say, screening level concentration, apparent effects threshold and sediment quality triad. Based on the evaluation of the two groups and seven individual approaches, it is concluded that, for chemical-by-chemical criteria, the equilibrium partitioning method shows promise; for criteria that are also applicable to chemical mixtures, the apparent effects threshold/sediment quality triad approaches appear to be most appropriate. Recommendations are made concerning specific immediate research needs, related to developing effective, usable sediment quality criteria.
Survival, reproduction and bioconcentration in invertebrates and fish exposed to hexachlorobenzene
Authors: Nebeker Alan V. , Griffis William L. , Wise Claudia M. , Hopkins Elmina , Barbitta Janet A. 
Published: March 2010

Abstract
The cladoceran Daphnia magna, the amphipods Hyalella azteca and Gammarus lacustris, the annelid worm Lumbriculus variegatus and the fathead minnow Pimephales promelas were exposed to hexachlorobenzene (HCB) in flow-through tests ranging from 2 to 68 d in duration to determine the effects of HCB on survival, tissue bioconcentration and Hyalella and Lumbriculus growth and reproduction.
No effects on survival, growth or reproduction were observed at concentrations of HCB up to saturation (5.0 μ/L) or at tissue HCB concentrations of up to 223 μg/g. Tissue HCB concentrations increased with increasing water concentrations, and tissue bioconcentration values were generally similar. Rapid uptake and change of tissue HCB concentration with change in water concentration occurred, with rapid depuration when the animals were no longer exposed to HCB in the water column, and tissue HCB concentrations were correlated closely with HCB water concentrations.
Allozyme genotype and time to death of mosquitofish, Gambusia affinis (baird and girard), during acute exposure to inorganic mercury
Authors: Diamond Stephen A. , Newman Michael C. , Mulvey Margaret , Dixon Philip M. , Martinson Douglas 
Published: March 2010

Abstract
Genetic plasticity in a mosquitofish (Gambusia affinis Baird and Girard) population was examined relative to acute mercury toxicity. Genotypes at eight loci (isocitrate dehydrogenase-1 and -2, mannosephosphate isomerase, glucosephosphate isomerase-2, fumarate hydratase, malate dehydrogenase-1, leucylglycylglycine peptidase and phenylalanylproline peptidase) were scored using starch gel electrophoresis. Two null hypotheses were tested: (a) time to death does not differ between genotypes at individual loci and (b) time to death does not differ with multiple-locus heterozygosity. Genotypes at three of the eight loci displayed significant effects on mosquitofish time to death. Multiple-locus heterozygosity also had a significant effect on time to death. Significant amounts of genetic plasticity were found in a population of mosquitofish with no previous exposure to inorganic mercury.
Insects as indicators of toxicity, bioaccumulation and bioavailability of environmental contaminants
Authors: Walton Barbara T. 
Published: March 2010

Abstract
The early involvement of entomologists in ecotoxicology is recognized in this article in celebration of the 70th birthday of Professor Robert L. Metcalf, who was among the first biologists to examine the potential for pesticides to produce unwanted environmental effects. The high sensitivity of insects to some toxicants and the potential insects have for biologically monitoring environmental contaminants is illustrated through review of developmental effects induced with benz[g]isoquinoline-5,10-dione (biquidone) and other chemicals in the cricket Acheta domesticus (L.). A teratogen-sensitive period of development is demonstrated prior to germ band formation in embryos of A. domesticus and of the field cricket Gryllus rubens (Scudder). An active mixed function oxidase system is shown for the embryos of both species through metabolism of [3H]benzo[a]pyrene to 7,8-dihydro-7,8-dihydroxybenzo[a]pyrene. Additional studies are cited to show that careful consideration of insect responses to toxicants can lead to the development of sensitive, cost-effective assays and monitoring approaches to assess the probable effects of chemical contamination in the environment.