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Sample records for interspecies toxicity assessment

  1. SURROGATE SPECIES IN ASSESSING CONTAMINANT RISK FOR ENDANGERED FISHES, INCLUDING INTERSPECIES TOXICITY CORRELATIONS

    EPA Science Inventory

    Rainbow trout, fathead minnows, and sheepshead minnows were tested as surrogate species to assess contaminant risk for 17 endangered fishes and one toad species. Acute toxicity tests were conducted with carbaryl, copper, 4-nonylphenol, pentachlorophenol, and permethrin in accorda...

  2. SURROGATE SPECIES IN ASSESSING CONTAMINANT RISK FOR ENDANGERED FISHES, INCLUDING INTERSPECIES TOXICITY CORRELATIONS

    EPA Science Inventory

    Rainbow trout, fathead minnows, and sheepshead minnows were tested as surrogate species to assess contaminant risk for 17 endangered fishes and one toad species. Acute toxicity tests were conducted with carbaryl, copper, 4-nonylphenol, pentachlorophenol, and permethrin in accorda...

  3. Validation and Application of Pharmacokinetic Models for Interspecies Extrapolations in Toxicity Risk Assessments of Volatile Organics

    DTIC Science & Technology

    1989-07-21

    GROUP SUB-GROUP Physiologically-based pharmacokinetic model Saturable metab- olism, Respiratory eliminationi Ialocarbon Inhalation expo- sure, H...nlocarbon oral exposure, Interspecles extrapolations, Pharmacokinetics , l,l,]-trichloroethane, 1,l-dichloroethylene, 19 ABSTRACT (Continue on reverse if...necessary and identify by block number) In pursuit of the goal of establishing a scientific basis for the interspecies extrapo- lation of pharmacokinetic

  4. Köln-Timişoara Molecular activity combined models toward interspecies toxicity assessment.

    PubMed

    Chicu, Sergiu A; Putz, Mihai V

    2009-11-20

    Aiming to provide a unified picture of computed activity - quantitative structure activity relationships, the so called Köln (ESIP-ElementSpecificInfluenceParameter) model for activity and Timisoara (Spectral-SAR) formulation of QSAR were pooled in order to assess the toxicity modeling and inter-toxicity correlation maps for aquatic organisms against paradigmatic organic compounds. The Köln ESIP model for estimation of a compound toxicity is based on the experimental measurement expressing the direct action of chemicals on the organism Hydractinia echinata so that the structural influence parameters are reflected by the metamorphosis degree itself. As such, the calculation of the structural parameters is absolutely necessary for correct evaluation and interpretation of the evolution of M(easured) and the C(computed) values. On the other hand, the Timişoara Spectral-SAR analysis offers correlation models and paths for H.e. species as well as for four other different organisms with which the toxicity may be inter-changed by means of the same mechanism of action induced by certain common chemicals.

  5. Köln-Timişoara Molecular Activity Combined Models toward Interspecies Toxicity Assessment

    PubMed Central

    Chicu, Sergiu A.; Putz, Mihai V.

    2009-01-01

    Aiming to provide a unified picture of computed activity – quantitative structure activity relationships, the so called Köln (ESIP-ElementSpecificInfluenceParameter) model for activity and Timisoara (Spectral-SAR) formulation of QSAR were pooled in order to assess the toxicity modeling and inter-toxicity correlation maps for aquatic organisms against paradigmatic organic compounds. The Köln ESIP model for estimation of a compound toxicity is based on the experimental measurement expressing the direct action of chemicals on the organism Hydractinia echinata so that the structural influence parameters are reflected by the metamorphosis degree itself. As such, the calculation of the structural parameters is absolutely necessary for correct evaluation and interpretation of the evolution of M(easured) and the C(computed) values. On the other hand, the Timişoara Spectral-SAR analysis offers correlation models and paths for H.e. species as well as for four other different organisms with which the toxicity may be inter-changed by means of the same mechanism of action induced by certain common chemicals. PMID:20057956

  6. Assessing Uncertainty of Interspecies Correlation Estimation Models for Aromatic Compounds

    EPA Science Inventory

    We developed Interspecies Correlation Estimation (ICE) models for aromatic compounds containing 1 to 4 benzene rings to assess uncertainty in toxicity extrapolation in two data compilation approaches. ICE models are mathematical relationships between surrogate and predicted test ...

  7. Assessing Uncertainty of Interspecies Correlation Estimation Models for Aromatic Compounds

    EPA Science Inventory

    We developed Interspecies Correlation Estimation (ICE) models for aromatic compounds containing 1 to 4 benzene rings to assess uncertainty in toxicity extrapolation in two data compilation approaches. ICE models are mathematical relationships between surrogate and predicted test ...

  8. Acute toxicity of benzophenone-type UV filters for Photobacterium phosphoreum and Daphnia magna: QSAR analysis, interspecies relationship and integrated assessment.

    PubMed

    Liu, Hui; Sun, Ping; Liu, Hongxia; Yang, Shaogui; Wang, Liansheng; Wang, Zunyao

    2015-09-01

    The hazardous potential of benzophenone (BP)-type UV filters is becoming an issue of great concern due to the wide application of these compounds in many personal care products. In the present study, the toxicities of BPs to Photobacterium phosphoreum and Daphnia magna were determined. Next, density functional theory (DFT) and comparative molecular field analysis (CoMFA) descriptors were used to obtain more detailed insight into the structure - activity relationships and to preliminarily discuss the toxicity mechanism. Additionally, the sensitivities of the two organisms to BPs and the interspecies toxicity relationship were compared. Moreover, an approach for providing a global index of the environmental risk of BPs to aquatic organisms is proposed. The results demonstrated that the mechanism underlying the toxicity of BPs to P. phosphoreum is primarily related to their electronic properties, and the mechanism of toxicity to D. magna is hydrophobicity. Additionally, D. magna was more sensitive than P. phosphoreum to most of the BPs, with the exceptions of the polyhydric BPs. Moreover, comparisons with published data revealed a high interspecies correlation coefficient among the experimental toxicity values for D. magna and Dugesia japonica. Furthermore, hydrophobicity was also found to be the most important descriptor of integrated toxicity. This investigation will provide insight into the toxicity mechanisms and useful information for assessing the potential ecological risk of BP-type UV filters.

  9. Development of Species Sensitivity Distributions for Wildlife Using Interspecies Toxicity Correlation Models

    EPA Science Inventory

    Species sensitivity distributions (SSD) are cumulative distributions of chemical toxicity of multiple species and have had limited application in wildlife risk assessment because of relatively small datasets of wildlife toxicity values. Interspecies correlation estimation (ICE) m...

  10. Development of Species Sensitivity Distributions for Wildlife Using Interspecies Toxicity Correlation Models

    EPA Science Inventory

    Species sensitivity distributions (SSD) are cumulative distributions of chemical toxicity of multiple species and have had limited application in wildlife risk assessment because of relatively small datasets of wildlife toxicity values. Interspecies correlation estimation (ICE) m...

  11. ESTIMATION OF CHEMICAL TOXICITY TO WILDLIFE SPECIES USING INTERSPECIES CORRELATION MODELS

    EPA Science Inventory

    Ecological risks to wildlife are typically assessed using toxicity data for relataively few species and with limited understanding of differences in species sensitivity to contaminants. Empirical interspecies correlation models were derived from LD50 values for 49 wildlife speci...

  12. ESTIMATION OF CHEMICAL TOXICITY TO WILDLIFE SPECIES USING INTERSPECIES CORRELATION MODELS

    EPA Science Inventory

    Ecological risks to wildlife are typically assessed using toxicity data for relataively few species and with limited understanding of differences in species sensitivity to contaminants. Empirical interspecies correlation models were derived from LD50 values for 49 wildlife speci...

  13. WEB-BASED INTERSPECIES CORRELATION ESTIMATION (WEB-ICE) FOR ACUTE TOXICITY: USER MANUAL V2

    EPA Science Inventory

    Predictive toxicological models are integral to environmental risk Assessment where data for most species are limited. Web-based Interspecies Correlation Estimation (Web-ICE) models are least square regressions that predict acute toxicity (LC50/LD50) of a chemical to a species, ...

  14. WEB-BASED INTERSPECIES CORRELATION ESTIMATION (WEB-ICE) FOR ACUTE TOXICITY: USER MANUAL V2

    EPA Science Inventory

    Predictive toxicological models are integral to environmental risk Assessment where data for most species are limited. Web-based Interspecies Correlation Estimation (Web-ICE) models are least square regressions that predict acute toxicity (LC50/LD50) of a chemical to a species, ...

  15. Interspecies toxicity correlations of rat, mouse and Photobacterium phosphoreum

    SciTech Connect

    Kaiser, K.L.E.; McKinnon, M.B. ); Fort, F.L. )

    1994-10-01

    This study investigates quantitatively the interspecies relationships of the acute toxicity of 684 organic chemicals to the rate, the mouse, and the luminescent marine bacterium Photobacterium phosphoreum, commonly known as the Microtox[reg sign] test. The results indicate significant relationships between the Microtox EC50 and rat and mouse LD50 values. The goodness of fit increases strongly from the oral to the intraperitoneal to the intravenous route of administration for each of the mouse and rat. Standard errors of the estimated rat values range from 0.52 to 0.72 log units of toxicity (after and before outlier removal, respectively) over a toxicity range of 4.6 (intraperitoneal) to 5.0 (oral) log units (mmol/kg body weight) of toxicity. For each of the three routes of administration, rat and mouse data are also highly correlated. This allows the computation of rat toxicities from mouse data and vice versa with standard errors of the estimates of 0.28 (intraperitoneal) to 0.30 (oral) log units.

  16. INTER-SPECIES MODELS FOR ACUTE AQUATIC TOXICITY BASED ON MECHANISM OF ACTION

    EPA Science Inventory

    This presentation will provide interspecies QSARs for acute toxicity to 17 aquatic species, such as fish, snail, tadpole, hydrozoan, crustacean, insect larvae, and bacteria developed using 5,000 toxic effect results for approximately 2400 chemicals.

  17. INTER-SPECIES MODELS FOR ACUTE AQUATIC TOXICITY BASED ON MECHANISM OF ACTION

    EPA Science Inventory

    This presentation will provide interspecies QSARs for acute toxicity to 17 aquatic species, such as fish, snail, tadpole, hydrozoan, crustacean, insect larvae, and bacteria developed using 5,000 toxic effect results for approximately 2400 chemicals.

  18. Augmenting aquatic species sensitivity distributions with interspecies toxicity estimation models

    EPA Science Inventory

    Species sensitivity distributions (SSD) are cumulative distribution functions of species toxicity values. The SSD approach is increasingly being used in ecological risk assessment, but is often limited by available toxicity data necessary for diverse species representation. In ...

  19. Augmenting aquatic species sensitivity distributions with interspecies toxicity estimation models

    EPA Science Inventory

    Species sensitivity distributions (SSD) are cumulative distribution functions of species toxicity values. The SSD approach is increasingly being used in ecological risk assessment, but is often limited by available toxicity data necessary for diverse species representation. In ...

  20. Using Web-based Interspecies Correlation Estimation (Web-ICE) models as a tool for acute toxicity prediction

    EPA Science Inventory

    In order to assess risk of contaminants to taxa with limited or no toxicity data available, Interspecies Correlation Estimation (ICE) models have been developed by the U.S. Environmental Protection Agency to extrapolate contaminant sensitivity predictions based on data from commo...

  1. Web-based Interspecies Correlation Estimation (Web-ICE) for Acute Toxicity: User Manual Version 3.1

    EPA Science Inventory

    Predictive toxicological models are integral to ecological risk assessment because data for most species are limited. Web-based Interspecies Correlation Estimation (Web-ICE) models are least square regressions that predict acute toxicity (LC50/LD50) of a chemical to a species, ge...

  2. Web-based Interspecies Correlation Estimation (Web-ICE) for Acute Toxicity: User Manual Version 3.1

    EPA Science Inventory

    Predictive toxicological models are integral to ecological risk assessment because data for most species are limited. Web-based Interspecies Correlation Estimation (Web-ICE) models are least square regressions that predict acute toxicity (LC50/LD50) of a chemical to a species, ge...

  3. Using Web-based Interspecies Correlation Estimation (Web-ICE) models as a tool for acute toxicity prediction

    EPA Science Inventory

    In order to assess risk of contaminants to taxa with limited or no toxicity data available, Interspecies Correlation Estimation (ICE) models have been developed by the U.S. Environmental Protection Agency to extrapolate contaminant sensitivity predictions based on data from commo...

  4. Estimation of chemical toxicity to wildlife species using interspecies correlation models.

    PubMed

    Raimondo, S; Mineau, P; Barron, M G

    2007-08-15

    Ecological risks to wildlife are typically assessed using toxicity data for relatively few species and with limited understanding of differences in species sensitivity to contaminants. Empirical interspecies correlation models were derived from LD50 values for 49 wildlife species and 951 chemicals. The standard wildlife test species Japanese quail (Coturnix japonica) and mallard (Anas platyrhynchos) were determined to be good surrogates for many species within the database. Cross-validation of all models predicted toxicity values within 5-fold and 10-fold of the actual values with 85 and 95% certainty, respectively. Model robustness was not consistently improved by developing correlation models within modes of action (MOA); however, improved models for neurotoxicants, carbamates, and direct acting organophosphorous acetylcholenesterase inhibiting compounds indicate that toxicity estimates may improve if MOA-specific models are built with robust datasets. There was a strong relationship between taxonomic distance and cross-validation prediction success (chi2 = 297, df = 12, p < 0.0001), with uncertainty increasing with larger taxonomic distance between the surrogate and predicted species. Interspecies toxicity correlations provide a tool for estimating contaminant sensitivity with known levels of uncertainty for a diversity of wildlife species.

  5. ESTIMATION OF AQUATIC SPECIES SENSITIVITY USING INTERSPECIES CORRELATION AND ACUTE TO CHRONIC TOXICITY MODELS

    EPA Science Inventory

    Abstract for presentation

    Estimation of aquatic species sensitivity using interspecies correlation and acute to chronic toxicity models

    Determining species sensitivity of aquatic organisms to contaminants is a critical component of criteria development and ecolog...

  6. Probabilistic derivation of the interspecies assessment factor for skin sensitization.

    PubMed

    Bil, W; Schuur, A G; Ezendam, J; Bokkers, B G H

    2017-08-01

    An interspecies sensitization assessment factor (SAF) is used in the quantitative risk assessment (QRA) for skin sensitization when a murine-based NESIL (No Expected Sensitization Induction Level) is taken as point of departure. Several studies showed that, on average, the murine sensitization threshold is in good correspondence with that determined in humans. However, on an individual level, the murine and human sensitization thresholds may differ considerably. In this study, the interspecies SAF was quantified by using a probabilistic approach, to be able to take these cases into account. As expected, the geometric means of the probability distributions of murine and human sensitization threshold ratios were close to one, but taking the 95 (th) percentile of these distributions resulted in an interspecies SAF of 15. By using this value, one is sure that with 95% probability, the sensitization threshold determined in mice does not underestimate the human threshold. It can be concluded that a murine-based NESIL requires the use of an interspecies SAF (of 15) in the QRA for skin sensitization, to correct for the differences between mice and humans. This empirically derived interspecies SAF contributes to refinement of the risk assessment methodology. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Acute Toxicity Prediction to Threatened and Endangered Species Using Interspecies Correlation Estimation (ICE) Models.

    PubMed

    Willming, Morgan M; Lilavois, Crystal R; Barron, Mace G; Raimondo, Sandy

    2016-10-04

    Evaluating contaminant sensitivity of threatened and endangered (listed) species and protectiveness of chemical regulations often depends on toxicity data for commonly tested surrogate species. The U.S. EPA's Internet application Web-ICE is a suite of Interspecies Correlation Estimation (ICE) models that can extrapolate species sensitivity to listed taxa using least-squares regressions of the sensitivity of a surrogate species and a predicted taxon (species, genus, or family). Web-ICE was expanded with new models that can predict toxicity to over 250 listed species. A case study was used to assess protectiveness of genus and family model estimates derived from either geometric mean or minimum taxa toxicity values for listed species. Models developed from the most sensitive value for each chemical were generally protective of the most sensitive species within predicted taxa, including listed species, and were more protective than geometric means models. ICE model estimates were compared to HC5 values derived from Species Sensitivity Distributions for the case study chemicals to assess protectiveness of the two approaches. ICE models provide robust toxicity predictions and can generate protective toxicity estimates for assessing contaminant risk to listed species.

  8. INTERSPECIES CORRELATION ESTIMATIONS: ACUTE TOXICITY TO AQUATIC ORGANISMS

    EPA Science Inventory

    Predictive toxicological models, including estimates of uncertainty, are necessary to address the trend towards probability-based ecological risk assessments. A method and software were developed to aid in estimating acute toxicity of chemicals to species where data is lacking, p...

  9. Interspecies quantitative structure-toxicity-toxicity (QSTTR) relationship modeling of ionic liquids. Toxicity of ionic liquids to V. fischeri, D. magna and S. vacuolatus.

    PubMed

    Das, Rudra Narayan; Roy, Kunal; Popelier, Paul L A

    2015-12-01

    Considering the increasing uses of ionic liquids (ILs) in various industrial processes and chemical engineering operations, a complete assessment of their hazardous profile is essential. In the absence of adequate experimental data, in silico modeling might be helpful in filling data gaps for the toxicity of ILs towards various ecological indicator organisms. Using the rationale of taxonomic relatedness, the development of predictive quantitative structure-toxicity-toxicity relationship (QSTTR) models allows predicting the toxicity of ILs to a particular species using available experimental toxicity data towards a different species. Such studies may employ, along with the available experimental toxicity data to a species, molecular structure features and physicochemical properties of chemicals as independent variables for prediction of the toxicity profile against another closely related species. A few such interspecies toxicity correlation models have been reported in the literature for diverse chemicals in general, but this approach has been rarely applied to the class of ionic liquids. The present study involves the use of IL toxicity data towards the bacteria Vibrio fischeri along with molecular structure derived information or computational descriptors like extended topochemical atom (ETA) indices, quantum topological molecular similarity (QTMS) descriptors and computed lipophilicity measure (logk0) for the interspecies exploration of the toxicity data towards green algae S. vacuolatus and crustacea Daphnia magna, separately. This modeling study has been performed in accordance with the OECD guidelines. Finally, predictions for a true external set have been performed to fill the data gap of toxicity towards daphnids and algae using the Vibrio toxicity data and molecular structure attributes.

  10. Acute toxicity prediction to threatened and endangered species using Interspecies Correlation Estimation (ICE) models

    EPA Science Inventory

    Evaluating contaminant sensitivity of threatened and endangered (listed) species and protectiveness of chemical regulations often depends on toxicity data for commonly tested surrogate species. The U.S. EPA’s Internet application Web-ICE is a suite of Interspecies Correlati...

  11. Acute toxicity prediction to threatened and endangered species using Interspecies Correlation Estimation (ICE) models

    EPA Science Inventory

    Evaluating contaminant sensitivity of threatened and endangered (listed) species and protectiveness of chemical regulations often depends on toxicity data for commonly tested surrogate species. The U.S. EPA’s Internet application Web-ICE is a suite of Interspecies Correlati...

  12. Valproic acid developmental toxicity and pharmacokinetics in the rhesus monkey: an interspecies comparison.

    PubMed

    Hendrickx, A G; Nau, H; Binkerd, P; Rowland, J M; Rowland, J R; Cukierski, M J; Cukierski, M A

    1988-10-01

    This study was undertaken to assess the developmental toxicity and drug distributional and metabolic characteristics of prenatal valproic acid (VPA) exposure in rhesus monkeys. Oral administration of 20-600 mg/kg/day VPA (approximately 1-15 X human therapeutic dose) to 33 animals on variable gestational days (GD) during organogenesis resulted in dose-dependent developmental toxicity manifested as increased embryo/fetal mortality, intrauterine growth retardation, and craniofacial and skeletal defects. Biphasic plasma elimination curves were observed for total and free VPA on the first (GD 21) and last (GD 50) days of treatment in the 100- and 200-mg/kg/day dose groups. VPA exhibited dose-independent elimination kinetics at the plasma concentrations observed in this study. There was no significant change in pharmacokinetic parameters (maternal plasma elimination rate, area under the curve, peak plasma concentration) between the first and last days of treatment at either dose level. Placental transfer studies indicated that embryos were exposed to half the free VPA concentrations present in maternal plasma on GD 37. Comparisons of interspecies sensitivity to VPA-induced developmental toxicity in the mouse, rat, monkey, and man are made.

  13. Ecotoxicity interspecies QAAR models from Daphnia toxicity of pharmaceuticals and personal care products.

    PubMed

    Sangion, A; Gramatica, P

    2016-10-01

    Pharmaceutical and Personal Care Products (PPCPs) became a class of contaminants of emerging concern because are ubiquitously detected in surface water and soil, where they can affect wildlife. Ecotoxicological data are only available for a few PPCPs, thus modelling approaches are essential tools to maximize the information contained in the existing data. In silico methods may be helpful in filling data gaps for the toxicity of PPCPs towards various ecological indicator organisms. The good correlation between toxicity toward Daphnia magna and those on two fish species (Pimephales promelas and Oncorhynchus mykiss), improved by the addition of one theoretical molecular descriptor, allowed us to develop predictive models to investigate the relationship between toxicities in different species. The aim of this work is to propose quantitative activity-activity relationship (QAAR) models, developed in QSARINS and validated for their external predictivity. Such models can be used to predict the toxicity of PPCPs to a particular species using available experimental toxicity data from a different species, thus reducing the tests on organisms of higher trophic level. Similarly, good QAAR models, implemented by molecular descriptors to improve the quality, are proposed here for fish interspecies. We also comment on the relevance of autocorrelation descriptors in improving all studied interspecies correlations.

  14. Development of Algal Interspecies Correlation Estimation Models for Chemical Hazard Assessment

    EPA Science Inventory

    Web-based Interspecies Correlation Estimation (ICE) is an application developed to predict the acute toxicity of a chemical from 1 species to another taxon. Web-ICE models use the acute toxicity value for a surrogate species to predict effect values for other species, thus potent...

  15. Development of Algal Interspecies Correlation Estimation Models for Chemical Hazard Assessment

    EPA Science Inventory

    Web-based Interspecies Correlation Estimation (ICE) is an application developed to predict the acute toxicity of a chemical from 1 species to another taxon. Web-ICE models use the acute toxicity value for a surrogate species to predict effect values for other species, thus potent...

  16. INTERSPECIES CORRELATION ESTIMATION (ICE) FOR ACUTE TOXICITY TO AQUATIC ORGANISMS AND WILDLIFE. II. USER MANUAL AND SOFTWARE

    EPA Science Inventory

    Asfaw, Amha, Mark R. Ellersieck and Foster L. Mayer. 2003. Interspecies Correlation Estimations (ICE) for Acute Toxicity to Aquatic Organisms and Wildlife. II. User Manual and Software. EPA/600/R-03/106. U.S. Environmental Protection Agency, National Health and Environmental Effe...

  17. INTERSPECIES CORRELATION ESTIMATION (ICE) FOR ACUTE TOXICITY TO AQUATIC ORGANISMS AND WILDLIFE. II. USER MANUAL AND SOFTWARE

    EPA Science Inventory

    Asfaw, Amha, Mark R. Ellersieck and Foster L. Mayer. 2003. Interspecies Correlation Estimations (ICE) for Acute Toxicity to Aquatic Organisms and Wildlife. II. User Manual and Software. EPA/600/R-03/106. U.S. Environmental Protection Agency, National Health and Environmental Effe...

  18. Estimation of Wildlife Hazard Levels Using Interspecies Correlation Models and Standard Laboratory Rodent Toxicity Data

    EPA Science Inventory

    Toxicity data from laboratory rodents are widely available and frequently used in human health assessments as an animal model. We explore the possibility of using single rodent acute toxicity values to predict chemical toxicity to a diversity of wildlife species and to estimate ...

  19. Estimation of Wildlife Hazard Levels Using Interspecies Correlation Models and Standard Laboratory Rodent Toxicity Data

    EPA Science Inventory

    Toxicity data from laboratory rodents are widely available and frequently used in human health assessments as an animal model. We explore the possibility of using single rodent acute toxicity values to predict chemical toxicity to a diversity of wildlife species and to estimate ...

  20. Comprehensive mollusk acute toxicity database improves the use of Interspecies Correlation Estimation (ICE) models to predict toxicity of untested freshwater and endangered mussel species

    EPA Science Inventory

    Interspecies correlation estimation (ICE) models extrapolate acute toxicity data from surrogate test species to untested taxa. A suite of ICE models developed from a comprehensive database is available on the US Environmental Protection Agency’s web-based application, Web-I...

  1. Comprehensive mollusk acute toxicity database improves the use of Interspecies Correlation Estimation (ICE) models to predict toxicity of untested freshwater and endangered mussel species

    EPA Science Inventory

    Interspecies correlation estimation (ICE) models extrapolate acute toxicity data from surrogate test species to untested taxa. A suite of ICE models developed from a comprehensive database is available on the US Environmental Protection Agency’s web-based application, Web-I...

  2. Needs for biological risk assessment in interspecies extrapolation.

    PubMed Central

    Clayson, D B

    1988-01-01

    This paper suggests that not all chemicals shown to be carcinogenic in animals may exert this effect in humans exposed to much lower amounts of the chemical. It is possible that agents which differ in their effects in humans and animals may be identified through the application of Biological Risk Assessment to the experimental results. Chemicals tested in systems in which untreated animals develop high background yields of tumors or in which high-dose toxicity may be a critical factor in the induction of carcinogenesis are suggested as candidates requiring very careful consideration before their carcinogenicity in humans is assumed. PMID:3289912

  3. Interspecies quantitative structure-activity-activity relationships (QSAARs) for prediction of acute aquatic toxicity of aromatic amines and phenols.

    PubMed

    Furuhama, A; Hasunuma, K; Aoki, Y

    2015-01-01

    We propose interspecies quantitative structure-activity-activity relationships (QSAARs), that is, QSARs with descriptors, to estimate species-specific acute aquatic toxicity. Using training datasets consisting of more than 100 aromatic amines and phenols, we found that the descriptors that predicted acute toxicities to fish (Oryzias latipes) and algae were daphnia toxicity, molecular weight (an indicator of molecular size and uptake) and selected indicator variables that discriminated between the absence or presence of various substructures. Molecular weight and the selected indicator variables improved the goodness-of-fit of the fish and algae toxicity prediction models. External validations of the QSAARs proved that algae toxicity could be predicted within 1.0 log unit and revealed structural profiles of outlier chemicals with respect to fish toxicity. In addition, applicability domains based on leverage values provided structural alerts for the predicted fish toxicity of chemicals with more than one hydroxyl or amino group attached to an aromatic ring, but not for fluoroanilines, which were not included in the training dataset. Although these simple QSAARs have limitations, their applicability is defined so clearly that they may be practical for screening chemicals with molecular weights of ≤364.9.

  4. Interspecies quantitative structure-activity relationships (QSARs) for eco-toxicity screening of chemicals: the role of physicochemical properties.

    PubMed

    Furuhama, A; Hasunuma, K; Aoki, Y

    2015-01-01

    In addition to molecular structure profiles, descriptors based on physicochemical properties are useful for explaining the eco-toxicities of chemicals. In a previous study we reported that a criterion based on the difference between the partition coefficient (log POW) and distribution coefficient (log D) values of chemicals enabled us to identify aromatic amines and phenols for which interspecies relationships with strong correlations could be developed for fish-daphnid and algal-daphnid toxicities. The chemicals that met the log D-based criterion were expected to have similar toxicity mechanisms (related to membrane penetration). Here, we investigated the applicability of log D-based criteria to the eco-toxicity of other kinds of chemicals, including aliphatic compounds. At pH 10, use of a log POW - log D > 0 criterion and omission of outliers resulted in the selection of more than 100 chemicals whose acute fish toxicities or algal growth inhibition toxicities were almost equal to their acute daphnid toxicities. The advantage of log D-based criteria is that they allow for simple, rapid screening and prioritizing of chemicals. However, inorganic molecules and chemicals containing certain structural elements cannot be evaluated, because calculated log D values are unavailable.

  5. Application of the Web-based Interspecies Correlation Estimation (Web-ICE) tool to assess risks of national pesticide registrations to federally listed (threatened and endangered) species

    EPA Science Inventory

    The National Academy of Science (NAS) recently recommended exploration of predictive tools, such as interspecies correlation estimation (ICE), to estimate acute toxicity values for listed species and support development of species sensitivity distributions (SSDs). We explored the...

  6. Application of the Web-based Interspecies Correlation Estimation (Web-ICE) tool to assess risks of national pesticide registrations to federally listed (threatened and endangered) species

    EPA Science Inventory

    The National Academy of Science (NAS) recently recommended exploration of predictive tools, such as interspecies correlation estimation (ICE), to estimate acute toxicity values for listed species and support development of species sensitivity distributions (SSDs). We explored the...

  7. Daphnia and fish toxicity of (benzo)triazoles: validated QSAR models, and interspecies quantitative activity-activity modelling.

    PubMed

    Cassani, Stefano; Kovarich, Simona; Papa, Ester; Roy, Partha Pratim; van der Wal, Leon; Gramatica, Paola

    2013-08-15

    Due to their chemical properties synthetic triazoles and benzo-triazoles ((B)TAZs) are mainly distributed to the water compartments in the environment, and because of their wide use the potential effects on aquatic organisms are cause of concern. Non testing approaches like those based on quantitative structure-activity relationships (QSARs) are valuable tools to maximize the information contained in existing experimental data and predict missing information while minimizing animal testing. In the present study, externally validated QSAR models for the prediction of acute (B)TAZs toxicity in Daphnia magna and Oncorhynchus mykiss have been developed according to the principles for the validation of QSARs and their acceptability for regulatory purposes, proposed by the Organization for Economic Co-operation and Development (OECD). These models are based on theoretical molecular descriptors, and are statistically robust, externally predictive and characterized by a verifiable structural applicability domain. They have been applied to predict acute toxicity for over 300 (B)TAZs without experimental data, many of which are in the pre-registration list of the REACH regulation. Additionally, a model based on quantitative activity-activity relationships (QAAR) has been developed, which allows for interspecies extrapolation from daphnids to fish. The importance of QSAR/QAAR, especially when dealing with specific chemical classes like (B)TAZs, for screening and prioritization of pollutants under REACH, has been highlighted.

  8. Interspecies Correlation Estimation (ICE) models predict supplemental toxicity data for SSDs

    EPA Science Inventory

    Species sensitivity distributions (SSD) require a large number of toxicity values for a diversity of taxa to define a hazard level protective of multiple species. For most chemicals, measured toxicity data are limited to a few standard test species that are unlikely to adequately...

  9. Interspecies Correlation Estimation (ICE) models predict supplemental toxicity data for SSDs

    EPA Science Inventory

    Species sensitivity distributions (SSD) require a large number of toxicity values for a diversity of taxa to define a hazard level protective of multiple species. For most chemicals, measured toxicity data are limited to a few standard test species that are unlikely to adequately...

  10. Assessing functional annotation transfers with inter-species conserved coexpression: application to Plasmodium falciparum

    PubMed Central

    2010-01-01

    Background Plasmodium falciparum is the main causative agent of malaria. Of the 5 484 predicted genes of P. falciparum, about 57% do not have sufficient sequence similarity to characterized genes in other species to warrant functional assignments. Non-homology methods are thus needed to obtain functional clues for these uncharacterized genes. Gene expression data have been widely used in the recent years to help functional annotation in an intra-species way via the so-called Guilt By Association (GBA) principle. Results We propose a new method that uses gene expression data to assess inter-species annotation transfers. Our approach starts from a set of likely orthologs between a reference species (here S. cerevisiae and D. melanogaster) and a query species (P. falciparum). It aims at identifying clusters of coexpressed genes in the query species whose coexpression has been conserved in the reference species. These conserved clusters of coexpressed genes are then used to assess annotation transfers between genes with low sequence similarity, enabling reliable transfers of annotations from the reference to the query species. The approach was used with transcriptomic data sets of P. falciparum, S. cerevisiae and D. melanogaster, and enabled us to propose with high confidence new/refined annotations for several dozens hypothetical/putative P. falciparum genes. Notably, we revised the annotation of genes involved in ribosomal proteins and ribosome biogenesis and assembly, thus highlighting several potential drug targets. Conclusions Our approach uses both sequence similarity and gene expression data to help inter-species gene annotation transfers. Experiments show that this strategy improves the accuracy achieved when using solely sequence similarity and outperforms the accuracy of the GBA approach. In addition, our experiments with P. falciparum show that it can infer a function for numerous hypothetical genes. PMID:20078859

  11. Interspecies Extrapolation

    EPA Science Inventory

    Interspecies extrapolation encompasses two related but distinct topic areas that are germane to quantitative extrapolation and hence computational toxicology-dose scaling and parameter scaling. Dose scaling is the process of converting a dose determined in an experimental animal ...

  12. Interspecies Extrapolation

    EPA Science Inventory

    Interspecies extrapolation encompasses two related but distinct topic areas that are germane to quantitative extrapolation and hence computational toxicology-dose scaling and parameter scaling. Dose scaling is the process of converting a dose determined in an experimental animal ...

  13. Web-based Interspecies Correlation Estimation (Web-ICE) for Acute Toxicity: User Manual Version 3.3

    EPA Science Inventory

    Information on the acute toxicity to multiple species is needed for the assessment of the risks to, and the protection of, individuals, populations, and ecological communities. However, toxicity data are limited for the majority of species, while standard test species are general...

  14. Web-based Interspecies Correlation Estimation (Web-ICE) for Acute Toxicity: User Manual Version 3.3

    EPA Science Inventory

    Information on the acute toxicity to multiple species is needed for the assessment of the risks to, and the protection of, individuals, populations, and ecological communities. However, toxicity data are limited for the majority of species, while standard test species are general...

  15. Identification of transcriptome SNPs between Xiphophorus lines and species for assessing allele specific gene expression within F₁ interspecies hybrids.

    PubMed

    Shen, Yingjia; Catchen, Julian; Garcia, Tzintzuni; Amores, Angel; Beldorth, Ion; Wagner, Jonathan; Zhang, Ziping; Postlethwait, John; Warren, Wes; Schartl, Manfred; Walter, Ronald B

    2012-01-01

    Variations in gene expression are essential for the evolution of novel phenotypes and for speciation. Studying allelic specific gene expression (ASGE) within interspecies hybrids provides a unique opportunity to reveal underlying mechanisms of genetic variation. Using Xiphophorus interspecies hybrid fishes and high-throughput next generation sequencing technology, we were able to assess variations between two closely related vertebrate species, Xiphophorus maculatus and Xiphophorus couchianus, and their F(1) interspecies hybrids. We constructed transcriptome-wide SNP polymorphism sets between two highly inbred X. maculatus lines (JP 163 A and B), and between X. maculatus and a second species, X. couchianus. The X. maculatus JP 163 A and B parental lines have been separated in the laboratory for ≈70 years and we were able to identify SNPs at a resolution of 1 SNP per 49 kb of transcriptome. In contrast, SNP polymorphisms between X. couchianus and X. maculatus species, which diverged ≈5-10 million years ago, were identified about every 700 bp. Using 6524 transcripts with identified SNPs between the two parental species (X. maculatus and X. couchianus), we mapped RNA-seq reads to determine ASGE within F(1) interspecies hybrids. We developed an in silico X. couchianus transcriptome by replacing 90,788 SNP bases for X. maculatus transcriptome with the consensus X. couchianus SNP bases and provide evidence that this procedure overcomes read mapping biases. Employment of the in silico reference transcriptome and tolerating 5 mismatches during read mapping allow direct assessment of ASGE in the F(1) interspecies hybrids. Overall, these results show that Xiphophorus is a tractable vertebrate experimental model to investigate how genetic variations that occur during speciation may affect gene interactions and the regulation of gene expression. Copyright © 2011 Elsevier Inc. All rights reserved.

  16. Toxicity of lead (Pb) to freshwater green algae: development and validation of a bioavailability model and inter-species sensitivity comparison.

    PubMed

    De Schamphelaere, K A C; Nys, C; Janssen, C R

    2014-10-01

    model to reduce uncertainty in site-specific risk assessment. A model-based comparison with other species indicated that the sensitivity difference between P. subcapitata and two of the most chronically Pb-sensitive aquatic invertebrates (the crustacean Ceriodaphnia dubia and the snail Lymnaea stagnalis) is strongly pH dependent, with P. subcapitata becoming the most sensitive of the three at pH > 7.4. This indicates that inter-species differences in Pb bioavailability relationships should be accounted for in risk assessment and in the derivation of water quality criteria or environmental quality standards for Pb. The chronic toxicity data with three algae species and the bioavailability model presented here will help to provide a stronger scientific basis for evaluating ecological effects of Pb in the freshwater environment.

  17. Influence of Taxonomic Relatedness and Chemical Mode of Action in Acute Interspecies Estimation Models for Aquatic species

    EPA Science Inventory

    Ecological risks to aquatic organisms are typically assessed using toxicity data for relatively few species and with limited understanding of relative species sensitivity. We developed a comprehensive set of interspecies correlation estimation (ICE) models for aquatic organisms a...

  18. Influence of Taxonomic Relatedness and Chemical Mode of Action in Acute Interspecies Estimation Models for Aquatic species

    EPA Science Inventory

    Ecological risks to aquatic organisms are typically assessed using toxicity data for relatively few species and with limited understanding of relative species sensitivity. We developed a comprehensive set of interspecies correlation estimation (ICE) models for aquatic organisms a...

  19. Reducing uncertainty in species sensitivity distributions with interspecies toxicity estimation models

    EPA Science Inventory

    Determining harmful levels of contaminants for a wide range of species is limited by available toxicological data. Ecological risk assessments typically depend on empirical data from only a few species that represent a narrow range of the life history spectrum. Extrapolation mo...

  20. Estuarine ambient toxicity assessment

    SciTech Connect

    Hartwell, S.I.; Dawson, C.E.; Jordahl, D.M.

    1994-12-31

    This study was to determine if sediment and water column ambient toxicity bioassay results correlate with fish community IBI assessments in tributaries of the Chesapeake Bay watersheds that are impacted by industrial, urban and agricultural land use patterns. A battery of water column and sediment toxicity tests were conducted monthly in coordination with fish community sampling in four sub estuaries of the Chesapeake Bay. Fish were sampled with seines and bottom trawls. An association was found between dissolved oxygen and species richness in the trawls. Water column bioassays indicated mild toxicological contamination in industrial watershed estuaries. Results varied by month and species. Water quality in the rural and agricultural watershed estuaries was generally good. Sediment bioassays demonstrated significant toxicity in the industrialized area. Effects were seen in the urbanized estuary, but to a lesser extent. Fish egg survival effects were observed in the agricultural watershed estuary. The rural estuary sediment produced variable, but non-significant results. The industrial and urban sites were contaminated with heavy metals and organics.

  1. Interspecies Extrapolations of Halocarbon Respiratory and Tissue Kinetics: Applications to Predicting Toxicity in Different Species.

    DTIC Science & Technology

    1992-09-04

    model formulation in the dog have also been procured in an extensive literature search. The partition coefficients for developing PBPK models for rats...procured in an extensive literature search. The partition coefficients fEu developing PBPK models for rats and dogs were determined from I detailed...have utility in risk assessments involving the internal dose of volatile organics. VII. ESTABLISHING TET PARTITION COEFFICIENT PARAMETERS FOR PBPK MODEL

  2. Assessing aquatic terrestrial toxicity

    SciTech Connect

    Hall, W.S.; Mirenda, R.J.

    1993-06-01

    it is recognized that the toxic effects of environmental samples cannot be predicted based on chemical concentration data alone. The EPA recommends an integrated approach that uses both chemical specific and whole effluent toxicity testing methods to control effluent toxicity. Toxicity tests allow for the consideration of site-specific factors that may increase or decrease the toxicity of a chemical in a given medium.

  3. Assessing Nanoparticle Toxicity

    NASA Astrophysics Data System (ADS)

    Love, Sara A.; Maurer-Jones, Melissa A.; Thompson, John W.; Lin, Yu-Shen; Haynes, Christy L.

    2012-07-01

    Nanoparticle toxicology, an emergent field, works toward establishing the hazard of nanoparticles, and therefore their potential risk, in light of the increased use and likelihood of exposure. Analytical chemists can provide an essential tool kit for the advancement of this field by exploiting expertise in sample complexity and preparation as well as method and technology development. Herein, we discuss experimental considerations for performing in vitro nanoparticle toxicity studies, with a focus on nanoparticle characterization, relevant model cell systems, and toxicity assay choices. Additionally, we present three case studies (of silver, titanium dioxide, and carbon nanotube toxicity) to highlight the important toxicological considerations of these commonly used nanoparticles.

  4. National Air Toxics Assessment

    EPA Pesticide Factsheets

    NATA is an ongoing comprehensive evaluation of air toxics in the U.S. As a screening tool, it helps air agencies prioritize pollutants, emission sources and locations of interest for further study to gain a better understanding of risks.

  5. First report on interspecies quantitative correlation of ecotoxicity of pharmaceuticals.

    PubMed

    Kar, Supratik; Roy, Kunal

    2010-10-01

    Pharmaceuticals being extensively and progressively used in human and veterinary medicine are emerging as significant environmental contaminants. Pharmaceuticals are designed to have a specific mode of action and many of them are persistent in the body. These features among others make pharmaceuticals to be evaluated for potential effects on aquatic flora and fauna. Low levels of pharmaceuticals have been detected in many countries in sewage treatment plant effluents, surface waters, groundwater and drinking waters. In contrast, there is a general scarcity of publicly available ecotoxicological data concerning pharmaceuticals. Interspecies toxicity correlations provide a tool for estimating contaminant sensitivity with known levels of uncertainty for a diversity of wildlife species. In this context, we have developed interspecies toxicity correlation between Daphnia magna (zooplankton) and fish (species according to OECD guidelines) assessing the ecotoxicological hazard potential of diverse 77 pharmaceuticals. The developed models are validated and consensus models are presented to predict toxicity of the individual compounds for any one species when the data for the other species are available. Informative illustrations of the contributing structural fragments which are responsible for the greater toxicity of the diverse pharmaceuticals are identified by the developed models. Developed models are also used to predict fish toxicities of 59 pharmaceuticals (for which Daphnia toxicities are present) and Daphnia toxicities of 30 pharmaceuticals (for which fish toxicities are present). This study will allow a better and comprehensive risk assessment of pharmaceuticals for which toxicity data is missing for a particular endpoint.

  6. Web-based Interspecies Correlation Estimation (Web-ICE) for Acute Toxicity: User Manual 3.2

    EPA Science Inventory

    The Web-ICE Endangered Species module simultaneously estimates toxicity to taxa representing threatened or endangered species using up to 25 surrogates. This module batch processes toxicity values for endangered species from all species, genus, and family level models available f...

  7. Web-based Interspecies Correlation Estimation (Web-ICE) for Acute Toxicity: User Manual 3.2

    EPA Science Inventory

    The Web-ICE Endangered Species module simultaneously estimates toxicity to taxa representing threatened or endangered species using up to 25 surrogates. This module batch processes toxicity values for endangered species from all species, genus, and family level models available f...

  8. Risk assessment for neurobehavioral toxicity

    SciTech Connect

    McMillan, D.E.

    1987-12-01

    A study of the National Academy of Sciences/National Research Council (NAS/NRC) found neurobehavioral toxicity to be one of the areas where almost no data are available for the assessment of toxicity. Using the NAS/NRC report and a data base from the American Conference of Government Industrial Hygienists (ACGIH), an estimate of the number of neurobehavioral toxins in commercial chemicals can be made. Although the assumption made in making such a calculation may be invalid, the exercise suggests that the number of neurobehavioral toxins may be quite large. There does seem to be general agreement as to what type of neurobehavioral test procedures are appropriate for regulatory purposes. Select committees have consistently recommended the use of test batteries that include schedule-controlled behavior, motor activity, and neuropathological examination following in vivo perfusion, for regulatory purposes. Alkyltin data developed from such a battery were applied to the risk assessment model employed by the United States Environmental Protection Agency (EPA) in their calculations of acceptable daily intake. Using this test battery and the EPA risk assessment model, the acceptable daily intake calculated is of the same order of magnitude as the total limit values established by the ACGIH. A number of special issues in neurobehavioral toxicity also are discussed, including the definition of adverse neurobehavioral toxic effect, species extrapolation, correlation of behavior and neuropathology, alternative methods, and quality of life issues.

  9. Interspecies Correlation Estimation - Applications in Water Quality Criteria and Ecological Risk Assessment

    EPA Science Inventory

    Water quality criteria (WQC) designate the maximum concentrations of water-borne toxicants that do not adversely affect specific protection goals under certain natural conditions. As the foundation of water quality standards, WQC provide a critical scientific basis for environmen...

  10. Interspecies Correlation Estimation - Applications in Water Quality Criteria and Ecological Risk Assessment

    EPA Science Inventory

    Water quality criteria (WQC) designate the maximum concentrations of water-borne toxicants that do not adversely affect specific protection goals under certain natural conditions. As the foundation of water quality standards, WQC provide a critical scientific basis for environmen...

  11. Inter-species and intra-annual variations of moss nitrogen utilization: Implications for nitrogen deposition assessment.

    PubMed

    Dong, Yu-Ping; Liu, Xue-Yan; Sun, Xin-Chao; Song, Wei; Zheng, Xu-Dong; Li, Rui; Liu, Cong-Qiang

    2017-07-07

    Moss nitrogen (N) concentrations and natural (15)N abundance (δ(15)N values) have been widely employed to evaluate annual levels and major sources of atmospheric N deposition. However, different moss species and one-off sampling were often used among extant studies, it remains unclear whether moss N parameters differ with species and different samplings, which prevented more accurate assessment of N deposition via moss survey. Here concentrations, isotopic ratios of bulk carbon (C) and bulk N in natural epilithic mosses (Bryum argenteum, Eurohypnum leptothallum, Haplocladium microphyllum and Hypnum plumaeforme) were measured monthly from August 2006 to August 2007 at Guiyang, SW China. The H. plumaeforme had significantly (P < 0.05) lower bulk N concentrations and higher δ(13)C values than other species. Moss N concentrations were significantly (P < 0.05) lower in warmer months than in cooler months, while moss δ(13)C values exhibited an opposite pattern. The variance component analyses showed that different species contributed more variations of moss N concentrations and δ(13)C values than different samplings. Differently, δ(15)N values did not differ significantly between moss species, and its variance mainly reflected variations of assimilated N sources, with ammonium as the dominant contributor. These results unambiguously reveal the influence of inter-species and intra-annual variations of moss N utilization on N deposition assessment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Assessment of aquatic experimental versus predicted and extrapolated chronic toxicity data of four structural analogues.

    PubMed

    Dom, Nathalie; Knapen, Dries; Blust, Ronny

    2012-01-01

    The present study was developed to assess the chronic toxicity predictions and extrapolations for a set of chlorinated anilines (aniline (AN), 4-chloroaniline (CA), 3,5-dichloroaniline (DCA) and 2,3,4-trichloroaniline (TCA)). Daphnia magna 21 d chronic experimental data was compared to the chronic toxicity predictions made by the US EPA ECOSAR QSAR tools and to acute-to-chronic extrapolations. Additionally, Species Sensitivity Distributions (SSDs) were constructed to assess the chronic toxicity variability among different species and to investigate the acute versus chronic toxicity in a multi-species context. Since chlorinated anilines are structural analogues with a designated polar narcotic mode of action, similar toxicity responses were assumed. However, rather large interchemical and interspecies differences in toxicity were observed. Compared to the other three test compounds, TCA exposure had a significantly larger impact on growth and reproduction of D. magna. Furthermore, this study illustrated that QSARs or a fixed ACR are not able to account for these interchemical and interspecies differences. Consequently, ECOSAR was found to be inadequate to predict the chronic toxicity of the anilines and the use of a fixed ACR (of 10) led to under of certain species. The experimental ACRs determined in D. magna were substantially different among the four aromatic amines (ACR of 32 for AN, 16.9 for CA, 5.7 for DCA and 60.8 for TCA). Furthermore, the SSDs illustrated that Danio rerio was rather insensitive to AN in comparison to another fish species, Phimphales promelas. It was therefore suggested that available toxicity data should be used in an integrative multi-species way, rather than using individual-based toxicity extrapolations. In this way, a relevant overview of the differences in species sensitivity is given, which in turn can serve as the basis for acute to chronic extrapolations.

  13. Proteomics in aquatic amphipods: can it be used to determine mechanisms of toxicity and interspecies responses after exposure to atrazine?

    PubMed

    Ralston-Hooper, Kimberly J; Sanchez, Brian C; Adamec, Jiri; Sepúlveda, María S

    2011-05-01

    Proteomics has gained popularity in the field of ecotoxicology as a holistic tool for unraveling novel mechanisms of toxicity and elucidating subtle effects of contaminant exposure. The holoarctic amphipod Diporeia spp. is declining at precipitous rates in the Great Lakes, and we are evaluating the use of the well-studied amphipod model Hyalella azteca as a surrogate for Diporeia spp. This article presents proteomics data from both amphipod species exposed to atrazine (ATZ) and one of its metabolites, desethylatrazine (DEA; 3 and 30 µg/L for 21 and 42 d). We used a proteomics approach to determine whether these two species of amphipods responded similarly to the same chemicals and to understand better the mechanisms of toxicity of ATZ and DEA in aquatic invertebrates. We observed disruption in energy production and mitochondrial function as well as hormesis in exposed organisms. In addition, we identified a two proteins (GAPDH and HSP 90 kDa) that have been linked to hormonal disruptions, suggesting potential endocrine disruption. Finally, we found that H. azteca and Diporeia spp. responded with similar proteomic profiles after ATZ and DEA exposure, suggesting that H. azteca may be used as a surrogate model organism for Diporeia spp.

  14. Interspecies differences in the hepatic metabolism of 2,3,7,8-tetrachlorodibenzo-p-dioxin: role in toxicity

    SciTech Connect

    Wroblewski, V.J.

    1987-01-01

    These studies examined the hepatic metabolism of TCDD in suspensions of isolated hepatocytes from the guinea pig and hamster. /sup 14/C- TCDD was metabolized at a similar rate in hepatocytes from the three species. TCDD pretreatment 72 hours prior to hepatocyte isolation increased cytochrome P-448-mediated monooxygenase activities and increased the rate of TCDD metabolism in rat and hamster hepatocytes 5-6-fold over the control rate. However, pretreatment of guinea pigs with TCDD had not effect on the rate of /sup 14/C-TCDD metabolism in isolated hepatocytes from this species. The findings suggest that the inability of TCDD to induce its own rate of hepatic metabolism in the guinea pig may contribute to the persistence of TCDD and unique sensitivity of this species to the acute toxicity of TCDD.

  15. National Air Toxic Assessments (NATA) Results

    EPA Pesticide Factsheets

    The National Air Toxics Assessment was conducted by EPA in 2002 to assess air toxics emissions in order to identify and prioritize air toxics, emission source types and locations which are of greatest potential concern in terms of contributing to population risk. This data source provides downloadable information on emissions at the state, county and census tract level.

  16. Guidelines for Reproductive Toxicity Risk Assessment

    EPA Pesticide Factsheets

    These guidelines discuss the scientific basis for concern about exposure to agents that cause reproductive toxicity and describe the principles and procedures to be followed in conducting risk assessments for reproductive toxicity.

  17. Environmental complex mixture toxicity assessment.

    PubMed Central

    Gardner, H S; Brennan, L M; Toussaint, M W; Rosencrance, A B; Boncavage-Hennessey, E M; Wolfe, M J

    1998-01-01

    Trichloroethylene (TCE) was found as a contaminant in the well supplying water to an aquatic testing laboratory. The groundwater was routinely screened by a commercial laboratory for volatile and semivolatile compounds, metals, herbicides, pesticides, and polychlorinated biphenyls using U.S. Environmental Protection Agency methods. Although TCE was the only reportable peak on the gas chromatograph, with average concentrations of 0.200 mg/l, other small peaks were also present, indicating the possibility that the contamination was not limited to TCE alone. A chronic 6-month carcinogenicity assay was conducted on-site in a biomonitoring trailer, using the Japanese medaka fish (Oryzias latipes) in an initiation-promotion protocol, with diethylnitrosamine (DEN) as the initiator and the TCE-contaminated groundwater as a promoter. Study results indicated no evidence of carcinogenic potential of the groundwater without initiation. There was, however, a tumor-promotional effect of the groundwater after DEN initiation. A follow-up laboratory study was conducted using reagent grade TCE added to carbon-filtered groundwater to simulate TCE concentrations comparable to those found in the contaminated groundwater. Study results indicated no promotional effects of TCE. These studies emphasize the necessity for on-site bioassays to assess potential environmental hazards. In this instance, chemical analysis of the groundwater identified TCE as the only reportable contaminant, but other compounds present below reportable limits were noted and may have had a synergistic effect on tumor promotion observed with the groundwater exposure. Laboratory toxicity testing of single compounds can produce toxicity data specific to that compound for that species but cannot take into account the possible toxic effects of mixtures of compounds. Images Figure 2 PMID:9860885

  18. Environmental complex mixture toxicity assessment.

    PubMed

    Gardner, H S; Brennan, L M; Toussaint, M W; Rosencrance, A B; Boncavage-Hennessey, E M; Wolfe, M J

    1998-12-01

    Trichloroethylene (TCE) was found as a contaminant in the well supplying water to an aquatic testing laboratory. The groundwater was routinely screened by a commercial laboratory for volatile and semivolatile compounds, metals, herbicides, pesticides, and polychlorinated biphenyls using U.S. Environmental Protection Agency methods. Although TCE was the only reportable peak on the gas chromatograph, with average concentrations of 0.200 mg/l, other small peaks were also present, indicating the possibility that the contamination was not limited to TCE alone. A chronic 6-month carcinogenicity assay was conducted on-site in a biomonitoring trailer, using the Japanese medaka fish (Oryzias latipes) in an initiation-promotion protocol, with diethylnitrosamine (DEN) as the initiator and the TCE-contaminated groundwater as a promoter. Study results indicated no evidence of carcinogenic potential of the groundwater without initiation. There was, however, a tumor-promotional effect of the groundwater after DEN initiation. A follow-up laboratory study was conducted using reagent grade TCE added to carbon-filtered groundwater to simulate TCE concentrations comparable to those found in the contaminated groundwater. Study results indicated no promotional effects of TCE. These studies emphasize the necessity for on-site bioassays to assess potential environmental hazards. In this instance, chemical analysis of the groundwater identified TCE as the only reportable contaminant, but other compounds present below reportable limits were noted and may have had a synergistic effect on tumor promotion observed with the groundwater exposure. Laboratory toxicity testing of single compounds can produce toxicity data specific to that compound for that species but cannot take into account the possible toxic effects of mixtures of compounds.

  19. Variation in sensitivity of aquatic species to toxicants: Practical consequences for effect assessment of chemical substances

    SciTech Connect

    Vaal, M.A.; Van Leeuwen, C.J.; Hoekstra, J.A.; Hermens, J.L.M.

    2000-04-01

    This study addresses the relation between the sensitivity of aquatic species and mode of action of different classes or organic chemicals. The authors analyzed large data sets of ecotoxicological information to reveal the interspecies variation in sensitivity, to relate this variation to the compounds' mode of action, and to explain the observed patterns using general biological information. Here the authors present a general framework and recommendations for risk assessment procedures. The authors recommend the use of toxicologically based classification schemes at an early stage of the risk assessment procedure. Screening programs are most efficiently run when only one species per compound is tested to prioritize substances. The toxicity of compounds belonging to the class of nonpolar narcotics is highly predictable and shows little interspecies variation. For these compounds quantitative structure-activity relationships (WSARs) can be used to estimate effect levels. Most effort should be put into testing reactive compounds and compounds with a specific mode of action as toxicity to some species can be 10{sup 5}--10{sup 6} times higher compared with less sensitive species. The use of assessment factors in effect assessment procedures may lead to an underestimation of effects on the more sensitive species. For many priority pollutants there is little information on their ecotoxicity. Predictive techniques are needed to compensate for this lack of data. Knowledge of the relation between modes of action of compounds and interspecies variation in sensitivity should be integrated in risk assessment procedures in order to make more efficient use of the limited financial resources available.

  20. Human and Rat ABC Transporter Efflux of Bisphenol A and Bisphenol A Glucuronide: Interspecies Comparison and Implications for Pharmacokinetic Assessment

    EPA Science Inventory

    Significant interspecies differences exist between human and rodent with respect to absorption, distribution, and excretion of bisphenol A (BPA) and its primary metabolite, BPA-glucuronide (BPA-G). ATP-Binding Cassette (ABC) transporter enzymes play important roles in these physi...

  1. Human and Rat ABC Transporter Efflux of Bisphenol A and Bisphenol A Glucuronide: Interspecies Comparison and Implications for Pharmacokinetic Assessment

    EPA Science Inventory

    Significant interspecies differences exist between human and rodent with respect to absorption, distribution, and excretion of bisphenol A (BPA) and its primary metabolite, BPA-glucuronide (BPA-G). ATP-Binding Cassette (ABC) transporter enzymes play important roles in these physi...

  2. National Air Toxics Assessment (NATA)

    EPA Pesticide Factsheets

    NATA provides estimates of the risk of cancer and other serious health effects from inhaling air toxics in order to inform both national and more localized efforts to identify and prioritize air toxics, emission source types.

  3. EXTRAPOLATION OF ACUTE TOXICITY AMONG AQUATIC SPECIES BASED ON MECHANISM OF ACTION

    EPA Science Inventory

    Presentation provides inter-species QSARs for acute toxicity to ciliates, fish and daphnia...The inter-species QSARs can be also useful in the analysis of the relative species sensitivity to a variety of pollutants and will be useful in assisting in risk assessments of potential ...

  4. Positive allosteric modulation of AMPA receptors from efficacy to toxicity: the interspecies exposure-response continuum of the novel potentiator PF-4778574.

    PubMed

    Shaffer, Christopher L; Hurst, Raymond S; Scialis, Renato J; Osgood, Sarah M; Bryce, Dianne K; Hoffmann, William E; Lazzaro, John T; Hanks, Ashley N; Lotarski, Susan; Weber, Mark L; Liu, JianHua; Menniti, Frank S; Schmidt, Christopher J; Hajós, Mihály

    2013-10-01

    α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) positive allosteric modulation (i.e., "potentiation") has been proposed to overcome cognitive impairments in schizophrenia, but AMPAR overstimulation can be excitotoxic. Thus, it is critical to define carefully a potentiator's mechanism-based therapeutic index (TI) and to determine confidently its translatability from rodents to higher-order species. Accordingly, the novel AMPAR potentiator N-{(3R,4S)-3-[4-(5-cyano-2-thienyl)phenyl]tetrahydro-2H-pyran-4-yl}propane-2-sulfonamide (PF-4778574) was characterized in a series of in vitro assays and single-dose animal studies evaluating AMPAR-mediated activities related to cognition and safety to afford an unbound brain compound concentration (Cb,u)-normalized interspecies exposure-response relationship. Because it is unknown which AMPAR subtype(s) may be selectively potentiated for an optimal TI, PF-4778574 binding affinity and functional potency were determined in rodent tissues expected to express a native mixture of AMPAR subunits and their associated proteins to afford composite pharmacological values. Functional activity was also quantified in recombinant cell lines stably expressing human GluA2 flip or flop homotetramers. Procognitive effects of PF-4778574 were evaluated in both rat electrophysiological and nonhuman primate (nhp) behavioral models of pharmacologically induced N-methyl-d-aspartate receptor hypofunction. Safety studies assessed cerebellum-based AMPAR activation (mouse) and motor coordination disruptions (mouse, dog, and nhp), as well as convulsion (mouse, rat, and dog). The resulting empirically derived exposure-response continuum for PF-4778574 defines a single-dose-based TI of 8- to 16-fold for self-limiting tremor, a readily monitorable clinical adverse event. Importantly, the Cb,u mediating each physiological effect were highly consistent across species, with efficacy and convulsion occurring at just fractions of the in vitro

  5. Validation and Application of Pharmacokinetic Models for Interspecies Extrapolations in Toxicity Risk Assessments of Volatile Organics

    DTIC Science & Technology

    1991-07-23

    have been identified as contaminants of food and drinking water supplies in the, U.S. (Symons et al., 1975; NOMS, 1977). Some of the halocarbons most...commonly identified in water supplies are l,l-dichloroethylene (1,I-DCE), trichloroethylene (TOE), and 1,1,1- trichloroethane (TRI). As indicated...to be primary sources of these halocarbons in 4 water supplies. Recently, the contamination of drinkins water supplies by the leakage of solvents

  6. Validation and Application of Pharmacokinetic Models for Interspecies Extrapolations in Toxicity Risk Assessments of Volatile Organics

    DTIC Science & Technology

    1988-08-30

    exposure to each chemical will be determined. Relative rates and magnitude of elimination of the test chemicals by metabolism and respiration will be...analyzing the role of pulmonary extraction/elimination. At least 2 doses and 2 vapor concentrations of each pair of test compounds will be utilized. In...adjustments in administered dose are necessary to achieve equal brain levels of test compounds in each species. An inhalation and oral exposure

  7. A novel algal toxicity testing technique for assessing the toxicity of both metallic and organic toxicants.

    PubMed

    Lin, Jui-Ho; Kao, Wei-Chen; Tsai, Kuo-Pei; Chen, Chung-Yuan

    2005-05-01

    This study presents a closed-system algal toxicity test technique that is capable of detecting the effects of both organic and metallic toxicants. Toxicity testing was conducted by transferring adequate amounts of algal suspension, dilution water (with culture growth medium), and toxicants into 300-mL BOD bottles. The BOD bottles were completely filled up with no head-space left. The initial cell density and the exposure time were 15,000 cells/mL and 48 h, respectively. The performance of the above test method was evaluated using three heavy metals and six organic toxicants based on three different test endpoints, i.e., dissolved oxygen production, algal growth rate, and cell density. The proposed test revealed excellent test sensitivity and reproducibility. Currently, none of the existing algal toxicity test protocols is adequate for assessing the toxicity of organic chemicals. The closed-system algal toxicity tests developed by previous researchers also may not be ideal because the enlarged headspace and/or enriched bicarbonate buffer may result in either underestimations of the exposure concentrations or insensitive responses to both heavy metals and organic toxicants. Compared to the aforementioned algal toxicity test methods, the proposed technique in the present study has a more general applicability under conditions such as effluent samples containing both metals and organic toxicants or samples with unknown compositions.

  8. ASSESSMENT OF MALE REPRODUCTIVE TOXICITY

    EPA Science Inventory

    This chapter reviews the subject of risk assessment in male reproductive toxicology. After providing an overview of the risk assessment process, laboratory test protocols, including those specified by EPA and used by NIEHS are summarized and discussed in detail with respect to t...

  9. MODULAR APPLICATION OF COMPUTATIONAL MODELS OF INHALED REACTIVE GAS DOSIMETRY FOR RISK ASSESSMENT OF RESPIRATORY TRACT TOXICITY: CHLORINE

    EPA Science Inventory

    Inhaled reactive gases typically cause respiratory tract toxicity with a prominent proximal to distal lesion pattern. This pattern is largely driven by airflow and interspecies differences between rodents and humans result from factors such as airway architecture, ventilation ra...

  10. MODULAR APPLICATION OF COMPUTATIONAL MODELS OF INHALED REACTIVE GAS DOSIMETRY FOR RISK ASSESSMENT OF RESPIRATORY TRACT TOXICITY: CHLORINE

    EPA Science Inventory

    Inhaled reactive gases typically cause respiratory tract toxicity with a prominent proximal to distal lesion pattern. This pattern is largely driven by airflow and interspecies differences between rodents and humans result from factors such as airway architecture, ventilation ra...

  11. THE FUTURE OF TOXICITY TESTING AND ASSESSMENT ...

    EPA Pesticide Factsheets

    The National Research Council's Board on Environmental Studies and Toxicology is conducting a two-part study to assess and advance current approaches to toxicity testing and assessment to meet regulatory data needs. The first part of the study was completed January 2006, in which the committee prepared a report reviewing selected aspects of several relevant reports by EPA and others on this topic. In the second part of the study currently underway, the committee will prepare a final report presenting a long-range vision and strategic plan for advancing the practices of toxicity testing and human health assessment for environmental contaminants. In developing the vision and strategic plan, the committee will consider evolving regulatory data needs; current toxicity testing guidelines and standards used by EPA and other federal agencies; the use of emerging science and tools (e.g., genomics, proteomics, transgenics, bioinformatics, computational toxicology, in vitro testing, and other alternatives to animal testing); and the challenges of incorporating more complex understanding of toxicity (e.g., toxicokinetics, mechanisms of action, systems biology) into human health risk assessment. The final report is expected to be released as early as the end of January, 2007. To develop a long-range vision and strategic plan for advancing the practices of toxicity testing and human health assessment for environmental contaminants.

  12. Interspecies extrapolation based on the RepDose database--a probabilistic approach.

    PubMed

    Escher, Sylvia E; Batke, Monika; Hoffmann-Doerr, Simone; Messinger, Horst; Mangelsdorf, Inge

    2013-04-12

    Repeated dose toxicity studies from the RepDose database (DB) were used to determine interspecies differences for rats and mice. NOEL (no observed effect level) ratios based on systemic effects were investigated for three different types of exposure: inhalation, oral food/drinking water and oral gavage. Furthermore, NOEL ratios for local effects in inhalation studies were evaluated. On the basis of the NOEL ratio distributions, interspecies assessment factors (AF) are evaluated. All data sets were best described by a lognormal distribution. No difference was seen between inhalation and oral exposure for systemic effects. Rats and mice were on average equally sensitive at equipotent doses with geometric mean (GM) values of 1 and geometric standard deviation (GSD) values ranging from 2.30 to 3.08. The local AF based on inhalation exposure resulted in a similar distribution with GM values of 1 and GSD values between 2.53 and 2.70. Our analysis confirms former analyses on interspecies differences, including also dog and human data. Furthermore it supports the principle of allometric scaling according to caloric demand in the case that body doses are applied. In conclusion, an interspecies distribution animal/human with a GM equal to allometric scaling and a GSD of 2.5 was derived.

  13. Comparison of Species Sensitivity Distributions Derived from Interspecies Correlation Models to Distributions used to Derive Water Quality Criteria

    EPA Science Inventory

    Species sensitivity distributions (SSD) require a large number of measured toxicity values to define a chemical’s toxicity to multiple species. This investigation comprehensively evaluated the accuracy of SSDs generated from toxicity values predicted from interspecies correlation...

  14. Comparison of Species Sensitivity Distributions Derived from Interspecies Correlation Models to Distributions used to Derive Water Quality Criteria

    EPA Science Inventory

    Species sensitivity distributions (SSD) require a large number of measured toxicity values to define a chemical’s toxicity to multiple species. This investigation comprehensively evaluated the accuracy of SSDs generated from toxicity values predicted from interspecies correlation...

  15. Interspecies physiological variation as a tool for cross-species assessments of global warming-induced endangerment: validation of an intrinsic determinant of macroecological and phylogeographic structure.

    PubMed

    Bernardo, Joseph; Ossola, Ryan J; Spotila, James; Crandall, Keith A

    2007-12-22

    Global warming is now recognized as the dominant threat to biodiversity because even protected populations and habitats are susceptible. Nonetheless, current criteria for evaluating species' relative endangerment remain purely ecological, and the accepted conservation strategies of habitat preservation and population management assume that species can mount ecological responses if afforded protection. The insidious threat from climate change is that it will attenuate or preclude ecological responses by species that are physiologically constrained; yet, quantitative, objective criteria for assessing relative susceptibility of diverse taxa to warming-induced stress are wanting. We explored the utility of using interspecies physiological variation for this purpose by relating species' physiological phenotypes to landscape patterns of ecological and genetic exchange. Using a salamander model system in which ecological, genetic and physiological diversity are well characterized, we found strong quantitative relationships of basal metabolic rates (BMRs) to both macroecological and phylogeographic patterns, with decreasing BMR leading to dispersal limitation (small contemporary ranges with marked phylogeographic structure). Measures of intrinsic physiological tolerance, which vary systematically with macroecological and phylogeographic patterns, afford objective criteria for assessing endangerment across a wide range of species and should be incorporated into conservation assessment criteria that currently rely exclusively upon ecological predictors.

  16. NATIONAL-SCALE ASSESSMENT OF AIR TOXICS RISKS

    EPA Science Inventory

    The national-scale assessment of air toxics risks is a modeling assessment which combines emission inventory development, atmospheric fate and transport modeling, exposure modeling, and risk assessment to characterize the risk associated with inhaling air toxics from outdoor sour...

  17. NATIONAL-SCALE ASSESSMENT OF AIR TOXICS RISKS

    EPA Science Inventory

    The national-scale assessment of air toxics risks is a modeling assessment which combines emission inventory development, atmospheric fate and transport modeling, exposure modeling, and risk assessment to characterize the risk associated with inhaling air toxics from outdoor sour...

  18. Toxicity assessment of urban stormwater runoff

    SciTech Connect

    Jacher, K.A.; Burton, G.A. Jr.

    1994-12-31

    Organic compounds such as petroleum derivatives, fuels, greases, and oil are considered major pollutants of nonpoint source runoff. Some polycyclic aromatic hydrocarbons (PAHs) have been shown to have carcinogenic effects. A compounding problem of PAH`s in runoff is that they exhibit a photoinduced toxicity to aquatic organisms. Stormwater runoff from urban areas was assessed using Ceriodaphnia dubia, Daphnia magna, Pimephales promelas and Hyalella azteca laboratory test methods. Photoreactive responses of runoff water from parking lots was measured in the laboratory and field validated using Hyalella azteca in situ assessment. Organism exposure to urban runoff showed significantly depressed survival compared to laboratory and base flow conditions. Photoreactive responses show a 50% increase in toxicity during laboratory and in situ exposures. Due to the widespread loadings of PAHs and increased solar UV levels due to the depletion of the ozone layer, potential exists for impacts on aquatic ecosystems and must be incorporated into nonpoint source pollution assessments.

  19. Chesapeake Bay ambient toxicity-assessment workshop report

    SciTech Connect

    Krome, E.C.

    1990-05-01

    Proceedings of a workshop conducted in Annapolis, Maryland, July 25-27, 1989. Its purpose was to provide resource managers with the necessary information to better assess and evaluate the significance of toxic contaminants as causes of mortality and impaired growth and reproduction of Bay organisms. Plenary presentations addressed population risk assessment; sediment toxicity assessment; whole organism toxicity assessment; and suborganismal toxicity assessment. Subsequent group sessions developed conclusions, findings and recommendations.

  20. Subacute toxicity assessment of annatto in rat.

    PubMed

    Bautista, A R P L; Moreira, E L T; Batista, M S; Miranda, M S; Gomes, I C S

    2004-04-01

    Increased human use of annatto (Bixa orellana L), a red yellow food colorant, demands generation of toxicity data. The toxic effects of annatto powder (bixin 27%) have been assessed following administration of a subacute regimen (4 weeks, 20 doses) in Wistar male and female rats. A full study with three dose levels was considered unnecessary since no sign of toxicity had been noted in a preliminary experiment with 1000 mg/kg body weight/day as was recommended by the OECD guideline. In this study, annatto administered by gavage at a dose level of 2000 mg/kg/day decreased male body weight gain, but had no effect on either food intake or food conversion efficiency. Haematological and plasma biochemical examination as well necropsy performed at the end of administration (29th day) and observation (43rd day) periods revealed no alterations related with annatto administration. Kidney apoptosis occurred in 20% treated female rats in restricted areas without proliferation or tubular segments modification. The precise nature of apoptosis was not investigated in the present study. These findings suggest that annatto was no toxic to the rat.

  1. Assessing behavioral toxicity with Caenorhabditis elegans.

    PubMed

    Anderson, Gary L; Cole, Russell D; Williams, Phillip L

    2004-05-01

    Behavior, even in simple metazoans, depends upon integrated processes at the subcellular, cellular, and organismal level, and thus is susceptible to disruption by a broad spectrum of chemicals. Locomotor behavior (movement) of the small free-living nematode Caenorhabditis elegans has proven to be useful in assessing toxicity. Recently reported observations suggest that behavioral change (reduced movement) occurs after 4 h of exposure to heavy metals, and that with abbreviated exposure, the concentration-response relationship for Pb (a known neurotoxic metal) differs from that for Cu. In this study, movement was evaluated after 4-h exposures for nine compounds from three chemical classes: organic pesticides, organic solvents, and heavy metals. Concentration-dependent reduction of movement was observed for all test compounds with the exception of mebendazole, for which test concentrations were limited by solubility. Within each chemical class, movement was more sensitive to the neurotoxic compounds than to substances not believed to be neurotoxic, as evidenced by behavioral effective concentration to reduce average worm movement to 50% of the control movement values (e.g., levamisole and chlorpyrifos < mebendazole, ethanol and acetone < dimethylsulfoxide, and Pb and Al < Cu). These observations are discussed as they relate to the use of acute behavioral tests in assessing general chemical toxicity, and the enhanced value of 4-h testing for the detection of neural toxicants.

  2. Thyroid toxicants: assessing reproductive health effects.

    PubMed Central

    Jahnke, Gloria D; Choksi, Neepa Y; Moore, John A; Shelby, Michael D

    2004-01-01

    A thyroid toxicant workshop sponsored by the National Toxicology Program Center for the Evaluation of Risks to Human Reproduction convened on 28-29 April 2003 in Alexandria, Virginia. The purpose of this workshop was to examine and discuss chemical-induced thyroid dysfunction in experimental animals and the relevance of reproductive and developmental effects observed for prediction of adverse effects in humans. Presentations highlighted and compared reproductive and developmental effects of thyroid hormones in humans and rodents. Rodent models of thyroid system dysfunction were presented. Animal testing protocols were reviewed, taking into account protocol designs that allow extrapolation to possible human health effects. Potential screening methods to assess toxicant-induced thyroid dysfunction were outlined, and postnatal bioassays of thyroid-related effects were discussed. PMID:14998754

  3. Organ-on-a-chip for assessing environmental toxicants.

    PubMed

    Cho, Soohee; Yoon, Jeong-Yeol

    2017-01-11

    Man-made xenobiotics, whose potential toxicological effects are not fully understood, are oversaturating the already-contaminated environment. Due to the rate of toxicant accumulation, unmanaged disposal, and unknown adverse effects to the environment and the human population, there is a crucial need to screen for environmental toxicants. Animal models and in vitro models are ineffective models in predicting in vivo responses due to inter-species difference and/or lack of physiologically-relevant 3D tissue environment. Such conventional screening assays possess limitations that prevent dynamic understanding of toxicants and their metabolites produced in the human body. Organ-on-a-chip systems can recapitulate in vivo like environment and subsequently in vivo like responses generating a realistic mock-up of human organs of interest, which can potentially provide human physiology-relevant models for studying environmental toxicology. Feasibility, tunability, and low-maintenance features of organ-on-chips can also make possible to construct an interconnected network of multiple-organs-on-chip toward a realistic human-on-a-chip system. Such interconnected organ-on-a-chip network can be efficiently utilized for toxicological studies by enabling the study of metabolism, collective response, and fate of toxicants through its journey in the human body. Further advancements can address the challenges of this technology, which potentiates high predictive power for environmental toxicology studies.

  4. Toxicity assessment of tobacco products in vitro.

    PubMed

    Manuppello, Joseph R; Sullivan, Kristie M

    2015-03-01

    Driven by new regulatory demands to demonstrate risk reduction, the toxicity assessment of tobacco products increasingly employs innovative in vitro methods, including biphasic cell and tissue cultures exposed to whole cigarette smoke at the air-liquid interface, cell transformation assays, and genomic analyses. At the same time, novel tobacco products are increasingly compared to traditional cigarettes. This overview of in vitro toxicology studies of tobacco products reported in the last five years provides evidence to support the prioritisation of in vitro over in vivo methods by industry and their recommendation by regulatory authorities. 2015 FRAME.

  5. Development of Interspecies Correlation Models for Petroleum Hydrocarbons

    EPA Science Inventory

    Estimating the consequences of petroleum products to water column organisms has commonly been hampered by limited acute toxicity data, which exists only for a relatively small number of test species. In this study, we developed petroleum-specific Interspecies Correlation Estimati...

  6. Development of Interspecies Correlation Models for Petroleum Hydrocarbons

    EPA Science Inventory

    Estimating the consequences of petroleum products to water column organisms has commonly been hampered by limited acute toxicity data, which exists only for a relatively small number of test species. In this study, we developed petroleum-specific Interspecies Correlation Estimati...

  7. Predictive Protein Toxicity and Its Use in Risk Assessment.

    PubMed

    Franceschi, Niccolò; Paraskevopoulos, Konstantinos; Waigmann, Elisabeth; Ramon, Matthew

    2017-06-01

    In the EU novel proteins used in food or feed are assessed for their potential toxic effects in humans and livestock animals. The discovery of clear molecular features linked to the toxicity of a protein may be an important step towards the use of predictive protein toxicity in risk assessment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. TOXICITY TESTS FOR SEDIMENT QUALITY ASSESSMENTS

    EPA Science Inventory

    Toxic sediments have contributed to a wide-variety of environmental problems around the world. The observed effects include direct toxic effects to aquatic life, bio-magnification of toxicants in the food chain, and economic impacts. This chapter discusses the use of toxicity...

  9. TOXICITY TESTS FOR SEDIMENT QUALITY ASSESSMENTS

    EPA Science Inventory

    Toxic sediments have contributed to a wide-variety of environmental problems around the world. The observed effects include direct toxic effects to aquatic life, bio-magnification of toxicants in the food chain, and economic impacts. This chapter discusses the use of toxicity...

  10. Interspecies somatic cell nucleus transfer with porcine oocytes as recipients: A novel bioassay system for assessing the competence of canine somatic cells to develop into embryos.

    PubMed

    Sugimura, S; Narita, K; Yamashiro, H; Sugawara, A; Shoji, T; Terashita, Y; Nishimori, K; Konno, T; Yoshida, M; Sato, E

    2009-09-01

    Interspecies somatic cell nucleus transfer (iSCNT) could be a useful bioassay system for assessing the ability of mammalian somatic cells to develop into embryos. To examine this possibility, we performed canine iSCNT using porcine oocytes, allowed to mature in vitro, as recipients. Canine fibroblasts from the tail tips and dewclaws of a female poodle (Fp) and a male poodle (Mp) were used as donors. We demonstrated that the use of porcine oocytes induced blastocyst formation in the iSCNT embryos cultured in porcine zygote medium-3. In Fp and Mp, the rate of blastocyst formation from cleaved embryos (Fp: 6.3% vs. 22.4%; and Mp: 26.1% vs. 52.4%) and the number of cells at the blastocyst stage (Fp: 30.7 vs. 60.0; and Mp: 27.2 vs. 40.1) were higher in the embryos derived from dewclaw cells than in those derived from tail-tip cells (P<0.05). The use of donor cells of any type in later passages decreased the rate of blastocyst formation. Treatment with trichostatin-A did not improve the rate of blastocyst formation from cleaved dewclaw cell-derived embryos but did so in the embryos derived from the tail-tip cells of Fp. Only blastocysts derived from dewclaw cells of Mp developed outgrowths. However, outgrowth formation was retrieved in the embryos derived from dewclaw cells of Fp by aggregation at the 4-cell stage. We inferred that iSCNT performed using porcine oocytes as recipients could represent a novel bioassay system for evaluating the developmental competence of canine somatic cells.

  11. Assessing the potential toxicity of resuspended sediment

    SciTech Connect

    Bonnet, C.; Babut, M.; Ferard, J.F.; Martel, L.; Garric, J.

    2000-05-01

    Two moderately contaminated freshwater sediments (Sorel Harbour, St. Lawrence River, Canada) were subjected to a suspension event. The objective was to assess the environmental impact of the disposal of dredged material in water, in particular, the short-term effects of dumping on the water column and the long-term effects of dredged sediment deposits. In a series of microcosms, the sediments were left to stand for 25 d under flow-through conditions. In a second series of microcosms, sediments were vigorously suspended for 15 min before being left to settle and were submitted to the same treatment as reference sediments during the following 25 d. Physicochemical and biological parameters (Daphnia magna and Hydra attenuata survival) were measured in overlying water throughout the experiment. Sediment toxicity was assessed with Chironomus tentans and Hyalella azteca exposed to sediments collected at both the beginning and end of the 25-d period. Pore-water toxicity was evaluated with D. magna. During the suspension process, in the Sorel Harbour mixed sediment overlying water, the authors observed effects on H. attenuata survival and ammonia and metals (chromium, copper, and zinc) releases. Meanwhile, in reference (nonmixed) and mixed sediments as well as in associated pore waters, there were no significant chemical modifications no biological effects after the 25-d experiments. The developed approach, which attempts to simulate a dumping process, aims at allowing the assessment of the short- and long-term hazards resulting from a resuspension process in overlying water and in resettled sediments using both chemical and biological measurements.

  12. Toxic ratio as an indicator of the intrinsic toxicity in the assessment of persistent, bioaccumulative, and toxic chemicals.

    PubMed

    Maeder, Valérie; Escher, Beate I; Scheringer, Martin; Hungerbühler, Konrad

    2004-07-01

    Persistence, bioconcentration, and toxicity (PBT) are important hazardous properties of organic chemicals. In PBT assessments, it is desirable that the three criteria P, B, and T are independent. However, this requirement is not fulfilled if an aqueous lethal concentration (LC50) is used as T indicator because LC50 includes both bioconcentration and intrinsic toxicity. Indicators for intrinsic toxicity such asthe internal lethal concentration (ILC) are independent of a chemical's bioconcentration potential. However, ILC50 data are scarce and difficult to measure. Therefore, the toxic ratio (TR) is proposed here as an alternative. TR is defined as the ratio of a chemical's LC50 estimated from a QSAR for baseline toxicity and the experimental LC50 value. TR can also be interpreted as a measure of the ILC relative to the ILC for baseline toxicity. A TR of 10 separates specifically toxic chemicals from baseline toxicants. With some 800 chemicals, the practicability of classifying chemicals in terms of TR is demonstrated. Employing TR as toxicity indicator leads to different T scores for 30% of the chemicals studied. The baseline toxicity of hydrophobic compounds with TR < 10 does not receive a high T score but is still indicated by a high B score. The toxicity of specifically toxic hydrophilic substances is given additional emphasis by high TR values. These classification changes require that the interpretation of the B and T dimensions in PBT assessments is redefined.

  13. Ecological risk assessment of contaminated soils through direct toxicity assessment.

    PubMed

    Fernández, María Dolores; Cagigal, Ekain; Vega, María Milagrosa; Urzelai, Arantzazu; Babín, Mar; Pro, Javier; Tarazona, José Vicente

    2005-10-01

    A microcosm (MS-3) with a multispecies soil system is introduced as an experimental tool for direct toxicity assessment of contaminated soils. The capacity of MS-3 to determine soil ecotoxicity potential was evaluated using samples from three sites contaminated with organic and/or inorganic compounds. Soils were toxic to soil-dwelling organisms (earthworm, plants, and microorganisms) and to aquatic organisms (algae and RTG-2 cell fish). As expected, responses varied substantially among different soils and organisms. The application of this evaluation system provided complementary information to the chemical characterization. For soils containing metals the toxic response was lower than predicted from total metal concentrations. For hydrocarbons, the toxicity response agreed with estimated values. The induction of EROD activity suggested the presence of dioxin-like compounds, which had not been addressed in the chemical characterization. The proposed multispecies system affords the measurement of 11 endpoints covering three soil and three aquatic taxonomic groups, reproduces soil conditions and gradients, and appears as an excellent complementary tool to chemical analysis for characterization of contaminated sites.

  14. In vitro assessments of nanomaterial toxicity.

    PubMed

    Jones, Clinton F; Grainger, David W

    2009-06-21

    Nanotechnology has grown from a scientific interest to a major industry with both commodity and specialty nanomaterial exposure to global populations and ecosystems. Sub-micron materials are currently used in a wide variety of consumer products and in clinical trials as drug delivery carriers and imaging agents. Due to the expected growth in this field and the increasing public exposure to nanomaterials, both from intentional administration and inadvertent contact, improved characterization and reliable toxicity screening tools are required for new and existing nanomaterials. This review discusses current methodologies used to assess nanomaterial physicochemical properties and their in vitro effects. Current methods lack the desired sensitivity, reliability, correlation and sophistication to provide more than limited, often equivocal, pieces of the overall nanomaterial performance parameter space, particularly in realistic physiological or environmental models containing cells, proteins and solutes. Therefore, improved physicochemical nanomaterial assays are needed to provide accurate exposure risk assessments and genuine predictions of in vivo behavior and therapeutic value. Simpler model nanomaterial systems in buffer do not accurately duplicate this complexity or predict in vivo behavior. A diverse portfolio of complementary material characterization tools and bioassays are required to validate nanomaterial properties in physiology.

  15. Lunar Airborne Dust Toxicity Hazard Assessments (Invited)

    NASA Astrophysics Data System (ADS)

    Cooper, B. L.; McKay, D. S.; Taylor, L. A.; Wallace, W. T.; James, J.; Riofrio, L.; Gonzalez, C. P.

    2009-12-01

    The Lunar Airborne Dust Toxicity Assessment Group (LADTAG) is developing data to set the permissible limits for human exposure to lunar dust. This standard will guide the design of airlocks and ports for EVA, as well as the requirements for filtering and monitoring the atmosphere in habitable vehicles, rovers and other modules. LADTAG’s recommendation for permissible exposure limits will be delivered to the Constellation Program in late 2010. The current worst-case exposure limit of 0.05 mg/m3, estimated by LADTAG in 2006, reflects the concern that lunar dust may be as toxic as quartz dust. Freshly-ground quartz is known to be more toxic than un-ground quartz dust. Our research has shown that the surfaces of lunar soil grains can be more readily activated by grinding than quartz. Activation was measured by the amount of free radicals generated—activated simulants generate Reactive Oxygen Species (ROS) i.e., production of hydroxyl free radicals. Of the various influences in the lunar environment, micrometeorite bombardment probably creates the most long-lasting reactivity on the surfaces of grains, although solar wind impingement and short-wavelength UV radiation also contribute. The comminution process creates fractured surfaces with unsatisfied bonds. When these grains are inhaled and carried into the lungs, they will react with lung surfactant and cells, potentially causing tissue damage and disease. Tests on lunar simulants have shown that dissolution and leaching of metals can occur when the grains are exposed to water—the primary component of lung fluid. However, simulants may behave differently than actual lunar soils. Rodent toxicity testing will be done using the respirable fraction of actual lunar soils (particles with physical size of less than 2.5 micrometers). We are currently separating the fine material from the coarser material that comprises >95% of the mass of each soil sample. Dry sieving is not practical in this size range, so a new system

  16. NATIONAL-SCALE ASSESSMENT OF AIR TOXICS RISKS ...

    EPA Pesticide Factsheets

    The national-scale assessment of air toxics risks is a modeling assessment which combines emission inventory development, atmospheric fate and transport modeling, exposure modeling, and risk assessment to characterize the risk associated with inhaling air toxics from outdoor sources. This national-scale effort will be initiated for the base year 1996 and repeated every three years thereafter to track trends and inform program development. Provide broad-scale understanding of inhalation risks for a subset of atmospherically-emitted air toxics to inform further data-gathering efforts and priority-setting for the EPA's Air Toxics Programs.

  17. Human Health Toxicity Values in Superfund Risk Assessments

    EPA Pesticide Factsheets

    This memorandum revises the hierarchy of human health toxicity values generally recommended for use inr isk assessments, originally presented in Risk Assessment Guidance for Superfund Volume I, Part A.

  18. Toxic congener-specific analysis of PCBs: assessment of toxicity in equivalents of TCDD

    SciTech Connect

    Olafsson, P.G.; Bryan, A.M.

    1987-01-01

    High resolution capillary gas chromatographic analysis of the polychlorobiphenyls (PCBs) present in snapping turtle eggs, provided quantitative data on selected toxic congeners. The concentrations of these congeners have been converted into equivalent toxic concentrations of 2,3,7,8-tetrachloro-p-dibenzodioxin (TCDD). The toxic equivalent factors (TEFs), necessary to effect this transformation were derived from EC/sub 50/ values (half the concentration of the toxic congener required to produce the maximum effect) for aryl hydrocarbon hydroxylase (AHH) induction associated with the corresponding toxic PCB congener or isomer. Summation of the resulting toxic equivalents provided a composite assessment of the toxicity of the PCB mixture in terms of an equivalent concentration of TCDD.

  19. Using Toxicity Tests in Ecological Risk Assessment

    EPA Pesticide Factsheets

    Toxicity tests are used to expose test organisms to a medium-water, sediment, or soil-and evaluate the effects of contamination on the survival, growth, reproduction, behavior and or other attributes of these organisms.

  20. THERMOREGULATION AND ITS INFLUENCE ON TOXICITY ASSESSMENT

    SciTech Connect

    Gordon, Christopher J.; Spencer, Pamela J.; Hotchkiss, Jon; Miller, Diane B.; Hinderliter, Paul M.; Pauluhn, Jeurgen

    2008-02-28

    The thermoregulatory system of laboratory rodents is susceptible to a variety of chemical toxicants. Because temperature directly affects the reaction of virtually all biological processes, it is critical to consider how changes in the thermoregulatory response to a toxicant may affect physiological, behavioral, and pathological endpoints. Researchers in industry and government laboratories are often faced with addressing how changes in body temperature of their experimental subjects may affect the outcome of a particular toxicity test and/or screening panel. However, many toxicologists are either unaware of the importance or ignore the potential impact of a toxic-induced change in body temperature. This paper endeavors to summarize the importance of thermoregulation in the study of toxicology and propose recommendations for thermometry that researchers may utilize in their toxicological studies.

  1. Pesticide Toxicity Index: a tool for assessing potential toxicity of pesticide mixtures to freshwater aquatic organisms

    USGS Publications Warehouse

    Nowell, Lisa H.; Norman, Julia E.; Moran, Patrick W.; Martin, Jeffrey D.; Stone, Wesley W.

    2014-01-01

    Pesticide mixtures are common in streams with agricultural or urban influence in the watershed. The Pesticide Toxicity Index (PTI) is a screening tool to assess potential aquatic toxicity of complex pesticide mixtures by combining measures of pesticide exposure and acute toxicity in an additive toxic-unit model. The PTI is determined separately for fish, cladocerans, and benthic invertebrates. This study expands the number of pesticides and degradates included in previous editions of the PTI from 124 to 492 pesticides and degradates, and includes two types of PTI for use in different applications, depending on study objectives. The Median-PTI was calculated from median toxicity values for individual pesticides, so is robust to outliers and is appropriate for comparing relative potential toxicity among samples, sites, or pesticides. The Sensitive-PTI uses the 5th percentile of available toxicity values, so is a more sensitive screening-level indicator of potential toxicity. PTI predictions of toxicity in environmental samples were tested using data aggregated from published field studies that measured pesticide concentrations and toxicity to Ceriodaphnia dubia in ambient stream water. C. dubia survival was reduced to ≤ 50% of controls in 44% of samples with Median-PTI values of 0.1–1, and to 0% in 96% of samples with Median-PTI values > 1. The PTI is a relative, but quantitative, indicator of potential toxicity that can be used to evaluate relationships between pesticide exposure and biological condition.

  2. Assessing the toxic effects of ethylene glycol ethers using Quantitative Structure Toxicity Relationship models

    SciTech Connect

    Ruiz, Patricia; Mumtaz, Moiz; Gombar, Vijay

    2011-07-15

    Experimental determination of toxicity profiles consumes a great deal of time, money, and other resources. Consequently, businesses, societies, and regulators strive for reliable alternatives such as Quantitative Structure Toxicity Relationship (QSTR) models to fill gaps in toxicity profiles of compounds of concern to human health. The use of glycol ethers and their health effects have recently attracted the attention of international organizations such as the World Health Organization (WHO). The board members of Concise International Chemical Assessment Documents (CICAD) recently identified inadequate testing as well as gaps in toxicity profiles of ethylene glycol mono-n-alkyl ethers (EGEs). The CICAD board requested the ATSDR Computational Toxicology and Methods Development Laboratory to conduct QSTR assessments of certain specific toxicity endpoints for these chemicals. In order to evaluate the potential health effects of EGEs, CICAD proposed a critical QSTR analysis of the mutagenicity, carcinogenicity, and developmental effects of EGEs and other selected chemicals. We report here results of the application of QSTRs to assess rodent carcinogenicity, mutagenicity, and developmental toxicity of four EGEs: 2-methoxyethanol, 2-ethoxyethanol, 2-propoxyethanol, and 2-butoxyethanol and their metabolites. Neither mutagenicity nor carcinogenicity is indicated for the parent compounds, but these compounds are predicted to be developmental toxicants. The predicted toxicity effects were subjected to reverse QSTR (rQSTR) analysis to identify structural attributes that may be the main drivers of the developmental toxicity potential of these compounds.

  3. Situational smoke toxicity testing: hazard assessment as the 'front end' of a smoke toxicity test.

    PubMed

    Clarke, F B; Hoover, J R

    1996-12-31

    Traditionally, the toxic potency of the smoke from a material or product is part of the assessment of the fire hazard in a given scenario. The assessment also requires a knowledge of virtually all the details of the fire environment and, until they are identified, a 'safe' or 'acceptable' level of smoke toxicity is a term without meaning. This paper suggests a method of using the knowledge of these factors to simplify smoke toxicity testing. Faster, cheaper, and better-targeted smoke toxicity tests would result if the rest of the hazard assessment were carried out first. This is accomplished by determining or specifying all the relevant fire properties except the toxic potency, identifying the other environmental conditions (such as those typical of an aircraft cabin interior) and the desired tenability limits (such as the minimum necessary escape time), and then solving the equations for the buildup of toxic conditions in terms of the single remaining unknown, the toxic potency. The result is the greatest toxic potency which would meet the requirements of the analysis. In this approach, a material or product is acceptable if its smoke is no more toxic then the computed result and unacceptable if it is not. It would not be necessary to obtain an EC50 (product concentration which will cause an effect in half the animals) or dose-response profile, only the response at whatever dose is dictated by the analysis. Two sample cases are presented to illustrate the technique.

  4. Acinetobacter bioreporter assessing heavy metals toxicity.

    PubMed

    Abd-El-Haleem, Desouky; Zaki, Sahar; Abulhamd, Ashraf; Elbery, Hassan; Abu-Elreesh, Gadallah

    2006-01-01

    This work was conducted to employ a whole cell-based biosensor to monitor toxicity of heavy metals in water and wastewater. An isolate of industrial wastewater bacterium, Acinetobacter sp. DF4, was genetically modified with lux reporter gene to create a novel bioluminescent bacterial strain, designated as DF4/PUTK2. This bioreporter can investigate the toxicity through light inhibition due to cell death or metabolic burden and the specific stress effects of the tested soluble materials simultaneously. The use of Acinetobacter DF4/PUTK2 as a bioluminescent reporter for heavy metal toxicity testing and for the application of wastewater treatment influent toxicity screening is presented in this study. Among eight heavy metals tested, the bioluminescence of DF4/PUTK2 was most sensitive to Zn, Cd, Fe, Co, Cr followed by Cu in order of decreasing sensitivity. The same pattern of sensitivity was observed when several contaminated water and wastewater effluents were assayed. This work suggested that luxCDABE -marked Acinetobacter bacterium DF4/PUTK2 can be used to bioassay the ecotoxicity of wastewater and effluent samples contaminated with heavy metals. Using this assay, it is possible to pre-select the more toxic samples for further chemical analysis and to discard wastewater samples with low or no inhibition because they are not toxic to the environment.

  5. Toxicity of the pesticide alpha-cypermethrin to four soil nontarget invertebrates and implications for risk assessment.

    PubMed

    Hartnik, Thomas; Sverdrup, Line E; Jensen, John

    2008-06-01

    Alpha-cypermethrin, a synthetic pyrethroid, is used as an insecticide in agricultural settings and is increasingly replacing organophosphates and carbamates because of lower application rates and lower toxicity to mammals. Because very little is known about the acute and chronic toxicity of this compound for soil-living organisms, the present study investigated acute and sublethal toxicity of alpha-cypermethrin for four terrestrial invertebrate species in an agricultural soil from Norway. Bioassays with the earthworm Eisenia fetida, the potworm Enchytraeus crypticus, the springtail Folsomia candida, and the land snail Helix aspersa were performed according to slightly modified versions of Organization for Economic Cooperation and Development (Paris, France) or International Organization for Standardization (Geneva, Switzerland) guidelines and resulted in median lethal concentrations of greater than >1,000 to 31.4 mg/kg and sublethal no-observed-effect concentrations of 2.51 to 82 mg/kg. A high acute to chronic ratio was found, especially in the earthworms. Interspecies differences in sensitivity may be explained by differences in exposure and differences in metabolization rate. When based on measured pore-water concentrations, terrestrial species overall appear to be approximately one order of magnitude less sensitive than aquatic species. Effect assessments conducted according to European guideline for risk assessment of pesticides reveal that assessments based on acute toxicity tests are not always conservative enough to determine environmentally safe concentrations in soil. Mandatory incorporation of sublethal toxicity data will ensure that in regions with temperate climate, the effects of pesticides on populations of soil-living organisms are unlikely.

  6. Cellular Metabolomics for Exposure and Toxicity Assessment

    EPA Science Inventory

    We have developed NMR automation and cell quench methods for cell culture-based metabolomics to study chemical exposure and toxicity. Our flow automation method is robust and free of cross contamination. The direct cell quench method is rapid and effective. Cell culture-based met...

  7. Regional Models for Sediment Toxicity Assessment

    EPA Science Inventory

    This paper investigates the use of empirical models to predict the toxicity of sediment samples within a region to laboratory test organisms based on sediment chemistry. In earlier work, we used a large nationwide database of matching sediment chemistry and marine amphipod sedim...

  8. Assessment of Runoff Toxicity from Coated Surfaces

    EPA Science Inventory

    Presented in this paper are results from a field and laboratory study of the potential runoff toxicity from coated surfaces. The study results qualified and quantified the types and concentrations of pollutants in runoff from surfaces sealed with a variety of products. Coatings a...

  9. In Vitro Toxicity Assessment Technique for Volatile ...

    EPA Pesticide Factsheets

    The U.S. Environmental Protection Agency is tasked with evaluating the human health, environmental, and wildlife effects of over 80,000 chemicals registered for use in the environment and commerce. The challenge is that sparse chemical data exists; traditional toxicity testing methods are slow, costly, involve animal studies, and cannot keep up with a chemical registry that typically grows by at least 1000 chemicals every year. In recent years, High Throughput Screening (HTS) has been used in order to prioritize chemicals for traditional toxicity screening or to complement traditional toxicity studies. HTS is an in vitro approach of rapidly assaying a large number of chemicals for biochemical activity using robotics and automation. However, no method currently exists for screening volatile chemicals such as air pollutants in a HTS fashion. Additionally, significant uncertainty regarding in vitro to in in vivo extrapolation (IVIVE) remains. An approach to bridge the IVIVE gap and the current lack of ability to screen volatile chemicals in a HTS fashion is by using a probe molecule (PrM) technique. The proposed technique uses chemicals with empirical human pharmacokinetic data as PrMs to study toxicity of molecules with no known data for gas-phase analysis. We are currently studying the xenobiotic-metabolizing enzyme CYP2A6 using transfected BEAS-2B bronchial epithelial cell line. The CYP2A6 pathway activity is studied by the formation of cotinine from nicot

  10. Cellular Metabolomics for Exposure and Toxicity Assessment

    EPA Science Inventory

    We have developed NMR automation and cell quench methods for cell culture-based metabolomics to study chemical exposure and toxicity. Our flow automation method is robust and free of cross contamination. The direct cell quench method is rapid and effective. Cell culture-based met...

  11. Assessment of Runoff Toxicity from Coated Surfaces

    EPA Science Inventory

    Presented in this paper are results from a field and laboratory study of the potential runoff toxicity from coated surfaces. The study results qualified and quantified the types and concentrations of pollutants in runoff from surfaces sealed with a variety of products. Coatings a...

  12. Regional Models for Sediment Toxicity Assessment

    EPA Science Inventory

    This paper investigates the use of empirical models to predict the toxicity of sediment samples within a region to laboratory test organisms based on sediment chemistry. In earlier work, we used a large nationwide database of matching sediment chemistry and marine amphipod sedim...

  13. Assessing the potential toxicity of new pharmaceuticals.

    PubMed

    Johnson, D E; Wolfgang, G H

    2001-09-01

    Optimizing chemical structures to create potentially safe drugs during discovery and early development relies on a combination of predictive algorithms, screening, formal toxicology studies, and early clinical trials. Early in the process three critical questions emerge that must be answered by a detailed "profiling" approach. These questions are: 1) is there a correlation between the chemical structure and potential toxicity that can be used to optimize structures of lead compounds, 2) can specific markers of potential toxicity can be identified carly and used as mechanistic decision-making screens, and 3) will exposures (plasma levels) in animal studies correlate with exposures encountered in the clinic thereby providing "coverage" for safety? Depending on the therapeutic class of compounds being considered and the level of knowledge available, feedback loops of information can be established to guide the development process.

  14. Ecotoxicogenomic assessment of diclofenac toxicity in soil.

    PubMed

    Chen, Guangquan; den Braver, Michiel W; van Gestel, Cornelis A M; van Straalen, Nico M; Roelofs, Dick

    2015-04-01

    Diclofenac is widely used as nonsteroidal anti-inflammatory drug leaving residues in the environment. To investigate effects on terrestrial ecosystems, we measured dissipation rate in soil and investigated ecotoxicological and transcriptome-wide responses in Folsomia candida. Exposure for 4 weeks to diclofenac reduced both survival and reproduction of F. candida in a dose-dependent manner. At concentrations ≥ 200 mg/kg soil diclofenac remained stable in the soil during a 21-day incubation period. Microarrays examined transcriptional changes at low and high diclofenac exposure concentrations. The results indicated that development and growth were severely hampered and immunity-related genes, mainly directed against bacteria and fungi, were significantly up-regulated. Furthermore, neural metabolic processes were significantly affected only at the high concentration. We conclude that diclofenac is toxic to non-target soil invertebrates, although its mode of action is different from the mammalian toxicity. The genetic markers proposed in this study may be promising early markers for diclofenac ecotoxicity.

  15. Toxic real estate; Marketing site assessments

    SciTech Connect

    Bishop, J.

    1989-03-01

    This paper reports on site assessment services in support of real estate transactions which appear to be an answer to marketing managers' dreams. It is a service that sells itself. Although the consensus among assessment consultants is that lenders and property developers currently are only dimly aware and somewhat resentful of the need for site assessments, the potential market for these services, they say, seems nearly boundless.

  16. Validating potential toxicity assays to assess petroleum hydrocarbon toxicity in polar soil.

    PubMed

    Harvey, Alexis Nadine; Snape, Ian; Siciliano, Steven Douglas

    2012-02-01

    Potential microbial activities are commonly used to assess soil toxicity of petroleum hydrocarbons (PHC) and are assumed to be a surrogate for microbial activity within the soil ecosystem. However, this assumption needs to be evaluated for frozen soil, in which microbial activity is limited by liquid water (θ(liquid)). Influence of θ(liquid) on in situ toxicity was evaluated and compared to the toxicity endpoints of potential microbial activities using soil from an aged diesel fuel spill at Casey Station, East Antarctica. To determine in situ toxicity, gross mineralization and nitrification rates were determined by the stable isotope dilution technique. Petroleum hydrocarbon-contaminated soil (0-8,000 mg kg(-1)), packed at bulk densities of 1.4, 1.7, and 2.0 g cm(-3) to manipulate liquid water content, was incubated at -5°C for one, two, and three months. Although θ(liquid) did not have a significant effect on gross mineralization or nitrification, gross nitrification was sensitive to PHC contamination, with toxicity decreasing over time. In contrast, gross mineralization was not sensitive to PHC contamination. Toxic response of gross nitrification was comparable to potential nitrification activity (PNA) with similar EC25 (effective concentration causing a 25% effect in the test population) values determined by both measurement endpoints (400 mg kg(-1) for gross nitrification compared to 200 mg kg(-1) for PNA), indicating that potential microbial activity assays are good surrogates for in situ toxicity of PHC contamination in polar regions.

  17. Assessing BMP Performance Using Microtox Toxicity Analysis

    EPA Science Inventory

    Best Management Practices (BMPs) have been shown to be effective in reducing runoff and pollutants from urban areas and thus provide a mechanism to improve downstream water quality. Currently, BMP performance regarding water quality improvement is assessed through measuring each...

  18. Assessing BMP Performance Using Microtox Toxicity Analysis

    EPA Science Inventory

    Best Management Practices (BMPs) have been shown to be effective in reducing runoff and pollutants from urban areas and thus provide a mechanism to improve downstream water quality. Currently, BMP performance regarding water quality improvement is assessed through measuring each...

  19. The evolution of toxic effluents in fires and the assessment of toxic hazard.

    PubMed

    Purser, D A

    1992-12-01

    Toxic hazard in fire depends upon three factors: the fire growth curve (mass loss rate of materials, kg/min) and volume dispersal (kg/m3), the yields of toxic products (e.g. kg CO/kg fuel burned) and the toxic potency of the products (exposure dose needed to cause toxic effects, e.g. lethal dose of CO in ppm.min). The first and second sets of data are obtainable from large-scale tests or small-scale tests and mathematical modelling, the third and some information on the second are derived from toxicity studies of combustion products in small-scale tests or of individual fire gases. Small-scale toxicity test data on materials expressed as lethal mass loss exposure doses (LCt50 g min m-3) can be used in Fractional Effective Dose (FED) hazard assessments, providing the decomposition conditions of the test reproduce those in the fire being examined; principally either non-flaming oxidative, early well-ventilated flaming, or vitiated post-flashover. Although bioassays are needed for a full toxicity assessment, it is now possible to predict the toxic potency of materials to some extent from analytical data alone. The suitability of the small-scale test decomposition conditions are determined in terms of non-flaming or flaming behaviour, temperature (or radiant flux), CO2/CO ratio and oxygen concentration. Existing small-scale test methods provide reasonable models for materials under non-flaming oxidative and early flaming conditions, although the data base for the latter is poor. Only the DIN 53436 method is able to model vitiated post-flashover decomposition conditions, but data for this condition are almost non-existent.

  20. Assessment of thiamethoxam toxicity to Chironomus riparius.

    PubMed

    Saraiva, Althiéris S; Sarmento, Renato A; Rodrigues, Andreia C M; Campos, Diana; Fedorova, Ganna; Žlábek, Vladimír; Gravato, Carlos; Pestana, João L T; Soares, Amadeu M V M

    2017-03-01

    The insecticide thiamethoxam (TMX) is a systemic neonicotinoid widely used for pest control in several agricultural crops. TMX mimics the action of acetylcholine causing uncontrolled muscular contraction eventually leading to insect death. TMX is being found in freshwater ecosystems at concentrations of up to 225µg/L. Still, chronic toxicity data for freshwater invertebrates is limited. Therefore, the aim of this study was to evaluate the acute and chronic effects (at organismal and biochemical levels) of TMX on the freshwater insect Chironomus riparius. C. riparius life history responses were significantly affected by TMX exposure, namely with a decrease in growth and delay in emergence. Concerning the biochemical responses, after a short exposure (48h) to TMX, our results showed that low concentrations of TMX significantly reduced CAT activity and LPO levels of C. riparius. No effects were observed in AChE, GST and ETS activities. Effects in terms of survival, development rates and biochemical responses of C. riparius exposed to low concentrations of TMX observed in this study suggest potential deleterious effects of this neonicotinoid on aquatic insects inhabiting freshwaters environments near agricultural areas. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Development of interspecies cloned embryos in yak and dog.

    PubMed

    Murakami, Masao; Otoi, Takeshige; Wongsrikeao, Pimprapar; Agung, Budiyanto; Sambuu, Rentsenkhand; Suzuki, Tatsuyuki

    2005-01-01

    Interspecies nuclear transfer (NT) could be an alternative to replicate animals when supply of recipient oocytes is limited or in vitro embryo production systems are incomplete. In the present study, embryonic development was assessed following interspecies NT of donor cumulus cells derived from yak and dog into the recipient ooplasm of domestic cow. The percentages of fusion and subsequent embryo development to the eight-cell stage of interspecies NT embryos were comparable to those of intraspecies NT embryos (cow-cow NT embryos). The percentage of development to blastocysts was significantly lower (p < 0.05) in yak-cow NT embryos than that in cow-cow NT embryos (10.9% vs. 39.8%). In dog-cow NT embryos, only one embryo (0.4%) developed to the blastocyst stage. These results indicate that interspecies NT embryos possess equally developmental competence to the eight-cell stage as intraspecies NT embryos, but the development to blastocysts is very low when dog somatic cells are used as the donor nuclei.

  2. Assessment of developmental toxicity: neuropsychological batteries.

    PubMed

    Bernstein, J H

    1994-06-01

    Assessment of change in behavioral functioning in children as a function of neurotoxicity is not a trivial undertaking. Psychological tests, widely (though erroneously) considered to be the "gold standard" for measurement of behavior in humans, are not adequate for the task; they tap the structure of cognition, not the behavioral repertoire, and cannot (alone) address developmental change. Comprehensive neurobehavioral assessment must be undertaken within a multidisciplinary assessment strategy incorporating knowledge of brain and brain development, cognitive processes and their development, brain-behavior relationships, and detailed knowledge of neurotoxicants, their action and the exposure thereto. Initial assessment batteries must be adequately broad ranging and must incorporate strategies and data for evaluating the impact of predictable nonbrain variables; they must also be cost efficient to respond to the realities of funding and the exigencies of field testing. Measures of neuropsychological outcome are optimally characterized as they relate to behavioral domains specified in terms of the competencies of infants and children of different ages; relevant information is derived from demographic, socioeconomic, medical, developmental, and educational sources, as well as from detailed observational data and performance on psychological tests. Two levels of assessment are proposed.

  3. Toxicity assessment of contaminated soils from an antitank firing range.

    PubMed

    Robidoux, Pierre Yves; Gong, Ping; Sarrazin, Manon; Bardai, Ghalib; Paquet, Louise; Hawari, Jalal; Dubois, Charles; Sunahara, Geoffrey I

    2004-07-01

    Explosives are released into the environment at production and processing facilities, as well as through field use. These compounds may be toxic at relatively low concentrations to a number of ecological receptors. A toxicity assessment was carried out on soils from an explosive-contaminated site at a Canadian Forces Area Training Center. Toxicity studies on soil organisms using endpoints such as microbial processes (potential nitrification activity, dehydrogenase activity, substrate-induced respiration, basal respiration), plant seedling and growth (Lactuca sativa and Hordeum vulgare), and earthworm (Eisenia andrei) growth and reproduction were carried out. Results showed that 1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane (HMX) was the principal polynitro-organic compound measured in soils. Soils from the contaminated site decreased microbial processes and earthworm reproduction; whereas plant growth was not significantly reduced. Toxicity to aquatic organisms and genotoxicity were also assessed on soil elutriates using Microtox (Vibrio fischeri), growth inhibition of algae (Selenastrum capricornutum), and SOS Chromotest (Escherichia coli). Results indicated that soil elutriates were generally not toxic to bacteria (Microtox) and algae. However, genotoxicity was found in a number of soil elutriate samples. Thus, the explosive-contaminated soils from the antitank firing range may represent a hazard for the soil organisms. Nevertheless, the global toxicity might have partially resulted from HMX as well as from other (not identified) contaminants such as heavy metals.

  4. Integrated fate and toxicity assessment for site contaminants

    SciTech Connect

    MacDonell, Margaret; Peterson, John; Finster, Molly; Douglas, R.

    2007-07-01

    Understanding the fate and toxicity of environmental contaminants is essential to framing practical management decisions. Forms and bioavailable concentrations often change over time due to natural physical, chemical, and biological processes. For some sites, hundreds of contaminants may be of initial interest, and even small projects can involve a substantial number of contaminants. With multiple assessments common, attention to effectiveness and efficiency is important, and integrating fate and toxicity information provides a valuable way to focus the analyses. Fate assessments help identify what forms may be present where and when, while toxicity information indicates what health effects could result if people were exposed. The integration process is illustrated by an application for the Hanford site, to support long-term management decisions for the cesium and strontium capsules. Fate data, health-based benchmarks, and related toxicity information were effectively combined to indicate performance targets for chemicals and radionuclides identified for capsule leachate that could migrate to groundwater. More than 50 relevant benchmarks and toxicity context were identified for 15 of the 17 study contaminants; values for chronic drinking water exposure provided the common basis for selected indicators. For two chemicals, toxicity information was identified from the scientific literature to guide the performance targets. (authors)

  5. Assessing Reproductive Toxicity of Two Environmental Toxicants with a Novel in vitro Human Spermatogenic Model

    PubMed Central

    Easley, Charles A.; Bradner, Joshua M.; Moser, Amber; Rickman, Chelsea A.; McEachin, Zachary T.; Merritt, Megan M.; Hansen, Jason M.; Caudle, W. Michael

    2015-01-01

    Environmental influences and insults by reproductive toxicant exposure can lead to impaired spermatogenesis or infertility. Understanding how toxicants disrupt spermatogenesis is critical for determining how environmental factors contribute to impaired fertility. While current animal models are available, understanding of the reproductive toxic effects on human fertility requires a more robust model system. We recently demonstrated that human pluripotent stem cells can differentiate into spermatogonial stem cells/spermatogonia, primary and secondary spermatocytes, and haploid spermatids; a model that mimics many aspects of human spermatogenesis. Here, using this model system, we examine the effects of 2-bromopropane (2-BP) and 1–2, Dibromo-3-chloropropane (DBCP) on in vitro human spermatogenesis. 2-BP and DBCP are non-endocrine disrupting toxicants that are known to impact male fertility. We show that acute treatment with either 2-BP or DBCP induces a reduction in germ cell viability through apoptosis. 2-BP and DBCP affect viability of different cell populations as 2-BP primarily reduces spermatocyte viability whereas DBCP exerts a much greater effect on spermatogonia. Acute treatment with 2-BP or DBCP also reduces the percentage of haploid spermatids. Both 2-BP and DBCP induce reactive oxygen species (ROS) formation leading to an oxidized cellular environment. Taken together, these results suggest that acute exposure with 2-BP or DBCP causes human germ cell death in vitro by inducing ROS formation. This system represents a unique platform for assessing human reproductive toxicity potential of various environmental toxicants in a rapid, efficient, and unbiased format. PMID:25863443

  6. Assessment of sediment contaminants and toxicity in the Delaware estuary

    SciTech Connect

    Costa, H.J.; Sauer, T.C.; Ward, T.J.; Boeri, R.L.; Nyman, R.M.

    1994-12-31

    In support of the Delaware Estuary Program`s Comprehensive Conservation and Management Plan, a study was performed to assess the spatial distribution of sediment toxicity in the Delaware Estuary and investigate potential causative contaminants. Twelve stations were sampled along the Delaware River covering 55 river miles between the Chesapeake and Delaware Canal and Torresdale, PA. Four additional stations were sampled in the mid-bay portion of Delaware Bay. Ten-day sediment static acute toxicity tests with amphipods (Ampelisca abdita) were performed for all stations. Sediments were analyzed for polynuclear aromatic hydrocarbons (PAHs), polychlorinated biphenyls, chlorinated pesticides, priority pollutant metals, and supporting parameters. Statistical analyses revealed positive correlations between sediment toxicity and PAH, lead, copper, and mercury concentrations. The highest incidences of sediment toxicity and highest concentrations of chemical contaminants occurred in the portion of the Delaware River between River Miles 60 and 75.

  7. [Perspective of predictive toxicity assessment of in vivo repeated dose toxicity using structural activity relationship].

    PubMed

    Ono, Atsushi

    2010-01-01

    Tens of thousands of existing chemicals have been widely used for manufacture, agriculture, household and other purposes in worldwide. Only approximately 10% of chemicals have been assessed for human health hazard. The health hazard assessment of residual large number of chemicals for which little or no information of their toxicity is available is urgently needed for public health. However, the conduct of traditional toxicity tests which involves using animals for all of these chemicals would be economically impractical and ethically unacceptable. (Quantitative) Structure-Activity Relationships [(Q)SARs] are expected as method to have the potential to estimate hazards of chemicals from their structure, while reducing time, cost and animal testing currently needed. Therefore, our studies have been focused on evaluation of available (Q)SAR systems for estimating in vivo repeated toxicity on the liver. The results from our preliminary analysis showed the distribution for LogP of the chemicals which have potential to induce liver toxicity was bell-shape and indicating the possibility to estimate liver toxicity of chemicals from their physicochemical property. We have developed (Q)SAR models to in vivo liver toxicity using three commercially available systems (DEREK, ADMEWorks and MultiCASE) as well as combinatorial use of publically available chemoinformatic tools (CDK, MOSS and WEKA). Distinct data-sets of the 28-day repeated dose toxicity test of new and existing chemicals evaluated in Japan were used for model development and performance test. The results that concordances of commercial systems and public tools were almost same which below 70% may suggest currently attainable knowledge of in silico estimation of complex biological process, though it possible to obtain complementary and enhanced performance by combining predictions from different programs. In future, the combinatorial application of in silico and in vitro tests might provide more accurate

  8. [The assessment of toxic liver injury].

    PubMed

    Kim, Dong Joon

    2009-01-01

    Liver injury due to prescription and nonprescription medications is a growing medical, scientific and public health problem. Drug-induced liver injury (DILI) is the single most common reason for regulatory actions, including failure of approval, removal from the marketplace and restriction of prescription. Worldwide, the estimated annual incidence rate of DILI is 13.9-24.0 per 100,000 inhabitants. At the same time, there is increasing concern about the potential risk for hepatotoxicity from complementary and alternative medicines (CAM) including herbal products because they are unregulated and not standardized with regard to their contents. Determining hepatotoxicity remains a major challenge in clinical practice due to a lack of reliable markers. The RUCAM/CIOMS scale have been proposed to establish a causal relationship between offending drug and liver injury. The efforts of Drug-Induced Liver Injury Network (DILIN, USA) directed toward the development of an abridged instrument in evaluating suspected drug-induced hepatotoxicity were presented at the National Institute of Health (NIH) Workshop, titled Drug-induced liver injury: Standardization of nomenclature and causality assessment, December, 2008. The main contents of the presentations and discussions at the NIH workshop are introduced in this article. This fine-tuned operations of RUCAM/CIOMS scale would enable a more confident assessment of causality and facilitate the collection of bona fide cases of drug-induced hepatotoxicity in Korea. Several demanding tasks for the near future in Korea are also proposed at the end.

  9. Toxicological Considerations, Toxicity Assessment, and Risk Management of Inhaled Nanoparticles.

    PubMed

    Bakand, Shahnaz; Hayes, Amanda

    2016-06-14

    Novel engineered nanoparticles (NPs), nanomaterial (NM) products and composites, are continually emerging worldwide. Many potential benefits are expected from their commercial applications; however, these benefits should always be balanced against risks. Potential toxic effects of NM exposure have been highlighted, but, as there is a lack of understanding about potential interactions of nanomaterials (NMs) with biological systems, these side effects are often ignored. NPs are able to translocate to the bloodstream, cross body membrane barriers effectively, and affect organs and tissues at cellular and molecular levels. NPs may pass the blood-brain barrier (BBB) and gain access to the brain. The interactions of NPs with biological milieu and resulted toxic effects are significantly associated with their small size distribution, large surface area to mass ratio (SA/MR), and surface characteristics. NMs are able to cross tissue and cell membranes, enter into cellular compartments, and cause cellular injury as well as toxicity. The extremely large SA/MR of NPs is also available to undergo reactions. An increased surface area of the identical chemical will increase surface reactivity, adsorption properties, and potential toxicity. This review explores biological pathways of NPs, their toxic potential, and underlying mechanisms responsible for such toxic effects. The necessity of toxicological risk assessment to human health should be emphasised as an integral part of NM design and manufacture.

  10. Toxicological Considerations, Toxicity Assessment, and Risk Management of Inhaled Nanoparticles

    PubMed Central

    Bakand, Shahnaz; Hayes, Amanda

    2016-01-01

    Novel engineered nanoparticles (NPs), nanomaterial (NM) products and composites, are continually emerging worldwide. Many potential benefits are expected from their commercial applications; however, these benefits should always be balanced against risks. Potential toxic effects of NM exposure have been highlighted, but, as there is a lack of understanding about potential interactions of nanomaterials (NMs) with biological systems, these side effects are often ignored. NPs are able to translocate to the bloodstream, cross body membrane barriers effectively, and affect organs and tissues at cellular and molecular levels. NPs may pass the blood–brain barrier (BBB) and gain access to the brain. The interactions of NPs with biological milieu and resulted toxic effects are significantly associated with their small size distribution, large surface area to mass ratio (SA/MR), and surface characteristics. NMs are able to cross tissue and cell membranes, enter into cellular compartments, and cause cellular injury as well as toxicity. The extremely large SA/MR of NPs is also available to undergo reactions. An increased surface area of the identical chemical will increase surface reactivity, adsorption properties, and potential toxicity. This review explores biological pathways of NPs, their toxic potential, and underlying mechanisms responsible for such toxic effects. The necessity of toxicological risk assessment to human health should be emphasised as an integral part of NM design and manufacture. PMID:27314324

  11. Essentiality, Toxicity and Uncertainty in the Risk Assessment of Manganese

    EPA Science Inventory

    Risk assessments of manganese by inhalation or oral routes of exposure typically acknowledge the duality of manganese as an essential element at low doses and a toxic metal at high doses. Previously, however, risk assessors were unable to describe manganese pharmacokinetics quant...

  12. PROSPECTIVE PREGNANCY STUDY DESIGNS FOR ASSESSING REPRODUCTIVE AND DEVELOPMENTAL TOXICANTS

    EPA Science Inventory

    Prospective Pregnancy Study Designs for Assessing Reproductive and Developmental Toxicants
    Germaine M. Buck,1 Courtney D. Johnson,1 Joseph Stanford,2 Anne Sweeney,3 Laura Schieve,4 John Rockett,5 Sherry G. Selevan,6 Steve Schrader 7

    Abstract
    The origin of successfu...

  13. PROSPECTIVE PREGNANCY STUDY DESIGNS FOR ASSESSING REPRODUCTIVE AND DEVELOPMENTAL TOXICANTS

    EPA Science Inventory

    Prospective Pregnancy Study Designs for Assessing Reproductive and Developmental Toxicants
    Germaine M. Buck,1 Courtney D. Johnson,1 Joseph Stanford,2 Anne Sweeney,3 Laura Schieve,4 John Rockett,5 Sherry G. Selevan,6 Steve Schrader 7

    Abstract
    The origin of successfu...

  14. Essentiality, Toxicity and Uncertainty in the Risk Assessment of Manganese

    EPA Science Inventory

    Risk assessments of manganese by inhalation or oral routes of exposure typically acknowledge the duality of manganese as an essential element at low doses and a toxic metal at high doses. Previously, however, risk assessors were unable to describe manganese pharmacokinetics quant...

  15. HPLC/MS analysis of toxic norditerpenoid alkaloids: Refinement of toxicity assessment of low larkspurs (Delphinium spp.)

    USDA-ARS?s Scientific Manuscript database

    The low larkspurs (Delphinium nuttallianum and D. andersonii) are two toxic plant species that are often fatally ingested by cattle on western U.S. rangelands. To assess the potential toxicity of the plants, methods are needed to identify and quantify the toxic N-methylsuccinimidoanthranoyllycacont...

  16. Assessing reproductive toxicity of two environmental toxicants with a novel in vitro human spermatogenic model.

    PubMed

    Easley, Charles A; Bradner, Joshua M; Moser, Amber; Rickman, Chelsea A; McEachin, Zachary T; Merritt, Megan M; Hansen, Jason M; Caudle, W Michael

    2015-05-01

    Environmental influences and insults by reproductive toxicant exposure can lead to impaired spermatogenesis or infertility. Understanding how toxicants disrupt spermatogenesis is critical for determining how environmental factors contribute to impaired fertility. While current animal models are available, understanding of the reproductive toxic effects on human fertility requires a more robust model system. We recently demonstrated that human pluripotent stem cells can differentiate into spermatogonial stem cells/spermatogonia, primary and secondary spermatocytes, and haploid spermatids; a model that mimics many aspects of human spermatogenesis. Here, using this model system, we examine the effects of 2-bromopropane (2-BP) and 1,2,dibromo-3-chloropropane (DBCP) on in vitro human spermatogenesis. 2-BP and DBCP are non-endocrine disrupting toxicants that are known to impact male fertility. We show that acute treatment with either 2-BP or DBCP induces a reduction in germ cell viability through apoptosis. 2-BP and DBCP affect viability of different cell populations as 2-BP primarily reduces spermatocyte viability, whereas DBCP exerts a much greater effect on spermatogonia. Acute treatment with 2-BP or DBCP also reduces the percentage of haploid spermatids. Both 2-BP and DBCP induce reactive oxygen species (ROS) formation leading to an oxidized cellular environment. Taken together, these results suggest that acute exposure with 2-BP or DBCP causes human germ cell death in vitro by inducing ROS formation. This system represents a unique platform for assessing human reproductive toxicity potential of various environmental toxicants in a rapid, efficient, and unbiased format. Copyright © 2015. Published by Elsevier B.V.

  17. Interspecies chimeras for human stem cell research.

    PubMed

    Masaki, Hideki; Nakauchi, Hiromitsu

    2017-07-15

    Interspecies chimeric assays are a valuable tool for investigating the potential of human stem and progenitor cells, as well as their differentiated progeny. This Spotlight article discusses the different factors that affect interspecies chimera generation, such as evolutionary distance, developmental timing, and apoptosis of the transplanted cells, and suggests some possible strategies to address them. A refined approach to generating interspecies chimeras could contribute not only to a better understanding of cellular potential, but also to understanding the nature of xenogeneic barriers and mechanisms of heterochronicity, to modeling human development, and to the creation of human transplantable organs. © 2017. Published by The Company of Biologists Ltd.

  18. Liquid versus solid phase bioassays for dredged material toxicity assessment.

    PubMed

    Casado-Martínez, M C; Fernández, N; Forja, J M; DelValls, T A

    2007-05-01

    Since 1994 the results of the analyses of key chemical compounds (trace metals, polychlorinated biphenyls and polycyclic aromatic hydrocarbons) and the comparison with the corresponding sediment quality guidelines (SQGs) are used in decision-making for dredged material management in Spain. Nonetheless in the last decades a tiered testing approach is promoted for assessing the physical and chemical characteristics of dredged sediments and their potential biological effects in the environment. Bioassays have been used for sediment toxicity assessment in Spain but few or no experiences are reported on harbour sediments. We studied the incidence of toxicity in the 7 d bioassay using rotifers (Brachionus plicatilis) and the 48 h bioassay using sea urchin (Paracentrotus lividus) embryos over a series of experiments employing 22 different elutriates. The relative performance of this exposure phase was not comparable to data on the 10-d acute toxicity test using the burrowing amphipod Corophium volutator and the polychaete Arenicola marina, carried out on the whole sediments. These results evidence the importance of the exposure route and the test selected in decision-making, as the toxicity registered for the undiluted elutriates was largely due to the different solubility of sediment-bound contaminants. This work and other studies indicate that for many sediments, a complete battery of test is recommended together with physico-chemical analyses to decide whether dredged sediments are suitable for open water disposal or not.

  19. Assessing variability in chemical acute toxicity of unionid mussels: Influence of intra- and interlaboratory testing, life stage, and species.

    PubMed

    Raimondo, Sandy; Lilavois, Crystal R; Lee, Larisa; Augspurger, Tom; Wang, Ning; Ingersoll, Chris G; Bauer, Candice; Hammer, Edward; Barron, Mace G

    2016-03-01

    The authors developed a toxicity database for unionid mussels to examine the extent of intra- and interlaboratory variability in acute toxicity tests with mussel larvae (glochidia) and juveniles; the extent of differential sensitivity of the 2 life stages; and the variation in sensitivity among commonly tested mussels (Lampsilis siliquoidea, Utterbackia imbecillis, and Villosa iris), commonly tested cladocerans (Daphnia magna and Ceriodaphnia dubia), and fish (Oncorhynchus mykiss, Pimephales promelas, and Lepomis macrochirus). The results of these analyses indicate that intralaboratory variability for median effect concentrations (EC50) averaged about 2-fold for both life stages, whereas interlaboratory variability averaged 3.6-fold for juvenile mussels and 6.3-fold for glochidia. The EC50s for juveniles and glochidia were within a factor of 2 of each other for 50% of paired records across chemicals, with juveniles more sensitive than glochidia by more than 2-fold for 33% of the comparisons made between life stages. There was a high concurrence of sensitivity of commonly tested L. siliquoidea, U. imbecillis, and V. iris to that of other mussels. However, this concurrence decreased as the taxonomic distance of the commonly tested cladocerans and fish to mussels increased. The compiled mussel database and determination of data variability will advance risk assessments by including more robust species sensitivity distributions, interspecies correlation estimates, and availability of taxon-specific empirically derived application factors for risk assessment. Published 2015 Wiley Periodicals Inc on behalf of SETAC. This article is a US Government work and, as such, is in the public domain in the United States of America.

  20. INTERSPECIES DOSIMETRY MODELS FOR PULMONARY PHARMACOLOGY

    EPA Science Inventory

    Interspecies Dosimetry Models for Pulmonary Pharmacology

    Ted B. Martonen, Jeffry D. Schroeter, and John S. Fleming

    Experimental Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangl...

  1. INTERSPECIES DOSIMETRY MODELS FOR PULMONARY PHARMACOLOGY

    EPA Science Inventory

    Interspecies Dosimetry Models for Pulmonary Pharmacology

    Ted B. Martonen, Jeffry D. Schroeter, and John S. Fleming

    Experimental Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangl...

  2. Biodegradability and toxicity assessment of bleach plant effluents treated anaerobically.

    PubMed

    Chaparro, T R; Botta, C M; Pires, E C

    2010-01-01

    As part of an experimental project on the treatment of bleach plant effluents the results of biodegradability and toxicity assessment of effluents from a bench-scale horizontal anaerobic immobilized bioreactor (HAIB) are discussed in this paper. The biodegradability of the bleach plant effluents from a Kraft pulp mill treated in the HAIB was evaluated using the modified Zahn-Wellens test. The inoculum came from a pulp mill wastewater treatment plant and the dissolved organic carbon (DOC) was used as the indicator of organic matter removal. The acute and chronic toxicity removal during the anaerobic treatment was estimated using Daphnia similis and Ceriodaphnia silvestrii respectively. Moreover, the evaluation of chromosome aberrations (CA), micronucleus frequencies (MN) and mitotic index (IM) in Allium cepa cells were used as genotoxicity indicators. The results indicate that the effluents from the anaerobic reactor are amenable to aerobic polishing. Acute and chronic toxicity were reduced by 90 and 81%, respectively. The largest CA and MN incidence in the meristematic cells of A. cepa were observed after exposure to the raw bleach plant effluent. The HAIB was able to reduce the acute and chronic toxicity as well as chromosome aberrations and the occurrence of micronucleus.

  3. Assessment of toxicity test endpoints for freshwater mussel larvae (glochidia).

    PubMed

    Fritts, Andrea K; Barnhart, M Christopher; Bradley, Megan; Liu, Na; Cope, W Gregory; Hammer, Edward; Bringolf, Robert B

    2014-01-01

    The objectives of the present study were to determine if the viability of freshwater mussel larvae (glochidia) is an ecologically relevant endpoint for toxicity tests and to define the appropriate duration of those tests. The authors assessed 1) how viability (the shell closure response to sodium chloride) compares with infectivity (ability to attach to a host fish and successfully metamorphose to the juvenile stage), and 2) the decline of viability and infectivity over time after glochidia were released from female mussels. Glochidia of 7 mussel species were isolated from females, placed in water, and subsampled daily for 2 d to 5 d. Viability, when ≥90%, was generally a good predictor of infectivity; however, when viability was <90%, infectivity was often disproportionately low, especially for glochidia collected near the end of the brooding period. Viability and infectivity declined more rapidly in natural water and sediment compared to reconstituted water. Following 24-h exposure to a toxicant (sodium chloride or copper), infectivity of the viable glochidia did not differ among concentrations of toxicants. The results indicate that viability is a valid proxy for infectivity and an ecologically relevant endpoint for standard toxicity tests with freshwater mussels for any test duration with control viability >90%.

  4. Safety assessment of essential and toxic metals in infant formulas.

    PubMed

    Sipahi, Hande; Eken, Ayşe; Aydın, Ahmet; Şahin, Gönül; Baydar, Terken

    2014-01-01

    The aim of this study was to assess toxic metal (Cd, Pb and Al) contamination and levels of three essential trace elements (Mn, Cr and Co) in 63 infant formulas. In addition, the levels of these metals in the study samples were compared with the acceptable limits of toxic heavy metals and the recommended daily allowances (RDAs) of essential trace elements. According to our results, the toxic metal levels measured in the formulas were within the acceptable limits, with the exception of Al levels in 8 of the 63 samples. In 16 samples, Mn levels exceeded 600 μg/day, and the Cr content in 7 samples was higher than 5.5 μg/day, these amounts being the adequate intake levels for infants. Cobalt levels in 10 formulas were higher than the RDA. In view of these findings, which indicate that metal levels in infant formulas are generally much higher than those found in breast milk, breast milk should be preferred for infant feeding. Moreover, since infants are potentially more susceptible to metals, infant foods should be monitored regularly and checked for contamination by toxic metals as well as for levels of essential trace elements.

  5. Cetuximab With Concurrent Chemoradiation for Esophagogastric Cancer: Assessment of Toxicity

    SciTech Connect

    Safran, Howard Suntharalingam, Mohan; Dipetrillo, Thomas; Ng, Thomas; Doyle, L. Austin; Krasna, Mark; Plette, Angela; Evans, Devon; Wanebo, Harold; Akerman, Paul; Spector, Jeremy; Kennedy, Nancy; Kennedy, Teresa

    2008-02-01

    Purpose: To determine the feasibility and toxicity of the addition of cetuximab with paclitaxel, carboplatin, and radiation for patients with esophagogastric cancer on a Phase II study. Methods and Materials: Patients with locoregional esophageal and proximal gastric cancer without distant organ metastases were eligible. All patients received cetuximab, paclitaxel, and carboplatin weekly for 6 weeks with 50.4 Gy radiation. Results: Sixty patients were enrolled, 57 with esophageal cancer and 3 with gastric cancer. Forty-eight had adenocarcinoma and 12 had squamous cell cancer. Fourteen of 60 patients (23%) had Grade 3 dermatologic toxicity consisting of a painful, pruritic acneiform rash on the face outside of the radiation field. The rates of Grades 3 and 4 esophagitis were 12% and 3%, respectively. Three patients had Grade 3/4 cetuximab hypersensitivity reactions and were not assessable for response. Forty of 57 patients (70%) had a complete clinical response after chemoradiation. Conclusion: Cetuximab can be safely administered with chemoradiation for esophageal cancer. Dermatologic toxicity and hypersensitivity reactions were associated with the addition of cetuximab. There was no increase in esophagitis or other radiation-enhanced toxicity.

  6. Aquatic acute toxicity assessments of molybdenum (+VI) to Daphnia magna.

    PubMed

    Wang, Chi-Wei; Liang, Chenju; Yeh, Hui-Ju

    2016-03-01

    Generally, molybdenum (Mo) metals in the environment are very rare, but wastewater discharges from industrial processes may contain high concentrations of Mo, which has the potential to contaminate water or soil if not handled properly. In this study, the impact of three common compounds of hexavalent Mo (sodium molybdate (Na2MoO4‧2H2O), ammonium molybdate ((NH4)6Mo7O24‧4H2O) and molybdenum trioxide (MoO3)) in an aquatic system were assessed based on 48-h exposure acute toxicity to Daphnia magna (D. magna). The LC50 toxicities for associated conjugate ions including Na(+), Cl(-), SO4(2-), and NH4(+) were determined. Furthermore, the LC50 values for the three forms of hexavalent Mo were determined, and the acute toxicities of the Mo forms were found to follow the order: (NH4)6Mo7O24‧4H2O > MoO3 > Na2MoO4‧2H2O in solution. (NH4)6Mo7O24‧4H2O exhibited the lowest LC50 of 43.3 mg L(-1) (corresponding to 23.5 mg Mo L(-1)) among the three molybdenum salts. The research confirmed that the toxicity of molybdenum in the aquatic system is highly dependent on the form of molybdenum salts used, and is also associated with the influence of the background water quality.

  7. Assessment of toxicity of nanoparticles using insects as biological models.

    PubMed

    Zhou, Yan; Rocha, Aracely; Sanchez, Carlos J; Liang, Hong

    2012-01-01

    Nanomaterials have become increasingly important in medicine, manufacturing, and consumer products. The fundamental understanding in effects of nanoparticles (NPs) on and their interactions with biomolecules and organismal systems have yet to be achieved. In this chapter, we firstly provide a brief review of the interactions between nanoparticles and biological systems. We will then provide an example by describing a novel method to assess the effects of NPs on biological systems, using insects as a model. Nanoparticles were injected into the central nervous system of the discoid cockroach (Blaberus discoidalis). It was found that insects became hyperactive compared to negative control (water injections). Our method could provide a generic method of assessing nanoparticles toxicity.

  8. Toxicity assessment of zero valent iron nanoparticles on Artemia salina.

    PubMed

    Kumar, Deepak; Roy, Rajdeep; Parashar, Abhinav; Raichur, Ashok M; Chandrasekaran, Natarajan; Mukherjee, Anita; Mukherjee, Amitava

    2017-05-01

    The present study deals with the toxicity assessment of two differently synthesized zero valent iron nanoparticles (nZVI, chemical and biological) as well as Fe(2+) ions on Artemia salina at three different initial concentrations of 1, 10, and 100 mg/L of these particles. The assessment was done till 96 h at time intervals of 24 h. EC50 value was calculated to evaluate the 50% mortality of Artemia salina at all exposure time durations. Between chemically and biologically synthesized nZVI nanoparticles, insignificant differences in the level of mortality were demonstrated. At even 24 h, Fe(2+) ion imparted complete lethality at the highest exposure concentration (100 mg/L). To understand intracellular oxidative stress because of zero valent iron nanoparticles, ROS estimation, SOD activity, GSH activity, and catalase activity was performed which demonstrated that ionic form of iron is quite lethal at high concentrations as compared with the same concentration of nZVI exposure. Lower concentrations of nZVI were more toxic as compared with the ionic form and was in order of CS-nZVI > BS-nZVI > Fe(2+) . Cell membrane damage and bio-uptake of nanoparticles were also evaluated for all three concentrations of BS-nZVI, CS-nZVI, and Fe(2+) using adult Artemia salina in marine water; both of which supported the observations made in toxicity assessment. This study can be further explored to exploit Artemia salina as a model organism and a biomarker in an nZVI prone aquatic system to detect toxic levels of these nanoparticles. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1617-1627, 2017. © 2017 Wiley Periodicals, Inc.

  9. Hardwiring microbes via direct interspecies electron transfer: mechanisms and applications.

    PubMed

    Cheng, Qiwen; Call, Douglas F

    2016-08-10

    Multicellular microbial communities are important catalysts in engineered systems designed to treat wastewater, remediate contaminated sediments, and produce energy from biomass. Understanding the interspecies interactions within them is therefore essential to design effective processes. The flow of electrons within these communities is especially important in the determination of reaction possibilities (thermodynamics) and rates (kinetics). Conventional models of electron transfer incorporate the diffusion of metabolites generated by one organism and consumed by a second, frequently referred to as mediated interspecies electron transfer (MIET). Evidence has emerged in the last decade that another method, called direct interspecies electron transfer (DIET), may occur between organisms or in conjunction with electrically conductive materials. Recent research has suggested that DIET can be stimulated in engineered systems to improve desired treatment goals and energy recovery in systems such as anaerobic digesters and microbial electrochemical technologies. In this review, we summarize the latest understanding of DIET mechanisms, the associated microorganisms, and the underlying thermodynamics. We also critically examine approaches to stimulate DIET in engineered systems and assess their effectiveness. We find that in most cases attempts to promote DIET in mixed culture systems do not yield the improvements expected based on defined culture studies. Uncertainties of other processes that may be co-occurring in real systems, such as contaminant sorption and biofilm promotion, need to be further investigated. We conclude by identifying areas of future research related to DIET and its application in biological treatment processes.

  10. Interspecies Correlation Estimation | US EPA

    EPA Pesticide Factsheets

    2016-02-22

    Web-ICE estimates acute toxicity (LC50/LD50) of a chemical to a species, genus, or family from the known toxicity of the chemical to a surrogate species. Web-ICE has modules to predict toxicity to aquatic and wildlife taxa and to generate Species Sensitivity Distributions (SSDs) from Web-ICE generated data. Page provides access to online calculators, documentation and data

  11. Assessing the toxicity of TBBPA and HBCD by zebrafish embryo toxicity assay and biomarker analysis.

    PubMed

    Hu, Jun; Liang, Yong; Chen, Minjie; Wang, Xiaorong

    2009-08-01

    Tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCD) are two of the most widely used brominated flame retardants (BFRs). The biological toxicity effect of TBBPA and HBCD was studied by means of zebrafish embryo toxicity assays in combination with three biomarkers, including superoxide dismutase (SOD), lipid peroxidation, (LPO), and heat shock protein (Hsp70). The standard zebrafish embryo assay showed that high concentrations of TBBPA (> or =0.75 mg/L) can cause lethality or malformation. For HBCD within the concentration range (0.002-10 mg/L), no endpoint was observed. Furthermore, SOD activities of zebrafish embryos exposed to TBBPA were increased with the increasing concentrations. SOD activities in the group treated by HBCD showed an increase followed by a decline. Regardless of TBBPA or HBCD, LPO were increased along with the increase of the concentration. The change pattern of Hsp70 levels was the same with LPO. All these results showed that TBBPA and HBCD could cause oxidative stress and Hsp70 overexpression, inducing acute toxicity to zebrafish embryo in a short-term exposure. The study also indicates that the zebrafish embryo assay in combination with the biomarkers is effective in aquatic environmental toxicology and risk assessment.

  12. Reactor modeling in heterogeneous photocatalysis: toxicity and biodegradability assessment.

    PubMed

    Satuf, M L; José, S; Paggi, J C; Brandi, R J; Cassano, A E; Alfano, O M

    2010-01-01

    Photocatalysis employing titanium dioxide is a useful method to degrade a wide variety of organic and inorganic pollutants from water and air. However, the application of this advanced oxidation process at industrial scale requires the development of mathematical models to design and scale-up photocatalytic reactors. In the present work, intrinsic kinetic expressions previously obtained in a laboratory reactor are employed to predict the performance of a bench scale reactor of different configuration and operating conditions. 4-Chlorophenol was chosen as the model pollutant. The toxicity and biodegradability of the irradiated mixture in the bench photoreactor was also assessed. Good agreement was found between simulation and experimental data. The root mean square error of the estimations was 9.9%. The photocatalytic process clearly enhances the biodegradability of the reacting mixture, and the initial toxicity of the pollutant was significantly reduced by the treatment.

  13. First report on development of quantitative interspecies structure-carcinogenicity relationship models and exploring discriminatory features for rodent carcinogenicity of diverse organic chemicals using OECD guidelines.

    PubMed

    Kar, Supratik; Roy, Kunal

    2012-04-01

    Different regulatory agencies in food and drug administration and environmental protection worldwide are employing quantitative structure-activity relationship (QSAR) models to fill the data gaps related with properties of chemicals affecting the environment and human health. Carcinogenicity is a toxicity endpoint of major concern in recent times. Interspecies toxicity correlations may provide a tool for estimating sensitivity towards toxic chemical exposure with known levels of uncertainty for a diversity of wildlife species. In this background, we have developed quantitative interspecies structure-carcinogenicity correlation models for rat and mouse [rodent species according to the Organization for Economic Cooperation and Development (OECD) guidelines] based on the carcinogenic potential of 166 organic chemicals with wide diversity of molecular structures, spanning a large number of chemical classes and biological mechanisms. All the developed models have been assessed according to the OECD principles for the validation of QSAR models. Consensus predictions for carcinogenicity of the individual compounds are presented here for any one species when the data for the other species are available. Informative illustrations of the contributing structural fragments of chemicals which are responsible for specific carcinogenicity endpoints are identified by the developed models. The models have also been used to predict mouse carcinogenicities of 247 organic chemicals (for which rat carcinogenicities are present) and rat carcinogenicities of 150 chemicals (for which mouse carcinogenicities are present). Discriminatory features for rat and mouse carcinogenicity values have also been explored.

  14. Developmental toxicity testing for safety assessment: new approaches and technologies.

    PubMed

    Knudsen, Thomas B; Kavlock, Robert J; Daston, George P; Stedman, Donald; Hixon, Mary; Kim, James H

    2011-10-01

    The ILSI Health and Environmental Sciences Institute's Developmental and Reproductive Toxicology Technical Committee held a 2-day workshop entitled "Developmental Toxicology-New Directions" in April 2009. The fourth session of this workshop focused on new approaches and technologies for the assessment of developmental toxicology. This session provided an overview of the application of genomics technologies for developmental safety assessment, the use of mouse embryonic stem cells to capture data on developmental toxicity pathways, dynamical cell imaging of zebrafish embryos, the use of computation models of development pathways and systems, and finally, high-throughput in vitro approaches being utilized by the EPA ToxCast program. Issues discussed include the challenges of anchoring in vitro predictions to relevant in vivo endpoints and the need to validate pathway-based predictions with targeted studies in whole animals. Currently, there are 10,000 to 30,000 chemicals in world-wide commerce in need of hazard data for assessing potential health risks. The traditional animal study designs for assessing developmental toxicity cannot accommodate the evaluation of this large number of chemicals, requiring that alternative technologies be utilized. Though a daunting task, technologies are being developed and utilized to make that goal reachable. © 2011 Wiley Periodicals, Inc.

  15. The mechanism of dioxin toxicity: relationship to risk assessment.

    PubMed Central

    Birnbaum, L S

    1994-01-01

    Risk characterization involves hazard identification, determination of dose-response relationships, and exposure assessment. Improvement of the risk assessment process requires inclusion of the best available science. Recent findings in the area of dioxin toxicity have led to a major effort to reassess its risk. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), commonly referred to as "dioxin," is the most toxic member of a class of related chemicals including the polyhalogenated dibenzo-p-dioxins, dibenzofurans, biphenyls, naphthalenes, azo- and azoxy-benzenes, whose toxicities can be expressed as fractional equivalencies of TCDD. These chemicals exert their effects through interaction with a specific intracellular protein, the Ah receptor. While binding to the receptor is necessary, it is not sufficient to bring about a chain of events leading to various responses including enzyme induction, immunotoxicity, reproductive and endocrine effects, developmental toxicity, chloracne, tumor promotion, etc. Some of these responses appear to be linear at low doses. Immunotoxicity and effects on the reproductive system appear to be among the most sensitive responses. The Ah receptor functions as a transcriptional enhancer, interacting with a number of other regulatory proteins (heat shock proteins, kinases, translocases, DNA binding species). Interaction with specific base sequences in the DNA appear to be modulated by the presence of other growth factors, hormones and their receptors as well as other regulatory proteins. Thus, dioxin appears to function as a hormone, initiating a cascade of events that is dependent upon the environment of each cell and tissue. While Ah receptor variants exist, all vertebrates examined have demonstrated such a protein with similar numbers of receptors and binding affinity for TCDD. Most species respond similarly to dioxin and related compounds. While a given species may be an outlier for a given response, it will behave like other animals for

  16. Pesticide Toxicity Index--a tool for assessing potential toxicity of pesticide mixtures to freshwater aquatic organisms.

    PubMed

    Nowell, Lisa H; Norman, Julia E; Moran, Patrick W; Martin, Jeffrey D; Stone, Wesley W

    2014-04-01

    Pesticide mixtures are common in streams with agricultural or urban influence in the watershed. The Pesticide Toxicity Index (PTI) is a screening tool to assess potential aquatic toxicity of complex pesticide mixtures by combining measures of pesticide exposure and acute toxicity in an additive toxic-unit model. The PTI is determined separately for fish, cladocerans, and benthic invertebrates. This study expands the number of pesticides and degradates included in previous editions of the PTI from 124 to 492 pesticides and degradates, and includes two types of PTI for use in different applications, depending on study objectives. The Median-PTI was calculated from median toxicity values for individual pesticides, so is robust to outliers and is appropriate for comparing relative potential toxicity among samples, sites, or pesticides. The Sensitive-PTI uses the 5th percentile of available toxicity values, so is a more sensitive screening-level indicator of potential toxicity. PTI predictions of toxicity in environmental samples were tested using data aggregated from published field studies that measured pesticide concentrations and toxicity to Ceriodaphnia dubia in ambient stream water. C. dubia survival was reduced to ≤50% of controls in 44% of samples with Median-PTI values of 0.1-1, and to 0% in 96% of samples with Median-PTI values >1. The PTI is a relative, but quantitative, indicator of potential toxicity that can be used to evaluate relationships between pesticide exposure and biological condition. Published by Elsevier B.V.

  17. Toxicity of lunar dust assessed in inhalation-exposed rats

    PubMed Central

    Lam, Chiu-wing; Scully, Robert R.; Zhang, Ye; Renne, Roger A.; Hunter, Robert L.; McCluskey, Richard A.; Chen, Bean T.; Castranova, Vincent; Driscoll, Kevin E.; Gardner, Donald E.; McClellan, Roger O.; Cooper, Bonnie L.; McKay, David S.; Marshall, Linda; James, John T.

    2015-01-01

    Humans will again set foot on the moon. The moon is covered by a layer of fine dust, which can pose a respiratory hazard. We investigated the pulmonary toxicity of lunar dust in rats exposed to 0, 2.1, 6.8, 20.8 and 60.6 mg/m3 of respirable-size lunar dust for 4 weeks (6 h/day, 5 days/week); the aerosols in the nose-only exposure chambers were generated from a jet-mill ground preparation of a lunar soil collected during the Apollo 14 mission. After 4 weeks of exposure to air or lunar dust, groups of five rats were euthanized 1 day, 1 week, 4 weeks or 13 weeks after the last exposure for assessment of pulmonary toxicity. Biomarkers of toxicity assessed in bronchoalveolar fluids showed concentration-dependent changes; biomarkers that showed treatment effects were total cell and neutrophil counts, total protein concentrations and cellular enzymes (lactate dehydrogenase, glutamyl transferase and aspartate transaminase). No statistically significant differences in these biomarkers were detected between rats exposed to air and those exposed to the two low concentrations of lunar dust. Dose-dependent histopathology, including inflammation, septal thickening, fibrosis and granulomas, in the lung was observed at the two higher exposure concentrations. No lesions were detected in rats exposed to ≤6.8 mg/m3. This 4-week exposure study in rats showed that 6.8 mg/m3 was the highest no-observable-adverse-effect level (NOAEL). These results will be useful for assessing the health risk to humans of exposure to lunar dust, establishing human exposure limits and guiding the design of dust mitigation systems in lunar landers or habitats. PMID:24102467

  18. Toxicity of lunar dust assessed in inhalation-exposed rats.

    PubMed

    Lam, Chiu-wing; Scully, Robert R; Zhang, Ye; Renne, Roger A; Hunter, Robert L; McCluskey, Richard A; Chen, Bean T; Castranova, Vincent; Driscoll, Kevin E; Gardner, Donald E; McClellan, Roger O; Cooper, Bonnie L; McKay, David S; Marshall, Linda; James, John T

    2013-10-01

    Humans will again set foot on the moon. The moon is covered by a layer of fine dust, which can pose a respiratory hazard. We investigated the pulmonary toxicity of lunar dust in rats exposed to 0, 2.1, 6.8, 20.8 and 60.6 mg/m(3) of respirable-size lunar dust for 4 weeks (6 h/day, 5 days/week); the aerosols in the nose-only exposure chambers were generated from a jet-mill ground preparation of a lunar soil collected during the Apollo 14 mission. After 4 weeks of exposure to air or lunar dust, groups of five rats were euthanized 1 day, 1 week, 4 weeks or 13 weeks after the last exposure for assessment of pulmonary toxicity. Biomarkers of toxicity assessed in bronchoalveolar fluids showed concentration-dependent changes; biomarkers that showed treatment effects were total cell and neutrophil counts, total protein concentrations and cellular enzymes (lactate dehydrogenase, glutamyl transferase and aspartate transaminase). No statistically significant differences in these biomarkers were detected between rats exposed to air and those exposed to the two low concentrations of lunar dust. Dose-dependent histopathology, including inflammation, septal thickening, fibrosis and granulomas, in the lung was observed at the two higher exposure concentrations. No lesions were detected in rats exposed to ≤6.8 mg/m(3). This 4-week exposure study in rats showed that 6.8 mg/m(3) was the highest no-observable-adverse-effect level (NOAEL). These results will be useful for assessing the health risk to humans of exposure to lunar dust, establishing human exposure limits and guiding the design of dust mitigation systems in lunar landers or habitats.

  19. Reconciling laboratory and field assessments of neonicotinoid toxicity to honeybees

    PubMed Central

    Henry, Mickaël; Cerrutti, Nicolas; Aupinel, Pierrick; Decourtye, Axel; Gayrard, Mélanie; Odoux, Jean-François; Pissard, Aurélien; Rüger, Charlotte; Bretagnolle, Vincent

    2015-01-01

    European governments have banned the use of three common neonicotinoid pesticides due to insufficiently identified risks to bees. This policy decision is controversial given the absence of clear consistency between toxicity assessments of those substances in the laboratory and in the field. Although laboratory trials report deleterious effects in honeybees at trace levels, field surveys reveal no decrease in the performance of honeybee colonies in the vicinity of treated fields. Here we provide the missing link, showing that individual honeybees near thiamethoxam-treated fields do indeed disappear at a faster rate, but the impact of this is buffered by the colonies' demographic regulation response. Although we could ascertain the exposure pathway of thiamethoxam residues from treated flowers to honeybee dietary nectar, we uncovered an unexpected pervasive co-occurrence of similar concentrations of imidacloprid, another neonicotinoid normally restricted to non-entomophilous crops in the study country. Thus, its origin and transfer pathways through the succession of annual crops need be elucidated to conveniently appraise the risks of combined neonicotinoid exposures. This study reconciles the conflicting laboratory and field toxicity assessments of neonicotinoids on honeybees and further highlights the difficulty in actually detecting non-intentional effects on the field through conventional risk assessment methods. PMID:26582026

  20. Validation of an LDH assay for assessing nanoparticle toxicity.

    PubMed

    Han, Xianglu; Gelein, Robert; Corson, Nancy; Wade-Mercer, Pamela; Jiang, Jingkun; Biswas, Pratim; Finkelstein, Jacob N; Elder, Alison; Oberdörster, Günter

    2011-09-05

    Studies showed that certain cytotoxicity assays were not suitable for assessing nanoparticle (NP) toxicity. We evaluated a lactate dehydrogenase (LDH) assay for assessing copper (Cu-40, 40nm), silver (Ag-35, 35nm; Ag-40, 40nm), and titanium dioxide (TiO(2)-25, 25nm) NPs by examining their potential to inactivate LDH and interference with β-nicotinamide adenine dinucleotide (NADH), a substrate for the assay. We also performed a dissolution assay for some of the NPs. We found that the copper NPs, because of their high dissolution rate, could interfere with the LDH assay by inactivating LDH. Ag-35 could also inactivate LDH probably because of the carbon matrix used to cage the particles during synthesis. TiO(2)-25 NPs were found to adsorb LDH molecules. In conclusion, NP interference with the LDH assay depends on the type of NPs and the suitability of the assay for assessing NP toxicity should be examined case by case. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  1. Reconciling laboratory and field assessments of neonicotinoid toxicity to honeybees.

    PubMed

    Henry, Mickaël; Cerrutti, Nicolas; Aupinel, Pierrick; Decourtye, Axel; Gayrard, Mélanie; Odoux, Jean-François; Pissard, Aurélien; Rüger, Charlotte; Bretagnolle, Vincent

    2015-11-22

    European governments have banned the use of three common neonicotinoid pesticides due to insufficiently identified risks to bees. This policy decision is controversial given the absence of clear consistency between toxicity assessments of those substances in the laboratory and in the field. Although laboratory trials report deleterious effects in honeybees at trace levels, field surveys reveal no decrease in the performance of honeybee colonies in the vicinity of treated fields. Here we provide the missing link, showing that individual honeybees near thiamethoxam-treated fields do indeed disappear at a faster rate, but the impact of this is buffered by the colonies' demographic regulation response. Although we could ascertain the exposure pathway of thiamethoxam residues from treated flowers to honeybee dietary nectar, we uncovered an unexpected pervasive co-occurrence of similar concentrations of imidacloprid, another neonicotinoid normally restricted to non-entomophilous crops in the study country. Thus, its origin and transfer pathways through the succession of annual crops need be elucidated to conveniently appraise the risks of combined neonicotinoid exposures. This study reconciles the conflicting laboratory and field toxicity assessments of neonicotinoids on honeybees and further highlights the difficulty in actually detecting non-intentional effects on the field through conventional risk assessment methods. © 2015 The Author(s).

  2. Validation of an LDH Assay for Assessing Nanoparticle Toxicity

    PubMed Central

    Han, Xianglu; Gelein, Robert; Corson, Nancy; Wade-Mercer, Pamela; Jiang, Jingkun; Biswas, Pratim; Finkelstein, Jacob N.; Elder, Alison; Oberdörster, Günter

    2014-01-01

    Studies showed that certain cytotoxicity assays were not suitable for assessing nanoparticle (NP) toxicity. We evaluated a lactate dehydrogenase (LDH) assay for assessing copper (Cu-40, 40 nm), silver (Ag-35, 35 nm; Ag-40, 40 nm), and titanium dioxide (TiO2-25, 25 nm) NPs by examining their potential to inactivate LDH and interference with β-nicotinamide adenine dinucleotide (NADH), a substrate for the assay. We also performed a dissolution assay for some of the NPs. We found that the copper NPs, because of their high dissolution rate, could interfere with the LDH assay by inactivating LDH. Ag-35 could also inactivate LDH probably because of the carbon matrix used to cage the particles during synthesis. TiO2-25 NPs were found to adsorb LDH molecules. In conclusion, NP interference with the LDH assay depends on the type of NPs and the suitability of the assay for assessing NP toxicity should be examined case by case. PMID:21722700

  3. Assessing variability in chemical acute toxicity of unionid mussels: Influence of intra- and inter-laboratory testing, life stage, and species

    USGS Publications Warehouse

    Raimondo, Sandy; Lilavois, Crystal R.; Lee, Larisa; Augspurger, Tom; Wang, Ning; Ingersoll, Christopher G.; Bauer, Candice R.; Hammer, Edward J.; Barron, Mace G.

    2016-01-01

    We developed a toxicity database for unionid mussels to examine the extent of intra- and inter-laboratory variability in acute toxicity tests with mussel larvae (glochidia) and juveniles; the extent of differential sensitivity of the two life stages; and the variation in sensitivity among commonly tested mussels (Lampsilis siliquoidea, Utterbackia imbecillis, Villosa iris), commonly tested cladocerans (Daphnia magna, Ceriodaphnia dubia) and fish (Oncorhynchus mykiss, Pimephales promelas, Lepomis macrochirus). The results of these analyses indicate intra-laboratory variability for median effect concentrations (EC50) averaged about 2 fold for both life stages, while inter-laboratory variability averaged 3.6 fold for juvenile mussels and 6.3 fold for glochidia. The EC50s for juveniles and glochidia were within a factor of 2 of each other for 50% of paired records across chemicals, with juveniles more sensitive than glochidia by more than 2 fold for 33% of the comparisons made between life stages. There was a high concurrence of the sensitivity of commonly tested L. siliquoidea, U. imbecillis, and V. iris to that of other mussels. However, this concurrence decreases as the taxonomic distance of the commonly tested cladocerans and fish to mussels increases. The compiled mussel database and determination of data variability will advance risk assessments by including more robust species sensitivity distributions, interspecies correlation estimates, and availability of taxon-specific empirically derived application factors for risk assessment.

  4. The assessment of neurobehavioral toxicity: SGOMSEC joint report.

    PubMed Central

    Fiedler, N; Feldman, R G; Jacobson, J; Rahill, A; Wetherell, A

    1996-01-01

    Exposure to neurobehavioral toxicants is a problem of international scope. Although many different procedures are available for the assessment of human behavioral function, performance tests are displacing traditional diagnostic tests for ascertaining the consequences of exposure to neurotoxic chemicals. Performance testing includes variables such as attention and concentration, sensory function, motor control, spatial relations, visuomotor coordination, memory, and affect. Special tests have also been devised for evaluating child development. One of the salient needs in these efforts is the construction of databases allowing access to normative data. PMID:8860321

  5. Use of higher plants as screens for toxicity assessment.

    PubMed

    Kristen, U

    1997-01-01

    This review deals with the use of entire plants, seedlings, cell suspension cultures and pollen tubes for the estimation of potential toxicity in the environment, and for risk assessment of chemicals and formulations of human relevance. It is shown that the roots of onions and various crop seedlings, as well as in vitro growing pollen tubes of some mono- and dicotyledonous plants, are most frequently used to obtain toxicity data by determination of root and tube growth inhibition. Both roots and pollen tubes are chloroplast free, non-photosynthetic systems and, therefore, with regard to their cytotoxic reactions are closer to vertebrate tissues and cells than are chloroplast-containing plant organs. Root tips and anthers of flower buds are shown to be applicable to genotoxicity screening by microscopic analysis of mitotic or meiotic aberrations during cell division or microspore development, respectively. The processes of mitosis and meiosis are similar in plants and animals. Therefore, meristematic and sporogenic tissues of plants generally show patterns of cytotoxic response similar to those of embryogenic and spermatogenic tissues of vertebrates. The suitability of root tips, cell suspensions and pollen tubes for the investigation of mechanisms of toxic action and for the analysis of structure-activity relationships is also demonstrated. Two plant-based assays, the Allium test and the pollen tube growth test, both currently being evaluated alongside with established mammalian in vivo and in vitro protocols, are emphasized with regard to their potential use as alternatives to animal in vivo toxicity tests. For both assays, preliminary results indicate that the tips of growing roots and the rapidly elongating pollen tubes of certain higher plant species are as reliable as mammalian cell lines for detecting basal cytotoxicity. It is suggested that seeds and pollen grains, in particular, provide easily storable and convenient systems for inexpensive, relatively

  6. Ecotoxicity of sediments in rivers: Invertebrate community, toxicity bioassays and the toxic unit approach as complementary assessment tools.

    PubMed

    de Castro-Català, Núria; Kuzmanovic, Maja; Roig, Neus; Sierra, Jordi; Ginebreda, Antoni; Barceló, Damià; Pérez, Sandra; Petrovic, Mira; Picó, Yolanda; Schuhmacher, Marta; Muñoz, Isabel

    2016-01-01

    The determination of the real toxicity of sediments in aquatic ecosystems is challenging and necessary for an appropriate risk assessment. Different approaches have been developed and applied over the last several decades. Currently, the joint implementation of chemical, ecological and toxicological tools is recommended for an appropriate and successful toxicity risk assessment. We chose the combination of the toxic unit approach with acute pore water tests (Vibrio fischeri, Pseudokirchneriella subcapitata and Daphnia magna) and whole-sediment exposure tests (V. fischeri, Chironomus riparius), together with invertebrate community composition (multivariate analyses) to detect short and long-term responses of the organisms in four rivers of the Iberian Peninsula. High toxicity was detected in three sites (the downstream sites of the Llobregat and the Júcar, and the most upstream site of the Ebro). We identified organophosphate insecticides and metals as the main variables responsible for this toxicity, particularly in the whole-sediment tests. In particular, chlorpyrifos was mostly responsible for the toxicity (TUs) of D. magna, coinciding with the C. riparius mortality (long-term toxicity) in the mentioned sites, and copper was the main pollutant responsible for the short-term toxicity of P. subcapitata. The combination of the different approaches allowed us to detect ecotoxicological effects in organisms and identify the main contributors to the toxicity in these multi-stressed rivers. Copyright © 2015. Published by Elsevier B.V.

  7. Assessment of the Aerosol Generation and Toxicity of Carbon Nanotubes

    PubMed Central

    O’Shaughnessy, Patrick T.; Adamcakova-Dodd, Andrea; Altmaier, Ralph; Thorne, Peter S.

    2014-01-01

    Current interest in the pulmonary toxicity of carbon nanotubes (CNTs) has resulted in a need for an aerosol generation system that is capable of consistently producing a CNT aerosol at a desired concentration level. This two-part study was designed to: (1) assess the properties of a commercially-available aerosol generator when producing an aerosol from a purchased powder supply of double-walled carbon nanotubes (DWCNTs); and (2) assess the pulmonary sub-acute toxicity of DWCNTs in a murine model during a 5-day (4 h/day) whole-body exposure. The aerosol generator, consisting of a novel dustfeed mechanism and venturi ejector was determined to be capable of producing a DWCNT consistently over a 4 h exposure period at an average level of 10.8 mg/m3. The count median diameter was 121 nm with a geometric standard deviation of 2.04. The estimated deposited dose was 32 µg/mouse. The total number of cells in bronchoalveolar lavage (BAL) fluid was significantly (p < 0.01) increased in exposed mice compared to controls. Similarly, macrophages in BAL fluid were significantly elevated in exposed mice, but not neutrophils. All animals exposed to CNT and euthanized immediately after exposure had changes in the lung tissues showing acute inflammation and injury; however these pathological changes resolved two weeks after the exposure.

  8. Field assessments in conjunction with whole effluent toxicity testing

    SciTech Connect

    La Point, T.W.; Waller, W.T.

    2000-01-01

    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.

  9. Toxicity assessment of unintentional exposure to multiple chemicals

    SciTech Connect

    Mumtaz, M.M. Ruiz, P.; De Rosa, C.T.

    2007-09-01

    Typically exposure to environmental chemicals is unintentional, and often the exposure is to chemical mixtures, either simultaneously or sequentially. When exposure occurs, in public health practice, it is prudent to ascertain if thresholds for harmful health effects are exceeded, whether by individual chemicals or by chemicals in combination. Three alternative approaches are available for assessing the toxicity of chemical mixtures. Each approach, however, has shortcomings. As the procedures of each approach are described in this paper, at various steps research needs are identified. Recently, reliance has increased on computational toxicology methods for predicting toxicological effects when data are limited. Advances in molecular biology, identification of biomarkers, and availability of accurate and sensitive methods allow us to more precisely define the relationships between multiple chemical exposures and health effects, both qualitatively and quantitatively. Key research needs are best fulfilled through collaborative research. It is through such collaborations that resources are most effectively leveraged to further develop and apply toxicity assessment methods that advance public health practices in vulnerable communities.

  10. Reliability of Quantitative Ultrasonic Assessment of Normal-Tissue Toxicity in Breast Cancer Radiotherapy

    SciTech Connect

    Yoshida, Emi J.; Chen Hao; Torres, Mylin; Andic, Fundagul; Liu Haoyang; Chen Zhengjia; Sun, Xiaoyan; Curran, Walter J.; Liu Tian

    2012-02-01

    Purpose: We have recently reported that ultrasound imaging, together with ultrasound tissue characterization (UTC), can provide quantitative assessment of radiation-induced normal-tissue toxicity. This study's purpose is to evaluate the reliability of our quantitative ultrasound technology in assessing acute and late normal-tissue toxicity in breast cancer radiotherapy. Method and Materials: Our ultrasound technique analyzes radiofrequency echo signals and provides quantitative measures of dermal, hypodermal, and glandular tissue toxicities. To facilitate easy clinical implementation, we further refined this technique by developing a semiautomatic ultrasound-based toxicity assessment tool (UBTAT). Seventy-two ultrasound studies of 26 patients (720 images) were analyzed. Images of 8 patients were evaluated for acute toxicity (<6 months postradiotherapy) and those of 18 patients were evaluated for late toxicity ({>=}6 months postradiotherapy). All patients were treated according to a standard radiotherapy protocol. To assess intraobserver reliability, one observer analyzed 720 images in UBTAT and then repeated the analysis 3 months later. To assess interobserver reliability, three observers (two radiation oncologists and one ultrasound expert) each analyzed 720 images in UBTAT. An intraclass correlation coefficient (ICC) was used to evaluate intra- and interobserver reliability. Ultrasound assessment and clinical evaluation were also compared. Results: Intraobserver ICC was 0.89 for dermal toxicity, 0.74 for hypodermal toxicity, and 0.96 for glandular tissue toxicity. Interobserver ICC was 0.78 for dermal toxicity, 0.74 for hypodermal toxicity, and 0.94 for glandular tissue toxicity. Statistical analysis found significant changes in dermal (p < 0.0001), hypodermal (p = 0.0027), and glandular tissue (p < 0.0001) assessments in the acute toxicity group. Ultrasound measurements correlated with clinical Radiation Therapy Oncology Group (RTOG) toxicity scores of patients

  11. Toxico-Cheminformatics: New and Expanding Public Resources to Support Chemical Toxicity Assessments

    EPA Science Inventory

    High-throughput screening (HTS) technologies, along with efforts to improve public access to chemical toxicity information resources and to systematize older toxicity studies, have the potential to significantly improve information gathering efforts for chemical assessments and p...

  12. Toxico-Cheminformatics: New and Expanding Public Resources to Support Chemical Toxicity Assessments

    EPA Science Inventory

    High-throughput screening (HTS) technologies, along with efforts to improve public access to chemical toxicity information resources and to systematize older toxicity studies, have the potential to significantly improve information gathering efforts for chemical assessments and p...

  13. Assessing aluminium toxicity in streams affected by acid mine drainage.

    PubMed

    Waters, A S; Webster-Brown, J G

    2013-01-01

    Acid mine drainage (AMD) has degraded water quality and ecology in streams on the Stockton Plateau, the site of New Zealand's largest open-cast coal mining operation. This has previously been attributed largely to the effects of acidity and elevated aluminium (Al) concentrations. However, the toxicity of dissolved Al is dependent on speciation, which is influenced by pH which affects Al hydrolysis, as well as the concentrations of organic carbon and sulphate which complex Al. Methods for the assessment of the toxic fraction of Al, by chemical analysis and geochemical modelling, have been investigated in selected streams on the Stockton Plateau, where dissolved Al concentrations ranged from 0.034 to 27 mg L(-1). Modelling using PHREEQC indicated that between 0.2 and 85% of the dissolved Al was present as the free ion Al(3+), the most toxic Al species, which dominated in waters of pH = 3.8-4.8. Al-sulphate complexation reduced the Al(3+) concentration at lower pH, while Al-organic and -hydroxide complexes dominated at higher pH. Macroinvertebrate richness in the streams identified an Al(3+) 'threshold' of approximately 0.42 mg/L, above which taxa declined rapidly. Colorimetric 'Aluminon' analysis on unpreserved, unfiltered waters provided a better estimation of Al(3+) concentrations than inductively couple plasma-mass spectrometry (ICP-MS) on filtered, acidified waters. The Aluminon method does not react with particulate Al or strong Al complexes, often registering as little as 53% of the dissolved Al concentration determined by ICP-MS.

  14. Toxicity assessment of nanosilver wound dressing in Wistar rat.

    PubMed

    Bidgoli, Sepideh Arbabi; Mahdavi, Moujan; Rezayat, Seyed Mahdi; Korani, Mitra; Amani, Amir; Ziarati, Parisa

    2013-05-07

    Antibiotic resistance to microorganisms is one of the major problems faced in the field of wound care in burns patients. Silver nanoparticles have come up as potent antimicrobial agent and are being evaluated in diverse medical applications ranging from silver based dressings to silver coated medical devices. We aimed in present study to test the release of nanosilver from nanosilver wound dressing and compare the dermal and systemic toxicity of nanosilver dressings in a repeated dose (21 days) model. Under general anesthesia, a limited standard 2nd degree burns were provided on the back of each rat in all treatment, negative control (simple dressing) and 5% silver nitrate groups, each contained 5 male wistar rats. According to the analysis made by atomic absorption spectrometry, the wound dressings released 0.599 ± 0.083 ppm of nanosilver during first 24 hrs of study. Daily observations were recoded and wounds were covered with new dressings each 24 hrs. Burn healing was observed in nanosilver wound dressing group in shorter time periods than the control groups. In toxicity assessment, this dressing didn't cause any hematological and histopathological abnormalities in treatment group but biochemical studies showed significant rise of plasma transaminase (ALT) at the endpoint (21 days) of the study (P=0.027). Portal mononuclear lymphoid and polymorphonuclear leukocyte infiltrations in three to four adjacent foci were recognized around the central hepatic vein in treatment group. Mild hepatotoxic effects of nanosilver wound dressing in wistar rat emphasize the necessity of more studies on toxicity potentials of low dose nanosilver by dermal applications.

  15. Assessing the toxicity and biodegradability of deep eutectic solvents.

    PubMed

    Wen, Qing; Chen, Jing-Xin; Tang, Yu-Lin; Wang, Juan; Yang, Zhen

    2015-08-01

    Deep eutectic solvents (DESs) have emerged as a new type of promising ionic solvents with a broad range of potential applications. Although their ecotoxicological profile is still poorly known, DESs are generally regarded as "green" because they are composed of ammonium salts and H-bond donors (HBDs) which are considered to be eco-friendly. In this work, cholinium-based DESs comprised of choline chloride (ChCl) and choline acetate (ChAc) as the salt and urea (U), acetamide (A), glycerol (G) and ethylene glycol (EG) as the HBD were evaluated for their toxic effects on different living organisms such as Escherichia coli (a bacterium), Allium sativum (garlic, a plant) and hydra (an invertebrate), and their biodegradabilities were assessed by means of closed bottle tests. These DESs possessed an anti-bacterial property and exhibited inhibitory effects on the test organisms adopted, depending on the composition and concentration of the DES. The mechanism for the impact of DESs and their components on different living organisms can be associated to their interactions with the cellular membranes. Not all DESs can be considered readily biodegradable. By extending the limited knowledge about the toxicity and biodegradation of this particular solvent family, this investigation on DESs provides insight into our structure-based understanding of their ecotoxicological behavior. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Alternative acute oral toxicity assessment under REACH based on sub-acute toxicity values.

    PubMed

    Gissi, Andrea; Louekari, Kimmo; Hoffstadt, Laurence; Bornatowicz, Norbert; Aparicio, Alberto Martin

    2016-11-08

    The REACH Regulation requires information on acute oral toxicity for substances produced or imported in quantities greater than one tonne per year. When registering, animal testing should be used as last resort. The standard acute oral toxicity test requires use of animals. Therefore, the European Chemicals Agency examined whether alternative ways exist to generate information on acute oral toxicity. The starting hypothesis was that low acute oral toxicity can be predicted from the results of low toxicity in oral sub-acute toxicity studies. Proving this hypothesis would allow avoiding acute toxicity oral testing whenever a sub-acute oral toxicity study is required or available and indicates low toxicity. ECHA conducted an analysis of the REACH database and found suitable studies on both acute oral and sub-acute oral toxicities for 1,256 substances. 415 of these substances had low toxicity in the sub-acute toxicity study (i.e. NO(A)EL at or above the classification threshold of 1,000 mg/kg). For 98% of these substances, low acute oral toxicity was also reported (i.e. LD₅₀ above the classification threshold of 2,000 mg/kg). On the other hand, no correlation was found between lower NO(A)ELs and LD₅₀. According to the REACH regulation, this approach for predicting acute oral toxicity needs to be considered as part of a weight of evidence analysis. Therefore, additional sources of information to support this approach are presented. Ahead of the last REACH registration deadline in 2018, ECHA estimates that registrants of about 550 substances can omit the in vivo acute oral study by using this adaptation.

  17. Essentiality, toxicity, and uncertainty in the risk assessment of manganese.

    PubMed

    Boyes, William K

    2010-01-01

    Risk assessments of manganese by inhalation or oral routes of exposure typically acknowledge the duality of manganese as an essential element at low doses and a toxic metal at high doses. Previously, however, risk assessors were unable to describe manganese pharmacokinetics quantitatively across dose levels and routes of exposure, to account for mass balance, and to incorporate this information into a quantitative risk assessment. In addition, the prior risk assessment of inhaled manganese conducted by the U.S. Environmental Protection Agency (EPA) identified a number of specific factors that contributed to uncertainty in the risk assessment. In response to a petition regarding the use of a fuel additive containing manganese, methylcyclopentadienyl manganese tricarbonyl (MMT), the U.S. EPA developed a test rule under the U.S. Clean Air Act that required, among other things, the generation of pharmacokinetic information. This information was intended not only to aid in the design of health outcome studies, but also to help address uncertainties in the risk assessment of manganese. To date, the work conducted in response to the test rule has yielded substantial pharmacokinetic data. This information will enable the generation of physiologically based pharmacokinetic (PBPK) models capable of making quantitative predictions of tissue manganese concentrations following inhalation and oral exposure, across dose levels, and accounting for factors such as duration of exposure, different species of manganese, and changes of age, gender, and reproductive status. The work accomplished in response to the test rule, in combination with other scientific evidence, will enable future manganese risk assessments to consider tissue dosimetry more comprehensively than was previously possible.

  18. ASSESSING RISKS FROM PHOTOACTIVATED TOXICITY OF PAHS TO AQUATIC ORGANISMS

    EPA Science Inventory

    Polycyclic aromatic hydrocarbons (PAHs) are one of the most ubiquitous classes of environmental contaminants. Although most PAHs are toxic only at concentrations large enough to cause narcosis, the toxicity of some can be greatly enhanced through mechanisms that involve molecul...

  19. Derivation of freshwater quality criteria for zinc using interspecies correlation estimation models to protect aquatic life in China.

    PubMed

    Feng, C L; Wu, F C; Dyer, S D; Chang, H; Zhao, X L

    2013-01-01

    Species sensitivity distributions (SSDs) are usually used in the development of water quality criteria and require a large number of toxicity values to define a hazard level to protect the majority of species. However, some toxicity data for certain chemicals are limited, especially for endangered and threatened species. Thus, it is important to predict the unknown species toxicity data using available toxicity data. To address this need, interspecies correlation estimation (ICE) models were developed by US EPA to predict acute toxicity of chemicals to diverse species based on a more limited data set of surrogate species toxicity data. Use of SSDs generated from ICE models allows for the prediction of protective water quality criteria, such as the HC5 (hazard concentration, 5th percentile). In the present study, we tested this concept using toxicity data collected for zinc. ICE-based-SSDs were generated using three surrogate species (common carp (Cyprinus carpio), rainbow trout (Oncorhynchus mykiss), and Daphnia magna) and compared with the measured-based SSD and corresponding HC5. The results showed that no significant differences were observed between the ICE- and the measured-based SSDs and HC5s. Furthermore, the examination of species placements within the SSDs indicated that the most sensitive species to zinc were invertebrates, especially crustaceans. Given the similarity of SSD and HC5s for zinc, the use of ICE to derive potential water quality criteria for diverse chemicals in China is proposed. Further, a combination of measured and ICE-derived data will prove useful for assessing water quality and chemical risks in the near future.

  20. Interspecies translation of disease networks increases robustness and predictive accuracy.

    PubMed

    Anvar, Seyed Yahya; Tucker, Allan; Vinciotti, Veronica; Venema, Andrea; van Ommen, Gert-Jan B; van der Maarel, Silvere M; Raz, Vered; 't Hoen, Peter A C

    2011-11-01

    Gene regulatory networks give important insights into the mechanisms underlying physiology and pathophysiology. The derivation of gene regulatory networks from high-throughput expression data via machine learning strategies is problematic as the reliability of these models is often compromised by limited and highly variable samples, heterogeneity in transcript isoforms, noise, and other artifacts. Here, we develop a novel algorithm, dubbed Dandelion, in which we construct and train intraspecies Bayesian networks that are translated and assessed on independent test sets from other species in a reiterative procedure. The interspecies disease networks are subjected to multi-layers of analysis and evaluation, leading to the identification of the most consistent relationships within the network structure. In this study, we demonstrate the performance of our algorithms on datasets from animal models of oculopharyngeal muscular dystrophy (OPMD) and patient materials. We show that the interspecies network of genes coding for the proteasome provide highly accurate predictions on gene expression levels and disease phenotype. Moreover, the cross-species translation increases the stability and robustness of these networks. Unlike existing modeling approaches, our algorithms do not require assumptions on notoriously difficult one-to-one mapping of protein orthologues or alternative transcripts and can deal with missing data. We show that the identified key components of the OPMD disease network can be confirmed in an unseen and independent disease model. This study presents a state-of-the-art strategy in constructing interspecies disease networks that provide crucial information on regulatory relationships among genes, leading to better understanding of the disease molecular mechanisms.

  1. INTERSPECIES CORRELATION ESTIMATES PREDICT PROTECTIVE ENVIRONMENTAL CONCENTRATIONS

    EPA Science Inventory

    Environmental risk assessments often use multiple single species toxicity test results and species sensitivity distributions (SSDs) to derive a predicted no-effect concentration in the environment, typically the 5th percentile of the SSD, termed the HC5. The shape and location of...

  2. INTERSPECIES CORRELATION ESTIMATES PREDICT PROTECTIVE ENVIRONMENTAL CONCENTRATIONS

    EPA Science Inventory

    Environmental risk assessments often use multiple single species toxicity test results and species sensitivity distributions (SSDs) to derive a predicted no-effect concentration in the environment, typically the 5th percentile of the SSD, termed the HC5. The shape and location of...

  3. Derivation of freshwater water quality criteria for dibutyltin dilaurate from measured data and data predicted using interspecies correlation estimate models.

    PubMed

    Zhang, Shengxin; Wang, Lei; Wang, Zhen; Fan, Deling; Shi, Lili; Liu, Jining

    2017-03-01

    Dibutyltin dilaurate (DBTL) is an organotin compound that has been widely detected in aquatic environments. However, the ecological risk assessment for DBTL is hard to perform due to the absence of water quality criteria (WQC) and lack of toxicity data. In this study, toxicity data were obtained from acute and chronic toxicity tests using aquatic species resident in China. Based on the species sensitivity distributions (SSDs) constructed from these test data, the acute water quality criterion (AWQC) and chronic water quality criterion (CWQC) were then derived to be 132 μg/L and 31.9 μg/L for DBTL. In order to valid the predicted data in the application to the protective criteria development and hazard assessment, the web-based interspecies correlation estimation (Web-ICE) system was used to estimate acute toxicities. Here two acute toxicity data groups for surrogate species were chosen from experimental data and QSAR Toolbox-predicted data separately, giving estimated data for prediction species using Web-ICE software. According to Kolmogorov-Smirnov test results, Web-ICE-based SSDs and measurement-based SSD were not significantly different. The results showed that the differences between measurement-based (132 μg/L) and Web-ICE-based AWQCs (39.7 μg/L and 58.5 μg/L) were statistically acceptable. Under certain conditions, it is therefore worth considering using the QSAR Toolbox plus Web-ICE method here to provide a beneficial supplement for developing preliminarily screen level toxicities in WQC when little or no relevant information are available. Besides, the geographic distribution of species was demonstrated not to be a significant factor in SSD establishment and WQC derivation.

  4. Benzothiazole toxicity assessment in support of synthetic turf field human health risk assessment.

    PubMed

    Ginsberg, Gary; Toal, Brian; Kurland, Tara

    2011-01-01

    Synthetic turf fields cushioned with crumb rubber may be a source of chemical exposure to those playing on the fields. Benzothiazole (BZT) may volatilize from crumb rubber and result in inhalation exposure. Benzothiazole has been the primary rubber-related chemical found in synthetic turf studies. However, risks associated with BZT have not been thoroughly assessed, primarily because of gaps in the database. This assessment provides toxicity information for a human health risk assessment involving BZT detected at five fields in Connecticut. BZT exerts acute toxicity and is a respiratory irritant and dermal sensitizer. In a genetic toxicity assay BZT was positive in Salmonella in the presence of metabolic activation. BZT metabolism involves ring-opening and formation of aromatic hydroxylamines, metabolites with mutagenic and carcinogenic potential. A structural analogue 2-mercaptobenzothiazole (2-MBZT) was more widely tested and so is used as a surrogate for some endpoints. 2-MBZT is a rodent carcinogen with rubber industry data supporting an association with human bladder cancer. The following BZT toxicity values were derived: (1) acute air target of 110 μg/m(3) based upon a BZT RD(50) study in mice relative to results for formaldehyde; (2) a chronic noncancer target of 18 μg/m(3) based upon the no-observed-adverse-effect level (NOAEL) in a subchronic dietary study in rats, dose route extrapolation, and uncertainty factors that combine to 1000; (3) a cancer unit risk of 1.8E-07/μg-m(3) based upon a published oral slope factor for 2-MBZT and dose-route extrapolation. While there are numerous uncertainties in the BZT toxicology database, this assessment enables BZT to be quantitatively assessed in risk assessments involving synthetic turf fields. However, this is only a screening-level assessment, and research that better defines BZT potency is needed.

  5. Improving Toxicity Assessment of Pesticide Mixtures: The Use of Polar Passive Sampling Devices Extracts in Microalgae Toxicity Tests

    PubMed Central

    Kim Tiam, Sandra; Fauvelle, Vincent; Morin, Soizic; Mazzella, Nicolas

    2016-01-01

    Complexity of contaminants exposure needs to be taking in account for an appropriate evaluation of risks related to mixtures of pesticides released in the ecosystems. Toxicity assessment of such mixtures can be made through a variety of toxicity tests reflecting different level of biological complexity. This paper reviews the recent developments of passive sampling techniques for polar compounds, especially Polar Organic Chemical Integrative Samplers (POCIS) and Chemcatcher® and the principal assessment techniques using microalgae in laboratory experiments. The progresses permitted by the coupled use of such passive samplers and ecotoxicology testing as well as their limitations are presented. Case studies combining passive sampling devices (PSD) extracts and toxicity assessment toward microorganisms at different biological scales from single organisms to communities level are presented. These case studies, respectively, aimed (i) at characterizing the “toxic potential” of waters using dose-response curves, and (ii) at performing microcosm experiments with increased environmental realism in the toxicant exposure in term of cocktail composition and concentration. Finally perspectives and limitations of such approaches for future applications in the area of environmental risk assessment are discussed. PMID:27667986

  6. Demonstration of the Web-based Interspecies Correlation Estimation (Web-ICE) modeling application

    EPA Science Inventory

    The Web-based Interspecies Correlation Estimation (Web-ICE) modeling application is available to the risk assessment community through a user-friendly internet platform (http://epa.gov/ceampubl/fchain/webice/). ICE models are log-linear least square regressions that predict acute...

  7. Demonstration of the Web-based Interspecies Correlation Estimation (Web-ICE) modeling application

    EPA Science Inventory

    The Web-based Interspecies Correlation Estimation (Web-ICE) modeling application is available to the risk assessment community through a user-friendly internet platform (http://epa.gov/ceampubl/fchain/webice/). ICE models are log-linear least square regressions that predict acute...

  8. A test strategy for the assessment of additive attributed toxicity of tobacco products.

    PubMed

    Kienhuis, Anne S; Staal, Yvonne C M; Soeteman-Hernández, Lya G; van de Nobelen, Suzanne; Talhout, Reinskje

    2016-08-01

    The new EU Tobacco Product Directive (TPD) prohibits tobacco products containing additives that are toxic in unburnt form or that increase overall toxicity of the product. This paper proposes a strategy to assess additive attributed toxicity in the context of the TPD. Literature was searched on toxicity testing strategies for regulatory purposes from tobacco industry and governmental institutes. Although mainly traditional in vivo testing strategies have been applied to assess toxicity of unburnt additives and increases in overall toxicity of tobacco products due to additives, in vitro tests combined with toxicogenomics and validated using biomarkers of exposure and disease are most promising in this respect. As such, tests are needed that are sensitive enough to assess additive attributed toxicity above the overall toxicity of tobacco products, which can associate assay outcomes to human risk and exposure. In conclusion, new, sensitive in vitro assays are needed to conclude whether comparable testing allows for assessment of small changes in overall toxicity attributed to additives. A more pragmatic approach for implementation on a short-term is mandated lowering of toxic emission components. Combined with risk assessment, this approach allows assessment of effectiveness of harm reduction strategies, including banning or reducing of additives.

  9. Stepping backward to improve assessment of PCB congener toxicities.

    PubMed Central

    Hansen, L G

    1998-01-01

    Polychlorinated biphenyls (PCBs) are ubiquitous global contaminants that have been intensively investigated for three decades. They are broad-acting toxicants occurring in complex mixtures and accurate risk assessment has proven to be elusive. Focusing on a limited set of end points and emphasizing a fixed set of congeners have led to more streamlined data sets that are meant to expedite hazard characterization and risk assessment for the most potent congeners--aryl hydrocarbon receptor (AhR) agonists. Unfortunately, this has made it impossible to confirm or deny significant contributions from the more prevalent components of the mixtures. PCBs may be only coincidentally present, rather than causal, in some diseases. Still, attempts to determine associations with incomplete residue data may lead to erroneous conclusions and make accurate risk assessment even more elusive. Responses not mediated through the AhR are presented and emphasize large data gaps. Dissimilar analytical reports emphasize that selection of analytes is not consistent. Collectively, these data confirm that AhR-focused objectives unintentionally created the impression that nonplanar PCBs have little if any potential for hazards to humans and wildlife. Near steady-state exposure of healthy adults are probably of minor consequence except for emerging correlations with non-Hodgkin's lymphoma; however, pulses of exposure to more labile mixtures may contribute to developmental effects without leaving a residue record. More broadly based criteria are suggested and harmonization of data collection and presentation are desirable. A more comprehensive list of PCB congeners is proposed that would provide more adequate data upon which to base associations with adverse outcomes. PMID:9539012

  10. Toxicity Assessment of Contaminated Soils of Solid Domestic Waste Landfill

    NASA Astrophysics Data System (ADS)

    Pasko, O. A.; Mochalova, T. N.

    2014-08-01

    The paper delivers the analysis of an 18-year dynamic pattern of land pollutants concentration in the soils of a solid domestic waste landfill. It also presents the composition of the contaminated soils from different areas of the waste landfill during its operating period. The authors calculate the concentrations of the following pollutants: chrome, nickel, tin, vanadium, lead, cuprum, zinc, cobalt, beryllium, barium, yttrium, cadmium, arsenic, germanium, nitrate ions and petrochemicals and determine a consistent pattern of their spatial distribution within the waste landfill area as well as the dynamic pattern of their concentration. Test-objects are used in experiments to make an integral assessment of the polluted soil's impact on living organisms. It was discovered that the soil samples of an animal burial site are characterized by acute toxicity while the area of open waste dumping is the most dangerous in terms of a number of pollutants. This contradiction can be attributed to the synergetic effect of the polluted soil, which accounts for the regularities described by other researchers.

  11. URBAN STORMWATER TOXIC POLLUTANTS: ASSESSMENT, SOURCES, AND TREATABILITY

    EPA Science Inventory

    This paper summarizes an investigation to characterize and treat selected storm water contaminants that are listed as toxic pollutants (termed toxicants in this paper) in the Clean Water Act, Section 307 (Arbuckle et al., 1991). The first project phase investigated typical toxica...

  12. Assessment of chronic inhalation non-cancer toxicity for diethylamine

    PubMed Central

    Grant, Roberta L.; Taiwo, Samuel O.; McCant, Darrell

    2015-01-01

    Abstract A non-cancer inhalation chronic toxicity assessment for diethylamine (DEA, CAS number 109-89-7) was conducted by the Texas Commission on Environmental Quality. A chronic Reference Value (ReV) was determined based on a high-quality study conducted in mice and rats by the National Toxicology Program. Chronic inhalation ReVs are health-based exposure concentrations used in assessing health risks of long-term (i.e. lifetime) chemical exposure. DEA is used industrially as an organic intermediate to produce corrosion inhibitors, and is widely used in rubber, pharmaceuticals, resins, pesticides, insect repellants, dye processing and as a polymerization inhibitor. Although systemic effects have been noted at higher concentrations, DEA acts primarily as a respiratory irritant with effects occurring in the upper respiratory tract. Rats were exposed to 0, 31, 62.5 and 125 ppm DEA and mice to 0, 16, 31 and 62.5 ppm DEA for 6 h/day, 5 days/week for 105 weeks. Mice were slightly more sensitive than rats. The critical effect identified in mice was hyperostosis in the turbinates although DEA caused a number of other non-neoplatic lesions. Dose–response data were suitable to benchmark concentration (BMC) modeling. The human equivalent point of departure (PODHEC) was calculated from the 95% lower limit of the BMC(10) using default duration and animal-to-human dosimetric adjustments. Total uncertainty factors of 90 were applied to the PODHEC to account for variation in sensitivity within the human population, toxicodynamic differences between mice and humans, and database uncertainty. The chronic ReV for DEA is 11 ppb (33 µg/m3). PMID:26671196

  13. Toxicity assessment for the horseshoe crab Carcinoscorpius rotundicauda collected from Cambodia.

    PubMed

    Ngy, Laymithuna; Yu, Chun-Fai; Takatani, Tomohiro; Arakawa, Osamu

    2007-05-01

    In this study, we assessed the toxicity of the horseshoe crab Carcinoscorpius rotundicauda collected from Cambodia within two successive months during rainy (April-May) and dry (December-January) seasons, respectively. Toxicity assessments of the collected specimens by standard mouse bioassay showed marked individual variation, and their toxin profiles by liquid chromatography/mass spectrometry (LC/MS) revealed tetrodotoxin (TTX) was the main toxin while no paralytic shellfish toxins (PSTs) were detected. All specimens were toxic and the highest toxicity values were 315, 113, 60, 47, 44 and 38 mouse units (MU)/g in the tissues of hepatic caecum, egg, viscera, muscle, intestine and testis, respectively. Although the current findings showed that the Cambodian C. rotundicauda was a moderately toxic species, they are not suitable for human consumption due to their toxicity. To the best of our knowledge, this is the first scientific study on toxic marine seafood ever investigated in Cambodian territorial waters.

  14. ROLE OF TOXICITY ASSESSMENT AND MONITORING IN MANAGING THE RECOVERY OF A WASTEWATER RECEIVING STREAM

    SciTech Connect

    Greeley Jr, Mark Stephen; Kszos, Lynn A; Stewart, Arthur J; Smith, John G

    2011-01-01

    We evaluate the roles of a long-term comprehensive toxicity assessment and monitoring program in management and for ecological recovery of a freshwater receiving stream impacted by industrial discharges and legacy contamination. National Pollution Discharge Elimination Permit (NPDES)-driven whole effluent toxicity (WET) tests using Ceriodaphnia and fathead minnows were conducted for more than twenty years to characterize wastewaters at the US National Nuclear Security Agency s Y-12 National Security Complex in Oak Ridge, Tennessee. Ambient toxicity tests also were conducted to assess water samples from EFPC, the stream receiving the wastewater discharges. The ambient tests were conducted as part of an extensive biological monitoring program that included routine surveys of fish, invertebrate and periphyton communities. WET testing, associated toxicant identification evaluations (TIEs), and ambient toxicity monitoring were instrumental in identifying toxicants and their sources at the Y-12 Complex, guiding modifications to wastewater treatment procedures, and assessing the success of various pollution-abatement actions. Through time, as requirements changed and water quality improved, the toxicity monitoring program became more focused. Ambient testing with Ceriodaphnia and fathead minnow larvae also was supplemented with less-standardized but more-sensitive alternative laboratory and in situ bioassays. The Y-12 Complex biological monitoring experience demonstrates the significant roles effluent and ambient toxicity testing can have in controlling and managing toxic discharges to receiving waters. It also emphasizes the value of supplementing WET and standardized ambient toxicity tests with alternative laboratory and in situ toxicity tests tailored to address specific problems.

  15. Interspecies gene function prediction using semantic similarity.

    PubMed

    Yu, Guoxian; Luo, Wei; Fu, Guangyuan; Wang, Jun

    2016-12-23

    Gene Ontology (GO) is a collaborative project that maintains and develops controlled vocabulary (or terms) to describe the molecular function, biological roles and cellular location of gene products in a hierarchical ontology. GO also provides GO annotations that associate genes with GO terms. GO consortium independently and collaboratively annotate terms to gene products, mainly from model organisms (or species) they are interested in. Due to experiment ethics, research interests of biologists and resources limitations, homologous genes from different species currently are annotated with different terms. These differences can be more attributed to incomplete annotations of genes than to functional difference between them. Semantic similarity between genes is derived from GO hierarchy and annotations of genes. It is positively correlated with the similarity derived from various types of biological data and has been applied to predict gene function. In this paper, we investigate whether it is possible to replenish annotations of incompletely annotated genes by using semantic similarity between genes from two species with homology. For this investigation, we utilize three representative semantic similarity metrics to compute similarity between genes from two species. Next, we determine the k nearest neighborhood genes from the two species based on the chosen metric and then use terms annotated to k neighbors of a gene to replenish annotations of that gene. We perform experiments on archived (from Jan-2014 to Jan-2016) GO annotations of four species (Human, Mouse, Danio rerio and Arabidopsis thaliana) to assess the contribution of semantic similarity between genes from different species. The experimental results demonstrate that: (1) semantic similarity between genes from homologous species contributes much more on the improved accuracy (by 53.22%) than genes from single species alone, and genes from two species with low homology; (2) GO annotations of genes from

  16. The effluent toxicity assessment toolbox international perspective on tools and concepts and opportunities for animal alternatives

    EPA Science Inventory

    Effluent testing has been utilized in many countries to assess potential ecological impacts and assist in determining necessary treatment options for environmental protection. However, it was only relatively recently that toxicity-based effluent assessments and subsequent dischar...

  17. Speciation studies and toxicity assessment of complex heavy metal mixtures

    SciTech Connect

    Bundy, K.J.; Mowat, F.

    1996-12-31

    The Microtox{trademark} bioassay and polarographic techniques were used together to identify specific oxidation states and toxicity of metals. The bioassay is based on light reduction by bioluminescent bacteria upon exposure to toxicants. In polarography, a mercury drop substrate`s potential is changed, and the substance of interest is electrochemically reduced. Reduction current is proportional to its concentration. The toxicity of solutions containing heavy metal pollutants was measured. Mercury was found to be most toxic with an acute one minute EC{sub 50} of 0.0162 mg/l. Cu(I) was least toxic. Speciation effects were observed; e.g., Cr(III) was less toxic than Cr(VI); Cu(II) was more toxic than Cu(I). Polarography (which is usually not used for multielement analysis) has been extended to Pb(II) and Cd(II) solution mixtures. Various mixtures were tested to determine if toxicity was predictable from that of individual components, or whether synergistic/antagonistic reactions occur. The resultant EC{sub 50} for a 50-50 As(V)/Cd(II) mixture was consistent with additive behavior; Pb(II)/Cd(II) and Pb(II)/Cu(I) mixtures exhibited antagonistic and synergistic interactions, respectively. Sediments soaked with Pb(II) and Cr(III) have been studied to determine the toxicity. For competitive sorption, the EC{sub 50} value is twice that for Cr(III) alone, presumably because preferential Cr(III) adsorption occurs, blocking Pb(II) adsorption to kaolin.

  18. Sequential assessment via daphnia and zebrafish for systematic toxicity screening of heterogeneous substances.

    PubMed

    Jang, Gun Hyuk; Park, Chang-Beom; Kang, Benedict J; Kim, Young Jun; Lee, Kwan Hyi

    2016-09-01

    Environment and organisms are persistently exposed by a mixture of various substances. However, the current evaluation method is mostly based on an individual substance's toxicity. A systematic toxicity evaluation of heterogeneous substances needs to be established. To demonstrate toxicity assessment of mixture, we chose a group of three typical ingredients in cosmetic sunscreen products that frequently enters ecosystems: benzophenone-3 (BP-3), ethylhexyl methoxycinnamate (EHMC), and titanium dioxide nanoparticle (TiO2 NP). We first determined a range of nominal toxic concentration of each ingredient or substance using Daphnia magna, and then for the subsequent organismal level phenotypic assessment, chose the wild-type zebrafish embryos. Any phenotype change, such as body deformation, led to further examinations on the specific organs of transgenic zebrafish embryos. Based on the systematic toxicity assessments of the heterogeneous substances, we offer a sequential environmental toxicity assessment protocol that starts off by utilizing Daphnia magna to determine a nominal concentration range of each substance and finishes by utilizing the zebrafish embryos to detect defects on the embryos caused by the heterogeneous substances. The protocol showed additive toxic effects of the mixtures. We propose a sequential environmental toxicity assessment protocol for the systematic toxicity screening of heterogeneous substances from Daphnia magna to zebrafish embryo in-vivo models. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Interspecies systems biology uncovers metabolites affecting C. elegans gene expression and life history traits.

    PubMed

    Watson, Emma; MacNeil, Lesley T; Ritter, Ashlyn D; Yilmaz, L Safak; Rosebrock, Adam P; Caudy, Amy A; Walhout, Albertha J M

    2014-02-13

    Diet greatly influences gene expression and physiology. In mammals, elucidating the effects and mechanisms of individual nutrients is challenging due to the complexity of both the animal and its diet. Here, we used an interspecies systems biology approach with Caenorhabditis elegans and two of its bacterial diets, Escherichia coli and Comamonas aquatica, to identify metabolites that affect the animal's gene expression and physiology. We identify vitamin B12 as the major dilutable metabolite provided by Comamonas aq. that regulates gene expression, accelerates development, and reduces fertility but does not affect lifespan. We find that vitamin B12 has a dual role in the animal: it affects development and fertility via the methionine/S-Adenosylmethionine (SAM) cycle and breaks down the short-chain fatty acid propionic acid, preventing its toxic buildup. Our interspecies systems biology approach provides a paradigm for understanding complex interactions between diet and physiology.

  20. Risk Assessment for Toxic Air Pollutants: A Citizen's Guide

    MedlinePlus

    ... East Lansing, MI 48824; $1.00 charge. Air Pollution. Fact Sheet LL. Write to: Dr. Maria Paviova; ... 919)541-0888. Other Health Risk Publications Air Pollution and Health Risk. Evaluating Exposures to Toxic Air ...

  1. Sediment quality assessment and Toxicity Identification Evaluation studies in Lavaca Bay, Texas -- An estuarine Superfund site

    SciTech Connect

    Carr, R.S.; Biedenbach, J.; Hooten, R.; May, L.; Teas, T.

    1995-12-31

    A sediment quality assessment survey was conducted in the Lavaca Bay system which has been designated a Superfund site because of elevated concentrations of mercury and other contaminants (e.g., PAHs) in the sediments. Twenty-four stations were sampled in the initial survey. Sediment pore water was extracted pneumatically and the toxicity of the pore water determined using the sea urchin fertilization and embryological development assays. Based on the results of the toxicity tests, aliquots of the toxic sediments were analyzed for metals, PAHs, and pesticides. Based on these results, several of the most toxic sites were resampled and a preliminary Toxicity Identification Evaluation (TIE) was performed with the pore water using the sea urchin fertilization test. Preliminary results indicated that the toxic components were removed by adsorption on a C-18 column but were not affected by EDTA additions and, therefore, the primary toxicants are hydrophobic in nature.

  2. Leachate composition and toxicity assessment: an integrated approach correlating physicochemical parameters and toxicity of leachates from MSW landfill in Delhi.

    PubMed

    Gupta, Anshu; Paulraj, R

    2017-07-01

    Landfills are considered the most widely practiced method for disposal of municipal solid waste (MSW) and 95% of the total MSW collected worldwide is disposed of in landfills. Leachate produced from MSW landfills may contain a number of pollutants and pose a potential environmental risk for surface as well as ground water. In the present study, chemical analysis and toxicity assessment of landfill leachate have been carried out. Leachate samples were collected from Ghazipur landfill site, New Delhi. Leachates were characterized by measuring the concentration of heavy metals (Pb, Cu, Cr and Ni), 5-day biochemical oxygen demand (BOD5), chemical oxygen demand (COD), pH, electrical conductivity and SO4(2)-. For toxicity testing of leachate, Triticum aestivum (wheat) was selected and testing was done in a time- and dose-dependent manner using the crude leachate. Median lethal concentration after 24 and 48 h of exposure was observed. The main objective of this study was to evaluate toxicity of MSW landfill leachate and establish a possible correlation between the measured physicochemical parameters and resultant toxicity. Statistical analysis showed that toxicity was dependent on the concentration of heavy metals (Pb, Cu), conductivity, and organic matter (COD and BOD5).

  3. Physical assessment of toxicology at nanoscale: nano dose-metrics and toxicity factor

    NASA Astrophysics Data System (ADS)

    Pompa, P. P.; Vecchio, G.; Galeone, A.; Brunetti, V.; Maiorano, G.; Sabella, S.; Cingolani, R.

    2011-07-01

    In this work, we propose a systematic and reproducible evaluation of nanoparticles (NPs) toxicology in living systems, based on a physical assessment and quantification of the toxic effects of NPs by the experimental determination of the key parameter affecting the toxicity outcome (i.e., the number of NPs) and of the NPs ``toxicity factor''. Such a strategy was applied to a well determined scenario, i.e., the ingestion of citrate-capped gold NPs (AuNPs) of different sizes by the model system Drosophila melanogaster. Using these AuNPs as a reference toxicity standard, we were able to define different regions in the multiparametric space of toxicity, enabling the classification of the toxic levels of other nanomaterials, such as quantum dots and pegylated AuNPs. This approach may pave the way to a systematic classification of nanomaterials, leading to important developments in risk assessment and regulatory approval, as well as in a wide range of nanomedicine applications.

  4. Assessing exposure to air toxics relative to asthma.

    PubMed

    Weisel, Clifford P

    2002-08-01

    Asthma is a respiratory disease whose prevalence has been increasing since the mid 1970s and that affects more than 14.6 million residents of the United States. Environmental triggers of asthma include air pollutants that are respiratory irritants. Air toxics emitted into the ambient air are listed in the 1990 Clean Air Act Amendments as hazardous air pollutants (HAPs) if they can adversely affect human health, including the respiratory tract. HAPs include particulate and gaseous-phase pollutants, individual organic compounds and metals, and mixtures. Associations between asthma exacerbation and both particles and indoor volatile organic compounds (VOCs), often referred to as indoor air quality, have been reported. Studies conducted in the United States, Canada, and Europe over the past two decades have shown that most people living in the developed countries spend the majority of their time indoors and that the air concentrations of many air toxics or HAPs are higher indoors than in the ambient air in urban, suburban, and rural settings. Elevated indoor air concentrations result from emissions of air toxics from consumer products, household furnishings, and personal activities. The Relationship of Indoor, Outdoor and Personal Air (RIOPA) study was designed to oversample homes in close proximity to ambient sources, excluding residences where smokers lived, to determine the contribution of ambient emissions to air toxics exposure. The ratios of indoor to outdoor air concentrations of some VOCs in homes measured during RIOPA were much greater than one, and for most other VOCs that had indoor-to-outdoor ratios close to unity in the majority of homes, elevated ratios were found in the paired samples with the highest concentration. Thus, although ambient emissions contribute to exposure of some air toxics indoors as well as outdoors, this was not true for all of the air toxics and especially for the higher end of exposures to most volatile organic air toxics examined

  5. Assessment of acrylamide toxicity using a battery of standardised bioassays.

    PubMed

    Zovko, Mira; Vidaković-Cifrek, Željka; Cvetković, Želimira; Bošnir, Jasna; Šikić, Sandra

    2015-12-01

    Acrylamide is a monomer widely used as an intermediate in the production of organic chemicals, e.g. polyacrylamides (PAMs). Since PAMs are low cost chemicals with applications in various industries and waste- and drinking water treatment, a certain amount of non-polymerised acrylamide is expected to end up in waterways. PAMs are non-toxic but acrylamide induces neurotoxic effects in humans and genotoxic, reproductive, and carcinogenic effects in laboratory animals. In order to evaluate the effect of acrylamide on freshwater organisms, bioassays were conducted on four species: algae Desmodesmus subspicatus and Pseudokirchneriella subcapitata, duckweed Lemna minor and water flea Daphnia magna according to ISO (International Organization for Standardisation) standardised methods. This approach ensures the evaluation of acrylamide toxicity on organisms with different levels of organisation and the comparability of results, and it examines the value of using a battery of low-cost standardised bioassays in the monitoring of pollution and contamination of aquatic ecosystems. These results showed that EC50 values were lower for Desmodesmus subspicatus and Pseudokirchneriella subcapitata than for Daphnia magna and Lemna minor, which suggests an increased sensitivity of algae to acrylamide. According to the toxic unit approach, the values estimated by the Lemna minor and Daphnia magna bioassays, classify acrylamide as slightly toxic (TU=0-1; Class 1). The results obtained from algal bioassays (Desmodesmus subspicatus and Pseudokirchneriella subcapitata) revealed the toxic effect of acrylamide (TU=1-10; Class 2) on these organisms.

  6. Assessment of the toxic potential of hydrocarbon containing sludges.

    PubMed

    Morelli, I S; Vecchioli, G I; Del Panno, M T; Garré, M I; Costanza, O R; Painceira, M T

    1995-01-01

    A short-time period microbial toxicity test-battery was used for the investigation of acute toxicity and genotoxicity of five hydrocarbon containing sludges. Four sludges were obtained from a petrochemical industry and the fifth from a petroleum refinery. Some of the sludges had been stored for long periods. Bioremediation potential assays for soils polluted with each of the sludges were also considered. The sludges did not show acute toxicity in any of the microbial tests performed. However, when the diethylether soluble fractions of these sludges were analyzed some of them showed acute toxicity, for which the clearest results were obtained with the resazurin reduction method. The greatest toxicity detected with the Resazurin based method was found in the diethylether extracts of the freshly collected (not stored) sludges. On the other hand, the diethylether soluble fraction of those sludges that had been stored showed genotoxicity when analyzed with the Salmonella/microsome assay. After the incorporation of the sludges into the soil, increased bacterial counts were noted and substantial hydrocarbon elimination was achieved in 30 days, showing that bioremediation may be a possible technology for cleaning soils polluted with these sludges.

  7. In vitro development of bison embryos using interspecies somatic cell nuclear transfer.

    PubMed

    Seaby, R P; Alexander, B; King, W A; Mastromonaco, G F

    2013-12-01

    Interspecies somatic cell nuclear transfer (interspecies SCNT) has been explored in many domestic and non-domestic animal species. However, problems arise during the development of these embryos, which may be related to species-specific differences in nuclear-cytoplasmic communication. The objectives of this study were to investigate the possibility of producing bison embryos in vitro using interspecies SCNT and assess the developmental potential of these embryos. Treatment groups consisted of cattle in vitro fertilization (IVF) and cattle SCNT as controls and wood bison SCNT, plains bison SCNT and wisent SCNT as experimental groups. Cleavage and blastocyst rates were assessed, and blastocyst quality was determined using total cell number, apoptotic incidence and relative quantification of mitochondria-related genes NRF1, MT-CYB and TFAM. These results indicate that embryos can be produced by interspecies SCNT in all bison species/subspecies (13.34-33.54% blastocyst rates). Although increased incidence of apoptosis was observed in bison SCNT blastocysts compared to cattle SCNT controls (10.45-12.69 vs 8.76, respectively) that corresponded with significantly lower cell numbers (80-87 cells vs >100 cells, respectively), no major differences were observed in the expression of NRF1, MT-CYB and TFAM. This study is the first to report the production of bison embryos by interspecies SCNT. Blastocyst development in all three bison species/subspecies was greater than the rates obtained in previous studies by IVF, which supports the potential role of SCNT for in vitro embryo production in this species. Yet, further investigation of developmental competence and the factors influencing blastocyst quality and viability is required.

  8. [Toxicity tests and their application in safety assessment of water quality].

    PubMed

    Xu, Jian-Ying; Zhao, Chun-Tao; Wei, Dong-Bin

    2014-10-01

    The safety of water quality has important impacts not only on the health of ecological system, but also on the survival and development of human beings. The conventional assessment methods for water quality based on the concentration limits are not reliable. The toxicity tests can vividly reflect the whole adverse biological effects of multiple chemicals in water body, which has been regarded as a necessary supplement for conventional water quality assessment methods based on physicochemical parameters. Considering the chemical pollutants usually have various adverse biological effects, the ecotoxicity testing methods, including lethality, genotoxicity, endocrine disrupting effects, were classified according to the different toxicity types. Then, the potential applications of toxicity testing methods and corresponding evaluation indices in evaluating the toxicity characteristics of ambient water samples were discussed. Particularly, the safety assessment methods for water quality based on the toxicity tests, including potential toxicology, toxicity unit classification system, potential ecotoxic effect probe, and safety assessment of water quality based on toxicity test battery, were summarized. This paper not only systematically reviewed the progress of toxicity tests and their application in safety assessment of water quality, but also provided the scientific basis for the further development in the future.

  9. Toxicity assessment through multiple endpoint bioassays in soils posing environmental risk according to regulatory screening values.

    PubMed

    Rodriguez-Ruiz, A; Asensio, V; Zaldibar, B; Soto, M; Marigómez, I

    2014-01-01

    Toxicity profiles of two soils (a brownfield in Legazpi and an abandoned iron mine in Zugaztieta; Basque Country) contaminated with several metals (As, Zn, Pb and Cu in Legazpi; Zn, Pb, Cd and Cu in Zugaztieta) and petroleum hydrocarbons (in Legazpi) were determined using a multi-endpoint bioassay approach. Investigated soils exceeded screening values (SVs) of regulatory policies in force (Basque Country; Europe). Acute and chronic toxicity bioassays were conducted with a selected set of test species (Vibrio fischeri, Dictyostelium discoideum, Lactuca sativa, Raphanus sativus and Eisenia fetida) in combination with chemical analysis of soils and elutriates, as well as with bioaccumulation studies in earthworms. The sensitivity of the test species and the toxicity endpoints varied depending on the soil. It was concluded that whilst Zugaztieta soil showed very little or no toxicity, Legazpi soil was toxic according to almost all the toxicity tests (solid phase Microtox, D. discoideum inhibition of fruiting body formation and developmental cycle solid phase assays, lettuce seed germination and root elongation test, earthworm acute toxicity and reproduction tests, D. discoideum cell viability and replication elutriate assays). Thus, albeit both soils had similar SVs, their ecotoxicological risk, and therefore the need for intervening, was different for each soil as unveiled after toxicity profiling based on multiple endpoint bioassays. Such a toxicity profiling approach is suitable to be applied for scenario-targeted soil risk assessment in those cases where applicable national/regional soil legislation based on SVs demands further toxicity assessment.

  10. Toxic Assessment of Triclosan and Triclocarban on Artemia salina.

    PubMed

    Xu, Xiaolu; Lu, Yin; Zhang, Deyong; Wang, Yinyin; Zhou, Xianshan; Xu, Huiying; Mei, Yu

    2015-12-01

    In this study, we investigated the possible acute toxic and genotoxic effects of triclosan (TCS) and triclocarban (TCC) on Artemia salina. Genotoxicity was evaluated using single-cell gel electrophoresis and apoptotic frequency assays (Annexin V-FITC/PI assay). Acute toxicity test results showed that TCC (LC50-24 h = 17.8 µg/L) was more toxic than TCS (LC50-24 h = 171.1 µg/L). Significant increases in both genotoxic biomarkers were observed at 24 h after initial exposure, indicating that these two chemicals are potentially dangerous for this aquatic biological model. Although further studies are required, a comparison of data both in vitro and in vivo allowed us to suggest possible mechanisms of action for TCS and TCC in this sentinel organism.

  11. Necessity of toxicity assessment in Turkish industrial discharges (examples from metal and textile industry effluents).

    PubMed

    Sponza, Delia Teresa

    2002-01-01

    Toxicity of some organic and inorganic chemicals to microorganisms is an important consideration in assessing their environmental impact against their economic benefits. Microorganisms play an important role in several environmental processes, both natural and engineered. Some organic and inorganics at toxic levels have been detected in industrial discharges resulting in plant upsets and discharge permit violations. In addition to this, even though in some cases the effluent wastewater does not exceed the discharge limits, the results of toxicity tests show potential toxicity. Toxicity knowledge of effluents can benefit treatment plant operators in optimising plant operation, setting pre-treatment standards, and protecting receiving water quality and in establishing sewer discharge permits to safeguard the plant. In the Turkish regulations only toxicity dilution factor (TDF) with fish is part of the toxicity monitoring program of permissible wastewater discharge. In various countries, laboratory studies involving the use of different organisms and protocol for toxicity assessment was conducted involving a number of discharges. In this study, it was aimed to investigate the acute toxicity of textile and metal industry wastewaters by traditional and enrichment toxicity tests and emphasize the importance of toxicity tests in wastewater discharge regulations. The enrichment toxicity tests are novel applications and give an idea whether there is potential toxicity or growth limiting and stimulation conditions. Different organisms were used such as bacteria (Floc and Coliform bacteria) algae (Chlorella sp.). fish (Lepistes sp.) and protozoan (Vorticella sp.) to represent four tropic levels. The textile industry results showed acute toxicity for at least one organism in 8 out of 23 effluent samples. Acute toxicity for at least two organisms in 7 out of 23 effluent sampling was observed for the metal industry. The toxicity test results were assessed with chemical analyses

  12. Interspecies differences in coagulation profile.

    PubMed

    Siller-Matula, Jolanta M; Plasenzotti, Roberto; Spiel, Alexander; Quehenberger, Peter; Jilma, Bernd

    2008-09-01

    Many animals are used in research on blood coagulation and fibrinolysis, but the relevance of animal models to human health is often questioned because of differences between species. The objective was to find an appropriate animal species, which mimics the coagulation profile in humans most adequately. Species differences in the coagulation profile with and without thrombin stimulation in vitro were assessed in whole blood by Rotation Thromboelastometry (ROTEM). Endogenous thrombin generation was measured in platelet-poor plasma. Measurements were performed in blood from five different species: humans, rats, pigs, sheep and rabbits. In humans and sheep, the clotting time (ROTEM) was in the same range with or without thrombin stimulation and a 100-fold lower dose of thrombin (0.002 IU) was required to cause a shortening in the clotting time as compared to rats, pigs and rabbits (0.2 IU) (p<0.05). Similarly, the endogenous thrombin potential (ETP) was in the same range in humans and sheep. The maximum clot firmness with or without thrombin stimulation was similar in rabbits and humans. The maximum lysis with or without thrombin stimulation was similar in humans and pigs. Significant species differences exist in the coagulation profile with or without thrombin stimulation. Most importantly, sheep had a clotting time most similar to humans and could thus be a suitable species for translational coagulation studies. Moreover, our findings confirm the potential usefulness of pigs as an experimental species to study fibrinolytic pathway and support the usefulness of rabbits as a species for examining platelets.

  13. Acute toxicity prediction to threatened and endangered ...

    EPA Pesticide Factsheets

    Evaluating contaminant sensitivity of threatened and endangered (listed) species and protectiveness of chemical regulations often depends on toxicity data for commonly tested surrogate species. The U.S. EPA’s Internet application Web-ICE is a suite of Interspecies Correlation Estimation (ICE) models that can extrapolate species sensitivity to listed taxa using least-squares regressions of the sensitivity of a surrogate species and a predicted taxon (species, genus, or family). Web-ICE was expanded with new models that can predict toxicity to over 250 listed species. A case study was used to assess protectiveness of genus and family model estimates derived from either geometric mean or minimum taxa toxicity values for listed species. Models developed from the most sensitive value for each chemical were generally protective of the most sensitive species within predicted taxa, including listed species, and were more protective than geometric means models. ICE model estimates were compared to HC5 values derived from Species Sensitivity Distributions for the case study chemicals to assess protectiveness of the two approaches. ICE models provide robust toxicity predictions and can generate protective toxicity estimates for assessing contaminant risk to listed species. Reporting on the development and optimization of ICE models for listed species toxicity estimation

  14. Acute toxicity prediction to threatened and endangered ...

    EPA Pesticide Factsheets

    Evaluating contaminant sensitivity of threatened and endangered (listed) species and protectiveness of chemical regulations often depends on toxicity data for commonly tested surrogate species. The U.S. EPA’s Internet application Web-ICE is a suite of Interspecies Correlation Estimation (ICE) models that can extrapolate species sensitivity to listed taxa using least-squares regressions of the sensitivity of a surrogate species and a predicted taxon (species, genus, or family). Web-ICE was expanded with new models that can predict toxicity to over 250 listed species. A case study was used to assess protectiveness of genus and family model estimates derived from either geometric mean or minimum taxa toxicity values for listed species. Models developed from the most sensitive value for each chemical were generally protective of the most sensitive species within predicted taxa, including listed species, and were more protective than geometric means models. ICE model estimates were compared to HC5 values derived from Species Sensitivity Distributions for the case study chemicals to assess protectiveness of the two approaches. ICE models provide robust toxicity predictions and can generate protective toxicity estimates for assessing contaminant risk to listed species. Reporting on the development and optimization of ICE models for listed species toxicity estimation

  15. New technologies and approaches in toxicity testing and risk assessment (ESOT)

    EPA Science Inventory

    The release of the National Research Council’s Report “Toxicity Testing in the 21st Century: A Vision and a Strategy” in 2007 initiated a broad-based movement in the toxicology community to re-think how toxicity testing and risk assessment are performed. Multiple efforts in the ...

  16. Estimating Toxicity Pathway Activating Doses for High Throughput Chemical Risk Assessments

    EPA Science Inventory

    Estimating a Toxicity Pathway Activating Dose (TPAD) from in vitro assays as an analog to a reference dose (RfD) derived from in vivo toxicity tests would facilitate high throughput risk assessments of thousands of data-poor environmental chemicals. Estimating a TPAD requires def...

  17. New technologies and approaches in toxicity testing and risk assessment (ESOT)

    EPA Science Inventory

    The release of the National Research Council’s Report “Toxicity Testing in the 21st Century: A Vision and a Strategy” in 2007 initiated a broad-based movement in the toxicology community to re-think how toxicity testing and risk assessment are performed. Multiple efforts in the ...

  18. Estimating Toxicity Pathway Activating Doses for High Throughput Chemical Risk Assessments

    EPA Science Inventory

    Estimating a Toxicity Pathway Activating Dose (TPAD) from in vitro assays as an analog to a reference dose (RfD) derived from in vivo toxicity tests would facilitate high throughput risk assessments of thousands of data-poor environmental chemicals. Estimating a TPAD requires def...

  19. Practical approaches for evaluating adrenal toxicity in nonclinical safety assessment

    PubMed Central

    Inomata, Akira; Sasano, Hironobu

    2015-01-01

    The adrenal gland has characteristic morphological and biochemical features that render it particularly susceptible to the actions of xenobiotics. As is the case with other endocrine organs, the adrenal gland is under the control of upstream organs (hypothalamic-pituitary system) in vivo, often making it difficult to elucidate the mode of toxicity of a test article. It is very important, especially for pharmaceuticals, to determine whether a test article-related change is caused by a direct effect or other associated factors. In addition, antemortem data, including clinical signs, body weight, food consumption and clinical pathology, and postmortem data, including gross pathology, organ weight and histopathologic examination of the adrenal glands and other related organs, should be carefully monitored and evaluated. During evaluation, the following should also be taken into account: (1) species, sex and age of animals used, (2) metabolic activation by a cytochrome P450 enzyme(s) and (3) physicochemical properties and the metabolic pathway of the test article. In this review, we describe the following crucial points for toxicologic pathologists to consider when evaluating adrenal toxicity: functional anatomy, blood supply, hormone production in each compartment, steroid biosynthesis, potential medulla-cortex interaction, and species and gender differences in anatomical features and other features of the adrenal gland which could affect vulnerability to toxic effects. Finally practical approaches for evaluating adrenal toxicity in nonclinical safety studies are discussed. PMID:26441474

  20. ASSESSING CONTAMINANT SENSITIVITY OF ENDANGERED AND THREATENED SPECIES: TOXICANT CLASSES

    EPA Science Inventory

    Under the Federal Insecticide, Fungicide and Rodenticide Act, the Toxic Substances Control Act and the Clean Water Act, the U.S. Environmental Protection Agency (EPA) is charged with determining if the manufacture, use, or disposal of a chemical will present an unreasonable risk ...

  1. Assessment of the In Vivo Toxicity of Gold Nanoparticles

    NASA Astrophysics Data System (ADS)

    Chen, Yu-Shiun; Hung, Yao-Ching; Liau, Ian; Huang, G. Steve

    2009-08-01

    The environmental impact of nanoparticles is evident; however, their toxicity due to their nanosize is rarely discussed. Gold nanoparticles (GNPs) may serve as a promising model to address the size-dependent biological response to nanoparticles because they show good biocompatibility and their size can be controlled with great precision during their chemical synthesis. Naked GNPs ranging from 3 to 100 nm were injected intraperitoneally into BALB/C mice at a dose of 8 mg/kg/week. GNPs of 3, 5, 50, and 100 nm did not show harmful effects; however, GNPs ranging from 8 to 37 nm induced severe sickness in mice. Mice injected with GNPs in this range showed fatigue, loss of appetite, change of fur color, and weight loss. Starting from day 14, mice in this group exhibited a camel-like back and crooked spine. The majority of mice in these groups died within 21 days. Injection of 5 and 3 nm GNPs, however, did not induce sickness or lethality in mice. Pathological examination of the major organs of the mice in the diseased groups indicated an increase of Kupffer cells in the liver, loss of structural integrity in the lungs, and diffusion of white pulp in the spleen. The pathological abnormality was associated with the presence of gold particles at the diseased sites, which were verified by ex vivo Coherent anti-Stoke Raman scattering microscopy. Modifying the surface of the GNPs by incorporating immunogenic peptides ameliorated their toxicity. This reduction in the toxicity is associated with an increase in the ability to induce antibody response. The toxicity of GNPs may be a fundamental determinant of the environmental toxicity of nanoparticles.

  2. Comparative in vitro toxicity assessment of perfluorinated carboxylic acids.

    PubMed

    Mahapatra, Cecon T; Damayanti, Nur P; Guffey, Samuel C; Serafin, Jennifer S; Irudayaraj, Joseph; Sepúlveda, Maria S

    2017-06-01

    Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are synthetic fluorinated compounds that are highly bioaccumulative and persistent organic pollutants. Perfluorooctanoic acid (PFOA), an eight-carbon chain perfluorinated carboxylic acid, was used heavily for the production of fluoropolymers, but concerns have led to its replacement by shorter carbon chain homologues such as perfluorohexanoic acid (PFHxA) and perfluorobutanoic acid (PFBA). However, limited toxicity data exist for these substitutes. We evaluated the toxicity of PFOA, PFHxA and PFBA on a zebrafish liver cell line and investigated the effects of exposure on cell metabolism. Gross toxicity after 96 h of exposure was highest for PFOA and PFO(-) , while PFHxA and PFBA exhibited lower toxicity. Although the structural similarity of these compounds to fatty acids suggests the possibility of interference with the transport and metabolism of lipids, we could not detect any differential expression of peroxisome proliferator-activated receptor (ppar-α, -β and -γ), fabp3 and crot genes after 96 h exposure to up to 10 ppm of the test compounds. However, we observed localized lipid droplet accumulation only in PFBA-exposed cells. To study the effects of these compounds on cell metabolism, we conducted fluorescence lifetime imaging microscopy using naturally fluorescent biomarkers, NADH and FAD. The fluorescence lifetimes of NADH and FAD and the bound/free ratio of each of these coenzymes decreased in a dose- and carbon length-dependent manner, suggesting disruption of cell metabolism. In sum, our study revealed that PFASs with shorter carbon chains are less toxic than PFOA, and that exposure to sublethal dosage of PFOA, PFHxA or PFBA affects cell metabolism. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  3. Metabolism of aflatoxins: key enzymes and interindividual as well as interspecies differences.

    PubMed

    Dohnal, Vlastimil; Wu, Qinghua; Kuča, Kamil

    2014-09-01

    Aflatoxins are potent hepatocarcinogen in animal models and suspected carcinogen in humans. The most important aflatoxin in terms of toxic potency and occurrence is aflatoxin B1 (AFB1). In this review, we mainly summarized the key metabolizing enzymes of AFB1 in animals and humans. Moreover, the interindividual and the interspecies differences in AFB1 metabolism are highly concerned. In human liver, CYP3A4 plays an important role in biotransforming AFB1 to the toxic product AFB1-8,9-epoxide. In human lung, CYP2A13 has a significant activity in metabolizing AFB1 to AFB1-8,9-epoxide and AFM1-8,9-epoxide. The epoxide of AFB1-8,9-epoxide could conjugate with glutathione to reduce the toxicity by glutathione-S-transferase (GST). In poultry species, CYP2A6, CYP3A37, CYP1A5, and CYP1A1 are responsible for bioactivation of AFB1. There are interindividual variations in the rate of activation of aflatoxins in various species, and there are also differences between children and adults. The age and living regions are important factors affecting resistance of species to AFB1. The rate of AFB1-8,9-epoxide formation and its conjugation with glutathione are key parameters in interspecies and interindividual differences in sensitivity to the toxic effect of AFB1. This review provides an important information for key metabolizing enzymes and the global metabolism of aflatoxins in different species.

  4. Interspecies Chimerism with Mammalian Pluripotent Stem Cells.

    PubMed

    Wu, Jun; Platero-Luengo, Aida; Sakurai, Masahiro; Sugawara, Atsushi; Gil, Maria Antonia; Yamauchi, Takayoshi; Suzuki, Keiichiro; Bogliotti, Yanina Soledad; Cuello, Cristina; Morales Valencia, Mariana; Okumura, Daiji; Luo, Jingping; Vilariño, Marcela; Parrilla, Inmaculada; Soto, Delia Alba; Martinez, Cristina A; Hishida, Tomoaki; Sánchez-Bautista, Sonia; Martinez-Martinez, M Llanos; Wang, Huili; Nohalez, Alicia; Aizawa, Emi; Martinez-Redondo, Paloma; Ocampo, Alejandro; Reddy, Pradeep; Roca, Jordi; Maga, Elizabeth A; Esteban, Concepcion Rodriguez; Berggren, W Travis; Nuñez Delicado, Estrella; Lajara, Jeronimo; Guillen, Isabel; Guillen, Pedro; Campistol, Josep M; Martinez, Emilio A; Ross, Pablo Juan; Izpisua Belmonte, Juan Carlos

    2017-01-26

    Interspecies blastocyst complementation enables organ-specific enrichment of xenogenic pluripotent stem cell (PSC) derivatives. Here, we establish a versatile blastocyst complementation platform based on CRISPR-Cas9-mediated zygote genome editing and show enrichment of rat PSC-derivatives in several tissues of gene-edited organogenesis-disabled mice. Besides gaining insights into species evolution, embryogenesis, and human disease, interspecies blastocyst complementation might allow human organ generation in animals whose organ size, anatomy, and physiology are closer to humans. To date, however, whether human PSCs (hPSCs) can contribute to chimera formation in non-rodent species remains unknown. We systematically evaluate the chimeric competency of several types of hPSCs using a more diversified clade of mammals, the ungulates. We find that naïve hPSCs robustly engraft in both pig and cattle pre-implantation blastocysts but show limited contribution to post-implantation pig embryos. Instead, an intermediate hPSC type exhibits higher degree of chimerism and is able to generate differentiated progenies in post-implantation pig embryos.

  5. Interspecies Interactions within Oral Microbial Communities

    PubMed Central

    Kuramitsu, Howard K.; He, Xuesong; Lux, Renate; Anderson, Maxwell H.; Shi, Wenyuan

    2007-01-01

    Summary: While reductionism has greatly advanced microbiology in the past 400 years, assembly of smaller pieces just could not explain the whole! Modern microbiologists are learning “system thinking” and “holism.” Such an approach is changing our understanding of microbial physiology and our ability to diagnose/treat microbial infections. This review uses oral microbial communities as a focal point to describe this new trend. With the common name “dental plaque,” oral microbial communities are some of the most complex microbial floras in the human body, consisting of more than 700 different bacterial species. For a very long time, oral microbiologists endeavored to use reductionism to identify the key genes or key pathogens responsible for oral microbial pathogenesis. The limitations of reductionism forced scientists to begin adopting new strategies using emerging concepts such as interspecies interaction, microbial community, biofilms, polymicrobial disease, etc. These new research directions indicate that the whole is much more than the simple sum of its parts, since the interactions between different parts resulted in many new physiological functions which cannot be observed with individual components. This review describes some of these interesting interspecies-interaction scenarios. PMID:18063722

  6. Assessment of Metal Toxicity in Marine Ecosystems: Comparative Toxicity Potentials for Nine Cationic Metals in Coastal Seawater.

    PubMed

    Dong, Yan; Rosenbaum, Ralph K; Hauschild, Michael Z

    2016-01-05

    This study is a first attempt to develop globally applicable and spatially differentiated marine comparative toxicity potentials (CTPs) or ecotoxicity characterization factors for metals in coastal seawater for use in life cycle assessment. The toxicity potentials are based exclusively on marine ecotoxicity data and take account of metal speciation and bioavailability. CTPs were developed for nine cationic metals (Cd, Cr(III), Co, Cu(II), Fe(III), Mn, Ni, Pb, and Zn) in 64 large marine ecosystems (LMEs) covering all coastal waters in the world. The results showed that the CTP of a specific metal varies 3-4 orders of magnitude across LMEs, largely due to different seawater residence times. Therefore, the highest toxicity potential for metals was found in the LMEs with the longest seawater residence times. Across metals, the highest CTPs were observed for Cd, Pb, and Zn. At the concentration levels occurring in coastal seawaters, Fe acts not as a toxic agent but as an essential nutrient and thus has CTPs of zero.

  7. A METHOD OF ASSESSING AIR TOXICS CONCENTRATIONS IN URBAN AREAS USING MOBILE PLATFORM MEASUREMENTS

    EPA Science Inventory

    The objective of this paper is to demonstrate an approach to characterize the spatial variability in ambient air concentrations using mobile platform measurements. This approach may be useful for air toxic assessments in Environmental Justice applications, epidemiological studies...

  8. Selected Issues Associated with the Risk Assessment Process for Pesticides with Persistent, Bioaccumulative, and Toxic Characteristics

    EPA Science Inventory

    This Scientific Advisory Panel meeting will address selected scientific issues associated with assessing the potential ecological risks resulting from use of a pesticide active ingredient which has persistent, bioaccumulative, and toxic (PBT) characteristics. EPA will pose speci...

  9. Selected Issues Associated with the Risk Assessment Process for Pesticides with Persistent, Bioaccumulative, and Toxic Characteristics

    EPA Science Inventory

    This Scientific Advisory Panel meeting will address selected scientific issues associated with assessing the potential ecological risks resulting from use of a pesticide active ingredient which has persistent, bioaccumulative, and toxic (PBT) characteristics. EPA will pose speci...

  10. Webinar Presentation: Epidemiologic Studies of the Effects of Toxic Exposures on Brain and Behavior: Neuropsychological Assessment

    EPA Pesticide Factsheets

    This presentation, Epidemiologic Studies of the Effects of Toxic Exposures on Brain and Behavior: Neuropsychological Assessment, was given at the NIEHS/EPA Children's Centers 2015 Webinar Series: Interdisciplinary Approaches to Neurodevelopment.

  11. Urban land use, air toxics and public health: Assessing hazardous exposures at the neighborhood scale

    SciTech Connect

    Corburn, Jason . E-mail: jtc2105@columbia.edu

    2007-03-15

    Land use data are increasingly understood as important indicators of potential environmental health risk in urban areas where micro-scale or neighborhood level hazard exposure data are not routinely collected. This paper aims to offer a method for estimating the distribution of air toxics in urban neighborhoods using land use information because actual air monitoring data rarely exist at this scale. Using Geographic Information System spatial modeling tools, we estimate air toxics concentrations across neighborhoods in New York City and statistically compare our model with the US Environmental Protection Agency's National Air Toxic Assessment and air monitoring data across three NYC neighborhoods. We conclude that land use data can act as a good proxy for estimating neighborhood scale air toxics, particularly in the absence of monitoring data. In addition, the paper suggests that land use data can expand the reach of environmental impact assessments that routinely exclude analyses of potential exposures to urban air toxics at the neighborhood scale.

  12. Use of hydra for chronic toxicity assessment of waters intended for human consumption.

    PubMed

    Arkhipchuk, Victor V; Blaise, Christian; Malinovskaya, Maria V

    2006-07-01

    Methods developed with the cnidarian, Hydra attenuata (Pallas), have proven effective for screening acute toxicity in aqueous samples, whereas their use in revealing (sub)chronic toxic effects have had mitigated success. We therefore sought to explore manifestations of hydra mortality and abnormal morphological changes, as well as the reproductive capacity of hydras to further enhance the bioassay sensitivity and to assess (sub)chronic toxicity. These parameters were recorded following the onset of experiments after 8, 12 and 19-21 days of hydra exposure. Results obtained with potable waters (30 brands of bottled waters and artesian waters from 9 wells) showed chronic sublethal and lethal effects or reproduction rate inhibition for most samples. The effectiveness of the hydra toxicity test was demonstrated in comparison with other widely used bioassays. Our previous and present investigations suggest that hydra is a reliable and relevant test organism for the assessment of acute and chronic water toxicity.

  13. Assessment of Acute Toxicity of Hexachloroethane in Laboratory Animals

    DTIC Science & Technology

    1978-01-09

    camphoraceous odor, readily sublimes without meltinq and is solubl,: in alcohol. benzene, chloroform, ether and oil: insoluble in water. It is used as a solvent...in explosives, as ý camphor suostitute in celluloid, and as a rubber vulcanizing accelerator.’ It is used in veterinary practice as an anthelminthic...moderately toxic orally, produced reversible eye irritation and little or no skin irritation. Although it sublimes at room temperature

  14. Toxicity assessment and microbial degradation of azo dyes.

    PubMed

    Puvaneswari, N; Muthukrishnan, J; Gunasekaran, P

    2006-08-01

    Toxic effluents containing azo dyes are discharged from various industries and they adversely affect water resources, soil fertility, aquatic organisms and ecosystem integrity. They pose toxicity (lethal effect, genotoxicity, mutagenicity and carcinogenicity) to aquatic organisms (fish, algae, bacteria, etc.) as well as animals. They are not readily degradable under natural conditions and are typically not removed from waste water by conventional waste water treatment systems. Benzidine based dyes have long been recognized as a human urinary bladder carcinogen and tumorigenic in a variety of laboratory animals. Several microorganisms have been found to decolourize, transform and even to completely mineralize azo dyes. A mixed culture of two Pseudomonas strains efficiently degraded mixture of 3-chlorobenzoate (3-CBA) and phenol/cresols. Azoreductases of different microorganisms are useful for the development of biodegradation systems as they catalyze reductive cleavage of azo groups (-N=N-) under mild conditions. In this review, toxic impacts of dyeing factory effluents on plants, fishes, and environment, and plausible bioremediation strategies for removal of azo dyes have been discussed.

  15. Toxicity assessment of refill liquids for electronic cigarettes.

    PubMed

    Varlet, Vincent; Farsalinos, Konstantinos; Augsburger, Marc; Thomas, Aurélien; Etter, Jean-François

    2015-04-30

    We analyzed 42 models from 14 brands of refill liquids for e-cigarettes for the presence of micro-organisms, diethylene glycol, ethylene glycol, hydrocarbons, ethanol, aldehydes, tobacco-specific nitrosamines, and solvents. All the liquids under scrutiny complied with norms for the absence of yeast, mold, aerobic microbes, Staphylococcus aureus, and Pseudomonas aeruginosa. Diethylene glycol, ethylene glycol and ethanol were detected, but remained within limits authorized for food and pharmaceutical products. Terpenic compounds and aldehydes were found in the products, in particular formaldehyde and acrolein. No sample contained nitrosamines at levels above the limit of detection (1 μg/g). Residual solvents such as 1,3-butadiene, cyclohexane and acetone, to name a few, were found in some products. None of the products under scrutiny were totally exempt of potentially toxic compounds. However, for products other than nicotine, the oral acute toxicity of the e-liquids tested seems to be of minor concern. However, a minority of liquids, especially those with flavorings, showed particularly high ranges of chemicals, causing concerns about their potential toxicity in case of chronic oral exposure.

  16. Toxicity Assessment of Refill Liquids for Electronic Cigarettes

    PubMed Central

    Varlet, Vincent; Farsalinos, Konstantinos; Augsburger, Marc; Thomas, Aurélien; Etter, Jean-François

    2015-01-01

    We analyzed 42 models from 14 brands of refill liquids for e-cigarettes for the presence of micro-organisms, diethylene glycol, ethylene glycol, hydrocarbons, ethanol, aldehydes, tobacco-specific nitrosamines, and solvents. All the liquids under scrutiny complied with norms for the absence of yeast, mold, aerobic microbes, Staphylococcus aureus, and Pseudomonas aeruginosa. Diethylene glycol, ethylene glycol and ethanol were detected, but remained within limits authorized for food and pharmaceutical products. Terpenic compounds and aldehydes were found in the products, in particular formaldehyde and acrolein. No sample contained nitrosamines at levels above the limit of detection (1 μg/g). Residual solvents such as 1,3-butadiene, cyclohexane and acetone, to name a few, were found in some products. None of the products under scrutiny were totally exempt of potentially toxic compounds. However, for products other than nicotine, the oral acute toxicity of the e-liquids tested seems to be of minor concern. However, a minority of liquids, especially those with flavorings, showed particularly high ranges of chemicals, causing concerns about their potential toxicity in case of chronic oral exposure. PMID:25941845

  17. Developmental toxicity risk assessment: consensus building, hypothesis formulation, and focused research.

    PubMed

    Kimmel, C A

    1996-01-01

    Risk assessment for developmental toxicity has become more defined over the last decade and the most recent EPA guidelines for developmental toxicity risk assessment were published in 1991. Development of approaches for risk assessment in this area have relied on building of consensus opinion among experts about the interpretation of developmental toxicity data. These discussions have aided in strengthening the scientific basis for risk assessment for developmental toxicity, including the default assumptions that must be used when more complete information on mechanisms of action and pharmacokinetics are unavailable. Such discussions continue on both a national and international basis. The EPA risk assessment guidelines outlined several major areas of research needed to strengthen risk assessment for developmental toxicity and led to the formulation of hypotheses to be tested in focused research projects. Several major research efforts have focused on dose-related mechanisms and biologically based modeling of specific agents, physiologically based pharmacokinetic models of pregnancy that can be scaled across species, and the influence of dose and duration of exposure on developmental outcomes, as well as the delineation of specific biomarkers of adverse developmental effects. Although such research initiatives will require a long-term effort, it is important that attention be focused now on those approaches that can improve the risk assessment process to avoid continued reliance on default approaches that have been used for the past 30 years or more. The impact of the EPA Guidelines for Developmental Toxicity Risk Assessment has been widespread. One of the main purposes for developing risk assessment guidelines by EPA was to communicate procedures to risk assessors inside the agency in an effort to promote consistency. In addition, the guidelines were to communicate to those outside the agency in private industry and other regulatory agencies how EPA would evaluate

  18. In vivo assessment of toxicity and pharmacokinetics of methylglyoxal

    SciTech Connect

    Ghosh, Manju; Talukdar, Dipa; Ghosh, Swapna; Bhattacharyya, Nivedita; Ray, Manju . E-mail: bcmr@mahendra.iacs.res.in; Ray, Subhankar

    2006-04-01

    Previous in vivo studies from several laboratories had shown remarkable curative effect of methylglyoxal on cancer-bearing animals. In contrast, most of the recent in vitro studies have assigned a toxic role for methylglyoxal. The present study was initiated with the objective to resolve whether methylglyoxal is truly toxic in vivo and to reassess its therapeutic potential. Four species of animals, both rodent and non-rodent, were treated with different doses of methylglyoxal through oral, subcutaneous and intravenous routes. Acute (treatment for only 1 day) toxicity tests had been done with mouse and rat. These animals received 2, 1 and 0.3 g of methylglyoxal/kg of body weight in a day through oral, subcutaneous and intravenous routes respectively. Chronic (treatment for around a month) toxicity test had been done with mouse, rat, rabbit and dog. Mouse, rat and dog received 1, 0.3 and 0.1 g of methylglyoxal/kg of body weight in a day through oral, subcutaneous and intravenous routes respectively. Rabbit received 0.55, 0.3 and 0.1 g of methylglyoxal/kg of body weight in a day through oral, subcutaneous and intravenous routes respectively. It had been observed that methylglyoxal had no deleterious effect on the physical and behavioral pattern of the treated animals. Fertility and teratogenecity studies were done with rats that were subjected to chronic toxicity tests. It had been observed that these animals produced healthy litters indicating no damage of the reproductive systems as well as no deleterious effect on the offspring. Studies on several biochemical and hematological parameters of methylglyoxal-treated rats and dogs and histological studies of several organs of methylglyoxal-treated mouse were performed. These studies indicated that methylglyoxal had no apparent deleterious effect on some vital organs of these animals. A detailed pharmacokinetic study was done with mouse after oral administration of methylglyoxal. The effect of methylglyoxal alone and in

  19. Evaluation of Chemical Warfare Agent Percutaneous Vapor Toxicity: Derivation of Toxicity Guidelines for Assessing Chemical Protective Ensembles.

    SciTech Connect

    Watson, A.P.

    2003-07-24

    Percutaneous vapor toxicity guidelines are provided for assessment and selection of chemical protective ensembles (CPEs) to be used by civilian and military first responders operating in a chemical warfare agent vapor environment. The agents evaluated include the G-series and VX nerve agents, the vesicant sulfur mustard (agent HD) and, to a lesser extent, the vesicant Lewisite (agent L). The focus of this evaluation is percutaneous vapor permeation of CPEs and the resulting skin absorption, as inhalation and ocular exposures are assumed to be largely eliminated through use of SCBA and full-face protective masks. Selection of appropriately protective CPE designs and materials incorporates a variety of test parameters to ensure operability, practicality, and adequacy. One aspect of adequacy assessment should be based on systems tests, which focus on effective protection of the most vulnerable body regions (e.g., the groin area), as identified in this analysis. The toxicity range of agent-specific cumulative exposures (Cts) derived in this analysis can be used as decision guidelines for CPE acceptance, in conjunction with weighting consideration towards more susceptible body regions. This toxicity range is bounded by the percutaneous vapor estimated minimal effect (EME{sub pv}) Ct (as the lower end) and the 1% population threshold effect (ECt{sub 01}) estimate. Assumptions of exposure duration used in CPE certification should consider that each agent-specific percutaneous vapor cumulative exposure Ct for a given endpoint is a constant for exposure durations between 30 min and 2 hours.

  20. Test of significant toxicity: a statistical application for assessing whether an effluent or site water is truly toxic.

    PubMed

    Denton, Debra L; Diamond, Jerry; Zheng, Lei

    2011-05-01

    The U.S. Environmental Protection Agency (U.S. EPA) and state agencies implement the Clean Water Act, in part, by evaluating the toxicity of effluent and surface water samples. A common goal for both regulatory authorities and permittees is confidence in an individual test result (e.g., no-observed-effect concentration [NOEC], pass/fail, 25% effective concentration [EC25]), which is used to make regulatory decisions, such as reasonable potential determinations, permit compliance, and watershed assessments. This paper discusses an additional statistical approach (test of significant toxicity [TST]), based on bioequivalence hypothesis testing, or, more appropriately, test of noninferiority, which examines whether there is a nontoxic effect at a single concentration of concern compared with a control. Unlike the traditional hypothesis testing approach in whole effluent toxicity (WET) testing, TST is designed to incorporate explicitly both α and β error rates at levels of toxicity that are unacceptable and acceptable, given routine laboratory test performance for a given test method. Regulatory management decisions are used to identify unacceptable toxicity levels for acute and chronic tests, and the null hypothesis is constructed such that test power is associated with the ability to declare correctly a truly nontoxic sample as acceptable. This approach provides a positive incentive to generate high-quality WET data to make informed decisions regarding regulatory decisions. This paper illustrates how α and β error rates were established for specific test method designs and tests the TST approach using both simulation analyses and actual WET data. In general, those WET test endpoints having higher routine (e.g., 50th percentile) within-test control variation, on average, have higher method-specific α values (type I error rate), to maintain a desired type II error rate. This paper delineates the technical underpinnings of this approach and demonstrates the benefits

  1. Severe Pulmonary Toxicity After Myeloablative Conditioning Using Total Body Irradiation: An Assessment of Risk Factors

    SciTech Connect

    Kelsey, Chris R.; Horwitz, Mitchell E.; Chino, Junzo P.; Craciunescu, Oana; Steffey, Beverly; Folz, Rodney J.; Chao, Nelson J.; Rizzieri, David A.; Marks, Lawrence B.

    2011-11-01

    Purpose: To assess factors associated with severe pulmonary toxicity after myeloablative conditioning using total body irradiation (TBI) followed by allogeneic stem cell transplantation. Methods and Materials: A total of 101 adult patients who underwent TBI-based myeloablative conditioning for hematologic malignancies at Duke University between 1998 and 2008 were reviewed. TBI was combined with high-dose cyclophosphamide, melphalan, fludarabine, or etoposide, depending on the underlying disease. Acute pulmonary toxicity, occurring within 90 days of transplantation, was scored using Common Terminology Criteria for Adverse Events version 3.0. Actuarial overall survival and the cumulative incidence of acute pulmonary toxicity were calculated via the Kaplan-Meier method and compared using a log-rank test. A binary logistic regression analysis was performed to assess factors independently associated with acute severe pulmonary toxicity. Results: The 90-day actuarial risk of developing severe (Grade 3-5) pulmonary toxicity was 33%. Actuarial survival at 90 days was 49% in patients with severe pulmonary toxicity vs. 94% in patients without (p < 0.001). On multivariate analysis, the number of prior chemotherapy regimens was the only factor independently associated with development of severe pulmonary toxicity (odds ratio, 2.7 per regimen). Conclusions: Severe acute pulmonary toxicity is prevalent after TBI-based myeloablative conditioning regimens, occurring in approximately 33% of patients. The number of prior chemotherapy regimens appears to be an important risk factor.

  2. Applicability of ambient toxicity testing to national or regional water-quality assessment

    USGS Publications Warehouse

    Elder, John F.

    1990-01-01

    Comprehensive assessment of the quality of natural waters requires a multifaceted approach. Descriptions of existing conditions may be achieved by various kinds of chemical and hydrologic analyses, whereas information about the effects of such conditions on living organisms depends on biological monitoring. Toxicity testing is one type of biological monitoring that can be used to identify possible effects of toxic contaminants. Based on experimentation designed to monitor responses of organisms to environmental stresses, toxicity testing may have diverse purposes in water-quality assessments. These purposes may include identification of areas that warrant further study because of poor water quality or unusual ecological features, verification of other types of monitoring, or assessment of contaminant effects on aquatic communities. Toxicity-test results are most effective when used as a complement to chemical analyses, hydrologic measurements, and other biological monitoring. However, all toxicity-testing procedures have certain limitations that must be considered in developing the methodology and applications of toxicity testing in any large-scale water-quality-assessment program. A wide variety of toxicity-test methods have been developed to fulfill the needs of diverse applications. The methods differ primarily in the selections made relative to four characteristics: (1) test species, (2) endpoint (acute or chronic), (3) test-enclosure type, and (4) test substance (toxicant) that functions as the environmental stress. Toxicity-test approaches vary in their capacity to meet the needs of large-scale assessments of existing water quality. Ambient testing, whereby the test organism is exposed to naturally occurring substances that contain toxicant mixtures in an organic or inorganic matrix, is more likely to meet these needs than are procedures that call for exposure of the test organisms to known concentrations of a single toxicant. However, meaningful

  3. Assessing metal toxicity in sediments of Yellow River wetland and its surrounding coastal areas, China

    NASA Astrophysics Data System (ADS)

    Li, Li; Wang, Xiaojing; Zhu, Aimei; Yang, Gang; Liu, Jihua

    2014-12-01

    Seventy one surface sediments were collected from Yellow River (YR) wetland and its surrounding coastal areas, mainly in Laizhou Bay, China. The equilibrium partitioning (EqP) model and empirical sediment quality guidelines (SQGs) were applied to assess the potential metal toxicity in the collected sediments. The results show that, based on the EqP model, 15% of stations exhibited potential metal toxicity. Several metals (Cu, Ni and Cr) exceeded the empirical SQGs (59-100% of the time), however these guidelines may not be suitable for use in the Bohai Sea owing to the background concentrations. As a result, the EqP model is found to be a more useful method for assessing potential metal toxicity in Bohai Sea sediment than the empirical SQGs. Additionally, we have provided new insights on assessing metal toxicity in sediment of low organic carbon and acid volatile sulfide concentrations, which may be useful for other coastal areas in China.

  4. TOXIC SUBSTANCES FROM COAL COMBUSTION A COMPREHENSIVE ASSESSMENT

    SciTech Connect

    A KOLKER; AF SAROFIM; CA PALMER; FE HUGGINS; GP HUFFMAN; J LIGHTY; JJ HELBLE; JOL WENDT; MR AMES; N YAP; R FINKELMAN; R. MAMANI-PACO; SJ MROCZKOWSKY; T PANAGIOTOU; W SEAMES

    1999-01-28

    The technical objectives of this project are: (a) To identify the effect of the mode-of-occurrence of toxic elements in coal on the partitioning of these elements among vapor, submicron fume, and fly ash during the combustion of pulverized coal, (b) To identify the mechanisms governing the post-vaporization interaction of toxic elements and major minerals or unburnt char, (c) To determine the effect of combustion environment (i.e., fuel rich or fuel lean) on the partitioning of trace elements among vapor, submicron fume, and fly ash during the combustion of pulverized coal, (d) To model the partitioning of toxic elements among various chemical species in the vapor phase and between the vapor phase and complex aluminosilicate melts, (e) To develop the new Toxics Partitioning Engineering Model (ToPEM), applicable to all combustion conditions including new fuels and coal blends, low-NO{sub x} combustion systems, and new power generation plants. A description of the work plan for accomplishing these objectives is presented in Section 2.1 of this report. The work discussed in this report covers the reporting period from 1 October 1998 to 31 December 1998. During this quarter, basic coal testing at USGS was completed. Total sulfur contents range from 0.43 wt-% in the Wyodak to 2.68 wt-% in the Ohio sample. In the North Dakota and Ohio samples, about half of the total sulfur is pyritic and half is organic. The North Dakota sample also contains a minor amount of sulfate, consistent with the presence of barite in this sample. In the Wyodak sample, the majority of the sulfur is organic. Preliminary mineralogy of the three Phase II coals was determined by SEM/EDX. The Ohio coal contains all of the five most common major phases: quartz, illitic clay, kaolinitic clay, pyrite and calcite. Based on this preliminary work, the North Dakota sample appears to lack both kaolinite and calcite, and the Wyodak sample appears to lack calcite. Subsequent SEM work will attempt to reconfirm

  5. Comparison of the sensitivity of seven marine and freshwater bioassays as regards antidepressant toxicity assessment.

    PubMed

    Minguez, Laetitia; Di Poi, Carole; Farcy, Emilie; Ballandonne, Céline; Benchouala, Amira; Bojic, Clément; Cossu-Leguille, Carole; Costil, Katherine; Serpentini, Antoine; Lebel, Jean-Marc; Halm-Lemeille, Marie-Pierre

    2014-11-01

    The hazards linked to pharmaceutical residues like antidepressants are currently a major concern of ecotoxicology because they may have adverse effects on non-target aquatic organisms. Our study assesses the ecotoxicity of three antidepressants (fluoxetine, sertraline and clomipramine) using a battery of marine and freshwater species representing different trophic levels, and compares the bioassay sensitivity levels. We selected the following bioassays: the algal growth inhibition test (Skeletonema marinoi and Pseudokirchneriella subcapitata), the microcrustacean immobilization test (Artemia salina and Daphnia magna), development and adult survival tests on Hydra attenuata, embryotoxicity and metamorphosis tests on Crassostrea gigas, and in vitro assays on primary cultures of Haliotis tuberculata hemocytes. The results showed high inter-species variability in EC50-values ranging from 43 to 15,600 µg/L for fluoxetine, from 67 to 4,400 µg/L for sertraline, and from 4.70 µg/L to more than 100,000 µg/L for clomipramine. Algae (S. marinoi and P. subcapitata) and the embryo-larval stages of the oyster C. gigas were the most sensitive taxa. This raises an issue due to their ecological and/or economic importance. The marine crustacean A. salina was the least sensitive species. This difference in sensitivity between bioassays highlights the importance of using a test battery.

  6. Plugging in or going wireless: strategies for interspecies electron transfer

    PubMed Central

    Shrestha, Pravin Malla; Rotaru, Amelia-Elena

    2014-01-01

    Interspecies exchange of electrons enables a diversity of microbial communities to gain energy from reactions that no one microbe can catalyze. The first recognized strategies for interspecies electron transfer were those that relied on chemical intermediates that are recycled through oxidized and reduced forms. Well-studied examples are interspecies H2 transfer and the cycling of sulfur intermediates in anaerobic photosynthetic communities. Direct interspecies electron transfer (DIET) in which two species establish electrical contact is an alternative. Electrical contacts documented to date include electrically conductive pili, as well as conductive iron minerals and conductive carbon moieties such as activated carbon and biochar. Interspecies electron transfer is central to the functioning of methane-producing microbial communities. The importance of interspecies H2 transfer in many methanogenic communities is clear, but under some circumstances DIET predominates. It is expected that further mechanistic studies and broadening investigations to a wider range of environments will help elucidate the factors that favor specific forms of interspecies electron exchange under different environmental conditions. PMID:24904551

  7. Synthesis and toxicity assessment of 3-oxobutanamides against human lymphocytes and isolated mitochondria.

    PubMed

    Razzaghi-Asl, Nima; Seydi, Enaytollah; Alikhani, Radin; Rezvani, Saba; Miri, Ramin; Salimi, Ahmad

    2017-03-07

    To reduce costly late-phase compound scrubbing, there has been an increased focus on assessing compounds within in vitro assays that predict properties of human safety liabilities, before preclinical in vivo studies. The aim of our study was to answer the questions that whether the toxicity risk of a series of 3-oxobutanamide derivatives could be predicted by using of human lymphocytes and their isolated mitochondria. Using biochemical and flow cytometry assessments, we demonstrated that exposure of lymphocytes and isolated mitochondria to five 3-oxobutanamide derivatives (1-5) did not exhibit remarkable toxicity at low concentrations (50-500μM) but toxicity could be observed at high concentrations (1000 and 2000μM), particularly for N-(5-(4-bromophenyl)-3-isoxazolyl)-3-oxobutanamide (4) and N-(2-benzothiazolyl)-3-oxo butanamide (5). Compounds 4, 5 and partly N-(5-methyl-3-isoxazol yl)-3-oxo butanamide (1) also showed a marked cellular and mitochondrial toxicity while compound 5 displayed superior toxicity. Compound 5 induced cytotoxicity on human blood lymphocytes which was associated with the generation of intracellular reactive oxygen species (ROS), mitochondrial membrane potential (MMP) collapse, lysosomal membrane injury, lipid peroxidation and depletion of glutathione. Our results suggested that among assessed compounds, increased toxicity of compound 5 compared to other compounds could be likely attributed to the presence of bromine substituent in 5. Finally our findings proposed that using of antioxidants and mitochondrial/lysosomal protective agents could be beneficial in decreasing the toxicity of 5.

  8. A comparative toxicity assessment of materials used in aquatic construction.

    PubMed

    Lalonde, Benoit A; Ernst, William; Julien, Gary; Jackman, Paula; Doe, Ken; Schaefer, Rebecca

    2011-10-01

    Comparative toxicity testing was performed on selected materials that may be used in aquatic construction projects. The tests were conducted on the following materials: (1) untreated wood species (hemlock [Tsuga ssp], Western red cedar (Thuja plicata), red oak [Quercus rubra], Douglas fir [Pseudotsuga menziesii], red pine [Pinus resinosa], and tamarack [Larix ssp]); (2) plastic wood; (3) Ecothermo wood hemlock stakes treated with preservatives (e.g., chromated copper arsenate [CCA], creosote, alkaline copper quaternary [ACQ], zinc naphthenate, copper naphthenate, and Lifetime Wood Treatment); (4) epoxy-coated steel; (5) hot-rolled steel; (6) zinc-coated steel; and (7) concrete. Those materials were used in acute lethality tests with rainbow trout, Daphnia magna, Vibrio fischeri and threespine stickleback. The results indicated the following general ranking of the materials (from the lowest to highest LC(50) values); ACQ > creosote > zinc naphthenate > copper naphthenate > CCA (treated at 22.4 kg/m(3)) > concrete > red pine > western red cedar > red oak > zinc-coated steel > epoxy-coated steel > CCA (6.4 kg/m(3)). Furthermore, the toxicity results indicated that plastic wood, certain untreated wood species (hemlock, tamarack, Douglas fir, and red oak), hot-rolled steel, Ecothermo wood, and wood treated with Lifetime Wood Treatment were generally nontoxic to the test species.

  9. Assessment of toxic metals in waste personal computers.

    PubMed

    Kolias, Konstantinos; Hahladakis, John N; Gidarakos, Evangelos

    2014-08-01

    Considering the enormous production of waste personal computers nowadays, it is obvious that the study of their composition is necessary in order to regulate their management and prevent any environmental contamination caused by their inappropriate disposal. This study aimed at determining the toxic metals content of motherboards (printed circuit boards), monitor glass and monitor plastic housing of two Cathode Ray Tube (CRT) monitors, three Liquid Crystal Display (LCD) monitors, one LCD touch screen monitor and six motherboards, all of which were discarded. In addition, concentrations of chromium (Cr), cadmium (Cd), lead (Pb) and mercury (Hg) were compared with the respective limits set by the RoHS 2002/95/EC Directive, that was recently renewed by the 2012/19/EU recast, in order to verify manufacturers' compliance with the regulation. The research included disassembly, pulverization, digestion and chemical analyses of all the aforementioned devices. The toxic metals content of all samples was determined using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The results demonstrated that concentrations of Pb in motherboards and funnel glass of devices with release dates before 2006, that is when the RoHS Directive came into force, exceeded the permissible limit. In general, except from Pb, higher metal concentrations were detected in motherboards in comparison with plastic housing and glass samples. Finally, the results of this work were encouraging, since concentrations of metals referred in the RoHS Directive were found in lower levels than the legislative limits. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Occupational health assessment of chromite toxicity among Indian miners

    PubMed Central

    Das, Alok Prasad; Singh, Shikha

    2011-01-01

    Elevated concentration of hexavalent chromium pollution and contamination has contributed a major health hazard affecting more than 2 lakh mine workers and inhabitants residing in the Sukinda chromite mine of Odisha, India. Despite people suffering from several forms of ill health, physical and mental deformities, constant exposure to toxic wastes and chronic diseases as a result of chromite mining, there is a tragic gap in the availability of 'scientific’ studies and data on the health hazards of mining in India. Occupational Safety and Health Administration, Odisha State Pollution Control Board and the Odisha Voluntary Health Association data were used to compile the possible occupational health hazards, hexavalent chromium exposure and diseases among Sukinda chromite mines workers. Studies were reviewed to determine the routes of exposure and possible mechanism of chromium induced carcinogenicity among the workers. Our studies suggest all forms of hexavalent chromium are regarded as carcinogenic to workers however the most important routes of occupational exposure to Cr (VI) are inhalation and dermal contact. This review article outlines the physical, chemical, biological and psychosocial occupational health hazards of chromite mining and associated metallurgical processes to monitor the mining environment as well as the miners exposed to these toxicants to foster a safe work environment. The authors anticipate that the outcome of this manuscript will have an impact on Indian chromite mining industry that will subsequently bring about improvements in work conditions, develop intervention experiments in occupational health and safety programs. PMID:21808494

  11. Toxicity Assessment of Expired Pesticides to Green Algae Pseudokirchneriella subcapitata

    PubMed Central

    Satyavani, G.; Chandrasehar, G.; Varma, K. Krishna; Goparaju, A.; Ayyappan, S.; Reddy, P. Neelakanta; Murthy, P. Balakrishna

    2012-01-01

    In order to investigate the effect of expired pesticides on the yield and growth rate of green algae Pseudokirchneriella subcapitata, a study was conducted as per the Organisation for Economic Cooperation and Development (OECD) guideline number 201. Fifteen expired pesticide formulations, most commonly used in Indian agriculture, were tested in comparison with their unexpired counterparts. The expired pesticide formulations studied belonged to various class and functional groups: organophosphate, pyrethroid-based insecticides; azole-based fungicides; acetamide, propionate, acetic acid-based herbicides; fungicides mixtures containing two actives—azole and dithiocarbamate. The toxicity endpoints of yield (EyC50: 0–72 h) and growth rate (ErC50: 0–72 h) of Pseudokirchneriella subcapitata for each pesticide formulation (both expired and unexpired pesticides) were determined statistically using TOXSTAT 3.5 version software. The results pointed out that some expired pesticide formulations exhibited higher toxicity to tested algal species, as compared to the corresponding unexpired pesticides. These data thus stress the need for greater care to dispose expired pesticides to water bodies, to avoid the effects on aquatic ecospecies tested. PMID:23762633

  12. Assessing and managing toxicities induced by kinase inhibitors.

    PubMed

    Castoldi, Raffaella E; Pennella, Giulia; Saturno, Grazia S; Grossi, Pietro; Brughera, Marco; Venturi, Miro

    2007-01-01

    Currently, several protein kinase-modulating compounds have received market approval across a range of diverse therapeutic indications. Furthermore, a large number of chemical and biological protein kinase-modulating compounds are undergoing testing at the preclinical and clinical level. Protein kinases are both major pharmacological targets and diagnostically useful. Progression of kinase modulators toward clinically viable therapies is aided by a reversible mechanism of action, short treatment durations and patient-compliant administration routes. However, the physiological role and essential functional activity of protein kinases in many organs and tissues complicates, to different extents, the development of useful, highly potent protein kinase modulators. In this review, we will highlight common problems in the development of these compounds and lessons learned from the extensive preclinical and clinical characterization of some key protein kinase modulators, some of which have either entered and successfully completed clinical trials or have been abandoned as a consequence of unacceptable toxicity issues. We will ultimately explore how molecular profiling tools combined with histopathological endpoints can be adopted to address and further understand these toxicities in humans and understand their relevance and characterization when identified during early animal experiments.

  13. Interspecies genetics of eating disorder traits

    PubMed Central

    Kas, Martien J. H.; Kaye, Walter H.; Mathes, Wendy Foulds; Bulik, Cynthia M.

    2008-01-01

    Family and twin studies have indicated that genetic factors play a role in the development of eating disorders, such as anorexia and bulimia nervosa, but novel views and tools may enhance the identification of neurobiological mechanisms underlying these conditions. Here we propose an integrative genetic approach to reveal novel biological substrates of eating disorder traits analogous in mouse and human. For example, comparable to behavioral hyperactivity that is observed in 40-80% of anorexia nervosa patients, inbred strains of mice with different genetic backgrounds are differentially susceptible to develop behavioral hyperactivity when food restricted. In addition, a list of characteristics that are relevant to eating disorders and approaches to their measurement in humans together with potential analogous rodent models has been generated. Interspecies genetics of neurobehavioral characteristics of eating disorders has the potential to open new roads to identify and functionally test genetic pathways that influence neurocircuits relevant for these heterogeneous psychiatric disorders. PMID:18646037

  14. Promoting Interspecies Electron Transfer with Biochar

    PubMed Central

    Chen, Shanshan; Rotaru, Amelia-Elena; Shrestha, Pravin Malla; Malvankar, Nikhil S.; Liu, Fanghua; Fan, Wei; Nevin, Kelly P.; Lovley, Derek R.

    2014-01-01

    Biochar, a charcoal-like product of the incomplete combustion of organic materials, is an increasingly popular soil amendment designed to improve soil fertility. We investigated the possibility that biochar could promote direct interspecies electron transfer (DIET) in a manner similar to that previously reported for granular activated carbon (GAC). Although the biochars investigated were 1000 times less conductive than GAC, they stimulated DIET in co-cultures of Geobacter metallireducens with Geobacter sulfurreducens or Methanosarcina barkeri in which ethanol was the electron donor. Cells were attached to the biochar, yet not in close contact, suggesting that electrons were likely conducted through the biochar, rather than biological electrical connections. The finding that biochar can stimulate DIET may be an important consideration when amending soils with biochar and can help explain why biochar may enhance methane production from organic wastes under anaerobic conditions. PMID:24846283

  15. Syntrophy Goes Electric: Direct Interspecies Electron Transfer.

    PubMed

    Lovley, Derek R

    2017-09-08

    Direct interspecies electron transfer (DIET) has biogeochemical significance, and practical applications that rely on DIET or DIET-based aspects of microbial physiology are growing. Mechanisms for DIET have primarily been studied in defined cocultures in which Geobacter species are one of the DIET partners. Electrically conductive pili (e-pili) can be an important electrical conduit for DIET. However, there may be instances in which electrical contacts are made between electron transport proteins associated with the outer membranes of the partners. Alternatively, DIET partners can plug into conductive carbon materials, such as granular activated carbon, carbon cloth, and biochar, for long-range electron exchange without the need for e-pili. Magnetite promotes DIET, possibly by acting as a substitute for outer-surface c-type cytochromes. DIET is the primary mode of interspecies electron exchange in some anaerobic digesters converting wastes to methane. Promoting DIET with conductive materials shows promise for stabilizing and accelerating methane production in digesters, permitting higher organic loading rates. Various lines of evidence suggest that DIET is important in terrestrial wetlands, which are an important source of atmospheric methane. DIET may also have a role in anaerobic methane oxidation coupled to sulfate reduction, an important control on methane releases. The finding that DIET can serve as the source of electrons for anaerobic photosynthesis further broadens its potential environmental significance. Microorganisms capable of DIET are good catalysts for several bioelectrochemical technologies and e-pili are a promising renewable source of electronic materials. The study of DIET is in its early stages, and additional investigation is required to better understand the diversity of microorganisms that are capable of DIET, the importance of DIET to carbon and electron flow in anaerobic environments, and the biochemistry and physiology of DIET.

  16. Assessment of the lung toxicity of copper oxide nanoparticles: current status.

    PubMed

    Ahamed, Maqusood; Akhtar, Mohd Javed; Alhadlaq, Hisham A; Alrokayan, Salman A

    2015-01-01

    Copper oxide nanoparticles (CuO NPs) are being used in several industrial and commercial products. Inhalation is one of the most significant routes of metal oxide NP exposure. Hence, the toxicity of CuO NPs in lung tissues is of great concern. In vitro studies have indicated that CuO NPs induce cytotoxicity, oxidative stress and genetic toxicity in cultivated human lung cells. Leaching of Cu ions, reactive oxygen species generation and autophagy appear to be the underlying mechanisms of Cu NP toxicity in lung cells. In vivo studies on the lung toxicity of CuO NPs are largely lacking. Some studies have shown that intratracheal instillation of CuO NPs induced oxidative stress, inflammation and neoplastic lesions in rats. This review critically assessed the current findings of the toxicity of CuO NPs in the lung.

  17. Assessment of sediment toxicity during anaerobic biodegradation of vegetable oil using Microtox and Hyalella azteca bioassays.

    PubMed

    Li, Zhengkai; Lee, Kenneth; Cobanli, Susan E; King, Thomas; Wrenn, Brian A; Doe, Kenneth G; Jackman, Paula M; Venosa, Albert D

    2007-02-01

    The potential ecological impacts of anaerobic degradation of vegetable oil on freshwater sediments were investigated. Sediment toxicity was evaluated using two regulatory biotests: the Microtox Solid Phase Test and an amphipod (Hyalella azteca) bioassay. The results of the Microtox test showed that the toxicity of the vegetable-oil-contaminated sediments (about 17-33 g oil/kg dry sediments) increased after 2 weeks incubation and then decreased to near background levels after incubation for 8 weeks under anaerobic conditions. The amphipod toxicity bioassay showed that the toxicity of fresh contaminated sediments decreased over time and returned to background levels within 8 weeks. These results suggest that the impact of vegetable oils on organisms within sediments may be limited. To account for the significance of environmental conditions, additional studies over a wide range of incubation conditions (e.g., temperature, nutrient concentration) and other test organisms at various trophic levels are recommended for both acute and chronic toxicity assessment.

  18. Compliance with the Air Toxics Hot Spots' Information and assessment Act of 1987, AB 2588

    SciTech Connect

    Cosgrove, K.; Mauricio, O. )

    1991-02-01

    Compliance with the Air Toxics Hot Spots Information and Assessment Act of 1987, AB 2588, requires certain facilities to submit (1) a comprehensive air toxics emission inventory plan, and (2) an emission inventory report and risk assessment (for high-priority facilities). The inventory plan shall include (1) a flow diagram identifying each actual and potential discrete emission point of release and the general location where fugitive emissions may occur; (2) a list of equipment and designation of the hazardous materials for which emissions are to be quantified; (3) quantification methods, and (4) reporting forms for each source as specified by the pending guidelines. Following agency approval, the emission inventory plan will be implemented and an air toxics emission report issued. The air toxics Inventory Report (ATIR) presents procedures for estimating releases of toxics. This report must be prepared for reporting year 1989. Reporting forms shall be prepared pursuant to the requirements specified in Subchapter 7.6, Section 93322 of Title 17 of the CCR. Following review of the emissions report air quality management districts, ARB, and the California Department of Health Services (DHA) will prioritize facilities and will consider (1) potency, toxicity, quantity, and volume of releases; (2) proximity of the facility to potential receptors; and (3) other factors that may indicate the facility poses significant risk. High-priority facilities will be required to submit health-risk assessments. The health-risk assessment is a detailed, comprehensive analysis to evaluate and predict dispersion of hazardous substances, and the potential for human exposure.

  19. Interspecies extrapolation in carcinogenesis: prediction between rats and mice.

    PubMed

    Gold, L S; Bernstein, L; Magaw, R; Slone, T H

    1989-05-01

    Interspecies extrapolation in carcinogenesis is studied by evaluating prediction from rats to mice and from mice to rats. The Carcinogenic Potency Database, which includes 3500 cancer tests conducted in rats or mice on 955 compounds, is used for the analysis. About half of the chemicals tested for carcinogenicity are positive in at least one test, and this proportion is similar when rats and mice are considered separately. For 392 chemicals tested in both species, 76% of the rat carcinogens are positive in the mouse, and 70% of mouse carcinogens are positive in the rat. When compounds composed solely of chlorine, carbon, hydrogen, and, optionally, oxygen are excluded from the analysis, 75% of mouse carcinogens are positive in the rat. Overall concordance (the percentage positive in both species plus the percentage negative in both) is 76%. Three factors that affect prediction between rats and mice are discussed: chemical class, mutagenicity in the Salmonella assay, and the dose level at which a chemical is toxic. Prediction is more accurate for mutagens than non-mutagens and for substances that are toxic at low (versus only at high) doses. Species differences are not the result of failure in the bioassay to attain the maximum tolerated dose in the negative species or of more frequent testing in the positive species. An analysis of the predictive value of positivity for the 10 most common target sites indicates that most sites are good predictors of carcinogenicity at some site in the other species; the poorest predictors among these common sites are the rat urinary bladder and the mouse liver.

  20. Assessing the pulmonary toxicity of single-walled carbon nanohorns

    SciTech Connect

    Lynch, Rachel M; Voy, Brynn H; Glass-Mattie, Dana F; Mahurin, Shannon Mark; Saxton, Arnold; Donnel, Robert L.; Cheng, Mengdawn

    2007-01-01

    Previous studies have suggested that single-walled carbon nanotubes (SWCNTs) may pose a pulmonary hazard. We investigated the pulmonary toxicity of single-walled carbon nanohorns (SWCNHs), a relatively new carbon-based nanomaterial that is structurally similar to SWCNTs. Mice were exposed to 30 {micro}g of surfactant-suspended SWCNHs or an equal volume of vehicle control by pharyngeal aspiration and sacrificed 24 hours or 7 days post-exposure. Total and differential cell counts and cytokine analysis of bronchoalveolar lavage fluid demonstrated a mild inflammatory response which was mitigated by day 7 post-exposure. Whole lung microarray analysis demonstrated that SWCNH-exposure did not lead to robust changes in gene expression. Finally, histological analysis showed no evidence of granuloma formation or fibrosis following SWCNH aspiration. These combined results suggest that SWCNH is a relatively innocuous nanomaterial when delivered to mice in vivo using aspiration as a delivery mechanism.

  1. Assessing the pulmonary toxicity of single-walled carbon nanohorns

    SciTech Connect

    Lynch, Rachel M; Voy, Brynn H; Glass-Mattie, Dana F; Mahurin, Shannon Mark; Saxton, Arnold; Donnel, Robert L.; Cheng, Mengdawn

    2007-01-01

    Previous studies have suggested that single-walled carbon nanotubes (SWCNTs) may be pose a pulmonary hazard. We investigated the pulmonary toxicity of single-walled carbon nanohorns (SWCNHs), a relatively new carbon-based nanomaterial that is structurally similar to SWCNTs. Mice were exposed to 30 g of surfactant-suspended SWCNHs by pharyngeal aspiration and sacrificed 24 hours or 7 days post exposure. Total and differential cell counts and cytokine analysis of bronchoalveolar lavage fluid demonstrated a mild inflammatory response which was mitigated by day 7 post exposure. Whole lung microarray analysis demonstrated that SWCNH-exposure did not lead to robust changes in gene expression. Finally, histological analysis showed no evidence of granuloma formation or fibrosis following SWCNH aspiration. These combined results suggest that SWCNH is a relatively innocuous nanomaterial when delivered to mice in vivo using aspiration as a delivery mechanism.

  2. Toxic substances form coal combustion--a co prehemsice assessment

    SciTech Connect

    Huggins, F.; Huffman, G.P.; Shah, N.

    1997-04-01

    The Clean Coal Act Amendments of 1990 identify a number of hazardous air pollutants as candidates for regulation. Should regulations be imposed on emission of these pollutants from coal-fired power plants, a sound understanding of the fundamental principles controlling their formation and partition will be needed. A new Toxics Partitioning Engineering Model (ToPEM) has been developed by a broad consortium to be useful to regulators and utility planners. During the last quarter coal analysis was completed on the final program coal, from the Wyodak Seam of the Powder River Basin, Combustion testing continued, including data collected on the self-sustained combustor. Efforts were directed to identify the governing mechanisms for trace element vaporization from the program coals. Mercury speciation and measurements were continued. Review of the existing trace element and organics emission literature was completed. And, model development was begun.

  3. Biodegradability and toxicity assessment of trans-chlordane photochemical treatment.

    PubMed

    Moradas, Gerly; Auresenia, Joseph; Gallardo, Susan; Guieysse, Benoit

    2008-11-01

    The removal of trans-chlordane (C(10)H(6)Cl(8)) from aqueous solutions was studied using UV, UV/H(2)O(2), UV/H(2)O(2)/Fe(2+), UV/TiO(2), or UV/TiO(2)/H(2)O(2) treatment using either UV/Vis blue lamps or UVC lamps (254 nm). H(2)O(2), FeSO(4) and TiO(2) were added at 1700, 456, and 2500 mgL(-1), respectively. trans-Chlordane was not significantly removed in non-irradiated controls and in samples irradiated with UV/Vis. It was also not removed in the absence of surfactant Triton X-114 added at 250 mgL(-1). In the presence of the surfactant, trans-chlordane concentration was reduced by 95-100% after 48 h of UVC and UVC/H(2)O(2) treatments and 70-80% after UVC/H(2)O(2)/Fe(2+), UVC/TiO(2) and UVC/H(2)O(2)/TiO(2) treatments. Based on these results, UVC, UVC/H(2)O(2) and UVC/TiO(2) treatments were further investigated. UVC treatment supported the highest pollutant removal (100% in 48 h), dechlorination efficiency (81% in 48 h), and detoxification to Lepidium sativum seed germination and activated sludge respiration although irradiated samples remained toxic to Chlorella vulgaris. Biodegradation of the UVC irradiated samples removed the source of algae toxicity but this could not be clearly attributed to the removal of trans-chlordane photoproducts because the surfactant interfered with the chemical and biological assays. Evidence was found that trans-chlordane was photodegraded through photolysis causing its successive dechlorination. trans-Chlordane removal was well described by a first order kinetic model at a rate of 0.21±0.01h(-1) at the 95% confidence interval.

  4. Aquatic toxicity of ivermectin in cattle dung assessed using microcosms.

    PubMed

    Mesa, Leticia M; Lindt, I; Negro, L; Gutierrez, M F; Mayora, G; Montalto, L; Ballent, M; Lifschitz, A

    2017-10-01

    Ivermectin (IVM) is a parasiticide widely used for livestock. It is a semisynthetic derivative of avermectin, a macrocyclic lactone produced by Streptomyces avermitilis. This drug is only partly metabolized by livestock; considerable amounts of parent drug are excreted mostly via feces. To simulate exposure of aquatic invertebrates and macrophytes to direct excretion of cattle dung into surface waters, a microcosm experiment with IVM spiked in cattle dung was conducted. The objectives of this study were to characterize accumulation of IVM in water, sediment+dung, roots of the floating fern Salvinia and the zooplankton Ceriodaphnia dubia, the amphipod Hyalella and the apple snail Pomacea; to determine the effect of this drug spiked in cattle dung on life-history traits of these invertebrates; and to evaluate the influence of IVM on aquatic nutrient cycling. Dung was spiked with IVM to attain concentrations of 1150, 458, 50 and 22µgkg(-1)dung fresh weight, approximating those found in cattle dung at days 3, 7, 16 and 29 following subcutaneous injection. Concentrations found in dung during the first week of excretion were lethally toxic to Ceriodaphnia dubia and Hyalella, whereas no mortality was observed in Pomacea. Concentrations of IVM in roots, sediment + dung and Pomacea increased significantly from the lowest to the highest treatment level. The effect of this drug on decomposition and release of nutrients from dung would have negative consequences for nutrient cycling in water. Increasing concentrations in sediment + dung with days of the experiment suggested that toxic concentrations would persist for an extended period in the water-sediment system. IVM represents an ecological risk for aquatic ecosystems, underscoring the need for livestock management strategies to limit its entry into water bodies. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. A rapid resazurin bioassay for assessing the toxicity of fungicides.

    PubMed

    Fai, Patricia Bi; Grant, Alastair

    2009-03-01

    Fungicides are widely used in agriculture, and released in large amounts to the environment. Methods used for antifungal susceptibility testing are cumbersome and time-consuming. As a result, very little attention has been paid to including fungal tests in the routine screening of pesticides and there are no reports in the literature of fungicide focussed effects directed analysis (EDA). In addition very little is known on the toxicity of fungicides to environmentally significant fungi. Here we report a rapid microplate-based resorufin fluorescence inhibition bioassay and compare it with a 24h microplate-based yeast growth inhibition bioassay using eight fungicides. The growth inhibition bioassay was sensitive, giving IC50 and IC90 values comparable to previously reported IC50 or MICs of these fungicides for Saccharomyces cerevisiae and other fungi. The resorufin fluorescence inhibition bioassay was both faster and more sensitive than the growth inhibition bioassay. Inhibitory concentrations obtained just after 30min of incubation with amphotericin B (AMB) and captan were at least a hundred fold lower than IC50s in the literature for fungi. The fluorescence bioassay showed only a small response to pyrazophos and thiabendazole but these only inhibited growth at high concentrations so this may reflect low sensitivity of S. cerevisiae to these particular fungicides. This bioassay can detect toxic effects of a range of fungicides from different chemical classes with different modes of action. It will be valuable for screening chemical libraries for fungicides and as a biomarker for detecting the effects of fungicides to non-target fungi.

  6. TOXIC SUBSTANCES FROM COAL COMBUSTION: A COMPREHENSIVE ASSESSMENT

    SciTech Connect

    C.L. Senior; T. Panagiotou; J.O.L. Wendt; W. Seames; F.E. Huggins; G.P Huffman; N. Yap; M.R. Ames; I.Olmez; T. Zeng; A.F. Sarofim; A. Kolker; R. Finkelman; J.J. Helble

    1998-07-16

    The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. With support from the Federal Energy Technology Center (FETC), the Electric Power Research Institute, and VTT (Finland), Physical Sciences Inc. (PSI) has teamed with researchers from USGS, the Massachusetts Institute of Technology (MIT), the University of Arizona (UA), the University of Kentucky (UK), the University of Connecticut (UC), the University of Utah (W) and the University of North Dakota Energy and Environmental Research Center (EERC) to develop a broadly applicable emissions model useful to regulators and utility planners. The new Toxics Partitioning Engineering Model (ToPEM) will be applicable to all combustion conditions including new fuels and coal blends, low-NO{sub x} combustion systems, and new power generation plants. Development of ToPEM will be based on PSI's existing Engineering Model for Ash Formation (EMAF). This report covers the reporting period from the submission of the draft Phase 1 Final Report through the end of June, 1998. During this period two of the three Phase 2 coals were procured and pulverized samples were distributed to team members. Analysis of Phase 1 X-Ray Absorption Fine Structure (XAFS) data, particularly of mercury in sorbent samples, continued. An improved method for identifying mercury compounds on sorbents was developed, leading to a clearer understanding of forms of mercury in char and sorbents exposed to flue gas. Additional analysis of Phase 1 large scale combustion data was performed to investigate mechanistic information related to the fate of the radionuclides Cs, Th, and Co. Modeling work for this period was focused on building and testing a sub-model for vaporization

  7. Assessment of toxic metals in waste personal computers

    SciTech Connect

    Kolias, Konstantinos; Hahladakis, John N. Gidarakos, Evangelos

    2014-08-15

    Highlights: • Waste personal computers were collected and dismantled in their main parts. • Motherboards, monitors and plastic housing were examined in their metal content. • Concentrations measured were compared to the RoHS Directive, 2002/95/EC. • Pb in motherboards and funnel glass of devices released <2006 was above the limit. • Waste personal computers need to be recycled and environmentally sound managed. - Abstract: Considering the enormous production of waste personal computers nowadays, it is obvious that the study of their composition is necessary in order to regulate their management and prevent any environmental contamination caused by their inappropriate disposal. This study aimed at determining the toxic metals content of motherboards (printed circuit boards), monitor glass and monitor plastic housing of two Cathode Ray Tube (CRT) monitors, three Liquid Crystal Display (LCD) monitors, one LCD touch screen monitor and six motherboards, all of which were discarded. In addition, concentrations of chromium (Cr), cadmium (Cd), lead (Pb) and mercury (Hg) were compared with the respective limits set by the RoHS 2002/95/EC Directive, that was recently renewed by the 2012/19/EU recast, in order to verify manufacturers’ compliance with the regulation. The research included disassembly, pulverization, digestion and chemical analyses of all the aforementioned devices. The toxic metals content of all samples was determined using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The results demonstrated that concentrations of Pb in motherboards and funnel glass of devices with release dates before 2006, that is when the RoHS Directive came into force, exceeded the permissible limit. In general, except from Pb, higher metal concentrations were detected in motherboards in comparison with plastic housing and glass samples. Finally, the results of this work were encouraging, since concentrations of metals referred in the RoHS Directive were found in

  8. Impact of Gestational Bisphenol A on Oxidative Stress and Free Fatty Acids: Human Association and Interspecies Animal Testing Studies

    PubMed Central

    Veiga-Lopez, Almudena; Pennathur, Subramaniam; Kannan, Kurunthachalam; Patisaul, Heather B.; Dolinoy, Dana C.; Zeng, Lixia

    2015-01-01

    Bisphenol A (BPA) is a high production volume chemical and an endocrine disruptor. Developmental exposures to BPA have been linked to adult metabolic pathologies, but the pathways through which these disruptions occur remain unknown. This is a comprehensive interspecies association vs causal study to evaluate risks posed by prenatal BPA exposure and to facilitate discovery of biomarkers of relevance to BPA toxicity. Samples from human pregnancies during the first trimester and at term, as well as fetal and/or adult samples from prenatally BPA-treated sheep, rats, and mice, were collected to assess the impact of BPA on free fatty acid and oxidative stress dynamics. Mothers exposed to higher BPA during early to midpregnancy and their matching term cord samples displayed increased 3-nitrotyrosine (NY), a marker of nitrosative stress. Maternal samples had increased palmitic acid, which was positively correlated with NY. Sheep fetuses and adult sheep and rats prenatally exposed to a human-relevant exposure dose of BPA showed increased systemic nitrosative stress. The strongest effect of BPA on circulating free fatty acids was observed in adult mice in the absence of increased oxidative stress. This is the first multispecies study that combines human association and animal causal studies assessing the risk posed by prenatal BPA exposure to metabolic health. This study provides evidence of the induction of nitrosative stress by prenatal BPA in both the mother and fetus at time of birth and is thus supportive of the use of maternal NY as a biomarker for offspring health. PMID:25603046

  9. Proteomic Assessment of Biochemical Pathways That Are Critical to Nickel-Induced Toxicity Responses in Human Epithelial Cells

    EPA Science Inventory

    Understanding the mechanisms underlying toxicity initiated by nickel, a ubiquitous environmental contaminant and known human carcinogen is necessary for proper assessment of its risks to human and environment. Among a variety of toxic mechanisms, disruption of protein responses a...

  10. Integration of Density Dependence and Concentration Response Models Provides an Ecologically Relevant Assessment of Populations Exposed to Toxicants

    EPA Science Inventory

    The assessment of toxic exposure on wildlife populations involves the integration of organism level effects measured in toxicity tests (e.g., chronic life cycle) and population models. These modeling exercises typically ignore density dependence, primarily because information on ...

  11. Proteomic Assessment of Biochemical Pathways That Are Critical to Nickel-Induced Toxicity Responses in Human Epithelial Cells

    EPA Science Inventory

    Understanding the mechanisms underlying toxicity initiated by nickel, a ubiquitous environmental contaminant and known human carcinogen is necessary for proper assessment of its risks to human and environment. Among a variety of toxic mechanisms, disruption of protein responses a...

  12. Integration of Density Dependence and Concentration Response Models Provides an Ecologically Relevant Assessment of Populations Exposed to Toxicants

    EPA Science Inventory

    The assessment of toxic exposure on wildlife populations involves the integration of organism level effects measured in toxicity tests (e.g., chronic life cycle) and population models. These modeling exercises typically ignore density dependence, primarily because information on ...

  13. Nanoparticle toxicity assessment using an in vitro 3-D kidney organoid culture model.

    PubMed

    Astashkina, Anna I; Jones, Clint F; Thiagarajan, Giridhar; Kurtzeborn, Kristen; Ghandehari, Hamid; Brooks, Benjamin D; Grainger, David W

    2014-08-01

    Nanocarriers and nanoparticles remain an intense pharmaceutical and medical imaging technology interest. Their entry into clinical use is hampered by the lack of reliable in vitro models that accurately predict in vivo toxicity. This study evaluates a 3-D kidney organoid proximal tubule culture to assess in vitro toxicity of the hydroxylated generation-5 PAMAM dendrimer (G5-OH) compared to previously published preclinical in vivo rodent nephrotoxicity data. 3-D kidney proximal tubule cultures were created using isolated murine proximal tubule fractions suspended in a biomedical grade hyaluronic acid-based hydrogel. Toxicity in these cultures to neutral G5-OH dendrimer nanoparticles and gold nanoparticles in vitro was assessed using clinical biomarker generation. Neutral PAMAM nanoparticle dendrimers elicit in vivo-relevant kidney biomarkers and cell viability in a 3-D kidney organoid culture that closely reflect toxicity markers reported in vivo in rodent nephrotoxicity models exposed to this same nanoparticle.

  14. Application of simple and low-cost toxicity tests for ecotoxicological assessment of industrial wastewaters.

    PubMed

    Aydin, Mehmet Emin; Aydin, Senar; Tongur, Süheyla; Kara, Gülnihal; Kolb, Marit; Bahadir, Müfit

    2015-01-01

    The objective of this study was to identify and to apply appropriate biotests having the advantages of being highly sensitive, easy to run, relatively inexpensive and able to substitute fish toxicity tests due to ethical reasons of animal welfare. To perform an ecotoxicological assessment of industrial wastewaters, different microbiotests were conducted to substitute the fish toxicity test with Lebistes reticulatus through Vibrio fischeri, Thamnocephalus platyurus, Daphnia magna, Lemna minor and Lepidium sativum representing different trophic levels in the aquatic and terrestrial ecosystems. Also, Algaltox F(TM) with Pseudokirchneriella subcapitata and Protox F(TM) with Tetrahymena thermophila tests were carried out. However, they could not be applied successfully for the wastewater samples. Wastewater samples from seven different industrial zones comprising different industries were subjected to characterization through measuring their physical-chemical parameters and their toxicity versus the above-mentioned organisms. T. platyurus, D. magna and L. reticulatus were the most sensitive test organisms investigated for the wastewaters. Considering toxic unit values, generally wastewater samples were toxic according to Thamnotox F(TM), Daphtox F(TM) and fish toxicity tests. As an important outcome, it was concluded that Daphtox F(TM) and Thamnotox F(TM) could be a good alternative for the fish toxicity test, which is so far the sole toxicity test accepted by the Turkish Water Pollution Control Regulation.

  15. Fluvial biofilms: A pertinent tool to assess beta-blockers toxicity.

    PubMed

    Bonnineau, Chloé; Guasch, Helena; Proia, Lorenzo; Ricart, Marta; Geiszinger, Anita; Romaní, Anna M; Sabater, Sergi

    2010-02-18

    Among increasingly used pharmaceutical products, beta-blockers have been commonly reported at low concentrations in rivers and littoral waters of Europe and North America. Little is known about the toxicity of these chemicals in freshwater ecosystems while their presence may lead to chronic pollution. Hence, in this study the acute toxicity of 3 beta-blockers: metoprolol, propranolol and atenolol on fluvial biofilms was assessed by using several biomarkers. Some were indicative of potential alterations in biofilm algae (photosynthetic efficiency), and others in biofilm bacteria (peptidase activity, bacterial mortality). Propranolol was the most toxic beta-blocker, mostly affecting the algal photosynthetic process. The exposure to 531microg/L of propranolol caused 85% of inhibition of photosynthesis after 24h. Metoprolol was particularly toxic for bacteria. Though estimated No-Effect Concentrations (NEC) were similar to environmental concentrations, higher concentrations of the toxic (503microg/L metoprolol) caused an increase of 50% in bacterial mortality. Atenolol was the least toxic of the three tested beta-blockers. Effects superior to 50% were only observed at very high concentration (707mg/L). Higher toxicity of metoprolol and propranolol might be due to better absorption within biofilms of these two chemicals. Since beta-blockers are mainly found in mixtures in rivers, their differential toxicity could have potential relevant consequences on the interactions between algae and bacteria within river biofilms.

  16. Assessment and prediction of joint algal toxicity of binary mixtures of graphene and ionic liquids.

    PubMed

    Wang, Zhuang; Zhang, Fan; Wang, Se; Peijnenburg, Willie J G M

    2017-10-01

    Graphene and ionic liquids (ILs) released into the environment will interact with each other. So far however, the risks associated with the concurrent exposure of biota to graphene and ILs in the environment have received little attention. The research reported here focused on observing and predicting the joint toxicity effects in the green alga Scenedesmus obliquus exposed to binary mixtures of intrinsic graphene (iG)/graphene oxide (GO) and five ILs of varying anionic and cationic types. The isolated ILs in the binary mixtures were the main contributors to toxicity. The binary GO-IL mixtures resulted in more severe joint toxicity than the binary iG-IL mixtures, irrespective of mixture ratios. The mechanism of the joint toxicity may be associated with the adsorption capability of the graphenes for the ILs, the dispersion stability of the graphenes in aquatic media, and modulation of the binary mixtures-induced oxidative stress. A toxic unit assessment showed that the graphene and IL toxicities were additive at low concentration of the mixtures but antagonistic at high concentration of the mixtures. Predictions made using the concentration addition and independent action models were close to the observed joint toxicities regardless of mixture types and mixture ratios. These findings provide new insights that are of use in the risk assessment of mixtures of engineered nanoparticles and other environmentally relevant contaminants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Web-based Interspecies Correlation Estimation

    EPA Science Inventory

    Web-ICE estimates acute toxicity (LC50/LD50) of a chemical to a species, genus, or family from the known toxicity of the chemical to a surrogate species. Web-ICE has modules to predict acute toxicity to aquatic (fish and invertebrates) and wildlife (birds and mammals) taxa for us...

  18. Web-ICE Bibliography | Interspecies Correlation Estimation ...

    EPA Pesticide Factsheets

    2016-02-22

    Web-ICE estimates acute toxicity (LC50/LD50) of a chemical to a species, genus, or family from the known toxicity of the chemical to a surrogate species. Web-ICE has modules to predict toxicity to aquatic and wildlife taxa and to generate Species Sensitivity Distributions (SSDs) from Web-ICE generated data. Page lists bibliography for Web-ICE

  19. Web-based Interspecies Correlation Estimation

    EPA Science Inventory

    Web-ICE estimates acute toxicity (LC50/LD50) of a chemical to a species, genus, or family from the known toxicity of the chemical to a surrogate species. Web-ICE has modules to predict acute toxicity to aquatic (fish and invertebrates) and wildlife (birds and mammals) taxa for us...

  20. Assessment of Supercritical Fluid Extraction Use in Whole Sediment Toxicity Identification Evaluations

    EPA Science Inventory

    In this investigation, supercritical fluid extraction (SFE) with pure CO2 was assessed as a confirmatory tool in Phase III of whole sediment toxicity identification evaluations (TIEs). The SFE procedure was assessed on two reference sediments and three contaminated sediments usi...

  1. A REGIONAL SCALE TOXICITY ASSESSMENT OF SEDIMENT IN THE MID-ATLANTIC AND SOUTHERN ROCKIES, USA

    EPA Science Inventory

    As part of the Environmental Monitoring and Assessment Program (EMAP), sediment samples were collected to assess toxicity on a regional scale in streams and rivers in the Mid-Atlantic U.S. in 1994, 1997 and 1998, and in the Colorado Rocky Mountains in 1994 and 1995. Sample sites...

  2. Assessment of Supercritical Fluid Extraction Use in Whole Sediment Toxicity Identification Evaluations

    EPA Science Inventory

    In this investigation, supercritical fluid extraction (SFE) with pure CO2 was assessed as a confirmatory tool in Phase III of whole sediment toxicity identification evaluations (TIEs). The SFE procedure was assessed on two reference sediments and three contaminated sediments usi...

  3. A REGIONAL SCALE TOXICITY ASSESSMENT OF SEDIMENT IN THE MID-ATLANTIC AND SOUTHERN ROCKIES, USA

    EPA Science Inventory

    As part of the Environmental Monitoring and Assessment Program (EMAP), sediment samples were collected to assess toxicity on a regional scale in streams and rivers in the Mid-Atlantic U.S. in 1994, 1997 and 1998, and in the Colorado Rocky Mountains in 1994 and 1995. Sample sites...

  4. Assessing BMP Performance Using Microtox Toxicity Analysis - Rhode Island

    EPA Science Inventory

    Best Management Practices (BMPs) have been shown to be effective in reducing runoff and pollutants from urban areas and thus provide a mechanism to improve downstream water quality. Currently, BMP performance regarding water quality improvement is assessed through measuring each...

  5. Assessing BMP Performance Using Microtox® Toxicity Analysis

    EPA Science Inventory

    Best Management Practices (BMPs) have been shown to be effective in reducing runoff and pollutants from urban areas and thus provide a mechanism to improve downstream water quality. Currently, BMP performance regarding water quality improvement is assessed through measuring each...

  6. Assessing BMP Performance Using Microtox Toxicity Analysis - Rhode Island

    EPA Science Inventory

    Best Management Practices (BMPs) have been shown to be effective in reducing runoff and pollutants from urban areas and thus provide a mechanism to improve downstream water quality. Currently, BMP performance regarding water quality improvement is assessed through measuring each...

  7. Assessing BMP Performance Using Microtox® Toxicity Analysis

    EPA Science Inventory

    Best Management Practices (BMPs) have been shown to be effective in reducing runoff and pollutants from urban areas and thus provide a mechanism to improve downstream water quality. Currently, BMP performance regarding water quality improvement is assessed through measuring each...

  8. Toxic substances from coal combustion -- A comprehensive assessment

    SciTech Connect

    Senior, C.L.; Panagiotou, T.; Huggins, F.E.; Huffman, G.P.; Yap, N.; Wendt, J.O.L.; Seames, W.; Ames, M.R.; Sarofim, A.F.; Lighty, J.; Kolker, A.; Finkelman, R.; Palmer, C.A.; Mroczkowsky, S.J.; Helble, J.J.; Mamani-Paco, R.

    1999-07-30

    The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. With support from the Federal Energy Technology Center (FETC), the Electric Power Research Institute, and VTT (Finland), Physical Sciences Inc. (PSI) has teamed with researchers from USGS, MIT, the University of Arizona (UA), the University of Kentucky (UK), the University of Connecticut (UC), the University of Utah (UU) and the University of North Dakota Energy and Environmental Research Center (EERC) to develop a broadly applicable emissions model useful to regulators and utility planners. The new Toxics Partitioning Engineering Model (ToPEM) will be applicable to all combustion conditions including new fuels and coal blends, low-NOx combustion systems, and new power generation plants. Development of ToPEM will be based on PSI's existing Engineering Model for Ash Formation (EMAF). This report covers the period from 1 April 1999 to 30 June 1999. During this quarter low temperature ashing and elemental analysis of the three Phase II coals were completed. Results from MIT and USGS are comparable. Plans were made for measurements of loss of trace elements during devolatilization and for single particle combustion studies at the University of Utah. The iodated charcoal trap was tested on coal combustion flue gas and was shown to collect both Hg and Se in from the vapor phase with 100% efficiency. Data from the University of Arizona self-sustained combustor were analyzed from the combustion of three coals: Ohio, Wyodak and Illinois No. 6. Ash size distributions and enrichment factors for selected trace elements were calculated. The correlation between the concentration of the more volatile trace elements in the ash and the

  9. Assessing atrazine-induced toxicities in Bufo bufo gargarizans Cantor.

    PubMed

    Sai, Linlin; Wu, Qingbo; Qu, Binpeng; Bo, Cunxiang; Yu, Gongchang; Jia, Qiang; Xie, Lin; Li, Yuezhong; Guo, Qiming; Ng, Jack C; Peng, Cheng

    2015-02-01

    Atrazine (AZ), a widely used herbicide has drawn attentions for its potential impacts on amphibians. This study aims to investigate the toxicity of AZ in Bufo bufo gargarizans Cantor (B. bufo gargarizans), a species of toad commonly found in China and countries in East Asia. We treated tadpoles with 0.1, 1, 10 and 100 μg/L AZ for 85 days and examined related parameters. The results showed that the mortality of the toads in the treatment group increased dramatically in a U-shaped dose-response relationship. The hindlimb extension and metamorphosis rate of the toads were significantly inhibited by AZ at 10 and 100 μg/L. Under the same condition, there were significant progressive changes in the testicular structures. Moreover, we found that AZ has no significant effects on growth, sex ratios, gonadal morphology, forelimb emergence and histology in the ovaries. Our results support the idea that environmental contaminants including AZ may be relevant to global amphibian decline.

  10. Bioactivity assessment and toxicity of crocin: a comprehensive review.

    PubMed

    Alavizadeh, Seyedeh Hoda; Hosseinzadeh, Hossein

    2014-02-01

    Since ancient times, saffron, the dried stigma of the plant Crocus sativus L. has been extensively used as a spice and food colorant; in folk medicine it has been reputed to be efficacious for the alleviation and treatment of ailments. In addition to the three founded major constituents including crocin, picrocrocin and safranal, presence of carotenoids, carbohydrates, proteins, anthocyanins, vitamins and minerals provide valuable insights into the health benefits and nutritional value of saffron. Of the carotenoids present in saffron, highly water-soluble crocin (mono and diglycosyl esters of a polyene dicarboxylic acid, named crocetin) is responsible for the majority of its color, and appears to possess various health-promoting properties, as an antioxidant, antitumor, memory enhancer, antidepressant, anxiolytic and aphrodisiac. It is also worth noting that the crocin principle of saffron exhibited high efficacy along with no major toxicity in experimental models. We would be remiss to not consider the great potential of saffron and crocin, which benefits the cuisine and health of human life throughout the world. The present study provides a comprehensive and updated report of empirical investigations on bioactivities and biological characteristics of crocin.

  11. General considerations in ocular toxicity risk assessment from the toxicologists' viewpoints.

    PubMed

    Onodera, Hiroshi; Sasaki, Shoji; Otake, Seiji; Tomohiro, Masayuki; Shibuya, Kazumoto; Nomura, Mamoru

    2015-06-01

    Humans commonly obtain approximately 80% of external information from vision. Since loss of vision markedly decreases quality of life, risk assessments for visual toxicity of new drugs are extremely important. However, the ICH S4 guideline for nonclinical toxicity study of new drugs only indicates a brief instruction for ophthalmologic examinations, and submitted data for drug approval according only to this guideline are not always considered sufficient in light of ocular toxicity risk assessments. The eye is an assembly of many specialized sub-organs which have specific functions, and its integral maintenance of homeostasis plays an important role of visual function. When only a part of integrity of functions is lost, overall function of the eye might be commonly disturbed. Therefore, understanding of anatomy and physiology of these sub-organs may help know mechanisms of observed ocular changes. In ophthalmologic examinations in nonclinical toxicity studies, it is vital to understand the principles and features of each examination. Comparisons of findings between pre and post drug treatment as well as considerations of species differences, strain differences, age differences, and location/degree of abnormalities are essential. In addition, many kinds of spontaneous ocular findings are well known in experimental animals. To differentiate treatment-related changes from spontaneous findings, mastering basic skills for ophthalmologic examinations and taking advantage of collection of background data are necessary. For ocular toxicity risk assessments, while an evaluation of "sight-threatening" effects is most critical matter, "quality of vision" related findings also should be considered. To extrapolate animal data to human, clinical significances of ocular toxicity findings should be evaluated based on considerations for "species differences", "safety margins", "reversibility", and "risk-benefit balance". In addition, a detailed recording of features of lesions is

  12. Multifaceted toxicity assessment of catalyst composites in transgenic zebrafish embryos.

    PubMed

    Jang, Gun Hyuk; Lee, Keon Yong; Choi, Jaewon; Kim, Sang Hoon; Lee, Kwan Hyi

    2016-09-01

    Recent development in the field of nanomaterials has given rise into the inquiries regarding the toxicological characteristics of the nanomaterials. While many individual nanomaterials have been screened for their toxicological effects, composites that accompany nanomaterials are not common subjects to such screening through toxicological assessment. One of the widely used composites that accompany nanomaterials is catalyst composite used to reduce air pollution, which was selected as a target composite with nanomaterials for the multifaceted toxicological assessment. As existing studies did not possess any significant data regarding such catalyst composites, this study focuses on investigating toxicological characteristics of catalyst composites from various angles in both in-vitro and in-vivo settings. Initial toxicological assessment on catalyst composites was conducted using HUVECs for cell viability assays, and subsequent in-vivo assay regarding their direct influence on living organisms was done. The zebrafish embryo and its transgenic lines were used in the in-vivo assays to obtain multifaceted analytic results. Data obtained from the in-vivo assays include blood vessel formation, mutated heart morphology, and heart functionality change. Our multifaceted toxicological assessment pointed out that chemical composites augmented with nanomaterials can too have toxicological threat as much as individual nanomaterials do and alarms us with their danger. This manuscript provides a multifaceted assessment for composites augmented with nanomaterials, of which their toxicological threats have been overlooked. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. A novel method for assessing the toxicity of silver nanoparticles in Caenorhabditis elegans.

    PubMed

    Luo, Xun; Xu, Shengmin; Yang, Yaning; Zhang, Yajun; Wang, Shunchang; Chen, Shaopeng; Xu, An; Wu, Lijun

    2017-02-01

    At present, nanotechnology has been producing nanoscale materials with unprecedented speed. Nanomaterials could be inevitably released into the environment owing to their widespread use, and their potential toxicity has caused a great concern. With regard to assessment of nanomaterial toxicity, many studies probably don't truly reflect their toxicity, because the nanoparticles were not stable and uniformly dispersed in the medium. In the present study, the semi-fluid nematode growth gelrite medium (NGG) was used to achieve better distribution of silver nanoparticles (AgNPs). We aimed to evaluate the toxicity of AgNPs in three different culture methods, such as the NGG, nematode growth medium (NGM) and K-medium (KM). Our transmission electron microscopy, hydrodynamic diameter, and inductively coupled plasma-atomic emission spectrometry results demonstrated that AgNPs homogeneously and stably dispersed in NGG compared to that in liquid KM. Furthermore, the conventional toxicity end points, such as body length, fecundity, lifespan, population growth, germline cell apoptosis, reactive oxygen species, and mitochondrial membrane potential were used to assess the toxicity of AgNPs to Caenorhabditis elegans (C. elegans) in NGG, NGM and KM. Our results showed that the toxicity of AgNPs obtained in the NGG test medium was much higher than that in the standard NGM and KM. In addition to the improved dispersion of nanoparticles, NGG also offered advantages for long-term studies and likely provided a convenient nematode toxicity testing method. These results revealed that the NGG test medium was a suitable and sensitive culture method for the evaluation of AgNPs toxicity using C. elegans. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Toxicity of Lunar Dust in Lungs Assessed by Examining Biomarkers in Exposed Mice

    NASA Technical Reports Server (NTRS)

    Lam, C.-W.; James, J. T.; Zeidler-Erdely, P. C.; Castranova, V.; Young, S. H.; Quan, C. L.; Khan-Mayberry, N.; Taylor, L. A.

    2009-01-01

    NASA plans to build an outpost on the Moon for prolonged human habitation and research. The lunar surface is covered by a layer of soil, of which the finest portion is highly reactive dust. NASA has invited NIOSH to collaboratively investigate the toxicity of lunar dust. Dust samples of respirable sizes were aerodynamically isolated from two lunar soil samples of different maturities (cosmic exposure ages) collected during the Apollo 16 mission. The lunar dust samples, titanium dioxide, or quartz, suspended in normal saline or in Survanta (a bovine lung surfactant), were given to groups of 5 mice (C-57 male) by intrapharyngeal aspiration at 1, 0.3, or 0.1 mg/mouse. The mice were euthanized 7 or 30 days later, and their lungs were lavaged to assess the toxicity biomarkers in bronchioalveolar lavage fluids. The acellular fractions were assayed for total proteins, lactate dehydrogenase activities, and cytokines; the cellular portions were assessed for total cell counts and cell differentials. Results from the high-dose groups showed that lunar dust, suspended in saline, was more toxic than TiO 2, but less toxic than quartz. Lunar dust particles aggregate and settle out rapidly in water or saline, but not in Survanta. Lunar dust suspended in Survanta manifested greater toxicity than lunar dust in saline. The increase in toxicity presumably was due to that Survanta gave a better particle dispersion in the lungs. The two lunar dust samples showed similar toxicity. The overall results showed that lunar dust is more toxic than TiO 2 but less toxic than quartz.

  15. Toxicity of Lunar Dust in Lungs Assessed by Examining Biomarkers in Exposed Mice

    NASA Technical Reports Server (NTRS)

    Lam, C.-W.; James, J. T.; Zeidler-Erdely, P. C.; Castranova, V.; Young, S. H.; Quan, C. L.; Khan-Mayberry, N.; Taylor, L. A.

    2009-01-01

    NASA plans to build an outpost on the Moon for prolonged human habitation and research. The lunar surface is covered by a layer of soil, of which the finest portion is highly reactive dust. NASA has invited NIOSH to collaboratively investigate the toxicity of lunar dust. Dust samples of respirable sizes were aerodynamically isolated from two lunar soil samples of different maturities (cosmic exposure ages) collected during the Apollo 16 mission. The lunar dust samples, titanium dioxide, or quartz, suspended in normal saline or in Survanta (a bovine lung surfactant), were given to groups of 5 mice (C-57 male) by intrapharyngeal aspiration at 1, 0.3, or 0.1 mg/mouse. The mice were euthanized 7 or 30 days later, and their lungs were lavaged to assess the toxicity biomarkers in bronchioalveolar lavage fluids. The acellular fractions were assayed for total proteins, lactate dehydrogenase activities, and cytokines; the cellular portions were assessed for total cell counts and cell differentials. Results from the high-dose groups showed that lunar dust, suspended in saline, was more toxic than TiO 2, but less toxic than quartz. Lunar dust particles aggregate and settle out rapidly in water or saline, but not in Survanta. Lunar dust suspended in Survanta manifested greater toxicity than lunar dust in saline. The increase in toxicity presumably was due to that Survanta gave a better particle dispersion in the lungs. The two lunar dust samples showed similar toxicity. The overall results showed that lunar dust is more toxic than TiO 2 but less toxic than quartz.

  16. Assessing acute toxicities of pre- and post-treatment industrial wastewaters with Hydra attenuata: A comparative study of acute toxicity with the fathead minnow, Pimephales promelas

    SciTech Connect

    Fu, L.J.; Staples, R.E.; Stahl, R.G. Jr. . Haskell Lab. for Toxicology and Industrial Medicine)

    1994-04-01

    This study was undertaken to (a) determine wastewater treatment effectiveness using two freshwater organisms, (b) compare acute toxicity results from the two species exposed to the wastewaters, and (c) link acute and potential developmental toxicity of wastewaters in one organism. The acute toxicities of several pretreatment and post-treatment industrial waste-water samples wee evaluated with adult Hydra attenuata and fathead minnows. The acute LC50s agreed closely when results in Hydra attenuata were compared with those from fathead minnow tests. Acute LC50s ranged from 3 to >100% of samples with hydra, and from 1.0 to >100% of sample with fathead minnows. The results provided strong evidence of treatment effectiveness because toxicity decreased with progressive stages of treatment. Previously the Hydra Developmental Toxicity Assay was used as a prescreen mainly for in vitro assessment of developmental toxicity with pure compounds and to prioritized toxicants according to selective toxicity to the developing embryo. Recently the authors modified the assay for testing natural waters and wastewaters; hence, some of the wastewater samples also were tested for their developmental toxicity. In this case, the relative selective toxicity of these wastewater samples ranged from 0.7 to 2.1, indicating that no sample was uniquely toxic to the developing embryo, although acute toxicity was manifested. Overall, their results indicate the Hydra Assay functions appropriately in assessments of acute and developmental toxicity of industrial wastewaters and may be a simple and useful tool in a battery of tests for broader scale detection of environmental hazards.

  17. The assessment of sewage sludge gasification by-products toxicity by ecotoxicologial test.

    PubMed

    Werle, Sebastian; Dudziak, Mariusz

    2015-08-01

    The process of gasification of sewage sludge generates by-products, which may be contaminated with toxic and hazardous substances, both organic and inorganic. It is therefore important to assess the environmental risk associated with this type of waste. The feasibility of using an ecotoxicological tests for this purpose was determined in the presented study. The applied tests contained indicator organisms belonging to various biological groups (bacteria, crustaceans, plants). The subject of the study were solid (ash, char) and liquid (tar) by-products generated during gasification (in a fixed bed reactor) of dried sewage sludge from various wastewater treatment systems. The tested samples were classified based on their toxic effect. The sensitivity of the indicator organisms to the tested material was determined. In-house procedures for the preparation for toxicity analysis of both sewage sludge and by-products generated during the gasification were presented. The scope of work also included the determination of the effect of selected process parameters (temperature, amount of gasifying agent) on the toxicity of gasification by-products depending on the sewage sludge source. It was shown that both the type of sewage sludge and the parameters of the gasification process affects the toxicity of the by-products of gasification. However, the results of toxicity studies also depend on the type of ecotoxicological test used, which is associated with a different sensitivity of the indicator organisms. Nevertheless, it may be concluded that the by-products formed during the gasification of the low toxicity sewage sludge can be regarded as non-toxic or low toxic. However, the results analysis of the gasification of the toxic sludge were not conclusive, which leads to further research needs in this area. © The Author(s) 2015.

  18. Toxic substances from coal combustion -- A comprehensive assessment

    SciTech Connect

    C.L. Senior; T. Panagiotou; F.E. Huggins; G.P. Huffman; N. Yap; J.O.L. Wendt; W. Seames; M.R. Ames; A.F Sarofim; J. Lighty; A. Kolker; R. Finkelman; C.A. Palmer; S.J. Mroczkowsky; J.J. Helble; R. Mamani-Paco

    1999-11-01

    The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. With support from the Federal Energy Technology Center (FETC), the Electric Power Research Institute, and VTT (Finland), Physical Sciences Inc. (PSI) has teamed with researchers from USGS, MIT, the University of Arizona (UA), the University of Kentucky (UK), the University of Connecticut (UC), the University of Utah (UU) and the University of North Dakota Energy and Environmental Research Center (EERC) to develop a broadly applicable emissions model useful to regulators and utility planners. The new Toxics Partitioning Engineering Model (ToPEM) will be applicable to all combustion conditions including new fuels and coal blends, low-NOx combustion systems, and new power generation plants. Development of ToPEM will be based on PSI's existing Engineering Model for Ash Formation (EMAF). This report covers the reporting period from 1 July 1999 to 30 September 1999. During this period the MIT INAA procedures were revised to improve the quality of the analytical results. Two steps have been taken to reduce the analytical errors. A new nitric acid leaching procedure, modified from ASTM procedure D2492, section 7.3.1 for determination of pyritic sulfur, was developed by USGS and validated. To date, analytical results have been returned for all but the last complete round of the four-step leaching procedure. USGS analysts in Denver have halted development of the cold vapor atomic fluorescence technique for mercury analysis procedure in favor of a new direct analyzer for Hg that the USGS is in the process of acquiring. Since early June, emphasis at USGS has been placed on microanalysis of clay minerals in project coals in preparation

  19. ISSUES IN SEDIMENT TOXICITY AND ECOLOGICAL RISK ASSESSMENT

    EPA Science Inventory

    This paper is based on a facilitated Workshop and Roundtable Discussion of key issues in sediment toxicology and ecological risk assessment (ERA) as applied to sediments that was held at the Conference on Dredged Material Management: Options and Environmental Considerations. The ...

  20. Development of a groundwater fungal strain as a tool for toxicity assessment.

    PubMed

    Lategan, Maria Josie; Hose, Grant C

    2014-12-01

    Despite the significant ecological role played by fungi in groundwater, their value as indicators of groundwater pollution is not known, as fungi are notoriously challenging to assess for toxicity because of their varied morphological components, in particular their filamentous structures. Hence they are rarely used in environmental risk assessments and monitoring programs for aquatic systems. A rapid, low cost, 1-step static toxicity test targeting the hyphal components of fungi was developed that subsequently demonstrated the sensitivity of a ubiquitous and dominant groundwater fungal strain to metal contaminants. The strain demonstrates sensitivity to chromium > copper > zinc and relative resistance to arsenic. The introduction of a novel group of groundwater microorganisms--the fungi-for toxicity evaluation will strengthen current risk assessment programs for these ecosystems. © 2014 SETAC.

  1. Assessing the aquatic hazard of some branched and linear nonionic surfactants by biodegradation and toxicity

    SciTech Connect

    Dorn, P.B.; Salanitro, J.P.; Evans, S.H.; Kravetz, L. . Westhollow Research Center)

    1993-10-01

    An aquatic hazard assessment was conducted for branched and linear nonionic surfactants using toxicity and biodegradation measurements. Four nonionic alcohol ethoxylate surfactants with different degrees of branching were evaluated for neat surfactant toxicity, degradation in laboratory sewage treatment units, and aquatic toxicity of treated effluents. Acute testing with neat surfactants showed ranges for EC50s of 1.3 to 11.6 mg/L for Daphnia, 1.6 to 6.1 mg/L for Pimephales promelas (fathead minnow), and 1.5 to 11.4 mg/L for Microtox[reg sign]. Chronic testing of algae showed NOECs of 1 to 10 mg/L and maximum acceptable toxicant concentrations (MATCs) of 0.8 to 14.2 mg/L. Seven-day chronic estimation tests showed MATCs of 0.6 to 41.4 mg/L for Pimephales promelas and 1 to 14 mg/L for Daphnia. Effluents collected from treatment units receiving a 50-mg/L surfactant feed at 25 C showed no acute toxicity to either Daphnia or fathead minnows, with the exception of a unit containing nonylphenol ethoxylate. Chronic effluent toxicity was greatest in effluent from the nonylphenol ethoxylate unit and least in the effluent from the linear alcohol ethoxylate unit. Chronic toxicity of the highly branched C[sub 13] alcohol ethoxylate effluent was greater than that for the linear alcohol ethoxylate unit effluent.

  2. Toxicity assessment of garden soils in the vicinity of mining areas in Southern Morocco.

    PubMed

    El Hamiani, Ouafae; El Khalil, Hicham; Lounate, Khalifa; Sirguey, Catherine; Hafidi, Mohamed; Bitton, Gabriel; Schwartz, Christophe; Boularbah, Ali

    2010-05-15

    The aim of the present work is the assessment of the concentration, toxicity and phytoavailability of heavy metals in garden soils in the vicinity of three mines (A, B and C) in South of Morocco by using concurrently selective chemical extractions, MetPLATE a toxicity bioassay and plant growth experiments. The tailings materials containing very high concentrations of Mn, Cu and Co in mine A, Co, Mn, Cr and Ni in mine B and Cu and Zn in mine C. The high toxicity of tailings from mine C (86.7% inhibition) and moderate toxicity of tailings from mine B (51.0% inhibition) were mainly due to the relative high concentrations of soluble Cu and Zn. Nevertheless, the low metal toxicity observed in most garden soils was confirmed by the low metal concentrations in the soil water extracts. In all garden soils, Lactuca sativa L. and Lolium multiflorum L. contained in their shoots Cd, Co, Cr, Cu and Ni below toxic concentrations while Zn (in all soils) and Mn in two soils from mine A were accumulated at concentrations high enough to be considered phytotoxic. The low biomass produced on garden soils in the vicinity of mines B and C is explained by the relative low toxicity compared to mine A. Transfer factor values for Zn were higher than those found for Mn for both plant species, confirming that this element is present at lower bioavailable fraction in soil than Zn. Copyright (c) 2009 Elsevier B.V. All rights reserved.

  3. A framework for assessing the impact of land use policy on community exposure to air toxics.

    PubMed

    Willis, Melvin R; Keller, Arturo A

    2007-04-01

    Our research focuses on the linkage between land use planning policy and the spatial pattern of exposure to air toxics emissions. Our objective is to develop a modeling framework for assessment of the community health risk implications of land use policy. The modeling framework is not intended to be a regulatory tool for small-scale land use decisions, but a long-range planning tool to assess the community health risk implications of alternative land use scenarios at a regional or subregional scale. This paper describes the development and application of an air toxic source model for generating aggregate emission factors for industrial and commercial zoning districts as a function of permitted uses. To address the uncertainty of estimating air toxics emission rates for planned general land use or zoning districts, the source model uses an emissions probability mass function that weights each incremental permitted land use activity by the likelihood of occurrence. We thus reduce the uncertainty involved in planning for development with no prior knowledge of the specific industries that may locate within the land use district. These air toxics emission factors can then be used to estimate pollutant atmospheric mass flux from land use zoning districts, which can then be input to air dispersion and human health risk assessment models to simulate the spatial pattern of air toxics exposure risk. The model database was constructed using the California Air Toxics Inventory, 1997 US Economic Census, and land assessment records from several California counties. The database contains information on more than 200 air toxics at the 2-digit Standard Industrial Classification (SIC) level. We present a case study to illustrate application of the model. LUAIRTOX, the interactive spreadsheet model that applies our methodology to the California data, is available at http://www2.bren.ucsb.edu/~mwillis/LUAIRTOX.htm.

  4. The BEAM-project: prediction and assessment of mixture toxicities in the aquatic environment

    NASA Astrophysics Data System (ADS)

    Backhaus, Thomas; Altenburger, Rolf; Arrhenius, Åsa; Blanck, Hans; Faust, Michael; Finizio, Antonio; Gramatica, Paola; Grote, Matthias; Junghans, Marion; Meyer, Wiebke; Pavan, Manuela; Porsbring, Tobias; Scholze, Martin; Todeschini, Roberto; Vighi, Marco; Walter, Helge; Horst Grimme, L.

    2003-11-01

    Freshwater and marine ecosystems are exposed to various multi-component mixtures of pollutants. Nevertheless, most ecotoxicological research and chemicals regulation focus on hazard and exposure assessment of individual substances only, the problem of chemical mixtures in the environment is ignored to a large extent. In contrast, the assessment of combination effects has a long tradition in pharmacology, where mixtures of chemicals are specifically designed to develop new products, e.g. human and veterinary drugs or agricultural and non-agricultural pesticides. In this area, two concepts are frequently used and are thought to describe fundamental relationships between single substance and mixture effects: Independent Action (Response Addition) and Concentration Addition. The question, to what extent these concepts may also be applied in an ecotoxicological and regulatory context may be considered a research topic of major importance, as the concepts would allow to make use of already existing single substance toxicity data for the predictive assessment of mixture toxicities. Two critical knowledge gaps are identified: (a) There is a lack of environmental realism, as a huge part of our current knowledge about the applicability of the concepts is restricted to artificial situations with respect to mixture composition or biological effect assessment. (b) The knowledge on what exactly is needed for using the concepts as tools for the predictive mixture toxicity assessment is insufficient. Both gaps seriously hamper the necessary, scientifically sound consideration of mixture toxicities in a regulatory context. In this paper, the two concepts will be briefly introduced, the necessity of considering the toxicities of chemical mixtures in the environment will be demonstrated and the applicability of Independent Action and Concentration Addition as tools for the prediction and assessment of mixture toxicities will be discussed. An overview of the specific aims and

  5. Assessment of the epigenetic toxicity of a mixture of PAHs before and after biodegradation

    SciTech Connect

    Ghoshal, S.; Upham, B.L.; Rummel, A.M.; Trosko, J.E.; Weber, W.J. Jr.

    1999-07-01

    Subsurface contamination by nonaqueous phase liquids containing various polycyclic aromatic hydrocarbons (PAHs) are common at many industrial sites. PAHs are known carcinogens and the assessment of the toxicity of such complex chemical mixtures are required for human health-risk analysis models. In addition, the evaluation of the toxicity of residual chemicals that remain after remediation at contaminated sites is important in assessing the efficacy of remediation. In this study, a nonaqueous phase liquid comprised of toluene and eight PAHs was subjected to biodegradation under controlled conditions. The changes in chemical composition caused by biodegradation, and epigenetic toxicity of the residual after biodegradation in comparison to the epigenetic toxicity of the initial mixture have been evaluated. The epigenetic toxicity was determined using an assay of the gap junctional intercellular communication inhibition exhibited in rat liver epithelial cell cultures. The results suggest that some higher molecular weight components of the nonaqueous phase were not eliminated by biodegradation and the qualitative toxicity of the remaining fraction was comparable to the untreated nonaqueous phase liquid.

  6. An enhanced tiered toxicity testing framework with triggers for assessing hazards and risks of commodity chemicals.

    PubMed

    Plunkett, Laura M; Kaplan, A Michael; Becker, Richard A

    2010-12-01

    This paper presents an enhanced integrated testing framework based on tiered testing and endpoint-specific decision triggers envisioned for application to commodity chemical safety assessments. The framework has two tiers in which exposure information can be integrated with hazard data at each Tier. Tier 1 tests are used to screen chemicals for major toxic effects (i.e., acute toxicity potential, target organs of repeat dose toxicity, genotoxicity potential, neurotoxicity potential, reproductive toxicity potential, immunotoxicity potential, and developmental toxicity potential), and to direct planning for more complex and targeted testing in Tier 2. The proposed decision triggers coupled with information on use and potential for exposure allow for scientifically-based decisions to be made about further testing in Tier 2, indicating which specific endpoints and tests warrant further evaluation, and which do not. The testing framework addresses risks to humans during all stages of development and provides data relevant to assessing hazards to sensitive subpopulations, such as infants and children. The REACH program in Europe and TSCA in the United States have led to an increased focus on development of hazard and risk information for chemicals used in industrial processes and consumer products. This framework and its toxicity decision triggers will allow for scientifically justified evaluation of chemicals that is comprehensive in terms of hazard screening, focuses resources on the specific complex tests that are most important for hazard characterization, and minimizes the use of animals. Copyright © 2010 Elsevier Inc. All rights reserved.

  7. Assessment of combined toxicity of heavy metals from industrial wastewaters on Photobacterium phosphoreum T3S

    NASA Astrophysics Data System (ADS)

    Zeb, BibiSaima; Ping, Zheng; Mahmood, Qaisar; Lin, Qiu; Pervez, Arshid; Irshad, Muhammad; Bilal, Muhammad; Bhatti, Zulfiqar Ahmad; Shaheen, Shahida

    2016-02-01

    This research work is focusing on the toxicities of heavy metals of industrial origin to anaerobic digestion of the industrial wastewater. Photobacterium phosphoreum T3S was used as an indicator organism. The acute toxicities of heavy metals on P. phosphoreum T3S were assessed during 15-min half inhibitory concentration (IC50) as indicator at pH 5.5-6. Toxicity assays involved the assessment of multicomponent mixtures using TU and MTI approaches. The results of individual toxicity indicated that the toxicity of Cd, Cu and Pb on P. phosphoreum increased with increasing concentrations and there was a linear correlation. The 15-min IC50 values of Cd, Cu and Pb were 0.537, 1.905 and 1.231 mg/L, respectively, and their toxic order was Cd > Pb > Cu. The combined effects of Cd, Cu and Pb were assayed by equivalent concentration mixing method. The results showed that the combined effects of Cd + Cu, Cd + Pb, Cu + Pb, Cd + Cu + Pb were antagonistic, antagonistic and partly additive. The combined effect of three heavy metals was partly additive.

  8. Assessment of combined toxicity of heavy metals from industrial wastewaters on Photobacterium phosphoreum T3S

    NASA Astrophysics Data System (ADS)

    Zeb, BibiSaima; Ping, Zheng; Mahmood, Qaisar; Lin, Qiu; Pervez, Arshid; Irshad, Muhammad; Bilal, Muhammad; Bhatti, Zulfiqar Ahmad; Shaheen, Shahida

    2017-07-01

    This research work is focusing on the toxicities of heavy metals of industrial origin to anaerobic digestion of the industrial wastewater. Photobacterium phosphoreum T3S was used as an indicator organism. The acute toxicities of heavy metals on P. phosphoreum T3S were assessed during 15-min half inhibitory concentration (IC50) as indicator at pH 5.5-6. Toxicity assays involved the assessment of multicomponent mixtures using TU and MTI approaches. The results of individual toxicity indicated that the toxicity of Cd, Cu and Pb on P. phosphoreum increased with increasing concentrations and there was a linear correlation. The 15-min IC50 values of Cd, Cu and Pb were 0.537, 1.905 and 1.231 mg/L, respectively, and their toxic order was Cd > Pb > Cu. The combined effects of Cd, Cu and Pb were assayed by equivalent concentration mixing method. The results showed that the combined effects of Cd + Cu, Cd + Pb, Cu + Pb, Cd + Cu + Pb were antagonistic, antagonistic and partly additive. The combined effect of three heavy metals was partly additive.

  9. Genetic Toxicity Assessment of Triazine T17-2

    DTIC Science & Technology

    1990-11-01

    locus in the CHO -Kl-BH4 Chinese hamster ovary ( CHO ) cell line as assessed by colony growth in the presence of 6-thioguanine (TG). Testing was...guanine phos- phoribosyl transferase (HGPRT) locus in Chinese hamster ovary cells under con- ditions with and without metabolic activation. The test...colorless, viscous liquid, was stored at room temperature. Indicator Cells The indicator cells used for this study were Chinese

  10. A human pluripotent stem cell platform for assessing developmental neural toxicity screening

    PubMed Central

    2013-01-01

    A lack of affordable and effective testing and screening procedures mean surprisingly little is known about the health hazards of many of the tens of thousands of chemicals in use in the world today. The recent rise in the number of children affected by neurological disorders such as autism has stirred valuable debate about the role chemicals play in our daily life, highlighting the need for improved methods of assessing chemicals for developmental neural toxicity. Current methods of testing chemicals for developmental neural toxicity include animal testing with rats or mice and in vitro testing using cultured primary cells or cell lines. Here, we review the current state of neural toxicity screening, analyze the limitations of these methods and, under the National Institutes of Health's new Microphysiological Systems initiative, describe a human pluripotent stem cell-based platform for developmental neural toxicity screens. PMID:24565336

  11. TOXIC SUBSTANCES FROM COAL COMBUSTION-A COMPREHENSIVE ASSESSMENT

    SciTech Connect

    C.L. Senior; F. Huggins; G.P. Huffman; N. Shah; N. Yap; J.O.L. Wendt; W. Seames; M.R. Ames; A.F. Sarofim; S. Swenson; J.S. Lighty; A. Kolker; R. Finkelman; C.A. Palmer; S.J. Mroczkowski; J.J. Helble; R. Mamani-Paco; R. Sterling; G. Dunham; S. Miller

    2001-06-30

    The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. With support from the National Energy Technology Laboratory (NETL), the Electric Power Research Institute, and VTT (Finland), Physical Sciences Inc. (PSI) has teamed with researchers from USGS, MIT, the University of Arizona (UA), the University of Kentucky (UK), the University of Connecticut (UC), the University of Utah (UU) and the University of North Dakota Energy and Environmental Research Center (EERC) to develop a broadly applicable emissions model useful to regulators and utility planners. The new Toxics Partitioning Engineering Model (ToPEM) will be applicable to all combustion conditions including new fuels and coal blends, low-NOx combustion systems, and new power generation plants. Development of ToPEM will be based on PSI's existing Engineering Model for Ash Formation (EMAF). The work discussed in this report covers the Phase II program. Five coals were studied (three in Phase I and two new ones in Phase II). In this work UK has used XAFS and Moessbauer spectroscopies to characterize elements in project coals. For coals, the principal use was to supply direct information about certain hazardous and other key elements (iron) to complement the more complete indirect investigation of elemental modes of occurrence being carried out by colleagues at USGS. Iterative selective leaching using ammonium acetate, HCl, HF, and HNO3, used in conjunction with mineral identification/quantification, and microanalysis of individual mineral grains, has allowed USGS to delineate modes of occurrence for 44 elements. The Phase II coals show rank-dependent systematic differences in trace-element modes of occurrence. The work at UU

  12. Risk assessment for neurobehavioral toxicity: SGOMSEC joint report.

    PubMed Central

    Hattis, D; Glowa, J; Tilson, H; Ulbrich, B

    1996-01-01

    Behavioral end points for neurotoxicity risk assessment have been developed and examined over the past three decades. They are now ready to move from simple qualitative guidelines, such as exemplified by reference doses, to more quantitative models, such as benchmark doses, based on dose-response information. Risk assessors, confronted by a wider array of methodologies and data than in the past, should be offered guidance in interpretation because now they have to deal with unaccustomed questions and problems. These include reversibility, susceptible populations, multiple end points, and the details of dose-response and dose-effect distributions. PMID:8860324

  13. Endangered species toxicity extrapolation using ICE models

    EPA Science Inventory

    The National Research Council’s (NRC) report on assessing pesticide risks to threatened and endangered species (T&E) included the recommendation of using interspecies correlation models (ICE) as an alternative to general safety factors for extrapolating across species. ...

  14. Endangered species toxicity extrapolation using ICE models

    EPA Science Inventory

    The National Research Council’s (NRC) report on assessing pesticide risks to threatened and endangered species (T&E) included the recommendation of using interspecies correlation models (ICE) as an alternative to general safety factors for extrapolating across species. ...

  15. Risk assessment of an abandoned pyrite mine in Spain based on direct toxicity assays.

    PubMed

    García-Gómez, Concepción; Sánchez-Pardo, Beatriz; Esteban, Elvira; Peñalosa, Jesús Manuel; Fernández, María Dolores

    2014-02-01

    This research reports the risk assessment of an abandoned pyrite mine using direct toxicity assays of soil and groundwater samples taken at the site. The toxicity of As and heavy metals from mining soils to soil and aquatic organisms was studied using the Multispecies Soil System (MS-3) in soil columns. Ecotoxicological assessment was performed with soil samples diluted with a control soil at concentrations of 12.5, 25, 50 and 100% test soil/soil (w/w). In this way, changes in the mobility and bioavailability of soil contaminants due to changes in geochemical soil properties via soil dilution were studied. The toxicity of water samples was tested on algae and Daphnia magna. The assessment of the mining area indicated that the current presence of As and heavy metals at the site may cause injuries to soil and aquatic organisms in the entire research area. Moreover, this investigation demonstrated that changes in geochemical conditions can increase the availability of arsenic and, consequently, the environmental risk of these soils. A good correlation was not found between toxicity parameters and the concentrations of soil contaminants based on total and extracted element concentrations. This finding reinforces the usefulness of direct toxicity assays for evaluating environmental risk. © 2013.

  16. Assessing structural and functional plankton responses to carbendazim toxicity.

    PubMed

    Slijkerman, Diana M E; Baird, Donald J; Conrad, Anne; Jak, Robbert G; van Straalen, Nico M

    2004-02-01

    A model ecosystem experiment was conducted to investigate the ability of an in situ Daphnia magna feeding bioassay to assess impairment of ecosystem function. Animals were deployed in model ecosystems dosed with different concentrations of the fungicide carbendazim, and effects on the postexposure feeding rate of D. magna were compared with effects on zooplankton species richness (ecosystem structure) and development of phytoplankton biomass (ecosystem function). In the medium-dosed systems (21 microg/L), a structural change was observed within the zooplankton community, but no indirect effects on phytoplankton development were detected. It appears that at this treatment level, functional redundancy was sufficient to prevent functional impairment despite species loss. The feeding assay did not show any response at this concentration. In the high-dosed systems (221 microg/L), structural changes in the zooplankton community were accompanied by increased development of phytoplankton biomass. The feeding bioassay also showed a significant response at this concentration. At the high treatment level, species loss resulted in functional impairment, indicating that at this level, functional redundancy could not compensate for loss of individuals. The D. magna feeding bioassay matched well with the functional response (i.e., the indirect effects on phytoplankton) in the dosed systems but not with the more subtle effects on zooplankton community structure. These results lend positive support to the use of in situ feeding bioassays in combination with structural indices, such as species richness, to assess the effects of stress on ecosystem functioning in a direct way.

  17. Model ecosystems with random nonlinear interspecies interactions

    NASA Astrophysics Data System (ADS)

    Santos, Danielle O. C.; Fontanari, José F.

    2004-12-01

    The principle of competitive exclusion in ecology establishes that two species living together cannot occupy the same ecological niche. Here we present a model ecosystem in which the species are described by a series of phenotypic characters and the strength of the competition between two species is given by a nondecreasing (modulating) function of the number of common characters. Using analytical tools of statistical mechanics we find that the ecosystem diversity, defined as the fraction of species that coexist at equilibrium, decreases as the complexity (i.e., number of characters) of the species increases, regardless of the modulating function. By considering both selective and random elimination of the links in the community web, we show that ecosystems composed of simple species are more robust than those composed of complex species. In addition, we show that the puzzling result that there exists either rich or poor ecosystems for a linear modulating function is not typical of communities in which the interspecies interactions are determined by a complementarity rule.

  18. Model ecosystems with random nonlinear interspecies interactions.

    PubMed

    Santos, Danielle O C; Fontanari, José F

    2004-12-01

    The principle of competitive exclusion in ecology establishes that two species living together cannot occupy the same ecological niche. Here we present a model ecosystem in which the species are described by a series of phenotypic characters and the strength of the competition between two species is given by a nondecreasing (modulating) function of the number of common characters. Using analytical tools of statistical mechanics we find that the ecosystem diversity, defined as the fraction of species that coexist at equilibrium, decreases as the complexity (i.e., number of characters) of the species increases, regardless of the modulating function. By considering both selective and random elimination of the links in the community web, we show that ecosystems composed of simple species are more robust than those composed of complex species. In addition, we show that the puzzling result that there exists either rich or poor ecosystems for a linear modulating function is not typical of communities in which the interspecies interactions are determined by a complementarity rule.

  19. Applicability of ambient toxicity testing to national or regional water-quality assessment

    USGS Publications Warehouse

    Elder, J.F.

    1989-01-01

    Comprehensive assessment of the quality of natural waters requires a multifaceted approach. Based on experimentation designed to monitor responses of organisms to environmental stresses, toxicity testing may have diverse purposes in water quality assessments. These purposes may include identification that warrant further study because of poor water quality or unusual ecological features, verification of other types of monitoring, or assessment of contaminant effects on aquatic communities. A wide variety of toxicity test methods have been developed to fulfill the needs of diverse applications. The methods differ primarily in the full selections made relative to four characteristics: (1) test species, (2) endpoints (acute or chronic), (3) test enclosure type, and (4) test substance (toxicant) that functions as the environmental stress. Toxicity test approachs vary in their capacity to meet the needs of large-scale assessments of existing water quality. Ambient testing is more likely to meet these needs than are the procedures that call for exposure of the test organisms to known concentrations of a single toxicant. However, meaningful interpretation of ambient test results depend on the existence of accompanying chemical analysis of the ambient media. The ambient test substance may be water or sediments. Sediment tests have had limited application, but they are useful because of the fact that most toxicants tend to accumulate in sediments, and many test species either inhabit the sediments or are in frequent contact with them. Biochemical testing methods, which have been developing rapidly in recent years, are likely to be among the most useful procedures for large-scale water quality assessments. They are relatively rapid and simple, and more importantly, they focus on biochemical changes that are the initial responses of virtually all organisms to environmental stimuli. Most species are sensitive to relatively few toxicants and their sensitivities vary as

  20. Probabilistic ecological risk assessment of effluent toxicity of a wastewater reclamation plant based on process modeling.

    PubMed

    Zeng, Siyu; Huang, Yunqing; Sun, Fu; Li, Dan; He, Miao

    2016-09-01

    The growing use of reclaimed wastewater for environmental purposes such as stream flow augmentation requires comprehensive ecological risk assessment and management. This study applied a system analysis approach, regarding a wastewater reclamation plant (WRP) and its recipient water body as a whole system, and assessed the ecological risk of the recipient water body caused by the WRP effluent. Instead of specific contaminants, two toxicity indicators, i.e. genotoxicity and estrogenicity, were selected to directly measure the biological effects of all bio-available contaminants in the reclaimed wastewater, as well as characterize the ecological risk of the recipient water. A series of physically based models were developed to simulate the toxicity indicators in a WRP through a typical reclamation process, including ultrafiltration, ozonation, and chlorination. After being validated against the field monitoring data from a full-scale WRP in Beijing, the models were applied to simulate the probability distribution of effluent toxicity of the WRP through Latin Hypercube Sampling to account for the variability of influent toxicity and operation conditions. The simulated effluent toxicity was then used to derive the predicted environmental concentration (PEC) in the recipient stream, considering the variations of the toxicity and flow of the upstream inflow as well. The ratio of the PEC of each toxicity indicator to its corresponding predicted no-effect concentration was finally used for the probabilistic ecological risk assessment. Regional sensitivity analysis was also performed with the developed models to identify the critical control variables and strategies for ecological risk management. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Behavioural toxicity assessment of silver ions and nanoparticles on zebrafish using a locomotion profiling approach.

    PubMed

    Ašmonaitė, Giedrė; Boyer, Scott; Souza, Karine Bresolin de; Wassmur, Britt; Sturve, Joachim

    2016-04-01

    Zebrafish (Danio rerio) is not only a widely used species in the Fish Embryo Toxicity (FET) test but also an emerging model in behavioural ecotoxicology. By using automatic behaviour tracking technology, locomotion of developing zebrafish (ZF) larvae can be accurately recorded and potentially used in an ecotoxicological context to detect toxicant-induced behavioural alterations. In this study, we explored if and how quantitative locomotion data can be used for sub-lethal toxicity testing within the FET framework. We exposed ZF embryos to silver ions and nanoparticles, which previously have been reported to cause neurodevelopmental toxicity and behavioural retardation in early-life stages of ZF. Exposure to a broad range of silver (Ag(+) and AgNPs) concentrations was conducted, and developmental toxicity was assessed using FET criteria. For behavioural toxicity assessment, locomotion of exposed ZF eleutheroembryos (120hpf) was quantified according to a customised behavioural assay in an automatic video tracking system. A set of repeated episodes of dark/light stimulation were used to artificially stress ZF and evoke photo-motor responses, which were consequently utilized for locomotion profiling. Our locomotion-based behaviour profiling approach consisted of (1) dose-response ranking for multiple and single locomotion variables; (2) quantitative assessment of locomotion structure; and (3) analysis of ZF responsiveness to darkness stimulation. We documented that both silver forms caused adverse effects on development and inhibited hatchability and, most importantly, altered locomotion. High Ag(+) and AgNPs exposures significantly suppressed locomotion and a clear shift in locomotion towards inactivity was reported. Additionally, we noted that low, environmentally relevant Ag(+) concentrations may cause subordinate locomotive changes (hyperactivity) in developing fish. Overall, it was concluded that our locomotion-based behaviour-testing scheme can be used jointly

  2. The intersection of risk assessment and neurobehavioral toxicity

    NASA Technical Reports Server (NTRS)

    Weiss, B.; Elsner, J.; Clarkson, T. W. (Principal Investigator)

    1996-01-01

    Neurobehavioral toxicology is now established as a core discipline of the environmental health sciences. Despite its recognized scientific prowess, stemming from its deep roots in psychology and neuroscience and its acknowledged successes, it faces additional demands and challenges. The latter, in fact, are a product of its achievements because success at one level leads to new and higher expectations. Now the discipline is counted upon to provide more definitive and extensive risk assessments than in the past. These new demands are the basis for the appraisals presented in the SGOMSEC 11 workshop. They extend beyond what would be offered in a primer of methodology. Instead, these appraisals are framed as issues into which what are usually construed as methodologies have been embedded.

  3. The intersection of risk assessment and neurobehavioral toxicity

    NASA Technical Reports Server (NTRS)

    Weiss, B.; Elsner, J.; Clarkson, T. W. (Principal Investigator)

    1996-01-01

    Neurobehavioral toxicology is now established as a core discipline of the environmental health sciences. Despite its recognized scientific prowess, stemming from its deep roots in psychology and neuroscience and its acknowledged successes, it faces additional demands and challenges. The latter, in fact, are a product of its achievements because success at one level leads to new and higher expectations. Now the discipline is counted upon to provide more definitive and extensive risk assessments than in the past. These new demands are the basis for the appraisals presented in the SGOMSEC 11 workshop. They extend beyond what would be offered in a primer of methodology. Instead, these appraisals are framed as issues into which what are usually construed as methodologies have been embedded.

  4. A New In Vivo Model System to Assess the Toxicity of Semiconductor Nanocrystals

    PubMed Central

    Tino, Angela; Ambrosone, Alfredo; Mattera, Lucia; Marchesano, Valentina; Susha, Andrei; Rogach, Andrey; Tortiglione, Claudia

    2011-01-01

    In the emerging area of nanotechnology, a key issue is related to the potential impacts of the novel nanomaterials on the environment and human health, so that this technology can be used with minimal risk. Specifically designed to combine on a single structure multipurpose tags and properties, smart nanomaterials need a comprehensive characterization of both chemicophysical properties and adequate toxicological evaluation, which is a challenging endeavour; the in vitro toxicity assays that are often employed for nanotoxicity assessments do not accurately predict in vivo response. To overcome these limitations and to evaluate toxicity characteristics of cadmium telluride quantum dots in relation to surface coatings, we have employed the freshwater polyp Hydra vulgaris as a model system. We assessed in vivo acute and sublethal toxicity by scoring for alteration of morphological traits, population growth rates, and influence on the regenerative capabilities providing new investigation clues for nanotoxicology purposes. PMID:21822433

  5. U. S. Environmental Protection Agency's inhalation RFD methodology: Risk assessment for air toxics

    SciTech Connect

    Jarabek, A.M.; Menache, M.G.; Overton, J.H.; Dourson, M.L.; Miller, F.J.

    1989-01-01

    The U.S. Environmental Protection Agency (U.S. EPA) has advocated the establishment of general and scientific guidelines for the evaluation of toxicological data and their use in deriving benchmark values to protect exposed populations from adverse health effects. The Agency's reference dose (RfD) methodology for deriving benchmark values for noncancer toxicity originally addressed risk assessment of oral exposures. The paper presents a brief background on the development of the inhalation reference dose (RFDi) methodology, including concepts and issues related to addressing the dynamics of the respiratory system as the portal of entry. Different dosimetric adjustments are described that were incorporated into the methodology to account for the nature of the inhaled agent (particle or gas) and the site of the observed toxic effects (respiratory or extrarespiratory). Impacts of these adjustments on the extrapolation of toxicity data of inhaled agents for human health risk assessment and future research directions are also discussed.

  6. Thermal stress and toxicity.

    PubMed

    Gordon, Christopher J; Johnstone, Andrew F M; Aydin, Cenk

    2014-07-01

    Elevating ambient temperature above thermoneutrality exacerbates toxicity of most air pollutants, insecticides, and other toxic chemicals. On the other hand, safety and toxicity testing of toxicants and drugs is usually performed in mice and rats maintained at sub-thermoneutral temperatures of ~22∘C. When exposed to chemical toxicants under these relatively cool conditions, rodents typically undergo a regulated hypothermic response, characterized by preference for cooler ambient temperatures and controlled reduction in core temperature. Reducing core temperature delays the clearance of most toxicants from the body; however, a mild hypothermia also improves recovery and survival from the toxicant. Raising ambient temperature to thermoneutrality and above increases the rate of clearance of the toxicant but also exacerbates toxicity. Furthermore, heat stress combined with work or exercise is likely to worsen toxicity. Body temperature of large mammals, including humans, does not decrease as much in response to exposure to a toxicant. However, heat stress can nonetheless worsen toxic outcome in humans through a variety of mechanisms. For example, heat-induced sweating and elevation in skin blood flow accelerates uptake of some insecticides. Epidemiological studies suggest that thermal stress may exacerbate the toxicity of airborne pollutants such as ozone and particulate matter. Overall, translating results of studies in rodents to that of humans is a formidable task attributed in part to the interspecies differences in thermoregulatory response to the toxicants and to thermal stress.

  7. Wildlife Species/Family Taxa Selection | Interspecies ...

    EPA Pesticide Factsheets

    2016-02-22

    Web-ICE estimates acute toxicity (LC50/LD50) of a chemical to a species, genus, or family from the known toxicity of the chemical to a surrogate species. Wildlife species and family taxa selection page. Page provides access to the ICE calculators

  8. Physiologic assessment of fetal compromise: biomarkers of toxic exposure

    SciTech Connect

    Longo, L.D.

    1987-10-01

    Understanding the physiologic and endocrinologic basis of fetal development is a major goal of perinatal biology. During the past decade a number of technological developments have allowed more precise evaluation of the fetus in utero and diagnosis of abnormalities. Despite these methodological achievements, however, there are no specific biological markers currently available to indicate that exposure to a given xenobiotic is associated with a cellular, subcellular, or pharmacodynamic event. This paper evaluates the following issues: what are some of the unique physiologic and endocrinologic features of the fetal milieu interieur. What problems are peculiar to fetal assessment. What are some examples of validated biomarkers and their applicability. What promising biomarkers are on the horizon. How may molecular probes be of value as biological markers of fetal compromise. What are some of the major research gaps and needs, and how should research priorities be set. Some of these topics are addressed. Moreover, the more general role(s) that various diagnostic methods and biological markers can have in an understanding of the regulation of fetal growth and differentiation and the role of xenobiotics in affecting the normal course of events are discussed.

  9. Assessment of phenolic herbicide toxicity and mode of action by different assays.

    PubMed

    Bettiol, Cinzia; De Vettori, Stefania; Minervini, Giovanni; Zuccon, Elisa; Marchetto, Davide; Ghirardini, Annamaria Volpi; Argese, Emanuele

    2016-04-01

    A phytotoxicity assay based on seed germination/root elongation has been optimized and used to evaluate the toxic effects of some phenolic herbicides. The method has been improved by investigating the influence of experimental conditions. Lepidium sativum was chosen as the most suitable species, showing high germinability, good repeatability of root length measurements, and low sensitivity to seed pretreatment. DMSO was the most appropriate solvent carrier for less water-soluble compounds. Three dinitrophenols and three hydroxybenzonitriles were tested: dinoterb, DNOC, 2,4-dinitrophenol, chloroxynil, bromoxynil, and ioxynil. Toxicity was also determined using the Vibrio fischeri Microtox® test, and a highly significant correlation was found between EC50 values obtained by the two assays. Dinoterb was the most toxic compound. The toxicity of hydroxybenzonitriles followed the order: ioxynil >bromoxynil >chloroxynil; L. sativum exhibited a slightly higher sensitivity than V. fischeri to these compounds. A QSAR analysis highlighted the importance of hydrophobic, electronic, and hydrogen-bonding interactions, in accordance with a mechanism of toxic action based on protonophoric uncoupling of oxidative phosphorylation. The results suggest that the seed germination/root elongation assay with L. sativum is a valid tool for the assessment of xenobiotic toxicity and can be recommended as part of a test battery.

  10. Long-term toxicity assessment of soils in a recovered area affected by a mining spill.

    PubMed

    Romero-Freire, A; García Fernández, I; Simón Torres, M; Martínez Garzón, F J; Martín Peinado, F J

    2016-01-01

    Residual pollution in the Guadiamar Green Corridor still remains after Aználcollar mine spill in 1998. The polluted areas are identified by the absence of vegetation, soil acidic pH and high concentrations of As, Pb, Zn and Cu. Soil toxicity was assessed by lettuce root elongation and induced soil respiration bioassays. In bare soils, total As and Pb concentrations and water-extractable levels for As, Zn and Cu exceeded the toxicity guidelines. Pollutants responsible for toxicity were different depending on the tested organism, with arsenic being most toxic for lettuce and the metal mixture to soil respiration. Soil properties, such as pH or organic carbon content, are key factors to control metal availability and toxicity in the area. According to our results, there is a risk of pollution to living organisms and the soil quality criteria established in the area should be revised to reduce the risk of toxicity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Development and application of a multimetal multibiotic ligand model for assessing aquatic toxicity of metal mixtures.

    PubMed

    Santore, Robert C; Ryan, Adam C

    2015-04-01

    A multimetal, multiple binding site version of the biotic ligand model (mBLM) has been developed for predicting and explaining the bioavailability and toxicity of mixtures of metals to aquatic organisms. The mBLM was constructed by combining information from single-metal BLMs to preserve compatibility between the single-metal and multiple-metal approaches. The toxicities from individual metals were predicted by assuming additivity of the individual responses. Mixture toxicity was predicted based on both dissolved metal and mBLM-normalized bioavailable metal. Comparison of the 2 prediction methods indicates that metal mixtures frequently appear to have greater toxicity than an additive estimation of individual effects on a dissolved metal basis. However, on an mBLM-normalized basis, mixtures of metals appear to be additive or less than additive. This difference results from interactions between metals and ligands in solutions including natural organic matter, processes that are accounted for in the mBLM. As part of the mBLM approach, a technique for considering variability was developed to calculate confidence bounds (called response envelopes) around the central concentration-response relationship. Predictions using the mBLM and response envelope were compared with observed toxicity for a number of invertebrate and fish species. The results show that the mBLM is a useful tool for considering bioavailability when assessing the toxicity of metal mixtures.

  12. Toxicity assessment of Titanium Dioxide and Cerium Oxide nanoparticles in Arabidopsis thaliana L.

    EPA Science Inventory

    The production and applications of nanoparticles (NP) in diverse fields has steadily increased in recent decades; however, knowledge about risks of NP to human health and ecosystems is still scarce. In this study, we assessed potential toxicity of two commercially used engineere...

  13. GENOMIC AND PROTEOMIC ANALYSIS OF SURROGATE TISSUES FOR ASSESSING TOXIC EXPOSURES AND DISEASE STATES

    EPA Science Inventory

    Genomic and Proteomic Analysis of Surrogate Tissues for Assessing Toxic Exposures and Disease States
    David J. Dix and John C. Rockett
    Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, USEPA, ...

  14. Evaluation of the Reference Envelope Approach for Assessing Toxicity in Contaminated Surficial Urban Freshwater Sediments

    EPA Science Inventory

    The reference envelope (RE) has been proposed as an alternative approach to assess sediment toxicity to overcome limitations imposed by the use of control sediments including differences in non-contaminant characteristics and low statistical power when many test sediments are com...

  15. Toxicity assessment of Titanium Dioxide and Cerium Oxide nanoparticles in Arabidopsis thaliana L.

    EPA Science Inventory

    The production and applications of nanoparticles (NP) in diverse fields has steadily increased in recent decades; however, knowledge about risks of NP to human health and ecosystems is still scarce. In this study, we assessed potential toxicity of two commercially used engineere...

  16. TECHNICAL CHALLENGES ASSOCIATED WITH ASSESSING THE IN VITRO PULMONARY TOXICITY OF CARBON NANOTUBES

    EPA Science Inventory

    Nanotechnology continues to produce a large number of diverse engineered nanomaterials (NMs) with novel physicochemical properties for a variety of applications. Test methods that accurately assess/predict the toxicity of NMs are critically needed and it is unclear whether curren...

  17. Assessment of Airborne Particles. Fundamentals, Applications, and Implications to Inhalation Toxicity.

    ERIC Educational Resources Information Center

    Mercer, Thomas T., Ed.; And Others

    Concern over chemical and radioactive particulate matter in industry and over rapidly increasing air pollution has stimulated research both on the properties of airborne particles and methods for assessing them and on their biological effects following inhalation. The Third Rochester International Conference on Environmental Toxicity was,…

  18. TECHNICAL CHALLENGES ASSOCIATED WITH ASSESSING THE IN VITRO PULMONARY TOXICITY OF CARBON NANOTUBES

    EPA Science Inventory

    Nanotechnology continues to produce a large number of diverse engineered nanomaterials (NMs) with novel physicochemical properties for a variety of applications. Test methods that accurately assess/predict the toxicity of NMs are critically needed and it is unclear whether curren...

  19. STRESS PATHWAY-BASED REPORTER ASSAYS TO ASSESS TOXICITY OF ENVIRONMENTAL CHEMICALS.

    EPA Science Inventory

    There is an increasing need for assays for the rapid and efficient assessment of toxicities of large numbers of environmental chemicals. To meet this need, we are developing cell-based reporter assays that measure the activation of key molecular stress pathways. We are using pro...

  20. Evaluation of the Reference Envelope Approach for Assessing Toxicity in Contaminated Surficial Urban Freshwater Sediments

    EPA Science Inventory

    The reference envelope (RE) has been proposed as an alternative approach to assess sediment toxicity to overcome limitations imposed by the use of control sediments including differences in non-contaminant characteristics and low statistical power when many test sediments are com...

  1. GENOMIC AND PROTEOMIC ANALYSIS OF SURROGATE TISSUES FOR ASSESSING TOXIC EXPOSURES AND DISEASE STATES

    EPA Science Inventory

    Genomic and Proteomic Analysis of Surrogate Tissues for Assessing Toxic Exposures and Disease States
    David J. Dix and John C. Rockett
    Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, USEPA, ...

  2. Toxicity Assessment of Six Titanium Dioxide Nanoparticles in Human Epidermal Keratinocytes

    EPA Science Inventory

    Toxicity Assessment of Six Titanium Dioxide Nanoparticles in Human Epidermal Keratinocytes Nanoparticle uptake in cells may be an important determinant of their potential cytotoxic and inflammatory effects. Six commercial TiO2 NP (A=Alfa Aesar,10nm, A*=Alfa Aesar 32nm, B=P25 27...

  3. Results of in vivo and in vitro studies for assessing prenatal toxicity

    SciTech Connect

    Neubert, D.; Blankenburg, G.; Chahoud, I.; Franz, G.; Herken, R.; Kastner, M.; Klug, S.; Koreger, J.; Krowke, R.; Lewandowski, C.; Merker, H.J.

    1986-12-01

    Examples of a combined approach using in vivo as well as in vitro methods for the assessment of prenatal toxicity are presented. The topics discussed include the analysis of the possible embryotoxic potential of valproic acid (VPA), female sex hormones, bis(tri-n-butyltin) oxide (TBTO), and acyclovir and the problem of supplementing in vitro systems with drug-metabolizing activity.

  4. Assessment of Airborne Particles. Fundamentals, Applications, and Implications to Inhalation Toxicity.

    ERIC Educational Resources Information Center

    Mercer, Thomas T., Ed.; And Others

    Concern over chemical and radioactive particulate matter in industry and over rapidly increasing air pollution has stimulated research both on the properties of airborne particles and methods for assessing them and on their biological effects following inhalation. The Third Rochester International Conference on Environmental Toxicity was,…

  5. STRESS PATHWAY-BASED REPORTER ASSAYS TO ASSESS TOXICITY OF ENVIRONMENTAL CHEMICALS.

    EPA Science Inventory

    There is an increasing need for assays for the rapid and efficient assessment of toxicities of large numbers of environmental chemicals. To meet this need, we are developing cell-based reporter assays that measure the activation of key molecular stress pathways. We are using pro...

  6. Toxicity Assessment of Six Titanium Dioxide Nanoparticles in Human Epidermal Keratinocytes

    EPA Science Inventory

    Toxicity Assessment of Six Titanium Dioxide Nanoparticles in Human Epidermal Keratinocytes Nanoparticle uptake in cells may be an important determinant of their potential cytotoxic and inflammatory effects. Six commercial TiO2 NP (A=Alfa Aesar,10nm, A*=Alfa Aesar 32nm, B=P25 27...

  7. Toxicity assessment of reference and natural freshwater sediments with the LuminoTox assay.

    PubMed

    Dellamatrice, P M; Monteiro, R T R; Blaise, C; Slabbert, J L; Gagné, F; Alleau, S

    2006-08-01

    We examined the possibility of adapting the LuminoTox, a recently-commercialized bioanalytical testing procedure initially developed for aqueous samples, to assess the toxic potential of sediments. This portable fluorescent biosensor uses photosynthetic enzyme complexes (PECs) to rapidly measure photosynthetic efficiency. LuminoTox testing of 14 CRM (Certified Reference Material) sediments was first undertaken with (1) a "solid phase assay" (Lum-SPA) in which PECs are in intimate contact with sediment slurries for a 15 min exposure period and (2) an elutriate assay (Lum-ELU) in which PECs are exposed for 15 min to sediment water elutriates. CRM sediment toxicity data were then compared with those generated with the Microtox Solid Phase Assay (Mic-SPA). A significant correlation (P < 0.05) was shown to exist between Lum-SPA and Mic-SPA, indicating that both tests display a similar toxicity response pattern for CRM sediments having differing contaminant profiles. The sediment elutriate Lum-ELU assay displayed toxicity responses (i.e. measurable IC20s) for eight of the 14 CRM sediments, suggesting that it is capable of determining the presence of sediment contaminants that are readily soluble in an aqueous elutriate. Lum-SPA and Mic-SPA bioassays were further conducted on 12 natural freshwater sediments and their toxicity responses were more weakly, yet significantly, correlated. Finally, Lum-SPA testing undertaken with increasing mixtures of kaolin clay confirmed that its toxicity responses, in a manner similar to those reported for the Mic-SPA assay, are also subject to the influence of grain size. While further studies will be required to more fully understand the relationship between Lum-SPA assay responses and the physicochemical makeup of sediments (e.g., grain size, combined presence of natural and anthropogenic contaminants), these preliminary results suggest that LuminoTox testing could be a useful screen to assess the toxic potential of solid media.

  8. Residual bioassay to assess the toxicity of Acaricides against Aceria guerreronis (Acari: Eriophyidae) under laboratory conditions.

    PubMed

    Monteiro, Vaneska B; Lima, Debora B; Gondim, Manoel G C; Siqueira, Herbert A A

    2012-08-01

    Aceria guerreronis Keifer (Acari: Eriophyidae) is considered a major pest of the coconut (Cocos nucifera L.), and the use of pesticides is the current method to control it. However, no standard toxicological tests exist to select and assess the efficiency of molecules against the coconut mite. The aim of this study was to develop a methodology that allows for the evaluation of the relative toxicity of acaricides to A. guerreronis through rapid laboratory procedures. We confined A. guerreronis on arenas made out of coconut leaflets and tested two application methods: immersing the leaf fragments in acaricides and spraying acaricides on the leaf fragments under a Potter spray tower. In the latter application method, we sprayed leaf fragments both populated with and devoid of mites. We evaluated the comparative toxicity of two populations (Itamaracá and Petrolina, Pernambuco, Brazil) by spraying on leaflets without mites and submitted the mortality data to probit analysis after 24 h of exposure. No difference was observed in the LC50, regardless of whether the leaflets were immersed or sprayed with acaricide (abamectin, chlorfenapyr or fenpyroximate). The toxicity of chlorfenapyr and fenpyroximate did not differ, irrespective of whether it was applied directly to the leaflet or to the mite; however, the toxicity of abamectin was higher when applied directly to the mite. Chlorpyrifos and abamectin toxicities were lower for the Petrolina population than for the Itamaracá population. Immersing and spraying coconut leaflets can be used to assess the mortality of A. guerreronis under laboratory conditions.

  9. Toxicity assessment for chlorpyrifos-contaminated soil with three different earthworm test methods.

    PubMed

    Zhou, Shi-Ping; Duan, Chang-Qun; Fu, Hui; Chen, Yu-Hui; Wang, Xue-Hua; Yu, Ze-Fen

    2007-01-01

    Earthworm toxicity tests are useful tools for terrestrial risk assessment but require a hierarchy of test designs that differ in effect levels (behavior, sublethal, lethal). In this study, the toxicity of chlorpyrifos contaminated soil on earthworms was assessed. In addition to the acute and chronic tests, an avoidance response test was applied. Earthworms were exposed to sublethal and lethal concentration of chlorpyrifos, and evaluated for acute toxicity, growth, fecundity and avoidance response after a certain exposure period. The test methods covered all important ecological relevant endpoints (acute, chronic, behavioral). Concentration of 78.91 mg/kg, chlorpyrifos caused significant toxic effects in all test methods, but at lower test concentrations, only significant chronic toxic effects could be observed. In present study, chlorpyrifos had adverse effect on growth and fecundity in earthworm exposed to 5 mg/kg chlorpyrifos after eight weeks. The avoidance response test, however, showed significant repellent effects at concentration of 40 mg/kg chlorpyrifos. For chlorpyrifos, concentration affecting avoidance response was far greater than growth and fecundity, it seemed likely that earthworms were not able to escape from pesticide-contaminated soil into the clean soil in field and hence were exposed continuously to elevated concentrations of pesticides.

  10. In vitro assessment of cobalt oxide particle toxicity: identifying and circumventing interference.

    PubMed

    Darolles, Carine; Sage, Nicole; Armengaud, Jean; Malard, Véronique

    2013-09-01

    The continuing development of nanotechnology necessitates the reliable assessment of potential adverse health consequences associated with human exposures. The physicochemical properties of nanomaterials can be responsible for unexpected interactions with components of classical toxicity assays, which may generate erroneous interpretations. In this paper, we describe how particle interference can be observed in in vitro toxicity tests (CellTiter Blue, CyQUANT, WST-1 and CellTiter-Glo assay) and in cell biology tests using flow cytometry (cell cycle analysis). We used cobalt oxide (Co3O4) particles as an example, but these assays can be performed, in principle, regardless of the nanoparticle considered. We have shown that cobalt particles interfere with most of these tests. We adapted the protocol of the CellTiter-Glo assay to circumvent this interference and demonstrated that, using this protocol, the toxicity level is consistent with results obtained using the clonogenic assay, which is considered to be the reference test. Before assessing particle toxicity using in vitro toxicity tests, interference testing should be performed to avoid false interpretations. Furthermore, in some cases of interference, protocol adaptation can be considered to allow the reliable use of these quick and convenient in vitro tests.

  11. Hydrobia ulvae feeding rates: A novel way to assess sediment toxicity.

    PubMed

    Shipp, Emily; Grant, Alastair

    2006-12-01

    Standard acute toxicity tests are widely used to assess contaminated sediments. However, such tests last 10 d or more and only provide information regarding lethality. Here, we present data concerning the use of a 28-d growth test and a 24-h test using feeding rate, as measured by egestion rate, of the marine snail Hydrobia ulvae. The test was used to assess the toxicity of estuarine sediments from a gradient of heavy metal contamination, and its sensitivity and ease of use were compared with those of 10-d tests using the amphipod crustacean Corophium volutator. Mortality of C. volutator and H. ulvae in 10-d lethal toxicity tests showed similar patterns of sensitivity. Lethality tests with both species showed no effects when carried out using sediments from a number of sites at which ecological impacts are known to occur. By contrast, growth over 28 d in H. ulvae was reduced at all sites where other studies have detected adverse ecological effects. Feeding rate after 24 h also was decreased at moderately contaminated sites where sediments were not acutely toxic, and it was a very good predictor of 28-d growth (r2 = 0.74). Both tests were straightforward to carry out, so H. ulvae has considerable potential as a test organism for chronic toxicity.

  12. Reference manual for toxicity and exposure assessment and risk characterization. CERCLA Baseline Risk Assessment

    SciTech Connect

    1995-03-01

    The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA, 1980) (CERCLA or Superfund) was enacted to provide a program for identifying and responding to releases of hazardous substances into the environment. The Superfund Amendments and Reauthorization Act (SARA, 1986) was enacted to strengthen CERCLA by requiring that site clean-ups be permanent, and that they use treatments that significantly reduce the volume, toxicity, or mobility of hazardous pollutants. The National Oil and Hazardous Substances Pollution Contingency Plan (NCP) (USEPA, 1985; USEPA, 1990) implements the CERCLA statute, presenting a process for (1) identifying and prioritizing sites requiring remediation and (2) assessing the extent of remedial action required at each site. The process includes performing two studies: a Remedial Investigation (RI) to evaluate the nature, extent, and expected consequences of site contamination, and a Feasibility Study (FS) to select an appropriate remedial alternative adequate to reduce such risks to acceptable levels. An integral part of the RI is the evaluation of human health risks posed by hazardous substance releases. This risk evaluation serves a number of purposes within the overall context of the RI/FS process, the most essential of which is to provide an understanding of ``baseline`` risks posed by a given site. Baseline risks are those risks that would exist if no remediation or institutional controls are applied at a site. This document was written to (1) guide risk assessors through the process of interpreting EPA BRA policy and (2) help risk assessors to discuss EPA policy with regulators, decision makers, and stakeholders as it relates to conditions at a particular DOE site.

  13. Health assessment of gasoline and fuel oxygenate vapors: Reproductive toxicity assessment

    PubMed Central

    Gray, Thomas M.; Steup, David; Roberts, Linda G.; O'Callaghan, James P.; Hoffman, Gary; Schreiner, Ceinwen A.; Clark, Charles R.

    2016-01-01

    Vapor condensates of baseline gasoline (BGVC), or gasoline-blended with methyl tertiary butyl ether (G/MTBE), ethyl t-butyl ether (G/ETBE), t-amyl methyl ether (G/TAME), diisopropyl ether (G/DIPE), ethanol (G/EtOH), or t-butyl alcohol (G/TBA) were evaluated for reproductive toxicity in rats at target concentrations of 2000, 10,000, or 20,000 mg/m3, 6 h/day, 7 days/week. BGVC and G/MTBE were assessed over two generations, the others for one generation. BGVC and G/MTBE F1 offspring were evaluated for neuropathology and changes in regional brain glial fibrillary acidic protein content. No neurotoxicity was observed. Male kidney weight was increased consistent with light hydrocarbon nephropathy. In adult rats, decreased body weight gain and increased liver weight were seen. Spleen weight decreased in adults and pups exposed to G/TBA. No pathological changes to reproductive organs occurred in any study. Decreased food consumption was seen in G/TAME lactating females. Transient decreases in G/TAME off-spring weights were observed during lactation. Except for a minor increase in time to mating in G/TBA which did not affect other reproductive parameters, there were no adverse reproductive findings. The NOAEL for reproductive and offspring parameters was 20,000 mg/m3 for all vapor condensates except for lower offspring NOAELs of 10,000 mg/m3 for G/TBA and 2000 mg/m3 for G/TAME. PMID:24813181

  14. Health assessment of gasoline and fuel oxygenate vapors: reproductive toxicity assessment.

    PubMed

    Gray, Thomas M; Steup, David; Roberts, Linda G; O'Callaghan, James P; Hoffman, Gary; Schreiner, Ceinwen A; Clark, Charles R

    2014-11-01

    Vapor condensates of baseline gasoline (BGVC), or gasoline-blended with methyl tertiary butyl ether (G/MTBE), ethyl t-butyl ether (G/ETBE), t-amyl methyl ether (G/TAME), diisopropyl ether (G/DIPE), ethanol (G/EtOH), or t-butyl alcohol (G/TBA) were evaluated for reproductive toxicity in rats at target concentrations of 2000, 10,000, or 20,000mg/m(3), 6h/day, 7days/week. BGVC and G/MTBE were assessed over two generations, the others for one generation. BGVC and G/MTBE F1 offspring were evaluated for neuropathology and changes in regional brain glial fibrillary acidic protein content. No neurotoxicity was observed. Male kidney weight was increased consistent with light hydrocarbon nephropathy. In adult rats, decreased body weight gain and increased liver weight were seen. Spleen weight decreased in adults and pups exposed to G/TBA. No pathological changes to reproductive organs occurred in any study. Decreased food consumption was seen in G/TAME lactating females. Transient decreases in G/TAME offspring weights were observed during lactation. Except for a minor increase in time to mating in G/TBA which did not affect other reproductive parameters, there were no adverse reproductive findings. The NOAEL for reproductive and offspring parameters was 20,000mg/m(3) for all vapor condensates except for lower offspring NOAELs of 10,000mg/m(3) for G/TBA and 2000mg/m(3) for G/TAME. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. [Risk assessment and risk control for occupational exposure to chemical toxicants from an isophorone nitrile device].

    PubMed

    Wang, Dejun; Fu, Xiaokuan; Kong, Fanling; Sui, Shaofeng; Jiang, Yuanyuan; Du, Yinglin; Zhou, Jingyang

    2014-06-01

    Risk assessment and risk control for occupational exposure to chemical toxicants were performed on an isophorone nitrile device with an annual production of 5,000 tons, based on improved Singaporean semi-quantitative risk assessment method, with consideration of actual situation in China and in the present project. With the use of engineering analysis and identification of occupational hazards in the improved Singaporean semi-quantitative risk assessment method, hazard rating (HR) and risk assessment were performed on chemical toxicants from an isophorone nitrile device with an annual production of 5,000 tons. The chemical toxicants in the isophorone nitrile device were mainly isophorone, hydrocyanic acid, methanol, phosphoric acid, sodium hydroxide, and sodium cyanide; the HR values were mild hazard (2), extreme hazard (5), mild hazard (2), mild hazard (2), moderate hazard (3), and extreme hazard (5), respectively, and the corresponding exposure rating (ER) values were 2.09, 2.72, 2.76, 1.68, 2.0, and 1.59, respectively. The risk of chemical toxicants in this project was assessed according to the formula Risk = [HR×ER](1/2). Hydrocyanic acid was determined as high risk, sodium hydroxide and sodium cyanide as medium risk, and isophorone, methanol, and phosphoric acid as low risk. Priority in handling of risks was determined by risk rating. The table of risk control measure was established for pre-assessment of occupational hazards. With risk assessment in this study, we concluded that the isophorone nitrile device with 5,000 ton annual production was a high-occupational hazard device. This device is a project of extreme occupational hazard. The improved Singaporean semi-quantitative risk assessment method is a scientific and applicable method, and is especially suitable for pre-evaluation of on-site project with no analogy.

  16. Toxicity testing strategies for assessing water-quality conditions in receiving streams

    SciTech Connect

    Stewart, A.J.

    1994-12-31

    This paper explores the use of short-term, EPA-approved laboratory toxicity tests for assessing water-quality conditions in streams and rivers. Strategies for the cost-effective application of such tests for long-term monitoring objectives are considered in the context of logistic constraints and statistical design. A subtle but important difference in objectives for effluent versus ambient testing is this: in effluent testing for regulatory purposes, a key objective is to determine how toxic an effluent is; in ambient testing, the main objective usually is that of determining if the water at a site is toxic. This difference shapes the strategy for cost-effective ambient testing and determines the framework for effective statistical analysis and interpretation of ambient toxicity test results. Recommendations derived as `` lessons learned`` from large-scale ambient toxicity testing programs for receiving streams at Department of Energy (DOE) facilities include: (1) testing more frequently with one species (preferably Ceriodaphnia) generally is more effective, in terms of information gained per dollar spent, than testing less frequently with two or more species; (2) use five or more sites per test period, plus two or more reference sites, whenever possible; (3) use four to six test periods per year; and (4) use diagnostic testing to supplement the ambient-testing program. Various laboratory and in situ methods for environmental assessment are now under development, but these methods probably will not gain acceptance for use in regulatory situations for many years. Rapid growth in need for ecological risk assessments outstrips the rate at which new test procedures are approved for regulatory purposes. Thus, laboratory tests for estimating possible environmental impacts of toxic or disruptive pollutants are likely to be used more frequently, not less frequently, during the next decade.

  17. Interspecies variation in axon-myelin relationships.

    PubMed

    Fraher, J P; O'Sullivan, A W

    2000-01-01

    The primary objective of this paper was to determine the extent and nature of interspecies differences in axon calibre and myelin sheath thickness and in the various relationships between these. Morphometric analysis of the axon perimeter-myelin sheath thickness relationship was performed on an equivalent nerve fibre population in a mammal, the rat, a bird, the chicken, an amphibian, the frog, a bony fish, the trout, and a cartilaginous fish, the dogfish. The abducent nerve was studied. It is especially suitable for this purpose because its fibres are closely similar in type and in peripheral distribution across the species studied. The relationship differed substantially between species. Differences were present in its setting, as described by the positions of the scatterplots, in the g ratio and in the regression and correlation data relating the parameters. Both parameters were markedly larger in the fish species than in all of the others. In addition, in rat, chicken, frog and trout, where large and small fibre classes could be differentiated clearly, the setting of the relationship between the two parameters was different for the two classes. In the main, variation in each of the parameters was greater between than within species. The larger fibres in the fish species were closely similar in axon perimeter and sheath thickness despite their long evolutionary separation. From this study and from others in the series, it may be concluded that there is no fixed or constant relationship between axon calibre and the thickness of the surrounding myelin sheath. Each nerve tends to have its own particular relationship and this differs between species.

  18. Interspecies Communication among Commensal and Pathogenic Streptococci

    PubMed Central

    Cook, Laura C.; LaSarre, Breah; Federle, Michael J.

    2013-01-01

    ABSTRACT Quorum sensing (QS) regulates diverse and coordinated behaviors in bacteria, including the production of virulence factors, biofilm formation, sporulation, and competence development. It is now established that some streptococci utilize Rgg-type proteins in concert with short hydrophobic peptides (SHPs) to mediate QS, and sequence analysis reveals that several streptococcal species contain highly homologous Rgg/SHP pairs. In group A streptococcus (GAS), two SHPs (SHP2 and SHP3 [SHP2/3]) were previously identified to be important in GAS biofilm formation. SHP2/3 are detected by two antagonistic regulators, Rgg2 and Rgg3, which control expression of the shp genes. In group B streptococcus (GBS), RovS is a known virulence gene regulator and ortholog of Rgg2, whereas no apparent Rgg3 homolog exists. Adjacent to rovS is a gene (shp1520) encoding a peptide nearly identical to SHP2. Using isogenic mutant strains and transcriptional reporters, we confirmed that RovS/SHP1520 comprise a QS circuit in GBS. More important, we performed experiments demonstrating that production and secretion of SHP1520 by GBS can modulate Rgg2/3-regulated gene expression in GAS in trans; likewise, SHP2/3 production by GAS can stimulate RovS-mediated gene regulation in GBS. An isolate of Streptococcus dysgalactiae subsp. equisimilis also produced a secreted factor capable of simulating the QS circuits of both GAS and GBS, and sequencing confirms the presence of an orthologous Rgg2/SHP2 pair in this species as well. To our knowledge, this is the first documented case of bidirectional signaling between streptococcal species in coculture and suggests a role for orthologous Rgg/SHP systems in interspecies communication between important human pathogens. PMID:23882015

  19. Coronavirus diversity, phylogeny and interspecies jumping.

    PubMed

    Woo, Patrick C Y; Lau, Susanna K P; Huang, Yi; Yuen, Kwok-Yung

    2009-10-01

    The SARS epidemic has boosted interest in research on coronavirus biodiversity and genomics. Before 2003, there were only 10 coronaviruses with complete genomes available. After the SARS epidemic, up to December 2008, there was an addition of 16 coronaviruses with complete genomes sequenced. These include two human coronaviruses (human coronavirus NL63 and human coronavirus HKU1), 10 other mammalian coronaviruses [bat SARS coronavirus, bat coronavirus (bat-CoV) HKU2, bat-CoV HKU4, bat-CoV HKU5, bat-CoV HKU8, bat-CoV HKU9, bat-CoV 512/2005, bat-CoV 1A, equine coronavirus, and beluga whale coronavirus] and four avian coronaviruses (turkey coronavirus, bulbul coronavirus HKU11, thrush coronavirus HKU12, and munia coronavirus HKU13). Two novel subgroups in group 2 coronavirus (groups 2c and 2d) and two novel subgroups in group 3 coronavirus (groups 3b and 3c) have been proposed. The diversity of coronaviruses is a result of the infidelity of RNA-dependent RNA polymerase, high frequency of homologous RNA recombination, and the large genomes of coronaviruses. Among all hosts, the diversity of coronaviruses is most evidenced in bats and birds, which may be a result of their species diversity, ability to fly, environmental pressures, and habits of roosting and flocking. The present evidence supports that bat coronaviruses are the gene pools of group 1 and 2 coronaviruses, whereas bird coronaviruses are the gene pools of group 3 coronaviruses. With the increasing number of coronaviruses, more and more closely related coronaviruses from distantly related animals have been observed, which were results of recent interspecies jumping and may be the cause of disastrous outbreaks of zoonotic diseases.

  20. Dioxin-like and non-dioxin-like toxic effects of polychlorinated biphenyls (PCBs): implications for risk assessment.

    PubMed

    Giesy, J P; Kannan, K

    1998-11-01

    Polychlorinated biphenyls (PCBs) are persistent, bioaccumulative, and toxic contaminants in the environment. Individual PCB congeners exhibit different physicochemical properties and biological activities that result in different environmental distributions and toxicity profiles. The variable composition of PCB residues in environmental matrices and their different mechanisms of toxicity complicate the development of scientifically based regulations for the risk assessment. In this article various approaches for the assessment of risks of PCBs have been critically examined. Recent developments in the toxic equivalency factor (TEF) approach for the assessment of toxic effects due to dioxin-like PCBs have been examined. PCB exposure studies that describe non-dioxin-like toxic effects, particularly neurobehavioral effects and their effective doses in animals were compiled. A comparative assessment of effective doses for dioxin-like and non-dioxin-like effects by PCBs has been made to evaluate the relative significance of non-ortho-and ortho-substituted PCBs in risk assessment. Using mink as an example, relative merits and implications of using TEF and total PCB approaches for assessing the potential for toxic effects in wildlife was examined. There are several advantages and limitations associated with each method used for PCB risk assessment. Toxic effects due to coplanar PCBs occur at relatively smaller concentrations than those due to non-dioxin-like PCBs and therefore the TEF approach derives the risk assessment of PCBs, in the environment. The need for the refinement of TEF approach for more accurate assessment of risks is discussed.

  1. Toxicity of citrate-capped AuNPs: an in vitro and in vivo assessment

    NASA Astrophysics Data System (ADS)

    Sabella, Stefania; Brunetti, Virgilio; Vecchio, Giuseppe; Galeone, Antonio; Maiorano, Gabriele; Cingolani, Roberto; Pompa, Pier Paolo

    2011-12-01

    In this study, we show that 15 nm citrate-capped AuNPs exert a remarkable toxicity in living systems. The assessment was performed by using well-characterized AuNPs, the combination of in vitro and in vivo models (namely two different cell lines and Drosophila melanogaster), exposure to low dosages of nanoparticles (in the sub-nanomolar concentration range), along with the application of several biological assays to monitor different aspects of the toxic effects, such as viability, genotoxicity, and molecular biomarkers.

  2. The use of bioassays for the risk assessment of toxic leachates: an experimental study.

    PubMed

    Irha, Natalya; Blinova, Irina

    2007-03-01

    Solid wastes from the oil-shale industry produce leachates containing toxic compounds such as heavy metals and persistent polycyclic aromatic hydrocarbons (PAH). The hazard to the environment represented by waste leachates depends not only on their chemical composition, but also on the mobility and bioavailability of toxic contaminants in soils. We evaluated the applicability of bioassays for toxicity assessment of the bioavailable fraction of heavy metals and PAH in soils, in experiments with samples of four different soil types (Rendzina, Brown pseudopodzolic, Typical brown, Sodpodzolic), the pH of which ranged from 6.2 to 7.2. The toxicity of the bioavailable fraction of the soil contaminants was assessed with the dehydrogenase enzyme activity assay, and with a Toxkit microbiotest with the crustacean, Thamnocephalus platyurus, after treatment of the soil samples with an artificial solution containing chromium (III), lead (II), copper (II), cadmium (II) and pyrene. The test results confirm those of earlier experiments, which characterised the sorption potential of investigated soils for the same compounds. Both tests turned out to be sufficiently sensitive, and hence can be recommended as effective and useful tools for the assessment of the bioavailable fraction of soil contaminants.

  3. Toxicovigilance: A new approach for the hazard identification and risk assessment of toxicants in human beings

    SciTech Connect

    Descotes, Jacques . E-mail: jacques-georges.descotes@chu-lyon.fr; Testud, Francois

    2005-09-01

    The concept of toxicovigilance encompasses the active detection, validation and follow-up of clinical adverse events related to toxic exposures in human beings. Poison centers are key players in this function as poisoning statistics are essential to define the cause, incidence and severity of poisonings occurring in the general population. In addition, the systematic search for unexpected shifts in the recorded causes of poisonings, e.g., following the introduction of a new product, or change in the formulation or recommended use of an old product, allows for a rapid detection of potential adverse health consequences and the implementation of preventive or corrective measures. However, toxicovigilance is genuinely a medical and not only a statistical approach of human toxicity issues. In contrast to epidemiology, toxicovigilance is based on the in-depth medical assessment of acute or chronic intoxications on an individual basis, which requires detailed information that poison centers can rarely obtain via emergency telephone calls and that epidemiologists cannot collect or process. Validation of this medical information must primarily be based on toxicological expertise to help identify causal links between otherwise unexplained pathological conditions and documented toxic exposures. Thus, toxicovigilance can contribute to hazard identification and risk assessment by providing medically validated data which are often overlooked in the process of risk assessment. So far, very few structured toxicovigilance systems have been set up and hopefully national and international initiatives will bridge this gap in our knowledge of the toxicity of many chemicals and commercial products in human beings.

  4. Toxicovigilance: a new approach for the hazard identification and risk assessment of toxicants in human beings.

    PubMed

    Descotes, Jacques; Testud, François

    2005-09-01

    The concept of toxicovigilance encompasses the active detection, validation and follow-up of clinical adverse events related to toxic exposures in human beings. Poison centers are key players in this function as poisoning statistics are essential to define the cause, incidence and severity of poisonings occurring in the general population. In addition, the systematic search for unexpected shifts in the recorded causes of poisonings, e.g., following the introduction of a new product, or change in the formulation or recommended use of an old product, allows for a rapid detection of potential adverse health consequences and the implementation of preventive or corrective measures. However, toxicovigilance is genuinely a medical and not only a statistical approach of human toxicity issues. In contrast to epidemiology, toxicovigilance is based on the in-depth medical assessment of acute or chronic intoxications on an individual basis, which requires detailed information that poison centers can rarely obtain via emergency telephone calls and that epidemiologists cannot collect or process. Validation of this medical information must primarily be based on toxicological expertise to help identify causal links between otherwise unexplained pathological conditions and documented toxic exposures. Thus, toxicovigilance can contribute to hazard identification and risk assessment by providing medically validated data which are often overlooked in the process of risk assessment. So far, very few structured toxicovigilance systems have been set up and hopefully national and international initiatives will bridge this gap in our knowledge of the toxicity of many chemicals and commercial products in human beings.

  5. Application of a lux-based bioassay to assess soil toxicity

    SciTech Connect

    Paton, G.I. |; Campbell, C.D.; Rattray, E.A.S.; Glover, L.A.; Killham, K.

    1995-12-31

    The expression of prokaryotic bioluminescence is linked with cell metabolism and accordingly bioassays have been developed using naturally bioluminescent bacteria to assess ecotoxicity. Advances in biotechnology have allowed the isolation of the lux genes (responsible for bioluminescence) from marine organisms and their insertion into terrestrial bacteria. This has enabled the use of ecologically relevant bacteria to assess toxicity by measuring bioluminescence response in the presence of toxins. The lux genes were inserted into Pseudomonas fluorescens and Rhizobium leguminosarum biovar trifolii as a multi-copy plasmid and also integrated into the chromosome. It was found that in aqueous solutions the plasmid constructs were more sensitive than the chromosomal constructs to a range of toxins. The order of toxicity for Ps. fluorescens was Zn = Cu > Cd > Ni > Cr > DCP and for R. trifolii Zn > Cu > Cd > DCP > Cr. The lux based bioassays were more reproducible and sensitive than ATP and dehydrogenase assays and offered greater sensitivity than Photobacterium phosphoreum assays to assess toxicity of inorganic pollutants. Extracts from 4 soil types were spiked with a range of toxins and when EC{sub 50} values were determined it was shown that toxicity was related to soil characteristics. This enabled the assay to be used to assess the Lee Valley soil experiment which represents an important international study of the effect of the application of contaminated sewage to land. High metal application rates had been shown to have serious implications for soil ecology. Chemical analysis, carried out 26 years after sewage addition confirmed that soil extracts still had increased metal concentrations. The lux-based bioassays, which proved to be rapid, reproducible and sensitive confirmed that the metals were still biologically available and hence toxic.

  6. Dissecting the assays to assess microbial tolerance to toxic chemicals in bioprocessing.

    PubMed

    Zingaro, Kyle A; Nicolaou, Sergios A; Papoutsakis, Eleftherios T

    2013-11-01

    Microbial strains are increasingly used for the industrial production of chemicals and biofuels, but the toxicity of components in the feedstock and product streams limits process outputs. Selected or engineered microbes that thrive in the presence of toxic chemicals can be assessed using tolerance assays. Such assays must reasonably represent the conditions the cells will experience during the intended process and measure the appropriate physiological trait for the desired application. We review currently used tolerance assays, and examine the many parameters that affect assay outcomes. We identify and suggest the use of the best-suited assays for each industrial bioreactor operating condition, discuss next-generation assays, and propose a standardized approach for using assays to examine tolerance to toxic chemicals. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Toxicity assessment of polycyclic aromatic hydrocarbons in sediments from European high mountain lakes.

    PubMed

    Quiroz, Roberto; Grimalt, Joan O; Fernández, Pilar

    2010-05-01

    Sediment quality guidelines and toxic equivalent factors have been used for assessment of the toxicity of sedimentary long-range atmospherically transported polycyclic aromatic hydrocarbons (PAHs) to the organisms living in high mountain European lakes. This method has provided indices that are consistent with experimental studies evaluating in situ sedimentary estrogenic activity or physiological response to AhR binding in fish from the same lakes. All examined lakes in north, central, west, northeast and southeast European mountains have shown sedimentary PAH concentrations that are above thresholds of no effect but only those situated in the southeast lakes district exhibited concentrations above the indices of probable effects. These mountains, Tatras, are also those having PAH concentrations of highest activity for AhR binding. Chrysene+triphenylene, dibenz[a]anthracene, benzo[k]fluoranthene and indeno[1,2,3-cd]pyrene are the main compounds responsible for the observed toxic effects.

  8. Comparative analysis of water quality and toxicity assessment methods for urban highway runoff.

    PubMed

    Chen, Rui-Hong; Li, Fei-Peng; Zhang, Hai-Ping; Jiang, Yue; Mao, Ling-Chen; Wu, Ling-Ling; Chen, Ling

    2016-05-15

    In this study, comparative analyses of highway runoff samples obtained from seventeen storm events have been conducted between the traditional water quality assessment method and biotoxicity tests, using zebrafish (Danio rerio) embryos and luminous bacteria (Vibrio qinghaiensis. Q67) to provide useful information for ecotoxicity assessment of urban highway runoff. The study results showed that the Nemerow pollution index based on US EPA recommended Criteria Maximum Concentrations (CMC) (as traditional water quality assessment method) had no significant correlation with luminous bacteria acute toxicity test results, while significant correlation has been observed with two indicators of 72 hpf (hours post fertilization) hour hatching rate and 96 hpf abnormality rate from the toxicity test with zebrafish embryos. It is therefore concluded that the level of mixture toxicity of highway runoff could not be adequately measured by the Nemerow assessment method. Moreover, the key pollutants identified from the water quality assessment and from the biotoxicity evaluation were not consistent. For biotoxic effect evaluation of highway runoff, three indexes were found to be sensitive, i.e. 24 hpf lethality and 96 hpf abnormality of zebrafish embryos, as well as the inhibition rate for luminous bacteria Q67. It is therefore recommended that these indexes could be incorporated into the traditional Nemerow method to provide a more reasonable evaluation of the highway runoff quality and ecotoxicity.

  9. Toxicity of five antibiotics and their mixtures towards photosynthetic aquatic organisms: implications for environmental risk assessment.

    PubMed

    González-Pleiter, Miguel; Gonzalo, Soledad; Rodea-Palomares, Ismael; Leganés, Francisco; Rosal, Roberto; Boltes, Karina; Marco, Eduardo; Fernández-Piñas, Francisca

    2013-04-15

    The individual and combined toxicities of amoxicillin, erythromycin, levofloxacin, norfloxacin and tetracycline have been examined in two organisms representative of the aquatic environment, the cyanobacterium Anabaena CPB4337 as a target organism and the green alga Pseudokirchneriella subcapitata as a non-target organism. The cyanobacterium was more sensitive than the green alga to the toxic effect of antibiotics. Erythromycin was highly toxic for both organisms; tetracycline was more toxic to the green algae whereas the quinolones levofloxacin and norfloxacin were more toxic to the cyanobacterium than to the green alga. Amoxicillin also displayed toxicity to the cyanobacterium but showed no toxicity to the green alga. The toxicological interactions of antibiotics in the whole range of effect levels either in binary or multicomponent mixtures were analyzed using the Combination Index (CI) method. In most cases, synergism clearly predominated both for the green alga and the cyanobacterium. The CI method was compared with the classical models of additivity Concentration Addition (CA) and Independent Action (IA) finding that CI could accurately predict deviations from additivity. Risk assessment was performed by calculating the ratio between Measured Environmental Concentration (MEC) and the Predicted No Effect Concentration (PNEC). A MEC/PNEC ratio higher than 1 was found for the binary erythromycin and tetracycline mixture in wastewater effluents, a combination which showed a strong synergism at low effect levels in both organisms. From the tested antibiotic mixtures, it can be concluded that certain specific combinations may pose a potential ecological risk for aquatic ecosystems with the present environmentally measured concentrations. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Reproduction of wild birds via interspecies germ cell transplantation.

    PubMed

    Kang, Seok Jin; Choi, Jin Won; Kim, Sun Young; Park, Kyung Je; Kim, Tae Min; Lee, Young Mok; Kim, Heebal; Lim, Jeong Mook; Han, Jae Yong

    2008-11-01

    The present study was conducted to apply an interspecies germ cell transfer technique to wild bird reproduction. Pheasant (Phasianus colchicus) primordial germ cells (PGCs) retrieved from the gonads of 7-day-old embryos were transferred to the bloodstream of 2.5-day-old chicken (Gallus gallus) embryos. Pheasant-to-chicken germline chimeras hatched from the recipient embryos, and 10 pheasants were derived from testcross reproduction of the male chimeras with female pheasants. Gonadal migration of the transferred PGCs, their involvement in spermatogenesis, and production of chimeric semen were confirmed. The phenotype of pheasant progenies derived from the interspecies transfer was identical to that of wild pheasants. The average efficiency of reproduction estimated from the percentage of pheasants to total progenies was 17.5%. In conclusion, interspecies germ cell transfer into a developing embryo can be used for wild bird reproduction, and this reproductive technology may be applicable in conserving endangered bird species.

  11. Blood Cytokines as Biomarkers of In Vivo Toxicity in Preclinical Safety Assessment: Considerations for Their Use

    PubMed Central

    Tarrant, Jacqueline M.

    2010-01-01

    In the drive to develop drugs with well-characterized and clinically monitorable safety profiles, there is incentive to expand the repertoire of safety biomarkers for toxicities without routine markers or premonitory detection. Biomarkers in blood are pursued because of specimen accessibility, opportunity for serial monitoring, quantitative measurement, and the availability of assay platforms. Cytokines, chemokines, and growth factors (here referred to collectively as cytokines) show robust modulation in proximal events of inflammation, immune response, and repair. These are key general processes in many toxicities; therefore, cytokines are commonly identified during biomarker discovery studies. In addition, multiplexed cytokine immunoassays are easily applied to biomarker discovery and routine toxicity studies to measure blood cytokines. However, cytokines pose several challenges as safety biomarkers because of a short serum half-life; low to undetectable baseline levels; lack of tissue-specific or toxicity-specific expression; complexities related to cytokine expression with multiorgan involvement; and species, strain, and interindividual differences. Additional challenges to their application are caused by analytical, methodological, and study design–related variables. A final consideration is the strength of the relationship between changes in cytokine levels and the development of phenotypic or functional manifestations of toxicity. These factors should inform the integrated judgment-based qualification of novel biomarkers in preclinical, and potentially clinical, risk assessment. The dearth of robust, predictive cytokine biomarkers for specific toxicities is an indication of the significant complexity of these challenges. This review will consider the current state of the science and recommendations for appropriate application of cytokines in preclinical safety assessment. PMID:20447938

  12. Assessment of hazard metrics for predicting field benthic invertebrate toxicity in the Detroit River, Ontario, Canada.

    PubMed

    McPhedran, Kerry N; Grgicak-Mannion, Alice; Paterson, Gord; Briggs, Ted; Ciborowski, Jan Jh; Haffner, G Douglas; Drouillard, Ken G

    2017-03-01

    Numerical sediment quality guidelines (SQGs) are frequently used to interpret site-specific sediment chemistry and predict potential toxicity to benthic communities. These SQGs are useful for a screening line of evidence (LOE) that can be combined with other LOEs in a full weight of evidence (WOE) assessment of impacted sites. Three common multichemical hazard quotient methods (probable effect concentration [PEC]-Qavg , PEC-Qmet , and PEC-Qsum ) and a novel (hazard score [HZD]) approach were used in conjunction with a consensus-based set of SQGs to evaluate the ability of different scoring metrics to predict the biological effects of sediment contamination under field conditions. Multivariate analyses were first used to categorize river sediments into distinct habitats based on a set of physicochemical parameters to include gravel, low and high flow sand, and silt. For high flow sand and gravel, no significant dose-response relationships between numerically dominant species and various toxicity metric scores were observed. Significant dose-response relationships were observed for chironomid abundances and toxicity scores in low flow sand and silt habitats. For silt habitats, the HZD scoring metric provided the best predictor of chironomid abundances compared to various PEC-Q methods according to goodness-of-fit tests. For low flow sand habitats, PEC-Qsum followed by HZD, provided the best predictors of chironomid abundance. Differences in apparent chironomid toxicity between the 2 habitats suggest habitat-specific differences in chemical bioavailability and indicator taxa sensitivity. Using an IBI method, the HZD, PEC-Qavg , and PEC-Qmet approaches provided reasonable correlations with calculated IBI values in both silt and low flow sand habitats but not for gravel or high flow sands. Computation differences between the various multi-chemical toxicity scoring metrics and how this contributes to bias in different estimates of chemical mixture toxicity scores are

  13. Full Toxicity Assessment of Genkwa Flos and the Underlying Mechanism in Nematode Caenorhabditis elegans

    PubMed Central

    Wu, Qiuli; Sun, Lingmei; Ruan, Qinli; Chen, Yanyan; Wang, Meng; Duan, Jinao; Wang, Dayong

    2014-01-01

    Genkwa Flos (GF), the dried flower bud from Daphne genkwa Sieb. et Zucc. (Thymelaeaceae), is a well-known and widely used traditional Chinese medicine. However, we know little about the in vivo mechanism of GF toxicity. Nematode Caenorhabditis elegans has been considered as a useful toxicity assay system by offering a system best suited for asking the in vivo questions. In the present study, we employed the prolonged exposure assay system of C. elegans to perform the full in vivo toxicity assessment of raw-processed GF. Our data show that GF exposure could induce the toxicity on lifespan, development, reproduction, and locomotion behavior. GF exposure not only decreased body length but also induced the formation of abnormal vulva. The decrease in brood size in GF exposed nematodes appeared mainly at day-1 during the development of adult nematodes. The decrease of locomotion behavior in GF exposed nematodes might be due to the damage on development of D-type GABAergic motor neurons. Moreover, we observed the induction of intestinal reactive oxygen species (ROS) production and alteration of expression patterns of genes required for development of apical domain, microvilli, and apical junction of intestine in GF exposed nematodes, implying the possible dysfunction of the primary targeted organ. In addition, GF exposure induced increase in defecation cycle length and deficits in development of AVL and DVB neurons controlling the defecation behavior. Therefore, our study implies the usefulness of C. elegans assay system for toxicity assessment from a certain Chinese medicine or plant extract. The observed toxicity of GF might be the combinational effects of oxidative stress, dysfunction of intestine, and altered defecation behavior in nematodes. PMID:24626436

  14. Interlaboratory study of the bioluminescence inhibition tests for rapid wastewater toxicity assessment.

    PubMed

    Farré, Marinella; Arranz, Francesc; Ribó, Joan; Barceló, Damià

    2004-02-27

    Several toxicity procedures are currently being used for the wastewater toxicity assessment. We have undertaken an interlaboratory comparison of the use of different bioluminescence inhibition toxicity tests based on Vibrio fischeri, in order to evaluate their reproducibility for the rapid wastewater toxicity assessment. Twenty-two laboratories took part in this study organized by the Institut Català de Tecnologia (ICT) and the Consejo Superior de Investigaciones Cientificas (CSIC). During the exercise, six series of six samples were analyzed along 5 months. Every batch of samples was composed by three real samples and three standard solutions. The real samples were: an untreated effluent of a paper industry, a sample from a first settlement of a wastewater treatment plant (WWTP) and the final effluent of the WWTP. The goals of the interlaboratory study were to evaluate the repeatability (r) and reproducibility (R) when different laboratories conduct the test, the influence of different matrix samples, the variability between different tests based on the same principle: the bioluminescence inhibition of V. fischeri, but involving different commercial devices and to determine the rate at which participating laboratories successfully completed tests initiated. The maximum number of outlier values was corresponding to a non-treated effluent from a paper industry. This also was the most complex and toxic sample analyzed. An increase on the non-convergent values obtained for the participants was observed at higher matrix complexity and at lower toxicity level. In comparison with other editions of this interlaboratory study the matrixes of real samples analyzed were more complex, nevertheless the final variability coefficient for the exercise was nearby to the average value for the past editions. Due to the high complexity of some samples involved in this intercalibration the stability of real samples were also followed during the test. On the other hand, no relation

  15. Assessment of comparative toxicities of lead and copper using plant assay.

    PubMed

    An, Youn-Joo

    2006-03-01

    The acute toxicities of lead (Pb) and copper (Cu) to important crop plants Sorghum bicolor, Cucumis sativus, Triticum aestivum, and Zea mays were compared. The EC50 values (the concentration of metals in the soil that reduces the growth of shoots and roots by 50%) were derived using the Trimmed Spearman-Karber method. The EC50s-shoot (root) in mg Pb kg-1 dry soil and mg Cu kg-1 dry soil were in the range of 519 to >1280 (285-445), and 48-232 (<40-110), respectively. Those concentrations are likely to occur in some abandoned mine areas in Korea. The figures indicate that Cu is more toxic than Pb to the plants in this study, and that root growth is more sensitive to the toxicity endpoint than shoot growth in Cu- or Pb-amended soils. On the other hand, seed germination is insensitive to both Pb and Cu toxicities. The Pb- and Cu-sensitive plants were also identified. Among the plants tested, T. aestivum and S. bicolor were most sensitive to Pb and Cu, respectively. Z. mays was most resistant to both Pb and Cu. The combined effects of Pb and Cu depend on the plant species, and no general phenomenon was observed. Bioaccumulations of Pb and Cu were observed in all test species, and they are concentration-dependent. These differences in the toxicities of Pb and Cu in plant species should be taken into account in biomonitoring and ecological risk assessment.

  16. Rat liver mitochondrial and microsomal tests for the assessment of quinone toxicity

    SciTech Connect

    Bramble, L.A.; Boardman, G.D.; Dietrich, A.M. . Dept. of Civil Engineering); Bevan, D.R. . Dept. of Biochemistry)

    1994-02-01

    Short-term toxicity tests using mitochondrial and microsomal metabolism were developed and applied to a series of eight quinones. In the mitochondrial assay, the degree to which test compounds inhibited mitochondrial respiration varied from an effective concentration (EC50) of 9 to 125 [mu]M. In the microsomal assay, the maximum percentage of increase over control oxygen consumption rates elicited by the quinones ranged from 8 to 837%. The ability of the compounds to stimulate microsomal oxygen uptake reflects their capability to redox cycle and form reactive oxygen species. Results of the mitochondrial and microsomal assay were statistically correlated with several quinone physicochemical parameters and qualitatively compared to reduction potential. The biological response observed in both test systems appeared to be most strongly influenced by the reduction potential of the quinone. Biomechanisms of action were suggested on the basis of this relationship. To assess the ability of the mitochondrial and microsomal assays to indicate toxicity of the quinonoid compounds, results were statistically correlated with literature-derived toxicity data. It was concluded that the mitochondrial assay appears to be a valid indicator of acute toxicity, whereas the microsomal assay better portends the potential for chronic toxicity.

  17. Hazard prioritization in ecological risk assessment through spatial analysis of toxicant gradients.

    PubMed

    Preston, Benjamin L

    2002-01-01

    The analysis of spatial relationships among the distribution of environmental stressors and observed or predicted adverse effects may be a useful method of prioritizing hazards in regional ecological risk assessment (ERA). Geographic information systems were used to compare the spatial distribution of toxicant concentrations in sediments of Chesapeake Bay with the distribution of areas in the basin where ecological impacts have historically been observed. Toxicants were then prioritized based upon the strength of their spatial association with the high impact areas. This method of hazard identification/prioritization was validated against the Chesapeake Bay Program's lists of toxics of concern and toxics of potential concern (TOC and TOPC, respectively). Of the 18 toxicants on the TOC/TOPC lists that were considered in the current study, 15 (83%) were identified as priority contaminants in the current study, 11 (73%) of which were either of primary or secondary concern. The use of spatial analysis tools in ERA may lead to more rapid and rigorous methods for prioritizing environmental risks.

  18. Fish acute toxicity syndromes and their use in the QSAR approach to hazard assessment.

    PubMed Central

    McKim, J M; Bradbury, S P; Niemi, G J

    1987-01-01

    Implementation of the Toxic Substances Control Act of 1977 creates the need to reliably establish testing priorities because laboratory resources are limited and the number of industrial chemicals requiring evaluation is overwhelming. The use of quantitative structure activity relationship (QSAR) models as rapid and predictive screening tools to select more potentially hazardous chemicals for in-depth laboratory evaluation has been proposed. Further implementation and refinement of quantitative structure-toxicity relationships in aquatic toxicology and hazard assessment requires the development of a "mode-of-action" database. With such a database, a qualitative structure-activity relationship can be formulated to assign the proper mode of action, and respective QSAR, to a given chemical structure. In this review, the development of fish acute toxicity syndromes (FATS), which are toxic-response sets based on various behavioral and physiological-biochemical measurements, and their projected use in the mode-of-action database are outlined. Using behavioral parameters monitored in the fathead minnow during acute toxicity testing, FATS associated with acetylcholinesterase (AChE) inhibitors and narcotics could be reliably predicted. However, compounds classified as oxidative phosphorylation uncouplers or stimulants could not be resolved. Refinement of this approach by using respiratory-cardiovascular responses in the rainbow trout, enabled FATS associated with AChE inhibitors, convulsants, narcotics, respiratory blockers, respiratory membrane irritants, and uncouplers to be correctly predicted. PMID:3297660

  19. Fish acute toxicity syndromes and their use in the QSAR approach to hazard assessment

    SciTech Connect

    McKim, J.M.; Bradbury, S.P.; Niemi, G.J.

    1987-04-01

    Implementation of the Toxic Substances Control Act of 1977 creates the need to reliably establish testing priorities because laboratory resources are limited and the number of industrial chemicals requiring evaluation is overwhelming. The use of quantitative structure activity relationship (QSAR) models as rapid and predictive screening tools to select more potentially hazardous chemicals for in-depth laboratory evaluation has been proposed. Further implementation and refinement of quantitative structure-toxicity relationships in aqueous toxicology and hazard assessment requires the development of a mode-of-action database. With such a database, a qualitative structure-activity relationship can be formulated to assign the proper mode of action, and respective QSAR, to a given chemical structure. In this review, the development of fish acute toxicity syndromes (FATS), which are toxic-response sets based on various behavioral and physiological-biochemical measurements, and their projected use in the mode-of-action database are outlined. Using behavioral parameters monitored in the fathead minnow during acute toxicity testing, FATS associated with acetylcholinesterase (AChE) inhibitors and narcotics could be reliably predicted. However, compounds classified as oxidative phosphorylation uncouplers or stimulants could not be resolved. Refinement of this approach by using respiratory-cardiovascular responses in the rainbow trout, enabled FATS associated with AChE inhibitors, convulsants, narcotics, respiratory blockers, respiratory membrane irritants, and uncouplers to be correctly predicted.

  20. Assessment of swimming activity as an indicator of sublethal toxicity to the fathead minnow

    SciTech Connect

    Hovland, D.N. Jr.

    1994-12-31

    A simple, sensitive acute-bioassay was developed that looks at spontaneous swimming activity as an indicator of sublethal effect due to toxic insult. Although a large amount of work has been done validating aquatic behavior testing, there are still no standardized testing procedures or protocols for their use in assessing environmental impact of pollutants. Attempts were made in this research to develop a behavioral test that was objective and provided a basis for standardization and use in effluent testing. Tests were performed using copper sulfate and zinc sulfate as reference toxicants. Testing procedures involved 24-hour exposures to a range of toxicant concentrations with 12 fathead minnows (Pimephales promelas) per concentration. Upon completion, during a 2-minute testing period in a cylindrical aquarium, individual fish were videotaped from above, then timed later to determine actual time in swimming motion, which was averaged for each concentration group. Results demonstrate the sensitivity of the test, as significant differences from controls in swimming activity were observed at concentrations of copper sulfate as low as 1.3 ppb and zinc sulfate as low as 3.5 ppb, both well below Federal criteria for water quality. It is hoped that further research will demonstrate the utility of sublethal, behavioral toxicity tests, and that these tests will be integrated into the battery of toxicity testing procedures currently used by regulatory agencies.

  1. Toxicity assessment of oil field produced water treated by evaporative processes to produce water to irrigation.

    PubMed

    Andrade, V T; Andrade, B G; Costa, B R S; Pereira, O A; Dezotti, M

    2010-01-01

    During the productive life of an oil well, a high quantity of produced water is extracted together with the oil, and it may achieve up to 99% in the end of the well's economical life. Desalination is one of mankind's earliest forms of saline water treatment, and nowadays, it is still a common process used throughout the world. A single-effect mechanical vapor compression (MVC) process was tested. This paper aims to assess the potential toxicity of produced water to be re-used in irrigation. Samples of both produced and distilled water were evaluated by 84 chemical parameters. The distilled produced water presented a reduction up to 97% for the majority of the analyzed parameters, including PAHs. Toxicity bioassays were performed with distilled produced water to evaluate the growth inhibition of Pseudokirchneriella subcapitata algae, the acute toxicity to Danio rerio fish, the germination inhibition of Lactuca sativa vegetable and the severity of toxicity, as well as behavior test with Lumbricid Earthworm Eisenia fetida. The ecotoxicological assays results showed no toxicity, indicating that the referred evaporative process can produce water to be reused in irrigation.

  2. Toxicity assessment of Arisaematis Rhizoma in rats by a (1)H NMR-based metabolomics approach.

    PubMed

    Dong, Ge; Wang, Junsong; Guo, Pingping; Wei, Dandan; Yang, Minghua; Kong, Lingyi

    2015-02-01

    Arisaematis Rhizoma (AR), a famous traditional Chinese medicine, has been widely used in Asia over thousands of years. Documented with noticeable toxicity in ancient books, AR has been used to treat various diseases in the clinic. Therefore, it is important to assess the toxicity of AR dynamically and holistically. In this study, a (1)H NMR-based metabolomics approach complemented with serum chemistry and histopathology has been applied to investigate the toxicity of AR. Rats were intragastrically administered with AR (0, 0.5 and 1 g kg(-1) body weight) for 30 days, and serum and urine samples were collected. Their (1)H NMR profiles were analyzed by multivariate pattern recognition techniques to denote metabolic variations induced by AR, and 13 metabolites in urine and 6 metabolites in serum were significantly altered, which suggested that disturbances in energy metabolism, perturbation of the gut microflora environment, membrane damage, folate deficiency and injury of kidneys are produced by AR. Histopathology showed a slight vacuolization of the glomerular matrix and edema of renal tubular epithelial cells in kidneys of AR administered rats, which were evidenced by increased levels of blood urea nitrogen and creatinine in serum chemistry. Our results indicated that oral administration of crude AR was found to induce slight renal toxicity. Therefore, precautions should be made to monitor the potential nephrotoxicity of AR in clinical use. The metabolomics approach provided a promising tool for the study and better understanding of TCM-induced toxicity dynamically and holistically.

  3. Toxicity assessment and geochemical model of chromium leaching from AOD slag.

    PubMed

    Liu, Bao; Li, Junguo; Zeng, Yanan; Wang, Ziming

    2016-02-01

    AOD (Argon Oxygen Decarburization) slag is a by-product of the stainless steel refining process. The leaching toxicity of chromium from AOD slag cannot be ignored in the recycling process of the AOD slag. To assess the leaching toxicity of the AOD slag, batch leaching tests have been performed. PHREEQC simulations combined with FactSage were carried out based on the detailed mineralogical analysis and petrophysical data. Moreover, Pourbaix diagram of the Cr-H2O system was protracted by HSC 5.0 software to explore the chromium speciation in leachates. It was found that AOD slag leachate is an alkaline and reductive solution. The Pourbaix diagram of the Cr-H2O system indicated that trivalent chromium, such as Cr(OH)4(-), is the major chromium species in the experimental Eh-pH region considered. However, toxic hexavalent chromium was released with maximum concentrations of 30 µg L(-1) and 18 µg L(-1) at L/S 10 and 100, respectively, during the earlier leaching stage. It concluded that the AOD slag possessed a certain leaching toxicity. After 10 d of leaching, trivalent chromium was the dominant species in the leachates, which corresponded to the results of PHREEQC simulation. Leaching toxicity of AOD slag is based on the chromium speciation and its transformation. Great attention should be focused on such factors as aging, crystal form of chromium-enriched minerals, and electrochemical characteristics of the leachates.

  4. Resazurin reduction assay, a useful tool for assessment of heavy metal toxicity in acidic conditions.

    PubMed

    Zare, Mohammadreza; Amin, Mohammad Mehdi; Nikaeen, Mahnaz; Bina, Bijan; Pourzamani, Hamidreza; Fatehizadeh, Ali; Taheri, Ensieh

    2015-05-01

    Almost all bioassays have been designed only for pH levels around 7; however, some toxicant characteristics may be different at lower pH values. In this study, a modified resazurin reduction method was used to evaluate the toxicity of heavy metals and metal plating wastewater on acid-tolerant (AT) and conventional bacteria at the natural and acidic pH conditions. According to our optimized protocol, resazurin was rapidly reduced by both conventional and AT active microorganisms. Considering the 30-min median effective concentration (30 min EC₅₀) values, conventional bacteria were comparatively more resistant than the acid-tolerant bacteria (ATB) in the case of exposure to Cd, Pb, Cr, and Zn, but the reverse case was found for Hg. After an exposure of 30 min, Cr and Hg showed the highest toxicity to ATB (30 min EC₅₀ values were 0.34 and 17.02 μmol/L, respectively), while Zn and Pb had a considerably lower toxicity. The modified resazurin reduction method successfully assessed the impact of metal plating wastewaters on the activities of conventional and AT bacteria. According to the findings where the wastewaters contain heavy metals, wastewater treatment facilities, which are dependent on ATB activity, should use bioassays at acidic pH values for better understanding of the effects of toxicants.

  5. Role of a comprehensive toxicity assessment and monitoring program in the management and ecological recovery of a wastewater receiving stream.

    PubMed

    Greeley, Mark S; Kszos, Lynn A; Morris, Gail W; Smith, John G; Stewart, Arthur J

    2011-06-01

    National Pollution Discharge Elimination Permit (NPDES)-driven effluent toxicity tests using Ceriodaphnia dubia and fathead minnows were conducted for more than 20 years to assess and monitor the effects of wastewaters at the United States (U.S.) Department of Energy Y-12 National Security Complex (Y-12 Complex) in Oak Ridge, Tennessee. Toxicity testing was also conducted on water samples from East Fork Poplar Creek (EFPC), the wastewater receiving stream, as part of a comprehensive biological monitoring and assessment program. In this paper, we evaluate the roles of this long-term toxicity assessment and monitoring program in the management and ecological recovery of EFPC. Effluent toxicity testing, associated toxicant evaluation studies, and ambient toxicity monitoring were instrumental in identifying toxicant sources at the Y-12 Complex, guiding modifications to wastewater treatment procedures, and assessing the success of various pollution-abatement actions. The elimination of untreated wastewater discharges, the dechlorination of remaining wastewater streams, and the implementation of flow management at the stream headwaters were the primary actions associated with significant reductions in the toxicity of stream water in the upper reaches of EFPC from the late 1980s through mid 1990s. Through time, as regulatory requirements changed and water quality improved, emphasis shifted from comprehensive toxicity assessments to more focused toxicity monitoring efforts. Ambient toxicity testing with C. dubia and fathead minnows was supplemented with less-standardized but more sensitive alternative laboratory toxicity tests and in situ bioassays. The Y-12 Complex biological monitoring experience demonstrates the value of toxicity studies to the management of a wastewater receiving stream.

  6. Role of a Comprehensive Toxicity Assessment and Monitoring Program in the Management and Ecological Recovery of a Wastewater Receiving Stream

    NASA Astrophysics Data System (ADS)

    Greeley, Mark S.; Kszos, Lynn A.; Morris, Gail W.; Smith, John G.; Stewart, Arthur J.

    2011-06-01

    National Pollution Discharge Elimination Permit (NPDES)-driven effluent toxicity tests using Ceriodaphnia dubia and fathead minnows were conducted for more than 20 years to assess and monitor the effects of wastewaters at the United States (U.S.) Department of Energy Y-12 National Security Complex (Y-12 Complex) in Oak Ridge, Tennessee. Toxicity testing was also conducted on water samples from East Fork Poplar Creek (EFPC), the wastewater receiving stream, as part of a comprehensive biological monitoring and assessment program. In this paper, we evaluate the roles of this long-term toxicity assessment and monitoring program in the management and ecological recovery of EFPC. Effluent toxicity testing, associated toxicant evaluation studies, and ambient toxicity monitoring were instrumental in identifying toxicant sources at the Y-12 Complex, guiding modifications to wastewater treatment procedures, and assessing the success of various pollution-abatement actions. The elimination of untreated wastewater discharges, the dechlorination of remaining wastewater streams, and the implementation of flow management at the stream headwaters were the primary actions associated with significant reductions in the toxicity of stream water in the upper reaches of EFPC from the late 1980s through mid 1990s. Through time, as regulatory requirements changed and water quality improved, emphasis shifted from comprehensive toxicity assessments to more focused toxicity monitoring efforts. Ambient toxicity testing with C. dubia and fathead minnows was supplemented with less-standardized but more sensitive alternative laboratory toxicity tests and in situ bioassays. The Y-12 Complex biological monitoring experience demonstrates the value of toxicity studies to the management of a wastewater receiving stream.

  7. Interspecies interactions are an integral determinant of microbial community dynamics

    PubMed Central

    Aziz, Fatma A. A.; Suzuki, Kenshi; Ohtaki, Akihiro; Sagegami, Keita; Hirai, Hidetaka; Seno, Jun; Mizuno, Naoko; Inuzuka, Yuma; Saito, Yasuhisa; Tashiro, Yosuke; Hiraishi, Akira; Futamata, Hiroyuki

    2015-01-01

    This study investigated the factors that determine the dynamics of bacterial communities in a complex system using multidisciplinary methods. Since natural and engineered microbial ecosystems are too complex to study, six types of synthetic microbial ecosystems (SMEs) were constructed under chemostat conditions with phenol as the sole carbon and energy source. Two to four phenol-degrading, phylogenetically and physiologically different bacterial strains were used in each SME. Phylogeny was based on the nucleotide sequence of 16S rRNA genes, while physiologic traits were based on kinetic and growth parameters on phenol. Two indices, J parameter and “interspecies interaction,” were compared to predict which strain would become dominant in an SME. The J parameter was calculated from kinetic and growth parameters. On the other hand, “interspecies interaction,” a new index proposed in this study, was evaluated by measuring the specific growth activity, which was determined on the basis of relative growth of a strain with or without the supernatant prepared from other bacterial cultures. Population densities of strains used in SMEs were enumerated by real-time quantitative PCR (qPCR) targeting the gene encoding the large subunit of phenol hydroxylase and were compared to predictions made from J parameter and interspecies interaction calculations. In 4 of 6 SEMs tested the final dominant strain shown by real-time qPCR analyses coincided with the strain predicted by both the J parameter and the interspecies interaction. However, in SMEII-2 and SMEII-3 the final dominant Variovorax strains coincided with prediction of the interspecies interaction but not the J parameter. These results demonstrate that the effects of interspecies interactions within microbial communities contribute to determining the dynamics of the microbial ecosystem. PMID:26539177

  8. Interspecies Variability in Propylene Glycol Dinitrate-Induced Methemoglobin Formation

    DTIC Science & Technology

    1985-11-01

    Interspecies Variability in Propylene Glycol Dinitrate-Induced Methemoglobin Formation’ * 2 J. F. WYMAN. B. H . GRAY. L. Hi. LEE. J. COLEMAN, C. FLEMMING...July 3. 1985 Interspecies \\’ariabilit% in Propylene Glkcol Dinitrate-Induced Methemoglohin Formation. Wsi’.J. F.GRAY. B. H .. LEE. L. H .. COLEMAN. J...and gI utathione-S-t ransferase. were assa~ed h % adaptation of existing methods to a centrifugal analtzer. ’The ab)~c ent~mes were rernosed from

  9. Personal care product preservatives: risk assessment and mixture toxicities with an industrial wastewater.

    PubMed

    Carbajo, Jose B; Perdigón-Melón, Jose A; Petre, Alice L; Rosal, Roberto; Letón, Pedro; García-Calvo, Eloy

    2015-04-01

    The aquatic toxicity of eight preservatives frequently used in personal care products (PCPs) (iodopropynyl butylcarbamate, bronopol, diazolidinyl urea, benzalkonium chloride, zinc pyrithione, propylparaben, triclosan and a mixture of methylchloroisothiazolinone and methylisothiazolinone) was assessed by means of two different approaches: a battery of bioassays composed of single species tests of bacteria (Vibrio fischeri and Pseudomonas putida) and protozoa (Tetrahymena thermophila), and a whole biological community resazurin-based assay using activated sludge. The tested preservatives showed considerable toxicity in the studied bioassays, but with a marked difference in potency. In fact, all biocides except propylparaben and diazolidinyl urea had EC50 values lower than 1 mg L(-1) in at least one assay. Risk quotients for zinc pyrithione, benzalkonium chloride, iodopropynyl butylcarbamate and triclosan as well as the mixture of the studied preservatives exceeded 1, indicating a potential risk for the process performance and efficiency of municipal sewage treatment plants (STPs). These four single biocides explained more than 95% of the preservative mixture risk in all bioassays. Each individual preservative was also tested in combination with an industrial wastewater (IWW) from a cosmetics manufacturing facility. The toxicity assessment was performed on binary mixtures (preservative + IWW) and carried out using the median-effect principle, which is a special case of the concept of Concentration Addition (CA). Almost 70% of all experiments resulted in EC50 values within a factor of 2 of the values predicted by the median-effect principle (CI values between 0.5 and 2). The rest of the mixtures whose toxicity was mispredicted by CA were assessed with the alternative concept of Independent Action (IA), which showed higher predictive power for the biological community assay. Therefore, the concept used to accurately predict the toxicity of mixtures of a preservative

  10. Embryonic Zebrafish Model - A Well-Established Method for Rapidly Assessing the Toxicity of Homeopathic Drugs

    PubMed Central

    Gupta, Himanshu R; Patil, Yogesh; Singh, Dipty

    2016-01-01

    Objectives: Advancements in nanotechnology have led to nanoparticle (NP) use in various fields of medicine. Although the potential of NPs is promising, the lack of documented evidence on the toxicological effects of NPs is concerning. A few studies have documented that homeopathy uses NPs. Unfortunately, very few sound scientific studies have explored the toxic effects of homeopathic drugs. Citing this lack of high-quality scientific evidence, regulatory agencies have been reluctant to endorse homeopathic treatment as an alternative or adjunct treatment. This study aimed to enhance our insight into the impact of commercially-available homeopathic drugs, to study the presence of NPs in those drugs and any deleterious effects they might have, and to determine the distribution pattern of NPs in zebrafish embryos (Danio rerio). Methods: Homeopathic dilutions were studied using high-resolution transmission electron microscopy with selected area electron diffraction (SAED). For the toxicity assessment on Zebrafish, embryos were exposed to a test solution from 4 - 6 hours post-fertilization, and embryos/larvae were assessed up to 5 days post-fertilization (dpf) for viability and morphology. Toxicity was recorded in terms of mortality, hatching delay, phenotypic defects and metal accumulation. Around 5 dpf was found to be the optimum developmental stage for evaluation. Results: The present study aimed to conclusively prove the presence of NPs in all high dilutions of homeopathic drugs. Embryonic zebrafish were exposed to three homeopathic drugs with two potencies (30CH, 200CH) during early embryogenesis. The resulting morphological and cellular responses were observed. Exposure to these potencies produced no visibly significant malformations, pericardial edema, and mortality and no necrotic and apoptotic cellular death. Conclusion: Our findings clearly demonstrate that no toxic effects were observed for these three homeopathic drugs at the potencies and exposure times used

  11. Biomarkers in Tubifex tubifex for the metalaxyl and metalaxyl-M toxicity assessment in artificial sediment.

    PubMed

    Di, Shanshan; Liu, Ruiquan; Cheng, Cheng; Chen, Li; Zhang, Wenjun; Tian, Zhongnan; Liu, Chunxiao; Zhou, Zhiqiang; Diao, Jinling

    2017-02-01

    Efficacy and potential environmental risks should be considered when applying enantiopure pesticides. In this study, Tubifex tubifex and its oxidative stress biomarkers were assessed for the toxicity of metalaxyl and metalaxyl-M in sediment. The toxicity assessment was conducted with artificial sediment and reconstituted water. Five test concentrations (from 0 to 100 mg/kg) were set for the short-term (4 days) exposure. The long-term (28 days) exposure was conducted with the environmental concentration (from 0.5 to 5 mg/kg). For the short-term exposure, the increase of superoxide dismutase (SOD) activity was observed, and a clear concentration-response relationship was found in the metalaxyl treatments. The decrease of catalase (CAT) and glutathione peroxidase (GPx) activity could be caused by oxidative stress. The decrease of glutathione (GSH) content and the increase of glutathione-S-transferase (GST) might be due to antioxidation defense and detoxification mechanisms. The increase of malondialdehyde (MDA) might be due to the saturation of antioxidant systems and the accumulation and toxicity of contaminations. In the long-term exposure, the changes of biomarkers in T. tubifex reflected the oxidative stress and detoxification metabolisms. GSH and the related enzymes were important in detoxification processes and involved in the oxidative stress in toxicity mechanism. The long-term direct contact bioassay is sensitive and appropriate to reflect the lower concentration of contaminants.

  12. Assessing health-related quality of life in patients with benign non-toxic goitre.

    PubMed

    Watt, Torquil; Cramon, Per; Frendl, Daniel M; Ware, John E

    2014-08-01

    Health-related quality of life (HRQoL) assessments are increasingly used to evaluate treatment effects and to shape the delivery of value based care. Valid generic and disease specific tools are available for quantifying HRQoL in patients with non-toxic goitre. However, few studies have applied these validated instruments to assess HRQoL in patients with benign non-toxic goitre. Limited evidence suggests that patients with non-toxic goitre have HRQoL impairments in multiple HRQoL domains. While the HRQoL-impact of non-toxic goitre may be small relative to other severely disabling medical conditions, treatment is almost exclusively elected for HRQoL indications. Thus better quantification of HRQoL, particularly at better (or more favorable) levels where many patients score, is essential. Web and mobile technologies have eased the ability to deliver surveys to patients. Routine consideration of HRQoL provides the opportunity to monitor the impact of treatment on the outcomes most meaningful for patients and the opportunity to help shape the delivery of value based health care.

  13. Assessment of in vivo systemic toxicity and biodistribution of iron-doped silica nanoshells.

    PubMed

    Mendez, Natalie; Liberman, Alexander; Corbeil, Jacqueline; Barback, Christopher; Viveros, Robert; Wang, James; Wang-Rodriguez, Jessica; Blair, Sarah L; Mattrey, Robert; Vera, David; Trogler, William; Kummel, Andrew C

    2017-04-01

    Silica nanoparticles are an emerging class of biomaterials which may be used as diagnostic and therapeutic tools for biomedical applications. In particular, hollow silica nanoshells are attractive due to their hollow core. Approximately 70% of a 500 nm nanoshell is hollow, therefore more particles can be administered on a mg/kg basis compared to solid nanoparticles. Additionally, their nanoporous shell permits influx/efflux of gases and small molecules. Since the size, shape, and composition of a nanoparticle can dramatically alter its toxicity and biodistribution, the toxicology of these nanomaterials was assessed. A single dose toxicity study was performed in vivo to assess the toxicity of 500 nm iron-doped silica nanoshells at clinically relevant doses of 10-20 mg/kg. This study showed that only a trace amount of silica was detected in the body 10 weeks post-administration. The hematology, biochemistry and pathological results show that the nanoshells exhibit no acute or chronic toxicity in mice. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Environmental footprints of brick kiln bottom ashes: Geostatistical approach for assessment of metal toxicity.

    PubMed

    Mondal, Ananya; Das, Subhasish; Sah, Rajesh Kumar; Bhattacharyya, Pradip; Bhattacharya, Satya Sundar

    2017-12-31

    Coal fired brick kiln factories generate significant of brick kiln bottom ash (BKBA) that contaminate soil and water environments of areas near the dumping sites through leaching of toxic metals (Pb, Cr, Cd, Zn, Mn, and Cu). However, characteristics and environmental effects of BKBAs are yet unknown. We collected BKBA samples from 32 strategic locations of two rapidly developing States (West Bengal and Assam) of India. Scanning electron microscope images indicated spherical and granular structures of BKBAs produced in West Bengal (WBKBA) and Assam (ABKBA) respectively; while energy dispersive spectroscopy and analytical assessments confirmed substantial occurrence of total organic C and nutrient elements (N, P, K, Ca, Mg, and S) in both the BKBAs. FTIR analysis revealed greater predominance of organic matter in ABKBAs than WBKBAs. Occurrence of toxic metals (Cd, Cr, Pb, Zn, Mn, and Cu) was higher in ABKBAs than in WBKBAs; while organic and residual fractions of metals were highly predominant in most of the BKBAs. Principal component analysis showed that metal contents and pH were the major distinguishing characteristics of the BKBAs generated in the two different environmental locations. Human health risk associated with BKBAs generated in Assam is of significant concern. Finally, geo-statistical tools enabled to predict the spatial distribution patterns of toxic metals contributed by the BKBAs in Assam and West Bengal respectively. Assessment of contamination index, geo-accumulation index, and ecological risk index revealed some BKBAs to be more toxic than others. Copyright © 2017. Published by Elsevier B.V.

  15. Acute toxicity assessment of Osthol content in bio-pesticides using two aquatic organisms

    PubMed Central

    Yim, Eun-Chae; Kim, Hyeon Joe; Kim, Seong-Jun

    2014-01-01

    Objectives This study focused on the assessment of acute toxicity caused by Osthol, a major component of environment-friendly biological pesticides, by using two aquatic organisms. Methods The assessment of acute toxicity caused by Osthol was conducted in Daphnia magna and by examining the morphological abnormalities in Danio rerio embryos. Results The median effective concentration value of Osthol in D. magna 48 hours after inoculation was 19.3 μM. The median lethal concentration of D. rerio embryo at 96 hours was 30.6 μM. No observed effect concentration and predicted no effect concentration values of Osthol in D. magna and D. rerio were calculated as 5.4 and 0.19 μM, respectively. There was an increase in the morphological abnormalities in D. rerio embryo due to Osthol over time. Coagulation, delayed hatching, yolk sac edema, pericardial edema, and pigmentation were observed in embryos at 24–48 hours. Symptoms of scoliosis and head edema occurred after 72 hours. In addition, bent tails, ocular defects, and symptoms of collapse were observed in fertilized embryo tissue within 96 hours. Ocular defects and pigmentation were the additional symptoms observed in this study. Conclusions Because Osthol showed considerable toxicity levels continuous toxicity evaluation in agro-ecosystems is necessary when bio-pesticides containing Osthol are used. PMID:25518842

  16. Assessing toxic levels of hydrocarbons on microbial degrader communities in vadose zone fill soils

    SciTech Connect

    Schoenberg, T.H.; Long, S.C.

    1995-12-31

    Authentic fill samples were collected from the vadose zone at a highway travel plaza. The contamination at the site is a combination of gasoline, diesel, and waste oil resulting from leaking underground storage tanks. Microbial assessments including plate counts and specific-degrader enumerations were performed to establish the presence of degrader microbial communities, and thus bioremediation potential. Contaminant levels were estimated in samples by quantifying headspace VOCs in collection jars. Physical soil characteristics including soil grain size distribution and moisture content were measured to evaluate the potential ecological variables that would affect implementation of a bioremediation technology. Toxicity screening using the Microtox{trademark} acute toxicity assay was used to compare the level of toxicity present among samples. These analyses were used to assess the potential for using in situ bioventing remediation to clean-up the leaking underground storage tank spill study site. High contaminant levels appear to have exerted a toxic effect and resulted in smaller total microbial community sizes in highly contaminated areas (thousands of ppmv) of the site. Microtox{trademark} EC50 results generally corroborated with the trends of the enumeration experiments. Microbial characterization results indicate that in situ bioremediation would be possible at the study site. Soil heterogeneity appears to pose the greatest challenges to the design and implementation of bioremediation at this site.

  17. Predicting algal growth inhibition toxicity: three-step strategy using structural and physicochemical properties.

    PubMed

    Furuhama, A; Hasunuma, K; Hayashi, T I; Tatarazako, N

    2016-05-01

    We propose a three-step strategy that uses structural and physicochemical properties of chemicals to predict their 72 h algal growth inhibition toxicities against Pseudokirchneriella subcapitata. In Step 1, using a log D-based criterion and structural alerts, we produced an interspecies QSAR between algal and acute daphnid toxicities for initial screening of chemicals. In Step 2, we categorized chemicals according to the Verhaar scheme for aquatic toxicity, and we developed QSARs for toxicities of Class 1 (non-polar narcotic) and Class 2 (polar narcotic) chemicals by means of simple regression with a hydrophobicity descriptor and multiple regression with a hydrophobicity descriptor and a quantum chemical descriptor. Using the algal toxicities of the Class 1 chemicals, we proposed a baseline QSAR for calculating their excess toxicities. In Step 3, we used structural profiles to predict toxicity either quantitatively or qualitatively and to assign chemicals to the following categories: Pesticide, Reactive, Toxic, Toxic low and Uncategorized. Although this three-step strategy cannot be used to estimate the algal toxicities of all chemicals, it is useful for chemicals within its domain. The strategy is also applicable as a component of Integrated Approaches to Testing and Assessment.

  18. Evaluating the national air toxics assessment (NATA): Comparison of predicted and measured air toxics concentrations, risks, and sources in Pittsburgh, Pennsylvania

    NASA Astrophysics Data System (ADS)

    Logue, Jennifer M.; Small, Mitchell J.; Robinson, Allen L.

    2011-01-01

    The National Air Toxics Assessment (NATA) is an ongoing modeling effort by the Environmental Protection Agency to predict air toxics concentrations, sources, and risks at the census tract level throughout the continental United States. To evaluate NATA, archived data collected at seven sites in and around Pittsburgh, Pennsylvania were compared to 2002 NATA predictions. The sites represent 3 different source regimes (mobile dominated, industrial point source dominated, and background). The evaluation considered 49 air toxics (37 gas-phase organics, 10 metals, coke oven emissions and diesel particulate matter); NATA's performance was judged based on model-measurement comparisons of concentrations, health risks, and source contributions. On a concentration basis, NATA performance varied widely ranging from excellent for carbon tetrachloride to differences of more than a factor of 100 for low concentration chlorinated compounds. However, predicted concentrations were generally within a factor of 2 of measured values for air toxics that were estimated to be the primary cancer risk drivers; therefore NATA provided reasonable estimates of the additive cancer risks and risk ranking of air toxics. NATA performs better on average in Pittsburgh than nationwide. Comparison of source apportionment results indicates that NATA consistently underestimated concentrations of compounds emitted by large point sources as well as concentrations of chlorinated compounds, but overestimated the risks from mobile sources in Pittsburgh. Therefore, in Pittsburgh, NATA sufficiently prioritizes air toxics that drive potential cancer risks, but does not identify the sources of these priority air toxics.

  19. Toxicity testing of dispersed oil requires adherence to standardized protocols to assess potential real world effects.

    PubMed

    Coelho, Gina; Clark, James; Aurand, Don

    2013-06-01

    Recently, several researchers have attempted to address Deepwater Horizon incident environmental fate and effects issues using laboratory testing and extrapolation procedures that are not fully reliable measures for environmental assessments. The 2013 Rico-Martínez et al. publication utilized laboratory testing approaches that severely limit our ability to reliably extrapolate such results to meaningful real-world assessments. The authors did not adopt key methodological elements of oil and dispersed oil toxicity standards. Further, they drew real-world conclusions from static exposure tests without reporting actual exposure concentrations. Without this information, it is not possible to compare their results to other research or real spill events that measured and reported exposure concentrations. The 1990s' Chemical Response to Oil Spills: Ecological Effects Research Forum program was established to standardize and conduct exposure characterization in oil and dispersed oil aquatic toxicity testing (Aurand and Coelho, 2005). This commentary raises awareness regarding the necessity of standardized test protocols.

  20. Preclinical safety assessments of nano-sized constructs on cardiovascular system toxicity: A case for telemetry.

    PubMed

    Cheah, Hoay Yan; Kiew, Lik Voon; Lee, Hong Boon; Japundžić-Žigon, Nina; Vicent, Marίa J; Hoe, See Ziau; Chung, Lip Yong

    2017-02-06

    While nano-sized construct (NSC) use in medicine has grown significantly in recent years, reported unwanted side effects have raised safety concerns. However, the toxicity of NSCs to the cardiovascular system (CVS) and the relative merits of the associated evaluation methods have not been thoroughly studied. This review discusses the toxicological profiles of selected NSCs and provides an overview of the assessment methods, including in silico, in vitro, ex vivo and in vivo models and how they are related to CVS toxicity. We conclude the review by outlining the merits of telemetry coupled with spectral analysis, baroreceptor reflex sensitivity analysis and echocardiography as an appropriate integrated strategy for the assessment of the acute and chronic impact of NSCs on the CVS. Copyright © 2017 John Wiley & Sons, Ltd.

  1. Online monitoring of cell metabolism to assess the toxicity of nanoparticles: the case of cobalt ferrite.

    PubMed

    Mariani, Valentina; Ponti, Jessica; Giudetti, Guido; Broggi, Francesca; Marmorato, Patrick; Gioria, Sabrina; Franchini, Fabio; Rauscher, Hubert; Rossi, François

    2012-05-01

    Different in vitro assays are successfully used to determine the relative cytotoxicity of a broad range of compounds. Nevertheless, different research groups have pointed out the difficulty in using the same tests to assess the toxicity of nanoparticles (NPs). In this study, we evaluated the possible use of a microphysiometer, Bionas 2500 analyzing system Bionas GmbH®, to detect in real time changes in cell metabolisms linked to NPs exposure. We focused our work on response changes of fibroblast cultures linked to exposure by cobalt ferrite NPs and compared the results to conventional in vitro assays. The measurements with the microphysiometer showed a cobalt ferrite cytotoxic effect, confirmed by the Colony Forming Efficiency assay. In conclusion, this work demonstrated that the measurement of metabolic parameters with a microphysiometer is a promising method to assess the toxicity of NPs and offers the advantage to follow on-line the cell metabolic changes.

  2. Speciation Methods Used to Assess Potential Health Effects of Toxic Metals in Environmental Materials

    USGS Publications Warehouse

    Wolf, Ruth E.; Morman, Suzette A.; Plumlee, Geoffrey S.

    2008-01-01

    Assessing potential exposures to toxic metals or metalloids such as arsenic and chromium in environmental materials is important in protecting public health. The chemical form of an element in, or released from, a material is also important, since some forms, such as Cr(VI), are more toxic than others, for example, Cr(III). We have used a variety of procedures to assess potential exposures to hexavalent chromium in ash and burned soils from October 2007 southern California wildfires. Synthetic lung-fluid and de-ionized water extractions simulate release in the lungs and potential environmental releases due to rainfall. Extracts were analyzed for specific chromium and arsenic species using HPLC-ICP-MS methodology. Results indicate that the highly oxidizing environment in wildfires promotes some chromium conversion to Cr(VI), and that the caustic alkalinity of ash enhances Cr(VI) release and stability in lung fluids and rainfall.

  3. Toxicity assessment of atmospheric particulate matter in the Mediterranean and Black Seas open waters.

    PubMed

    Mesquita, Sofia R; Dachs, Jordi; van Drooge, Barend L; Castro-Jiménez, Javier; Navarro-Martín, Laia; Barata, Carlos; Vieira, Natividade; Guimarães, Laura; Piña, Benjamin

    2016-03-01

    Atmospheric deposition of particulate matter (PM) is recognized as a relevant input vector for toxic compounds, such as polycyclic aromatic hydrocarbons (PAHs), into the marine environment. In this work we aimed to analyse the biological activity and potential adverse effects of PM constituents to aquatic organisms. Organic extracts of atmospheric PM samples from different sub-basins of the Mediterranean and Black Seas were screened using different toxicological tests. A yeast-based assay (AhR-RYA) revealed that dioxin-like activity correlated with the concentration of total PAHs in the PM samples, as well as with their predicted toxic equivalent values (TEQs). Although the zebrafish embryotoxicity test (the ZET assay) showed no major phenotypical adverse effects, up-regulation of mRNA expression of cyp1a, fos and development-related genes (previously described as related to PM toxicity) was observed in exposed embryos when compared to controls. Results showed that mRNA patterns of the studied genes followed a similar geographic distribution to both PAH content and dioxin-like activity of the corresponding extracts. The analysis also showed a distinct geographical pattern of activation of pancreatic markers previously related to airborne pollution, probably indicating a different subset of uncharacterized particle-bound toxicants. We propose the combination of the bioassays tested in the present study to be applied to future research with autochthonous species to assess exposure and potential toxic effects of ambient PM. The present study emphasizes the need for more in-depth studies into the toxic burden of atmospheric PM on aquatic ecosystems, in order to improve future regulatory guidelines.

  4. Assessing contaminant sensitivity of endangered and threatened aquatic species: Part I. Acute toxicity of five chemicals

    USGS Publications Warehouse

    Dwyer, F.J.; Mayer, F.L.; Sappington, L.C.; Buckler, D.R.; Bridges, C.M.; Greer, I.E.; Hardesty, D.K.; Henke, C.E.; Ingersoll, C.G.; Kunz, J.L.; Whites, D.W.; Augspurger, T.; Mount, D.R.; Hattala, K.; Neuderfer, G.N.

    2005-01-01

    Assessment of contaminant impacts to federally identified endangered, threatened and candidate, and state-identified endangered species (collectively referred to as "listed" species) requires understanding of a species' sensitivities to particular chemicals. The most direct approach would be to determine the sensitivity of a listed species to a particular contaminant or perturbation. An indirect approach for aquatic species would be application of toxicity data obtained from standard test procedures and species commonly used in laboratory toxicity tests. Common test species (fathead minnow, Pimephales promelas; sheepshead minnow, Cyprinodon variegatus; and rainbow trout, Oncorhynchus mykiss) and 17 listed or closely related species were tested in acute 96-hour water exposures with five chemicals (carbaryl, copper, 4-nonylphenol, pentachlorophenol, and permethrin) representing a broad range of toxic modes of action. No single species was the most sensitive to all chemicals. For the three standard test species evaluated, the rainbow trout was more sensitive than either the fathead minnow or sheepshead minnow and was equal to or more sensitive than listed and related species 81% of the time. To estimate an LC50 for a listed species, a factor of 0.63 can be applied to the geometric mean LC50 of rainbow trout toxicity data, and more conservative factors can be determined using variance estimates (0.46 based on 1 SD of the mean and 0.33 based on 2 SD of the mean). Additionally, a low- or no-acute effect concentration can be estimated by multiplying the respective LC50 by a factor of approximately 0.56, which supports the United States Environmental Protection Agency approach of multiplying the final acute value by 0.5 (division by 2). When captive or locally abundant populations of listed fish are available, consideration should be given to direct testing. When direct toxicity testing cannot be performed, approaches for developing protective measures using common test

  5. Sediment and water toxicity evaluations for the Clinch River ecological risk assessment

    SciTech Connect

    Gonzalez, A.M.; Phipps, T.L.; Kszos, L.A.

    1995-12-31

    The sediment and surface water at three sites in the Clinch River and six sites in Poplar Creek were evaluated by means of toxicity tests with aquatic organisms. The results of these tests were used as one of the lines of evidence in an assessment of ecological risk due to contaminants, transported from the Oak Ridge Reservation, to the off-site sediment and water environment. Results from a suite of six whole sediment, elutriate and pore water toxicity tests were summarized in terms of survival (Hyalella azteca, Daphnia magna, Anodonta imbecillis, Ceriodaphnia dubia), fecundity (Daphnia magna) or light output reduction (Microtox{reg_sign}). Results from the water toxicity tests were summarized in terms of reduction in survival or fecundity of C. dubia, and survival or growth of Pimephales promelas. Toxicity test results (covering a period of about 1 6 months) showed little difference between reference site media and media from sites of concern. They also showed no strong spatial or temporal response pattern. These results are further supported by the presence of indigenous Chironomus and Hexagenia spp. in the sediment samples. Toxicity results will be discussed with respect to three issues. Two criteria were used to define significant differences between reference sites and sites of concern: a difference of 20%, and statistical significance at a = 0.05. Secondly, the relevance of comparing mean responses to control vs. reference site will be discussed. Lastly, toxicity results are consistent with site characterization information which suggest that contaminants of concern in sediment are buried under clean sediment, effectively isolating the material from potential human or ecological exposure.

  6. Assessing contaminant sensitivity of endangered and threatened aquatic species: part I. Acute toxicity of five chemicals.

    PubMed

    Dwyer, F J; Mayer, F L; Sappington, L C; Buckler, D R; Bridges, C M; Greer, I E; Hardesty, D K; Henke, C E; Ingersoll, C G; Kunz, J L; Whites, D W; Augspurger, T; Mount, D R; Hattala, K; Neuderfer, G N

    2005-02-01

    Assessment of contaminant impacts to federally identified endangered, threatened and candidate, and state-identified endangered species (collectively referred to as "listed" species) requires understanding of a species' sensitivities to particular chemicals. The most direct approach would be to determine the sensitivity of a listed species to a particular contaminant or perturbation. An indirect approach for aquatic species would be application of toxicity data obtained from standard test procedures and species commonly used in laboratory toxicity tests. Common test species (fathead minnow, Pimephales promelas; sheepshead minnow, Cyprinodon variegatus; and rainbow trout, Oncorhynchus mykiss) and 17 listed or closely related species were tested in acute 96-hour water exposures with five chemicals (carbaryl, copper, 4-nonylphenol, pentachlorophenol, and permethrin) representing a broad range of toxic modes of action. No single species was the most sensitive to all chemicals. For the three standard test species evaluated, the rainbow trout was more sensitive than either the fathead minnow or sheepshead minnow and was equal to or more sensitive than listed and related species 81% of the time. To estimate an LC50 for a listed species, a factor of 0.63 can be applied to the geometric mean LC50 of rainbow trout toxicity data, and more conservative factors can be determined using variance estimates (0.46 based on 1 SD of the mean and 0.33 based on 2 SD of the mean). Additionally, a low- or no-acute effect concentration can be estimated by multiplying the respective LC50 by a factor of approximately 0.56, which supports the United States Environmental Protection Agency approach of multiplying the final acute value by 0.5 (division by 2). When captive or locally abundant populations of listed fish are available, consideration should be given to direct testing. When direct toxicity testing cannot be performed, approaches for developing protective measures using common test

  7. Assessing the toxicity of sediments using the medaka embryo-larval assay and 2 other bioassays.

    PubMed

    Barhoumi, Badreddine; Clérandeau, Christelle; Landi, Laure; Pichon, Anaïk; Le Bihanic, Florane; Poirier, Dominique; Anschutz, Pierre; Budzinski, Hélène; Driss, Mohamed Ridha; Cachot, Jérôme

    2016-09-01

    Sediments are sinks for aquatic pollutants, and analyzing toxicity in such complex matrices is still challenging. To evaluate the toxicity of bioavailable pollutants accumulated in sediments from the Bizerte lagoon (Tunisia), a novel assay, the medaka embryo-larval assay by sediment contact, was applied. Japanese medaka (Oryzias latipes) embryos were incubated in direct contact with sediment samples up to hatching. Lethal and sublethal adverse effects were recorded in embryos and larvae up to 20 d postfertilization. Results from medaka embryo-larval assay were compared with cytotoxicity (Microtox®), genotoxicity (SOS chromotest), and pollutant content of sediments. The results highlight differences in the contamination profile and toxicity pattern between the different studied sediments. A significant correlation was shown between medaka embryo-larval assay by sediment contact and SOS chromotest responses and concentrations of most organic pollutants studied. No correlation was shown between pollutant levels and Microtox. According to the number of sediment samples detected as toxic, medaka embryo-larval assay by sediment contact was more sensitive than Microtox, which in turn was more sensitive than the SOS chromotest; and medaka embryo-larval assay by sediment contact allowed sediment toxicity assessment of moderately polluted sediments without pollutant extraction and using an ecologically realistic exposure scenario. Although medaka embryo-larval assay by sediment contact should be tested on a larger sample set, the results show that it is sensitive and convenient enough to monitor the toxicity of natural sediments. Environ Toxicol Chem 2016;35:2270-2280. © 2016 SETAC. © 2016 SETAC.

  8. ELEMENTAL ANALYSIS OF RESPIRABLE TIRE PARTICLES AND ASSESSMENT OF CARDIO-PULMONARY TOXICITY IN RATS

    EPA Science Inventory

    Elemental Analysis of Respirable Tire Particles and Assessment of Cardio-pulmonary Toxicity in Rats

    R.R. Gottipolu, PhD1, E. Landa, PhD2, J.K. McGee, MS1, M.C. Schladweiler, BS1, J.G. Wallenborn, MS3, A.D. Ledbetter, BS1, J.E. Richards, MS1 and U.P. Kodavanti, PhD1. 1NHEER...

  9. Biomarkers of Oxidative Stress in the Assessment of Enantioselective Toxicity of Chiral Pesticides.

    PubMed

    Ye, Xiaoqing; Liu, Ying; Li, Feixue

    2017-01-01

    In biological systems, the individual stereoisomers of chiral substances possess significantly different biochemical properties because the specific structure-activity relationships are required for a common site on biomolecules. In the past decade, there has been increasing concern over the enantioselective toxicity of environmental chiral pollutants, especially chiral pesticides. Different responses and activities of a pair of enantiomers of chiral pesticides were often observed. Therefore, assessment of the enantioselective toxicological properties of chiral pesticides is a prerequisite in application of single-isomer products and particularly important for environmental protection. The development of biomarkers that can predict enantioselective effects from chiral pesticides has recently been gained more and more attention. The biomarkers of oxidative stress have become a topic of significant interest for toxic assessments. In this review, we summarized current knowledge and advances in the understanding of enantiomeric oxidative processes in biological systems in response to chiral pesticides. The consistent results in two types of chiral insecticides (synthetic pyrethroids and organochlorine pesticides) showed the significant difference in cytotoxicity of enantiomers, suggesting the antioxidant enzymes are reliable biomarkers for the assessment of toxicity of chiral chemicals. Results indicate that antioxidant enzymes are sensitive and valid biomarkers to assess the oxidative damage caused by chiral herbicides. In addition, it can be inferred that the enantioselectivity of chiral herbicides on antioxidant enzymes exists in other species. Compared with insecticides and herbicides, researches about the enantioselectivity of oxidative stress caused by chiral fungicides are quite limited. Only two kinds of chiral fungicides has been used to study the enantioselectivity of oxidative stress by now. The current knowledge that enantioselective processes of oxidative

  10. ELEMENTAL ANALYSIS OF RESPIRABLE TIRE PARTICLES AND ASSESSMENT OF CARDIO-PULMONARY TOXICITY IN RATS

    EPA Science Inventory

    Elemental Analysis of Respirable Tire Particles and Assessment of Cardio-pulmonary Toxicity in Rats

    R.R. Gottipolu, PhD1, E. Landa, PhD2, J.K. McGee, MS1, M.C. Schladweiler, BS1, J.G. Wallenborn, MS3, A.D. Ledbetter, BS1, J.E. Richards, MS1 and U.P. Kodavanti, PhD1. 1NHEER...

  11. Assessing potential dietary toxicity of heavy metals in selected vegetables and food crops.

    PubMed

    Islam, Ejaz ul; Yang, Xiao-e; He, Zhen-li; Mahmood, Qaisar

    2007-01-01

    Heavy metals, such as cadmium, copper, lead, chromium and mercury, are important environmental pollutants, particularly in areas with high anthropogenic pressure. Their presence in the atmosphere, soil and water, even in traces can cause serious problems to all organisms, and heavy metal bioaccumulation in the food chain especially can be highly dangerous to human health. Heavy metals enter the human body mainly through two routes namely: inhalation and ingestion, ingestion being the main route of exposure to these elements in human population. Heavy metals intake by human populations through food chain has been reported in many countries. Soil threshold for heavy metal toxicity is an important factor affecting soil environmental capacity of heavy metal and determines heavy metal cumulative loading limits. For soil-plant system, heavy metal toxicity threshold is the highest permissible content in the soil (total or bioavailable concentration) that does not pose any phytotoxic effects or heavy metals in the edible parts of the crops does not exceed food hygiene standards. Factors affecting the thresholds of dietary toxicity of heavy metal in soil-crop system include: soil type which includes soil pH, organic matter content, clay mineral and other soil chemical and biochemical properties; and crop species or cultivars regulated by genetic basis for heavy metal transport and accumulation in plants. In addition, the interactions of soil-plant root-microbes play important roles in regulating heavy metal movement from soil to the edible parts of crops. Agronomic practices such as fertilizer and water managements as well as crop rotation system can affect bioavailability and crop accumulation of heavy metals, thus influencing the thresholds for assessing dietary toxicity of heavy metals in the food chain. This paper reviews the phytotoxic effects and bioaccumulation of heavy metals in vegetables and food crops and assesses soil heavy metal thresholds for potential dietary

  12. Assessing potential dietary toxicity of heavy metals in selected vegetables and food crops*

    PubMed Central

    Islam, Ejaz ul; Yang, Xiao-e; He, Zhen-li; Mahmood, Qaisar

    2007-01-01

    Heavy metals, such as cadmium, copper, lead, chromium and mercury, are important environmental pollutants, particularly in areas with high anthropogenic pressure. Their presence in the atmosphere, soil and water, even in traces can cause serious problems to all organisms, and heavy metal bioaccumulation in the food chain especially can be highly dangerous to human health. Heavy metals enter the human body mainly through two routes namely: inhalation and ingestion, ingestion being the main route of exposure to these elements in human population. Heavy metals intake by human populations through food chain has been reported in many countries. Soil threshold for heavy metal toxicity is an important factor affecting soil environmental capacity of heavy metal and determines heavy metal cumulative loading limits. For soil-plant system, heavy metal toxicity threshold is the highest permissible content in the soil (total or bioavailable concentration) that does not pose any phytotoxic effects or heavy metals in the edible parts of the crops does not exceed food hygiene standards. Factors affecting the thresholds of dietary toxicity of heavy metal in soil-crop system include: soil type which includes soil pH, organic matter content, clay mineral and other soil chemical and biochemical properties; and crop species or cultivars regulated by genetic basis for heavy metal transport and accumulation in plants. In addition, the interactions of soil-plant root-microbes play important roles in regulating heavy metal movement from soil to the edible parts of crops. Agronomic practices such as fertilizer and water managements as well as crop rotation system can affect bioavailability and crop accumulation of heavy metals, thus influencing the thresholds for assessing dietary toxicity of heavy metals in the food chain. This paper reviews the phytotoxic effects and bioaccumulation of heavy metals in vegetables and food crops and assesses soil heavy metal thresholds for potential dietary

  13. Ecotoxicological assessment of flocculant modified soil for lake restoration using an integrated biotic toxicity index.

    PubMed

    Wang, Zhibin; Zhang, Honggang; Pan, Gang

    2016-06-15

    Flocculant modified soils/clays are being increasingly studied as geo-engineering materials for lake restoration and harmful algal bloom control. However, the potential impacts of adding these materials in aquatic ecological systems remain unclear. This study investigated the potential effects of chitosan, cationic starch, chitosan modified soils (MS-C) and cationic starch modified soils (MS-S) on the aquatic organisms by using a bioassay battery. The toxicity potential of these four flocculants was quantitatively assessed using an integrated biotic toxicity index (BTI). The test system includes four aquatic species, namely Chlorella vulgaris, Daphnia magna, Cyprinus carpio and Limnodrilus hoffmeisteri, which represent four trophic levels in the freshwater ecosystem. Results showed that median effect concentrations (EC50) of the MS-C and MS-S were 31-124 times higher than chitosan and cationic starch, respectively. D. magna was the most sensitive species to the four flocculants. Histological examination of C. carpio showed that significant pathological changes were found in gills. Different from chitosan and cationic starch, MS-C and MS-S significantly alleviated the acute toxicities of chitosan and cationic starch. The toxicity order of the four flocculants based on BTI were cationic starch > chitosan > MS-S > MS-C. The results suggested that BTI can be used as a quantitative and comparable indicator to assess biotic toxicity for aquatic geo-engineering materials. Chitosan or cationic starch modified soil/clay materials can be used at their optimal dosage without causing substantial adverse effects to the bioassay battery in aquatic ecosystem.

  14. Safety Assessment of Ocimum Basilicum Hydroalcoholic Extract in Wistar Rats: Acute and Subchronic Toxicity Studies

    PubMed Central

    Rasekh, Hamid Reza; Hosseinzadeh, Leila; Mehri, Soghra; Kamli-Nejad, Mohammad; Aslani, Majid; Tanbakoosazan, Farahnaz

    2012-01-01

    Objective(s) Ocimum basilicum L. is widely used in folk medicine of many countries including . Both O. basilicum and its oil extract have received considerable attention for their potential medicinal properties, but there are a few reports about possible toxicity of this plant. Therefore, in the present study, acute and subchronic toxicity of O. basilicum hydroalcohlic extract have been evaluated in Wistar rats. Materials and Methods For the acute toxicity assessment, five groups of 10 animals (5 male, 5 female) received four different single dose of extract orally, the animals were, then, kept under observation for 14 days. For subchronic toxicity, the animals were divided into four groups (5 male, 5 female) and were gavaged daily by 50, 200 and 500 mg/kg of extract. Mortality, clinical signs, body weight changes, food and water consumption, and hematological and biochemical parameters were monitored during the study period. On the 45th day, animals were sacrificed and gross findings, weight of liver and left kidney and liver histological markers were assessed. Results The results of acute study indicated that LD50 of O. basilicum is higher than 5 mg/kg. In subchronic study, no adverse effects were observed on serum parameters in male and female rats. The hematological results showed a reduction in the hematocrit, platelets and RBC in both sexes. No abnormalities were observed in other parameters. Conclusion Based on the results of this study, present data suggest that hematologic system could serve as a target organ in oral toxicity of this plant. PMID:23493182

  15. A multispecies study to assess the toxic and genotoxic effect of pharmaceuticals: furosemide and its photoproduct.

    PubMed

    Isidori, Marina; Nardelli, Angela; Parrella, Alfredo; Pascarella, Luigia; Previtera, Lucio

    2006-05-01

    Pharmaceutical products for humans and animals, as well as their related metabolites end up in the aquatic environment after use. Recent investigations show that concentrations of pharmaceuticals are detectable in the order of ng/l-mug/l in municipal wastewater, groundwater and also drinking water. Little is known about the effects, and the hazard of long-term exposure to low concentrations of pharmaceuticals for non-target aquatic organisms. This study was designed to assess the ecotoxicity of furosemide, a potent diuretic agent, and its photoproduct in the aquatic environment. Bioassays were performed on bacteria, algae, rotifers and microcrustaceans to assess acute and chronic toxicity, while the SOS Chromotest and the Ames test were utilized to detect the genotoxic potential of the investigated compounds. A first approach to risk characterization was to calculate the environmental impact of furosemide by measured environmental concentration and predicted no effect concentration ratio (MEC/PNEC). To do so we used occurrence data reported in the literature and our toxicity results. The results showed that acute toxicity was in the order of mg/l for the crustaceans and absent for bacteria and rotifers. Chronic exposure to these compounds caused inhibition of growth population on the consumers, while the algae did not seem to be affected. A mutagenic potential was found for the photoproduct compared to the parental compound suggesting that byproducts ought to be considered in the environmental assessment of drugs. The risk calculated for furosemide suggested its harmlessness on the aquatic compartment.

  16. Toxicity assessment for petroleum-contaminated soil using terrestrial invertebrates and plant bioassays.

    PubMed

    Hentati, Olfa; Lachhab, Radhia; Ayadi, Mariem; Ksibi, Mohamed

    2013-04-01

    The assessment of soil quality after a chemical or oil spill and/or remediation effort may be measured by evaluating the toxicity of soil organisms. To enhance our understanding of the soil quality resulting from laboratory and oil field spill remediation, we assessed toxicity levels by using earthworms and springtails testing and plant growth experiments. Total petroleum hydrocarbons (TPH)-contaminated soil samples were collected from an oilfield in Sfax, Tunisia. Two types of bioassays were performed. The first assessed the toxicity of spiked crude oil (API gravity 32) in Organization for Economic Co-operation and Development artificial soil. The second evaluated the habitat function through the avoidance responses of earthworms and springtails and the ability of Avena sativa to grow in TPH-contaminated soils diluted with farmland soil. The EC50 of petroleum-contaminated soil for earthworms was 644 mg of TPH/kg of soil at 14 days, with 67 % of the earthworms dying after 14 days when the TPH content reached 1,000 mg/kg. The average germination rate, calculated 8 days after sowing, varied between 64 and 74 % in low contaminated soils and less than 50 % in highly contaminated soils.

  17. The use of established skeletal muscle cell lines to assess potential toxicity from embedded metal fragments.

    PubMed

    Kane, Michele A; Kasper, Christine E; Kalinich, John F

    2009-03-01

    The use of novel materials on the modern battlefield, both in military munitions as well as in Improvised Explosive Devices, opens the possibility of wounds with embedded fragments whose health effects and toxicity characteristics have not been fully investigated, if at all. The costly and time-consuming nature of standard two-year lifespan studies prohibits the testing of many materials. In this report, we describe an in vitro system for rapidly assessing potential toxicity of metals and metal mixtures. Using rat L6 and mouse C2C12 skeletal muscle cells and tests for cellular viability, we have shown that two militarily relevant tungsten alloy mixtures (W/Ni/Co and W/Ni/Fe) significantly decreased the metabolic viability of rat L6 cells, whereas the viability of mouse C2C12 cells was not affected by W/Ni/Co and only slightly affected by W/Ni/Fe. In addition, viability assessed through lysosomal uptake of neutral red dye was not affected by either mixture in either cell line indicating that the mitochondria may be the target organelle of these unique metal mixtures. Development of this in vitro screening system may provide a procedure by which the potential toxicities of embedded metal fragments can be rapidly assessed.

  18. Off-site toxic consequence assessment: a simplified modeling procedure and case study.

    PubMed

    Guarnaccia, Joe; Hoppe, Tom

    2008-11-15

    An assessment of off-site exposure from spills/releases of toxic chemicals can be conducted by compiling site-specific operational, geographic, demographic, and meteorological data and by using screening-level public-domain modeling tools (e.g., RMP Comp, ALOHA and DEGADIS). In general, the analysis is confined to the following: event-based simulations (allow for the use of known, constant, atmospheric conditions), known receptor distances (on the order of miles or less), short time scale for the distances considered (order of 10's of minutes or less), gently sloping rough terrain, dense and neutrally buoyant gas dispersion, known chemical inventory and infrastructure (used to define source-term), and known toxic endpoint (defines significance). While screening-level models are relatively simple to use, care must be taken to ensure that the results are meaningful. This approach allows one to assess risk from catastrophic release (e.g., via terrorism), or plausible release scenarios (related to standard operating procedures and industry standards). In addition, given receptor distance and toxic endpoint, the model can be used to predict the critical spill volume to realize significant off-site risk. This information can then be used to assess site storage and operation parameters and to determine the most economical and effective risk reduction measures to be applied.

  19. A comparison of mixture toxicity assessment: examining the chronic toxicity of atrazine, permethrin and chlorothalonil in mixtures to Ceriodaphnia cf. dubia.

    PubMed

    Phyu, Y L; Palmer, C G; Warne, M St J; Hose, G C; Chapman, J C; Lim, R P

    2011-11-01

    Pesticides predominantly occur in aquatic ecosystems as mixtures of varying complexity, yet relatively few studies have examined the toxicity of pesticide mixtures. Atrazine, chlorothalonil and permethrin are widely used pesticides that have different modes of action. This study examined the chronic toxicities (7-d reproductive impairment) of these pesticides in binary and ternary mixtures to the freshwater cladoceran Ceriodaphnia cf. dubia. The toxicity of the mixtures was compared to that predicted by the independent action (IA) model for mixtures, as this is the most appropriate model for chemicals with different modes of action. Following this they were compared to the toxicity predicted by the concentration addition (CA) model for mixtures. According to the IA model, the toxicity of the chlorothalonil plus atrazine mixture conformed to antagonism, while that of chlorothalonil and permethrin conformed to synergism. The toxicity of the atrazine and permethrin mixture as well as the ternary mixture conformed to IA implying there was either no interaction between the components of these mixtures and/or in the case of the ternary mixture the interactions cancelled each other out to result in IA. The synergistic and antagonistic mixtures deviated from IA by factors greater than 3 and less than 2.5, respectively. When the toxicity of the mixtures was compared to the predictions of the CA model, the binary mixture of chlorothalonil plus atrazine, permethrin plus atrazine and the ternary mixture all conformed to antagonism, while the binary mixture of chlorothalonil plus permethrin conformed to CA. Using the CA model provided estimates of mixture toxicity that did not markedly underestimate the measured toxicity, unlike the IA model, and therefore the CA model is the most suitable to use in ecological risk assessments of these pesticides.

  20. The water flea (Daphnia magna) as a sensitive indicator for the assessment of toxicity of synthetic detergents.

    PubMed

    Lal, H; Misra, V; Viswanathan, P N; Murti, C R

    1984-10-01

    The water flea (Daphnia magna) was used as a sensitive indicator for assessing the toxicity due to synthetic detergents. Acute and chronic toxicity of detergents to the water flea was studied under laboratory conditions by following the median tolerance limit (TLM) at 48 hr and the rate of survival. A significant decrease in the rate of reproduction (number of hatching and neonates produced) were found at 21 days. During acute toxicity studies behavioural changes were also noticed.

  1. Nutrition Can Modulate the Toxicity of Environmental Pollutants: Implications in Risk Assessment and Human Health

    PubMed Central

    Ormsbee, Lindell; McClain, Craig J.; Watkins, Bruce A.; Blumberg, Bruce; Bachas, Leonidas G.; Sanderson, Wayne; Thompson, Claudia; Suk, William A.

    2012-01-01

    Background: The paradigm of human risk assessment includes many variables that must be viewed collectively in order to improve human health and prevent chronic disease. The pathology of chronic diseases is complex, however, and may be influenced by exposure to environmental pollu-tants, a sedentary lifestyle, and poor dietary habits. Much of the emerging evidence suggests that nutrition can modulate the toxicity of environmental pollutants, which may alter human risks associated with toxicant exposures. Objectives: In this commentary, we discuss the basis for recommending that nutrition be considered a critical variable in disease outcomes associated with exposure to environmental pollutants, thus establishing the importance of incorporating nutrition within the context of cumulative risk assessment. Discussion: A convincing body of research indicates that nutrition is a modulator of vulnerability to environmental insults; thus, it is timely to consider nutrition as a vital component of human risk assessment. Nutrition may serve as either an agonist or an antagonist (e.g., high-fat foods or foods rich in antioxidants, respectively) of the health impacts associated with exposure to environmental pollutants. Dietary practices and food choices may help explain the large variability observed in human risk assessment. Conclusion: We recommend that nutrition and dietary practices be incorporated into future environmental research and the development of risk assessment paradigms. Healthful nutrition interventions might be a powerful approach to reduce disease risks associated with many environmental toxic insults and should be considered a variable within the context of cumulative risk assessment and, where appropriate, a potential tool for subsequent risk reduction. PMID:22357258

  2. Interspecies hybridization and recombination in Saccharomyces wine yeasts.

    PubMed

    Sipiczki, Matthias

    2008-11-01

    The ascomycetous yeasts traditionally referred to as the Saccharomyces sensu stricto complex are a group of closely related species that are isolated by a postzygotic barrier. They can easily hybridize; and their allodiploid hybrids propagate by mitotic divisions as efficiently as the parental strains, but can barely divide by meiosis, and thus rarely produce viable spores (sterile interspecies hybrids). The postzygotic isolation is not effective in allotetraploids that are able to carry out meiosis and produce viable spores (fertile interspecies hybrids). By application of molecular identification methods, double (Saccharomyces cerevisiae x Saccharomyces uvarum and S. cerevisiae x Saccharomyces kudriavzevii) and triple (S. cerevisiae x S. uvarum x S. kudriavzevii) hybrids were recently identified in yeast populations of fermenting grape must and cider in geographically distinct regions. The genetic analysis of these isolates and laboratory-bred hybrids revealed great variability of hybrid genome structures and demonstrated that the alloploid genome of the zygote can undergo drastic changes during mitotic and meiotic divisions of the hybrid cells. This genome-stabilization process involves loss of chromosomes and genes and recombination between the partner genomes. This article briefly reviews the results of the analysis of interspecies hybrids, proposes a model for the mechanism of genome stabilization and highlights the potential of interspecies hybridization in winemaking.

  3. Use of comparative genomics approaches to characterize interspecies differences in response to environmental chemicals: Challenges, opportunities, and research needs

    SciTech Connect

    Burgess-Herbert, Sarah L.; Euling, Susan Y.

    2013-09-15

    A critical challenge for environmental chemical risk assessment is the characterization and reduction of uncertainties introduced when extrapolating inferences from one species to another. The purpose of this article is to explore the challenges, opportunities, and research needs surrounding the issue of how genomics data and computational and systems level approaches can be applied to inform differences in response to environmental chemical exposure across species. We propose that the data, tools, and evolutionary framework of comparative genomics be adapted to inform interspecies differences in chemical mechanisms of action. We compare and contrast existing approaches, from disciplines as varied as evolutionary biology, systems biology, mathematics, and computer science, that can be used, modified, and combined in new ways to discover and characterize interspecies differences in chemical mechanism of action which, in turn, can be explored for application to risk assessment. We consider how genetic, protein, pathway, and network information can be interrogated from an evolutionary biology perspective to effectively characterize variations in biological processes of toxicological relevance among organisms. We conclude that comparative genomics approaches show promise for characterizing interspecies differences in mechanisms of action, and further, for improving our understanding of the uncertainties inherent in extrapolating inferences across species in both ecological and human health risk assessment. To achieve long-term relevance and consistent use in environmental chemical risk assessment, improved bioinformatics tools, computational methods robust to data gaps, and quantitative approaches for conducting extrapolations across species are critically needed. Specific areas ripe for research to address these needs are recommended.

  4. Use of the aquatic plant Elodea canadensis to assess toxicity and genotoxicity of Yenisei River sediments.

    PubMed

    Zotina, Tatiana A; Trofimova, Elena A; Medvedeva, Marina Yu; Dementyev, Dmitry V; Bolsunovsky, Alexander Ya

    2015-10-01

    The toxicity, cytotoxicity, and genotoxicity of bulk sediments from the Yenisei River (Siberia, Russia) were estimated in laboratory bioassays based on several endpoints in the aquatic plant Elodea canadensis. The bottom sediment samples were collected in the Yenisei River upstream and downstream of the sources of chemical and radioactive contamination. The testing revealed different sensitivities of Elodea endpoints to the quality of the bottom sediment: weight of shoots < length of shoots < mitotic index < length of roots < percentage of abnormal cells. The response of the genotoxicity endpoint (percentage of cells with chromosome abnormalities in roots of Elodea) was the highest in sediments with chemical pollution, whereas the highest inhibition of toxicity endpoints (shoot and root length) occurred in sediments with the highest level of radioactive pollution. The extreme response of Elodea endpoints to the quality of certain sediment samples may be regarded as related to the possible presence of unknown toxicants. The results show that E. canadensis can be used as an indicator species in laboratory contact testing of bottom sediment. The responses of shoot and root length growth endpoints of Elodea can be recommended as basic sensitivity indicators of bottom sediment toxicity. Analysis of cells carrying abnormal chromosomes in the apical root meristem of Elodea can be performed optionally in the same test to assess the genotoxicity of sediments. © 2015 SETAC.

  5. Aquatic toxicity assessment of the additive 6-methylcoumarine using four experimental systems.

    PubMed

    Jos, A; Repetto, G; Ríos, J C; Del Peso, A; Salguero, M; Cameán, A M

    2009-01-01

    The toxicity assessment of chemicals is one of the main issues in the current policies in order to protect the health of the environment and human beings. Food and cosmetic additives have been extensively studied in relation to their toxicity to humans, but data about their ecotoxicological effects are scarce. The aim of this study was to evaluate the toxic effects of the additive 6-methylcoumarine in the aquatic milieu using a test battery comprising experimental model systems from different trophic levels. The inhibition of bioluminiscence was studied in the bacteria Vibrio fischeri (decomposer), the inhibition of growth was evaluated in the alga Chlorella vulgaris (producer) and immobilization was studied in the cladoceran Daphnia magna (first consumer). Finally, several end points were evaluated in the RTG-2 salmonid fish cell line, including neutral red uptake, protein content, methylthiazol tetrazolium salt metabolization, glucose-6-phosphate dehydrogenase activity, lactate dehydrogenase activity and leakage, and morphology. The sensitivity of the test systems employed was as follows: V. fischeri > D. magna > C. vulgaris > RTG-2 cell line. The results show that 6-methylcoumarine is not expected to produce acute toxic effects on the aquatic biota. However, chronic and synergistic effects with other chemicals cannot be excluded and should be further investigated.

  6. Safety assessment of vitacoxib: Acute and 90-day sub-chronic oral toxicity studies.

    PubMed

    Wang, Jianzhong; Sun, Feifei; Tang, Shusheng; Zhang, Suxia; Lv, Pengyue; Li, Jing; Cao, Xingyuan

    2017-02-24

    Vitacoxib, is a newly developed coxibs NSAID (selective inhibitors of cyclooxygenase-2). To date, no experimental data have been published concerning its safety for use as an additive in the human diet. In the present study, we assessed the acute and sub-chronic toxicity of vitacoxib administered by gavage. The acute toxicity tests in Sprague Dawley (SD) rats and ICR mice demonstrated that vitacoxib at a dose of 5000 mg/kg BW failed to alter any of the parameters studied. In the 90-day sub-chronic toxicity test, vitacoxib was administered to SD rats at the doses of 0 (control), 5, 10, 20, 30, and 60 mg/kg BW. The results demonstrated that there were no significant differences for most indexes of sub-chronic toxicity throughout the experiment at the dose of 5-20 mg/kg BW, indicating no apparent dose-dependent. However, there were significant histopathology changes in the liver and kidney, and alterations in some biochemical parameters in the 60 mg/kg BW group. Based on these findings, the gavage LD50 was determined to be > 5000 mg/kg in SD rats and ICR mice, and the 90-day gavage no-observed-adverse-effect level (NOAEL) of vitacoxib was considered to be 20 mg/kg BW under the present study conditions.

  7. Bivalve embryo bioassay to assess the potential toxicity of dredged material before dumping

    SciTech Connect

    Quiniou, F.

    1995-12-31

    Dredged harbor sediments frequently contain a wide spectrum of contaminants in addition to a significant percentage of organic matter. Also, dredging and dumping activities into sea water, of these highly contaminated soil may induce a harmful effect on the environment. In France, in accordance with Oslo convention guidelines, a working group on dredging activities and environment (GEODE) created since 1991 decided to set up a pilot research program to assess the intrinsic toxicity of four harbor sludges. Intrinsic toxicity of harbor muds were tested by solid phase (whole sediment) and aqueous extract bioassays (sea water elutriates) using the sublethal toxicity test bivalve embryo bioassay (Crassostrea gigas). Elutriates enable them to detect the toxicity of contaminants which may be released in the soluble form into the water column during dredging operations. While, whole sediment integrate the synergistic effects of all the contaminants (hydrophilic and hydrophobic) including pore water. Bioassays results, correlated to chemical analysis, are compared to contaminant levels determined by French working group GEODE and Canadian sediment quality criteria.

  8. Toxicity of Lunar Dust in Lungs Assessed by Examining Biomarkers in Exposed Mice

    NASA Technical Reports Server (NTRS)

    Lam, C.-W.; James, J. T.; Zeidler-Erdely, P. C.; Castranova, V.; Young, S. H.; Quan, C. L.; Khan-Mayberry, N.; Taylor, L. A.

    2010-01-01

    NASA is contemplating to build an outpost on the Moon for prolonged human habitation and research. The lunar surface is covered by a layer of soil, of which the finest portion is highly reactive dust. Dust samples of respirable sizes were aerodynamically isolated from two lunar soil samples of different maturities (cosmic exposure ages) collected during the Apollo 16 mission. The lunar dust samples, TiO2, or quartz, suspended in normal saline were given to groups of 5 C57 male mice by intrapharyngeal aspiration at 0. 1, 0.3, or 1.0 mg/mouse. Because lunar dust aggregates rapidly in aqueous media, some tests were conducted with dusts suspended in Survanta/saline (1:1). The mice were euthanized 7 or 30 days later, and their lungs were lavaged to assess the presence of toxicity biomarkers in bronchioalveolar lavage fluids. The overall results showed that the two lunar dust samples were similar in toxicity, they were more toxic than T102 , but less toxic than quartz. This preliminary study is a part of the large study to obtain data for setting exposure limits for astronauts living on the Moon

  9. Assessment of toxic effects of triclosan on the terrestrial snail (Achatina fulica).

    PubMed

    Wang, Xiaonan; Liu, Zhengtao; Wang, Wanhua; Yan, Zhenguang; Zhang, Cong; Wang, Weili; Chen, Lihong

    2014-08-01

    Triclosan (TCS) is a broad-spectrum antimicrobial agent used in personal care products, and as a result, is widespread in the environment. Toxicity tests of TCS on aquatic organisms have been reported, but limited toxicity data on terrestrial species are available. In this study, the 28-d chronic toxicity of TCS on the biomass, shell diameter growth, and total food intake of the terrestrial snail Achatina fulica were tested. Moreover, biochemical responses, including changes in the activity of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), and the content of malondialdehyde (MDA), were examined after 14-d and 28-d exposure. Results showed that TCS had toxic effects on the biomass, shell diameter growth, and total food intake of A. fulica with no observed effect concentration (NOEC) values of 24 mg kg(-1). As for the antioxidant enzymes, TCS caused significant oxidative stress even at the low concentration of 24 mg kg(-1). The CAT and POD activities at the high concentrations of 200 and 340 mg kg(-1), respectively, were significantly inhibited. The SOD and CAT activity in treatments below 118 mg kg(-1) and the MDA content in all treatments showed dose-effect relationships. This study demonstrated that TCS caused adverse effects on terrestrial invertebrates, and provided valuable information for the risk assessment imposed by TCS in the terrestrial environment.

  10. Acute toxicity assessment of explosive-contaminated soil extracting solution by luminescent bacteria assays.

    PubMed

    Xu, Wenjie; Jiang, Zhenming; Zhao, Quanlin; Zhang, Zhenzhong; Su, Hongping; Gao, Xuewen; Ye, Zhengfang

    2016-11-01

    Explosive-contaminated soil is harmful to people's health and the local ecosystem. The acute toxicity of its extracting solution was tested by bacterial luminescence assay using three kinds of luminescent bacteria to characterize the toxicity of the soil. An orthogonal test L 16 (4(5)) was designed to optimize the soil extracting conditions. The optimum extracting conditions were obtained when the ultrasonic extraction time, ultrasonic extraction temperature, and the extraction repeat times were 6 h, 40 °C, and three, respectively. Fourier transform infrared spectroscopy (FTIR) results showed that the main components of the contaminated soil's extracting solution were 2,4-dinitrotoluene-3-sulfonate (2,4-DNT-3-SO3(-)); 2,4-dinitrotoluene-5-sulfonate (2,4-DNT-5-SO3(-)); and 2,6-dinitrotoluene (2,6-DNT). Compared with Photobacterium phosphoreum and Vibrio fischeri, Vibrio qinghaiensis sp. Nov. is more suitable for assessing the soil extracting solution's acute toxicity. Soil washing can remove most of the contaminants toxic to luminescent bacterium Vibrio qinghaiensis sp. Nov., suggesting that it may be a potential effective remediation method for explosive-contaminated soil.

  11. Ciguatera risk assessment in two toxic sites of French Polynesia using the receptor-binding assay.

    PubMed

    Darius, H T; Ponton, D; Revel, T; Cruchet, P; Ung, A; Tchou Fouc, M; Chinain, M

    2007-10-01

    Ciguatera Fish Poisoning (CFP) is a tropical syndrome well known in remote archipelagos where the population is still dependent on fish resources. In order to assess the ciguatera risk in two islands of French Polynesia, Tubuai (Australes) and Nuku Hiva (Marquesas), a study was carried out on both Gambierdiscus populations as well as on various fish species using the receptor-binding assay (RBA) to detect and quantify ciguatoxins. Relationship between RBA data and size or weight of fish was evaluated, and when only few individuals for a particular species were available the trophic level was used to help comparisons between studied areas. According to epidemiological data, toxic versus safe areas were explored and compared in both islands. In Tubuai Island, Gambierdiscus cells were surprisingly absent in the north area, considered as a toxic area, but almost 94% of fishes were classified as RBA+. In contrast, the south area, supposed to be safe, was evolving to be a risky area because of the presence of Gambierdiscus cells and 74% of fishes being RBA+. In Nuku Hiva Island, Gambierdiscus cells were present in the toxic areas, Anaho, Taiohae and Taipivei, with two toxic blooms in Anaho Bay, but none in Terre Déserte, the fishing area of this island. With RBA data, fishes were analyzed to be RBA+ at a high percentage in Anaho and Taiohae, higher than in Taipivei and Terre Déserte areas. In general, our findings were congruent with epidemiological data and the knowledge of local people only for risky fish species.

  12. Assessment of heavy metals bioavailability and toxicity toward Vibrio fischeri in sediment of the Huelva estuary.

    PubMed

    Rosado, Daniel; Usero, José; Morillo, José

    2016-06-01

    Relationship between toxicity and bioavailable metals in sediments from the Huelva estuary and its littoral of influence was analyzed. Toxicity was assessed with Microtox® bioassay using a marine luminescent bacterium: Vibrio fischeri. Bioavailable metals were considered as both, acid extractable fraction of BCR procedure and the sum of exchangeable and bound to carbonates fractions of Tessier sequential extraction. A bioavailable metals index was calculated to integrate results in a single figure. Toxicity and bioavailable metals showed a similar pattern. Higher levels were found in the estuary than in the littoral (140 TU/g). In Huelva estuary, highest levels were found in the Tinto estuary (5725 TU/g), followed by the Odiel estuary (5100 TU/g) and the Padre Santo Canal (2500 TU/g). Results in this area were well over than those in nearby estuaries. Furthermore, they are similar to or even higher than those in other polluted sediments around the world. Bioavailable metal index showed a stronger correlation with acid extractable fraction of BCR (R(2) = 0.704) than that for the sum of exchangeable and bound to carbonates fractions of Tessier (R(2) = 0.661). These results suggest that bioavailable metals are an important source of sediment toxicity in the Huelva estuary and its littoral of influence, an area with one of the highest mortality risks of Spain. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Assessing chemical toxicity of ionic liquids on Vibrio fischeri: Correlation with structure and composition.

    PubMed

    Montalbán, Mercedes G; Hidalgo, Juana M; Collado-González, Mar; Díaz Baños, F Guillermo; Víllora, Gloria

    2016-07-01

    One of the most important properties of ionic liquids is their non-volatility, making them potentially "green" alternatives to volatile organic compounds. However, they are widely soluble in water, meaning that they can be released into aquatic ecosystems and so contribute to water pollution. Nevertheless, although the toxicity of ILs has been widely assessed in the literature, the information is still scarce due to the great number of ionic liquids that have been synthesized. The present work reports the toxicity of twenty-nine imidazolium-, pyridinium- and ammonium-based ionic liquids towards the bioluminescent photobacterium Vibrio fischeri. When the effect of the type of anion, the length of the alkyl chain of the cation, the cation core and the presence of a functionalized side chain in the cation on ionic liquid toxicity were analyzed, the main influence was seen to be exercised by the alkyl chain length. A Quantitative Structure-Activity Relationships-based method was used to compare the experimental results with previously estimated values and very good agreement was obtained. A relationship between the toxicity, expressed as Log EC50, and the 1-octanol-water partition coefficient was established.

  14. Applicability of toxicity bioassays to ecological risk assessment in arid and semiarid ecosystems.

    SciTech Connect

    Markwiese, J. T.; Ryti, R. T.; Hooten, M. M.; Michael, D. I.; Hlohowskyj, I.; Environmental Assessment; Neptune and Company, Inc.

    2001-01-01

    Substantial tracts of land in the southwestern and western U.S. are undergoing or will require ERA. Toxicity bioassays employed in baseline ERAs are, for the most part. representative of mesic systems, and highly standardized test species (e.g., lettuce, earthworm) are generally not relevant to arid system toxicity testing. Conversely, relevant test species are often poorly characterized with regard to toxicant sensitivity and culture conditions. The applicability of toxicity bioassays to ecological risk assessment in arid and semiarid ecosystems was reviewed for bacteria and fungi, plants, terrestrial invertebrates, and terrestrial vertebrates. Bacteria and fungi are critical to soil processes, and understanding their ecology is important to understanding the ecological relevance of bioassays targeting either group. Terrestrial bacteria require a water film around soil particles to be active, while soil fungi can remain active in extremely dry soils. It is therefore expected that fungi will be of greater importance to arid and semiarid systems (Whitford 1989). If microbial processes are to be measured in soils of arid environments, it is recommended that bioassays target fungi. Regardless of the taxa studied, problems are associated with the standardization and interpretability of microbial tests, and regulatory acceptance may hinder widespread incorporation of microbial toxicity bioassays in arid system risk assessments. Plant toxicity bioassays are gaining recognition as sensitive indicators of soil conditions because they can provide a cost-effective and relatively rapid assessment of soil quality for both pre- and postremediation efforts. Although the choices of suitable plant species for assessing mesic system soils are numerous, the choices for arid system soils are limited. Guidance is provided for evaluating plant species with regard to their suitability for serving as representative arid system flora. Terrestrial invertebrates can survive and flourish in

  15. Comparative assessment of three in vitro exposure methods for combustion toxicity.

    PubMed

    Lestari, Fatma; Markovic, Boban; Green, Anthony R; Chattopadhyay, Gautam; Hayes, Amanda J

    2006-01-01

    A comparative assessment of three approaches for the use of human cells in vitro to investigate combustion toxicity was conducted. These included one indirect and two direct (passive and dynamic) exposure methods. The indirect method used an impinger system in which culture medium was used to trap the toxicants, whilst the direct exposure involved the use of a Horizontal Harvard Navicyte Chamber at the air/liquid interface. The cytotoxic effects of thermal decomposition products were assessed using the MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay (Promega) on a selection of human cells including: HepG2, A549 and skin fibroblasts. A small scale laboratory fire test using a vertical tube furnace was designed for the generation of combustion products. Polymethyl methacrylate (PMMA) was selected as a model polymer to study the cytotoxic effects of combustion products. NOAEC (no observable adverse effect concentration), IC10 (10% inhibitory concentration), IC50 (50% inhibitory concentration) and TLC (total lethal concentration) values were determined from dose response curves. Assessment using the NRU (neutral red uptake) and ATP (adenosine triphosphate) assays on human lung derived cells (A549) was also undertaken. Comparison between in vitro cytotoxicity results against published toxicity data for PMMA combustion and predicted LC50 (50% lethal concentration) values calculated from identified compounds using GCMS (gas chromatography mass spectrometry) was determined. The results suggested that the indirect exposure method did not appear to simulate closely exposure via inhalation, whilst exposure at the air/liquid interface by using the dynamic method proved to be a more representative method of human inhalation. This exposure method may be a potential system for in vitro cytotoxicity testing in combustion toxicity.

  16. Application of short-term inhalation studies to assess the inhalation toxicity of nanomaterials

    PubMed Central

    2014-01-01

    Background A standard short-term inhalation study (STIS) was applied for hazard assessment of 13 metal oxide nanomaterials and micron-scale zinc oxide. Methods Rats were exposed to test material aerosols (ranging from 0.5 to 50 mg/m3) for five consecutive days with 14- or 21-day post-exposure observation. Bronchoalveolar lavage fluid (BALF) and histopathological sections of the entire respiratory tract were examined. Pulmonary deposition and clearance and test material translocation into extra-pulmonary organs were assessed. Results Inhaled nanomaterials were found in the lung, in alveolar macrophages, and in the draining lymph nodes. Polyacrylate-coated silica was also found in the spleen, and both zinc oxides elicited olfactory epithelium necrosis. None of the other nanomaterials was recorded in extra-pulmonary organs. Eight nanomaterials did not elicit pulmonary effects, and their no observed adverse effect concentrations (NOAECs) were at least 10 mg/m3. Five materials (coated nano-TiO2, both ZnO, both CeO2) evoked concentration-dependent transient pulmonary inflammation. Most effects were at least partially reversible during the post-exposure period. Based on the NOAECs that were derived from quantitative parameters, with BALF polymorphonuclear (PMN) neutrophil counts and total protein concentration being most sensitive, or from the severity of histopathological findings, the materials were ranked by increasing toxic potency into 3 grades: lower toxic potency: BaSO4; SiO2.acrylate (by local NOAEC); SiO2.PEG; SiO2.phosphate; SiO2.amino; nano-ZrO2; ZrO2.TODA; ZrO2.acrylate; medium toxic potency: SiO2.naked; higher toxic potency: coated nano-TiO2; nano-CeO2; Al-doped nano-CeO2; micron-scale ZnO; coated nano-ZnO (and SiO2.acrylate by systemic no observed effect concentration (NOEC)). Conclusion The STIS revealed the type of effects of 13 nanomaterials, and micron-scale ZnO, information on their toxic potency, and the location and reversibility of effects

  17. Dioxin-like and non-dioxin-like toxic effects of polychlorinated biphenyls (PCBs): implications for risk assessment.

    PubMed

    Giesy, J P; Kannan, K; Blankenship, A L; Jones, P D; Hilscherova, K

    2000-07-01

    Polychlorinated biphenyls (PCBs) are persistent, bioaccumulative and toxic contaminants in the environment. Individual PCB congeners exhibit different physico-chemical properties and biological activities which result in different environmental distributions and toxicity profiles. The variable composition of PCB residues in environmental matrices and their different mechanisms of toxicity, complicate the development of scientifically based regulations for the risk assessment. Various approaches for the assessment of risks of PCBs have been critically examined. Recent developments in the toxic equivalency factor (TEF) approach for the assessment of toxic effects due to dioxin-like PCBs have been examined. PCB exposure studies which describe non-dioxin-like toxic effects, particularly neuro-behavioral effects and their effective doses in animals were also considered. A comparative assessment of effective doses for dioxin-like and non-dioxin-like effects by PCBs was made to evaluate the relative significance of non-ortho and ortho-substituted PCBs in risk assessment. Using mink as an example, relative merits and implications of using TEF and total PCB approaches for assessing the potential for toxic effects in wildlife was examined.

  18. Life cycle toxicity assessment of earthworms exposed to cadmium-contaminated soils.

    PubMed

    Chen, Wei-Yu; Li, Wen-Hsuan; Ju, Yun-Ru; Liao, Chung-Min; Liao, Vivian Hsiu-Chuan

    2017-01-27

    Cadmium (Cd) is of great concern in the soil environment and it can damage terrestrial organisms. The purpose of this study was to employ a toxicokinetic/toxicodynamic (TK/TD) approach to investigate the effects of toxicologically relevant Cd accumulation on the life cycle growth of earthworms (Lumbricus rubellus and Eisenia fetida) and to assess potential terrestrial ecosystem risk. We reanalyzed growth toxicity and whole body and pellet accumulation data linked with TK/TD and life cycle growth models to estimate key rate constants. The growth risk of earthworms exposed to Cd was also assessed. This study found that the estimated whole body killing rate constant (0.114 g d μg(-1)) was much lower than that of pellet (0.248 g d μg(-1)). The recovery rate constant for whole body (6.02 d(-1)) was much higher than that of pellet (2.91 d(-1)). We also employed a life cycle-based probabilistic risk assessment model to estimate the growth inhibition risk for earthworms in response to environmentally relevant concentrations of Cd in Taiwan. Results showed that earthworms had a 90% growth inhibition probability risk of body weight, which was lower than 872.33 mg based on assessment of toxicologically relevant Cd accumulation. This study suggests that toxicologically relevant Cd accumulation could accurately reflect the capacity of Cd toxicity to earthworms. The integrated life cycle toxicity of earthworms exposed to Cd in this study provides a robust and applicable tool for the management of ecological risk assessment of Cd-contaminated soil.

  19. Toxicokinetics/toxicodynamics links bioavailability for assessing arsenic uptake and toxicity in three aquaculture species.

    PubMed

    Chen, Wei-Yu; Liao, Chung-Min

    2012-11-01

    The purpose of this study was to link toxicokinetics/toxicodynamics (TK/TD) and bioavailability-based metal uptake kinetics to assess arsenic (As) uptake and bioaccumulation in three common farmed species of tilapia (Oreochromis mossambicus), milkfish (Chanos chanos), and freshwater clam (Corbicula fluminea). We developed a mechanistic framework by linking damage assessment model (DAM) and bioavailability-based Michaelis-Menten model for describing TK/TD and As uptake mechanisms. The proposed model was verified with published acute toxicity data. The estimated TK/TD parameters were used to simulate the relationship between bioavailable As uptake and susceptibility probability. The As toxicity was also evaluated based on a constructed elimination-recovery scheme. Absorption rate constants were estimated to be 0.025, 0.016, and 0.175 mL g(-1) h(-1) and As uptake rate constant estimates were 22.875, 63.125, and 788.318 ng g(-1) h(-1) for tilapia, milkfish, and freshwater clam, respectively. Here we showed that a potential trade-off between capacities of As elimination and damage recovery was found among three farmed species. Moreover, the susceptibility probability can also be estimated by the elimination-recovery relations. This study suggested that bioavailability-based uptake kinetics and TK/TD-based DAM could be integrated for assessing metal uptake and toxicity in aquatic organisms. This study is useful to quantitatively assess the complex environmental behavior of metal uptake and implicate to risk assessment of metals in aquaculture systems.

  20. MOAtox: A comprehensive mode of action and acute aquatic toxicity database for predictive model development.

    PubMed

    Barron, M G; Lilavois, C R; Martin, T M

    2015-04-01

    The mode of toxic action (MOA) has been recognized as a key determinant of chemical toxicity and as an alternative to chemical class-based predictive toxicity modeling. However, the development of quantitative structure activity relationship (QSAR) and other models has been limited by the availability of comprehensive high quality MOA and toxicity databases. The current study developed a dataset of MOA assignments for 1213 chemicals that included a diversity of metals, pesticides, and other organic compounds that encompassed six broad and 31 specific MOAs. MOA assignments were made using a combination of high confidence approaches that included international consensus classifications, QSAR predictions, and weight of evidence professional judgment based on an assessment of structure and literature information. A toxicity database of 674 acute values linked to chemical MOA was developed for fish and invertebrates. Additionally, species-specific measured or high confidence estimated acute values were developed for the four aquatic species with the most reported toxicity values: rainbow trout (Oncorhynchus mykiss), fathead minnow (Pimephales promelas), bluegill (Lepomis macrochirus), and the cladoceran (Daphnia magna). Measured acute toxicity values met strict standardization and quality assurance requirements. Toxicity values for chemicals with missing species-specific data were estimated using established interspecies correlation models and procedures (Web-ICE; http://epa.gov/ceampubl/fchain/webice/), with the highest confidence values selected. The resulting dataset of MOA assignments and paired toxicity values are provided in spreadsheet format as a comprehensive standardized dataset available for predictive aquatic toxicology model development.

  1. STRUCTURE-ACTIVITY APPROACHES AND DATA EXPLORATION TOOLS FOR PRIORITIZING AND ASSESSING THE TOXICITY OF HAZARDOUS AIR POLLUTANTS

    EPA Science Inventory


    STRUCTURE-ACTIVITY APPROACHES AND DATA EXPLORATION TOOLS FOR PRIORITIZING AND ASSESSING THE TOXICITY OF HAZARDOUS AIR POLLUTANTS

    Hazardous Air Pollutants (HAPs) refers to a set of structurally diverse environmental chemicals, many with limited toxicity data, that have...

  2. Modified Whole Effluent Toxicity Test to Assess and Decouple Wastewater Effects from Environmental Gradients

    PubMed Central

    Sauco, Sebastián; Gómez, Julio; Barboza, Francisco R.; Lercari, Diego; Defeo, Omar

    2013-01-01

    Environmental gradients and wastewater discharges produce aggregated effects on marine populations, obscuring the detection of human impact. Classical assessment methods do not include environmental effects in toxicity tests designs, which could lead to incorrect conclusions. We proposed a modified Whole Effluent Toxicity test (mWET) that includes environmental gradients in addition to effluent dilutions, together with the application of Generalized Linear Mixed Models (GLMM) to assess and decouple those effects. We tested this approach, analyzing the lethal effects of wastewater on a marine sandy beach bivalve affected by an artificial canal freshwater discharge used for rice crops irrigation. To this end, we compared bivalve mortality between canal water dilutions (CWd) and salinity controls (SC: without canal water). CWd were prepared by diluting the water effluent (sampled during the pesticide application period) with artificial marine water. The salinity gradient was included in the design by achieving the same final salinities in both CWd and SC, allowing us to account for the effects of salinity by including this variable as a random factor in the GLMM. Our approach detected significantly higher mortalities in CWd, indicating potential toxic effects of the effluent discharge. mWET represents an improvement over the internationally standardized WET tests, since it considers environmental variability and uses appropriate statistical analyses. PMID:23755304

  3. Assessing time-integrated dissolved concentrations and predicting toxicity of metals during diel cycling in streams

    USGS Publications Warehouse

    Balistrieri, Laurie S.; Nimick, David A.; Mebane, Christopher A.

    2012-01-01

    Evaluating water quality and the health of aquatic organisms is challenging in systems with systematic diel (24 hour) or less predictable runoff-induced changes in water composition. To advance our understanding of how to evaluate environmental health in these dynamic systems, field studies of diel cycling were conducted in two streams (Silver Bow Creek and High Ore Creek) affected by historical mining activities in southwestern Montana. A combination of sampling and modeling tools were used to assess the toxicity of metals in these systems. Diffusive Gradients in Thin Films (DGT) samplers were deployed at multiple time intervals during diel sampling to confirm that DGT integrates time-varying concentrations of dissolved metals. Thermodynamic speciation calculations using site specific water compositions, including time-integrated dissolved metal concentrations determined from DGT, and a competitive, multiple-metal biotic ligand model incorporated into the Windemere Humic Aqueous Model Version 6.0 (WHAM VI) were used to determine the chemical speciation of dissolved metals and biotic ligands. The model results were combined with previously collected toxicity data on cutthroat trout to derive a relationship that predicts the relative survivability of these fish at a given site. This integrative approach may prove useful for assessing water quality and toxicity of metals to aquatic organisms in dynamic systems and evaluating whether potential changes in environmental health of aquatic systems are due to anthropogenic activities or natural variability.

  4. Safety assessment comparison methodology for toxic and radioactive wastes (SACO version 1.0)

    SciTech Connect

    Torres, C.; Simon, I.; Agueero, A.; Little, R.H.; Smith, G.M.

    1993-12-31

    As part of a research contract jointly funded by the Commission of the European Communities (CEC) and Empresa Nacional de Residuos Radiactivos S.A. (Enresa, Spain), the Instituto de Medioambiente of the CIEMAT Research Centre and Intera (UK) are developing and testing a general methodology (SACO) to assess the post-disposal environmental impact produced by waste disposal practices. The scope of the methodology includes toxic, radioactive and mixed hazardous wastes. The term toxic is interpreted broadly to include any kind of liquid or solid non-radioactive waste which could give rise to some detrimental environmental effects post-disposal. Radioactive wastes considered include the full range from low to high level solid wastes arising inside and outside the nuclear power industry. Mixed hazardous waste is taken to be waste presenting both radioactive and other toxic hazard potential. In this paper SACO version 1.0 methodology is presented and it is applied to the assessment of the impact of shallow and deep disposal of waste.

  5. Assessment of chronic toxicity from stormwater runoff in Lincoln Creek, Milwaukee, WI

    SciTech Connect

    Kleist, J.; Crunkilton, R.

    1995-12-31

    Stormwater runoff is believed to be responsible for a severely degraded biotic community in Lincoln Creek, a stream which drains portions of metropolitan Milwaukee. A previous study using Ceriodaphnia dubia and Pimephales promelas indicated little or no acute toxicity could be attributed to stormwater runoff. The purpose of this study was to assess the potential for chronic toxicity in the stream during periods of stormwater runoff. Reproduction and survival in Daphnia magna, and growth and survival in P. promelas were monitored to assess chronic effects. Seven consecutive 14 day tests were performed between June and September, 1994, in eighteen flow-through aquaria housed within a US Geological Survey gauging station located adjacent to Lincoln Creek. Mortality in D. magna consistently did not occur before day 4 of exposure, but averaged 64% at day 14. Reproduction in D. magna and growth in P. promelas in surviving individuals was not significantly reduced; all effects were manifested as mortality. Results of data analysis after 14 days of exposure contrast markedly with analysis made earlier in the same test. Statistical interpretation of the mortality data at typical endpoints of 48 hours for invertebrates and 96 hours for fish failed to identify adverse impacts of stormwater runoff the authors observed in longer exposures. Short-term toxicity tests appear insensitive to the detection of contaminant related effects. Long-term tests (greater than 7 days) were needed to identify adverse biological impacts that could in part explain the severely degraded biotic community of this urban stream.

  6. Acute toxicity assessment of choline by inhalation, intraperitoneal and oral routes in Balb/c mice.

    PubMed

    Mehta, Amit Kumar; Arora, Naveen; Gaur, Shailendra Nath; Singh, Bhanu Pratap

    2009-08-01

    Studies suggest that choline has potential to be used as a dietary supplement and a drug for immune inflammatory diseases like asthma and rhinitis. But there are apprehensions regarding adverse effects of choline when given orally in high doses. To address this knowledge gap, toxicity assessment of choline chloride was carried out by intranasal (i.n.), oral and intraperitoneal (i.p.) routes in Balb/c mice for 28days. Body weight, food and water consumption of mice were recorded daily. Hematology and clinical chemistry were assessed to check hepatocellular functions and morphological alterations of the cells. Splenocyte counts were analysed for evaluating cellular immunity. Liver function test was performed by assaying different enzyme systems in serum such as, urea, blood urea nitrogen (BUN), creatinine, alanine aminotransferase (ALT), and aspartate aminotransferase (AST). Body weight, food and water consumption did not differ between mice treated with choline and the saline control group. Hematologic and biochemical variables were not affected with any increase in serum toxicity marker enzymes indicating normal liver functioning. Choline administration did not affect total cholesterol and high density lipoprotein levels as compared to their respective controls. Urea and blood urea nitrogen levels in choline treated mice were not different than controls. Creatinine level was, however, higher than control in i.p. treatment group, but other parameters were normal. In conclusion, the repeated consumption of choline chloride via i.n. and oral or i.p. routes did not cause toxicity in mice in the toxicological endpoints examined.

  7. Zebrafish and clean water technology: assessing soil bioretention as a protective treatment for toxic urban runoff.

    PubMed

    McIntyre, J K; Davis, J W; Incardona, J P; Stark, J D; Anulacion, B F; Scholz, N L

    2014-12-01

    Urban stormwater contains a complex mixture of contaminants that can be acutely toxic to aquatic biota. Green stormwater infrastructure (GSI) is a set of evolving technologies intended to reduce impacts on natural systems by slowing and filtering runoff. The extent to which GSI methods work as intended is usually assessed in terms of water quantity (hydrology) and quality (chemistry). Biological indicators of GSI effectiveness have received less attention, despite an overarching goal of protecting the health of aquatic species. Here we use the zebrafish (Danio rerio) experimental model to evaluate bioinfiltration as a relatively inexpensive technology for treating runoff from an urban highway with dense motor vehicle traffic. Zebrafish embryos exposed to untreated runoff (48-96h; six storm events) displayed an array of developmental abnormalities, including delayed hatching, reduced growth, pericardial edema, microphthalmia (small eyes), and reduced swim bladder inflation. Three of the six storms were acutely lethal, and sublethal toxicity was evident across all storms, even when stormwater was diluted by as much as 95% in clean water. As anticipated from exposure to cardiotoxic polycyclic aromatic hydrocarbons (PAHs), untreated runoff also caused heart failure, as indicated by circulatory stasis, pericardial edema, and looping defects. Bioretention treatment dramatically improved stormwater quality and reversed nearly all forms of developmental toxicity. The zebrafish model therefore provides a versatile experimental platform for rapidly assessing GSI effectiveness.

  8. A statistical evaluation of the effects of gender differences in assessment of acute inhalation toxicity

    PubMed Central

    Price, Charlotte; Stallard, Nigel; Creton, Stuart; Indans, Ian; Guest, Robert; Griffiths, David; Edwards, Philippa

    2010-01-01

    Acute inhalation toxicity of chemicals has conventionally been assessed by the median lethal concentration (LC50) test (organisation for economic co-operation and development (OECD) TG 403). Two new methods, the recently adopted acute toxic class method (ATC; OECD TG 436) and a proposed fixed concentration procedure (FCP), have recently been considered, but statistical evaluations of these methods did not investigate the influence of differential sensitivity between male and female rats on the outcomes. This paper presents an analysis of data from the assessment of acute inhalation toxicity for 56 substances. Statistically significant differences between the LC50 for males and females were found for 16 substances, with greater than 10-fold differences in the LC50 for two substances. The paper also reports a statistical evaluation of the three test methods in the presence of unanticipated gender differences. With TG 403, a gender difference leads to a slightly greater chance of under-classification. This is also the case for the ATC method, but more pronounced than for TG 403, with misclassification of nearly all substances from Globally Harmonised System (GHS) class 3 into class 4. As the FCP uses females only, if females are more sensitive, the classification is unchanged. If males are more sensitive, the procedure may lead to under-classification. Additional research on modification of the FCP is thus proposed. PMID:20488841

  9. Acute toxicity assessment of camphor in biopesticides by using Daphnia magna and Danio rerio.

    PubMed

    Yim, Eun-Chae; Kim, Hyeon-Joe; Kim, Seong-Jun

    2014-01-01

    An ecofriendly alternative to chemical pesticides is bio-pesticides, which are derived from natural sources. The interest in bio-pesticides is based on the disadvantages associated with chemical pesticides. We conducted acute toxicity assessments of camphor, a major component of bio-pesticides, by using Daphnia magna (D. magna) as well as assessed the morphological abnormalities that occurred in Danio rerio (D. rerio) embryos. The median effective concentration of camphor on D. magna after 48 hours was 395.0 μM, and the median lethal concentration on D. rerio embryos after 96 hours was 838.6 μM. The no observed effect concentration and predicted no effect concentration of camphor on D. magna, which was more sensitive than D. rerio, were calculated as 55.2 μM and 3.95 μM, respectively. Morphological abnormalities in D. rerio embryos exposed to camphor increased over time. Coagulation, delayed hatching, yolk sac edema, pericardial edema, and pigmentation of embryos mainly appeared between 24 and 48 hours. Further, symptoms of scoliosis and head edema occurred after 72 hours. In addition, bent tails, ocular defects and collapsed symptoms of fertilized embryonic tissue were observed after 96 hours. The camphor toxicity results suggest that continuous observations on the ecosystem are necessary to monitor toxicity in areas where biological pesticides containing camphor are sprayed.

  10. Acute toxicity assessment of camphor in biopesticides by using Daphnia magna and Danio rerio

    PubMed Central

    Yim, Eun-Chae; Kim, Hyeon-Joe; Kim, Seong-Jun

    2014-01-01

    Objectives An ecofriendly alternative to chemical pesticides is bio-pesticides, which are derived from natural sources. The interest in bio-pesticides is based on the disadvantages associated with chemical pesticides. Methods We conducted acute toxicity assessments of camphor, a major component of bio-pesticides, by using Daphnia magna (D. magna) as well as assessed the morphological abnormalities that occurred in Danio rerio (D. rerio) embryos. Results The median effective concentration of camphor on D. magna after 48 hours was 395.0 μM, and the median lethal concentration on D. rerio embryos after 96 hours was 838.6 μM. The no observed effect concentration and predicted no effect concentration of camphor on D. magna, which was more sensitive than D. rerio, were calculated as 55.2 μM and 3.95 μM, respectively. Morphological abnormalities in D. rerio embryos exposed to camphor increased over time. Coagulation, delayed hatching, yolk sac edema, pericardial edema, and pigmentation of embryos mainly appeared between 24 and 48 hours. Further, symptoms of scoliosis and head edema occurred after 72 hours. In addition, bent tails, ocular defects and collapsed symptoms of fertilized embryonic tissue were observed after 96 hours. Conclusions The camphor toxicity results suggest that continuous observations on the ecosystem are necessary to monitor toxicity in areas where biological pesticides containing camphor are sprayed. PMID:25234414

  11. Rapid assessment of chemical contamination and toxicity equivalents at a hazardous waste site

    SciTech Connect

    Mashburn, W.E.; Johnson, K.A.; Weisskopf, C.P.; Dickerson, R.L.

    1994-12-31

    Utilizing a new monitoring technique, contaminant burdens are assessed at a hazardous waste site containing polychlorinated biphenyls (PCBs). This approach utilizes a sampling technique which allows for chemical characterization without the costly and time consuming collection and transportation of large samples from the field to the laboratory. In addition, this approach will allow for determination of toxicity equivalents without the use of living organisms. Soil extracts are obtained from a passive sampling device (PSD) constructed of a polymeric membrane containing C{sub 18} sorbent which measures the bioavailable chemical contaminants. The PSDs are deployed in the soil, retrieved from the field and then eluted in the laboratory. The extracts are used for quantitation and determination of chemical identity, concentration, and biological significance. An enzyme induction assay is used to assess toxicity equivalents of the environmental samples. The H411E rat hepatoma cell line was dosed with differing concentrations of PCB Aroclor 1254 to establish a dose-response relationship based on the induction of CytochromeP-450 by measuring the EROD/PROD activity. The cells were then dosed with serial dilutions of PSD extracts to determine toxicity equivalents. A correlation between contaminant concentration and enzyme induction was found with the extracts.

  12. The Applicability of Oxidative Stress Biomarkers in Assessing Chromium Induced Toxicity in the Fish Labeo rohita

    PubMed Central

    Khare, Ankur; Dange, Swati

    2014-01-01

    The evaluation of metal's toxicity in freshwater is one of the imperative areas of research and there is an emergent concern on the development of techniques for detecting toxic effects in aquatic animals. Oxidative stress biomarkers are very useful in assessing the health of aquatic life and more in depth studies are necessary to establish an exact cause effect relationship. Therefore, to study the effectiveness of this approach, a laboratory study was conducted in the fish Labeo rohita as a function of hexavalent chromium and the toxicity indices using a battery of oxidative stress biomarkers such as catalase (CAT), superoxide dismutase (SOD), and glutathione reductase (GR) in the liver, muscle, gills, and brain have been studied along with biometric parameters, behavioral changes, and Cr bioaccumulation. A significant increased HSI was observed in contrast to CF which reduced significantly. SOD, CAT, and GR activity increased significantly in all the tissues of treated fishes. The bioaccumulation of Cr was highest in liver followed by gills, muscle, and brain. This study highlights the significance of using a set of integrated biomarker and advocate to include these parameters in National Water Quality Monitoring Program in areas potentially polluted with metals to assess the health of the ecosystem. PMID:25302308

  13. Assessment of toxicity and biodegradability on activated sludge of priority and emerging pollutants.

    PubMed

    Tobajas, Montserrat; Verdugo, Verónica; Polo, Alicia M; Rodriguez, Juan J; Mohedano, Angel F

    2016-01-01

    Several methods for evaluating the toxicity and biodegradability of hazardous pollutants (chlorinated compounds, chemical additives and pharmaceuticals) have been studied in this work. Different bioassays using representative bacteria of marine and terrestrial ecosystems such as Vibrio fischeri and Pseudomonas putida have been used to assess the ecotoxicity. Activated sludge was used to analyse the effect of those pollutants in a biological reactor of a sewage treatment plant (STP). The results demonstrate that none of the compounds is toxic to activated sludge, except ofloxacin to P. putida. The additives tested can be considered moderately toxic according to the more sensitive V. fischeri assays, whereas the EC50 values of the pharmaceuticals depend on the specific microorganism used in each test. Regarding the biodegradability, respirometric measurements were carried out for fast biodegradability assessment and the Zahn-Wellens test for inherent biodegradability. The evolution of the specific oxygen uptake rate (SOUR) showed that only diethyl phthalate was easily biodegradable and acetylsalicylic acid was partially biodegradable (98% and 65% degradation, respectively). The persistence of dichloromethane, ofloxacin and hidrochlorothiazide was confirmed along the 28 days of the Zahn-Wellens test whereas 1,1,1-trichloroethane showed inherent biodegradability (74% removal). Most of the chlorinated compounds, pharmaceuticals, bisphenol A and ethylenediaminetetraacetic acid were partially degraded in 28 d with total organic carbon (TOC) reduction ranging from 21% to 51%. Sulphamethoxazole showed certain biodegradation (50% removal) with TOC decrease around 31%, which indicates the formation of non-biodegradable by-products.

  14. Ability of radiation therapists to assess radiation-induced skin toxicity.

    PubMed

    Acharya, Urvi; Cox, Jennifer; Rinks, Marianne; Gaur, Pankaj; Back, Michael

    2013-06-01

    Radiation therapy has seen enhancement of the radiation therapist (RT) role, with RTs and nurses performing duties that were traditionally in the radiation oncologist's (RO) domain. This study aimed to assess whether RTs can consistently grade radiation-induced skin toxicity and their concordance with the gradings given by ROs. Digital photographs of skin reactions were taken at weeks 1, 3 and 6 of radiotherapy on nine patients with breast cancer. The randomly ordered photographs were reviewed once by eight ROs and four RO registrars and on two occasions separated by 6 weeks by 17 RTs. All graded the skin toxicities using the revised Radiation Therapy Oncology Group system. No significant difference was seen between the median scores of the RTs at the first scoring session and the RO/Registrar group. The RTs at both measurement times showed greater inter-rater reliability than the RO/Registrars (W = 0.6866, time 1 and 0.6981 time 2, vs. 0.6517), with the experienced RTs the most consistent (W = 0.7078). The RTs also showed high intra-rater reliability (rho = 0.8461, P < 0.0010). These results from RTs with no specific preparation indicate that experienced RTs could assess breast cancer skin toxicity as part of their role. © 2013 The Authors. Journal of Medical Imaging and Radiation Oncology © 2013 The Royal Australian and New Zealand College of Radiologists.

  15. Spatial distribution and toxicity assessment of heavy metals in sediments of Liaohe River, northeast China.

    PubMed

    He, Yan; Meng, Wei; Xu, Jian; Zhang, Yuan; Liu, Sisi; Guo, Changsheng

    2015-10-01

    Twenty-four surface sediment samples were collected from Liaohe River in June 2014 for the analysis of total concentrations of Cu, Pb, Zn, Cd, Ni, Fe, and Mn. The spatial distribution of heavy metals in Liaohe River was site specific, with Hun River as the most polluted river mainly affected by industrial and human activities. The contents of acid-volatile sulfide (AVS) and simultaneously extracted metals (SEMs) in Liaohe River varied significantly, ranging from 0.03 to 19.4 μmol/g and 0.14 to 10.8 μmol/g, respectively. Sulfate-reducing bacteria (SRB) community size, organic matter and sulfate availability, and sediment redox status may be the main factors affecting the AVS distribution. Among all the acid-extracted metals, Zn was dominant in all samples, whereas much more toxic Cd contributed less than 1.0 % to the total SEMs. Sediment quality guidelines (SQGs) and AVS-SEM models were used to predict the sediment toxicity. Results revealed that only a small portion of sites exhibited potential metal toxicity to aquatic biota, while adverse effects should rarely occur in majority of sites. Comparison of the two assessment methods showed inconsistent results, indicating that each method had its own limitations. The combination of different methods will be more convincing as to the sediment quality assessment.

  16. Risk assessment of toxic heavy metals in the abandoned metal mine areas, Korea

    NASA Astrophysics Data System (ADS)

    Lee, J. S.; Chon, H. T.

    2003-04-01

    The purpose of this study is to assess the risk of adverse health effects on human exposure to toxic heavy metals influenced by past mining activities. Environmental geochemical survey was undertaken in the abandoned metal mine areas (Dongil Au-Ag-Cu-Zn mine, Okdong Cu-Pb-Zn mine, Myungbong Au-Ag mine). After appropriate sample preparation, tailings, soils, crop plants and groundwaters were analyzed for As, Cd, Cu, Pb and Zn by ICP-AES and ICP-MS. Health risk assessment of toxic heavy metals has been performed with chemical analytical data for environmental media. Arsenic and other heavy metals are highly elevated in the tailings from the Dongil mine (8,720 As mg/kg, 5.9 Cd mg/kg, 3,610 Cu mg/kg, 5,850 Pb mg/kg, 630 Zn mg/kg), but heavy metals except As from the Okdong mine (72 As mg/kg, 53.6 Cd mg/kg, 910 Cu mg/kg, 1,590 Pb mg/kg, 5,720 Zn mg/kg) and only As from the Myungbong mine (5,810 As mg/kg). These significant concentrations can impact on soils and waters around the tailing files. Also, elevated levels of As, Cd, Cu, Pb and Zn are found in agricultural soils from these mine areas. Risk assessment modeling is subdivided into main four stages, i.e. hazard identification, exposure assessment, toxicity (dose-response) assessment and risk characterization. In order to assess exposure it is necessary to calculate the average daily dose (ADD) of contaminant via the three identified pathways (soil, groundwater and food (rice grain) pathways). In dose-response assessment for non-carcinogens, reference doses (RfD) are calculated and that for carcinogens, slope factors (SF) are obtained by US-EPA IRIS database. In risk characterization, the results of toxicity assessment and exposure assessment are integrated to arrive at quantitative estimates of cancer risks and hazard quotients. Toxic (non-cancer) risks are indicated in terms of a hazard quotient (H.Q.) and this risk exists for H.Q.>1. The H.Q. values for only As from the Dongil and Myungbong mine areas are 2.1 and

  17. Toxicity assessment of individual ingredients of synthetic-based drilling muds (SBMs).

    PubMed

    Bakhtyar, Sajida; Gagnon, Marthe Monique

    2012-09-01

    Synthetic-based drilling muds (SBMs) offer excellent technical characteristics while providing improved environmental performance over other drilling muds. The low acute toxicity and high biodegradability of SBMs suggest their discharge at sea wo