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Sample records for toxic oxygen-derived species

  1. VORICONAZOLE TOXICITY IN MULTIPLE PENGUIN SPECIES.

    Science.gov (United States)

    Hyatt, Michael W; Georoff, Timothy A; Nollens, Hendrik H; Wells, Rebecca L; Clauss, Tonya M; Ialeggio, Donna M; Harms, Craig A; Wack, Allison N

    2015-12-01

    Aspergillosis is a common respiratory fungal disease in penguins managed under human care. Triazole antifungal drugs, including itraconazole, are most commonly used for treatment; however, itraconazole treatment failures from drug resistance are becoming more common, requiring newer treatment options. Voriconazole, a newer triazole, is being used more often. Until recently, no voriconazole pharmacokinetic studies had been performed in penguins, leading to empiric dosing based on other avian studies. This has led to increased anecdotal reporting of apparent voriconazole toxicity in penguins. This report describes 18 probable and 6 suspected cases of voriconazole toxicity in six penguin species from nine institutions: 12 African penguins (Spheniscus demersus), 5 Humboldt penguins (Spheniscus humboldti), 3 Magellanic penguins (Spheniscus magellanicus), 2 gentoo penguins (Pygoscelis papua papua), 1 macaroni penguin (Eudyptes chrysolophus), and 1 emperor penguin (Aptenodytes forsteri). Observed clinical signs of toxicity included anorexia, lethargy, weakness, ataxia, paresis, apparent vision changes, seizure-like activity, and generalized seizures. Similar signs of toxicity have also been reported in humans, in whom voriconazole therapeutic plasma concentration for Aspergillus spp. infections is 2-6 μg/ml. Plasma voriconazole concentrations were measured in 18 samples from penguins showing clinical signs suggestive of voriconazole toxicity. The concentrations ranged from 8.12 to 64.17 μg/ml, with penguins having plasma concentrations above 30 μg/ml exhibiting moderate to severe neurologic signs, including ataxia, paresis, and seizures. These concentrations were well above those known to result in central nervous system toxicity, including encephalopathy, in humans. This case series highlights the importance of species-specific dosing of voriconazole in penguins and plasma therapeutic drug monitoring. Further investigation, including pharmacokinetic studies, is

  2. Toxicity of fluoride to aquatic species and evaluation of toxicity modifying factors.

    Science.gov (United States)

    Pearcy, Krysta; Elphick, James; Burnett-Seidel, Charlene

    2015-07-01

    The present study was performed to investigate the toxicity of fluoride to a variety of freshwater aquatic organisms and to establish whether water quality variables contribute substantively to modifying its toxicity. Water hardness, chloride, and alkalinity were tested as possible toxicity modifying factors for fluoride using acute toxicity tests with Hyalella azteca and Oncorhynchus mykiss. Chloride appeared to be the major toxicity modifying factor for fluoride in these acute toxicity tests. The chronic toxicity of fluoride was evaluated with a variety of species, including 3 fish (Pimephales promelas, O. mykiss, and Salvelinus namaycush), 3 invertebrates (Ceriodaphnia dubia, H. azteca, and Chironomus dilutus), 1 plant (Lemna minor), and 1 alga (Pseudokirchneriella subcapitata). Hyalella azteca was the most sensitive species overall, and O. mykiss was the most sensitive species of fish. The role of chloride as a toxicity modifying factor was inconsistent between species in the chronic toxicity tests. © 2015 SETAC.

  3. 7-oxygenated Derivatives of Dehydroepiandrosterone and Obesity

    Directory of Open Access Journals (Sweden)

    B. Sedláčková

    2012-01-01

    Full Text Available 7-hydroxy/oxo derivatives of dehydroepiandrosterone are potential regulators of the local cortisol activity due to their competition in the cortisolcortisone balance mediated by 11β-hydroxysteroid dehydrogenase. 7-hydroxydehydroepiandrosterone is marketed as anti-obesity medication, though no clinical study aimed at the benefit of administering 7-oxygenated derivatives of dehydroepiandrosterone has appeared until now. We tried to show whether there exist differences in levels of circulating 7-hydroxy/oxo-dehydroepiandrosterone derivatives between lean and obese boys and girls. From a cohort of adolescents investigated within the frame of anti-obesity programme 10 obese boys and 10 obese girls were compared with age-matched lean boys and girls in their anthropometric data, and concentrations of both epimers of 7-hydroxydehydroepiandrosterone and 7-oxo-dehydroepiandrosterone were determined by the RIA method. The basal levels of 7α-hydroxy-dehydroepiandrosterone were significantly higher in obese boys than in lean boys but not in girls. The association was found for anthropometric parameters and 7α-hydroxy-dehydroepiandrosterone, however again only in boys and not in girls. Higher levels of 7α-hydroxydehydroepiandrosterone its positive association with anthropometric data in obese boys may serve as a sign that, at least in boys, 7-oxygenated 5-ene-steroids may take part in regulating the hormonal signal for fat formation or distribution.

  4. Novel view on predicting acute toxicity: Decomposing toxicity data in species vulnerability and chemical potency.

    NARCIS (Netherlands)

    Jager, D.T.; Posthuma, L.; Zwart, D.D.; van de Meent, D.

    2007-01-01

    Chemical risk assessment usually applies empirical methods to predict toxicant effects on different species. We propose a more mechanism-oriented approach, and introduce a method to decompose toxicity data in a contribution from the chemical (potency) and from the exposed species (vulnerability). We

  5. Comparative toxicity of ten organic chemicals to four earthworm species

    Energy Technology Data Exchange (ETDEWEB)

    Neuhauser, E.F.; Durkin, P.R.; Malecki, M.R.; Anatra, M.

    1986-01-01

    Ten organic chemicals were tested for toxicity to four earthworm species: Allolobophora tuberculata, Eisenia fetida, Eudrilus eugeniae and Perionyx excavatus, using the European Economic Community's (EEC) earthworm artificial soil and contact testing procedure. The phenols were the most toxic chemicals tested, followed by the amine, substituted benzenes, halogenated aliphatic hydrocarbon, polycyclic aromatic hydrocarbon and phthalate as the least toxic chemical tested. Correlations among species within each type of test for a given chemical were extremely high, suggesting that the selection of earthworm test species does not markedly affect the assessment of a chemical's toxicity. The correlation between the two tests was low for all test species. The contact test LC50 for a given chemical cannot be directly correlated to an artificial soil test LC50 for the same earthworm species.

  6. Endangered species toxicity extrapolation using ICE models

    Science.gov (United States)

    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. ...

  7. Plant species responses to oil degradation and toxicity reduction in ...

    African Journals Online (AJOL)

    Vegetated plots were established by planting different plant species – legumes and vegetable (Abelmoschus, esculentus, Telfaria occidentalis and Vigna unguiculata) and applied with sawdust and chromolaena leaves at different intensities of oil pollution. Toxicity of the soil was evaluated using germination percentage, ...

  8. Development of thresholds of excess toxicity for environmental species and their application to identification of modes of acute toxic action.

    Science.gov (United States)

    Li, Jin J; Zhang, Xu J; Yang, Yi; Huang, Tao; Li, Chao; Su, Limin; Zhao, Yuan H; Cronin, Mark T D

    2018-03-01

    The acute toxicity of organic pollutants to fish, Daphnia magna, Tetrahymena pyriformis, and Vibrio fischeri was investigated. The results indicated that the Toxicity Ratio (TR) threshold of log TR =1, which has been based on the distribution of toxicity data to fish, can also be used to discriminate reactive or specifically acting compounds from baseline narcotics for Daphnia magna and Vibrio fischeri. A log TR=0.84 is proposed for Tetrahymena pyriformis following investigation of the relationships between the species sensitivity and the absolute averaged residuals (AAR) between the predicted baseline toxicity and the experimental toxicity. Less inert compounds exhibit relatively higher toxicity to the lower species (Tetrahymena pyriformis and Vibrio fischeri) than the higher species (fish and Daphnia magna). A greater number of less inert compounds with log TR greater than the thresholds was observed for Tetrahymena pyriformis and Vibrio fischeri. This may be attributed to the hydrophilic compounds which may pass more easily through cell membranes than the skin or exoskeleton of organisms and have higher bioconcentration factors in the lower species, leading to higher toxicity. Most of classes of chemical associated with excess toxicity to one species also exhibited excess toxicity to other species, however, a few classes with excess toxicity to one species exhibiting narcotic toxicity to other species and thus may have different MOAs between species. Some ionizable compounds have log TR much lower than one because of the over-estimated log K OW . The factors that influence the toxicity ratio calculated from baseline level are discussed in this paper. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Evaluation of multiwalled carbon nanotubes toxicity in two fish species.

    Science.gov (United States)

    Cimbaluk, Giovani Valentin; Ramsdorf, Wanessa Algarte; Perussolo, Maiara Carolina; Santos, Hayanna Karla Felipe; Da Silva De Assis, Helena Cristina; Schnitzler, Mariane Cristina; Schnitzler, Danielle Caroline; Carneiro, Pedro Gontijo; Cestari, Marta Margarete

    2018-04-15

    Carbon Nanotubes are among the most promising materials for the technology industry. Their unique physical and chemical proprieties may reduce the production costs and improve the efficiency of a large range of products. However, the same characteristics that have made nanomaterials interesting for industry may be responsible for inducing toxic effects on the aquatic organisms. Since the carbon nanotubes toxicity is still a controversial issue, we performed tests of acute and subchronic exposure to a commercial sample of multiwalled carbon nanotubes in two fish species, an exotic model (Danio rerio) and a native one (Astyanax altiparanae). Using the alkaline version of the comet assay on erythrocytes and the piscine micronucleous, also performed on erythrocytes, it was verified that the tested carbon nanotubes sample did not generate apparent genotoxicity by means of single/double DNA strand break or clastogenic/aneugenic effects over any of the species, independently of the exposure period. Although, our findings indicate the possibility of the occurrence of CNTs-DNA crosslinks. Apparently, the sample tested induces oxidative stress after subchronic exposure as shown by activity of superoxide dismutase and catalase. The data obtained by the activity levels of acetylcholinesterase suggests acute neurotoxicity in Astyanax altiparanae and subchronic neurotoxicity in Danio rerio. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

    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.

  11. Toxicity and utilization of chemical weapons: does toxicity and venom utilization contribute to the formation of species communities?

    Science.gov (United States)

    Westermann, Fabian L; McPherson, Iain S; Jones, Tappey H; Milicich, Lesley; Lester, Philip J

    2015-08-01

    Toxicity and the utilization of venom are essential features in the ecology of many animal species and have been hypothesized to be important factors contributing to the assembly of communities through competitive interactions. Ants of the genus Monomorium utilize a variety of venom compositions, which have been reported to give them a competitive advantage. Here, we investigate two pairs of Monomorium species, which differ in the structural compositions of their venom and their co-occurrence patterns with the invasive Argentine ant. We looked at the effects of Monomorium venom toxicity, venom utilization, and aggressive physical interactions on Monomorium and Argentine ant survival rates during arena trials. The venom toxicity of the two species co-occurring with the invasive Argentine ants was found to be significantly higher than the toxicity of the two species which do not. There was no correlation between venom toxicity and Monomorium survival; however, three of the four Monomorium species displayed significant variability in their venom usage which was associated with the number of Argentine ant workers encountered during trials. Average Monomorium mortality varied significantly between species, and in Monomorium smithii and Monomorium antipodum, aggressive interactions with Argentine ants had a significant negative effect on their mortality. Our study demonstrates that different factors and strategies can contribute to the ability of a species to withstand the pressure of a dominant invader at high abundance, and venom chemistry appears to be only one of several strategies utilized.

  12. Evaluation of the toxic properties of naturally weathered Exxon Valdez crude oil to surrogate wildlife species

    International Nuclear Information System (INIS)

    Stubblefield, W.A.; Hancock, G.A.; Ford, W.H.; Prince, H.H.; Ringer, R.K.

    1995-01-01

    The toxic properties of naturally weathered Exxon Valdez crude oil (WEVC) to avian and mammalian wildlife species were evaluated using the surrogate species, mallard duck, Anas platyrhynchos, and European ferret, Mustela putorius. This study was conducted to evaluate the potential for toxic (rather than physical) injury to wildlife species that may have been exposed to WEVC, either through external contact or through dietary uptake. Previous studies have assessed the toxicity of unweathered crude oils, including Alaska North Slope Crude, but little information exists regarding the toxicity of a naturally weathered crude oil, typical of that encountered following a spill. A battery of laboratory toxicity tests was conducted, in compliance with standard and published test procedures, to evaluate acute and subchronic toxicity of WEVC. These included tests of food avoidance, reproductive effects, and direct eggshell application toxicity. Naturally weathered EVC, recovered postspill from Prince William Sound, was used as the test material. 36 refs., 7 figs., 4 tabs

  13. Analysis of Toxic and Non-Toxic Alexandrium (Dinophyceae) Species Using Ribosomal RNA Gene Sequences

    Science.gov (United States)

    1993-02-01

    Therriault, J.-C. (1988). Cladistic analysis of electrophoretic variants within the toxic dinoflagellate genus Protogonyaulax. Botanica Marina 31: 39- 51. 8... Botanica Marina 34: 575-587. Halegraeff, G. M., and Bolch, C.J. (1992). Transport of toxic dinoflagellate cysts via ship’s ballast water: implications...analysis of electrophoretic variants within the toxic dinoflagellate genus Protogonv-u.!a,. Botanica Marina 31: 39-51. Curran, J., Baillie, D.L

  14. Endangered Species Case - Washington Toxics Coalition v. EPA

    Science.gov (United States)

    This Web page provides information on the Washington Toxics Coalition v. EPA case, related to protection of Pacific salmon and steelhead, and links to the biological opinions issued by the NMFS and EPA’s responses.

  15. A REVIEW OF SINGLE SPECIES TOXICITY TESTS: ARE THE TESTS RELIABLE PREDICTORS OF AQUATIC ECOSYSTEM COMMUNITY RESPONSES?

    Science.gov (United States)

    This document provides a comprehensive review to evaluate the reliability of indicator species toxicity test results in predicting aquatic ecosystem impacts, also called the ecological relevance of laboratory single species toxicity tests.

  16. The toxicity of sulfolane and DIPA from sour gas plants to aquatic species

    International Nuclear Information System (INIS)

    Lintott, D.R.; Goudey, J.S.; Wilson, J.; Swanson, S.; Drury, C.

    1997-01-01

    The ecological effects of sulfolane and diisopropanolamine (DIPA), which are used to remove sulfur compounds from natural gas, were studied to establish risk-based cleanup criteria and to evaluate effective remedial measures. Toxicity tests were conducted on both the parent compounds and the thermal and biological degradation products. Toxicity testing focused on aquatic species because surface outlets, such as creeks, were found to be the major pathways for the water soluble DIPA and sulfolane chemicals. Sulfolane proved to be relatively non-toxic to aquatic species, with the exception of bacteria. DIPA was relatively toxic to algae at pH found in ground and surface waters. Aqueous and methanol reclaimer bottom extracts from five different gas plant sites were also tested using modified acute toxicity screening tests with different species. The reclaimer bottoms were found to be highly toxic to all species tested. DIPA and sulfolane did not entirely account for the toxicity of the reclaimer bottoms. Inorganic salts and metals present in reclaimer bottoms were found not to contribute to toxicity directly. The same was true for DIPA and sulfolane degradation products. 3 refs., 7 tabs., 8 figs

  17. The toxicity of sulfolane and DIPA from sour gas plants to aquatic species

    Energy Technology Data Exchange (ETDEWEB)

    Lintott, D.R.; Goudey, J.S. [HydroQual Consultants, Inc., Calgary, AB (Canada); Wilson, J.; Swanson, S. [Golder Associates, Calgary, AB (Canada); Drury, C. [Shell Canada Ltd., Calgary, AB (Canada). Calgary Research Centre

    1997-12-31

    The ecological effects of sulfolane and diisopropanolamine (DIPA), which are used to remove sulfur compounds from natural gas, were studied to establish risk-based cleanup criteria and to evaluate effective remedial measures. Toxicity tests were conducted on both the parent compounds and the thermal and biological degradation products. Toxicity testing focused on aquatic species because surface outlets, such as creeks, were found to be the major pathways for the water soluble DIPA and sulfolane chemicals. Sulfolane proved to be relatively non-toxic to aquatic species, with the exception of bacteria. DIPA was relatively toxic to algae at pH found in ground and surface waters. Aqueous and methanol reclaimer bottom extracts from five different gas plant sites were also tested using modified acute toxicity screening tests with different species. The reclaimer bottoms were found to be highly toxic to all species tested. DIPA and sulfolane did not entirely account for the toxicity of the reclaimer bottoms. Inorganic salts and metals present in reclaimer bottoms were found not to contribute to toxicity directly. The same was true for DIPA and sulfolane degradation products. 3 refs., 7 tabs., 8 figs.

  18. TOXICITY OF PENTACHLOROPHENOL TO ENDANGERED AND SURROGATE FISH SPECIES

    Science.gov (United States)

    Water quality criteria (WQC) generally are based on the responses of easily cultured and tested surrogate species. Little is known about the relative sensitivity of surrogate and endangered species. The objective of this study was to compare acute and chronic (early life-stage) ...

  19. Toxicity of chlorpyrifos on some marine cyanobacteria species

    International Nuclear Information System (INIS)

    Shoaib, N.; Siddiqui, A.; Khalid, H.

    2012-01-01

    Pakistan is an agricultural country and a wide variety of pesticides are used on its cropland. Pesticides pose serious threats to the natural ecosystem. In the present study cyanobacteria (blue green algae) were used to assess the ecotoxicological effect of chlorpyrifos (organophosphate pesticide). Cyanobacteria are the base of the food web providing food resource to consumers in higher trophic level. Cyanobacteria were isolated and purified from water samples collected from Manora channel. Fast growing cultures of cyanobacteria were used to assess the toxicity of test pesticide . The Light and Dark method was used to determine the primary production of the organisms. The acute toxicity of chlorpyrifos was determined by calculating IC/sub 50/ of the test organisms. The IC/sub 50/ was found to be 0.074, 0.013, 0.08 and 0.3 ppm for Synechocystis aquatilis, Komvophoron minutum, Gloeocapsa crepidinum and Gloeocapsa sanguinea when exposed to chlorpyrifos pesticide . Laboratory experiments with cyanobacteria have demonstrated that organophosphate pesticides are potent inhibitors of photosynthesis. (author)

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

    Science.gov (United States)

    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...

  1. Formulated Beta-Cyfluthrin Shows Wide Divergence in Toxicity among Bird Species

    OpenAIRE

    Addy-Orduna, Laura M.; Zaccagnini, María-Elena; Canavelli, Sonia B.; Mineau, Pierre

    2011-01-01

    It is generally assumed that the toxicity of pyrethroid insecticides to birds is negligible, though few species have been tested. The oral acute toxicity of formulated beta-cyfluthrin was determined for canaries (Serinus sp.), shiny cowbirds (Molothrus bonariensis), and eared doves (Zenaida auriculata). Single doses were administered to adults by gavage. Approximate lethal doses 50 (LD50) and their confidence intervals were determined by approximate D-optimal design. Canaries were found to be...

  2. Assessing contaminant sensitivity of endangered and threatened aquatic species: Part III. Effluent toxicity tests

    Science.gov (United States)

    Dwyer, F.J.; Hardesty, D.K.; Henke, C.E.; Ingersoll, C.G.; Whites, D.W.; Augspurger, T.; Canfield, T.J.; Mount, D.R.; Mayer, F.L.

    2005-01-01

    Toxicity tests using standard effluent test procedures described by the U.S. Environmental Protection Agency were conducted with Ceriodaphnia dubia, fathead minnows (Pimephales promelas), and seven threatened and endangered (listed) fish species from four families: (1) Acipenseridae: shortnose sturgeon (Acipenser brevirostrum); (2) Catostomidae; razorback sucker (Xyrauchen texanus); (3) Cyprinidae: bonytail chub (Gila elegans), Cape Fear shiner (Notropis mekistocholas) Colorado pikeminnow (Ptychocheilus lucius), and spotfin chub (Cyprinella monacha); and (4) Poecillidae: Gila topminnow (Poeciliopsis occidentalis). We conducted 7-day survival and growth studies with embryo-larval fathead minnows and analogous exposures using the listed species. Survival and reproduction were also determined with C. dubia. Tests were conducted with carbaryl, ammonia-or a simulated effluent complex mixture of carbaryl, copper, 4-nonylphenol, pentachlorophenol and permethrin at equitoxic proportions. In addition, Cape Fear shiners and spotfin chub were tested using diazinon, copper, and chlorine. Toxicity tests were also conducted with field-collected effluents from domestic or industrial facilities. Bonytail chub and razorback suckers were tested with effluents collected in Arizona whereas effluent samples collected from North Carolina were tested with Cape Fear shiner, spotfin chub, and shortnose sturgeon. The fathead minnow 7-day effluent test was often a reliable estimator of toxic effects to the listed fishes. However, in 21 % of the tests, a listed species was more sensitive than fathead minnows. More sensitive species results varied by test so that usually no species was always more or less sensitive than fathead minnows. Only the Gila topminnow was consistently less sensitive than the fathead minnow. Listed fish species were protected 96% of the time when results for both fathead minnows and C. dubia were considered, thus reinforcing the value of standard whole

  3. Protectiveness of Species Sensitivity Distribution Hazard Concentrations for Acute Toxicity Used in Endangered Species Risk Assessment

    Science.gov (United States)

    A primary objective of threatened and endangered species conservation is to ensure that chemical contaminants and other stressors do not adversely affect listed species. Assessments of the ecological risks of chemical exposures to listed species often rely on the use of surrogate...

  4. Selenium species-dependent toxicity, bioavailability and metabolic transformations in Caenorhabditis elegans.

    Science.gov (United States)

    Rohn, Isabelle; Marschall, Talke Anu; Kroepfl, Nina; Jensen, Kenneth Bendix; Aschner, Michael; Tuck, Simon; Kuehnelt, Doris; Schwerdtle, Tanja; Bornhorst, Julia

    2018-05-17

    The essential micronutrient selenium (Se) is required for various systemic functions, but its beneficial range is narrow and overexposure may result in adverse health effects. Additionally, the chemical form of the ingested selenium contributes crucially to its health effects. While small Se species play a major role in Se metabolism, their toxicological effects, bioavailability and metabolic transformations following elevated uptake are poorly understood. Utilizing the tractable invertebrate Caenorhabditis elegans allowed for an alternative approach to study species-specific characteristics of organic and inorganic Se forms in vivo, revealing remarkable species-dependent differences in the toxicity and bioavailability of selenite, selenomethionine (SeMet) and Se-methylselenocysteine (MeSeCys). An inverse relationship was found between toxicity and bioavailability of the Se species, with the organic species displaying a higher bioavailability than the inorganic form, yet being less toxic. Quantitative Se speciation analysis with HPLC/mass spectrometry revealed a partial metabolism of SeMet and MeSeCys. In SeMet exposed worms, identified metabolites were Se-adenosylselenomethionine (AdoSeMet) and Se-adenosylselenohomocysteine (AdoSeHcy), while worms exposed to MeSeCys produced Se-methylselenoglutathione (MeSeGSH) and γ-glutamyl-MeSeCys (γ-Glu-MeSeCys). Moreover, the possible role of the sole selenoprotein in the nematode, thioredoxin reductase-1 (TrxR-1), was studied comparing wildtype and trxr-1 deletion mutants. Although a lower basal Se level was detected in trxr-1 mutants, Se toxicity and bioavailability following acute exposure was indistinguishable from wildtype worms. Altogether, the current study demonstrates the suitability of C. elegans as a model for Se species dependent toxicity and metabolism, while further research is needed to elucidate TrxR-1 function in the nematode.

  5. Addition of contaminant bioavailability and species susceptibility to a sediment toxicity assessment: Application in an urban stream in China

    International Nuclear Information System (INIS)

    Li, Huizhen; Sun, Baoquan; Chen, Xin; Lydy, Michael J.; You, Jing

    2013-01-01

    Sediments collected from an urban creek in China exhibited high acute toxicity to Hyalella azteca with 81.3% of sediments being toxic. A toxic unit (TU) estimation demonstrated that the pyrethroid, cypermethrin, was the major contributor to toxicity. The traditional TU approach, however, overestimated the toxicity. Reduced bioavailability of sediment-associated cypermethrin due to sequestration explained the overestimation. Additionally, antagonism among multiple contaminants and species susceptibility to various contaminants also contributed to the unexpectedly low toxicity to H. azteca. Bioavailable TUs derived from the bioavailability-based approaches, Tenax extraction and matrix-solid phase microextraction (matrix-SPME), showed better correlations with the noted toxicity compared to traditional TUs. As the first successful attempt to use matrix-SPME for estimating toxicity caused by emerging insecticides in field sediment, the present study found freely dissolved cypermethrin concentrations significantly improved the prediction of sediment toxicity to H. azteca compared to organic carbon normalized and Tenax extractable concentrations. Highlights: •Over 80% sediments from an urban stream in China were acutely toxic to H. azteca. •Toxic unit analysis showed cypermethrin was the major contributor to toxicity. •The traditional toxic unit approach overestimated sediment toxicity. •Reduced bioavailability was the reason for overestimating sediment toxicity. •Freely dissolved cypermethrin concentrations greatly improved toxicity prediction. -- Field sediment toxicity caused by current-use pesticides could be more accurately evaluated by incorporating bioavailability measurements into the toxic unit analysis

  6. Using Bioassays and Species Sensitivity Distributions to Assess Herbicide Toxicity towards Benthic Diatoms

    Science.gov (United States)

    Larras, Floriane; Bouchez, Agnès; Rimet, Frédéric; Montuelle, Bernard

    2012-01-01

    Although benthic diatoms are widely used in ecological studies of aquatic systems, there is still a dearth of data concerning species sensitivities towards several contaminants. Within the same community, different species may respond differently depending on their physiological and ecological characteristics. This lack of knowledge makes specific appropriate risk assessment impossible. To find out whether species sensitivity distribution (SSD) could be used to estimate the risk of herbicide toxicity for diatoms, we need to know whether their sensitivity depends on their physiological and ecological characteristics. We carried out single-species bioassays on 11 diatom species exposed to 8 herbicides. Dose-responses relationships were used to extrapolate the Effective Concentration 5 (EC5) and the Effective Concentration 50 (EC50) for each exposure. These data were used to fit a SSD curve for each herbicide, and to determine the Hazardous concentration 5 (HC5) and 50 (HC50). Our results revealed a high level of variability of the sensitivity in the set of species tested. For photosystem-II inhibitor (PSII) herbicides, diatoms species displayed a typical grouping of sensitivity levels consistent with their trophic mode and their ecological guild. N-heterotroph and “motile” guild species were more tolerant of PSII inhibitors, while N-autotroph and “low profile” guild species were more sensitive. Comprehensive SSD curves were obtained for 5 herbicides, but not for sulfonylurea herbicides or for dimetachlor, which had toxicity levels that were below the range of concentration tested. The SSD curves provided the following ranking of toxicity: diuron> terbutryn> isoproturon> atrazine> metolachlor. The HC that affected 5% of the species revealed that, even at the usual environmental concentrations of herbicides, diatom assemblages could be affected, especially by isoproturon, terbutryn, and diuron. PMID:22952981

  7. Using bioassays and species sensitivity distributions to assess herbicide toxicity towards benthic diatoms.

    Directory of Open Access Journals (Sweden)

    Floriane Larras

    Full Text Available Although benthic diatoms are widely used in ecological studies of aquatic systems, there is still a dearth of data concerning species sensitivities towards several contaminants. Within the same community, different species may respond differently depending on their physiological and ecological characteristics. This lack of knowledge makes specific appropriate risk assessment impossible. To find out whether species sensitivity distribution (SSD could be used to estimate the risk of herbicide toxicity for diatoms, we need to know whether their sensitivity depends on their physiological and ecological characteristics. We carried out single-species bioassays on 11 diatom species exposed to 8 herbicides. Dose-responses relationships were used to extrapolate the Effective Concentration 5 (EC(5 and the Effective Concentration 50 (EC(50 for each exposure. These data were used to fit a SSD curve for each herbicide, and to determine the Hazardous concentration 5 (HC(5 and 50 (HC(50. Our results revealed a high level of variability of the sensitivity in the set of species tested. For photosystem-II inhibitor (PSII herbicides, diatoms species displayed a typical grouping of sensitivity levels consistent with their trophic mode and their ecological guild. N-heterotroph and "motile" guild species were more tolerant of PSII inhibitors, while N-autotroph and "low profile" guild species were more sensitive. Comprehensive SSD curves were obtained for 5 herbicides, but not for sulfonylurea herbicides or for dimetachlor, which had toxicity levels that were below the range of concentration tested. The SSD curves provided the following ranking of toxicity: diuron> terbutryn> isoproturon> atrazine> metolachlor. The HC that affected 5% of the species revealed that, even at the usual environmental concentrations of herbicides, diatom assemblages could be affected, especially by isoproturon, terbutryn, and diuron.

  8. Can commonly measurable traits explain differences in metal accumulation and toxicity in earthworm species?

    NARCIS (Netherlands)

    Qiu, H.; Peijnenburg, W.J.G.M.; van Gestel, C.A.M.; Vijver, M.G.

    2014-01-01

    There is no clear consensus in the literature on the metal accumulation pattern and sensitivity of different earthworm species. In the present study, accumulation and toxicity of Cu, Cd, Ni, and Zn in the earthworms Lumbricus rubellus (epigeic), Aporrectodea longa (anecic), and Eisenia fetida

  9. Assessment of Toxic Metals and feed habits of the snail Pomacea specie from the Amatitlan Lake

    International Nuclear Information System (INIS)

    Roesch Palomo, R.R.

    1998-01-01

    In the present thesis an assesment of cadmium, cooper, cromium VI, and lead was made in samples of snail pomacea specie from the Amatitlan Lake. We conclude that the comsuption of this mollusk is toxic for human health. The concentration of heavy metals like cadmium, cooper shows that are not recomended for human comsuption according to Spanish and FAO/PAHO standards

  10. Mobility and Attenuation Dynamics of Potentially Toxic Chemical Species at an Abandoned Copper Mine Tailings Dump

    Directory of Open Access Journals (Sweden)

    Wilson Mugera Gitari

    2018-02-01

    Full Text Available Large volumes of disposed mine tailings abound in several regions of South Africa, as a consequence of unregulated, unsustainable long years of mining activities. Tailings dumps occupy a large volume of valuable land, and present a potential risk for aquatic systems, through leaching of potentially toxic chemical species. This paper reports on the evaluation of the geochemical processes controlling the mobility of potentially toxic chemical species within the tailings profile, and their potential risk with regard to surface and groundwater systems. Combination of X-ray fluorescence (XRF, X-ray diffraction (XRD, and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS techniques, show that the tailing profiles are uniform, weakly altered, and vary slightly with depth in both physical and geochemical properties, as well as mineralogical composition. Mineralogical analysis showed the following order of abundance: quartz > epidote > chlorite > muscovite > calcite > hematite within the tailings profiles. The neutralization of the dominant alumino-silicate minerals and the absence of sulfidic minerals, have produced medium alkaline pH conditions (7.97–8.37 at all depths and low concentrations of dissolved Cu (20.21–47.9 µg/L, Zn (0.88–1.80 µg/L, Pb (0.27–0.34 µg/L, and SO42− (15.71–55.94 mg/L in the tailings profile leachates. The relative percentage leach for the potentially toxic chemical species was low in the aqueous phase (Ni 0.081%, Cu 0.006%, and Zn 0.05%. This indicates that the transport load of potentially toxic chemical species from tailings to the aqueous phase is very low. The precipitation of secondary hematite has an important known ability to trap and attenuate the mobility of potentially toxic chemical species (Cu, Zn, and Pb by adsorption on the surface area. Geochemical modelling MINTEQA2 showed that the tailings leachates were below saturation regarding oxyhydroxide minerals, but oversaturated with Cu

  11. Oral bioaccessibility of toxic and essential elements in raw and cooked commercial seafood species available in European markets

    NARCIS (Netherlands)

    Alves, Ricardo N.; Maulvault, Ana L.; Barbosa, Vera L.; Fernandez-Tejedor, Margarita; Tediosi, Alice; Kotterman, Michiel; Heuvel, van den Fredericus H.M.; Robbens, Johan; Fernandes, José O.; Romme Rasmussen, Rie; Sloth, Jens J.; Marques, António

    2017-01-01

    The oral bioaccessibility of several essential and toxic elements was investigated in raw and cooked commercially available seafood species from European markets. Bioaccessibility varied between seafood species and elements. Methylmercury bioaccessibility varied between 10 (octopus) and 60%

  12. Comparative Toxicities of Newer and Conventional Insecticides: Against Four Generalist Predator Species.

    Science.gov (United States)

    Prabhaker, Nilima; Naranjo, Steven; Perring, Thomas; Castle, Steven

    2017-12-05

    Generalist insect predators play an essential role in regulating the populations of Bemisia tabaci and other pests in agricultural systems, but may be affected negatively by insecticides applied for pest management. Evaluation of insecticide compatibility with specific predator species can provide a basis for making treatment decisions with the aim of conserving natural enemies. Eleven insecticides representing six modes of action groups were evaluated for toxicity against four predator species and at different developmental stages. Full-concentration series bioassays were conducted on laboratory-reared or insectary-supplied predators using Petri dish and systemic uptake bioassay techniques. Highest toxicities were observed with imidacloprid and clothianidin against first and second instar nymphs of Geocoris punctipes (Say) (Hemiptera: Geocoridae). Later instar nymphs were less susceptible to neonicotinoid treatments based on higher LC50s observed with imidacloprid, thiamethoxam, and dinotefuran against third or fourth instar nymphs. The pyrethroid insecticide bifenthrin was highly toxic against adults of G. punctipes and Orius insidiosus (Say) (Hemiptera: Anthocoridae). Standard concentration/mortality evaluation of nonacute toxicity insecticides, including buprofezin, pyriproxyfen, spirotetramat, and spiromesifen, was inconclusive in terms of generating probit statistics. However, low mortality levels of insects exposed for up to 120 h suggested minimal lethality with the exception of pyriproxyfen that was mildly toxic to Chrysoperla rufilabris (Burmeister) (Neuroptera: Chrysopidae). Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  13. Formulated Beta-Cyfluthrin Shows Wide Divergence in Toxicity among Bird Species

    Directory of Open Access Journals (Sweden)

    Laura M. Addy-Orduna

    2011-01-01

    Full Text Available It is generally assumed that the toxicity of pyrethroid insecticides to birds is negligible, though few species have been tested. The oral acute toxicity of formulated beta-cyfluthrin was determined for canaries (Serinus sp., shiny cowbirds (Molothrus bonariensis, and eared doves (Zenaida auriculata. Single doses were administered to adults by gavage. Approximate lethal doses 50 (LD50 and their confidence intervals were determined by approximate D-optimal design. Canaries were found to be substantially more sensitive to formulated beta-cyfluthrin (LD50=(170±41 mg/kg than the other two species tested (LD50=(2234±544 mg/kg and LD50=(2271±433 mg/kg, resp.. The LD50 obtained for canaries was also considerably lower than typical toxicity values available in the literature for pyrethroids. This study emphasizes the need for testing a broader range of species with potentially toxic insecticides, using modern up and down test designs with minimal numbers of birds.

  14. Formulated Beta-Cyfluthrin Shows Wide Divergence in Toxicity among Bird Species.

    Science.gov (United States)

    Addy-Orduna, Laura M; Zaccagnini, María-Elena; Canavelli, Sonia B; Mineau, Pierre

    2011-01-01

    It is generally assumed that the toxicity of pyrethroid insecticides to birds is negligible, though few species have been tested. The oral acute toxicity of formulated beta-cyfluthrin was determined for canaries (Serinus sp.), shiny cowbirds (Molothrus bonariensis), and eared doves (Zenaida auriculata). Single doses were administered to adults by gavage. Approximate lethal doses 50 (LD(50)) and their confidence intervals were determined by approximate D-optimal design. Canaries were found to be substantially more sensitive to formulated beta-cyfluthrin (LD(50) = (170 ± 41) mg/kg) than the other two species tested (LD(50) = (2234 ± 544) mg/kg and LD(50) = (2271 ± 433) mg/kg, resp.). The LD(50) obtained for canaries was also considerably lower than typical toxicity values available in the literature for pyrethroids. This study emphasizes the need for testing a broader range of species with potentially toxic insecticides, using modern up and down test designs with minimal numbers of birds.

  15. Photoactivated toxicity of PAH to endangered fishes and standard laboratory test species

    International Nuclear Information System (INIS)

    Buckler, D.R.; Mount, D.R.; Tillitt, D.E.

    1994-01-01

    Polynuclear aromatic hydrocarbons (PAH) have been detected in water and sediment from the San Juan River Basin, located in the Four Corners area of the southwestern US. In addition to possessing extensive oil and gas deposits, the San Juan contains several threatened or endangered fish species such as Colorado squawfish and razorback suckers. Proposed expansion of oil and gas development in the basin has sparked concerns that potential increases in PAH loading may jeopardize these and other native fishes. In response, the authors conducted laboratory exposures of threatened and endangered species to various PAH both with and without accompanying exposure to UV light. As predicted from the literature, exposure to UV light caused a marked photo-activated toxicity response in all species; however, the sensitivity to PAH both with and without UV exposure varied among species and lifestages. Supplemental studies were conducted to evaluate the physiological mechanisms for variation in sensitivity between species and lifestage

  16. Phytoprotective effect of arbuscular mycorrhizal fungi species against arsenic toxicity in tropical leguminous species.

    Science.gov (United States)

    de Melo, Rangel Wesley; Schneider, Jerusa; de Souza, Costa Enio Tarso; Sousa, Soares Cláudio Roberto Fonsêca; Guimarães, Guilherme Luiz Roberto; de Souza, Moreira Fatima Maria

    2014-01-01

    Arbuscular mycorrhizal fungi (AMF) improve the tolerance of hosting plants to arsenic (As) in contaminated soils. This work assessed the phytoprotective effect of Glomus etunicatum, Acaulospora morrowiae, Gigaspora gigantea, and Acaulospora sp. on four leguminous species (Acacia mangium, Crotalaria juncea, Enterolobium contortisiliquum, and Stizolobium aterrimum) in an As-contaminated soil from a gold mining area. AMF root colonization, biomass production, As and P accumulation, as well as arsenic translocation index (TI) from roots to shoots were measured. The AMF phytoprotective effect was assessed by the P/As ratio and the activity of plant antioxidant enzymes. The AMF colonization ranged from 24 to 28%. In general, all leguminous species had low As TI when inoculated with AMF species. Inoculation of C. juncea with Acaulospora sp. improved significantly As accumulation in roots, and decreased the activity of ascorbate peroxidase (APX) and superoxide dismutase (SOD), highlighting its phytoprotective effect and the potential use of this symbiosis for phytoremediation of As-contaminated soils. However, S. aterrimum has also shown a potential for phytoremediation irrespectively of AMF inoculation. APX was a good indicator of the phytoprotective effect against As contamination in C. juncea and A. mangium. In general P/As ratio in shoots was the best indicator of the phytoprotective effect of all AMF species in all plant species.

  17. Hybrid silica materials for detection of toxic species and clinical diagnosis

    OpenAIRE

    Pascual Vidal, Lluís

    2017-01-01

    The present PhD thesis entitled "Silica Hybrid Materials for detection of toxic species and clinical diagnosis" is focused on the design and synthesis of new hybrid materials, using different silica supports as inorganic scaffolds, with applications in recognition, sensing and diagnostic protocols. The first chapter of the PhD thesis is devoted to the definition and classification of hybrid materials, relying on concepts of Nanotechnology, Supramolecular and Materials Chemistry. State o...

  18. Copper toxicity to different field-collected cladoceran species: intra-and inter-species sensitivity

    International Nuclear Information System (INIS)

    Bossuyt, Bart T.A.; Janssen, Colin R.

    2005-01-01

    The acute copper sensitivity of 44 European freshwater cladocerans, from four families (Daphniidae, Bosminidae, Macrothricidae, Chydoridae) and 13 genera (Daphnia, Ctenodaphnia, Ceriodaphnia, Simocephalus, Scapholeberis, Bosmina, Acantholeberis, Alona, Acroperus, Chydorus, Eurycercus, Disparalona and Pleuroxus) were assayed. The 48-h EC 50 s of field-collected organisms tested in reconstituted standard laboratory water ranged from 5.3 to 70.6 μg Cu L -1 . Only among Ctenodaphnia were significant intra-species differences observed. Significant inter-species differences were noted among Alonina and Daphnia. Between all genera tested, a maximum of a 12-fold difference in copper sensitivity was noted. Most animals were more sensitive than a laboratory D. magna clone. A weak non-significant increasing trend was noted between mean cladoceran 48-h EC 50 and ambient copper concentration of the different aquatic systems, suggesting acclimation/adaptation in the field. A positive relationship was also observed between the 48-h EC 50 of the field-collected cladoceran species (without the Chydoridae family) and the size of the organisms. - Zooplankton living in natural waters are more sensitive to copper than laboratory animals

  19. Copper toxicity to different field-collected cladoceran species: intra-and inter-species sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Bossuyt, Bart T.A. [Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent University, J. Plateaustraat 22, B-9000 Ghent (Belgium)]. E-mail: bart.bossuyt@ugent.be; Janssen, Colin R. [Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent University, J. Plateaustraat 22, B-9000 Ghent (Belgium)

    2005-07-15

    The acute copper sensitivity of 44 European freshwater cladocerans, from four families (Daphniidae, Bosminidae, Macrothricidae, Chydoridae) and 13 genera (Daphnia, Ctenodaphnia, Ceriodaphnia, Simocephalus, Scapholeberis, Bosmina, Acantholeberis, Alona, Acroperus, Chydorus, Eurycercus, Disparalona and Pleuroxus) were assayed. The 48-h EC{sub 50}s of field-collected organisms tested in reconstituted standard laboratory water ranged from 5.3 to 70.6 {mu}g Cu L{sup -1}. Only among Ctenodaphnia were significant intra-species differences observed. Significant inter-species differences were noted among Alonina and Daphnia. Between all genera tested, a maximum of a 12-fold difference in copper sensitivity was noted. Most animals were more sensitive than a laboratory D. magna clone. A weak non-significant increasing trend was noted between mean cladoceran 48-h EC{sub 50} and ambient copper concentration of the different aquatic systems, suggesting acclimation/adaptation in the field. A positive relationship was also observed between the 48-h EC{sub 50} of the field-collected cladoceran species (without the Chydoridae family) and the size of the organisms. - Zooplankton living in natural waters are more sensitive to copper than laboratory animals.

  20. Comparative toxicity of pentachlorophenol to three earthworm species in artificial soil

    Energy Technology Data Exchange (ETDEWEB)

    Fitzgerald, D.; Lanno, R.P.; Farwell, A.; Dixon, D.G. [Univ. of Waterloo, Ontario (Canada). Dept. of Biology

    1994-12-31

    Although methods for standardized toxicity tests with earthworms exist, many of the test parameters and conditions have not been validated in actual tests and with different species of worms. This study evaluated the toxicity of pentachlorophenol (PCP) to three species of earthworms, Lumbricus terrestris, Eisenia fetida, and Eudrilus eugeniae using various methods of data analysis and body residues. Tests were conducted in artificial soil for a period of 28 days or until an Acute Lethality Threshold (ALT) was reached. An intensive temporal sampling regime was applied to generate sufficient data for the accurate estimation of ALTs using both LC50/time and time-to-death/soil concentration methods of data analysis. L. terrestris was tested at 15 C, E. eugeniae at 24 C, and E. fetida at both temperatures. Total body residues of PCP were measured by GC following cryogenic separation of the lipid fraction of the worm. ALTs were significantly different between E. fetida and the two larger species of worms. No effect of temperature on the ALT for E. fetida was observed, although the time taken to reach the ALT increased at the lower temperature. The relationship of PCP residues at mortality will be discussed in terms of the effects of species, body size and temperature. Limitations of the artificial soil based upon growth curves of worms will also be examined.

  1. When dinner is dangerous: toxic frogs elicit species-specific responses from a generalist snake predator.

    Science.gov (United States)

    Phillips, Ben; Shine, Richard

    2007-12-01

    In arms races between predators and prey, some evolved tactics are unbeatable by the other player. For example, many types of prey are inedible because they have evolved chemical defenses. In this case, prey death removes any selective advantage of toxicity to the prey but not the selective advantage to a predator of being able to consume the prey. In the absence of effective selection for postmortem persistence of the toxicity then, some chemical defenses probably break down rapidly after prey death. If so, predators can overcome the toxic defense simply by waiting for that breakdown before consuming the prey. Floodplain death adders (Acanthophis praelongus) are highly venomous frog-eating elapid snakes native to northern Australia. Some of the frogs they eat are nontoxic (Litoria nasuta), others produce gluelike mucus when seized by a predator (Limnodynastes convexiusculus), and one species (Litoria dahlii) is dangerously toxic to snakes. Both the glue and the toxin degrade within about 20 min of prey death. Adders deal with these prey types in different and highly stereotyped ways: they consume nontoxic frogs directly but envenomate and release the other taxa, waiting until the chemical defense loses its potency before consuming the prey.

  2. Acute and chronic toxicity of neonicotinoids to nymphs of a mayfly species and some notes on seasonal differences

    NARCIS (Netherlands)

    Brink, Van den P.J.; Smeden, Van J.M.; Bekele, R.S.; Dierick, Wiebe; Gelder, De Daphne M.; Noteboom, Maarten; Roessink, Ivo

    2016-01-01

    Mayfly nymphs are among the most sensitive taxa to neonicotinoids. The present study presents the acute and chronic toxicity of 3 neonicotinoids (imidacloprid, thiacloprid, and thiamethoxam) to a mayfly species (Cloeon dipterum) and some notes on the seasonality of the toxicity of imidacloprid to

  3. Framework for Optimizing Selection of Interspecies Correlation Estimation Models to Address Species Diversity and Toxicity Gaps in an Aquatic Database

    Science.gov (United States)

    The Chemical Aquatic Fate and Effects (CAFE) database is a tool that facilitates assessments of accidental chemical releases into aquatic environments. CAFE contains aquatic toxicity data used in the development of species sensitivity distributions (SSDs) and the estimation of ha...

  4. Oral bioaccessibility of toxic and essential elements in raw and cooked commercial seafood species available in European markets

    DEFF Research Database (Denmark)

    Alves, Ricardo N.; Maulvault, Ana L.; Barbosa, Vera L.

    2017-01-01

    The oral bioaccessibility of several essential and toxic elements was investigated in raw and cooked commercially available seafood species from European markets. Bioaccessibility varied between seafood species and elements. Methylmercury bioaccessibility varied between 10 (octopus) and 60...... % (monkfish). Arsenic (> 64%) was the toxic element showing the highest bioaccessibility. Concerning essential elements bioaccessibility in raw seafood, selenium (73 %) and iodine (71 %) revealed the highest percentages. The bioaccessibility of elements in steamed products increased or decreased according...

  5. Comparative toxicity of imidacloprid and thiacloprid to different species of soil invertebrates.

    Science.gov (United States)

    de Lima E Silva, Cláudia; Brennan, Nicola; Brouwer, Jitske M; Commandeur, Daniël; Verweij, Rudo A; van Gestel, Cornelis A M

    2017-05-01

    Neonicotinoid insecticides have come under increasing scrutiny for their impact on non-target organisms, especially pollinators. The current scientific literature is mainly focused on the impact of these insecticides on pollinators and some aquatic insects, leaving a knowledge gap concerning soil invertebrates. This study aimed at filling this gap, by determining the toxicity of imidacloprid and thiacloprid to five species of soil invertebrates: earthworms (Eisenia andrei), enchytraeids (Enchytraeus crypticus), Collembola (Folsomia candida), oribatid mites (Oppia nitens) and isopods (Porcellio scaber). Tests focused on survival and reproduction or growth, after 3-5 weeks exposure in natural LUFA 2.2 standard soil. Imidacloprid was more toxic than thiacloprid for all species tested. F. candida and E. andrei were the most sensitive species, with LC 50 s of 0.20-0.62 and 0.77 mg/kg dry soil for imidacloprid and 2.7-3.9 and 7.1 mg/kg dry soil for thiacloprid. EC 50 s for effects on the reproduction of F. candida and E. andrei were 0.097-0.30 and 0.39 mg/kg dry soil for imidacloprid and 1.7-2.4 and 0.44 mg/kg dry soil for thiacloprid. The least sensitive species were O. nitens and P. scaber. Enchytraeids were a factor of 5-40 less sensitive than the taxonomically related earthworm, depending on the endpoint considered. Although not all the species showed high sensitivity to the neonicotinoids tested, these results raise awareness about the effects these insecticides can have on non-target soil invertebrates.

  6. Synergistic toxicity of Macondo crude oil and dispersant Corexit 9500A® to the Brachionus plicatilis species complex (Rotifera)

    International Nuclear Information System (INIS)

    Rico-Martínez, Roberto; Snell, Terry W.; Shearer, Tonya L.

    2013-01-01

    Using the marine rotifer Brachionus plicatilis acute toxicity tests, we estimated the toxicity of Corexit 9500A ® , propylene glycol, and Macondo oil. Ratios of 1:10, 1:50 and 1:130 for Corexit 9500A ® :Macondo oil mixture represent: maximum exposure concentrations, recommended ratios for deploying Corexit (1:10–1:50), 1:130 the actual dispersant:oil ratio used in the Deep Water Horizon spill. Corexit 9500A ® and oil are similar in their toxicity. However, when Corexit 9500A ® and oil are mixed, toxicity to B. manjavacas increases up to 52-fold. Extrapolating these results to the oil released by the Macondo well, suggests underestimation of increased toxicity from Corexit application. We found small differences in sensitivity among species of the B. plicatilis species complex, likely reflecting phylogenetic similarity. Just 2.6% of the water-accommodated fraction of oil inhibited rotifer cyst hatching by 50%, an ecologically significant result because rotifer cyst in sediments are critical resources for the recolonization of populations each Spring. - Highlights: ► We determined LC50's of Corexit 9500A ® , propylene glycol, and oil to B. plicatilis. ► Corexit 9500A ® and oil are equivalent in toxicity. ► When Corexit 9500A ® and oil are mixed, toxicity increases 52-fold to B. plicatilis. ► Results suggest underestimation of increased toxicity due to Corexit application. ► Sensitivity differences are small among species of the B. plicatilis species complex. - Using Brachionus plicatilis acute toxicity tests we estimated Corexit 9500A ® and oil toxicity. When these compounds are mixed a 52-fold increase in toxicity was observed.

  7. Paracetamol degradation intermediates and toxicity during photo-Fenton treatment using different iron species.

    Science.gov (United States)

    Trovó, Alam G; Pupo Nogueira, Raquel F; Agüera, Ana; Fernandez-Alba, Amadeo R; Malato, Sixto

    2012-10-15

    The photo-Fenton degradation of paracetamol (PCT) was evaluated using FeSO(4) and the iron complex potassium ferrioxalate (FeOx) as iron source under simulated solar light. The efficiency of the degradation process was evaluated considering the decay of PCT and total organic carbon concentration and the generation of carboxylic acids, ammonium and nitrate, expressed as total nitrogen. The results showed that the degradation was favored in the presence of FeSO(4) in relation to FeOx. The higher concentration of hydroxylated intermediates generated in the presence of FeSO(4) in relation to FeOx probably enhanced the reduction of Fe(III) to Fe(II) improving the degradation efficiency. The degradation products were determined using liquid chromatography electrospray time-of-flight mass spectrometry. Although at different concentrations, the same intermediates were generated using either FeSO(4) or FeOx, which were mainly products of hydroxylation reactions and acetamide. The toxicity of the sample for Vibrio fischeri and Daphnia magna decreased from 100% to less than 40% during photo-Fenton treatment in the presence of both iron species, except for D. magna in the presence of FeOx due to the toxicity of oxalate to this organism. The considerable decrease of the sample toxicity during photo-Fenton treatment using FeSO(4) indicates a safe application of the process for the removal of this pharmaceutical. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Toxic metal tolerance in native plant species grown in a vanadium mining area.

    Science.gov (United States)

    Aihemaiti, Aikelaimu; Jiang, Jianguo; Li, De'an; Li, Tianran; Zhang, Wenjie; Ding, Xutong

    2017-12-01

    Vanadium (V) has been extensively mined in China and caused soil pollution in mining area. It has toxic effects on plants, animals and humans, posing potential health risks to communities that farm and graze cattle adjacent to the mining area. To evaluate in situ phytoremediation potentials of native plants, V, chromium, copper and zinc concentrations in roots and shoots were measured and the bioaccumulation (BAF) and translocation (TF) efficiencies were calculated. The results showed that Setaria viridis accumulated greater than 1000 mg kg -1 V in its shoots and exhibited TF > 1 for V, Cr, Zn and BAF > 1 for Cu. The V accumulation amount in the roots of Kochia scoparia also surpassed 1000 mg kg -1 and showed TF > 1 for Zn. Chenopodium album had BAF > 1 for V and Zn and Daucus carota showed TF > 1 for Cu. Eleusine indica presented strong tolerance and high metal accumulations. S. viridis is practical for in situ phytoextractions of V, Cr and Zn and phytostabilisation of Cu in V mining area. Other species had low potential use as phytoremediation plant at multi-metal polluted sites, but showed relatively strong resistance to V, Cr, Cu and Zn toxicity, can be used to vegetate the contaminated soils and stabilise toxic metals in V mining area.

  9. Acute toxicity of zinc to several aquatic species native to the Rocky Mountains.

    Science.gov (United States)

    Brinkman, Stephen F; Johnston, Walter D

    2012-02-01

    National water-quality criteria for the protection of aquatic life are based on toxicity tests, often using organisms that are easy to culture in the laboratory. Species native to the Rocky Mountains are poorly represented in data sets used to derive national water-quality criteria. To provide additional data on the toxicity of zinc, several laboratory acute-toxicity tests were conducted with a diverse assortment of fish, benthic invertebrates, and an amphibian native to the Rocky Mountains. Tests with fish were conducted using three subspecies of cutthroat trout (Colorado River cutthroat trout Oncorhynchus clarkii pleuriticus, greenback cutthroat trout O. clarkii stomias, and Rio Grande cutthroat trout O. clarkii virginalis), mountain whitefish (Prosopium williamsoni), mottled sculpin (Cottus bairdi), longnose dace (Rhinichthys cataractae), and flathead chub (Platygobio gracilis). Aquatic invertebrate tests were conducted with mayflies (Baetis tricaudatus, Drunella doddsi, Cinygmula sp. and Ephemerella sp.), a stonefly (Chloroperlidae), and a caddis fly (Lepidostoma sp.). The amphibian test was conducted with tadpoles of the boreal toad (Bufo boreas). Median lethal concentrations (LC(50)s) ranged more than three orders of magnitude from 166 μg/L for Rio Grande cutthroat trout to >67,000 μg/L for several benthic invertebrates. Of the organisms tested, vertebrates were the most sensitive, and benthic invertebrates were the most tolerant.

  10. An investigation of boron-toxicity in leaves of two citrus species differing in boron-tolerance using comparative proteomics.

    Science.gov (United States)

    Sang, Wen; Huang, Zeng-Rong; Qi, Yi-Ping; Yang, Lin-Tong; Guo, Peng; Chen, Li-Song

    2015-06-18

    Limited data are available on boron (B)-toxicity-responsive proteins in plants. We first applied 2-dimensional electrophoresis (2-DE) to compare the effects of B-toxicity on leaf protein profiles in B-tolerant Citrus sinensis and B-intolerant Citrus grandis seedlings, and identified 27 (20) protein species with increased abundances and 23 (25) protein species with decreased abundances from the former (latter). Generally speaking, B-toxicity increased the abundances of protein species involved in antioxidation and detoxification, proteolysis, cell transport, and decreased the abundances of protein species involved in protein biosynthesis in the two citrus species. The higher B-tolerance of C. sinensis might include following several aspects: (a) protein species related to photosynthesis and energy metabolism in C. sinensis leaves were more adaptive to B-toxicity than in C. grandis ones, which was responsible for the higher photosynthesis and for the better maintenance of energy homeostasis in the former; and (b) the increased requirement for detoxification of reactive oxygen species and cytotoxic compounds due to decreased photosynthesis was less in B-toxic C. sinensis leaves than in B-toxic C. grandis ones. B-toxicity-responsive protein species involved in coenzyme biosynthesis differed between the two species, which might also contribute to the higher B-tolerance of C. sinensis. B-toxicity occurs in many regions all over the world, especially in arid and semiarid regions due to the raising of B-rich water tables with high B accumulated in topsoil. In China, B-toxicity often occurs in some citrus orchards. However, the mechanisms of citrus B-tolerance are still not fully understood. Here, we first used 2-DE to identify some new B-toxicity-responsive-proteins involved in carbohydrate and energy metabolism, antioxidation and detoxification, signal transduction and nucleotide metabolism. Our results showed that proteins involved in photosynthesis and energy metabolism

  11. Photoluminescent Gold Nanoclusters in Cancer Cells: Cellular Uptake, Toxicity, and Generation of Reactive Oxygen Species.

    Science.gov (United States)

    Matulionyte, Marija; Dapkute, Dominyka; Budenaite, Laima; Jarockyte, Greta; Rotomskis, Ricardas

    2017-02-10

    In recent years, photoluminescent gold nanoclusters have attracted considerable interest in both fundamental biomedical research and practical applications. Due to their ultrasmall size, unique molecule-like optical properties, and facile synthesis gold nanoclusters have been considered very promising photoluminescent agents for biosensing, bioimaging, and targeted therapy. Yet, interaction of such ultra-small nanoclusters with cells and other biological objects remains poorly understood. Therefore, the assessment of the biocompatibility and potential toxicity of gold nanoclusters is of major importance before their clinical application. In this study, the cellular uptake, cytotoxicity, and intracellular generation of reactive oxygen species (ROS) of bovine serum albumin-encapsulated (BSA-Au NCs) and 2-(N-morpholino) ethanesulfonic acid (MES)capped photoluminescent gold nanoclusters (Au-MES NCs) were investigated. The results showed that BSA-Au NCs accumulate in cells in a similar manner as BSA alone, indicating an endocytotic uptake mechanism while ultrasmall Au-MES NCs were distributed homogeneously throughout the whole cell volume including cell nucleus. The cytotoxicity of BSA-Au NCs was negligible, demonstrating good biocompatibility of such BSA-protected Au NCs. In contrast, possibly due to ultrasmall size and thin coating layer, Au-MES NCs exhibited exposure time-dependent high cytotoxicity and higher reactivity which led to highly increased generation of reactive oxygen species. The results demonstrate the importance of the coating layer to biocompatibility and toxicity of ultrasmall photoluminescent gold nanoclusters.

  12. Photoluminescent Gold Nanoclusters in Cancer Cells: Cellular Uptake, Toxicity, and Generation of Reactive Oxygen Species

    Directory of Open Access Journals (Sweden)

    Marija Matulionyte

    2017-02-01

    Full Text Available In recent years, photoluminescent gold nanoclusters have attracted considerable interest in both fundamental biomedical research and practical applications. Due to their ultrasmall size, unique molecule-like optical properties, and facile synthesis gold nanoclusters have been considered very promising photoluminescent agents for biosensing, bioimaging, and targeted therapy. Yet, interaction of such ultra-small nanoclusters with cells and other biological objects remains poorly understood. Therefore, the assessment of the biocompatibility and potential toxicity of gold nanoclusters is of major importance before their clinical application. In this study, the cellular uptake, cytotoxicity, and intracellular generation of reactive oxygen species (ROS of bovine serum albumin-encapsulated (BSA-Au NCs and 2-(N-morpholino ethanesulfonic acid (MEScapped photoluminescent gold nanoclusters (Au-MES NCs were investigated. The results showed that BSA-Au NCs accumulate in cells in a similar manner as BSA alone, indicating an endocytotic uptake mechanism while ultrasmall Au-MES NCs were distributed homogeneously throughout the whole cell volume including cell nucleus. The cytotoxicity of BSA-Au NCs was negligible, demonstrating good biocompatibility of such BSA-protected Au NCs. In contrast, possibly due to ultrasmall size and thin coating layer, Au-MES NCs exhibited exposure time-dependent high cytotoxicity and higher reactivity which led to highly increased generation of reactive oxygen species. The results demonstrate the importance of the coating layer to biocompatibility and toxicity of ultrasmall photoluminescent gold nanoclusters.

  13. Possible mechanism for species difference on the toxicity of pivalic acid between dogs and rats

    International Nuclear Information System (INIS)

    Yamaguchi, Toshiro; Nakajima, Yoshitsugu; Nakamura, Yutaka

    2006-01-01

    In a high dose toxicity study of pivalic acid (PA), PA caused skeletal muscle disorder in dog, and a significant increase of pivaloyl carnitine (PC) was observed in canine muscle, but not in rat muscle. In order to understand species difference of the toxicity of PA, we compared the in vitro metabolism of PA among dog, rat and rabbit, especially focussing on the carnitine conjugate. Canine muscle showed low, but significant carnitine conjugating activity, while that of rat was negligible. Canine kidney mitochondria had significant activity in the pivaloyl CoA synthesis (7 nmol/mg protein/h), but muscle mitochondria showed only trace activity. Both kidney and muscle mitochondria displayed similar carnitine acyltransferase activity (2-3 nmol/mg protein/h) towards pivaloyl CoA. On the other hand, with respect to the activity of carnitine acyltransferase in the reverse direction using PC as substrate, canine muscle mitochondria showed higher activity than that of kidney mitochondria. This means that PC is not the final stable metabolite, but is converted easily to pivaloyl CoA in canine muscle. These results suggest one of the possible mechanisms for canine selective muscle disorder to be as follows. Only canine muscle can metabolize PA to its carnitine conjugate slowly, but significantly. In canine muscle, PC is not the final stable metabolite; it is easily converted to pivaloyl CoA. As carnitine conjugation is thought to be the only detoxification metabolic route in canine muscle, under certain circumstances such as carnitine deficiency, the risk of exposure with toxic pivaloyl CoA might increase and the CoASH pool in canine muscle might be exhausted, resulting in toxicity in canine muscle

  14. Examining the joint toxicity of chlorpyrifos and atrazine in the aquatic species: Lepomis macrochirus, Pimephales promelas and Chironomus tentans

    International Nuclear Information System (INIS)

    Tyler Mehler, W.; Schuler, Lance J.; Lydy, Michael J.

    2008-01-01

    The joint toxicity of chlorpyrifos and atrazine was compared to that of chlorpyrifos alone to discern any greater than additive response using both acute toxicity testing and whole-body residue analysis. In addition, acetylcholinesterase (AChE) inhibition and biotransformation were investigated to evaluate the toxic mode of action of chlorpyrifos in the presence of atrazine. The joint toxicity of atrazine and chlorpyrifos exhibited no significant difference in Lepomis macrochirus compared to chlorpyrifos alone; while studies performed with Pimephales promelas and Chironomus tentans, did show significant differences. AChE activity and biotransformation showed no significant differences between the joint toxicity of atrazine and chlorpyrifos and that of chlorpyrifos alone. From the data collected, the combination of atrazine and chlorpyrifos pose little additional risk than that of chlorpyrifos alone to the tested fish species. - The joint toxicity between atrazine and chlorpyrifos caused greater than additive responses in invertebrates, but the interactions in vertebrates was less pronounced

  15. Examining the joint toxicity of chlorpyrifos and atrazine in the aquatic species: Lepomis macrochirus, Pimephales promelas and Chironomus tentans

    Energy Technology Data Exchange (ETDEWEB)

    Tyler Mehler, W.; Schuler, Lance J. [Fisheries and Illinois Aquaculture Center and Department of Zoology, Southern Illinois University at Carbondale, Carbondale, IL 62901-6511 (United States); Lydy, Michael J. [Fisheries and Illinois Aquaculture Center and Department of Zoology, Southern Illinois University at Carbondale, Carbondale, IL 62901-6511 (United States)], E-mail: mlydy@siu.edu

    2008-03-15

    The joint toxicity of chlorpyrifos and atrazine was compared to that of chlorpyrifos alone to discern any greater than additive response using both acute toxicity testing and whole-body residue analysis. In addition, acetylcholinesterase (AChE) inhibition and biotransformation were investigated to evaluate the toxic mode of action of chlorpyrifos in the presence of atrazine. The joint toxicity of atrazine and chlorpyrifos exhibited no significant difference in Lepomis macrochirus compared to chlorpyrifos alone; while studies performed with Pimephales promelas and Chironomus tentans, did show significant differences. AChE activity and biotransformation showed no significant differences between the joint toxicity of atrazine and chlorpyrifos and that of chlorpyrifos alone. From the data collected, the combination of atrazine and chlorpyrifos pose little additional risk than that of chlorpyrifos alone to the tested fish species. - The joint toxicity between atrazine and chlorpyrifos caused greater than additive responses in invertebrates, but the interactions in vertebrates was less pronounced.

  16. DFT calculations on 1,4-dithiine and S-oxygenated derivatives

    Directory of Open Access Journals (Sweden)

    E. Vessally

    2008-12-01

    Full Text Available The molecular structures of 1,4-dithiine and S-oxygenated derivatives are studied using B3LYP/6-311++G** level of theory. These compounds have 8π-electrons in the ring. This led to stabilization of non-planar conformation. DFT calculations show that 1,4-dithiine, C4H4SS, 1,4-dithiine-1-oxide, C4H4SOS, 1,4-dithiine-1,4-dioxide, C4H4SOSO and 1,4-dithiine-1,1,4-trioxide, C4H4SO2SO; have boat conformation. 1,4-dithiine-1,1-dioxide, C4H4SO2S, have a shadow boat conformation. 1,4-dithiine-1,1,4,4-tetraoxide, C4H4SO2SO2, have a planar conformation.

  17. Oral bioaccessibility of toxic and essential elements in raw and cooked commercial seafood species available in European markets

    KAUST Repository

    Alves, Ricardo N.; Maulvault, Ana L.; Barbosa, Vera L.; Fernandez-Tejedor, Margarita; Tediosi, Alice; Kotterman, Michiel; van den Heuvel, Fredericus H.M.; Robbens, Johan; Fernandes, José O.; Romme Rasmussen, Rie; Sloth, Jens J.; Marques, Antó nio

    2017-01-01

    The oral bioaccessibility of several essential and toxic elements was investigated in raw and cooked commercially available seafood species from European markets. Bioaccessibility varied between seafood species and elements. Methylmercury bioaccessibility varied between 10 (octopus) and 60% (monkfish). Arsenic (>64%) was the toxic element showing the highest bioaccessibility. Concerning essential elements bioaccessibility in raw seafood, selenium (73%) and iodine (71%) revealed the highest percentages. The bioaccessibility of elements in steamed products increased or decreased according to species. For example, methylmercury bioaccessibility decreased significantly after steaming in all species, while zinc bioaccessibility increased in fish (tuna and plaice) but decreased in molluscs (mussel and octopus).Together with human exposure assessment and risk characterization, this study could contribute to the establishment of new maximum permissible concentrations for toxic elements in seafood by the European food safety authorities, as well as recommended intakes for essential elements.

  18. Oral bioaccessibility of toxic and essential elements in raw and cooked commercial seafood species available in European markets

    KAUST Repository

    Alves, Ricardo N.

    2017-11-17

    The oral bioaccessibility of several essential and toxic elements was investigated in raw and cooked commercially available seafood species from European markets. Bioaccessibility varied between seafood species and elements. Methylmercury bioaccessibility varied between 10 (octopus) and 60% (monkfish). Arsenic (>64%) was the toxic element showing the highest bioaccessibility. Concerning essential elements bioaccessibility in raw seafood, selenium (73%) and iodine (71%) revealed the highest percentages. The bioaccessibility of elements in steamed products increased or decreased according to species. For example, methylmercury bioaccessibility decreased significantly after steaming in all species, while zinc bioaccessibility increased in fish (tuna and plaice) but decreased in molluscs (mussel and octopus).Together with human exposure assessment and risk characterization, this study could contribute to the establishment of new maximum permissible concentrations for toxic elements in seafood by the European food safety authorities, as well as recommended intakes for essential elements.

  19. Venom toxicity and composition in three Pseudomyrmex ant species having different nesting modes.

    Science.gov (United States)

    Touchard, Axel; Labrière, Nicolas; Roux, Olivier; Petitclerc, Frédéric; Orivel, Jérôme; Escoubas, Pierre; Koh, Jennifer M S; Nicholson, Graham M; Dejean, Alain

    2014-09-01

    We aimed to determine whether the nesting habits of ants have influenced their venom toxicity and composition. We focused on the genus Pseudomyrmex (Pseudomyrmecinae) comprising terrestrial and arboreal species, and, among the latter, plant-ants that are obligate inhabitants of myrmecophytes (i.e., plants sheltering ants in hollow structures). Contrary to our hypothesis, the venom of the ground-dwelling species, Pseudomyrmex termitarius, was as efficacious in paralyzing prey as the venoms of the arboreal and the plant-ant species, Pseudomyrmex penetrator and Pseudomyrmex gracilis. The lethal potency of P. termitarius venom was equipotent with that of P. gracilis whereas the venom of P. penetrator was less potent. The MALDI-TOF MS analysis of each HPLC fraction of the venoms showed that P. termitarius venom is composed of 87 linear peptides, while both P. gracilis and P. penetrator venoms (23 and 26 peptides, respectively) possess peptides with disulfide bonds. Furthermore, P. penetrator venom contains three hetero- and homodimeric peptides consisting of two short peptidic chains linked together by two interchain disulfide bonds. The large number of peptides in P. termitarius venom is likely related to the large diversity of potential prey plus the antibacterial peptides required for nesting in the ground. Whereas predation involves only the prey and predator, P. penetrator venom has evolved in an environment where trees, defoliating insects, browsing mammals and ants live in equilibrium, likely explaining the diversity of the peptide structures. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Biochemical and standard toxic effects of acetaminophen on the macrophyte species Lemna minor and Lemna gibba.

    Science.gov (United States)

    Nunes, Bruno; Pinto, Glória; Martins, Liliana; Gonçalves, Fernando; Antunes, Sara C

    2014-09-01

    Acetaminophen is globally one of the most prescribed drugs due to its antipyretic and analgesic properties. However, it is highly toxic when the dosage surpasses the detoxification capability of an exposed organism, with involvement of an already described oxidative stress pathway. To address the issue of the ecotoxicity of acetaminophen, we performed acute exposures of two aquatic plant species, Lemna gibba and Lemna minor, to this compound. The selected biomarkers were number of fronds, biomass, chlorophyll content, lipid peroxidation (TBARS assay), and proline content. Our results showed marked differences between the two species. Acetaminophen caused a significant decrease in the number of fronds (EC50 = 446.6 mg/L), and the establishment of a dose-dependent peroxidative damage in L. minor, but not in L. gibba. No effects were reported in both species for the indicative parameters chlorophyll content and total biomass. However, the proline content in L. gibba was substantially reduced. The overall conclusions point to the occurrence of an oxidative stress scenario more prominent for L. minor. However, the mechanisms that allowed L. gibba to cope with acetaminophen exposure were distinct from those reported for L. minor, with the likely involvement of proline as antioxidant.

  1. Toxicity of crude oil to early life stages of two fish species

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, L.M.; Hodson, P.V. [Queen' s Univ., Kingston, ON (Canada). Dept. of Biology; Brown, R.S. [Queen' s Univ., Kingston, ON (Canada). Dept. of Chemistry; King, T.; Lee, K. [Department of Fisheries and Oceans, Dartmouth, NS (Canada). Bedford Inst. of Oceanography

    2004-07-01

    Fish exposed to crude oil in their early life stages exhibit signs of dioxin-like toxicity which is linked to the presence of alkyl-substituted polycyclic aromatic hydrocarbons (PAHs). Exposure is characterized by the presence of blue-sac disease which manifests itself in edema, hemorrhaging, deformities and induction of CYP1A enzymes. In this study, the extent of CYP1A induction and BSD was compared in the early life stages of rainbow trout and Japanese medaka following exposure to two crude oils (Scotian Shelf and Alaskan North Slope Crude). Embryos were exposed to a broad range of concentrations of chemically enhanced water fractions of both oils which have unique PAH composition and chemical characteristics. It was assumed that Alaskan North Slope Crude would be more toxic than Scotian Shelf because it has a higher PAH concentration. The occurrence and severity of BSD was characterized along with the extent of PAH exposure. Preliminary results confirm that PAH exposure is greater for Alaskan North Slope Crude and that the responses of the two fish species were highly correlated.

  2. Antibiofilm Activity, Compound Characterization, and Acute Toxicity of Extract from a Novel Bacterial Species of Paenibacillus

    Directory of Open Access Journals (Sweden)

    Saad Musbah Alasil

    2014-01-01

    Full Text Available The effectiveness of many antimicrobial agents is currently decreasing; therefore, it is important to search for alternative therapeutics. Our study was carried out to assess the in vitro antibiofilm activity using microtiter plate assay, to characterize the bioactive compounds using Ultra Performance Liquid Chromatography-Diode Array Detection and Liquid Chromatography-Mass Spectrometry and to test the oral acute toxicity on Sprague Dawley rats of extract derived from a novel bacterial species of Paenibacillus strain 139SI. Our results indicate that the crude extract and its three identified compounds exhibit strong antibiofilm activity against a broad range of clinically important pathogens. Three potential compounds were identified including an amino acid antibiotic C8H20N3O4P (MW 253.237, phospholipase A2 inhibitor C21H36O5 (MW 368.512, and an antibacterial agent C14H11N3O2 (MW 253.260. The acute toxicity test indicates that the mortality rate among all rats was low and that the biochemical parameters, hematological profile, and histopathology examination of liver and kidneys showed no significant differences between experimental groups P>0.05. Overall, our findings suggest that the extract and its purified compounds derived from novel Paenibacillus sp. are nontoxic exhibiting strong antibiofilm activity against Gram-positive and Gram-negative pathogens that can be useful towards new therapeutic management of biofilm-associated infections.

  3. DETERMINATION OF THE TOXIC EFFECTS OF MERCURY IN THE Brachiaria dictyoneura (Fig. & De Not. Stapf SPECIES

    Directory of Open Access Journals (Sweden)

    Gladis E. Morales

    2013-03-01

    Full Text Available In this research has been evaluated, on a laboratory scale, the toxic effect of mercury on the root development and biomass growth of the Brachiaria dictyoneura species, with the goal of finding an adequate concentration interval for the study on the accumulation of Hg (II. Brachiaria dictyoneura seeds were exposed to different amounts of mercury, the germination kinetics were determined, and after a 20 day growth period the length of the roots and the biomass were measured. There were found harmful effects on the root development starting at 25 mg*kg-1 Hg (II; for the dry biomass the differences were found starting at 5 mg*kg-1 Hg (II and starting at 75 mg*kg-1 Hg (II for the seed emergency time, therefore, working with concentrations not exceeding 25 mg Hg(II*kg-1 of substrate is suggested.

  4. Determination of phytoextraction potential of plant species for toxic elements in soils of abandoned sulphide-mining areas

    International Nuclear Information System (INIS)

    Freitas, M.C.; Anawar, H.M.; Dionisio, I.; Dung, H.M.; Canha, N.; Bettencourt, A.; Capelo, S.; Henriques, F.; Pinto-Gomes, C.J.

    2009-01-01

    This study has determined contamination levels in soils and plants from the Sao Domingos mining area, Portugal, by k 0 -INAA. Total concentrations of As, Sb, Cr, Hg, Cu, Zn and Fe in soils were very high, exceeding the maximum limits in Portuguese legislation. Concentrations of toxic elements like As, Sb and Zn were highest in roots of Erica andevalensis, Juncus acutus, Agrostis castellana and Nicotiana glauca. Additionally, As, Br, Cr, Fe, Sb and Zn in all organs of most plants were above toxicity levels. Those species that accumulated relatively high concentrations of toxic elements in roots (and tops) may be cultivated for phytostabilisation of similar areas. (author)

  5. Characterization of Morus species in respect to micro, macro, and toxic elements

    Directory of Open Access Journals (Sweden)

    Radojković Marija M.

    2014-01-01

    Full Text Available This study examines the mineral composition of the extracts of the fruits, leaves and roots of white mulberry (Morus alba L. and black mulberry (Morus nigra L. grown in Serbia. All extract samples of white and black mulberry were analyzed for the content of micro (B, Co, Cr, Cu, Fe, Li, Mn, Ni, Se, Sr, Zn, macro (Ca, Mg, Na, and toxic metals (Al, As, Cd, Hg, Pb by inductively coupled plasma optical emission spectrometry (ICP-OES. The study revealed that parts of the plant had statistically significant impact on the levels of the examined elements among the two Morus species. All extracts contained high amounts of Ca, Mg, Na, B, Cu, Fe, Mn and Zn. The studies showed that in the most of extracts dominant macro element was Mg (591- 1942 μg/g of dry extract, while dominant microelements were Zn, B, Cu in all extracts, except for the black mulberry leaves, whose extract was most abundant in Fe (143 μg/g of dry extract. The highest content of micro and macro elements was detected in the extract of black mulberry leaves. This work contributes to the knowledge of the nutritional properties of Morus species. The obtained results may be useful in the evaluation of new dietary and food products.[ Projekat Ministarstva nauke Republike Srbije, br. TR 31013

  6. Toxic properties of specific radiation determinant molecules, derived from radiated species

    Science.gov (United States)

    Popov, Dmitri; Maliev, Vecheslav; Kedar, Prasad; Casey, Rachael; Jones, Jeffrey

    Introduction: High doses of radiation induce the formation of radiation toxins in the organs of irradiated mammals. After whole body irradiation, cellular macromolecules and cell walls are damaged as a result of long-lived radiation-induced free radicals, reactive oxygen species, and fast, charged particles of radiation. High doses of radiation induce breaks in the chemical bonds of macromolecules and cross-linking reactions via chemically active processes. These processes result in the creation of novel modified macromolecules that possess specific toxic and antigenic properties defined by the type and dose of irradiation by which they are generated. Radiation toxins isolated from the lymph of irradiated animals are classified as hematotoxic, neurotoxic, and enteric non-bacterial (GI) radiation toxins, and they play an important role in the development of hematopoietic, cerebrovascular, and gastrointestinal acute radiation syndromes (ARS). Seven distinct toxins derived from post-irradiated animals have been designated as Specific Radiation Determinants (SRD): SRD-1 (neurotoxic radiation toxin generated by the cerebrovascular form of ARS), SRD-3 (enteric non-bacterial radiation toxins generated by the gastrointestinal form of ARS), and SRD-4 (hematotoxic radiation toxins generated by the hematological, bone marrow form of ARS). SRD-4 is further subdivided into four groups depending on the severity of the ARS induced: SRD-4/1, mild ARS; SRD-4/2, moderate ARS; SRD-4/3, severe ARS; and SRD-4/4, extremely severe ARS. The seventh SRD, SRD-2 is a toxic extract derived from animals suffering from a fourth form of ARS, as described in European literature and produces toxicity primarily in the autonimic nervous system. These radiation toxins have been shown to be responsible for the induction of important pathophysiological, immunological, and biochemical reactions in ARS. Materials and Methods: These studies incorporated the use of statistically significant numbers of a

  7. Toxicity of proton-metal mixtures in the field: Linking stream macroinvertebrate species diversity to chemical speciation and bioavailability

    Energy Technology Data Exchange (ETDEWEB)

    Stockdale, Anthony [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Tipping, Edward, E-mail: et@ceh.ac.uk [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Lofts, Stephen [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Ormerod, Stephen J. [Catchment Research Group, Cardiff School of Biosciences, Cardiff University, Cardiff CF10 3US (United Kingdom); Clements, William H. [Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, CO 80523 (United States); Blust, Ronny [Ecophysiology, Biochemistry and Toxicology Group, Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium)

    2010-10-01

    Understanding metal and proton toxicity under field conditions requires consideration of the complex nature of chemicals in mixtures. Here, we demonstrate a novel method that relates streamwater concentrations of cationic metallic species and protons to a field ecological index of biodiversity. The model WHAM-F{sub TOX} postulates that cation binding sites of aquatic macroinvertebrates can be represented by the functional groups of natural organic matter (humic acid), as described by the Windermere Humic Aqueous Model (WHAM6), and supporting field evidence is presented. We define a toxicity function (F{sub TOX}) by summing the products: (amount of invertebrate-bound cation) x (cation-specific toxicity coefficient, {alpha}{sub i}). Species richness data for Ephemeroptera, Plecoptera and Trichoptera (EPT), are then described with a lower threshold of F{sub TOX}, below which all organisms are present and toxic effects are absent, and an upper threshold above which organisms are absent. Between the thresholds the number of species declines linearly with F{sub TOX}. We parameterised the model with chemistry and EPT data for low-order streamwaters affected by acid deposition and/or abandoned mines, representing a total of 412 sites across three continents. The fitting made use of quantile regression, to take into account reduced species richness caused by (unknown) factors other than cation toxicity. Parameters were derived for the four most common or abundant cations, with values of {alpha}{sub i} following the sequence (increasing toxicity) H{sup +} < Al < Zn < Cu. For waters affected mainly by H{sup +} and Al, F{sub TOX} shows a steady decline with increasing pH, crossing the lower threshold near to pH 7. Competition effects among cations mean that toxicity due to Cu and Zn is rare at lower pH values, and occurs mostly between pH 6 and 8.

  8. Structure-odor relationships of linalool, linalyl acetate and their corresponding oxygenated derivatives

    Science.gov (United States)

    Elsharif, Shaimaa; Banerjee, Ashutosh; Buettner, Andrea

    2015-10-01

    Linalool 1 is an odorant that is commonly perceived as having a pleasant odor, but is also known to elicit physiological effects such as inducing calmness and enhancing sleep. However, no comprehensive studies are at hand to show which structural features are responsible for these prominent effects. Therefore, a total of six oxygenated derivatives were synthesized from both 1 and linalyl acetate 2, and were tested for their odor qualities and relative odor thresholds (OTs) in air. Linalool was found to be the most potent odorant among the investigated compounds, with an average OT of 3.2 ng/L, while the 8-hydroxylinalool derivative was the least odorous compound with an OT of 160 ng/L; 8-carboxylinalool was found to be odorless. The odorant 8-oxolinalyl acetate, which has very similar odor properties to linalool, was the most potent odorant besides linalool, exhibiting an OT of 5.9 ng/L. By comparison, 8-carboxylinalyl acetate had a similar OT (6.1 ng/L) as its corresponding 8-oxo derivative but exhibited divergent odor properties (fatty, greasy, musty). Overall, oxygenation on carbon 8 had a substantial effect on the aroma profiles of structural derivatives of linalool and linalyl acetate.

  9. Structure-odor relationships of linalool, linalyl acetate and their corresponding oxygenated derivatives

    Directory of Open Access Journals (Sweden)

    Shaimaa eElsharif

    2015-10-01

    Full Text Available Linalool 1 is an odorant that is commonly perceived as having a pleasant odor, but is also known to elicit physiological effects such as inducing calmness and enhancing sleep. However, no comprehensive studies are at hand to show which structural features are responsible for these prominent effects. Therefore, a total of six oxygenated derivatives were synthesized from both 1 and linalyl acetate 2, and were tested for their odor qualities and relative odor thresholds (OTs in air. Linalool was found to be the most potent odorant among the investigated compounds, with an average OT of 3.2 ng/L, while the 8-hydroxylinalool derivative was the least odorous compound with an OT of 160 ng/L; 8-carboxylinalool was found to be odorless. The odorant 8-oxolinalyl acetate, which has very similar odor properties to linalool, was the most potent odorant besides linalool, exhibiting an OT of 5.9 ng/L. By comparison, 8-carboxylinalyl acetate had a similar OT (6.1 ng/L as its corresponding 8-oxo derivative but exhibited divergent odor properties (fatty, greasy, musty. Overall, oxygenation on carbon 8 had a substantial effect on the aroma profiles of structural derivatives of linalool and linalyl acetate.

  10. TOXICITY COMPARISON OF BIOSURFACTANTS AND SYNTHETIC SURFACTANTS USED IN OIL SPILL REMEDIATION TO TWO ESTUARINE SPECIES

    Science.gov (United States)

    The relative environmental toxicities of synthetic and biogenic surfactants used in oil spill remediation efforts are not well understood. Acute and chronic toxicities of three synthetic surfactants and three microbially produced surfactants were determined and compared in this s...

  11. Elimination of Whole Effluent Toxicity NPDES Permit Limits through the Use of an Alternative Testing Species and Reasonable Potential Analysis

    International Nuclear Information System (INIS)

    PAYNE, W.L.

    2004-01-01

    The cladoceran, Ceriodaphnia dubia (C. dubia), is required by the State of South Carolina to be used in whole effluent toxicity (WET) compliance tests in order to meet limits contained within National Pollutant Discharge Elimination System (NPDES) permits. Westinghouse Savannah River Company (WSRC) experienced WET test failures for no clear reason over a long period of time. Toxicity identification examinations on effluents did not indicate the presence of toxicants; therefore, the WET test itself was brought under suspicion. Research was undertaken with an alternate cladoceran, Daphnia ambigua (D. ambigua). It was determined that this species survives better in soft water, so approval was obtained from regulating authorities to use this ''alternate'' species in WET tests. The result was better test results and elimination of non-compliances. The successful use of D. ambigua allowed WSRC to gain approval from the South Carolina Department of Health and Environmental Control (SCDHEC) to remove WET limits from the NPDES permit

  12. Use of butterflies as nontarget insect test species and the acute toxicity and hazard of mosquito control insecticides.

    Science.gov (United States)

    Hoang, Tham C; Pryor, Rachel L; Rand, Gary M; Frakes, Robert A

    2011-04-01

    Honeybees are the standard insect test species used for toxicity testing of pesticides on nontarget insects for the U.S. Environmental Protection Agency (U.S. EPA) under the Federal Insecticide Fungicide and Rodenticide Act (FIFRA). Butterflies are another important insect order and a valued ecological resource in pollination. The current study conducted acute toxicity tests with naled, permethrin, and dichlorvos on fifth larval instar (caterpillars) and adults of different native Florida, USA, butterfly species to determine median lethal doses (24-h LD50), because limited acute toxicity data are available with this major insect group. Thorax- and wing-only applications of each insecticide were conducted. Based on LD50s, thorax and wing application exposures were acutely toxic to both caterpillars and adults. Permethrin was the most acutely toxic insecticide after thorax exposure to fifth instars and adult butterflies. However, no generalization on acute toxicity (sensitivity) of the insecticides could be concluded based on exposures to fifth instars versus adult butterflies or on thorax versus wing exposures of adult butterflies. A comparison of LD50s of the butterflies from this study (caterpillars and adults) with honeybee LD50s for the adult mosquito insecticides on a µg/organism or µg/g basis indicates that several butterfly species are more sensitive to these insecticides than are honeybees. A comparison of species sensitivity distributions for all three insecticides shows that permethrin had the lowest 10th percentile. Using a hazard quotient approach indicates that both permethrin and naled applications in the field may present potential acute hazards to butterflies, whereas no acute hazard of dichlorvos is apparent in butterflies. Butterflies should be considered as potential test organisms when nontarget insect testing of pesticides is suggested under FIFRA. Copyright © 2011 SETAC.

  13. Survival of added bacterial species and metabolism of toxic compounds in natural environments

    International Nuclear Information System (INIS)

    King, V.M.

    1987-01-01

    Bacteria able to degrade either 2,4-dichlorophenol (DCP) or phenanthrene (PHEN) were isolated from polluted freshwater environments. Two isolates able to degrade each compound were tested for mineralization with a sensitive 14 C assay and for survival in lake water and sewage using a selective medium. One DCP isolate was identified as Alcaligenes paradoxus and the other as Alcaligenes sp. One PHEN isolate was identified as Pseudomonas fluorescens and the other as Pseudomonas sp. All four isolates survived and grew in sterile environments which indicated that starvation would not be a factor in survival of these strains. The number of organisms declined immediately in number in nonsterile lake water. However, they did survive or even grow in nonsterile sewage for a short period before declining in number. Biotic factors appeared to be influential for survival and mineralization of target compounds in many environments. The removal of protozoa, which prey on bacteria, improved survival of the added cells, but had no influence on the mineralization of 10 μg DCP/L. In comparison, degradation of 10 and 25 mg DCP/L stopped after a few days. Yeast nitrogen base appeared to overcome the lack of nutrient regeneration, a function attributed to protozoa. The additional nutrients increased toxicant mineralization, especially when seeded with appropriate species. Thus, protozoa may limit growth of added cells but appear to be needed for mineralization of higher concentrations of DCP

  14. Assessment of mechanisms of metal-induced reproductive toxicity in aquatic species as a biomarker of exposure

    International Nuclear Information System (INIS)

    Anderson, M.; George, W.; Sikka, S.; Kamath, B.; Preslan, J.; Agrawal, K.; Rege, A.

    1993-01-01

    This project is designed to identify heavy metals and organic contaminants of concern which could impact on the biota in the Louisiana wetlands by assessment of uptake and bioaccumulation of contaminants and their effects on reproductive processes as biomarkers of exposure. Heavy metals (lead, cadmium, cobalt, and mercury) have been demonstrated to have toxic effects on reproduction in mammals and several aquatic species. Hexachlorobenzene (HCB) is an persistent environmental contaminant which has been measured in human serum, fat, semen, and follicular fluid. HCB has been shown to be a reproductive toxin in rats and primates. Polychlorinated biphenyls (PCBs) are prevalent chlorinated hydrocarbons currently contaminating our environment. PCBs resist degradation and are insoluble in water; however, they bioaccumulate in aquatic species. Disturbances of the reproductive systems are not only sensitive indicators of toxicity but threatens the propagation of a species

  15. Synergistic toxicity of Macondo crude oil and dispersant Corexit 9500A(®) to the Brachionus plicatilis species complex (Rotifera).

    Science.gov (United States)

    Rico-Martínez, Roberto; Snell, Terry W; Shearer, Tonya L

    2013-02-01

    Using the marine rotifer Brachionus plicatilis acute toxicity tests, we estimated the toxicity of Corexit 9500A(®), propylene glycol, and Macondo oil. Ratios of 1:10, 1:50 and 1:130 for Corexit 9500A(®):Macondo oil mixture represent: maximum exposure concentrations, recommended ratios for deploying Corexit (1:10-1:50), 1:130 the actual dispersant:oil ratio used in the Deep Water Horizon spill. Corexit 9500A(®) and oil are similar in their toxicity. However, when Corexit 9500A(®) and oil are mixed, toxicity to B. manjavacas increases up to 52-fold. Extrapolating these results to the oil released by the Macondo well, suggests underestimation of increased toxicity from Corexit application. We found small differences in sensitivity among species of the B. plicatilis species complex, likely reflecting phylogenetic similarity. Just 2.6% of the water-accommodated fraction of oil inhibited rotifer cyst hatching by 50%, an ecologically significant result because rotifer cyst in sediments are critical resources for the recolonization of populations each Spring. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Petroleum Hydrocarbon Mixture Toxicity and a Trait Based Approach to Soil Invertebrate Species for Site Specific Risk Assessments.

    Science.gov (United States)

    Gainer, Amy; Cousins, Mark; Hogan, Natacha; Siciliano, Steven D

    2018-05-05

    Although petroleum hydrocarbons (PHCs) released to the environment typically occur as mixtures, PHC remediation guidelines often reflect individual substance toxicity. It is well documented that groups of aliphatic PHCs act via the same mechanism of action, nonpolar narcosis and, theoretically, concentration addition mixture toxicity principles apply. To assess this theory, ten standardized acute and chronic soil invertebrate toxicity tests on a range of organisms (Eisenia fetida, Lumbricus terrestris, Enchytraeus crypticus, Folsomia candida, Oppia nitens and Hypoaspis aculeifer) were conducted with a refined PHC binary mixture. Reference models for concentration addition and independent action were applied to the mixture toxicity data with consideration of synergism, antagonism and dose level toxicity. Both concentration addition and independent action, without further interactions, provided the best fit with observed response to the mixture. Individual fraction effective concentration values were predicted from optimized, fitted reference models. Concentration addition provided a better estimate than independent action of individual fraction effective concentrations based on comparison with available literature and species trends observed in toxic responses to the mixture. Interspecies differences in standardized laboratory soil invertebrate species responses to PHC contaminated soil was reflected in unique traits. Diets that included soil, large body size, permeable cuticle, low lipid content, lack of ability to molt and no maternal transfer were traits linked to a sensitive survival response to PHC contaminated soil in laboratory tests. Traits linked to sensitive reproduction response in organisms tested were long life spans with small clutch sizes. By deriving single fraction toxicity endpoints considerate of mixtures, we reduce resources and time required in conducting site specific risk assessments for the protection of soil organism's exposure pathway. This

  17. Using aquatic macroinvertebrate species traits to build test batteries for sediment toxicity assessment: accounting for the diversity of potential biological responses to toxicants.

    Science.gov (United States)

    Ducrot, Virginie; Usseglio-Polatera, Philippe; Péry, T Alexandre R R; Mouthon, Jacques; Lafont, Michel; Roger, Marie-Claude; Garric, Jeanne; Férard, Jean-François

    2005-09-01

    An original species-selection method for the building of test batteries is presented. This method is based on the statistical analysis of the biological and ecological trait patterns of species. It has been applied to build a macroinvertebrate test battery for the assessment of sediment toxicity, which efficiently describes the diversity of benthic macroinvertebrate biological responses to toxicants in a large European lowland river. First, 109 potential representatives of benthic communities of European lowland rivers were selected from a list of 479 taxa, considering 11 biological traits accounting for the main routes of exposure to a sediment-bound toxicant and eight ecological traits providing an adequate description of habitat characteristics used by the taxa. Second, their biological and ecological trait patterns were compared using coinertia analysis. This comparison allowed the clustering of taxa into groups of organisms that exhibited similar life-history characteristics, physiological and behavioral features, and similar habitat use. Groups exhibited various sizes (7-35 taxa), taxonomic compositions, and biological and ecological features. Main differences among group characteristics concerned morphology, substrate preferendum and habitat utilization, nutritional features, maximal size, and life-history strategy. Third, the best representatives of the mean biological and ecological characteristics of each group were included in the test battery. The final selection was composed of Chironomus riparius (Insecta: Diptera), Branchiura sowerbyi (Oligochaeta: Tubificidae), Lumbriculus variegatus (Oligochaeta: Lumbriculidae), Valvata piscinalis (Gastropoda: Valvatidae), and Sericostoma personatum (Trichoptera: Sericostomatidae). This approach permitted the biological and ecological variety of the battery to be maximized. Because biological and ecological traits of taxa determine species sensitivity, such maximization should permit the battery to better account

  18. Salicylic Acid Alleviates Aluminum Toxicity in Soybean Roots through Modulation of Reactive Oxygen Species Metabolism

    Directory of Open Access Journals (Sweden)

    Ning Liu

    2017-11-01

    Full Text Available As an important signal molecule, salicylic acid (SA improves plant tolerance to aluminum (Al stress. The objective of this study was to investigate the effects of exogenous SA application on the dynamics of endogenous SA and reactive oxygen species in soybean (Glycine max L. exposed to Al stress. The roots of soybean seedlings were exposed to a combination of AlCl3 (30 μM and SA (10 μM/PAC (100 μM, paclobutrazol, SA biosynthesis inhibitor for 3, 6, 9, and 12 h. Al stress induced an increase in endogenous SA concentration in a time-dependent manner, also verified by the up-regulated expression of GmNPR1, an SA-responsive gene. Al stress increased the activities of phenylalanine ammonia-lyase (PAL and benzoic acid 2-hydroxylase (BA2H, and the contents of SA, O2- and malondialdehyde (MDA in the root apex. The application of exogenous SA increased PAL and BA2H, and reduced O2- and MDA contents in soybean roots under Al stress. PAC inhibited the SA induced increase in BA2H activity. In addition, the SA application resulted in a rapid increase in hydrogen peroxide (H2O2 concentration under Al stress, followed by a sharp decrease. Compared with the plants exposed to Al alone, Al+SA plants possessed higher activities of superoxide dismutase, peroxidase, and ascorbate peroxidase, and lower catalase activity, indicating that SA alleviated Al-induced oxidative damage. These results suggested that PAL and BA2H were involved in Al-induced SA production and showed that SA alleviated the adverse effects of Al toxicity by modulating the cellular H2O2 level and the antioxidant enzyme activities in the soybean root apex.

  19. Reactive oxygen species are crucial for hydroxychavicol toxicity toward KB epithelial cells.

    Science.gov (United States)

    Jeng, J H; Wang, Y J; Chang, W H; Wu, H L; Li, C H; Uang, B J; Kang, J J; Lee, J J; Hahn, L J; Lin, B R; Chang, M C

    2004-01-01

    Betel quid (BQ) chewing shows a strong correlation to the incidence of oral submucous fibrosis (OSF), leukoplakia and oral cancer. BQ contains mainly areca nut, lime, Piper betle leaf (PBL) and the inflorescence of P. betle (IPB). Hydroxychavicol (4-allyl-catechol, HC), as a major phenolic compound in PBL and IPB, is shown to induce oxidative stress, glutathione (GSH) depletion and cell cycle deregulation. Using bivariate BrdU/PI flow cytometry, KB cells in DNA synthesis (S phase) are shown to be sensitive to the toxic effect of HC and show cell cycle arrest and apoptosis following exposure to 0.1 and 0.3 mM HC. HC-induced apoptosis and cell cycle arrest are associated with mitochondrial membrane potential (delta Psim) depolarization as revealed by a decrease in rhodamine fluorescence. N-acetyl-L-cysteine (1 mM), superoxide dismutase (100 U/ml) and catalase (1000 U/ml) were effective in prevention of HC-induced GSH depletion (as indicated by chloromethylfluorescein fluorescence), reactive oxygen species (ROS) production (by dichlorofluorescein fluorescence), cell cycle arrest and apoptosis. However, dimethylthiourea (2 mM), neocuproine (1 mM), 1,10-phenanthroline (200 microM) and desferrioxamine (0.5 mM) showed little effect on HC-induced cell changes. HC elevated the cellular and mitochondrial GSH levels at moderate concentrations (0.05-0.1 mM), whereas at a concentration of 0.3 mM, inhibitory effects were noted. These results indicate that HC consumption may be associated with BQ-chewing-related oral mucosal diseases via GSH depletion, ROS production, mitochondrial dysfunction, cell cycle disturbance and the induction of apoptosis. These events are related to the production of superoxide radicals and hydrogen peroxide.

  20. Salicylic acid alleviates aluminum toxicity in soybean roots through modulation of reactive oxygen species metabolism

    Science.gov (United States)

    Liu, Ning; Song, Fengbin; Zhu, Xiancan; You, Jiangfeng; Yang, Zhenming; Li, Xiangnan

    2017-11-01

    As an important signal molecule, salicylic acid (SA) improves plant tolerance to aluminum (Al) stress. The objective of this study was to investigate the effects of exogenous SA application on the dynamics of endogenous SA and reactive oxygen species in soybean (Glycine max L.) exposed to Al stress. The roots of soybean seedlings were exposed to a combination of AlCl3 (30 μM) and SA (10 μM)/PAC (100 μM, paclobutrazol, SA biosynthesis inhibitor) for 3, 6, 9 and 12 h. Al stress induced an increase in endogenous SA concentration in a time-dependent manner, also verified by the up-regulated expression of GmNPR1, an SA-responsive gene. Al stress increased the activities of phenylalanine ammonia-lyase (PAL) and benzoic acid 2-hydroxylase (BA2H), and the contents of SA, O2- and malondialdehyde (MDA) in the root apex. The application of exogenous SA increased PAL and BA2H, and reduced O2- and MDA contents in soybean roots under Al stress. PAC inhibited the SA induced increase in BA2H activity. In addition, the SA application resulted in a rapid increase in hydrogen peroxide (H2O2) concentration under Al stress, followed by a sharp decrease. Compared with the plants exposed to Al alone, Al+SA plants possessed higher activities of superoxide dismutase, peroxidase and ascorbate peroxidase, and lower catalase activity, indicating that SA alleviated Al-induced oxidative damage. These results suggested that PAL and BA2H were involved in Al-induced SA production and showed that SA alleviated the adverse effects of Al toxicity by modulating the cellular H2O2 level and the antioxidant enzyme activities in the soybean root apex.

  1. Toxicity of puffer fish: two species (Lagocephalus laevigatus, linaeus 1766 and Sphoeroides spengleri, Bloch 1785 from the Southeastern Brazilian coast

    Directory of Open Access Journals (Sweden)

    J. S. Oliveira

    2003-01-01

    Full Text Available In Brazil, where puffer fish are considered poisonous, there are few documented cases on human consumption and consequent poisoning. In this study, toxicity of two puffer fish species from the Brazilian coast was examined. Specimens of Sphoeroides spengleri and Lagocephalus laevigatus were caught in São Sebastião Channel (North coast of São Paulo State, Brazil between January 1996 and May 1997. Acidic ethanol extracts from muscle and skin plus viscera were tested for mice acute toxicity using the standard method of Kawabata. Polar extracts of S. spengleri showed high toxicity up to 946 MU/g. Extracts from L. laevigatus showed very low levels of toxicity, never exceeding 1.7 MU/g. All extracts from both species blocked amielinic nerve fiber evoked impulses of crustacean legs; this effect reverted on washing similar to the standard tetrodotoxin TTX. The aqueous extract solutions were partially purified using an ionic exchange column (Amberlit GC-50 followed by treatment with activated charcoal (Norit-A. The presence of TTX and their analogs in the semi-purified extracts were confirmed by HPLC and mass spectrometry (MALDI-TOF.

  2. Persistence and extinction of a stochastic single-species population model in a polluted environment with impulsive toxicant input

    Directory of Open Access Journals (Sweden)

    Meng Liu

    2013-10-01

    Full Text Available A stochastic single-species population system in a polluted environment with impulsive toxicant input is proposed and studied. Sufficient conditions for extinction, non-persistence in the mean, strong persistence in the mean and stochastic permanence of the population are established. The threshold between strong persistence in the mean and extinction is obtained. Some simulation figures are introduced to illustrate the main results.

  3. Diversity of Micrurus Snake Species Related to Their Venom Toxic Effects and the Prospective of Antivenom Neutralization

    Science.gov (United States)

    Tanaka, Gabriela D.; Furtado, Maria de Fátima D.; Portaro, Fernanda C. V.; Sant'Anna, Osvaldo Augusto; Tambourgi, Denise V.

    2010-01-01

    Background Micrurus snake bites can cause death by muscle paralysis and respiratory arrest, few hours after envenomation. The specific treatment for coral snake envenomation is the intravenous application of heterologous antivenom and, in Brazil, it is produced by horse immunization with a mixture of M. corallinus and M. frontalis venoms, snakes that inhabit the South and Southeastern regions of the country. However, this antivenom might be inefficient, considering the existence of intra- and inter-specific variations in the composition of the venoms. Therefore, the aim of the present study was to investigate the toxic properties of venoms from nine species of Micrurus: eight present in different geographic regions of Brazil (M. frontalis, M. corallinus, M. hemprichii, M. spixii, M. altirostris, M. surinamensis, M. ibiboboca, M. lemniscatus) and one (M. fulvius) with large distribution in Southeastern United States and Mexico. This study also analyzed the antigenic cross-reactivity and the neutralizing potential of the Brazilian coral snake antivenom against these Micrurus venoms. Methodology/Principal Findings Analysis of protein composition and toxicity revealed a large diversity of venoms from the nine Micrurus species. ELISA and Western blot assays showed a varied capability of the therapeutic antivenom to recognize the diverse species venom components. In vivo and in vitro neutralization assays indicated that the antivenom is not able to fully neutralize the toxic activities of all venoms. Conclusion These results indicate the existence of a large range of both qualitative and quantitative variations in Micrurus venoms, probably reflecting the adaptation of the snakes from this genus to vastly dissimilar habitats. The data also show that the antivenom used for human therapy in Brazil is not fully able to neutralize the main toxic activities present in the venoms from all Micrurus species occurring in the country. It suggests that modifications in the

  4. Toxicity to Chicks of Aspergillus and Penicillium Species Isolated from Moldy Pecans 1

    Science.gov (United States)

    Doupnik, Ben; Bell, D. K.

    1971-01-01

    Isolates of Aspergillus chevalieri, A. flavus, A. ochraceus, A. repens, and Penicillium funiculosum and complexes of P. citrinum-P. implicatum isolated from moldy pecan meats were toxic to chicks. PMID:5564681

  5. EARLY LIFE STAGE TOXICITY OF COPPER TO ENDANGERED AND SURROGATE FISH SPECIES

    Science.gov (United States)

    Water quality criteria (WQC) for the protection of aquatic life have not explicitly considered the degree of protection afforded to aquatic species listed as endangered or threatened under the U.S. Endangered Species Act (listed species) . Most WQCs are based primarily on respon...

  6. Comparative toxicity of two oil dispersants, superdispersant-25 and corexit 9527, to a range of coastal species.

    Science.gov (United States)

    Scarlett, Alan; Galloway, Tamara S; Canty, Martin; Smith, Emma L; Nilsson, Johanna; Rowland, Steven J

    2005-05-01

    The acute toxicity of the oil dispersant Corexit 9527 reported in the literature is highly variable. No peer-reviewed data exist for Superdispersant-25 (SD-25). This study compares the toxicity of the two dispersants to a range of marine species representing different phyla occupying a wide range of niches: The marine sediment-dwelling amphipod Corophium volutator (Pallas), the common mussel Mytilus edulis (L.), the symbiotic snakelocks anemone Anemonia viridis (Forskål), and the seagrass Zostera marina (L.). Organisms were exposed to static dispersant concentrations for 48-h and median lethal concentration (LC50), median effect concentration (EC50), and lowest-observable-effect concentration (LOEC) values obtained. The sublethal effects of 48-h exposures and the ability of species to recover for up to 72 h after exposure were quantified relative to the 48-h endpoints. Results indicated that the anemone lethality test was the most sensitive with LOECs of 20 ppm followed by mussel feeding rate, seagrass photosynthetic index and amphipod lethality, with mussel lethality being the least sensitive with LOECs of 250 ppm for both dispersants. The results were consistent with current theory that dispersants act physically and irreversibly on the respiratory organs and reversibly, depending on exposure time, on the nervous system. Superdispersant-25 was found overall to be less toxic than Corexit 9527 and its sublethal effects more likely to be reversible following short-term exposure.

  7. Toxicity of algal-derived aldehydes to two invertebrate species: Do heavy metal pollutants have a synergistic effect?

    International Nuclear Information System (INIS)

    Taylor, Rebecca L.; Caldwell, Gary S.; Bentley, Matthew G.

    2005-01-01

    The recent discovery of the production of anti-proliferative aldehydes in a variety of microalgal species has lead to considerable investigation into the effects of these toxins on aquatic invertebrates. Studies have, however, rarely considered the impact pollutants may have on grazer responses to algal toxins. In this study, the acute toxicities of five aldehydes to the rotifer Brachionus plicatilis and nauplii of the brine shrimp Artemia salina are examined using immersion assays. In addition, the effect of a representative of these aldehydes in the presence of sub-lethal levels of heavy metals was examined. B. plicatilis generally showed greater sensitivity to the aldehydes than A. salina. The polyunsaturated 2-trans,4-trans-decadienal was the most toxic to both species having 24 h LD 50 values of 7 and 20 μM for B. plicatilis and A. salina, respectively. The remaining aldehydes had different orders of toxicity for the two species with a stronger relationship observed between mortality and aldehyde carbon-chain length for A. salina whereas B. plicatilis mortality showed a stronger dependence on the presence of carbon-carbon double bonds in the aldehydes. The presence of 1 μM of copper sulphate in solutions of decadienal resulted in the reduction of the 24 h LD 50 of decadienal by approximately a third for both species. 1 μM of copper chloride in solutions of decadienal reduced the 24 h LD 50 of decadienal to A. salina nauplii by approximately 11% and 1 μM zinc sulphate caused a reduction of only 3%. Pre-exposure of the organisms to 1 μM copper sulphate had no significant impact on their subsequent mortality in decadienal. The ecological implications and the possible mechanisms for the action of copper sulphate on the response of organisms to decadienal are discussed

  8. Toxicity of algal-derived aldehydes to two invertebrate species: Do heavy metal pollutants have a synergistic effect?

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Rebecca L. [School of Marine Science and Technology, University of Newcastle upon Tyne, Ridley Building, Claremont Road, Newcastle upon Tyne NE1 7RU (United Kingdom)]. E-mail: r.l.taylor@ncl.ac.uk; Caldwell, Gary S. [School of Marine Science and Technology, University of Newcastle upon Tyne, Ridley Building, Claremont Road, Newcastle upon Tyne NE1 7RU (United Kingdom); Bentley, Matthew G. [School of Marine Science and Technology, University of Newcastle upon Tyne, Ridley Building, Claremont Road, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2005-08-15

    The recent discovery of the production of anti-proliferative aldehydes in a variety of microalgal species has lead to considerable investigation into the effects of these toxins on aquatic invertebrates. Studies have, however, rarely considered the impact pollutants may have on grazer responses to algal toxins. In this study, the acute toxicities of five aldehydes to the rotifer Brachionus plicatilis and nauplii of the brine shrimp Artemia salina are examined using immersion assays. In addition, the effect of a representative of these aldehydes in the presence of sub-lethal levels of heavy metals was examined. B. plicatilis generally showed greater sensitivity to the aldehydes than A. salina. The polyunsaturated 2-trans,4-trans-decadienal was the most toxic to both species having 24 h LD{sub 50} values of 7 and 20 {mu}M for B. plicatilis and A. salina, respectively. The remaining aldehydes had different orders of toxicity for the two species with a stronger relationship observed between mortality and aldehyde carbon-chain length for A. salina whereas B. plicatilis mortality showed a stronger dependence on the presence of carbon-carbon double bonds in the aldehydes. The presence of 1 {mu}M of copper sulphate in solutions of decadienal resulted in the reduction of the 24 h LD{sub 50} of decadienal by approximately a third for both species. 1 {mu}M of copper chloride in solutions of decadienal reduced the 24 h LD{sub 50} of decadienal to A. salina nauplii by approximately 11% and 1 {mu}M zinc sulphate caused a reduction of only 3%. Pre-exposure of the organisms to 1 {mu}M copper sulphate had no significant impact on their subsequent mortality in decadienal. The ecological implications and the possible mechanisms for the action of copper sulphate on the response of organisms to decadienal are discussed.

  9. The Sensitive and Simple Measurement of Underivatized Cholesterol and Its Oxygen Derivatives in Biological Materials by Capillary Gas Chromatography Coupled to a Mass-Selective Detector

    Czech Academy of Sciences Publication Activity Database

    Czauderna, M.; Marounek, Milan; Dušková, D.; Kowalczyk, J.

    2013-01-01

    Roč. 25, č. 4 (2013), s. 655-667 ISSN 1233-2356 Institutional support: RVO:67985904 Keywords : cholesterol * oxygen derivatives of cholesterol * gas chromatography Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.485, year: 2013

  10. Repellency and toxicity of three Impatients species (Balsaminaceae) extracts on Myzus persicae Sulzer (Homoptera: Aphididae)

    Czech Academy of Sciences Publication Activity Database

    Pavela, R.; Vrchotová, Naděžda; Šerá, Božena

    2009-01-01

    Roč. 2009, - (2009), s. 48-51 ISSN 0974-391X R&D Projects: GA MZe(CZ) QH72117 Institutional research plan: CEZ:AV0Z60870520 Keywords : Impatiens * repellency * toxicity Subject RIV: EH - Ecology, Behaviour

  11. Toxicity of waters from the Rochester Embayment Area of Concern to the plankton species Pseudokirchneriella subcapitata and Ceriodaphnia dubia

    Science.gov (United States)

    Baldigo, Barry P.; Duffy, Brian T.; Smith, Alexander J.; George, Scott D.

    2016-01-01

    The lower Genesee River and Rochester Embayment of Lake Ontario are a designated Area of Concern (AOC) under the binational Great Lakes Water Quality Agreement. The “degradation of phytoplankton and zooplankton populations” or plankton Beneficial Use Impairment (BUI) was classified as unknown and in need of further assessment in this AOC because water quality data suggested plankton communities could be effected and community data were either unavailable or indicated impacts. The plankton BUI may now be obsolete because local contaminant sources have been largely eliminated. The present study was conducted between July 2013 and August 2014 to assess the BUI-removal criteria: “AOC plankton bioassays confirm that toxicity in ambient waters (i.e., no growth inhibition) is not significantly higher than comparable non-AOC controls”. Acute and chronic toxicity of waters from 13 sites were quantified seasonally using standardized bioassays with the green alga Pseudokirchneriella subcapitata and water flea Ceriodaphnia dubia to test the hypothesis that toxicity of waters from AOC sites was not higher than that of waters from comparable non-AOC reference sites. Survival and reproduction of C. dubia did not differ significantly between site types, systems, or months. The growth of P. subcapitata did not differ between site types, but differed among systems and months. All results indicate that waters from AOC sites were no more toxic to both plankton species than waters from reference sites. Assuming test species represent natural plankton assemblages, water quality should not negatively affect survival and growth of resident plankton populations in the Rochester Embayment AOC.

  12. Effects of exogenous oxygen derived free radicals on myocardial capillary permeability, vascular tone, and incidence of ventricular arrhythmias in the canine heart

    DEFF Research Database (Denmark)

    Svendsen, Jesper Hastrup; Bjerrum, P J

    1992-01-01

    The aim was to examine the effects of exogenous oxygen derived free radicals on myocardial capillary permeability for a small hydrophilic indicator, postischaemic vascular tone, and the occurrence of arrhythmias in the canine heart in vivo.......The aim was to examine the effects of exogenous oxygen derived free radicals on myocardial capillary permeability for a small hydrophilic indicator, postischaemic vascular tone, and the occurrence of arrhythmias in the canine heart in vivo....

  13. Toxin and species identification of toxic octopus implicated into food poisoning in Taiwan.

    Science.gov (United States)

    Wu, Ya-Jung; Lin, Chun-Lan; Chen, Chien-Hung; Hsieh, Cheng-Hong; Jen, Hsiao-Chin; Jian, Shi-Jie; Hwang, Deng-Fwu

    2014-12-01

    A food poisoning incident due to ingestion of unknown octopus occurred in Taipei in December, 2010. The serum and urine from victims (male 38 and 43 years old) were collected, determined the toxicity, and identified tetrodotoxin (TTX) by high-performance liquid chromatography with tandem mass spectrometry (LC-MS/MS). It was found that only urine contained the trace of TTX. Then, two retained specimen (one without blue ring in the skin and another with small blue ring in the skin) were collected from victims and examined for the toxicity and toxin. Meanwhile, 6 specimens of octopus without blue ring in the skin and 4 specimens of octopus with blue ring in the skin were re-collected from the market. Both retained octopus samples were found to contain TTX. However, re-collected market's octopus without blue ring in the skin did not show to contain TTX the and was identified as Octopus aegina by using the analysis of cytochrome b gene (Cyt b) and cytochrome c oxidase subunit I gene (COI). Only octopus with blue ring in the skin contained TTX and was identified as Hapalochlaena fasciata by using the analysis of Cyt b and COI. Therefore, this octopus food poisoning was caused by toxic octopus H. fasciata and the causative agent was TTX. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. The Effect of Various Species of Macroalgae on the Growth, Survival, and Toxicity of Karenia brevis

    Science.gov (United States)

    Gardner, K. G.; Lovko, V. J.; Henry, M. S.

    2016-02-01

    Harmful algal blooms (HABs) caused by the dinoflagellate Karenia brevis produce toxins that result in negative impacts to both humans and the environment. Little is known about the termination stages of these blooms, and few viable control mechanisms have been suggested. Natural, algae derived compounds have been proposed as a way to limit bloom growth and reduce brevetoxins in the water column. The work presented here examines the ability of macroalgae to inhibit the growth or survival of K. brevis, similar to what has been demonstrated with other red tide species. Additionally, we attempted to determine if macroalgae decreases water column brevetoxins which, to our knowledge, has not been tested with macroalgae but has been demonstrated in other studies with microalgal species. The macroalgae species Dictyota sp. and Gracilaria sp. caused 100% mortality of K. brevis in under 24 hours. Compared to the control, 7 other species significantly decreased the growth rate of K. brevis. The Dictyota treatments showed significant toxin reduction and increase of the antitoxin brevanol. These results indicate that some combination of compounds produced by macroalgae inhibit growth and survival of K. brevis and possibly limit their toxin production. Future studies will attempt to isolate and identify these compounds and test their effects on other marine organisms such as diatoms. Determining the interactions between HAB species K. brevis and macroalgal species will provide insights on the mechanism of bloom termination and a potential control method.

  15. Chemical composition, toxicity and antioxidant activities of essential oils of stem bark of Nigerian species of guava (Psidium guajava Linn.)

    Science.gov (United States)

    Fasola, Taiye R.; Oloyede, Ganiyat Kehinde; Aponjolosun, Babalola S.

    2011-01-01

    Essential oil from the stem bark of Nigerian species of Psidium guajava of the family Myrtaceae was obtained by hydro-distillation using an all-glass Clavenger apparatus. GC and GC/MS analysis were carried out on the essential oil and was found to contain 62 compounds constituting 99.98 % of the total oil composition. The principal constituents are hydrocarbons, amines, amides and esters with 3,6-dioxa-2,4,5,7-tetraoctane,2,2,4,4,5,5,7,7-octamethyl (11.67 %) and cyclononane (10.66 %) dominating the total essential oil. Brine shrimp lethality test was carried out to determine the toxicity of the oils to living organisms (shrimps). LC50 value (µg/ml) of 1.0009 obtained showed that the essential oil of P. guajava stem bark was toxic. The antioxidant property of essential oil was investigated by measuring the decrease in absorption at 517 nm of 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) in a UV/visible spectrophotometer. The oil showed better activity as a radical scavenger than α-tocopherol. The oil activity was 71.83 % at 0.2 mg/ml and the absorption is stoichiometric with respect to the number of electron taken up. Thus, the results of this study showed that the essential oil from P. guajava was not only toxic; it possessed antioxidant activity, which could exert beneficial actions against pathological alterations caused by the presence of highly reactive free radicals. The toxicity of the oil can be taken advantage of in the therapy of diseases involving cell or tumor growth. PMID:27857663

  16. Phytoextraction of potentially toxic elements by six tree species growing on hazardous mining sludge.

    Science.gov (United States)

    Mleczek, Mirosław; Goliński, Piotr; Krzesłowska, Magdalena; Gąsecka, Monika; Magdziak, Zuzanna; Rutkowski, Paweł; Budzyńska, Sylwia; Waliszewska, Bogusława; Kozubik, Tomisław; Karolewski, Zbigniew; Niedzielski, Przemysław

    2017-10-01

    The aim of the study was to compare the phytoextraction abilities of six tree species (Acer platanoides L., Acer pseudoplatanus L., Betula pendula Roth, Quercus robur L., Tilia cordata Miller, Ulmus laevis Pall.), cultivated on mining sludge contaminated with arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), thallium (Tl), and zinc (Zn). All six tree species were able to survive on such an unpromising substrate. However, A. platanoides and T. cordata seedlings grown on the polluted substrate showed significantly lower biomass than control plants (55.5 and 45.6%, respectively). As, Cd, Cu, Pb, and Tl predominantly accumulated in the roots of all the analyzed tree species with the following highest contents: 1616, 268, 2432, 547, and 856 mg kg -1 , respectively. Zn was predominantly localized in shoots with the highest content of 5801 and 5732 mg kg -1 for U. laevis and A. platanoides, respectively. A. platanoides was the most effective in Zn phytoextaction, with a bioconcentration factor (BCF) of 8.99 and a translocation factor (TF) of 1.5. Furthermore, with the exception of A. pseudoplatanus, the analyzed tree species showed a BCF > 1 for Tl, with the highest value for A. platanoides (1.41). However, the TF for this metal was lower than 1 in all the analyzed tree species. A. platanoides showed the highest BCF and a low TF and could, therefore, be a promising species for Tl phytostabilization. In the case of the other analyzed tree species, their potential for effective phytoextraction was markedly lower. Further studies on the use of A. platanoides in phytoremediation would be worth conducting.

  17. Toxicity of fire retardant chemicals and fire suppressant foams to vertebrate and invertebrate wildlife species

    Science.gov (United States)

    Vyas, Nimish B.; Hill, Elwood F.

    1996-01-01

    Under laboratory conditions, acute single-dose oral toxicity tests (LD50) were conducted with three fire retardant chemicals (Fire-Trol GTS-R, Phos-Chek D75-F, and Fire-Trol LCG-R) and two fire suppressant foams (Silv-Ex and Phos-Chek WD-881) to determine effects on adult northern bobwhite, American kestrel, red-winged blackbird, and white-footed mouse. In addition, earthworms were exposed (LC50) for 14 days in treated soil.In general, no toxic responses were evident. For northern bobwhite, the LD50 for all five chemicals was >2000 mg a.l./kg of body mass. American kestrels regurgitated all chemicals except Silv-ex; LD50s all exceeded 2000 mg/kg. The LD50 for red-winged blackbird was also >2000 mg/kg for all chemicals except Fire-Trol GTS-R which is currently undergoing further testing. In addition, the LD50 for white-footed mouse was >2000 mg/kg for Phos-Chek D75F. The 14-day LC50 for earthworms was >1000 ppm for all chemicals. Therefore, we concluded that these retardants and foams do not pose an acute hazard to adult birds, mammals, or earthworms. However, ecological studies to evaluate the potential effects of these formulations on vertebrate behavior and population dynamics are in progress.

  18. Comparative toxicity of a brominated flame retardant (tetrabromobisphenol A) on microalgae with single and multi-species bioassays.

    Science.gov (United States)

    Debenest, Timothée; Petit, Anne-Nöelle; Gagné, François; Kohli, Mohan; Nguyen, Nien; Blaise, Christian

    2011-09-01

    The potential threat of emerging chemicals to the aquatic flora is a major issue. The purpose of the study was to develop a multispecies microalgae test in order to determine the impact of species interactions on the cytoxicity of an emergent toxic contaminant: the tetrabromobisphenol A (TBBPA). Single and multi-species tests were thus performed to study the effects of this flame retardant on two microalgae (Pseudokirchneriella subcapitata and Nitzschia palea) commonly observed in freshwater. A synthetic medium was designed to allow the growth of both species. The algae were exposed to 1.8, 4.8, 9.2, 12.9 and 16.5 μM of TBBPA for 72 h. After staining with fluorescein diacetate (FDA), viable cells of each alga species were analyzed by flow cytometry based on chlorophyll autofluorescence and intracellular esterase activity. Density and abundance of viable cells were assessed to follow the population growth and the cell viability. In TBBPA treated samples, the growth of the two microalgae was significantly inhibited at the three highest concentrations (9.2, 12.9 and 16.5 μM) in the two tests. At the end of the experiment (t=72 h), the cell viability was also significantly smaller at these concentrations. The decreases of growth rate and viable cell abundance in TBBPA treated populations of N. palea were significantly higher in multi-species test in comparison with the single-species test. No significant differences were noticed between the two tests for P. subcapitata populations exposed to TBBPA. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  19. Multi-criteria Ranking Under Pareto Inclusive Criterion of Preference: An Application in Ranking Some Fungi Species with Respect to Their Toxicity

    Directory of Open Access Journals (Sweden)

    Gniadek Agnieszka

    2014-12-01

    Full Text Available This study aims at demonstrating the usefulness of the Pareto in- clusive criterion methodology for comparative analyses of fungi toxicity. The toxicity of fungi is usually measured using a scale of several ranks. In practice, the ranks of toxicity are routinely grouped into only four conventional classes of toxicity: from a class of no toxicity, low toxicity, and moderate toxicity, to a class of high toxicity. The illustrative material included the N = 61 fungi samples obtained from three species: A. ochraceus, A. niger and A. flavus. In accordance with the Pareto approach, four partial criterions of the worst toxi- city were defined, a single criterion used for each conventional class of toxicity. Finally, the odds ratios (OR were calculated separately for each partial cri- terion, and the significance of the hypotheses OR = 1 was estimated. It was stated that A. ochraceus fungi are distinctly more toxic than the two remaining ones with respect to the all considered four partial criterions, with significance equal to p = 0.04, p = 0.04, p = 0.007 and p = 0.005, respectively. Thus, the suggested method illustrated its utility in the case under study.

  20. New applications in EPA’s ECOTOX Knowledge System: Assimilating relative potencies of metals across chemical and biological species from literature-based toxicity effects data.

    Science.gov (United States)

    Toxicity of metals in field settings can vary widely among ionic chemical species and across biological receptors. Thus, a challenge often found in developing TRVs for the risk assessment of metals is identifying the most appropriate metal and biological species combinations for...

  1. Toxicity of five forest insecticides to cutthroat trout and two species of aquatic invertebrates

    Science.gov (United States)

    Woodward, D.F.; Mauck, W.L.

    1980-01-01

    The Northern Rocky Mountain region has had scattered infestation of the western spruce budworm Christoneura occidentalis since the early 1900's (U.S. DEPARTMENT OF AGRICULTURE (USDA) 1976b). On the basis of aerial surveys in 1975, TUNNOCK et al. (1976), estimated that budworm defoliation occurred on 2,278,804 acres of six National Forests in Montana. Since the use of DDT was banned in 1972, there has been a need to develop alternative insecticides with the efficacy of DDT but without its environmental risk. These insecticides must be effective in controlling the budworm, but should not persist in the environment or be toxic to other organisms. The organophosphate and carbamate insecticides are relatively nonpersistent and generally present only a moderate hazard to fish when applied according to label recommendations. The USDA Forest Service has been investigating the effectiveness of these two classes of insecticides against the budworm, and the Columbia National Fisheries Research Laboratory of the U.S. Fish and Wildlife Service has been cooperating with the Forest Service conducted pilot control projects in eastern Montana in 1975 and 1976 to determine the efficacy and environmental impact of acephate, carbaryl, and trichlorfon in controlling the western budworm (USDA 1976 b). In 1975, a similar type project was carried out in Maine with aminocarb, fenitrothion, and trichlorfon (USDA 1976 a).Acephate, fenitrothion, and trichlorfon (organophosphate insecticides) and aminocarb and carbaryl (carbamate insecticides) were selected for toxicity tests against cutthroat trout (Salmo clarki), a stonefly (Pteronarcella badia), and a freshwater amphipod (Gammarus pseudolimnaeus) edemic in streams of the northern Rocky Mountains. Populations of cutthroat trout inhabit lakes and streams in the Rocky Mountains which include some of the most pristine habitat and fisheries in North America. Pteronarcella and Gammarus provide forage for cutthroat trout and feed on decaying

  2. An evaluation of the toxicity and bioaccumulation of bismuth in the coastal environment using three species of macroalga

    International Nuclear Information System (INIS)

    Kearns, James; Turner, Andrew

    2016-01-01

    Bismuth is a heavy metal whose biogeochemical behaviour in the marine environment is poorly defined. In this study, we exposed three different species of macroalga (the chlorophyte, Ulva lactuca, the phaeophyte, Fucus vesiculosus, and the rhodophyte, Chondrus crispus) to different concentrations of Bi (up to 50 μg L −1 ) under controlled, laboratory conditions. After a period of 48-h, the phytotoxicity of Bi was measured in terms of chlorophyll fluorescence quenching, and adsorption and internalisation of Bi determined by ICP after EDTA extraction and acid digestion, respectively. For all algae, both the internalisation and total accumulation of Bi were proportional to the concentration of aqueous metal. Total accumulation followed the order: F. vesiculosus > C. crispus > U. lactuca; with respective accumulation factors of about 4200, 1700 and 600 L kg −1 . Greatest internalisation (about 33% of total accumulated Bi) was exhibited by C. crispus, the only macroalga to display a phytotoxic response in the exposures. A comparison of the present results with those reported in the literature suggests that Bi accumulation by macroalgae is significantly lower than its accumulation by marine plankton (volume concentration factors of 10 5 to 10 7 ), and that the phytotoxicity of Bi is low relative to other heavy metals like Ag and Tl. - Highlights: • Very little is understood about the biogeochemistry of bismuth. • We exposed three species of coastal macroalga to variable concentrations of Bi. • Greatest accumulation was exhibited by Fucus vesiculosus. • Greatest internalisation was exhibited by Chondus crispus. • C. crispus was the only macroalga to display a toxic response. - Bismuth is accumulated by three species of marine macroalga but exhibits only moderate toxicity to the rhodophyte, Chondrus crispus.

  3. Accumulation of elements by edible mushroom species: part I. Problem of trace element toxicity in mushrooms.

    Science.gov (United States)

    Mleczek, Mirosław; Siwulski, Marek; Stuper-Szablewska, Kinga; Rissmann, Iwona; Sobieralski, Krzysztof; Goliński, Piotr

    2013-01-01

    The aim of this study was to evaluate Cd, Co, Cu, Hg, Ni, Pb, Sr and Zn accumulation in six edible mushroom species and to assess their risk and benefits to human consumers. Mushrooms (Leccinium aurantiacum, Xerocomus badius, Lactarius deliciosus, Boletus edulis, Cantharellus cibarius and Suillus luteus) were collected from selected regions of Poland during 1990-2010. The highest diversity between studied mushroom species was observed in terms of Cu and Zn accumulation. Significant differences in the accumulation efficiency were found among the six mushroom species examined. The most efficient were Boletus edulis (Cd and Hg), Suillus luteus (Cu and Sr), and Lactarius deliciosus (Pb and Zn). In the case of Co and Ni, the most effective were Xerocomus badius and Leccinium aurantiacum, respectively. The calculated bioconcentration factor (BCF) values of Cd, Cu, Hg, Sr and Zn were > 1 for all species in this study while Co, Ni and Pb usually were bioexcluded (BCF luteus collected in Poland is safe and this finding largely agrees with results from recent studies by other authors.

  4. Toxicity of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) in three vertebrate species.

    Science.gov (United States)

    Johnson, Mark S; McFarland, Craig A; Bazar, Matthew A; Quinn, Michael J; LaFiandra, Emily May; Talent, Larry G

    2010-04-01

    The explosive, octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine or high-melting explosive (HMX), has been found in soils in areas used for testing and training by the military. Many of these areas contain habitat for valued wildlife species. In an effort to better understand the environmental consequences from exposure, a reptilian (western fence lizard [Sceloporus occidentalis]), an amphibian (red-backed salamander [Plethodon cinereus]), and a mammalian species (rabbit [Oryctolagus cuniculus]) were exposed to HMX under controlled laboratory conditions. Lizards and rabbits were exposed to HMX by way of corn oil through gavage, and salamanders were exposed to HMX in soil. Two deaths occurred from acute oral exposures to lizards to 5000 mg HMX/kg BW. Histological and gross pathologic assessment suggested gut impaction as a possible cause of death. Salamanders exposed to concentrations of HMX in soil 24 h after oral exposures. An LD(50) for rabbits was calculated as 93 mg/kg (95% confidence interval 76-117). A subacute 14-day testing regime found a lowest observed effect level of 10 mg/kg-d and a no observed adverse effect level of 5 mg/kg-d based on hyperkinesia and seizure incidence, although changes suggesting functional hepatic alterations were also found. These data suggest that physiologic differences between species, particularly in gastrointestinal structure and function, can affect the absorption of HMX and hence lead to marked differences in toxicity from exposure to the same compound.

  5. Cadmium toxicity in Maize (Zea mays L.): consequences on antioxidative systems, reactive oxygen species and cadmium accumulation.

    Science.gov (United States)

    Anjum, Shakeel Ahmad; Tanveer, Mohsin; Hussain, Saddam; Bao, Mingchen; Wang, Longchang; Khan, Imran; Ullah, Ehsan; Tung, Shahbaz Atta; Samad, Rana Abdul; Shahzad, Babar

    2015-11-01

    Increased cadmium (Cd) accumulation in soils has led to tremendous environmental problems, with pronounced effects on agricultural productivity. Present study investigated the effects of Cd stress imposed at various concentrations (0, 75, 150, 225, 300, 375 μM) on antioxidant activities, reactive oxygen species (ROS), Cd accumulation, and productivity of two maize (Zea mays L.) cultivars viz., Run Nong 35 and Wan Dan 13. Considerable variations in Cd accumulation and in behavior of antioxidants and ROS were observed under Cd stress in both maize cultivars, and such variations governed by Cd were concentration dependent. Exposure of plant to Cd stress considerably increased Cd concentration in all plant parts particularly in roots. Wan Dan 13 accumulated relatively higher Cd in root, stem, and leaves than Run Nong 35; however, in seeds, Run Nong 35 recorded higher Cd accumulation. All the Cd toxicity levels starting from 75 μM enhanced H2O2 and MDA concentrations and triggered electrolyte leakage in leaves of both cultivars, and such an increment was more in Run Nong 35. The ROS were scavenged by the enhanced activities of superoxide dismutase, peroxidase, catalase, ascorbate peroxidase, and glutathione peroxidase in response to Cd stress, and these antioxidant activities were higher in Wan Dan 13 compared with Run Nong 35 at all Cd toxicity levels. The grain yield of maize was considerably reduced particularly for Run Nong 35 under different Cd toxicity levels as compared with control. The Wan Dan 13 was better able to alleviate Cd-induced oxidative damage which was attributed to more Cd accumulation in roots and higher antioxidant activities in this cultivar, suggesting that manipulation of these antioxidants and enhancing Cd accumulation in roots may lead to improvement in Cd stress tolerance.

  6. Polynuclear aromatic hydrocarbons (PAHs) mediate cadmium toxicity to an emergent wetland species

    International Nuclear Information System (INIS)

    Zhang, Zhenhua; Rengel, Zed; Meney, Kathy; Pantelic, Ljiljana; Tomanovic, Radmila

    2011-01-01

    Growth and pollutant removal by emergent wetland plants may be influenced by interactions among mixed pollutants in constructed wetlands. A glasshouse experiment was conducted to investigate interactive effects of cadmium (Cd) x polynuclear aromatic hydrocarbons (PAHs) x plant treatments on growth of Juncus subsecundus, Cd and PAH removal from soil and the total number of microorganisms in soil. Growth and biomass of J. subsecundus were significantly influenced by interaction of Cd and PAHs, significantly decreasing with either Cd or PAH additions, but with the effect of Cd on plant growth being stronger than that of PAHs. The mixture of low Cd and low PAH lessened Cd toxicity to plants, resulting in improved plant growth and increased Cd accumulation in plant tissues, thus enhancing Cd removal by plants. The dissipation of PAHs in soils was significantly influenced by interactions of Cd, PAH and plant presence or absence. The total number of microorganisms in soils was significantly increased by the PAH additions. The interactive effect of Cd and PAHs on plant growth may be linked to the changes in the abundance of microorganisms in the rhizosphere, probably via a positive effect of PAH metabolites and/or phytohormones produced by microorganisms on plant growth.

  7. Toxicity of essential oils from leaves of Piperaceae species in rice stalk stink bug eggs, Tibraca limbativentris (Hemiptera: Pentatomidae

    Directory of Open Access Journals (Sweden)

    Diones Krinski

    Full Text Available ABSTRACT Tibraca limbativentris to is an important rice pest and occurs in all rice-growing regions of Latin America. The control this insect is accomplished with synthetic chemical insecticides, however, new approaches are needed to reduce risks to the environment, to the natural enemies and also to avoid the onset of insecticides resistance. This study was designed to assess the toxicity of essential oils (EOs from leaves of Piper aduncum, P. gaudichaudianum, P. malacophyllum, P. marginatum and P. tuberculatum (Piperaceae on rice stalk stink bug eggs, T. limbativentris. Essential oils were extracted with steam distillation and dilutions were made for bioassays at concentrations of 0.25; 0.5; 1.0; 2.0 and 4.0%. Essential oils from all species of Piperaceae displayed ovicidal activity. The LC50 values indicated that both younger and older eggs were susceptible to these oils. Ovicidal activity is related to the potential toxicity of several compounds, especially dilapiolle, myristicin, cubebene, α-guaiene, longifolene, prezizane, spathulenol, sabinene and δ-2-carene. Thus, EOs tested showed promising results for use as biorational botanical insecticides.

  8. Toxicity of organic and inorganic nanoparticles to four species of white-rot fungi

    International Nuclear Information System (INIS)

    Galindo, T.P.S.; Pereira, R.; Freitas, A.C.; Santos-Rocha, T.A.P.; Rasteiro, M.G.; Antunes, F.; Rodrigues, D.; Soares, A.M.V.M.; Gonçalves, F.

    2013-01-01

    The rapid development of nanoparticles (NP) for industrial applications and large-volume manufacturing, with its subsequent release into the environment, raised the need to understand and characterize the potential effects of NP to biota. Accordingly, this work aimed to assess sublethal effects of five NP to the white-rot fungi species Trametes versicolor, Lentinus sajor caju, Pleurotus ostreatus, and Phanerochaete chrysosporium. Each species was exposed to serial dilutions of the following NP: organic-vesicles of SDS/DDAB and of Mo/NaO; gold-NP, quantum dot CdSe/ZnS, and Fe/Co. Fungi growth rate was monitored every day, and at the end of assay the mycelium from each replicate was collected to evaluate possible changes in its chemical composition. For all NP-suspensions the following parameters were characterized: hydrodynamic diameter, surface charge, aggregation index, zeta potential, and conductivity. All tested NP tended to aggregate when suspended in aqueous media. The obtained results showed that gold-NP, CdSe/ZnS, Mo/NaO, and SDS/DDAB significantly inhibited the growth of fungi with effects on the mycelium chemical composition. Among the tested NP, gold-NP and CdSe/ZnS were the ones exerting a higher effect on the four fungi. Finally to our knowledge, this is the first study reporting that different types of NP induce changes in the chemical composition of fungi mycelium. - Highlights: • Nanoparticles (NP) tend to aggregate when in aqueous suspensions. • Chemical composition revealed to be very important in the ecotoxicity of NP. • Observed effects suggested diversified modes of action of different NP. • White-rot fungi species exhibit great differences in their sensitivity to NP

  9. Toxicity of organic and inorganic nanoparticles to four species of white-rot fungi

    Energy Technology Data Exchange (ETDEWEB)

    Galindo, T.P.S., E-mail: pgalindo@ua.pt [CESAM, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); Departamento de Biologia, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); Pereira, R. [CESAM, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre 4169-007 Porto (Portugal); Freitas, A.C.; Santos-Rocha, T.A.P. [CESAM, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); Departamento de Química, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); ISEIT, Instituto Piaget Viseu, Estrada do Alto do Gaio, Lordosa, 3515-776 Viseu (Portugal); Rasteiro, M.G.; Antunes, F. [Department of Chemical Engineering, University of Coimbra, 3030-290 Coimbra (Portugal); Rodrigues, D. [CESAM, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); Departamento de Química, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); ISEIT, Instituto Piaget Viseu, Estrada do Alto do Gaio, Lordosa, 3515-776 Viseu (Portugal); Soares, A.M.V.M.; Gonçalves, F. [CESAM, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); Departamento de Biologia, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); and others

    2013-08-01

    The rapid development of nanoparticles (NP) for industrial applications and large-volume manufacturing, with its subsequent release into the environment, raised the need to understand and characterize the potential effects of NP to biota. Accordingly, this work aimed to assess sublethal effects of five NP to the white-rot fungi species Trametes versicolor, Lentinus sajor caju, Pleurotus ostreatus, and Phanerochaete chrysosporium. Each species was exposed to serial dilutions of the following NP: organic-vesicles of SDS/DDAB and of Mo/NaO; gold-NP, quantum dot CdSe/ZnS, and Fe/Co. Fungi growth rate was monitored every day, and at the end of assay the mycelium from each replicate was collected to evaluate possible changes in its chemical composition. For all NP-suspensions the following parameters were characterized: hydrodynamic diameter, surface charge, aggregation index, zeta potential, and conductivity. All tested NP tended to aggregate when suspended in aqueous media. The obtained results showed that gold-NP, CdSe/ZnS, Mo/NaO, and SDS/DDAB significantly inhibited the growth of fungi with effects on the mycelium chemical composition. Among the tested NP, gold-NP and CdSe/ZnS were the ones exerting a higher effect on the four fungi. Finally to our knowledge, this is the first study reporting that different types of NP induce changes in the chemical composition of fungi mycelium. - Highlights: • Nanoparticles (NP) tend to aggregate when in aqueous suspensions. • Chemical composition revealed to be very important in the ecotoxicity of NP. • Observed effects suggested diversified modes of action of different NP. • White-rot fungi species exhibit great differences in their sensitivity to NP.

  10. Cadmium toxicity induced contrasting patterns of concentrations of free sarcosine, specific amino acids and selected microelements in two Noccaea species.

    Science.gov (United States)

    Zemanová, Veronika; Pavlík, Milan; Pavlíková, Daniela

    2017-01-01

    Cadmium (Cd) toxicity affects numerous metabolic processes in plants. In the presence of Cd, plants accumulate specific amino acids which may be beneficial to developing Cd tolerance. Our study aimed to characterize the changes in the metabolism of selected free amino acids that are associated with Cd tolerance, and investigate the levels of selected microelements in order to relate these changes to the adaptation strategies of two metallophytes-Noccaea caerulescens (Redlschlag, Austria) and Noccaea praecox (Mežica, Slovenia). The plants were exposed to Cd contamination (90 mg Cd/kg soil) for 120 days in a pot experiment. Our results showed higher Cd accumulation in N. praecox compared to N. caerulescens. Cadmium contamination reduced the zinc and nickel levels in both species and a mixed effect was determined for copper and manganese content. Differences in free amino acid metabolism were observed between the two metallophytes growing under Cd-free and Cd-loaded conditions. Under Cd-free conditions, aromatic amino acids (phenylalanine, tryptophan and tyrosine) and branched-chain amino acids (leucine, isoleucine and valine) were accumulated more in the leaves of N. praecox than in N. caerulescens. Cd stress increased the content of these amino acids in both species but this increase was significant only in N. caerulescens leaves. Marked differences in the responses of the two species to Cd stress were shown for alanine, phenylalanine, threonine and sarcosine. Cadmium contamination also induced an increase of threonine as alanine and sarcosine decrease, which was larger in N. caerulescens than in N. praecox. All these factors contribute to the higher adaptation of N. praecox to Cd stress.

  11. Uptake and accumulation of potentially toxic elements in colonized plant species around the world's largest antimony mine area, China.

    Science.gov (United States)

    Long, Jiumei; Tan, Di; Deng, Sihan; Lei, Ming

    2018-04-11

    To provide information on reclamation of multi-heavy metal polluted soils with conception of phytostabilization, a field survey on the uptake and accumulation of potentially toxic elements such as antimony (Sb), arsenic (As), lead (Pb), cadmium (Cd), copper (Cu), and zinc (Zn) in colonized plant species around the world's largest antimony mine area, China, was conducted. Samples including leaves and shoots (including roots and stems) of colonized plants as well as rhizospheric soils were collected from eight sampling zones in the studied area. The results showed that the contents of Cu, Zn, and Pb in rhizospheric soils below plants were comparable to the corresponding background values of Hunan province, otherwise Sb, Cd, and As contents were extremely high (17-106, 17-87, and 3-7 times of the corresponding background values). The highest concentration of Sb was found in Aster subulatus (410 mg kg -1 ); Cd, As, and Zn were in Herba bidentis bipinnatae (10.9, 264, and 265 mg kg -1 , respectively); and Cu was in Artemisia lavandulaefolia (27.1 mg kg -1 ). It also exhibited that all the contents of As in leaves were several times of those in shoots of plants, Cd and other heavy metals showed in a similar pattern in several studied species, implying that the uptake route of these heavy metals via foliar might contribute to the accumulation. With high bioconcentration factors of heavy metals (more than 1, except for Zn), together with the growth abundance, Herba bidentis bipinnatae was considered as the most suitable colonized species for phytostabilization of the multi-heavy metal pollution in soils on this antimony mine area.

  12. Herbicide toxicity, selectivity and hormesis of nicosulfuron on 10 Trichogrammatidae (Hymenoptera) species parasitizing Anagasta ( = Ephestia) kuehniella (Lepidoptera: Pyralidae) eggs.

    Science.gov (United States)

    Leite, Germano L D; de Paulo, Paula D; Zanuncio, José C; Tavares, Wagner De S; Alvarenga, Anarelly C; Dourado, Luan R; Bispo, Edilson P R; Soares, Marcus A

    2017-01-02

    Selective agrochemicals including herbicides that do not affect non-target organisms such as natural enemies are important in the integrated pest management (IPM) programs. The aim of this study was to evaluate the herbicide toxicity, selectivity and hormesis of nicosulfuron, recommended for the corn Zea mays L. (Poaceae) crop, on 10 Trichogrammatidae (Hymenoptera) species. A female of each Trichogramma spp. or Trichogrammatoidea annulata De Santis, 1972 was individually placed in plastic test tubes (no choice) with a cardboard containing 45 flour moth Anagasta ( = Ephestia) kuehniella Zeller, 1879 (Lepidoptera: Pyralidae) eggs. Parasitism by these natural enemies was allowed for 48 h and the cardboards were sprayed with the herbicide nicosulfuron at 1.50 L.ha -1 , along with the control (only distilled water). Nicosulfuron reduced the emergence rate of Trichogramma bruni Nagaraja, 1983 females, but increased that of Trichogramma pretiosum Riley, 1879, Trichogramma acacioi Brun, Moraes and Smith, 1984 and T. annulata females. Conversely, this herbicide increased the emergence rate of Trichogramma brasiliensis Ashmead, 1904, T. bruni, Trichogramma galloi Zucchi, 1988 and Trichogramma soaresi Nagaraja, 1983 males and decreased those of T. acacioi, Trichogramma atopovilia Oatman and Platner, 1983 and T. pretiosum males. In addition, nicosulfuron reduced the sex ratio of T. galloi, Trichogramma bennetti Nagaraja and Nagarkatti, 1973 and T. pretiosum and increased that of T. acacioi, T. bruni, T. annulata, Trichogramma demoraesi Nagaraja, 1983, T. soaresi and T. brasiliensis. The herbicide nicosulfuron was "harmless" (class 1, <30% reduction) for females and the sex ratio of all Trichogrammatidae species based on the International Organization for Biological Control (IOBC) classification. The possible hormesis effect of nicosulfuron on Trichogrammatidae species and on the bacterium Wolbachia sp. (Rickettsiales: Rickettsiaceae) was also discussed.

  13. Lysosomal membrane permeabilization: Carbon nanohorn-induced reactive oxygen species generation and toxicity by this neglected mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Mei, E-mail: happy_deercn@163.com [Nanotube Research Center, National Institute of Advanced Industrial Science and Technology 5-2, 1-1-1 Higashi, Tsukuba 305-8565 (Japan); Zhang, Minfang; Tahara, Yoshio; Chechetka, Svetlana; Miyako, Eijiro [Nanotube Research Center, National Institute of Advanced Industrial Science and Technology 5-2, 1-1-1 Higashi, Tsukuba 305-8565 (Japan); Iijima, Sumio [Nanotube Research Center, National Institute of Advanced Industrial Science and Technology 5-2, 1-1-1 Higashi, Tsukuba 305-8565 (Japan); Faculty of Science and Technology, Meijo University, 1-501 Shiogamaguchi, Tenpaku, Nagoya 468-8502 (Japan); Yudasaka, Masako, E-mail: m-yudasaka@aist.go.jp [Nanotube Research Center, National Institute of Advanced Industrial Science and Technology 5-2, 1-1-1 Higashi, Tsukuba 305-8565 (Japan)

    2014-10-01

    Understanding the molecular mechanisms responsible for the cytotoxic effects of carbon nanomaterials is important for their future biomedical applications. Carbon nanotubular materials induce the generation of reactive oxygen species (ROS), which causes cell death; however, the exact details of this process are still unclear. Here, we identify a mechanism of ROS generation that is involved in the apoptosis of RAW264.7 macrophages caused by excess uptake of carbon nanohorns (CNHs), a typical type of carbon nanotubule. CNH accumulated in the lysosomes, where they induced lysosomal membrane permeabilization (LMP) and the subsequent release of lysosomal proteases, such as cathepsins, which in turn caused mitochondrial dysfunction and triggered the generation of ROS in the mitochondria. The nicotinamide adenine dinucleotide phosphate oxidase was not directly involved in CNH-related ROS production, and the ROS generation cannot be regulated by mitochondrial electron transport chain. ROS fed back to amplify the mitochondrial dysfunction, leading to the subsequent activation of caspases and cell apoptosis. Carbon nanotubules commonly accumulate in the lysosomes after internalization in cells; however, lysosomal dysfunction has not attracted much attention in toxicity studies of these materials. These results suggest that LMP, a neglected mechanism, may be the primary reason for carbon nanotubule toxicity. - Highlights: • We clarify an apoptotic mechanism of RAW264.7 cells caused by carbon nanohorns. • In the meantime, the mechanism of CNH-induced ROS generation is identified. • LMP is the initial factor of CNH-induced ROS generation and cell death. • Cathepsins work as mediators that connect LMP and mitochondrial dysfunction.

  14. Toxicity of nano-TiO2 on algae and the site of reactive oxygen species production

    International Nuclear Information System (INIS)

    Li, Fengmin; Liang, Zhi; Zheng, Xiang; Zhao, Wei; Wu, Miao; Wang, Zhenyu

    2015-01-01

    Highlights: • The growth of two species of algae was inhibited under nano-TiO 2 exposure. • Oxidative stress was one of the mechanisms of toxicity of nano-TiO 2 on algae. • The site of ROS production was the electron transfer chain of chloroplast. - Abstract: Given the extensive use of nanomaterials, they may enter aquatic environments and harm the growth of algae, which are primary producers in an aquatic ecosystem. Thus, the balance of an aquatic ecosystem may be destroyed. In this study, Karenia brevis and Skeletonema costatum were exposed to nano-TiO 2 (anatase, average particle size of 5–10 nm, specific surface area of 210 ± 10 m 2 g −1 ) to assess the effects of nano-TiO 2 on algae. The findings of transmission electron microscopy-energy dispersive X-ray spectroscopy (TEM-EDX) and scanning electron microscopy (SEM) demonstrate aggregation of nano-TiO 2 in the algal suspension. Nano-TiO 2 was also found to be inside algal cells. The growth of the two species of algae was inhibited under nano-TiO 2 exposure. The 72 h EC 50 values of nano-TiO 2 to K. brevis and S. costatum were 10.69 and 7.37 mg L −1 , respectively. TEM showed that the cell membrane of K. brevis was destroyed and its organelles were almost undistinguished under nano-TiO 2 exposure. The malondialdehyde (MDA) contents of K. brevis and S. costatum significantly increased compared with those of the control (p < 0.05). Meanwhile, superoxide dismutase (SOD) and catalase activities (CAT) of K. brevis and S. costatum changed in different ways. The reactive oxygen species (ROS) levels in both species were significantly higher than those of the control (p < 0.05). The site of ROS production and accumulation in K. brevis and S. costatum under nano-TiO 2 exposure was explored with the addition of inhibitors of different electron transfer chains. This study indicated that nano-TiO 2 in algal suspensions inhibited the growth of K. brevis and S. costatum. This effect was attributed to oxidative

  15. Toxicity of nano-TiO{sub 2} on algae and the site of reactive oxygen species production

    Energy Technology Data Exchange (ETDEWEB)

    Li, Fengmin, E-mail: lifengmin@ouc.edu.cn [Key Laboratory of Marine Environmental Science and Ecology, Ministry of Education, College of Environmental Science and Technology, Ocean University of China, Qingdao 266100 (China); Liang, Zhi [Key Laboratory of Marine Environmental Science and Ecology, Ministry of Education, College of Environmental Science and Technology, Ocean University of China, Qingdao 266100 (China); Zheng, Xiang, E-mail: zhengxiang7825@sina.com [School of Environment and Natural Resources, Renmin University of China, Beijing 100872 (China); Zhao, Wei; Wu, Miao; Wang, Zhenyu [Key Laboratory of Marine Environmental Science and Ecology, Ministry of Education, College of Environmental Science and Technology, Ocean University of China, Qingdao 266100 (China)

    2015-01-15

    Highlights: • The growth of two species of algae was inhibited under nano-TiO{sub 2} exposure. • Oxidative stress was one of the mechanisms of toxicity of nano-TiO{sub 2} on algae. • The site of ROS production was the electron transfer chain of chloroplast. - Abstract: Given the extensive use of nanomaterials, they may enter aquatic environments and harm the growth of algae, which are primary producers in an aquatic ecosystem. Thus, the balance of an aquatic ecosystem may be destroyed. In this study, Karenia brevis and Skeletonema costatum were exposed to nano-TiO{sub 2} (anatase, average particle size of 5–10 nm, specific surface area of 210 ± 10 m{sup 2} g{sup −1}) to assess the effects of nano-TiO{sub 2} on algae. The findings of transmission electron microscopy-energy dispersive X-ray spectroscopy (TEM-EDX) and scanning electron microscopy (SEM) demonstrate aggregation of nano-TiO{sub 2} in the algal suspension. Nano-TiO{sub 2} was also found to be inside algal cells. The growth of the two species of algae was inhibited under nano-TiO{sub 2} exposure. The 72 h EC{sub 50} values of nano-TiO{sub 2} to K. brevis and S. costatum were 10.69 and 7.37 mg L{sup −1}, respectively. TEM showed that the cell membrane of K. brevis was destroyed and its organelles were almost undistinguished under nano-TiO{sub 2} exposure. The malondialdehyde (MDA) contents of K. brevis and S. costatum significantly increased compared with those of the control (p < 0.05). Meanwhile, superoxide dismutase (SOD) and catalase activities (CAT) of K. brevis and S. costatum changed in different ways. The reactive oxygen species (ROS) levels in both species were significantly higher than those of the control (p < 0.05). The site of ROS production and accumulation in K. brevis and S. costatum under nano-TiO{sub 2} exposure was explored with the addition of inhibitors of different electron transfer chains. This study indicated that nano-TiO{sub 2} in algal suspensions inhibited the growth

  16. Effects of sediment-spiked lufenuron on benthic macroinvertebrates in outdoor microcosms and single-species toxicity tests

    Energy Technology Data Exchange (ETDEWEB)

    Brock, T.C.M., E-mail: theo.brock@wur.nl [Alterra, Wageningen University and Research Centre, P.O. Box 47, 6700 AA Wageningen (Netherlands); Bas, D.A. [Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam (Netherlands); Belgers, J.D.M. [Alterra, Wageningen University and Research Centre, P.O. Box 47, 6700 AA Wageningen (Netherlands); Bibbe, L. [Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam (Netherlands); Boerwinkel, M-C.; Crum, S.J.H. [Alterra, Wageningen University and Research Centre, P.O. Box 47, 6700 AA Wageningen (Netherlands); Diepens, N.J. [Department of Aquatic Ecology and Water Quality Management, Wageningen University, P.O. Box 47, 6700 AA Wageningen (Netherlands); Kraak, M.H.S.; Vonk, J.A. [Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam (Netherlands); Roessink, I. [Alterra, Wageningen University and Research Centre, P.O. Box 47, 6700 AA Wageningen (Netherlands)

    2016-08-15

    Highlights: • In outdoor microcosms constructed with lufenuron-spiked sediment we observed that this insecticide persistent in the sediment compartment. • Sediment exposure to lufenuron caused population-level declines (insects and crustaceans) and increases (mainly oligochaete worms) of benthic invertebrates. • The direct and indirect effects observed in the microcosms were supported by results of sediment-spiked single species tests with Chironomus riparius, Hyalella azteca and Lumbriculus variegatus. • The tier-1 effect assessment procedure for sediment organisms recommended by the European Food Safety Authority is protective for the treatment-related responses observed in the microcosm test. - Abstract: Sediment ecotoxicity studies were conducted with lufenuron to (i) complement the results of a water-spiked mesocosm experiment with this lipophilic benzoylurea insecticide, (ii) to explore the predictive value of laboratory single-species tests for population and community-level responses of benthic macroinvertebrates, and (iii) to calibrate the tier-1 effect assessment procedure for sediment organisms. For this purpose the concentration-response relationships for macroinvertebrates between sediment-spiked microcosms and those of 28-d sediment-spiked single-species toxicity tests with Chironomus riparius, Hyalella azteca and Lumbriculus variegatus were compared. Lufenuron persisted in the sediment of the microcosms. On average, 87.7% of the initial lufenuron concentration could still be detected in the sediment after 12 weeks. Overall, benthic insects and crustaceans showed treatment-related declines and oligochaetes treatment-related increases. The lowest population-level NOEC in the microcosms was 0.79 μg lufenuron/g organic carbon in dry sediment (μg a.s./g OC) for Tanytarsini, Chironomini and Dero sp. Multivariate analysis of the responses of benthic macroinvertebrates revealed a community-level NOEC of 0.79 μg a.s./g OC. The treatment

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

    Energy Technology Data Exchange (ETDEWEB)

    De Schamphelaere, K.A.C., E-mail: karel.deschamphelaere@ugent.be; Nys, C., E-mail: chnys.nys@ugent.be; Janssen, C.R., E-mail: colin.janssen@ugent.be

    2014-10-15

    Highlights: • Chronic toxicity of Pb varied 4-fold among three algae species. • The use of an organic P avoided Pb precipitation in the experiments. • pH and Dissolved Organic Carbon strongly affect Pb toxicity, Ca and Mg do not. • A bioavailability model was developed that accurately predicts toxicity. • Algae may become the most sensitive species to Pb above pH 7.4. - Abstract: Scientifically sound risk assessment and derivation of environmental quality standards for lead (Pb) in the freshwater environment are hampered by insufficient data on chronic toxicity and bioavailability to unicellular green algae. Here, we first performed comparative chronic (72-h) toxicity tests with three algal species in medium at pH 6, containing 4 mg fulvic acid (FA)/L and containing organic phosphorous (P), i.e. glycerol-2-phosphate, instead of PO{sub 4}{sup 3−} to prevent lead-phosphate mineral precipitation. Pseudokirchneriella subcapitata was 4-fold more sensitive to Pb than Chlorella kesslerii, with Chlamydomonas reinhardtii in the middle. The influence of medium physico-chemistry was therefore investigated in detail with P. subcapitata. In synthetic test media, higher concentrations of fulvic acid or lower pH protected against toxicity of (filtered) Pb to P. subcapitata, while effects of increased Ca or Mg on Pb toxicity were less clear. When toxicity was expressed on a free Pb{sup 2+} ion activity basis, a log-linear, 260-fold increase of toxicity was observed between pH 6.0 and 7.6. Effects of fulvic acid were calculated to be much more limited (1.9-fold) and were probably even non-existent (depending on the affinity constant for Pb binding to fulvic acid that was used for calculating speciation). A relatively simple bioavailability model, consisting of a log-linear pH effect on Pb{sup 2+} ion toxicity linked to the geochemical speciation model Visual Minteq (with the default NICA-Donnan description of metal and proton binding to fulvic acid), provided relatively

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    Highlights: • Chronic toxicity of Pb varied 4-fold among three algae species. • The use of an organic P avoided Pb precipitation in the experiments. • pH and Dissolved Organic Carbon strongly affect Pb toxicity, Ca and Mg do not. • A bioavailability model was developed that accurately predicts toxicity. • Algae may become the most sensitive species to Pb above pH 7.4. - Abstract: Scientifically sound risk assessment and derivation of environmental quality standards for lead (Pb) in the freshwater environment are hampered by insufficient data on chronic toxicity and bioavailability to unicellular green algae. Here, we first performed comparative chronic (72-h) toxicity tests with three algal species in medium at pH 6, containing 4 mg fulvic acid (FA)/L and containing organic phosphorous (P), i.e. glycerol-2-phosphate, instead of PO 4 3− to prevent lead-phosphate mineral precipitation. Pseudokirchneriella subcapitata was 4-fold more sensitive to Pb than Chlorella kesslerii, with Chlamydomonas reinhardtii in the middle. The influence of medium physico-chemistry was therefore investigated in detail with P. subcapitata. In synthetic test media, higher concentrations of fulvic acid or lower pH protected against toxicity of (filtered) Pb to P. subcapitata, while effects of increased Ca or Mg on Pb toxicity were less clear. When toxicity was expressed on a free Pb 2+ ion activity basis, a log-linear, 260-fold increase of toxicity was observed between pH 6.0 and 7.6. Effects of fulvic acid were calculated to be much more limited (1.9-fold) and were probably even non-existent (depending on the affinity constant for Pb binding to fulvic acid that was used for calculating speciation). A relatively simple bioavailability model, consisting of a log-linear pH effect on Pb 2+ ion toxicity linked to the geochemical speciation model Visual Minteq (with the default NICA-Donnan description of metal and proton binding to fulvic acid), provided relatively accurate toxicity

  19. Fatty acid composition of bacteria associated with the toxic dinoflagellate Ostreopsis lenticularis and with Caribbean Palythoa species.

    Science.gov (United States)

    Carballeira, N M; Emiliano, A; Sostre, A; Restituyo, J A; González, I M; Colón, G M; Tosteson, C G; Tosteson, T R

    1998-06-01

    The fatty acid composition of a Pseudomonas sp. (Alteromonas) and its host, the dinoflagellate Ostreopsis lenticularis, vectors in ciguatera fish poisoning, has been studied. The major fatty acids in O. lenticularis were 16:0, 20:5n-3, and 22:6n-3, but 18:2n-6, 18:3n-3, and 18:n-3 were also identified. In contrast to other dinoflagellates, 1 8:5n-3 was not detected in O. lenticularis. Even-chain fatty acids such as 9-16:1, 11-18:1, and 13-20:1 predominated in the Pseudomonas sp. from O. lenticularis, but 1 6-20% of (E)-11-methyl-12-octadecenoic acid was also identified. The chirality of the latter was confirmed by total synthesis (28% overall yield) starting from oxacyclotridecan-2-one. The fatty acid compositions of two other Pseudomonas species, from the palytoxin-producing zoanthids Palythoa mamillosa and P. caribdea, were also studied and were similar to that of the Pseudomonas sp. from O. lenticularis. The possibility of using some of these fatty acids as chemotaxonomic lipids in identifying marine animals that consume toxic dinoflagellates or zoanthids is discussed.

  20. Surveillance guidelines for toxic algal species of Italian sea and lake waters; Indicazioni per il controllo delle specie algali tossiche delle acque marine e lacustri italiane: Studio delle coste e di un lago del Lazio: 1994-1995

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, Milena; Congestri, Roberta; Buzzelli, Elena [Istituot Superiore di Sanita` , Rome (Italy). Lab. di Igiene Ambientale

    1997-09-01

    The health conditions of the coasts of the Rome district and of a large lake in the northern area of the Latium Region were examined to evaluate the toxic algal species, during a 14-month study carried on in cooperation with the Region and the local prevention units of the Region. The study shows the existence of a mesotrophic state in the coastal waters of the lake Bolsena, and a trophic level increased in last years, along the sea coasts of the Rome district. alga populations of genus Dinophysis, harmless to bathing activities, but able to contaminate the edible molluscs with toxins of the okadaic acid group, have been found. The technical occurrences of this study points out the operators`need of a taxonomic atlas, collecting all the toxic algal species known in the Mediterranean basin. This report includes a number of drawings of all the signaled species, each one followed by a fried schedule with the main taxonomic characteristics.

  1. Genetic and toxinological characterization of North Atlantic strains of the dinoflagellate Ostreopsis and allelopathic interactions with toxic and non-toxic species from the genera Prorocentrum, Coolia and Gambierdiscus.

    Science.gov (United States)

    García-Portela, María; Riobó, Pilar; Franco, José Mariano; Bañuelos, Rosa Mª; Rodríguez, Francisco

    2016-12-01

    The genus Ostreopsis includes several toxic species that can develop blooms in benthic ecosystems, with potential harmful consequences for human health and marine invertebrates. Despite of this, little is known about the allelopathic interactions between these organisms and other co-occurring microalgae that exploit similar spatial and nutrient resources in benthic ecosystems. The aim of this study was to follow these interactions in cultures of two Ostreopsis ribotypes with different toxin profiles (O. cf. ovata contained ovatoxins-a, b, c and e, while only ovatoxin-d was found in O .sp. "Lanzarote-type"), mixed with species of three benthic dinoflagellate genera (Coolia, Prorocentrum and Gambierdiscus), isolated from the same area (North East Atlantic, Canary Islands). In a first experiment, the potential allelopathic effects on growth rates were followed, in mixed cultures of Coolia monotis (a non toxic species) exposed to the clarified medium and to cells of O. sp."Lanzarote-type" and O. cf. ovata. Growth delayed in C. monotis was observed specially in clarified medium, while the O. sp. "Lanzarote-type" strain attained much lower densities in mixed cultures. In a second experiment, we examined the potential effects of clarified media from O. sp."Lanzarote-type" and O. cf. ovata on the adherence capacity in two toxic species (Prorocentrum hoffmannianum and Gambierdiscus excentricus). Contrasting effects were found: a significant increase of adherence capacity in P. hoffmannianum vs attachment decline in G. excentricus, that experienced also severe deleterious effects (cell lysis). Our results suggest the existence of weak to moderate allelopathic interactions between the studied organisms, although the outcome is dependent on the species involved. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Toxicity of nickel-spiked freshwater sediments to benthic invertebrates-Spiking methodology, species sensitivity, and nickel bioavailability

    Science.gov (United States)

    Besser, John M.; Brumbaugh, William G.; Kemble, Nile E.; Ivey, Chris D.; Kunz, James L.; Ingersoll, Christopher G.; Rudel, David

    2011-01-01

    This report summarizes data from studies of the toxicity and bioavailability of nickel in nickel-spiked freshwater sediments. The goal of these studies was to generate toxicity and chemistry data to support development of broadly applicable sediment quality guidelines for nickel. The studies were conducted as three tasks, which are presented here as three chapters: Task 1, Development of methods for preparation and toxicity testing of nickel-spiked freshwater sediments; Task 2, Sensitivity of benthic invertebrates to toxicity of nickel-spiked freshwater sediments; and Task 3, Effect of sediment characteristics on nickel bioavailability. Appendices with additional methodological details and raw chemistry and toxicity data for the three tasks are available online at http://pubs.usgs.gov/sir/2011/5225/downloads/.

  3. Species differences in drug glucuronidation: Humanized UDP-glucuronosyltransferase 1 mice and their application for predicting drug glucuronidation and drug-induced toxicity in humans.

    Science.gov (United States)

    Fujiwara, Ryoichi; Yoda, Emiko; Tukey, Robert H

    2018-02-01

    More than 20% of clinically used drugs are glucuronidated by a microsomal enzyme UDP-glucuronosyltransferase (UGT). Inhibition or induction of UGT can result in an increase or decrease in blood drug concentration. To avoid drug-drug interactions and adverse drug reactions in individuals, therefore, it is important to understand whether UGTs are involved in metabolism of drugs and drug candidates. While most of glucuronides are inactive metabolites, acyl-glucuronides that are formed from compounds with a carboxylic acid group can be highly toxic. Animals such as mice and rats are widely used to predict drug metabolism and drug-induced toxicity in humans. However, there are marked species differences in the expression and function of drug-metabolizing enzymes including UGTs. To overcome the species differences, mice in which certain drug-metabolizing enzymes are humanized have been recently developed. Humanized UGT1 (hUGT1) mice were created in 2010 by crossing Ugt1-null mice with human UGT1 transgenic mice in a C57BL/6 background. hUGT1 mice can be promising tools to predict human drug glucuronidation and acyl-glucuronide-associated toxicity. In this review article, studies of drug metabolism and toxicity in the hUGT1 mice are summarized. We further discuss research and strategic directions to advance the understanding of drug glucuronidation in humans. Copyright © 2017 The Japanese Society for the Study of Xenobiotics. Published by Elsevier Ltd. All rights reserved.

  4. Improving reptile ecological risk assessment: oral and dermal toxicity of pesticides to a common lizard species (Sceloporus occidentalis).

    Science.gov (United States)

    Weir, Scott M; Yu, Shuangying; Talent, Larry G; Maul, Jonathan D; Anderson, Todd A; Salice, Christopher J

    2015-08-01

    Reptiles have been understudied in ecotoxicology, which limits consideration in ecological risk assessments. The goals of the present study were 3-fold: to improve oral and dermal dosing methodologies for reptiles, to generate reptile toxicity data for pesticides, and to correlate reptile and avian toxicity. The authors first assessed the toxicity of different dosing vehicles: 100 μL of water, propylene glycol, and acetone were not toxic. The authors then assessed the oral and dermal toxicity of 4 pesticides following the up-and-down procedure. Neither brodifacoum nor chlorothalonil caused mortality at doses ≤ 1750 μg/g. Under the "neat pesticide" oral exposure, endosulfan (median lethal dose [LD50] = 9.8 μg/g) was more toxic than λ-cyhalothrin (LD50 = 916.5 μg/g). Neither chemical was toxic via dermal exposure. An acetone dosing vehicle increased λ-cyhalothrin toxicity (oral LD50 = 9.8 μg/g; dermal LD50 = 17.5 μg/g), but not endosulfan. Finally, changes in dosing method and husbandry significantly increased dermal λ-cyhalothrin LD50s, which highlights the importance of standardized methods. The authors combined data from the present study with other reptile LD50s to correlate with available avian data. When only definitive LD50s were used in the analysis, a strong correlation was found between avian and reptile toxicity. The results suggest it is possible to build predictive relationships between avian and reptile LD50s. More research is needed, however, to understand trends associated with chemical classes and modes of action. © 2015 SETAC.

  5. Assessment of sediment toxicity in the Lagoon of Venice (Italy) using a multi-species set of bioassays.

    Science.gov (United States)

    Picone, Marco; Bergamin, Martina; Losso, Chiara; Delaney, Eugenia; Arizzi Novelli, Alessandra; Ghirardini, Annamaria Volpi

    2016-01-01

    Within the framework of a Weight of Evidence (WoE) approach, a set of four toxicity bioassays involving the amphipod Corophium volutator (10 d lethality test on whole sediment), the sea urchin Paracentrotus lividus (fertilization and embryo toxicity tests on elutriate) and the pacific oyster Crassostrea gigas (embryo toxicity test on elutriate) was applied to sediments from 10 sampling sites of the Venice Lagoon (Italy). Sediments were collected during three campaigns carried out in May 2004 (spring campaign), October 2004 (autumn campaign) and February 2005 (winter campaign). Toxicity tests were performed on all sediment samples. Sediment grain-size and chemistry were measured during spring and autumn campaigns. This research investigated (i) the ability of toxicity tests in discriminating among sites with different contamination level, (ii) the occurrence of a gradient of effect among sampling sites, (iii) the possible correlation among toxicity tests, sediment chemistry, grain size and organic carbon, and (iv) the possible occurrence of toxicity seasonal variability. Sediment contamination levels were from low to moderate. No acute toxicity toward amphipods was observed, while sea urchin fertilization was affected only in few sites in just a single campaign. Short-term effects on larval development of sea urchin and oyster evidenced a clear spatial trend among sites, with increasing effects along the axis connecting the sea-inlets with the industrial area. The set of bioassays allowed the identification of a spatial gradient of effect, with decreasing toxicity from the industrial area toward the sea-inlets. Multivariate data analysis showed that the malformations of oyster embryos were significantly correlated to the industrial contamination (metals, polynuclear aromatic hydrocarbons, hexachlorobenzene and polychlorinated biphenyls), while sea urchin development to sediment concentrations of As, Cr and organic carbon. Both embryo toxicity tests were

  6. Measured Copper Toxicity to Cnesterodon decemmaculatus (Pisces: Poeciliidae and Predicted by Biotic Ligand Model in Pilcomayo River Water: A Step for a Cross-Fish-Species Extrapolation

    Directory of Open Access Journals (Sweden)

    María Victoria Casares

    2012-01-01

    Full Text Available In order to determine copper toxicity (LC50 to a local species (Cnesterodon decemmaculatus in the South American Pilcomayo River water and evaluate a cross-fish-species extrapolation of Biotic Ligand Model, a 96 h acute copper toxicity test was performed. The dissolved copper concentrations tested were 0.05, 0.19, 0.39, 0.61, 0.73, 1.01, and 1.42 mg Cu L-1. The 96 h Cu LC50 calculated was 0.655 mg L-1 (0.823-0.488. 96-h Cu LC50 predicted by BLM for Pimephales promelas was 0.722 mg L-1. Analysis of the inter-seasonal variation of the main water quality parameters indicates that a higher protective effect of calcium, magnesium, sodium, sulphate, and chloride is expected during the dry season. The very high load of total suspended solids in this river might be a key factor in determining copper distribution between solid and solution phases. A cross-fish-species extrapolation of copper BLM is valid within the water quality parameters and experimental conditions of this toxicity test.

  7. Comparison of the relative sensitivity of Arctic species to dispersed oil using total petroleum and PAH measures of toxicity

    Science.gov (United States)

    Extended periods of open water have expanded the potential opportunities for petroleum and gas exploration and production in the Arctic, increasing the focus on understanding the potential impacts of released oil on aquatic organisms. However, information regarding the toxicity o...

  8. Increased Expression of Simple Ganglioside Species GM2 and GM3 Detected by MALDI Imaging Mass Spectrometry in a Combined Rat Model of Aβ Toxicity and Stroke.

    Directory of Open Access Journals (Sweden)

    Sarah Caughlin

    Full Text Available The aging brain is often characterized by the presence of multiple comorbidities resulting in synergistic damaging effects in the brain as demonstrated through the interaction of Alzheimer's disease (AD and stroke. Gangliosides, a family of membrane lipids enriched in the central nervous system, may have a mechanistic role in mediating the brain's response to injury as their expression is altered in a number of disease and injury states. Matrix-Assisted Laser Desorption Ionization (MALDI Imaging Mass Spectrometry (IMS was used to study the expression of A-series ganglioside species GD1a, GM1, GM2, and GM3 to determine alteration of their expression profiles in the presence of beta-amyloid (Aβ toxicity in addition to ischemic injury. To model a stroke, rats received a unilateral striatal injection of endothelin-1 (ET-1 (stroke alone group. To model Aβ toxicity, rats received intracerebralventricular (i.c.v. injections of the toxic 25-35 fragment of the Aβ peptide (Aβ alone group. To model the combination of Aβ toxicity with stroke, rats received both the unilateral ET-1 injection and the bilateral icv injections of Aβ25-35 (combined Aβ/ET-1 group. By 3 d, a significant increase in the simple ganglioside species GM2 was observed in the ischemic brain region of rats who received a stroke (ET-1, with or without Aβ. By 21 d, GM2 levels only remained elevated in the combined Aβ/ET-1 group. GM3 levels however demonstrated a different pattern of expression. By 3 d GM3 was elevated in the ischemic brain region only in the combined Aβ/ET-1 group. By 21 d, GM3 was elevated in the ischemic brain region in both stroke alone and Aβ/ET-1 groups. Overall, results indicate that the accumulation of simple ganglioside species GM2 and GM3 may be indicative of a mechanism of interaction between AD and stroke.

  9. A new species of solitary Meteorus (Hymenoptera: Braconidae) reared from caterpillars of toxic butterflies (Lepidoptera: Nymphalidae) in Ecuador.

    Science.gov (United States)

    Shaw, Scott R; Jones, Guinevere Z

    2009-01-01

    A new species of parasitoid wasp, Meteorus rugonasus Shaw and Jones (Hymenoptera: Braconidae), is described from the Yanayacu Biological Station, Napo Province, Ecuador. The new species is diagnosed and compared to other species in the genus. It was reared from larvae of Pteronymia zerlina (Hewitson, 1855) (Lepidoptera: Nymphalidae, Ithomiinae) found feeding on leaves of Solanum (Solanaceae). The parasitoid is solitary. This is the first record of a Meteorus species attacking ithomiine Nymphalidae. A new species of parasitoid wasp, Meteorus rugonasus Shaw and Jones (Hymenoptera: Braconidae), is described from the Yanayacu Biological Station, Napo Province, Ecuador. The new species is diagnosed and compared to other species in the genus. It was reared from larvae of Pteronymia zerlina (Hewitson, 1855) (Lepidoptera: Nymphalidae, Ithomiinae) found feeding on leaves of Solanum (Solanaceae). The parasitoid is solitary. This is the first record of a Meteorus species attacking ithomiine Nymphalidae.

  10. A New Species of Solitary Meteorus (Hymenoptera: Braconidae) Reared from Caterpillars of Toxic Butterflies (Lepidoptera: Nymphalidae) in Ecuador

    OpenAIRE

    Shaw, Scott R.; Jones, Guinevere Z.

    2009-01-01

    A new species of parasitoid wasp, Meteorus rugonasus Shaw and Jones (Hymenoptera: Braconidae), is described from the Yanayacu Biological Station, Napo Province, Ecuador. The new species is diagnosed and compared to other species in the genus. It was reared from larvae of Pteronymia zerlina (Hewitson, 1855) (Lepidoptera: Nymphalidae, Ithomiinae) found feeding on leaves of Solanum (Solanaceae). The parasitoid is solitary. This is the first record of a Meteorus species attacking ithomiine Nympha...

  11. Comparative Toxicity of Louisiana Sweet Crude Oil (LSC) and Chemically Dispersed LSC to Two Gulf of Mexico Aquatic Test Species.

    Science.gov (United States)

    Environmental Protection Agency released peer reviewed results from the second phase of its independent toxicity testing on mixtures of eight oil dispersants with Louisiana Sweet Crude Oil. EPA conducted the tests as part of an effort to ensure that EPA decisions remain grounded ...

  12. Persistence and extinction of a single-species population system in a polluted environment with random perturbations and impulsive toxicant input

    International Nuclear Information System (INIS)

    Liu Meng; Wang Ke

    2012-01-01

    Highlights: ► Random population model with pulse toxicant input in polluted environments. ► Threshold between persistence and extinction is obtained. ► Different random noises have different effects on the persistence of the population. ► Impulsive period plays a key role in determining persistence of the population. ► Simulation figures support the analytical findings. - Abstract: Taking both white noises and colored noises into account, a stochastic single-species model with Markov switching and impulsive toxicant input in a polluted environment is proposed and investigated. Sufficient conditions for extinction, non-persistence in the mean, weak persistence and stochastic permanence are established. The threshold between weak persistence and extinction is obtained. Some simulation figures are introduced to illustrate the main results.

  13. Ecological characterization of toxic phytoplankton species (Dinophysis spp., Dinophyceae) in Slovenian mariculture areas (Gulf of Trieste, Adriatic Sea) and the implications for monitoring

    International Nuclear Information System (INIS)

    France, Janja . E-mail france@mbss.org; Mozetic, Patricija

    2006-01-01

    Diarrhetic shellfish poisoning (DSP) events are often registered in Slovenian mariculture areas (Gulf of Trieste, Adriatic Sea) and are related to the occurrence of Dinophysis spp. The annual dynamic of this genus and succession of the most important species were studied at two shellfish farms during monitoring fieldwork in the period 1995-2003. Results indicate that the Dinophysis genus maintains a relatively stable inter-annual dynamic at both sites. The Dinophysis community is characterized by two surface maxima in June and September, while in the middle layer only the autumn peak is pronounced (peak median 92 cells l -1 ). Occasional abundance maxima of around 2000 cells l -1 in the surface layer indicate that potential outbursts of toxic species are less predictable than their seasonal dynamic. On the basis of multivariate analysis, Dinophysis sacculus was characterized as a typical late spring-early summer species, and Dinophysis caudata and Dinophysis fortii as autumn species. Correlation analysis revealed the influence of stratified conditions only on the most abundant species, D. sacculus. Ecological characteristics of the species were combined with shellfish safety requirements towards a more effective monitoring

  14. Acute toxicity of sodium bicarbonate, a major component of coal bed natural gas produced waters, to 13 aquatic species as defined in the laboratory

    Science.gov (United States)

    Harper, David D.; Farag, Aïda M.; Skaar, Don

    2014-01-01

    Water produced during coal bed natural gas (CBNG) extraction in the Powder River Structural Basin of Wyoming and Montana (USA) may contain concentrations of sodium bicarbonate (NaHCO3) of more than 3000 mg/L. The authors evaluated the acute toxicity of NaHCO3, also expressed as bicarbonate (HCO3−), to 13 aquatic organisms. Of the 13 species tested, 7 had a median lethal concentration (LC50) less than 2000 mg/L NaHCO3, or 1300 mg/L HCO3−. The most sensitive species were Ceriodaphnia dubia, freshwater mussels (Lampsilis siliquoidea), pallid sturgeon (Scaphirhynchus albus), and shovelnose sturgeon (Scaphirhynchus platorynchus). The respective LC50s were 989 mg/L, 1120 mg/L, 1249 mg/L, and 1430 mg/L NaHCO3, or 699 mg/L, 844 mg/L, 831 mg/L, and 1038 mg/L HCO3−. Age affected the sensitivity of fathead minnows, even within life stage. Two days posthatch, fathead minnows were more sensitive to NaHCO3 and HCO3− compared with 4-d-old fish, even though fish up to 14 d old are commonly used for toxicity evaluations. The authors recommend that ion toxicity exposures be conducted with organisms less than 24 h posthatch to ensure that experiments document the most sensitive stage of development. The results of the present study, along with historical and current research regarding the toxicity of bicarbonate, may be useful to establish regulatory standards for HCO3−.

  15. The neutral species of the weak base trimethoprim is more toxic to willow trees (Salix viminalis) than the cation

    DEFF Research Database (Denmark)

    Mikes, O.; Trapp, Stefan

    2011-01-01

    The acute toxicity of the veterinary antibiotic trimethoprim (TMP) to willow trees was tested at three different pH levels in hydroponic solutions with TMP concentrations of 1, 10, 100 or 1000 mg/L. The pH variation was achieved by using ammonium (pH 4.3, low) or nitrate (pH 6.4, medium) as nitro......The acute toxicity of the veterinary antibiotic trimethoprim (TMP) to willow trees was tested at three different pH levels in hydroponic solutions with TMP concentrations of 1, 10, 100 or 1000 mg/L. The pH variation was achieved by using ammonium (pH 4.3, low) or nitrate (pH 6.4, medium...

  16. Effect of Common Species of Florida Landscaping Plants on the Efficacy of Attractive Toxic Sugar Baits Against Aedes albopictus.

    Science.gov (United States)

    Seeger, Kelly E; Scott, Jodi M; Muller, Gunter C; Qualls, Whitney A; Xue, Rui-De

    2017-06-01

    Attractive toxic sugar bait (ATSB) was applied to 5 different types of commonly found plants in landscaping of northeastern Florida. The ATSB applications were assessed for possible plant effects and preference against Aedes albopictus in semifield evaluations. Positive and negative controls consisted of plants sprayed with attractive sugar bait (no toxicant) and plants with nothing applied. Bioassays were conducted on stems with leaf clippings and on full plants to assess any difference in mosquito mortality on the different plants. Plants utilized in these evaluations were Indian hawthorne, Yaupon holly, Japanese privet, Loropetalum ruby, and podocarpus. In both assays, no significant difference was observed in the effect of ATSBs on adult female mosquitoes based on the type of plant. ATSB could be applied to common landscape plants for adult Ae. albopictus control.

  17. Migration of nonylphenol from food-grade plastic is toxic to the coral reef fish species Pseudochromis fridmani.

    Science.gov (United States)

    Hamlin, Heather J; Marciano, Kathleen; Downs, Craig A

    2015-11-01

    Nonylphenol (NP) is a non-ionic surfactant used extensively in industrial applications, personal care products, and many plastics. We exposed marine orchid dottybacks (Pseudochromis fridmani) for 48h to either glass, Teflon, or two bags labeled as FDA food-grade polyethylene (PE1 and PE2) from different manufacturers. The PE2 bags leached high levels of NP into the contact water, which were taken up by the fish, and decreased short and long-term survival. Concentrations of NP that leached from the bags were consistent with 96h LC50 values determined in this study, indicating NP is the likely toxic agent. Despite being similarly labeled, the NP concentrations that leached from the bags and the resultant toxicity to the fish varied dramatically between manufacturers. This study highlights that some plastics, labeled as food-safe, can be highly toxic to aquatic animals, and could pose a greater threat to humans than previously realized. This study also highlights risks for aquatic animals exposed to increasing quantities of plastic waste. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. A novel technology for neutralizing acidity and attenuating toxic chemical species from acid mine drainage using cryptocrystalline magnesite tailings

    CSIR Research Space (South Africa)

    Masindi, Vhahangwele

    2016-04-01

    Full Text Available neutralize and attenuate elevated concentrations of chemical species in AMD to within prescribed legal frameworks for water use in agricultural and industrial sectors in South Africa....

  19. Colorimetric Detection of Caspase 3 Activity and Reactive Oxygen Derivatives: Potential Early Indicators of Thermal Stress in Corals

    Directory of Open Access Journals (Sweden)

    Mickael Ros

    2016-01-01

    Full Text Available There is an urgent need to develop and implement rapid assessments of coral health to allow effective adaptive management in response to coastal development and global change. There is now increasing evidence that activation of caspase-dependent apoptosis plays a key role during coral bleaching and subsequent mortality. In this study, a “clinical” approach was used to assess coral health by measuring the activity of caspase 3 using a commercial kit. This method was first applied while inducing thermal bleaching in two coral species, Acropora millepora and Pocillopora damicornis. The latter species was then chosen to undergo further studies combining the detection of oxidative stress-related compounds (catalase activity and glutathione concentrations as well as caspase activity during both stress and recovery phases. Zooxanthellae photosystem II (PSII efficiency and cell density were measured in parallel to assess symbiont health. Our results demonstrate that the increased caspase 3 activity in the coral host could be detected before observing any significant decrease in the photochemical efficiency of PSII in the algal symbionts and/or their expulsion from the host. This study highlights the potential of host caspase 3 and reactive oxygen species scavenging activities as early indicators of stress in individual coral colonies.

  20. Chemical composition and fumigant toxicity of the essential oils from 16 species of Eucalyptus against Haematobia irritans (Diptera: Muscidae) adults

    OpenAIRE

    Juan, Laura W.; Lucía Mulas, Alejandro; Zerba, Eduardo N.; Harrand, Leonel; Marco, Martín; Masuh, Hector M.

    2011-01-01

    Oils extracted from various species of Eucalyptus (Eucalyptus badjensis Beuzev & Welch, Eucalyptus badjensis x Eucalyptus nitens, Eucalyptus benthamii variety dorrigoensis Maiden & Cambage, Eucalyptus botryoides Smith, Eucalyptus dalrympleana Maiden, Eucalyptus fastigata Deane & Maiden, Eucalyptus nobilis L.A.S. Johnson & K. D. Hill, Eucalyptus polybractea R. Baker, Eucalyptus radiata ssp. radiata Sieber ex Spreng, Eucalyptus resinifera Smith, Eucalyptus robertsonii Blakely, Eucalyptus rubida...

  1. Suitability of seven species of soil-inhabiting invertebrates for testing toxicity of pesticides in soil pore water

    NARCIS (Netherlands)

    Ronday, R.; Houx, N.W.H.

    1996-01-01

    This study assessed the suitability of seven species of soil invertebrates for toxicologically testing pesticides in water. Requirements were that the organisms must survive in water, be easy to handle, be easy to breed, be sensitive to pesticides, and show unambiguous toxicological effects. The

  2. Analysis of certain fatty acids and toxic metal bioaccumulation in various tissues of three fish species that are consumed by Turkish people.

    Science.gov (United States)

    Kaya, Gökçe; Türkoğlu, Semra

    2017-04-01

    Concentrations of toxic metals (Mn, Ni, Hg, Cd, Pb, Cr) in the muscle, skin, and liver of Mugil cephalus, Mullus barbatus, and Pagellus erythrinus which were purchased in large supermarkets of Elazig, and Mullus barbatus, which were caught on the sea of İskenderun Bay, Turkey, were analyzed. Fundamental analyses were carried out by inductively coupled plasma-mass spectrometry (ICP-MS) after samples were prepared by microwave digestion. Mean metal concentrations in different tissues were varied in the ranges of Cd 4-426, Cr 116-4458, Mn 141-24774, Hg 9-471, Pb 96-695, and Ni 68-6581 μg kg -1 , for wet weight. The investigated metal bioaccumulation in the muscles of fish species, in general, was lower than those in the liver and skin. This method was verified by NCS ZC73016 chicken trace element-certified reference material analysis. In addition, fatty acids in the muscles of three fish species were analyzed. According to the gas chromatography (GC) results of fatty acids, the monounsaturated fatty acids (MUFA) were found to be between 23.76 and 31.97%. The fatty acids' polyunsaturated fatty acids (PUFA) ratio was found to be between 13.67 and 30.71% and saturated fatty acids ratios were determined in the range of 24.06-32.30%. In all fish species, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) ratio, which increase the value of these fish species, were high. These results show that these three fish species are good sources of fatty acids.

  3. Microcosm investigations of stormwater pond sediment toxicity to embryonic and larval amphibians: Variation in sensitivity among species

    Energy Technology Data Exchange (ETDEWEB)

    Snodgrass, Joel W. [Department of Biological Sciences, Towson University, 8000 York Road, Towson, MD 21252 (United States)], E-mail: jsnodgrass@towson.edu; Casey, Ryan E. [Department of Chemistry, Towson University, 8000 York Road, Towson, MD 21252 (United States); Joseph, Debra; Simon, Judith A. [Department of Biological Sciences, Towson University, 8000 York Road, Towson, MD 21252 (United States)

    2008-07-15

    Stormwater ponds have become common features of modern development and often represent significant amounts of open space in urbanized areas. Although stormwater ponds may provide habitat for wildlife, factors responsible for producing variation in wildlife use of ponds have received limited attention. To investigate the role of variation in species tolerances of pollutants in structuring pond-breeding amphibian assemblages, we exposed species tolerant (Bufo americanus) and not tolerant (Rana sylvatica) of urbanization to pond sediments in laboratory microcosms. Pond microcosms had elevated sediment metal levels and chloride water concentrations. Among R. sylvatica embryos, exposure to pond sediments resulted in 100% mortality. In contrast, B. americanus embryos and larvae experienced only sublethal effects (i.e., reduced size at metamorphosis) due to pond sediment exposure. Our results suggest variation in pollutant tolerance among early developmental stages of amphibians may act in concert with terrestrial habitat availability to structure amphibian assemblages associated with stormwater ponds. - Variation among species in sensitivity to pollutants can influence stormwater pond amphibian assemblages.

  4. Development of a standardized reproduction toxicity test with the earthworm species Eisenia fetida andrei using copper, pentachlorophenol and 2,4-dichloroaniline

    Energy Technology Data Exchange (ETDEWEB)

    van Gestel, C.A.; van Dis, W.A.; van Breemen, E.M.; Sparenburg, P.M. (National Institute of Public Health and Environmental Protection, BA Bilthoven (Netherland))

    1989-12-01

    This article describes a standardized test method for determining the effect of chemical substances on the reproduction of the earthworm Eisenia fetida andrei. It is based on the existing guidelines for acute toxicity testing with earthworms, and for reasons of standardization the same artificial soil substrate and earthworm species were chosen as prescribed by these guidelines. After being preconditioned for one week in untreated soil, earthworms are exposed to the chemical substances for 3 weeks. The number of cocoons produced is determined, and cocoons are incubated in untreated artificial soil for 5 weeks to assess hatchability. Results are presented from toxicity experiments with pentachlorophenol, copper, and 2,4-dichloroaniline. For these compounds no-effect levels (NEL) for cocoon production were 32, 60-120, and 56 mg.kg-1 dry soil, respectively. Hatching of cocoons was influenced by pentachlorophenol (NEL, 10 mg.kg-1), but not by copper and dichloroaniline. Following exposure, earthworms were incubated in clean soil again to study the possibility of recovery of cocoon production. For copper and dichloroaniline earthworms did recover cocoon production to a level as high as the control level or even higher; in case of pentachlorophenol, cocoon production was still reduced after 3 weeks in clean soil.

  5. Future needs and recommendations in the development of species sensitivity distributions: Estimating toxicity thresholds for aquatic ecological communities and assessing impacts of chemical exposures.

    Science.gov (United States)

    Belanger, Scott; Barron, Mace; Craig, Peter; Dyer, Scott; Galay-Burgos, Malyka; Hamer, Mick; Marshall, Stuart; Posthuma, Leo; Raimondo, Sandy; Whitehouse, Paul

    2017-07-01

    A species sensitivity distribution (SSD) is a probability model of the variation of species sensitivities to a stressor, in particular chemical exposure. The SSD approach has been used as a decision support tool in environmental protection and management since the 1980s, and the ecotoxicological, statistical, and regulatory basis and applications continue to evolve. This article summarizes the findings of a 2014 workshop held by the European Centre for Toxicology and Ecotoxicology of Chemicals and the UK Environment Agency in Amsterdam, The Netherlands, on the ecological relevance, statistical basis, and regulatory applications of SSDs. An array of research recommendations categorized under the topical areas of use of SSDs, ecological considerations, guideline considerations, method development and validation, toxicity data, mechanistic understanding, and uncertainty were identified and prioritized. A rationale for the most critical research needs identified in the workshop is provided. The workshop reviewed the technical basis and historical development and application of SSDs, described approaches to estimating generic and scenario-specific SSD-based thresholds, evaluated utility and application of SSDs as diagnostic tools, and presented new statistical approaches to formulate SSDs. Collectively, these address many of the research needs to expand and improve their application. The highest priority work, from a pragmatic regulatory point of view, is to develop a guidance of best practices that could act as a basis for global harmonization and discussions regarding the SSD methodology and tools. Integr Environ Assess Manag 2017;13:664-674. © 2016 SETAC. © 2016 SETAC.

  6. Potentially toxic contamination of sediments, water and two animal species in Lake Kalimanci, FYR Macedonia: Relevance to human health

    International Nuclear Information System (INIS)

    Vrhovnik, Petra; Arrebola, Juan P.; Serafimovski, Todor; Dolenec, Tadej; Šmuc, Nastja Rogan; Dolenec, Matej; Mutch, Elaine

    2013-01-01

    The objectives of the research were: (1) to examine the concentrations of metals in Vimba melanops and Rana temporaria and (2) to evaluate the potential risks of the contaminated organisms to human health in Makedonska Kamenica region. Analyses identified high levels of Cr, Hg, Ni and Pb in studied animals, which also exceeded their permissible levels in food. In sediment and soil samples, levels of Cd, Cu, Cr, Pb, Zn and As were perceived, while Cd, Cu, Ni, Pb, Se and As were increased in water samples. Results of transfer factor revealed that the examined animals had higher bioaccumulation rate from surrounding waters than from sediments or soils. The accomplished Health Risk Index disclosed that studied animals can have considerably high health risks for inhabitants. Conclusively, they could be considered as highly contaminated with metals and can consequently harm human health, especially children in their early development stages. -- Highlights: •The study merges the accumulation of PTE in animal species, sediments, soils and water. •Correlation between different media and their impact to living organisms'. •Considerably high health risks for inhabitants. -- In the Makedonska Kamenica region had been described several potential sources of exposure therefore exists the potential threat to human health

  7. Toxicity of nano-TiO2 on algae and the site of reactive oxygen species production.

    Science.gov (United States)

    Li, Fengmin; Liang, Zhi; Zheng, Xiang; Zhao, Wei; Wu, Miao; Wang, Zhenyu

    2015-01-01

    Given the extensive use of nanomaterials, they may enter aquatic environments and harm the growth of algae, which are primary producers in an aquatic ecosystem. Thus, the balance of an aquatic ecosystem may be destroyed. In this study, Karenia brevis and Skeletonema costatum were exposed to nano-TiO2 (anatase, average particle size of 5-10 nm, specific surface area of 210±10 m(2) g(-1)) to assess the effects of nano-TiO2 on algae. The findings of transmission electron microscopy-energy dispersive X-ray spectroscopy (TEM-EDX) and scanning electron microscopy (SEM) demonstrate aggregation of nano-TiO2 in the algal suspension. Nano-TiO2 was also found to be inside algal cells. The growth of the two species of algae was inhibited under nano-TiO2 exposure. The 72 h EC50 values of nano-TiO2 to K. brevis and S. costatum were 10.69 and 7.37 mg L(-1), respectively. TEM showed that the cell membrane of K. brevis was destroyed and its organelles were almost undistinguished under nano-TiO2 exposure. The malondialdehyde (MDA) contents of K. brevis and S. costatum significantly increased compared with those of the control (pTiO2 exposure was explored with the addition of inhibitors of different electron transfer chains. This study indicated that nano-TiO2 in algal suspensions inhibited the growth of K. brevis and S. costatum. This effect was attributed to oxidative stress caused by ROS production inside algal cells. The levels of anti-oxidative enzymes changed, which destroyed the balance between oxidation and anti-oxidation. Thus, algae were damaged by ROS accumulation, resulting in lipid oxidation and inhibited algae growth. The inhibitors of the electron transfer chain showed that the site of ROS production and accumulation in K. brevis cells was the chloroplast. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Comparative study of activities in reactive oxygen species production/defense system in mitochondria of rat brain and liver, and their susceptibility to methylmercury toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Mori, N.; Hirayama, K. [Kumamoto University, School of Health Science, Kumamoto (Japan); Yasutake, A. [National Institute for Minamata Disease, Minamata (Japan)

    2007-11-15

    The involvement of oxidative stress has been suggested as a mechanism for neurotoxicity caused by methylmercury (MeHg), but the mechanism for MeHg selective toxicity in the central nervous system is still unclear. In this research, to clarify the mechanism of selective neurotoxicity caused by MeHg, the oxygen consumption levels, the reactive oxygen species (ROS) production rates and several antioxidant levels in mitochondria were compared among the cerebrum, cerebellum and liver of male Wistar rats. In addition, the alterations of these indexes were examined in MeHg-intoxicated rats (oral administration of 10 mg/kg day, for 5 days). Although the cerebrum and cerebellum in intact rats showed higher mitochondrial oxygen consumption levels and ROS production rates than the liver, glutathione peroxidase (GPX) and superoxide dismutase (SOD) activities were much lower in the cerebrum and cerebellum than in the liver. Especially, the cerebellum showed the highest oxygen consumption and ROS production rate and the lowest mitochondrial glutathione (GSH) levels among the tissues examined. In the MeHg-treated rats, decrease in the oxygen consumption and increase in the ROS generation were found only in the cerebellum mitochondria, despite a lower Hg accumulation in the mitochondrial fraction compared to the liver. Since MeHg treatment produced an enhancement of ROS generation in cerebellum mitochondria supplemented with succinate substrates, MeHg-induced oxidative stress might affect the complex II-III mediated pathway in the electron transfer chain in the cerebellum mitochondria. Our study suggested that inborn factors, high production system activity and low defense system activity of ROS in the brain, would relate to the high susceptibility of the central nervous system to MeHg toxicity. (orig.)

  9. Linking hydrogen-mediated boron toxicity tolerance with improvement of root elongation, water status and reactive oxygen species balance: a case study for rice.

    Science.gov (United States)

    Wang, Yu; Duan, Xingliang; Xu, Sheng; Wang, Ren; Ouyang, Zhaozeng; Shen, Wenbiao

    2016-12-01

    Boron is essential for plant growth but hazardous when present in excess. As the antioxidant properties of hydrogen gas (H 2 ) were recently described in plants, oxidative stress induced by excess boron was investigated along with other biological responses during rice (Oryza sativa) seed germination to study the beneficial role of H 2 METHODS: Rice seeds were pretreated with exogenous H 2 Using physiological, pharmacological and molecular approaches, the production of endogenous H 2 , growth status, reactive oxygen species (ROS) balance and relative gene expression in rice were measured under boron stress to investigate mechanisms of H 2 -mediated boron toxicity tolerance. In our test, boron-inhibited seed germination and seedling growth, and endogenous H 2 production, were obviously blocked by exogenously applying H 2 The re-establishment of ROS balance was confirmed by reduced lipid peroxidation and ROS accumulation. Meanwhile, activities of catalase (CAT) and peroxidase (POX) were increased. Suppression of pectin methylesterase (PME) activity and downregulation of PME transcripts by H 2 were consistent with the alleviation of root growth inhibition caused by boron. Water status was improved as well. This result was confirmed by the upregulation of genes encoding specific aquaporins (AQPs), the maintenance of low osmotic potential and high content of soluble sugar. Increased transcription of representative AQP genes (PIP2;7 in particular) and BOR2 along with decreased BOR1 mRNA may contribute to lowering boron accumulation. Hydrogen provides boron toxicity tolerance mainly by improving root elongation, water status and ROS balance. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Ebselen protects against behavioral and biochemical toxicities induced by 3-nitropropionic acid in rats: correlations between motor coordination, reactive species levels, and succinate dehydrogenase activity.

    Science.gov (United States)

    Wilhelm, Ethel A; Bortolatto, Cristiani F; Jesse, Cristiano R; Luchese, Cristiane

    2014-12-01

    The protective effect of ebselen was investigated against 3-nitropropionic acid (3-NP)-induced behavioral and biochemical toxicities in rats. Ebselen (10 or 25 mg/kg, intragastrically) was administered to rats 30 min before 3-NP (20 mg/kg, intraperitoneally) once a day for a period of 4 days. Locomotor activity, motor coordination, and body weight gain were determined. The striatal content of reactive oxygen species (ROS), reduced glutathione (GSH), ascorbic acid (AA), and protein carbonyl as well as catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione-S-transferase (GST) activities was determined 24 h after the last dose of 3-NP. Na(+)/ K(+)-ATPase, succinate dehydrogenase (SDH), and δ-aminolevulinic dehydratase (δ-ALA-D) activities were also determined. The results demonstrated that ebselen at a dose of 25 mg/kg, but not at 10 mg/kg, protected against (1) a decrease in locomotor activity, motor coordination impairment, and body weight loss; (2) striatal oxidative damage, which was characterized by an increase in ROS levels, protein carbonyl content, and GR activity, an inhibition of CAT and GPx activities, and a decrease in GSH levels; and (3) an inhibition of SDH and Na(+)/K(+)-ATPase activities, induced by 3-NP. GST activity and AA levels were not modified by ebselen or 3-NP. Ebselen was not effective against the inhibition of δ-ALA-D activity induced by 3-NP. The results revealed a significant correlation between SDH activity and ROS levels, and SDH activity and latency to fall (rotarod test). The present study highlighted the protective effect of ebselen against 3-NP-induced toxicity in rats.

  11. Ecological risk assessment on a cadmium contaminated soil landfill-a preliminary evaluation based on toxicity tests on local species and site-specific information

    International Nuclear Information System (INIS)

    Chen, C.-M.; Liu, M.-C.

    2006-01-01

    In recent years, methodology of ecological risk assessment has been developed and applied frequently for addressing various circumstances where ecological impacts are suspected or have occurred due to environmental contamination; however, its practice is very limited in Taiwan. In 1982, brown rice from rice paddy fields in Da-Tan, Tau-Yuan, was found to be contaminated with Cd and Pb due to illegal discharges of wastewater, known as the 'Cd rice' incidence. Cadmium laden soil was transferred to a constructed landfill in an industrial park 15 years after the incident. Possible leakage of the landfill was suspected by committee members of a supervising board for the remediation process, and a preliminary ecological risk evaluation was requested. A possible risk scenario was that groundwater contamination due to the leachate containing Cd and Pb from the landfill could result in pollution of coastal water, and subsequently produce toxic effects to aquatic organisms. Chemical dissipation in groundwater systems was simulated and short-term chronic toxicity tests on larvae of three local aquatic species were also performed to determine the no-observed adverse-effect concentrations (NOAECs), as well as the predicted no effect concentrations (PNECs), of the two metals in the organisms tested. The hazard quotient (HQ), the ratio of predicted environmental concentrations (PECs) to PNECs, was used for risk characterization. A worst-case-scenario calculation showed that the maximum Cd concentration at 60 m and farther downstream from the site in the groundwater system would be 0.0028 mg l -1 with a maximum initial concentration of 0.65 mg l -1 in the leachate, while for Pb, the highest concentration of 0.044 mg l -1 would be reached at a distance of 40 m and farther, which was based on an initial concentration of 4.4 mg l -1 in the leachate; however, both cases would only occur 80 years after the initiation of leakage. A presumed dilution factor of 100 was used to calculate

  12. SALMONELLA SPECIES

    African Journals Online (AJOL)

    DR. AMINU

    ... of Salmonella species serotypes in relation to age and sex among children, ..... However, most antimicrobials show sufficient selective toxicity to be of value in ... salmonellosis should be given good attention (Barrow et al., 2007). To reduce ...

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

    Science.gov (United States)

    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 sensitiv...

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

    Science.gov (United States)

    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 se...

  15. Impact of solar UV radiation on toxicity of ZnO nanoparticles through photocatalytic reactive oxygen species (ROS) generation and photo-induced dissolution

    Science.gov (United States)

    The present study investigated the impact of solar UV radiation on ZnO nanoparticle toxicity through photocatalytic ROS generation and photo-induced dissolution. Toxicity of ZnO nanoparticles to Daphnia magna was examined under laboratory light versus simulated solar UV radiatio...

  16. Method for aquatic multiple species toxicant testing: acute toxicity of 10 chemicals to 5 vertebrates and 2 invertebrates. [Pimephales promelas; Carassius auratus; Ictalurus punctatus; Lepomis macrochirus; Salmo gairdneri; Orconectes immunis; Aplexa hypnorum

    Energy Technology Data Exchange (ETDEWEB)

    Phipps, G.L.; Holcombe, G.W.

    1985-01-01

    A method was developed to simultaneously ascertain 96 h LC/sub 50/ values for seven freshwater species in a single flow through test with measured concentrations. It allows interspecific comparisons, easy determination of the most sensitive species, and cuts cost of labor, materials and chemical analysis for measured concentration tests. Species tested included fathead minnows Pimephales promelas, goldfish Carassius auratus, channel catfish Ictalurus punctatus, bluegill Lepomis macrochirus, rainbow trout Salmo gairdneri, crayfish Orconectes immunis and snails Aplexa hypnorum. Compounds tested were pentachlorophenol, 2-chloroethanol, 2,4-pentanedione, hexachloroethane, ..cap alpha..-bromo-2',5'-dimethoxyacetophenone, benzaldehyde, 1,3-dichloro-4,6-dinitro-benzene, dursban, sevin and cadmium chloride. The LC/sub 50/ values from these multiple species tests compared favourably with those determined using single species tests at this laboratory, usually within 20%.

  17. Introducing Toxics

    OpenAIRE

    David C. Bellinger

    2013-01-01

    With this inaugural issue, Toxics begins its life as a peer-reviewed, open access journal focusing on all aspects of toxic chemicals. We are interested in publishing papers that present a wide range of perspectives on toxicants and naturally occurring toxins, including exposure, biomarkers, kinetics, biological effects, fate and transport, treatment, and remediation. Toxics differs from many other journals in the absence of a page or word limit on contributions, permitting authors to present ...

  18. Control of insects with fumigants at low temperatures: toxicity of mixtures of methyl bromide and acrylonitrile to three species of insects

    Energy Technology Data Exchange (ETDEWEB)

    Bond, E.J.; Buckland, C.T.

    1976-12-15

    Acrylonitrile can be mixed with methyl bromide to increase toxicity so that the quantity of methyl bromide required for control of Sitophilus granarius (L.), Tenebrio molitor L., and Tribolium confusum Jacquelin duval is reduced by one half. Mixtures of methyl bromide and acrylonitrile are considerably more effective at low temperatures than methyl bromide alone.

  19. Development of Alternatives to Chronic Ecotoxicity Tests: Predicting Early-life Stage and Endocrine-mediated Toxicity in Aquatic Vertebrate Species

    Science.gov (United States)

    In June 2010, the ILSI Health and Environmental Sciences Institute (HESI) with support from sanofi-aventis, NC3Rs, the Humane Society, L’Oreal, and ECVAM, held a workshop aimed at examining critical science needs related to the development of alternatives to chronic fish toxicity...

  20. Application of Multi-Species Microbial Bioassay to Assess the Effects of Engineered Nanoparticles in the Aquatic Environment: Potential of a Luminous Microbial Array for Toxicity Risk Assessment (LumiMARA on Testing for Surface-Coated Silver Nanoparticles

    Directory of Open Access Journals (Sweden)

    YounJung Jung

    2015-07-01

    Full Text Available Four different manufactured surface-coated silver nanoparticles (AgNPs with coating of citrate, tannic acid, polyethylene glycol, and branched polyethylenimine were used in this study. The toxicity of surface-coated AgNPs was evaluated by a luminous microbial array for toxicity risk assessment (LumiMARA using multi-species of luminescent bacteria. The salt stability of four different AgNPs was measured by UV absorbance at 400 nm wavelength, and different surface-charged AgNPs in combination with bacteria were observed using scanning electron microscopy (SEM. Both branched polyethylenimine (BPEI-AgNPs and polyethylene glycol (PEG-AgNPs were shown to be stable with 2% NaCl (non-aggregation, whereas both citrate (Cit-AgNPs and tannic acid (Tan-AgNPs rapidly aggregated in 2% NaCl solution. The values of the 50% effective concentration (EC50 for BPEI-AgNPs in marine bacteria strains (1.57 to 5.19 mg/L were lower than those for the other surface-coated AgNPs (i.e., Cit-AgNPs, Tan-AgNPs, and PEG-AgNPs. It appears that the toxicity of AgNPs could be activated by the interaction of positively charged AgNPs with the negatively charged bacterial cell wall from the results of LumiMARA. LumiMARA for toxicity screening has advantageous compared to a single-species bioassay and is applicable for environmental samples as displaying ranges of assessment results.

  1. Modeling Aquatic Toxicity through Chromatographic Systems.

    Science.gov (United States)

    Fernández-Pumarega, Alejandro; Amézqueta, Susana; Farré, Sandra; Muñoz-Pascual, Laura; Abraham, Michael H; Fuguet, Elisabet; Rosés, Martí

    2017-08-01

    Environmental risk assessment requires information about the toxicity of the growing number of chemical products coming from different origins that can contaminate water and become toxicants to aquatic species or other living beings via the trophic chain. Direct toxicity measurements using sensitive aquatic species can be carried out but they may become expensive and ethically questionable. Literature refers to the use of chromatographic measurements that correlate to the toxic effect of a compound over a specific aquatic species as an alternative to get toxicity information. In this work, we have studied the similarity in the response of the toxicity to different species and we have selected eight representative aquatic species (including tadpoles, fish, water fleas, protozoan, and bacteria) with known nonspecific toxicity to chemical substances. Next, we have selected four chromatographic systems offering good perspectives for surrogation of the eight selected aquatic systems, and thus prediction of toxicity from the chromatographic measurement. Then toxicity has been correlated to the chromatographic retention factor. Satisfactory correlation results have been obtained to emulate toxicity in five of the selected aquatic species through some of the chromatographic systems. Other aquatic species with similar characteristics to these five representative ones could also be emulated by using the same chromatographic systems. The final aim of this study is to model chemical products toxicity to aquatic species by means of chromatographic systems to reduce in vivo testing.

  2. Future Needs and Recommendations in the Development of Species Sensitivity Distributions: Estimating Toxicity Thresholds for Aquatic Ecological Communities and Assessing Impacts of Chemical Exposures

    Science.gov (United States)

    A species sensitivity distribution (SSD) is a probability model of the variation of species sensitivities to a stressor, in particular chemical exposure. The SSD approach has been used as a decision support tool in environmental protection and management since the 1980s, and the ...

  3. Toxicity of noradrenaline, a novel anti-biofouling component, to two non-target zooplankton species, Daphnia magna and Ceriodaphnia dubia.

    Science.gov (United States)

    Overturf, C L; Wormington, A M; Blythe, K N; Gohad, N V; Mount, A S; Roberts, A P

    2015-05-01

    Noradrenaline (NA) is the active component of novel antifouling agents and acts by preventing attachment of fouling organisms. The goal of this study was to examine the toxicity of NA to the non-target zooplankton D. magna and C. dubia. Neonates were exposed to one of five concentrations of NA and effects on survival, reproduction and molting were determined. Calculated LC50 values were determined to be 46 and 38 μM in C. dubia and D. magna, respectively. A 10-day C. dubia study found that reproduction metrics were significantly impacted at non-lethal concentrations. In D. magna, concentrations greater than 40 μM significantly impacted molting. A toxicity test was conducted with D. magna using oxidized NA, which yielded similar results. These data indicate that both NA and oxidized NA are toxic to non-target zooplankton. Results obtained from this study can be used to guide future ecological risk assessments of catecholamine-based antifouling agents. Copyright © 2015. Published by Elsevier Inc.

  4. Separations chemistry of toxic metals

    International Nuclear Information System (INIS)

    Smith, P.; Barr, M.; Barrans, R.

    1996-01-01

    Sequestering and removing toxic metal ions from their surroundings is an increasingly active area of research and is gaining importance in light of current environmental contamination problems both within the DOE complex and externally. One method of separating metal ions is to complex them to a molecule (a ligand or chelator) which exhibits specific binding affinity for a toxic metal, even in the presence of other more benign metals. This approach makes use of the sometimes subtle differences between toxic and non-toxic metals resulting from variations in size, charge and shape. For example, toxic metals such as chromium, arsenic, and technetium exist in the environment as oxyanions, negatively charged species with a characteristic tetrahedral shape. Other toxic metals such as actinides and heavy metals are positively charged spheres with specific affinities for particular donor atoms such as oxygen (for actinides) and nitrogen (for heavy metals). In most cases the toxic metals are found in the presence of much larger quantities of less toxic metals such as sodium, calcium and iron. The selectivity of the chelators is critical to the goal of removing the toxic metals from their less toxic counterparts. The approach was to build a ligand framework that complements the unique characteristics of the toxic metal (size, charge and shape) while minimizing interactions with non-toxic metals. The authors have designed ligands exhibiting specificity for the target metals; they have synthesized, characterized and tested these ligands; and they have shown that they exhibit the proposed selectivity and cooperative binding effects

  5. Acute toxicity and sublethal effects of the mixture glyphosate (Roundup® Active and Cosmo-Flux®411F to anuran embryos and tadpoles of four Colombian species

    Directory of Open Access Journals (Sweden)

    Liliana Marcela Henao Muñoz

    2015-03-01

    Full Text Available Glyphosate is the most widely used herbicide in the world with application in agriculture, forestry, industrial weed control, garden and aquatic environments. However, its use is highly controversial for the possible impact on not-target organisms, such as amphibians, which are vanishing at an alarming and rapid rate. Due to the high solubility in water and ionic nature, the glyphosate requires of surfactants to increase activity. In addition, for the control of coca (Erythroxylum coca and agricultural weeds in Colombia, formulated glyphosate is mixed and sprayed with the adjuvant Cosmo-Flux®411F to increase the penetration and activity of the herbicide. This study evaluates the acute toxic and sublethal effects (embryonic development, tadpole body size, tadpole swimming performance of the mixture of the formulated glyphosate Roundup® Active and Cosmo-Flux®411F to anuran embryos and tadpoles of four Colombian species under 96h laboratory standard tests and microcosms, which are more similar to field conditions as they include soil, sand and macrophytes. In the laboratory, embryos and tadpoles of Engystomops pustulosus were the most tolerant (LC50=3 904µg a.e./L; LC50=2 799µg a.e./L, respectively, while embryos and tadpoles of Hypsiboas crepitans (LC50=2 203µg a.e./L; LC50=1 424µg a.e./L, respectively were the most sensitive. R. humboldti and R. marina presented an intermediate toxicity. Embryos were significantly more tolerant to the mixture than tadpoles, which could be likely attributed to the exclusion of chemicals by the embryonic membranes and the lack of organs, such as gills, which are sensitive to surfactants. Sublethal effects were observed for the tadpole body size, but not for the embryonic development and tadpole swimming performance. In microcosms, no toxicity (LC50 could not be estimated, or sublethal responses were observed at concentrations up to fourfold (14.76kg glyphosate a.e./ha the highest field application rate of 3

  6. Species-specific differences in peroxisome proliferation, catalase, and SOD2 upregulation as well as toxicity in human, mouse, and rat hepatoma cells induced by the explosive and environmental pollutant 2,4,6-trinitrotoluene.

    Science.gov (United States)

    Naumenko, Ekaterina Anatolevna; Ahlemeyer, Barbara; Baumgart-Vogt, Eveline

    2017-03-01

    2,4,6-Trinitrotoluene (TNT) has been widely used as an explosive substance and its toxicity is still of interest as it persisted in polluted areas. TNT is metabolized in hepatocytes which are prone to its toxicity. Since analysis of the human liver or hepatocytes is restricted due to ethical reasons, we investigated the effects of TNT on cell viability, reactive oxygen species (ROS) production, peroxisome proliferation, and antioxidative enzymes in human (HepG2), mouse (Hepa 1-6), and rat (H4IIEC3) hepatoma cell lines. Under control conditions, hepatoma cells of all three species were highly comparable exhibiting identical proliferation rates and distribution of their cell cycle phases. However, we found strong differences in TNT toxicity with the lowest IC 50 values (highest cell death rate) for rat cells, whereas human and mouse cells were three to sevenfold less sensitive. Moreover, a strong decrease in cellular dehydrogenase activity (MTT assay) and increased ROS levels were noted. TNT caused peroxisome proliferation with rat hepatoma cells being most responsive followed by those from mouse and human. Under control conditions, rat cells contained fivefold higher peroxisomal catalase and mitochondrial SOD2 activities and a twofold higher capacity to reduce MTT than human and mouse cells. TNT treatment caused an increase in catalase and SOD2 mRNA and protein levels in human and mouse, but not in rat cells. Similarly, human and mouse cells upregulated SOD2 activity, whereas rat cells failed therein. We conclude that TNT induced oxidative stress, peroxisome proliferation and mitochondrial damage which are highest in rat cells rendering them most susceptible toward TNT. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 989-1006, 2017. © 2016 Wiley Periodicals, Inc.

  7. Toxic Elements

    DEFF Research Database (Denmark)

    Hajeb, Parvaneh; Shakibazadeh, Shahram; Sloth, Jens Jørgen

    2016-01-01

    Food is considered the main source of toxic element (arsenic, cadmium, lead, and mercury) exposure to humans, and they can cause major public health effects. In this chapter, we discuss the most important sources for toxic element in food and the foodstuffs which are significant contributors to h...

  8. Concentrations of p-synephrine in fruits and leaves of Citrus species (Rutaceae) and the acute toxicity testing of Citrus aurantium extract and p-synephrine.

    Science.gov (United States)

    Arbo, M D; Larentis, E R; Linck, V M; Aboy, A L; Pimentel, A L; Henriques, A T; Dallegrave, E; Garcia, S C; Leal, M B; Limberger, R P

    2008-08-01

    Dietary supplements containing bitter orange unripe fruit extract/p-synephrine are consumed worldwide for lose weight. This study were conducted to determine the concentration of p-synephrine in unripe fruits and leaves from Citrus aurantium Lin, C. sinensis Osbeck, C. deliciosa Ten, C. limon Burm and C. limonia Osbeck, collected in Southern Brazil, and to evaluate the acute toxicity of C. aurantium extract and p-synephrine. A high performance liquid chromatographic method with diode array detector (HPLC-DAD) was optimized and validated for determination of p-synephrine. The results indicate that all of analyzed samples present p-synephrine in amounts that range from 0.012% to 0.099% in the unripe fruits and 0.029 to 0.438% in the leaves. Acute oral administration of C. aurantium extracts (2.5% p-synephrine, 300-5,000 mg/kg) in mice produced reduction of locomotor activity, p-synephrine (150-2,000 mg/kg) produced piloerection, gasping, salivation, exophtalmia and reduction in locomotor activity, which was confirmed in spontaneous locomotor activity test. All the effects were reversible and persisted for 3-4h. The toxic effects observed seem to be related with adrenergic stimulation and should alert for possible side effects of p-synephrine and C. aurantium.

  9. Toxicity of organic compounds to marine invertebrate embryos and larvae: a comparison between the sea urchin embryogenesis bioassay and alternative test species.

    Science.gov (United States)

    Bellas, Juan; Beiras, Ricardo; Mariño-Balsa, José Carlos; Fernández, Nuria

    2005-04-01

    This study investigated the toxic effects of the insecticides lindane and chlorpyrifos, the herbicide diuron, the organometallic antifoulant tributyltin (TBT), and the surfactant sodium dodecyl sulfate (SDS) on the early life stages of Paracentrotus lividus (Echinodermata, Euechinoidea), Ciona intestinalis (Chordata, Ascidiacea), Maja squinado and Palaemon serratus (Arthropoda, Crustacea) in laboratory acute toxicity tests. The assays studied embryogenesis success from fertilized egg to normal larvae in P. lividus (48 h incubation at 20 degrees C) and C. intestinalis (24 h incubation at 20 degrees C), and larval mortality at 24 and 48 h in M. squinado and P. serratus. For P. lividus, the median effective concentrations (EC50) reducing percentages of normal larvae by 50% were: 350 microg l(-1) for chlorpyrifos, 5500 microg l(-1) for diuron, 4277 microg l(-1) for SDS, and 0.309 microg l(-1) for TBT. For C. intestinalis, the EC50 values affecting embryogenesis success were 5666 microg l(-1) for chlorpyrifos, 24,397 microg (l-1) for diuron, 4412 microg l(-1) for lindane, 5145 microg I(-1) for SDS, and 7.1 microg l(-1) for TBT. The median lethal concentrations (LC50) for M. squinado larval survival were 0.84 microg l(-1) (24 h) and 0.79 microg l(-1) (48 h) for chlorpyrifos, 2.23 microg(l(-1) (24 h) and 2.18 microg l(-1) (48 h) for lindane, and 687 microg l(-1) (48 h) for SDS. For P. serratus the LC50 values obtained were 0.35 microg l(-1) (24 h) and 0.22 microg l(-1) (48 h) for chlorpyrifos, 3011 microg l(-1) (24 h) and 3044 microg l(-1) (48 h) for diuron, 5.20 microg l(-1) (24 h) and 5.59 microg l(-1) (48 h) for lindane, and 22.30 microg l(-1) (24 h) and 17.52 microg l(-1) (48 h) for TBT. Decapod larvae, as expected, were markedly more sensitive to the insecticides than sea urchins and ascidians, and SDS was the least toxic compound tested for these organisms. Lowest observed effect concentrations (LOEC) of TBT for sea urchin and ascidian embryos, chlorpyrifos and

  10. Introducing Toxics

    Directory of Open Access Journals (Sweden)

    David C. Bellinger

    2013-04-01

    Full Text Available With this inaugural issue, Toxics begins its life as a peer-reviewed, open access journal focusing on all aspects of toxic chemicals. We are interested in publishing papers that present a wide range of perspectives on toxicants and naturally occurring toxins, including exposure, biomarkers, kinetics, biological effects, fate and transport, treatment, and remediation. Toxics differs from many other journals in the absence of a page or word limit on contributions, permitting authors to present their work in as much detail as they wish. Toxics will publish original research papers, conventional reviews, meta-analyses, short communications, theoretical papers, case reports, commentaries and policy perspectives, and book reviews (Book reviews will be solicited and should not be submitted without invitation. Toxins and toxicants concern individuals from a wide range of disciplines, and Toxics is interested in receiving papers that represent the full range of approaches applied to their study, including in vitro studies, studies that use experimental animal or non-animal models, studies of humans or other biological populations, and mathematical modeling. We are excited to get underway and look forward to working with authors in the scientific and medical communities and providing them with a novel venue for sharing their work. [...

  11. Ammonium tolerance and toxicity of Actinoscirpus grossus - A candidate species for use in tropical constructed wetland systems

    DEFF Research Database (Denmark)

    Piwpuan, Narumol; Jampeetong, Arunothai; Brix, Hans

    2014-01-01

    affect growth and performance of this species. We examined growth, morphological and physiological responses of A. grossus to NH4+ concentrations of 0.5, 2.5, 5, 10 and 15 mM under hydroponic growth conditions. The relative growth rates (RGR) of the plants were highest at 2.5 mM NH4+ but significantly...

  12. Antimony Toxicity

    Directory of Open Access Journals (Sweden)

    Shyam Sundar

    2010-12-01

    Full Text Available Antimony toxicity occurs either due to occupational exposure or during therapy. Occupational exposure may cause respiratory irritation, pneumoconiosis, antimony spots on the skin and gastrointestinal symptoms. In addition antimony trioxide is possibly carcinogenic to humans. Improvements in working conditions have remarkably decreased the incidence of antimony toxicity in the workplace. As a therapeutic, antimony has been mostly used for the treatment of leishmaniasis and schistosomiasis. The major toxic side-effects of antimonials as a result of therapy are cardiotoxicity (~9% of patients and pancreatitis, which is seen commonly in HIV and visceral leishmaniasis co-infections. Quality control of each batch of drugs produced and regular monitoring for toxicity is required when antimonials are used therapeutically.

  13. Antimony Toxicity

    OpenAIRE

    Sundar, Shyam; Chakravarty, Jaya

    2010-01-01

    Antimony toxicity occurs either due to occupational exposure or during therapy. Occupational exposure may cause respiratory irritation, pneumoconiosis, antimony spots on the skin and gastrointestinal symptoms. In addition antimony trioxide is possibly carcinogenic to humans. Improvements in working conditions have remarkably decreased the incidence of antimony toxicity in the workplace. As a therapeutic, antimony has been mostly used for the treatment of leishmaniasis and schistosomiasis. The...

  14. Oxygen toxicity

    Directory of Open Access Journals (Sweden)

    C. A. van der Westhuizen

    1990-07-01

    Full Text Available Oxygen has been discovered about 200 years ago. Since then the vital physiological involvement of oxygen in various biologi­cal processes, mainly energy production, has been established. However, in the body molecular oxygen can be converted to toxic oxygen metabolites such as superoxide anion, hydrogen peroxide, the hydroxyl radical and singlet oxygen. These toxic metabolites are produced mainly in the mitochondria, plasma membranes and endoplasmic reticulum.

  15. Survival, Pb-uptake and behaviour of three species of earthworm in Pb treated soils determined using an OECD-style toxicity test and a soil avoidance test

    International Nuclear Information System (INIS)

    Langdon, Caroline J.; Hodson, Mark E.; Arnold, Rebecca E.; Black, Stuart

    2005-01-01

    Mature (clitellate) Eisenia andrei Bouche (ultra epigeic), Lumbricus rubellus Hoffmeister (epigeic), and Aporrectodea caliginosa (Savigny) (endogeic) earthworms were placed in soils treated with Pb(NO 3 ) 2 to have concentrations in the range 1000 to 10 000 mg Pb kg -1 . After 28 days LC50 -95%confidencelimit +95%confidencelimit values were E. andrei5824 -361 +898 mg Pb kg -1 , L. rubellus2867 -193 +145 mg Pb kg -1 and A. caliginosa2747 -304 +239 mg Pb kg -1 and EC50s for weight change were E. andrei2841 -68 +150 mg Pb kg -1 , L. rubellus1303 -201 +240 mg Pb kg -1 and A. caliginosa1208 -206 +212 mg Pb kg -1 . At any given soil Pb concentration, Pb tissue concentrations after 28 days were the same for all three earthworm species. In a soil avoidance test there was no difference between the behaviour of the different species. The lower sensitivity to Pb exhibited by E. andrei is most likely due to physiological adaptations associated with the modes of life of the earthworms, and could have serious implications for the use of this earthworm as the species of choice in standard toxicological testing.

  16. Modulatory effect of curcumin on ketamine-induced toxicity in rat thymocytes: Involvement of reactive oxygen species (ROS and the phosphoinositide 3-kinase (PI3K/protein kinase B (Akt pathway

    Directory of Open Access Journals (Sweden)

    Svetlana Pavlovic

    2018-03-01

    Full Text Available Ketamine is a widely used anesthetic in pediatric clinical practice. Previous studies have demonstrated that ketamine induces neurotoxicity and has a modulatory effect on the cells of the immune system. Here, we evaluated the potential protective effect and underlying mechanisms of natural phenolic compound curcumin against ketamine-induced toxicity in rat thymocytes. Rat thymocytes were exposed to 100 µM ketamine alone or combined with increasing concentrations of curcumin (0.3, 1, and 3 μM for 24 hours. Cell viability was analyzed with CCK-8 assay kit. Apoptosis was analyzed using flow cytometry and propidium iodide as well as Z-VAD-FMK and Z-LEHD-FMK inhibitors. Reactive oxygen species (ROS production and mitochondrial membrane potential [MMP] were measured by flow cytometry. Colorimetric assay with DEVD-pNA substrate was used for assessing caspase-3 activity. Involvement of phosphoinositide 3-kinase (PI3K/protein kinase B (Akt signaling pathway was tested with Wortmannin inhibitor. Ketamine induced toxicity in cells, increased the number of hypodiploid cells, caspase-3 activity and ROS production, and inhibited the MMP. Co-incubation of higher concentrations of curcumin (1 and 3 μM with ketamine markedly decreased cytotoxicity, apoptosis rate, caspase-3 activity, and ROS production in rat thymocytes, and increased the MMP. Application of Z-VAD-FMK (a pan caspase inhibitor or Z-LEHD-FMK (caspase-9 inhibitor with ketamine effectively attenuated the ketamine-induced apoptosis in rat thymocytes. Administration of Wortmannin (a PI3K inhibitor with curcumin and ketamine significantly decreased the protective effect of curcumin on rat thymocytes. Our results indicate that ketamine-induced toxicity in rat thymocytes mainly occurs through the mitochondria-mediated apoptotic pathway and that the PI3K/Akt signaling pathway is involved in the anti-apoptotic effect of curcumin.

  17. Detection of toxic effects of Cd{sup 2+} on different fish species via liver cytochrome P450-dependent monooxygenase activities and FTIR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Henczova, Maria; Deer, Aranka Kiss [University of Szeged, Department of Biochemistry, P.O. Box 533, Szeged (Hungary); Komlosi, Viktoria [Chemical Research Center of the Hungarian Academy of Sciences, Department of Molecular Spectroscopy, P.O. Box 17, Budapest (Hungary); Mink, Janos [Chemical Research Center of the Hungarian Academy of Sciences, Department of Molecular Spectroscopy, P.O. Box 17, Budapest (Hungary); University of Veszprem, Faculty of Information Technology, Research Institute of Chemistry and Process Engineering; Analytical Chemistry Research Group of the Hungarian Academy of Sciences, P.O. Box 158, Veszprem (Hungary)

    2006-06-15

    The in vivo and in vitro effects of Cd{sup 2+} and the CYP1A inductor {beta}-naphthoflavone({beta}-NF) on the hepatic cytochrome P450 (Cyt 450) monooxygenases were studied in silver carp (Hypophthalmichtys molitrix V.), wels (Silurus glanis L.), and carp (Cyprinus carpio). In vivo treatment of carp with a high dose of Cd{sup 2+} (10 mg kg{sup -1}, for 3 days) caused a strong inhibition of 7-ethoxyresorufin-O-deethylase (EROD) and a lower inhibition of 7-ethoxycoumarin-O-deethylase (ECOD) activity. The low-dose cadmium treatment (2 mg kg{sup -1} Cd{sup 2+}, for 6+3 days) resulted in 4-fold increase in EROD and a 3-fold increase in ECOD activity. The combined treatment with Cd{sup 2+} and {beta}-NF in both cases led to a loss of EROD inducibility. The silver carp and wels were treated with 10 mg L{sup -1} Cd{sup 2+} for 72 h in water. The Cyt P450 content in the wels liver microsomes was increased significantly after treatment for 48 h, whereas there was only a slight, not significant increase in Cyt P450 content in the silver carp microsomes. While the Cd{sup 2+} treatment resulted in inhibition of the CYP1A isoenzymes (EROD and ECOD), the APND (aminopyrene-N-demethylase, CYP2B or CYP3A isoenzyme) activity was increased 3- to 4-fold in both fish species. In vitro experiments of the effect of Cd{sup 2+} led to a concentration-dependent inhibition in all three investigated fish species. The ECOD isoenzyme of silver carp was the most sensitive to Cd{sup 2+}. The lowest concentration of Cd{sup 2+} resulted in 50% inhibition. The APND isoenzyme was similarly sensitive to Cd{sup 2+} in all three investigated fish species. The most sensitive species was the wels, and the least sensitive were the carp isoenzyme. FTIR spectroscopy confirmed that cadmium caused damage to the protein structure. These results support the enzyme activity measurements measured in vivo and in vitro. (orig.)

  18. ALKALOIDAL COMPOSITION AND TOXICITY STUDIES OF THREE ...

    African Journals Online (AJOL)

    Mattock's test for unsaturated pyrrolizidine alkaloids (hepatotoxic) revealed that only C. retusa contained these alkaloids amongst the three species. This indicated that this is a potentially toxic specie. The alkaloids of C. retusa were toxic to albino (Wistar) rats. Marked microscopic lesions were found, principally in the liver.

  19. MECHANISM OF TOXICITY AND RESISTANCE TO D-MANNOSE AND CERTAIN DERIVATIVES IN SPECIES OF THE GENUS CHLORELLA BEIJ.(1) (2).

    Science.gov (United States)

    Gross, R E

    1968-06-01

    d-Mannose and related derivatives, e.g., d-glucosa-mine and 2-deoxy-species of the genus Chlorella. Manometric studies showed differences in the effects of these compounds on substrate-induced O2 uptake, indicating different modes of action. In a clonal culture, shaken in the light, mannose produced a lag phase of 7 days during which only ca. 0.05% of the cells continued to grow. From, these cells a resistant strain was isolated. Prolonged incubation in glucose media in darkness brought about a reversion to the sensitive condition. These metabolic shifts could not be explained on the basis of adaptation or nuclear gene mutation because of the permanency and high frequency of the resistant cells. The mechanism was suggested to be cytoplasmically controlled. The shift in sensitivity to the inhibitors was considered a reproducible characteristic of certain species. In contrast to the normal, rnannose-sensitive strain of C. infusionum var. acetophila, cells of a resistant strain carried a gelatinous envelope. The resistant strain utilized glucosamine as a source of nitrogen, but lost the capacity to use sugars for dark growth. This was reflected in drastic reductions in glucose and mannose uptake. The hexokinase activities in cell extracts were equivalent for both strains. The resistant strain did not accumulate hexose-6-phos-phates and showed an increased phosphatase activity at an alkaline pH.

  20. Translational research into species differences of endocrine toxicity via steroidogenesis inhibition by SMP-028 — For human safety in clinical study

    International Nuclear Information System (INIS)

    Nishizato, Yohei; Imai, Satoki; Okahashi, Noriko; Yabunaka, Atsushi; Kunimatsu, Takeshi; Kikuchi, Kaoru; Yabuki, Masashi

    2014-01-01

    SMP-028 is a drug candidate developed for the treatment of asthma. In a 13-week repeated dose toxicity study of SMP-028 in rats and monkeys, differences of endocrine toxicological events between rats and monkeys were observed. In rats, these toxicological events mainly consisted of pathological changes in the adrenal, testis, ovary, and the other endocrine-related organs. On the other hand, in monkeys, no toxicological events were observed. The goal of this study is to try to understand the reason why only rats, but not monkeys, showed toxicological events following treatment with SMP-028 and to eventually predict the possible toxicological effect of this compound on human endocrine organs. Our results show that SMP-028 inhibits neutral cholesterol esterase more strongly than other steroidogenic enzymes in rats. Although SMP-028 also inhibits monkeys and human neutral cholesterol esterase, this inhibition is much weaker than that of rat neutral cholesterol esterase. These results indicate (1) that the difference in endocrine toxicological events between rats and monkeys is mainly due to inhibition of steroidogenesis by SMP-028 in rats, not in monkeys, and (2) that SMP-028 may not affect steroidogenesis in humans and therefore might cause no endocrine toxicological events in clinical studies. - Highlights: • SMP-028 inhibits neutral CEase more strongly than other steroidogenic enzymes in rats. • Inhibition of neutral CEase in rats by SMP-028 suppresses steroidogenesis in vivo. • SMP-028 does not inhibit neutral CEase in monkeys in vivo. • Steroidogenesis pathway in monkeys treated with SMP-028 was not suppressed. • SMP-028 may not inhibit LIPE in humans in vivo

  1. Translational research into species differences of endocrine toxicity via steroidogenesis inhibition by SMP-028 — For human safety in clinical study

    Energy Technology Data Exchange (ETDEWEB)

    Nishizato, Yohei, E-mail: yohei-nishizato@ds-pharma.co.jp [Preclinical Research Laboratories, Dainippon Sumitomo Pharma Co., Ltd., 33-94, Enoki-cho, Suita, Osaka 564-0053 (Japan); Imai, Satoki [Preclinical Research Laboratories, Dainippon Sumitomo Pharma Co., Ltd., 33-94, Enoki-cho, Suita, Osaka 564-0053 (Japan); Okahashi, Noriko [Research Planning and Intelligence, Dainippon Sumitomo Pharma Co., Ltd., 33-94, Enoki-cho, Suita, Osaka 564-0053 (Japan); Yabunaka, Atsushi; Kunimatsu, Takeshi [Preclinical Research Laboratories, Dainippon Sumitomo Pharma Co., Ltd., 33-94, Enoki-cho, Suita, Osaka 564-0053 (Japan); Kikuchi, Kaoru [Innovative Drug Discovery Laboratories, Dainippon Sumitomo Pharma Co., Ltd., 33-94, Enoki-cho, Suita, Osaka 564-0053 (Japan); Yabuki, Masashi [Preclinical Research Laboratories, Dainippon Sumitomo Pharma Co., Ltd., 33-94, Enoki-cho, Suita, Osaka 564-0053 (Japan)

    2014-05-01

    SMP-028 is a drug candidate developed for the treatment of asthma. In a 13-week repeated dose toxicity study of SMP-028 in rats and monkeys, differences of endocrine toxicological events between rats and monkeys were observed. In rats, these toxicological events mainly consisted of pathological changes in the adrenal, testis, ovary, and the other endocrine-related organs. On the other hand, in monkeys, no toxicological events were observed. The goal of this study is to try to understand the reason why only rats, but not monkeys, showed toxicological events following treatment with SMP-028 and to eventually predict the possible toxicological effect of this compound on human endocrine organs. Our results show that SMP-028 inhibits neutral cholesterol esterase more strongly than other steroidogenic enzymes in rats. Although SMP-028 also inhibits monkeys and human neutral cholesterol esterase, this inhibition is much weaker than that of rat neutral cholesterol esterase. These results indicate (1) that the difference in endocrine toxicological events between rats and monkeys is mainly due to inhibition of steroidogenesis by SMP-028 in rats, not in monkeys, and (2) that SMP-028 may not affect steroidogenesis in humans and therefore might cause no endocrine toxicological events in clinical studies. - Highlights: • SMP-028 inhibits neutral CEase more strongly than other steroidogenic enzymes in rats. • Inhibition of neutral CEase in rats by SMP-028 suppresses steroidogenesis in vivo. • SMP-028 does not inhibit neutral CEase in monkeys in vivo. • Steroidogenesis pathway in monkeys treated with SMP-028 was not suppressed. • SMP-028 may not inhibit LIPE in humans in vivo.

  2. Radionuclide toxicity

    International Nuclear Information System (INIS)

    Galle, P.

    1982-01-01

    The aim of this symposium was to review the radionuclide toxicity problems. Five topics were discussed: (1) natural and artificial radionuclides (origin, presence or emission in the environment, human irradiation); (2) environmental behaviour of radionuclides and transfer to man; (3) metabolism and toxicity of radionuclides (radioiodine, strontium, rare gas released from nuclear power plants, ruthenium-activation metals, rare earths, tritium, carbon 14, plutonium, americium, curium and einsteinium, neptunium, californium, uranium) cancerogenous effects of radon 222 and of its danghter products; (4) comparison of the hazards of various types of energy; (5) human epidemiology of radionuclide toxicity (bone cancer induction by radium, lung cancer induction by radon daughter products, liver cancer and leukaemia following the use of Thorotrast, thyroid cancer; other site of cancer induction by radionuclides) [fr

  3. Toxicity of some heavy metals to copepods Acartia spinicauda and Tortanus forcipatus

    Digital Repository Service at National Institute of Oceanography (India)

    Madhupratap, M.; Achuthankutty, C.T.; Nair, S.R.S.

    Copper was most toxic to the species tested followed by cadmium and zinc The estuarine species Acartia spinicauda was more sensitive to the toxicants that the marine species Tortanus forcipatus The 48 hr LC50 values are presented....

  4. Complexities of bloom dynamics in the toxic dinoflagellate Alexandrium fundyense revealed through DNA measurements by imaging flow cytometry coupled with species-specific rRNA probes

    Science.gov (United States)

    Brosnahan, Michael L.; Farzan, Shahla; Keafer, Bruce A.; Sosik, Heidi M.; Olson, Robert J.; Anderson, Donald M.

    2014-05-01

    Measurements of the DNA content of different protist populations can shed light on a variety of processes, including cell division, sex, prey ingestion, and parasite invasion. Here, we modified an Imaging FlowCytobot (IFCB), a custom-built flow cytometer that records images of microplankton, to measure the DNA content of large dinoflagellates and other high-DNA content species. The IFCB was also configured to measure fluorescence from Cy3-labeled rRNA probes, aiding the identification of Alexandrium fundyense (syn. A. tamarense Group I), a photosynthetic dinoflagellate that causes paralytic shellfish poisoning (PSP). The modified IFCB was used to analyze samples from the development, peak and termination phases of an inshore A. fundyense bloom (Salt Pond, Eastham, MA, USA), and from a rare A. fundyense ‘red tide’ that occurred in the western Gulf of Maine, offshore of Portsmouth, NH (USA). Diploid or G2 phase (‘2C’) A. fundyense cells were frequently enriched at the near-surface, suggesting an important role for aggregation at the air-sea interface during sexual events. Also, our analysis showed that large proportions of A. fundyense cells in both the Salt Pond and red tide blooms were planozygotes during bloom decline, highlighting the importance of sexual fusion to bloom termination. At Salt Pond, bloom decline also coincided with a dramatic rise in infections by the parasite genus Amoebophrya. The samples that were most heavily infected contained many large cells with higher DNA-associated fluorescence than 2C vegetative cells, but these cells' nuclei were also frequently consumed by Amoebophrya trophonts. Neither large cell size nor increased DNA-associated fluorescence could be replicated by infecting an A. fundyense culture of vegetative cells. Therefore, we attribute these characteristics of the large Salt Pond cells to planozygote maturation rather than Amoebophrya infection, though an interaction between infection and planozygote maturation may

  5. Toxic shock syndrome

    Science.gov (United States)

    Staphylococcal toxic shock syndrome; Toxic shock-like syndrome; TSLS ... Toxic shock syndrome is caused by a toxin produced by some types of staphylococcus bacteria. A similar problem, called toxic shock- ...

  6. Human Toxicity

    DEFF Research Database (Denmark)

    Jolliet, Olivier; Fantke, Peter

    2015-01-01

    all chemicals and impact pathways characterizes the contribution of each factor to the total variation of 10–12 orders of magnitude in impacts per kg across all chemicals. This large variation between characterisation factors for different chemicals as well as the 3 orders of magnitude uncertainty....... As a whole, the assessment of toxicity in LCA has progressed on a very sharp learning curve during the past 20 years. This rapid progression is expected to continue in the coming years, focusing more on direct exposure of workers to chemicals during manufacturing and of consumers during product use...

  7. General aspects of metal toxicity.

    Science.gov (United States)

    Kozlowski, H; Kolkowska, P; Watly, J; Krzywoszynska, K; Potocki, S

    2014-01-01

    This review is focused on the general mechanisms of metal toxicity in humans. The possible and mainly confirmed mechanisms of their action are discussed. The metals are divided into four groups due to their toxic effects. First group comprises of metal ions acting as Fenton reaction catalyst mainly iron and copper. These types of metal ions participate in generation of the reactive oxygen species. Metals such as nickel, cadmium and chromium are considered as carcinogenic agents. Aluminum, lead and tin are involved in neurotoxicity. The representative of the last group is mercury, which may be considered as a generally toxic metal. Fenton reaction is a naturally occurring process producing most active oxygen species, hydroxyl radical: Fe(2+) + He2O2 ↔ Fe(3+) + OH(-) + OH(•) It is able to oxidize most of the biomolecules including DNA, proteins, lipids etc. The effect of toxicity depends on the damage of molecules i.e. production site of the hydroxyl radical. Chromium toxicity depends critically on its oxidation state. The most hazardous seems to be Cr(6+) (chromates) which are one of the strongest inorganic carcinogenic agents. Cr(6+) species act also as oxidative agents damaging among other nucleic acids. Redox inactive Al(3+), Cd(2+) or Hg(2+) may interfere with biology of other metal ions e.g. by occupying metal binding sites in biomolecules. All these aspects will be discussed in the review.

  8. REPRODUCTIVE TOXICITY OF PHTHALATE ESTERS

    Science.gov (United States)

    Phthalate esters display several modes of toxicity in mammalian species. In the rat, in utero exposure at relatively low dosage levels disrupts development of the reproductive system of the male rat by altering fetal testis hormone production. This presentation is a review of t...

  9. Molecular toxicity mechanism of nanosilver

    Directory of Open Access Journals (Sweden)

    Danielle McShan

    2014-03-01

    Full Text Available Silver is an ancient antibiotic that has found many new uses due to its unique properties on the nanoscale. Due to its presence in many consumer products, the toxicity of nanosilver has become a hot topic. This review summarizes recent advances, particularly the molecular mechanism of nanosilver toxicity. The surface of nanosilver can easily be oxidized by O2 and other molecules in the environmental and biological systems leading to the release of Ag+, a known toxic ion. Therefore, nanosilver toxicity is closely related to the release of Ag+. In fact, it is difficult to determine what portion of the toxicity is from the nano-form and what is from the ionic form. The surface oxidation rate is closely related to the nanosilver surface coating, coexisting molecules, especially thiol-containing compounds, lighting conditions, and the interaction of nanosilver with nucleic acids, lipid molecules, and proteins in a biological system. Nanosilver has been shown to penetrate the cell and become internalized. Thus, nanosilver often acts as a source of Ag+ inside the cell. One of the main mechanisms of toxicity is that it causes oxidative stress through the generation of reactive oxygen species and causes damage to cellular components including DNA damage, activation of antioxidant enzymes, depletion of antioxidant molecules (e.g., glutathione, binding and disabling of proteins, and damage to the cell membrane. Several major questions remain to be answered: (1 the toxic contribution from the ionic form versus the nano-form; (2 key enzymes and signaling pathways responsible for the toxicity; and (3 effect of coexisting molecules on the toxicity and its relationship to surface coating.

  10. Active prey selection in two pelagic copepods feeding on potentially toxic and non-toxic dinoflagellates

    DEFF Research Database (Denmark)

    Schultz, Mette; Kiørboe, Thomas

    2009-01-01

    Grazing on two red tide dinoflagellates, the potentially toxic Karenia mikimotoi and the non-toxic Gyrodinium instriatum, was examined in two species of marine copepods, Pseudocalanus elongatus and Temora longicornis. Both copepods cleared K. mikimotoi at rates that were a little lower but compar......Grazing on two red tide dinoflagellates, the potentially toxic Karenia mikimotoi and the non-toxic Gyrodinium instriatum, was examined in two species of marine copepods, Pseudocalanus elongatus and Temora longicornis. Both copepods cleared K. mikimotoi at rates that were a little lower...

  11. Petroleum hydrocarbon toxicity to corals: A review.

    Science.gov (United States)

    Turner, Nicholas R; Renegar, D Abigail

    2017-06-30

    The proximity of coral reefs to coastal urban areas and shipping lanes predisposes corals to petroleum pollution from multiple sources. Previous research has evaluated petroleum toxicity to coral using a variety of methodology, including monitoring effects of acute and chronic spills, in situ exposures, and ex situ exposures with both adult and larval stage corals. Variability in toxicant, bioassay conditions, species and other methodological disparities between studies prevents comprehensive conclusions regarding the toxicity of hydrocarbons to corals. Following standardized protocols and quantifying the concentration and composition of toxicant will aid in comparison of results between studies and extrapolation to actual spills. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Crotalaria incana l. and leucaena leucocephala lam. (leguminosae): toxicity indicator species of petroleum hydrocarbons in soil; Crotalaria incana l. y leucaena leucocephala lam. (leguminosae): especies indicadoras de toxicidad por hidrocarburos de petroleo en el suelo

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez Luna, Dinora; Castellan Estrada, Mepivoseth; Rivera Cruz, Maria del C.; Ortiz Ceballos, Angel I.; Izquierdo R., Francisco [Colegio de Postgraduados, Campus Montecillo, Montecillo, Estado de Mexico (Mexico)]. E-mail: dinovaz@colpos.mx

    2010-07-01

    This study assesses the toxic effects produced by a Gleysol molic soil contaminated with crude oil on seedlings of two species of legumes. A phytotoxic impact index (IIF) was generated, which includes five parameters measured by relative rates of impact (IRIF{sub (x)}) for variables; emergency, height, root length, aboveground biomass and root biomass. Bioassays were conducted under a completely randomized design with three replications under semi-controlled conditions, to assess the sensitivity of Leucaena leucocephala and Crotalaria incana at different concentrations of TPH (total petroleum hydrocarbons). Effects were highly significant (P {<=} 0.01) with increasing concentrations of HTP in substrate. The emergence of L. leucocephala was 29 % lower with 80 000 mgkg{sup -1} HTP, while C. incana decreased 30 % with 32 000 mgkg{sup -1} TPH respect to control. Both species showed a five-day delay in the emergence of seedlings when exposed to high levels of TPH. A significant decrease in the accumulation of dry matter (DM) at concentrations above 20 000 mgkg{sup -1} TPH was observed in both species. The respective IIF declined of 50 % with 80 000 and 25 000 mgkg{sup -1} TPH, but L. leucocephala had no significant effect with 10 000 mgkg{sup -1} TPH. Finally, the EC50 in L. leucocephala, is presented with 80 000 mgkg{sup -1} TPH whereas in C. incana this parameter is noted from 25 000 mgkg{sup -1} TPH. [Spanish] En este estudio se evaluaron los efectos toxicos que produce un suelo Gleysol molico contaminado con petroleo crudo, sobre plantulas de dos especies de leguminosas. Para ello se genero un indice de impacto fitotoxico (IIF) que integra cinco parametros, medidos a traves de indices relativos de impacto (IRIF{sub (x)}) para las variables emergencia, altura, longitud radicular, biomasa aerea y biomasa radicular. Los bioensayos se realizaron bajo un diseno completamente al azar, con tres repeticiones, en condiciones semicontroladas, para evaluar la sensibilidad de

  13. Distributed Structure Searchable Toxicity

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Distributed Structure Searchable Toxicity (DSSTox) online resource provides high quality chemical structures and annotations in association with toxicity data....

  14. Classification of baseline toxicants for QSAR predictions to replace fish acute toxicity studies.

    Science.gov (United States)

    Nendza, Monika; Müller, Martin; Wenzel, Andrea

    2017-03-22

    Fish acute toxicity studies are required for environmental hazard and risk assessment of chemicals by national and international legislations such as REACH, the regulations of plant protection products and biocidal products, or the GHS (globally harmonised system) for classification and labelling of chemicals. Alternative methods like QSARs (quantitative structure-activity relationships) can replace many ecotoxicity tests. However, complete substitution of in vivo animal tests by in silico methods may not be realistic. For the so-called baseline toxicants, it is possible to predict the fish acute toxicity with sufficient accuracy from log K ow and, hence, valid QSARs can replace in vivo testing. In contrast, excess toxicants and chemicals not reliably classified as baseline toxicants require further in silico, in vitro or in vivo assessments. Thus, the critical task is to discriminate between baseline and excess toxicants. For fish acute toxicity, we derived a scheme based on structural alerts and physicochemical property thresholds to classify chemicals as either baseline toxicants (=predictable by QSARs) or as potential excess toxicants (=not predictable by baseline QSARs). The step-wise approach identifies baseline toxicants (true negatives) in a precautionary way to avoid false negative predictions. Therefore, a certain fraction of false positives can be tolerated, i.e. baseline toxicants without specific effects that may be tested instead of predicted. Application of the classification scheme to a new heterogeneous dataset for diverse fish species results in 40% baseline toxicants, 24% excess toxicants and 36% compounds not classified. Thus, we can conclude that replacing about half of the fish acute toxicity tests by QSAR predictions is realistic to be achieved in the short-term. The long-term goals are classification criteria also for further groups of toxicants and to replace as many in vivo fish acute toxicity tests as possible with valid QSAR

  15. Toxicity of common ions to marine organisms

    International Nuclear Information System (INIS)

    Pillard, D.A.; DuFresne, D.L.; Evans, J.

    1995-01-01

    Produced waters from oil and gas drilling operations are typically very saline, and these may cause acute toxicity to marine organisms due to osmotic imbalances as well as to an excess or deficiency of specific common ions. In order to better understand the relationship between toxicity and ion concentration, laboratory toxicity tests were conducted using mysid shrimp (Mysidopsis bahia), sheepshead minnow (Cyprinodon variegatus), and inland silverside (Menidia beryllina). For each species the ionic concentration of standard laboratory water was proportionally increased or decreased to produce test solutions with a range of salinities. Organisms were exposed for 48 hours. Individual ions (sodium, potassium, calcium, magnetsium, strontium, chloride, bromide, sulfate, bicarbonate, and borate) were also manipulated to examine individual ion toxicity. The three test species differ in their tolerance of salinity. Mysid shrimp show a marked decrease in survival at salinities less than approximately 5 ppt. Both fish species tolerated low salinity water, however, silversides were less tolerant of saline waters (salinity greater than 40 ppt). There were also significant differences in the responses of the organisms to different ions. The results show that the salinity of the test solution may play an important role in the responses of the organisms to the produced water effluent. Predictable toxicity/ion relationships developed in this study can be used to estimate whether toxicity in a produced water is a result of common ions, salinity, or some other unknown toxicant

  16. Toxicity of medicinal plants used in traditional medicine in Northern Peru.

    Science.gov (United States)

    Bussmann, R W; Malca, G; Glenn, A; Sharon, D; Nilsen, B; Parris, B; Dubose, D; Ruiz, D; Saleda, J; Martinez, M; Carillo, L; Walker, K; Kuhlman, A; Townesmith, A

    2011-09-01

    The plant species reported here are traditionally used in Northern Peru for a wide range of illnesses. Most remedies are prepared as ethanol or aqueous extracts and then ingested. The aim of this study was to evaluate the potential toxicity of these extracts. The toxicity of ethanolic and water extracts of 341 plant species was determined using a brine-shrimp assay. Overall 24% of the species in water extract and 76% of the species in alcoholic extract showed elevated toxicity levels to brine-shrimp. Although in most cases multiple extracts of the same species showed very similar toxicity values, in some cases the toxicity of different extracts of the same species varied from non-toxic to highly toxic. Traditional preparation methods take different toxicity levels in aqueous and ethanol extracts into account when choosing the appropriate solvent for the preparation of a remedy. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  17. Toxic ornamental plants in Venezuela

    Directory of Open Access Journals (Sweden)

    Carlos Varela Romero

    2017-01-01

    Full Text Available The aim of this research was to contribute information on toxic ornamental plants in Venezuela. Information on taxonomy, common names, habit, origin, status, location, propagation and toxicology (part of the plant, effects was compiled from articles, books, catalogs, herbarium collections. A botanical analysis (taxonomy, common names, habit, origin, status, location, propagation and toxicology (part of the plant, effects was performed. The information about plant poisoning cases was requested to SIMET (Pharmacy faculty -UCV. Seventy-eight species were found in 34 families, the most important were: Apocynaceae (10 genera/12 species, Araceae (9/9, Euphorbiaceae (4/10 and Solanaceae (5/6. Genus Euphorbia was the most species rich. Most species were exotic species (79.5% and shrubs (32.1%. The entire plant (35 and latex (19 were the most toxic parts and the most frequent accidental ingestion (61.5%. Twenty cases were reported between 2009-2013, of which 80% were minors, female and urban areas. There is very little information published in Hispanic American countries

  18. The Effects of Temperature and Hydrostatic Pressure on Metal Toxicity: Insights into Toxicity in the Deep Sea.

    Science.gov (United States)

    Brown, Alastair; Thatje, Sven; Hauton, Chris

    2017-09-05

    Mineral prospecting in the deep sea is increasing, promoting concern regarding potential ecotoxicological impacts on deep-sea fauna. Technological difficulties in assessing toxicity in deep-sea species has promoted interest in developing shallow-water ecotoxicological proxy species. However, it is unclear how the low temperature and high hydrostatic pressure prevalent in the deep sea affect toxicity, and whether adaptation to deep-sea environmental conditions moderates any effects of these factors. To address these uncertainties we assessed the effects of temperature and hydrostatic pressure on lethal and sublethal (respiration rate, antioxidant enzyme activity) toxicity in acute (96 h) copper and cadmium exposures, using the shallow-water ecophysiological model organism Palaemon varians. Low temperature reduced toxicity in both metals, but reduced cadmium toxicity significantly more. In contrast, elevated hydrostatic pressure increased copper toxicity, but did not affect cadmium toxicity. The synergistic interaction between copper and cadmium was not affected by low temperature, but high hydrostatic pressure significantly enhanced the synergism. Differential environmental effects on toxicity suggest different mechanisms of action for copper and cadmium, and highlight that mechanistic understanding of toxicity is fundamental to predicting environmental effects on toxicity. Although results infer that sensitivity to toxicants differs across biogeographic ranges, shallow-water species may be suitable ecotoxicological proxies for deep-sea species, dependent on adaptation to habitats with similar environmental variability.

  19. A toxicity reduction evaluation for an oily waste treatment plant exhibiting episodic effluent toxicity.

    Science.gov (United States)

    Erten-Unal, M; Gelderloos, A B; Hughes, J S

    1998-07-30

    A Toxicity Reduction Evaluation (TRE) was conducted on the oily wastewater treatment plant (Plant) at a Naval Fuel Depot. The Plant treats ship and ballast wastes, berm water from fuel storage areas and wastes generated in the fuel reclamation plant utilizing physical/chemical treatment processes. In the first period of the project (Period I), the TRE included chemical characterization of the plant wastewaters, monitoring the final effluent for acute toxicity and a thorough evaluation of each treatment process and Plant operating procedures. Toxicity Identification Evaluation (TIE) procedures were performed as part of the overall TRE to characterize and identify possible sources of toxicity. Several difficulties were encountered because the effluent was saline, test organisms were marine species and toxicity was sporadic and unpredictable. The treatability approach utilizing enhancements, improved housekeeping, and operational changes produced substantial reductions in the acute toxicity of the final effluent. In the second period (Period II), additional acute toxicity testing and chemical characterization were performed through the Plant to assess the long-term effects of major unit process improvements for the removal of toxicity. The TIE procedures were also modified for saline wastewaters to focus on suspected class of toxicants such as surfactants. The TRE was successful in reducing acute toxicity of the final effluent through process improvements and operational modifications. The results indicated that the cause of toxicity was most likely due to combination of pollutants (matrix effect) rather than a single pollutant.

  20. Developmental toxicity of organotin compounds in animals

    Directory of Open Access Journals (Sweden)

    Lijiao eWu

    2014-09-01

    Full Text Available Organotin compounds (OTs have been used as biocides in antifouling paints and agriculture. The IMO introduced a global ban on the use of OTs in antifouling systems in 2001 due to their high toxicity. However, OTs have still been detected in the environment and pose a threat to the ecosystem. Several research groups have summarized the analytical methods, environmental fate, biochemistry, reproductive toxicity and mechanisms of actions of OTs. Here, we reviewed the developmental toxicity of OTs in various organisms such as sea urchin, ascidian, mussel and fish. The differences in sensitivity to OT exposure exist not only in different species but also at different stages in the same species. Though some hypotheses have been proposed to explain the developmental toxicity of OTs, the solid evidences are greatly in need.

  1. Comparison of Toxicities to Vibrio fischeri and Fish Based on Discrimination of Excess Toxicity from Baseline Level

    Science.gov (United States)

    Wang, Xiao H.; Yu, Yang; Huang, Tao; Qin, Wei C.; Su, Li M.; Zhao, Yuan H.

    2016-01-01

    Investigations on the relationship of toxicities between species play an important role in the understanding of toxic mechanisms to environmental organisms. In this paper, the toxicity data of 949 chemicals to fish and 1470 chemicals to V. fischeri were used to investigate the modes of action (MOAs) between species. The results show that although there is a positive interspecies correlation, the relationship is poor. Analysis on the excess toxicity calculated from toxic ratios (TR) shows that many chemicals have close toxicities and share the same MOAs between the two species. Linear relationships between the toxicities and octanol/water partition coefficient (log KOW) for baseline and less inert compounds indicate that the internal critical concentrations (CBRs) approach a constant both to fish and V. fischeri for neutral hydrophobic compounds. These compounds share the same toxic mechanisms and bio-uptake processes between species. On the other hand, some hydrophilic compounds exhibit different toxic effects with greatly different log TR values between V. fischeri and fish species. These hydrophilic compounds were identified as reactive MOAs to V. fischeri, but not to fish. The interspecies correlation is improved by adding a hydrophobic descriptor into the correlation equation. This indicates that the differences in the toxic ratios between fish and V. fischeri for these hydrophilic compounds can be partly attributed to the differences of bioconcentration between the two species, rather than the differences of reactivity with the target macromolecules. These hydrophilic compounds may more easily pass through the cell membrane of V. fischeri than the gill and skin of fish, react with the target macromolecules and exhibit excess toxicity. The compounds with log KOW > 7 exhibiting very low toxicity (log TR toxicity and MOAs. PMID:26901437

  2. Intracellular bacteria: the origin of dinoflagellate toxicity.

    Science.gov (United States)

    Silva, E S

    1990-01-01

    Dinoflagellate blooms of the same species have been registered either as toxic or nontoxic and, in the latter case, toxicity may be of different types. A hypothesis has been formulated according to which the bacteria having in some way taken part in the toxin formation are either inside the dinoflagellate cell or in the nutritive liquid. The presence of intracellular bacteria in those microorganisms has been studied mainly in material from cultures, a few from the sea, and several strains were isolated from different species. Experiments with crossed inoculations have shown that the bacterial strain from Gonyaulax tamarensis caused the cells of some other species to become toxic. From nontoxic clonal cultures of Prorocentrum balticum, Glenodinium foliaceum, and Gyrodinium instriatum, after inoculation of that bacterial strain, cultures were obtained whose cell extracts showed the same kind of toxicity as G. tamarensis. No toxic action could be found in the extracts of the bacterial cells form the assayed strains. The interference of intracellular bacteria in the metabolism of dinoflagellates must be the main cause of their toxicity.

  3. Toxicity alarm: Case history

    International Nuclear Information System (INIS)

    Hogan, D.; Retallack, J.

    1993-01-01

    In late fall 1991, the Novacor petrochemical plant near Joffre, Alberta experienced a toxicity alarm, the first since its startup 14 years ago. Fish exposed to a normal toxicity test were stressed within 2 h and showed 100% mortality after 24 h. A history of the events leading up to, during, and after the toxicity alarm is presented. The major effluent sources were three cooling water systems. Although these sources are well characterized, the event causes were not immediately clear. Initial toxic screening indicated that one was very toxic, another moderately toxic, and the third not toxic at all. All three systems utilized the same chemical treatment program to avoid fouling: stabilized phosphates with minor variants. The most toxic of the cooling systems operated at 10-12 cycles, had three chemicals for biocide control, and had three makeup streams. Toxic and nontoxic system characteristics were compared. An in-depth modified toxicity identification and evaluation program was then performed to identify and evaluate the cause of the toxicity alarm for future prevention. The most probable causes of toxicity were identified by elimination. The combination of high numbers of cycles, hydrocarbons in the makeup water, and bromine added as an antifoulant resulted in formation of aromatic bromamines which are capable of causing the toxic condition experienced. 2 tabs

  4. Toxic substances handbook

    Science.gov (United States)

    Junod, T. L.

    1979-01-01

    Handbook, published in conjunction with Toxic Substances Alert Program at NASA Lewis Research Center, profiles 187 toxic chemicals in their relatively pure states and include 27 known or suspected carcinogens.

  5. Yellow phosphorus process to convert toxic chemicals to non-toxic products

    Science.gov (United States)

    Chang, S.G.

    1994-07-26

    The present invention relates to a process for generating reactive species for destroying toxic chemicals. This process first contacts air or oxygen with aqueous emulsions of molten yellow phosphorus. This contact results in rapid production of abundant reactive species such as O, O[sub 3], PO, PO[sub 2], etc. A gaseous or liquid aqueous solution organic or inorganic chemicals is next contacted by these reactive species to reduce the concentration of toxic chemical and result in a non-toxic product. The final oxidation product of yellow phosphorus is phosphoric acid of a quality which can be recovered for commercial use. A process is developed such that the byproduct, phosphoric acid, is obtained without contamination of toxic species in liquids treated. A gas stream containing ozone without contamination of phosphorus containing species is also obtained in a simple and cost-effective manner. This process is demonstrated to be effective for destroying many types of toxic organic, or inorganic, compounds, including polychlorinated biphenyls (PCB), aromatic chlorides, amines, alcohols, acids, nitro aromatics, aliphatic chlorides, polynuclear aromatic compounds (PAH), dyes, pesticides, sulfides, hydroxyamines, ureas, dithionates and the like. 20 figs.

  6. Predictive acute toxicity tests with pesticides.

    Science.gov (United States)

    Brown, V K

    1983-01-01

    By definition pesticides are biocidal products and this implies a probability that pesticides may be acutely toxic to species other than the designated target species. The ways in which pesticides are manufactured, formulated, packaged, distributed and used necessitates a potential for the exposure of non-target species although the technology exists to minimize adventitious exposure. The occurrence of deliberate exposure of non-target species due to the misuse of pesticides is known to happen. The array of predictive acute toxicity tests carried out on pesticides and involving the use of laboratory animals can be justified as providing data on which hazard assessment can be based. This paper addresses the justification and rationale of this statement.

  7. Endangered Species

    Science.gov (United States)

    EPA's Endangered Species Protection Program helps promote recovery of listed species. The ESPP determines if pesticide use in a geographic area may affect any listed species. Find needed limits on pesticide use in Endangered Species Protection Bulletins.

  8. Toxic substances alert program

    Science.gov (United States)

    Junod, T. L.

    1978-01-01

    A toxicity profile is provided, of 187 toxic substances procured by NASA Lewis Research Center during a 3 1/2 year period, including 27 known or suspected carcinogens. The goal of the program is to assure that the center's health and safety personnel are aware of the procurement and use of toxic substances and to alert and inform the users of these materials as to the toxic characteristics and the control measures needed to ensure their safe use. The program also provides a continuing record of the toxic substances procured, who procured them, what other toxic substances the user has obtained in the past, and where similar materials have been used elsewhere at the center.

  9. Fluorinated analogs of malachite green: synthesis and toxicity.

    Science.gov (United States)

    Kraus, George A; Jeon, Insik; Nilsen-Hamilton, Marit; Awad, Ahmed M; Banerjee, Jayeeta; Parvin, Bahram

    2008-04-27

    A series of fluorinated analogs of malachite green (MG) have been synthesized and their toxicity to Saccharomyces cerevisiae and a human ovarian epithelial cell line examined. The toxicity profiles were found to be different for these two species. Two analogs, one with 2,4-difluoro substitution and the other with 2-fluoro substitution seem to be the most promising analogs because they showed the lowest toxicity to the human cells.

  10. Fluorinated Analogs of Malachite Green: Synthesis and Toxicity

    Directory of Open Access Journals (Sweden)

    Bahram Parvin

    2008-04-01

    Full Text Available A series of fluorinated analogs of malachite green (MG have been synthesizedand their toxicity to Saccharomyces cerevisiae and a human ovarian epithelial cell lineexamined. The toxicity profiles were found to be different for these two species. Twoanalogs, one with 2,4-difluoro substitution and the other with 2-fluoro substitution seem tobe the most promising analogs because they showed the lowest toxicity to the human cells.

  11. Dehydropyrrolizidine alkaloid toxicity, cytotoxicity, and carcinogenicity

    Science.gov (United States)

    Dehyro-pyrrolizidine alkaloid (PA)-containing plants compose about 5% of the world’s flowering plants and they commonly poison livestock, wildlife and humans. Previous work has produced considerable understanding of PA toxicity, species susceptibility, conditions and routes of exposure, toxin metab...

  12. Brine Shrimp Toxicity Evaluation Of Some Tanzanian Plants Used ...

    African Journals Online (AJOL)

    Plants which are used by traditional healers in Tanzania have been evaluated to obtain preliminary data of their toxicity using the brine shrimps test. The results indicate that 9 out of 44 plant species whose extracts were tested exhibited high toxicity with LC50 values below 20μg/ml. These include Aloe lateritia Engl.

  13. Efficiency of using green algae as biological controllers against toxic ...

    African Journals Online (AJOL)

    Efficiency of using green algae as biological controllers against toxic algal taxa in cultured ... of two green algal species as biological control of the growth of toxic blue-green algae. ... African Journal of Aquatic Science 2014, 39(4): 443–450 ...

  14. Fungal isolates and their toxicity from different ecosystems in ...

    African Journals Online (AJOL)

    ONOS

    2010-08-23

    Aug 23, 2010 ... fungal species behave unexpectedly in different ecosystems. That is why the main ... All the isolates from marine environment were non toxic to brine ... by animals or humans. Severe health problems and death have occurred.

  15. Launch Area Toxic Risk Analysis Program (LATRA) Toxicology Review

    National Research Council Canada - National Science Library

    Prince, Joseph

    1996-01-01

    .... Therefore, a literature search of three species of rocket emissions was performed to identify health effects information useful to HQ Space Command for managing the risk from these toxic clouds...

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

    Science.gov (United States)

    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...

  17. Comparison of toxicity of class-based organic chemicals to algae and fish based on discrimination of excess toxicity from baseline level.

    Science.gov (United States)

    Li, Jin J; Tai, Hong W; Yu, Yang; Wen, Yang; Wang, Xiao H; Zhao, Yuan H

    2015-07-01

    Toxicity data to fish and algae were used to investigate excess toxicity between species. Results show that chemicals exhibiting excess toxicity to fish also show excess toxicity to algae for most of the compounds. This indicates that they share the same mode of action between species. Similar relationships between logKOW and toxicities to fish and algae for baseline and less inert compounds suggest that they have similar critical body residues in the two species. Differences in excess toxicity for some compounds suggest that there is a difference of physiological structure and metabolism between fish and algae. Some reactive compounds (e.g. polyamines) exhibit greater toxic effects for algae than those for fish because of relatively low bio-uptake potential of these hydrophilic compounds in fish as compared with that in algae. Esters exhibiting greater toxicity in fish than that in algae indicate that metabolism can affect the discrimination of excess toxicity from baseline level. Algae growth inhibition is a very good surrogate for fish lethality. This is not only because overall toxicity sensitivity to algae is greater than that to fish, but also the excess toxicity calculated from algal toxicity can better reflect reactivity of compounds with target molecules than fish toxicity. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Females and Toxic Leadership

    Science.gov (United States)

    2012-12-14

    labeled as toxic, can he or she be rehabilitated?; Are there leadership styles that can be promoted to combat toxic leadership?; and Are the senior...examines leadership styles that are favorable for female leaders, and offers Transformational/Adaptive leadership as a style promising rehabilitative tools

  19. Mechanisms of Phosphine Toxicity

    Directory of Open Access Journals (Sweden)

    Nisa S. Nath

    2011-01-01

    Full Text Available Fumigation with phosphine gas is by far the most widely used treatment for the protection of stored grain against insect pests. The development of high-level resistance in insects now threatens its continued use. As there is no suitable chemical to replace phosphine, it is essential to understand the mechanisms of phosphine toxicity to increase the effectiveness of resistance management. Because phosphine is such a simple molecule (PH3, the chemistry of phosphorus is central to its toxicity. The elements above and below phosphorus in the periodic table are nitrogen (N and arsenic (As, which also produce toxic hydrides, namely, NH3 and AsH3. The three hydrides cause related symptoms and similar changes to cellular and organismal physiology, including disruption of the sympathetic nervous system, suppressed energy metabolism and toxic changes to the redox state of the cell. We propose that these three effects are interdependent contributors to phosphine toxicity.

  20. Plume residence and toxic material accumulation

    International Nuclear Information System (INIS)

    Spigarelli, S.A.; Holpuch, R.

    1975-01-01

    Increased growth rates and 137 Cs concentrations in plume resident trout are thought to be the result of increased metabolism, food consumption, and activity caused by exposure to increased water temperature and flow in thermal discharges. These exposure conditions could contribute to increased accumulation of biologically active, toxic substances by primary forage and predator fish species in the Great Lakes. Uptake and retention of various toxic substances by predators depend on concentrations in forage species (trophic transfer), ambient water, and point source effluents (direct uptake). Contaminants of immediate concern in Great Lakes systems (e.g., chlorinated hydrocarbons) accumulate in adipose tissue, and body concentrations have been correlated with total lipid content in fish. In addition to direct toxic effects on fish, many lipophilic contaminants are known to cause severe human health problems when ingested at concentrations commonly found in Lake Michigan salmonids. Although power plants may or may not be the direct source of a toxic substance, the thermal discharge environment may contribute to the accumulation of toxic substances in fish and the transfer of these materials to man

  1. Toxicity of Kalanchoe spp to chicks.

    Science.gov (United States)

    Williams, M C; Smith, M C

    1984-03-01

    Leaves of Kalanchoe daigremontiana, K tubiflora, K fedtschenkoi, K tomentosa, K tomentosa X K beharensis, and 4 cultivars of K blossfeldiana were tested for toxicity to 2-week-old Leghorn chicks. These species were analyzed for percentage of alkaloids, aliphatic nitro compounds, soluble oxalates, and nitrates and were examined qualitatively for cyanogenic glycosides. The solubility of the toxic principle in K daigremontiana was determined. Leaves of K daigremontiana, K tubiflora, and K fedtschenkoi were toxic to chicks at dosage levels of 8 to 12 mg/g of body weight. Toxic signs included depression, muscular incoordination, twitching and spiraling of the neck, tremors, convulsions, paralysis, and death. Kalanchoe tomentosa, K tomentosa X K beharensis, and 4 cultivars of K blossfeldiana were nontoxic at the highest dosage levels tested. Aliphatic nitro compounds and cyanogenic glycosides were not detected in any species. Alkaloids, nitrates, and soluble oxalates were present only in nontoxic concentrations. The toxic principle in K daigremontiana was soluble in 50%, 80%, and 100% ethanol, slightly soluble in water and acetone, and insoluble in benzene, chloroform, and ether.

  2. Toxic phytoplankton in San Francisco Bay

    Science.gov (United States)

    Rodgers, Kristine M.; Garrison, David L.; Cloern, James E.

    1996-01-01

    The Regional Monitoring Program (RMP) was conceived and designed to document the changing distribution and effects of trace substances in San Francisco Bay, with focus on toxic contaminants that have become enriched by human inputs. However, coastal ecosystems like San Francisco Bay also have potential sources of naturally-produced toxic substances that can disrupt food webs and, under extreme circumstances, become threats to public health. The most prevalent source of natural toxins is from blooms of algal species that can synthesize metabolites that are toxic to invertebrates or vertebrates. Although San Francisco Bay is nutrient-rich, it has so far apparently been immune from the epidemic of harmful algal blooms in the world’s nutrient-enriched coastal waters. This absence of acute harmful blooms does not imply that San Francisco Bay has unique features that preclude toxic blooms. No sampling program has been implemented to document the occurrence of toxin-producing algae in San Francisco Bay, so it is difficult to judge the likelihood of such events in the future. This issue is directly relevant to the goals of RMP because harmful species of phytoplankton have the potential to disrupt ecosystem processes that support animal populations, cause severe illness or death in humans, and confound the outcomes of toxicity bioassays such as those included in the RMP. Our purpose here is to utilize existing data on the phytoplankton community of San Francisco Bay to provide a provisional statement about the occurrence, distribution, and potential threats of harmful algae in this Estuary.

  3. Use of zeolite for removing ammonia and ammonia-caused toxicity in marine toxicity identification evaluations.

    Science.gov (United States)

    Burgess, R M; Perron, M M; Cantwell, M G; Ho, K T; Serbst, J R; Pelletier, M C

    2004-11-01

    Ammonia occurs in marine waters including effluents, receiving waters, and sediment interstitial waters. At sufficiently high concentrations, ammonia can be toxic to aquatic species. Toxicity identification evaluation (TIE) methods provide researchers with tools for identifying aquatic toxicants. For identifying ammonia toxicity, there are several possible methods including pH alteration and volatilization, Ulva lactuca addition, microbial degradation, and zeolite addition. Zeolite addition has been used successfully in freshwater systems to decrease ammonia concentrations and toxicity for several decades. However, zeolite in marine systems has been used less because ions in the seawater interfere with zeolite's ability to adsorb ammonia. The objective of this study was to develop a zeolite method for removing ammonia from marine waters. To accomplish this objective, we performed a series of zeolite slurry and column chromatography studies to determine uptake rate and capacity and to evaluate the effects of salinity and pH on ammonia removal. We also assessed the interaction of zeolite with several toxic metals. Success of the methods was also evaluated by measuring toxicity to two marine species: the mysid Americamysis bahia and the amphipod Ampelisca abdita. Column chromatography proved to be effective at removing a wide range of ammonia concentrations under several experimental conditions. Conversely, the slurry method was inconsistent and variable in its overall performance in removing ammonia and cannot be recommended. The metals copper, lead, and zinc were removed by zeolite in both the slurry and column treatments. The zeolite column was successful in removing ammonia toxicity for both the mysid and the amphipod, whereas the slurry was less effective. This study demonstrated that zeolite column chromatography is a useful tool for conducting marine water TIEs to decrease ammonia concentrations and characterize toxicity.

  4. Pulmonary toxicity of manufactured nanoparticles

    Science.gov (United States)

    Peebles, Brian Christopher

    Manufactured nanomaterials have become ubiquitous in science, industry, and medicine. Although electron microscopy and surface probe techniques have improved understanding of the physicochemical properties of nanomaterials, much less is known about what makes nanomaterials toxic. Particulate matter less than 2.5 mum in effective aerodynamic diameter is easily inhaled and taken deep into the lungs. The toxicity of inhaled particulate matter is related to its size and surface chemistry; for instance, the smaller the size of particles, the greater their specific surface area. The chemistry and toxicity of insoluble particles depends on their surface area, since chemical reactions may happen with the environment on the surface. Oxidation and reduction may occur on the surfaces of particles after they are produced. For instance, it is known that carbonaceous particles from vehicle exhaust and industrial emission may interact with reactive species like ozone in their ambient environment, altering the surface chemistry of the particles. Reaction with species in the environment may cause changes in the chemical functionality of the surface and change the toxic properties of the particles when they are inhaled. Furthermore, metals on the surface of inhalable particles can contribute to their toxicity. Much attention has been given to the presence of iron on the surfaces of inhalable particles in the environment. After particle inhalation, particles are endocytosed by alveolar macrophages in the immune response to foreign matter. They are exposed to hydrogen peroxide in the oxidative burst, which can cause the iron-mediated production of hydroxyl free radicals via the Fenton reaction, causing oxidative stress that leads to inflammation and cell death. The toxicity of particles that contain metals depends on the redox activity and bioavailability of the metals, the causes of thich have not yet been adequately explored. In this thesis, electron paramagnetic spectroscopy showed

  5. Toxicity identification evaluations of produced-water effluents

    International Nuclear Information System (INIS)

    Sauer, T.C.; Costa, H.J.; Brown, J.S.; Ward, T.J.

    1997-01-01

    Toxicity identification evaluations (TIEs) were performed on 14 produced-water (PW) samples of various salinities from inland and offshore oil- and gas-production facilities operated by different companies in Wyoming, Texas, California, and Louisiana (USA) to evaluate the efficacy of TIE procedures in determining potential toxicants in PW effluents. The research involved acute (24- and 48-h) freshwater and marine toxicity tests on whole PW and PW fractions generated by standard US Environmental Protection Agency and PW-specific fractionation schemes. Factors influencing PW TIEs were investigated, such as the effect of salinity in selecting fractionation manipulations, the effect of toxicity test replication (i.e., reproducibility) in distinguishing changes in toxicities between whole PW and its fractions, and the suitability of different test species in PW TIEs. The results obtained and lessons learned from conducting these PW TIEs are presented in this article. Components, or fractions, contributing to toxicity differed for each PW with no specific fraction being consistently toxic. For most PW samples, toxicity attributed to any one fraction represented only part of the toxicity of the whole sample. However, no more than two fraction types were identified as potential toxicants in any sample. Potential toxicants identified during this study, besides salinity, included acidic and basic organic compound class fractions, particulates removed by filtration at pH 11, ammonia, hydrocarbons, hydrogen sulfide, material removed by pH change, and volatile compounds

  6. Toxicity of Engineered Nanoparticles to Aquatic Invertebrates

    DEFF Research Database (Denmark)

    Cupi, Denisa; Sørensen, Sara Nørgaard; Skjolding, Lars Michael

    2016-01-01

    This chapter provides a targeted description of some of the most important processes that influence toxicity and uptake of nanoparticles in aquatic invertebrates. It discusses silver nanoparticles (Ag NPs), on how aspects of dissolution and chemical species obtained from this process can influence...... ecotoxicity of aquatic invertebrates. The chapter focuses on how fullerenes affect the toxicity of other pollutants, but also reflect on the fate and behavior of C60 in the aquatic environment, as well as ecotoxicity to aquatic invertebrates. It presents the case of titanium dioxide nanoparticles (TiO2 NPs...... on bioaccumulation focusing on the effect of nanoparticle coating, uptake, and depuration in aquatic invertebrates....

  7. Pediatric Toxic Shock Syndrome

    Directory of Open Access Journals (Sweden)

    Jennifer Yee

    2017-09-01

    Full Text Available Audience: This scenario was developed to educate emergency medicine residents on the diagnosis and management of a pediatric patient with toxic shock syndrome. The case is also appropriate for teaching of medical students and advanced practice providers, as well as a review of the principles of crisis resource management, teamwork, and communication. Introduction: Toxic shock syndrome is a low-frequency, high-acuity scenario requiring timely identification and aggressive management. If patients suffering from this condition are managed incorrectly, they may progress into multi-organ dysfunction and potentially death. Toxic shock syndrome has been associated with Streptococcus and Staphylococcus aureus (Staph. Approximately half of Staph cases are associated with menstruation, which was first described in the 1970s-1980s and was associated with the use of absorbent tampons.1 Group A Streptococcus may cause complications such as necrotizing fasciitis and gangrenous myositis.2 Pediatric patients may present critically ill from toxic shock syndrome. Providers need to perform a thorough history and physical exam to discern the source of infection. Management requires aggressive care with antibiotics and IV fluids. Objectives: By the end of this simulation session, the learner will be able to: 1 Recognize toxic shock syndrome. 2 Review the importance of a thorough physical exam. 3 Discuss management of toxic shock syndrome, including supportive care and the difference in antibiotic choices for streptococcal and staphylococcal toxic shock syndrome. 4 Appropriately disposition a patient suffering from toxic shock syndrome. 5 Communicate effectively with team members and nursing staff during a resuscitation of a critically ill patient. Method: This session was conducted using high-fidelity simulation, followed by a debriefing session and lecture on toxic shock syndrome.

  8. Predicting molybdenum toxicity to higher plants: Estimation of toxicity threshold values

    Energy Technology Data Exchange (ETDEWEB)

    McGrath, S.P., E-mail: steve.mcgrath@bbsrc.ac.u [Soil Science Department, Centre for Soils and Ecosystems Function, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ (United Kingdom); Mico, C.; Zhao, F.J.; Stroud, J.L. [Soil Science Department, Centre for Soils and Ecosystems Function, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ (United Kingdom); Zhang, H.; Fozard, S. [Division of Environmental Science, Lancaster University, Lancaster LA1 4YQ (United Kingdom)

    2010-10-15

    Four plant species (oilseed rape, Brassica napus L.; red clover, Trifolium pratense L.; ryegrass, Lolium perenne L.; and tomato, Lycopersicon esculentum L.) were tested on ten soils varying widely in soil properties to assess molybdenum (Mo) toxicity. A larger range (66-fold-609-fold) of added Mo concentrations resulting in 50% inhibition of yield (ED{sub 50}) was found among soils than among plant species (2-fold-38-fold), which illustrated that the soils differed widely in the expression of Mo toxicity. Toxicity thresholds based on soil solution Mo narrowed the variation among soils compared to thresholds based on added Mo concentrations. We conclude that plant bioavailability of Mo in soil depends on Mo solubility, but this alone did not decrease the variability in observed toxicity enough to be used in risk assessment and that other soil properties influencing Mo toxicity to plants need to be considered. - Mo toxicity thresholds varied widely in different soils and therefore soil properties need to be taken into account in order to assess the risk of Mo exposure.

  9. Toxicities of emamectin benzoate homologues and photodegradates to Lepidoptera.

    Science.gov (United States)

    Argentine, Joseph A; Jansson, Richard K; Starner, Van R; Halliday, W Ross

    2002-12-01

    The toxicity of a number of emamectin benzoate homologues and photodegradates to five species of Lepidoptera was investigated using diet and foliar bioassays. The emamectin benzoate homologues B1a and B1b were equally toxic in the diet and foliar assays to Spodoptera exigua (Hübner), Heliothis virescens (F.), Tricoplusia ni (Hübner), and Spodoptera frugiperda (J. E. Smith), within each of these species. Plutella xylostella (L.) was the most sensitive species to emamectin benzoate. The AB1a photodegradate of emamectin benzoate was as toxic as the parent compound in the diet assay. However, in the foliage assay AB1a was 4.4-fold less toxic to S. exigua than the parent compound. The MFB1a photodegradate of emamectin benzoate was as toxic as the parent compound to P. xylostella, and 3.1 to 6.2 times as toxic as the parent compound to the other species in the diet assay. The order of toxicity of the photodegradates were AB1a > MFB1a > FAB1a > 8,9-Z-MAB1a > PAB1a.

  10. Electronic Cigarette Toxicity.

    Science.gov (United States)

    Payne, J Drew; Michaels, David; Orellana-Barrios, Menfil; Nugent, Kenneth

    2017-04-01

    Electronic cigarettes (e-cigarettes) are often advertised as a healthier product when compared with traditional cigarettes. Currently, there are limited data to support this and only a threat of federal regulation from the US Food and Drug Administration. Calls to poison control centers about e-cigarette toxicity, especially in children, and case reports of toxic exposures have increased over the past 3 years. This research letter reports the frequency of hazardous exposures to e-cigarettes and characterizes the reported adverse health effects associated with e-cigarette toxicity.

  11. Toxicity Estimation Software Tool (TEST)

    Science.gov (United States)

    The Toxicity Estimation Software Tool (TEST) was developed to allow users to easily estimate the toxicity of chemicals using Quantitative Structure Activity Relationships (QSARs) methodologies. QSARs are mathematical models used to predict measures of toxicity from the physical c...

  12. Developmental toxicity of engineered nanomaterials in rodents

    Energy Technology Data Exchange (ETDEWEB)

    Ema, Makoto, E-mail: ema-makoto@aist.go.jp; Gamo, Masashi; Honda, Kazumasa

    2016-05-15

    We summarized significant effects reported in the literature on the developmental toxicity of engineered nanomaterials (ENMs) in rodents. The developmental toxicity of ENMs included not only structural abnormalities, but also death, growth retardation, and behavioral and functional abnormalities. Most studies were performed on mice using an injection route of exposure. Teratogenic effects were indicated when multi-walled carbon nanotubes (MWCNTs), single-walled carbon nanotubes (SWCNTs), and TiO{sub 2}-nanoparticles were administered to mice during early gestation. Reactive oxygen species levels were increased in placentas and malformed fetuses and their placentas after prenatal exposure to MWCNTs and SWCNTs, respectively. The pre- and postnatal mortalities and growth retardation in offspring increased after prenatal exposure to ENMs. Histopathological and functional abnormalities were also induced in placentas after prenatal exposure to ENMs. Maternal exposure to ENMs induced behavioral alterations, histopathological and biochemical changes in the central nervous system, increased susceptibility to allergy, transplacental genotoxicity, and vascular, immunological, and reproductive effects in offspring. The size- and developmental stage-dependent placental transfer of ENMs was noted after maternal exposure. Silver accumulated in the visceral yolk sac after being injected with Ag-NPs during early gestation. Although currently available data has provided initial information on the potential developmental toxicity of ENMs, that on the developmental toxicity of ENMs is still very limited. Further studies using well-characterized ENMs, state-of the-art study protocols, and appropriate routes of exposure are required in order to clarify these developmental effects and provide information suitable for risk assessments of ENMs. - Highlights: • We review the developmental toxicity studies of engineered nanomaterials (ENMs). • Various developmental endpoints have been

  13. SURROGATE SPECIES IN ASSESSING CONTAMINANT RISK FOR ENDANGERED FISHES

    Science.gov (United States)

    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 accord...

  14. Toxicity Reference Database

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Toxicity Reference Database (ToxRefDB) contains approximately 30 years and $2 billion worth of animal studies. ToxRefDB allows scientists and the interested...

  15. Toxics Release Inventory (TRI)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Toxics Release Inventory (TRI) is a dataset compiled by the U.S. Environmental Protection Agency (EPA). It contains information on the release and waste...

  16. Thermoregulatory responses to environmental toxicants: The interaction of thermal stress and toxicant exposure

    International Nuclear Information System (INIS)

    Leon, Lisa R.

    2008-01-01

    Thermal stress can have a profound impact on the physiological responses that are elicited following environmental toxicant exposure. The efficacy by which toxicants enter the body is directly influenced by thermoregulatory effector responses that are evoked in response to high ambient temperatures. In mammals, the thermoregulatory response to heat stress consists of an increase in skin blood flow and moistening of the skin surface to dissipate core heat to the environment. These physiological responses may exacerbate chemical toxicity due to increased permeability of the skin, which facilitates the cutaneous absorption of many environmental toxicants. The core temperature responses that are elicited in response to high ambient temperatures, toxicant exposure or both can also have a profound impact on the ability of an organism to survive the insult. In small rodents, the thermoregulatory response to thermal stress and many environmental toxicants (such as organophosphate compounds) is often biphasic in nature, consisting initially of a regulated reduction in core temperature (i.e., hypothermia) followed by fever. Hypothermia is an important thermoregulatory survival strategy that is used by small rodents to diminish the effect of severe environmental insults on tissue homeostasis. The protective effect of hypothermia is realized by its effects on chemical toxicity as molecular and cellular processes, such as lipid peroxidation and the formation of reactive oxygen species, are minimized at reduced core temperatures. The beneficial effects of fever are unknown under these conditions. Perspective is provided on the applicability of data obtained in rodent models to the human condition

  17. USE OF ZEOLITE FOR REMOVING AMMONIA AND AMMONIA-CAUSED TOXCITY IN MARINE TOXICITY IDENTIFCATION EVALUATIONS (TIES)

    Science.gov (United States)

    Ammonia occurs in marine waters including effluents, receiving waters, and sediment interstitial waters. At sufficiently high concentrations, ammonia can be toxic to aquatic species. Toxicity identification evaluation (TIE) methods provide researchers with tools for identifyi...

  18. Acute toxicity of selected heavy metals to Oreochromis ...

    African Journals Online (AJOL)

    Copper was more toxic than lead and iron to both life stages. The species sensitivity distributions of O. mossambicus, as well as those of freshwater fish species from the ECOTOX database and literature, were closely predicted by the models for all three metals. The sensitivity of O. mossambicus to copper, iron and lead ...

  19. Cisplatin carbonato complexes. Implications for uptake, antitumor properties, and toxicity.

    Science.gov (United States)

    Centerwall, Corey R; Goodisman, Jerry; Kerwood, Deborah J; Dabrowiak, James C

    2005-09-21

    The reaction of aquated cisplatin with carbonate which is present in culture media and blood is described. The first formed complex is a monochloro monocarbonato species, which upon continued exposure to carbonate slowly forms a biscarbonato complex. The formation of carbonato species under conditions that simulate therapy may have important implications for uptake, antitumor properties, and toxicity of cisplatin.

  20. Fumigant Toxicity of Crushed Bulbs of Two Allium Species to Callosobruchus maculatus (Fabricius (Coleoptera: Bruchidae Toxicidad Fumigante para Callosobruchus maculatus (Fabriciu (Coleoptera: Bruchidae de Bulbos Trozados de Especies Allium

    Directory of Open Access Journals (Sweden)

    T.I Ofuya

    2010-09-01

    Full Text Available Fumigant toxicity of crushed fresh bulbs of Allium sativum L. and A. cepa L. to the Callosobruchus maculatus (Fabricius, a major pest of stored cowpea (Vigna unguiculata (L. Walp. seeds was assessed under laboratory conditions in Akure, Nigeria. In the tests, 20 g of infested cowpea seeds were suspended in a piece of muslin cloth, over an amount of crushed bulb in a container with a tightly fitted lid. Adult emergence was completely prevented from freshly laid eggs of C. maculatus on cowpea seeds that was fumigated with 6.0 g or more of crushed bulbs of A. sativum. Such fumigated seeds were not holed at all. Other amounts of A. sativum tested (1.0, 2.0, 3.0, 4.0 and 5.0 g significantly reduced C. maculatus adult emergence from fumigated eggs and seed holing in comparison with the control. Crushed A. sativum was ineffective in preventing adult emergence from fumigated C. maculatus larvae in seeds. The fumigant effect of crushed A. cepa did not kill all C. maculatus eggs. An amount of 7.0 g significantly reduced C. maculatus adult emergence from fumigated eggs and seed holing in comparison with the control. There is good prospect in using crushed bulbs of A. sativum> as fumigant in C. maculatus control in stored cowpea seeds.Se evaluó la toxicidad fumigante de bulbos frescos trozados de Allium sativum L. y A. cepa L. sobre Callosobruchus maculatus (Fabricius, una importante plaga de semilla almacenada de caupí Vigna unguiculata (L. Walp. bajo condiciones de laboratorio en Akure, Nigeria. En las pruebas, 20 g de semillas infestadas se suspendieron en un trozo de tela sobre cierta cantidad de bulbos trozados en un contenedor con una tapa ajustada. Se previno completamente la emergencia de adultos desde huevos recién puestos de C. maculatus en semillas de caupí que se fumigaron con 6,0 g o más de bulbos de A. sativum. Estas semillas fumigadas no estaban ahuecadas. Otras cantidades de A. sativum probadas (1.0, 2.0, 3.0, 4.0 y 5.0 g redujeron

  1. Marine Biotoxins: Occurrence, Toxicity, and Detection Methods

    Science.gov (United States)

    Asakawa, M.

    2017-04-01

    This review summarizes the role of marine organisms as vectors of marine biotoxins, and discusses the need for surveillance to protect public health and ensure the quality of seafood. I Paralytic shellfish poison (PSP) and PSP-bearing organisms-PSP is produced by toxic dinoflagellates species belonging to the genera Alexandrium, Gymnodinium, and Pyrodinium. Traditionally, PSP monitoring programs have only considered filter-feeding molluscs that concentrate these toxic algae, however, increasing attention is now being paid to higher-order predators that carry PSP, such as carnivorous gastropods and crustaceans. II. Tetrodotoxin (TTX) and TTX-bearing organisms - TTX is the most common natural marine toxin that causes food poisonings in Japan, and poses a serious public health risk. TTX was long believed to be present only in pufferfish. However, TTX was detected in the eggs of California newt Taricha torosa in 1964, and since then it has been detected in a wide variety of species belonging to several different phyla. In this study, the main toxic components in the highly toxic ribbon worm Cephalothrix simula and the greater blue-ringed octopus Hapalochlaena lunulata from Japan were purified and analysed.

  2. Toxicity and antinociceptive effects of Hamelia patens

    Directory of Open Access Journals (Sweden)

    Angel Josabad Alonso-Castro

    Full Text Available Abstract Many medicinal herbs are used in folk medicine without taking into account their toxicity. Hamelia patens Jacq. (Rubiaceae, a Mexican endemic species, is used for the empirical treatment of pain. The aim of this work was to evaluate the toxicity and antinociceptive effects of ethanolic extracts of H. patens leaves. The toxicity of H. patens leaves (500–5000 mg/kg was evaluated in acute (14 days and subacute (28 days assays. In the subacute assay, a blood analysis (both hematology and chemistry was carried out. The antinociceptive effects of H. patens leaves (50–200 mg/kg were evaluated using thermal-induced nociception (hot plate and the chemical-induced nociceptive tests (acid acetic and formalin. In the acute toxicity test, the LD50 estimated for H. patens leaves was 2964 mg/kg i.p. and >5000 mg/kg p.o., whereas in the subacute test HPE did not affect hematological or biochemical parameters. In chemical-induced nociception models, H. patens (100 and 200 mg/kg p.o. showed antinociceptive effects with similar activity than 100 mg/kg naproxen. In the hot plate test, HPE at 100 mg/kg (17% and 200 mg/kg (25% showed moderate antinociceptive effects. HPE could be a good source of antinociceptive agents because of its good activity and low toxicity.

  3. A review of reproductive toxicity of microcystins

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Liang, E-mail: chan91@yeah.net [Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Chen, Jun, E-mail: chenjun@ihb.ac.cn [Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); Zhang, Xuezhen, E-mail: xuezhen@mail.hzau.edu.cn [College of Fisheries, Huazhong Agricultural University, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070 (China); Xie, Ping, E-mail: xieping@ihb.ac.cn [Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China)

    2016-01-15

    Highlights: • Reproductive toxicity of MCs on mammals, fishes, amphibians, and birds is reviewed. • PP1/2A inhibition and oxidative stress are important toxic mechanisms of MCs. • Reproductive toxicity of MCs may be closely related to endocrine-disrupting effects. • The trans-generational toxicity of microcystins is a matter of concern. • Data concerning female reproductive and sex-specific effects of MCs are lacking. - Abstract: Animal studies provide strong evidence of positive associations between microcystins (MCs) exposure and reproductive toxicity, representing a threat to human reproductive health and the biodiversity of wild life. This paper reviews current knowledge of the reproductive toxicity of MCs, with regard to mammals, fishes, amphibians, and birds, mostly in males. Toxicity of MCs is primarily governed by the inhibition of protein phosphatases 1 and 2A (PP1 and PP2A) and disturbance of cellular phosphorylation balance. MCs exposure is related to excessive production of reactive oxygen species (ROS) and oxidative stress, leading to cytoskeleton disruption, mitochondria dysfunction, endoplasmic reticulum (ER) stress, and DNA damage. MCs induce cell apoptosis mediated by the mitochondrial and ROS and ER pathways. Through PP1/2A inhibition and oxidative stress, MCs lead to differential expression/activity of transcriptional factors and proteins involved in the pathways of cellular differentiation, proliferation, and tumor promotion. MC-induced DNA damage is also involved in carcinogenicity. Apart from a direct effect on testes and ovaries, MCs indirectly affect sex hormones by damaging the hypothalamic-pituitary-gonad (HPG) axis and liver. Parental exposure to MCs may result in hepatotoxicity and neurotoxicity of offspring. We also summarize the current research gaps which should be addressed by further studies.

  4. A review of reproductive toxicity of microcystins

    International Nuclear Information System (INIS)

    Chen, Liang; Chen, Jun; Zhang, Xuezhen; Xie, Ping

    2016-01-01

    Highlights: • Reproductive toxicity of MCs on mammals, fishes, amphibians, and birds is reviewed. • PP1/2A inhibition and oxidative stress are important toxic mechanisms of MCs. • Reproductive toxicity of MCs may be closely related to endocrine-disrupting effects. • The trans-generational toxicity of microcystins is a matter of concern. • Data concerning female reproductive and sex-specific effects of MCs are lacking. - Abstract: Animal studies provide strong evidence of positive associations between microcystins (MCs) exposure and reproductive toxicity, representing a threat to human reproductive health and the biodiversity of wild life. This paper reviews current knowledge of the reproductive toxicity of MCs, with regard to mammals, fishes, amphibians, and birds, mostly in males. Toxicity of MCs is primarily governed by the inhibition of protein phosphatases 1 and 2A (PP1 and PP2A) and disturbance of cellular phosphorylation balance. MCs exposure is related to excessive production of reactive oxygen species (ROS) and oxidative stress, leading to cytoskeleton disruption, mitochondria dysfunction, endoplasmic reticulum (ER) stress, and DNA damage. MCs induce cell apoptosis mediated by the mitochondrial and ROS and ER pathways. Through PP1/2A inhibition and oxidative stress, MCs lead to differential expression/activity of transcriptional factors and proteins involved in the pathways of cellular differentiation, proliferation, and tumor promotion. MC-induced DNA damage is also involved in carcinogenicity. Apart from a direct effect on testes and ovaries, MCs indirectly affect sex hormones by damaging the hypothalamic-pituitary-gonad (HPG) axis and liver. Parental exposure to MCs may result in hepatotoxicity and neurotoxicity of offspring. We also summarize the current research gaps which should be addressed by further studies.

  5. Haloacetonitriles: metabolism and toxicity.

    Science.gov (United States)

    Lipscomb, John C; El-Demerdash, Ebtehal; Ahmed, Ahmed E

    2009-01-01

    The haloacetonitriles (HANs) exist in drinking water exclusively as byproducts of disinfection. HANs are found in drinking water more often, and in higher concentrations, when surface water is treated by chloramination. Human exposure occurs through consumption of finished drinking water; oral and dermal contact also occurs, and results from showering, swimming and other activities. HANs are reactive and are toxic to gastrointestinal tissues following oral administration. Such toxicity is characterized by GSH depletion, increased lipid peroxidation, and covalent binding of HAN-associated radioactivity to gut tissues. The presence of GSH in cells is an important protective mechanism against HAN toxicity; depletion of cellular GSH results in increased toxicity. Some studies have demonstrated an apparently synergistic effect between ROS and HAN administration, that may help explain effects observed in GI tissues. ROS are produced in gut tissues, and in vitro evidence indicates that ROS may contribute to the degradation and formation of reactive intermediates from HANs. The rationale for ROS involvement may involve HAN-induced depletion of GSH and the role of GSH in scavenging ROS. In addition to effects on GI tissues, studies show that HAN-derived radiolabel is found covalently bound to proteins and DNA in several organs and tissues. The addition of antioxidants to biologic systems protects against HAN-induced DNA damage. The protection offered by antioxidants supports the role of oxidative stress and the potential for a threshold in han-induced toxicity. However, additional data are needed to substantiate evidence for such a threshold. HANs are readily absorbed from the GI tract and are extensively metabolized. Elimination occurs primarily in urine, as unconjugated one-carbon metabolites. Evidence supports the involvement of mixed function oxidases, the cytochrome P450 enzyme family and GST, in HAN metabolism. Metabolism represents either a detoxification or

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

    Science.gov (United States)

    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...

  7. Comparative toxicity of chemicals to earthworms

    Energy Technology Data Exchange (ETDEWEB)

    Callahan, C.A.; Shirazi, M.A. (Environmental Protection Agency, Corvallis, OR (United States)); Neuhauser, E.F. (Niagara Mohawk Power Corp., Syracuse, NY (United States))

    1994-02-01

    The concentration-response (mortality) relationships of four species of earthworms, Eisenia fetida (Savigny), Allolobophora tuberculata (Eisen), Eudrilus eugeniae (Kinberg), and Perionyx excavatus (Perrier) are summarized for 62 chemicals and two test protocols. A Weibull function is used to summarize these data for each chemical in terms of sensitivity and toxicity, in addition to the LC50. The estimation of the Weibull parameters a and k summarize the entire concentration-response relationship. This technique should be applicable to a variety of testing protocols with different species whenever the goal is summarizing the shape of the concentration-response curves to fully evaluate chemical impact on organisms. In some cases for these data four orders of magnitude separate LC50s of the soil test and the contact test for the same chemical and species. All four species appear to be similar in range of toxicity and tolerance to these chemicals, suggesting that Eisenia fetida and may be representative of these four species and these chemicals.

  8. The toxicity of plutonium

    International Nuclear Information System (INIS)

    Crouse, P.L.

    1994-01-01

    Shipments of plutonium occasionally pass around the Cape coastal waters on its way to Japan from Europe. This invariably leads to a great deal of speculation of the dangers involved and of the extreme toxicity of plutonium, with the media and environmental groups claiming that (a) plutonium is the most toxic substance known to man, and that (b) a few kilograms of plutonium ground finely and dispersed in the atmosphere could kill every human being on earth. Comparisons with other poisons are drawn, e.g. common inorganic chemicals and biological agents. The original scare around the extraordinary toxicity of Pu seems to have started in 1974 with the claims of Tamplin and Cochran's hot particle theory about plutonium lodging in the sensitive portions of the lungs in small concentrated aggregates where they are much more effective in producing cancers. This theory, however, is regarded as thoroughly discredited by the experts in the field of radiotoxicity. 8 refs

  9. Iron metabolism and toxicity

    International Nuclear Information System (INIS)

    Papanikolaou, G.; Pantopoulos, K.

    2005-01-01

    Iron is an essential nutrient with limited bioavailability. When present in excess, iron poses a threat to cells and tissues, and therefore iron homeostasis has to be tightly controlled. Iron's toxicity is largely based on its ability to catalyze the generation of radicals, which attack and damage cellular macromolecules and promote cell death and tissue injury. This is lucidly illustrated in diseases of iron overload, such as hereditary hemochromatosis or transfusional siderosis, where excessive iron accumulation results in tissue damage and organ failure. Pathological iron accumulation in the liver has also been linked to the development of hepatocellular cancer. Here we provide a background on the biology and toxicity of iron and the basic concepts of iron homeostasis at the cellular and systemic level. In addition, we provide an overview of the various disorders of iron overload, which are directly linked to iron's toxicity. Finally, we discuss the potential role of iron in malignant transformation and cancer

  10. Major ion toxicity in effluents: A review with permitting recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Goodfellow, W.L.; Ausley, L.W.; Burton, D.T.; Denton, D.L.; Dorn, P.B.; Grothe, D.R.; Heber, M.A.; Norberg-King, T.J.; Rodgers, J.H. Jr.

    2000-01-01

    Effluent toxicity testing methods have been well defined, but for the most part, these methods do not attempt to segregate the effects of active ionic concentrations and ion imbalances upon test and species performances. The role of various total dissolved solids in effluents on regulatory compliance has emerged during the last few years and has caused confusion in technical assessment and in permitting and compliance issues. This paper assesses the issue of ionic strength and ion imbalance, provides a brief summary of applicable data, presents several case studies demonstrating successful tools to address toxicity resulting from salinity and ion imbalance, and provides recommendations for regulatory and compliance options to manage discharges with salinity/ion imbalance issues. Effluent toxicity resulting from inorganic ion imbalance and the ion concentration of the effluent is pervasive in permitted discharge from many industrial process and municipal discharges where process streams are concentrated, adjusted, or modified. This paper discusses procedures that use weight-of-evidence approaches to identify ion imbalance toxicity, including direct measurement, predictive toxicity models for freshwater, exchange resins, mock effluents, and ion imbalance toxicity with tolerant/susceptible test species. Cost-effective waste treatment control options for a facility whose effluent is toxic because of total dissolved solids (TDS) or because of specific ion(s) are scarce at best. Depending on the discharge situation, TDS toxicity may not be viewed with the same level of concern as other, more traditional, toxicants. These discharge situations often do not require the conservative safety factors required by other toxicants. Selection of the alternative regulatory solutions discussed in this paper may be beneficial, especially because they do not require potentially expensive or high-energy-using treatment options that may be ineffective control options. The information

  11. Speciation in Metal Toxicity and Metal-Based Therapeutics

    Directory of Open Access Journals (Sweden)

    Douglas M. Templeton

    2015-04-01

    Full Text Available Metallic elements, ions and compounds produce varying degrees of toxicity in organisms with which they come into contact. Metal speciation is critical to understanding these adverse effects; the adjectives “heavy” and “toxic” are not helpful in describing the biological properties of individual elements, but detailed chemical structures are. As a broad generalization, the metallic form of an element is inert, and the ionic salts are the species that show more significant bioavailability. Yet the salts and other chelates of a metal ion can give rise to quite different toxicities, as exemplified by a range of carcinogenic potential for various nickel species. Another important distinction comes when a metallic element is organified, increasing its lipophilicity and hence its ability to penetrate the blood brain barrier, as is seen, for example, with organic mercury and tin species. Some metallic elements, such as gold and platinum, are themselves useful therapeutic agents in some forms, while other species of the same element can be toxic, thus focusing attention on species interconversions in evaluating metal-based drugs. The therapeutic use of metal-chelating agents introduces new species of the target metal in vivo, and this can affect not only its desired detoxification, but also introduce a potential for further mechanisms of toxicity. Examples of therapeutic iron chelator species are discussed in this context, as well as the more recent aspects of development of chelation therapy for uranium exposure.

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

    Directory of Open Access Journals (Sweden)

    Charles A. Easley, IV

    2015-05-01

    Full Text Available 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.

  13. External radiation toxicity

    International Nuclear Information System (INIS)

    Fritz, T.E.

    1979-01-01

    The section contains summaries of research on neutron and gamma-ray toxicity in rodents, late effects of low-dose rate, whole-body, protracted exposure to 60 Co gamma rays on young adult beagles, and the effects of protracted, low-dose rate exposure to 60 Co gamma rays on preclinical leukemic phase-related changes in the granulopoietic system of beagles

  14. Local anaesthetic toxicity

    African Journals Online (AJOL)

    Local anaesthetic toxicity has been known since the introduction of local anaesthetic drugs into anaesthetic practice more than a hundred ... was the first to think of cocaine as a narcotic. ..... anaesthetics act as Na+ channel-blocking agents, they slow down .... all neurons, leading to global CNS depression, slowing and.

  15. Toxicity of lunar dust

    NARCIS (Netherlands)

    Linnarsson, D.; Carpenter, J.; Fubini, B.; Gerde, P.; Loftus, D.; Prisk, K.; Staufer, U.; Tranfield, E.; van Westrenen, W.

    2012-01-01

    The formation, composition and physical properties of lunar dust are incompletely characterised with regard to human health. While the physical and chemical determinants of dust toxicity for materials such as asbestos, quartz, volcanic ashes and urban particulate matter have been the focus of

  16. Uranium: biokinetics and toxicity

    International Nuclear Information System (INIS)

    Menetrier, F.; Renaud-Salis, V.; Flury-Herard, A.

    2000-01-01

    This report was achieved as a part of a collaboration with the Fuel Cycle Direction. Its aim was to give the state of the art about: the behaviour of uranium in the human organism (biokinetics) after ingestion, its toxicity (mainly renal) and the current regulation about its incorporation. Both in the upstream and in the downstream of the fuel cycle, uranium remains, quantitatively, the first element in the cycle which is, at the present time, temporarily disposed or recycled. Such a considerable quantity of uranium sets the problem of its risk on the health. In the long term, the biosphere may be affected and consequently the public may ingest water or food contaminated with uranium. In this way, radiological and chemical toxicity risk may be activated. This report emphasizes: the necessity of confirming some experimental and epidemiological biokinetic data used or not in the ICRP models. Unsolved questions remain about the gastrointestinal absorption according to chemical form (valency state, mixtures...), mass and individual variations (age, disease) further a chronic ingestion of uranium. It is well established that uranium is mainly deposited in the skeleton and the kidney. But the skeleton kinetics following a chronic ingestion and especially in some diseases has to be more elucidated; the necessity of taking into account uranium at first as a chemical toxic, essentially in the kidney and determining the threshold of functional lesion. In this way, it is important to look for some specific markers; the problem of not considering chemical toxicity of uranium in the texts regulating its incorporation

  17. How toxic is ibogaine?

    NARCIS (Netherlands)

    Litjens, Ruud P. W.; Brunt, Tibor M.

    2016-01-01

    Ibogaine is a psychoactive indole alkaloid found in the African rainforest shrub Tabernanthe Iboga. It is unlicensed but used in the treatment of drug and alcohol addiction. However, reports of ibogaine's toxicity are cause for concern. To review ibogaine's pharmacokinetics and pharmacodynamics,

  18. Monosodium Glutamate Toxicity

    African Journals Online (AJOL)

    Dr Olaleye

    The brain is reportedly sensitive to monosodium glutamate (MSG) toxicity via oxidative stress. Sida acuta leaf ethanolic .... wherein the right hemisphere, was preserved for histology and fixed in 10% ... Biochemical Assays: The left hemisphere of the brain samples was ...... development in male and female rats. Exp Physiol.

  19. Nanomaterials and Retinal Toxicity

    Science.gov (United States)

    The neuroretina should be considered as a potential site of nanomaterial toxicity. Engineered nanomaterials may reach the retina through three potential routes of exposure including; intra­ vitreal injection of therapeutics; blood-borne delivery in the retinal vasculature an...

  20. Toxic Hazards in Aviation.

    Science.gov (United States)

    1981-04-01

    Pasteur, Lillm,FRANCE. (2) CONISH H.H., EARTH M.L.& IANNi F.L, "Comparative Toxicology of Platics during Thar-modecoqiorition Intsw-re8posium on...Pyrolysnis and Combustion of Materials" Firm and Materials (1976).1, 29-35 (8) ALAAIE Y."Toxicity of Platic dacomposition ProductsŖd Annu~al Progress

  1. Tracking pyrethroid toxicity in surface water samples: Exposure dynamics and toxicity identification tools for laboratory tests with Hyalella azteca (Amphipoda).

    Science.gov (United States)

    Deanovic, Linda A; Stillway, Marie; Hammock, Bruce G; Fong, Stephanie; Werner, Inge

    2018-02-01

    Pyrethroid insecticides are commonly used in pest control and are present at toxic concentrations in surface waters of agricultural and urban areas worldwide. Monitoring is challenging as a result of their high hydrophobicity and low toxicity thresholds, which often fall below the analytical methods detection limits (MDLs). Standard daphnid bioassays used in surface water monitoring are not sensitive enough to protect more susceptible invertebrate species such as the amphipod Hyalella azteca and chemical loss during toxicity testing is of concern. In the present study, we quantified toxicity loss during storage and testing, using both natural and synthetic water, and presented a tool to enhance toxic signal strength for improved sensitivity of H. azteca toxicity tests. The average half-life during storage in low-density polyethylene (LDPE) cubitainers (Fisher Scientific) at 4 °C of 5 pyrethroids (permethrin, bifenthrin, lambda-cyhalothrin, cyfluthrin, and esfenvalerate) and one organophosphate (chlorpyrifos; used as reference) was 1.4 d, and piperonyl butoxide (PBO) proved an effective tool to potentiate toxicity. We conclude that toxicity tests on ambient water samples containing these hydrophobic insecticides are likely to underestimate toxicity present in the field, and mimic short pulse rather than continuous exposures. Where these chemicals are of concern, the addition of PBO during testing can yield valuable information on their presence or absence. Environ Toxicol Chem 2018;37:462-472. © 2017 SETAC. © 2017 SETAC.

  2. [Advance in study on zearalenone's toxicity and determination].

    Science.gov (United States)

    He, Qing-Hua; Xu, Yang

    2005-07-01

    The article is intended to introduce the zearalenone's toxicity, determination methods and prevention. Zearalenone is one of the most widely distributed mycotoxins produces by Fusarium Species, it is harm to animals and human. And it can induce human liver cancer,carcinoma of tesis esophagus cancer. Now we use high-performance liquid chromatography, gas chromatography, thin layer chromatography, non-toxicity determinations to detect it.

  3. Estimation of toxicity using the Toxicity Estimation Software Tool (TEST)

    Science.gov (United States)

    Tens of thousands of chemicals are currently in commerce, and hundreds more are introduced every year. Since experimental measurements of toxicity are extremely time consuming and expensive, it is imperative that alternative methods to estimate toxicity are developed.

  4. Toxic industrial deposit remediation by ant activity

    Science.gov (United States)

    Jilkova, Veronika; Frouz, Jan

    2016-04-01

    Toxic industrial deposits are often contaminated by heavy metals and the substrates have low pH values. In such systems, soil development is thus slowed down by high toxicity and acidic conditions which are unfavourable to soil fauna. Ants (Hymenoptera, Formicidae) are considered tolerant to heavy metal pollution and are known to increase organic matter content and microbial activity in their nests. Here, we focused on soil remediation caused by three ant species (Formica sanguinea, Lasius niger, and Tetramorium sp.) in an ore-washery sedimentation basin near Chvaletice (Czech Republic). Soil samples were taken from the centre of ant nests and from the nest surroundings (>3 m from nests). Samples were then analyzed for microbial activity and biomass and contents of organic matter and nutrients. As a result, ant species that most influenced soil properties was F. sanguinea as there were higher microbial activity and total nitrogen and ammonia contents in ant nests than in the surrounding soil. We expected such a result because F. sanguinea builds conspicuous large nests and is a carnivorous species that brings substantial amounts of nitrogen in insect prey to their nests. Effects of the other two ant species might be lower because of smaller nests and different feeding habits as they rely mainly on honeydew from aphids or on plant seeds that do not contain much nutrients.

  5. Differential toxicity and influence of salinity on acute toxicity of ...

    African Journals Online (AJOL)

    Differential toxicity and influence of salinity on acute toxicity of copper sulphate and lead nitrate against Oreochromis niloticus. KA Bawa-Allah, F Osuala, J Effiong. Abstract. This study investigated the salinity-tolerance of Oreochromis niloticus and the influence of salinity changes on the acute toxicities of copper sulphate ...

  6. Reproductive toxicity testing of vaccines

    International Nuclear Information System (INIS)

    Verdier, Francois; Barrow, Paul C.; Burge, Joeelle

    2003-01-01

    Vaccines play a major role in the prevention of human birth defects by protecting the pregnant woman from teratogenic or otherwise harmful infections. Until now, it has not been common practice to perform preclinical developmental toxicity tests for new vaccines. Despite the excellent safety record of vaccines, increased attention is now being given to the feasibility of screening new vaccines for developmental hazards in animals before their use in humans. Contrary to previous assumptions, many vaccines are now given to potentially pregnant women. Any new components of the vaccine formulation (adjuvants, excipients, stabilisers, preservatives, etc...) could also be tested for influences on development, although based on past experience the risks are limited by the very low dosages used. The conferred immunity following vaccination lasts for several years. Therefore, the developing conceptus may theoretically be exposed to the induced antibodies and/or sensitised T-cells, even if the pregnant woman was last vaccinated during childhood (particularly if she encounters the antigen during pregnancy through exposure to infection). However, it should be kept in mind that viral or bacterial infections represent a higher risk for a pregnant woman than the potential adverse effects related to vaccination or the associated immune response. Non-clinical safety studies may be employed as an aid for hazard identification. In these studies interactions of the vaccine with the maternal immune system or with the developmental systems of the offspring are considered. Post-natal examinations are necessary to detect all possible manifestations of developmental toxicity, such as effects on the immune system. Species selection for the preclinical studies is based on immunogenicity to the vaccine and the relative timing and rate of transfer of maternal antibodies to the offspring. A single study design is proposed for the pre- and post-natal developmental assessments of vaccines in

  7. Biological control of toxic cyanobacteri

    CSIR Research Space (South Africa)

    Ndlela, Luyanda L

    2017-05-01

    Full Text Available . Ecotoxicity studies: is toxicity reduced? (Testing on daphnids, fish and human cell lines) Resulting impacts on cyanotoxins (Toxin conformation changes, ELISA detection) Competition assays against toxic cyanobacteria (Can Bacillus etc. outcompete...

  8. Allegheny County Toxics Release Inventory

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — The Toxics Release Inventory (TRI) data provides information about toxic substances released into the environment or managed through recycling, energy recovery, and...

  9. Toxic waste liquor disposal

    International Nuclear Information System (INIS)

    Burton, W.R.

    1985-01-01

    Toxic waste liquors, especially radio active liquors, are disposed in a sub-zone by feeding down a bore hole a first liquid, then a buffer liquid (e.g. water), then the toxic liquors. Pressure variations are applied to the sub-zone to mix the first liquid and liquors to form gels or solids which inhibit further mixing and form a barrier between the sub-zone and the natural waters in the environment of the sub-zone. In another example the location of the sub-zone is selected so that the environement reacts with the liquors to produce a barrier around the zone. Blind bore holes are used to monitor the sub-zone profile. Materials may be added to the liquor to enhance barrier formation. (author)

  10. Portable, accurate toxicity testing

    International Nuclear Information System (INIS)

    Sabate, R.W.; Stiffey, A.V.; Dewailly, E.L.; Hinds, A.A.; Vieaux, G.J.

    1994-01-01

    Ever tightening environmental regulations, severe penalties for non-compliance, and expensive remediation costs have stimulated development of methods to detect and measure toxins. Most of these methods are bioassays that must be performed in the laboratory; none previously devised has been truly portable. The US Army, through the Small Business Innovative Research program, has developed a hand-held, field deployable unit for testing toxicity of battlefield water supplies. This patented system employs the measurable quenching, in the presence of toxins, of the natural bioluminescence produced by the marine dinoflagellate alga Pyrocystis lunula. The procedure's inventor used it for years to measure toxicity concentrations of chemical warfare agents actually, their simulants, primarily in the form of pesticides and herbicides plus assorted toxic reagents, waterbottom samples, drilling fluids, even blood. While the procedure is more precise, cheaper, and faster than most bioassays, until recently it was immobile. Now it is deployable in the field. The laboratory apparatus has been proven to be sensitive to toxins in concentrations as low as a few parts per billion, repeatable within a variation of 10% or less, and unlike some other bioassays effective in turbid or colored media. The laboratory apparatus and the hand-held tester have been calibrated with the EPA protocol that uses the shrimplike Mysidopsis bahia. The test organism tolerates transportation well, but must be rested a few hours at the test site for regeneration of its light-producing powers. Toxicity now can be measured confidently in soils, water columns, discharge points, and many other media in situ. Most significant to the oil industry is that drilling fluids can be monitored continuously on the rig

  11. Lead toxicity: current concerns.

    OpenAIRE

    Goyer, R A

    1993-01-01

    Over the 20-year period since the first issue of Environmental Health Perspectives was published, there has been considerable progress in the understanding of the potential toxicity of exposure to lead. Many of these advances have been reviewed in published symposia, conferences, and review papers in EHP. This brief review identifies major advances as well as a number of current concerns that present opportunities for prevention and intervention strategies. The major scientific advance has be...

  12. Toxic Substances Control Act

    Energy Technology Data Exchange (ETDEWEB)

    1992-05-15

    This Reference Book contains a current copy of the Toxic Substances Control Act and those regulations that implement the statute and appear to be most relevant to DOE activities. The document is provided to DOE and contractor staff for informational purposes only and should not be interpreted as legal guidance. Questions concerning this Reference Book may be directed to Mark Petts, EH-231 (202/586-2609).

  13. Kombucha--toxicity alert.

    Science.gov (United States)

    The Kombucha mushroom, also known as Manchurian mushroom, is a mail-order product touted to lower blood pressure and raise T-cell counts. No controlled trials have been conducted to test these claims. Aspergillus, a mold that may grow on the Kombucha mushroom, attacks the brain and may be fatal to persons with weakened immune systems. Reported toxicity reactions have included stomach problems and yeast infections. Taking Kombucha in combination with other drugs may affect the drugs potency.

  14. Toxicity of nitrogen pentoxide

    Energy Technology Data Exchange (ETDEWEB)

    Diggle, W M; Gage, J C

    1954-01-01

    Two ppM N/sub 2/O/sub 5/ for 4 h or 1 ppM, 4 h/day for 12 days produced acute pulmonary edema in rats. Ten daily 4-h exposures to 0.5 ppM produced no edema but respiratory distress. NO/sub 2/ produced no edema (some hemorrhage) at 80 mg/m/sup 3/. Nitric acid vapor (63 mg/m/sup 3/) had no obvious toxic effect.

  15. Plant species responses to oil degradation and toxicity reduction in ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-01-05

    Jan 5, 2009 ... contaminated soil and sediment is an emerging techno- logy that promises effective and inexpensive clean up of certain hazardous wastes (Simeon 1993; Nwoko, 1995). Some of these processes occurs within the plants and involves the degradation or breakdown of organic and inorganic contaminants ...

  16. Evaluating pyrene toxicity on Arctic key copepod species Calanus hyperboreus

    DEFF Research Database (Denmark)

    Nørregaard, Rasmus Dyrmose; Nielsen, Torkel Gissel; Friis Møller, Eva

    2014-01-01

    was unaffected. The hatching success was also unaffected, although the total reproductive output was reduced with increased pyrene concentrations. Accumulation of pyrene in the copepods was higher in feeding than starving females and only trace amounts of the phase I metabolite 1-hydroxypyrene, were found...

  17. Modern toxic antipersonnel projectiles.

    Science.gov (United States)

    Gaillard, Yvan; Regenstreif, Philippe; Fanton, Laurent

    2014-12-01

    In the spring of 1944, Kurt von Gottberg, the SS police chief in Minsk, was shot and injured by 2 Soviet agents. Although he was only slightly injured, he died 6 hours later. The bullets were hollow and contained a crystalline white powder. They were 4-g bullets, semi-jacketed in cupronickel, containing 28 mg of aconitine. They were later known as akonitinnitratgeschosse. The Sipo (the Nazi security police) then ordered a trial with a 9-mm Parabellum cartridge containing Ditran, an anticholinergic drug with hallucinogenic properties causing intense mental confusion. In later years, QNB was used and given the NATO code BZ (3-quinuclidinyl-benzylate). It was proven that Saddam Hussein had this weapon (agent 15) manufactured and used it against the Kurds. Serbian forces used the same type of weapon in the Bosnian conflict, particularly in Srebrenica.The authors go on to list the Cold War toxic weapons developed by the KGB and the Warsaw pact countries for the discreet elimination of dissidents and proindependence leaders who had taken refuge in the West. These weapons include PSZh-13 launchers, the Troika electronic sequential pistol, and the ingenious 4-S110T captive piston system designed by the engineer Stechkin. Disguised as a cigarette case, it could fire a silent charge of potassium cyanide. This rogues gallery also includes the umbrella rigged to inject a pellet of ricin (or another phytalbumin of similar toxicity, such as abrin or crotin) that was used to assassinate the Bulgarian writer and journalist Georgi Markov on September 7, 1978, in London.During the autopsy, the discovery of a bullet burst into 4 or 5 parts has to make at once suspecting the use of a toxic substance. Toxicological analysis has to look for first and foremost aconitine, cyanide, suxamethonium, Ditran, BZ, or one of the toxic phytalbumins. The use of such complex weapons has to make suspect a powerful organization: army, secret service, terrorism. The existence of the Russian UDAR spray

  18. Evaluation of metals, metalloids, and ash mixture toxicity using sediment toxicity testing.

    Science.gov (United States)

    Stojak, Amber; Bonnevie, Nancy L; Jones, Daniel S

    2015-01-01

    In December 2008, a release of 4.1 million m(3) of coal ash from the Tennessee Valley Authority Kingston Fossil Plant occurred. Ash washed into the Emory River and migrated downstream into the Clinch and Tennessee Rivers. A Baseline Ecological Risk Assessment evaluated risks to ecological receptors from ash in the river system post-dredging. This article describes the approach used and results from sediment toxicity tests, discussing any causal relationships between ash, metals, and toxicity. Literature is limited in the realm of aquatic coal combustion residue (CCR) exposures and the potential magnitude of effects on benthic invertebrates. Sediment samples along a spectrum of ash content were used in a tiered toxicity testing approach and included a combination of 10 day sediment toxicity acute tests and longer-term, partial life cycle "definitive" tests with 2 species (Hyalella azteca and Chironomus dilutus). Arsenic, and to a lesser extent Se, in the ash was the most likely toxicant causing observed effects in the laboratory toxicity tests. Sites in the Emory River with the greatest statistical and biologically significant effects had As concentrations in sediments twice the probable effects concentration of 33 mg/kg. These sites contained greater than 50% ash. Sites with less than approximately 50% ash in sediments exhibited fewer significant toxic responses relative to the reference sediment in the laboratory. The results discussed here present useful evidence of only limited effects occurring from a worst-case exposure pathway. These results provided a valuable line of evidence for the overall assessment of risks to benthic invertebrates and to other ecological receptors, and were crucial to risk management and development of project remediation goals. © 2014 SETAC.

  19. Thyroid cancer in toxic and non-toxic multinodular goiter

    Directory of Open Access Journals (Sweden)

    Cerci C

    2007-01-01

    Full Text Available Background : Many authors have claimed that hyperthyroidism protects against thyroid cancer and believed that the incidence of malignancy is lower in patients with toxic multinodular goiter (TMG than in those with non-toxic multinodular goiter. But in recent studies, it was reported that the incidence of malignancy with TMG is not as low as previously thought. Aim : To compare the thyroid cancer incidence in patients with toxic and non-toxic multinodular goiter. Settings and Design : Histology reports of patients treated surgically with a preoperative diagnosis of toxic and non-toxic multinodular goiter were reviewed to identify the thyroid cancer incidence. Patients having a history of neck irradiation or radioactive iodine therapy were excluded from the study. Materials and Methods : We reviewed 294 patients operated between 2001-2005 from toxic and non-toxic multinodular goiter. One hundred and twenty-four of them were toxic and 170 were non-toxic. Hyperthyroidism was diagnosed by elevated tri-iodothyroinine / thyroxine ratios and low thyroid-stimulating hormone with clinical signs and symptoms. All patients were evaluated with ultrasonography and scintigraphy and fine needle aspiration biopsy. Statistical Analysis Used : Significance of the various parameters was calculated by using ANOVA test. Results : The incidence of malignancy was 9% in the toxic and 10.58% in the non-toxic multinodular goiter group. Any significant difference in the incidence of cancer and tumor size between the two groups could not be detected. Conclusions : The incidence of malignancy in toxic multinodular goiter is not very low as thought earlier and is nearly the same in non-toxic multinodular goiter.

  20. Glutathione attenuates uranyl toxicity in Lactococcus lactis

    Energy Technology Data Exchange (ETDEWEB)

    Fahmy, Karim; Oertel, Jana [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Biophysics; Obeid, M. [Technische Univ. Dresden (Germany); Solioz, M. [Bern Univ. (Switzerland)

    2017-06-01

    We investigated the role of intracellular glutathione (GSH), which in a large number of taxa plays a role in the protection against the toxicity of heavy metals. Anaerobically grown Lactococcus lactis containing an inducible GSH synthesis pathway was used as a model organism allowing the study of GSH-dependent uranyl detoxification without interference from additional reactive oxygen species. Microcalorimetric measurements of the metabolic heat showed that intracellular GSH attenuates the toxicity of uranium at a concentration in the range of 10-150 μM. Isothermal titration calorimetry revealed the endothermic binding of U(VI) to the carboxyl group(s) of GSH. The data indicate that the primary detoxifying mechanism is the intracellular sequestration of carboxyl-coordinated U(VI) into an insoluble complex with GSH.

  1. Glutathione attenuates uranyl toxicity in Lactococcus lactis

    International Nuclear Information System (INIS)

    Fahmy, Karim; Oertel, Jana; Solioz, M.

    2017-01-01

    We investigated the role of intracellular glutathione (GSH), which in a large number of taxa plays a role in the protection against the toxicity of heavy metals. Anaerobically grown Lactococcus lactis containing an inducible GSH synthesis pathway was used as a model organism allowing the study of GSH-dependent uranyl detoxification without interference from additional reactive oxygen species. Microcalorimetric measurements of the metabolic heat showed that intracellular GSH attenuates the toxicity of uranium at a concentration in the range of 10-150 μM. Isothermal titration calorimetry revealed the endothermic binding of U(VI) to the carboxyl group(s) of GSH. The data indicate that the primary detoxifying mechanism is the intracellular sequestration of carboxyl-coordinated U(VI) into an insoluble complex with GSH.

  2. Molecular and ionic mimicry and the transport of toxic metals

    Science.gov (United States)

    Bridges, Christy C.; Zalups, Rudolfs K.

    2008-01-01

    Despite many scientific advances, human exposure to, and intoxication by, toxic metal species continues to occur. Surprisingly, little is understood about the mechanisms by which certain metals and metal-containing species gain entry into target cells. Since there do not appear to be transporters designed specifically for the entry of most toxic metal species into mammalian cells, it has been postulated that some of these metals gain entry into target cells, through the mechanisms of ionic and/or molecular mimicry, at the site of transporters of essential elements and/or molecules. The primary purpose of this review is to discuss the transport of selective toxic metals in target organs and provide evidence supporting a role of ionic and/or molecular mimicry. In the context of this review, molecular mimicry refers to the ability of a metal ion to bond to an endogenous organic molecule to form an organic metal species that acts as a functional or structural mimic of essential molecules at the sites of transporters of those molecules. Ionic mimicry refers to the ability of a cationic form of a toxic metal to mimic an essential element or cationic species of an element at the site of a transporter of that element. Molecular and ionic mimics can also be sub-classified as structural or functional mimics. This review will present the established and putative roles of molecular and ionic mimicry in the transport of mercury, cadmium, lead, arsenic, selenium, and selected oxyanions in target organs and tissues. PMID:15845419

  3. Molecular and ionic mimicry and the transport of toxic metals

    International Nuclear Information System (INIS)

    Bridges, Christy C.; Zalups, Rudolfs K.

    2005-01-01

    Despite many scientific advances, human exposure to, and intoxication by, toxic metal species continues to occur. Surprisingly, little is understood about the mechanisms by which certain metals and metal-containing species gain entry into target cells. Since there do not appear to be transporters designed specifically for the entry of most toxic metal species into mammalian cells, it has been postulated that some of these metals gain entry into target cells, through the mechanisms of ionic and/or molecular mimicry, at the site of transporters of essential elements and/or molecules. The primary purpose of this review is to discuss the transport of selective toxic metals in target organs and provide evidence supporting a role of ionic and/or molecular mimicry. In the context of this review, molecular mimicry refers to the ability of a metal ion to bond to an endogenous organic molecule to form an organic metal species that acts as a functional or structural mimic of essential molecules at the sites of transporters of those molecules. Ionic mimicry refers to the ability of a cationic form of a toxic metal to mimic an essential element or cationic species of an element at the site of a transporter of that element. Molecular and ionic mimics can also be sub-classified as structural or functional mimics. This review will present the established and putative roles of molecular and ionic mimicry in the transport of mercury, cadmium, lead, arsenic, selenium, and selected oxyanions in target organs and tissues

  4. Molecular characterization and identification of markers for toxic and non-toxic varieties of Jatropha curcas L. using RAPD, AFLP and SSR markers.

    Science.gov (United States)

    Sudheer Pamidimarri, D V N; Singh, Sweta; Mastan, Shaik G; Patel, Jalpa; Reddy, Muppala P

    2009-07-01

    Jatropha curcas L., a multipurpose shrub has acquired significant economic importance for its seed oil which can be converted to biodiesel, is emerging as an alternative to petro-diesel. The deoiled seed cake remains after oil extraction is toxic and cannot be used as a feed despite having best nutritional contents. No quantitative and qualitative differences were observed between toxic and non-toxic varieties of J. curcas except for phorbol esters content. Development of molecular marker will enable to differentiate non-toxic from toxic variety in a mixed population and also help in improvement of the species through marker assisted breeding programs. The present investigation was undertaken to characterize the toxic and non-toxic varieties at molecular level and to develop PCR based molecular markers for distinguishing non-toxic from toxic or vice versa. The polymorphic markers were successfully identified specific to non-toxic and toxic variety using RAPD and AFLP techniques. Totally 371 RAPD, 1,442 AFLP markers were analyzed and 56 (15.09%) RAPD, 238 (16.49%) AFLP markers were found specific to either of the varieties. Genetic similarity between non-toxic and toxic verity was found to be 0.92 by RAPD and 0.90 by AFLP fingerprinting. In the present study out of 12 microsatellite markers analyzed, seven markers were found polymorphic. Among these seven, jcms21 showed homozygous allele in the toxic variety. The study demonstrated that both RAPD and AFLP techniques were equally competitive in identifying polymorphic markers and differentiating both the varieties of J. curcas. Polymorphism of SSR markers prevailed between the varieties of J. curcas. These RAPD and AFLP identified markers will help in selective cultivation of specific variety and along with SSRs these markers can be exploited for further improvement of the species through breeding and Marker Assisted Selection (MAS).

  5. Is LSD toxic?

    Science.gov (United States)

    Nichols, David E; Grob, Charles S

    2018-03-01

    LSD (lysergic acid diethylamide) was discovered almost 75 years ago, and has been the object of episodic controversy since then. While initially explored as an adjunctive psychiatric treatment, its recreational use by the general public has persisted and on occasion has been associated with adverse outcomes, particularly when the drug is taken under suboptimal conditions. LSD's potential to cause psychological disturbance (bad trips) has been long understood, and has rarely been associated with accidental deaths and suicide. From a physiological perspective, however, LSD is known to be non-toxic and medically safe when taken at standard dosages (50-200μg). The scientific literature, along with recent media reports, have unfortunately implicated "LSD toxicity" in five cases of sudden death. On close examination, however, two of these fatalities were associated with ingestion of massive overdoses, two were evidently in individuals with psychological agitation after taking standard doses of LSD who were then placed in maximal physical restraint positions (hogtied) by police, following which they suffered fatal cardiovascular collapse, and one case of extreme hyperthermia leading to death that was likely caused by a drug substituted for LSD with strong effects on central nervous system temperature regulation (e.g. 25i-NBOMe). Given the renewed interest in the therapeutic potential of LSD and other psychedelic drugs, it is important that an accurate understanding be established of the true causes of such fatalities that had been erroneously attributed to LSD toxicity, including massive overdoses, excessive physical restraints, and psychoactive drugs other than LSD. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Toxic potential of palytoxin.

    Science.gov (United States)

    Patocka, Jiří; Gupta, Ramesh C; Wu, Qing-hua; Kuca, Kamil

    2015-10-01

    This review briefly describes the origin, chemistry, molecular mechanism of action, pharmacology, toxicology, and ecotoxicology of palytoxin and its analogues. Palytoxin and its analogues are produced by marine dinoflagellates. Palytoxin is also produced by Zoanthids (i.e. Palythoa), and Cyanobacteria (Trichodesmium). Palytoxin is a very large, non-proteinaceous molecule with a complex chemical structure having both lipophilic and hydrophilic moieties. Palytoxin is one of the most potent marine toxins with an LD50 of 150 ng/kg body weight in mice exposed intravenously. Pharmacological and electrophysiological studies have demonstrated that palytoxin acts as a hemolysin and alters the function of excitable cells through multiple mechanisms of action. Palytoxin selectively binds to Na(+)/K(+)-ATPase with a Kd of 20 pM and transforms the pump into a channel permeable to monovalent cations with a single-channel conductance of 10 pS. This mechanism of action could have multiple effects on cells. Evaluation of palytoxin toxicity using various animal models revealed that palytoxin is an extremely potent neurotoxin following an intravenous, intraperitoneal, intramuscular, subcutaneous or intratracheal route of exposure. Palytoxin also causes non-lethal, yet serious toxic effects following dermal or ocular exposure. Most incidents of palytoxin poisoning have manifested after oral intake of contaminated seafood. Poisonings in humans have also been noted after inhalation, cutaneous/systemic exposures with direct contact of aerosolized seawater during Ostreopsis blooms and/or through maintaining aquaria containing Cnidarian zoanthids. Palytoxin has a strong potential for toxicity in humans and animals, and currently this toxin is of great concern worldwide.

  7. Haemolytic glycoglycerolipids from Gymnodinium species.

    Science.gov (United States)

    Parrish, C C; Bodennec, G; Gentien, P

    1998-03-01

    Glycoglycerolipids derived from microalgae can be a source of biologically active substances including toxins. Such glycolipids were analysed in two isolates of toxic marine dinoflagellates from European waters. The lipids of Gymnodinium mikimotoi contained 17% of monogalactosyl diacylglycerol (MGDG) and digalactosyl diacylglycerol (DGDG), while in Gymnodinium sp. the proportion was 35%. MGDG and DGDG from both species were haemolytic. The major unsaturated fatty acid in both algal glycolipids was 18:5 omega 3.

  8. Metal metabolism and toxicity

    International Nuclear Information System (INIS)

    Bhattacharyya, M.H.; Larsen, R.P.; Whelton, B.D.; Moretti, E.S.; Peterson, D.P.; Oldham, R.D.

    1985-01-01

    This research focuses on the role of pregnancy and lactation in susceptibility to the toxic effects of cadmium and lead. Responses under investigation include lead-induced changes in pathways for vitamin D and calcium metabolism and cadmium-induced alterations in kidney function and skeletal structure. The second area focuses on the gastrointestinal absorption of plutonium and other actinide elements. Studies currently being conducted in nonhuman primates to develop a procedure to determine GI absorption values of uranium and plutonium that does not require sacrifice of the animal. 6 refs

  9. Control of air toxics

    International Nuclear Information System (INIS)

    Livengood, C.D.

    1995-01-01

    For more than 10 years, Argonne National Laboratory has supported the US DOE's Flue Gas Cleanup Program objective by developing new or improved environmental controls for industries that use fossil fuels. Argonne's pollutant emissions research has ranged from experiments in the basic chemistry of pollution-control systems, through laboratory-scale process development and testing, to pilot-scale field tests of several technologies. The work on air toxics is currently divided into two components: Investigating measures to improve the removal of mercury in existing pollution-control systems applied to coal combustion; and, Developing sensors and control techniques for emissions found in the textile industry

  10. The toxic effects of chlorophenols and associated mechanisms in fish

    International Nuclear Information System (INIS)

    Ge, Tingting; Han, Jiangyuan; Qi, Yongmei; Gu, Xueyan; Ma, Lin; Zhang, Chen; Naeem, Sajid; Huang, Dejun

    2017-01-01

    Highlights: • We review the toxic effects of chlorophenols (CPs) and underlying mechanisms in fish. • CPs induce lethal effects, oxidative stress, endocrine disruption, reproductive toxicity and apoptosis in fish. • CPs exhibit toxicity through multiple signaling pathways in fish and different pathways co-exist under the same conditions. • Studies on DNA methylation provide new insights into our understanding of epigenetic mechanisms of CPs-induced toxicity. • Mechanisms studies on CPs toxicity performed under environmental concentrations need more attentions. - Abstract: Chlorophenols (CPs) are ubiquitous contaminants in the environment primarily released from agricultural and industrial wastewater. These compounds are not readily degraded naturally, and easily accumulate in organs, tissues and cells via food chains, further leading to acute and chronic toxic effects on aquatic organisms. Herein, we review the available literature regarding CP toxicity in fish, with special emphasis on the potential toxic mechanisms. CPs cause oxidative stress via generation of reactive oxygen species, induction of lipid peroxidation and/or oxidative DNA damage along with inhibition of antioxidant systems. CPs affect immune system by altering the number of mature B cells and macrophages, while suppressing phagocytosis and down-regulating the expression of immune factors. CPs also disrupt endocrine function by affecting hormone levels, or inducing abnormal gene expression and interference with hormone receptors. CPs at relatively higher concentrations induce apoptosis via mitochondria-mediated pathway, cell death receptor-mediated pathway, and/or DNA damage-mediated pathway. CPs at relatively lower concentrations promote cell proliferation, and foster cancers-prone environment by increasing the rate of point mutations and oxidative DNA lesions. These toxic effects in fish are induced directly by CPs per se or indirectly by their metabolic products. In addition, recent

  11. The toxic effects of chlorophenols and associated mechanisms in fish

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Tingting; Han, Jiangyuan; Qi, Yongmei; Gu, Xueyan; Ma, Lin; Zhang, Chen; Naeem, Sajid; Huang, Dejun, E-mail: huangdj@lzu.edu.cn

    2017-03-15

    Highlights: • We review the toxic effects of chlorophenols (CPs) and underlying mechanisms in fish. • CPs induce lethal effects, oxidative stress, endocrine disruption, reproductive toxicity and apoptosis in fish. • CPs exhibit toxicity through multiple signaling pathways in fish and different pathways co-exist under the same conditions. • Studies on DNA methylation provide new insights into our understanding of epigenetic mechanisms of CPs-induced toxicity. • Mechanisms studies on CPs toxicity performed under environmental concentrations need more attentions. - Abstract: Chlorophenols (CPs) are ubiquitous contaminants in the environment primarily released from agricultural and industrial wastewater. These compounds are not readily degraded naturally, and easily accumulate in organs, tissues and cells via food chains, further leading to acute and chronic toxic effects on aquatic organisms. Herein, we review the available literature regarding CP toxicity in fish, with special emphasis on the potential toxic mechanisms. CPs cause oxidative stress via generation of reactive oxygen species, induction of lipid peroxidation and/or oxidative DNA damage along with inhibition of antioxidant systems. CPs affect immune system by altering the number of mature B cells and macrophages, while suppressing phagocytosis and down-regulating the expression of immune factors. CPs also disrupt endocrine function by affecting hormone levels, or inducing abnormal gene expression and interference with hormone receptors. CPs at relatively higher concentrations induce apoptosis via mitochondria-mediated pathway, cell death receptor-mediated pathway, and/or DNA damage-mediated pathway. CPs at relatively lower concentrations promote cell proliferation, and foster cancers-prone environment by increasing the rate of point mutations and oxidative DNA lesions. These toxic effects in fish are induced directly by CPs per se or indirectly by their metabolic products. In addition, recent

  12. Toxicity of tritium

    International Nuclear Information System (INIS)

    Dobson, R.L.

    1979-01-01

    Among radionuclides of importance in atomic energy, 3 H has relatively low toxicity. The main health and environmental worry is the possibility that significant biological effects may follow from protracted exposure to low concentrations in water. To examine this possible hazard and measure toxicity at low tritium concentrations, chronic exposure studies were done on mice and monkeys. During vulnerable developmental periods animals were exposed to 3 HOH, and mice were exposed also to 60 Co gamma irradiation and energy-related chemical agents. The biological endpoint measured was the irreversible loss of female germ cells. Effects from tritium were observed at surprisingly low concentrations where 3 H was found more damaging than previously thought. Comparisons between tritium and gamma radiation showed the relative biological effectiveness (RBE) to be greater than 1 and to reach approximately 3 at very low exposures. For perspective, other comparisons were made: between radiation and chemical agents, which revealed parallels in action on germ cells, and between pre- and postnatal exposure, which warn of possible special hazard to the fetus from both classes of energy-related byproducts

  13. Toxic compounds in honey.

    Science.gov (United States)

    Islam, Md Nazmul; Khalil, Md Ibrahim; Islam, Md Asiful; Gan, Siew Hua

    2014-07-01

    There is a wealth of information about the nutritional and medicinal properties of honey. However, honey may contain compounds that may lead to toxicity. A compound not naturally present in honey, named 5-hydroxymethylfurfural (HMF), may be formed during the heating or preservation processes of honey. HMF has gained much interest, as it is commonly detected in honey samples, especially samples that have been stored for a long time. HMF is a compound that may be mutagenic, carcinogenic and cytotoxic. It has also been reported that honey can be contaminated with heavy metals such as lead, arsenic, mercury and cadmium. Honey produced from the nectar of Rhododendron ponticum contains alkaloids that can be poisonous to humans, while honey collected from Andromeda flowers contains grayanotoxins, which can cause paralysis of limbs in humans and eventually leads to death. In addition, Melicope ternata and Coriaria arborea from New Zealand produce toxic honey that can be fatal. There are reports that honey is not safe to be consumed when it is collected from Datura plants (from Mexico and Hungary), belladonna flowers and Hyoscamus niger plants (from Hungary), Serjania lethalis (from Brazil), Gelsemium sempervirens (from the American Southwest), Kalmia latifolia, Tripetalia paniculata and Ledum palustre. Although the symptoms of poisoning due to honey consumption may differ depending on the source of toxins, most common symptoms generally include dizziness, nausea, vomiting, convulsions, headache, palpitations or even death. It has been suggested that honey should not be considered a completely safe food. Copyright © 2013 John Wiley & Sons, Ltd.

  14. Thallium toxicity in humans.

    Science.gov (United States)

    Cvjetko, Petra; Cvjetko, Ivan; Pavlica, Mirjana

    2010-03-01

    Thallium is a naturally occurring trace element, widely distributed in the earth's crust, but at very low concentrations. It does not have a known biological use and does not appear to be an essential element for life. It has been considered one of the most toxic heavy metals.Occasionally, there are reports on thallium poisoning as results of suicide or murder attempt or accident. The main threat to humans is through occupational exposure, environmental contamination, and accumulation in food, mainly in vegetables grown on contaminated soil. Increasing use in emerging new technologies and demanding high-tech industry constantly raise concern about exposure risk to all living organisms. Thallium is considered a cumulative poison that can cause adverse health effects and degenerative changes in many organs. The effects are the most severe in the nervous system. The exact mechanism of thallium toxicity still remains unknown, although impaired glutathione metabolism, oxidative stress, and disruption of potassium-regulated homeostasis may play a role. The lack of data about mutagenic, carcinogenic, or teratogenic effects of thallium compounds in humans calls for further research.

  15. Molecular toxicity of nanomaterials.

    Science.gov (United States)

    Chang, Xue-Ling; Yang, Sheng-Tao; Xing, Gengmei

    2014-10-01

    With the rapid developments in the fields of nanoscience and nanotechnlogy, more and more nanomaterials and their based consumer products have been used into our daily life. The safety concerns of nanomaterials have been well recognized by the scientific community and the public. Molecular mechanism of interactions between nanomaterials and biosystems is the most essential topic and final core of the biosafety. In the last two decades, nanotoxicology developed very fast and toxicity phenomena of nanomaterials have been reported. To achieve better understanding and detoxication of nanomaterials, thorough studies of nanotoxicity at molecular level are important. The interactions between nanomaterials and biomolecules have been widely investigated as the first step toward the molecular nanotoxicology. The consequences of such interactions have been discussed in the literature. Besides this, the chemical mechanism of nanotoxicology is gaining more attention, which would lead to a better design of nontoxic nanomaterials. In this review, we focus on the molecular nanotoxicology and explore the toxicity of nanomaterials at molecular level. The molecular level studies of nanotoxicology are summarized and the published nanotoxicological data are revisited.

  16. Gomphrena claussenii, a Zn and Cd hyperbioindicator species

    NARCIS (Netherlands)

    Tomaz Villafort Carvalho, M.

    2016-01-01

    Gomphrena claussenii, a Zn and Cd hyperbioindicator species

    A small group of plant species called metallophytes have evolved the ability to grow in highly metal-enriched soils that are toxic to other plants. Some of these metal-tolerant species have evolved the ability to accumulate high

  17. Why are Functional Amyloids Non-Toxic in Humans?

    Directory of Open Access Journals (Sweden)

    Matthew P. Jackson

    2017-09-01

    Full Text Available Amyloids were first identified in association with amyloidoses, human diseases in which proteins and peptides misfold into amyloid fibrils. Subsequent studies have identified an array of functional amyloid fibrils that perform physiological roles in humans. Given the potential for the production of toxic species in amyloid assembly reactions, it is remarkable that cells can produce these functional amyloids without suffering any obvious ill effect. Although the precise mechanisms are unclear, there are a number of ways in which amyloid toxicity may be prevented. These include regulating the level of the amyloidogenic peptides and proteins, minimising the production of prefibrillar oligomers in amyloid assembly reactions, sequestrating amyloids within membrane bound organelles, controlling amyloid assembly by other molecules, and disassembling the fibrils under physiological conditions. Crucially, a better understanding of how toxicity is avoided in the production of functional amyloids may provide insights into the prevention of amyloid toxicity in amyloidoses.

  18. Predicting molybdenum toxicity to higher plants: Influence of soil properties

    Energy Technology Data Exchange (ETDEWEB)

    McGrath, S.P., E-mail: steve.mcgrath@bbsrc.ac.u [Soil Science Department, Centre for Soils and Ecosystems Functions, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ (United Kingdom); Mico, C. [Soil Science Department, Centre for Soils and Ecosystems Functions, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ (United Kingdom); Curdy, R. [Laboratory for Environmental Biotechnology (LBE), Swiss Federal Institute of Technology Lausanne (EPFL) Station 6 CH, 1015 Lausanne (Switzerland); Zhao, F.J. [Soil Science Department, Centre for Soils and Ecosystems Functions, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ (United Kingdom)

    2010-10-15

    The effect of soil properties on the toxicity of molybdenum (Mo) to four plant species was investigated. Soil organic carbon or ammonium-oxalate extractable Fe oxides were found to be the best predictors of the 50% effective dose (ED{sub 50}) of Mo in different soils, explaining > 65% of the variance in ED{sub 50} for four species except for ryegrass (26-38%). Molybdenum concentrations in soil solution and consequently plant uptake were increased when soil pH was artificially raised because sorption of Mo to amorphous oxides is greatly reduced at high pH. The addition of sulphate significantly decreased Mo uptake by oilseed rape. For risk assessment, we suggest that Mo toxicity values for plants should be normalised using soil amorphous iron oxide concentrations. - Amorphous iron oxides or organic carbon were found to be the best predictors of the toxicity threshold values of Mo to higher plants on different soils.

  19. Predicting molybdenum toxicity to higher plants: Influence of soil properties

    International Nuclear Information System (INIS)

    McGrath, S.P.; Mico, C.; Curdy, R.; Zhao, F.J.

    2010-01-01

    The effect of soil properties on the toxicity of molybdenum (Mo) to four plant species was investigated. Soil organic carbon or ammonium-oxalate extractable Fe oxides were found to be the best predictors of the 50% effective dose (ED 50 ) of Mo in different soils, explaining > 65% of the variance in ED 50 for four species except for ryegrass (26-38%). Molybdenum concentrations in soil solution and consequently plant uptake were increased when soil pH was artificially raised because sorption of Mo to amorphous oxides is greatly reduced at high pH. The addition of sulphate significantly decreased Mo uptake by oilseed rape. For risk assessment, we suggest that Mo toxicity values for plants should be normalised using soil amorphous iron oxide concentrations. - Amorphous iron oxides or organic carbon were found to be the best predictors of the toxicity threshold values of Mo to higher plants on different soils.

  20. Do oil dispersants make spilled oil more toxic to fish?

    International Nuclear Information System (INIS)

    Hodson, P.

    2010-01-01

    The Deepwater Horizon blowout in the Gulf of Mexico was the world's largest oil spill in terms of duration and volume spilled. Clean-up operations, which involved the continuous and wide-spread use of oil dispersant at the surface and at the seabed discharge point at 1500 metres depth, gave rise to public concern about dispersant toxicity. Reports from the United States Environmental Protection Agency (EPA) claimed little difference in acute toxicity to marine fish and invertebrate species among commonly available dispersants and between dispersed and non-dispersed Louisiana Sweet Crude. Technically, the toxicity of waterborne hydrocarbons does not vary with chemical dispersion. However, the EPA omitted any consideration of loading, and misled the public about the risks of dispersant use in oil clean-up. This study examined the chronic toxicity of dispersed oil to fish embryos. The study revealed that toxicity expressed as oil loading increases by a factor of 10 to 1000 times with dispersion, largely because 10 to 1000 times more oil enters the water column. Since the action of dispersant is on the exposure component of the risk equation, not on the potency of the toxic components of oil, then the risk of oil toxicity to fish increases an equivalent amount.

  1. Toxicity of petroleum hydrocarbon distillates to soil organisms.

    Science.gov (United States)

    Cermak, Janet H; Stephenson, Gladys L; Birkholz, Detlef; Wang, Zhendi; Dixon, D George

    2010-12-01

    Canadian standards for petroleum hydrocarbons in soil are based on four distillate ranges (F1, C6-C10; F2, >C10-C16; F3, >C16-C34; and F4, >C34). Concerns have arisen that the ecological soil contact standards for F3 may be overly conservative. Oil distillates were prepared and characterized, and the toxicity of F3 and two subfractions, F3a (>C16-C23) and F3b (>C23-C34), to earthworms (Eisenia andrei), springtails (Orthonychiurus folsomi), and northern wheatgrass (Elymus lanceolatus), as well as the toxicity of F2 to earthworms, was determined. Clean soil was spiked with individual distillates and measured concentrations were determined for select tests. Results agree with previous studies with these distillates. Reported toxicities of crude and petroleum products to invertebrates were generally comparable to that of F3 and F3a. The decreasing order of toxicity was F3a > F3 > F3b with invertebrates, and F3a > F3b > F3 with plants. The toxicities of F3a and F3b were not sufficiently different to recommend regulating hydrocarbons based on these distillate ranges. The results also suggest that test durations may be insufficient for determining toxicity of higher distillate ranges, and that the selection of species and endpoints may significantly affect interpretation of toxicity test results. Copyright © 2010 SETAC.

  2. Edaravone Decreases Paraquat Toxicity in A549 Cells and Lung Isolated Mitochondria

    OpenAIRE

    Shokrzadeh, Mohammad; Shaki, Fatemeh; Mohammadi, Ebrahim; Rezagholizadeh, Neda; Ebrahimi, Fatemeh

    2014-01-01

    Edaravone, an antioxidant and radical scavenger, showed protective effects against oxidative stress-like condition. Paraquat (PQ) is toxic herbicide considerable evidence suggests that oxidative stress and mitochondrial dysfunction contribute to PQ toxicity. In this study, protective effect of edaravone against PQ induced toxicity and reactive oxygen species (ROS) generation in A549 cells and lung isolated mitochondria were evaluated. A549 cells and lung isolated mitochondria were divided int...

  3. Acute Toxicity of Tributyltins and Tributyltin Leachates from Marine Antibiofouling Paints.

    Science.gov (United States)

    1982-09-10

    RO-0184 224 ACUTE TOXICITY OF TRIBUTYLTINS AND TRIBUTYLTIN i/I LEACHATES FROM MARINE ANTIBIOFOULING PAINTS(U) CALIFORNIA UNIV OAKLAND NAVAL...Classification) (U) ACUTE TOXICITY OF TRIBUTYLTINS AND TRIBUTYLTIN LEACHATES FROM MARINE ANTIBIOFOULING PAINTS 12, PERSO A UHR Laugin, Koy"., Linden, Olof and...xins causing acute toxicity or two amphipou species at concentrations as low as 10 g/L . Orchestia traskiana was exposed to bis ( tributyltin ) oxide

  4. Nitrite toxicity assessment in Danio rerio and Poecilia reticulata

    Directory of Open Access Journals (Sweden)

    Petra Doleželová

    2011-01-01

    Full Text Available Nitrite is a natural component of the nitrogen cycle in the environment. Although it usually occurs in low concentrations, elevated concentrations caused by effluents or affected nitrification process can lead to serious health deterioration of fish. Two aquarium fish zebrafish (Danio rerio and guppy (Poecilia reticulata are recommended to use as model organisms in toxicity tests. However, their sensitivity to nitrite can differ. The aim of this study was to define acute toxicity of nitrite by the semistatic method according to OECD No. 203 (Fish, Acute toxicity test. The series of 4 acute toxicity tests was performed, with 10 fish of both species used for each concentration and for the control. The 96hLC50 NO2- value for D. rerio and P. reticulata was 242.55 ± 15.79 mg·l-1 and 30.2 ± 8.74 mg·l-1, respectively. We have proved significant difference (p D. rerio and P. reticulata. The results showed different sensitivities to nitrites in tested fish species, which could be related to species-specific branchial chloride uptake mechanism. This is the first study on this fish species.

  5. The neonicotinoid imidachloprid shows high chronic toxicity to mayfly nymphs

    NARCIS (Netherlands)

    Roessink, I.; Merga, L.B.; Zweers, A.J.; Brink, van den P.J.

    2013-01-01

    The present study evaluated the acute and chronic toxicity of imidacloprid to a range of freshwater arthropods. Mayfly and caddisfly species were most sensitive to short-term imidacloprid exposures (10 tests), whereas the mayflies showed by far the most sensitive response to long-term exposure of

  6. THE ROLE OF INORGANIC ION IMBALANCE IN AQUATIC TOXICITY TESTING

    Science.gov (United States)

    Effluent toxicity testing methods have been well defined, but to a large part have not attempted to segregate the effects of active ionic concentrations and ion imbalances upon test and species performances. The role that various total dissolved solids in effluents have on regula...

  7. Toxicity of essential oil compounds against Exorista sorbillans ...

    African Journals Online (AJOL)

    Essential oils of Ageratum conyzoides and Ocimum species are potential candidates for management of Exorista sorbillans (Wiedemann) (Diptera: Culicidae), a serious pest of silkworm. Considering that the pure compounds in essential oil may exhibit efficacy against the parasitoid, contact and topical toxicity of 22 essential ...

  8. Toxic mechanisms of copper oxide nanoparticles in epithelial kidney cells

    DEFF Research Database (Denmark)

    Thit, Amalie; Selck, Henriette; Bjerregaard, Henning F.

    2015-01-01

    and levels of reduced glutathione (GSH) and eventually cell death. We show that ROS (Reactive Oxygen Species) generation plays a key role and occurs early in Poly toxicity as Poly-induced DNA damage and cell death could be mitigated by the antioxidant NAC (N-acetyl-cysteine). Here we propose a model...

  9. The Toxicity of plant material, Drimia Altissima (Urginea Altissima ...

    African Journals Online (AJOL)

    Background: Rodents are important pests of public health and agricultural importance, capable of transmitting diseases to humans and causing crop damage. The present rodent control strategy depends primarily on synthetic rodenticides, which are highly toxic, affect non-target species, and are expensive. Naturally ...

  10. Toxicity of dissolved and precipitated aluminium to marine diatoms.

    Science.gov (United States)

    Gillmore, Megan L; Golding, Lisa A; Angel, Brad M; Adams, Merrin S; Jolley, Dianne F

    2016-05-01

    Localised aluminium contamination can lead to high concentrations in coastal waters, which have the potential for adverse effects on aquatic organisms. This research investigated the toxicity of 72-h exposures of aluminium to three marine diatoms (Ceratoneis closterium (formerly Nitzschia closterium), Minutocellus polymorphus and Phaeodactylum tricornutum) by measuring population growth rate inhibition and cell membrane damage (SYTOX Green) as endpoints. Toxicity was correlated to the time-averaged concentrations of different aluminium size-fractions, operationally defined as aluminium exposure varied between diatom species. C. closterium was the most sensitive species (10% inhibition of growth rate (72-h IC10) of 80 (55-100)μg Al/L (95% confidence limits)) while M. polymorphus (540 (460-600)μg Al/L) and P. tricornutum (2100 (2000-2200)μg Al/L) were less sensitive (based on measured total aluminium). Dissolved aluminium was the primary contributor to toxicity in C. closterium, while a combination of dissolved and precipitated aluminium forms contributed to toxicity in M. polymorphus. In contrast, aluminium toxicity to the most tolerant diatom P. tricornutum was due predominantly to precipitated aluminium. Preliminary investigations revealed the sensitivity of C. closterium and M. polymorphus to aluminium was influenced by initial cell density with aluminium toxicity significantly (paluminium toxicity to diatoms do not involve compromising the plasma membrane. These results indicate that marine diatoms have a broad range in sensitivity to aluminium with toxic mechanisms related to both dissolved and precipitated aluminium. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Wild lettuce (Lactuca virosa) toxicity

    OpenAIRE

    Besharat, Sima; Besharat, Mahsa; Jabbari, Ali

    2009-01-01

    Wild lettuce (Lactuca virosa) can cause toxic effects when eaten. Wild lettuce grows in the north of Iran and some natives consume it unaware of its adverse side effects. We describe eight patients with manifestations of wild lettuce toxicity, admitted to a general hospital affiliated to the Golestan University of Medical Sciences. All the patients recovered (although one had to spend 48 h in the intensive care unit) and no chronic complications were reported. A clinical suspicion of toxicity...

  12. Cyclophosphamide-induced pulmonary toxicity

    International Nuclear Information System (INIS)

    Siemann, D.W.; Macler, L.; Penney, D.P.

    1986-01-01

    Unlike radiation effects, pulmonary toxicity following drug treatments may develop soon after exposure. The dose-response relationship between Cyclophosphamide and lung toxicity was investigated using increased breathing frequency assays used successfully for radiation induced injury. The data indicate that release of protein into the alveolus may play a significant role in Cy induced pulmonary toxicity. Although the mechanism responsible for the increased alveolar protein is as yet not identified, the present findings suggest that therapeutic intervention to inhibit protein release may be an approach to protect the lungs from toxic effects. (UK)

  13. Toxicity of diuron in human cancer cells.

    Science.gov (United States)

    Huovinen, Marjo; Loikkanen, Jarkko; Naarala, Jonne; Vähäkangas, Kirsi

    2015-10-01

    Diuron is a substituted phenylurea used as a herbicide to control broadleaf and grass weeds and as a biocidal antifouling agent. Diuron is carcinogenic in rat urinary bladder and toxic to the reproductive system of oysters, sea urchins and lizards. The few studies carried out in human cells do not include the genotoxicity of diuron. We have investigated the toxicity of diuron in human breast adenocarcinoma (MCF-7) and human placental choriocarcinoma (BeWo) cells. The production of reactive oxygen species (ROS) was statistically significantly increased in both cell lines but only at the highest 200 μM concentration. Diuron clearly reduced the viability of BeWo, but not MCF-7 cells. The relative cell number was decreased in both cell lines indicative of inhibition of cell proliferation. In the Comet assay, diuron increased DNA fragmentation in MCF-7 but not in BeWo cells. The expressions of p53 protein, a marker for cell stress, and p21 protein, a transcriptional target of p53, were increased, but only in MCF-7 cells. In conclusion, our results suggest that diuron is cytotoxic and potentially genotoxic in a tissue-specific manner and that ROS play a role in its toxicity. Thus, exposure to diuron may exert harmful effects on fetal development and damage human health. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. E-Cigarette Toxicity?

    Science.gov (United States)

    Tegin, Gulay; Mekala, Hema Madhuri; Sarai, Simrat Kaur; Lippmann, Steven

    2018-01-01

    Tobacco smoking is the most preventable cause of morbidity and mortality. In just a few short years, electronic cigarettes (e-cigarettes) have become increasingly popular, especially for younger individuals. Many people believe that e-cigarettes are safe. The inhaled aerosols of e-cigarettes contain numerous potential toxicities, some of which could be dangerous for health with long-term use. The safety of prolonged aerosol exposure is not known. The use of e-cigarettes as a harm-reduction tool at stopping tobacco smoking is not uniformly successful. E-cigarettes may be safer than tobacco products, but repeated prolonged exposure to their aerosols has its own considerable potential risk. The long-term health consequences of their use remain to be established. Physicians should vigorously discourage the use of e-cigarettes and tobacco products, with special emphasis on abstinence for younger people and during pregnancy or lactation.

  15. Metal and proton toxicity to lake zooplankton: A chemical speciation based modelling approach

    International Nuclear Information System (INIS)

    Stockdale, Anthony; Tipping, Edward; Lofts, Stephen; Fott, Jan; Garmo, Øyvind A.; Hruska, Jakub; Keller, Bill; Löfgren, Stefan; Maberly, Stephen C.; Majer, Vladimir; Nierzwicki-Bauer, Sandra A.; Persson, Gunnar; Schartau, Ann-Kristin; Thackeray, Stephen J.

    2014-01-01

    The WHAM-F TOX model quantifies the combined toxic effects of protons and metal cations towards aquatic organisms through the toxicity function (F TOX ), a linear combination of the products of organism-bound cation and a toxic potency coefficient for each cation. We describe the application of the model to predict an observable ecological field variable, species richness of pelagic lake crustacean zooplankton, studied with respect to either acidification or the impacts of metals from smelters. The fitted results give toxic potencies increasing in the order H + TOX to relate combined toxic effects of protons and metal cations towards lake crustacean zooplankton. • The fitted results give toxic potencies increasing in the order H + TOX model has been applied to field data for pelagic lake crustacean zooplankton. The fitted results give metal toxic potencies increasing in the order H + < Al < Cu < Zn < Ni

  16. Toxicity of high salinity tannery wastewater and effects on constructed wetland plants

    DEFF Research Database (Denmark)

    Calheirosa, C.S.C.; Silva, G.; Quitério, P.V.B.

    2012-01-01

    The toxicity of high salinity tannery wastewater produced after an activated sludge secondary treatment on the germination and seedling growth of Trifolium pratense, a species used as indicator in toxicity tests, was evaluated. Growth was inhibited by wastewater concentrations >25% and undiluted ...

  17. Children's Ability to Recognise Toxic and Non-Toxic Fruits

    Science.gov (United States)

    Fancovicova, Jana; Prokop, Pavol

    2011-01-01

    Children's ability to identify common plants is a necessary prerequisite for learning botany. However, recent work has shown that children lack positive attitudes toward plants and are unable to identify them. We examined children's (aged 10-17) ability to discriminate between common toxic and non-toxic plants and their mature fruits presented in…

  18. Microsomal biotransformation of chlorpyrifos, parathion and fenthion in rainbow trout (Oncorhynchus mykiss) and coho salmon (Oncorhynchus kisutch): mechanistic insights into interspecific differences in toxicity

    OpenAIRE

    Lavado, Ramon; Schlenk, Daniel

    2010-01-01

    Rainbow trout often serve as a surrogate species evaluating xenobiotic toxicity in cold-water species including other salmonids of the same genus, which are listed as threatened or endangered. Biotransformation tends to show species-specific patterns that influence susceptibility to xenobiotic toxicity, particularly organophoshpate insecticides (OPs). To evaluate the contribution of biotransformation in the mechanism of toxicity of three organophosphate (phosphorothionate) insecticides, chlor...

  19. Plant toxicity, adaptive herbivory, and plant community dynamics

    Science.gov (United States)

    Feng, Z.; Liu, R.; DeAngelis, D.L.; Bryant, J.P.; Kielland, K.; Stuart, Chapin F.; Swihart, R.K.

    2009-01-01

    We model effects of interspecific plant competition, herbivory, and a plant's toxic defenses against herbivores on vegetation dynamics. The model predicts that, when a generalist herbivore feeds in the absence of plant toxins, adaptive foraging generally increases the probability of coexistence of plant species populations, because the herbivore switches more of its effort to whichever plant species is more common and accessible. In contrast, toxin-determined selective herbivory can drive plant succession toward dominance by the more toxic species, as previously documented in boreal forests and prairies. When the toxin concentrations in different plant species are similar, but species have different toxins with nonadditive effects, herbivores tend to diversify foraging efforts to avoid high intakes of any one toxin. This diversification leads the herbivore to focus more feeding on the less common plant species. Thus, uncommon plants may experience depensatory mortality from herbivory, reducing local species diversity. The depensatory effect of herbivory may inhibit the invasion of other plant species that are more palatable or have different toxins. These predictions were tested and confirmed in the Alaskan boreal forest. ?? 2009 Springer Science+Business Media, LLC.

  20. Toxicological Response of Poecilia reticulata, Hyla species and ...

    African Journals Online (AJOL)

    PROF HORSFALL

    response of Poecilia reticulata, Hyla and Culex species was investigated using acute and chronic toxicity tests. ... responses over a 28 day period. .... sample. A control with only de-chlorinated tap water ..... landfills using luminescent bacteria.

  1. Toxic polyacetylenes in the genus Bupleurum (Apiaceae) - Distribution, toxicity, molecular mechanism and analysis.

    Science.gov (United States)

    Lin, Meiyu; Zhang, Weidong; Su, Juan

    2016-12-04

    The genus Bupleurum includes approximately 200 species that are widely distributed in the Northern Hemisphere, Eurasia and North Africa. Certain species of this genus have long been used as antiphlogistic, antipyretic and analgesic agents in traditional folk medicine. As described in the Chinese Pharmacopoeia, the roots of Bupleurum chinense DC. and B. scorzonerifolium Willd. are the herbal materials that compose Chaihu (Radix Bupleuri), a well-known TCM herb. This review aims to provide up-to-date and comprehensive information regarding the distribution, toxicity, molecular mechanism and relatively new methods for the qualitative and quantitative determination of polyacetylenes in different Bupleurum species. The information needed for this paper were sourced from publishing sites such as Elsevier, science Direct, PubMed; electronic search engines such as Scopus and Web of Science, Google scholar; other scientific database sites for chemicals such as ChemSpider, PubChem, SciFinder, and also from on line books. Polyacetylenes, which are widely distributed in genus Bupleurum of the Apiaceae family, have high toxicity. Among polyacetylenes, bupleurotoxin, acetylbupleurotoxin and oenanthotoxin have strong neurotoxicity. Through previous research, it was found that the toxicity of Bupleurum polyacetylenes manifested as epileptic seizures, with the target of toxicity being the brain. The neurotoxicity of polyacetylenes exhibits a relationship with the γ-aminobutyric acid (GABA) receptor pathway, and polyacetylenes have been shown to inhibit GABA-induced currents (I GABA ) in a competitive manner. The plants of genus Bupleurum have been used in traditional medicine for thousands of years. However, certain species of this genus are poisonous, and it was attributed to the high content of polyacetylenes. The present review indicates that certain polyacetylenes in the genus Bupleurum have highly neurotoxic effects. The major challenge with regard to toxic polyacetylenes is

  2. Acute toxicity of anionic and non-ionic surfactants to aquatic organisms.

    Science.gov (United States)

    Lechuga, M; Fernández-Serrano, M; Jurado, E; Núñez-Olea, J; Ríos, F

    2016-03-01

    The environmental risk of surfactants requires toxicity measurements. As different test organisms have different sensitivity to the toxics, it is necessary to establish the most appropriate organism to classify the surfactant as very toxic, toxic, harmful or safe, in order to establish the maximum permissible concentrations in aquatic ecosystems. We have determined the toxicity values of various anionic surfactants ether carboxylic derivatives using four test organisms: the freshwater crustacean Daphnia magna, the luminescent bacterium Vibrio fischeri, the microalgae Selenastrum capricornutum (freshwater algae) and Phaeodactylum tricornutum (seawater algae). In addition, in order to compare and classify the different families of surfactants, we have included a compilation of toxicity data of surfactants collected from literature. The results indicated that V. fischeri was more sensitive to the toxic effects of the surfactants than was D. magna or the microalgae, which was the least sensitive. This result shows that the most suitable toxicity assay for surfactants may be the one using V. fischeri. The toxicity data revealed considerable variation in toxicity responses with the structure of the surfactants regardless of the species tested. The toxicity data have been related to the structure of the surfactants, giving a mathematical relationship that helps to predict the toxic potential of a surfactant from its structure. Model-predicted toxicity agreed well with toxicity values reported in the literature for several surfactants previously studied. Predictive models of toxicity is a handy tool for providing a risk assessment that can be useful to establish the toxicity range for each surfactant and the different test organisms in order to select efficient surfactants with a lower impact on the aquatic environment. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Novel Molecular Strategies Against Sulfur Mustard Toxicity

    Directory of Open Access Journals (Sweden)

    Zeki Ilker Kunak

    2012-04-01

    Full Text Available Among the available chemical warfare agents, sulfur mustard (SM, also known as mustard gas, has been widely used chemical weapon. In our laboratory, we have shown that, acute toxicity of SM is related to reactive oxygen and nitrogen species, DNA damage, poly(ADP-ribose polymerase activation and energy depletion within the affected cell. In spite of the knowledge about acute SM-induced cellular toxicity, unfortunately, it is not clear how mustard gas causes severe multi-organ damage years after even a single exposure. A variety of treatment modalities including antioxidants, anti-inflammatory drugs and others have resulted no promising results. We, therefore, made an attempt whether epigenetic aberrations may contribute to pathogenesis of mustard poisoning. The term epigenetic describes the study of inheritable alterations in gene expression that occur in the absence of changes in genome sequence. Therefore, epigenetic gene regulation requires molecular mechanisms that encode information in addition to the DNA base sequence and can be propagated through mitosis and meiosis. Our current understanding of epigenetic regulation of gene expression involves basically two classes of molecular mechanisms: histone modifications and DNA methylation. Preliminary evidence obtained from our laboratory reveals that exposure to mustards may not only cause nitro-oxidative stress and DNA (genetic damage, but epigenetic perturbations as well. Epigenetic therapy is a new and rapidly developing field in pharmacology. Epigenetic drugs alone or in combination with conventional drugs may prove to be a significant advance over the conventional drugs used to treat both acute and delayed SM toxicity. Future studies are urgently needed to clarify the mechanism of delayed SM-induced toxicity and novel treatment modalities. [TAF Prev Med Bull 2012; 11(2.000: 231-236

  4. Air toxics emissions from an IGCC process

    Energy Technology Data Exchange (ETDEWEB)

    Mojtahedi, W.; Norrbacka, P. [Enviropower Inc., Espoo (Finland); Hinderson, A. [Vattenfall (Sweden); Rosenberg, R.; Zilliacus, R.; Kurkela, E.; Nieminen, M. [VTT Energy, Espoo (Finland); Hoffren, H. [IVO International Oy, Vantaa (Finland)

    1996-12-01

    The so-called simplified coal gasification combined cycle process, incorporating air gasification and hot gas cleanup, promises high power generation efficiency in an environmentally acceptable manner. Increasingly more stringent environmental regulations have focused attention on the emissions of not only SO{sub 2} and NO{sub x} but also on the so-called air toxics which include a number of toxic trace elements. As result of recent amendments to the United States Clean Air Act, IGCC emissions of eleven trace elements: antimony, arsenic, beryllium, cadmium, chromium, cobalt, lead, manganese, mercury, nickel, selenium - as well as the radionuclides uranium and thorium may be regulated. Similarly, air missions standards in Europe include a limit of 0.05 mg Nm{sup 3} for mercury and cadmium and 1.0 3/Nm{sup 3} for other class I trace elements. A suitable sampling/measuring system has been developed in this project (in cooperation with Imatran Voima Oy, Electric Power Research Institute (EPRI) and Radian Cooperation) which will be used in the pressurized gasification tests. This will enable an accurate measurement of the volatilized trace element species, at high temperature and pressure, which may be found in the vapour phase. Models are being developed that can be used to determine not only the chemical equilibrium composition of gaseous, liquid and solid phases, but also possible interactions of the gaseous species with aerosol particles and surfaces, These should be used to more accurately assess the impact of the toxic trace metals emitted from the simplified IGCC system

  5. Hydroxycut-induced Liver Toxicity

    African Journals Online (AJOL)

    hanumantp

    Annals of Medical and Health Sciences Research | Jan-Feb 2014 | Vol 4 ... supplements can be responsible for documented or undocumented adverse drug effects. The ... Keywords: Hydroxycut, Liver toxicity, Nutritional supplements ... Caffeine anhydrous: 200 mg* ... series and review of liver toxicity from herbal weight loss.

  6. One Health and Toxic Cyanobacteria

    Science.gov (United States)

    One Health and toxic cyanobacteria Blooms of toxic freshwater blue-green algae or cyanobacteria (HABs) have been in the news after HABs associated with human and animal health problems have been reported in Florida, California and Utah during 2016. HABs occur in warm, slow moving...

  7. Toxic Leadership in Educational Organizations

    Science.gov (United States)

    Green, James E.

    2014-01-01

    While research on the traits and skills of effective leaders is plentiful, only recently has the phenomenon of toxic leadership begun to be investigated. This research report focuses on toxic leadership in educational organizations--its prevalence, as well as the characteristics and early indicators. Using mixed methods, the study found four…

  8. Building a developmental toxicity ontology.

    Science.gov (United States)

    Baker, Nancy; Boobis, Alan; Burgoon, Lyle; Carney, Edward; Currie, Richard; Fritsche, Ellen; Knudsen, Thomas; Laffont, Madeleine; Piersma, Aldert H; Poole, Alan; Schneider, Steffen; Daston, George

    2018-04-03

    As more information is generated about modes of action for developmental toxicity and more data are generated using high-throughput and high-content technologies, it is becoming necessary to organize that information. This report discussed the need for a systematic representation of knowledge about developmental toxicity (i.e., an ontology) and proposes a method to build one based on knowledge of developmental biology and mode of action/ adverse outcome pathways in developmental toxicity. This report is the result of a consensus working group developing a plan to create an ontology for developmental toxicity that spans multiple levels of biological organization. This report provide a description of some of the challenges in building a developmental toxicity ontology and outlines a proposed methodology to meet those challenges. As the ontology is built on currently available web-based resources, a review of these resources is provided. Case studies on one of the most well-understood morphogens and developmental toxicants, retinoic acid, are presented as examples of how such an ontology might be developed. This report outlines an approach to construct a developmental toxicity ontology. Such an ontology will facilitate computer-based prediction of substances likely to induce human developmental toxicity. © 2018 Wiley Periodicals, Inc.

  9. Polish Toxic Currency Options

    Directory of Open Access Journals (Sweden)

    Waldemar Gontarski

    2009-06-01

    Full Text Available Toxic currency options are defined on the basis of the opposition to the nature (essence of an option contract, which is justified in terms of norms founded on the general law clause of characteristics (nature of a relation (which represents an independent premise for imposing restrictions on the freedom of contracts. So-understood toxic currency options are unlawful. Indeed they contravene iuris cogentis regulations. These include for instance option contracts, which are concluded with a bank, if the bank has not informed about option risk before concluding the contract; or the barrier options, which focus only on the protection of bank’s interests. Therefore, such options may appear to be invalid. Therefore, performing contracts for toxic currency options may be qualified as a criminal mismanagement. For the sake of security, the manager should then take into consideration filing a claim for stating invalidity (which can be made in a court verdict. At the same time, if the supervisory board member in a commercial company, who can also be a subject to mismanagement offences, commits an omission involving lack of reaction (for example, if he/she fails to notify of the suspected offence committed by the management board members acting to the company’s detriment when the management board makes the company conclude option contracts which are charged with absolute invalidity the supervisory board member so acting may be considered to act to the company’s detriment. In the most recent Polish jurisprudence and judicature the standard of a “good host” is treated to be the last resort for determining whether the manager’s powers resulting from criminal regulations were performed. The manager of the exporter should not, as a rule, issue any options. Issuing options always means assuming an obligation. In the case of currency put options it is an absolute obligation to purchase a given amount in euro at exchange rate set in advance. On the

  10. Control of toxic marine dinoflagellate blooms by serial parasitic killers.

    Science.gov (United States)

    Chambouvet, Aurelie; Morin, Pascal; Marie, Dominique; Guillou, Laure

    2008-11-21

    The marine dinoflagellates commonly responsible for toxic red tides are parasitized by other dinoflagellate species. Using culture-independent environmental ribosomal RNA sequences and fluorescence markers, we identified host-specific infections among several species. Each parasitoid produces 60 to 400 offspring, leading to extraordinarily rapid control of the host's population. During 3 consecutive years of observation in a natural estuary, all dinoflagellates observed were chronically infected, and a given host species was infected by a single genetically distinct parasite year after year. Our observations in natural ecosystems suggest that although bloom-forming dinoflagellates may escape control by grazing organisms, they eventually succumb to parasite attack.

  11. Toxicity of road salt to Nova Scotia amphibians.

    Science.gov (United States)

    Collins, Sara J; Russell, Ronald W

    2009-01-01

    The deposition of chemical pollutants into roadside wetlands from runoff is a current environmental concern. In northern latitudes, a major pollutant in runoff water is salt (NaCl), used as de-icing agents. In this study, 26 roadside ponds were surveyed for amphibian species richness and chloride concentration. Acute toxicity tests (LC(50)) were performed on five locally common amphibian species using a range of environmentally significant NaCl concentrations. Field surveys indicated that spotted salamanders (Ambystoma maculatum) and wood frogs (Rana sylvatica) did not occupy high chloride ponds. American toads (Bufo americanus) showed no pond preference based on chloride concentration. Acute toxicity tests showed spotted salamanders and wood frogs were most sensitive to chloride, and American toads were the least. Spring peepers (Pseudacris crucifer) and green frogs (Rana clamitans) showed intermediate sensitivities. We concluded that chloride concentrations in ponds due to application of de-icing salts, influenced community structure by excluding salt intolerant species.

  12. Toxic releases from power plants

    International Nuclear Information System (INIS)

    Rubin, E.S.

    1999-01-01

    Beginning in 1998, electric power plants burning coal or oil must estimate and report their annual releases of toxic chemicals listed in the Toxics Release Inventory (TRI) published by the US Environmental Protection Agency (EPA). This paper identifies the toxic chemicals of greatest significance for the electric utility sector and develops quantitative estimates of the toxic releases reportable to the TRI for a representative coal-fired power plant. Key factors affecting the magnitude and types of toxic releases for individual power plants also are discussed. A national projection suggests that the magnitude of electric utility industry releases will surpass those of the manufacturing industries which current report to the TRI. Risk communication activities at the community level will be essential to interpret and provide context for the new TRI results

  13. VARIATIONS IN REPRODUCTIVE TOXICANT IDENTIFICATION

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, F

    2008-05-13

    Reproductive toxicants are a very important class of compounds. They present unique hazards to those of child bearing ages, perform their 'dirty work' using a wide variety of mechanisms on a number of different organs, and are regulatorily important. Because of all of this, properly identifying reproductive toxicants is important, but fraught with difficulty. In this paper we will describe types or reproductive toxicants, their importance, and both mistakes and good practices that people who are not experts in reproductive toxicology may use in their attempts to identify them. Additionally, this paper will focus on chemical reproductive toxicants and will not address biological agents that could affect reproductive toxicity although many principles outlined here could be applied to that endeavor.

  14. Assessment of toxicity on chelating agent DTPA (diethylenetriaminepentaacetic acid)

    International Nuclear Information System (INIS)

    Fukuda, Satoshi

    1989-01-01

    DTPA (diethylenetriaminepentaacetic acid) is a very important chelating agent to decorporate the radionuclides such as plutonium and americium from human body. However, before DTPA will be administered to humans, the toxicity should be clarified. This report described the summary on data of DTPA toxicities obtained from animal experiments and assessment on the safety for humans, based on the results that compared their data among animal species. In short, Ca-DTPA is less toxic than Zn-DTPA when it is injected intravenously, while Zn-DTPA is less toxic than Ca-DTPA when it is administered orally. Both DTPAs acted on the serum calcium metabolism and induced the functional damages of cardiovascular system. Particularly, it is stressed that Zn-DTPA by intravenous injection occurred the heart failure, increases of blood pressure and pulse with hypocalcemia in even normal rats and beagle dogs. Other side effects by both DTPAs were also observed in the intestine, liver, kidney and bone. It is estimated that there are almost no species differences on DTPA toxicity between animals and humans. As a result, it is concluded that DTPA should be used very carefully for humans, with reference to the results obtained from animal experiments. (author) 61 refs

  15. Assessment of toxicity on chelating agent DTPA (diethylenetriaminepentaacetic acid)

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Satoshi (National Inst. of Radiological Sciences, Chiba (Japan))

    1989-09-01

    DTPA (diethylenetriaminepentaacetic acid) is a very important chelating agent to decorporate the radionuclides such as plutonium and americium from human body. However, before DTPA will be administered to humans, the toxicity should be clarified. This report described the summary on data of DTPA toxicities obtained from animal experiments and assessment on the safety for humans, based on the results that compared their data among animal species. In short, Ca-DTPA is less toxic than Zn-DTPA when it is injected intravenously, while Zn-DTPA is less toxic than Ca-DTPA when it is administered orally. Both DTPAs acted on the serum calcium metabolism and induced the functional damages of cardiovascular system. Particularly, it is stressed that Zn-DTPA by intravenous injection occurred the heart failure, increases of blood pressure and pulse with hypocalcemia in even normal rats and beagle dogs. Other side effects by both DTPAs were also observed in the intestine, liver, kidney and bone. It is estimated that there are almost no species differences on DTPA toxicity between animals and humans. As a result, it is concluded that DTPA should be used very carefully for humans, with reference to the results obtained from animal experiments. (author) 61 refs.

  16. Acute and chronic toxicity of boron to a variety of freshwater organisms.

    Science.gov (United States)

    Soucek, David J; Dickinson, Amy; Koch, Brian T

    2011-08-01

    Boron enters the aquatic environment from various sources, including weathering of borates, sewage effluents, coal combustion, use of cleaning compounds, and agrochemicals. The present study was designed to generate data on acute and chronic boron toxicity in support of an update of water quality standards in Illinois, USA. We examined the acute toxicity of boron to eight different freshwater organisms including a fish, an insect, two crustaceans, and four bivalve mollusks. To our knowledge, this is the first study to present data on the toxicity of boron to freshwater mollusks. We also sought to clarify whether hardness or pH affect boron toxicity to aquatic life, and to quantify chronic effect levels in two freshwater species. Sensitivity among the various species ranged widely, with the fathead minnow (Pimephales promelas) being the most sensitive. Neither pH nor hardness had a consistent effect on acute boron toxicity to two crustaceans (Ceriodaphnia dubia and Hyalella azteca), but we observed evidence that chloride reduces boron toxicity to H. azteca. The fathead minnow, while more acutely sensitive than the other species, had a lower acute to chronic ratio than did H. azteca, which had reduced reproduction at 13 mg/L. While we do not know the extent to which the eight tested species represent the range of sensitivities of native but untested species in Illinois, the current water quality standard for Illinois (1 mg/L) is conservative with regard to the native species tested thus far. Copyright © 2011 SETAC.

  17. Anaerobic biodegradability and toxicity of complex or toxicant wastewater

    International Nuclear Information System (INIS)

    Wills Betancur, B.A.

    1995-01-01

    As a first approximation to wastewater classification in susceptibility terms to treatment by anaerobic biological system, anaerobic biodegradability trials are accomplished to leached of sanitary landfill, to wastewater of coffee grain wet treatment plant and to wastewater of fumaric acid recuperation plant. In the last Plant, anaerobic toxicity trials and lethal toxicity on the Daphnia pulex micro-crustacean are made too. Anaerobic biological trials are made continuing the Wageningen University (Holland) Methodology (1.987). Lethal toxicity biological trials are made following the Standard Methods for the Examination of Water and Wastewater(18th edition, 1992). In development of this investigation project is found that fumaric acid recuperation plant leached it has a low anaerobic biodegradability, a high anaerobic toxicity and a high lethal toxicity over Daphnia pulex, for such reasons this leached is cataloged as complex and toxic wastewater. The other hand, wastewater of coffee grain wet treatment plant and wastewater of sanitary landfill they are both highly biodegradability and not-toxic, for such reasons these wastewaters are cataloged as susceptible to treatment by anaerobic biological system

  18. Long-term evaluation of lethal and sublethal toxicity of industrial effluents using Daphnia magna and Moina macrocopa.

    Science.gov (United States)

    Yi, Xianliang; Kang, Sung-Wook; Jung, Jinho

    2010-06-15

    Acute toxicity and feeding rate inhibition of effluent from a wastewater treatment plant and its adjacent stream water on Daphnia magna and Moina macrocopa were comparatively studied. The acute toxicity of the final effluent (FE) fluctuated greatly over the sampling period from January to August 2009. Toxicity identification results of the FE in July 2009 showed that Cu originating from the Fenton's reagent was likely a key toxicant. In addition, the feeding rate of both species was still inhibited by the FEs in which acute toxicity was not observed. These findings indicate that the feeding response would be a useful tool for monitoring sublethal effects of industrial effluents. For the acute toxicity test, M. macrocopa was more sensitive than D. magna, but the opposite result was true in the case of the feeding rate inhibition. These suggest that different species have different sensitivities to toxic chemicals and to the test methods. Copyright 2010 Elsevier B.V. All rights reserved.

  19. Time-resolved studies define the nature of toxic IAPP intermediates, providing insight for anti-amyloidosis therapeutics

    Science.gov (United States)

    Abedini, Andisheh; Plesner, Annette; Cao, Ping; Ridgway, Zachary; Zhang, Jinghua; Tu, Ling-Hsien; Middleton, Chris T; Chao, Brian; Sartori, Daniel J; Meng, Fanling; Wang, Hui; Wong, Amy G; Zanni, Martin T; Verchere, C Bruce; Raleigh, Daniel P; Schmidt, Ann Marie

    2016-01-01

    Islet amyloidosis by IAPP contributes to pancreatic β-cell death in diabetes, but the nature of toxic IAPP species remains elusive. Using concurrent time-resolved biophysical and biological measurements, we define the toxic species produced during IAPP amyloid formation and link their properties to induction of rat INS-1 β-cell and murine islet toxicity. These globally flexible, low order oligomers upregulate pro-inflammatory markers and induce reactive oxygen species. They do not bind 1-anilnonaphthalene-8-sulphonic acid and lack extensive β-sheet structure. Aromatic interactions modulate, but are not required for toxicity. Not all IAPP oligomers are toxic; toxicity depends on their partially structured conformational states. Some anti-amyloid agents paradoxically prolong cytotoxicity by prolonging the lifetime of the toxic species. The data highlight the distinguishing properties of toxic IAPP oligomers and the common features that they share with toxic species reported for other amyloidogenic polypeptides, providing information for rational drug design to treat IAPP induced β-cell death. DOI: http://dx.doi.org/10.7554/eLife.12977.001 PMID:27213520

  20. Toxic epidermal necrolysis.

    Science.gov (United States)

    Pereira, Frederick A; Mudgil, Adarsh Vijay; Rosmarin, David M

    2007-02-01

    Toxic epidermal necrolysis (TEN) is an unpredictable, life-threatening drug reaction associated with a 30% mortality. Massive keratinocyte apoptosis is the hallmark of TEN. Cytotoxic T lymphocytes appear to be the main effector cells and there is experimental evidence for involvement of both the Fas-Fas ligand and perforin/granzyme pathways. Optimal treatment for these patients remains to be clarified. Discontinuation of the offending drug and prompt referral to a burn unit are generally agreed upon steps. Beyond that, however, considerable controversy exists. Evidence both pro and con exists for the use of IVIG, systemic corticosteroid, and other measures. There is also evidence suggesting that combination therapies may be of value. All the clinical data, however, is anecdotal or based on observational or retrospective studies. Definitive answers are not yet available. Given the rarity of TEN and the large number of patients required for a study to be statistically meaningful, placebo controlled trials are logistically difficult to accomplish. The absence of an animal model further hampers research into this condition. This article reviews recent data concerning clinical presentation, pathogenesis and treatment of TEN. At the conclusion of this learning activity, participants should have acquired a more comprehensive knowledge of our current understanding of the classification, clinical presentation, etiology, pathophysiology, prognosis, and treatment of TEN.

  1. The toxicity of plutonium

    International Nuclear Information System (INIS)

    Ramsden, D.; Johns, T.F.

    1977-01-01

    Reference is made to recent publications concerned with the radiotoxicity of inhaled insoluble Pu compounds. The publications are a paper by Thorne and Vennart (Nature 263:555 (1976)), a report entitled 'The Toxicity of Plutonium', (London (HMSO), 1975), and the 'Sixth Report of the Royal Commission on Environmental Pollution', (Cmnd. 6618, London (HMSO), 1976). Thorne and Vennart concluded that the previously accepted value for the maximum permissible annual intake (MPAI) of such compounds may be too high by a factor of about five, and a similar conclusion was reached in the other two publications. It is thought by the present authors that the methods which have been used to suggest new values for the MPAI are unduly pessimistic for high-fired PuO 2 ; calculations have been based on the lung model of ICRP Publication 19 'The Metabolism of Compounds of Plutonium and the Other Actinides', (International Commission of Radiological Protection, 1972). This involves concluding that the risks to bone and liver are comparable to those for lung. This is discussed and it is thought that the previously established idea that the lung is the critical organ remains substantially correct for the case of high-fired PuO 2 . (U.K.)

  2. Oral toxicity study of certain plant extracts containing pyrrolizidine alkaloids.

    Science.gov (United States)

    Şeremet, Oana Cristina; Bărbuceanu, Florica; Ionică, Floriana Elvira; Margină, Denisa Marilena; GuŢu, Claudia Maria; Olaru, Octavian Tudorel; Ilie, Mihaela; Gonciar, Veaceslav; Negreş, Simona; ChiriŢă, Cornel

    2016-01-01

    Pyrrolizidine alkaloids (PAs) are a class of toxic compounds which are found in plants. Poisoning caused by these toxins is associated with acute and chronic liver damage. Tussilago farfara (coltsfoot), Petasites hybridus (common butterbur), Senecio vernalis (eastern groundsel) and Symphytum officinale (comfrey) are traditional phytotherapic species, which beside the therapeutic bioactive compounds contain PAs. The aim of the paper was to assess the safety of some dry extracts obtained from these species. For the determination of acute toxicity, Organization for Economic Cooperation and Development (OECD) Guideline No. 423 was used. For the determination of repeated dose oral toxicity, Senecionis vernalis herba and Symphyti radix extracts (250 mg÷kg) were administrated, by gavage, for 28 days, and their effects on animal weight, liver and biliary functions, hepatic tissue and oxidative stress were investigated. After the acute toxicity testing, the dry extracts were placed in the GHS Category V (LD50>5000 mg÷kg, p.o.). For the subacute toxicity testing, no death or any signs of toxicity were observed. Also, no significant differences in biochemical parameters were observed between control and treated groups. The observed histopathological lesions were non-specific and were not consistent with the data reported in the literature for PAs exposure. In conclusion, the administration for 28 days, of the tested extracts, in a dose which correspond to a PAs concentration over the limits imposed in some countries, produced no hepatic and biliary toxic effects. Further studies, extended over a longer period of time, are needed in order to determine the safety of plant extracts containing PAs.

  3. Evaluating the Zebrafish Embryo Toxicity Test for Pesticide ...

    Science.gov (United States)

    Given the numerous chemicals used in society, it is critical to develop tools for accurate and efficient evaluation of potential risks to human and ecological receptors. Fish embryo acute toxicity tests are 1 tool that has been shown to be highly predictive of standard, more resource-intensive, juvenile fish acute toxicity tests. However, there is also evidence that fish embryos are less sensitive than juvenile fish for certain types of chemicals, including neurotoxicants. The utility of fish embryos for pesticide hazard assessment was investigated by comparing published zebrafish embryo toxicity data from pesticides with median lethal concentration 50% (LC50) data for juveniles of 3 commonly tested fish species: rainbow trout, bluegill sunfish, and sheepshead minnow. A poor, albeit significant, relationship (r2 = 0.28; p embryo and juvenile fish toxicity when pesticides were considered as a single group, but a much better relationship (r2 = 0.64; p embryo toxicity test endpoints are particularly insensitive to neurotoxicants. These results indicate that it is still premature to replace juvenile fish toxicity tests with embryo-based tests such as the Organisation for Economic Co-op

  4. Toxicity of carbon nanotubes to freshwater aquatic invertebrates

    Science.gov (United States)

    Mwangi, Joseph N.; Wang, Ning; Ingersoll, Christopher G.; Hardesty, Doug K.; Brunson, Eric L.; Li, Hao; Deng, Baolin

    2012-01-01

    Carbon nanotubes (CNTs) are hydrophobic in nature and thus tend to accumulate in sediments if released into aquatic environments. As part of our overall effort to examine the toxicity of carbon-based nanomaterials to sediment-dwelling invertebrates, we have evaluated the toxicity of different types of CNTs in 14-d water-only exposures to an amphipod (Hyalella azteca), a midge (Chironomus dilutus), an oligochaete (Lumbriculus variegatus), and a mussel (Villosa iris) in advance of conducting whole-sediment toxicity tests with CNTs. The results of these toxicity tests conducted with CNTs added to water showed that 1.00g/L (dry wt) of commercial sources of CNTs significantly reduced the survival or growth of the invertebrates. Toxicity was influenced by the type and source of the CNTs, by whether the materials were precleaned by acid, by whether sonication was used to disperse the materials, and by species of the test organisms. Light and electron microscope imaging of the surviving test organisms showed the presence of CNTs in the gut as well as on the outer surface of the test organisms, although no evidence was observed to show penetration of CNTs through cell membranes. The present study demonstrated that both the metals solubilized from CNTs such as nickel and the "metal-free" CNTs contributed to the toxicity.

  5. Acute and subacute toxicity of Schinus terebinthifolius bark extract.

    Science.gov (United States)

    Lima, L B; Vasconcelos, C F B; Maranhão, H M L; Leite, V R; Ferreira, P A; Andrade, B A; Araújo, E L; Xavier, H S; Lafayette, S S L; Wanderley, A G

    2009-12-10

    Schinus terebinthifolius Raddi (Anacardiaceae) has long been used in traditional Brazilian medicine, especially to treat inflammatory and haemostatic diseases. The objective of this study was to evaluate the acute and subacute toxicity (45 days) of Schinus terebinthifolius via the oral route in Wistar rats of both sexes. For the acute toxicity test, the dried extract of Schinus terebinthifolius bark was administered in doses from 0.625 to 5.0 g/kg (n=5/group/sex) and in the subacute toxicity test the following doses were used: 0.25, 0.625 and 1.5625 g/kg/day (n=13/group/sex), for 45 consecutive days. In the acute toxicity test, Schinus terebinthifolius did not produce any toxic signs or deaths. The subacute treatment with Schinus terebinthifolius did not alter either the body weight gain or the food and water consumption. The hematological and biochemical analysis did not show significant differences in any of the parameters examined in female or male groups, except in two male groups, in which the treatment with Schinus terebinthifolius (0.25 and 0.625 g/kg) induced an increase of mean corpuscular volume values (2.9 and 2.6%, respectively). These variations are within the physiological limits described for the specie and does not have clinical relevance. The acute and subacute administration of the dried extract of Schinus terebinthifolius bark did not produced toxic effects in Wistar rats.

  6. Dietary compounds as modulators of metals and metalloids toxicity.

    Science.gov (United States)

    Jadán-Piedra, Carlos; Chiocchetti, Gabriela Matuoka; Clemente, María Jesús; Vélez, Dinoraz; Devesa, Vicenta

    2017-07-07

    A large part of the population is exposed to metals and metalloids through the diet. Most of the in vivo studies on its toxicokinetics and toxicity are conducted by means of exposure through drinking water or by intragastric or intraperitoneal administration of aqueous standards, and therefore they do not consider the effect of the food matrix on the exposure. Numerous studies show that some components of the diet can modulate the toxicity of these food contaminants, reducing their effect on a systemic level. Part of this protective role may be due to a reduction of intestinal absorption and subsequent tissue accumulation of the toxic element, although it may also be a consequence of their ability to counteract the toxicity directly by their antioxidant and/or anti-inflammatory activity, among other factors. The present review provides a compilation of existing information about the effect that certain components of the diet have on the toxicokinetics and toxicity of the metals and metalloids of greatest toxicological importance that are present in food (arsenic, cadmium, lead, and mercury), and of their most toxic chemical species.

  7. Toxicity of inhaled alpha-emitting radionuclides - Status report

    International Nuclear Information System (INIS)

    Muggenburg, B.A.; Mewhinney, J.A.; Guilmette, R.A.; Gillett, N.A.; Diel, J.H.; Lundgren, D.L.; Hahn, F.F.; Boecker, B.B.; McClellan, R.O.

    1988-01-01

    The toxicity of inhaled alpha-emitting radionuclides is being investigated in a series of interrelated dose-response studies. Dogs, rodents, and nonhuman primates have been exposed to monodisperse or polydisperse aerosols of the oxides of 239 Pu, 238 Pu, 241 Am, or 244 Cm to measure the relative importance of average organ dose, local dose around particles, specific activity, chemical form, particle size, and number of particles inhaled to the development of biological effects. The influence of animal species, age at exposure, and pre-existing lung disease, as well as the effects of repeated exposure, are also being studied, because they may influence the toxicity of these radionuclides. (author)

  8. TOXIC PYRROLIZIDINE ALKALOIDS OF ECHIUM AMOENUM FISCH. & MEY.

    Directory of Open Access Journals (Sweden)

    MITRA MEHRABANI

    2006-06-01

    Full Text Available Toxic pyrrolizidine alkaloids are present in some species of Echium (Boraginaceae. In this study petals of Echium amoenum Fisch. & Mey. (Gol-e-Gavzaban as a popular herbal medicine in Iran, were investigated for pyrrolizidine alkaloids (PAs. The alkaloids were separated and purified by preparative TLC and characterized by IR, one and two dimensional 1H and 13C-NMR and Mass spectroscopy. Four toxic alkaloids namely: echimidine I, echimidine isomer II, 7-angeloyl retronecine III and 7-tigloyl retronecine IV were identified.

  9. Toxicity ratios: Their use and abuse in predicting the risk from induced cancer

    International Nuclear Information System (INIS)

    Mays, C.W.; Taylor, G.N.; Lloyd, R.D.

    1986-01-01

    The toxicity ratio concept assumes the validity of certain relationships. In some examples for bone sarcoma induction, the approximate toxicity of 239 Pu in man can be calculated algebraically from the observed toxicity in the radium-dial painters and the ratio of 239 Pu/ 226 Ra toxicities in suitable laboratory mammals. In a species highly susceptible to bone sarcoma induction, the risk coefficients for both 239 Pu and 226 Ra are elevated, but the toxicity ratio of 239 Pu to 226 Ra tends to be similar to the ratio in resistant species. Among the tested species the toxicity ratio of 239 Pu to 226 Ra ranged from 6 to 22 (a fourfold range), whereas their relative sensitivities to 239 Pu varied by a factor of 150. The toxicity ratio approach can also be used to estimate the actinide risk to man from liver cancer, by comparing to the Thorotrast patients; from lung cancer, by comparing to the uranium miners and the atomic-bomb survivors; and from neutron-induced cancers, by comparing to cancers induced by gamma rays. The toxicity ratio can be used to predict the risk to man from a specific type of cancer that has been reliably induced by a reference radiation in humans and that can be induced by both the reference and the investigated radiation in suitable laboratory animals. 26 refs., 3 figs., 1 tab

  10. Comparative effects of fumonisins on sphingolipid metabolism and toxicity in ducks and turkeys.

    Science.gov (United States)

    Benlasher, Emad; Geng, Xiuyu; Nguyen, Ngoc Thanh Xuan; Tardieu, Didier; Bailly, Jean-Denis; Auvergne, Alain; Guerre, Philippe

    2012-03-01

    Fumonisins (FBs) are mycotoxins that are found worldwide in maize and maize products. Their main toxic effects have been well characterized in poultry, but differences between species have been demonstrated. Ducks appeared very sensitive to toxicity, whereas turkeys are more resistant. At the same time, alterations of sphingolipid metabolism, with an increase of the concentration of the free sphinganine (Sa) in serum and liver, have been demonstrated in the two species, but the link between the toxicity of FBs and Sa accumulation remains difficult to interpret. The aim of the present work was to compare the effects of FBs (10 mg FB1 + FB2/kg body weight) on sphingolipid metabolism in ducks and turkeys. Growth, feed consumption, and serum biochemistry were also investigated to evaluate toxicity. The main results showed that FBs increased Sa concentrations in liver and serum in ducks and turkeys, but these accumulations were not directly correlated with toxicity. Sa accumulation was higher in the livers of turkeys than in ducks, whereas Sa levels were higher in the sera of ducks than in turkeys. Hepatic toxicity was more pronounced in ducks than in turkeys and accompanied a decrease of body weight and an increase of serum biochemistry in ducks but not in turkeys. So, although FBs increase Sa concentration in the livers of both species, this effect is not directly proportional to toxicity. The mechanisms of FB toxicity and/or the mechanisms of protection of ducks and turkeys to the Sa accumulation within the liver remain to be established.

  11. Evaluation of genetic diversity between toxic and non toxic Jatropha ...

    African Journals Online (AJOL)

    Massimo

    Indian varieties and a non-toxic variety of Mexican origin by means of about 400 RAPD ... evaluate the level of polymorphism and the capacity to discriminate between the ..... Population genetic software for teaching and research. Mol. Ecol.

  12. Predictive value of species sensitivity distributions for effects of herbicides in freshwater ecosystems

    NARCIS (Netherlands)

    Brink, van den P.J.; Blake, N.; Brock, T.C.M.; Maltby, L.

    2006-01-01

    In this article we present a review of the laboratory and field toxicity of herbicides to aquatic ecosystems. Single-species acute toxicity data and ( micro) mesocosm data were collated for nine herbicides. These data were used to investigate the importance of test species selection in constructing

  13. Haloacetic acids in the aquatic environment. Part I: macrophyte toxicity

    International Nuclear Information System (INIS)

    Hanson, Mark L.; Solomon, Keith R.

    2004-01-01

    Haloacetic acids (HAAs) are contaminants of aquatic ecosystems with numerous sources, both anthropogenic and natural. The toxicity of HAAs to aquatic plants is generally uncharacterized. Laboratory tests were conducted with three macrophytes (Lemna gibba, Myriophyllum sibiricum and Myriophyllum spicatum) to assess the toxicity of five HAAs. Myriophyllum spp. has been proposed as required test species for pesticide registration in North America, but few studies have been conducted under standard test conditions. The HAAs in the present experiments were monochloroacetic acid (MCA), dichloroacetic acid (DCA), trichloroacetic acid (TCA), trifluoroacetic acid (TFA) and chlorodifluoroacetic acid (CDFA). MCA was the most toxic to Myriophyllum spp. with EC 50 values ranging from 8 to 12.4 mg/l depending on the endpoint, followed by DCA (EC 50 range 62-722.5 mg/l), TCA (EC 50 range 49.5-1702.6 mg/l), CDFA (EC 50 range 105.3 to >10,000 mg/l) and with TFA (EC 50 range 222.1 to 10,000 mg/l) the least toxic. Generally, L. gibba was less sensitive to HAA toxicity than Myriophyllum spp., with the difference in toxicity between them approximately threefold. The range of toxicity within Myriophyllum spp. was normally less than twofold. Statistically, plant length and node number were the most sensitive endpoints as they had the lowest observed coefficients of variation, but they were not the most sensitive to HAA toxicity. Toxicological sensitivity of endpoints varied depending on the measure of effect chosen and the HAA, with morphological endpoints usually an order of magnitude more sensitive than pigments for all plant species. Overall, mass and root measures tended to be the most sensitive indicators of HAA toxicity. The data from this paper were subsequently used in an ecological risk assessment for HAAs and aquatic plants. The assessment found HAAs to be of low risk to aquatic macrophytes and the results are described in the second manuscript of this series

  14. Toxicity of Uranium Adsorbent Materials using the Microtox Toxicity Test

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jiyeon [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jeters, Robert T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gill, Gary A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kuo, Li-Jung [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bonheyo, George T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-10-01

    The Marine Sciences Laboratory at the Pacific Northwest National Laboratory evaluated the toxicity of a diverse range of natural and synthetic materials used to extract uranium from seawater. The uranium adsorbent materials are being developed as part of the U. S. Department of Energy, Office of Nuclear Energy, Fuel Resources Program. The goal of this effort was to identify whether deployment of a farm of these materials into the marine environment would have any toxic effects on marine organisms.

  15. A COMPREHENSIVE REVIEW OF TOXIC LEADERSHIP

    Science.gov (United States)

    2016-02-05

    characteristics of a toxic leader , but labels the characteristics - leader types.  Deceptive  Autocratic  Egotistic  Incompetent  Ignorant...3 Characteristics of a Toxic Leader ...5 Table 2: Toxic Leader Characteristics

  16. National Air Toxic Assessments (NATA) Results

    Data.gov (United States)

    U.S. Environmental Protection Agency — 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...

  17. An Embryonic Field of Study: The Aquatic Fate and Toxicity of Diluted Bitumen.

    Science.gov (United States)

    Alsaadi, Ftoon; Hodson, Peter V; Langlois, Valerie S

    2018-01-01

    Canada has experienced a significant increase in the transport of diluted bitumen (dilbit), a predominant oil sands product that combines bitumen with diluents derived from oil-gas condensates and other proprietary compounds. The proportion of diluent and the chemical composition of dilbit vary to meet seasonal transport requirements. While the toxic effects of a variety of crude and refined oils are well-studied, the toxicity of dilbit to aquatic species is less well known. This focused review summarizes dilbit production, chemistry, and the few data on toxicity to aquatic species. These data suggest that un-weathered dilbit would cause effects on fish equivalent to those of conventional oils, but its toxicity may be lower, depending on interactions among test conditions, the behavior of dilbit added to water and the species tested.

  18. Acute toxicity of vanadium to the threespine stickleback, Gasterosteus aculeatus

    Energy Technology Data Exchange (ETDEWEB)

    Gravenmier, J.J.; Johnston, D.W.; Arnold, W.R. [Blasland Bouck & Lee Inc, Petaluma, CA (US)

    2005-02-15

    Vanadium is widely distributed, occurring in many types of minerals, coal, and petroleum. Anthropogenic sources of vanadium originate from the production, processing, and wastes of these materials. The aquatic toxicity of vanadium to fish species is not well characterized. This study focused on the three-spined stickleback, Gasterosteus aculeatus, a small and widely distributed euryhaline species of fish. The three-spined stickleback is used as an effluent-monitoring species in both Canada and the United States. Five 96-h static renewal acute toxicity tests were performed in moderately hard water with adult fish. The geometric mean and range of the five 96-h LC{sup 50}s based on measured concentrations of total vanadium in the test solution were 3.17 and 2.35-4.07 mg V/L, respectively. A conservative estimation of a safe concentration of vanadium that would not affect survival of adult three-spined sticklebacks over a 96-h exposure period in moderately hard water is approximately 0.30 mg V/L. A comparison with other fish species previously tested suggests that the three-spined stickleback is intermediate in sensitivity to vanadium. Information reported from this study may be useful in effluent toxicity identification evaluations and ecological risk assessments related to vanadium.

  19. Comparing rat and rabbit embryo-fetal developmental toxicity ...

    Science.gov (United States)

    A database of embryo-fetal developmental toxicity (EFDT) studies of 379 pharmaceutical compounds in rat and rabbit was analyzed for species differences based on toxicokinetic parameters of area under the curve (AUC) and maximum concentration (Cmax) at the developmental adverse effect level (dLOAEL). For the vast majority of cases (83% based on AUC of n=283), dLOAELs in rats and rabbits were within the same order of magnitude (less than 10-fold different) when compared based on available data on AUC and Cmax exposures. For 13.5% of the compounds the rabbit was more sensitive and for 3.5% of compounds the rat was more sensitive when compared based on AUC exposures. For 12% of the compounds the rabbit was more sensitive and for 1.3% of compounds the rat was more sensitive based on Cmax exposures. When evaluated based on human equivalent dose (HED) conversion using standard factors, the rat and rabbit were equally sensitive. The relative extent of embryo-fetal toxicity in the presence of maternal toxicity was not different between species. Overall effect severity incidences were distributed similarly in rat and rabbit studies. Individual rat and rabbit strains did not show a different general distribution of systemic exposure LOAELs as compared to all strains combined for each species. There were no apparent species differences in the occurrence of embryo-fetal variations. Based on power of detection and given differences in the nature of developmental effects betwe

  20. Evaluation of effects of long term exposure on lethal toxicity with mammals

    International Nuclear Information System (INIS)

    Verma, Vibha; Yu, Qiming J.; Connell, Des W.

    2014-01-01

    The relationship between exposure time (LT 50 ) and lethal exposure concentration (LC 50 ) has been evaluated over relatively long exposure times using a novel parameter, Normal Life Expectancy (NLT), as a long term toxicity point. The model equation, ln(LT 50 ) = aLC 50 ν + b, where a, b and ν are constants, was evaluated by plotting lnLT 50 against LC 50 using available toxicity data based on inhalation exposure from 7 species of mammals. With each specific toxicant a single consistent relationship was observed for all mammals with ν always <1. Use of NLT as a long term toxicity point provided a valuable limiting point for long exposure times. With organic compounds, the Kow can be used to calculate the model constants a and v where these are unknown. The model can be used to characterise toxicity to specific mammals and then be extended to estimate toxicity at any exposure time with other mammals. -- Highlights: • Model introduces a new parameter, normal life expectancy, to explain changes in toxicity with time. • Model is innovatory as it can be used to calculate toxicity at any, particularly long exposure times. • Toxicity is influenced by normal life expectancy of the organism particularly longer exposure times. • The model was applicable to all the mammals (7 species) evaluated. • The model can be used to predict toxicity at different exposure times with untested mammals species. -- The RLE model provides a mathematical description of the change in toxicity over time for a particular chemical. This represents a major advance on the use of Haber's Rule in toxicology

  1. Toxicity of heavy metals in the environment

    National Research Council Canada - National Science Library

    Oehme, F.W

    1978-01-01

    ... as the fundamental mechanisms of toxicity resulting from heavy metal chemicals. The more common toxic heavy metals, along with their biochemistry and associated clinical syndromes, are then described...

  2. 2011 NATA - Air Toxics Monitors

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset includes annual (2005 - 2013) statistics of measured ambient air toxics concentrations (in micrograms per cubic meter) and associated risk estimates for...

  3. Borocaptate sodium (BSH) toxicity issues

    International Nuclear Information System (INIS)

    LaHann, T.

    1995-01-01

    ISU's Center for Toxicology Research has been conducting toxicity testing of borocaptate sodium (BSH) to aid in assessing if proposed human studies of BSH are likely to be acceptably safe. This report describes BSH interactions with other biological agents

  4. Acute toxicity of ingested fluoride.

    Science.gov (United States)

    Whitford, Gary Milton

    2011-01-01

    This chapter discusses the characteristics and treatment of acute fluoride toxicity as well as the most common sources of overexposure, the doses that cause acute toxicity, and factors that can influence the clinical outcome. Cases of serious systemic toxicity and fatalities due to acute exposures are now rare, but overexposures causing toxic signs and symptoms are not. The clinical course of systemic toxicity from ingested fluoride begins with gastric signs and symptoms, and can develop with alarming rapidity. Treatment involves minimizing absorption by administering a solution containing calcium, monitoring and managing plasma calcium and potassium concentrations, acid-base status, and supporting vital functions. Approximately 30,000 calls to US poison control centers concerning acute exposures in children are made each year, most of which involve temporary gastrointestinal effects, but others require medical treatment. The most common sources of acute overexposures today are dental products - particularly dentifrices because of their relatively high fluoride concentrations, pleasant flavors, and their presence in non-secure locations in most homes. For example, ingestion of only 1.8 ounces of a standard fluoridated dentifrice (900-1,100 mg/kg) by a 10-kg child delivers enough fluoride to reach the 'probably toxic dose' (5 mg/kg body weight). Factors that may influence the clinical course of an overexposure include the chemical compound (e.g. NaF, MFP, etc.), the age and acid-base status of the individual, and the elapsed time between exposure and the initiation of treatment. While fluoride has well-established beneficial dental effects and cases of serious toxicity are now rare, the potential for toxicity requires that fluoride-containing materials be handled and stored with the respect they deserve. Copyright © 2011 S. Karger AG, Basel.

  5. The Toxicity of Depleted Uranium

    OpenAIRE

    Briner, Wayne

    2010-01-01

    Depleted uranium (DU) is an emerging environmental pollutant that is introduced into the environment primarily by military activity. While depleted uranium is less radioactive than natural uranium, it still retains all the chemical toxicity associated with the original element. In large doses the kidney is the target organ for the acute chemical toxicity of this metal, producing potentially lethal tubular necrosis. In contrast, chronic low dose exposure to depleted uranium may not produce a c...

  6. Evaluation of Daphnia ambigua for Routine Aquatic Toxicity Testing at the Savannah River Site

    International Nuclear Information System (INIS)

    Specht, W.L.; Harmon, S.M.

    1997-09-01

    Short-term whole effluent toxicity testing, which is currently a requirement of the U.S. EPA's National Pollution Discharge Elimination System (NPDES), commonly uses the cladoceran species Ceriodaphnia dubia. Despite the advantages to using a common test species to model the toxic effects of effluents, it could be argued that toxicity test results would be more meaningful if a wider variety of test organisms were commonly used. One particular argument against C. dubia is that tests conducted with this species do not always reflect local, site-specific conditions. The careful selection and use of an indigenous test species would produce a more realistic model of local instream effects and would account for regional differences in water quality. Permitted effluent discharges from Savannah River Site (SRS), a government weapons facility operated by the U.S. Department of Energy, require toxicity testing with C. dubia. However, water quality in these receiving streams is markedly different (lower pH and hardness) from standard laboratory water used for the culturing and testing of C. dubia, and it has been shown that this receiving water presents varying degrees of toxicity to C. dubia. Based on these results, it is possible that toxic effects observed during an effluent study could be the result of test organism stress from the dilution water and not the effects of SRS effluents. Therefore, this study addressed the substitution of C. dubia with an indigenous cladoceran species, Daphnia ambigua for routine regulatory testing at SRS. Given the indigenous nature of this species, combined with the fact that it has been successfully cultured by other investigators, D. ambigua was ideal for consideration as a replacement for C. dubia, but further study of the overall success and sensitivity of laboratory-reared D. ambigua was required. This investigation determined that D. ambigua could be laboratory cultured with only minimal changes to established regulatory protocol and

  7. Mollusc reproductive toxicity tests - Development and validation of test guidelines

    DEFF Research Database (Denmark)

    Ducrot, Virginie; Holbech, Henrik; Kinnberg, Karin Lund

    . Draft standard operating procedures (SOPs) have been designed based upon literature and expert knowledge from project partners. Pre-validation studies have been implemented to validate the proposed test conditions and identify issues in performing the SOPs and analyzing test results. Pre-validation work......The Organisation for Economic Cooperation and Development is promoting the development and validation of mollusc toxicity tests within its test guidelines programme, eventually aiming for the standardization of mollusc apical toxicity tests. Through collaborative work between academia, industry...... and stakeholders, this study aims to develop innovative partial life-cycle tests on the reproduction of the freshwater gastropods Potamopyrgus antipodarum and Lymnaea stagnalis, which are relevant candidate species for the standardization of mollusc apical toxicity tests assessing reprotoxic effects of chemicals...

  8. Endangered Species Day | Endangered Species Coalition

    Science.gov (United States)

    Annual Top 10 Report Protecting the Endangered Species Act Wildlife Voices Stand for Wolves Endangered Campaigns Wildlife Voices Protecting the Endangered Species Act Annual Top 10 Report Endangered Species Day Stand for Wolves Vanishing BOOK: A Wild Success The Endangered Species Act at 40 Endangered Species The

  9. Ciguatoxicity of Gambierdiscus and Fukuyoa species from the Caribbean and Gulf of Mexico.

    Directory of Open Access Journals (Sweden)

    R Wayne Litaker

    Full Text Available Dinoflagellate species belonging to the genera Gambierdiscus and Fukuyoa produce ciguatoxins (CTXs, potent neurotoxins that concentrate in fish causing ciguatera fish poisoning (CFP in humans. While the structures and toxicities of ciguatoxins isolated from fish in the Pacific and Caribbean are known, there are few data on the variation in toxicity between and among species of Gambierdiscus and Fukuyoa. Quantifying the differences in species-specific toxicity is especially important to developing an effective cell-based risk assessment strategy for CFP. This study analyzed the ciguatoxicity of 33 strains representing seven Gambierdiscus and one Fukuyoa species using a cell based Neuro-2a cytotoxicity assay. All strains were isolated from either the Caribbean or Gulf of Mexico. The average toxicity of each species was inversely proportional to growth rate, suggesting an evolutionary trade-off between an investment in growth versus the production of defensive compounds. While there is 2- to 27-fold variation in toxicity within species, there was a 1740-fold difference between the least and most toxic species. Consequently, production of CTX or CTX-like compounds is more dependent on the species present than on the random occurrence of high or low toxicity strains. Seven of the eight species tested (G. belizeanus, G. caribaeus, G. carolinianus, G. carpenteri, Gambierdiscus ribotype 2, G. silvae and F. ruetzleri exhibited low toxicities, ranging from 0 to 24.5 fg CTX3C equivalents cell-1, relative to G. excentricus, which had a toxicity of 469 fg CTX3C eq. cell-1. Isolates of G. excentricus from other regions have shown similarly high toxicities. If the hypothesis that G. excentricus is the primary source of ciguatoxins in the Atlantic is confirmed, it should be possible to identify areas where CFP risk is greatest by monitoring only G. excentricus abundance using species-specific molecular assays.

  10. Ciguatoxicity of Gambierdiscus and Fukuyoa species from the Caribbean and Gulf of Mexico

    Science.gov (United States)

    Holland, William C.; Hardison, D. Ransom; Pisapia, Francesco; Hess, Philipp; Kibler, Steven R.; Tester, Patricia A.

    2017-01-01

    Dinoflagellate species belonging to the genera Gambierdiscus and Fukuyoa produce ciguatoxins (CTXs), potent neurotoxins that concentrate in fish causing ciguatera fish poisoning (CFP) in humans. While the structures and toxicities of ciguatoxins isolated from fish in the Pacific and Caribbean are known, there are few data on the variation in toxicity between and among species of Gambierdiscus and Fukuyoa. Quantifying the differences in species-specific toxicity is especially important to developing an effective cell-based risk assessment strategy for CFP. This study analyzed the ciguatoxicity of 33 strains representing seven Gambierdiscus and one Fukuyoa species using a cell based Neuro-2a cytotoxicity assay. All strains were isolated from either the Caribbean or Gulf of Mexico. The average toxicity of each species was inversely proportional to growth rate, suggesting an evolutionary trade-off between an investment in growth versus the production of defensive compounds. While there is 2- to 27-fold variation in toxicity within species, there was a 1740-fold difference between the least and most toxic species. Consequently, production of CTX or CTX-like compounds is more dependent on the species present than on the random occurrence of high or low toxicity strains. Seven of the eight species tested (G. belizeanus, G. caribaeus, G. carolinianus, G. carpenteri, Gambierdiscus ribotype 2, G. silvae and F. ruetzleri) exhibited low toxicities, ranging from 0 to 24.5 fg CTX3C equivalents cell-1, relative to G. excentricus, which had a toxicity of 469 fg CTX3C eq. cell-1. Isolates of G. excentricus from other regions have shown similarly high toxicities. If the hypothesis that G. excentricus is the primary source of ciguatoxins in the Atlantic is confirmed, it should be possible to identify areas where CFP risk is greatest by monitoring only G. excentricus abundance using species-specific molecular assays. PMID:29045489

  11. Toxicity of zinc oxide nanoparticles to zebrafish embryo: a physicochemical study of toxicity mechanism

    International Nuclear Information System (INIS)

    Bai Wei; Zhang Zhiyong; Tian Wenjing; He Xiao; Ma Yuhui; Zhao Yuliang; Chai Zhifang

    2010-01-01

    The biological impact of engineered nanomaterials released into the aquatic environment is a major concern. In this work, the properties of ZnO nanoparticles (nano-ZnO, 30 nm) were characterized in a water suspension (E3 medium), and a zebrafish 96-h post fertilization (hpf) embryo-larval test was performed to assess the toxicity of nano-ZnO suspension. Nano-ZnO was found to readily form aggregates with different sizes; small aggregates (142.4-517.7 nm) were still suspended in E3 medium, but large aggregates (>1 μm) quickly deposited on the bottom of 24-well plates; nano-ZnO was partially dissolved to Zn species (Zn (dis) ) in E3 medium. In the nano-ZnO suspension, small aggregates, Zn (dis) , and large aggregates might jointly exert influence on the development of zebrafish embryos. The embryo toxicity test revealed that nano-ZnO killed zebrafish embryos (50 and 100 mg/L), retarded the embryo hatching (1-25 mg/L), reduced the body length of larvae, and caused tail malformation after the 96 hpf exposure. Zn (dis) only partially contributed to the toxicity of nano-ZnO. This research highlights the need to further investigate the ecotoxicity of nano-ZnO in the water environment.

  12. Radiation toxicity in dogs

    International Nuclear Information System (INIS)

    Fritz, T.E.; Lombard, L.S.; Poole, C.M.

    1981-01-01

    The overall goal of this project is measurement of the late effects of low doses of ionizing radiation in a large, relatively long-lived animal, the dog, to aid in assessing hazards and understanding mechanisms of radiaton damage in man. Young adult beagles are given whole-body exposures to protracted irradiation (22 hours/day, 7 days/week) from 60 Co gamma ray sources. They are exposed: (1) until they die; or (2) until they accumulate predetermined total doses of irradiation. The dogs are monitored regularly by clinical, hematological, and pathological examinations. End points determined are times to death (life shortening), causes of death, and characterization of all pathological processes. Monitoring of the hematopoietic system is emphasized because of the importance of myelogenous leukemia and related myeloproliferative disorders as shown by data in other experimental species and in man. Earlier exposures, given continuously until death or terminated at predetermined total ic fields associated with energy transmission. Proteins in human urine and selected tissues are examined by two-dimensional electrophoresis to detect disease and pollutant related changes. Assessment of human risk associated with nuclearing collective dose commitment will result in more attention being paid to potential releases of radionuclides at relatively short times after disposal

  13. 78 FR 37176 - Addition of Nonylphenol Category; Community Right-to-Know Toxic Chemical Release Reporting

    Science.gov (United States)

    2013-06-20

    ... species of marine animals; the blue mussel (Mytilus edulis), the three-spined stickleback fish...., A. Bergman, A. Granmo, and M. Berggren. 1990. Bioaccumulation of 4-nonylphenol in marine animals--A... previously peer reviewed (Ref. 3). A. Acute Toxicity to Aquatic Animals 1. Freshwater Species. The acute...

  14. Relative toxicity of oil dispersants to Mytilus viridis and Macrobrachium idella

    Digital Repository Service at National Institute of Oceanography (India)

    DeSilva, C.; Row, A.

    ) was almost identical for both the species tested, although there was a significant shift in the range of LC sub(50) values, indicating that one species is less sensitive than the other. Oil dispersant mixtures were less toxic than the dispersants alone...

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

    Science.gov (United States)

    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, ...

  16. Resveratrol prevents ammonia toxicity in astroglial cells.

    Directory of Open Access Journals (Sweden)

    Larissa Daniele Bobermin

    Full Text Available Ammonia is implicated as a neurotoxin in brain metabolic disorders associated with hyperammonemia. Acute ammonia toxicity can be mediated by an excitotoxic mechanism, oxidative stress and nitric oxide (NO production. Astrocytes interact with neurons, providing metabolic support and protecting against oxidative stress and excitotoxicity. Astrocytes also convert excess ammonia and glutamate into glutamine via glutamine synthetase (GS. Resveratrol, a polyphenol found in grapes and red wines, exhibits antioxidant and anti-inflammatory properties and modulates glial functions, such as glutamate metabolism. We investigated the effect of resveratrol on the production of reactive oxygen species (ROS, GS activity, S100B secretion, TNF-α, IL-1β and IL-6 levels in astroglial cells exposed to ammonia. Ammonia induced oxidative stress, decreased GS activity and increased cytokines release, probably by a mechanism dependent on protein kinase A (PKA and extracellular signal-regulated kinase (ERK pathways. Resveratrol prevented ammonia toxicity by modulating oxidative stress, glial and inflammatory responses. The ERK and nuclear factor-κB (NF-κB are involved in the protective effect of resveratrol on cytokines proinflammatory release. In contrast, other antioxidants (e.g., ascorbic acid and trolox were not effective against hyperammonemia. Thus, resveratrol could be used to protect against ammonia-induced neurotoxicity.

  17. Resveratrol Prevents Ammonia Toxicity in Astroglial Cells

    Science.gov (United States)

    Guerra, Maria Cristina; Leite, Marina Concli; Souza, Diogo Onofre; Gonçalves, Carlos-Alberto; Gottfried, Carmem

    2012-01-01

    Ammonia is implicated as a neurotoxin in brain metabolic disorders associated with hyperammonemia. Acute ammonia toxicity can be mediated by an excitotoxic mechanism, oxidative stress and nitric oxide (NO) production. Astrocytes interact with neurons, providing metabolic support and protecting against oxidative stress and excitotoxicity. Astrocytes also convert excess ammonia and glutamate into glutamine via glutamine synthetase (GS). Resveratrol, a polyphenol found in grapes and red wines, exhibits antioxidant and anti-inflammatory properties and modulates glial functions, such as glutamate metabolism. We investigated the effect of resveratrol on the production of reactive oxygen species (ROS), GS activity, S100B secretion, TNF-α, IL-1β and IL-6 levels in astroglial cells exposed to ammonia. Ammonia induced oxidative stress, decreased GS activity and increased cytokines release, probably by a mechanism dependent on protein kinase A (PKA) and extracellular signal-regulated kinase (ERK) pathways. Resveratrol prevented ammonia toxicity by modulating oxidative stress, glial and inflammatory responses. The ERK and nuclear factor-κB (NF-κB) are involved in the protective effect of resveratrol on cytokines proinflammatory release. In contrast, other antioxidants (e.g., ascorbic acid and trolox) were not effective against hyperammonemia. Thus, resveratrol could be used to protect against ammonia-induced neurotoxicity. PMID:23284918

  18. Dehydropyrrolizidine Alkaloid Toxicity, Cytotoxicity, and Carcinogenicity

    Directory of Open Access Journals (Sweden)

    Bryan L. Stegelmeier

    2016-11-01

    Full Text Available Dehydropyrrolizidine alkaloid (DHPA-producing plants have a worldwide distribution amongst flowering plants and commonly cause poisoning of livestock, wildlife, and humans. Previous work has produced considerable understanding of DHPA metabolism, toxicity, species susceptibility, conditions, and routes of exposure, and pathogenesis of acute poisoning. Intoxication is generally caused by contaminated grains, feed, flour, and breads that result in acute, high-dose, short-duration poisoning. Acute poisoning produces hepatic necrosis that is usually confirmed histologically, epidemiologically, and chemically. Less is known about chronic poisoning that may result when plant populations are sporadic, used as tisanes or herbal preparations, or when DHPAs contaminate milk, honey, pollen, or other animal-derived products. Such subclinical exposures may contribute to the development of chronic disease in humans or may be cumulative and probably slowly progress until liver failure. Recent work using rodent models suggest increased neoplastic incidence even with very low DHPA doses of short durations. These concerns have moved some governments to prohibit or limit human exposure to DHPAs. The purpose of this review is to summarize some recent DHPA research, including in vitro and in vivo DHPA toxicity and carcinogenicity reports, and the implications of these findings with respect to diagnosis and prognosis for human and animal health.

  19. Determination of leachate toxicity through acute toxicity using Daphnia pulex and anaerobic toxicity assays

    OpenAIRE

    Carabalí-Rivera, Y. S; Barba-Ho, L. E; Torres-Lozada, P

    2017-01-01

    ABSTRACT The municipal solid waste (MSW) of large cities, in particular the ones of developing countries, is mainly disposed in landfills (LFs), whose inadequate management generates the emission of greenhouse gases and the production of leachates with high concentrations of organic and inorganic matter and, occasionally heavy metals. In this study, the toxicity of the leachates from an intermediate-age municipal landfill was evaluated by ecotoxicity and anaerobic toxicity tests. The acute to...

  20. Toxic stress and child refugees.

    Science.gov (United States)

    Murray, John S

    2018-01-01

    The purpose of this article was to describe the phenomenon of toxic stress and its impact on the physical and mental health of child refugees. Almost two decades ago, researchers found that recurring adverse childhood events (ACEs; e.g., physical, psychological, and sexual abuse, neglect, and household dysfunction such as substance abuse, mental illness, and criminal behavior) were associated with a significant increase in serious illnesses during adulthood. Illnesses include heart, lung, and liver disease, cancer, and bone fractures. The scientists reported that experiencing four or more ACEs during childhood significantly increases the risk for toxic stress. Toxic stress is defined as the exposure to extreme, frequent, and persistent adverse events without the presence of a supportive caretaker. There is a paucity of literature related to toxic stress and child refugees. However, it has been clearly established that the prolonged brutal and traumatizing war in Syria is having a profound impact on the physical and mental health of child refugees at a distressing rate. Prevention of toxic stress should be a primary goal of all pediatric healthcare professionals working with child refugees. While this seems daunting given the population, and the seemingly insurmountable stressors they experience, some basic interventions should be considered. Providing basic anticipatory guidance to parents and caregivers of child refugees, to encourage positive parenting and strengthening support networks, will be highly effective in developing the requisite buffers that mitigate the effects of stress and avoid toxic stress. Efforts should also be focused on addressing caregiver stress and improving their ability to provide safe, reliable, and nurturing care that will help to mitigate any stress response experienced by a child. It is critical that greater awareness be placed on the effects of toxic stress on child refugees who are exposed to significant adverse events early in life

  1. Catecholate siderophores protect bacteria from pyochelin toxicity.

    Directory of Open Access Journals (Sweden)

    Conrado Adler

    Full Text Available Bacteria produce small molecule iron chelators, known as siderophores, to facilitate the acquisition of iron from the environment. The synthesis of more than one siderophore and the production of multiple siderophore uptake systems by a single bacterial species are common place. The selective advantages conferred by the multiplicity of siderophore synthesis remains poorly understood. However, there is growing evidence suggesting that siderophores may have other physiological roles besides their involvement in iron acquisition.Here we provide the first report that pyochelin displays antibiotic activity against some bacterial strains. Observation of differential sensitivity to pyochelin against a panel of bacteria provided the first indications that catecholate siderophores, produced by some bacteria, may have roles other than iron acquisition. A pattern emerged where only those strains able to make catecholate-type siderophores were resistant to pyochelin. We were able to associate pyochelin resistance to catecholate production by showing that pyochelin-resistant Escherichia coli became sensitive when biosynthesis of its catecholate siderophore enterobactin was impaired. As expected, supplementation with enterobactin conferred pyochelin resistance to the entE mutant. We observed that pyochelin-induced growth inhibition was independent of iron availability and was prevented by addition of the reducing agent ascorbic acid or by anaerobic incubation. Addition of pyochelin to E. coli increased the levels of reactive oxygen species (ROS while addition of ascorbic acid or enterobactin reduced them. In contrast, addition of the carboxylate-type siderophore, citrate, did not prevent pyochelin-induced ROS increases and their associated toxicity.We have shown that the catecholate siderophore enterobactin protects E. coli against the toxic effects of pyochelin by reducing ROS. Thus, it appears that catecholate siderophores can behave as protectors of

  2. Latitudinal patterns in plant defense: evolution of cardenolides, their toxicity and induction following herbivory.

    Science.gov (United States)

    Rasmann, Sergio; Agrawal, Anurag A

    2011-05-01

    Attempts over the past 50 years to explain variation in the abundance, distribution and diversity of plant secondary compounds gave rise to theories of plant defense. Remarkably, few phylogenetically robust tests of these long-standing theories have been conducted. Using >50 species of milkweed (Asclepias spp.), we show that variation among plant species in the induction of toxic cardenolides is explained by latitude, with higher inducibility evolving more frequently at lower latitudes. We also found that: (1) the production of cardenolides showed positive-correlated evolution with the diversity of cardenolides, (2) greater cardenolide investment by a species is accompanied by an increase in an estimate of toxicity (measured as chemical polarity) and (3) instead of trading off, constitutive and induced cardenolides were positively correlated. Analyses of root and shoot cardenolides showed concordant patterns. Thus, milkweed species from lower latitudes are better defended with higher inducibility, greater diversity and added toxicity of cardenolides. © 2011 Blackwell Publishing Ltd/CNRS.

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

    Science.gov (United States)

    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.

  4. Oxaliplatin-Related Ocular Toxicity

    Directory of Open Access Journals (Sweden)

    Marina Mesquida

    2010-11-01

    Full Text Available We report the case of a 52-year-old woman with advanced colorectal cancer who was treated with oxaliplatin on a FOLFOX schedule. After 3 cycles of chemotherapy, she started to complain of visual loss, altered color vision and neurological symptoms. Due to the suspicion of ocular and neurological toxicity, antineoplastic treatment was stopped. Her visual field showed a concentric bilateral scotoma and the electrooculogram test revealed severe impairment of the retinal pigment epithelium. Visual acuity, color vision and visual field recovered completely 8 months later, although electrooculogram remained abnormal. Ocular toxicity has been reported as an infrequent adverse event of oxaliplatin. Findings in this case indicate toxicity of this chemotherapeutic agent on the retinal pigment epithelium, which has not been reported before. This damage could be permanent, and it thus differs from previously described oxaliplatin-induced ocular toxicities, which are usually transient and reversible. With increasing use of oxaliplatin as first-line treatment in advanced colorectal cancer, we have to be aware of this possible toxicity.

  5. A comparison of sediment toxicity test methods at three Great Lake Areas of Concern

    Science.gov (United States)

    Burton, G. Allen; Ingersoll, Christopher G.; Burnett, LouAnn C.; Henry, Mary; Hinman, Mark L.; Klaine, Stephen J.; Landrum, Peter F.; Ross, Phillipe; Tuchman, Marc

    1996-01-01

    The significance of sediment contamination is often evaluated using sediment toxicity (bioassay) testing. There are relatively few “standardized” test methods for evaluating sediments. Popular sediment toxicity methods examine the extractable water (elutriate), interstitial water, or whole (bulk) sediment phases using test species spanning the aquatic food chain from bacteria to fish. The current study was designed to evaluate which toxicity tests were most useful in evaluations of sediment contamination at three Great Lake Areas of Concern. Responses of 24 different organisms including fish, mayflies, amphipods, midges, cladocerans, rotifers, macrophytes, algae, and bacteria were compared using whole sediment or elutriate toxicity assays. Sediments from several sites in the Buffalo River, Calumet River (Indiana Harbor), and Saginaw River were tested, as part of the U.S. Environmental Protection Agency's (USEPA) Assessment and Remediation of Contaminated Sediments (ARCS) Project. Results indicated several assays to be sensitive to sediment toxicity and able to discriminate between differing levels of toxicity. Many of the assay responses were significantly correlated to other toxicity responses and were similar based on factor analysis. For most applications, a test design consisting of two to three assays should adequately detect sediment toxicity, consisting of various groupings of the following species: Hyalella azteca, Ceriodaphnia dubia, Chironomus riparius, Chironomus tentans, Daphnia magna, Pimephales promelas, Hexagenia bilineata, Diporeia sp., Hydrilla verticillata, or Lemna minor.

  6. Identification of a Plant Phytosterol with Toxicity against Arthropod Pests

    Directory of Open Access Journals (Sweden)

    J.R.M. Thacker

    1999-06-01

    Full Text Available A crude plant extract that was toxic to spider mites in a leaf dip bioassay was subjected to detailed chemical analysis using chromatographic and spectroscopic techniques, The analyses revealed that the major active chemical was probably fl-sitosterol-3-glucostdc, a known phytosterol. The literature indicates that this chemical has been identified in a number of plant species and that it has been tested for utility in a number of medical therapies. It has not so far been assayed for the control of arthropod posts, the data indicate that this compound may be of use in the control of pest species, especially spider mites.

  7. Widespread genetic switches and toxicity resistance proteins for fluoride.

    Science.gov (United States)

    Baker, Jenny L; Sudarsan, Narasimhan; Weinberg, Zasha; Roth, Adam; Stockbridge, Randy B; Breaker, Ronald R

    2012-01-13

    Most riboswitches are metabolite-binding RNA structures located in bacterial messenger RNAs where they control gene expression. We have discovered a riboswitch class in many bacterial and archaeal species whose members are selectively triggered by fluoride but reject other small anions, including chloride. These fluoride riboswitches activate expression of genes that encode putative fluoride transporters, enzymes that are known to be inhibited by fluoride, and additional proteins of unknown function. Our findings indicate that most organisms are naturally exposed to toxic levels of fluoride and that many species use fluoride-sensing RNAs to control the expression of proteins that alleviate the deleterious effects of this anion.

  8. Development of a suitable test method for evaluating the toxicity of contaminated soils to earthworms in Canada

    Energy Technology Data Exchange (ETDEWEB)

    Stephenson, G.L. [Univ. of Guelph, Ontario (Canada); Scroggins, R. [Environment Canada, Gloucester, Ontario (Canada). Method Development and Application Section

    1995-12-31

    Environment Canada has embarked on a five year program to develop, standardize, and validate a battery of soil toxicity tests which can be used to assess the relative toxicity of contaminants in soils to terrestrial organisms. These tests must be applicable to soil conditions typically found in Canadian environments and the test species must be representative of the species of soil invertebrates or plants inhabiting soil ecosystems in Canada. One of the toxicity tests being developed is designed to assess the toxicity of contaminated soils to earthworms. Five of the potential test species belong to the Lumbricidae family and include the Canadian worm (Allobophora calignosa/Aporrectodea tuberculate), the European bark worm (Dendrodtilus rubidus (rubida)), the pink soil worm (Eisenia rosea), the red marsh worm (Lumbricus rubellus), and the Canadian night crawler or dew worm (Lumbricus terrestris). The sixth species, the white pot worm (Enchytraeus albidus), belongs to the Enchytraeidae family. Further assessment reduced the number of representative species to three. Most earthworm test methods have been developed to assess the toxicity of chemically-spiked artificial soils to Eisenia fetida or E. andrei. Test methods have also been developed to assess the relative toxicity of contaminated soils from hazardous waste sites. Comparative acute toxicity data for three species of earthworm exposed to a hydrocarbon contamination will be presented. Comparative toxicity data for the same three species of earthworm will also be presented using test procedures and conditions that have been modified to accommodate biological differences among the species of earthworm. Recommendations regarding test design, methods, and conditions optimal for each test species will be summarized and discussed with respect to the precision of test results.

  9. Toxicity of road salt to Nova Scotia amphibians

    International Nuclear Information System (INIS)

    Collins, Sara J.; Russell, Ronald W.

    2009-01-01

    The deposition of chemical pollutants into roadside wetlands from runoff is a current environmental concern. In northern latitudes, a major pollutant in runoff water is salt (NaCl), used as de-icing agents. In this study, 26 roadside ponds were surveyed for amphibian species richness and chloride concentration. Acute toxicity tests (LC 50 ) were performed on five locally common amphibian species using a range of environmentally significant NaCl concentrations. Field surveys indicated that spotted salamanders (Ambystoma maculatum) and wood frogs (Rana sylvatica) did not occupy high chloride ponds. American toads (Bufo americanus) showed no pond preference based on chloride concentration. Acute toxicity tests showed spotted salamanders and wood frogs were most sensitive to chloride, and American toads were the least. Spring peepers (Pseudacris crucifer) and green frogs (Rana clamitans) showed intermediate sensitivities. We concluded that chloride concentrations in ponds due to application of de-icing salts, influenced community structure by excluding salt intolerant species. - Salt toxicity is presented as a mechanism affecting the distribution of amphibians and structure of amphibian communities in roadside wetlands

  10. Gulf of Mexico mud toxicity limitations

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, H.E.; Beardmore, D.H. (Phillips Petroleum Co., Bartlesville, OK (USA)); Stewart, W.S. (Drilling Specialties Co. (US))

    1989-10-01

    Because of the Environmental Protection Agency's recent toxicity limits on drilling mud discharges for offshore Gulf of Mexico, Phillips Petroleum conducted a mud toxicity study based on both field and lab tests. The study, discussed in this article, found the polyanionic cellulose-sulfomethylated quebracho-chrome lignosulfonate mud Phillips had been using would comfortably pass the toxicity limitations. The study also found barite and thinners were of low toxicity, and hydrocarbons and surfactants were highly toxic.

  11. Wild lettuce (Lactuca virosa) toxicity.

    Science.gov (United States)

    Besharat, Sima; Besharat, Mahsa; Jabbari, Ali

    2009-01-01

    Wild lettuce (Lactuca virosa) can cause toxic effects when eaten. Wild lettuce grows in the north of Iran and some natives consume it unaware of its adverse side effects. We describe eight patients with manifestations of wild lettuce toxicity, admitted to a general hospital affiliated to the Golestan University of Medical Sciences. All the patients recovered (although one had to spend 48 h in the intensive care unit) and no chronic complications were reported. A clinical suspicion of toxicity caused by wild lettuce intake and an accurate history formed the basis of the diagnosis. Conservative treatment, vital sign monitoring, control of patient intake and output, and reducing patient agitation provided the basis for treatment.

  12. Methoxsalen-induced macular toxicity

    Directory of Open Access Journals (Sweden)

    Aditya Maitray

    2017-01-01

    Full Text Available Psoralen compounds such as methoxsalen are photosensitizer agents used in conjunction with ultraviolet A (UVA radiation exposure as photochemotherapy (Psoralens and ultraviolet-A therapy [PUVA therapy] for certain epidermal skin disorders such as psoriasis and vitiligo. Methoxsalen has been shown to be associated with premature cataract formation by forming adducts with lens proteins following oral administration and subsequent UVA exposure. Hence, the use of UV-filtering glasses is recommended during PUVA therapy sessions. Ocular tissues can be exposed to its photosensitizing effect with subsequent UV radiation exposure through sunlight if the patient was to be without protective eye glasses, potentially causing macular toxicity. Till date, there have been no reports in the literature of any posterior segment ocular toxicity arising from methoxsalen use. Here, we describe a case of a bilateral macular toxicity in a middle-aged male treated with methoxsalen for vitiligo.

  13. Aluminium Toxicity Targets in Plants

    Directory of Open Access Journals (Sweden)

    Sónia Silva

    2012-01-01

    Full Text Available Aluminium (Al is the third most abundant metallic element in soil but becomes available to plants only when the soil pH drops below 5.5. At those conditions, plants present several signals of Al toxicity. As reported by literature, major consequences of Al exposure are the decrease of plant production and the inhibition of root growth. The root growth inhibition may be directly/indirectly responsible for the loss of plant production. In this paper the most remarkable symptoms of Al toxicity in plants and the latest findings in this area are addressed. Root growth inhibition, ROS production, alterations on root cell wall and plasma membrane, nutrient unbalances, callose accumulation, and disturbance of cytoplasmic Ca2+ homeostasis, among other signals of Al toxicity are discussed, and, when possible, the behavior of Al-tolerant versus Al-sensitive genotypes under Al is compared.

  14. Methylmercury toxicity and functional programming.

    Science.gov (United States)

    Grandjean, Philippe

    2007-01-01

    Adverse health effects of developmental toxicants may induce abnormal functional programming that leads to lasting functional deficits. This notion is considered from epidemiological evidence using developmental methylmercury neurotoxicity as an example. Accumulating evidence indicates that adverse effects may occur even at low-level methylmercury exposures from seafood and freshwater fish. Neurobehavioral outcomes are usually non-specific, and imprecise exposure assessment results in a bias toward the null. Essential nutrients may promote the development of certain brain functions, thereby causing confounding bias. The functional deficits caused by prenatal methylmercury exposure appear to be permanent, and their extent may depend on the joint effect of toxicants and nutrients. The lasting functional changes caused by neurodevelopmental methylmercury toxicity fit into the pattern of functional programming, with effects opposite to those linked to beneficial stimuli.

  15. The distribution of fruit and seed toxicity during development for eleven neotropical trees and vines in Central Panama.

    Science.gov (United States)

    Beckman, Noelle G

    2013-01-01

    Secondary compounds in fruit mediate interactions with natural enemies and seed dispersers, influencing plant survival and species distributions. The functions of secondary metabolites in plant defenses have been well-studied in green tissues, but not in reproductive structures of plants. In this study, the distribution of toxicity within plants was quantified and its influence on seed survival was determined in Central Panama. To investigate patterns of allocation to chemical defenses and shifts in allocation with fruit development, I quantified variation in toxicity between immature and mature fruit and between the seed and pericarp for eleven species. Toxicity of seed and pericarp was compared to leaf toxicity for five species. Toxicity was measured as reduced hyphal growth of two fungal pathogens, Phoma sp. and Fusarium sp., and reduced survivorship of brine shrimp, Artemia franciscana, across a range of concentrations of crude extract. I used these measures of potential toxicity against generalist natural enemies to examine the effect of fruit toxicity on reductions of fruit development and seed survival by vertebrates, invertebrates, and pathogens measured for seven species in a natural enemy removal experiment. The seed or pericarp of all vertebrate- and wind-dispersed species reduced Artemia survivorship and hyphal growth of Fusarium during the immature and mature stages. Only mature fruit of two vertebrate-dispersed species reduced hyphal growth of Phoma. Predispersal seed survival increased with toxicity of immature fruit to Artemia during germination and decreased with toxicity to fungi during fruit development. This study suggests that fruit toxicity against generalist natural enemies may be common in Central Panama. These results support the hypothesis that secondary metabolites in fruit have adaptive value and are important in the evolution of fruit-frugivore interactions.

  16. The distribution of fruit and seed toxicity during development for eleven neotropical trees and vines in Central Panama.

    Directory of Open Access Journals (Sweden)

    Noelle G Beckman

    Full Text Available Secondary compounds in fruit mediate interactions with natural enemies and seed dispersers, influencing plant survival and species distributions. The functions of secondary metabolites in plant defenses have been well-studied in green tissues, but not in reproductive structures of plants. In this study, the distribution of toxicity within plants was quantified and its influence on seed survival was determined in Central Panama. To investigate patterns of allocation to chemical defenses and shifts in allocation with fruit development, I quantified variation in toxicity between immature and mature fruit and between the seed and pericarp for eleven species. Toxicity of seed and pericarp was compared to leaf toxicity for five species. Toxicity was measured as reduced hyphal growth of two fungal pathogens, Phoma sp. and Fusarium sp., and reduced survivorship of brine shrimp, Artemia franciscana, across a range of concentrations of crude extract. I used these measures of potential toxicity against generalist natural enemies to examine the effect of fruit toxicity on reductions of fruit development and seed survival by vertebrates, invertebrates, and pathogens measured for seven species in a natural enemy removal experiment. The seed or pericarp of all vertebrate- and wind-dispersed species reduced Artemia survivorship and hyphal growth of Fusarium during the immature and mature stages. Only mature fruit of two vertebrate-dispersed species reduced hyphal growth of Phoma. Predispersal seed survival increased with toxicity of immature fruit to Artemia during germination and decreased with toxicity to fungi during fruit development. This study suggests that fruit toxicity against generalist natural enemies may be common in Central Panama. These results support the hypothesis that secondary metabolites in fruit have adaptive value and are important in the evolution of fruit-frugivore interactions.

  17. Evaluating the toxicity of selected types of nanochemicals.

    Science.gov (United States)

    Kumar, Vineet; Kumari, Avnesh; Guleria, Praveen; Yadav, Sudesh Kumar

    2012-01-01

    . NPs have produced an array of different toxic effects in many different types of in vivo and in vitro studies. The types of effects that NPs have produced are those on the pulmonary, cardiac, reproductive, renal and cutaneous systems, as well as on various cell lines. After exposures, significant accumulations of NPs have been found in the lungs, brain, liver, spleen, and bones of test species. It has been well established that the degree of toxicity produced by NPs is linked to their surface properties. Soluble NPs are rendered toxic because of their constituents; however, the situation is entirely different for insoluble NPs. Stable metal oxides do not show any toxicity, whereas metallic NPs that have redox potential may be cytotoxic and genotoxic. The available data on NP toxicity is unfortunately limited, and hence, does not allow scientists to yet make a significant quantitative risk assessment of the safety of synthesized NPs. In this review, we have endeavored to illustrate the importance of having and using results from existing nanotoxicological studies and for developing new and more useful future risk assessment systems. Increased efforts of both an individual and collective nature are required to explore the future pros and cons of nanotechnology.

  18. Toxicity of sediment-associated pesticides to Chironomus dilutus and Hyalella azteca.

    Science.gov (United States)

    Ding, Yuping; Weston, Donald P; You, Jing; Rothert, Amanda K; Lydy, Michael J

    2011-07-01

    Two hundred sediment samples were collected and their toxicity evaluated to aquatic species in a previous study in the agriculturally dominated Central Valley of California, United States. Pyrethroid insecticides were the main contributors to the observed toxicity. However, mortality in approximately one third of the toxic samples could not be explained solely by the presence of pyrethroids in the matrices. Hundreds of pesticides are currently used in the Central Valley of California, but only a few dozen are analyzed in standard environmental monitoring. A significant amount of unexplained sediment toxicity may be due to pesticides that are in widespread use that but have not been routinely monitored in the environment, and even if some of them were, the concentrations harmful to aquatic organisms are unknown. In this study, toxicity thresholds for nine sediment-associated pesticides including abamectin, diazinon, dicofol, fenpropathrin, indoxacarb, methyl parathion, oxyfluorfen, propargite, and pyraclostrobin were established for two aquatic species, the midge Chironomus dilutus and the amphipod Hyalella azteca. For midges, the median lethal concentration (LC₅₀) of the pesticides ranged from 0.18 to 964 μg/g organic carbon (OC), with abamectin being the most toxic and propargite being the least toxic pesticide. A sublethal growth endpoint using average individual ash-free dry mass was also measured for the midges. The no-observable effect concentration values for growth ranged from 0.10 to 633 μg/g OC for the nine pesticides. For the amphipods, fenpropathrin was the most toxic, with an LC₅₀ of 1-2 μg/g OC. Abamectin, diazinon, and methyl parathion were all moderately toxic (LC₅₀s 2.8-26 μg/g OC). Dicofol, indoxacarb, oxyfluorfen, propargite, and pyraclostrobin were all relatively nontoxic, with LC₅₀s greater than the highest concentrations tested. The toxicity information collected in the present study will be helpful in decreasing the

  19. DOPA Decarboxylase Modulates Tau Toxicity.

    Science.gov (United States)

    Kow, Rebecca L; Sikkema, Carl; Wheeler, Jeanna M; Wilkinson, Charles W; Kraemer, Brian C

    2018-03-01

    The microtubule-associated protein tau accumulates into toxic aggregates in multiple neurodegenerative diseases. We found previously that loss of D 2 -family dopamine receptors ameliorated tauopathy in multiple models including a Caenorhabditis elegans model of tauopathy. To better understand how loss of D 2 -family dopamine receptors can ameliorate tau toxicity, we screened a collection of C. elegans mutations in dopamine-related genes (n = 45) for changes in tau transgene-induced behavioral defects. These included many genes responsible for dopamine synthesis, metabolism, and signaling downstream of the D 2 receptors. We identified one dopamine synthesis gene, DOPA decarboxylase (DDC), as a suppressor of tau toxicity in tau transgenic worms. Loss of the C. elegans DDC gene, bas-1, ameliorated the behavioral deficits of tau transgenic worms, reduced phosphorylated and detergent-insoluble tau accumulation, and reduced tau-mediated neuron loss. Loss of function in other genes in the dopamine and serotonin synthesis pathways did not alter tau-induced toxicity; however, their function is required for the suppression of tau toxicity by bas-1. Additional loss of D 2 -family dopamine receptors did not synergize with bas-1 suppression of tauopathy phenotypes. Loss of the DDC bas-1 reduced tau-induced toxicity in a C. elegans model of tauopathy, while loss of no other dopamine or serotonin synthesis genes tested had this effect. Because loss of activity upstream of DDC could reduce suppression of tau by DDC, this suggests the possibility that loss of DDC suppresses tau via the combined accumulation of dopamine precursor levodopa and serotonin precursor 5-hydroxytryptophan. Published by Elsevier Inc.

  20. Toxic clinical hypoxic radiation sensitizers plus radiation-induced toxicity

    International Nuclear Information System (INIS)

    Richmond, R.C.

    1984-01-01

    The operational definition espoused twelve years ago that clinical hypoxic radiation sensitizers should be nontoxic interferes with the recognition and research of useful radiation sensitizers. Eight years ago the toxic antitumor drug cis-dichlorodiammineplatinum(II) was reported to be a hypoxic radiation sensitizer and the selective antitumor action of this drug was stressed as potentially creating tumor-targeted radiation sensitization. This rationale of oxidative antitumor drugs as toxic and targeted clinical sensitizers is useful, and has led to the study reported here. The antitumor drug cis-(1,1-cyclobutane-dicarboxylato)diammineplatinum(II), or JM-8, is being tested in clinical trials. Cells of S. typhimurium in PBS in the presence of 0.2mM JM-8 are found to be sensitized to irradiation under hypoxic, but not oxic, conditions. JM-8 is nontoxic to bacteria at this concentration, but upon irradiation the JM-8 solution becomes highly toxic. This radiation induced toxicity of JM-8 preferentially develops from hypoxic solution, and thus contributes to the rationale of hypoxic tumor cell destruction

  1. CADDIS Volume 2. Sources, Stressors and Responses: Unspecified Toxic Chemicals

    Science.gov (United States)

    Intro to the unspecified toxic chemicals module, when to list toxic chemicals as a candidate cause, ways to measure toxic chemicals, simple and detailed conceptual diagrams for toxic chemicals, toxic chemicals module references and literature reviews.

  2. Toxicities of sediments below 10 effluent outfalls to near-coastal areas of the Gulf of Mexico

    International Nuclear Information System (INIS)

    Lewis, M.; Weber, D.; Stanley, R.

    1995-01-01

    The chemical quality and toxicities of sediments collected in the receiving waters below 10 wastewater outfalls to Northwest Florida coastal areas were evaluated at multiple stations during 1994--1996. Eight types of toxicity tests using 11 test species were used to assess acute and chronic toxicity of the sediments collected below industrial, municipal, power generation and pulp mill outfalls. The primary objectives of the study were to evaluate the relative ability of different assessment procedures to detect toxicity and to provide some much-needed perspective on the impact of major point sources on sediment quality in Gulf of Mexico estuaries. The major chemical contaminants were heavy metals and PAHs. Acute and chronic toxicities were noted. Results of tests with sediment collected at the same location but several months later often differed. The most sensitive species were mysids and an estuarine amphipod. The least sensitive species were fish and macrophyte seedlings. There was poor correlation of effluent toxicity to sediment toxicity in the receiving water. Toxicity of the effluents was greater than that of the sediments. Overall, the unavailability of relevant chronic toxicity methods, uncertain criteria for choice of control stations, lack of guidance on frequency of testing and the dynamic physical and chemical characteristics of sediments are factors that need consideration if sediment monitoring is to be part of the NPDES regulatory process

  3. Toxic Marine Puffer Fish in Thailand Seas and Tetrodotoxin They Contained

    Directory of Open Access Journals (Sweden)

    Hisao Kurazono

    2011-10-01

    Full Text Available A total of 155 puffers caught from two of Thailand’s seas, the Gulf of Siam and the Andaman seas, during April to July 2010 were included in this study. Among 125 puffers from the Gulf of Siam, 18 were Lagocephalus lunaris and 107 were L. spadiceus which were the same two species found previously in 2000–2001. Thirty puffers were collected from the Andaman seas, 28 Tetraodon nigroviridis and two juvenile Arothron reticularis; the two new species totally replaced the nine species found previously in 1992–1993. Conventional mouse bioassay was used to determine the toxicity in all fish tissue extracts, i.e., liver, reproductive tissue, digestive tissue and muscle. One of each of the species L. lunaris and L. spadiceus (5.56 and 0.93%, respectively were toxic. All 28 T. nigroviridis and 2 A. reticularis (100% from the Andaman seas were toxic. The toxicity scores in T. nigroviridis tissues were much higher than in the respective tissues of the other three fish species. Liquid chromatography/tandem mass spectrometry (LC-MS/MS revealed that the main toxic principle was tetrodotoxin (TTX. This study is the first to report TTX in L. spadiceus. Our findings raised a concern for people, not only Thais but also inhabitants of other countries situated on the Andaman coast; consuming puffers of the Andaman seas is risky due to potential TTX intoxication.

  4. The insects as an assessment tool of ecotoxicology associated with metal toxic plants.

    Science.gov (United States)

    Azmat, Rafia; Moin, Sumeira; Saleem, Ailyan

    2018-04-01

    In this article, the assessment of lethal effects of Copper (Cu) on Luffa acutangula and Spinacia oleracea plants investigated in relation to the presence of insect species Oxycarenus hyalinipennis. The analysis of Cu-treated plants displays the information of rapid growth of Oxycarenus hyalinipennis species in triplicate. However, results showed that the impact of metal toxicity appeared as the reduced growth rate of plants, and dense growth of the insect species Oxycarenus halinipennis followed by the chewing/degradation of the toxic plant. The insect's inductees into polluted plants were justified by morphological and primary molecular level using plant stress hypothesis through analysis of the primary chemistry of leaves and roots. That includes various sugar contents which substantiated that these compounds act as the best feeding stimulant from oviposition to adult stage of the insects and accountable for the enactment of insects in the toxic plants. The relationship of these insects to the toxic plants linked with the higher contents of glucose, carbohydrates, and cellulose. The higher carbohydrate and cellulose content in both plants species under Cu accumulation exhibited more signs of insect mutilation over control plants and the lack of chemical resistances allowed the adult insects to spread, survive, reproduce and live long. The presence of insects developed relationships that assimilate all developmental, biological, and the interactive toxicity of Cu in both plant species which indicate the risk associated with these plants. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. A Framework for Spatial Risk Assessments: Potential Impacts of Nonindigenous Invasive Species on Native Species

    Directory of Open Access Journals (Sweden)

    Craig R. Allen

    2006-06-01

    Full Text Available Many populations of wild animals and plants are declining and face increasing threats from habitat fragmentation and loss as well as exposure to stressors ranging from toxicants to diseases to invasive nonindigenous species. We describe and demonstrate a spatially explicit ecological risk assessment that allows for the incorporation of a broad array of information that may influence the distribution of an invasive species, toxicants, or other stressors, and the incorporation of landscape variables that may influence the spread of a species or substances. The first step in our analyses is to develop species models and quantify spatial overlap between stressor and target organisms. Risk is assessed as the product of spatial overlap and a hazard index based on target species vulnerabilities to the stressor of interest. We illustrate our methods with an example in which the stressor is the ecologically destructive nonindigenous ant, Solenopsis invicta, and the targets are two declining vertebrate species in the state of South Carolina, USA. A risk approach that focuses on landscapes and that is explicitly spatial is of particular relevance as remaining undeveloped lands become increasingly uncommon and isolated and more important in the management and recovery of species and ecological systems. Effective ecosystem management includes the control of multiple stressors, including invasive species with large impacts, understanding where those impacts may be the most severe, and implementing management strategies to reduce impacts.

  6. ToxCast Profiling in a Human Stem Cell Assay for Developmental Toxicity (CompTox CoP)

    Science.gov (United States)

    Standard practice for assessing disruptions in embryogenesis involves testing pregnant animals of two species, typically rats and rabbits, exposed during major organogenesis and evaluated just prior to term. Under this design the major manifestations of developmental toxicity are...

  7. A Review of the Toxicity of Compounds Found in Herbal Dietary Supplements.

    Science.gov (United States)

    Hudson, Amy; Lopez, Elizabeth; Almalki, Ahmad J; Roe, Amy L; Calderón, Angela I

    2018-04-19

    Use of herbal dietary supplements by the public is common and has been happening for centuries. In the United States, the Food and Drug Administration has a limited scope of regulation over marketed herbal dietary supplements, which may contain toxic botanical compounds that pose a public health risk. While the Food and Drug Administration has made efforts to prohibit the sale of unsafe herbal dietary supplements, numerous reports have proliferated of adverse events due to these supplements. This literature review investigates bioactive plant compounds commonly used in herbal dietary supplements and their relative toxicities. Using primarily the National Library of Medicine journal database and SciFinder for current reports, 47 toxic compounds in 55 species from 46 plant families were found to demonstrate harmful effects due to hepatic, cardiovascular, central nervous system, and digestive system toxicity. This review further contributes a novel and comprehensive view of toxicity across the botanical dietary market, and investigates the toxicity of the top ten botanical dietary supplements purchased in the United States of America to gauge the exposure risk of toxicity to the public. The criteria of measuring toxicity in this review (plant compound, family, quantity, and toxicity effects) across the entire market in the United States, with special attention to those supplements whose exposure to the consumer is maximal, provides a unique contribution to the investigation of botanical supplements. Georg Thieme Verlag KG Stuttgart · New York.

  8. Identification of the cause of weak acute toxicity to rainbow trout at a petroleum refinery

    International Nuclear Information System (INIS)

    Arnold, W.R.; Zaleski, R.T.; Biddinger, G.R.

    1995-01-01

    The refinery in question performs flow through acute toxicity tests on its effluent four times per month using three fish species: fathead minnows (Pimephales promelas), threespine sticklebacks (Gasterosteus oculeatus) and rainbow trout (Oncorhynchus mykiss). Several months of monitoring data indicated a transient low level acute toxicity to rainbow trout. In most cases, several days were required for mortality to occur in the flow through tests and numerous attempts to reproduce toxicity in static and static renewal tests were unsuccessful. A decision was made to manipulate the effluent in an attempt to enhance the toxic effect in the static mode so that conventional methods could be used to identify the cause. these tests indicated that toxicity was pH dependent. Additional testing, using EPA's Phase 1 Toxicity Identification Evaluation methods suggested that the cause of toxicity was probably an organic acid. Experiments were subsequently begun to identify the specific cause and source of toxicity. This paper reviews the problems confronted during the various phases of the study and the decisions that were made that eventually led to an understanding of the basis of toxicity

  9. Triclosan: environmental exposure, toxicity and mechanisms of action.

    Science.gov (United States)

    Dann, Andrea B; Hontela, Alice

    2011-05-01

    Triclosan [5-chloro-2-(2,4-dichlorophenoxy)phenol; TCS] is a broad spectrum antibacterial agent used in personal care, veterinary, industrial and household products. TCS is commonly detected in aquatic ecosystems, as it is only partially removed during the wastewater treatment process. Sorption, biodegradation and photolytic degradation mitigate the availability of TCS to aquatic biota; however the by-products such as methyltriclosan and other chlorinated phenols may be more resistant to degradation and have higher toxicity than the parent compound. The continuous exposure of aquatic organisms to TCS, coupled with its bioaccumulation potential, have led to detectable levels of the antimicrobial in a number of aquatic species. TCS has been also detected in breast milk, urine and plasma, with levels of TCS in the blood correlating with consumer use patterns of the antimicrobial. Mammalian systemic toxicity studies indicate that TCS is neither acutely toxic, mutagenic, carcinogenic, nor a developmental toxicant. Recently, however, concern has been raised over TCS's potential for endocrine disruption, as the antimicrobial has been shown to disrupt thyroid hormone homeostasis and possibly the reproductive axis. Moreover, there is strong evidence that aquatic species such as algae, invertebrates and certain types of fish are much more sensitive to TCS than mammals. TCS is highly toxic to algae and exerts reproductive and developmental effects in some fish. The potential for endocrine disruption and antibiotic cross-resistance highlights the importance of the judicious use of TCS, whereby the use of TCS should be limited to applications where it has been shown to be effective. Copyright © 2011 John Wiley & Sons, Ltd.

  10. Baltimore Air Toxics Study (BATS)

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, D.A. [Sullivan Environmental Consulting, Inc., Alexandria, VA (United States)

    1996-12-31

    The Baltimore Air Toxics Study is one of the three urban air toxics initiatives funded by EPA to support the development of the national air toxics strategy. As part of this project, the Air Quality Integrated Management System (AIMS) is under development. AIMS is designed to bring together the key components of urban air quality management into an integrated system, including emissions assessment, air quality modeling, and air quality monitoring. Urban area source emissions are computed for a wide range of pollutants and source categories, and are joined with existing point source emissions data. Measured air quality data are used to evaluate the adequacy of the emissions data and model treatments as a function of season, meteorological parameters, and daytime/nighttime conditions. Based on tested model performance, AIMS provides the potential to improve the ability to predict air quality benefits of alternative control options for criteria and toxic air pollutants. This paper describes the methods used to develop AIMS, and provides examples from its application in the Baltimore metropolitan area. The use of AIMS in the future to enhance environmental management of major industrial facilities also will be addressed in the paper.

  11. Gossypol Toxicity from Cottonseed Products

    Directory of Open Access Journals (Sweden)

    Ivana Cristina N. Gadelha

    2014-01-01

    Full Text Available Gossypol is a phenolic compound produced by pigment glands in cotton stems, leaves, seeds, and flower buds (Gossypium spp.. Cottonseed meal is a by-product of cotton that is used for animal feeding because it is rich in oil and proteins. However, gossypol toxicity limits cottonseed use in animal feed. High concentrations of free gossypol may be responsible for acute clinical signs of gossypol poisoning which include respiratory distress, impaired body weight gain, anorexia, weakness, apathy, and death after several days. However, the most common toxic effects is the impairment of male and female reproduction. Another important toxic effect of gossypol is its interference with immune function, reducing an animal’s resistance to infections and impairing the efficiency of vaccines. Preventive procedures to limit gossypol toxicity involve treatment of the cottonseed product to reduce the concentration of free gossypol with the most common treatment being exposure to heat. However, free gossypol can be released from the bound form during digestion. Agronomic selection has produced cotton varieties devoid of glands producing gossypol, but these varieties are not normally grown because they are less productive and are more vulnerable to attacks by insects.

  12. Oxidative stress in chemical toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Kappus, H.

    1986-05-01

    The toxic effect of compounds which undergo redox cycling enzymatic one-electron reduction are reviewed. First of all, the enzymatic reduction of these compounds leads to reactive intermediates, mainly radicals which react with oxygen, whereby superoxide anion radicals are formed. Further oxygen metabolites are hydrogen peroxide, singlet oxygen and hydroxyl radicals. The role of these oxygen metabolites in toxicity is discussed. The occurrence of lipid peroxidation during redox cycling of quinonoide compounds, e.g., adriamycin, and the possible relationship to their toxicity is critically evaluated. It is shown that iron ions play a crucial role in lipid peroxidation induced by redox cycling compounds. DNA damage by metal chelates, e.g., bleomycin, is discussed on the basis of findings that enzymatic redox cycling of a bleomycin-iron complex has been observed. The involvement of hydroxyl radicals in bleomycin-induced DNA damage occurring during redox cycling in cell nuclei is claimed. Redox cycling of other substances, e.g., aromatic amines, is discussed in relation to carcinogenesis. Other chemical groups, e.g., nitroaromatic compounds, hydroxylamines and azo compounds are included. Other targets for oxygen radical attack, e.g., proteins, are also dealt with. It is concluded that oxygen radical formation by redox cycling may be a critical event in toxic effects of several compounds if the protective mechanisms of cells are overwhelmed.

  13. Holiday Plants with Toxic Misconceptions

    Directory of Open Access Journals (Sweden)

    Zabrina N. Evens

    2012-12-01

    Full Text Available Several plants are used for their decorative effect during winter holidays. This review explores the toxic reputation and proposed management for exposures to several of those, namely poinsettia (Euphorbia pulcherrima, English holly (Ilex aquifolium, American holly (Ilex opaca,bittersweet (Solanum dulcamara, Jerusalem cherry (Solanum pseudocapsicum, Americanmistletoe (Phoradendron serotinum, and European mistletoe (Viscum album.

  14. Effect of toxic substance on delayed competitive allelopathic phytoplankton system with varying parameters through stability and bifurcation analysis

    International Nuclear Information System (INIS)

    Pal, D.; Mahapatra, G.S.

    2016-01-01

    Highlights: • We study a delayed two species competitive system with imprecise biological parameters. • We consider impreciseness in the form of interval number. • We introduce parametric functional form of interval number to study the model. • We study the effect of toxicant and time delay under impreciseness. • We discuss the chaotic behavior of the model. - Abstract: We have studied the combined effect of toxicant and fluctuation of the biological parameters on the dynamical behaviors of a delayed two-species competitive system with imprecise biological parameters. Due to the global increase of harmful phytoplankton blooms, the study of dynamic interactions between two competing phytoplankton species in the presence of toxic substances is an active field of research now days. The ordinary mathematical formulation of models for two competing phytoplankton species, when one or both the species liberate toxic substances, is unable to capture the oscillatory and highly variable growth of phytoplankton populations. The deterministic model never predicts the sudden localized behavior of certain species. These obstacles of mathematical modeling can be overcomed if we include interval variability of biological parameters in our modeling approach. In this investigation, we construct imprecise models of allelopathic interactions between two competing phytoplankton species as a parametric differential equation model. We incorporate the effect of toxicant on the species in two different cases known as toxic inhibition and toxic stimulatory system. We have discussed the existence of various equilibrium points and stability of the system at these equilibrium points. In case of toxic stimulatory system, the delay model exhibits a stable limit cycle oscillation. Analytical findings are supported through exhaustive numerical simulations.

  15. Modelling interactions of toxicants and density dependence in wildlife populations

    Science.gov (United States)

    Schipper, Aafke M.; Hendriks, Harrie W.M.; Kauffman, Matthew J.; Hendriks, A. Jan; Huijbregts, Mark A.J.

    2013-01-01

    1. A major challenge in the conservation of threatened and endangered species is to predict population decline and design appropriate recovery measures. However, anthropogenic impacts on wildlife populations are notoriously difficult to predict due to potentially nonlinear responses and interactions with natural ecological processes like density dependence. 2. Here, we incorporated both density dependence and anthropogenic stressors in a stage-based matrix population model and parameterized it for a density-dependent population of peregrine falcons Falco peregrinus exposed to two anthropogenic toxicants [dichlorodiphenyldichloroethylene (DDE) and polybrominated diphenyl ethers (PBDEs)]. Log-logistic exposure–response relationships were used to translate toxicant concentrations in peregrine falcon eggs to effects on fecundity. Density dependence was modelled as the probability of a nonbreeding bird acquiring a breeding territory as a function of the current number of breeders. 3. The equilibrium size of the population, as represented by the number of breeders, responded nonlinearly to increasing toxicant concentrations, showing a gradual decrease followed by a relatively steep decline. Initially, toxicant-induced reductions in population size were mitigated by an alleviation of the density limitation, that is, an increasing probability of territory acquisition. Once population density was no longer limiting, the toxicant impacts were no longer buffered by an increasing proportion of nonbreeders shifting to the breeding stage, resulting in a strong decrease in the equilibrium number of breeders. 4. Median critical exposure concentrations, that is, median toxicant concentrations in eggs corresponding with an equilibrium population size of zero, were 33 and 46 μg g−1 fresh weight for DDE and PBDEs, respectively. 5. Synthesis and applications. Our modelling results showed that particular life stages of a density-limited population may be relatively insensitive to

  16. Glutathione transferase activity and oocyte development in copepods exposed to toxic phytoplankton

    DEFF Research Database (Denmark)

    Kozlowsky-Suzuki, Betina; Koski, Marja; Hallberg, Eric

    2009-01-01

    toxins generally observed in copepods. In addition, decreasing gross growth efficiency (GGE) of copepods with increasing concentration of toxic diets could be caused either by a high expenditure coping with toxins (e.g., increase in the activity of detoxification enzymes) or by a deterioration...... of reproductive tissues. To assess the effect of toxic phytoplankton on the activity of detoxification enzymes and on oocyte maturation of Acartia tonsa and Temora longicornis, feeding and egg production experiments were carried out with a variety of toxic diets and an adequate non-toxic food control (Rhodomonas...... spp.) all provided as single species diets. Toxic diets included the nodularin-producing cyanobacterium Nodularia spumigena, the dinoflagellates Alexandrium minutum, and A. tamarense, which contained Paralytic Shellfish Poisoning (PSP) toxins, the dinoflagellate Prorocentrum lima with Diarrhetic...

  17. Field Validation of Toxicity Tests to Evaluate the Potential for Beneficial Use of Produced Water

    Energy Technology Data Exchange (ETDEWEB)

    Joseph Bidwell; Jonathan Fisher; Naomi Cooper

    2008-03-31

    This study investigated potential biological effects of produced water contamination derived from occasional surface overflow and possible subsurface intrusion at an oil production site along the shore of Skiatook Lake, Oklahoma. We monitored basic chemistry and acute toxicity to a suite of standard aquatic test species (fathead minnow-Pimephales promelas, Daphnia pulex, Daphnia magna, and Ceriodaphnia dubia) in produced water and in samples taken from shallow groundwater wells on the site. Toxicity identification evaluations and ion toxicity modeling were used to identify toxic constituents in the samples. Lake sediment at the oil production site and at a reference site were also analyzed for brine intrusion chemically and by testing sediment toxicity using the benthic invertebrates, Chironomus dilutus, and Hyallela azteca. Sediment quality was also assessed with in situ survival and growth studies with H. azteca and the Asian clam, Corbicula fluminea, and by benthic macroinvertebrate community sampling. The produced water was acutely toxic to the aquatic test organisms at concentrations ranging from 1% to 10% of the whole produced water sample. Toxicity identification evaluation and ion toxicity modeling indicated major ion salts and hydrocarbons were the primary mixture toxicants. The standardized test species used in the laboratory bioassays exhibited differences in sensitivity to these two general classes of contaminants, which underscores the importance of using multiple species when evaluating produced water toxicity. Toxicity of groundwater was greater in samples from wells near a produced water injection well and an evaporation pond. Principle component analyses (PCA) of chemical data derived from the groundwater wells indicated dilution by lake water and possible biogeochemical reactions as factors that ameliorated groundwater toxicity. Elevated concentrations of major ions were found in pore water from lake sediments, but toxicity from these ions was

  18. Foraging response and acclimation of ambush feeding and feeding-current feeding copepods to toxic dinoflagellates

    DEFF Research Database (Denmark)

    Xu, Jiayi; Nielsen, Lasse Tor; Kiørboe, Thomas

    2018-01-01

    reticulatum. We hypothesize (1) that ambush feeders are less affected by toxic algae than feeding-current feeders, (2) that copepods acclimate to the toxic algae, and (3) that phytoplankton cells previously exposed to copepod cues elicit stronger responses. Both copepod species consumed the toxic algae...... to examine the response and temporal acclimation (5 d) of two copepods with different foraging behaviors to toxic dinoflagellates. Feeding-current feeding Temora longicornis and ambush feeding Acartia tonsa were offered three strains of toxic Alexandrium tamarense and a nontoxic control Protoceratium...... at a reduced rate and there was no difference in their net-response, but the mechanisms differed. T. longicornis responded in strain-specific ways by reducing its feeding activity, by rejecting captured algae, or by regurgitating consumed cells. A. tonsa reduced its consumption rate, jump frequency, and jump...

  19. Toxicity of seven foliar insecticides to four insect parasitoids attacking citrus and cotton pests.

    Science.gov (United States)

    Prabhaker, Nilima; Morse, J G; Castle, S J; Naranjo, S E; Henneberry, T J; Toscano, N C

    2007-08-01

    Laboratory studies were carried out to compare the toxicity of seven foliar insecticides to four species of adult beneficial insects representing two families of Hymenoptera: Aphelinidae (Aphytis melinus Debach, Eretmocerus eremicus Rose & Zolnerowich, and Encarsiaformosa Gahan) and Mymaridae (Gonatocerus ashmeadi Girault) that attack California red scale, Aonidiella aurantii (Maskell); sweetpotato whitefly, Bemisia tabaci (Gennadius) (both E. eremicus and E. formosa); and glassy-winged sharpshooter, Homalodisca vitripennis (Germar), respectively. Insecticides from four pesticide classes were evaluated using a petri dish bioassay technique across a range of concentrations to develop dosage-mortality regressions. Insecticides tested included acetamiprid (neonicotinoid); chlorpyrifos (organophosphate); bifenthrin, cyfluthrin, and fenpropathrin (pyrethroids); and buprofezin and pyriproxyfen (insect growth regulators [IGRs]). Chlorpyrifos was consistently the most toxic pesticide to all four species of beneficial insects tested based on LC50 values recorded 24 h posttreatment compared with 48-h LC50 values with the neonicotinoid and pyrethroids or 96 h with the IGRs. Among the three pyrethroids, fenpropathrin was usually less toxic (except similar toxicity to A. melinus) than was cyfluthrin, and it was normally less toxic (except similar toxicity with E. formosa) than was bifenthrin. Acetamiprid was generally less toxic than bifenthrin (except similar toxicity with G. ashmeadi). The IGRs buprofezin and pyriproxyfen were usually less toxic than the contact pesticides, but we did not test for possible impacts on female fecundity. For all seven pesticides tested, A. melinus was the most susceptible parasitoid of the four test species. The data presented here will provide pest managers with specific information on the compatibility of select insecticides with natural enemies attacking citrus and cotton, Gossypium hirsutum L., pests.

  20. Mercury-Resistant Marine Bacteria and their Role in Bioremediation of Certain Toxicants

    Digital Repository Service at National Institute of Oceanography (India)

    De, J.

    of heavy metals (mercury, cadmium, lead to name a few). Without efficient retention technologies, toxic chemicals including Hg are let into the environment, endangering ecosystems and public health. The main focus in this section is on literature review... toxicity. For the most sensitive species, Daphnia magna, the NOTEL for reproductive impairment is 3 ppb for inorganic mercury and lesser than 0.04 ppb for methylmercury (Canstein, 2000). Hence it is of great importance for both environment and public health...

  1. The dynamics of toxic microcystis strains and microcystin production in two hypertrofic South African reservoirs

    OpenAIRE

    Barnard, Sandra; Conradie, Karin Ronel

    2012-01-01

    The South African impoundments of Hartbeespoort and Roodeplaat experience excessive blooms of Microcystis species each year. Microcystins, produced primarily by strains of cyanobacteria belonging to the genera Microcystis, Anabaena and Planktothrix, are harmful cyanobacterial hepatotoxins. These bloom-forming cyanobacteria form toxic and non-toxic strains that co-occur and are visually indistinguishable, but can be identified and quantified molecularly. We described the relationships between ...

  2. Quantification of silver nanoparticle toxicity to algae in soil via photosynthetic and flow-cytometric analyses

    OpenAIRE

    Nam, Sun-Hwa; Il Kwak, Jin; An, Youn-Joo

    2018-01-01

    Soil algae, which have received attention for their use in a novel bioassay to evaluate soil toxicity, expand the range of terrestrial test species. However, there is no information regarding the toxicity of nanomaterials to soil algae. Thus, we evaluated the effects of silver nanoparticles (0–50 mg AgNPs/kg dry weight soil) on the soil alga Chlamydomonas reinhardtii after six days, and assessed changes in biomass, photosynthetic activity, cellular morphology, membrane permeability, esterase ...

  3. Testing a Microarray to Detect and Monitor Toxic Microalgae in Arcachon Bay in France

    Directory of Open Access Journals (Sweden)

    Linda K. Medlin

    2013-03-01

    Full Text Available Harmful algal blooms (HABs occur worldwide, causing health problems and economic damages to fisheries and tourism. Monitoring agencies are therefore essential, yet monitoring is based only on time-consuming light microscopy, a level at which a correct identification can be limited by insufficient morphological characters. The project MIDTAL (Microarray Detection of Toxic Algae—an FP7-funded EU project—used rRNA genes (SSU and LSU as a target on microarrays to identify toxic species. Furthermore, toxins were detected with a newly developed multiplex optical Surface Plasmon Resonance biosensor (Multi SPR and compared with an enzyme-linked immunosorbent assay (ELISA. In this study, we demonstrate the latest generation of MIDTAL microarrays (version 3 and show the correlation between cell counts, detected toxin and microarray signals from field samples taken in Arcachon Bay in France in 2011. The MIDTAL microarray always detected more potentially toxic species than those detected by microscopic counts. The toxin detection was even more sensitive than both methods. Because of the universal nature of both toxin and species microarrays, they can be used to detect invasive species. Nevertheless, the MIDTAL microarray is not completely universal: first, because not all toxic species are on the chip, and second, because invasive species, such as Ostreopsis, already influence European coasts.

  4. Lethal body concentrations and accumulation patterns determine time-dependent toxicity of cadmium in soil arthropods

    Energy Technology Data Exchange (ETDEWEB)

    Crommentuijn, T.; Doodeman, C.J.A.M.; Doornekamp, A.; Pol, J.J.C. van der; Bedaux, J.J.M.; Gestel, C.A.M. van (Vrije Univ., Amsterdam (Netherlands))

    1994-11-01

    Time-dependent toxicity in bioassays is usually explained in terms of uptake and elimination kinetics of the toxicant. By comparing different species with essentially different accumulation kinetics, a firm test of this concept may be made. This article compares the sensitivity of six soil arthropods, the collembolans Orchesella cincta and Tomocerus minor, the oribatid mite Platynothrus peltifer, the isopods Porcellio scaber and Oniscus asellus, and the diplopod Cylindroiulus britannicus, when exposed to cadmium in the food. Survival was determined at various time intervals; accumulation of cadmium in the animals was measured at one time interval. Kinetic-based toxicity models were fitted to the data, and estimates were obtained for lethal body concentration, uptake rate constant, elimination rate constant, and ultimate LC50. Two different accumulation patterns could be discerned; these were correlated with time-survival relationships. One, species that have the possibility to eliminate cadmium will reach an equilibrium for the internal concentration and also an ultimate LC50. Two, species that are unable to eliminate cadmium but store it in the body will have an ultimate LC50 equal to zero. For these species the time in which the lethal body concentration is reached is more important. Taxonomically related species appeared to have comparable accumulation patterns, but lethal body concentrations differed. It is concluded that knowledge of the accumulation pattern is indispensable for the evaluation of species' sensitivities to toxicants.

  5. Using biodynamic models to reconcile differences between laboratory toxicity tests and field biomonitoring with aquatic insects

    Science.gov (United States)

    Buchwalter, D.B.; Cain, D.J.; Clements, W.H.; Luoma, S.N.

    2007-01-01

    Aquatic insects often dominate lotic ecosystems, yet these organisms are under-represented in trace metal toxicity databases. Furthermore, toxicity data for aquatic insects do not appear to reflect their actual sensitivities to metals in nature, because the concentrations required to elicit toxicity in the laboratory are considerably higher than those found to impact insect communities in the field. New approaches are therefore needed to better understand how and why insects are differentially susceptible to metal exposures. Biodynamic modeling is a powerful tool for understanding interspecific differences in trace metal bioaccumulation. Because bioaccumulation alone does not necessarily correlate with toxicity, we combined biokinetic parameters associated with dissolved cadmium exposures with studies of the subcellular compartmentalization of accumulated Cd. This combination of physiological traits allowed us to make predictions of susceptibility differences to dissolved Cd in three aquatic insect taxa: Ephemerella excrucians, Rhithrogena morrisoni, and Rhyacophila sp. We compared these predictions with long-term field monitoring data and toxicity tests with closely related taxa: Ephemerella infrequens, Rhithrogena hageni, and Rhyacophila brunea. Kinetic parameters allowed us to estimate steady-state concentrations, the time required to reach steady state, and the concentrations of Cd projected to be in potentially toxic compartments for different species. Species-specific physiological traits identified using biodynamic models provided a means for better understanding why toxicity assays with insects have failed to provide meaningful estimates for metal concentrations that would be expected to be protective in nature. ?? 2007 American Chemical Society.

  6. Different toxicity mechanisms between bare and polymer-coated copper oxide nanoparticles in Lemna gibba

    International Nuclear Information System (INIS)

    Perreault, François; Popovic, Radovan; Dewez, David

    2014-01-01

    In this report, we investigated how the presence of a polymer shell (poly(styrene-co-butyl acrylate) alters the toxicity of CuO NPs in Lemna gibba. Based on total Cu concentration, core–shell CuO NPs were 10 times more toxic than CuO NPs, inducing a 50% decrease of growth rate at 0.4 g l −1 after 48-h of exposure while a concentration of 4.5 g l −1 was required for CuO NPs for a similar effect. Toxicity of CuO NPs was mainly due to NPs solubilization in the media. Based on the accumulated copper content in the plants, core–shell CuO NPs induced 4 times more reactive oxygen species compared to CuO NPs and copper sulfate, indicating that the presence of the polymer shell changed the toxic effect induced in L. gibba. This effect could not be attributed to the polymer alone and reveals that surface modification may change the nature of NPs toxicity. -- Highlights: • Bare and polymer-coated CuO nanoparticles were toxic to Lemna gibba. • Toxicity of bare CuO was mainly due to solubilized soluble copper. • Coated CuO accumulated inside the plants four times more. • Formation of reactive oxygen species was increased by polymer coating. • Coating of nanomaterials modifies mechanisms of action at cellular level. -- Polymer coating increases oxidative stress effect by core–shell CuO nanoparticles

  7. Pharmacokinetic drivers of toxicity for basic molecules: Strategy to lower pKa results in decreased tissue exposure and toxicity for a small molecule Met inhibitor

    International Nuclear Information System (INIS)

    Diaz, Dolores; Ford, Kevin A.; Hartley, Dylan P.; Harstad, Eric B.; Cain, Gary R.; Achilles-Poon, Kirsten; Nguyen, Trung; Peng, Jing; Zheng, Zhong; Merchant, Mark; Sutherlin, Daniel P.; Gaudino, John J.; Kaus, Robert; Lewin-Koh, Sock C.; Choo, Edna F.; Liederer, Bianca M.; Dambach, Donna M.

    2013-01-01

    Several toxicities are clearly driven by free drug concentrations in plasma, such as toxicities related to on-target exaggerated pharmacology or off-target pharmacological activity associated with receptors, enzymes or ion channels. However, there are examples in which organ toxicities appear to correlate better with total drug concentrations in the target tissues, rather than with free drug concentrations in plasma. Here we present a case study in which a small molecule Met inhibitor, GEN-203, with significant liver and bone marrow toxicity in preclinical species was modified with the intention of increasing the safety margin. GEN-203 is a lipophilic weak base as demonstrated by its physicochemical and structural properties: high LogD (distribution coefficient) (4.3) and high measured pKa (7.45) due to the basic amine (N-ethyl-3-fluoro-4-aminopiperidine). The physicochemical properties of GEN-203 were hypothesized to drive the high distribution of this compound to tissues as evidenced by a moderately-high volume of distribution (Vd > 3 l/kg) in mouse and subsequent toxicities of the compound. Specifically, the basicity of GEN-203 was decreased through addition of a second fluorine in the 3-position of the aminopiperidine to yield GEN-890 (N-ethyl-3,3-difluoro-4-aminopiperidine), which decreased the volume of distribution of the compound in mouse (Vd = 1.0 l/kg), decreased its tissue drug concentrations and led to decreased toxicity in mice. This strategy suggests that when toxicity is driven by tissue drug concentrations, optimization of the physicochemical parameters that drive tissue distribution can result in decreased drug concentrations in tissues, resulting in lower toxicity and improved safety margins. -- Highlights: ► Lower pKa for a small molecule: reduced tissue drug levels and toxicity. ► New analysis tools to assess electrostatic effects and ionization are presented. ► Chemical and PK drivers of toxicity can be leveraged to improve safety.

  8. Allelopathic assessment of selected invasive species of pakistan

    Energy Technology Data Exchange (ETDEWEB)

    Akhtar, S. [International Islamic Univ., Islamabad (Pakistan). Dept. of Bioinformatics and Biotechnology; Bangash, N. [Pir Mehr Ali Shah Arid Agriculture Univ., Peshawar (Pakistan). Dept. of Environmental Sciences; Asghar, R. [Mirpur Univ. of Science and Technology, Azad Jammu and Kashmir (Pakistan)

    2014-10-15

    Invader species are a great threat to local flora. Eight invader species of Pakistan were screened for their allelopathic activity through sandwich method. Toxic (inhibitory) and non-toxic (stimulatory) effects were assessed by recording their effect on germination and growth of lettuce. Radicle and plumule growth of lettuce were recorded at 5, 10 and 50 mg leaves concentrations of each species. Among all species the growth activity was found to be concentration dependent. Except Eutcalyptus glabra all species resulted in inhibitory effects at 5, 10 and 50 mg leaves concentrations. Xanthium strumarium and Cannabis sativa showed strong inhibitory effects on radicle and plumule growth of lettuce. Maximum inhibition was recorded at highest concentration; even growth of lettuce was stopped with 50 mg leaves concentration of C. sativa. (author)

  9. Allelopathic assessment of selected invasive species of pakistan

    International Nuclear Information System (INIS)

    Akhtar, S.

    2014-01-01

    Invader species are a great threat to local flora. Eight invader species of Pakistan were screened for their allelopathic activity through sandwich method. Toxic (inhibitory) and non-toxic (stimulatory) effects were assessed by recording their effect on germination and growth of lettuce. Radicle and plumule growth of lettuce were recorded at 5, 10 and 50 mg leaves concentrations of each species. Among all species the growth activity was found to be concentration dependent. Except Eutcalyptus glabra all species resulted in inhibitory effects at 5, 10 and 50 mg leaves concentrations. Xanthium strumarium and Cannabis sativa showed strong inhibitory effects on radicle and plumule growth of lettuce. Maximum inhibition was recorded at highest concentration; even growth of lettuce was stopped with 50 mg leaves concentration of C. sativa. (author)

  10. Low toxic maghemite nanoparticles for theranostic applications

    Directory of Open Access Journals (Sweden)

    Kuchma EA

    2017-08-01

    Full Text Available Elena A Kuchma,* Peter V Zolotukhin, Anna A Belanova, Mikhail A Soldatov, Tatiana A Lastovina, Stanislav P Kubrin, Anatoliy V Nikolsky, Lidia I Mirmikova, Alexander V Soldatov* The Smart Materials Research Center, Southern Federal University of Russia, Rostov-on-Don, Russia *These authors contributed equally to this work Background: Iron oxide nanoparticles have numerous and versatile biological properties, ranging from direct and immediate biochemical effects to prolonged influences on tissues. Most applications have strict requirements with respect to the chemical and physical properties of such agents. Therefore, developing rational design methods of synthesis of iron oxide nanoparticles remains of vital importance in nanobiomedicine.Methods: Low toxic superparamagnetic iron oxide nanoparticles (SPIONs for theranostic applications in oncology having spherical shape and maghemite structure were produced using the fast microwave synthesis technique and were fully characterized by several complementary methods (transmission electron microscopy [TEM], X-ray diffraction [XRD], dynamic light scattering [DLS], X-ray photoelectron spectroscopy [XPS], X-ray absorption near edge structure [XANES], Mossbauer spectroscopy, and HeLa cells toxicity testing.Results: TEM showed that the majority of the obtained nanoparticles were almost spherical and did not exceed 20 nm in diameter. The averaged DLS hydrodynamic size was found to be ~33 nm, while that of nanocrystallites estimated by XRD was ~16 nm. Both XRD and XPS studies evidenced the maghemite (γ-Fe2O3 atomic and electronic structure of the synthesized nanoparticles. The XANES data analysis demonstrated the structure of the nanoparticles being similar to that of macroscopic maghemite. The Mossbauer spectroscopy revealed the γ-Fe2O3 phase of the nanoparticles and vibration magnetometry study showed that reactive oxygen species in HeLa cells are generated both in the cytoplasm and the nucleus

  11. Aqueous solubility, dispersibility and toxicity of biodiesels

    International Nuclear Information System (INIS)

    Hollebone, B.P.; Fieldhouse, B.; Lumley, T.C.; Landriault, M.; Doe, K.; Jackman, P.

    2007-01-01

    The renewed interest in the use of biological fuels can be attributed to that fact that feedstocks for fatty-acid ester biodiesels are renewable and can be reclaimed from waste. Although there are significant benefits to using biodiesels, their increased use leaves potential for accidental release to the environment. Therefore, their environmental behaviours and impacts must be evaluated along with the risk associated with their use. Biodiesel fuels may be made from soy oil, canola oil, reclaimed restaurant grease, fish oil and animal fat. The toxicological fate of biofuel depends on the variability of its chemical composition. This study provided an initial assessment of the aqueous fate and effects of biodiesel from a broad range of commonly available feedstocks and their blends with petroleum diesels. The study focused primarily on the fate and impact of these fuels in fresh-water. The use of chemical dispersion as a countermeasure for saltwater was also investigated. The exposure of aquatic ecosystems to biodiesels and petroleum diesel occurs via the transfer of material from the non-aqueous phase liquid (NAPL) into the aqueous phase, as both soluble and dispersed components. The aqueous solubilities of the fuels were determined from the equilibrium water-accommodated fraction concentrations. The acute toxicities of many biodiesels were reported for 3 test species used by Environment Canada for toxicological evaluation, namely rainbow trout, the water flea and a luminescent bacterium. This study also evaluated the natural potential for dispersion of the fuels in the water column in both low and high-energy wave conditions. Chemical dispersion as a potential countermeasure for biodiesel spills was also evaluated using solubility testing, acute toxicity testing, and dispersibility testing. It was shown that biodiesels have much different fates and impacts from petroleum diesels. The compounds partitioning into the water column are also very different for each

  12. Comparative sensitivity of five species of macrophytes and six species of algae to atrazine, metribuzin, alachlor, and metolachlor

    Science.gov (United States)

    Fairchild, James F.; Ruessler, Shane; Carlson, A. Ron

    1998-01-01

    This study determined the relative sensitivity of five species of aquatic macrophytes and six species of algae to four commonly used herbicides (atrazine, metribuzin, alachlor, and metolachlor). Toxicity tests consisted of 96-h (duckweed and algae) or 14-d (submerged macrophytes) static exposures. The triazine herbicides (atrazine and metribuzin) were significantly more toxic to aquatic plants than were the acetanilide herbicides (alachlor and metolachlor). Toxicity studies ranked metribuzin > atrazine > alachlor > metolachlor in decreasing order of overall toxicity to aquatic plants. Relative sensitivities of macrophytes to these herbicides decreased in the order of Ceratophyllum > Najas > Elodea > Lemna > Myriophyllum. Relative sensitivities of algae to herbicides decreased in the order of Selenastrum > Chlorella > Chlamydomonas > Microcystis > Scenedesmus > Anabaena. Algae and macrophytes were of similar overall sensitivities to herbicides. Data indicated that Selenastrum, a commonly tested green alga, was generally more sensitive compared to other plant species. Lemna minor, a commonly tested floating vascular plant, was of intermediate sensitivity, and was fivefold less sensitive than Ceratophyllum, which was the most sensitive species tested. The results indicated that no species was consistently most sensitive, and that a suite of aquatic plant test species may be needed to perform accurate risk assessments of herbicides.

  13. Toxic Release Inventory Chemicals by Groupings

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Toxics Release Inventory (TRI) makes available information for more than 600 toxic chemicals that are being used, manufactured, treated, transported, or released...

  14. Information Search of Toxic-Free Ammunition

    National Research Council Canada - National Science Library

    Adelman, Stephen

    1994-01-01

    Task Order No. 0001, Information Search of Toxic-Free Ammunition addresses issues related to toxic and environmentally harmful effects caused by the use of some of the current small arms ammunition...

  15. Agency for Toxic Substances and Disease Registry

    Science.gov (United States)

    ... Z # Search Form Controls Search The CDC submit Agency for Toxic Substances and Disease Registry Note: Javascript ... gov . Recommend on Facebook Tweet Share Compartir The Agency for Toxic Substances and Disease Registry (ATSDR) , based ...

  16. Toxic chemicals: risk prevention through use reduction

    National Research Council Canada - National Science Library

    Higgins, Thomas E; Sachdev, Jayanti A; Engleman, Stephen A

    2011-01-01

    ... on the actual toxicity of chemicals currently in use, discusses variables that contribute to the relative toxicity of a substance, compares alternate emphases in existing programs for reducing environmental...

  17. Health risks associated with inhaled nasal toxicants

    NARCIS (Netherlands)

    Feron, VJ; Arts, JHE; Kuper, CF; Slootweg, PJ; Woutersen, RA

    2001-01-01

    Health risks of inhaled nasal toxicants were reviewed with emphasis on chemically induced nasal lesions in humans, sensory irritation, olfactory and trigeminal nerve toxicity, nasal immunopathology and carcinogenesis, nasal responses to chemical mixtures, in vitro models, and nasal dosimetry- and

  18. Volatile organic compounds emitted by filamentous fungi isolated from flooded homes after Hurricane Sandy show toxicity in a Drosophila bioassay.

    Science.gov (United States)

    Zhao, G; Yin, G; Inamdar, A A; Luo, J; Zhang, N; Yang, I; Buckley, B; Bennett, J W

    2017-05-01

    Superstorm Sandy provided an opportunity to study filamentous fungi (molds) associated with winter storm damage. We collected 36 morphologically distinct fungal isolates from flooded buildings. By combining traditional morphological and cultural characters with an analysis of ITS sequences (the fungal DNA barcode), we identified 24 fungal species that belong to eight genera: Penicillium (11 species), Fusarium (four species), Aspergillus (three species), Trichoderma (two species), and one species each of Metarhizium, Mucor, Pestalotiopsis, and Umbelopsis. Then, we used a Drosophila larval assay to assess possible toxicity of volatile organic compounds (VOCs) emitted by these molds. When cultured in a shared atmosphere with growing cultures of molds isolated after Hurricane Sandy, larval toxicity ranged from 15 to 80%. VOCs from Aspergillus niger 129B were the most toxic yielding 80% mortality to Drosophila after 12 days. The VOCs from Trichoderma longibrachiatum 117, Mucor racemosus 138a, and Metarhizium anisopliae 124 were relatively non-toxigenic. A preliminary analysis of VOCs was conducted using solid-phase microextraction-gas chromatography-mass spectrometry from two of the most toxic, two of the least toxic, and two species of intermediate toxicity. The more toxic molds produced higher concentrations of 1-octen-3-ol, 3-octanone, 3-octanol, 2-octen-1-ol, and 2-nonanone; while the less toxic molds produced more 3-methyl-1-butanol and 2-methyl-1-propanol, or an overall lower amount of volatiles. Our data support the hypothesis that at certain concentrations, some VOCs emitted by indoor molds are toxigenic. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Metallothionein provides zinc-mediated protective effects against methamphetamine toxicity in SK-N-SH cells.

    Science.gov (United States)

    Ajjimaporn, Amornpan; Swinscoe, John; Shavali, Shaik; Govitrapong, Piyarat; Ebadi, Manuchair

    2005-11-30

    Methamphetamine (METH) is a drug of abuse and neurotoxin that induces Parkinson's-like pathology after chronic usage by targeting dopaminergic neurons. Elucidation of the intracellular mechanisms that underlie METH-induced dopaminergic neuron toxicity may help in understanding the mechanism by which neurons die in Parkinson's disease. In the present study, we examined the role of reactive oxygen species (ROS) in the METH-induced death of human dopaminergic SK-N-SH cells and further assessed the neuroprotective effects of zinc and metallothionein (MT) against METH-induced toxicity in culture. METH significantly increased the production of reactive oxygen species, decreased intracellular ATP levels and reduced the cell viability. Pre-treatment with zinc markedly prevented the loss of cell viability caused by METH treatment. Zinc pre-treatment mainly increased the expression of metallothionein and prevented the generation of reactive oxygen species and ATP depletion caused by METH. Chelation of zinc by CaEDTA caused a significant decrease in MT expression and loss of protective effects of MT against METH toxicity. These results suggest that zinc-induced MT expression protects dopaminergic neurons via preventing the accumulation of toxic reactive oxygen species and halting the decrease in ATP levels. Furthermore, MT may prevent the loss of mitochondrial functions caused by neurotoxins. In conclusion, our study suggests that MT, a potent scavenger of free radicals is neuroprotective against dopaminergic toxicity in conditions such as drug of abuse and in Parkinson's disease.

  20. Species concept and speciation

    Directory of Open Access Journals (Sweden)

    Amal Y. Aldhebiani

    2018-03-01

    Full Text Available Defining and recognizing a species has been a controversial issue for a long time. To determine the variation and the limitation between species, many concepts have been proposed. When a taxonomist study a particular taxa, he/she must adopted a species concept and provide a species limitation to define this taxa. In this paper some of species concepts are discussed starting from the typological species concepts to the phylogenetic concept. Positive and negative aspects of these concepts are represented in addition to their application. Keywords: Species concept, Species limitation, Species, Taxonomy, Classification

  1. Toxicity of herbal medicines with interest to SUS: a review

    Directory of Open Access Journals (Sweden)

    Ciciane Pereira Marten Fernandes

    2016-11-01

    Full Text Available Abstract: In Brazil, ever since colonization plants have been used as natural products; thus, the National Health Surveillance Agency has been establishing rules for herbal medicine regulation; in this light, 71 plant species were chosen and empirically used in the country to investigate their medicinal properties. Currently, 12 of these 71 plants have been approved to be used in SUS (Public Health System, the remaining species still need further research. Thusly, this review aimed to seek information from toxicological studies on the plants that have not yet been officially approved, to stimulate new research in the field, promoting an economical and functional impact. In order to obtain the information, the keywords plant name + toxicity and/or toxicological studies were searched in the most prominent databases, both in English and in Portuguese. The ten plants with the most references were included in this review. Among the ten plants assessed, three have all the required studies required by the National Health Surveillance Agency, two of which we recommend the immediate adoption by SUS. In general, three plants have a determined LD50, nine have reproductive toxicity data, and five have not yet shown any sign of toxicity.

  2. Mechanisms for regulating oxygen toxicity in phytophagous insects.

    Science.gov (United States)

    Ahmad, S; Pardini, R S

    1990-01-01

    The antioxidant enzymatic defense of insects for the regulation of oxygen toxicity was investigated. Insect species examined were lepidopterous larvae of the cabbage looper (Trichoplusia ni), southern armyworm (Spodoptera eridania), and black swallowtail (Papilio polyxenes). These phytophagous species are subject to both endogenous and exogenous sources of oxidative stress from toxic oxygen radicals, hydrogen peroxide (H2O2) and lipid peroxides (LOOH). In general, the constitutive levels of the enzymes superoxide dismutase (SOD), catalase (CAT), glutathione transferase (GT), and its peroxidase activity (GTpx), and glutathione reductase (GR), correlate well with natural feeding habits of these insects and their relative susceptibility to prooxidant plant allelochemicals, quercetin (a flavonoid), and xanthotoxin (a photoactive furanocoumarin). Induction of SOD activity which rapidly destroys superoxide radicals, appears to be the main response to dietary prooxidant exposure. A unique observation includes high constitutive activity of CAT and a broader subcellular distribution in all three insects than observed in most mammalian species. These attributes of CAT appear to be important in the prevention of excessive accumulation of cytotoxic H2O2. Unlike mammalian species, insects possess very low levels of a GPOX-like activity toward H2O2. Irrefutable proof that this activity is due to a selenium-dependent GPOX found in mammals, is lacking at this time. However, the activity of selenium-independent GTpx is unusually high in insects, suggesting that GTpx and not GPOX plays a prominent role in scavenging deleterious LOOHs. The GSSG generated from the GPOX and GTpx reactions may be reduced to GSH by GR activity. A key role of SOD in protecting insects from prooxidant toxicity was evident when its inhibition resulted in enhanced toxicity towards prooxidants. The role of antioxidant compounds in protecting these insects from toxic forms of oxygen has not been explored in

  3. Methylmercury toxicity and functional programming

    DEFF Research Database (Denmark)

    Grandjean, Philippe

    2007-01-01

    : Accumulating evidence indicates that adverse effects may occur even at low-level methylmercury exposures from seafood and freshwater fish. Neurobehavioral outcomes are usually non-specific, and imprecise exposure assessment results in a bias toward the null. Essential nutrients may promote the development......PURPOSE: Adverse health effects of developmental toxicants may induce abnormal functional programming that leads to lasting functional deficits. This notion is considered from epidemiological evidence using developmental methylmercury neurotoxicity as an example. MOST IMPORTANT FINDINGS...... of certain brain functions, thereby causing confounding bias. The functional deficits caused by prenatal methylmercury exposure appear to be permanent, and their extent may depend on the joint effect of toxicants and nutrients. PRINCIPAL CONCLUSIONS: The lasting functional changes caused...

  4. Behavioral toxicity of selected radioprotectors

    Science.gov (United States)

    Landauer, M. R.; Davis, H. D.; Kumar, K. S.; Weiss, J. F.

    1992-10-01

    Effective radioprotection with minimal behavioral disruption is essential for the selection of protective agents to be used in manned spaceflight. This overview summarizes the studies on the behavioral toxicity of selected radioprotectors classified as phosphorothioates (WR-2721, WR-3689), bioactive lipids (16, 16 dimethylprostaglandin E2(DiPGE2), platelet activating factor (PAF), leukotriene C4), and immunomodulators (glucan, synthetic trehalose dicorynomycolate, and interleukin-1). Behavioral toxicity was examined in laboratory mice using a locomotor activity test. For all compounds tested, there was a dose-dependent decrease in locomotor behavior that paralleled the dose-dependent increase in radioprotection. While combinations of radioprotective compounds (DiPGE2 plus WR-2721) increased radioprotection, they also decreased locomotor activity. The central nervous system stimulant, caffeine, was able to mitigate the locomotor decrement produced by WR-3689 or PAF.

  5. Toxic Anterior Segment Syndrome (TASS

    Directory of Open Access Journals (Sweden)

    Özlem Öner

    2011-12-01

    Full Text Available Toxic anterior segment syndrome (TASS is a sterile intraocular inflammation caused by noninfectious substances, resulting in extensive toxic damage to the intraocular tissues. Possible etiologic factors of TASS include surgical trauma, bacterial endotoxin, intraocular solutions with inappropriate pH and osmolality, preservatives, denatured ophthalmic viscosurgical devices (OVD, inadequate sterilization, cleaning and rinsing of surgical devices, intraocular lenses, polishing and sterilizing compounds which are related to intraocular lenses. The characteristic signs and symptoms such as blurred vision, corneal edema, hypopyon and nonreactive pupil usually occur 24 hours after the cataract surgery. The differential diagnosis of TASS from infectious endophthalmitis is important. The main treatment for TASS formation is prevention. TASS is a cataract surgery complication that is more commonly seen nowadays. In this article, the possible underlying causes as well as treatment and prevention methods of TASS are summarized. (Turk J Oph thal mol 2011; 41: 407-13

  6. Small molecule fluoride toxicity agonists.

    Science.gov (United States)

    Nelson, James W; Plummer, Mark S; Blount, Kenneth F; Ames, Tyler D; Breaker, Ronald R

    2015-04-23

    Fluoride is a ubiquitous anion that inhibits a wide variety of metabolic processes. Here, we report the identification of a series of compounds that enhance fluoride toxicity in Escherichia coli and Streptococcus mutans. These molecules were isolated by using a high-throughput screen (HTS) for compounds that increase intracellular fluoride levels as determined via a fluoride riboswitch reporter fusion construct. A series of derivatives were synthesized to examine structure-activity relationships, leading to the identification of compounds with improved activity. Thus, we demonstrate that small molecule fluoride toxicity agonists can be identified by HTS from existing chemical libraries by exploiting a natural fluoride riboswitch. In addition, our findings suggest that some molecules might be further optimized to function as binary antibacterial agents when combined with fluoride. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Salicylate toxicity model of tinnitus

    Directory of Open Access Journals (Sweden)

    Daniel eStolzberg

    2012-04-01

    Full Text Available Salicylate, the active component of the common drug aspirin, has mild analgesic, antipyretic, and anti-inflammatory effects at moderate doses. At higher doses, however, salicylate temporarily induces moderate hearing loss and the perception of a high-pitch ringing in humans and animals. This phantom perception of sound known as tinnitus is qualitatively similar to the persistent subjective tinnitus induced by high-level noise exposure, ototoxic drugs or aging which affects ~14% of the general population. For over a quarter century, auditory scientists have used the salicylate toxicity model to investigate candidate biochemical and neurophysiological mechanisms underlying phantom sound perception. In this review, we summarize some of the intriguing biochemical and physiological effects associated with salicylate-induced tinnitus, some of which occur in the periphery and others in the central nervous system. The relevance and general utility of the salicylate toxicity model in understanding phantom sound perception in general are discussed.

  8. Quantitative Adverse Outcome Pathways and their Utility to Ecological Risk Assessments of Endangered Species

    Science.gov (United States)

    Ecological risk assessments of endangered species are often hampered by a lack of knowledge about the sensitivity of endangered species to chemicals of concern. However, traditional in vivo toxicity testing of endangered species is often not possible for practical and ethical rea...

  9. FLUORIDE TOXICITY – A HARSH REALITY

    OpenAIRE

    Bandlapalli Pavani; Mandava Ragini; David Banji; Otilia J F Banji; N Gouri Pratusha

    2011-01-01

    There are many incidents of fluoride toxicity whether it is acute or chronic. Fluoride toxicity is an environmental hazard which arises from the upper layers of geological crust and is dissolved in water. Prolonged drinking of such water causes chronic fluoride toxicity. Use of fluoride containing compounds for various purposes such as dental products, metal, glass, refrigerator and chemical industries act as a source of fluoride poisoning and increase the risk of toxicity. This review reflec...

  10. Abacavir-induced liver toxicity

    Directory of Open Access Journals (Sweden)

    Maria Diletta Pezzani

    2016-09-01

    Full Text Available Abacavir-induced liver toxicity is a rare event almost exclusively occurring in HLA B*5701-positive patients. Herein, we report one case of abnormal liver function tests occurring in a young HLA B*5701-negative woman on a stable nevirapine-based regimen with no history of liver problems or alcohol abuse after switching to abacavir from tenofovir. We also investigated the reasons for abacavir discontinuation in a cohort of patients treated with abacavir-lamivudine-nevirapine.

  11. Acute and chronic arsenic toxicity

    OpenAIRE

    Ratnaike, R

    2003-01-01

    Arsenic toxicity is a global health problem affecting many millions of people. Contamination is caused by arsenic from natural geological sources leaching into aquifers, contaminating drinking water and may also occur from mining and other industrial processes. Arsenic is present as a contaminant in many traditional remedies. Arsenic trioxide is now used to treat acute promyelocytic leukaemia. Absorption occurs predominantly from ingestion from the small intestine, though minimal absorption o...

  12. Toxic metals in the atmosphere

    International Nuclear Information System (INIS)

    Munoz-Ribadeneira, F.J.; Mo, T.; Canoy, M.J.

    1975-05-01

    Methods used in Puerto Rico for monitoring toxic metals in the atmosphere are described. Air sampling machines are placed at heights from 15 to 25 ft above the surface and the tapes are subjected to neutron activation and γ spectroscopy. The concentrations of up to 33 elements can be determined with precision and sensitivity without destroying the tapes, which can then be used for analysis by other methods. (U.S.)

  13. Plant responses to metal toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Briat, J.F. [Montpellier-2 Univ., 34 (France). Biochimie et physiologie moleculaire des plantes, CNRS, URA 2133; Lebrun, M. [Montpellier-2 Univ., 34 (France). Biochimie et physiologie vegetale appliquee

    1999-01-01

    Increased metal concentration in the soils, up to toxic levels, is becoming an important environmental problem. Safety rule evolution will require solutions in order to cope with food safety rules, and to freeze metal leakage from heavily metal-poisoned soils, such as those from industrial fallows. In this context, plants could serve to develop bio-assays in order to promote new standards, more realistic than the mass of a given metal per kg of soil, that does not consider the metal bio-disponibility. Plants could also be used for phyto-extraction and/or phyto-stabilization. To reach these objectives, a genetic approach could be useful to generate metal-tolerant plants with enough biomass. In this work is more particularly studied the plant responses to metal toxicity. Metal toxicity for living organisms involves oxidative and /or genotoxic mechanisms. Plant protection against metal toxicity occurs, at least in part, through control of root metal uptake and of long distance metal transport. Inside cells, proteins such as ferritins and metallothioneins, and glutathione-derived peptides named phyto-chelatins, participate in excess metal storage and detoxification. Low molecular weight organic molecules, mainly organic acids and amino acids and their derivatives, also play an important role in plant metal homeostasis. When these systems are overloaded, oxidative stress defense mechanisms are activated. Molecular and cellular knowledge of these processes will be necessary to improve plant metal resistance. Occurrence of naturally tolerant plants which hyper accumulate metals provides helpful tools for this research. (authors) 130 refs.

  14. Developmental toxicity of engineered nanomaterials

    DEFF Research Database (Denmark)

    Hougaard, Karin S.; Hansen, Jitka S.; Jackson, Petra

    2016-01-01

    Study of air pollution indicates that minute particles may adversely interfere with pregnancy and fetal development. As engineering of nanoparticles have emerged, so has concern that these might interfere with reproductive and developmental functions. This is because nanotechnology may potentially...... increase the overall particle burden in air and introduce particles with novel characteristics and surface reactivity. To evaluate safety for pregnant women, we have studied developmental toxicity of engineered nanoparticles (ENPs), following exposure of pregnant mice by inhalation (ENPs of titanium...

  15. Coumafuryl (Fumarin) toxicity in chicks.

    Science.gov (United States)

    Munger, L L; Su, J J; Barnes, H J

    1993-01-01

    Coumafuryl (Fumarin) toxicity was diagnosed in chickens less than 1 week of age. Mortality rate was 100%. Necropsy showed crops and gizzards to be full of feed. There was diffuse hemorrhage and unclotted blood in the abdomen and thorax. Histological examination showed congestion and hemorrhage. Chemical analysis of crop and gizzard contents contained approximately 340 ppm coumafuryl. The source of the coumafuryl was found to be the wood-straw mats in the chick boxes.

  16. Pathological features of glutaminase toxicity.

    Science.gov (United States)

    Baskerville, A.; Hambleton, P.; Benbough, J. E.

    1980-01-01

    In an investigation of the toxicity of the anti-tumour enzyme glutaminase Rhesus monkeys, marmosets, rabbits and mice were given various doses of chemically modified glutaminase parenterally. The enzyme induced diarrhoea and dysentery and at all but the lowest doses caused illness which was fatal within 10 days. Pathological lesions produced were hepatic lipidosis and glycogen accumulation, and, in the primates, acute necrotizing colitis. Images Fig. 1 Fig. 2 PMID:6775661

  17. Dietary zinc and its toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Lantzsch, H J

    1973-01-01

    First signs of Zn-toxicity in rats appeared at 1000 to 2000 ppm Zn in food. They were characterized by growth inhibition by the appearance of a microcytic hypochromic anemia by a reversible impairment of the ability to reproduce by disturbances in fat metabolism and by Zn-accumulation especially in the liver and the skeleton. Available results in the literature concerning alimentary Zn-toxicity in horses are few. At a daily doses of 8000 mg Zn during gestation there were no noticeable adverse effects either in the mare or the foal. While with young lambs addition of Zn of up to 1000 ppm enhanced growth, food intake and feed efficiency, with older lambs it gave rise to depressions. Available results of experiments with milk cows are equally insufficient. At Zn-concentration of 40 to 80 ppm, which may be reached in normal foodstuff, there appears to be a disturbance in the metabolism of cellulose in the rumen. In spite of this fact and notwithstanding the insufficiently examined influence of high Zn-concentrations in food on the Cu-metabolism, the limit of Zn-tolerance can be given at 1000 mg per kg of food. If dissolved, Zn is far more toxic. With calves there wre no signs of clinical toxicity up to Zn-concentrations in the food of 3000 ppm. Above 900 ppm there appeared depression in growth and deterioration in the feed efficiency. Ae 1700 ppm there was a decrease infood intake. Increased Zn-intake lead to a growing Zn-accumulation in several organs and tissues, with the accumulation in the liver, bones, kidneys, pancreas and the gastrointestinal tract being of special significance. With cessation of Zn-intake in food, Zn-accumulation slowly disappeared. As a result of high Zn-intake there appears to be synergistic and antagonistic interdependent effects with the metabolism of other trace elements (Cu, Fe) and minerals (Ca, Na, P).

  18. The politics of toxic waste

    International Nuclear Information System (INIS)

    Rahm, D.

    1998-01-01

    Toxic waste, and the public policy that deals with it, is a complex issue. Much of the complexity stems from the science and technology embedded in the topic, but a great deal also results from the intricate interactions between the social organizations and institutions involved. The politics of toxic waste plays out within three key aspects of this complexity. The first of these is the nature of the intergovernmental relations involved. For toxic waste issues, these intergovernmental relations can be between sovereign states or between a nation and an international governing organization, or they may be restricted to a domestic context. If the later is the case, the relationship can be between federal, state, and local governments or between different bureaus, departments, or agencies within the same level of government. A second feature of this complexity can be seen in the consequences of divergent organizational or institutional interests. When conflicting organizational or institutional perspectives, positions, or concerns arise, public policy outcomes are affected.The tug and pull of competing actors move policy in the direction favored by the winner. This may or may not be the most rational alternative. A third aspect of this interorganizational puzzle involves the question of where the locus of authority for decisionmaking resides and to what extent stakeholders, who do not possess direct authority, can influence policy outcomes

  19. Joint toxic effects on Caenorhabditis elegans

    NARCIS (Netherlands)

    Jonker, M.J.

    2003-01-01

    In polluted areas organisms are generally exposed to mixtures of toxic chemicals rather than a single toxicant only. Since the number of mixture toxicity studies with regard to soil systems is limited, the research in this thesis was focused on investigating ecotoxicological consequences of

  20. Toxicity of pyrolysis gases from polyether sulfone

    Science.gov (United States)

    Hilado, C. J.; Olcomendy, E. M.

    1979-01-01

    A sample of polyether sulfone was evaluated for toxicity of pyrolysis gases, using the toxicity screening test method developed at the University of San Francisco. Animal response times were relatively short at pyrolysis temperatures of 600 to 800 C, with death occurring within 6 min. The principal toxicant appeared to be a compound other than carbon monoxide.

  1. Toxicity assessment of volatile organic compounds and polycyclic aromatic hydrocarbons in motorcycle exhaust

    International Nuclear Information System (INIS)

    Chang, C.-T.; Chen, B.-Y.

    2008-01-01

    This study investigates the toxicity of various pollutant species from motorcycle exhaust via dose-response analysis and margin of safety using Escherichia coli DH5α. The toxicity evaluation of the major components of motorcycle exhaust volatile organic compounds (VOCs), collected with impinger, and polycyclic aromatic hydrocarbons (PAHs), collected with filter and XAD-2, is essential to determine emission standards for motorcycles. The toxicity of benzene (B), toluene (T), ethyl benzene (E) and xylene (X) was selected for comparison as standard VOCs emitted from motorcycles. In addition, three types of reformulated gasoline (high oxygenate and high benzene content (No. 1), low oxygen and high benzene (No. 2), and low oxygen and low benzene (No. 3) were prepared to reveal combined toxicity of individual compositions. Motorcycle exhaust is significantly more toxic than BTEX due to the highly toxic VOCs generated from incomplete combustion. Overall toxicity evaluation showed that the toxicity, indicated as EC 50 , was approximately as follows: PAHs > two-stroke engines > four-stroke engines > BTEX

  2. Toxicity assessment of volatile organic compounds and polycyclic aromatic hydrocarbons in motorcycle exhaust.

    Science.gov (United States)

    Chang, Chang-Tang; Chen, Bor-Yann

    2008-05-30

    This study investigates the toxicity of various pollutant species from motorcycle exhaust via dose-response analysis and margin of safety using Escherichia coli DH5 alpha. The toxicity evaluation of the major components of motorcycle exhaust volatile organic compounds (VOCs), collected with impinger, and polycyclic aromatic hydrocarbons (PAHs), collected with filter and XAD-2, is essential to determine emission standards for motorcycles. The toxicity of benzene (B), toluene (T), ethyl benzene (E) and xylene (X) was selected for comparison as standard VOCs emitted from motorcycles. In addition, three types of reformulated gasoline (high oxygenate and high benzene content (No. 1), low oxygen and high benzene (No. 2), and low oxygen and low benzene (No. 3) were prepared to reveal combined toxicity of individual compositions. Motorcycle exhaust is significantly more toxic than BTEX due to the highly toxic VOCs generated from incomplete combustion. Overall toxicity evaluation showed that the toxicity, indicated as EC50, was approximately as follows: PAHs>two-stroke engines>four-stroke engines>BTEX.

  3. Species accounts. Chapter 4

    Science.gov (United States)

    Margaret K. Trani; W. Mark Ford; Brian R., eds. Chapman

    2007-01-01

    Narrative accounts for each species are presented by several authors in a consistent format to convey specific information relative to that mammal. The orders are arranged phylogenetically; families and species are arranged alphabetically to facilitate finding a particular species.

  4. Toxicity of inhaled alpha-emitting radionuclides - Status report

    Energy Technology Data Exchange (ETDEWEB)

    Muggenburg, B A; Mewhinney, J A; Guilmette, R A; Gillett, N A; Diel, J H; Lundgren, D L; Hahn, F F; Boecker, B B; McClellan, R O

    1988-12-01

    The toxicity of inhaled alpha-emitting radionuclides is being investigated in a series of interrelated dose-response studies. Dogs, rodents, and nonhuman primates have been exposed to monodisperse or polydisperse aerosols of the oxides of {sup 239}Pu, {sup 238}Pu, {sup 241}Am, or {sup 244}Cm to measure the relative importance of average organ dose, local dose around particles, specific activity, chemical form, particle size, and number of particles inhaled to the development of biological effects. The influence of animal species, age at exposure, and pre-existing lung disease, as well as the effects of repeated exposure, are also being studied, because they may influence the toxicity of these radionuclides. (author)

  5. Silver nanoparticles and silver nitrate induce high toxicity to Pseudokirchneriella subcapitata, Daphnia magna and Danio rerio

    International Nuclear Information System (INIS)

    Ribeiro, Fabianne; Gallego-Urrea, Julián Alberto; Jurkschat, Kerstin; Crossley, Alison; Hassellöv, Martin; Taylor, Cameron; Soares, Amadeu M.V.M.; Loureiro, Susana

    2014-01-01

    Silver nanoparticles (AgNP) have gained attention over the years due to the antimicrobial function of silver, which has been exploited industrially to produce consumer goods that vary in type and application. Undoubtedly the increase of production and consumption of these silver-containing products will lead to the entry of silver compounds into the environment. In this study we have used Pseudokirchneriella subcapitata, Daphnia magna and Danio rerio as model organisms to investigate the toxicity of AgNP and AgNO 3 by assessing different biological endpoints and exposure periods. Organisms were exposed following specific and standardized protocols for each species/endpoints, with modifications when necessary. AgNP were characterized in each test-media by Transmission Electron Microscopy (TEM) and experiments were performed by Dynamic Light Scattering (DLS) to investigate the aggregation and agglomeration behavior of AgNP under different media chemical composition and test-period. TEM images of AgNP in the different test-media showed dissimilar patterns of agglomeration, with some agglomerates inside an organic layer, some loosely associated particles and also the presence of some individual particles. The toxicity of both AgNO 3 and AgNP differ significantly based on the test species: we found no differences in toxicity for algae, a small difference for zebrafish and a major difference in toxicity for Daphnia magna. - Highlights: •Effects of silver nanoparticles and nitrate were compared in three aquatic species. •The presence of food on the immobilization assay for Daphnia magna significantly decreased AgNP toxicity. •AgNP and AgNO 3 differ in toxicity according to the test species and endpoint. •AgNP and AgNO 3 induced dissimilar abnormalities on zebrafish embryos' development. •AgNP behavior in the test media will rule its bioavailability and uptake and therefore toxicity

  6. Silver nanoparticles and silver nitrate induce high toxicity to Pseudokirchneriella subcapitata, Daphnia magna and Danio rerio

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Fabianne, E-mail: ribeiro.f@ua.pt [Department of Biology and CESAM, University of Aveiro. Campus Universitario de Santiago, 3810-193. Aveiro (Portugal); Gallego-Urrea, Julián Alberto [Department of Chemistry and Molecular Biologyx, University of Gothenburg, Kemivägen 4, 41296 Gothenburg (Sweden); Jurkschat, Kerstin; Crossley, Alison [Department of Materials, Oxford University Begbroke Science Park OX5 1PF (United Kingdom); Hassellöv, Martin [Department of Chemistry and Molecular Biologyx, University of Gothenburg, Kemivägen 4, 41296 Gothenburg (Sweden); Taylor, Cameron [Department of Materials, Oxford University Begbroke Science Park OX5 1PF (United Kingdom); Soares, Amadeu M.V.M.; Loureiro, Susana [Department of Biology and CESAM, University of Aveiro. Campus Universitario de Santiago, 3810-193. Aveiro (Portugal)

    2014-01-01

    Silver nanoparticles (AgNP) have gained attention over the years due to the antimicrobial function of silver, which has been exploited industrially to produce consumer goods that vary in type and application. Undoubtedly the increase of production and consumption of these silver-containing products will lead to the entry of silver compounds into the environment. In this study we have used Pseudokirchneriella subcapitata, Daphnia magna and Danio rerio as model organisms to investigate the toxicity of AgNP and AgNO{sub 3} by assessing different biological endpoints and exposure periods. Organisms were exposed following specific and standardized protocols for each species/endpoints, with modifications when necessary. AgNP were characterized in each test-media by Transmission Electron Microscopy (TEM) and experiments were performed by Dynamic Light Scattering (DLS) to investigate the aggregation and agglomeration behavior of AgNP under different media chemical composition and test-period. TEM images of AgNP in the different test-media showed dissimilar patterns of agglomeration, with some agglomerates inside an organic layer, some loosely associated particles and also the presence of some individual particles. The toxicity of both AgNO{sub 3} and AgNP differ significantly based on the test species: we found no differences in toxicity for algae, a small difference for zebrafish and a major difference in toxicity for Daphnia magna. - Highlights: •Effects of silver nanoparticles and nitrate were compared in three aquatic species. •The presence of food on the immobilization assay for Daphnia magna significantly decreased AgNP toxicity. •AgNP and AgNO{sub 3} differ in toxicity according to the test species and endpoint. •AgNP and AgNO{sub 3} induced dissimilar abnormalities on zebrafish embryos' development. •AgNP behavior in the test media will rule its bioavailability and uptake and therefore toxicity.

  7. Comparative chronic toxicity of imidacloprid, clothianidin, and thiamethoxam to Chironomus dilutus and estimation of toxic equivalency factors.

    Science.gov (United States)

    Cavallaro, Michael C; Morrissey, Christy A; Headley, John V; Peru, Kerry M; Liber, Karsten

    2017-02-01

    Nontarget aquatic insects are susceptible to chronic neonicotinoid insecticide exposure during the early stages of development from repeated runoff events and prolonged persistence of these chemicals. Investigations on the chronic toxicity of neonicotinoids to aquatic invertebrates have been limited to a few species and under different laboratory conditions that often preclude direct comparisons of the relative toxicity of different compounds. In the present study, full life-cycle toxicity tests using Chironomus dilutus were performed to compare the toxicity of 3 commonly used neonicotinoids: imidacloprid, clothianidin, and thiamethoxam. Test conditions followed a static-renewal exposure protocol in which lethal and sublethal endpoints were assessed on days 14 and 40. Reduced emergence success, advanced emergence timing, and male-biased sex ratios were sensitive responses to low-level neonicotinoid exposure. The 14-d median lethal concentrations for imidacloprid, clothianidin, and thiamethoxam were 1.52 μg/L, 2.41 μg/L, and 23.60 μg/L, respectively. The 40-d median effect concentrations (emergence) for imidacloprid, clothianidin, and thiamethoxam were 0.39 μg/L, 0.28 μg/L, and 4.13 μg/L, respectively. Toxic equivalence relative to imidacloprid was estimated through a 3-point response average of equivalencies calculated at 20%, 50%, and 90% lethal and effect concentrations. Relative to imidacloprid (toxic equivalency factor [TEF] = 1.0), chronic (lethality) 14-d TEFs for clothianidin and thiamethoxam were 1.05 and 0.14, respectively, and chronic (emergence inhibition) 40-d TEFs were 1.62 and 0.11, respectively. These population-relevant endpoints and TEFs suggest that imidacloprid and clothianidin exert comparable chronic toxicity to C. dilutus, whereas thiamethoxam induced comparable effects only at concentrations an order of magnitude higher. However, the authors caution that under field conditions, thiamethoxam readily degrades to

  8. Toxic Stress: Effects, Prevention and Treatment

    Directory of Open Access Journals (Sweden)

    Hillary A. Franke

    2014-11-01

    Full Text Available Children who experience early life toxic stress are at risk of long-term adverse health effects that may not manifest until adulthood. This article briefly summarizes the findings in recent studies on toxic stress and childhood adversity following the publication of the American Academy of Pediatrics (AAP Policy Report on the effects of toxic stress. A review of toxic stress and its effects is described, including factors of vulnerability, resilience, and the relaxation response. An integrative approach to the prevention and treatment of toxic stress necessitates individual, community and national focus.

  9. Evaluation of lithium as a toxicant and the modifying effect of sodium

    International Nuclear Information System (INIS)

    Kszos, L.A.; Stewart, A.J.; O'Reilly, S.E.

    1995-01-01

    Routine compliance tests conducted for a groundwater treatment facility at the Y-12 Plant on the Department of Energy's (DOE) Oak Ridge Reservation (ORR), TN, showed that the effluent was acutely toxic to Ceriodaphnia dubia and fathead minnow (Pimephales promelas) larvae. An evaluation of suspected contaminants revealed that increased toxicity coincided with increased concentrations of lithium. Lithium is a light, strong metal that is used in DOE operations, including fusion weapons and fission reactors. Little has been published about lithium toxicity. Toxicity tests were conducted with fathead minnows and C. dubia using lithium chloride and lithium tetraborate. Dilute mineral water (DMW) or the receiving stream water (East Fork Poplar Creek) was used as the dilution water in the toxicity evaluation. A concentration of 1 mg Li/L in DMW reduced the survival of both test species; 0.5 mg Li/L in DMW reduced C. dubia reproduction and minnow growth. Sodium appears to influence the toxicity of Li; the metal was six times more toxic in the low-sodium DMW than in stream water containing 30 mg Na/L. Tests with LiCl in combination with NaCl and NA 2 SO 4 demonstrated that the presence of sodium reduced the toxicity of Li to C. dubia. In laboratory tests with a snail (Elimia clavaeformis) common on the ORR, the feeding rate declined in 0.15 mg Li/L. Because Li has also been demonstrated to be toxic to several plant species, tests with LiCi were also conducted using buttercrunch lettuce (Lactuca saliva). The EC 50 for seed growth after 8 d incubation was 37.5 mg Li/L. These findings are significant because of widespread industrial use and potential accumulation of Li in soils

  10. Ammonia production, excretion, toxicity, and defense in fish: A Review

    Directory of Open Access Journals (Sweden)

    Alex Y K Ip

    2010-10-01

    Full Text Available Many fishes are ammonotelic but some species can detoxify ammonia to glutamine or urea. Certain fish species can accumulate high levels of ammonia in the brain or defense against ammonia toxicity by enhancing the effectiveness of ammonia excretion through active NH4+ transport, manipulation of ambient pH, or reduction in ammonia permeability through the branchial and cutaneous epithelia. Recent reports on ammonia toxicity in mammalian brain reveal the importance of permeation of ammonia through the blood-brain barrier and passages of ammonia and water through transporters in the plasmalemma of brain cells. Additionally, brain ammonia toxicity could be related to the passage of glutamine through the mitochondrial membranes into the mitochondrial matrix. On the other hand, recent reports on ammonia excretion in fish confirm the involvement of Rhesus glycoproteins in the branchial and cutaneous epithelia. Therefore, this review focuses on both the earlier literature and the up-to-date information on the problems and mechanisms concerning the permeation of ammonia, as NH3, NH4+ or proton-neutral nitrogenous compounds, across mitochondrial membranes, the blood-brain barrier, the plasmalemma of neurons, and the branchial and cutaneous epithelia of fish. It also addresses how certain fishes with high ammonia tolerance defend against ammonia toxicity through the regulation of the permeation of ammonia and related nitrogenous compounds through various types of membranes. It is hoped that this review would revive the interests in investigations on the passage of ammonia through the mitochondrial membranes and the blood-brain barrier of ammonotelic fishes and fishes with high brain ammonia-tolerance, respectively.

  11. Sublethal Effects in Pest Management: A Surrogate Species Perspective on Fruit Fly Control

    Directory of Open Access Journals (Sweden)

    John E. Banks

    2017-07-01

    Full Text Available Tephritid fruit flies are economically important orchard pests globally. While much effort has focused on controlling individual species with a combination of pesticides and biological control, less attention has been paid to managing assemblages of species. Although several tephritid species may co-occur in orchards/cultivated areas, especially in mixed-cropping schemes, their responses to pesticides may be highly variable. Furthermore, predictive efforts about toxicant effects are generally based on acute toxicity, with little or no regard to long-term population effects. Using a simple matrix model parameterized with life history data, we quantified the responses of several tephritid species to the sublethal effects of a toxicant acting on fecundity. Using a critical threshold to determine levels of fecundity reduction below which species are driven to local extinction, we determined that threshold levels vary widely for the three tephritid species. In particular, Bactrocera dorsalis was the most robust of the three species, followed by Ceratitis capitata, and then B. cucurbitae, suggesting individual species responses should be taken into account when planning for area-wide pest control. The rank-order of susceptibility contrasts with results from several field/lab studies testing the same species, suggesting that considering a combination of life history traits and individual species susceptibility is necessary for understanding population responses of species assemblages to toxicant exposure.

  12. Lunar Airborne Dust Toxicity Hazard Assessments (Invited)

    Science.gov (United States)

    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

  13. The acute toxicity of clove oil to fish Danio rerio and Poecilia reticulata

    Directory of Open Access Journals (Sweden)

    Petra Doleželová

    2011-01-01

    Full Text Available Clove oil (active substance eugenol is an anaesthetic used in aquaculture for stress prevention and prevention of mechanical damage during veterinary procedures. The aim of this study was to determine the acute toxicity of clove oil in two aquarium fish species - zebrafish (Danio rerio and guppy (Poecilia reticulata, which are considered the most commonly used model organisms in toxicity testing. The semi-static method according to OECD no. 203 (Fish, Acute toxicity test was used for testing the toxicity of clove oil for juvenile fish. A series of 5 acute toxicity tests was performed, with 10 fish of both species used for each concentration and for the control. The results obtained (number of dead individuals at particular test concentrations were subjected to a probit analysis using the EKO-TOX 5.2 program in order to determine 96hLC50 clove oil values. The significance of the difference between 96hLC50 values in D. rerio and P. reticulata was tested using the Mann-Whitney non-parametric test. The 96hLC50 mean value for clove oil was 18.2 ± 5.52 mg·l–1 in juvenile D. rerio and 21.7 ± 0.8 mg·l–1 in P. reticulata. In spite of variability in clove oil composition, acute toxicity values of clove oil for juvenile stages of both fish species were comparable. The results did not show different sensitivities to clove oil in tested fish species. This is the first similar study in these fish species.

  14. Acute toxicity of heavy metals towards freshwater ciliated protists

    International Nuclear Information System (INIS)

    Madoni, Paolo; Romeo, Maria Giuseppa

    2006-01-01

    The acute toxicity of five heavy metals to four species of freshwater ciliates (Colpidium colpoda, Dexiotricha granulosa, Euplotes aediculatus, and Halteria grandinella) was examined in laboratory tests. After exposing the ciliates to soluble compound of cadmium, copper, chromium, lead, and nickel at several selected concentrations, the mortality rate was registered and the LC 5 values (with 95% confidence intervals) were calculated. Large differences appeared in sensitivities of the four species to the metals. H. grandinella showed the highest sensitivity for cadmium (0.07 mg l -1 , LC 5 ) and lead (0.12 mg l -1 , LC 5 ), whilst E. aediculatus showed the highest sensitivity for nickel (0.03 mg l -1 , LC 5 ). The comparison with data obtained with other species indicate that Halteria grandinella and Euplotes aediculatus are excellent and convenient bioindicator for evaluating the toxicity of waters and wastewaters polluted by heavy metals. The short time (24 h) and simplicity of the test procedure enable this test to be used in laboratory studies. - Ciliated protozoa are suitable bioindicators of heavy metal pollution in freshwater environments

  15. Acute toxicity of heavy metals towards freshwater ciliated protists

    Energy Technology Data Exchange (ETDEWEB)

    Madoni, Paolo [Dipartimento di Scienze Ambientali, Universita degli Studi di Parma, Parco Area delle Scienze 11/A, 43100 Parma (Italy)]. E-mail: paolo.madoni@unipr.it; Romeo, Maria Giuseppa [Dipartimento di Scienze Ambientali, Universita degli Studi di Parma, Parco Area delle Scienze 11/A, 43100 Parma (Italy)

    2006-05-15

    The acute toxicity of five heavy metals to four species of freshwater ciliates (Colpidium colpoda, Dexiotricha granulosa, Euplotes aediculatus, and Halteria grandinella) was examined in laboratory tests. After exposing the ciliates to soluble compound of cadmium, copper, chromium, lead, and nickel at several selected concentrations, the mortality rate was registered and the LC{sub 5} values (with 95% confidence intervals) were calculated. Large differences appeared in sensitivities of the four species to the metals. H. grandinella showed the highest sensitivity for cadmium (0.07 mg l{sup -1}, LC{sub 5}) and lead (0.12 mg l{sup -1}, LC{sub 5}), whilst E. aediculatus showed the highest sensitivity for nickel (0.03 mg l{sup -1}, LC{sub 5}). The comparison with data obtained with other species indicate that Halteria grandinella and Euplotes aediculatus are excellent and convenient bioindicator for evaluating the toxicity of waters and wastewaters polluted by heavy metals. The short time (24 h) and simplicity of the test procedure enable this test to be used in laboratory studies. - Ciliated protozoa are suitable bioindicators of heavy metal pollution in freshwater environments.

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

    Science.gov (United States)

    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. © Springer Science+Business Media, LLC 2011

  17. Protein Nanoscaffolds for Delivering Toxic Inorganic Cargo to Cancer Cells

    Science.gov (United States)

    Cioloboc, Daniela

    Targeted delivery of anticancer drugs or prodrugs to tumors can minimize systemic toxicity and side effects. This study develops platforms for targeted delivery of two potentially less systemically toxic prodrugs by exploiting the native and/or bioinorganic properties of two ferritins, both of which function naturally as iron storage proteins. Two delivery approaches were investigated. The first system was designed to serve as either an enhancement or alternative to traditional photodynamic therapy by generating hydroxyl radical in addition to singlet oxygen as the toxic reactive oxygen species. This system used Escherichia coli bacterioferritin (Bfr) loaded with 2,500 irons and multiple zinc-porphyrin (ZnP) photosensitizers. Ferrous iron was released by photoreduction of ferric iron stored within the Bfr protein shell. Hydroxyl radicals were generated via the Fenton reaction between hydrogen peroxide and the released ferrous iron. The outer surface of the Bfr protein shell was coated with peptides that specifically bind to a receptor known to be overexpressed in many tumor cells and tumor vasculature. The iron-loaded peptide-ZnP-Bfr was endocytosed by melanoma cells, where it showed photo-triggered release of iron and light-dependent cytotoxicity. The second system, built around human heavy chain ferritin (HFn), was loaded with arsenate as a less toxic "prodrug" and designed to release arsenic in its toxic, therapeutically effective reduced form, arsenic trioxide (ATO). The Hfn shell was coated with peptides targeting receptors that are hyperexpressed in triple negative breast cancers. The arsenate/iron-loaded-Hfn was endocytosed by a breast cancer cell line and showed cytotoxicity equivalent to that of free ATO on an arsenic basis, whereas the "empty" or iron-only loaded Hfn showed no cytotoxicity. Although HFn has previously been used to deliver organic drugs and imaging agents, these new results demonstrate that both Bfr and HFn can be manipulated to function

  18. Transcriptomic and physiological analysis of common duckweed Lemna minor responses to NH4(+) toxicity.

    Science.gov (United States)

    Wang, Wenguo; Li, Rui; Zhu, Qili; Tang, Xiaoyu; Zhao, Qi

    2016-04-18

    Plants can suffer ammonium (NH4 (+)) toxicity, particularly when NH4 (+) is supplied as the sole nitrogen source. However, our knowledge about the underlying mechanisms of NH4 (+) toxicity is still largely unknown. Lemna minor, a model duckweed species, can grow well in high NH4 (+) environment but to some extent can also suffer toxic effects. The transcriptomic and physiological analysis of L. minor responding to high NH4 (+) may provide us some interesting and useful information not only in toxic processes, but also in tolerance mechanisms. The L. minor cultured in the Hoagland solution were used as the control (NC), and in two NH4 (+) concentrations (NH4 (+) was the sole nitrogen source), 84 mg/L (A84) and 840 mg/L (A840) were used as stress treatments. The NH4 (+) toxicity could inhibit the growth of L. minor. Reactive oxygen species (ROS) and cell death were studied using stained fronds under toxic levels of NH4 (+). The malondialdehyde content and the activities of superoxide dismutase and peroxidase increased from NC to A840, rather than catalase and ascorbate peroxidase. A total of 6.62G nucleotides were generated from the three distinct libraries. A total of 14,207 differentially expressed genes (DEGs) among 70,728 unigenes were obtained. All the DEGs could be clustered into 7 profiles. Most DEGs were down-regulated under NH4 (+) toxicity. The genes required for lignin biosynthesis in phenylpropanoid biosynthesis pathway were up-regulated. ROS oxidative-related genes and programmed cell death (PCD)-related genes were also analyzed and indicated oxidative damage and PCD occurring under NH4 (+) toxicity. The first large transcriptome study in L. minor responses to NH4 (+) toxicity was reported in this work. NH4 (+) toxicity could induce ROS accumulation that causes oxidative damage and thus induce cell death in L. minor. The antioxidant enzyme system was activated under NH4 (+) toxicity for ROS scavenging. The phenylpropanoid pathway was stimulated under

  19. Predicting dietborne metal toxicity from metal influxes

    Science.gov (United States)

    Croteau, M.-N.; Luoma, S.N.

    2009-01-01

    Dietborne metal uptake prevails for many species in nature. However, the links between dietary metal exposure and toxicity are not well understood. Sources of uncertainty include the lack of suitable tracers to quantify exposure for metals such as copper, the difficulty to assess dietary processes such as food ingestion rate, and the complexity to link metal bioaccumulation and effects. We characterized dietborne copper, nickel, and cadmium influxes in a freshwater gastropod exposed to diatoms labeled with enriched stable metal isotopes. Metal influxes in Lymnaea stagnalis correlated linearly with dietborne metal concentrations over a range encompassing most environmental exposures. Dietary Cd and Ni uptake rate constants (kuf) were, respectively, 3.3 and 2.3 times higher than that for Cu. Detoxification rate constants (k detox) were similar among metals and appeared 100 times higher than efflux rate constants (ke). Extremely high Cu concentrations reduced feeding rates, causing the relationship between exposure and influx to deviate from linearity; i.e., Cu uptake rates leveled off between 1500 and 1800 nmol g-1 day-1. L. stagnalis rapidly takes up Cu, Cd, and Ni from food but detoxifies the accumulated metals, instead of reducing uptake or intensifying excretion. Above a threshold uptake rate, however, the detoxification capabilities of L. stagnalis are overwhelmed.

  20. Assaying environmental nickel toxicity using model nematodes.

    Directory of Open Access Journals (Sweden)

    David Rudel

    Full Text Available Although nickel exposure results in allergic reactions, respiratory conditions, and cancer in humans and rodents, the ramifications of excess nickel in the environment for animal and human health remain largely undescribed. Nickel and other cationic metals travel through waterways and bind to soils and sediments. To evaluate the potential toxic effects of nickel at environmental contaminant levels (8.9-7,600 µg Ni/g dry weight of sediment and 50-800 µg NiCl2/L of water, we conducted assays using two cosmopolitan nematodes, Caenorhabditis elegans and Pristionchus pacificus. We assayed the effects of both sediment-bound and aqueous nickel upon animal growth, developmental survival, lifespan, and fecundity. Uncontaminated sediments were collected from sites in the Midwestern United States and spiked with a range of nickel concentrations. We found that nickel-spiked sediment substantially impairs both survival from larval to adult stages and adult longevity in a concentration-dependent manner. Further, while aqueous nickel showed no adverse effects on either survivorship or longevity, we observed a significant decrease in fecundity, indicating that aqueous nickel could have a negative impact on nematode physiology. Intriguingly, C. elegans and P. pacificus exhibit similar, but not identical, responses to nickel exposure. Moreover, P. pacificus could be tested successfully in sediments inhospitable to C. elegans. Our results add to a growing body of literature documenting the impact of nickel on animal physiology, and suggest that environmental toxicological studies could gain an advantage by widening their repertoire of nematode species.

  1. Assaying environmental nickel toxicity using model nematodes

    Science.gov (United States)

    Rudel, David; Douglas, Chandler; Huffnagle, Ian; Besser, John M.; Ingersoll, Christopher G.

    2013-01-01

    Although nickel exposure results in allergic reactions, respiratory conditions, and cancer in humans and rodents, the ramifications of excess nickel in the environment for animal and human health remain largely undescribed. Nickel and other cationic metals travel through waterways and bind to soils and sediments. To evaluate the potential toxic effects of nickel at environmental contaminant levels (8.9-7,600 µg Ni/g dry weight of sediment and 50-800 µg NiCl2/L of water), we conducted assays using two cosmopolitan nematodes, Caenorhabditis elegans and Pristionchus pacificus. We assayed the effects of both sediment-bound and aqueous nickel upon animal growth, developmental survival, lifespan, and fecundity. Uncontaminated sediments were collected from sites in the Midwestern United States and spiked with a range of nickel concentrations. We found that nickel-spiked sediment substantially impairs both survival from larval to adult stages and adult longevity in a concentration-dependent manner. Further, while aqueous nickel showed no adverse effects on either survivorship or longevity, we observed a significant decrease in fecundity, indicating that aqueous nickel could have a negative impact on nematode physiology. Intriguingly, C. elegansand P. pacificus exhibit similar, but not identical, responses to nickel exposure. Moreover, P. pacificus could be tested successfully in sediments inhospitable to C. elegans. Our results add to a growing body of literature documenting the impact of nickel on animal physiology, and suggest that environmental toxicological studies could gain an advantage by widening their repertoire of nematode species.

  2. An Evolutionary Perspective on Toxic Leadership

    Directory of Open Access Journals (Sweden)

    Lucia Ovidia VREJA

    2016-12-01

    Full Text Available Charles Darwin’s prediction from 1859, that future psychology was going to be built on principles derived from evolutionary theory came at last to be fulfilled. Nowadays, there are at least four disciplines that attempt to explain human behaviours as evolutionary adaptations (or maladaptations to the natural and/or social environment: human sociobiology, human behavioural ecology, evolutionary psychology, memetics and gene–culture coevolution theory (in our view, the most adequate of all. According to gene–culture coevolution theory, articulated language was the singular phenomenon that permitted humans to become a cultural species, and from that moment on culture become itself a selection factor. Culture means transmission of information from one generation to the next and learning from other individuals’ experiences, trough language. So, it is of critical importance to have good criteria for the selection of those individuals from whom we should learn. Yet when humans also choose their leaders from among those role-models, according to the same criteria, this mechanism can become a maladaptation and the result can be toxic leadership.

  3. Dithiobiuret toxicity in the rat

    International Nuclear Information System (INIS)

    Williams, K.D.

    1985-01-01

    Raising the daily dose of dithiobiuret (DTB) in male rats from 0.5 to 1 to 5 mg/kg shortened the latency to the onset of flaccid muscle tone and associated diminished performance in a treadmill test from 7 to 5 to 3 days, respectively. Concomitant with the development of flaccid muscle tone gastrocnemius muscle contractions elicited by high frequency motor nerve stimulation were lower in peak tension and tended to fade more rapidly in DTB-treated rats than in control rats. Remarkably, rats treated with highly daily doses (10-16 mg/kg) of DTB were resistant to the expected development of DTB-induced flaccid muscle tone, and tetanic contractile abnormalities but a corresponding refractoriness to body weight loss, decreased fed and water intake, diuresis, and depression in water balance was not present. This nonselectivity of the refractory responses supported the results of a histopathological study indicating that DTB-induced neuromuscular toxicity was unlikely to be secondary to effect on other organ systems. It is not known whether the ultimate neurotoxin is DTB or a metabolite. In this regard, two pathways for the metabolism of DTB were proposed based on the results of thin-layer chromatography of urine samples from rats treated with either 14 C- or 35 S-DTB. One pathway involved the reversible oxidation of DTB to the disulfide-containing compound thiuret, and the other involved the replacement of a sulfur atom with oxygen to form monothiobiuret. Thiuret, but not monothiobiuret, possessed comparable toxicity to STB. This further suggested that redox cycling between DTB and thiuret could be an important contributing factor to the toxicity of DTB

  4. Lysophospholipase inhibition by organophosphorus toxicants

    International Nuclear Information System (INIS)

    Quistad, Gary B.; Casida, John E.

    2004-01-01

    Lysophospholipases (LysoPLAs) are a large family of enzymes for removing lysophospholipids from cell membranes. Potent inhibitors are needed to define the importance of LysoPLAs as targets for toxicants and potential therapeutics. This study considers organophosphorus (OP) inhibitors with emphasis on mouse brain total LysoPLA activity relative to the mipafox-sensitive neuropathy target esterase (NTE)-LysoPLA recently established as 17% of the total activity and important in the action of OP delayed toxicants. The most potent inhibitors of total LysoPLA in mouse brain are isopropyl dodecylphosphonofluoridate (also for LysoPLA of Vibrio bacteria), ethyl octylphosphonofluoridate (EOPF), and two alkyl-benzodioxaphosphorin 2-oxides (BDPOs)[(S)-octyl and dodecyl] (IC50 2-8 nM). OP inhibitors acting in vitro and in vivo differentiate a more sensitive portion but not a distinct NTE-LysoPLA compared with total LysoPLA activity. For 10 active inhibitors, NTE-LysoPLA is 17-fold more sensitive than total LysoPLA, but structure-activity comparisons give a good correlation (r 2 = 0.94) of IC50 values, suggesting active site structural similarity or identity. In mice 4 h after intraperitoneal treatment with discriminating doses, EOPF, tribufos (a plant defoliant), and dodecanesulfonyl fluoride inhibit 41-57% of the total brain LysoPLA and 85-99% of the NTE-LysoPLA activity. Total LysoPLA as well as NTE-LysoPLA is decreased in activity in Nte +/- -haploinsufficient mice compared to their Nte +/+ littermates. The lysolecithin level of spinal cord but not brain is elevated significantly following EOPF treatment (3 mg/kg), thereby focusing attention on localized rather than general alterations in lysophospholipid metabolism in OP-induced hyperactivity and toxicity

  5. Molecular basis of cadmium toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Nath, R; Prasad, R; Palinal, V K; Chopra, R K

    1984-01-01

    Cadmium has been shown to manifest its toxicity in human and animals by mainly accumulating in almost all of the organs. The kidney is the main target organ where it is concentrated mainly in the cortex. Environmental exposure of cadmium occurs via food, occupational industries, terrestrial and aquatic ecosystem. At molecular level, cadmium interferes with the utilization of essential metals e.g. Ca, Zn, Se, Cr and Fe and deficiencies of these essential metals including protein and vitamins, exaggerate cadmium toxicity, due to its increased absorption through the gut and greater retention in different organs as metallothionein (Cd-Mt). Cadmium transport, across the intestinal and renal brush border membrane vesicles, is carrier mediated and it competes with zinc and calcium. It has been postulated that cadmium shares the same transport system. Cadmium inhibits protein synthesis, carbohydrate metabolism and drug metabolizing enzymes in liver of animals. Chronic environmental exposure of cadmium produces hypertension in experimental animals. Functional changes accompanying cadmium nephropathy include low molecular weight proteinuria which is of tubular origin associated with excess excretion of proteins such as beta 2 microglobulin, metallothionein and high molecular weight proteinuria of glomerular origin (excretion of proteins such as albumin IgG, transferrin etc.). Recent data has shown that metallothionein is more nephrotoxic to animals. Cadmium is also toxic to central nervous system. It causes an alterations of cellular functions in lungs. Cadmium affects both humoral and cell mediated immune response in animals. Cadmium induces metallothionein in liver and kidney but under certain nutritional deficiencies like protein-calorie malnutrition and calcium deficiency, enhanced induction and greater accumulation of cadmium metallothionein has been observed.

  6. Chronic toxicity of nickel-spiked freshwater sediments: variation in toxicity among eight invertebrate taxa and eight sediments

    Science.gov (United States)

    Besser, John M.; Brumbaugh, William G.; Ingersoll, Christopher G.; Ivey, Chris D.; Kunz, James L.; Kemble, Nile E.; Schlekat, Christian E.; Garman, Emily R.

    2013-01-01

    This study evaluated the chronic toxicity of Ni-spiked freshwater sediments to benthic invertebrates. A 2-step spiking procedure (spiking and sediment dilution) and a 2-stage equilibration period (10 wk anaerobic and 1 wk aerobic) were used to spike 8 freshwater sediments with wide ranges of acid-volatile sulfide (AVS; 0.94–38 µmol/g) and total organic carbon (TOC; 0.42–10%). Chronic sediment toxicity tests were conducted with 8 invertebrates (Hyalella azteca, Gammarus pseudolimnaeus, Chironomus riparius, Chironomus dilutus, Hexagenia sp., Lumbriculus variegatus, Tubifex tubifex, and Lampsilis siliquoidea) in 2 spiked sediments. Nickel toxicity thresholds estimated from species-sensitivity distributions were 97 µg/g and 752 µg/g (total recoverable Ni; dry wt basis) for sediments with low and high concentrations of AVS and TOC, respectively. Sensitive species were tested with 6 additional sediments. The 20% effect concentrations (EC20s) for Hyalella and Gammarus, but not Hexagenia, were consistent with US Environmental Protection Agency benchmarks based on Ni in porewater and in simultaneously extracted metals (SEM) normalized to AVS and TOC. For Hexagenia, sediment EC20s increased at less than an equimolar basis with increased AVS, and toxicity occurred in several sediments with Ni concentrations in SEM less than AVS. The authors hypothesize that circulation of oxygenated water by Hexagenia led to oxidation of AVS in burrows, creating microenvironments with high Ni exposure. Despite these unexpected results, a strong relationship between Hexagenia EC20s and AVS could provide a basis for conservative site-specific sediment quality guidelines for Ni.

  7. Metabolism and toxicity of neptunium

    International Nuclear Information System (INIS)

    Nenot, J.C.

    1983-08-01

    The biological behaviour and toxicity of neptunium were studied. Neptunium was administered either intravenously or intramuscularly in rats. In contrast to other transuranium elements the distribution patterns of neptunium in the case of intravenous injection is not dependent on the physico-chemical state. Urinary excretion is high. The distribution after intramuscular injection showed a rather fast migration from the injection site. 237 Neptonium in urine was approximately equal to bone deposit. Neptunium behaviour followed that of alkaline earths rather than that of transplutonium elements

  8. Physiology and toxicity of fluoride

    OpenAIRE

    Dhar Vineet; Bhatnagar Maheep

    2009-01-01

    Fluoride has been described as an essential element needed for normal development and growth of animals and extremely useful for human beings. Fluoride is abundant in the environment and the main source of fluoride to humans is drinking water. It has been proved to be beneficial in recommended doses, and at the same time its toxicity at higher levels has also been well established. Fluoride gets accumulated in hard tissues of the body and has been know to play an important role in mineralizat...

  9. Air toxics research in Finland

    International Nuclear Information System (INIS)

    Hahkala, M.

    1994-01-01

    Air toxics research in Finland has developed rapidly in recent years. Though they have no enormous environmental problems in Finland, the author feels that they have to increase their knowledge of more efficient energy production and control technology. Enormous emission sources are around them, but there are also huge markets for know-how and technology in the energy sector. Two Finnish national research programs will ensure the continuity of the development efforts concerning combustion technology and environmental aspects at both theoretical and practical levels

  10. Copper toxicity in housed lambs

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, A H; Valks, D A; Appleton, M A; Shaw, W B

    1969-09-27

    Copper toxicity among 170 lambs artificially reared indoors at High Mowthorpe NAAS Experimental Husbandry Farm is reported. Although only three lambs were lost it is not unreasonable to suggest that the liver copper levels of the lambs which were slaughtered would have been high and losses could have been much heavier had there been any further copper supplementation. Even a copper level of 20 ppm in lamb concentrates given to lambs reared artificially indoors is dangerous, and intakes of much less than 38 mg per lamb per day can be fatal if given of a prolonged period. 5 references, 1 table.

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

    Science.gov (United States)

    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...

  12. Reactive oxygen species: role in the development of cancer and various chronic conditions

    Directory of Open Access Journals (Sweden)

    Waris Gulam

    2006-05-01

    Full Text Available Abstract Oxygen derived species such as superoxide radical, hydrogen peroxide, singlet oxygen and hydroxyl radical are well known to be cytotoxic and have been implicated in the etiology of a wide array of human diseases, including cancer. Various carcinogens may also partly exert their effect by generating reactive oxygen species (ROS during their metabolism. Oxidative damage to cellular DNA can lead to mutations and may, therefore, play an important role in the initiation and progression of multistage carcinogenesis. The changes in DNA such as base modification, rearrangement of DNA sequence, miscoding of DNA lesion, gene duplication and the activation of oncogenes may be involved in the initiation of various cancers. Elevated levels of ROS and down regulation of ROS scavengers and antioxidant enzymes are associated with various human diseases including various cancers. ROS are also implicated in diabtes and neurodegenerative diseases. ROS influences central cellular processes such as proliferation a, apoptosis, senescence which are implicated in the development of cancer. Understanding the role of ROS as key mediators in signaling cascades may provide various opportunities for pharmacological intervention.

  13. Agroforestry Species Switchboard

    DEFF Research Database (Denmark)

    Kindt, R.; John, I.; Ordonez, J.

    2016-01-01

    The current version of the Agroforestry Species Switchboard documents the presence of a total of 26,135 plant species (33,813 species including synonyms) across 19 web-based databases. When available, hyperlinks to information on the selected species in particular databases are provided. In total...

  14. Evaluation of toxic and interactive toxic effects of three agrochemicals and copper using a battery of microbiotests.

    Science.gov (United States)

    Kungolos, A; Emmanouil, C; Tsiridis, V; Tsiropoulos, N

    2009-08-01

    Three commonly used test organisms of different trophic levels (Vibrio fischeri, Pseudokirchneriella subcapitata and Daphnia magna) were exposed to selected agrochemicals (fosthiazate, metalaxyl-M, imidacloprid) and copper, in single doses or in binary mixtures. The toxicity of each single compound varied up to two orders of magnitude, depending on the test species examined. V. fischeri was the most sensitive test organism regarding fosthiazate and metalaxyl-M, indicating an IC(50) value of 0.20 mg/L (0.17-0.25 mg/L) and 0.88 mg/L (0.35-1.57 mg/L), respectively. Imidacloprid was the least toxic compound, indicating an EC(50) value on D. magna of 64.6 mg/L (43.3-122.5 mg/L) and an IC(50) value on V. fischeri of 226 mg/L (159-322 mg/L), while for imidacloprid at a concentration of 1000 mg/L the effect on P. subcapitata was lower than 50%. Copper was the most toxic compound towards all test organisms exhibiting the highest toxic effect on P. subcapitata, with an IC(50) value of 0.05 mg/L (0.003-0.008 mg/L). The toxic effects of the binary mixtures have been compared to the theoretically expected effect, resulting from a simple mathematical model based on the theory of probabilities. The independent action model was used in order to predict the theoretically expected effect. The interactive effects were mostly antagonistic or additive, while in few cases (interactive effects of metalaxyl-M and copper on V. fischeri) a synergistic mode of action was observed for some concentration combinations. Experiments showed that interactive effects of chemicals may vary depending on the test species used as well as on the chemicals and their respective concentrations. Although most of the concentrations of chemicals tested in this study are higher than the ones usually found in natural environment, the evaluation of their interactive toxic effects using a battery of bioassays may comprise a useful tool for the estimation of the environmental hazard of chemicals.

  15. Toxicity and metal speciation in acid mine drainage treated by passive bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Neculita, C.M.; Vigneaul, B.; Zagury, G.J. [Ecole Polytechnic, Montreal, PQ (Canada)

    2008-08-15

    Sulfate-reducing passive bioreactors treat acid mine drainage (AMD) by increasing its pH and alkalinity and by removing metals as metal sulfide precipitates. In addition to discharge limits based on physicochemical parameters, however, treated effluent is required to be nontoxic. Acute and sublethal toxicity was assessed for effluent from 3.5-L column bioreactors filled with mixtures of natural organic carbon sources and operated at different hydraulic retention times (HRTs) for the treatment of a highly contaminated AMD. Effluent was first tested for acute (Daphnia magna and Oncorhynchus mykiss) and sublethal (Pseudokirchneriella subcapitata, Ceriodaphnia dabia, and Lemna minor) toxicity. Acute toxicity was observed for D. magna, and a toxicity identification evaluation (TIE) procedure was then performed to identify potential toxicants. Finally, metal speciation in the effluent was determined using ultrafiltration and geochemical modeling for the interpretation of the toxicity results. The 10-d HRT effluent was nonacutely lethal for 0. mykiss but acutely lethal for D. magna. The toxicity to D. magna, however, was removed by 2 h of aeration, and the TIE procedure suggested iron as a cause of toxicity. Sublethal toxicity of the 10-d HRT effluent was observed for all test species, but it was reduced compared to the raw AMD and to a 7.3-d HRT effluent. Data regarding metal speciation indicated instability of both effluents during aeration and were consistent with the toxicity being caused by iron. Column bioreactors in operation for more than nine months efficiently improved the physicochemical quality of highly contaminated AMD at different HRTs.

  16. On the occurrence and toxicity of Cylindrospermopsis raciborskii in Poland

    Directory of Open Access Journals (Sweden)

    Rzymski Piotr

    2017-03-01

    Full Text Available Cylindrospermopsis raciborskii which belongs to the order of Nostocales has continuously been at the centre of interest of various research groups owing to its great ecological plasticity, wide distribution and potential to produce different metabolites known to be harmful for humans and animals. Over recent decades, Polish strains of C. raciborskii have also been studied with regard to these issues. The present paper is a brief review of the present state of knowledge respecting the occurrence and toxicity of this species with emphasis on Polish strains, and indicates potential directions for future research.

  17. Summary and recommendations for research on tritium toxicity

    International Nuclear Information System (INIS)

    1979-01-01

    Lengthy presentations on many aspects of 3 H and its toxicity were given: 3 H Decay - Anticipated Q, J. Booz; Influence of Dose and Dose Rate on RBE, L. Feinendegen; 3 H Effects on Stem Cells and Dominant Lethals, A. Carsten; 3 H Incorporation into Murine Molecular Species, S. Commerford; 3 H and Hemopoietic Effects, T. Fliedner; Evidence for Site-Specific Genetic Transmutation Effects, M. Bender; 3 H and Effect on Testes, A. Lambert; 3 H and Oocytes, L. Dobson; and 2 H Incorporation into Oocytes as a Stable Isotope Tracer for 3 H, D. Slatkin

  18. TBI-Induced Formation of Toxic Tau and Its Biochemical Similarities to Tau in AD Brains

    Science.gov (United States)

    2017-10-01

    produces high quantities of protein (0.1-1.5mg tau from 1.5g of frozen tissue), preserves tau phosphorylation, and removes the vast majority of...disease This project seeks to establish extracellular soluble species of tau as major toxic species responsible for reduction of synaptic...competitive renewal grant is to optimize ultrasound parameters for non- invasive opening of the BBB. Dr. Lewis Brown 5R01MH098786-02 (Andrew J. Dwork

  19. The Toxicity of Depleted Uranium

    Directory of Open Access Journals (Sweden)

    Wayne Briner

    2010-01-01

    Full Text Available Depleted uranium (DU is an emerging environmental pollutant that is introduced into the environment primarily by military activity. While depleted uranium is less radioactive than natural uranium, it still retains all the chemical toxicity associated with the original element. In large doses the kidney is the target organ for the acute chemical toxicity of this metal, producing potentially lethal tubular necrosis. In contrast, chronic low dose exposure to depleted uranium may not produce a clear and defined set of symptoms. Chronic low-dose, or subacute, exposure to depleted uranium alters the appearance of milestones in developing organisms. Adult animals that were exposed to depleted uranium during development display persistent alterations in behavior, even after cessation of depleted uranium exposure. Adult animals exposed to depleted uranium demonstrate altered behaviors and a variety of alterations to brain chemistry. Despite its reduced level of radioactivity evidence continues to accumulate that depleted uranium, if ingested, may pose a radiologic hazard. The current state of knowledge concerning DU is discussed.

  20. A Miniscale Algal Toxicity Test

    DEFF Research Database (Denmark)

    Arensberg, Pia; Hemmingsen, Vicky H.; Nyholm, Niels

    1995-01-01

    A simple miniscale (approx. 1 - 2.5 ml) toxicity test procedure with the freshwater green algaSelenastrum capricornutum is described. The procedure fulfils the validity criteria of the ISO (International Association for Standardization) standard test protocol. Practically identical concentration-...... days to 2 days (minitest as well as larger volume tests) in order to avoid excessive biomass growth. Shortening tests to 2 days appears necessary if light intensity and temperature are near the upper limits of the intervals stated in the ISO standard.......A simple miniscale (approx. 1 - 2.5 ml) toxicity test procedure with the freshwater green algaSelenastrum capricornutum is described. The procedure fulfils the validity criteria of the ISO (International Association for Standardization) standard test protocol. Practically identical concentration......-response curves were obtained with the ISO standard test and the minitest for potassium dichromate and 3,5-dichlorophenol. The minitest is conveniently carried out using 2.5 ml test volume in 20 ml glass scintillation vials, placed on a microplate shaker or on an ordinary shaking table, but smaller containers...