bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of polychlorinated biphenyl 126 on green frog (Rana clamitans) and leopard frog (Rana pipiens) hatching success, development, and metamorphosis
Authors: Rosenshield Michele Laura , Jofré Mariana Beatriz , Karasov William Henry
Published: March 2010

Although increasing evidence links planar chlorinated hydrocarbons, such as polychlorinated biphenyls (PCBs), to decreases in survival and reproduction of fish, mammals, and birds near Green Bay, Wisconsin, and the Great Lakes, USA, relatively little is known of their bioaccumulation or of their possible effects in amphibians. We exposed embryos and larvae of two ranid species commonly occurring in the Green Bay ecosystem, the green frog (Rana clamitans) and the leopard frog (Rana pipiens), to PCB 126, a model coplanar PCB compound. Nominal concentrations ranged from 0.005 to 50 μg/L, and exposure lasted through metamorphosis. Tissue concentrations of PCB 126 in tadpoles that did not metamorphose by the end of the experiment ranged from 1.2 to 9,600 ng/g wet mass. No significant mortality of embryos occurred before hatching; however, survival of larvae was significantly reduced at the highest concentration for both species. Few deformities were observed, but the incidence of edema was significantly higher in tadpoles exposed to 50 μg/L. Swimming speed and growth of tadpoles was also significantly reduced in this treatment. The percent of tadpoles that reached metamorphosis was significantly lower in green frogs at the highest concentration, and no leopard frogs survived past day 47 of the experiment in this treatment. At high concentrations, PCB 126 affected both ranid species; however, sublethal effects were not apparent for the parameters we measured at concentrations that occur in water in the Green Bay ecosystem.
Toxicity of conventional, elemental chlorine-free, and totally chlorine-free kraft-pulp bleaching effluents assessed by shortterm lethal and sublethal bioassays
Authors: Tarkpea Maria , Eklund Britta , Linde Margareta , Bengtsson Bengt-Erik
Published: March 2010

The toxicity of nine effluents from Swedish kraft-pulp mills using conventional, elemental chlorine-free (ECF) and totally chlorine-free (TCF) bleaching processes was studied. Effluents represented six different processes: conventional-softwood 30% ClO2; ECF-softwood; TCF-hardwood, for which all the samples were taken before and after secondary treatment; conventional-softwood 8% ClO2; TCF-softwood O3/H2O2; and TCF-softwood H2O2. Comparison of effluents, which had not undergone secondary treatment, suggested that those from mills using conventional bleached pulp were the most toxic, with toxic emission factors (TEF) ≈ 1,000 according to the Microtox® test (AZUR Environmental, Carlsbad, CA, USA). In the acute Nitocra spinipes test, the conventional-softwood 8% ClO2 and the ECF-softwood effluents before secondary treatment were the most toxic, with TEF ≈ 700. In the reproduction test, N. spinipes was two to three times more sensitive than in the lethal test. The species most sensitive to the effluents investigated was the macroalga Ceramium strictum, with TEF values up to 3,000. The conventional effluent using a substitution of 8% ClO2 was the most toxic, and the TCF effluents were the least toxic. Degradation treatment of the ECF and TCF effluents for 28 d in the laboratory did not eliminate acute lethal effects on N. spinipes and the Microtox bacterium.
Multiple Computer-Automated structure evaluation program study of aquatic toxicity 1: Guppy
Authors: Klopman Gilles , Saiakhov Roustem , Rosenkranz Herbert S , Hermens Joop L M
Published: March 2010

An acute fish toxicity model was constructed on the basis of a wide series of experimental data for guppy. The Multiple Computer-Automated Structure Evaluation program was used to construct the model. The created model possesses very good predictive ability. It can correctly predict acute toxicity for guppy for 80% of compounds with an average error of only 0.63 log unit per median lethal concentration. The importance of the narcosis effect was demonstrated. The main toxicophores, corresponding to polar narcosis and to the reactive chemicals, were identified.
Methods for the diagnosis of acute 3-chloro-p-toluidine hydrochloride poisoning in birds and the estimation of secondary hazards to wildlife
Authors: Johnston John J , Hurlbut Daniel B , Avery Michael L , Rhyan Jack C
Published: March 2010

Female boat-tailed grackles poisoned with 3-chloro-p-toluidine hydrochloride (CPTH) were analyzed by necropsy and gas chromatography-mass spectrometry (GC-MS). The necropsies identified the presence of a white precipitate in the pericardium, which had been previously reported as a characteristic of CPTH-exposed birds. The GC-MS method, which utilized deuterated CPTH as a surrogate, quantified CPTH residues in the breast tissue and gastrointestinal tract of CPTH-exposed birds. Comparison of these techniques indicated that the GC-MS method was more accurate for assessing CPTH poisoning in birds. Regression analyses of consumption versus residue data indicated that the sum of breast and gastrointestinal residues can be used as an estimator of CPTH exposure. Comparison of CPTH residues in grackles with toxicity data for a variety of scavenger and predator species provided risk quotients of less than 0.1. Analysis of these data suggests that secondary hazards associated with the use of CPTH as an avicide for the control of pest birds are minimal.
Sensitivity of amphibian embryos and tadpoles to Mimic® 240 LV insecticide following single or double exposures
Authors: Pauli Bruce D , Coulson Donna R , Berrill Michael
Published: March 2010

Mimic® 240 LV is a novel, narrow-spectrum insecticide containing the active ingredient tebufenozide. Tebufenozide mimics the action of the insect molting hormone ecdysone and shows specific activity toward larval Lepidoptera. In Canada, Mimic 240 LV has been proposed for use in forest pest control, whereas a different formulation has been registered for use in agriculture. We examined the effects of single and double pulses of Mimic 240 LV (tebufenozide) on the development, growth, and predator avoidance behavior of four frog species (wood frogs Rana sylvatica, leopard frogs R. pipiens, green frogs R. clamitans, and bullfrogs R. catesbeiana) exposed in the laboratory as embryos or tadpoles. Nominal doses ranged from 3.0 mg/L to 9.0 mg/L tebufenozide, and exposures were terminated at 96 h following single, or 192 h following double, exposures. More than 90% of the animals exposed as embryos hatched. Embryos exposed late in development and subsequently hatching into tebufenozide-contaminated water all hatched and responded normally. Tadpole growth was not delayed following exposure, and premetamorphic green frogs successfully completed metamorphosis following exposure to the highest concentration. The results suggest that Mimic 240 LV, when used at the suggested application rates, will not severely affect the aquatic stages of ranid amphibians.
Vitamins A1, A2, and E in minks exposed to polychlorinated biphenyls (Aroclor 1242®) and copper, VIA diet based on freshwater or marine fish
Authors: Käkelä Reijo , Käkelä Anne , Hyvärinen Heikki , Asikainen Juha , Dahl Sanna-Kaisa
Published: March 2010

Minks (Mustela vison) fed diets based on either freshwater fish or marine fish were exposed to 1 mg of polychlorinated biphenyls (PCBs) (Aroclor 1242®) daily for 28 d. To minks on the freshwater diet, copper (62 mg/kg food) was also given with or without PCBs. The marine diet (vitamin-rich plus additional supplements) included more vitamin A1 and E than the freshwater diet. We studied how the exposures affected levels of vitamins A1, A2, and E in liver and adipose tissues and levels of vitamins A1 and A2 in plasma. In females and males on the freshwater diet, the hepatic level of vitamin A2 was decreased because of the PCBs, and in these males the hepatic levels of vitamin E also decreased. Interestingly, with coexposure to PCBs and copper, the vitamin levels were, in general, close to the control values. In adipose tissues also, the PCBs induced significant changes in the concentrations of vitamins A1 and A2. In plasma, vitamins A1 and A2 were decreased in all patterns of exposure and on both diets. However, plasma thyroxine was slightly increased, a finding opposite to that reported previously in rodent studies. The results suggest that, in mink, diet greatly modulates the responses to PCBs, which may also differ in males and females. Furthermore, vitamins A1 and A2 may not be metabolized equally during PCB administration.
Prediction of ecotoxicity of hydrocarbon-contaminated soils using physicochemical parameters
Authors: Wong Diana C L , Chai Eric Y , Chu Karin K , Dorn Philip B
Published: March 2010

The physicochemical properties of eight hydrocarbon-contaminated soils were used to predict toxicity to earthworms (Eisenia fetida) and plants. The toxicity of these preremediated soils was assessed using earthworm avoidance, survival, and reproduction and seed germination and root growth in four plant species. No-observed-effect and 25% inhibitory concentrations were determined from the earthworm and plant assays. Physical property measurements and metals analyses of the soils were conducted. Hydrocarbon contamination was characterized by total petroleum hydrocarbons, oil and grease, and GC boiling-point distribution. Univariate and multivariate statistical methods were used to examine relationships between physical and chemical properties and biological endpoints. Soil groupings based on physicochemical properties and toxicity from cluster and principal component analyses were generally similar. Correlation analysis identified a number of significant relationships between soil parameters and toxicity that were used in univariate model development. Total petroleum hydrocarbons by gas chromatography and polars were identified as predictors of earthworm avoidance and survival and seed germination, explaining 65 to 75% of the variation in the data. Asphaltenes also explained 83% of the variation in seed germination. Gravimetric total petroleum hydrocarbons explained 40% of the variation in earthworm reproduction, whereas 43% of the variation in plant root growth was explained by asphaltenes. Multivariate one-component partial least squares models, which identified predictors similar to those identified by the univariate models, were also developed for worm avoidance and survival and seed germination and had predictive powers of 42 and 29%, respectively.
Lifetime pharmacokinetic model for hydrophobic contaminants in marine mammals
Authors: Hickie Brendan E , Mackay Donald , de Koning Jason
Published: March 2010

A physiologically based pharmacokinetic model is developed that describes the uptake and release of a hydrophobic organic chemical by a marine mammal over its entire lifetime, i.e., from birth to death. This model is applied to polychlorinated biphenyls (PCBs) in the beluga whale (Delphinapterus leucas). The processes treated are growth; uptake from food, milk, and air; disposition of the chemical among arterial and venous blood, liver, muscle, blubber, and rapidly perfused tissues; and losses by metabolism, release in exhaled air, and by egestion. A separate model is developed for females, which includes pregnancy, birth, and lactation. Food consumption is deduced from size, growth, and from activity-dependent bioenergetic data. The results obtained by simulating continuous PCB exposure over a 30-year period are in accordance with reported concentrations and show the importance of milk transfer to both mother and progeny and the tendency for continued accumulation over the animal's lifetime. Implications of the results are discussed, especially the need for improved data on diets, gut absorption characteristics, and various physiological parameters used in the model.
Environmental monitoring for linear alkylbenzene sulfonate, alcohol ethoxylate, alcohol ethoxy sulfate, alcohol sulfate, and soap
Authors: Matthijs Eddy , Holt Martin S , Kiewiet Anton , Rijs Gerard B J
Published: March 2010

An extensive monitoring program was executed jointly by the Dutch Soap Association (NVZ) and the Dutch authorities. Flow proportional samples of raw, settled, and treated sewage from seven representative municipal sewage treatment plants were collected over three consecutive days. The samples were analyzed for detergent surfactants, including linear alkylbenzene sulfonate (LAS), alcohol ethoxylate (AE), alcohol ethoxylated sulfate (AES), alcohol sulfate, (AS) and soap, using state-of-the-art analytical methods. All surfactants were removed by more than 99% during sewage treatment. The concentrations of the surfactants in the treated sewage averaged 39 μg/L for LAS, 6.2 μg/L for AE, 6.5 μg/L for AES, 5.7 μg/L for AS, and 174 μg/L for soap. These measured surfactant concentrations form the basis for the exposure element of the aquatic risk assessment for the surfactants studied. In addition, the field studies indicated that in-sewer removal can play a significant role in reducing the concentrations of surfactants entering the sewage treatment plant.
Effects and bioavailability of 2,4,6-trinitrotoluene in spiked and field-contaminated soils to indigenous microorganisms
Authors: Gong Ping , Siciliano Steven D , Greer Charles W , Paquet Louise , Hawari Jalal , Sunahara Geoffrey I
Published: March 2010

The response of potential nitrification activity (PNA), nitrogen-fixation activity (NFA), and dehydrogenase activity (DHA) in soil to 2,4,6-trinitrotoluene (TNT) was assessed. Two garden soils of contrasting texture (sandy loam vs clay loam) were spiked with TNT (25–1,000 mg TNT/kg). Soil microbial activities and TNT residues were analyzed 1 week later. The estimated IC50 (concentration causing 50% inhibition) ranged from 39 to 533 mg/kg of the acetonitrile-extractable (AE) TNT (1 week after spiking), depending on indicators and soils. The lowest LOEC (lowest-observed-effect concentration) was 1 mg AE TNT/kg. Field soil (0–15 cm) was collected from three known contaminated sites in an abandoned TNT manufacturing facility. Microbial toxicity significantly correlated to TNT levels in these soils. The LOEC and NOEC (no-observed-effect concentration) values were site and indicator specific, with the lowest LOEC being 1 mg AE TNT/kg and the lowest NOEC being 0.4 mg AE TNT/kg. The IC50 of the pooled field samples was 51 mg AE TNT/kg for PNA or 157 mg AE TNT/kg for DHA. These results indicate that microbial responses were consistent and comparable between the laboratory and the field and that TNT could significantly inhibit soil microbial activities at very low levels. Both AE TNT and deionized water–extractable (DW) TNT concentrations correlated well with microbial toxicity, but AE TNT provided a better evaluation of TNT bioavailability than did DW TNT.
Reductive dechlorination of polychlorinated biphenyls: Interactions of dechlorinating microorganisms with methanogens and sulfate reducers
Authors: Kim Jongseol , Rhee G-Yull
Published: March 2010

The potential role of methanogens and sulfate reducers in polychlorinated biphenyl (PCB) dechlorination was investigated using the specific inhibitors 2-bromoethanesulfonate for methanogens and molybdate for sulfate reducers and the most probable number technique. Sediments were spiked with Aroclor® 1248 (300 μg/g). The inhibition of sulfate reducers did not have any effect on Aroclor 1248 dechlorination or on the size of dechlorinating populations, which indicates that they were not directly involved. On the other hand, the inhibition of methanogens reduced the rate and extent of dechlorination but did not affect the size of dechlorinating populations. These results indicate that there are at least two different dechlorinating populations—one of which requires the presence of methanogens for dechlorination and the other of which can dechlorinate independently. In the absence of methanogenesis, meta-substituted congeners, such as 25-2′5′-, 23-2′5′-, and 25-2′-chlorobiphenyls, were not dechlorinated. When both inhibitors were added, there was no dechlorination or growth of dechlorinating microorganisms, probably because of the growth inhibition by the high redox potential stemming from the absence of the two major respirators or because of the combined effects of inhibitors themselves.
Enhanced anaerobic transformations of carbon tetrachloride by soil organic matter
Authors: Collins Richard , Picardal Flynn
Published: March 2010

Aaerobic, reductive dehalogenation of carbon tetrachloride (CT) by Shewanella putrefaciens 200 is enhanced by the presence of a high-organic-carbon soil. In microbial incubations without soil, 29% of the initial 3 ppm (19.5 μM) CT was transformed after 33 h, whereas 64% was transformed after only 18 h when soil was present. In sterile, biomimetic systems using a chemical reductant, 20 mM dithiothreitol, similar results were observed, suggesting that abiotic electron-transfer mediators in the soil were catalyzing the reaction. Destruction of 62% of the soil organic carbon by H2O2 resulted in a soil that was less effective in enhancing CT dechlorination. Following separation of the soil organic matter into three humic fractions, the humic acid (HA) fraction catalyzed the dechlorination reaction to a greater extent (270–442 μg of CT per gram of HA) than did the fulvic acid (FA) fraction (149–234 μg of CT per gram of FA), and both were more effective than the fraction containing humin and inorganic minerals (19–26 μg of CT per gram). The results are consistent with a mechanism involving humic functional groups that serve as electron-transfer mediators able to enhance the reductive transformation of CT in the presence of a microbial or chemical reductant. Humic functional group analyses showed that the FA contained more total acidity and carboxylic acidity than did the HA; however, both fractions contained similar amounts of total carbonyl groups and quinone carbonyls. Abiotic, HA-mediated CT transformation in the presence or absence of 20 mM dithiothreitol was found to be pH dependent. At pH 3.6, little CT transformation was observed regardless of whether dithiothreitol was present or not. At circumneutral pH, HA-mediated CT transformation required the presence of dithiothreitol. At pH 8.7, HA-mediated reductive CT transformation occurred both in the absence or presence of dithiothreitol although the transformation was greater in the presence of a reductant. Trichloromethane (chloroform [CF]) production at pH 8.7 was much lower than at circumneutral pH, and volatile organic compounds other than CF were not detected as products in any case.
Comparison of four methods of predicting newly measured octanol/water coefficients (log Kow) for heterocyclic nitrogen compounds and the partition mechanism
Authors: Li Li , Wang Liansheng , Han Shuokui , Zhang Zheng
Published: March 2010

Log Kow values for 14 heterocyclic nitrogen compounds (by traditional shake-flask method) were reported. Reverse phase–high-performance liquid chromatography (RP-HPLC) method and three estimation models—linear solvation energy relationship, molecular connectivity indices (MCIs), and quantum chemical descriptors—were used to study the partition mechanism and to establish the correlations of the models with the measured log Kow values by stepwise variable regression. Research on the partition mechanism showed that the molecular bulk properties and the hydrogen bond interaction were the most important factors influencing the partition process. Comparison of the quality of the models was made among the four methods. According to the simplicity of the method, the availability of the descriptors, and the closeness of correlation with the measured log Kow values, the RP-HPLC method was not satisfactory, while the MCIs method introducing the non–disperse force factor was the most satisfactoy.
Qualification of spontaneous undirected locomotor behavior of fish for sublethal toxicity testing. Part I. Variability of measurement parameters under general test conditions
Authors: Vogl Claus , Grillitsch Britta , Wytek Rudolf , Spieser O Hunrich , Scholz Wilfried
Published: March 2010

An automated, personal computer–based video-processing, object-recognition, and object-tracing system was used to record and analyze undirected spontaneous locomotor behavior of small groups of undisturbed semiadult zebra fish (Brachydanio rerio) in laboratory tanks. The primary data provided by the monitoring system were the individually assigned, time-stamped coordinates of the fish in two-dimensional projection. Secondary parameters (position, velocity of movement in the horizontal and the vertical direction, and temporal intraindividual and interindividual association) were calculated. The computed parameters offered a multidimensional description of spontaneous undirected swimming behavior of the fish and proved to be largely independent of water temperature, length, weight, and sex ratio of the zebra fish within the standardized range, but varied significantly with the feeding regime, time of day, number of fish per tank, and batch. Statistical characteristics of the behavioral parameters confirmed them as being appropriate for parametric statistical analyses.
Qualification of spontaneous undirected locomotor behavior of fish for sublethal toxicity testing. Part II. Variability of measurement parameters under toxicant-induced stress
Authors: Grillitsch Britta , Vogl Claus , Wytek Rudolf
Published: March 2010

Spontaneous locomotor behavior of semiadult zebra fish (Brachydanio rerio) was recorded under sublethal short-term exposure to the anionic technical surfactant, linear alkylbenzene sulfonate (C10–13-LAS) and cadmium in single compound tests using an automated video-monitoring and object-tracing system. Vertical position and swimming velocity in the horizontal and vertical directions were used as behavioral measurement parameters. Data were analyzed by different statistical methods. In pairwise comparisons, consistent, statistically significant, and toxicant-induced alterations of locomotor behavior were observed only for test concentrations, which also caused aspectoric symptoms of intoxication. This comparatively low sensitivity of the behavioral indication criteria was related to high variation in the measurement parameters and corresponding high, minimum detectable, statistically significant, and toxicant-induced deviations. In contrast, results obtained by regression analysis showed significant trends in locomotor activity over the range of toxicant concentrations tested. Thus, our findings support the inappropriateness of no observed effect concentrations and the lowest observed effect concentrations as summary measures of toxicity and indicate that the regression analysis approach is superior to the analysis of variance approach.
Effects of humic substances on the bioconcentration of polycyclic aromatic hydrocarbons: Correlations with spectroscopic and chemical properties of humic substances
Authors: Haitzer Markus , Abbt-Braun Gudrun , Traunspurger Walter , Steinberg Christian EW
Published: March 2010

The presence of dissolved humic substances (HS, fulvic and humic acids) generally reduces the up take of hydrophobic organic compounds into aquatic organisms. The extent of this effect depends both on the concentration and on the origin of the HS. The aim of this study was to investigate the role of qualitative differences between HS from different origins. The effects of seven different HS on the bioconcentration of pyrene and benzo[a]pyrene (BaP) in the nematode Caenorhabditis elegans were related to the spectroscopic and chemical properties of the HS. The effect of each humic material on the bioconcentration of pyrene or BaP was quantified as a “biologically determined” partition coefficient KDOC. We observed significant linear relationships between KDOC and the atomic H/C ratio, the specific absorptivity at 254 nm, the content of aromatic carbons (as determined by 13C nuclear magnetic resonance spectroscopy, the copper-complexing capacity, the content of phenolic OH groups, and the molecular weight of the HS. There was no discernible relationship of KDOC with the atomic (N + O)/C ratio, an indicator of the polarity of HS. Taken together, our results show that the variability in the effects of HS from different origins could be related to variations in bulk properties of the HS. Parameters describing the aromaticity of the humic materials seemed to be most useful for estimating effects of HS on the bioconcentration of pyrene and BaP.
Assessment of nonpoint-source runoff in a stream using in situ and laboratory approaches
Authors: Tucker Kathryn A , Jr. G Allen Burton,
Published: March 2010

Anthropogenic activities that change a watershed can cause adverse impacts to receiving water. Agricultural and urban runoff are the two leading causes of surface-water impairment in the United States. When assessing pollutant sources and their effects on aquatic ecosystems, and prior to implementing source controls, it is necessary to define the systems stressors and receptors of exposure. Toxicity assays are a key component to integrative assessments that include habitat (physical), chemical, and indigenous community characterization. Traditional toxicity assay methods and the use of water-quality criteria are often inappropriate because of exposure design and effect assumptions. Hyalella azteca and Chironomus tentans were exposed in situ for varying time periods during both low- and high-flow conditions to determine the effect of urban and agricultural runoff. Short-term chronic and acute toxicity of urban and agricultural runoff was then measured in the laboratory and related to in situ test results. Nonpoint-source (NPS) runoff from urban areas was often more acutely toxic to organisms in the laboratory as compared to in situ results. Conversely, toxicity to the organisms was greater at the agricultural site during in situ exposures when compared to laboratory. In situ assays were an essential and integral component of NPS runoff assessments. They provided unique information that complemented laboratory toxicity, habitat, benthic community, and physicochemcial characterizations.
Environmental contaminants in great blue herons (Ardea herodias) from the Lower Columbia and Willamette Rivers, Oregon and Washington, USA
Authors: Thomas Carmen M , Anthony Robert G
Published: March 2010

Great blue heron (Ardea herodias) eggs and prey items were collected from six colonies in Oregon and Washington, USA, during 1994 to 1995. Contaminant concentrations, reproductive success, and biomagnification factors were determined and effects of residue levels were measured by H4IIE rat hepatoma bioassays. Mean residue concentrations in heron eggs and prey items were generally low. However, elevated concentrations of polychlorinated biphenyls (PCBs) were detected in eggs and prey from Ross Island on the Willamette River. Biomagnification factors varied among sites. Sites were not significantly different in H4IIE tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQs), although the TCDD-EQ for Karlson Island was 9 to 20 times greater than that of any other site. Large differences existed between toxic equivalents calculated from egg residue concentrations and TCDD-EQs, which indicated nonadditive interactions among the compounds. Tetrachlorodibenzo-p-dioxin equivalents and nest failure were positively correlated with TCDD concentration. Fledging and reproductive rates were similar to those determined for healthy heron populations, however, indicating that any adverse effects were occurring at the individual level and not at the colony level. Our results support the use of great blue herons as a biomonitor for contamination in aquatic ecosystems. Their relatively low sensitivity to organochlorine contaminants and high trophic position allows contaminant accumulation and biomagnification without immediate adverse effects that are often seen in other, more sensitive species.
Sensitivity to nitrate and nitrite in pond-breeding amphibians from the Pacific Northwest, USA
Authors: Marco Adolfo , Quilchano Consuelo , Blaustein Andrew R
Published: March 2010

In static experiments, we studied the effects of nitrate and nitrite solutions on newly hatched larvae of five species of amphibians, namely Rana pretiosa, Rana aurora, Bufo boreas, Hyla regilla, and Ambystoma gracile. When nitrate or nitrite ions were added to the water, some larvae of some species reduced feeding activity, swam less vigorously, showed disequilibrium and paralysis, suffered abnormalities and edemas, and eventually died. The observed effects increased with both concentration and time, and there were significant differences in sensitivity among species. Ambrystoma gracile displayed the highest acute effect in water with nitrate and nitrite. The three ranid species had acute effects in water with nitrite. In chronic exposures, R. pretiosa was the most sensitive species to nitrates and nitrites. All species showed 15-d LC50s lower than 2 mg N-NO2-/L. For both N ions, B. boreas was the least sensitive amphibian. All species showed a high mortality at the U.S. Environmental Protection Agency-recommended limits of nitrite for warm-water fishes (5 mg N-NO2-/L) and a significant larval mortality at the recommended limits of nitrite concentration for drinking water (1 mg N-NO2-/L). The recommended levels of nitrate for warm-water fishes (90 mg N-NO3-/L) were highly toxic for R. pretiosa and A. gracile larvae.
In vitro phytotoxicity screening test using immobilized spinach thylakoids
Authors: Laberge Denise , Chartrand Josee , Rouillon Regis , Carpentier Robert
Published: March 2010

Several pollutants found in water inhibit the photosynthetic electron transport chain, and therefore affect the growth of phytoplankton and aquatic plants. In this study, thylakoid membranes isolated from spinach leaves were used in a microelectro-chemical cell to generate photocurrent. The toxic effect of an inhibitor is observed by a decrease in the photocurrent. To improve the stability of their biological functions, the thylakoid membranes were immobilized in an albumin–glutaraldehyde cross-linked matrix. The developmental work of this phytotoxicity test was done by using the herbicide atrazine as the reference toxicant. Results on reproducibility were in the range generally accepted for standardized bioassays. The phytotoxicity of herbicides from various chemical classes including photosynthetic and nonphotosynthetic inhibitors was evaluated. Toxicity responses of the immobilized thylakoid test to photosynthetic inhibitors compared favorably with literature data for the algal growth inhibition test using Selen-astrum capricornutum. The detection capabilities of the photosynthetic microassay for cyanazine, metribuzin, diuron, and propanil met the recommandation for the water quality guidelines for raw water. Characteristics of this in vitro approach such as rapidity, experimental simplicity, and cost effectiveness are also discussed.
Isolation and tentative identification of compound in bleached-kraft mill effluent capable of causing mixed-function oxygenase induction in fish
Authors: Burnison B Kent , Comba Michael E , Carey John H , Parrott Joanne , Sherry James P
Published: March 2010

A substance isolated from a bleached-kraft mill effluent, capable of causing mixed-function oxygenase (MFO) induction in rainbow trout and in a hepatocyte cell line, was tentatively identified. The MFO-inducing chemicals in final pulp-mill effluent were isolated with the use of C18 solid-phase extraction and high-performance liquid chromatography fractionation. Compound identifications for the MFO-inducing fractions were made using gas chromatography with low- and high-resolution mass spec-trometry. In comparing data from each of three fractionation trials, we noted that MFO activity corresponded best with the presence of a compound tentatively identified as a chlorinated pterostilbene. The parent compound belongs to the pinosylvin family, a group of naturally occurring substances that are often present in coniferous trees.
Toxicity of C 10 −, C 11 −, C 12 −, and C 14 −Polychlorinated alkanes to Japanese medaka (Oryzias latipes) embryos
Authors: Fisk Aaron T , Tomy Gregg T , Muir Derek CG
Published: March 2010

Japanese medaka (Oryzias latipes) eggs were exposed to aqueous concentrations of six polychlorinated n-alkane (PCA) standards (C10H155Cl65, C10H153Cl67, C11H184Cl56, C12H195Cl65, C14H24,9Cl5.1, and C14H23, 3Cl67) of known carbon chain length and chlorine content to assess their toxicity. Eggs were also exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to act as a positive control. Chlorinated paraffins are complex industrial products for which there is a lack of toxicological data on individual congeners. High aqueous concentrations of C10H155Cl65 and C10H15,3Cl6,7 (9,600 and 7,700 ng/ml, respectively) caused 100% mortality in eggs, but no other significant mortalities or lesions were observed at lower concentrations or in any eggs exposed to the other PCAs. Larvae from eggs exposed to high concentrations of the C10-, C11- and C12-PCAs were extremely lethargic or did not move, although a heart beat was present. The concentrations in these exposures and the tissue concentrations of the larvae were at levels that should elicit narcosis. Concentrations of the C14-PCAs in larvae did not reach narcotic levels, and larvae in these exposures appeared normal with no signs of narcosis. The TCDD was found to be extremely embryotoxic, consistent with past work using Japanese medaka eggs. The ratio of LC50 of TCDD to the LC50 of the PCAs, based on acute toxicity and TCDD results, were all <0.0001, and most were <0.000001. These results suggest that the acute mechanism of toxicity of lower chlorinated, short (C10-13) and medium (C14-18) carbon chain PCAs is narcosis and that chlorine substitution on the terminal carbons of PCAs does not significantly increase nor decrease the toxicity of C10- and C14-PCAs. However, additional work is needed to assess a greater range of PCAs as well as their sublethal effects and chronic toxicity.
Life-cycle studies with marine copepods (Tisbe battagliai) exposed to 20-hydroxyecdysone and diethylstilbestrol
Authors: Hutchinson Thomas H , Pounds Nadine A , Hampel Miriam , Williams Tim D
Published: March 2010

Life-cycle effects of a reference ecdysteroid, 20-hydroxyecdysone (20-HEC) and the model xenoestrogen, diethylstil-bestrol (DES) in Tisbe battagliai (Crustacea, Copepoda, Harpacticoida) have been evaluated. T. battagliai is a sexually reproducing species that is representative of an ecologically diverse group of aquatic Crustacea and is highly amenable to laboratory life-cycle studies. Newly released (<24-h old) Copepod nauplii were exposed to 20-HEC or DES and effects monitored in terms of survival, development, and sex ratio after 10 d at 20 ± 1°C. A mortality of ≈40% occurred after 9-d exposure to 20-HEC at 269 μg/L, whereas significant (17.5%) mortality (p < 0.05) occurred after 4-d exposure to DES at 100 μg/L. Adult males and females were paired after day 10, and exposures continued to investigate effects on reproductive output (21-d total exposure). In summary, the 21-d LC50 values (with 95% confidence intervals) for 20-HEC and DES were 53.4 μg/L (36.5–78.7) and 31.6 μg/L (10–100), respectively. For 20-HEC, the 21-d no observed effect concentration (NOEC) for survival was 26.9 μg/L, whereas reproduction was a more sensitive endpoint (NOEC = 8.7 μg/L). For DES, survival and reproduction were equally sensitive, and both gave an NOEC value of 10 μg/L (all based on nominal concentrations). These results suggest that the 21-d life-cycle protocol using T. battagliai holds much promise as an in vivo test for developmental and reproductive effects in aquatic Crustacea.
Effect of sulfometuron methyl and nicosulfuron on development and metamorphosis in Xenopus laevis: Impact of purity
Authors: Fort Douglas J , Rogers Robert , Copley Holly , Bruning Lizbeth , Stover Enos L , Rapaport Dave
Published: March 2010

Analytically impure (∼85–88%) and purified (99.5%) preparations of two sulfonylurea herbicides, sulfometuron methyl and nicosulfuron, were evaluated for short- and long-term developmental effects on organogenesis (0–4 d) and limb development (0–30 d), and impact on metamorphosis (tail resorption [50–64 d]). Overall, the analytically impure sulfonylurea herbicides were more developmentally toxic than the purified preparations. Purified preparations did not induce early embryo–larval developmental effects or effects on hind limb development, although the rate of tail resorption was slowed at relatively high concentrations. Tail resorption rates were slowed significantly and abnormal limb development was induced by the analytically impure sulfonylurea herbicides. The process of organogenesis as monitored by the traditional frog embryo teratogenesis assay—Xenopus (FETAX) test was the least sensitive stage of development monitored in this study. Although some maldevelopment was induced at the limit of aqueous solubility of the analytically impure material, the severity of the malformations with the impure preparations was moderate. Based on this study, the analytically impure herbicides were more developmentally toxic than purified preparations of the same herbicides, which exerted little effect at maximum soluble concentrations. Thus, the capacity of purified nicosulfuron and sulfometuron methyl to interfere with amphibian development and maturation seems to be relatively low.
A probabilistic risk assessment of the effects of methylmercury and PCBs on mink and kingfishers along East Fork Poplar Creek, Oak Ridge, Tennessee, USA
Authors: Moore Dwayne RJ , Sample Bradley E , Suter Glenn W , Parkhurst Benjamin R , Teed R Scott
Published: March 2010

Over fifty years of operations, sorage, and disposal of wastes from the U.S. Department of Energy (U.S. DOE) Y-12 nuclear weapons facility at Oak Ridge, Tennessee, USA, has resulted in the contamination of water, sediment, biota, and floodplain soils of East Fork Poplar Creek. A preliminary assessment revealed that methylmercury and polychlorinated biphenyls (PCBs) were the contaminants of most concern. Because these contaminants are persistent, accumulate in tissues, and biomagnify up the food chain, piscivorous wildlife are the biota at greatest risk of exposure. The objective of this study was to estimate the risks posed by methylmercury and PCBs to two piscivorous species: mink and belted kingfishers. We conducted Monte Carlo simulations to estimate total daily intakes of each contaminant by each species and then integrated the resulting distributions with their respective dose–response curves to estimate risks. The results indicate that methylmercury poses a moderate risk to female mink (24% probability of at least 15% mortality) and kingfishers (50% probability of at least a 12–28% decline in fecundity depending on location). The PCBs pose a very serious risk to mink (52% probability of at least a 50% decline in reproductive fecundity), a species known to be especially sensitive to the effects of organochlorine substances, but little risk to kingfishers (<5% probability of a decline in reproductive fecundity greater than 10% at any location).
Risk-based decision making: The east fork poplar creek case study
Authors: Moore Dwayne RJ , Sample Bradley E , Suter Glenn W , Parkhurst Benjamin R , Teed R Scott
Published: March 2010

A Probabilistic risk assessment revealed that methylmercury released from the U.S. Department of Energy(DOE) Y-12 weapons facility at Oak Ridge, Tennessee, USA, poses moderate risks to mink and kingfishers residing near the receiving waters of East Fork Poplar Creek. Polychlorinated biphenyls (PCBs) released from this facility pose severe risks to mink but little risk to kingfishers. The objective of this study was to use a risk-based decision-making approach to select remedial cleanup levels for each of these contaminants. We conducted Monte Carlo simulations to estimate total daily intakes of each contaminant by mink (mercury and PCBs) and kingfishers (PCBs only) for a range of exposure-reduction scenarios. The resulting exposure distributions were then integrated with their respective dose–response curves to estimate postremediation risks. The results indicated that total mercury levels in surface water would need to be reduced from current levels (mean = 0.225 μg/L) to 0.03 to 0.05 μg/L to reduce risks to very low levels (<5% probability of ≥10% mortality) for both mink and kingfishers. If interested parties define acceptable risk as, for example, a 20% probability of ≥10% mortality, then mercury levels would need to be reduced to 0.14 μg/L. The PCBs analysis indicated that reducing water-borne exposures would produce only a modest reduction in risk to mink because much of the current exposure is through terrestrial exposure pathways.
Field assessments in conjunction with whole effluent toxicity testing
Authors: La Point Thomas W , Waller William T
Published: March 2010

Whole effluent toxicity (WET) tests are widely used to assess potential effects of wastewater discharges on aquatic life. This paper represents a summary of chapters in a 1996 Society of Environmental Toxicology and Chemistry–sponsored workshop and a literature review concerning linkages between WET testing and associated field biomonitoring. Most published studies thus far focus primarily on benthic macroinvertebrates and on effluent-dominated stream systems in which effluents demonstrate little or no significant acute toxicity. Fewer studies examine WET test predictability in other aquatic ecosystems (e.g., wetlands, estuaries, large rivers) or deal with instream biota such as fish and primary producers. Published results indicate that standards for the usual WET freshwater test species, Ceriodaphnia dubia and Pimephales promelas, may not always protect most of the species inhabiting a receiving stream. Although WET tests are useful in predicting aquatic individual responses, they are not meant to directly measure natural population or community responses. Further, they do not address bioconcentration or bioaccumulation of hydrophobic compounds; do not assess eutrophication effects in receiving systems; and lastly, do not reflect genotoxic effects or function to test for endocrine-disrupting chemicals. Consequently, a more direct evaluation of ecosystem health, using bioassessment techniques, may be needed to properly evaluate aquatic systems affected by wastewater discharges.
Correspondence between whole effluent toxicity and the presence of priority substances in complex industrial effluents
Authors: Sarakinos Helen C , Bermingham Norman , White Paul A , Rasmussen Joseph B
Published: March 2010

The purpose of this study was to examine broad-scale correlation between presence of priority substances and whole effluent toxicity (WET) across a range of industry types. Using regression analysis, we examined how chemical-based inferred toxicity predicted measured WET of the effluents. Whole effluent toxicity was determined using a suite of acute and chronic bioassays; chemical-based toxicity was inferred from concentrations of priority chemicals and from published chemical toxicity values. When inferred toxicity was corrected for bioavailable metal and ion concentrations, 43% of the variability in measured toxicity was explained. For many industries, priority contaminants accounted for WET, and their toxic action was generally additive. However, industry-specific analysis of the residuals highlighted effluent types for which there was over one order of magnitude variation in inferred and measured toxicity. In particular, chemical-based assessments tended to overestimate toxicity of effluents containing high concentrations of metals and to underestimate toxicity of pulp mill effluents.
Whole effluent toxicity of sewage treatment plants in the hawkesbury–nepean watershed, New South Wales, Australia, toCeriodaphnia dubiaandSelenastrum capricornutum
Authors: Bailey Howard C , Krassoi Rick , Elphick James R , Mulhall Ann-Maree , Hunt Peta , Tedmanson Louise , Lovell Adam
Published: March 2010

This paper describes the results of whole effluent toxicity tests conducted with Ceriodaphnia dubia and Selenastrum capricornutum on sewage treatment plant effluents in the Hawkesbury–Nepean watershed in New South Wales, Australia. Effluents from 18 sewage treatment plants were evaluated for acute and chronic toxicity. Toxicity identification evaluations were performed on toxic samples to determine the cause of toxicity. Fifteen of the facilities sampled exhibited acute or chronic toxicity to C. dubia. Organophosphorus pesticides (OPs) (e.g., diazinon, chlorpyrifos, and chlorfenvinphos) accounted for toxicity in the majority of samples. Ammonia also contributed to toxicity in one sample, an unidentified OP was responsible for toxicity in another sample, and unidentified transient toxicant(s) were present in four samples. Transient toxicity was not due to surfactants (methylene blue active substances, cobalt thiocyanate active substances, or nonyl- or octylphenolethoxylates) or to a polymer used to dewater the sludge. The most likely cause of the transient toxicity was chlorpyrifos, which rapidly dissipated when stored in polyethylene containers. Only two effluent samples reduced the cell numbers of S. capricornutum. In both cases, toxicity dissipated too rapidly to identify its cause.
Assessment of whole effluent toxicity test variability: Partitioning sources of variability
Authors: Warren-Hicks William J , Parkhurst Benjamin R , Moore Dwayne RJ , Teed R Scott , Baird Rodger B , Berger Robert , Denton Debra L , Pletl James J
Published: March 2010

In this article, we quantify the variability of toxicity tests used in whole effluent toxicity (WET) testing and ambient water testing and demonstrate how knowledge of this variability can be used in the interpretation of compliance with WET limits in National Pollutant Discharge Elimination System permits. Whole effluent toxicity test endpoint accuracy and precision are important factors in establishing the credibility of test results. Initially, we developed a national data set consisting of raw reference toxicant data from freshwater and marine tests. The data set consisted of the most commonly used test species, protocols, and laboratories and included results from multiple tests over time within single laboratories. Using a random-effects model, we evaluate and estimate the following variance components: between-laboratory variability, variability as a function of dilution concentration, variability of toxicity tests conducted over time, and random error. A variance components model was used to calculate the relative contribution of each variance component to the total variability in specific test endpoints. All analyses were conducted separately for specific reference toxicant, test species, and test protocol combinations. We demonstrate how to use the resulting variance estimates to calculate the minimum significant difference expected for specific test species and test protocols and present an application with WET test data. We present an application using actual WET test results and make recommendations for ensuring the quality of the information resulting from future WET testing.