bluuebunny/crossref_metadata_2025 huggingface dataset:
Fate of commercial disperse dyes in sediments
Authors: Yen C-P. C. , Perenich T. A. , Baughman George L.
Published: March 2010

Kinetics of disappearance of seven different disperse dyes were determined in compacted sediments at room temperature. The commercial dyes (in dispersed solid form) were representative of nitroazo, anthraquinone, and quinoline structures that are widely used. Reaction rates were found to be first order over at least two half-lives and were different for the three groups of dyes. Half-lives were on the order of hours, days, and months for the nitroazobenzene, aminoanthraquinone, and quinoline dyes, respectively. Stability of the latter is consistent with detection of a quinoline dye in treatment plant sludge and in sediment from a water body receiving treated effluent. The azobenzene dyes are degraded by cleavage of the azo group to give anilines and ring-substituted phenylenediamines from the diazo component of the molecule. Products from the other portion (coupling component) of the molecule are unidentified, as yet, but are expected to be N, N-disubstituted phenylenediamines. Products of the anthraquinone dyes were unidentified, except for the case of a nitrated dye on which the nitro group was reduced.
Genotoxicologic evaluation of ozonated/chlorinated drinking water: Cytogenetic effects of XAD-fractions on cultured human cells
Authors: Varga Csaba
Published: March 2010

Ozonated and chlorinated drinking water produced by a surface water treatment plant was examined to determine if genotoxins were formed by the treatment process The examined technology included ozonation (oxidation) and chlorination (disinfection), but excluded granular activated carbon or slow sand filtration following the ozonation step Investigations involved cytogenetic assays, chromosomal aberration, and sister chromatid exchange (SCE) analyses of 70-h human peripheral lymphocyte cultures treated with water isolates obtained on XAD resins Neutral XAD 2/4, XAD-8, and acidic XAD-2/4–8 fractions were tested separately in 1-, 10-, 20-μl/ml concentrations of the 7,000-fold isolates without metabolic activation A weak but significant (p < 0.05) SCE-inducing activity could be detected only upon treatment with the neutral XAD-2/4 fraction Clastogenicity and mitotic inhibition were not observed in the given concentration range
Bacterial mutagenicity and acute toxicity of solvent and aqueous extracts of soil samples from an abandoned chemical manufacturing site
Authors: Donnelly K. C. , Brown K. W. , Anderson C. S. , Thomas J. C. , Scott B. R.
Published: March 2010

Using a grid pattern, a total of 50 soil borings (DCT 1 through DCT 50) were collected from an abandoned chemical manufacturing facility. Split samples were obtained from six cores collected from a centralized location near a former wastewater lagoon. An additional sample from the 2.1- to 2.4-m depth of core DCT 20 was obtained as representative of the waste present on site. Three subsamples from each of the six cores or a total of 18 samples were sequentially extracted with methylene chloride and methanol for testing in mutagenicity and acute toxicity assays. A separate batch extraction with water was conducted and evaluated, using both chemical and biological test methods. The maximum mutagenic response was 3,237 net revertants induced with metabolic activation by 1 mg of the methanol extract of the 0- to 0.6-m depth at sampling location DCT 32. The water extract of the 0- to 0.6-m depth at sampling location DCT 32 induced 737 net revertants per mg. At sampling location DCT 24, the water extract induced 0.74, 1.32, and 2.5 toxic units in the Microtox® assay and 935, 69, and 39 net revertants per mg in the mutagenicity assay at the 0- to 0.3-, 1.2- to 1.4-, and 2.1- to 2.4-m depths, respectively. The chemical analysis of the samples from location DCT 24 indicated that the concentration of 2,3,6-trichlorobenzene acetic acid ranged from 16 ppm in the 0- to 0.3-m depth and to 0.95 ppm and below the detection limits at the 1.2- to 1.4- and 2.1- to 2.4-m depths. The methanol extract of the soil from the 0- to 0.3-m depth induced 19.2 toxic units in the acute toxicity assay and 1,467 net revertants in the mutagenicity assay. These results suggest that the most accurate site assessment is obtained when a water extract is evaluated to measure leaching potential and a solvent extract is evaluated to determine the relative total hazard of the sample. In addition, the combined use of chemical analysis, mutagenicity, and acute toxicity bioassays provides more accurate information from which to make a risk assessment.
Ammonia toxicity to macrophytes (common duckweed and rice) using static and renewal methods
Authors: Wang Wuncheng
Published: March 2010

Ammonia is a widespread contaminant that occurs in municipal wastewaters, industrial wastewaters, and agricultural wastes. Most ammonia toxicity studies deal with species of fish and macroinvertebrates, but very little information is available on ammonia phytotoxicity. The objectives of this study were to compare ammonia toxicity by using static and renewal methods and to compare phytotoxicity tests by using the vascular plants common duckweed and rice. Un-ionized ammonia-N at the rate of 8.85 mg/L inhibited rice seedling growth by 27%, using the renewal method, whereas the same amount caused insignificant effects on rice growth, using the static method. Ammonia-N at up to 8.85 mg/L did not inhibit duckweed growth, using the static method. By using the renewal method, un-ionized ammonia-N at concentrations greater than 3.0 mg/L depressed duckweed growth noticeably (20% or more). The increased ammonia concentration inhibited duckweed growth correspondingly, producing a linear relation for the concentration-inhibition effect. An un-ionized ammonia-N concentration of 7.16 mg/L was calculated to cause 50% duckweed growth inhibition (IC50), and 95% confidence limits ranged from 6.33 to 8.47 mg/L.
Effect of exposure time on the acute toxicities of permethrin, fenitrothion, carbaryl and carbofuran to mosquito larvae
Authors: Parsons J. T. , Surgeoner G. A.
Published: March 2010

Static toxicity tests were used to assess the acute toxicity to third-instar Aedes aegypti (L.) to short-term exposures of five insecticides (technical permethrin, microencapsulated permethrin, fenitrothion, carbaryl, and carbofuran). Larvae were exposed to each insecticide for times of 0.25, 0.5, 1, 2, 4, 8, or 24 h, then transferred to clean water and reared to the adult stage. Technical permethrin was most toxic to Aedes aegypti, followed by fenitrothion, microencapsulated permethrin, carbofuran, and carbaryl (24 h LC50 values, based on survival to the adult stage, were 0.45, 3.1, 21.6, 90.0, and 510.0 μg/L, respectively).

Acute toxicity increased with increasing exposure time to all five insecticides. However, the relationship between exposure time and acute toxicity differed among insecticides. The increase in acute toxicity was greater over short than over long exposures for technical permethrin, carbaryl, and carbofuran (LC50 values decreased 11.2 to 22.4-fold over a 0.5- to 4-h exposure, and 2.6- to 5.2-fold over a 4- to 24-h exposure). The opposite was true for microencapsulated permethrin (LC50 values decreased 3.6-fold over a 0.5- to 4-h exposure, and 6.2-fold over a 4- to 24-h exposure). Acute toxicity to fenitrothion increased proportionately with increasing exposure time.

Some larvae recovered from immobilization following short (0.5- to 4-h) exposures to technical permethrin, microencapsulated permethrin, carbaryl, and carbofuran (EC50 values based on immobilization immediately after exposure terminated were 0 to 15 times lower than corresponding LC50 values). However, ability to recover decreased with increasing exposure time such that no recovery from immobilization occurred after 8 or 24 h exposure. Larvae did not recover from immobilization following exposure to fenitrothion. These results indicate the need for a postexposure observational period to fully assess acute toxicity following exposure to insecticides.
Environmental factors correlated to dichlorophenol dechlorination in anoxic freshwater sediments
Authors: Hale Dorothy D. , Rogers John E. , Wiegel Juergen
Published: March 2010

The reductive dechlorination of three dichlorophenol (DCP) isomers was studied in anoxic sediments collected every other month for a year from five sites in one pond. Several physical, chemical, and microbiological characteristics of the sediments also were determined to identify correlations with DCP dechlorination that may be used to predict the persistence of these compounds in anoxic sediments. Stepwise regression indicated that for 2,5- and 3,4-DCP, sediment pH, redox potential (Eh), and concentration of sulfate and nitrate accounted for 83% of the variation in T50 values (time for dechlorination of 50% of a DCP to a monochlorophenol). Although the number of sediment microorganisms that dechlorinate 2,4-DCP varied two orders of magnitude in sediments collected during the study year, regression analysis indicated that neither this nor any other variables could account for greater than 50% of the variation in T50 values for 2,4-DCP. Chlorine was preferentially removed from the aromatic ring in the order ortho > para > meta; however, the influence of chlorine position on the ring on the persistence of the DCPs was generally not statistically significant.
Distribution of cadmium in an octanol/water system in the presence of xanthates and diethyldithiocarbamate
Authors: Block Mats
Published: March 2010

The octanol/water partition coefficient of cadmium was measured in the presence of ethyl-, isopropyl-, isobutyl-, and amylxanthates and diethyldithiocarbamate. For each complexing agent, the threshold concentration at which hydrophobic cadmium complexes started to appear was established. Cadmium was shown to form hydrophobic complexes with xanthates and diethyldithiocarbamate (maximal log POW = 1.73–2.64) at total ligand concentrations of 10−6 to 10−1 M. The proportion of cadmium in the octanol phase began to increase within the range of approximately 10−6.5 to 10−6 M for xanthate and approximately 10−5.0 M for diethyldithiocarbamate.
Effect of carbon-rich waste materials on movement and sorption of atrazine in a sandy, coarse-textured soil
Authors: Guo Lei , Bicki Thomas J. , Hinesly Thomas D. , Felsot Allan S.
Published: March 2010

Soil columns were used to investigate leaching of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] in a Plainfield sandy soil amended with waste activated carbon (WAC), digested municipal sewage sludge (DMS), or animal manure. Lower amounts of atrazine were consistently observed in leachates from soil with amendments than from soil without amendments. Ability of the three wastes to reduce leaching of atrazine followed the order WAC ≫ DMS > animal manure. Atrazine recovery in leachate ranged from 0.1% from soil amended with WAC at 2.1 t of total carbon per ha (t C/ha) to 77.4% from unamended soil. Mobility of atrazine in amended soil was inversely related to its sorption coefficient, KOC. Reduction in amount of leached atrazine by application of DMS or manure may also have involved increased degradation and/or formation of bound residues. Findings of this study provide basic information for possible utilization of waste materials in coarse-textured soils to reduce leaching of pesticides to ground water.
Chromosomal aberrations in native small mammals (peromyscus leucopus) at a petrochemical waste disposal site: II. Cryptic and inherited aberrations detected by G-band analysis
Authors: Mcbee Karen
Published: March 2010

Wild rodents (Peromyscus leucopus) collected from a hazardous waste site polluted with petrochemicals and known to have significantly increased frequencies of somatic chromosome aberrations in a standard metaphase chromosome aberration (SMCA) assay were examined by G-banding, a differential staining technique. Several classes of aberrations not detectable with SMCA were identified, including Robertsonian fusions, pericentric and paracentric inversions, and interstitial deletions. Four classes of these more cryptic aberrations were significantly higher in animals from the hazardous waste site compared to animals from reference sites. Several animals also carried apparently inherited aberrations in chromosomes 5, 10, and 21, suggesting that aberrations induced in a parent may be transmitted to offspring. When all classes of aberrations were converted to numbers of lesions per cell, animals from the hazardous waste site did not show elevated frequencies of lesions or aberrant cells, compared to animals from reference sites, unless inherited aberrations were removed from the data set. Then animals collected from the hazardous waste site showed a significantly increased number of aberrations per cell. Two chromosomes (5 and 21) sustained more aberrations than the other members of the complement, suggesting that some chromosomes may be more susceptible to induced damage than others. The method of G-banding itself may obscure much of the damage attributable to single chromatid breaks in SMCA but reveals types of damage not detectable in SMCA, indicating that the application of any single genetic assay technique may seriously underestimate actual levels of induced damage in exposed organisms.
Uptake and elimination of radioactivity from rainbow trout (oncorhynchus mykiss) following exposure to [14C-ring]-2-phenyldodecane
Authors: Burke Alison B. , Millburn Peter , Huckle Keith R. , Hutson David H.
Published: March 2010

The bioconcentration and elimination of radioactivity was monitored in rainbow trout exposed to [ring-14C]-2-phenyldodecane in a flow-through system. The uptake of radioactivity from the water at 15°C into the tissues was rapid, with equilibrium concentrations being approached at about 10 d. The bioconcentration factor (BCF) (Cfish/Cwater) measured in whole fish was 443. After 28 d exposure, fish were transferred to tanks containing clean water, and the clearance of radioactivity from tissues was monitored for a further 28 d in two test groups; one was maintained on a growth diet and the other on a rationed feed. Radioactivity was cleared rapidly from fish in both groups. Bile was a significant route of elimination. The effect of temperature was studied. When fish were exposed at a water temperature of 4°C, less [14C]-2-phenyldodecane was taken up, giving a lower BCF value for radioactivity (149) than the level at 15°C. The higher BCF at 15°C was due to the greater effect of temperature on uptake (k1 values) than on the elimination (k2 values). The BCF value predicted for 2-phenyldodecane based on water solubility or partition coefficient data is between 20,000 and 3,500,000. However, 2-phenyldodecane is susceptible to rapid and extensive biotransformation by fish. This metabolism limits the bioconcentration of the detergent alkylate in fish tissues.
Use of small artificial ponds for assessment of hazards to aquatic ecosystems
Authors: Heimbach Fred , Pflueger Wolfgang , Ratte Hans-Toni
Published: March 2010

Field tests with natural ponds often lack sufficient replication and/or control, making interpretation and evaluation of results difficult. For the assessment of potential hazards of chemicals to aquatic ecosystems, small artificial ponds have become increasingly valuable. Artificial pond ecosystems should, as far as possible, reflect natural conditions, contain all trophic levels with a high diversity of organisms, and, most importantly, be logistically and experimentally manageable. To fulfill these conditions, 5-m3-volume ponds, interconnected by closable locks, were provided with natural lake sediment and well water. Caged fish were added to each pond, and the interconnecting locks were kept open until identical physicochemical and biological conditions had been established. At this time, the ponds were isolated from one another and experiments with a pyrethroid insecticide (Baythroid®) containing cyfluthrin as the active ingredient (a.i.) were conducted. The results of these field tests, which include both the fate and the biological effects of the insecticide, were compared with data obtained in larger natural ponds. Overall, the results were similar, indicating that useful information on the potential hazard of chemicals can be obtained in small artificial ponds.
Statistical treatment of data from microbial toxicity tests
Authors: Nyholm Niels , Sørensen Per Settergren , Kusk K. Ole , Christensen Erik R.
Published: March 2010

The response measured in microbial toxicity tests is typically a continuous variable, and the associated error is an experimental error related to the physical measurement of the response and to handling differences between experimental units (e.g., test flasks). The traditional statistical theory for treating quantal (or categorical) data from tests with animals is based on the concept of a tolerance distribution for individual test subjects that is not appropriate for microbial tests. Data from microbial tests should be dealt with by conventional curve-fitting techniques without any confusion with tolerance distributions. Using an empirical mathematical function that describes a sigmoid curve, concentration–response curves can be fitted by nonlinear regression directly onto the data or by weighted linear regression after a linear transformation of the data. Calculation of confidence intervals around the estimated EC figures (calculated effective concentrations that cause a certain percentage of inhibition; for example, EC10 for 10% inhibition) is less complicated with weighted linear regression on transformed data than it is with nonlinear regression. The paper provides a general discussion of the problem of analyzing data from microbial toxicity tests and gives some examples of feasible methods.
Photolysis of aryl ketones with varying vapor pressures on soil
Authors: Kieatiwong Somchai , Miller Glenn C.
Published: March 2010

The photolysis of a series of aryl ketones on air-dried soil surfaces was examined to establish whether vapor transport has an effect on the rate and extent of photolysis. If vapor transport were significant on light-exposed soils, then differences in the observed photolysis rate profiles would be expected, with the compounds having higher vapor pressures exhibiting the greatest photolysis. The aryl ketones, including hexanophenone, octanophenone, dodecanophenone, hexadecanophenone, and octadecanophenone, had nearly identical photolysis rates in solution exposed to sunlamps (Λmax 310 nm). The vapor pressures of these five compounds (25 °C) were estimated by a capillary gas chromatographic method and varied from 8.7 × 10−3 to 8.4 × 10−8 torr. The compounds were irradiated for 15 d on an air-dried sandy loam soil surface. The photolysis rate profiles of the four aryl ketones with vapor pressures from 1.3 × 10−3 torr to 8.4 × 10−8 torr were identical within experimental error, whereas the most volatile congener, hexanophenone, showed approximately 10% greater loss. Volatilization of hexanophenone appears to have caused the compound to move into the light-exposed soil surface to a greater extent than the other compounds. These results suggest that vaporization is not important for loss or transport of the compounds with vapor pressures less than 1.3 × 10−3 torr on air-dried soils within the 15-d irradiation.
Effects of low dissolved oxygen on survival, growth and reproduction of Daphnia, Hyalella and Gammarus
Authors: Nebeker Alan V. , Dominguez Stephen E. , Chapman Gary A. , Onjukka Samuel T. , Stevens Donald G.
Published: March 2010

Daphnia magna, Daphnia pulex, Hyalella azteca, and Gammarus lacustris were exposed to low dissolved oxygen concentrations in the laboratory. Acute and chronic exposures were conducted to develop data for use in the U.S. Environmental Protection Agency's (EPA's) water quality criteria document for dissolved oxygen. Daphnia magna had two 48-h LC50s (50% mortality) of 0.6 and 0.7 mg/L, a highest-adverse-effect concentration of 0.6, and a lowest-no-adverse-effect concentration of 0.9 mg/L O2 (based on reproduction). Daphnia pulex had a 48-h LC50 of 0.5, two 96-h LC50s of 0.4 and 0.7, a highest-adverse-effect concentration of 1.6, and a lowest-no-adverse-effect concentration of 2.1 mg/L O2 (based on reproduction). Hyalella azteca had 96-h and 30-d LC50s of <0.3 mg/L, a highest-adverse-effect concentration of 1.2, and a lowest-no-adverse-effect concentration of > 1.2 (based on reproduction). Gammarus lacustris had two 7-d LC50s of <0.2 mg/L, a highest-adverse-effect concentration of <0.2, and a lowest-no-adverse-effect concentration of 0.1 mg/L O2 (based on survival). Lack of access to the water surface increased mortality. Nitrogen-stripped and vacuum-degassed test water produced the same mortality. Results of this study indicate that dissolved oxygen concentrations adequate to avoid impairment of fish production, as outlined in the EPA's water quality criteria document, should provide reasonable protection for these four species.
Comparative acute sensitivity of larval topsmelt, Atherinops affinis, and inland silverside, Menidia beryllina, to 11 chemicals
Authors: Hemmer Michael J. , Middaugh Douglas P. , Comparetta Valerie
Published: March 2010

Larval topsmelt (Atherinops affinis) and inland silversides (Menidia beryllina) were exposed in 96-h static acute toxicity tests to 11 chemicals to determine the relative sensitivity of the two atherinid species. High to low LC50 ratios for endosulfan, methoxychlor, carbophenothion, chlorpyrifos, terbufos, fenvalerate, permethrin, 4-nitrophenol, and sodium lauryl sulfate were within a factor of <2 for the two species. Atherinops affinis was more sensitive to both azinphos-methyl and 2,4-dinitrophenol by factors of 6.7 and 4.4, respectively. Comparisons of the relative sensitivity of Atherinops affinis with three freshwater fish species (Lepomis macrochirus, Oncorhynchus mykiss, Pimephales promelas) and one estuarine fish species (Cyprinodon variegatus) are presented. Sensitivities were similar between Atherinops affinis and the two most sensitive freshwater species, Lepomis macrochirus and Oncorhynchus mykiss. Atherinops affinis is easily transported, cultured, and maintained in the laboratory and readily adaptable for use in toxicological studies.
Use of the mayfly Stenonema Modestum (Heptageniidae) in subacute toxicity assessments
Authors: Diamond Jerome M. , Winchester Erik L. , Mackler Donald G. , Gruber David
Published: March 2010

This study presents the results of subacute toxicity testing with the mayfly (Ephemeroptera), species Stenonema modestum (Heptageniidae). This species is ubiquitous to many streams in the eastern United States and Canada and is associated with unpolluted sediments and water. The results show that counts of molts or exuviae over a 7–14-d exposure period can be a sensitive indicator of chronic growth effects. Molt production was a more sensitive indicator of pollutant effects than length of organism or width of head capsule measurements. Tests using coal mine effluents indicated that the 7-d molt production end point was often more sensitive than the 14-d molt or survival end point. This was due to either a short-term stimulatory effect on molting or effluent variability over time. Molt stimulation was not observed in tests using NaCl or silver nitrate. Tests with these compounds and coal mine effluents demonstrated that the methods and end points provide repeatable and relatively sensitive data. Test precision was comparable to U.S. Environmental Protection Agency 7-d short-term chronic tests. Molt production of Stenonema modestum in laboratory tests proved to be a reliable predictor of instream effects due to a metal-finishing effluent. Furthermore, simultaneous tests of sediment elutriates and ambient samples from the stream pinpointed probable mechanisms behind the observed instream impact on Stenonema modestum. This method should be amenable to other mayfly species, making it a potentially useful tool in site-specific water quality and sediment quality studies.
Toxicity of trace element and salinity mixtures to striped bass (Morone saxatilis) and Daphnia magna
Authors: Dwyer F. J. , Burch S. A. , Ingersoll C. G. , Hunn J. B.
Published: March 2010

Acute toxicity tests with reconstituted water were conducted to investigate the relationship between water hardness, salinity, and a mixture of trace elements found in irrigation drain waters entering Stillwater Wildlife Management Area (SWMA), near Fallon, Nevada. The SWMA has been the site of many fish kills in recent years, and previous toxicity studies indicated that one drain water, Pintail Bay, was acutely toxic to organisms acclimated or cultured in fresh water or salt water. This toxicity could reflect both the ionic composition of this saline water and the presence of trace elements. The lowest water salinity tested with Daphnia magna was near the upper salinity tolerance of these organisms; therefore, we were unable to differentiate between the toxic effects of ion composition and those of trace elements. In toxicity tests conducted with striped bass (Morone saxatilis), we found that the extent to which salinity was lethal to striped bass depended on the ion composition of that salinity. Survival of striped bass increased as hardness increased. In addition, a trace element mixture was toxic to striped bass, even though the concentrations of individual elements were below expected acutely lethal concentrations. Although salinity is an important water quality characteristic, the ionic composition of the water must be considered when one assesses the hazard of irrigation drain waters to aquatic organisms.
Uptake and accumulation of selenium by terrestrial plants growing on a coal fly ash landfill. Part I: Corn
Authors: Arthur Mary A. , Rubin Gail , Schneider Robert E. , Weinstein Leonard H.
Published: March 2010

This study was conducted to examine the suitability of growing corn (Zea mays L.) on a closed coal fly ash landfill. Previous work indicated that selenium (Se) was the potentially toxic element most likely to be taken up by plants grown on these landfills. This experiment tested differences in Se concentration in three cultivars of corn — Agway 135 (Agway, Inc., Syracuse, NY), Halsey 2273 (Halsey Farms, Ithaca, NY), and Golden Cross Bantam (Agway, Inc., Syracuse, NY) — and two cultivation techniques — no-till and conventional. Selenium concentrations in corn grown on the landfill were consistently higher than those in corn grown on nonlandfill sites. There were no significant differences among two field corn cultivars and one sweet corn cultivar in Se concentrations in vegetative tissues harvested in August 1989. However, there were significant differences between the two field corn cultivars in the Se concentrations of leaves and kernels harvested in October 1989. Corn grown with no-till agriculture had significantly higher concentrations of Se in leaves and kernels never attained toxic levels, indicating that corn grown on fly ash landfills may be safe for human or livestock consumption. However, large variability among varieties and tissues suggests that the use of fly ash landfills for growing agricultural crops should be undertaken only after extensive field trials.
Interaction of naturally occurring neurotoxins and the pyrethroid insecticide deltamethrin with rainbow trout (Oncorhynchus Mykiss) brain sodium channels
Authors: Rubin Jared G. , Soderlund David M.
Published: March 2010

A radiosodium flux assay was employed to characterize the pharmacological properties of trout brain voltage-sensitive sodium channels and to define the response of those channels to the synthetic pyrethroid insecticide deltamethrin The uptake of 22Na+ into trout brain synaptoneurosomes was measured in the presence of a number of sodium channel-directed ligands The sodium channel activators aconitine, veratridine, and batrachotoxin stimulated 22Na+ uptake into trout brain synaptoneurosomes in a dose-dependent manner Batrachotoxin was the most efficacious and potent activator having a maximal sodium uptake at saturating concentrations (Emax) of 6 2 nmol/mg protein and a concentration producing a half maximal response (K0 5) of 3 5 μM Veratridine and aconitine produced Emax values of 3 3 and 3 8 nmol/mg protein and K0 5 values of 16 2 and 11 9 μM, respectively Scorpion (Leiurus quinquestriatus) venom (10 μg per incubation) lowered the K0 5 of batrachotoxin, aconitine, and veratridine and increased Emax for aconitine and veratridine Concentrations of tetrodotoxin above 1 μM completely inhibited 22Na+ uptake The effects of the pyrethroid insecticide deltamethrin on activator-dependent 22Na+ flux were measured to determine if the hypersensitivity of fish to pyrethroid intoxication was related to intrinsic properties of the piscine sodium channel Deltamethrin (20 μM) enhanced veratridine- but not aconitine-dependent 22Na+ flux Deltamethrin also caused a three-fold shift in the potency of batrachotoxin with no effect on Emax Our results demonstrate the presence of functional sodium channels in trout brain synaptoneurosomes that share many of the pharmacological properties of mammalian voltage-sensitive sodium channels However, the sodium uptake assay employed in this study has limitations for assessing pyrethroid potencies in piscine brain preparations
Performance characteristics of effluent toxicity tests: Variability and its implications for regulatory policy
Authors: Warren-Hicks William , Parkhurst Benjamin R.
Published: March 2010

An essential consideration when imposing a requirement for, or evaluating the results generated by, effluent toxicity tests in the National Pollutant Discharge Elimination System (NPDES) permit program is the amount of uncertainty in the measured test end point Variability in effluent toxicity test results is explored by examining round-robin test data with Daphnia magna, fathead minnows, and Certodaphnia dubia as test organisms Inter and intralaboratory percentages of survival of the test organisms are examined by using plots, descriptive statistics, and logistic regression models The results of the analyses demonstrate that the variation in survival is large (0-100% for some test solutions) In addition, the amount of variability is shown to be a function of the toxicity of the test solution The variability in survival is shown to be larger than the variability associated with the LC50 (a model-based end point) The large variability in effluent toxicity tests can have significant implications for the interpretation of toxicity test results used to measure compliance with effluent toxicity limits
Effects of chlorinated phenols on rat embryonic and hepatic mitochondrial oxidative phosphorylation
Authors: Narasimhan Tumkur R. , Safe Stephen H. , Mayura Kittane , Clement Beverly A. , Phillips Timothy D.
Published: March 2010

Chlorinated phenols (CPs), including pentachlorophenol, selected positional isomers from each major group of CPs, and phenol were previously selected from 38 possible compounds and ranked according to developmental toxicity. The present study was designed to utilize these compounds (and a variety of chemical derivatives) to elucidate the mechanism(s) of developmental toxicity of the chlorinated phenols. Mitochondria were isolated by differential centrifugation from rat embryos (REM) and maternal liver (MLM) on day 15 of gestation. The higher CPs, i.e., pentachlorophenol (C5P), 2,3,4,5-tetrachlorophenol (2,3,4,5-C4P), and 2,3,5-trichlorophenol (2,3,5-C3P) at concentrations > 1.33 μM, inhibited ADP phosphorylation and state 4 respiration in the presence of either glutamate plus malate or α-ketoglutarate or succinate. These compounds also exerted a significant uncoupling activity at a concentration of 1.33 μM, with C5P > 2,3,4,5-C4P > 2,3,5-C3P. The lower CPs, i.e., 3,5-dichlorophenol (3,5-C2P), 4-chlorophenol (4-CP), and phenol, produced comparable mitochondrial effects, but only at a higher concentration (20 μM). Enhanced mitochondrial ATPase activity (with and without Mg2+) was induced by C5P, 2,3,4,5-C4P and 2,3,5-C3P at concentrations that exhibited maximum uncoupling activity. The CPs (except for the derivative C5P-anisole) caused significant mitochondrial swelling. The reversal of oligomycin-inhibited respiration by C5P from REM or MLM was also reproducible in the intact Hydra attenuata. A correlation of 0.9 (p = 0.0151) between CP-induced uncoupling activity and the reciprocal of the minimal affective concentration in the Hydra developmental assay was observed. These findings suggest that CPs may elicit their effects by interacting with target cell mitochondria.
Influence of xanthates on the uptake of 109Cd by eurasian dace (Phoxinus phoxinus) and rainbow trout (oncorhynchus mykiss)
Authors: Block Mats , Glynn Anders Wicklund
Published: March 2010

Xanthates form hydrophobic complexes with heavy metals and may therefore have the potential to facilitate the uptake of metals from water by fish. In this paper results are presented supporting the hypothesis that the increased availability is due to the hydrophobic properties of the complexes.
Copper toxicity to Paratya australiensis. IV. Relationship with ecdysis
Authors: Daly Helen R. , Hart Barry T. , Campbell Ian C.
Published: March 2010

Postmolt individuals of the freshwater prawn Paratya australiensis were more sensitive to copper toxicity than individuals at other stages of the molt cycle. In contrast to other reports, molting frequently was not increased by exposure to sublethal concentrations of copper.
The role of property-reactivity relationships in meeting the EPA's needs for environmental fate constants
Authors: Donaldson William T.
Published: March 2010

During the next 10 years, the Environmental Protection Agency may consider as many as 70,000 chemicals for potential risk to humans and the environment. As many as 14 kinetic and equilibrium constants can be required for predicting the fate and transport of each chemical, and relatively few reliable constants are available in the literature. Laboratory measurement of the needed constants is prohibitively expensive (as much as $7 billion for all constants and chemicals combined) and too slow for rapid response to site-specific evaluations. Development of reliable computational methods holds promise of a 100-to 1000-fold reduction in cost of providing fate constants within a reasonable time frame.
Prediction of octanol/water partition coefficient (KOW) with algorithmically derived variables
Authors: Niemi Gerald J. , Basak Subhash C. , Grunwald Greg , Veith Gilman D.
Published: March 2010

A statistical model was developed with algorithmically derived independent variables based on chemical structure for prediction of octanol/water partition coefficients (Kow) measured for more than 4,000 chemicals. The procedure first classified the chemicals into 14 groups based on the number of hydrogen bonds, and then best-subsets, multiple-regression analysis was used to predict Kow within groups. In addition, a training set/test set approach was used to provide an independent evaluation of the sensitivity of the model to the number of chemicals and variables used within each group. In general, the explained variation (r2) was higher and the standard error of the estimates (see) lower in the training sets as compared with the test set groups, whereas analyses of the combined data sets were generally intermediate. Explained variation among the 14 groups, using the combined data sets, ranged from 63 to 90%, and see ranged from 0.37 to 0.78 in logarithmic units. Plots of the residuals indicated a normal scatter. These results are similar to reported error rates in other models.
Quantitative structure-activity relationships of nonspecific and specific toxicants in several organism species
Authors: Ikemoto Yuji , Motoba Kazuhiko , Suzuki Takashi , Uchida Matazaemon
Published: March 2010

The toxicities to Oryzias latipes, Daphnia pulex, and Chlorella vulgaris of nonspecific toxicants (alkanols, substituted benzenes, and alkyl toluates) were well collineated with the logarithm of the octanol/water partition coefficient, log Kow. However, specific toxicants such as 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), lindane, diflubenzuron, rotenone, buprofezin, dieldrin, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), and fenvalerate exhibited excess toxicities dependent on the test organism species. The species-specific excess toxicities were much higher than those expected from log Kow and seemed to appear only when the test organisms possessed the specific sites for the toxicants. However, the toxicities of n-butyl- and n-propyl-p-toluates to Oryzias latipes were slightly lower than those predicted from log Kow. The toxicity alleviation corresponded well to the ester biodegradability measured in the fish toxicity assay system. Thus simple quantitative structure-activity relationships (QSARs), using solely log Kow with an appropriate set of compounds and bioassay systems, are useful not only for predicting the environmental toxicity of nonspecific toxicants and specific toxicants, including their mechanism of action, but also for assessment of their biodegradability.
An equation describing the time course and variability in uptake and toxicity of narcotic chemicals to fish
Authors: MacKay D. , Puig H. , McCarty L. S.
Published: March 2010

An equation is proposed to express the time course of uptake of organic chemicals by fish. The chemicals' octanol/water partition coefficients are used to describe equilibrium partitioning, whereas the clearance rate constant, estimated as a function of water- and organic-phase series resistances to transport, is used to describe the time course of uptake. The probability of the concentration of chemical in the fish causing a defined toxic end point is expressed by using a modified Weibull distribution function that contains an adjustable parameter describing variability in organism response. The effect of metabolism can be included if desired. The combined uptake and probability equations are tested by using mortality data for fathead minnows exposed to 18 narcotic chemicals. A single set of parameters is obtained to fit the entire data set. The equation highlights the importance of considering the kinetics of toxicant accumulation when interpreting toxicity results, especially for hydrophobic chemicals, and reinforces the fact that a common organism residue level (in either molar volume or molarity) is associated with 50% mortality in acute bioassays with narcotic organic chemicals. Assorted features of the equations and their applicability to toxicants with specific modes of action are discussed.
Ecosystem-level changes that may be expected in a changing global climate: A british columbia perspective
Authors: Kimmins James P. , Lavender Denis P.
Published: March 2010

British Columbia is a vast province encompassing a wide latitudinal and elevational range. Four of the five major classes of climate in the world are found in British Columbia, where prevailing westerly winds from the Pacific and a series of north-south mountain ranges have produced widely differing local climates. The predicted global warming may result in the migration of species and communities upslope and toward the north, but the heterogeneous nature of the present landscape suggests that such migration may not be as pronounced as that likely to occur in regions of Canada with less relief. Effects of climatic warming on long-lived temperate zone trees include possible increased frost damage in early spring; reduced seed production; increased insect and disease incidence; increased damage to forests by wildfire; and, in the warmer parts of coastal British Columbia, a winter climate too warm to satisfy the chilling requirements of some perennial plants.
Forest health along a wet sulfate/ph deposition gradient in north-central pennsylvania
Authors: Nash Bruce L. , Davis Donald D. , Skelly John M.
Published: March 2010

A well-defined gradient of wet atmospheric depositions characterized by SO4, NO3, H, and NH4 ions has been described in north-central Pennsylvania. The forests of this region are of the oak/hickory type as they extend across the Allegheny Plateau. Sulfate levels along a 160-km west-east gradient varied from approximately 40 kg/ha to 25 kg/ha in the western and eastern portions, respectively. The objective of this research project was to determine if forest trees along the gradient showed anomalous characteristics that might be related to acidic atmospheric deposition. Trees were relatively healthy across the gradient, as measured by observations of crown transparency, twig dieback, and trunk condition. No general relationship was apparent between overall tree health and deposition patterns. Specific disorders noted at greater frequencies at the high deposition portion of the gradient included the presence of insect borers on white oak trunks and early fall coloration of red maple. Disorders observed at greater frequencies at the low deposition portion of the gradient included twig and branch dieback of red oak, white oak, and red maple; chlorosis of red oak; and thrips injury of red maple. A direct cause-and-effect relationship between the pollution gradient and these disorders has not been established.
Uptake and accumulation of selenium by terrestrial plants growing on a coal fly ash landfill. Part 2. Forage and root crops
Authors: Arthur Mary A. , Woodbury Peter B. , Schneider Robert E. , Weinstein Leonard H. , Rubin Gail
Published: March 2010

Plants grown on fly ash landfills can accumulate relatively high concentrations of selenium (Se), although concentrations can vary greatly among and within species. We examined the accumulation of Se in forage and root crops grown on a fly ash landfill and nonlandfill sites and the relationship of soil Se to plant Se concentrations. Because sulfur (S) can act as a competitive ion with Se in plant uptake of nutrients, gypsum (CaSO4.2H2O) was applied to soil on a fly ash landfill to determine whether Se was reduced in plants in its presence. Slightly more Se was accumulated in plants grown on the landfill than on the nonlandfill site. Total Se concentration in soil was poorly correlated with Se concentration in alfalfa plants grown on the landfill. In alfalfa (Medicago sativa L.), oats (Avena sativa L.), and rutabaga (Brassica napus L.), application of gypsum at rates of 5.6 to 16.8 t ha−1 reduced the uptake of Se from that of plants grown without gypsum. Results from this study indicate that gypsum amendment may be effective in decreasing the uptake of Se by plants growing on a fly ash landfill, but the response is quite variable, probably due to variability in concentration and availability of Se in the soil cap. The use of gypsum in limiting Se uptake by plants offers a possible management tool to control the cycling of Se through plants to other biota on fly ash landfills.
Response of female California quail (Callipepla californica) to methyl parathion treatment of their home ranges during the nesting period
Authors: Kilbride Kevin M. , Crawford John A. , Williams Bill A.
Published: March 2010

Fifty-eight female California quail (Callipepla californica) were trapped and fitted with transmitters at the E.E. Wilson Wildlife Area, Oregon, from April to July in 1988 and in 1989. Radiotelemetry was used to monitor hen movements daily throughout two breeding seasons (May to mid-August). Home ranges for the first half of incubation for 15 of 22 nesting hens were treated with methyl parathion 4E (n = 7) or water (n = 8) at a rate of 0.56 kg active ingredient per hectare. No measurable effects were found for nest attentiveness from pre- to post-treatment period within the methyl parathion (p = 0.47) and water (p = 0.57) groups and use of treated areas between groups (p = 1.00). Also, no measurable effects were found for rates of nest success (p = 0.61), nest abandonment (p = 0.20), and recruitment to 15 d post-hatch (p = 0.40) between the methyl parathion and water groups. However, a lower hatching rate (p = 0.02) was found in eggs from hens in the methyl parathion group.
The importance of humic acids to proton and cadmium binding in sediments
Authors: Fu Gongmin , Allen Herbert E. , Cao Yang
Published: March 2010

We used potentiometric titration to study the sorption of hydrogen and cadmium ions by three sediments and the humic acid (HA) extracted from each of these sediments. The acidity constants for both sediment and HA were estimated using a discrete monoprotic acid model. Similar pK values were found for the sediments and the HAs. The pK values are 4.48, 6.10, 7.56, and 9.50 for sediment RS3; 4.03, 6.46, and 8.42 for HA(RS3); 4.00, 5.76, 7.81, and 9.90 for sediment RS4; 4.11, 6.94, and 8.69 for HA(RS4); 3.90, 5.83, 7.90, and 9.78 for sediment RS6; 3.63, 6.23, and 8.24 for HA(RS6). Cadmium binding to sediment and HA was treated as surface complexation of cadmium by ligands. A nonlinear optimization program was used to treat the sorption isotherm data at pH 4.5 and 6.5. Conditional stability constants for cadmium binding to the sediment and HA at pH 4.5 are 4.04 for sediment RS3 and 3.95 for HA(RS3), 4.71 for sediment RS4 and 4.64 for HA(RS4), and 4.56 for sediment RS6 and 4.54 for HA(RS6). At pH 6.5 the conditional constants for cadmium binding are 5.03 for sediment RS3 and 4.92 for HA(RS3), 6.08 for sediment RS4 and 6.02 for HA(RS4), and 5.92 for sediment RS6 and 5.80 for HA(RS6). We also examined the correlation between cadmium binding to sediments and to the HAs extracted from sediments. All the binding of added cadmium by these sediments can be explained by HAs.
Treated municipal wastewaters: Effects of organic fractions on development and growth of fishes
Authors: Weis Peddrick , Weis Judith S. , Chen Chien-Min , Greenberg Arthur
Published: March 2010

Effluents from publicly owned treatment works (POTW) supply >98% of point-source pollutants and 13% of total freshwater input to the Hudson-Raritan estuary. We have studied the effects of chlorinated secondarily treated effluents on the sensitive early life stages of three species of fish common to this estuary. One source of effluents is a POTW that receives about half of its input from industrial sources. Previously, we demonstrated effects on development and growth of estuarine fishes of the effluent at ⩽ 10% in seawater. This report presents similar studies using organic fractions of the effluent at concentrations equivalent to 10% in seawater in order to identify the most toxic class of compounds. We have found that the toxicity of batches of this effluent is quite variable in toxicity when tested with embryos of the winter flounder (Pseudopleuronectes americanus) or mummichog (Fundulus heteroclitus). In different batches of effluent, the organic base fraction or the organic acid fraction was primarily responsible for the toxicity.
Behavior of sunfish exposed to herbicides: A field study
Authors: Bettoli Phillip W. , Clark Patrick W.
Published: March 2010

An underwater closed-circuit video system was used to remotely monitor and record the behavior of bluegills (Lepomis macrochirus) and redear sunfish (Lepomis microlophus) guarding their nests before, during, and after applications of aquatic herbicides. Nests were sprayed to achieve a nominal concentration of 4 mg/L of either a dipotassium salt of endothall (Aquathol-KD̊), a dimethylamine salt of 2,4-dichlorophenoxyacetic acid (2,4-D), or water (control). No significant differences in rates of nest abandonment existed among the three treatments (p > 0.10). Abandonment averaged 5.17 min for both species and herbicide treatments, whereas the herbicides persisted in the water column for at least 45 min. When abandonment occurred, congeners nearly always intruded on the nest to feed on eggs or fry. After spraying, the adjusted mean frequency of rim circling, fanning, and agonistic behaviors exhibited by bluegills guarding eggs did not differ among the three treatments (p ⩾ 0.35). These results suggest the two herbicides will not elicit pronounced shifts in reproductive behavior of sunfish when they are properly applied.