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Sample records for algal toxicity tests

  1. Short-term algal toxicity test based on phosphate uptake.

    PubMed

    Kaneko, H Hidehiro; Shimada, Akiko; Hirayama, Kimiaki

    2004-04-01

    In order to develop a short-term algal toxicity test, the growth of and the phosphate uptake by the green alga Selenastrum capricornutum during batch culture were observed. In the control medium, S. capricornutum took up phosphate earlier than it grew. It was also observed that the phosphate uptake was inhibited by the presence of a toxicant. From these results, phosphate uptake was considered as one of the useful effect parameters for a short-term algal toxicity test. As the removal rate of phosphate from the medium is a function of the amount of algal cell initially inoculated, the test period is variable. The relationship between the amount of inoculation and phosphate uptake was examined and the test conditions suitable for a 3-h toxicity test were established as one example. According to this test procedure, the inhibitory effect of some toxicants on the phosphate uptake was determined. For comparison, a conventional algal assay based on algal growth was also performed. The EC50s for both tests were close. This indicated that the algal toxicity test method proposed in this paper would be useful for the uses where rapidity is required. PMID:15087199

  2. Development and application of a marine sediment porewater toxicity test using algal spores

    SciTech Connect

    Hooten, R.; Carr, R.S.

    1995-12-31

    An acute pore water toxicity test protocol using germination and growth of marine macroalgae as endpoints was developed to indicate the presence of toxic compounds in marine/estuarine and sediment porewater samples. Zoospores collected from Ulva fasciata and U. lactuca were used as test organisms. Preliminary results with sodium dodecyl sulfate (SDS, a reference toxicant) indicate that zoospores germination and growth of embryonic gametophytes are as sensitive as the sea urchin fertilization and embryological development toxicity tests. Algal germination and growth data for copper, mercury and other metals will be presented. The results of tests utilizing this algal assay with sediment pore water from contaminated sediments will be compared with more traditional sediment toxicity test methods.

  3. Controlling silver nanoparticle exposure in algal toxicity testing – A matter of timing

    PubMed Central

    Baun, Anders

    2015-01-01

    The aquatic ecotoxicity testing of nanoparticles is complicated by unstable exposure conditions resulting from various transformation processes of nanoparticles in aqueous suspensions. In this study, we investigated the influence of exposure timing on the algal test response to silver nanoparticles (AgNPs), by reducing the incubation time and by aging the AgNPs in algal medium prior to testing. The freshwater green algae Pseudokirchneriella subcapitata were exposed to AgNO3, NM-300 K (a representative AgNP) and citrate stabilized AgNPs from two different manufacturers (AgNP1 and AgNP2) in a standard algal growth inhibition test (ISO 8692:2004) for 48 h and a short-term (2 h) 14C-assimilation test. For AgNO3, similar responses were obtained in the two tests, whereas freshly prepared suspensions of citrate stabilized AgNPs were less toxic in the 2-h tests compared to the 48-h tests. The 2-h test was found applicable for dissolved silver, but yielded non-monotonous concentration–response relationships and poor reproducibility for freshly prepared AgNP suspensions. However, when aging AgNPs in algal medium 24 h prior to testing, clear concentration–response patterns emerged and reproducibility increased. Prolonged aging to 48 h increased toxicity in the 2-h tests whereas aging beyond 48 h reduced toxicity. Our results demonstrate that the outcome of algal toxicity testing of AgNPs is highly influenced not only by the test duration, but also by the time passed from the moment AgNPs are added to the test medium. This time-dependency should be considered when nanomaterial dispersion protocols for ecotoxicity testing are developed. PMID:24842597

  4. No-observed-effect concentrations in batch and continuous algal toxicity tests

    SciTech Connect

    Chao, M.R.; Chen, C.Y.

    2000-06-01

    In this study, the authors compare the no-observed-effect concentrations (NOECs) of Cd, Ni, Zn, Cu, and Pb based on different response parameters, using batch and continuous algal toxicity tests. For both batch and continuous tests, parameters based on total cell volume (TCV) were found to be less sensitive than those related to cell densities. The above observation mainly occurred because, under the stresses from metal toxicants evaluated in this and a previous study, the mean cell volume (MCV) of algae increased considerably. The increase of MCV compensates for the effects brought about by the reduction in cell density and eventually results in less variation in TCVs. This study shows that parameters based on cell density are quite sensitive and ideal for the estimation of NOECs. In addition, comparison of the NOEC values derived from different culture techniques shows that the continuous methods generally yields lower NOEC values than that obtained by the batch tests. The results of this study also indicate that the NOEC provides more protection to the test organism than the effective concentration at 10% growth reduction (EC10). For toxicity test methods that produce small variations among replicates, the NOEC is still a good indicator of low toxic effect. Furthermore, for the continuous algal toxicity test, a relatively simple approach is proposed to determine the NOEC values based on the algal culture's control charts. The proposed method produced identical results as those based on conventional hypothesis-testing methods.

  5. 40 CFR 797.1050 - Algal acute toxicity test.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... seq.). This guideline prescribes test procedures and conditions using freshwater and marine algae to... definitions also apply to this guideline: (1) Algicidal means having the property of killing algae. (2... volumes of nutrient medium and/or test solution. Start the test by introducing algae into the test...

  6. 40 CFR 797.1050 - Algal acute toxicity test.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... seq.). This guideline prescribes test procedures and conditions using freshwater and marine algae to... definitions also apply to this guideline: (1) Algicidal means having the property of killing algae. (2... volumes of nutrient medium and/or test solution. Start the test by introducing algae into the test...

  7. 40 CFR 797.1050 - Algal acute toxicity test.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... seq.). This guideline prescribes test procedures and conditions using freshwater and marine algae to... definitions also apply to this guideline: (1) Algicidal means having the property of killing algae. (2... volumes of nutrient medium and/or test solution. Start the test by introducing algae into the test...

  8. 40 CFR 797.1050 - Algal acute toxicity test.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... seq.). This guideline prescribes test procedures and conditions using freshwater and marine algae to... definitions also apply to this guideline: (1) Algicidal means having the property of killing algae. (2... volumes of nutrient medium and/or test solution. Start the test by introducing algae into the test...

  9. 40 CFR 797.1050 - Algal acute toxicity test.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... seq.). This guideline prescribes test procedures and conditions using freshwater and marine algae to... definitions also apply to this guideline: (1) Algicidal means having the property of killing algae. (2... volumes of nutrient medium and/or test solution. Start the test by introducing algae into the test...

  10. Comparison of toxicity to terrestrial plants with algal growth inhibition by herbicides

    SciTech Connect

    Garten, C.T. Jr.; Frank, M.L.

    1984-10-01

    The toxicities of 21 different herbicides to algae (Selenastrum capricornutum and Chlorella vulgaris) and to terrestrial plants (radishes, barley, and bush beans or soybeans) were compared to order to determine the feasibility of using a short-term (96-h) algal growth inhibition test for identifying chemicals having potential toxicity in a 4-week terrestrial plant bioassay. The toxicity of each test chemical, usually in combination with a commercial formulation, was evaluated at six nominal concentrations, between 0 and 100 mg/L growth medium in the algal bioassay or between 0 and 100 mg/kg substate in the terrestrial plant bioassay, in terms of both (1) the no-observed-effect concentration (NOEC), i.e., the highest concentration tested at which no significant (P < 0.05, one-sided test) reduction in algal growth rate or in terrestrial plant yield, relative to controls, was observed; and (2) the concentration at which algal growth rate or terrestrial plant yield was reduced by 50% or more relative to controls. There was generally poor agreement between results from the two types of bioassays; results from algal growth inhibition tests were not significantly correlated with results from the terrestrial plant bioassays. Overall, there was an approximately 50% chance of an algal bioassay, using Selenastrum capricornutum, successfully screening (detecting) herbicide levels that reduced terrestrial plant yield. The results indicated that algal growth inhibition tests cannot be used generically to predict phytotoxicity of herbicides to terrestrial plant species. 7 references, 14 tables.

  11. ALGAL AND PLANT TOXICITY TESTING

    EPA Science Inventory

    The evaluation of the phytotoxicity of a chemical is an essential component of the ecological risk assessment of that compound. Primary producers form an essential trophic level of any ecosystem. Further, since all chemicals introduced into the environmental ultimately find their...

  12. Algal blooms reduce the uptake of toxic methylmercury in freshwater food webs.

    PubMed

    Pickhardt, Paul C; Folt, Carol L; Chen, Celia Y; Klaue, Bjoern; Blum, Joel D

    2002-04-01

    Mercury accumulation in fish is a global public health concern, because fish are the primary source of toxic methylmercury to humans. Fish from all lakes do not pose the same level of risk to consumers. One of the most intriguing patterns is that potentially dangerous mercury concentrations can be found in fish from clear, oligotrophic lakes whereas fish from greener, eutrophic lakes often carry less mercury. In this study, we experimentally tested the hypothesis that increasing algal biomass reduces mercury accumulation at higher trophic levels through the dilution of mercury in consumed algal cells. Under bloom dilution, as algal biomass increases, the concentration of mercury per cell decreases, resulting in a lower dietary input to grazers and reduced bioaccumulation in algal-rich eutrophic systems. To test this hypothesis, we added enriched stable isotopes of Hg to experimental mesocosms and measured the uptake of toxic methylmercury (CH3 200Hg+) and inorganic 201Hg2+ by biota at several algal concentrations. We reduced absolute spike detection limits by 50-100 times compared with previous techniques, which allowed us to conduct experiments at the extremely low aqueous Hg concentrations that are typical of natural systems. We found that increasing algae reduced CH3Hg+ concentrations in zooplankton 2-3-fold. Bloom dilution may provide a mechanistic explanation for lower CH3Hg+ accumulation by zooplankton and fish in algal-rich relative to algal-poor systems. PMID:11904388

  13. Role of initial cell density of algal bioassay of toxic chemicals.

    PubMed

    Singh, Prashant Kumar; Shrivastava, Alok Kumar

    2016-07-01

    A variety of toxicants such as, metal ions, pesticides, dyes, etc. are continuously being introduced anthropogenically in the environment and adversely affect to the biotic component of the ecosystem. Therefore, the assessment of negative effects of these toxicants is required. However, toxicity assessment anticipated by chemical analysis are extremely poor, therefore the application of the living systems for the same is an excellent approach. Concentration of toxicant as well as cell density both influenced the result of the algal toxicity assay. Here, Scenedesmus sp, a very fast growing green microalgae was selected for study the effects of initial cell densities on the toxicity of Cu(II), Cd(II), Zn(II), paraquat and 2,4-D. Results demonstrated concentration dependent decrease in biomass and specific growth rate of Scenedesmus sp. on exposure of abovesaid toxicants. Paraquat and 2,4-D emerged as extremely toxic to the test alga which reflected from the lowest EC value and very steep decline in biomass was evident with increasing concentration of paraquat and 2,4-D in the medium. Result also demonstrated that initial cell density is a very important parameter than specific growth rate for algal bioassay of various toxicants. Present study clearly illustrated that the use of smaller cell density is always recommended for assaying toxicity of chemicals in algal assays. PMID:26593761

  14. Copepod Trajectory Characteristics in Thin Layers of Toxic Algal Exudates

    NASA Astrophysics Data System (ADS)

    Webster, D. R.; True, A. C.; Weissburg, M. J.; Yen, J.

    2013-11-01

    Recently documented thin layers of toxic phytoplankton (``cryptic blooms'') are modeled in a custom flume system for copepod behavioral assays. Planar laser-induced fluorescence (LIF) measurements quantify the spatiotemporal structure of the chemical layers ensuring a close match to in situ bloom conditions and allowing for quantification of threshold dissolved toxin levels that induce behavioral responses. Assays with the copepods Acartia tonsa (hop-sinker) and Temora longicornis (cruiser) in thin layers of toxic exudates from the common dinoflagellate Karenia brevis (cell equivalent ~ 1 - 10,000 cells/mL) examine the effects of dissolved toxic compounds and copepod species on swimming trajectory characteristics. Computation of parameters such as swimming speed and the fractal dimension of the two-dimensional trajectory (F2D) allows for statistical evaluation of copepod behavioral responses to dissolved toxic compounds associated with harmful algal blooms (HABs). Changes in copepod swimming behavior caused by toxic compounds can significantly influence predator, prey, and mate encounter rates by altering the fracticality (``diffuseness'' or ``volume-fillingness'') of a copepod's trajectory. As trophic mediators linking primary producers and higher trophic levels, copepods can significantly influence HAB dynamics and modulate large scale ecological effects through their behavioral interactions with toxic blooms.

  15. Apparent toxicity resulting from the sequestering of nutrient trace metals during standard Selenastrum capricornutum toxicity tests.

    PubMed

    Ward, Timothy J; Rausina, Gary A; Stonebraker, Peter M; Robinson, William E

    2002-10-01

    The water accommodated fractions (WAFs) of aqueous mixtures of three lubricant additives showed significant apparent toxicity to the freshwater alga, Selenastrum capricornutum, and experiments were conducted to investigate the hypothesis that toxicity resulted from the removal of one or more essential nutrients from the test medium by the lubricant additives. Algal growth effects were noted at ashless dispersant A concentrations as low as 0.5 x mg l(-1) and growth was completely inhibited at 100 mg x l(-1). Algal cells transferred from the 100 mg x l(-1) WAF of ashless dispersant A to fresh medium at the end of a standard 96-h toxicity test resumed growing at a rate similar to growth in undosed algal medium, indicating that the effect was algistatic rather than algicidal. Fortifying the iron (Fe) and disodium ethylenediaminetetraacetic acid (EDTA) concentrations of the WAF with 200% of the concentrations used in the formulation of algal medium after 24 h of exposure caused a resumption of algal growth at a rate comparable to the control growth, and a resulting EL50 value above 100 mg x l(-1). Similar effects were observed when the two other lubricant additives were tested at WAF concentrations that completely inhibited algal growth during standard toxicity tests: fortification of a 50 mg x l(-1) WAF of ZnDTP with 1000% of the Fe and EDTA used in the formulation of algal medium caused a resumption of growth at a rate statistically identical to the control growth, and the fortification of a 2800 mg x l(-1) WAF of ashless dispersant B with 700% of the entire complement of nutrients used in the formulation of algal medium caused a resumption of growth at a rate comparable to the control. The indirect toxic effect of these lubricant additives to algae results from the sequestration of one or more nutrient metals essential for algal growth. Standard algal toxicity tests with these lubricant additives may, therefore, have little environmental relevance because the complex

  16. Polyurethane and alginate immobilized algal biomass for the removal of aqueous toxic metals

    SciTech Connect

    Fry, I.V.; Mehlhorn, R.J.

    1992-12-01

    We describe the development of immobilized, processed algal biomass for use as an adsorptive filter in the removal of toxic metals from waste water. To fabricate an adsorptive filter from precessed biomass several crucial criteria must be met, including: (1) high metal binding capacity, (2) long term stability (both mechanical and chemical), (3) selectivity for metals of concern (with regard to ionic competition), (4) acceptable flow capacity (to handle large volumes in short time frames), (5) stripping/regeneration (to recycle the adsorptive filter and concentrate the toxic metals to manageable volumes). This report documents experiments with processed algal biomass (Spirulina platensis and Spirulina maxima) immobilized in either alginate gel or preformed polyurethane foam. The adsorptive characteristics of these filters were assessed with regard to the criteria listed above.

  17. Toxicity Estimation Software Tool (TEST)

    EPA Science Inventory

    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...

  18. Physicochemical transformation and algal toxicity of engineered nanoparticles in surface water samples.

    PubMed

    Zhang, Luqing; Li, Jingyi; Yang, Kun; Liu, Jingfu; Lin, Daohui

    2016-04-01

    Most studies on the behavior and toxicity of engineered nanoparticles (NPs) have been conducted in artificial water with well-controlled conditions, which are dramatically different from natural waters with complex compositions. To better understand the fate and toxicity of NPs in the natural water environment, physicochemical transformations of four NPs (TiO2, ZnO, Ag, and carbon nanotubes (CNTs)) and their toxicities towards a unicellular green alga (Chlorella pyrenoidosa) in four fresh water and one seawater sample were investigated. Results indicated that water chemistry had profound effects on aggregation, dissolution, and algal toxicity of the NPs. The strongest homoaggregation of the NPs was associated with the highest ionic strength, but no obvious correlation was observed between the homoaggregation of NPs and pH or dissolved organic matter content of the water samples. The greatest dissolution of ZnO NPs also occurred in seawater with the highest ionic strength, while the dissolution of Ag NPs varied differently from ZnO NPs. The released Zn(2+) and especially Ag(+) mainly accounted for the algal toxicity of ZnO and Ag NPs, respectively. The NP-cell heteroagglomeration occurred generally for CNTs and Ag NPs, which contributed to the observed nanotoxicity. However, there was no significant correlation between the observed nanotoxicity and the type of NP or the water chemistry. It was thus concluded that the physicochemical transformations and algal toxicities of NPs in the natural water samples were caused by the combined effects of complex water quality parameters rather than any single influencing factor alone. These results will increase our knowledge on the fate and effects of NPs in the aquatic environment.

  19. Linking algal growth inhibition to chemical activity: baseline toxicity required 1% of saturation.

    PubMed

    Schmidt, Stine N; Mayer, Philipp

    2015-02-01

    Recently, high-quality data were published on the algal growth inhibition caused by 50 non-polar narcotic compounds, of which 39 were liquid compounds with defined water solubility. In the present study, the toxicity data for these liquids were applied to challenge the chemical activity range for baseline toxicity. First, the reported effective concentrations (EC50) were divided by the respective water solubilities (S water), since the obtained EC50/S water ratio essentially equals the effective chemical activity (Ea50). The majority of EC50/S water ratios were within the expected chemical activity range of 0.01-0.1 for baseline toxicity, and none of the ratios were significantly below 0.01. On a practical level, these findings suggest EC50 values for baseline toxicity to be at or above 1% of liquid solubility, which would have been accurate or conservative for all 39 liquids with defined water solubility in the applied dataset. On an environmental risk assessment level, predicted no-effect concentrations (PNECs) for baseline toxicity could even be set as a percentage of saturation, which can easily be extended to mixtures. However, EC50 values well below 1% of liquid saturation can still occur and would be a direct indication of excess toxicity.

  20. Environmental feedbacks and engineered nanoparticles: mitigation of silver nanoparticle toxicity to Chlamydomonas reinhardtii by algal-produced organic compounds.

    PubMed

    Stevenson, Louise M; Dickson, Helen; Klanjscek, Tin; Keller, Arturo A; McCauley, Edward; Nisbet, Roger M

    2013-01-01

    The vast majority of nanotoxicity studies measures the effect of exposure to a toxicant on an organism and ignores the potentially important effects of the organism on the toxicant. We investigated the effect of citrate-coated silver nanoparticles (AgNPs) on populations of the freshwater alga Chlamydomonas reinhardtii at different phases of batch culture growth and show that the AgNPs are most toxic to cultures in the early phases of growth. We offer strong evidence that reduced toxicity occurs because extracellular dissolved organic carbon (DOC) compounds produced by the algal cells themselves mitigate the toxicity of AgNPs. We analyzed this feedback with a dynamic model incorporating algal growth, nanoparticle dissolution, bioaccumulation of silver, DOC production and DOC-mediated inactivation of nanoparticles and ionic silver. Our findings demonstrate how the feedback between aquatic organisms and their environment may impact the toxicity and ecological effects of engineered nanoparticles.

  1. Environmental Feedbacks and Engineered Nanoparticles: Mitigation of Silver Nanoparticle Toxicity to Chlamydomonas reinhardtii by Algal-Produced Organic Compounds

    PubMed Central

    Stevenson, Louise M.; Dickson, Helen; Klanjscek, Tin; Keller, Arturo A.; McCauley, Edward; Nisbet, Roger M.

    2013-01-01

    The vast majority of nanotoxicity studies measures the effect of exposure to a toxicant on an organism and ignores the potentially important effects of the organism on the toxicant. We investigated the effect of citrate-coated silver nanoparticles (AgNPs) on populations of the freshwater alga Chlamydomonas reinhardtii at different phases of batch culture growth and show that the AgNPs are most toxic to cultures in the early phases of growth. We offer strong evidence that reduced toxicity occurs because extracellular dissolved organic carbon (DOC) compounds produced by the algal cells themselves mitigate the toxicity of AgNPs. We analyzed this feedback with a dynamic model incorporating algal growth, nanoparticle dissolution, bioaccumulation of silver, DOC production and DOC-mediated inactivation of nanoparticles and ionic silver. Our findings demonstrate how the feedback between aquatic organisms and their environment may impact the toxicity and ecological effects of engineered nanoparticles. PMID:24086348

  2. Influence of global change-related impacts on the mercury toxicity of freshwater algal communities.

    PubMed

    Val, Jonatan; Muñiz, Selene; Gomà, Joan; Navarro, Enrique

    2016-01-01

    The climatic-change related increase of temperatures, are expected to alter the distribution and survival of freshwater species, ecosystem functions, and also the effects of toxicants to aquatic biota. This study has thus assessed, as a first time, the modulating effect of climate-change drivers on the mercury (Hg) toxicity of freshwater algal photosynthesis. Natural benthic algal communities (periphyton) have been exposed to Hg under present and future temperature scenarios (rise of 5 °C). The modulating effect of other factors (also altered by global change), as the quality and amount of suspended and dissolved materials in the rivers, has been also assessed, exposing algae to Hg in natural river water or a synthetic medium. The EC50 values ranged from the 0.15-0.74 ppm for the most sensitive communities, to the 24-40 ppm for the most tolerant. The higher tolerance shown by communities exposed to higher Hg concentrations, as Jabarrella was in agreement with the Pollution Induced Community Tolerance concept. In other cases, the dominance of the invasive diatom Didymosphenia geminata explained the tolerance or sensitivity of the community to the Hg toxicity. Results shown that while increases in the suspended solids reduced Hg bioavailability, changes in the dissolved materials - such as organic carbon - may increase it and thus its toxic effects on biota. The impacts of the increase of temperatures on the toxicological behaviour of periphyton (combining both changes at species composition and physiological acclimation) would be certainly modulated by other effects at the land level (i.e., alterations in the amount and quality of dissolved and particulate substances arriving to the rivers).

  3. Influence of global change-related impacts on the mercury toxicity of freshwater algal communities.

    PubMed

    Val, Jonatan; Muñiz, Selene; Gomà, Joan; Navarro, Enrique

    2016-01-01

    The climatic-change related increase of temperatures, are expected to alter the distribution and survival of freshwater species, ecosystem functions, and also the effects of toxicants to aquatic biota. This study has thus assessed, as a first time, the modulating effect of climate-change drivers on the mercury (Hg) toxicity of freshwater algal photosynthesis. Natural benthic algal communities (periphyton) have been exposed to Hg under present and future temperature scenarios (rise of 5 °C). The modulating effect of other factors (also altered by global change), as the quality and amount of suspended and dissolved materials in the rivers, has been also assessed, exposing algae to Hg in natural river water or a synthetic medium. The EC50 values ranged from the 0.15-0.74 ppm for the most sensitive communities, to the 24-40 ppm for the most tolerant. The higher tolerance shown by communities exposed to higher Hg concentrations, as Jabarrella was in agreement with the Pollution Induced Community Tolerance concept. In other cases, the dominance of the invasive diatom Didymosphenia geminata explained the tolerance or sensitivity of the community to the Hg toxicity. Results shown that while increases in the suspended solids reduced Hg bioavailability, changes in the dissolved materials - such as organic carbon - may increase it and thus its toxic effects on biota. The impacts of the increase of temperatures on the toxicological behaviour of periphyton (combining both changes at species composition and physiological acclimation) would be certainly modulated by other effects at the land level (i.e., alterations in the amount and quality of dissolved and particulate substances arriving to the rivers). PMID:26024757

  4. Eco-evolutionary feedbacks between private and public goods: evidence from toxic algal blooms.

    PubMed

    Driscoll, William W; Hackett, Jeremiah D; Ferrière, Régis

    2016-01-01

    The importance of 'eco-evolutionary feedbacks' in natural systems is currently unclear. Here, we advance a general hypothesis for a particular class of eco-evolutionary feedbacks with potentially large, long-lasting impacts in complex ecosystems. These eco-evolutionary feedbacks involve traits that mediate important interactions with abiotic and biotic features of the environment and a self-driven reversal of selection as the ecological impact of the trait varies between private (small scale) and public (large scale). Toxic algal blooms may involve such eco-evolutionary feedbacks due to the emergence of public goods. We review evidence that toxin production by microalgae may yield 'privatised' benefits for individual cells or colonies under pre- and early-bloom conditions; however, the large-scale, ecosystem-level effects of toxicity associated with bloom states yield benefits that are necessarily 'public'. Theory predicts that the replacement of private with public goods may reverse selection for toxicity in the absence of higher level selection. Indeed, blooms often harbor significant genetic and functional diversity: bloom populations may undergo genetic differentiation over a scale of days, and even genetically similar lineages may vary widely in toxic potential. Intriguingly, these observations find parallels in terrestrial communities, suggesting that toxic blooms may serve as useful models for eco-evolutionary dynamics in nature. Eco-evolutionary feedbacks involving the emergence of a public good may shed new light on the potential for interactions between ecology and evolution to influence the structure and function of entire ecosystems.

  5. Eco-evolutionary feedbacks between private and public goods: evidence from toxic algal blooms.

    PubMed

    Driscoll, William W; Hackett, Jeremiah D; Ferrière, Régis

    2016-01-01

    The importance of 'eco-evolutionary feedbacks' in natural systems is currently unclear. Here, we advance a general hypothesis for a particular class of eco-evolutionary feedbacks with potentially large, long-lasting impacts in complex ecosystems. These eco-evolutionary feedbacks involve traits that mediate important interactions with abiotic and biotic features of the environment and a self-driven reversal of selection as the ecological impact of the trait varies between private (small scale) and public (large scale). Toxic algal blooms may involve such eco-evolutionary feedbacks due to the emergence of public goods. We review evidence that toxin production by microalgae may yield 'privatised' benefits for individual cells or colonies under pre- and early-bloom conditions; however, the large-scale, ecosystem-level effects of toxicity associated with bloom states yield benefits that are necessarily 'public'. Theory predicts that the replacement of private with public goods may reverse selection for toxicity in the absence of higher level selection. Indeed, blooms often harbor significant genetic and functional diversity: bloom populations may undergo genetic differentiation over a scale of days, and even genetically similar lineages may vary widely in toxic potential. Intriguingly, these observations find parallels in terrestrial communities, suggesting that toxic blooms may serve as useful models for eco-evolutionary dynamics in nature. Eco-evolutionary feedbacks involving the emergence of a public good may shed new light on the potential for interactions between ecology and evolution to influence the structure and function of entire ecosystems. PMID:26612461

  6. Artifacts in ambient toxicity testing

    SciTech Connect

    Kszos, L.A.; Stewart, A.J.

    1992-01-01

    Short-term toxicity tests with fathead minnow (Pimephales promelas) larvae and Ceriodaphnia dubia can be used to estimate the acute or chronic toxicity of effluents or receiving water. The results of effluent toxicity tests may need to be interpreted differently from the results of ambient toxicity tests. In this paper we provide examples of common artifacts, which can cause either false positives or false negatives, that we have encountered when these tests are used in ambient assessments. The examples we provide are drawn from diverse effluent and ambient water toxicity tests conducted at the Oak Ridge National Laboratory from March, 1985 through November, 1991. Three types of artifacts which have been encountered when using these tests in ambient applications are explored here. One type involves unusual replicate-specific variance in survival of fathead minnow larvae. The second and third types of artifacts affect the C. dubia test and appear to be related to food availability.

  7. Artifacts in ambient toxicity testing

    SciTech Connect

    Kszos, L.A.; Stewart, A.J.

    1992-10-01

    Short-term toxicity tests with fathead minnow (Pimephales promelas) larvae and Ceriodaphnia dubia can be used to estimate the acute or chronic toxicity of effluents or receiving water. The results of effluent toxicity tests may need to be interpreted differently from the results of ambient toxicity tests. In this paper we provide examples of common artifacts, which can cause either false positives or false negatives, that we have encountered when these tests are used in ambient assessments. The examples we provide are drawn from diverse effluent and ambient water toxicity tests conducted at the Oak Ridge National Laboratory from March, 1985 through November, 1991. Three types of artifacts which have been encountered when using these tests in ambient applications are explored here. One type involves unusual replicate-specific variance in survival of fathead minnow larvae. The second and third types of artifacts affect the C. dubia test and appear to be related to food availability.

  8. Development and evaluation of multispecies test protocols for assessing chemical toxicity

    SciTech Connect

    Garten, C.T. Jr.; Suter, G.W. II; Blaylock, B.G.

    1985-06-01

    Toxicity testing is a well-recognized tool to assist in evaluating the hazards of chemicals to individual biological species. Multispecies toxicity tests, however, are now well developed. Three test systems were examined: the legume-Rhizobium symbiosis for N-fixation, soil microbial populations, and algal multispecies interactions. Test protocols were to be developed and tested using several different chemicals. Test protocols for the legume-Rhizobium and soil microorganisms systems were developed and are presented. The algal multispecies system will require more research, and thus no protocol was recommended at this time. Separate abstracts were prepared for each test system. (ACR)

  9. Evolution of algal toxicity during (photo)oxidative degradation of diuron.

    PubMed

    Mestankova, Hana; Escher, Beate; Schirmer, Kristin; von Gunten, Urs; Canonica, Silvio

    2011-01-25

    In the aquatic environment and in engineered water treatment systems, organic contaminants can undergo oxidative and photochemical transformations. For an overall risk assessment, the toxicity of the resulting transformation products has to be investigated. In this study, the toxicity of degradation products of diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) formed during its degradation by four (photo)oxidative processes (direct phototransformation, triplet-induced photosensitized oxidation, oxidation by hydroxyl radicals and ozone) was investigated in buffered aqueous solution. The toxicity was evaluated using the combined algae test with Pseudokirchneriella subcapitata that determines both, specific inhibition of photosynthesis and inhibition of the growth rate. The comparison between evolution of toxicity and degradation kinetics indicated that the toxicity during all studied processes was caused predominantly by diuron whereas the formation of degradation products did not contribute to the mixture toxicity. This implies that, if any more toxic transformation products than diuron were formed, their concentration was not sufficiently high to affect the mixture toxicity, which was dominated by the parent compound diuron. On this account, no further studies on identification of degradation products and their toxicity are needed. This study presents an example of a systematic and simple first tier method to assess the toxicity of degradation products. PMID:21122928

  10. Toxicity testing using Caenorhabditis elegans

    SciTech Connect

    Middendorf, P.J.; Dusenbery, D.B.; Williams, P.L.

    1995-12-31

    Caenorhabditis elegans is a small free-living nematode that is representative of what may be the most abundant animal group. It has been promoted as a possible model organism for toxicity testing in the laboratory and in field evaluations in part because more is known about its biology than any other animal, Toxicity tests using C. elegans have been developed with lethality, reproduction, and behavior as end points. The tests have also been developed to varying degrees using standard laboratory media, water, and soil. The results of the tests when exposing C. elegans to a variety of metals, inorganic, and organic compounds indicate it is typically at least as sensitive as other species currently used, such as Daphnia and earthworms, and is generally much easier to maintain in the laboratory. The advantages and disadvantages of C. elegans and the state of development of the tests will be discussed.

  11. Toxicity testing with the marine algae, Symbiodinium kawagutii (Dinophyceae)

    SciTech Connect

    Gorrie, J.R.; Bidwell, J.R.; Rippingale, R.J.

    1994-12-31

    The dinoflagellate, Symbiodinium kawagutii, is among the algal taxa which exist in symbiosis with a range of marine invertebrates. S. kawagutii is commonly found in association with the Hawaiian stony coral, Montipora verrucosa. The algae has been successfully cultured in the laboratory using a common marine algal growth media (Guillard f/2), and sufficient cell densities were achieved in a 96-hr bioassay to allow statistical evaluation of toxicity data. A 96-hr EC{sub 50} of 6.47 mg/L (95% C.I.: 3.54--9.88 mg/L) was calculated after exposure to potassium dichromate. Wide distribution of the coral host and ecological importance of the symbiosis make S. kawagutii an excellent candidate species for hazard evaluation in tropical marine ecosystems. Continuing research will seek to further refine the bioassay, including the use of a microplate technique for more rapid testing.

  12. Toxicity testing of organic chemicals in groundwater polluted with landfill leachate

    SciTech Connect

    Baun, A.; Kloeft, L.; Bjerg, P.L.; Nyholm, N.

    1999-09-01

    A method for assessment of toxicity of nonvolatile organic chemicals contaminants in groundwater polluted with landfill leachate has been evaluated. The biotests utilized were composed of an algal growth inhibition test (Selenastrum capricornutum), a daphnia immobilization test (Daphnia magna), and a bacterial genotoxicity test (umuC, Salmonella typhimurium). The feasibility of the selected biotests was investigated for a series of groundwater samples collected along pollution gradients downstreams of two landfills in Jutland, Denmark. Two different approaches were used, direct toxicity testing of whole groundwater samples, and toxicity testing of concentrates obtained by solid-phase extraction. Direct testing of whole groundwater samples produced toxic responses, but the complex sample matrix masked the toxicity of the organic chemical contaminants of interest. Solid-phase extraction was used successfully as an on-site method that eliminated ion toxicity and produced biotest responses that reflected the toxicity of the nonvolatile organic chemical contaminants in the groundwater.

  13. Evaluation of municipal waste incinerator fly ash toxicity and the role of cadmium by two aquatic toxicity tests

    SciTech Connect

    Kaneko, Hidehiro

    1996-12-31

    Fly ash from a municipal solid waste incinerator in Japan is regulated under the hazardous waste regulation Waste under Special Control, according to the Amendment of the Waste Disposal and Public Cleansing Law, because it contains high concentrations of heavy metals which are available for leaching. To evaluate the toxicity of fly ash, a fly ash leachate was prepared according to the Japanese standard leaching procedure. The chemical analysis of the leachate showed that possibly one of the most toxic substances was cadmium. The toxicity of the leachate and the cadmium was determined by algal assay and a Daphnia acute toxicity test. The results showed that the leachate was about seven times more toxic to the growth of algae and 20 to 30 times more toxic to the survival of Daphnia than expected from its cadmium concentration. The toxicity interaction between cadmium and the other constituents in the leachate was also examined. The toxicity of cadmium showed an additive effect with the other constituents in the leachate in algal assay. In the Daphnia test, however, cadmium showed an antagonistic effect.

  14. Lysing bloom-causing alga Phaeocystis globosa with microbial algicide: An efficient process that decreases the toxicity of algal exudates

    PubMed Central

    Cai, Guanjing; Yang, Xujun; Lai, Qiliang; Yu, Xiaoqi; Zhang, Huajun; Li, Yi; Chen, Zhangran; Lei, Xueqian; Zheng, Wei; Xu, Hong; Zheng, Tianling

    2016-01-01

    Algicidal microbes could effectively remove the harmful algae from the waters. In this study, we were concerned with the ecological influence of an algicide extracted from Streptomyces alboflavus RPS, which could completely lyse the Phaeocystis globosa cells within two days. In microcosms, 4 μg/mL of the microbial algicide could efficiently remove P. globosa cells without suppressing other aquatic organisms. Bioluminescent assays confirmed that the toxicity of microbial algicide at this concentration was negligible. Interestingly, the toxicity of P. globosa exudates was also significantly reduced after being treated with the algicide. Further experiments revealed that the microbial algicide could instantly increase the permeability of the plasma membrane and disturb the photosynthetic system, followed by the deformation of organelles, vacuolization and increasing oxidative stress. The pre-incubation of N-acetyl cysteine (NAC) verified that the rapid damages to the plasma membrane and photosynthetic system caused the algal death in the early phase, and the increasing oxidative stress killed the rest. The late accumulation and possible release of CAT also explained the decreasing toxicity of the algal culture. These results indicated that this microbial algicide has great potential in controlling the growth of P. globosa on site. PMID:26847810

  15. Spectral modeling for the identification and quantification of algal blooms: A test of approach

    SciTech Connect

    Malthus, T.J.; Grieve, L.; Harwar, M.D.

    1997-06-01

    The aim of this paper is to develop and test a Monte Carlo modelling approach for the characterization of reflectance for different bloom-forming marine phytoplankton species. The model was tested on optical data for four species (Dunaliella salina, Pavlova pinguis, Emiliania huxleyi and Synechocystes spp.) and simulations performed over a range of chlorophyll concentrations. Discriminant analysis identified 10 key wavelengths which could be used to maximize the separation between the four species. The resulting wavelengths were combined in a neural network to show 100% accuracy in classifying species type. Further simulations were undertaken to investigate the effect of aquatic humus on reflectance characteristics and the change in wavelengths for algal discrimination. The implications for the development of algorithms for the identification of algal bloom species type by remote sensing are briefly discussed.

  16. POREWATER TOXICITY TESTING: AN OVERVIEW

    EPA Science Inventory

    Sediments act as sinks for contaminants, where they may build up to toxic levels. Sediments containing toxic levels of contaminants pose a risk to aquatic life, human health, and wildlife. There is an overwhelming amount of evidence that demonstrates chemicals in sediments are re...

  17. BIOEQUIVALENCE APPROACH FOR WHOLE EFFLUENT TOXICITY TESTING

    EPA Science Inventory

    Increased use of whole effluent toxicity (WET) tests in the regulatory arena has brought increased concern over the statistical analysis of WET test data and the determination of toxicity. One concern is the issue of statistical power. A number of WET tests may pass the current...

  18. Identification and characterization of potentially algal-lytic marine bacteria strongly associated with the toxic dinoflagellate Alexandrium catenella.

    PubMed

    Amaro, Ana M; Fuentes, María S; Ogalde, Sandra R; Venegas, Juan A; Suárez-Isla, Benjamín A

    2005-01-01

    The toxic dinoflagellate Alexandrium catenella isolated from fjords in Southern Chile produces several analogues of saxitoxin and has been associated with outbreaks of paralytic shellfish poisoning. Three bacterial strains, which remained in close association with this dinoflagellate in culture, were isolated by inoculating the dinoflagellate onto marine agar. The phenotypically different cultivable bacterial colonies were purified. Their genetic identification was done by polymerase chain reaction amplification of the 16S rRNA genes. Partial sequence analysis suggested that the most probable affiliations were to two bacterial phyla: Proteobacteria and the Cytophaga group. The molecular identification was complemented by morphological data and biochemical profiling. The three bacterial species, when grown separately from phytoplankton cells in high-nutrient media, released algal-lytic compounds together with aminopeptidase, lipase, glucosaminidase, and alkaline phosphatase. When the same bacteria, free of organic nutrients, were added back to the algal culture they displayed no detrimental effects on the dinoflagellate cells and recovered their symbiotic characteristics. This observation is consistent with phylogenetic analysis that reveals that these bacteria correspond to species distinct from other bacterial strains previously classified as algicidal bacteria. Thus, bacterial-derived lytic activities are expressed only in the presence of high-nutrient culture media and it is likely that in situ environmental conditions may modulate their expression. PMID:15926994

  19. Development of toxicant identification procedures for whole sediment toxicity tests

    SciTech Connect

    Mount, D.R.; Henke, C.E.; Ingersoll, C.G.; Besser, J.M.; Ankley, G.T.; Norberg-King, T.J.; West, C.W.

    1995-12-31

    To effectively assess and manage contaminated sediments, identifying the specific contaminants responsible for sediment toxicity is highly desirable. Though effective toxicity identification evaluation (TIE) methods are well established for water column toxicity, new TIE methodologies are needed that address the special characteristics of whole sediment toxicity tests. Much of the effort to date has focused on the assessment of ammonia toxicity. Whereas pH manipulation is a key tool used to characterize ammonia toxicity in water column TIE, control of pH in interstitial water is much more challenging. Direct addition of hard acid has shown undesirable side effects (e.g., liberation and oxidation of iron), while CO{sub 2}-enrichment is limited in penetration of fine-grained sediments. Biological buffers (MES and POPSO) incorporated into the sediment are effective at altering interstitial pH without causing direct toxicity to Chironomus tentans, Lumbriculus variegatus, and to a lesser extent Hyalella azteca, but the range of pH control achieved has been small ({+-} 0.5 units). Introduction of aquatic plants reduces ammonia concentrations in the water column, but may not provide sufficient control of interstitial water. To date, the most promising results have been achieved using zeolite; adding zeolite to sediment produces moderate reductions in interstitial ammonia concentrations and is non-toxic to the organisms referenced above. Attempts to induce microbial removal of ammonia have been unsuccessful thus far. This presentation will review these and other sediment TIE methods currently under development in laboratories.

  20. Toxicity of four potentially ichthyotoxic marine phytoflagellates determined by four different test methods.

    PubMed

    Meldahl, A S; Edvardsen, B; Fonnum, F

    1994-07-01

    The toxicity of the marine phytoflagellates Prymnesium parvum. Prymnesium patelliferum, Chrysochromulina polylepis, and Chrysochromulina leadbeateri isolated from ichthyotoxic blooms in Norwegian coastal waters was compared using four different test methods developed for the detection of toxins produced by these species. The test methods were (1) lethality to the crustacean Artemia salina exposed to living algae, (2) hemolytic activity (lysis of human erythrocytes) by crude algal lipid extracts, and inhibition of the uptake of the neurotransmitters L-glutamate and gamma-aminobutyric acid (GABA) into (3) synaptosomes and (4) synaptic vesicles of rat brain by crude algal lipid extracts. All test methods indicated different levels of toxicity among the algal species. Prymnesium parvum, P. patelliferum, and C. polylepis were toxic as determined by all four test methods. The cultured strain of C. leadbeateri, although isolated from a toxic algal bloom, appeared nontoxic by the methods used here, and served as a negative control. The hemolytic activity of P. parvum extract was about nine times higher than that of P. patelliferum extract, whereas the activity was only two to three times higher using the other three methods. Chrysochromulina polylepis had higher toxic activity than P. patelliferum except for less inhibitory effect on synaptosomes. The inhibition of synaptosomal and vesicular neurotransmitter uptake systems by extracts of P. parvum, P. patelliferum, and C. polylepis appeared to be due to similar mechanisms of action, since similar inhibition ratios between the uptake of L-glutamate and GABA were obtained in both synaptosomes and synaptic vesicles. We suggest that P. parvum, P. patelliferum, and C. polylepis produce a set of similar toxins and that the relative amounts of each toxin vary among the three species. PMID:7912738

  1. Influence of light, nutrients, and temperature on the toxicity of atrazine to the algal species Raphidocelis subcapitata: Implications for the risk assessment of herbicides.

    PubMed

    Baxter, Leilan; Brain, Richard A; Lissemore, Linda; Solomon, Keith R; Hanson, Mark L; Prosser, Ryan S

    2016-10-01

    The acute toxicity of herbicides to algae is commonly assessed under conditions (e.g., light intensity, water temperature, concentration of nutrients, pH) prescribed by standard test protocols. However, the observed toxicity may vary with changes in one or more of these parameters. This study examined variation in toxicity of the herbicide atrazine to a representative green algal species Raphidocelis subcapitata (formerly Pseudokirchneriella subcapitata) with changes in light intensity, water temperature, concentrations of nutrients or combinations of these three parameters. Conditions were chosen that could be representative of the intensive corn growing Midwestern region of the United States of America where atrazine is used extensively. Varying light intensity (4-58µmol/m(2)s) resulted in no observable trend in 96-h EC50 values for growth rate. EC50 values for PSII yield generally increased with decreasing light intensity but not significantly in all cases. The 96-h EC50 values for growth rate decreased with decreases in temperature (20-5°C) from standard conditions (25°C), but EC50 values for PSII yield at lower temperatures were not significantly different from standard conditions. Finally, there was no clear trend in 96-h EC50 values for both endpoints with increases in nitrogen (4.1-20mg/L) and phosphorus (0.24-1.2mg/L). The 96-h EC50 values for both endpoints under combinations of conditions mimicking aquatic systems in the Midwestern U.S. were not significantly different from EC50 values generated under standard test conditions. This combination of decreased light intensity and temperature and increased nutrients relative to standard conditions does not appear to significantly affect the observed toxicity of atrazine to R. subcapitata. For atrazine specifically, and for perhaps other herbicides, this means current laboratory protocols are useful for extrapolating to effects on algae under realistic environmental conditions. PMID:27340884

  2. Influence of light, nutrients, and temperature on the toxicity of atrazine to the algal species Raphidocelis subcapitata: Implications for the risk assessment of herbicides.

    PubMed

    Baxter, Leilan; Brain, Richard A; Lissemore, Linda; Solomon, Keith R; Hanson, Mark L; Prosser, Ryan S

    2016-10-01

    The acute toxicity of herbicides to algae is commonly assessed under conditions (e.g., light intensity, water temperature, concentration of nutrients, pH) prescribed by standard test protocols. However, the observed toxicity may vary with changes in one or more of these parameters. This study examined variation in toxicity of the herbicide atrazine to a representative green algal species Raphidocelis subcapitata (formerly Pseudokirchneriella subcapitata) with changes in light intensity, water temperature, concentrations of nutrients or combinations of these three parameters. Conditions were chosen that could be representative of the intensive corn growing Midwestern region of the United States of America where atrazine is used extensively. Varying light intensity (4-58µmol/m(2)s) resulted in no observable trend in 96-h EC50 values for growth rate. EC50 values for PSII yield generally increased with decreasing light intensity but not significantly in all cases. The 96-h EC50 values for growth rate decreased with decreases in temperature (20-5°C) from standard conditions (25°C), but EC50 values for PSII yield at lower temperatures were not significantly different from standard conditions. Finally, there was no clear trend in 96-h EC50 values for both endpoints with increases in nitrogen (4.1-20mg/L) and phosphorus (0.24-1.2mg/L). The 96-h EC50 values for both endpoints under combinations of conditions mimicking aquatic systems in the Midwestern U.S. were not significantly different from EC50 values generated under standard test conditions. This combination of decreased light intensity and temperature and increased nutrients relative to standard conditions does not appear to significantly affect the observed toxicity of atrazine to R. subcapitata. For atrazine specifically, and for perhaps other herbicides, this means current laboratory protocols are useful for extrapolating to effects on algae under realistic environmental conditions.

  3. Evaluation of anticoagulant activity of two algal polysaccharides.

    PubMed

    Faggio, C; Pagano, M; Dottore, A; Genovese, G; Morabito, M

    2016-09-01

    Marine algae are important sources of phycocolloids like agar, carrageenans and alginates used in industrial applications. Algal polysaccharides have emerged as an important class of bioactive products showing interesting properties. The aim of our study was to evaluate the potential uses as anticoagulant drugs of algal sulphate polysaccharides extracted from Ulva fasciata (Chlorophyta) and Agardhiella subulata (Rhodophyta) collected in Ganzirri Lake (Cape Peloro Lagoon, north-eastern Sicily, Italy). Toxicity of algal extracts through trypan blue test and anticoagulant action measured by activated partial thromboplastin time (APTT), prothrombin time (PT) test has been evaluated. Algal extracts showed to prolong the PT and APTT during the coagulation cascade and to avoid the blood coagulation of samples. Furthermore, the algal extracts lack toxic effects towards cellular metabolism and their productions are relatively at low cost. This permits to consider the algae as the biological source of the future.

  4. Literature review on duckweed toxicity testing

    SciTech Connect

    Wang, W. )

    1990-06-01

    Duckweed commonly refers to a group of floating, flowering plants of the family Lemnaceae. Duckweed plants are fast growing and widely distributed. They are easy to culture and to test. Some reports suggest that duckweed plants are tolerant to environmental toxicity. Other studies, however, indicate that duckweed plants are as sensitive to toxicity as other aquatic species. Duckweed plants are especially suitable for use in complex effluent bioassays, and for testing herbicide pollution in the aquatic environment, lake and river pollution, sediment toxicity, and the like. Duckweed and algae represent different levels of complexity in the plant kingdom. They complement each other as phytotoxicity test organisms, instead of mutually excluding each other. Many duckweed species have been studied, primarily of the Lemna and Spirodela genera. Lemna minor and L. gibba have been recommended as standard test species. Differences in duckweed test methodology occur with regard to test types, test vessels, control tests, nutrient media, end points, and applications. 76 references.

  5. Literature review on duckweed toxicity testing.

    PubMed

    Wang, W

    1990-06-01

    Duckweed commonly refers to a group of floating, flowering plants of the family Lemnaceae. Duckweed plants are fast growing and widely distributed. They are easy to culture and to test. Some reports suggest that duckweed plants are tolerant to environmental toxicity. Other studies, however, indicate that duckweed plants are as sensitive to toxicity as other aquatic species. Duckweed plants are especially suitable for use in complex effluent bioassays, and for testing herbicide pollution in the aquatic environment, lake and river pollution, sediment toxicity, and the like. Duckweed and algae represent different levels of complexity in the plant kingdom. They complement each other as phytotoxicity test organisms, instead of mutually excluding each other. Many duckweed species have been studied, primarily of the Lemna and Spirodela genera. Lemna minor and L. gibba have been recommended as standard test species. Differences in duckweed test methodology occur with regard to test types, test vessels, control tests, nutrient media, end points, and applications.

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

    PubMed

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

    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 24h LD(50) values of 7 and 20 microM 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 microM of copper sulphate in solutions of decadienal resulted in the reduction of the 24h LD(50) of decadienal by approximately a third for both species. 1 microM of copper chloride in solutions of decadienal reduced the 24h LD(50) of decadienal to A. salina nauplii by approximately 11% and 1 microM zinc sulphate caused a reduction of only 3%. Pre-exposure of the organisms to 1 microM 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. PMID:15927283

  7. Efficient algal bioassay based on short-term photosynthetic response

    SciTech Connect

    Giddings, J.M.; Stewart, A.J.; O'Neill, R.V.; Gardner, R.H.

    1981-01-01

    A procedure is described for measuring effects of toxicants on algal photosynthesis (H/sup 14/CO/sub 3/ uptake) in 4-h experiments. Results for individual aromatic compounds and the waste-soluble fraction (WSF) of a synthetic oil are presented as examples of applications of the bioassay. The toxicity of the WSF varied among the seven algal species tested, and responses of some species were pH-dependent. Data presented here indicate that algal photosynthesis is inhibited at toxicant concentrations similar to those that cause acute effects in aquatic animals. A model of a pelagic ecosystem is used to demonstrate that even temporary (7-d) inhibition of algal photosynthesis can have a measurable impact on other trophic levels, particularly if the other trophic levels are also experiencing toxic effects.

  8. Toxicity testing of ground water, surface water and waste water in the island of Cyprus

    SciTech Connect

    McNaughton, E.; Kouris, D.; Guden, H.; Gokcekus, H.

    1995-12-31

    The island of Cyprus is an exporter of agricultural products to the European Community (EC). Public health and environmental toxicity testing programs on the island, especially in the Greek-dominated south, are based on EC models. Following EC guidelines, an environmental toxicology laboratory is being established at the State Laboratory in Nicosia. It will test water for toxicity using the acute Daphnia magna survival test, the chronic 4-day algal growth test (Selenastrum capricomutum), Microtox and Mutatox. During a 6-month survey of water and wastewater using the acute Ceriodaphnia dubia test and the algal growth test, the question of the relevance of environmental toxicity testing in an ecosystem devoid of natural year round freshwater sources, excepting ground water, was examined. Municipal wells, potable and agricultural water reservoirs, municipal and industrial effluent were tested. Preliminary studies showed some municipal well water to be toxic to freshwater species, probably due to high salt content. Water from a newly developed reservoir was toxic, probably due to its location at the base of eroding hills recently mined for copper. Effluent from a paper factory was toxic, but the reservoir into which it flows was not, nor was the sulfide-rich water toxic to untreated seeds. For the water-deficient ecosystem of Cyprus, the environmental testing program must be different from those developed for the European continent. The choice of appropriate test species, the need to focus on water quality for public health and agricultural use, and the possible benefits of nutrient-enriched waste water flowing into sterile ocean water, must all be considered.

  9. Comparison of standard acute toxicity tests with rapid-screening toxicity tests

    SciTech Connect

    Toussaint, M.W.; Shedd, T.R.; VanDerSchal, W.H.; Leather, G.R.

    1995-10-01

    This study compared the relative sensitivity of five inexpensive, rapid toxicity tests to the sensitivity of five standard aquatic acute toxicity tests through literature review and testing. The rapid toxicity tests utilized organisms that require little culturing or handling prior to testing: a freshwater rotifer (Branchionus ccalyciflorus); brine shrimp (Artemia salina); lettuce (Lactuca sativa); and two microbial tests (Photo bacterium phosphoreum - Microtox test, and a mixture of bacterial species - the polytox test). Standard acute toxicity test species included water fleas (Daphnia magna and Ceriadaphnta dubia), green algae (Setenastrum capricarnutum), fathead minnows (Pimephalespromelas), and mysid shrimp (Mysidopsis bahia). Sensitivity comparisons between rapid and standard acute toxicity tests were based on LC5O/EC50 data from 11 test chemicals. Individually, the lettuce and rotifer tests ranked most similar in sensitivity to the standard tests, while Microtox fell just outside the range of sensitivities represented by the group of standard acute toxicity tests. The brine shrimp and Polytox tests were one or more orders of magnitude different from the standard acute toxicity tests for most compounds. The lettuce, rotifer, and Microtox tests could be used as a battery for preliminary toxicity screening of chemicals. Further evaluation of complex real-world environmental samples is recommended.

  10. A comparison of standard acute toxicity tests with rapid-screening toxicity tests

    SciTech Connect

    Toussaint, M.W.; Shedd, T.R.; Schalie, W.H. van der; Leather, G.R.

    1995-05-01

    This study compared the relative sensitivity of five inexpensive, rapid toxicity tests to the sensitivity of five standard aquatic acute toxicity tests through literature review and testing. The rapid toxicity tests utilized organisms that require little culturing or handling prior to testing: a freshwater rotifer (Branchionus calyciflorus); brine shrimp (Artemia salina); lettuce (Lactuca sativa); and two microbial tests (Photobacterium phosphoreum--Microtox{reg_sign} test, and a mixture of bacterial species--the Polytox{reg_sign} test). Standard acute toxicity test species included water fleas (Daphnia magna and Ceriodaphnia dubia), green algae (Selenastrum capricornutum), fathead minnows (Pimephales promelas), and mysid shrimp (Mysidopsis bahia). Sensitivity comparisons between rapid and standard acute toxicity tests were based on LC50/EC50 data from 11 test chemicals. Individually, the lettuce and rotifer tests ranked most similar in sensitivity to the standard tests, while Microtox fell just outside the range of sensitivities represented by the group of standard acute toxicity tests. The brine shrimp and Polytox tests were one or more orders of magnitude different from the standard acute toxicity tests for most compounds. The lettuce, rotifer, and Microtox tests could be used as a battery for preliminary toxicity screening of chemicals. Further evaluation of complex real-world environmental samples is recommended.

  11. REGULATORY APPLICATIONS OF POREWATER TOXICITY TESTING

    EPA Science Inventory

    The purpose of this chapter is to evaluate the use of porewater toxicity tests in regulatory applications, including their potential use in the development of sediment quality guideline (SQG) values. Specifically, the following discussion focuses on the appropriateness and readin...

  12. Automated Test Systems for Toxic Vapor Detectors

    NASA Technical Reports Server (NTRS)

    Mattson, C. B.; Hammond, T. A.; Schwindt, C. J.

    1997-01-01

    The NASA Toxic Vapor Detection Laboratory (TVDL) at the Kennedy Space Center (KSC), Florida, has been using Personal Computer based Data Acquisition and Control Systems (PCDAS) for about nine years. These systems control the generation of toxic vapors of known concentrations under controlled conditions of temperature and humidity. The PCDAS also logs the test conditions and the test article responses in data files for analysis by standard spreadsheets or custom programs. The PCDAS was originally developed to perform standardized qualification and acceptance tests in a search for a commercial off-the-shelf (COTS) toxic vapor detector to replace the hydrazine detectors for the Space Shuttle launch pad. It has since become standard test equipment for the TVDL and is indispensable in producing calibration standards for the new hydrazine monitors at the 10 part per billion (ppb) level. The standard TVDL PCDAS can control two toxic vapor generators (TVG's) with three channels each and two flow/ temperature / humidity (FTH) controllers and it can record data from up to six toxic vapor detectors (TVD's) under test and can deliver flows from 5 to 50 liters per minute (L/m) at temperatures from near zero to 50 degrees Celsius (C) using an environmental chamber to maintain the sample temperature. The concentration range for toxic vapors depends on the permeation source installed in the TVG. The PCDAS can provide closed loop control of temperature and humidity to two sample vessels, typically one for zero gas and one for the standard gas. This is required at very low toxic vapor concentrations to minimize the time required to passivate the sample delivery system. Recently, there have been several requests for information about the PCDAS by other laboratories with similar needs, both on and off KSC. The purpose of this paper is to inform the toxic vapor detection community of the current status and planned upgrades to the automated testing of toxic vapor detectors at the

  13. Automated Test Systems for Toxic Vapor Detectors

    NASA Technical Reports Server (NTRS)

    Mattson, C. B.; Hammond, T. A.; Schwindt, C. J.

    1997-01-01

    The NASA Toxic Vapor Detection Laboratory (TVDL) at the Kennedy Space Center (KSC), Florida, has been using Personal Computer based Data Acquisition and Control Systems (PCDAS) for about nine years. These systems control the generation of toxic vapors of known concentrations under controlled conditions of temperature and humidity. The PCDAS also logs the test conditions and the test article responses in data files for analysis by standard spreadsheets or custom programs. The PCDAS was originally developed to perform standardized qualification and acceptance tests in a search for a commercial off-the-shelf (COTS) toxic vapor detector to replace the hydrazine detectors for the Space Shuttle launch pad. It has since become standard test equipment for the TVDL and is indispensable in producing calibration standards for the new hydrazine monitors at the 10 part per billion (ppb) level. The standard TVDL PCDAS can control two toxic vapor generators (TVG's) with three channels each and two flow/temperature/humidity (FIFH) controllers and it can record data from up to six toxic vapor detectors (TVD's) under test and can deliver flows from 5 to 50 liters per minute (L/m) at temperatures from near zero to 50 degrees Celsius (C) using an environmental chamber to maintain the sample temperature. The concentration range for toxic vapors depends on the permeation source installed in the TVG. The PCDAS can provide closed loop control of temperature and humidity to two sample vessels, typically one for zero gas and one for the standard gas. This is required at very low toxic vapor concentrations to minimize the time required to passivate the sample delivery system. Recently, there have been several requests for information about the PCDAS by other laboratories with similar needs, both on and off KSC. The purpose of this paper is to inform the toxic vapor detection community of the current status and planned upgrades to the automated testing of toxic vapor detectors at the Kennedy

  14. Toxicity testing in chemical safety evaluation.

    PubMed

    Bus, James S

    2007-02-01

    The modern era of chemistry has resulted in dramatic improvements in the overall human condition. In addition to new pharmaceuticals, modern chemistry has brought with it enormous health and social benefits Introduction of chemistry-based technologies, however, has also been clearly associated with potential human health risks. The dramatic increase in pharmaceutical and chemical technologies in the post World War II era, coupled with associated examples of demonstrated human toxicity, led to development and application of an expanded and standardized battery of animal and other toxicity tests designed to characterize the potential hazards and risks associated with chemical exposures. This unit discusses the current approach to industrial chemical and pesticide toxicity testing.

  15. Algal photosynthetic responses to toxic metals and herbicides assessed by chlorophyll a fluorescence.

    PubMed

    Kumar, K Suresh; Dahms, Hans-Uwe; Lee, Jae-Seong; Kim, Hyung Chul; Lee, Won Chan; Shin, Kyung-Hoon

    2014-06-01

    Chlorophyll a fluorescence is established as a rapid, non-intrusive technique to monitor photosynthetic performance of plants and algae, as well as to analyze their protective responses. Apart from its utility in determining the physiological status of photosynthesizers in the natural environment, chlorophyll a fluorescence-based methods are applied in ecophysiological and toxicological studies to examine the effect of environmental changes and pollutants on plants and algae (microalgae and seaweeds). Pollutants or environmental changes cause alteration of the photosynthetic capacity which could be evaluated by fluorescence kinetics. Hence, evaluating key fluorescence parameters and assessing photosynthetic performances would provide an insight regarding the probable causes of changes in photosynthetic performances. This technique quintessentially provides non-invasive determination of changes in the photosynthetic apparatus prior to the appearance of visible damage. It is reliable, economically feasible, time-saving, highly sensitive, versatile, accurate, non-invasive and portable; thereby comprising an excellent alternative for detecting pollution. The present review demonstrates the applicability of chlorophyll a fluorescence in determining photochemical responses of algae exposed to environmental toxicants (such as toxic metals and herbicides). PMID:24632123

  16. Algal photosynthetic responses to toxic metals and herbicides assessed by chlorophyll a fluorescence.

    PubMed

    Kumar, K Suresh; Dahms, Hans-Uwe; Lee, Jae-Seong; Kim, Hyung Chul; Lee, Won Chan; Shin, Kyung-Hoon

    2014-06-01

    Chlorophyll a fluorescence is established as a rapid, non-intrusive technique to monitor photosynthetic performance of plants and algae, as well as to analyze their protective responses. Apart from its utility in determining the physiological status of photosynthesizers in the natural environment, chlorophyll a fluorescence-based methods are applied in ecophysiological and toxicological studies to examine the effect of environmental changes and pollutants on plants and algae (microalgae and seaweeds). Pollutants or environmental changes cause alteration of the photosynthetic capacity which could be evaluated by fluorescence kinetics. Hence, evaluating key fluorescence parameters and assessing photosynthetic performances would provide an insight regarding the probable causes of changes in photosynthetic performances. This technique quintessentially provides non-invasive determination of changes in the photosynthetic apparatus prior to the appearance of visible damage. It is reliable, economically feasible, time-saving, highly sensitive, versatile, accurate, non-invasive and portable; thereby comprising an excellent alternative for detecting pollution. The present review demonstrates the applicability of chlorophyll a fluorescence in determining photochemical responses of algae exposed to environmental toxicants (such as toxic metals and herbicides).

  17. Potentials for Indication of Potentially Harmful Toxic Algal Blooms Using PROBA1-CHRIS Hyperspectral Imagery- A Case Study in Burkina Faso

    NASA Astrophysics Data System (ADS)

    Beiermann, Timo

    2010-12-01

    Toxic algal blooms are an issue affecting water quality and can cause harmful health impacts. The aim of the conducted case study is to assess such blooms by chlorophyll a and phycocyanin detection as indicators of the occurrence. Using demonstrated single reflectance ratio algorithms published as in [7] and processed with provided tools for hyperspectral Proba1-CHRIS imagery in a study site including Loumbila reservoir near Ouagadougou, capital of Burkina Faso to investigate potentials of this approach.

  18. Avian models for toxicity testing

    USGS Publications Warehouse

    Hill, E.F.; Hoffman, D.J.

    1984-01-01

    The use of birds as test models in experimental and environmental toxicology as related to health effects is reviewed, and an overview of descriptive tests routinely used in wildlife toxicology is provided. Toxicologic research on birds may be applicable to human health both directly by their use as models for mechanistic and descriptive studies and indirectly as monitors of environmental quality. Topics include the use of birds as models for study of teratogenesis and embryotoxicity, neurotoxicity, behavior, trends of environmental pollution, and for use in predictive wildlife toxicology. Uses of domestic and wild-captured birds are discussed.

  19. Bioequivalence approach for whole effluent toxicity testing

    SciTech Connect

    Shukla, R.; Wang, Q.; Fulk, F.; Deng, C.; Denton, D.

    2000-01-01

    Increased use of whole effluent toxicity (WET) tests in the regulatory arena has brought increased concern over the statistical analysis of WET test data and the determination of toxicity. One concern is the issue of statistical power. A number of WET tests may pass the current hypothesis test approach because they lack statistical power to detect relevant toxic effects because of large within-test variability. Additionally, a number of WET tests may fail the current approach because they possess excessive statistical power, as a result of small within-test variability, and detect small differences that may not be biologically relevant. The strengths and limitations of both the traditional hypothesis test approach and the bioequivalence approach for use in the National Pollutant Discharge Elimination System program were evaluated. Data from 5,213 single-concentration, short-term chronic WET tests with Ceriodaphnia dubia provided the database for analysis. Comparison of results between the current approach and the bioequivalence approach indicates that the current approach to WET testing is generally sound but that adopting the proposed bioequivalence approach resolves concerns of statistical power. Specifically, within this data set, applying the bioequivalence approach resulted in failure for tests with relatively large test variability and a pass for tests with relatively small within-test variability.

  20. An unprecedented coastwide toxic algal bloom linked to anomalous ocean conditions

    NASA Astrophysics Data System (ADS)

    McCabe, Ryan M.; Hickey, Barbara M.; Kudela, Raphael M.; Lefebvre, Kathi A.; Adams, Nicolaus G.; Bill, Brian D.; Gulland, Frances M. D.; Thomson, Richard E.; Cochlan, William P.; Trainer, Vera L.

    2016-10-01

    A coastwide bloom of the toxigenic diatom Pseudo-nitzschia in spring 2015 resulted in the largest recorded outbreak of the neurotoxin, domoic acid, along the North American west coast. Elevated toxins were measured in numerous stranded marine mammals and resulted in geographically extensive and prolonged closures of razor clam, rock crab, and Dungeness crab fisheries. We demonstrate that this outbreak was initiated by anomalously warm ocean conditions. Pseudo-nitzschia australis thrived north of its typical range in the warm, nutrient-poor water that spanned the northeast Pacific in early 2015. The seasonal transition to upwelling provided the nutrients necessary for a large-scale bloom; a series of spring storms delivered the bloom to the coast. Laboratory and field experiments confirming maximum growth rates with elevated temperatures and enhanced toxin production with nutrient enrichment, together with a retrospective analysis of toxic events, demonstrate the potential for similarly devastating ecological and economic disruptions in the future.

  1. Toxicity test method development in southeast Asia

    SciTech Connect

    McPherson, C.A.

    1995-12-31

    Use of aquatic toxicity tests is relatively new in southeast Asia. As part of the ASEAN-Canada Cooperative Programme on Marine Science -- Phase 2, which includes development of marine environmental criteria, a need for tropical toxicity data was identified. A step-wise approach was used for test method development (simple, acute tests and easily measured endpoints first, then more complex short-term chronic methods), for test specific selection (using species found throughout the region first, and then considering species with narrower geographic distribution), and for integration of quality assurance/quality control (QA/QC) practices into all laboratory activities. Development of test protocols specifically for tropical species included acute and chronic toxicity tests with marine fish, invertebrates and algae. Criteria for test species selection will be reviewed. Method development was based on procedures and endpoints already widely used in North America and Europe (e.g., 96-h LC50 with fish), but adapted for use with tropical species. For example, a bivalve larval development test can use the same endpoints but the duration is only 24 hours. Test method development included research on culture and holding procedures, determination of test conditions (e.g., duration, test containers), and identification of appropriate endpoints. Acute tests with fish and invertebrates were developed first. The next step was development of short-term chronic tests to measure phytoplankton growth, bivalve and echinoderm embryo or larval development, and larval fish growth. The number of species and types of tests was increased in a staged approach, as laboratories became better equipped and personnel gained practical experience. In most cases, method development coincided with training workshops to introduce the principles of toxicity testing.

  2. New Zealand sediment toxicity testing methodologies

    SciTech Connect

    Hickey, C.W.; Roper, D.S.; Nipper, M.; Martin, M.L.

    1995-12-31

    Sediment toxicity testing in New Zealand is developing against a background of an increasing public desire for environmental protection and strict legislative requirements that contaminant discharges should not have any significant adverse effects on aquatic life. The importance of sediment contamination and its potential immediate and long term adverse effects on aquatic biota in general is becoming widely recognized, This has lead to an effort to develop acute and chronic sediment toxicity tests with organisms representative of the New Zealand indigenous biota. An amphipod species occurring in both freshwater and estuarine environments, Chaetocorophium cf lucasi, and the marine bivalve Macomona liliana, a common inhabitant of intertidal sandflats, have been evaluated for their sensitivity to natural sediment characteristics. The amphipod and bivalve are presently being used for testing sediment acute (10d) and chronic toxicity (20--30d), with survival and growth as test endpoints, and the bivalve has shown to be a useful organism for behavioral tests with burial and sediment avoidance by movement and drifting as endpoints. The estuarine bivalve Arthritica bifurca, abundant in muddy sediments, is a self-fertilizing hermaphroditic species and its suitability for sediment tests with a reproductive endpoint is underway. Freshwater sphaeriid bivalves, Sphaerium novazelandiae, are also being used for survival, growth, reproduction and behavioral endpoints. Sensitivity to reference toxicants and results for contaminated sediments will be presented and discussed in relation to sediment quality criteria developed elsewhere.

  3. Development and application of a marine sediment pore-water toxicity test using Ulva fasciata zoospores

    SciTech Connect

    Hooten, R.L.; Carr, R.S.

    1998-01-01

    An acute (96 h) pore-water toxicity test protocol using germination and growth of Ulva fasciata zoospores as endpoints was developed to test the toxicity of marine and estuarine sediment pore-water samples. Tests with an organic toxicant (sodium dodecyl sulfate; SDS), three metals (Cd, Cu, and Zn), and ammonia (NH{sub 3}) were conducted to determine zoospore sensitivity. Zoospore germination and gametophyte growth were as sensitive to SDS as sea urchin (Arbacia punctulata) fertilization and embryological development. Zoospore sensitivity to metals was greater than or comparable to that of adult macroalgae. Zoospores were less sensitive to NH{sub 3} than were other commonly used toxicity test organisms. Test results using this algal assay with sediment pore-water samples with high NH{sub 3} concentrations were compared with results from sea urchin fertilization and embryological development tests for the same samples. Ulva fasciata zoospore germination was not affected by samples with high NH{sub 3} concentrations that were toxic in both sea urchin tests. Zoospore tolerance of NH{sub 3} and sensitivity to other contaminants indicate that their response may be useful in toxicity identification evaluation studies with pore-water samples that contain high concentrations of unionized NH{sub 3}.

  4. Development and application of a marine sediment pore-water toxicity test using Ulva fasciata zoospores

    USGS Publications Warehouse

    Hooten, R.L.; Carr, R.S.

    1998-01-01

    An acute (96 h) pore-water toxicity test protocol using germination and growth of Ulva fasciata zoospores as endpoints was developed to test the toxicity of marine and estuarine sediment pore-water samples. Tests with an organic toxicant (sodium dodecyl sulfate; SDS), three metals (Cd, Cu, and Zn), and ammonia (NH3) were conducted to determine zoospore sensitivity. Zoospore germination and gametophyte growth were as sensitive to SDS as sea urchin (Arbacia punctulata) fertilization and embryological development. Zoospore sensitivity to metals was greater than or comparable to that of adult macroalgae. Zoospores were less sensitive to NH3 than were other commonly used toxicity test organisms. Test results using this algal assay with sediment pore-water samples with high NH3 concentrations were compared with results from sea urchin fertilization and embryological development tests for the same samples. Ulva fasciata zoospore germination was not affected by samples with high NH3 concentrations that were toxic in both sea urchin tests. Zoospore tolerance of NH3 and sensitivity to other contaminants indicate that their response may be useful in toxicity identification evaluation studies with pore-water samples that contain high concentrations of unionized NH3.

  5. Toxicity test of a dental commercial composite

    PubMed Central

    Ponce-Bravo, Santa; Martínez-Rivera, José-Luis; Garcés-Ortíz, Maricela

    2015-01-01

    Background International rules must be followed for testing biosecurity in dental materials. A new brand of restorative material appeared in the market and regulations indicated that it should be tested for toxicity. Objectives The aim of this study was to determine the 90-day sub chronic toxicity of one triethylene glycol dimethacrylate containing composite (MEDENTAL Light-Cure Composite™) orally administered to rats according to Organization for Economic Co-Operation and Development no. 48 guidelines and the requirements specified in the ISO 10993-11. Material and Methods Wistar rats ate the polymerized composite during 90 days and were observed to determine changes in their behavior, eye and skin signs and other attitudes such as aggressiveness, posture, walking and response to handling. After 90 days were sacrificed to ascertain blood alterations, we did special hematological tests and assessed microscopic slides from 33 different organs. Results We recorded no significant changes in clinical behavior of the animals. Microscopic review of the H&E stained slides obtained from the analyzed organs showed no abnormal inflammatory or cytological changes and all hematological special tests were within normal limits. Conclusions Results of this study show that under our experimental conditions the MEDENTAL Light-Cure Composite™ does not produce inflammatory or cytological changes suggestive of toxicity. Key words:Dental materials, composite resin, toxicity, inflammation, TEGDMA. PMID:26155348

  6. Genetic and acute toxicological evaluation of an algal oil containing eicosapentaenoic acid (EPA) and palmitoleic acid.

    PubMed

    Collins, M L; Lynch, B; Barfield, W; Bull, A; Ryan, A S; Astwood, J D

    2014-10-01

    Algal strains of Nannochloropsis sp. were developed, optimized, cultivated and harvested to produce a unique composition of algal oil ethyl esters (Algal-EE) that are naturally high in eicosapentaenoic acid (EPA, 23-30%) and palmitoleic acid (20-25%), and contain no docosahexaenoic acid (DHA). Algal-EE was evaluated for mutagenic activity (Ames bacterial reverse mutation, in vitro mammalian chromosome aberration, in vivo micronucleus test) and for acute oral toxicity in Sprague-Dawley rats. In the acute toxicity study, rats received a single oral gavaged dose of Algal-EE (2000 mg/kg body weight). Clinical observations were made for 14 days before sacrifice on Day 15. Macroscopic evaluation involved the examination of all organs in the cranial, thoracic, and abdominal cavities. Algal-EE showed no evidence of mutagenicity, did not produce an increase in the frequency of structural chromosome aberrations, and did not cause an increase in the induction of micronucleated polychromatic erythrocytes. There were no macroscopic abnormalities. Algal-EE up to 2000 mg/kg body weight did not affect body weight, organ appearance or produce any toxic-related signs of morbidity. The acute median lethal dose (LD50) of Algal-EE was >2000 mg/kg body weight. Based on these assays, Algal-EE does not appear to have any genetic or acute oral toxicity. PMID:25057807

  7. Evaluation of the aquatic toxicity of two veterinary sulfonamides using five test organisms.

    PubMed

    De Liguoro, Marco; Di Leva, Vincenzo; Gallina, Guglielmo; Faccio, Elisabetta; Pinto, Gabriele; Pollio, Antonino

    2010-10-01

    The aquatic toxicity of sulfaquinoxaline (SQO) and sulfaguanidine (SGD) was evaluated on the following test organisms: Daphnia magna (reproduction test), Pseudokirchneriella subcapitata, Scenedesmus dimorphus, Synecococcus leopoliensis (algal growth inhibition test) and Lemna gibba (duckweed growth inhibition test). Furthermore, the additivity of the two compounds was measured on D. magna (acute immobilisation test) and P. subcapitata (algal growth inhibition test) using the isobologram method. Results show that SQO and SGD are more toxic to green algae and daphnids, respectively, than other veterinary sulfonamides (SAs) and that their mixtures have a less then additive interaction. Taking into account the highest concentrations detected so far in surface waters for SQO (0.112 μg L(-1)) and for SGD (0.145 μg L(-1)) and the lowest NOECs obtained with the five test organisms, divided by an assessment factor of 10, the following PNECs and risk quotients (RQs) were calculated. SQO: PNEC 2 μg L(-1); RQ 0.056. SGD: PNEC 39.5 μg L(-1); RQ 0.004. Consequently, at the concentrations actually detected in the aquatic environment, the two SAs alone should not harm the freshwater organisms. However, it seems advisable, for veterinary mass treatments, the use of other SAs that have a lesser impact on the aquatic environment. Furthermore, considering the high probability of having complex mixtures of different SAs residues in water, each individual contamination should be evaluated by applying to the SAs mixtures the conservative criteria of additivity. PMID:20673955

  8. Contact tests for pentachlorophenol toxicity to earthworms

    SciTech Connect

    Spontak, D.A.

    1994-12-31

    The standardized contact filter paper test (EEC and OECD) provides an effective screening test for toxicity to earthworms in a laboratory setting. A need exists for a reliable and inexpensive technique for non-laboratory settings where screening is desired, but facilities cannot provide for the acquisition and maintenance of the glass vials required by the standardized test. This study evaluated two modifications of the standardized test using clear polyethylene bags, with and without filter paper, with Eisenia fetida and domesticated surface-feeding earthworms. The tests were conducted according to EEC and OECD guidelines. Results of the modified tests corresponded in dose and effect to the standardized contact filter paper test indicating the usefulness of the modified tests.

  9. The developmental toxicity testing of biologics.

    PubMed

    Hazelden, Keith P

    2013-01-01

    The characteristics of biologic drugs, as compared with small molecules, confer significant advantages for both the drug developer and the prospective patients. The necessity for, and the timing of, developmental toxicity testing in the preclinical program must be considered. Choice of an appropriate test system is of particular importance, one that shows pharmacodynamic activity comparable to man. Where the conventional rodent/non-rodent species show such functional cross-reactivity, those species can be used in developmental testing, but often the only relevant species will be a nonhuman primate, in which case an extended study design (the ePPND) should be the default. Such an approach provides appropriate toxicity screening while reducing animal usage.

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

    EPA Science Inventory

    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.

  11. A model for field toxicity tests

    USGS Publications Warehouse

    Kaiser, Mark S.; Finger, Susan E.

    1996-01-01

    Toxicity tests conducted under field conditions present an interesting challenge for statistical modelling. In contrast to laboratory tests, the concentrations of potential toxicants are not held constant over the test. In addition, the number and identity of toxicants that belong in a model as explanatory factors are not known and must be determined through a model selection process. We present one model to deal with these needs. This model takes the record of mortalities to form a multinomial distribution in which parameters are modelled as products of conditional daily survival probabilities. These conditional probabilities are in turn modelled as logistic functions of the explanatory factors. The model incorporates lagged values of the explanatory factors to deal with changes in the pattern of mortalities over time. The issue of model selection and assessment is approached through the use of generalized information criteria and power divergence goodness-of-fit tests. These model selection criteria are applied in a cross-validation scheme designed to assess the ability of a model to both fit data used in estimation and predict data deleted from the estimation data set. The example presented demonstrates the need for inclusion of lagged values of the explanatory factors and suggests that penalized likelihood criteria may not provide adequate protection against overparameterized models in model selection.

  12. Whole embryo culture and toxicity testing.

    PubMed

    Piersma, A H

    1993-11-01

    The use of post-implantation embryo culture in toxicity testing has been the subject of research as well as debate. Advantages of the method include reduced animal use, and reduced cost and time in comparison with in vivo testing. In addition, the method yields many developmental endpoints: it allows the direct and controlled addition of small amounts of compounds, and the incorporation of metabolizing systems is possible. Disadvantages include the technical skill required, the restricted culture duration, the artificial route of administration of test compounds and the absence of the maternal compartment (and hence the absence of a measure for adult toxicity). Several studies using a variety of compounds have shown promising results with respect to correlations between in vivo effects and the outcome of embryo culture. The question of how a meaningful validation study should be designed is still a matter of dispute. Issues under discussion include: the purpose of validation, culture conditions, endpoint definition, choice of compounds to be tested, the status of in vivo data on test compounds, presentation of results, double-blind and interlaboratory design, and the position of the test within a testing strategy. The validity of whole embryo culture as a toxicity screening test is likely to vary considerably between classes of compounds. Therefore, validation studies with larger sets of related compounds may be more meaningful than those with many unrelated compounds. Whole embryo culture may provide a significant contribution to risk assessment by use in screening, and for mechanistic, structure-activity, and dose-response studies. PMID:20732278

  13. Effect-directed analysis of sediment-associated algal toxicants at selected hot spots in the river Elbe basin with a special focus on bioaccessibility.

    PubMed

    Schwab, Katrin; Altenburger, Rolf; Lübcke-von Varel, Urte; Streck, Georg; Brack, Werner

    2009-07-01

    Benthic algae are the dominant primary producers in many rivers and may be at risk of being affected by sediment-associated toxicants. Toxicity as well as bioaccessibility should be considered for the identification of major toxicants affecting benthic algae. Thus, effect-directed analysis (EDA) combining biotesting, fractionation, and chemical analysis was combined with both exhaustive and bioaccessibility-directed extraction to identify the major toxicants in sediments at three industrial sites in the Elbe River basin (Bitterfeld, Most, and Prelouc). Exhaustive accelerated solvent extraction was used together with bioaccessibility-directed extraction with TENAX in aqueous suspension. Growth inhibition of the green alga Scenedesmus vacuolatus identified polycyclic aromatic compounds as important algal toxicants at all three sites, while in Bitterfeld and Prelouc additional toxicants, such as N-phenyl-2-naphthylamine and 7H-benzo[de]anthracen-7-one, played an important role. Confirmation of the identified compounds was based on the index of confirmation quality (ICQ) comparing the effect of an artificial mixture to that of the original sample. The results suggest a successful confirmation of identified toxicants for most fractions with ICQ values between 0.5 and 2. The bioaccessibility of toxicants decreased in the order Prelouc > Bitterfeld > Most as determined by the investigation of TENAX samples. Similar total concentrations of toxicants in Prelouc and Most sediment result in bioaccessible concentrations in Prelouc that exceed those in Most by a factor of 10 to 20. The extraction with TENAX with a subsequent EDA proved to be a powerful tool for prioritizing contaminants and contaminated sites with respect to the hazard of sediment-associated toxicants to green algae. PMID:19228079

  14. Ocular Toxicity Testing of Lunar Dust

    NASA Technical Reports Server (NTRS)

    Meyers, Valerie E.

    2010-01-01

    This slide presentation reviews the use of ocular testing to determine the toxicity of lunar dust. The OECD recommendations are reviewed. With these recommendations in mind the test methodology was to use EpiOcular, tissues derived from normal human epidermal keratinocytes, the cells of which have been differentiated on cell culture inserts to form a multi-layered structure, which closely parallels the corneal epithelium and to dose the tissue with 100 mg dust from various sources. The in-vitro study provides evidence that lunar dust is not severely corrosive or irritating, however, in vitro tests have limitations, and in vivo tests provides a more complete scenario, and information, it is recommended that in vivo tests be performed.

  15. Harmful Algal Blooms

    USGS Publications Warehouse

    Graham, Jennifer L.

    2007-01-01

    What are Harmful Algal Blooms (HABs)? Freshwater and marine harmful algal blooms (HABs) can occur anytime water use is impaired due to excessive accumulations of algae. HAB occurrence is affected by a complex set of physical, chemical, biological, hydrological, and meteorological conditions making it difficult to isolate specific causative environmental factors. Potential impairments include reduction in water quality, accumulation of malodorous scums in beach areas, algal production of toxins potent enough to poison both aquatic and terrestrial organisms, and algal production of taste-and-odor compounds that cause unpalatable drinking water and fish. HABs are a global problem, and toxic freshwater and (or) marine algae have been implicated in human and animal illness and death in over 45 countries worldwide and in at least 27 U.S. States (Yoo and others, 1995; Chorus and Bartram, 1999; Huisman and others, 2005).

  16. In vitro models for liver toxicity testing

    PubMed Central

    Soldatow, Valerie Y.; LeCluyse, Edward L.; Griffith, Linda G.; Rusyn, Ivan

    2013-01-01

    Over the years, various liver-derived in vitro model systems have been developed to enable investigation of the potential adverse effects of chemicals and drugs. Liver tissue slices, isolated microsomes, perfused liver, immortalized cell lines, and primary hepatocytes have been used extensively. Immortalized cell lines and primary isolated liver cells are currently most widely used in vitro models for liver toxicity testing. Limited throughput, loss of viability, and decreases in liver-specific functionality and gene expression are common shortcomings of these models. Recent developments in the field of in vitro hepatotoxicity include three-dimensional tissue constructs and bioartificial livers, co-cultures of various cell types with hepatocytes, and differentiation of stem cells into hepatic lineage-like cells. In an attempt to provide a more physiological environment for cultured liver cells, some of the novel cell culture systems incorporate fluid flow, micro-circulation, and other forms of organotypic microenvironments. Co-cultures aim to preserve liver-specific morphology and functionality beyond those provided by cultures of pure parenchymal cells. Stem cells, both embryonic- and adult tissue-derived, may provide a limitless supply of hepatocytes from multiple individuals to improve reproducibility and enable testing of the individual-specific toxicity. This review describes various traditional and novel in vitro liver models and provides a perspective on the challenges and opportunities afforded by each individual test system. PMID:23495363

  17. Standards for reporting fish toxicity tests

    USGS Publications Warehouse

    Cope, O.B.

    1961-01-01

    The growing impetus of studies on fish and pesticides focuses attention on the need for standardized reporting procedures. Good methods have been developed for laboratory and field procedures in testing programs and in statistical features of assay experiments; and improvements are being made on methods of collecting and preserving gish, invertebrates, and other materials exposed to economic poisons. On the other had, the reporting of toxicity data in a compete manner has lagged behind, and today's literature is little improved over yesterday's with regard to completeness and susceptibility to interpretation.

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

    SciTech Connect

    Park, Jiyeon; Jeters, Robert T.; Gill, Gary A.; Kuo, Li-Jung; Bonheyo, George T.

    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.

  19. TOXICITY TESTS FOR SEDIMENT QUALITY ASSESSMENTS

    EPA Science Inventory

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

  20. Effect of test conditions on the toxicity of copper to juvenile unionid mussels

    SciTech Connect

    Keller, A.E.; Ruessler, D.S.; Kernaghan, N.J.

    1999-07-01

    During the past twenty years, unionid mussels have declined in both abundance and diversity throughout the eastern United States. As a result, there has been an increased call to evaluate the toxicity of various pollutants to unionids in an attempt to separate habitat-caused losses from those precipitated by aquatic contaminants. Few toxicity data for unionids were available until recently because unionids are not easily cultured and no test method had been developed for these animals. Therefore, water quality criteria developed by the USEPA in the 1970s and 1980s were derived from data lacking any information on unionid mussel sensitivities. The Tennessee Valley Authority (TVA) has advocated the use of a 9-day toxicity test method its scientists developed in the late 1980s. This method, which requires the use of silt, an algal mixture for food and daily changes of water, is not only more labor intensive, it also introduces sources of variation with the use of silt and algae, as well as being substantially different from the standard 96-h fathead minnow or zooplankton tests. The evaluation of TVA's suggested test conditions indicate that the use of a 16L:8D light regime, with or without silt or algae did not result in a change in the toxicity of dissolved copper to juvenile Utterbackia imbecillis mussels compared to that recorded using TVA's test conditions.

  1. Live algae as a vector candidate for hydrophobic polychlorinated biphenyls translocation to bivalve filter feeders for laboratory toxicity test.

    PubMed

    Jo, Qtae; Kim, Su-Kyoung; Lee, Chae Sung; Lee, Pil Yong

    2011-11-01

    Live algae carrying hydrophobic xenobiotics can be an effective vector candidate for the chemical translocation to filter feeders in the laboratory toxicity test, but information on their application is lacking. Time-course uptake and elimination of polychlorinated biphenyls (PCBs) (0, 50, 100, and 500 ng g(-1) by two key algal foods, Isochrysis galbana and Tetraselmis suecica, were measured. Both of the algae achieved maximum concentration in an hourafter PCBs exposure regardless the chemical concentrations in our time-course measurements (0, 1, 5, 10, 24, 48 and 72 hrs). Once achieved the maximum concentration, the algae shortly exhibited elimination or eliminating tendency depending on the chemical concentrations. Algae exposed to the chemical for 1 and 24 hrs (hereafter 1 and 24 hr vectors, respectively) were then evaluated as a chemical translocation vector by feeding test to larval and spat Crassostrea gigas. In the feeding test the 24 hr vector, which contained lower chemicals than the 1-hr vector, appeared to be more damaging the early lives of the oyster. This was particularly significant for vectors of higher PCBs (p<0.05), probably due to algal reduction in food value by the prolonged chemical stress. These findings imply that 1 hr exposure is long enough for a generation of algal vector for laboratory toxicity test, minimizing data error resulted from reduction in food value by longer chemical stress.

  2. 40 CFR 797.1400 - Fish acute toxicity test.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... test. If the toxicity of the test substance is not already known, a range finding test should be... analyzed. (F) If the measured concentrations of dissolved test substance are considerably lower (e.g., of the test substance.......

  3. 40 CFR 797.1400 - Fish acute toxicity test.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... test. If the toxicity of the test substance is not already known, a range finding test should be... analyzed. (F) If the measured concentrations of dissolved test substance are considerably lower (e.g., of the test substance.......

  4. The influence of a toxic cyanobacterial bloom and water hydrology on algal populations and macroinvertebrate abundance in the upper littoral zone of Lake Krugersdrift, South Africa.

    PubMed

    Oberholster, Paul J; Botha, Anna-Maria; Ashton, Peter J

    2009-01-01

    The biological interactions and the physical and chemical properties of the littoral zone of Lake Krugersdrift were studied for a 4-month period when a dense, toxic cyanobacterial bloom dominated by Microcystis aeruginosa was present in the main lake basin. The presence of a toxic strain of M. aeruginosa was confirmed through the use of ELISA and molecular markers that detect the presence of the mcyB and mcyD genes of the mcy gene cluster that synthesizes microcystin. An increase in Microcystis toxicity at sites dominated by the cyanobacterial scum was accompanied by an increase in total abundance of the macroinvertebrate families Hirudinae, Chironomidae, and Tubificidae. Sites located away from the cyanobacterial scum had a lower abundance but a higher diversity of macroinvertebrates. The water quality under the Microcystis scum was characterized by low pH values, low concentrations of dissolved oxygen, and lower total alkalinity values. The periphytic alga Ulothrix zonata was absent in areas dominated by the cyanobacterial scum, possibly as a result of overshadowing by the scum or direct toxic allelopathic effects on growth and photosynthesis. The diatom Diatoma vulgare dominated the benthic algal flora beneath the cyanobacterial scum.

  5. Paradigm shift in toxicity testing and modeling.

    PubMed

    Sun, Hongmao; Xia, Menghang; Austin, Christopher P; Huang, Ruili

    2012-09-01

    The limitations of traditional toxicity testing characterized by high-cost animal models with low-throughput readouts, inconsistent responses, ethical issues, and extrapolability to humans call for alternative strategies for chemical risk assessment. A new strategy using in vitro human cell-based assays has been designed to identify key toxicity pathways and molecular mechanisms leading to the prediction of an in vivo response. The emergence of quantitative high-throughput screening (qHTS) technology has proved to be an efficient way to decompose complex toxicological end points to specific pathways of targeted organs. In addition, qHTS has made a significant impact on computational toxicology in two aspects. First, the ease of mechanism of action identification brought about by in vitro assays has enhanced the simplicity and effectiveness of machine learning, and second, the high-throughput nature and high reproducibility of qHTS have greatly improved the data quality and increased the quantity of training datasets available for predictive model construction. In this review, the benefits of qHTS routinely used in the US Tox21 program will be highlighted. Quantitative structure-activity relationships models built on traditional in vivo data and new qHTS data will be compared and analyzed. In conjunction with the transition from the pilot phase to the production phase of the Tox21 program, more qHTS data will be made available that will enrich the data pool for predictive toxicology. It is perceivable that new in silico toxicity models based on high-quality qHTS data will achieve unprecedented reliability and robustness, thus becoming a valuable tool for risk assessment and drug discovery.

  6. Toxic equivalent concentrations (TEQs) for baseline toxicity and specific modes of action as a tool to improve interpretation of ecotoxicity testing of environmental samples.

    PubMed

    Escher, Beate I; Bramaz, Nadine; Mueller, Jochen F; Quayle, Pamela; Rutishauser, Sibylle; Vermeirssen, Etiënne L M

    2008-05-01

    The toxic equivalency concept is a widely applied method to express the toxicity of complex mixtures of compounds that act via receptor-mediated mechanisms such as induction of the arylhydrocarbon or estrogen receptors. Here we propose to extend this concept to baseline toxicity, using the bioluminescence inhibition test with Vibrio fischeri, and an integrative ecotoxicity endpoint, algal growth rate inhibition. Both bioassays were validated by comparison with literature data and quantitative structure-activity relationships (QSARs) for baseline toxicity were developed for all endpoints. The novel combined algae test, with Pseudokirchneriella subcapitata, allows for the simultaneous evaluation of specific inhibition of photosynthesis and growth rate. The contributions of specific inhibition of photosynthesis and non-specific toxicity could be differentiated by comparing the time and endpoint pattern. Photosynthesis efficiency, measured with the saturation pulse method after 2 h of incubation, served as indicator of specific inhibition of photosynthesis by photosystem II inhibitors. Diuron equivalents were defined as toxicity equivalents for this effect. The endpoint of growth rate over 24 h served to derive baseline toxicity equivalent concentrations (baseline-TEQ). By performing binary mixture experiments with reference compounds and complex environmental samples from a sewage treatment plant and a river, the TEQ concept was validated. The proposed method allows for easier interpretation and communication of effect-based water quality monitoring data and provides a basis for comparative analysis with chemical analytical monitoring. PMID:18449398

  7. Developmental and reproductive toxicity testing of vaccines.

    PubMed

    Barrow, Paul

    2012-03-01

    The majority of new preventative and therapeutic vaccines are now assessed for developmental toxicity according to guidelines issued by the FDA in 2006. Despite the absence of confirmed effects in humans, vaccines are frequently suspected of having adverse side-effects on the development of children. Such suspicions are perhaps unavoidable considering the extremely widespread use of vaccines. The preclinical developmental toxicology studies are designed to assess possible influences of each component of the vaccine formulation-and the induced antibodies-on the development of the conceptus, neonate and suckling organism. Immune modulation by a vaccine or an adjuvant could, for instance, affect the outcome of pregnancy by interfering with the natural shift in immune balance of the mother during gestation. Maternal immunoglobulins are transferred from the mother to the offspring in order to confer passive immunity during early life. This maternal antibody transport is prenatal in humans and monkeys, but tends to be delayed until after birth in other species. Therefore, a suitable model species needs to be chosen for preclinical studies in order to ensure exposure of the foetus to the induced maternal antibodies following vaccination. Rabbits are the best laboratory model for prenatal immunoglobulin transfer, but rodents are more practical for the necessary postnatal investigations. Non-human primates are the only appropriate models for the testing of vaccines that are not immunogenic in lower species. It is advisable to test new adjuvants separately according to the ICH S5(R2) guidelines. Preclinical paediatric investigations are not currently required for vaccines, even though most vaccines are given to children. Other areas of regulatory concern include developmental immunotoxicity and effects on the preimplantation embryo. Because of the limitations of the available animal models for developmental toxicity testing, pharmacovigilance is essential.

  8. Optimal conditions for three brood chronic toxicity test method using a freshwater macroinvertebrate Moina macrocopa.

    PubMed

    Oh, Sorin; Choi, Kyungho

    2012-06-01

    Freshwater cladocera such as Daphnia magna and Ceriodaphnia dubia have been used extensively for freshwater toxicity test worldwide. However, these species may not be indigenous in certain geographical regions, which restrict the utility of these organisms as test species. In the present study, we investigated optimal culture and test conditions for an indigenous freshwater macroinvertebrate of Korea, Moina macrocopa. The culture conditions that were evaluated included water temperature (20°C and 25°C), rearing media (moderately hard water or MHW, with or without selenium supplementation, or Elendt M4), and food density (2.5 × 10(7) and 5 × 10(7) cells/mL of Selenastrum capricornutum), and their effects on the life history characteristics of M. macrocopa were determined. Population growth rate of M. macrocopa was maximized at 25°C with 5 × 10(7) cells/mL of algal food density in MHW. A series of chronic three brood reference toxicant tests were conducted under the ideal culture conditions that were identified here, and the results of the tests indicated reliable reproducibility of the test protocol. Optimal culture and test conditions that were identified for M. macrocopa in the present study are suggested for evaluation of chronic toxicity of chemicals and industrial or municipal discharge. PMID:21769559

  9. Exposure Science for Chemical Prioritization and Toxicity Testing

    EPA Science Inventory

    Currently, a significant research effort is underway to apply new technologies to screen and prioritize chemicals for toxicity testing as well as to improve understanding of toxicity pathways (Dix et al. 2007, Toxicol Sci; NRC, 2007, Toxicity Testing in the 21st Century; Collins ...

  10. Comparison of bulk sediment and sediment elutriate toxicity testing methods

    EPA Science Inventory

    Elutriate bioassays are among numerous methods that exist for assessing the potential toxicity of sediments in aquatic systems. In this study, interlaboratory results were compared from 96-hour Ceriodaphnia dubia and Pimephales promelas static-renewal acute toxicity tests conduct...

  11. Status and applications of echinoid (phylum echinodermata) toxicity test methods

    SciTech Connect

    Bay, S.; Burgess, R.; Nacci, D.

    1993-01-01

    The use of echinoderms for toxicity testing has focused primarily on sea urchins and sand dollars (Strongylocentrotus purpuratus, Arbacia punctulata, Lytechinus pictus, and Dendraster excentricus, for example). The status and relative sensitivity of various test methods are described. The most frequently used test methods consist of short-term exposures of sea urchin sperm or embryos; these tests can be easily conducted at all times of the year by using species with complementary spawning cycles or laboratory conditioned populations of a single species. Data from reference toxicant and effluent toxicity tests are summarized. Information on the precision and sensitivity of echinoid test methods are limited and preclude rigorous comparisons with other test methods. The available data indicate that the sensitivity and precision of these methods are comparable to short-term chronic methods for other marine invertebrates and fish. Recent application of the sperm test in toxicity identification evaluations (TIEs) and studies of effluent toxicity decay and sediment toxicity illustrate the versatility of this rapid (10 to 60 min exposure) test method. Embryo tests typically use a 48 to 96 h exposure period and measure the occurrence of embryo malformations. Most recent applications of the embryo test have been for the assessment of sediment elutriate toxicity. Adult echinoderms are not frequently used to assess effluent or receiving water toxicity. Recent studies have had success in using the adult life stage of urchins and sand dollars to assess the effects of contaminated sediment on growth, behavior, and bioaccumulation.

  12. Relative leaching and aquatic toxicity of pressure-treated wood products using batch leaching tests.

    PubMed

    Stook, Kristin; Tolaymat, Thabet; Ward, Marnie; Dubey, Brajesh; Townsend, Timothy; Solo-Gabriele, Helena; Bitton, Gabriel

    2005-01-01

    Size-reduced samples of southern yellow pine dimensional lumber, each treated with one of five different waterborne chemical preservatives, were leached using 18-h batch leaching tests. The wood preservatives included chromated copper arsenate (CCA), alkaline copper quaternary, copper boron azole, copper citrate, and copper dimethyldithiocarbamate. An unpreserved wood sample was tested as well. The batch leaching tests followed methodology prescribed in the U.S. Environmental Protection Agency toxicity characteristic leaching procedure (TCLP). The wood samples were first size-reduced and then leached using four different leaching solutions (synthetic landfill leachate, synthetic rainwater, deionized water, and synthetic seawater). CCA-treated wood leached greater concentrations of arsenic and copper relative to chromium, with copper leaching more with the TCLP and synthetic seawater. Copper leached at greater concentrations from the arsenic-free preservatives relative to CCA. Arsenic leached from CCA-treated wood at concentrations above the U.S. federal toxicity characteristic limit (5 mg/L). All of the arsenic-free alternatives displayed a greater degree of aquatic toxicity compared to CCA. Invertebrate and algal assays were more sensitive than Microtox. Examination of the relative leaching of the preservative compounds indicated that the arsenic-free preservatives were advantageous over CCA with respect to waste disposal and soil contamination issues but potentially posed a greater risk to aquatic ecosystems. PMID:15667090

  13. Relative leaching and aquatic toxicity of pressure-treated wood products using batch leaching tests.

    PubMed

    Stook, Kristin; Tolaymat, Thabet; Ward, Marnie; Dubey, Brajesh; Townsend, Timothy; Solo-Gabriele, Helena; Bitton, Gabriel

    2005-01-01

    Size-reduced samples of southern yellow pine dimensional lumber, each treated with one of five different waterborne chemical preservatives, were leached using 18-h batch leaching tests. The wood preservatives included chromated copper arsenate (CCA), alkaline copper quaternary, copper boron azole, copper citrate, and copper dimethyldithiocarbamate. An unpreserved wood sample was tested as well. The batch leaching tests followed methodology prescribed in the U.S. Environmental Protection Agency toxicity characteristic leaching procedure (TCLP). The wood samples were first size-reduced and then leached using four different leaching solutions (synthetic landfill leachate, synthetic rainwater, deionized water, and synthetic seawater). CCA-treated wood leached greater concentrations of arsenic and copper relative to chromium, with copper leaching more with the TCLP and synthetic seawater. Copper leached at greater concentrations from the arsenic-free preservatives relative to CCA. Arsenic leached from CCA-treated wood at concentrations above the U.S. federal toxicity characteristic limit (5 mg/L). All of the arsenic-free alternatives displayed a greater degree of aquatic toxicity compared to CCA. Invertebrate and algal assays were more sensitive than Microtox. Examination of the relative leaching of the preservative compounds indicated that the arsenic-free preservatives were advantageous over CCA with respect to waste disposal and soil contamination issues but potentially posed a greater risk to aquatic ecosystems.

  14. Toxicity testing of trinitrotoluene-contaminated soil composts

    SciTech Connect

    Honeycutt, M.E.; McFarland, V.A.; Jarvis, A.S.

    1997-10-01

    The Mutatox{trademark} assay and earthworm acute toxicity test were employed to evaluate the efficacy of composting in reducing the toxicity of TNT-contaminated soils. The Mutatox assay is a proprietary bacterial bioluminescence test that determines the mutagenic potential of sample extracts. The earthworm acute toxicity test was chosen because it exposes the organisms to the unaltered contaminant/solid matrix. Rockeye soil, a TNT-contaminated soil collected from a military installation, was composted using two methods. This yielded five samples, Rockeye, Compost A composting. Soil extracts were prepared for Mutatox using the sonification method. Ten serial dilution samples were tested soils/artificial soil were tested in the earthworm toxicity test. In the Rockeye soil samples, a toxic response was shown in both test methods. Mutatox indicated no toxicity in Composts A and B after composting but did not show a positive mutagenic response in the lower serial dilutions. The LC50s for Compost A and B after composting in the earthworm toxicity test were 35.3% and 100%, respectively. Using Mutatox and the earthworm toxicity test together provides a sensitive means of monitoring the effectiveness of various composting techniques for remediating TNT-contaminated soils.

  15. Inexpensive non-toxic flocculation of microalgae contradicts theories; overcoming a major hurdle to bulk algal production.

    PubMed

    Schlesinger, Ami; Eisenstadt, Doron; Bar-Gil, Amicam; Carmely, Hilla; Einbinder, Shai; Gressel, Jonathan

    2012-01-01

    There are two major energy and cost constraints to bulk production of single cell microalgae for biofuels or feed: expensive culture systems with high capital costs and high energy requirements for mixing and gas exchange; and the cost of harvesting using high-speed continuous centrifugation for dewatering. This report deals with the latter; harvesting by flocculation where theory states that alkaline flocculants neutralize the repelling surface charge of algal cells, allowing them to coalesce into a floc. It had been assumed that with such electrostatic flocculation, the more cells to be flocculated, the more flocculant needed, in a linear stoichiometric fashion, rendering flocculation overly expensive. Counter to theory of electrostatic flocculation, we find that the amount of alkaline flocculant needed is a function of the logarithm of cell density, with dense cultures requiring an order of magnitude less base than dilute suspensions, with flocculation occurring at a lower pH. Various other theories abound that flocculation can be due to multi-valent cross-linking, or co-precipitation with phosphate or with magnesium and calcium, but are clearly not relevant with the flocculants we used. Monovalent bases that cannot cross-link or precipitate phosphate work with the same log-linear stoichiometry as the divalent bases, obviating those theories, leaving electrostatic flocculation as the only tenable theory of flocculation with the materials used. The cost of flocculation of dense cultures with this procedure should be below $1.00/T algae for mixed calcium:magnesium hydroxides.

  16. Biologically Relevant Exposure Science for 21st Century Toxicity Testing

    EPA Science Inventory

    High visibility efforts in toxicity testing and computational toxicology including the recent NRC report, Toxicity Testing in the 21st Century: a Vision and Strategy (NRC, 2007), raise important research questions and opportunities for the field of exposure science. The authors ...

  17. TESTING THE EFFECTS OF OCEAN ACIDIFICATION ON ALGAL METABOLISM: CONSIDERATIONS FOR EXPERIMENTAL DESIGNS(1).

    PubMed

    Hurd, Catriona L; Hepburn, Christopher D; Currie, Kim I; Raven, John A; Hunter, Keith A

    2009-12-01

    Ocean acidification describes changes in the carbonate chemistry of the ocean due to the increased absorption of anthropogenically released CO2 . Experiments to elucidate the biological effects of ocean acidification on algae are not straightforward because when pH is altered, the carbon speciation in seawater is altered, which has implications for photosynthesis and, for calcifying algae, calcification. Furthermore, photosynthesis, respiration, and calcification will themselves alter the pH of the seawater medium. In this review, algal physiologists and seawater carbonate chemists combine their knowledge to provide the fundamental information on carbon physiology and seawater carbonate chemistry required to comprehend the complexities of how ocean acidification might affect algae metabolism. A wide range in responses of algae to ocean acidification has been observed, which may be explained by differences in algal physiology, timescales of the responses measured, study duration, and the method employed to alter pH. Two methods have been widely used in a range of experimental systems: CO2 bubbling and HCl/NaOH additions. These methods affect the speciation of carbonate ions in the culture medium differently; we discuss how this could influence the biological responses of algae and suggest a third method based on HCl/NaHCO3 additions. We then discuss eight key points that should be considered prior to setting up experiments, including which method of manipulating pH to choose, monitoring during experiments, techniques for adding acidified seawater, biological side effects, and other environmental factors. Finally, we consider incubation timescales and prior conditioning of algae in terms of regulation, acclimation, and adaptation to ocean acidification. PMID:27032579

  18. Model validation in aquatic toxicity testing: implications for regulatory practice.

    PubMed

    McCarty, L S

    2012-08-01

    Toxicity test validity is contingent on whether models and assumptions are appropriate and sufficient. A quality control evaluation of the acute toxicity testing protocol using the US. EPA fathead minnow database focused around three key assumptions that ensure results represent valid toxicological metrics: 1, it must be possible to estimate steady-state LC50s; 2, LC50s should occur at equivalent exposure durations; 3, all substantive toxicity modifying factors should be adequately controlled. About 8% of the tests failed the first assumption and are invalid and unusable. Examination of remaining data indicated variance from unquantified effects of toxicity modifying factors remained in LC50s, thereby failing assumption three. Such flaws in toxicity data generated via recommended LC50 testing protocols means resultant data do not represent consistent, comparable measures of relative toxicity. Current regulations employing LC50 testing data are acceptable due to the use of semiquantitative, policy-driven development guidance that considers such data uncertainty. Quantitative applications such as QSARs, mixture toxicity, and regulatory chemical grouping can be compromised. These validation failures justify a formal quality control review of the LC50 toxicity testing protocol. Interim improvements in the design, execution, interpretation, and regulatory applications of LC50 and related protocols using exposure-based dose surrogates are warranted.

  19. The use of turbidostat culture in investigation of algal heavy-metal toxicity and rotifer population dynamics

    SciTech Connect

    Bennett, W.N.

    1989-01-01

    Using the green alga Chlorella pyrenoidosa Chick, the heavy metals selenium as selenate, cadmium, cadmium + manganese and cadmium + zinc were investigated to assess their toxicity in terms of changes in {mu}{sub max}. It was shown that increases of sublethal concentrations of Se produced a near linear decrease in {mu}{sub max}. A {mu}{sub max}IC{sub 50} was calculated to be 10.1 {mu}M Se. A concentration of 1.8 {mu}M Cd produced a 62% decrease in {mu}{sub max} after 2 generating lag. A recovery of {mu}{sub max} was observed when MnCl{sub 2} or ZnCl{sub 2} was added to the medium in which populations were experiencing sublethal Cd toxicity. The amelioration responses were incomplete with regard to full recovery of {mu}{sub max} and last 20 generations for the Cd-Mn exposure and 7 generations for the Cd-Zn exposure. Measurement of {mu}{sub max} is turbidostat culture was shown to provide a very sensitive measure of toxicity. For the first time, a metazoan, the rotifer Brachionus calyciflorus Pallas, was grown in turbidostat culture and maintained near its {mu}{sub max} for many generations. It was discovered that {mu}{sub max} was subject to selection in this species and increased 51% from 0.053 h{sup {minus}1} to 0.080 h{sup {minus}1} over 8 mo at 25{degree}C.

  20. Mixture toxicity of wood preservative products in the fish embryo toxicity test.

    PubMed

    Coors, Anja; Dobrick, Jan; Möder, Monika; Kehrer, Anja

    2012-06-01

    Wood preservative products are used globally to protect wood from fungal decay and insects. We investigated the aquatic toxicity of five commercial wood preservative products, the biocidal active substances and some formulation additives contained therein, as well as six generic binary mixtures of the active substances in the fish embryo toxicity test (FET). Median lethal concentrations (LC50) of the single substances, the mixtures, and the products were estimated from concentration-response curves and corrected for concentrations measured in the test medium. The comparison of the experimentally observed mixture toxicity with the toxicity predicted by the concept of concentration addition (CA) showed less than twofold deviation for all binary mixtures of the active substances and for three of the biocidal products. A more than 60-fold underestimation of the toxicity of the fourth product by the CA prediction was detected and could be explained fully by the toxicity of one formulation additive, which had been labeled as a hazardous substance. The reason for the 4.6-fold underestimation of toxicity of the fifth product could not be explained unambiguously. Overall, the FET was found to be a suitable screening tool to verify whether the toxicity of formulated wood preservatives can reliably be predicted by CA. Applied as a quick and simple nonanimal screening test, the FET may support approaches of applying component-based mixture toxicity predictions within the environmental risk assessment of biocidal products, which is required according to European regulations.

  1. On the performance of acute toxicity tests using the National Reference Toxicant Database

    SciTech Connect

    Zaidhk, B.

    1995-12-31

    The US National Reference Toxicant Database was used to compile data from 158 Ceriodaphnia dubia, and 187 fathead minnow acute toxicity tests. The data are analyzed using the EPA flow-chart for acute toxicity tests to determine the distribution of test methods selected. The data are reanalyzed using maximum likelihood estimation assuming probit, logit and Gompertz tolerance distributions and non-parametrically using the Spearman-Karber method with and without trimming. The results of these analyses are compared with respect to mean square error for the parametric methods and confidence intervals for the point estimate for all analyses.

  2. EVALUATION OF ALTERNATIVE REFERENCE TOXICANTS FOR USE IN THE EARTHWORM TOXICITY TEST

    EPA Science Inventory

    The use of the 14-d earthworm toxicity test to aid in the evaluation of the ecological impact of contaminated soils is becoming increasingly widespread. However,the method is in need of further standardization. As part of this continuing process, the choice of reference toxicants...

  3. Exploring waiving opportunities for mammalian acute systemic toxicity tests.

    PubMed

    Graepel, Rabea; Asturiol, David; Prieto, Pilar; Worth, Andrew P

    2016-07-01

    A survey was carried out to explore opportunities for waiving mammalian acute systemic toxicity tests. We were interested in finding out whether data from a sub-acute toxicity test could be used to predict the outcome of an acute systemic toxicity test. The survey was directed at experts in the field of toxicity testing, and was carried out in the context of the upcoming 2018 final registration deadline for chemicals under the EU REACH Regulation. In addition to the survey, a retrospective data analysis of chemicals that had already been registered with the European Chemicals Agency, and for which both acute and sub-acute toxicity data were available, was carried out. This data analysis was focused on chemicals that were administered via the oral route. The answers to the questionnaire showed a willingness to adopt waiving opportunities. In addition, the responses showed that data from a sub-acute toxicity test or dose-range finding study might be useful for predicting chemicals that do not require classification for acute oral toxicity (LD50 > 2000mg/kg body weight). However, with the exception of substances that fall into the non-classified category, it is difficult to predict current acute oral toxicity categories. PMID:27494626

  4. Isolation and characterization of exopolysaccharide secreted by a toxic dinoflagellate, Amphidinium carterae Hulburt 1957 and its probable role in harmful algal blooms (HABs).

    PubMed

    Mandal, Subir Kumar; Singh, Ravindra Pal; Patel, Vipul

    2011-10-01

    Extracellular polymeric substances (EPS) produced by a toxic dinoflagellate Amphidinium carterae Hulburt 1957 was isolated and characterized. Molecular masses of the EPS were about 233 and 1,354 kDa. Spectral analyses by (1)H nuclear magnetic resonance and Fourier Transformed-Infrared Spectroscopy revealed the characteristic of the functional groups viz. primary amine, carboxyl, halide, and sulfate groups present in the EPS. However, five elements (C, O, Na, S, and Ca) were detected by scanning electron microscopy - energy dispersive X-ray spectroscopy (SEM-EDX) analysis. X-ray diffraction and differential scanning calorimetric analysis confirmed the amorphous nature of EPS, which was comprised of an average particle size of 13.969 μm (d 0.5) with 181 nm average roughness. Two monosaccharide constituents, galactose (73.13%) and glucose (26.87%) were detected by gas chromatography-mass spectroscopy analysis. Thermal gravimetric analysis revealed that degradation of EPS obtained from A. carterae takes place in three steps. The EPS produced by A. carterae was found to be beneficial for the growth of both A. carterae and Bacillus pumilus. The potential heterogeneous properties of EPS may play an important role in harmful algal bloom.

  5. Employment of CEPEX enclosures for monitoring toxicity of Hg and Zn on in situ structural and functional characteristics of algal communities of River Ganga in Varanasi, India.

    PubMed

    Rai, L C; Singh, A K; Mallick, N

    1990-10-01

    Effects of Hg and Zn on in situ nitrogen fixation, autotrophic index, pigment diversity, 14CO2 uptake, and change in algal community structure of Ganges water have been studied for the first time using CEPEX chambers in aquatic ecosystem of India. A concentration-dependent decrease in in situ nitrogenase activity of Ganges water with Hg and Zn has been noticed. No ethylene production was observed at 0.8 microgram/ml of Hg. However, an increase in the autotrophic index was observed in CEPEX enclosures treated with Hg and Zn. The AI value was maximum at 0.8 microgram/ml Hg after an incubation of 15 days. An increase in pigment diversity also followed the pattern of AI with the test metals used. Inhibition of 14CO2 uptake of phytoplankton of Ganges water was maximum at 0.8 microgram/ml Hg (79%) followed by Zn (69%). Carbon fixation showed an increase for 1 hr, after which no appreciable change was noticed. Maximum inhibition of algal number was observed at 0.8 microgram/ml Hg followed by 8.0 micrograms/ml of Zn in the CEPEX chamber. Members of Chlorophyceae showed more tolerance than Cyanophyceae and Bacillariophyceae. The filamentous forms were more tolerant to Hg and Zn. In contrast, unicellular forms were more sensitive to Hg. The test of significance (ANOVA) showed that metal-induced variations in pigment diversity, the autotrophic index, and the 14CO2 uptake were highly significant (P less than 0.001).

  6. Sensitivity or artifact? -- IQ Toxicity Test -- effluent values

    SciTech Connect

    Hayes, K.R.; Novotny, A.N.; Batista, N.

    1995-12-31

    Several complex effluents were DAPHNIA MAGNA IQ TOXICITY TESTED -- (1.25 hours) and conventionally tested with Daphnia magna (48 hours). In many samples the IQ Technology yielded low EC50 values while the 48 hour exposures yielded no acute toxicity. Possible explanations have been suggested for this occurrence such as: genotoxicity, mutagenicity, substrate interference, and enzyme satiation. To identify the causative agent(s) of this response a Toxicity Identification Evaluation was performed on one of the samples. To define the nature of the response, THE SOS-CHROMOTEST KIT and THE MUTA-CHROMOPLATE KIT were utilized to characterize genotoxicity and mutagenicity respectively. The sample did not test positive for genotoxicity but tested positive for mutagenicity only after activation with S9 enzymes, suggesting the presence of promutagens. Additional work needs to be performed to correlate IQ TOXICITY TEST sensitivity with positive MUTA-CHROMOPLATE response.

  7. Reference toxicants for toxicity testing using Caenorhabditis elegans in aquatic media

    SciTech Connect

    Cressman, C.P. III; Williams, P.L.

    1997-09-01

    Caenorhabditis elegans aquatic toxicity assays were standardized with five common reference toxicants: CdCl{sub 2}, NaCl, KCl, sodium lauryl sulfate (SLS), and sodium pentachlorophenate (PCP). Aquatic toxicity testing was conducted in 3 media: a standard C. elegans medium; EPA moderately hard reconstituted water; and EPA moderately hard mineral water. Test duration in each medium was 24h without a food source, and 24h and 48h with Escherichia coli strain OP50 as a food source. Each test was replicated three times with each replicate having 6 wells per concentration, 10 worms per well. LC{sub 50} values were calculated using probit analysis. The average LC{sub 50}s for each set of replications were compared to assess sensitivity and reproducibility of the data, identifying expected variation between replicate tests. These reference toxicants increase the database for C. elegans and provide a benchmark for further application.

  8. Evaluation of new aquatic toxicity test methods for oil dispersants

    SciTech Connect

    Pace, C.B.; Clark, J.R.; Bragin, G.E.

    1994-12-31

    Current aquatic toxicity test methods used for dispersant registration do not address real world exposure scenarios. Current test methods require 48 or 96 hour constant exposure conditions. In contrast, environmentally realistic exposures can be described as a pulse in which the initial concentration declines over time. Recent research using a specially designed testing apparatus (the California system) has demonstrated that exposure to Corexit 9527{reg_sign} under pulsed exposure conditions may be 3 to 22 times less toxic compared to continuous exposure scenarios. The objectives of this study were to compare results of toxicity tests using the California test system to results from standardized tests, evaluate sensitivity of regional (Holmesimysis cast and Atherinops affinis) vs. standard test species (Mysidopsis bahia and Menidia beryllina) and determine if tests using the California test system and method are reproducible. All tests were conducted using Corexit 9527{reg_sign} as the test material. Standard toxicity tests conducted with M. bahia and H. cast resulted in LC50s similar to those from tests using the California apparatus. LC50s from tests conducted in the authors` laboratory with the California system and standard test species were within a factor of 2 to 6 of data previously reported for west coast species. Results of tests conducted with H. cast in the laboratory compared favorably to data reported by Singer et al. 1991.

  9. Rapid toxicity testing based on yeast respiratory activity

    SciTech Connect

    Haubenstricker, M.E. ); Meier, P.G.; Mancy, K.H. ); Brabec, M.J. )

    1990-05-01

    Rapid and economical techniques are needed to determine the effects of environmental contaminants. At present, the main methods to assess the impact of pollutants are based on chemical analysis of the samples. Invertebrate and vertebrate exposures have been used over the last two decades in assessing acute and chronic toxicities. However, these tests are labor intensive and require several days to complete. An alternative to whole organism exposure is to determine toxic effects in monocellular systems. Another approach for assessing toxicity is to monitor sensitive, nonspecific, subcellular target sites such as mitochondria. Changes in mitochondrial function which could indicate a toxic effect can be demonstrated readily after addition of a foreign substance. In initial assessments of various chemicals, rat liver mitochondria (RLM) were evaluated as a biological sensor of toxicity. False toxicity assessments will result if these ions are present even though they are generally considered nontoxic. Because of these disadvantages, an alternative mitochondrial system, such as found in bakers yeast, was evaluated.

  10. Physiological responses of Manila clams Venerupis (=Ruditapes) philippinarum with varying parasite Perkinsus olseni burden to toxic algal Alexandrium ostenfeldii exposure.

    PubMed

    Lassudrie, Malwenn; Soudant, Philippe; Richard, Gaëlle; Henry, Nicolas; Medhioub, Walid; da Silva, Patricia Mirella; Donval, Anne; Bunel, Mélanie; Le Goïc, Nelly; Lambert, Christophe; de Montaudouin, Xavier; Fabioux, Caroline; Hégaret, Hélène

    2014-09-01

    Manila clam stock from Arcachon Bay, France, is declining, as is commercial harvest. To understand the role of environmental biotic interactions in this decrease, effects of a toxic dinoflagellate, Alexandrium ostenfeldii, which blooms regularly in Arcachon bay, and the interaction with perkinsosis on clam physiology were investigated. Manila clams from Arcachon Bay, with variable natural levels of perkinsosis, were exposed for seven days to a mix of the nutritious microalga T-Iso and the toxic dinoflagellate A. ostenfeldii, a producer of spirolides, followed by seven days of depuration fed only T-Iso. Following sacrifice and quantification of protozoan parasite Perkinsus olseni burden, clams were divided into two groups according to intensity of the infection ("Light-Moderate" and "Moderate-Heavy"). Hemocyte and plasma responses, digestive enzyme activities, antioxidant enzyme activities in gills, and histopathological responses were analyzed. Reactive oxygen species (ROS) production in hemocytes and catalase (CAT) activity in gills increased with P. olseni intensity of infection in control clams fed T-Iso, but did not vary among A. ostenfeldii-exposed clams. Exposure to A. ostenfeldii caused tissue alterations associated with an inflammatory response and modifications in hemocyte morphology. In the gills, superoxide dismutase (SOD) activity decreased, and an increase in brown cell occurrence was seen, suggesting oxidative stress. Observations of hemocytes and brown cells in tissues during exposure and depuration suggest involvement of both cell types in detoxication processes. Results suggest that exposure to A. ostenfeldii disrupted the pro-/anti-oxidant response of clams to heavy P. olseni intensity. In addition, depressed mitochondrial membrane potential (MMP) in hemocytes of clams exposed to A. ostenfeldii suggests that mitochondrial functions are regulated to maintain homeostasis of digestive enzyme activity and condition index. PMID:24858898

  11. Physiological responses of Manila clams Venerupis (=Ruditapes) philippinarum with varying parasite Perkinsus olseni burden to toxic algal Alexandrium ostenfeldii exposure.

    PubMed

    Lassudrie, Malwenn; Soudant, Philippe; Richard, Gaëlle; Henry, Nicolas; Medhioub, Walid; da Silva, Patricia Mirella; Donval, Anne; Bunel, Mélanie; Le Goïc, Nelly; Lambert, Christophe; de Montaudouin, Xavier; Fabioux, Caroline; Hégaret, Hélène

    2014-09-01

    Manila clam stock from Arcachon Bay, France, is declining, as is commercial harvest. To understand the role of environmental biotic interactions in this decrease, effects of a toxic dinoflagellate, Alexandrium ostenfeldii, which blooms regularly in Arcachon bay, and the interaction with perkinsosis on clam physiology were investigated. Manila clams from Arcachon Bay, with variable natural levels of perkinsosis, were exposed for seven days to a mix of the nutritious microalga T-Iso and the toxic dinoflagellate A. ostenfeldii, a producer of spirolides, followed by seven days of depuration fed only T-Iso. Following sacrifice and quantification of protozoan parasite Perkinsus olseni burden, clams were divided into two groups according to intensity of the infection ("Light-Moderate" and "Moderate-Heavy"). Hemocyte and plasma responses, digestive enzyme activities, antioxidant enzyme activities in gills, and histopathological responses were analyzed. Reactive oxygen species (ROS) production in hemocytes and catalase (CAT) activity in gills increased with P. olseni intensity of infection in control clams fed T-Iso, but did not vary among A. ostenfeldii-exposed clams. Exposure to A. ostenfeldii caused tissue alterations associated with an inflammatory response and modifications in hemocyte morphology. In the gills, superoxide dismutase (SOD) activity decreased, and an increase in brown cell occurrence was seen, suggesting oxidative stress. Observations of hemocytes and brown cells in tissues during exposure and depuration suggest involvement of both cell types in detoxication processes. Results suggest that exposure to A. ostenfeldii disrupted the pro-/anti-oxidant response of clams to heavy P. olseni intensity. In addition, depressed mitochondrial membrane potential (MMP) in hemocytes of clams exposed to A. ostenfeldii suggests that mitochondrial functions are regulated to maintain homeostasis of digestive enzyme activity and condition index.

  12. THE TOXCAST PROGRAM FOR PRIORITIZING TOXICITY TESTING OF ENVIRONMENTAL CHEMICALS

    EPA Science Inventory

    The United States Environmental Protection Agency (EPA) is developing methods for utilizing computational chemistry, high-throughput screening (HTS) and various toxicogenomic technologies to predict potential for toxicity and prioritize limited testing resources towards chemicals...

  13. Enzyme biosynthesis in bacteria as a basis for toxicity testing

    SciTech Connect

    Dutton, R.J.

    1988-01-01

    An assay based on the inhibition of {beta}-galactosidase biosynthesis was compared to a similar assay based on the inhibition of {beta}-galactosidase activity. In both test, Escherichia coli were induced to synthesize {beta}-galactosidase by exposure to isopropyl-{beta}-thiogalactoside (IPTG). The induction step preceded contact of the cells with toxic chemicals in the enzyme activity assay, whereas in the enzyme biosynthesis test, IPTG was added following contact of cells with the toxicant. Relative sensitivity was judged on the basis of responses to heavy metals and organic toxicants of environmental importance. Comparison of these results to median inhibitory concentration data (IC50s) achieved with other microbial systems, Daphnia bioassay, and fish bioassay indicate that the enzyme activity test was sensitive to heavy metals, but was insensitive to organic toxicants. The test based on inhibition of {beta}-galactosidase biosynthesis was sensitive to both heavy metals and organics.

  14. Bacterial and enzymatic bioassays for toxicity testing in the environment

    SciTech Connect

    Bitton, G.; Koopman, B. )

    1992-01-01

    Microbioassays using bacteria or enzymes are increasingly applied to measure chemical toxicity in the environment. Attractive features of these assays may include low cost, rapid response to toxicants, high sample throughput, modest laboratory equipment and space requirements, low sample volume, portability, and reproducible responses. Enzymatic tests rely on measurement of either enzyme activity or enzyme biosynthesis. Dehydrogenases are the enzymes most used in toxicity testing. Assay of dehydrogenase activity is conveniently carried out using oxidoreduction dyes such as tetrazolium salts. Other enzyme activity tests utilize ATPases, esterases, phosphatases, urease, luciferase, beta-galactosidase, protease, amylase, or beta-glucosidase. Recently, the inhibition of enzyme (beta-galactosidase, tryptophanase, alpha-glucosidase) biosynthesis has been explored as a basis for toxicity testing. Enzyme biosynthesis was found to be generally more sensitive to organic chemicals than enzyme activity.107 references.

  15. The Toxicity Estimation Software Tool (T.E.S.T.)

    EPA Science Inventory

    The Toxicity Estimation Software Tool (T.E.S.T.) has been developed to estimate toxicological values for aquatic and mammalian species considering acute and chronic endpoints for screening purposes within TSCA and REACH programs.

  16. Neutral red uptake cytotoxicity tests for estimating starting doses for acute oral toxicity tests.

    PubMed

    Stokes, William S; Casati, Silvia; Strickland, Judy; Paris, Michael

    2008-05-01

    In vitro cytotoxicity assays can be used as alternative toxicity tests to reduce the total number of animals needed for acute oral toxicity tests. This unit describes two methods for determining the in vitro cytotoxicity of test substances using neutral red uptake (NRU) and using the in vitro data to determine starting doses for in vivo acute oral systemic toxicity tests, e.g., the up-and-down procedure or the acute toxic class method. The use of the NRU methods to determine starting doses for acute oral toxicity tests may reduce the number of animals required, and for relatively toxic substances, this approach may also reduce the number of animals that die or require humane euthanasia due to severe toxicity. An interlaboratory validation study has demonstrated that the methods are useful and reproducible for these purposes. Two standardized protocols provide details for performing NRU tests with rodent and human cells.

  17. Hypersalinity toxicity thresholds for nine California ocean plan toxicity test protocols.

    PubMed

    Voorhees, Jennifer P; Phillips, Bryn M; Anderson, Brian S; Siegler, Katie; Katz, Scott; Jennings, Lydia; Tjeerdema, Ron S; Jensen, Joanna; de la Paz Carpio-Obeso, Maria

    2013-11-01

    Currently, several desalination facilities have been proposed to operate or are actually operating in California. These facilities' use of reverse osmosis (RO) may discharge hypersaline reject brine into the marine environment. The risks, if any, this brine would pose to coastal receiving waters are unknown. To test the toxicity of hypersaline brine in the absence of any additional toxic constituents, we prepared brine and tested it with the seven toxicity test organisms listed in the 2009 California Ocean Plan. The most sensitive protocols were the marine larval development tests, whereas the most tolerant to increased salinities were the euryhaline topsmelt, mysid shrimp, and giant kelp tests. Reject brines from the Monterey Bay Aquarium's RO desalination facility were also tested with three species. The effects of the aquarium's brine effluent on topsmelt, mussels, and giant kelp were consistent with those observed in the salinity tolerance experiments. This information will be used by regulators to establish receiving water limitations for hypersaline discharges.

  18. In vitro testing for lung toxicity.

    PubMed

    Ciabattoni, G; Montuschi, P; Curró, D; Preziosi, P

    1993-09-01

    We characterized the pattern of arachidonic acid metabolites released from sensitized isolated guinea pig lungs undergoing anaphylactic reactions after ovalbumin challenge. TXB(2) (the stable hydrolysis product of (TXA(2)) is the most abundant product: it was released at an average of 13.7 +/- 7.0 ng/min (+/-SD, n = 33) during the anaphylactic reaction (i.e. a five- to six-fold increase in comparison with the basal release). Its level correlates with both the bronchoconstrictor response and LTC(4) and LTB(4) release. In non-sensitized lungs the release of basal TXB(2) increased about five-fold during a 10-min exposure to a formaldehyde aerosol at the dose of 10 ppm; this increase was concomitant with an 87.5 +/- 10.0% (+/-SD) reduction of the tracing recording the pressure-volume variations in the lung. No change in the release of lipoxygenase products was observed after exposure to formaldehyde aerosol. Pre-treatment with N-acetylcysteine (10(-3)-10(-4)m) reduced both formaldehyde-induced bronchoconstriction and the increase of TXB(2) release. An acid-water aerosol, resembling the composition of acid rain, strongly increased TXB(2) release in the pH range 4.5 to 2.5, without affecting the lipoxygenase pathway of arachidonic acid metabolism. These data suggest that exposure to toxicants that irritate the respiratory tract selectively enhances TXB(2) release, while an antigen challenge stimulates both the cyclooxygenase and lipoxygenase pathways of lung arachidonate metabolism. Thus, the different pattern of arachidonic acid cascade activation may predict a direct toxic effect or an allergic reaction when the xenobiotic is injected into the pulmonary artery or administered by way of inhalation as an aerosol. More recently vasoactive intestinal polypeptide (VIP) has been proposed as a modulator of lung inflammation and airway constriction. In sensitized lungs the antigen challenge induced a five-fold increase in VIP release, coinciding with the increase of

  19. The challenges of testing metal and metal oxide nanoparticles in algal bioassays: titanium dioxide and gold nanoparticles as case studies.

    PubMed

    Hartmann, Nanna B; Engelbrekt, Christian; Zhang, Jingdong; Ulstrup, Jens; Kusk, Kresten Ole; Baun, Anders

    2013-09-01

    Aquatic toxicology of engineered nanoparticles is challenged by methodological difficulties stemming partly from highly dynamic and poorly understood behavior of nanoparticles in biological test systems. In this paper scientific and technical challenges of testing not readily soluble nanoparticles in standardised algal growth inhibition tests are highlighted with specific focus on biomass quantification methods. This is illustrated through tests with TiO2 and Au nanoparticles, for which cell-nanoparticle interactions and behavior was studied during incubation. Au NP coating layers changed over time and TiO2 nanoparticle aggregation/agglomeration increased as a function of concentration. Three biomass surrogate measuring techniques were evaluated (coulter counting, cell counting in haemocytometer, and fluorescence of pigment extracts) and out of these the fluorometric methods was found to be most suitable. Background correction was identified as a key issue for biomass quantification, complicated by algae-particle interactions and nanoparticle transformation. Optimisation of the method is needed to reduce further particle interference on measurements.

  20. Rice seed toxicity tests for organic and inorganic substances.

    PubMed

    Wang, W

    1994-01-01

    Plant seed toxicity tests can be used to evaluate hazardous waste sites and to assess toxicity of complex effluents and industrial chemicals. Conventional plant seed toxicity tests are performed using culture dishes containing filter paper. Some reports indicate that filter papers might interfere with the toxicity of inorganic substances. In this study, a plastic seed tray was used. Rice was used as the test species.A comparison of results in the literature and this study revealed that variation of test species, methods, exposure duration, and other factors may affect the test results. The results of this study showed that the order of decreasing toxicity of metal ions was Cu>Ag>Ni>Cd>Cr(VI)>Pb>Zn>Mn>NaF for rice. The test results were similar to those reported in the literature for lettuce Ag>Ni>Cd,Cu>Cr(VI)>Zn>Mn, millet Cu,Ni>Cd>Cr(VI)>Zn>Mn, and ryegrass Cu>Ni>Mn>Pb>Cd>Zn>Al>Hg>Cr>Fe. The order of decreasing toxicity of organic herbicides was paraquat, 2,4-D>glyphosate>bromacil. PMID:24221291

  1. Rice seed toxicity tests for organic and inorganic substances

    USGS Publications Warehouse

    Wang, W.

    1994-01-01

    Plant seed toxicity tests can be used to evaluate hazardous waste sites and to assess toxicity of complex effluents and industrial chemicals. Conventional plant seed toxicity tests are performed using culture dishes containing filter paper. Some reports indicate that filter papers might interfere with the toxicity of inorganic substances. In this study, a plastic seed tray was used. Rice was used as the test species. A comparison of results in the literature and this study revealed that variation of test species, methods, exposure duration, and other factors may affect the test results. The results of this study showed that the order of decreasing toxicity of metal ions was Cu>Ag>Ni>Cd>Cr(VI)>Pb>Zn>Mn>NaF for rice. The test results were similar to those reported in the literature for lettuce Ag>Ni>Cd,Cu>Cr (VI)>Zn>Mn, millet Cu,Ni>Cd>Cr(VI)>Zn>Mn, and ryegrass Cu>Ni>Mn>>Pb>Cd>Zn> Al>Hg>Cr>Fe. The order of decreasing toxicity of organic herbicides was paraquat, 2,4-D>>glyphosate>bromacil.

  2. Marine toxicity tests development with a New Zealand echinoid

    SciTech Connect

    Nipper, M.G.; Roper, D.S.; Martin, M.L.; Williams, E.K.

    1995-12-31

    The generally low levels of contamination around New Zealand lead to the search for a sensitive toxicity test, which could be used to screen effluent and to detect contaminant effects in coastal waters and sediments. Echinoid early life stage tests were considered ideal candidates. However, the adaptation of international toxicity test methods to indigenous species has not been straightforward or troublefree! The echinoid Fellaster zelandiae was selected because it is abundant around New Zealand and is fertile year round. Fertilization tests showed that gamete density, rather than sperm/egg ratio, was a crucial factor for successful control fertilization rates. This method, however, presented several problems related to (1) temporal variability in the quality of sperm batches, (2) rapid reduction of egg quality and viability after spawning, and (3) highly variable sensitivity in reference toxicant tests. Embryo tests were more reliable, with good control results (> 80% normal embryos) and consistent sensitivity to a reference toxicant, zinc sulfate. EC{sub 50} values averaged 0.06 mg Zn/L, comparable to the sensitivity of echinoid species used elsewhere. Brine prepared by freezing seawater was suitable for adjusting the salinity of effluents, with more than 90% normal embryos developing in brine diluted with UV-treated deionized water as a test-control. The assessment of the embryo development test as a tool for screening sediment toxicity (using sediment pore water), is presently underway, concurrently with growth and behavioral endpoint tests using indigenous amphipods and bivalves.

  3. Harmonization of standard toxicity test methods used in North America

    SciTech Connect

    Ingersoll, C.G.; Dwyer, F.J.; Ankley, G.T.

    1995-12-31

    Over the past two years, Environment Canada (EC) and the US Environmental Protection Agency (EPA) have developed standard methods for conducting toxicity and bioaccumulation tests with freshwater, estuarine, and marine sediments. Existing ASTM methods were used as a basis to harmonize these methods for conducting testing with either field-collected or laboratory-spiked sediments. For freshwater toxicity tests, methods are described by EC and EPA for the amphipod Hyalella azteca and the midges Chironomus tentans and C. riparius. Endpoints include 10- to 14-d survival of growth. Methods are also described by EPA for conducting 28-d bioaccumulation tests with the oligochaete Lumbriculus variegatus. For estuarine and marine toxicity tests, methods are described for several amphipods (i.e., Rhepoxynius abronius, Ampelisca abdita, Eohaustorius estuarius, Leptocheirus plumulosus). Endpoints include 10-d survival and reburial. EC is also developing methods for conducting toxicity tests with Atlantic, Pacific, and Arctic Canadian species of polychaetes. Methods are described by EPA for conducting 28-d bioaccumulation tests with a variety of mollusks (i.e., Macoma spp.) and polychaetes (i.e., Nereis spp.). Slight inconsistencies in methods between freshwater and estuarine/marine testing or between EC and EPA testing include: (1) static vs. flow-through conditions, (2) sieving of sediment, (3) types and quantity of food, (4) age of test organisms, or (4) duration of the test and required endpoints. Additional research is in progress to: (1) develop chronic toxicity tests with amphipods and midges measuring survival, growth, or reproduction, (2) develop whole-sediment toxicity identification evaluation (TIE) procedures, (3) refine sediment spiking procedures, and (4) field-validate laboratory tests.

  4. A New Toxicity Test Using the Freshwater Copepod Cyclops vernalis.

    PubMed

    Marus, Emma M; Elphick, James R; Bailey, Howard C

    2015-09-01

    The cladocerans Ceriodaphnia dubia and Daphnia magna are widely used in environmental toxicity testing and the test methodologies for these species are well developed. However, copepods are a much more abundant contributor to zooplankton in many lakes, but they are not routinely used in toxicity tests. Therefore, we propose toxicity test methods for the freshwater copepod, Cyclops vernalis assessing effects on its survival and growth. A case study is presented in which the proposed test was performed with a range of concentrations of total dissolved solids (TDS) and used as part of a test battery to develop a site-specific water quality objective. C. vernalis was less sensitive to TDS compared to D. magna and C. dubia, but similarly sensitive to an alga, a diatom, a rotifer, a chironomid, and two fish species. No adverse effects were observed on survival or growth of C. vernalis at TDS concentrations up to 1500 mg/L. PMID:26183385

  5. 40 CFR 797.1330 - Daphnid chronic toxicity test.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... for asexual (parthenogenic) reproduction. For automatic feeding devices, a suggested rate is 5 to 7 mg... cultured to produce test organisms through reproduction. (2) Chronic toxicity test means a method used to... an extended period of time. In this test guideline, mortality and reproduction (and...

  6. 40 CFR 797.1330 - Daphnid chronic toxicity test.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for asexual (parthenogenic) reproduction. For automatic feeding devices, a suggested rate is 5 to 7 mg... cultured to produce test organisms through reproduction. (2) Chronic toxicity test means a method used to... an extended period of time. In this test guideline, mortality and reproduction (and...

  7. 76 FR 38169 - Toxic Substances Control Act Chemical Testing; Receipt of Test Data

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-29

    ... AGENCY Toxic Substances Control Act Chemical Testing; Receipt of Test Data AGENCY: Environmental... chemicals listed in the Toxic Substances Control Act (TSCA) section 4 test rule titled ``In Vitro Dermal Absorption Rate Testing of Certain Chemicals of Interest to the Occupational Safety and Health...

  8. Multispecies methods of testing for toxicity: use of the Rhizobium-legume symbiosis in nitrogen fixation and correlations between responses by algae and terrestrial plants

    SciTech Connect

    Garten Jr, Charles T

    1991-12-01

    Responses of the Rhizobium-legume symbiotic relationship to long-term (5- to 7-week) and short-term (2-week) exposures of copper sulfate, 2,4-dichlorophenoxyacetic acid, and streptomycin sulfate were examined in bush beans and clover. Toxic effects were evaluated by comparing plant biomass (yield), nodulation success, nitrogen fixation rate as indicated by acetylene reduction, and plant nitrogen content in controls and in plants exposed to various concentrations of the chemicals. Plants with long-term continuous root exposure were affected more than plants with short-term exposure, as indicated by reductions in nitrogen fixation rates and plant growth. Although rates of acetylene reduction (nitrogen fixation) were depressed, plant biomass and the numbers of root nodules produced were simpler, less expensive indices of exposure. In a second test, the responses of algae (Selenastrum capricornutum and Chlorella vulgaris) and terrestrial plants (radishes, barley, bush beans, and soybeans) to 21 different herbicides were compared to evaluate the use of a short-term (96-h) algal growth inhibition test for identifying chemicals potentially toxic to terrestrial plants. Two test end points were evaluated: (1) the highest concentration resulting in no statistically significant reduction in the growth rate of algae or terrestrial plants, and (2) the concentration at which algal growth or terrestrial plant biomass was reduced by 50%. Test results were correlated for the two algae and for all pairs of vascular plants. However, results of the algal tests did not correlate with those of the terrestrial plants. Furthermore, according to tests with Selenastrum capricornutum, there was only a 50% chance of successfully identifying herbicide levels that reduced terrestrial plant biomass. For the herbicides and species examined, short-term toxicity tests with algae were not good indicators of toxicity to terrestrial plants.

  9. Toxicity testing of heavy-metal-polluted soils with algae Selenastrum capricornutum: a soil suspension assay.

    PubMed

    Aruoja, Villem; Kurvet, Imbi; Dubourguier, Henri-Charles; Kahru, Anne

    2004-08-01

    A small-scale Selenastrum capricornutum (Rhapidocelis subcapitata) growth inhibition assay was applied to the toxicity testing of suspensions of heavy-metal-polluted soils. The OECD 201 standard test procedure was followed, and algal biomass was measured by the fluorescence of extracted chlorophyll. The soils, which contained up to (per kilogram) 1390 mg of Zn, 20 mg of Cd, and 1050 mg of Pb were sampled around lead and zinc smelters in northern France. The water extractability of the metals in suspensions (1 part soil/99 parts water w/v) was not proportional to the pollution level, as extractability was lower for soil samples that were more polluted. Thus, the same amount of metals could be leached out of soils of different levels of pollution, showing that total concentrations of heavy metals in soil (currently used for risk assessment purposes) are poor predictors of the real environmental risk via the soil-water path. Despite high concentrations of water-extracted zinc (0.6-1.4 mg/L of Zn in the test), exceeding by approximately 10-fold the EC(50) value for S. capricornutum (0.1 mg Zn/L), 72-h algal growth in the soil extracts was comparable or better than growth in the standard control OECD mineral medium. The soil suspension stimulated the growth of algae up to eightfold greater than growth using the OECD control medium. Growth stimulation of algae was observed even when soil suspensions contained up to 12.5 mg Zn/L and could not be explained by supplementary nitrogen, phosphorous, and carbonate leached from the soil. However, if the growth of algae in suspensions of clean and polluted soils was compared, a dose-dependent inhibitory effect of metals on algal growth was demonstrated. Thus, as soil contains nutrients/supplements that mask the adverse effect of heavy metals, a clean soil that has properties similar to the polluted soils should be used instead of mineral salt solution as a control for analysis of the ecotoxicity of soils. PMID:15269912

  10. A new biological test of water toxicity-yeast Saccharomyces cerevisiae conductometric test.

    PubMed

    Dolezalova, Jaroslava; Rumlova, Lubomira

    2014-11-01

    This new biological test of water toxicity is based on monitoring of specific conductivity changes of yeast Saccharomyces cerevisiae suspension as a result of yeast fermentation activity inhibition in toxic conditions. The test was verified on ten substances with various mechanisms of toxic effect and the results were compared with two standard toxicity tests based on Daphnia magna mobility inhibition (EN ISO 6341) and Vibrio fischeri bioluminescence inhibition (EN ISO 11348-2) and with the results of the S. cerevisiae lethal test (Rumlova and Dolezalova, 2012). The new biological test - S. cerevisiae conductometric test - is an express method developed primarily for field conditions. It is applicable in case of need of immediate information about water toxicity. Fast completion is an advantage of this test (time necessary for test completion is about 60min), the test is simple and the test organism - dried instant yeast - belongs among its biggest advantages because of its long-term storage life and broad availability.

  11. Economical test methods for developmental neurobehavioral toxicity.

    PubMed

    Bignami, G

    1996-04-01

    The assessment of behavioral changes produced by prenatal or early postnatal exposure to potentially noxious agents requires both the designing of ad hoc tests and the adaptation of tests for adult animals to the characteristics of successive developmental stages. The experience in designing tests is still more limited than in the adaptation of tests, but several tests have already proven their usefulness; some examples are the suckling test, the homing test, and evaluations of dam-pup and pup-pup interactions. Functional observational batteries can exploit the development at specified postnatal ages of several reflexes and responses that are absent at birth in altricial rodent species with a short pregnancy such as the rat and the mouse. In neonates, the assessment of early treatment effects can rely not only on deviations from normal responding but also on changes in the time of appearance of otherwise normal response patterns. The same applies to other end points such as responses to pain and various types of spontaneous motor/exploratory activities, including reactivity to a variety of drug challenges that can provide information on the regulatory systems whose development may be affected by early treatments. In particular, the analysis of ontogenetic dissociations (i.e., differential early treatment effects depending jointly on developmental stage at the time of exposure, age of testing, and response end point) can be of considerable value in the study of treatments' mechanisms of action. Overall, it appears that behavioral teratological assessments can be effectively used both proactively, i.e., in risk assessment prior to any human exposure, and reactively. In the latter case, these assessments could have special value in the face of agents suspected to produce borderline changes in developing humans, whose innocuousness or noxiousness can be difficult to establish in the absence of hard evidence of teratogenicity.

  12. Effects of four rice paddy herbicides on algal cell viability and the relationship with population recovery.

    PubMed

    Nagai, Takashi; Ishihara, Satoru; Yokoyama, Atsushi; Iwafune, Takashi

    2011-08-01

    Paddy herbicides are a high-risk concern for aquatic plants, including algae, because they easily flow out from paddy fields into rivers, with toxic effects. The effect on algal population dynamics, including population recovery after timed exposure, must be assessed. Therefore, we demonstrated concentration-response relationships of four paddy herbicides for algal growth inhibition and mortality, and the relationship between the effect on algal cell viability and population recovery following exposure. We used SYTOX Green dye assay and flow cytometry to assess cell viability of the alga Pseudokirchneriella subcapitata. Live cells could be clearly distinguished from dead cells during herbicide exposure. Our results showed that pretilachlor and quinoclamine had both algicidal and algistatic effects, whereas bensulfuron-methyl only had an algistatic effect, and pentoxazone only had an algicidal effect. Then, a population recovery test following a 72-h exposure was conducted. The algal population recovered in all tests, but the periods required for recovery differed among exposure concentrations and herbicides. The periods required for recovery were inconsistent with the dead cell ratio at the beginning of the recovery test; that is, population recovery could not be described only by cell viability. Consequently, the temporal effect of herbicides and subsequent recovery of the algal population could be described not only by the toxicity characteristics but also by toxicokinetics, such as rate of uptake, transport to the target site, and elimination of the substance from algal cells. PMID:21590715

  13. Evaluation of alternative reference toxicants for use in the earthworm toxicity test

    SciTech Connect

    Yeardley, R.B. Jr.; Lazorchak, J.M.; Pence, M.A.

    1995-07-01

    The use of the 14-d earthworm toxicity test to aid in the evaluation of the ecological impact of contaminated soils is becoming increasingly widespread. However, the method is in need of further standardization. As part of this continuing process, the choice of reference toxicants was evaluated. Reference toxicants were rated in relation to the following criteria: (a) reproducibility, (b) low human health hazard, (c) feasibility of measurement, and (d) chemical stability. Potassium chloride (KCl) and ammonium chloride (NH{sub 4}Cl) were evaluated as possible alternatives to the one currently in common use, 2-chloroacetamide. Potassium chloride rated the best for the combination of the four criteria, followed by NH{sub 4}Cl and 2-chloroacetamide. Coefficients of variation (C.V.s) from control charts of six definitive tests were use to measure reproducibility. The best reproducibility (lowest C.V.) was shown by KCl, followed by NH{sub 4}Cl and 2-chloroacetamide. Toxicants ranked KCl < NH{sub 4}Cl {much_lt} 2-chloroacetamide in terms of health hazard; and KCl = NH{sub 4}Cl > 2-chloroacetamide in terms of measurement feasibility. Both 2-chloroacetamide and NH{sub 4}Cl changed in concentration during testing. Evidence is also presented that 2-chloroacetamide degrades rapidly during testing, and that, as dead worms decay, ammonification may be adding another toxicant, ammonia, to tests.

  14. A COMPARISON OF BULK SEDIMENT TOXICITY TESTING METHODS AND SEDIMENT ELUTRIATE TOXICITY

    EPA Science Inventory

    Bulk sediment toxicity tests are routinely used to assess the level and extent of contamination in natural sediments. While reliable, these tests can be resource intensive, requiring significant outlays of time and materials. The purpose of this study was to compare the results ...

  15. Oral Toxicity Study and Skin Sensitization Test of a Cricket

    PubMed Central

    Ryu, Hyeon Yeol; Lee, Somin; Ahn, Kyu Sup; Kim, Hye Jin; Lee, Sang Sik; Ko, Hyuk Ju; Lee, Jin Kyu; Cho, Myung-Haing; Ahn, Mi Young; Kim, Eun Mi; Lim, Jeong Ho; Song, Kyung Seuk

    2016-01-01

    Crickets have been attracting considerable interest in the field of nutrition and toxicology due to the global exhaustion of food resulting from a growing population. The cricket is normally eaten in several countries after roasting, similar to the grasshopper; however, safety evaluation data on cricket powder is limited. Here, we performed general toxicity studies of cricket powder including a single, 2-week repeated dose range evaluation test, a 13-week repeated oral dose toxicity test in Sprague-Dawley rats, a single oral dose toxicity test in Beagle dogs, and a skin sensitization test in guinea pigs following the Organization for Economic Cooperation and Development test guidelines 406 and 408 in addition to Good Laboratory Practice. To investigate the NOAEL and target organs of cricket powder, Sprague-Dawley rats were allocated to 4 groups: vehicle control, 1,250 mg/kg, 2,500 mg/kg, 5,000 mg/kg dose test groups and cricket powder was administered over 13 weeks after single dose and dose range finding studies in rats based on the results of the single oral administration toxicity study in rats and Beagle dogs. The results of the study showed that the NOAEL of cricket powder was over 5,000 mg/kg for both sexes of rats without adverse effects in a 13-week repeated oral toxicity study and there was no skin hypersensitivity reaction. Therefore, our results reveal that crickets can be widely used as a new substitute food or nutrient resource. PMID:27123167

  16. Acute systemic toxicity--prospects for tiered testing strategies.

    PubMed

    Botham, P A

    2004-04-01

    After many years of controversy and debate, the LD50 test was finally deleted by the end of 2002. Three alternative animal tests, the Fixed Dose Procedure, the Acute Toxic Class Method and the Up and Down Procedure have been developed which give rise to significant improvements in animal welfare. They have recently undergone revision to improve their scientific performance but more importantly to increase their regulatory acceptance. They can now be used within a strategy for acute toxicity testing for all types of test substances and for all regulatory and in-house purposes. In vitro cytotoxicity tests could be used as adjuncts to these alternative animal tests within the next year or so to improve dose level selection and thus give further modest improvements in the numbers of animals used. However, the total replacement of animal tests requires a considerable amount of further test development, followed by validation, and is at least 10 years away.

  17. The influence of time on lead toxicity and bioaccumulation determined by the OECD earthworm toxicity test.

    PubMed

    Davies, Nicola A; Hodson, Mark E; Black, Stuart

    2003-01-01

    Internationally agreed standard protocols for assessing chemical toxicity of contaminants in soil to worms assume that the test soil does not need to equilibrate with the chemical to be tested prior to the addition of the test organisms and that the chemical will exert any toxic effect upon the test organism within 28 days. Three experiments were carried out to investigate these assumptions. The first experiment was a standard toxicity test where lead nitrate was added to a soil in solution to give a range of concentrations. The mortality of the worms and the concentration of lead in the survivors were determined. The LC50s for 14 and 28 days were 5311 and 5395 microgPb g(-1)soil respectively. The second experiment was a timed lead accumulation study with worms cultivated in soil containing either 3000 or 5000 microgPb g(-1)soil. The concentration of lead in the worms was determined at various sampling times. Uptake at both concentrations was linear with time. Worms in the 5000 microg g(-1) soil accumulated lead at a faster rate (3.16 microg Pb g(-1)tissue day(-1)) than those in the 3000 microg g(-1) soil (2.21 microg Pb g(-1)tissue day(-1)). The third experiment was a timed experiment with worms cultivated in soil containing 7000 microgPb g(-1)soil. Soil and lead nitrate solution were mixed and stored at 20 degrees C. Worms were added at various times over a 35-day period. The time to death increased from 23 h, when worms were added directly after the lead was added to the soil, to 67 h when worms were added after the soil had equilibrated with the lead for 35 days. In artificially Pb-amended soils the worms accumulate Pb over the duration of their exposure to the Pb. Thus time limited toxicity tests may be terminated before worm body load has reached a toxic level. This could result in under-estimates of the toxicity of Pb to worms. As the equilibration time of artificially amended Pb-bearing soils increases the bioavailability of Pb decreases. Thus addition of

  18. The status of toxicity tests with sediment in Brazil

    SciTech Connect

    Araujo, R.P.A.

    1995-12-31

    The earliest studies in Brazil aiming to evaluate sediment quality through toxicity tests started in the beginning of the 80`s. These were developed by the Environmental Sanitation Agency of Sao Paulo State (CETESB) in Cubatao River and Billings Reservoir, which are located in industrialized and populous regions. Elutriate phase sediment toxicity tests were run with Daphnia similis. In the Cubatao River Basin the combination of toxicity, chemistry data and benthic community structure provided clear indications of sites with different levels of pollution. At this time there was a consensus that the study of a complex compartment such as sediment needed improvements in sampling and analysis procedures. Only in the 90`s the investigations involving sediment toxicity assessment were resumed by CETESB, and it was clear that integrative studies were needed in order to make environmental quality assessment. This kind of studies were conducted by CETESB in some highly polluted areas of Sao Paulo State, Ceriodaphnia dubia and Photobacterium phosphoreum interstitial water tests and Hyalella sp whole sediment tests were run, and the results correlated with several sediment organic and inorganic contaminants. The Sediment Quality Triad proposed by Chapman was applied in one of these studies. This approach was extremely useful in interpreting the data. At the same time marine sediment toxicity tests were developed by CETESB in collaboration with Sao Paulo University, and tests were run with the amphipods Tiburonella viscana, Battyporeiapus bisetosus; tanaidacean Kalliapseudes shubarti and the echinoderm Lytechinus variegatus. The embryo test with L. variegatus was the most adequate in these studies. Nowadays there are other groups in some universities developing sediment toxicity tests with Hyalella and Chironomus in response to a growing concern in Brazil to establish adequate sediment quality assessment guidelines.

  19. GENETIC VARIATION FOR COPPER RESISTANCE IN FATHEAD MINNOW TOXICITY TESTS

    EPA Science Inventory

    Unexplained variation in the results of aquatic organism toxicity tests is a consistently observed and troubling phenomenon. Possible sources of variation include differences in condition or nutritional status of the population prior to the test, as well as age, density and hand...

  20. POREWATER CHEMISTRY: EFFECTS OF SAMPLING, STORAGE, HANDLING, AND TOXICITY TESTING

    EPA Science Inventory

    As a general principle, it is nearly impossible to remove a porewater sample from sediment, use it in a toxicity testing vessel with test organisms, and prevent changes in the chemistry of the natural and anthropogenic organic and inorganic constituents. The degree of change in t...

  1. 40 CFR 797.1330 - Daphnid chronic toxicity test.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., growth) are the criteria of toxicity. (3) EC 50 means that experimentally derived concentration of test substance in dilution water that is calculated to affect 50 percent of a test population during continuous... same dilution water, conditions, procedures and daphnids from the same population (culture...

  2. Reproductive and developmental toxicity testing: Examination of the extended one-generation reproductive toxicity study guideline.

    PubMed

    Saghir, Shakil A; Dorato, Michael A

    2016-08-01

    An important aspect of safety assessment of chemicals (industrial and agricultural chemicals and pharmaceuticals) is determining their potential reproductive and developmental toxicity. A number of guidelines have outlined a series of separate reproductive and developmental toxicity studies from fertilization through adulthood and in some cases to second generation. The Extended One-Generation Reproductive Toxicity Study (EOGRTS) is the most recent and comprehensive guideline in this series. EOGRTS design makes toxicity testing progressive, comprehensive, and efficient by assessing key endpoints across multiple life-stages at relevant doses using a minimum number of animals, combining studies/evaluations and proposing tiered-testing approaches based on outcomes. EOGRTS determines toxicity during preconception, development of embryo/fetus and newborn, adolescence, and adults, with specific emphasis on the nervous, immunological, and endocrine systems, EOGRTS also assesses maternal and paternal toxicity. However, EOGRTS guideline is complex, criteria for selecting doses is unclear, and monitoring systemic dose during the course of the study for better interpretation and human relevance is not clear. This paper discusses potential simplification of EOGRTS, suggests procedures for relevant dose selection and monitors systemic dose at multiple life-stages for better interpretation of data and human relevance.

  3. Comparison of ethanol toxicity to Daphnia magna and Ceriodaphnia dubia tested at two different temperatures: static acute toxicity test results

    SciTech Connect

    Takahashi, I.T.; Cowgill, U.M.; Murphy, P.G.

    1987-08-01

    Ethanol is a commonly used solvent in toxicity testing, yet there are few studies in the literature devoted to its toxicity to zooplankton. The purpose of this study was to compare the response of Daphnia magna Straus 1820 and Ceriodaphnia dubia J. Richard 1894 to ethanol. Two temperatures were selected because most toxicity data involving D. magna has been carried out at 20/sup 0/C while all discussions concerning C. dubia appear to relate to temperatures oscillating around 25/sup 0/C. Thus, the response of these two organisms to ethanol was examined at 20/sup 0/C and at 24/sup 0/C.r

  4. Baker's yeast assay procedure for testing heavy metal toxicity

    SciTech Connect

    Bitton, G.; Koopman, B.; Wang, H.D.

    1984-01-01

    Baker's yeast (Saccharomyces cerevisiae) is microorganism which is commercially available and sold as packaged dry pellets in any food store at low cost. Studies have been undertaken on the effects of organic xenobiotics as well as heavy metals on yeast metabolism. This type of study has been generally useful in examining the mechanism(s) of chemical toxicity. However, a rapid and quantitative toxicity test using S. cerevisiae as the test organism has not been developed. The purpose of this study was to develop a toxicity assay for heavy metals, using commercial dry yeast as the test microorganism. This rapid and simple procedure is based on the reduction of 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyltetrazolium chloride (INT) to INT-formazan by the yeast electron transport system. The scoring of active cells following exposure to heavy metals was undertaken according to the MINT (malachite green-INT) method developed by Bitton and Koopman.

  5. Use of blue crab (Callinectes sapidus) embryos for toxicity testing

    SciTech Connect

    Lee, R.; O`Malley, K.

    1995-12-31

    After fertilization, blue crab embryos develop in egg sacs attached to the female pleopods, often referred to as the sponge. Lipovitellin and lipid droplets in the egg sacs provide energy and nutrition for the developing embryos. Embryos were removed from the sponge and transferred to 24 well culture plates containing sea water with or without toxicants, Each well contained 10 embryos. After 7 to 10 days, embryos hatched to swimming zoea. The effects of toxicants at various concentrations on hatching were determined and the EC{sub 50} calculated. For example, the EC{sub 50} for tributyltin, fenvalerate and mercuric chloride were 50, 30 and 90 ng/liter, respectively. The hatching success of control embryos ranged from 95 to 98%. Formation of the heart, eyespot formation, appendage formation and utilization rate of lipovitellin were also effected by exposure to toxicants. At a low concentration of mercuric ion (30ng/liter) the heart formed, but there was no heart beat. Eyespot formation was abnormal in the presence of high concentrations of cadmium (2 {micro}g/liter) and zinc (5 {micro}g/liter), Crab embryos offer many advantages for toxicity testing of pure compounds or mixtures in water, including toxicity testing of sediment pore water. The crab embryos may also serve as models to understand the effect of specific toxicants on the heart and eye spots of crustaceans.

  6. Resolving some practical questions about Daphnia acute toxicity tests

    SciTech Connect

    Barera, Y.; Adams, W.J.

    1981-10-01

    Acute toxicity tests were performed with six age groups of Daphnia magna, ranging from less than or equal to6 h to 216 h, and with five chemicals, selected on the basis of their physical and chemical properties as well as their acute toxicity to D. magna. The age of the daphnids did not significantly alter the 48-h EC/sub 50/ values for the chemicals tested. The maximum difference observed in the 48-h EC/sub 50/ values between the 6-h and 216-h age groups was a factor of 3.9 for linear alkylbenzene sulfonate (LAS). For purposes of standardization, it appears that D. magna up to 48 h of age at the beginning of the test can be used to conduct acute toxicity tests with most chemicals. The results of static acute toxicity tests conducted with butylbenzyl phthalate (BBP) and D. magna in the presence and absence of several commonly used solvents indicate that the acute toxicity of this chemical is not altered by the use of a solvent carrier. The 48-h EC/sub 50/ value for BBP without a solvent was 1.0 mg/L, compared with a range of 1.6 to 2.2 mg/L when acetone, dimethylformamide, ethanol, or triethylene glycol were used as solvent carriers. The acute toxicities of the solvents in the absence of BBP were also determined for D. magna. The values ranged from 9.3 to 52.4 g/L. The results of static acute tests performed with D. magna and BBP in the presence of various concentrations of daphnid foods (algae or trout chow), indicate that the 48-h EC/sub 50/ values increase proportionally with an increase in food concentrations. These results suggest that acute toxicity tests with D. magna should be conducted in the presence of food with chemicals with a high Ksigma if the results are to be used to select the test concentrations for a chronic study with daphnids. The type of food and the concentration used in the acute test should be the same as those used in a chronic test.

  7. Control group response variability in short-term toxicity tests

    SciTech Connect

    Gast, L.C.; Shimp, C.; Wang, Q.; Shukla, R.; Fulk, F.

    1995-12-31

    The US EPA`s National Reference Toxicant Database (NRTDB) has afforded an excellent opportunity to examine and document variability in responses within control groups (i.e. zero concentration of the toxicant.) The NRTDB has compiled acute and chronic reference toxicant test results for eight species and currently contains results for 32 laboratories and generally eight to ten tests for a species within each laboratory. The Ceriodaphnia dubia Survival and Reproduction test and the Pimephales promelas (fathead minnow) Survival and Growth test are the most frequently represented chronic tests with 331 and 144 sets of test data, respectively. For this presentation, Ceriodaphnia dubia reproduction data, expressed as total numbers of young in the test period, and fathead minnow survival and growth data were analyzed using a variance components model. The information regarding the control population is useful in examining the sources of inter and intralaboratory variability of chronic testing. In addition, this control population response variability information will be valuable for characterizing what can be termed as ``practically equivalent responses`` between a control and an effluent. The preliminary analysis indicates considerable between-test variability; however, this variability is not consistent across laboratories. Results of further exploration on this issue will be presented.

  8. Comparisons of Sediment Test Volumes for Freshwater Solid Phase Sediment Toxicity Tests

    EPA Science Inventory

    Laboratory tests with benthic macroinvertebrates are commonly used to assess the potential toxicity of contaminated sediments, and detailed standard test procedures have been developed for various species. For freshwater, two benthic organisms, Hyalella azteca and Chironomus dil...

  9. Troubleshooting methods for toxicity testing of airborne chemicals in vitro.

    PubMed

    Bakand, Shahnaz; Hayes, Amanda

    2010-01-01

    Toxicology studies of adverse effects induced by inhaled chemicals are technically challenging, due to the requirement of highly controlled experimental conditions needed to achieve reproducible and comparable results. Therefore, many considerations must be fulfilled before adopting in vitro bioassay test systems for toxicity screening of airborne materials. However, recent methodological and technical breakthroughs of in vitro methods have the potential to fulfil the essential requirements of toxicity testing for airborne chemicals. Technology has now become available that allows cells to be cultured on permeable microporous membranes in transwell or snapwell inserts providing a very close contact between target cells and test atmospheres to study the cellular interactions caused by airborne chemical exposures without any interfering culture medium. Using a direct exposure technique at the air-liquid interface, target cells can be continuously exposed to airborne chemicals on their apical side, while being nourished from their basolateral side. Test atmospheres with different physicochemical characteristics such as gases, vapours, solid and liquid aerosols and more recently nanoaerosols, can be delivered into human target cells using static and/or direct dynamic exposure methods. Therefore, toxicological risk assessments of airborne chemicals and even complex atmospheres can be achieved using in vitro test methods in parallel with real-time air monitoring techniques to fulfil the general regulatory requirements of newly developed chemical or pharmaceutical products with the potential for inhalational exposure. In this review current toxicological methods for toxicity testing of inhaled chemicals are presented. Further, to demonstrate the potential application of in vitro methods for studying inhalation toxicity, more advanced exposure techniques developed for toxicity screening of airborne chemicals are discussed.

  10. Scanning respirometer for toxicity tests using micro-organisms

    NASA Astrophysics Data System (ADS)

    Zhang, Min-Quan; Li, Xiang-Ming; Wong, Yuk-Shan; Kwan, FolkYear

    1995-09-01

    A novel respirometer is developed for microbial toxicity tests. The respirometer is based on luminescent quenching of oxygen to measure the concentration of dissolved oxygen in cell vessels and evaluate the toxicity of chemicals by monitoring the effect of toxicants on cell respiration of micro-organisms. The oxygen sensing element is ruthenium complex absorbed on the surface of silica particles followed by immobilizing on a silicone rubber film. The oxygen sensing film is coated on the inner bottom of a transparent cell vessel. A sensing device scanning under the cell vessel is used for remote monitoring of the oxygen concentration inside the cell vessels so that a large number of samples can be handled in one batch. The sensing device includes the excitation light sources and an optical cable connected to a filter and a photomultiplier tube for detecting the luminescence in the cell vessel which can then be related to the dissolved oxygen concentration inside the cell vessel. The movement of the sensing device and data acquisition are controlled by a personal computer. The toxicity of heavy metals to activated sludge, soil bacteria and E. coli were tested using the present device. The scanning respirometer provides a new alternative for fast and large scale screening and monitoring of toxicants using micro-organisms.

  11. Controlling type-1 error rates in whole effluent toxicity testing

    SciTech Connect

    Smith, R.; Johnson, S.C.

    1995-12-31

    A form of variability, called the dose x test interaction, has been found to affect the variability of the mean differences from control in the statistical tests used to evaluate Whole Effluent Toxicity Tests for compliance purposes. Since the dose x test interaction is not included in these statistical tests, the assumed type-1 and type-2 error rates can be incorrect. The accepted type-1 error rate for these tests is 5%. Analysis of over 100 Ceriodaphnia, fathead minnow and sea urchin fertilization tests showed that when the test x dose interaction term was not included in the calculations the type-1 error rate was inflated to as high as 20%. In a compliance setting, this problem may lead to incorrect regulatory decisions. Statistical tests are proposed that properly incorporate the dose x test interaction variance.

  12. Toxicity testing in the 21st century beyond environmental chemicals.

    PubMed

    Rovida, Costanza; Asakura, Shoji; Daneshian, Mardas; Hofman-Huether, Hana; Leist, Marcel; Meunier, Leo; Reif, David; Rossi, Anna; Schmutz, Markus; Valentin, Jean-Pierre; Zurlo, Joanne; Hartung, Thomas

    2015-01-01

    After the publication of the report titled Toxicity Testing in the 21st Century - A Vision and a Strategy, many initiatives started to foster a major paradigm shift for toxicity testing - from apical endpoints in animal-based tests to mechanistic endpoints through delineation of pathways of toxicity (PoT) in human cell based systems. The US EPA has funded an important project to develop new high throughput technologies based on human cell based in vitro technologies. These methods are currently being incorporated into the chemical risk assessment process. In the pharmaceutical industry, the efficacy and toxicity of new drugs are evaluated during preclinical investigations that include drug metabolism, pharmacokinetics, pharmacodynamics and safety toxicology studies. The results of these studies are analyzed and extrapolated to predict efficacy and potential adverse effects in humans. However, due to the high failure rate of drugs during the clinical phases, a new approach for a more predictive assessment of drugs both in terms of efficacy and adverse effects is getting urgent. The food industry faces the challenge of assessing novel foods and food ingredients for the general population, while using animal safety testing for extrapolation purposes is often of limited relevance. The question is whether the latest paradigm shift proposed by the Tox21c report for chemicals may provide a useful tool to improve the risk assessment approach also for drugs and food ingredients.

  13. EP-toxicity testing of mercury removal resin grout

    SciTech Connect

    Mersman, K.E.

    1984-07-18

    To determine which category a waste will fit into, the EPA requires a classification test. The test, EP-toxicity, consists of a physical integrity test followed by an extraction. For the case of the mercury removal resin grout, the mercury concentration in the extract cannot exceed 0.2 mg/L if the waste is to be classified as ``solid waste.`` Otherwise, the waste is classified as ``hazardous.`` Simulated process solutions were used to load the mercury removal resin. The resin was solidified with the addition of cement and water using a formulation based on grout formulations typically used to solidify power reactor ion exchange resins. Envirodyne Engineers of St. Louis, Missouri, an EPA sanctioned laboratory, performed the EP-toxicity test for the two samples. One sample was a blank which was made with unloaded resin. For the formulation tested, the EP-toxicity test results showed that the mercury removal resin grout does not fit into the ``hazardous waste`` category.

  14. An evaluation of the whole effluent toxicity test method

    SciTech Connect

    Osteen, D.V.

    1999-12-17

    Whole effluent toxicity (WET) testing has become increasingly more important to the Environmental Protection Agency (EPA) and the States in the permitting of wastewater discharges from industry and municipalities. The primary purpose of the WET test is to protect aquatic life by predicting the effect of an effluent on the receiving stream. However, there are both scientific and regulatory concerns that using WET tests to regulate industrial effluents may result in either false positives and/or false negatives. In order to realistically predict the effect of an effluent on the receiving stream, the test should be as representative as possible of the conditions in the receiving stream. Studies (Rand and Petrocelli 1985) suggested several criteria for an ideal aquatic toxicity test organism, one of which is that the organism be indigenous to, or representative of, the ecosystem receiving the effluent. The other component needed in the development of a predictive test is the use of the receiving stream water or similar synthetic water as the control and dilution water in the test method. Use of an indigenous species and receiving water in the test should help reduce the variability in the method and allow the test to predict the effect of the effluent on the receiving stream. The experience with toxicity testing at the Savannah River Site (SRS) has yielded inconclusive data because of the inconsistency and unreliability of the results. The SRS contention is that the WET method in its present form does not adequately mimic actual biological/chemical conditions of the receiving streams and is neither reasonable nor accurate. This paper discusses the rationale for such a position by SRS on toxicity testing in terms of historical permitting requirements, outfall effluent test results, standard test method evaluation, scientific review of alternate test species, and concerns over the test method expressed by other organizations. This paper presents the Savannah River Site

  15. Use of neomysis mercedis (crustacea: mysidacea) for estuarine toxicity tests

    SciTech Connect

    Brandt, O.M.; Fujimura, R.W.; Finlayson, B.J. )

    1993-03-01

    The mysid Neomysis mercedis was examined as a test organism for use in acute toxicity tests at intermediate salinities characteristic of estuarine waters. Several sensitive invertebrate species are available for marine assessments (mysids) and freshwater tests (cladocerans), but few are available for estuarine toxicity tests. Observations in the laboratory indicate that Neomysis mercedis can be reared successfully at a temperature of 17[degrees]C, a salinity of 2%, and a population density less than 5/L. Brine shrimp nauplii Artemia salina, algae, and commercial foods were used to sustain mysid cultures. Neomysis mercedis is vivaparous and can complete its life cycle in 3-4 months. Neomysis mercedis is as sensitive as or more sensitive to toxicants than the marine mysid Mysidopsis bahia and the freshwater cladocerans Daphnia magna, Ceriodaphnia dubia, and Simocephalus serrulatus. The mean 96-h LC50 values (concentrations lethal to half the test animals) for N. mercedis, in increasing order, were 0.20 [mu]g/L for thiobencarb, and for malathion, 14 [mu]g/L for carbofuran, 150 [mu]g/L for copper sulfate, 280 [mu]g/L for thiobencarb, and 1,600 [mu]g/L for molinate. Neonates (5 d postrelease) were generally more sensitive than older juveniles. Coefficients of variation (100[center dot]SD/mean) of LC50 values varied from 21 to 35%. 37 refs., 2 figs., 7 tabs.

  16. Interference of an algal nutritional supplement with a urinary metabolic screening test for glycosaminoglycans in a dog suspected to have a storage disease.

    PubMed

    Sewell, Adrian C; Pankraz, Alexander

    2013-12-01

    The finding of excess urinary glycosaminoglycans (GAG) is the first step in the laboratory diagnosis of mucopolysaccharidosis (MPS). Urinary screening tests are based upon the binding of GAG to dimethylmethylene blue. Alternatively, paper spot tests using toluidine blue are used in human and veterinary laboratory medicine. Positive samples undergo GAG isolation for subsequent characterization. Here, we describe a 3-year-old English Cocker Spaniel with a positive urinary GAG test, but without other clinical signs of MPS. Urine samples were strongly positive with the dimethylmethylene blue test, and isolated GAG subjected to electrophoresis on cellulose acetate revealed a band co-migrating with dermatan sulfate. However, the isolated GAG were resistant to digestion with chondroitinase ABC, suggesting that the band did not represent dermatan sulfate. This was confirmed by mobility of the isolated GAG different from dermatan sulfate on agarose gel electrophoresis. MPS types VI and VII were excluded by enzyme assay. To test the hypothesis of a nutritional source, a healthy control dog was fed the same dog food as the index case. His urine showed a comparable abnormal GAG screening test and electrophoretic pattern. In addition, the analysis of an algal supplement present in the administered dog food showed a similar electrophoretic GAG pattern. The Cocker Spaniel was not available for further testing after withdrawal of the supplement. Algae contain highly sulfated fucans and galactans, and it appears that commercial dog food containing such algal, and possibly other, supplements can give rise to false-positive urinary MPS screening tests.

  17. The Role of Toxicity Testing in NASA's Future Missions

    NASA Technical Reports Server (NTRS)

    Whitfield, Steve; Davis, Samuel; Wise, Harry; Moore, Robin

    2005-01-01

    NASA has deemed it necessary to perform the Toxicity Test (offgassing of toxic products) on all non-metallic materials proposed for use in habitable environments onboard the Shuttle and International Space Station flS,!J. This requirement stems from the desire to maintain a healthy, breathable atmosphere for the astronauts. As Shuttle missions have lengthened and with the habitation of the International Space Station, the need for understanding and controlling the contaminants in breathable atmospheres has increased. The increased duration of humans in space present two concerns to the astronauts with regard to their breathing air: 1. Breathing the on-board air. 2. Improved cleaning/filtering of existing air. Trends using existing toxicity data for materials and an understanding of the air cleaning/filtering capabilities in relation to Spacecraft Maximum Allowable Concentrations (SMAC) of offgassed components are explored. Recommendations are made for materials selection practices that should be followed to ensure a safe and healthy breathing environment for astronauts aboard these long term projects. The importance and relevance of Toxicity testing and materials selection in conjunction with the new NASA missions of creating a human presence on the Moon and traveling to Mars are described.

  18. Algal biofuels.

    PubMed

    Razeghifard, Reza

    2013-11-01

    The world is facing energy crisis and environmental issues due to the depletion of fossil fuels and increasing CO2 concentration in the atmosphere. Growing microalgae can contribute to practical solutions for these global problems because they can harvest solar energy and capture CO2 by converting it into biofuel using photosynthesis. Microalgae are robust organisms capable of rapid growth under a variety of conditions including in open ponds or closed photobioreactors. Their reduced biomass compounds can be used as the feedstock for mass production of a variety of biofuels. As another advantage, their ability to accumulate or secrete biofuels can be controlled by changing their growth conditions or metabolic engineering. This review is aimed to highlight different forms of biofuels produced by microalgae and the approaches taken to improve their biofuel productivity. The costs for industrial-scale production of algal biofuels in open ponds or closed photobioreactors are analyzed. Different strategies for photoproduction of hydrogen by the hydrogenase enzyme of green algae are discussed. Algae are also good sources of biodiesel since some species can make large quantities of lipids as their biomass. The lipid contents for some of the best oil-producing strains of algae in optimized growth conditions are reviewed. The potential of microalgae for producing petroleum related chemicals or ready-make fuels such as bioethanol, triterpenic hydrocarbons, isobutyraldehyde, isobutanol, and isoprene from their biomass are also presented.

  19. In situ toxicity testing with locally collected Daphnia

    SciTech Connect

    Snyder-Conn, E.

    1993-07-01

    Daphnia middlendorffiana from local tundra ponds were transplanted into five reserve pits (sumps with used drilling wastes and precipitation) at drill sites in the Prudhoe Bay oil field. Concurrently, Daphnia were transplanted into tundra ponds adjacent to the reserve pits (near ponds), into more distant but connected ponds (distant ponds), and into control ponds to evaluate the toxicity of the fluids along contaminant gradients. Twenty adult Daphnia were placed in eight waxed flow-through containers and exposed to the conditions of each test site. In each exposure container, the ratios of the number of dead Daphnia to the total number of adult Daphnia, the number of young Daphnia to the total number of adult Daphnia, the number of molting Daphnia to the total number of adult Daphnia, and the number of released ephippia to the total number of adult Daphnia were determined. The results not only indicate the utility of in situ testing of invertebrate toxicity but suggest that under certain conditions in situ tests may be more sensitive than traditional laboratory toxicity tests.

  20. Antioxidant, Antimicrobial Activity and Toxicity Test of Pilea microphylla

    PubMed Central

    Modarresi Chahardehi, Amir; Ibrahim, Darah; Fariza Sulaiman, Shaida

    2010-01-01

    A total of 9 plant extracts were tested, using two different kinds of extracting methods to evaluate the antioxidant and antimicrobial activities from Pilea microphylla (Urticaceae family) and including toxicity test. Antioxidant activity were tested by using DPPH free radical scavenging, also total phenolic contents and total flavonoid contents were determined. Toxicity assay carried out by using brine shrimps. Methanol extract of method I (ME I) showed the highest antioxidant activity at 69.51 ± 1.03. Chloroform extract of method I (CE I) showed the highest total phenolic contents at 72.10 ± 0.71 and chloroform extract of method II (CE II) showed the highest total flavonoid contents at 60.14 ± 0.33. The antimicrobial activity of Pilea microphylla extract was tested in vitro by using disc diffusion method and minimum inhibitory concentration (MIC). The Pilea microphylla extract showed antibacterial activity against some Gram negative and positive bacteria. The extracts did not exhibit antifungal and antiyeast activity. The hexane extract of method I (HE I) was not toxic against brine shrimp (LC50 value was 3880 μg/ml). Therefore, the extracts could be suitable as antimicrobial and antioxidative agents in food industry. PMID:20652052

  1. Toxicity testing and instream biological monitoring in evaluating municipal effluents

    SciTech Connect

    Krier, K.; Pontasch, K.

    1995-12-31

    Twelve streams receiving municipal wastewater treatment plant effluents were evaluated in riffle areas above and below the outfall using the Environmental Protection Agency`s Rapid Bioassessment Protocols (RBPs) for benthic macroinvertebrates. Eight of the sites evaluated using RBP 1 exhibited stream health in the downstream riffles equaling or exceeding the upstream riffles. RBP 1 results suggested possible impacts at the remaining four sites, and these sites were more intensely evaluated using RBPs 2 and 3, acute effluent toxicity tests with Daphnia magna, and quantification of periphytic chlorophyll a and ash free dry weight (AFDW). Results from RBP 2 indicated three of the four sites evaluated have similar taxonomic richness above and below the outfall, while one site is heavily impacted by organic pollutants. Toxicity tests with 100% effluent resulted in no mortality with any of the four effluents tested. Relative to the respective upstream sites, chlorophyll a was significantly increased at one downstream site and significantly reduced at another. AFDW was similar above and below the outfalls in all streams. These results suggest that laboratory toxicity tests may not always be adequate predictors of instream biological effects.

  2. Non-animal Replacements for Acute Toxicity Testing.

    PubMed

    Barker-Treasure, Carol; Coll, Kevin; Belot, Nathalie; Longmore, Chris; Bygrave, Karl; Avey, Suzanne; Clothier, Richard

    2015-07-01

    Current approaches to predicting adverse effects in humans from acute toxic exposure to cosmetic ingredients still heavily necessitate the use of animals under EU legislation, particularly in the context of the REACH system, when cosmetic ingredients are also destined for use in other industries. These include the LD50 test, the Up-and-Down Procedure and the Fixed Dose Procedure, which are regarded as having notable scientific deficiencies and low transferability to humans. By expanding on previous in vitro tests, such as the animal cell-based 3T3 Neutral Red Uptake (NRU) assay, this project aims to develop a truly animal-free predictive test for the acute toxicity of cosmetic ingredients in humans, by using human-derived cells and a prediction model that does not rely on animal data. The project, funded by Innovate UK, will incorporate the NRU assay with human dermal fibroblasts in animal product-free culture, to generate an in vitro protocol that can be validated as an accepted replacement for the currently available in vivo tests. To date, the project has successfully completed an assessment of the robustness and reproducibility of the method, by using sodium lauryl sulphate (SLS) as a positive control, and displaying analogous results to those of the original studies with mouse 3T3 cells. Currently, the testing of five known ingredients from key groups (a surfactant, a preservative, a fragrance, a colour and an emulsifier) is under way. The testing consists of initial range-finding runs followed by three valid runs of a main experiment with the appropriate concentration ranges, to generate IC50 values. Expanded blind trials of 20 ingredients will follow. Early results indicate that this human cell-based test holds the potential to replace aspects of in vivo animal acute toxicity testing, particularly with reference to cosmetic ingredients.

  3. Non-animal Replacements for Acute Toxicity Testing.

    PubMed

    Barker-Treasure, Carol; Coll, Kevin; Belot, Nathalie; Longmore, Chris; Bygrave, Karl; Avey, Suzanne; Clothier, Richard

    2015-07-01

    Current approaches to predicting adverse effects in humans from acute toxic exposure to cosmetic ingredients still heavily necessitate the use of animals under EU legislation, particularly in the context of the REACH system, when cosmetic ingredients are also destined for use in other industries. These include the LD50 test, the Up-and-Down Procedure and the Fixed Dose Procedure, which are regarded as having notable scientific deficiencies and low transferability to humans. By expanding on previous in vitro tests, such as the animal cell-based 3T3 Neutral Red Uptake (NRU) assay, this project aims to develop a truly animal-free predictive test for the acute toxicity of cosmetic ingredients in humans, by using human-derived cells and a prediction model that does not rely on animal data. The project, funded by Innovate UK, will incorporate the NRU assay with human dermal fibroblasts in animal product-free culture, to generate an in vitro protocol that can be validated as an accepted replacement for the currently available in vivo tests. To date, the project has successfully completed an assessment of the robustness and reproducibility of the method, by using sodium lauryl sulphate (SLS) as a positive control, and displaying analogous results to those of the original studies with mouse 3T3 cells. Currently, the testing of five known ingredients from key groups (a surfactant, a preservative, a fragrance, a colour and an emulsifier) is under way. The testing consists of initial range-finding runs followed by three valid runs of a main experiment with the appropriate concentration ranges, to generate IC50 values. Expanded blind trials of 20 ingredients will follow. Early results indicate that this human cell-based test holds the potential to replace aspects of in vivo animal acute toxicity testing, particularly with reference to cosmetic ingredients. PMID:26256397

  4. Technical considerations regarding toxicity testing of commercial bioremediation agents

    SciTech Connect

    Bidwell, J.R.; Cavender, R.C.; Cherry, D.S.; Merski, A.T.; Cianciarulo, F.L.

    1995-12-31

    The toxicological evaluation of commercial bioremediation agents (CBAs) for use on oil spills is under consideration by the USEPA. Currently, acute and chronic bioassays are conducted with the CBA alone and with CBA that has been diluted with the water soluble fraction (WSF) of a crude oil. Endpoints are expressed as a concentration of the CBA. This approach may not address the toxicological issue of CBA use since it (1) does not determine if the CBA affects toxicity of the oil itself, and (2) does not consider temporal aspects associated with byproducts of oil degradation. The present study was conducted to address these issues. A CBA was mixed with unweathered crude oil from 1 to 42 days. The WSF of the mixture was then drawn off and acute bioassays were conducted with silverside minnows, Menidia beryllina, and mysid shrimp, Mysidopsis bahia. For silversides, 96-hr LC50 values ranged from 42.7% WSF after 1 day mixing to 10.5% after 42 days. Toxicity increased sharply between days 4 and 7 when the 96-hr LC50 dropped from 39.0 to 18.2% WSF. A similar trend occurred for mysid shrimp. The presence of the CBA caused a more rapid increase in the toxicity of the oil as compared to bioassays in which oil was mixed alone and then tested. These data indicate that the interaction of CBAs with oil, and associated temporal trends in toxicity, are important aspects to consider in hazard evaluation of these products. The current proposed CBA toxicity testing protocol does not effectively address these issues.

  5. Applicability of subchronic toxicity test with Hyalella azteca for toxicity identification evaluation programs

    SciTech Connect

    Putt, A.E.; Jop, K.M.

    1995-12-31

    A series of screening tests including the short-term chronic exposure of Ceriodaphnia dubia to sediment pore waters, 10-day exposures of Chironomus tentans and Hyalella azteca to bulk sediments and a bioaccumulation study with Lumbriculus variegatus were performed as part of an ecological risk assessment of Plow Shop Pond, Fort Devens, Massachusetts. Chronic endpoints such as reproduction and growth indicated sediment toxicity, however, a toxicity identification evaluation program was initiated to further define the source and extent of the toxicity. A short-term chronic exposure with C. dubia was a logical choice for the TIE, however, since amphipods are epibenthic organisms, they are a better surrogate of sediment dwelling organisms than a water column species such as C. dubia. Observations performed during H. azteca culture suggested that this species of amphipod could thrive in the water column for up to three weeks. Therefore, 7-day old H. azteca were exposed to pore water samples under static-renewal conditions for 10 days. Survival and growth (i.e., dry weight) were determined at the termination of each exposure. Laboratory control group performance consistently averaged a {>=}90% survival and {>=}43 {micro}g of dry weight per amphipod. Growth of amphipods used in each exposure generally exceeded two times the initial body weight after 10 days of exposure. Previous studies have indicated that the growth and reproductive response of H. azteca are positively correlated for a given set of exposure conditions. The results of these 10-day subchronic exposures with H. azteca provide a consistent and reliable measure of the chronic sediment toxicity with a benthic invertebrate for toxicity identification evaluation programs.

  6. Undetected Toxicity Risk in Pharmacogenetic Testing for Dihydropyrimidine Dehydrogenase

    PubMed Central

    Falvella, Felicia Stefania; Caporale, Marta; Cheli, Stefania; Martinetti, Antonia; Berenato, Rosa; Maggi, Claudia; Niger, Monica; Ricchini, Francesca; Bossi, Ilaria; Di Bartolomeo, Maria; Sottotetti, Elisa; Bernardi, Francesca Futura; de Braud, Filippo; Clementi, Emilio; Pietrantonio, Filippo

    2015-01-01

    Fluoropyrimidines, the mainstay agents for the treatment of colorectal cancer, alone or as a part of combination therapies, cause severe adverse reactions in about 10%–30% of patients. Dihydropyrimidine dehydrogenase (DPD), a key enzyme in the catabolism of 5-fluorouracil, has been intensively investigated in relation to fluoropyrimidine toxicity, and several DPD gene (DPYD) polymorphisms are associated with decreased enzyme activity and increased risk of fluoropyrimidine-related toxicity. In patients carrying non-functional DPYD variants (c.1905+1G>A, c.1679T>G, c.2846A>T), fluoropyrimidines should be avoided or reduced according to the patients’ homozygous or heterozygous status, respectively. For other common DPYD variants (c.496A>G, c.1129-5923C>G, c.1896T>C), conflicting data are reported and their use in clinical practice still needs to be validated. The high frequency of DPYD polymorphism and the lack of large prospective trials may explain differences in studies’ results. The epigenetic regulation of DPD expression has been recently investigated to explain the variable activity of the enzyme. DPYD promoter methylation and its regulation by microRNAs may affect the toxicity risk of fluoropyrimidines. The studies we reviewed indicate that pharmacogenetic testing is promising to direct personalised dosing of fluoropyrimidines, although further investigations are needed to establish the role of DPD in severe toxicity in patients treated for colorectal cancer. PMID:25906475

  7. Using single-species toxicity tests, community-level responses, and toxicity identification evaluations to investigate effluent impacts

    SciTech Connect

    Maltby, L.; Clayton, S.A.; Yu, H.; McLoughlin, N.; Wood, R.M.; Yin, D.

    2000-01-01

    Whole effluent toxicity (WET) tests are increasingly used to monitor compliance of consented discharges, but few studies have related toxicity measured using WET tests to receiving water impacts. Here the authors adopt a four-stage procedure to investigate the toxicity and biological impact of a point source discharge and to identify the major toxicants. In stage 1, standard WET tests were employed to determine the toxicity of the effluent. This was then followed by an assessment of receiving water toxicity using in situ deployment of indigenous (Gammarus pulex) and standard (Daphnia magna) test species. The third stage involved the use of biological survey techniques to assess the impact of the discharge on the structure and functioning of the benthic macroinvertebrate community. In stage 4, toxicity identification evaluations (TIE) were used to identify toxic components in the effluent. Receiving-water toxicity and ecological impact detected downstream of the discharge were consistent with the results of WET tests performed on the effluent. Downstream of the discharge, there was a reduction in D. magna survival, in G. pulex survival and feeding rate, in detritus processing, and in biotic indices based on macroinvertebrate community structure. The TIE studies suggested that chlorine was the principal toxicant in the effluent.

  8. Produced water toxicity tests accurately measure the produced water toxicity in marine environments?

    SciTech Connect

    Douglas, W.S.; Veil, J.A.

    1996-10-01

    U.S. Environmental Protection Agency (EPA) Region VI has issued a general permit for offshore oil and gas discharges to the Gulf of Mexico that places numerical limits on whole effluent toxicity (WEI) for produced water. Recently proposed EPA general permits for other produced water discharges in Regions VI and X also include enforceable numerical limits on WET. Clearly, the industry will be conducting extensive produced water WET testing. Unfortunately, the WET test may not accurately measure the toxicity of the chemical constituents of produced water. Rather the mortality of test organisms may be attributable to (1) the high salinity of produced water, which causes salinity shock to the organisms, or (2) an ionic imbalance caused by excesses or deficiencies of one or more of seawater`s essential ions in the test chambers. Both of these effects are likely to be mitigated in actual offshore discharge settings, where the receiving water will be seawater and substantial dilution will be probable. Thus, the additional salinity of produced water will be rapidly assimilated, and the proper marine ionic balance will be quickly restored. Regulatory authorities should be aware of these factors when interpreting WET test results.

  9. Field assessments in conjunction with whole effluent toxicity testing

    SciTech Connect

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

    2000-01-01

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

  10. 78 FR 69414 - Toxic Substances Control Act Chemical Testing; Receipt of Test Data

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-19

    ... October 21, 2011 (76 FR 65385) (FRL-8885-5) (docket ID number EPA-HQ-OPPT-2009-0112). The table in this... AGENCY Toxic Substances Control Act Chemical Testing; Receipt of Test Data AGENCY: Environmental Protection Agency (EPA). ACTION: Notice. SUMMARY: This notice announces EPA's receipt of test data on...

  11. Bioavailability of fluoranthene in freshwater sediment toxicity tests

    SciTech Connect

    Suedel, B.C.; Rodgers, J.H. Jr. ); Clifford, P.A. )

    1993-01-01

    To examine equilibrium-partitioning model predictions of interstitial water concentrations of fluoranthene as part of the equilibrium-partitioning (EqP) approach to sediment quality criteria development, the bioavailability (toxicity) of fluoranthene-amended sediment to Hyalella azteca, Daphnia magna, and Chironomus tentans was determined. Fluoranthene was added to three freshwater sediments with similar organic carbon content. Predicted interstitial water concentrations from the equilibrium-partitioning model were similar to measured interstitial water concentrations for WRFS and TR sediment, but the model underpredicted measured values for LF sediment by a factor of two. EC50s for Daphnia magna, Hyalella azteca, and Chironomus tentans in interstitial water were a factor of two to five greater for LF than for WRFS and TR sediments. Factors other than organic carbon content of sediments probably contributed to the variability in bioavailability of fluoranthene. Based on 10-d sediment toxicity tests with Hylella azteca, Daphnia magna, and Chironomus tentans, organic carbon-normalized sediment concentrations were better predictors of toxicity than interstitial water and bulk sediment fluoranthene concentrations. In 10-d aqueous-phase tests with fluoranthene, Chironomus tentans and Hyalella azteca were twice as sensitive as Daphnia magna.

  12. Establishing relative sensitivities of various toxicity testing organisms to ammonia

    SciTech Connect

    Karle, L.M.; Mayhew, H.L.; Barrows, M.E.; Karls, R.K.

    1994-12-31

    The toxicity of ammonia to various organisms was examined to develop a baseline for mortality in several commonly used testing species. This baseline data will assist in choosing the proper test species and in interpreting results as they pertain to ammonia. Responses for two juvenile fish species, three marine amphipods, and two species of mysid shrimp were compared for their sensitivity to levels of ammonia. All mortality caused by ammonia in the bottom-dwelling Citharichthys stigmaeus occurred within 24 h of exposure, whereas mortality in the silverside, Menidia beryllina, occurred over the entire 96-h test duration. Responses to ammonia varied among the amphipods Rhepoxynius abronius, Ampelisca abdita, and Eohaustorius estuarius. R. abronius and A. abdita showed similar sensitivity to ammonia at lower concentrations; A. abdita appeared more sensitive than R. abronius at levels above 40 mg/L. Concentrations of ammonia required to produce significant mortality in the amphipod E. estuarius were far higher than the other species examined (> 100 mg/L NH{sub 3}). A comparison of ammonia toxicity with two commonly used invertebrates, Holmesimysis sculpts and Mysidopsis bahia, suggest that these two species of mysid have similar sensitivities to ammonia. Further studies with ammonia that examine sensitivity of different organisms should be conducted to assist regulatory and environmental agencies in determining appropriate test species and in interpreting toxicological results as they may be affected by levels of ammonia.

  13. Current and future needs for developmental toxicity testing.

    PubMed

    Makris, Susan L; Kim, James H; Ellis, Amy; Faber, Willem; Harrouk, Wafa; Lewis, Joseph M; Paule, Merle G; Seed, Jennifer; Tassinari, Melissa; Tyl, Rochelle

    2011-10-01

    A review is presented of the use of developmental toxicity testing in the United States and international regulatory assessment of human health risks associated with exposures to pharmaceuticals (human and veterinary), chemicals (agricultural, industrial, and environmental), food additives, cosmetics, and consumer products. Developmental toxicology data are used for prioritization and screening of pharmaceuticals and chemicals, for evaluating and labeling of pharmaceuticals, and for characterizing hazards and risk of exposures to industrial and environmental chemicals. The in vivo study designs utilized in hazard characterization and dose-response assessment for developmental outcomes have not changed substantially over the past 30 years and have served the process well. Now there are opportunities to incorporate new technologies and approaches to testing into the existing assessment paradigm, or to apply innovative approaches to various aspects of risk assessment. Developmental toxicology testing can be enhanced by the refinement or replacement of traditional in vivo protocols, including through the use of in vitro assays, studies conducted in alternative nonmammalian species, the application of new technologies, and the use of in silico models. Potential benefits to the current regulatory process include the ability to screen large numbers of chemicals quickly, with the commitment of fewer resources than traditional toxicology studies, and to refine the risk assessment process through an enhanced understanding of the mechanisms of developmental toxicity and their relevance to potential human risk. As the testing paradigm evolves, the ability to use developmental toxicology data to meet diverse critical regulatory needs must be retained.

  14. Testing toxic substances for protection of the environment.

    PubMed

    Draggan, S; Giddings, J M

    1978-01-01

    The Toxic Substances Control Act requires pre-production testing of chemicals for potential hazards to human and environmental health. Effective control of chemicals requires evaluations of chemical hazard that go beyond determinations of toxicity to humans to include the effects, transport, and fat of chemicals in the environemnt. Formulation of meaningful hazard evaluations depends on integrating information from tests of chemical effects, transport, and fate or by developing testing tools that integrate these factors during experimentation. Chemical effects may be acute or chronic and they may be observed individual organisms, populations or organisms, or in total ecosystems. Chemical transport through the environment depends on physico-chemical characteristics of the chemical and the medium (soil, water, or air) as well as environmental factors and biotic processes. The ultimate fate of chemicals (persistence, transformation, or degradation) is determined by numerous physical and biological processes occurring in the environment, and must be acknowledged to effectively determine the hazard. Many techniques are available for the separate and routine evaluation of the effects, transport and fate of environmental contaminants. However, separate identification of the importance and magnitude of each of these factors limits their utility in assessments of chemical hazard. The microcosm (model ecosystem) method integrates many of these tests in replicable experimental units, and may provide substantial information on chemical hazard in ecosystem context. PMID:622550

  15. Combinatorial QSAR modeling of chemical toxicants tested against Tetrahymena pyriformis.

    PubMed

    Zhu, Hao; Tropsha, Alexander; Fourches, Denis; Varnek, Alexandre; Papa, Ester; Gramatica, Paola; Oberg, Tomas; Dao, Phuong; Cherkasov, Artem; Tetko, Igor V

    2008-04-01

    Selecting most rigorous quantitative structure-activity relationship (QSAR) approaches is of great importance in the development of robust and predictive models of chemical toxicity. To address this issue in a systematic way, we have formed an international virtual collaboratory consisting of six independent groups with shared interests in computational chemical toxicology. We have compiled an aqueous toxicity data set containing 983 unique compounds tested in the same laboratory over a decade against Tetrahymena pyriformis. A modeling set including 644 compounds was selected randomly from the original set and distributed to all groups that used their own QSAR tools for model development. The remaining 339 compounds in the original set (external set I) as well as 110 additional compounds (external set II) published recently by the same laboratory (after this computational study was already in progress) were used as two independent validation sets to assess the external predictive power of individual models. In total, our virtual collaboratory has developed 15 different types of QSAR models of aquatic toxicity for the training set. The internal prediction accuracy for the modeling set ranged from 0.76 to 0.93 as measured by the leave-one-out cross-validation correlation coefficient ( Q abs2). The prediction accuracy for the external validation sets I and II ranged from 0.71 to 0.85 (linear regression coefficient R absI2) and from 0.38 to 0.83 (linear regression coefficient R absII2), respectively. The use of an applicability domain threshold implemented in most models generally improved the external prediction accuracy but at the same time led to a decrease in chemical space coverage. Finally, several consensus models were developed by averaging the predicted aquatic toxicity for every compound using all 15 models, with or without taking into account their respective applicability domains. We find that consensus models afford higher prediction accuracy for the

  16. What food and feeding rates are optimum for the Chironomus dilutus sediment toxicity test method?

    EPA Science Inventory

    Laboratory tests with benthic macroinvertebrates conducted using standard toxicity test procedures are used to assess the potential toxicity of contaminated sediments. Results are compared across sites or for batches of samples, and the performance of organisms in control treatme...

  17. Beryllium toxicity testing in the suspension culture of mouse fibroblasts.

    PubMed

    Rössner, P; Bencko, V

    1980-01-01

    Suspension culture of mouse fibroblast cell line L-A 115 was used to test beryllium toxicity in the presence of magnesium ions. Beryllium added to the MEM cultivation medium was bound in a complex with sulphosalicylic acid BeSSA complex, because the use of beryllium chloride turned out to yield ineffective beryllium phosphate that formed macroscopically detectable insoluble opacities. The BeSSA complex was used in the concentration range: 10(-3)--10(-9)M, magnesium was used in 3 concentrations: 10(-1)M, 5 x 10(-2)M and 10(-2)M. Growth curve analysis revealed pronounced beryllium toxicity at the concentration of 10(-3)M, magnesium-produced toxic changes were observed only at the concentration of 10(-1)M. No competition between the beryllium and magnesium ions was recorded. It is assumed that the possible beryllium-magnesium competition was significantly modified by the use of BeSSA complex-bound beryllium.

  18. Toxicity testing for human in vitro fertilization programs.

    PubMed

    Ackerman, S B; Stokes, G L; Swanson, R J; Taylor, S P; Fenwick, L

    1985-09-01

    Using a mouse embryo culture system, several procedures and materials associated with human in vitro fertilization protocols were tested for potential toxicity. Also, quality-control assays were performed for media prepared by nine different human in vitro fertilization programs. Detrimental effects upon embryo development were observed when culture media were exposed to the following substances: surgical instruments sterilized with Cidex or Cidex-7 or sterilized with ethylene oxide after packaging in Nest Protector Packs, various brands of surgical gloves, and various synthetic materials being evaluated as possible needle or catheter "liners." Results from comparative testing of media and serum supplements prepared by different in vitro programs indicated a wide range in culture medium quality, as assayed by the ability of the reagents to support mouse embryo development. The importance of an animal model system available to all human in vitro programs for routine quality-control analysis and testing of novel uses of materials and innovative methods is discussed.

  19. Tests for oil/dispersant toxicity: In situ laboratory assays

    SciTech Connect

    Wright, D.A.; Coelho, G.M.; Aurand, D.V.

    1995-12-31

    As part of its readiness program in oil spill response, the Marine Pollution Control Unit (MPCU), Department of Transport, U.K. conducts annual field trials in the North Sea, approximately 30 nautical miles from the southeast coast of England. The trials take the form of controlled releases of crude oil or Medium Fuel/Gas Oil mix (MFO), with and without the application of Corexit 9527 dispersant. In 1994 and 1995 the authors conducted a series of in situ toxicity bioassays in association with these spills with included 48h LC50 tests for turbot (Scophthalmus maximus) and oyster (Crassostrea gigas) larvae, a 48 h oyster (C. gigas) embryonic development test and two full life-cycle assays using the copepods Acartia tonsa and Tisbe battagliai. Tests were also conducted in the Chesapeake Bay laboratory using estuarine species including the copepod Eurytemora affinis and the inland silverside Menidia beryllina. Here, the authors report on the results of these assays, together with 1996 in situ toxicity data resulting from Norwegian field trials in the northern North Sea.

  20. Organotypic liver culture models: Meeting current challenges in toxicity testing

    PubMed Central

    LeCluyse, Edward L.; Witek, Rafal P.; Andersen, Melvin E.; Powers, Mark J.

    2012-01-01

    Prediction of chemical-induced hepatotoxicity in humans from in vitro data continues to be a significant challenge for the pharmaceutical and chemical industries. Generally, conventional in vitro hepatic model systems (i.e. 2-D static monocultures of primary or immortalized hepatocytes) are limited by their inability to maintain histotypic and phenotypic characteristics over time in culture, including stable expression of clearance and bioactivation pathways, as well as complex adaptive responses to chemical exposure. These systems are less than ideal for longer-term toxicity evaluations and elucidation of key cellular and molecular events involved in primary and secondary adaptation to chemical exposure, or for identification of important mediators of inflammation, proliferation and apoptosis. Progress in implementing a more effective strategy for in vitro-in vivo extrapolation and human risk assessment depends on significant advances in tissue culture technology and increasing their level of biological complexity. This article describes the current and ongoing need for more relevant, organotypic in vitro surrogate systems of human liver and recent efforts to recreate the multicellular architecture and hemodynamic properties of the liver using novel culture platforms. As these systems become more widely used for chemical and drug toxicity testing, there will be a corresponding need to establish standardized testing conditions, endpoint analyses and acceptance criteria. In the future, a balanced approach between sample throughput and biological relevance should provide better in vitro tools that are complementary with animal testing and assist in conducting more predictive human risk assessment. PMID:22582993

  1. Discovering less toxic ionic liquids by using the Microtox® toxicity test.

    PubMed

    Hernández-Fernández, F J; Bayo, J; Pérez de los Ríos, A; Vicente, M A; Bernal, F J; Quesada-Medina, J

    2015-06-01

    New Microtox® toxicity data of 16 ionic liquids of different cationic and anionic composition were determined. The ionic liquids 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate, [BMPyr(+)][TFO(-)], 1-butyl-1-methylpyrrolidinium chloride, [BMPyr(+)][Cl(-)], hydroxypropylmethylimidazolium fluoroacetate, [HOPMIM(+)][FCH2COO(-)], and hydroxypropylmethylimidazolium glycolate [HOPMIM(+)][glycolate(-)] were found to be less toxic than conventional organic solvent such as chloroform or toluene, accoding the Microtox® toxicity assays. The toxicity of pyrrolidinium cation was lower than the imidazolium and pyridinium ones. It was found that the inclusion of an hydroxyl group in the alkyl chain length of the cation also reduce the toxicity of the ionic liquid. To sum up, the Microtox® toxicity assays can be used as screening tool to easily determined the toxicity of a wide range of ionic liquids and the toxicity data obtained could allow the obtention of structure-toxicity relationships to design less toxic ionic liquids.

  2. Algal culture studies for CELSS

    NASA Technical Reports Server (NTRS)

    Radmer, R.; Behrens, P.; Arnett, K.; Gladue, R.; Cox, J.; Lieberman, D.

    1987-01-01

    Microalgae are well-suited as a component of a Closed Environmental Life Support System (CELSS), since they can couple the closely related functions of food production and atmospheric regeneration. The objective was to provide a basis for predicting the response of CELSS algal cultures, and thus the food supply and air regeneration system, to changes in the culture parameters. Scenedesmus growth was measured as a function of light intensity, and the spectral dependence of light absorption by the algae as well as algal respiration in the light were determined as a function of cell concentration. These results were used to test and confirm a mathematical model that describes the productivity of an algal culture in terms of the competing processes of photosynthesis and respiration. The relationship of algal productivity to cell concentration was determined at different carbon dioxide concentrations, temperatures, and light intensities. The maximum productivity achieved by an air-grown culture was found to be within 10% of the computed maximum productivity, indicating that CO2 was very efficiently removed from the gas stream by the algal culture. Measurements of biomass productivity as a function of cell concentration at different light intensities indicated that both the productivity and efficiency of light utilization were greater at higher light intensities.

  3. A SURROGATE SUBCHRONIC TOXICITY TEST METHOD FOR WATERS WITH HIGH TOTAL DISSOLVED SOLIDS

    EPA Science Inventory

    Total dissolved solids (TDS) are often identified as a toxicant in whole-effluent toxicity (WET) testing. The primary test organism used in WET testing, Ceriodaphnia dubia, is very sensitive to TDS ions, which can be problematic when differentiating the toxicity of TDS from those...

  4. Non-animal methodologies within biomedical research and toxicity testing.

    PubMed

    Knight, Andrew

    2008-01-01

    Laboratory animal models are limited by scientific constraints on human applicability, and increasing regulatory restrictions, driven by social concerns. Reliance on laboratory animals also incurs marked - and in some cases, prohibitive - logistical challenges, within high-throughput chemical testing programmes, such as those currently underway within Europe and the US. However, a range of non-animal methodologies is available within biomedical research and toxicity testing. These include: mechanisms to enhance the sharing and assessment of existing data prior to conducting further studies, and physicochemical evaluation and computerised modelling, including the use of structure-activity relationships and expert systems. Minimally-sentient animals from lower phylogenetic orders or early developmental vertebral stages may be used, as well as microorganisms and higher plants. A variety of tissue cultures, including immortalised cell lines, embryonic and adult stem cells, and organotypic cultures, are also available. In vitro assays utilising bacterial, yeast, protozoal, mammalian or human cell cultures exist for a wide range of toxic and other endpoints. These may be static or perfused, and may be used individually, or combined within test batteries. Human hepatocyte cultures and metabolic activation systems offer potential assessment of metabolite activity and organ-organ interaction. Microarray technology may allow genetic expression profiling, increasing the speed of toxin detection, well prior to more invasive endpoints. Enhanced human clinical trials utilising micro- dosing, staggered dosing, and more representative study populations and durations, as well as surrogate human tissues, advanced imaging modalities and human epidemiological, sociological and psycho- logical studies, may increase our understanding of illness aetiology and pathogenesis, and facilitate the development of safe and effective pharmacologic interventions. Particularly when human tissues

  5. Toxicity testing, risk assessment, and options for dredged material management.

    PubMed

    Munns, Wayne R; Berry, Walter J; Dewitt, Theodore H

    2002-04-01

    Programs for evaluating proposed discharges of dredged material into waters of the United States specify a tiered testing and evaluation protocol that includes performance of acute and chronic bioassays to assess toxicity of the dredged sediments. Although these evaluations reflect the toxicological risks associated with disposal activities to some degree, analysis activities are limited to the sediments of each dredging project separately. Cumulative risks to water column and benthic organisms at and near the designated disposal site are therefore difficult to assess. An alternate approach is to focus attention on the disposal site, with the goal of understanding more directly the risks of multiple disposal events to receiving ecosystems. Here we review current US toxicity testing and evaluation protocols, and describe an application of ecological risk assessment that allows consideration of the temporal and spatial components of risk to receiving aquatic ecosystems. When expanded to include other disposal options, this approach can provide the basis for holistic management of dredged material disposal. PMID:12139319

  6. Validation and sensitivity comparisons of micro-scale toxicity tests for the evaluation of freshwater sediment toxicity

    SciTech Connect

    Riebel, P.; Bureau, J.; Blaise, C.; Michaud, J.R.

    1995-12-31

    A three-year study is currently underway to develop a representative and cost-effective battery of toxicity tests for evaluating freshwater sediment and porewater toxicity. Among the tests currently being evaluated are the following: Microtox{trademark} chronic test, Microtox{trademark} solid-phase test, Microtox{trademark} liquid phase test, Thamnotoxkit F{trademark}, Rotoxkit F{trademark}, Daphnia magna IQ test{trademark}, Sediment Toxkit, SOS Chromotest, a Selenastrum capricornutum short exposure assay, and trout hepatocyte assays. Conventional sediment tests with Chironomus tentans, Hyalella azteca and Lumbriculus variegatus, as well as benthic macroinvertebrate community assessments and sediment chemical characterizations are being conducted at two contaminated sites. Toxicity test reproducibility, sensitivity, practicality, cost and ecological relevance are discussed.

  7. Prediction of joint algal toxicity of nano-CeO2/nano-TiO2 and florfenicol: Independent action surpasses concentration addition.

    PubMed

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

    2016-08-01

    Co-exposure of aquatic organisms to engineered nanoparticles (ENPs) and antibiotics is likely to take place in the environment. However, the impacts of co-exposure on aquatic organisms are virtually unknown and understanding the joint toxicity of ENPs and antibiotics is a topic of importance. The independent action (IA) model and the concentration addition (CA) model are two of the most common approaches to mixture toxicity assessment. In this study, the joint toxicity of two ENPs (nCeO2 and nTiO2) and one antibiotic (florfenicol, FLO) to Chlorella pyrenoidosa was determined to compare the applicability of the IA and the CA model. Concentration-response analyses were performed for single toxicants and for binary mixtures containing FLO and one of the ENPs at two suspended particle concentrations. The effect concentrations and the observed effects of the binary mixtures were compared to the predictions of the joint toxicity. The observed toxicity associated with the nCeO2 or nTiO2 exposure was enhanced by the concomitant FLO exposure. The joint toxicity of nCeO2 and FLO was significantly higher than that of nTiO2 and FLO. Predictions based on the IA and CA models tend to underestimate the overall toxicity (in terms of median effect concentration) of the binary mixtures, but IA performs better than CA, irrespective of the effect level under consideration and the types of mixtures studied. This result underpins the need to consider the effects of mixtures of ENPs and organic chemicals on aquatic organisms, and the practicability of the IA and CA methods in toxicity assessment of ENPs.

  8. Zooplankton interactions with toxic phytoplankton: Some implications for food web studies and algal defence strategies of feeding selectivity behaviour, toxin dilution and phytoplankton population diversity

    NASA Astrophysics Data System (ADS)

    Barreiro, A.; Guisande, C.; Maneiro, I.; Vergara, A. R.; Riveiro, I.; Iglesias, P.

    2007-11-01

    This study focuses on the interactions between toxic phytoplankton and zooplankton grazers. The experimental conditions used are an attempt to simulate situations that have, so far, received little attention. We presume the phytoplankton community to be a set of species where a population of a toxic species is intrinsically diverse by the presence of coexisting strains with different toxic properties. The other species in the community may not always be high-quality food for herbivorous zooplankton. Zooplankton populations may have developed adaptive responses to sympatric toxic phytoplankton species. Zooplankton grazers may perform a specific feeding behaviour and its consequences on fitness will depend on the species ingested, the effect of toxins, and the presence of mechanisms of toxin dilution and compensatory feeding. Our target species are a strain of the dinoflagellate Alexandrium minutum and a sympatric population of the copepod Acartia clausi. Mixed diets were used with two kinds of A. minutum cells: non-toxic and toxic. The flagellate Rhodomonas baltica and the non-toxic dinoflagellate Alexandrium tamarense were added as accompanying species. The effect of each alga was studied in separate diets. The toxic A. minutum cells were shown to have negative effects on egg production, hatching success and total reproductive output, while, in terms of its effect on fitness, the non-toxic A. minutum was the best quality food offered. R. baltica and A. tamarense were in intermediate positions. In the mixed diets, copepods showed a strong preference for toxic A. minutum cells and a weaker one for A. tamarense cells, while non-toxic A. minutum was slightly negatively selected and R. baltica strongly negatively selected. Although the level of toxins accumulated by copepods was very similar, in both the diet with only toxic A. minutum cells and in the mixed diet, the negative effects on fitness in the mixed diet could be offset by toxin dilution mechanisms. The

  9. Fractionating nanosilver: importance for determining toxicity to aquatic test organisms.

    PubMed

    Kennedy, Alan J; Hull, Matthew S; Bednar, Anthony J; Goss, Jennifer D; Gunter, Jonas C; Bouldin, Jennifer L; Vikesland, Peter J; Steevens, Jeffery A

    2010-12-15

    This investigation applied novel techniques for characterizing and fractionating nanosilver particles and aggregates and relating these measurements to toxicological endpoints. The acute toxicity of eight nanosilver suspensions of varying primary particle sizes (10-80 nm) and coatings (citrate, polyvinylpyrrolidone, EDTA, proprietary) was assessed using three aquatic test organisms (Daphnia magna, Pimephales promelas, Pseudokirchneriella subcapitata). When 48-h lethal median concentrations (LC50) were expressed as total silver, both D. magna and P. promelas were significantly more sensitive to ionic silver (Ag(+)) as AgNO(3) (mean LC50 = 1.2 and 6.3 μg/L, respectively) relative to a wide range in LC50 values determined for the nanosilver suspensions (2 -126 μg/L). However, when LC50 values for nanosilver suspensions were expressed as fractionated nanosilver (Ag(+) and/or <4 nm particles), determined by ultracentrifugation of particles and confirmed field-flow-fractograms, the LC50 values (0.3-5.6 μg/L) were comparable to the values obtained for ionic Ag(+) as AgNO(3). These results suggest that dissolved Ag(+) plays a critical role in acute toxicity and underscores the importance of characterizing dissolved fractions in nanometal suspensions.

  10. Thymoquinone therapy abrogates toxic effect of cadmium on rat testes.

    PubMed

    Fouad, A A; Jresat, I

    2015-05-01

    The protective effect of thymoquinone was investigated against cadmium-induced testicular toxicity in rats. Testicular toxicity was induced by a single intraperitoneal (i.p.) injection of cadmium chloride (2 mg kg(-1) ). Thymoquinone treatment (10 mg kg(-1)  day(-1) , i.p.) was applied for five consecutive days, starting 3 days before cadmium administration. Thymoquinone significantly attenuated the cadmium-induced decreases in serum testosterone, and testicular reduced glutathione and superoxide dismutase activity and significantly decreased the elevations of testicular malondialdehyde, nitric oxide and cadmium ion levels resulted from cadmium chloride administration. Also, thymoquinone ameliorated the cadmium-induced testicular tissue injury observed by histopathological examination. In addition, thymoquinone significantly decreased the cadmium-induced expression of inducible nitric oxide synthase, tumour necrosis factor-α, cyclooxygenase-2, nuclear factor-κB and caspase-3 in testicular tissue. It was concluded that thymoquinone, through its antioxidant and anti-inflammatory activities, may represent a potential candidate to protect the testes against the detrimental effect of cadmium exposure. PMID:24735446

  11. Formulated sediment for use in whole-sediment toxicity testing

    SciTech Connect

    Kemble, N.E.; Dwyer, F.J.; Hardesty, D.K.; Ingersoll, C.G.

    1995-12-31

    A formulated control sediment was developed to provide consistent and acceptable biological endpoints for a variety of species used in whole sediment toxicity testing. In an attempt to develop such a sediment the authors conducted multiple tests to evaluate: (1) {alpha}-cellulose as an organic carbon source, (2) various TOC concentrations, (3) various grain sizes, (4) different food types, and (5) overlying waters. Studies were conducted with the amphipod Hyalella azteca the midges Chironomus riparius, Chironomus tentans and the oligochaete Lumbriculus variegatus in 10 d exposures and H. azteca in 28 d exposures. Sediment from West Bearskin Lake Minnesota was used as a control sediment with each species in each test. Survival of test organisms in all of the 10-d experiments, with the exception of C. riparius, was above the acceptable levels for a control sediment. Survival in the formulated sediments also was not significantly different when compared to the control sediment. Amphipod survival in the 28-d exposures was low; however, the use of reconstituted water in combination with the formulated sediment may have been a problem. The authors are currently evaluating various types of overlying water with formulated sediments and sublethal endpoints in each of the exposures (i.e., growth, sexual maturation or head capsule width).

  12. Tigriopus fulvus: The interlaboratory comparison of the acute toxicity test.

    PubMed

    Faraponova, Olga; Giacco, Elisabetta; Biandolino, Francesca; Prato, Ermelinda; Del Prete, Francesco; Valenti, Alessandra; Sarcina, Stefania; Pasteris, Andrea; Montecavalli, Adele; Comin, Stefano; Cesca, Claudia; Francese, Marco; Cigar, Monica; Piazza, Veronica; Falleni, Fabrizio; Lacchetti, Ines

    2016-02-01

    The paper reports the results of an interlaboratory comparison involving 11 laboratories, with the objectives of apply and validate a new standardized ecotoxicological method on marine crustacean Tigriopus fulvus. Copper was chosen as reference toxicant as indicated in the official method. The results of two independent tests performed by all the participants, demonstrated that the new method is simple, fast and easy to learn. This is confirmed even by the values of z-score index calculated for each laboratory and the relative coefficient of variation (CV) which are 6.32% after 24h, 6.56 after 48h and 35.3% after 96h, mentioned in the ISO standards for the precision of interlaboratory assays. Therefore its use could be recommended in environmental studies and monitoring. PMID:26584461

  13. An interlaboratory comparison of sediment elutriate preparation and toxicity test methods

    EPA Science Inventory

    Elutriate bioassays are among numerous methods that exist for assessing the potential toxicity of sediments in aquatic systems. In this study, interlaboratory results were compared from 96-hour Ceriodaphnia dubia and Pimephales promelas static-renewal acute toxicity tests conduct...

  14. AN ENVIRONMENTAL TECHNOLOGY VERIFICATION (ETV) TESTING OF SEVEN TECHNOLOGIES DETECTING TOXICITY IN DRINKING WATER (R2)

    EPA Science Inventory

    Rapid toxicity technologies can detect certain toxins and with testing it can be determined their susceptibility to interfering chemical in controlled experimental matrix. Rapid toxicity technologies do not identify or determine the concentrations of specific contaminants, but s...

  15. Towards sensible toxicity testing for nanomaterials: proposal for the specification of test design

    NASA Astrophysics Data System (ADS)

    Potthoff, Annegret; Weil, Mirco; Meißner, Tobias; Kühnel, Dana

    2015-12-01

    During the last decade, nanomaterials (NM) were extensively tested for potential harmful effects towards humans and environmental organisms. However, a sound hazard assessment was so far hampered by uncertainties and a low comparability of test results. The reason for the low comparability is a high variation in the (1) type of NM tested with regard to raw material, size and shape and (2) procedures before and during the toxicity testing. This calls for tailored, nanomaterial-specific protocols. Here, a structured approach is proposed, intended to lead to test protocols not only tailored to specific types of nanomaterials, but also to respective test system for toxicity testing. There are existing standards on single procedures involving nanomaterials, however, not all relevant procedures are covered by standards. Hence, our approach offers a detailed way of weighting several plausible alternatives for e.g. sample preparation, in order to decide on the procedure most meaningful for a specific nanomaterial and toxicity test. A framework of several decision trees (DT) and flow charts to support testing of NM is proposed as a basis for further refinement and in-depth elaboration. DT and flow charts were drafted for (1) general procedure—physicochemical characterisation, (2) choice of test media, (3) decision on test scenario and application of NM to liquid media, (4) application of NM to the gas phase, (5) application of NM to soil and sediments, (6) dose metrics, (S1) definition of a nanomaterial, and (S2) dissolution. The applicability of the proposed approach was surveyed by using experimental data retrieved from studies on nanoscale CuO. This survey demonstrated the DT and flow charts to be a convenient tool to systematically decide upon test procedures and processes, and hence pose an important step towards harmonisation of NM testing.

  16. Aquatic toxicity testing for multicomponent compounds with special reference to preparation of test solution

    SciTech Connect

    Tadokoro, H.; Maeda, M.; Kawashima, Y.; Kitano, M.; Hwang, D.F.; Yoshida, T. )

    1991-02-01

    An adequate method of determining the toxicity of a compound consisting of multiple components, such as creosote, coal tar, and coal tar pitch, was studied for different test solution preparation methods, i.e., direct dosing without filtration, diluting the stock solution of saturated concentration, and dispersing with acetone. Killifish, Oryzias latipes, as a freshwater fish; red sea bream, Pagrus major, as a saltwater fish; and daphnia, Daphnia magna, as a representative crustacean, were used for testing. The chemical analysis of each preparation of test solution with gas chromatography revealed an entirely different profile of the components. The highest toxicity was obtained with preparation by acetone dispersion. That was followed by the preparations with direct dosing method and with the method of dilution of saturated concentration stock solution. Considering the results obtained, the direct dosing method with a suitable settling time may provide useful information enabling extrapolation of the test results to the natural environment for complex multicomponent compounds.

  17. Custom-designed nanomaterial libraries for testing metal oxide toxicity.

    PubMed

    Pokhrel, Suman; Nel, André E; Mädler, Lutz

    2013-03-19

    Advances in aerosol technology over the past 10 years have enabled the generation and design of ultrafine nanoscale materials for many applications. A key new method is flame spray pyrolysis (FSP), which produces particles by pyrolyzing a precursor solution in the gas phase. FSP is a highly versatile technique for fast, single-step, scalable synthesis of nanoscale materials. New innovations in particle synthesis using FSP technology, including variations in precursor chemistry, have enabled flexible, dry synthesis of loosely agglomerated, highly crystalline ultrafine powders (porosity ≥ 90%) of binary, ternary, and mixed-binary-and-ternary oxides. FSP can fulfill much of the increasing demand, especially in biological applications, for particles with specific material composition, high purity, and high crystallinity. In this Account, we describe a strategy for creating nanoparticle libraries (pure or Fedoped ZnO or TiO₂) utilizing FSP and using these libraries to test hypotheses related to the particles' toxicity. Our innovation lies in the overall integration of the knowledge we have developed in the last 5 years in (1) synthesizing nanomaterials to address specific hypotheses, (2) demonstrating the electronic properties that cause the material toxicity, (3) understanding the reaction mechanisms causing the toxicity, and (4) extracting from in vitro testing and in vivo testing in terrestrial and marine organisms the essential properties of safe nanomaterials. On the basis of this acquired knowledge, we further describe how the dissolved metal ion from these materials (Zn²⁺ in this Account) can effectively bind with different cell constituents, causing toxicity. We use Fe-S protein clusters as an example of the complex chemical reactions taking place after free metal ions migrate into the cells. As a second example, TiO₂ is an active material in the UV range that exhibits photocatalytic behavior. The induction of electron-hole (e⁻/h⁺) pairs followed by

  18. Developmental toxicity, acute toxicity and mutagenicity testing in freshwater snails Biomphalaria glabrata (Mollusca: Gastropoda) exposed to chromium and water samples.

    PubMed

    Tallarico, Lenita de Freitas; Borrely, Sueli Ivone; Hamada, Natália; Grazeffe, Vanessa Siqueira; Ohlweiler, Fernanda Pires; Okazaki, Kayo; Granatelli, Amanda Tosatte; Pereira, Ivana Wuo; Pereira, Carlos Alberto de Bragança; Nakano, Eliana

    2014-12-01

    A protocol combining acute toxicity, developmental toxicity and mutagenicity analysis in freshwater snail Biomphalaria glabrata for application in ecotoxicological studies is described. For acute toxicity testing, LC50 and EC50 values were determined; dominant lethal mutations induction was the endpoint for mutagenicity analysis. Reference toxicant potassium dichromate (K2Cr2O7) was used to characterize B. glabrata sensitivity for toxicity and cyclophosphamide to mutagenicity testing purposes. Compared to other relevant freshwater species, B. glabrata showed high sensitivity: the lowest EC50 value was obtained with embryos at veliger stage (5.76mg/L). To assess the model applicability for environmental studies, influent and effluent water samples from a wastewater treatment plant were evaluated. Gastropod sensitivity was assessed in comparison to the standardized bioassay with Daphnia similis exposed to the same water samples. Sampling sites identified as toxic to daphnids were also detected by snails, showing a qualitatively similar sensitivity suggesting that B. glabrata is a suitable test species for freshwater monitoring. Holding procedures and protocols implemented for toxicity and developmental bioassays showed to be in compliance with international standards for intra-laboratory precision. Thereby, we are proposing this system for application in ecotoxicological studies.

  19. Genetically Defined Strains in Drug Development and Toxicity Testing.

    PubMed

    Festing, Michael F W

    2016-01-01

    There is growing concern about the poor quality and lack of repeatability of many pre-clinical experiments involving laboratory animals. According to one estimate as much as $28 billion is wasted annually in the USA alone in such studies. A decade ago the FDA's "Critical path" white paper noted that "The traditional tools used to assess product safety-animal toxicology and outcomes from human studies-have changed little over many decades and have largely not benefited from recent gains in scientific knowledge. The inability to better assess and predict product safety leads to failures during clinical development and, occasionally, after marketing." Repeat-dose 28-days and 90-days toxicity tests in rodents have been widely used as part of a strategy to assess the safety of drugs and chemicals but their repeatability and power to detect adverse effects have not been formally evaluated.The guidelines (OECD TG 407 and 408) for these tests specify the dose levels and number of animals per dose but do not specify the strain of animals which should be used. In practice, almost all the tests are done using genetically undefined "albino" rats or mice in which the genetic variation, a major cause of inter-individual and strain variability, is unknown and uncontrolled. This chapter suggests that a better strategy would be to use small numbers of animals of several genetically defined strains of mice or rats instead of the undefined animals used at present. Inbred strains are more stable providing more repeatable data than outbred stocks. Importantly their greater phenotypic uniformity should lead to more powerful and repeatable tests. Any observed strain differences would indicate genetic variation in response to the test substance, providing key data. We suggest that the FDA and other regulators and funding organizations should support research to evaluate this alternative. PMID:27150081

  20. Toxicity testing: the search for an in vitro alternative to animal testing.

    PubMed

    May, J E; Xu, J; Morse, H R; Avent, N D; Donaldson, C

    2009-01-01

    Prior to introduction to the clinic, pharmaceuticals must undergo rigorous toxicity testing to ensure their safety. Traditionally, this has been achieved using in vivo animal models. However, besides ethical reasons, there is a continual drive to reduce the number of animals used for this purpose due to concerns such as the lack of concordance seen between animal models and toxic effects in humans. Adequate testing to ensure any toxic metabolites are detected can be further complicated if the agent is administered in a prodrug form, requiring a source of cytochrome P450 enzymes for metabolism. A number of sources of metabolic enzymes have been utilised in in vitro models, including cell lines, primary human tissue and liver extracts such as S9. This review examines current and new in vitro models for toxicity testing, including a new model developed within the authors' laboratory utilising HepG2 liver spheroids within a co-culture system to examine the effects of chemotherapeutic agents on other cell types.

  1. Reproducibility of a life-cycle toxicity test with Daphnia magna

    SciTech Connect

    Parkhurst, B.R.; Forte, J.L.; Wright, G.P.

    1981-01-01

    Standardized chronic life-cycle toxicity testing procedures for aquatic species are described. The reproducibility of chronic toxicity and points using the static-renewal method with Daphnia magna are investigated. The objectives were to determine if the lowest rejected concentrations tested (LRCTs) obtained for six different toxicity criteria in static-renewal tests with acridine were reproducible over time and to determine the relative sensitivity and variability of the toxicity criteria. Two of the six toxicity criteria, numbers of young per brood and the young produced per female, were found to be reliable and sensitive for estimating the LRCT for acridine to D. magna. (RJC)

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

    PubMed

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

    2011-05-01

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

  3. Integrated testing strategies for toxicity employing new and existing technologies.

    PubMed

    Combes, Robert D; Balls, Michael

    2011-07-01

    We have developed individual, integrated testing strategies (ITS) for predicting the toxicity of general chemicals, cosmetics, pharmaceuticals, inhaled chemicals, and nanoparticles. These ITS are based on published schemes developed previously for the risk assessment of chemicals to fulfil the requirements of REACH, which have been updated to take account of the latest developments in advanced in chemico modelling and in vitro technologies. In addition, we propose an ITS for neurotoxicity, based on the same principles, for incorporation in the other ITS. The technologies are deployed in a step-wise manner, as a basis for decision-tree approaches, incorporating weight-of-evidence stages. This means that testing can be stopped at the point where a risk assessment and/or classification can be performed, with labelling in accordance with the requirements of the regulatory authority concerned, rather than following a checklist approach to hazard identification. In addition, the strategies are intelligent, in that they are based on the fundamental premise that there is no hazard in the absence of exposure - which is why pharmacokinetic modelling plays a key role in each ITS. The new technologies include the use of complex, three-dimensional human cell tissue culture systems with in vivo-like structural, physiological and biochemical features, as well as dosing conditions. In this way, problems of inter-species extrapolation and in vitro/in vivo extrapolation are minimised. This is reflected in the ITS placing more emphasis on the use of volunteers at the whole organism testing stage, rather than on existing animal testing, which is the current situation.

  4. 40 CFR Appendix Ix to Part 268 - Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B)

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 28 2012-07-01 2012-07-01 false Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B) IX Appendix IX to Part 268 Protection of.... 268, App. IX Appendix IX to Part 268—Extraction Procedure (EP) Toxicity Test Method and...

  5. 40 CFR Appendix Ix to Part 268 - Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B)

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 27 2014-07-01 2014-07-01 false Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B) IX Appendix IX to Part 268 Protection of.... 268, App. IX Appendix IX to Part 268—Extraction Procedure (EP) Toxicity Test Method and...

  6. 40 CFR Appendix Ix to Part 268 - Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B)

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 27 2011-07-01 2011-07-01 false Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B) IX Appendix IX to Part 268 Protection of.... 268, App. IX Appendix IX to Part 268—Extraction Procedure (EP) Toxicity Test Method and...

  7. 40 CFR Appendix Ix to Part 268 - Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B)

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B) IX Appendix IX to Part 268 Protection of.... 268, App. IX Appendix IX to Part 268—Extraction Procedure (EP) Toxicity Test Method and...

  8. Results of acute and chronic toxicity tests conducted at SRS NPDES outfalls, July--October 1991

    SciTech Connect

    Specht, W.L.

    1992-01-01

    Acute (48 hour LC50) and chronic (7-day reproductive impairment) toxicity tests were conducted on Ceriodaphnia dubia in water collected from 53 NPDES outfalls. All tests were conducted at the in-stream waste concentration. only 12 of the 53 outfalls showed no evidence of toxicity. Twenty-eight of the outfalls were acutely toxic, often producing 100% mortality during the first day of exposure. Fourteen outfalls had no discharge at the time of sampling and could not be tested. Three outfalls were not tested because their toxicity has been adequately characterized in other investigations. Elevated concentrations of total residual chlorine are suspected to be responsible for the observed toxicity of many NPDES outfalls, particularly the sanitary wastewater treatment plants. Chemical data from previous studies indicate that metals may also be present in toxic concentrations at many outfalls. Toxicity identification and reduction options are discussed.

  9. Algal Toxins Alter Copepod Feeding Behavior

    PubMed Central

    Hong, Jiarong; Talapatra, Siddharth; Katz, Joseph; Tester, Patricia A.; Waggett, Rebecca J.; Place, Allen R.

    2012-01-01

    Using digital holographic cinematography, we quantify and compare the feeding behavior of free-swimming copepods, Acartia tonsa, on nutritional prey (Storeatula major) to that occurring during exposure to toxic and non-toxic strains of Karenia brevis and Karlodinium veneficum. These two harmful algal species produce polyketide toxins with different modes of action and potency. We distinguish between two different beating modes of the copepod’s feeding appendages–a “sampling beating” that has short durations (<100 ms) and involves little fluid entrainment and a longer duration “grazing beating” that persists up to 1200 ms and generates feeding currents. The durations of both beating modes have log-normal distributions. Without prey, A. tonsa only samples the environment at low frequency. Upon introduction of non-toxic food, it increases its sampling time moderately and the grazing period substantially. On mono algal diets for either of the toxic dinoflagellates, sampling time fraction is high but the grazing is very limited. A. tonsa demonstrates aversion to both toxic algal species. In mixtures of S. major and the neurotoxin producing K. brevis, sampling and grazing diminish rapidly, presumably due to neurological effects of consuming brevetoxins while trying to feed on S. major. In contrast, on mixtures of cytotoxin producing K. veneficum, both behavioral modes persist, indicating that intake of karlotoxins does not immediately inhibit the copepod’s grazing behavior. These findings add critical insight into how these algal toxins may influence the copepod’s feeding behavior, and suggest how some harmful algal species may alter top-down control exerted by grazers like copepods. PMID:22629336

  10. Algal toxins alter copepod feeding behavior.

    PubMed

    Hong, Jiarong; Talapatra, Siddharth; Katz, Joseph; Tester, Patricia A; Waggett, Rebecca J; Place, Allen R

    2012-01-01

    Using digital holographic cinematography, we quantify and compare the feeding behavior of free-swimming copepods, Acartia tonsa, on nutritional prey (Storeatula major) to that occurring during exposure to toxic and non-toxic strains of Karenia brevis and Karlodinium veneficum. These two harmful algal species produce polyketide toxins with different modes of action and potency. We distinguish between two different beating modes of the copepod's feeding appendages-a "sampling beating" that has short durations (<100 ms) and involves little fluid entrainment and a longer duration "grazing beating" that persists up to 1200 ms and generates feeding currents. The durations of both beating modes have log-normal distributions. Without prey, A. tonsa only samples the environment at low frequency. Upon introduction of non-toxic food, it increases its sampling time moderately and the grazing period substantially. On mono algal diets for either of the toxic dinoflagellates, sampling time fraction is high but the grazing is very limited. A. tonsa demonstrates aversion to both toxic algal species. In mixtures of S. major and the neurotoxin producing K. brevis, sampling and grazing diminish rapidly, presumably due to neurological effects of consuming brevetoxins while trying to feed on S. major. In contrast, on mixtures of cytotoxin producing K. veneficum, both behavioral modes persist, indicating that intake of karlotoxins does not immediately inhibit the copepod's grazing behavior. These findings add critical insight into how these algal toxins may influence the copepod's feeding behavior, and suggest how some harmful algal species may alter top-down control exerted by grazers like copepods. PMID:22629336

  11. Early Evolution of the Toxicity Identification Evaluation Process: Contributions from the USEPA Effluent Testing Program

    EPA Science Inventory

    As part of its whole effluent testing program, the USEPA developed an effects-directed analysis (EDA) approach to identifying the cause of toxicity in toxic effluents or ambient waters, an EDA process termed a “Toxicity Identification Evaluation” (TIE), which is the focus of this...

  12. Fish embryo toxicity test: identification of compounds with weak toxicity and analysis of behavioral effects to improve prediction of acute toxicity for neurotoxic compounds.

    PubMed

    Klüver, Nils; König, Maria; Ortmann, Julia; Massei, Riccardo; Paschke, Albrecht; Kühne, Ralph; Scholz, Stefan

    2015-06-01

    The fish embryo toxicity test has been proposed as an alternative for the acute fish toxicity test, but concerns have been raised for its predictivity given that a few compounds have been shown to exhibit a weak acute toxicity in the fish embryo. In order to better define the applicability domain and improve the predictive capacity of the fish embryo test, we performed a systematic analysis of existing fish embryo and acute fish toxicity data. A correlation analysis of a total of 153 compounds identified 28 compounds with a weaker or no toxicity in the fish embryo test. Eleven of these compounds exhibited a neurotoxic mode of action. We selected a subset of eight compounds with weaker or no embryo toxicity (cyanazine, picloram, aldicarb, azinphos-methyl, dieldrin, diquat dibromide, endosulfan, and esfenvalerate) to study toxicokinetics and a neurotoxic mode of action as potential reasons for the deviating fish embryo toxicity. Published fish embryo LC50 values were confirmed by experimental analysis of zebrafish embryo LC50 according to OECD guideline 236. Except for diquat dibromide, internal concentration analysis did not indicate a potential relation of the low sensitivity of fish embryos to a limited uptake of the compounds. Analysis of locomotor activity of diquat dibromide and the neurotoxic compounds in 98 hpf embryos (exposed for 96 h) indicated a specific effect on behavior (embryonic movement) for the neurotoxic compounds. The EC50s of behavior for neurotoxic compounds were close to the acute fish toxicity LC50. Our data provided the first evidence that the applicability domain of the fish embryo test (LC50s determination) may exclude neurotoxic compounds. However, neurotoxic compounds could be identified by changes in embryonic locomotion. Although a quantitative prediction of acute fish toxicity LC50 using behavioral assays in fish embryos may not yet be possible, the identification of neurotoxicity could trigger the conduction of a conventional fish

  13. Toxicity testing moves from the legislature to the petri dish-and back.

    PubMed

    Gura, Trisha

    2008-08-22

    With the growing cost of using animals to test the safety of new chemicals and an increasing backlog of chemicals awaiting testing, the quest for cell-based in vitro alternatives for toxicity testing is gaining momentum. PMID:18724925

  14. Rapid toxicity testing based on mitochondrial respiratory activity

    SciTech Connect

    Haubenstricker, M.E. ); Holodnick, S.E.; Mancy, K.H. ); Brabec, M.J. )

    1990-05-01

    The need exists for rapid and inexpensive methods to determine the health effects of environmental contaminants on biological systems. One of the current research approaches for assessing cytotoxicity is to monitor the respiratory activity of the mitochondrion, a sensitive, nonspecific subcellular target site. Detected changes in mitochondrial function after the addition of a test chemical could be correlated to toxic effects. Mitochondrial respiration can be characterized by three indices: state 3 and state 4 respiratory rates, and the respiratory control ratio (RCR). State 4, the idle or resting state, results when coupled mitochondrial respire in a medium containing inorganic phosphate and a Kreb's cycle substrate in the absence of a phosphate acceptor such as adenosine diphosphate (ADP). In the presence of ADP the respiration rate increases to a maximum (state 3), accompanied by phosphorylation of ADP to adenosine triphosphate (ATP). The ratio of state 3 to state 4, or RCR, indicates how tightly the oxidative phosphorylation process is coupled. The synthesis of ATP by mitochondria is influenced by a number of compounds, most of which are either uncouplers or inhibitors.

  15. Aquatic toxicity of leachates generated from electronic devices.

    PubMed

    Dagan, Roi; Dubey, Brajesh; Bitton, Gabriel; Townsend, Timothy

    2007-08-01

    Heavy metal leaching of electronic waste has been documented in recent literature. Heavy metal aquatic toxicity in the toxicity characteristic (TC) leachates produced from 56 electronic devices were tested using the aquatic toxicity assays such as Ceriodaphnia dubia 48-hr acute toxicity assay, the Selenatastrum capricornutum chronic algal growth inhibition assay (test used only for circuit-board leachates), and the MetPLATE acute heavy metal toxicity tests. The electronic devices tested, include 9 circuit boards (printed wire boards), 2 videocassette recorders, 4 remote controls, 1 cathode ray tube, 15 cellular phones, 1 calculator, 5 smoke detectors and their PC board components, 3 printers, 4 laptop computers, and 7 personal computer central processing units (CPUs). The toxicity tests showed toxicity in 51 of the 56 Toxicity Characteristic Leaching Procedure leachates of electronic devices assayed.

  16. Impacts of low-molecular-weight organic acids on aquatic behavior of graphene nanoplatelets and their induced algal toxicity and antioxidant capacity.

    PubMed

    Wang, Zhuang; Gao, Yucheng; Wang, Se; Fang, Hao; Xu, Defu; Zhang, Fan

    2016-06-01

    Knowledge of the interaction between graphene-based materials and low-molecular-weight organic acids (LOAs) is essential to understand fate and effects of graphene-based materials in the aquatic environment, but this interaction remains poorly elucidated. In this study, the effects of LOAs on the physicochemical properties of graphene nanoplatelets (GNPs) in an aqueous medium and on the GNP toxicity to algae were studied. The unicellular green alga Scenedesmus obliquus was exposed to GNP suspensions in the presence of benzoic acid or gallic acid at various concentrations. The GNPs had smaller hydrodynamic sizes and the GNP suspensions were more stable and had higher or lower surface zeta potentials in the presence of LOAs than when LOAs were not present. The toxic effects in S. obliquus cultures incubated with GNP suspensions containing LOAs were related to the LOA concentration, and the presence of LOAs caused three effects: stimulation, alleviation, and synergistic inhibition. The intensities of the effects mainly correlated with the LOA concentration, the extent of agglomeration, and particle-induced oxidative stress. The results indicate that the environmental fates and toxicities of GNPs are strongly affected by the binding of GNPs to LOAs. PMID:26898932

  17. Testing a Microarray to Detect and Monitor Toxic Microalgae in Arcachon Bay in France

    PubMed Central

    Kegel, Jessica U.; Del Amo, Yolanda; Costes, Laurence; Medlin, Linda K.

    2013-01-01

    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.

  18. Testing a Microarray to Detect and Monitor Toxic Microalgae in Arcachon Bay in France.

    PubMed

    Kegel, Jessica U; Del Amo, Yolanda; Costes, Laurence; Medlin, Linda K

    2013-01-01

    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. PMID:27605178

  19. Development of a new integrative toxicity index based on an improvement of the sea urchin embryo toxicity test.

    PubMed

    Morroni, L; Pinsino, A; Pellegrini, D; Regoli, F; Matranga, V

    2016-01-01

    The sea urchin embryo toxicity test is classically used to assess the noxious effects of contaminated marine waters and sediments. In Italian guidelines on quality of dredged sediments, the standard toxicity criteria used for this assay are based on a single endpoint at 48 hours of development, corresponding to the pluteus stage. Different typologies of abnormalities, including those which occur at earlier stages, are not categorized, thus preventing the evaluation of the actual teratogenic hazards. A new integrative toxicity index has been developed in this study based on the analysis of two developmental stages, at 24 and 48h post-fertilization, and the differentiation between development delays and germ layers impairments: the new toxicity index is calculated by integrating the frequency of abnormal embryos with the severity of such abnormalities. When tested on dredged sediments, the evaluation of increasing levels of toxicity affecting embryonic outcomes enhanced the capability to discriminate different samples, appearing particularly relevant to validate the sea urchin embryo toxicity assay, and supporting its utility in practical applications such as the sediments classification in harbor areas.

  20. Development of algal interspecies correlation estimation models for chemical hazard assessment.

    PubMed

    Brill, Jessica L; Belanger, Scott E; Chaney, Joel G; Dyer, Scott D; Raimondo, Sandy; Barron, Mace G; Pittinger, Charles A

    2016-09-01

    Web-based Interspecies Correlation Estimation (ICE) is an application developed to predict the acute toxicity of a chemical from 1 species to another taxon. Web-ICE models use the acute toxicity value for a surrogate species to predict effect values for other species, thus potentially filling in data gaps for a variety of environmental assessment purposes. Web-ICE has historically been dominated by aquatic and terrestrial animal prediction models. Web-ICE models for algal species were essentially absent and are addressed in the present study. A compilation of public and private sector-held algal toxicity data were compiled and reviewed for quality based on relevant aspects of individual studies. Interspecies correlations were constructed from the most commonly tested algal genera for a broad spectrum of chemicals. The ICE regressions were developed based on acute 72-h and 96-h endpoint values involving 1647 unique studies on 476 unique chemicals encompassing 40 genera and 70 species of green, blue-green, and diatom algae. Acceptance criteria for algal ICE models were established prior to evaluation of individual models and included a minimum sample size of 3, a statistically significant regression slope, and a slope estimation parameter ≥0.65. A total of 186 ICE models were possible at the genus level, with 21 meeting quality criteria; and 264 ICE models were developed at the species level, with 32 meeting quality criteria. Algal ICE models will have broad utility in screening environmental hazard assessments, data gap filling in certain regulatory scenarios, and as supplemental information to derive species sensitivity distributions. Environ Toxicol Chem 2016;35:2368-2378. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

  1. Flocculation of harmful algal blooms by modified attapulgite and its safety evaluation.

    PubMed

    Tang, Yi; Zhang, Hong; Liu, Xianan; Cai, Dongqing; Feng, Huiyun; Miao, Chunguang; Wang, Xiangqin; Wu, Zhengyan; Yu, Zengliang

    2011-04-01

    Natural attapulgite (N-AT) and modified attapulgite (M-AT) were used in this study to evaluate their flocculation efficiencies and mechanisms in freshwater containing harmful algal blooms through conventional jar test procedure. The experimental results showed that the efficiency of flocculation can be significantly improved by M-AT under appropriate conditions. It was found that the attapulgite modified by hydrochloric acid was similar to polyaluminum ferric silicate chloride (PAFSiC). The high efficiency for M-AT to flocculate Microcystis aeruginosa in freshwater was due to the mechanism of bridging and netting effect. Caenorhabditis elegans was used to detect the toxicity of N-AT and M-AT. The results showed that there was no significant toxicity on this organism. Attapulgite is a natural material, which can be readily available, abundant, and relatively inexpensive. Using modified attapulgite to remove the harmful algal blooms could have the advantages of high effectiveness, low cost, and low impact on the environment.

  2. Field validation of 10-day freshwater sediment toxicity tests using Hyalella azteca and Chironomus tentans

    SciTech Connect

    Becker, D.S.; Bigham, G.N.

    1995-12-31

    Two of the toxicity tests commonly used to evaluate freshwater sediments are the 10-day amphipod (Hyalella azteca) and chironomid (Chironomus tentans) tests. EPA and ASTM have recently developed standardized protocols for these tests. Although both tests are considered sensitive indicators of sediment toxicity, little information exists on how well test results correspond to adverse biological effects in the field. In this study, the lethal and sublethal (i.e., biomass) responses of the two toxicity tests were compared with alterations of benthic macroinvertebrate assemblages (i.e., benthic effects) at 56 stations in Onondaga Lake, New York. The lake has received municipal and industrial discharges for more than 100 years, and sediment chemical concentrations range widely throughout the lake. Toxicity results for Onondaga Lake were compared with reference conditions using the t-test, and benthic effects were determined using classification analysis of log-transformed taxa abundances. In general, a relatively high level of agreement was found between results of the toxicity tests and alterations of benthic assemblages. Significant (P < 0.05) correlations were found between all toxicity test endpoints and taxa richness of benthic assemblages. In addition, significant concordance (P {le} 0.01, binomial test) was found between toxicity designations for the 56 stations based on toxicity tests and toxicity designations based on benthic effects. Despite the general level of agreement among the various biological indicators, chironomid biomass and benthic effects were found to be the most sensitive indicators of toxicity, whereas amphipod survival and biomass were the least sensitive indicators. This study suggests that results of the 10-day amphipod and chironomid toxicity tests are highly predictive of adverse biological effects in the field.

  3. OECD validation study to assess intra- and inter-laboratory reproducibility of the zebrafish embryo toxicity test for acute aquatic toxicity testing.

    PubMed

    Busquet, François; Strecker, Ruben; Rawlings, Jane M; Belanger, Scott E; Braunbeck, Thomas; Carr, Gregory J; Cenijn, Peter; Fochtman, Przemyslaw; Gourmelon, Anne; Hübler, Nicole; Kleensang, André; Knöbel, Melanie; Kussatz, Carola; Legler, Juliette; Lillicrap, Adam; Martínez-Jerónimo, Fernando; Polleichtner, Christian; Rzodeczko, Helena; Salinas, Edward; Schneider, Katharina E; Scholz, Stefan; van den Brandhof, Evert-Jan; van der Ven, Leo T M; Walter-Rohde, Susanne; Weigt, Stefan; Witters, Hilda; Halder, Marlies

    2014-08-01

    The OECD validation study of the zebrafish embryo acute toxicity test (ZFET) for acute aquatic toxicity testing evaluated the ZFET reproducibility by testing 20 chemicals at 5 different concentrations in 3 independent runs in at least 3 laboratories. Stock solutions and test concentrations were analytically confirmed for 11 chemicals. Newly fertilised zebrafish eggs (20/concentration and control) were exposed for 96h to chemicals. Four apical endpoints were recorded daily as indicators of acute lethality: coagulation of the embryo, lack of somite formation, non-detachment of the tail bud from the yolk sac and lack of heartbeat. Results (LC50 values for 48/96h exposure) show that the ZFET is a robust method with a good intra- and inter-laboratory reproducibility (CV<30%) for most chemicals and laboratories. The reproducibility was lower (CV>30%) for some very toxic or volatile chemicals, and chemicals tested close to their limit of solubility. The ZFET is now available as OECD Test Guideline 236. Considering the high predictive capacity of the ZFET demonstrated by Belanger et al. (2013) in their retrospective analysis of acute fish toxicity and fish embryo acute toxicity data, the ZFET is ready to be considered for acute fish toxicity for regulatory purposes.

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

    USGS Publications Warehouse

    Elder, John F.

    1990-01-01

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

  5. Pyrrolizidine Alkaloids: Testing for Toxic Constituents of Comfrey.

    ERIC Educational Resources Information Center

    Vollmer, John J.; And Others

    1987-01-01

    Discusses the possibilities of toxins present in medicinal herbs. Describes an experiment in which toxic constituents can be selectively detected by thin-layer chromatography and NMR spectroscopy. (TW)

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

    PubMed

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

    2016-08-01

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

  7. COMPARATIVE TOXICITY TESTING OF SELECTED BENTHIC AND EPIBENTHIC ORGANISMS FOR THE DEVELOPMENT OF SEDIMENT QUALITY TEST PROTOCOLS

    EPA Science Inventory

    Sediment contamination has resulted in the need to develop an appropriate suite of toxicity tests to assess ecotoxicological impacts on estuarine ecosystems. Existing Environmental Protection Agency (EPA) protocols recommend a number of test organisms, including amphipods, polych...

  8. Toxicity of 8-Hydroxyquinoline in Cryprinus carpio Using the Acute Toxicity Test, Hepatase Activity Analysis and the Comet Assay.

    PubMed

    Yan, Shuaiguo; Chen, Lili; Dou, Xiaofei; Qi, Meng; Du, Qiyan; He, Qiaoqiao; Nan, Mingge; Chang, Zhongjie; Nan, Ping

    2015-08-01

    To evaluate the environmental toxicity of 8-hydroxyquinoline (8-HOQ), an important industrial raw material found in China's major ornamental fish, Cryprinus carpio, using the acute toxicity test, hepatase activity analysis and the comet assay. The results indicated that 8-HOQ had significant acute toxicity in adult C. carpio with a 96 h-LC50 of 1.15 and 0.22 mg L(-1) hepatic quinoline residues as assessed by HPLC. 8-HOQ also induced genotoxicity in the form of strand breaks in the DNA of hepatic cells as shown by the comet assay. With regard to physiological toxicity, 8-HOQ induced a decrease in the activities of hepatic GOT and GPT with increased exposure concentration and time. These data suggest that 8-HOQ may be toxic to the health of aquatic organisms when accidentally released into aquatic ecosystems. The data also suggest that the comet assay may be used in biomonitoring to determine 8-HOQ genotoxicity and hepatic GPT and GOT activities may be potential biomarkers of physiological toxicity.

  9. Toxicity of 8-Hydroxyquinoline in Cryprinus carpio Using the Acute Toxicity Test, Hepatase Activity Analysis and the Comet Assay.

    PubMed

    Yan, Shuaiguo; Chen, Lili; Dou, Xiaofei; Qi, Meng; Du, Qiyan; He, Qiaoqiao; Nan, Mingge; Chang, Zhongjie; Nan, Ping

    2015-08-01

    To evaluate the environmental toxicity of 8-hydroxyquinoline (8-HOQ), an important industrial raw material found in China's major ornamental fish, Cryprinus carpio, using the acute toxicity test, hepatase activity analysis and the comet assay. The results indicated that 8-HOQ had significant acute toxicity in adult C. carpio with a 96 h-LC50 of 1.15 and 0.22 mg L(-1) hepatic quinoline residues as assessed by HPLC. 8-HOQ also induced genotoxicity in the form of strand breaks in the DNA of hepatic cells as shown by the comet assay. With regard to physiological toxicity, 8-HOQ induced a decrease in the activities of hepatic GOT and GPT with increased exposure concentration and time. These data suggest that 8-HOQ may be toxic to the health of aquatic organisms when accidentally released into aquatic ecosystems. The data also suggest that the comet assay may be used in biomonitoring to determine 8-HOQ genotoxicity and hepatic GPT and GOT activities may be potential biomarkers of physiological toxicity. PMID:26067700

  10. Anodonta imbecillis copper sulfate reference toxicant test, Clinch River - Environmental Restoration Program (CR-ERP)

    SciTech Connect

    Simbeck, D.J.

    1997-06-01

    Reference toxicant testing using juvenile freshwater mussels was conducted as part of the CR-ERP biomonitoring study of Clinch River sediments to assess the sensitivity of test organisms and the overall performance of the test. Tests were conducted using moderately hard synthetic water spiked with known concentrations of copper as copper sulfate. Toxicity testing of copper sulfate reference toxicant was conducted from May 12-21, 1993. The organisms used for testing were juvenile fresh-water mussels (Anodonta imbecillis). Results from this test showed an LC{sub 50} value of 1.12 mg Cu/L which is lower than the value of 2.02 mg Cu/L obtained in a previous test. Too few tests have been conducted with copper as the toxicant to determine a normal range of values.

  11. Evaluation of three soil toxicity tests used to monitor acceptable endpoints

    SciTech Connect

    Brinkmann, M.; Stroo, H.; Leuschner, A.; Leuteritz, D.; Stromberg, M.; Brourman, M.

    1995-12-31

    Three terrestrial toxicity tests were used to evaluate the efficacy of biological treatment of creosote and pentachlorophenol impacted soils at a Superfund site. Microtox, 5-day lettuce seed, and 14-day earthworm toxicity tests were performed on 10 soil samples at the beginning and end of 3 months of land treatment. Secondary endpoints of root length and earthworm weight loss were also evaluated. EC50 and LC50 values were calculated using a Trimmed Logit Statistical Program and compared to toxicity of 10 background samples collected from the site. Results for initial soils demonstrated toxicity with three of the five endpoints. End treatment results showed no measurable toxicity using all endpoints. Toxicity testing results are critical for obtaining regulatory approval for the full-scale treatment system. Post treatment closure requirements for the site will be based on bioassay results. Evaluation of the three tests used showed the Microtox test to be the most sensitive to this type of toxicity. Lettuce seed germination results were the least sensitive of the three primary endpoints chosen. Of the secondary endpoint criteria, root length demonstrated reliable EC50 values and showed toxicity trends similar to Microtox and earthworm tests. The earthworm weight loss endpoint was not a useful toxicity measurement at 14 days.

  12. Factors affecting toxicity test endpoints in sensitive life stages of native Gulf of Mexico species.

    PubMed

    Echols, B S; Smith, A J; Rand, G M; Seda, B C

    2015-05-01

    Indigenous species are less commonly used in laboratory aquatic toxicity tests compared with standard test species due to (1) limited availability lack of requisite information necessary for their acclimation and maintenance under laboratory conditions and (2) lack of information on their sensitivity and the reproducibility of toxicity test results. As part of the Natural Resource Damage Assessment aquatic toxicity program in response to the Deepwater Horizon Oil incident (2010), sensitive life stages of native Gulf of Mexico species were evaluated in laboratory toxicity tests to determine the potential effects of the spill. Fish (n = 5) and invertebrates (n = 2) selected for this program include the following: the Florida pompano (Trachinotus carolinus), red drum (Sciaenops ocellatus), spotted sea trout (Cynoscion nebulosus), cobia (Rachycentron canadum), red porgy (Pagrus pagrus), blue crab (Callinectes sapidus), and the common moon jellyfish (Aurelia aurita). Initially in the program, to establish part of the background information, acute tests with reference toxicants (CdCl2, KCl, CuSO4) were performed with each species to establish data on intraspecies variability and test precision as well as identify other factors that may affect toxicity results. Median lethal concentration (LC50) values were calculated for each acute toxicity test with average LC50 values ranging from 248 to 862 mg/L for fish exposures to potassium chloride. Variability between test results was determined for each species by calculating the coefficient of variation (%CV) based on LC50 values. CVs ranged from 11.2 % for pompano (96-h LC50 value) to 74.8 % for red porgy 24-h tests. Cadmium chloride acute toxicity tests with the jellyfish A. aurita had the lowest overall CV of 3.6 %. By understanding acute toxicity to these native organisms from a compound with known toxicity ranges and the variability in test results, acute tests with nonstandard species can be better interpreted and used

  13. Factors affecting toxicity test endpoints in sensitive life stages of native Gulf of Mexico species.

    PubMed

    Echols, B S; Smith, A J; Rand, G M; Seda, B C

    2015-05-01

    Indigenous species are less commonly used in laboratory aquatic toxicity tests compared with standard test species due to (1) limited availability lack of requisite information necessary for their acclimation and maintenance under laboratory conditions and (2) lack of information on their sensitivity and the reproducibility of toxicity test results. As part of the Natural Resource Damage Assessment aquatic toxicity program in response to the Deepwater Horizon Oil incident (2010), sensitive life stages of native Gulf of Mexico species were evaluated in laboratory toxicity tests to determine the potential effects of the spill. Fish (n = 5) and invertebrates (n = 2) selected for this program include the following: the Florida pompano (Trachinotus carolinus), red drum (Sciaenops ocellatus), spotted sea trout (Cynoscion nebulosus), cobia (Rachycentron canadum), red porgy (Pagrus pagrus), blue crab (Callinectes sapidus), and the common moon jellyfish (Aurelia aurita). Initially in the program, to establish part of the background information, acute tests with reference toxicants (CdCl2, KCl, CuSO4) were performed with each species to establish data on intraspecies variability and test precision as well as identify other factors that may affect toxicity results. Median lethal concentration (LC50) values were calculated for each acute toxicity test with average LC50 values ranging from 248 to 862 mg/L for fish exposures to potassium chloride. Variability between test results was determined for each species by calculating the coefficient of variation (%CV) based on LC50 values. CVs ranged from 11.2 % for pompano (96-h LC50 value) to 74.8 % for red porgy 24-h tests. Cadmium chloride acute toxicity tests with the jellyfish A. aurita had the lowest overall CV of 3.6 %. By understanding acute toxicity to these native organisms from a compound with known toxicity ranges and the variability in test results, acute tests with nonstandard species can be better interpreted and used

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

    EPA Science Inventory

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

  15. The Adverse Outcome Pathway: A conceptual framework to support toxicity testing in the 21st century

    EPA Science Inventory

    The field of regulatory toxicity testing is at a turning point. The U.S. National Research Council (NRC) envisioned a shift away from traditional toxicity testing and towards a focused effort to explore and understand pathways perturbed by biologically active substances or their ...

  16. Strategies for integrating transcriptional profiling into high throughput toxicity testing (SOT Symposium Workshop presentation)

    EPA Science Inventory

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

  17. ARS Research on Harmful Algal Blooms in SE USA Aquaculture Impoundments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As part of an EPA sponsored state of knowledge symposium on toxic cyanobacteria, six workgroups were established to assess published literature. A review of ARS research on harmful algal blooms was made by the incumbent. Aquaculture systems have had four types of freshwater toxic algal blooms. De...

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

  2. Population growth rate determinants for Arbacia: Evaluating ecological relevance of toxicity test endpoints

    SciTech Connect

    Nacci, D.; Gleason, T.; Munns, W.R. Jr.

    1995-12-31

    A population dynamics model for the sea urchin, Arbacia punctulata, was recently developed incorporating life stage endpoints frequently measured in acute and chronic toxicity studies. Model elasticity analysis was used to demonstrate that population growth rate was influenced most by adult survival and least by early life stage success, calling into question the ecological relevance of results from standardized Arbacia fertilization and larval development toxicity tests. Two approaches were used to continue this evaluation. Actual and hypothetical dose-response curves for toxicant exposures over multiple life stages were used to evaluate contributions to population growth rate of stage-specific toxicant effects. Additionally, relationships between critical life stages were developed from laboratory data for Arbacia. The results of this analysis underscore the importance of understanding both endpoint sensitivity to toxicants and sensitivity of population growth rate to test endpoints in determining the ecological relevance of toxicity tests results.

  3. Terrestrial isopods -- a good choice for toxicity testing of pollutants in the terrestrial environment

    SciTech Connect

    Drobne, D.

    1997-06-01

    Terrestrial isopods are suitable invertebrates for testing the relative toxicities of chemicals present in the terrestrial environment. Terrestrial isopods respond in numerous ways to elevated concentrations of chemicals in their food, but only a few of these responses can be used as toxicological endpoints. The most suitable are changes in reproduction, food consumption, moult cycle duration, and structure of the digestive glands. These responses are able to provide accurate indications of sublethal toxicity. Toxicity tests with terrestrial isopods could be much more reliable through the use of positive controls. A positive control with a reference toxicant could also be supplemented by a reference endpoint. The most suitable reference endpoint is change of food consumption rate. Toxicity testing with terrestrial isopods is a very promising method for fast, routine, and inexpensive laboratory determination of the relative toxicities of chemicals in the terrestrial environment.

  4. ASSESSING CONTAMINANT SENSITIVITY OF ENDANGERED AND THREATENED SPECIES: EFFLUENT TOXICITY TESTS

    EPA Science Inventory

    Toxicity tests using standard effluent test procedures were conducted (EPA 1994) with Ceriodaphnia dubia and fathead minnows and four endangered fish species: bonytail chub (Gila elegans), Colorado squawfish (Ptychocheilus lucias ), razorback sucker (Xyrauchen texanus) and Gila t...

  5. AN EVALUATION OF THE 7-DAY TOXICITY TEST WITH AMERICAMYSIS BAHIA (FORMERLY MYSIDOPSIS BAHIA)

    EPA Science Inventory

    The 7-d test measuring survival, growth, and fecundity of Americamysis bahia formerly Mysidopsis bahia) was developed for estimating the chronic toxicity of effluents and associated receiving waters for National Pollutant Discharge Elimination System permits. Currently, this test...

  6. Leachate toxicity assessment by responses of algae Nitellopsis obtusa membrane ATPase and cell resting potential, and with Daphtoxkit F magna test.

    PubMed

    Jurkoniene, S; Maksimov, G; Darginaviciene, J; Sadauskas, K; Vitkus, R; Manusadzianas, L

    2004-08-01

    A microscale bioassay based on 50% inhibition of K(+), Mg(2+)-ATPase activity in a microsomal fraction isolated from Nitellopsis obtusa cells was developed. Compared to that for a plasma membrane fraction purified in a sucrose gradient, the preparation procedure for a microsomal fraction is less time consuming and the yield is substantially higher. Characteristics of the microsomal preparation proved to be similar to those of the highly purified plasma membrane preparation (Manusadzianas et al., 2002), at least for heavy metals. Sensitivity to CuSO(4) of the frozen (-8 degrees C) microsomal fraction [49 +/- 17 (SD) microM; n = 8] did not significantly differ from that of the freshly isolated one (52 +/- 30, n = 8), at least for 40 days. Toxicity of leachate water from Kairiai (northern Lithuania) solid waste landfill was assessed by taking samples from various points including temporary reservoirs and analyzing them immediately after spillage (summer 2002) and after storage for almost 2 years at 4 degrees C-6 degrees C. Two tests with the macrophytic alga Nitellopsis obtusa (Charatox, 45-min EC(50) of resting potential depolarization, and ATPase assay, IC(50) of membrane ATPase activity) and one test with the crustacean Daphnia magna (Daphtoxkit F, 48-h 50% immobilization) tests were used. In general, all three tests showed successively decreasing values of landfill leachate toxicity with an increasing degree of dilution with surface waters. The possibility of employing preserved algal preparations on demand in test batteries seems to be promising, especially in emergencies.

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

    PubMed

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

    2015-01-01

    The objective of this study was to identify and to apply appropriate biotests having the advantages of being highly sensitive, easy to run, relatively inexpensive and able to substitute fish toxicity tests due to ethical reasons of animal welfare. To perform an ecotoxicological assessment of industrial wastewaters, different microbiotests were conducted to substitute the fish toxicity test with Lebistes reticulatus through Vibrio fischeri, Thamnocephalus platyurus, Daphnia magna, Lemna minor and Lepidium sativum representing different trophic levels in the aquatic and terrestrial ecosystems. Also, Algaltox F(TM) with Pseudokirchneriella subcapitata and Protox F(TM) with Tetrahymena thermophila tests were carried out. However, they could not be applied successfully for the wastewater samples. Wastewater samples from seven different industrial zones comprising different industries were subjected to characterization through measuring their physical-chemical parameters and their toxicity versus the above-mentioned organisms. T. platyurus, D. magna and L. reticulatus were the most sensitive test organisms investigated for the wastewaters. Considering toxic unit values, generally wastewater samples were toxic according to Thamnotox F(TM), Daphtox F(TM) and fish toxicity tests. As an important outcome, it was concluded that Daphtox F(TM) and Thamnotox F(TM) could be a good alternative for the fish toxicity test, which is so far the sole toxicity test accepted by the Turkish Water Pollution Control Regulation. PMID:25951939

  8. Harmful Algal Blooms (HABs)

    MedlinePlus

    ... Topics Eighth Annual National Conference on Health Communication, Marketing & Media August 19-21, 2014 Atlanta, GA Harmful Algal Blooms Recommend on Facebook Tweet Share Compartir On this Page What's the ...

  9. ExpoCast: Exposure Science for Prioritization and Toxicity Testing

    EPA Science Inventory

    The US EPA is completing the Phase I pilot for a chemical prioritization research program, called ToxCastTM. Here EPA is developing methods for using computational chemistry, high-throughput screening, and toxicogenomic technologies to predict potential toxicity and prioritize l...

  10. Effect of the test media and toxicity of LAS on the growth of Isochrysis galbana.

    PubMed

    Garrido-Perez, M C; Perales-VargasMachuca, J A; Nebot-Sanz, E; Sales-Márquez, D

    2008-11-01

    In this paper, the toxicity of linear alkylbenzene sulfonate (LAS) was evaluated in the marine microalga Isochrysis galbana using data of growth inhibition toxicity tests at 96-h exposure time. Toxicity was examined in standard conditions and by means of the modification of two variables of the test media: (1) the dilution water and (2) the content of nutrients in the test medium. For this purpose, a total of 10 toxicity test were designed: five dilution waters, four natural marine waters and one synthetic seawater; each in two different nutritive conditions, saturated nutrient concentration (SC) by the addition of modified f/2 nutritive medium, and natural nutrient concentration (NC), i.e., without the addition of f/2. At threshold toxicity levels, the dilution waters used in the test and the nutrient concentrations did not affect the toxicity of LAS. At IC50 concentrations, the toxicity of LAS is influenced by both variables: under SC conditions, the toxic effect of LAS diminishes, obtaining in all the tests IC50 > 10 mg/L LAS. Under NC conditions, IC50 concentrations ranging between 3.15 and 9.26 mg/L LAS have been obtained.

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

    PubMed

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

    2014-10-01

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

  12. A comparison of sediment toxicity test methods at three Great Lake Areas of Concern

    USGS Publications Warehouse

    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.

  13. Possible importance of algal toxins in the Salton Sea, California

    USGS Publications Warehouse

    Reifel, K.M.; McCoy, M.P.; Rocke, T.E.; Tiffany, M.A.; Hurlbert, S.H.; Faulkner, D.J.

    2002-01-01

    toxic. All sample extracts tested in the mouse bioassay showed no activity. One sample extract taken from the bloom of the small dinoflagellate was highly active (100% mortality across all concentrations) in the brine shrimp lethality assay, but the active material could not be isolated. While dense algal blooms are common at the Salton Sea, no evidence gathered in this study suggests that algal toxins are present within phytoplankton cells; however, toxins actively excreted by cells may have been missed. Blooms of phytoplankton likely contribute to wildlife mortality at the Salton Sea. Possible mechanisms including intoxication due to ingestion of feathers in grebes and waterlogging caused by changes in surface tension are discussed.

  14. Pilot study for ambient toxicity testing in Chesapeake bay. Year two report

    SciTech Connect

    Hall, L.W.; Ziegenfuss, M.C.; Fischer, S.A.; Anderson, R.D.; Killen, W.D.

    1992-11-01

    The primary goal of the ambient toxicity testing pilot study was to identify toxic areas in living resource habitats of the Chesapeake Bay watershed by using a battery of standardized, directly modified or recently developed water column, sediment and suborganismal toxicity tests. Tests were conducted twice at the following stations: Potomac River-Morgantown, Potomac River-Dahlgren, Patapsco River and Wye River. A suite of inorganic and organic contaminants was evaluated in the water column and sediment during these tests. Standard water quality conditions were also evaluated in water and sediment from all stations.

  15. Tests for bioequivalence of control media and test media in studies of toxicity

    SciTech Connect

    Erickson, W.P.; McDonald, L.L.

    1995-07-01

    Statistical tests of the classical (null) hypothesis--that there is no difference in effects of control media and tested--are commonly used to make statistical inferences toward the no-observed-adverse-effect concentration. However, failing to rejects this hypothesis is not considered as scientific proof the hypothesis is true. An effect may exist, but high variation due to inadequate replication, variation in experimental units, or imprecise measurement techniques may yield data for which the hypothesis is not rejected. An experiment may also be too precise, yielding effects that are statistically significant but not biologically important. The authors propose the use of tests of bioequivalence of control media and test media to alleviate these unsatisfactory characteristics of tests and of the classical hypotheses for regulatory decisions. They review and illustrate the test for bioequivalence using acute and chronic toxicity data. They also define a procedure for determining the level of effect at which there will be high power to refute the hypothesis that there is a lack of bioequivalence if in fact the biological response in the control media is identical to the responses in the test media.

  16. 40 CFR 795.120 - Gammarid acute toxicity test.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., lowest and middle test concentrations. (v) The test duration is 96 hours. The test is unacceptable if.... (C) Gammarids used in a particular test shall be of similar age and/or size and from the same...

  17. 40 CFR 795.120 - Gammarid acute toxicity test.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., lowest and middle test concentrations. (v) The test duration is 96 hours. The test is unacceptable if.... (C) Gammarids used in a particular test shall be of similar age and/or size and from the same...

  18. 40 CFR 795.120 - Gammarid acute toxicity test.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... definitions also apply to this guideline: Death means the lack of reaction of a test organism to gentle... dilution water through each chamber is adjusted to the rate desired. In a static test, the test substance is introduced into each test chamber. In a flow-through test, the rate in which the test substance...

  19. 40 CFR 797.1400 - Fish acute toxicity test.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... construction materials, test chambers, and testing apparatus to dilution water or to test solutions prior to... tank with no recycling. (7) Incipient LC 50 means that test substance concentration, calculated from... substance. (F) A test substance delivery system for flow-through tests. (ii) Construction...

  20. 40 CFR 797.1400 - Fish acute toxicity test.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... construction materials, test chambers, and testing apparatus to dilution water or to test solutions prior to... tank with no recycling. (7) Incipient LC 50 means that test substance concentration, calculated from... substance. (F) A test substance delivery system for flow-through tests. (ii) Construction...

  1. Cell cultures are more sensitive than Saccharamoyces cervisiae tests for assessing the toxicity of aquatic pollutants

    SciTech Connect

    Mochida, K.; Gomyoda, M.; Fujita, T.; Yamagata, K.

    1988-07-01

    Cultured fish and human cells have been used as bioassay systems for the evaluation of the toxicity of aquatic pollutants. Numerous assays using bacteria and yeast have also been used for such purposes. The authors report the toxicity of aquatic pollutants (Cd, Hg, and Ni), using cell culture systems and the yeast Saccharomyces cervisiae test. Cd, Hg, and Ni were chosen as model compounds of pollutants because the related toxicity is now fairly well established.

  2. Assessment of four different test designs for Hyalella azteca 10 days sediment toxicity test

    SciTech Connect

    Ramirez-Romero, P. |; Oris, J.T.; Bailer, J.; DePoy, M.

    1995-12-31

    The purpose of this study was to assess the adequacy of four experimental designs of the Hyalella azteca 10 days sediment toxicity test. The authors conducted a series of sediment toxicity tests using an EPA recommended experimental design (8 chambers with 10 organisms per treatment) and three other designs. These had the same total number of organisms (80) per treatment and the same sediment:water ratio (1:1.5) but different number of chambers (4,2,1). The number of organisms recovered, the time to sort and count the animals, as well as the time to make a water change were compared for these four designs. Logistic regression was used to analyze the recovery data while one-way analysis of variance methods were used to analyze the time responses. The results showed that the four treatments were comparable in terms of proportion of organisms recovered. However, the sorting time and the water change time decreased as the number of chambers decreased, making those designs with less chambers more desirable.

  3. Sediment toxicity testing with the amphipod Ampelisca abdita in Calcasieu Estuary, Louisiana

    USGS Publications Warehouse

    Redmond, M.S.; Crocker, P.A.; McKenna, K.M.; Petrocelli, E.A.; Scott, K.J.; Demas, C.R.

    1996-01-01

    Discharges from chemical and petrochemical manufacturing facilities have contaminated portions of Louisiana's Calcasieu River estuary with a variety of organic and inorganic contaminants. As part of a special study, sediment toxicity testing was conducted to assess potential impact to the benthic community. Ten-day flow-through sediment toxicity tests with the amphipod Ampelisca abdita revealed significant toxicity at 68% (26 of 38) of the stations tested. A. abdita mortality was highest in the effluent-dominated bayous, which are tributaries to the Calcasieu River. Mortality was correlated with total heavy metal and total organic compound concentrations in the sediments. Ancillary experiments showed that sediment interstitial water salinity as low as 2.5 o/o-o did not significantly affect A. abdita's, response in the flow-through system; sediment storage for 7 weeks at 4??C did not significantly affect toxicity. Sediment toxicity to A. abdita was more prevalent than receiving water toxicity using three short-term chronic bioassays. Results suggest that toxicity testing using this amphipod is a valuable tool when assessing sediments containing complex contaminant mixtures and for assessing effects of pollutant loading over time. In conjunction with chemical analyses, the testing indicated that the effluent-dominated, brackish bayous (Bayou d'Inde and Bayou Verdine) were the portions of the estuary most impacted by toxicity.

  4. Studies with the USF/NASA toxicity screening test method - Oxygen concentrations with various test conditions

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Cumming, H. J.; Solis, A. N.

    1977-01-01

    Continuing efforts to increase the versatility of the USF/NASA toxicity screening test method have included the use of different test conditions in order to simulate various fire environments. The use of air flow at flow rates of 16 to 48 ml/sec maintains oxygen concentrations above 19 percent throughout the 30 min exposure period, compared to above 16 percent without forced air flow. These levels of oxygen are well within the tolerance range of mice, and approach the oxygen levels found in many real fire situations. Proposed minimum oxygen levels based on experience with rats are unduly restrictive on the use of other species such as mice, and tend to eliminate the cost savings which may more than justify the selection of mice.

  5. Concentration-time data in toxicity tests and resulting relationships

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Brauer, D. P.

    1979-01-01

    Periodic analyses for carbon monoxide and methane in the animal exposure chamber during pyrolysis of polyethylene at 800 C without forced air flow showed that the concentrations of these compounds increased with exposure time. These observations, and similar observations for polyurethane flexible foam, permitted the calculation of carbon monoxide toxicity in terms of a DP (Death Product Concentration) value, in addition to flammability in terms of HC (Hydro Carbon) value. Observed DP values exceeding the critical DP(CO) value of 47,200 ppm-min for carbon monoxide may indicate that lethal exposures were reached earlier but not immediately manifested because of the time delay involved in physiological processes. On the basis of this DP(CO) value, carbon monoxide could have been the sole toxicant in the case of polyethylene, polypropylene, polyoxymethylene, polystyrene, polycarbonate, ethylene propylene diene rubber, and wood.

  6. Relationships between exposure and dose in aquatic toxicity tests for organic chemicals.

    PubMed

    Mackay, Donald; McCarty, Lynn S; Arnot, Jon A

    2014-09-01

    There is continuing debate about the merits of exposure-based toxicity metrics such as median lethal concentration (LC50) versus organism-based metrics such as critical body residue (CBR) as indicators of chemical toxicity to aquatic organisms. To demonstrate relationships and differences between these 2 metrics, the authors applied a simple one-compartment toxicokinetic mass-balance model for water-exposed fish for a series of hypothetical organic chemicals exhibiting baseline narcotic toxicity. The authors also considered the influence of several toxicity-modifying factors. The results showed that the results of standard toxicity tests, such as the LC50, are strongly influenced by several modifying factors, including chemical and organism characteristics such as hydrophobicity, body size, lipid content, metabolic biotransformation, and exposure durations. Consequently, reported LC50s may not represent consistent dose surrogates and may be inappropriate for comparing the relative toxicity of chemicals. For comparisons of toxicity between chemicals, it is preferable to employ a delivered dose metric, such as the CBR. Reproducible toxicity data for a specific combination of chemical, exposure conditions, and organism can be obtained only if the extent of approach to steady state is known. Suggestions are made for revisions in test protocols, including the use of models in advance of empirical testing, to improve the efficiency and effectiveness of tests and reduce the confounding influences of toxicity-modifying factors, especially exposure duration and metabolic biotransformation. This will assist in linking empirical measurements of LC50s and CBRs, 2 different but related indicators of aquatic toxicity, and thereby improve understanding of the large existing database of aquatic toxicity test results.

  7. Algal Bloom Detection from HICO

    NASA Astrophysics Data System (ADS)

    Amin, Ruhul; Gould, Richard

    2014-05-01

    Ocean color satellites provide daily, global views of marine bio-optical properties in the upper ocean at various spatial scales. The most productive area of the global ocean is the coastal zone which is heavily impacted by urban and agricultural runoff, transportation, recreation, and oil and gas production. In recent years, harmful algal blooms (HABs) have become one of the serious environmental problems in the coastal areas on a global scale. The global nature of the problem has expanded in its frequency, severity, and extent over the last several decades. Human activities and population increases have contributed to an increase in various toxic and noxious algal species in the coastal regions worldwide. Eutrophication in estuaries and coastal waters is believed to be the major factor causing HABs. In this study, we assess the applicability of the Red Band Difference (RBD) HAB detection algorithm on data from the Hyperspectral Imager for the Coastal Ocean (HICO). Our preliminary results show that due to various uncertainties such as atmospheric correction, calibration and possibly also the relatively low signal-to-noise ratio of HICO for fluorescence detection, it is difficult to extract the fluorescence portion of the reflectance spectrum that RBD uses for bloom detection. We propose an improved bloom detection technique for HICO using red and NIR bands. Our results are validated using other space-borne and ground based measurements.

  8. Alternative testing systems for evaluating noncarcinogenic, hematologic toxicity.

    PubMed Central

    Parchment, R E

    1998-01-01

    Hematopoietic tissues are the targets of numerous xenobiotics. Clinical hematotoxicity is either a decrease or an increase in peripheral blood cell counts in one or more cell lineages--a cytopenia or a cytosis, respectively--that carries a risk of an adverse clinical event. The purpose of in vitro hematotoxicology is the prediction of these adverse hematologic effects from the effects of the toxicants on human hematopoietic targets under controlled experimental conditions in the laboratory. Building on its important foundations in experimental hematology and the wealth of hematotoxicology data found in experimental oncology, this field of alternative toxicology has developed rapidly during the past decade. Although the colony-forming unit-granulocyte/monocyte neutrophil progenitor is most frequently evaluated, other defined progenitors and stem cells as well as cell types found in the marrow stroma can be evaluated in vitro. End points have been proposed for predicting toxicant exposure levels at the maximum tolerated dose and the no observable adverse effect level for the neutrophil lineage, and several clinical prediction models for neutropenia have developed to the point that they are ready for prospective evaluation and validation in both preclinical species and humans. Known predictive end points are the key to successful comparisons across species or across chemical structures when in vitro dose-response curves are nonparallel. Analytical chemistry support is critical for accurate interpretation of in vitro data and for relating the in vitro pharmacodynamics to the in vivo pharmacokinetics. In contrast to acute neutropenia, anemia and acute thrombocytopenia, as well as adverse effects from chronic toxicant exposure, are much more difficult to predict from in vitro data. Pharmacologic principles critical for clinical predictions from in vitro data very likely will apply to toxicities to other proliferative tissues, such as mucositis. PMID:9599702

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

    SciTech Connect

    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

  10. Gamma Radiation Reduced Toxicity of Azoxystrobin Tested on Artemia franciscana.

    PubMed

    Dvorak, P; Zdarsky, M; Benova, K; Falis, M; Tomko, M

    2016-06-01

    Fungicide azoxystrobin toxicity was monitored by means of a 96-h biotest with Artemia franciscana nauplius stages after exposure to solutions with concentrations of 0.2, 0.4, 0.6 and 0.8 mg L(-1) irradiated with (60)Co gamma radiation with doses of 1, 2.5, 5 and 10 kGy. The effects of ionization radiation on azoxystrobin toxicity were mainly manifested by a statistically significant reduction of lethality after 72- and 96-h exposure. A maximum reduction of lethality of 72 % was achieved using doses of 1-5 kGy for an azoxystrobin initial concentration of 0.4 mg L(-1) and after 72 h of exposure. At a 96-h exposure, a difference of lethal effects reached up to 70 % for a dose of 10 kGy. The observed effect of gamma ionizing radiation on azoxystrobin toxicity suggest that this approach can be applied as an alternative for a reduction of azoxystrobin residua in food. PMID:27107585

  11. Evaluation of an alternative in vitro test battery for detecting reproductive toxicants in a grouping context.

    PubMed

    Kroese, E Dinant; Bosgra, Sieto; Buist, Harrie E; Lewin, Geertje; van der Linden, Sander C; Man, Hai-yen; Piersma, Aldert H; Rorije, Emiel; Schulpen, Sjors H W; Schwarz, Michael; Uibel, Frederik; van Vugt-Lussenburg, Barbara M A; Wolterbeek, Andre P M; van der Burg, Bart

    2015-08-01

    Previously we showed a battery consisting of CALUX transcriptional activation assays, the ReProGlo assay, and the embryonic stem cell test, and zebrafish embryotoxicity assay as 'apical' tests to correctly predict developmental toxicity for 11 out of 12 compounds, and to explain the one false negative [7]. Here we report on applying this battery within the context of grouping and read across, put forward as a potential tool to fill data gaps and avoid animal testing, to distinguish in vivo non- or weak developmental toxicants from potent developmental toxicants within groups of structural analogs. The battery correctly distinguished 2-methylhexanoic acid, monomethyl phthalate, and monobutyltin trichloride as non- or weak developmental toxicants from structurally related developmental toxicants valproic acid, mono-ethylhexyl phthalate, and tributyltin chloride, respectively, and, therefore, holds promise as a biological verification model in grouping and read across approaches. The relevance of toxicokinetic information is indicated.

  12. Toxicity assessment of sediments from three European river basins using a sediment contact test battery.

    PubMed

    Tuikka, A I; Schmitt, C; Höss, S; Bandow, N; von der Ohe, P C; de Zwart, D; de Deckere, E; Streck, G; Mothes, S; van Hattum, B; Kocan, A; Brix, R; Brack, W; Barceló, D; Sormunen, A J; Kukkonen, J V K

    2011-01-01

    The toxicity of four polluted sediments and their corresponding reference sediments from three European river basins were investigated using a battery of six sediment contact tests representing three different trophic levels. The tests included were chronic tests with the oligochaete Lumbriculus variegatus, the nematode Caenorhabditis elegans and the mudsnail Potamopyrgus antipodarum, a sub-chronic test with the midge Chironomus riparius, an early life stage test with the zebra fish Danio rerio, and an acute test with the luminescent bacterium Vibrio fischeri. The endpoints, namely survival, growth, reproduction, embryo development and light inhibition, differed between tests. The measured effects were compared to sediment contamination translated into toxic units (TU) on the basis of acute toxicity to Daphnia magna and Pimephales promelas, and multi-substance Potentially Affected Fractions of species (msPAF) as an estimate for expected community effects. The test battery could clearly detect toxicity of the polluted sediments with test-specific responses to the different sediments. The msPAF and TU-based toxicity estimations confirmed the results of the biotests by predicting a higher toxic risk for the polluted sediments compared to the corresponding reference sediments, but partly having a different emphasis from the biotests. The results demonstrate differences in the sensitivities of species and emphasize the need for data on multiple species, when estimating the effects of sediment pollution on the benthic community.

  13. Development of protocols for chronic toxicity testing of Pacific marine species

    SciTech Connect

    Langdon, C.J.; Seim, W.K.; Hoffman, R.L.; Weber, L.

    1990-03-01

    The development of a year-round capability for conducting short-term toxicity tests for estimating chronic-effect levels of toxic materials with a native Pacific coast fish and a native Pacific coast mysid shrimp was the goal of the project. In order to achieve acceptable sensitivity as a surrogate for chronic toxicity tests, targeting the reproductive portion of the mysid life cycle and all or part of the embryonic, larval, or early post-larval portion of the fish life cycle was deemed necessary. This targeting is consistent with conclusions based upon earlier work in developing similar tests with Atlantic coast, Gulf coast, and freshwater fish and invertebrates.

  14. Computerized In Vitro Test for Chemical Toxicity Based on Tetrahymena Swimming Patterns

    NASA Technical Reports Server (NTRS)

    Noever, David A.; Matsos, Helen C.; Cronise, Raymond J.; Looger, Loren L.; Relwani, Rachna A.; Johnson, Jacqueline U.

    1994-01-01

    An apparatus and a method for rapidly determining chemical toxicity have been evaluated as an alternative to the rabbit eye initancy test (Draize). The toxicity monitor includes an automated scoring of how motile biological cells (Tetrahymena pyriformis) slow down or otherwise change their swimming patterns in a hostile chemical environment. The method, called the motility assay (MA), is tested for 30 s to determine the chemical toxicity in 20 aqueous samples containing trace organics and salts. With equal or better detection limits, results compare favorably to in vivo animal tests of eye irritancy.

  15. Passive Dosing in Chronic Toxicity Tests with the Nematode Caenorhabditis elegans.

    PubMed

    Fischer, Fabian; Böhm, Leonard; Höss, Sebastian; Möhlenkamp, Christel; Claus, Evelyn; Düring, Rolf-Alexander; Schäfer, Sabine

    2016-09-01

    In chronic toxicity tests with Caenorhabditis elegans, it is necessary to feed the nematode with bacteria, which reduces the freely dissolved concentration (Cfree) of hydrophobic organic chemicals (HOCs), leading to poorly defined exposure with conventional dosing procedures. We examined the efficacy of passive dosing of polycyclic aromatic hydrocarbons (PAHs) using silicone O-rings to control exposure during C. elegans toxicity testing and compared the results to those obtained with solvent spiking. Solid-phase microextraction and liquid-liquid extraction were used to measure Cfree and the chemicals taken up via ingestion. During toxicity testing, Cfree decreased by up to 89% after solvent spiking but remained constant with passive dosing. This led to a higher apparent toxicity on C. elegans exposed by passive dosing than by solvent spiking. With increasing bacterial cell densities, Cfree of solvent-spiked PAHs decreased while being maintained constant with passive dosing. This resulted in lower apparent toxicity under solvent spiking but an increased apparent toxicity with passive dosing, probably as a result of the higher chemical uptake rate via food (CUfood). Our results demonstrate the utility of passive dosing to control Cfree in routine chronic toxicity testing of HOCs. Moreover, both chemical uptake from water or via food ingestion can be controlled, thus enabling the discrimination of different uptake routes in chronic toxicity studies.

  16. Passive Dosing in Chronic Toxicity Tests with the Nematode Caenorhabditis elegans.

    PubMed

    Fischer, Fabian; Böhm, Leonard; Höss, Sebastian; Möhlenkamp, Christel; Claus, Evelyn; Düring, Rolf-Alexander; Schäfer, Sabine

    2016-09-01

    In chronic toxicity tests with Caenorhabditis elegans, it is necessary to feed the nematode with bacteria, which reduces the freely dissolved concentration (Cfree) of hydrophobic organic chemicals (HOCs), leading to poorly defined exposure with conventional dosing procedures. We examined the efficacy of passive dosing of polycyclic aromatic hydrocarbons (PAHs) using silicone O-rings to control exposure during C. elegans toxicity testing and compared the results to those obtained with solvent spiking. Solid-phase microextraction and liquid-liquid extraction were used to measure Cfree and the chemicals taken up via ingestion. During toxicity testing, Cfree decreased by up to 89% after solvent spiking but remained constant with passive dosing. This led to a higher apparent toxicity on C. elegans exposed by passive dosing than by solvent spiking. With increasing bacterial cell densities, Cfree of solvent-spiked PAHs decreased while being maintained constant with passive dosing. This resulted in lower apparent toxicity under solvent spiking but an increased apparent toxicity with passive dosing, probably as a result of the higher chemical uptake rate via food (CUfood). Our results demonstrate the utility of passive dosing to control Cfree in routine chronic toxicity testing of HOCs. Moreover, both chemical uptake from water or via food ingestion can be controlled, thus enabling the discrimination of different uptake routes in chronic toxicity studies. PMID:27494096

  17. Periphyton photosynthesis as an indicator of effluent toxicity: Relationship to effects on animal test species

    SciTech Connect

    Lewis, M.A.

    1992-01-01

    The use of freshwater and marine plants in effluent toxicity evaluations is uncommon despite the presence of test methods and recommendations for their use. It has been assumed that aquatic plants are less sensitive than animal test species and consequently, results from toxicity tests with invertebrates and fish have been used often as a surrogate data base. The study evaluated the ability of these animal toxicity tests to provide safe concentrations for in-stream periphyton. The toxicity of several samples of a treated municipal effluent were determined during a five-month period by monitoring short-term changes in periphyton photosynthesis (carbon-14 uptake) and by observing the effects on young production and survival of cultured daphnids and the fathead minnow. The effect levels from the various tests were compared. The effluent was seldom acutely toxic to Daphnia magna and the fathead minnow (Pimephales promelas) but it was consistently acutely and chronically toxic to Ceriodaphnia dubia. Chronic effect levels ranged between 17 and 71% effluent. Significant inhibition and stimulation of periphyton photosynthesis occurred at concentrations of 6 to 39% effluent. Periphyton photosynthesis was a more sensitive effect parameter than animal survival and in some cases than Ceriodaphnia reproductive performance. The results indicate that effluent toxicity tests conducted routinely with daphnids and fish may not be sufficient to predict effects on indigenous flora in receiving waters.

  18. Promoting the 3Rs to enhance the OECD fish toxicity testing framework.

    PubMed

    Hutchinson, Thomas H; Wheeler, James R; Gourmelon, Anne; Burden, Natalie

    2016-04-01

    Fish toxicity testing has been conducted since the 1860's in order to help define safe levels of chemical contaminants in lakes, rivers and coastal waters. The historical emphasis on acute lethality testing of chemicals has more recently focussed on long term sublethal effects of chemicals on fish and their prey species. Fish toxicity testing is now embedded in much environment legislation on chemical safety while it is recognized that animal use should be Replaced, Reduced and Refined (the 3Rs) where possible. The OECD Fish Toxicity Testing Framework provides a useful structure with which to address the needs of environmental safety assessment whilst implementing the 3Rs. This commentary aims to promote the implementation of the recommendations of the OECD Fish Toxicity Testing Framework. PMID:26873775

  19. 40 CFR 797.1400 - Fish acute toxicity test.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... adjusted to the rate desired. (ii) The test substance is introduced into each test chamber. In a flow..., photodegradation, chemical reaction, volatilization, or sorption. (iii) Measurement of test substance. (A) For... includes determining the flow rate through each chamber and the concentration of the test...

  20. Development of a test system for screening toxic substances: a comparison using organic substances

    SciTech Connect

    Thomas, C.L.

    1985-01-01

    The purpose of this research was to develop a test system for screening toxic substances by predicting their aquatic ecosystem effects. The system studied was a static, one liter microcosm with a diverse species assemblage. The microcosm was composed of biotic inoculum, chemically defined medium and sediment. The biotic inoculum contained primary producers, grazers, carnivores and decomposers. Three different types of sediment were studied: sand, clay, and clay plus sand. Four organic chemicals: phenol, triethylene glycol (TEG), quinoline and naphthoquinone were evaluated with this test system. The toxicities of TEG, quinoline and naphthoquinone were compared for each sediment type. Toxicity was evaluated in terms of the chemical's effects on primary productivity and heterotrophic activity though other effects are also noted. Naphthoquinone concentration exhibited no correlation between ecosystem property values and therefore, could not be ranked. Phenol exhibited the greatest toxicity to net production immediately after the toxicant addition. Quinoline was most toxic to net production over the longer time scale. TEG exhibited the least toxicity to net production, however, TEG exhibited higher toxicity to heterotrophic activity than either quinoline or phenol. Although the type of sediment used in the microcosms did not change the relative toxicities of the chemicals, the microcosms with clay sediment always were observed to exhibit lower net production and higher variability.

  1. TPK Sarimukti, Cipatat, West Bandung compost toxicity test using Allium test

    NASA Astrophysics Data System (ADS)

    Wardini, Trimurti Hesti; Notodarmojo, Peni Astrini

    2015-09-01

    TPK Sarimukti, Cipatat, West Bandung produced 2 kinds of compost from traditional market waste, liquid and solid compost. The aim of this research is to evaluate toxicity of compost produced in TPK Sarimukti using shallots (Allium cepa). Tests carried out by treated shallots with liquid compost (2,5%, 5%, 10% and 12,5% (w/v)) or solid compost (25%, 50%, 75% and 100% (w/v)) for 48 hours. Results showed reduced root growth rate and mitotic index (MI) in accordance with increased concentrations of compost. Sub lethal concentrations are liquid compost 5% and 10% and solid compost 75%. Lethal concentrations are liquid compost 12,5 % and solid compost 100%. Micronuclei (MN) increased with increase in liquid compost concentration. MN found at very high frequencies in highest solid compost concentration (100%), but very low at lower concentrations. Cells with binuclei and cell necrosis increased with increasing concentrations of given compost. Nuclear anomalies (NA) found in high frequency in 75% and 100% solid compost. Based on research, we can conclude that liquid compost is more toxic because it can reduce MI and root growth rate at lower concentrations than solid compost. Both types of compost have genotoxic properties because it can induce chromosome aberration (CA), MN, binuclei and NA formation.

  2. TPK Sarimukti, Cipatat, West Bandung compost toxicity test using Allium test

    SciTech Connect

    Wardini, Trimurti Hesti; Notodarmojo, Peni Astrini

    2015-09-30

    TPK Sarimukti, Cipatat, West Bandung produced 2 kinds of compost from traditional market waste, liquid and solid compost. The aim of this research is to evaluate toxicity of compost produced in TPK Sarimukti using shallots (Allium cepa). Tests carried out by treated shallots with liquid compost (2,5%, 5%, 10% and 12,5% (w/v)) or solid compost (25%, 50%, 75% and 100% (w/v)) for 48 hours. Results showed reduced root growth rate and mitotic index (MI) in accordance with increased concentrations of compost. Sub lethal concentrations are liquid compost 5% and 10% and solid compost 75%. Lethal concentrations are liquid compost 12,5 % and solid compost 100%. Micronuclei (MN) increased with increase in liquid compost concentration. MN found at very high frequencies in highest solid compost concentration (100%), but very low at lower concentrations. Cells with binuclei and cell necrosis increased with increasing concentrations of given compost. Nuclear anomalies (NA) found in high frequency in 75% and 100% solid compost. Based on research, we can conclude that liquid compost is more toxic because it can reduce MI and root growth rate at lower concentrations than solid compost. Both types of compost have genotoxic properties because it can induce chromosome aberration (CA), MN, binuclei and NA formation.

  3. Toxicity tests of soil contaminated by recycling of scrap plastics

    SciTech Connect

    Wong, M.H.; Chui, V.W. )

    1990-03-01

    The present investigation studied the toxicity of soil contaminated by untreated discharge from a factory that recycles used plastics. The nearby agricultural areas and freshwater fish ponds were polluted with high concentrations of Cu, Ni, and Mn. Water extracts from the contaminated soil retarded root growth of Brassica chinensis (Chinese white cabbage) and Cynodon dactylon (Bermuda grass) where their seeds were obtained commercially. The contaminated populations of C. dactylon, Panicum repen (panic grass), and Imperata cylindrica (wooly grass) were able to withstand higher concentrations of Cu, Ni, and Mn, especially C. dactylon, when compared with their uncontaminated counterparts.

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

    PubMed

    Werle, Sebastian; Dudziak, Mariusz

    2015-08-01

    The process of gasification of sewage sludge generates by-products, which may be contaminated with toxic and hazardous substances, both organic and inorganic. It is therefore important to assess the environmental risk associated with this type of waste. The feasibility of using an ecotoxicological tests for this purpose was determined in the presented study. The applied tests contained indicator organisms belonging to various biological groups (bacteria, crustaceans, plants). The subject of the study were solid (ash, char) and liquid (tar) by-products generated during gasification (in a fixed bed reactor) of dried sewage sludge from various wastewater treatment systems. The tested samples were classified based on their toxic effect. The sensitivity of the indicator organisms to the tested material was determined. In-house procedures for the preparation for toxicity analysis of both sewage sludge and by-products generated during the gasification were presented. The scope of work also included the determination of the effect of selected process parameters (temperature, amount of gasifying agent) on the toxicity of gasification by-products depending on the sewage sludge source. It was shown that both the type of sewage sludge and the parameters of the gasification process affects the toxicity of the by-products of gasification. However, the results of toxicity studies also depend on the type of ecotoxicological test used, which is associated with a different sensitivity of the indicator organisms. Nevertheless, it may be concluded that the by-products formed during the gasification of the low toxicity sewage sludge can be regarded as non-toxic or low toxic. However, the results analysis of the gasification of the toxic sludge were not conclusive, which leads to further research needs in this area. PMID:25827844

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

    PubMed

    Werle, Sebastian; Dudziak, Mariusz

    2015-08-01

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

  6. Interlaboratory Evaluation of Hyalella Azteca and Chironomus Tentans Short-term and Long-term Sediment Toxicity Tests

    EPA Science Inventory

    This paper presents the results of interlaboratory toxicity tests on sediment toxicity methods for use in routine testing and this data has been presented in an EPA report and this is a summary of that data.

  7. Toxicity testing strategies for assessing water-quality conditions in receiving streams

    SciTech Connect

    Stewart, A.J.

    1994-12-31

    This paper explores the use of short-term, EPA-approved laboratory toxicity tests for assessing water-quality conditions in streams and rivers. Strategies for the cost-effective application of such tests for long-term monitoring objectives are considered in the context of logistic constraints and statistical design. A subtle but important difference in objectives for effluent versus ambient testing is this: in effluent testing for regulatory purposes, a key objective is to determine how toxic an effluent is; in ambient testing, the main objective usually is that of determining if the water at a site is toxic. This difference shapes the strategy for cost-effective ambient testing and determines the framework for effective statistical analysis and interpretation of ambient toxicity test results. Recommendations derived as `` lessons learned`` from large-scale ambient toxicity testing programs for receiving streams at Department of Energy (DOE) facilities include: (1) testing more frequently with one species (preferably Ceriodaphnia) generally is more effective, in terms of information gained per dollar spent, than testing less frequently with two or more species; (2) use five or more sites per test period, plus two or more reference sites, whenever possible; (3) use four to six test periods per year; and (4) use diagnostic testing to supplement the ambient-testing program. Various laboratory and in situ methods for environmental assessment are now under development, but these methods probably will not gain acceptance for use in regulatory situations for many years. Rapid growth in need for ecological risk assessments outstrips the rate at which new test procedures are approved for regulatory purposes. Thus, laboratory tests for estimating possible environmental impacts of toxic or disruptive pollutants are likely to be used more frequently, not less frequently, during the next decade.

  8. Environmental impact assessment of tailings dispersal from a uranium mine using toxicity testing protocols

    SciTech Connect

    Rippon, G.D.; Riley, S.J.

    1996-12-01

    Toxicity testing is a means of establishing the environmental risk of uranium tailings release. It is valuable in designing tailings containment structures because it assists in setting acceptable levels of risk of the design. This paper presents details of toxicity tests of the tailings from Ranger Uranium Mine, Northern Territory, Australia. The results suggest that the non-radiological toxicity of the tailings is low. The environmental risk of a tailings release is more likely to be related to the physical impacts of the tailings, including infilling of billabongs and changes in the sedimentology of riparian ecosystems rather than their biogeochemical impact. Two major results were: (1) water from treatment with washed tailing fines was not toxic to Hydra viridissima, and (2) mixtures of washed tailings fines and natural floodplain sediment (overlying water or elutriates) were not toxic to Hydra viridissima or Moinodaphnia macleayi. 33 refs., 4 figs., 3 tabs.

  9. Evaluation of the sensitivity of freshwater organisms used in toxicity tests of wastewater from explosives company.

    PubMed

    Ribeiro, Elaine Nolasco; da Silva, Flávio Teixeira; de Paiva, Teresa Cristina Brazil

    2012-10-01

    Explosives industries are a source of toxic discharge. The aim of this study was to compare organisms sensitivity (Daphnia similis, Danio rerio, Escherichia coli and Pseudomonas putida) in detecting acute toxicity in wastewater from two explosives, 2,4,6-TNT (TNT) and nitrocellulose. The samples were collected from an explosives company in the Paraiba Valley, São Paulo, Brazil. The effluents from TNT and nitrocellulose production were very toxic for tested organisms. Statistical tests indicated that D. similis and D. rerio were the most sensitive organisms for toxicity detection in effluents from 2,4,6-TNT and nitrocellulose production. The P. putida bacteria was the organism considered the least sensitive in indicating toxicity in effluents from nitrocellulose.

  10. ADAPTING THE MEDAKA EMBRYO ASSAY TO A HIGH-THROUGHPUT APPROACH FOR DEVELOPMENTAL TOXICITY TESTING.

    EPA Science Inventory

    Chemical exposure during embryonic development may cause persistent effects, yet developmental toxicity data exist for very few chemicals. Current testing procedures are time consuming and costly, underlining the need for rapid and low cost screening strategies. While in vitro ...

  11. EPA'S TOXCAST PROGRAM FOR PREDICTING HAZARD AND PRIORITIZING TOXICITY TESTING OF ENVIRONMENTAL CHEMICALS

    EPA Science Inventory

    EPA is developing methods for utilizing computational chemistry, high-throughput screening (HTS) and various toxicogenomic technologies to predict potential for toxicity and prioritize limited testing resources towards chemicals that likely represent the greatest hazard to human ...

  12. EPA's Toxcast ™ Program for Predicting Hazard and Priortizing Toxicity Testing of Environemntal Chemicals (T)

    EPA Science Inventory

    EPA is developing methods for utilizing computational chemistry, high-throughput screening (HTS) and various toxicogenomic technologies to predict potential for toxicity and prioritize limited testing resources towards chemicals that likely represent the greatest hazard to human ...

  13. EPAS TOXCAST PROGRAM FOR PREDICTING HAZARD AND PRIORITIZING TOXICITY TESTING OF ENVIRONMENTAL CHEMICALS(S).

    EPA Science Inventory

    EPAs National Center for Computational Toxicology is developing methods that apply computational chemistry, high-throughput screening (HTS) and genomic technologies to predict potential toxicity and prioritize the use of limited testing resources.

  14. A Roadmap for the Development of Alternative (Non-Animal) Methods for Systemic Toxicity Testing

    EPA Science Inventory

    Systemic toxicity testing forms the cornerstone for the safety evaluation of substances. Pressures to move from traditional animal models to novel technologies arise from various concerns, including: the need to evaluate large numbers of previously untested chemicals and new prod...

  15. Evaluation of an alternative in vitro test battery for detecting reproductive toxicants.

    PubMed

    Piersma, A H; Bosgra, S; van Duursen, M B M; Hermsen, S A B; Jonker, L R A; Kroese, E D; van der Linden, S C; Man, H; Roelofs, M J E; Schulpen, S H W; Schwarz, M; Uibel, F; van Vugt-Lussenburg, B M A; Westerhout, J; Wolterbeek, A P M; van der Burg, B

    2013-07-01

    The application of alternative methods in developmental and reproductive toxicology is challenging in view of the complexity of mechanisms involved. A battery of complementary test systems may provide a better prediction of developmental and reproductive toxicity than single assays. We tested twelve compounds with varying mechanisms of toxic action in an assay battery including 24 CALUX transcriptional activation assays, mouse cardiac embryonic stem cell test, ReProGlo assay, zebrafish embryotoxicity assay, and two CYP17 and two CYP19 activity assays. The battery correctly detected 11/12 compounds tested, with one false negative occurring, which could be explained by the absence of the specific mechanism of action of this compound in the battery. Toxicokinetic modeling revealed that toxic concentrations were in the range expected from in vivo reproductive toxicity data. This study illustrates added value of combining assays that contain complementary biological processes and mechanisms, increasing predictive value of the battery over individual assays.

  16. 76 FR 38170 - Toxic Substances Control Act Chemical Testing; Receipt of Test Data

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-29

    ... issue of March 16, 2006 (71 FR 13708) (FRL-7335-2). Section 4(d) of TSCA (15 U.S.C. 2603(d)) requires... Toxicity to Fish. 9. Acute Toxicity to Aquatic Invertebrates. 10. Toxicity to Aquatic Plants, e.g.,...

  17. 40 CFR 797.1950 - Mysid shrimp chronic toxicity test.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    .... (A) Any change in the temperature and chemistry of the water used for holding or culturing the test... total organic carbon (or chemical oxygen demand) shall be measured on each batch. (v) Test...

  18. 40 CFR 797.1950 - Mysid shrimp chronic toxicity test.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    .... (A) Any change in the temperature and chemistry of the water used for holding or culturing the test... total organic carbon (or chemical oxygen demand) shall be measured on each batch. (v) Test...

  19. 40 CFR 797.1950 - Mysid shrimp chronic toxicity test.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .... (A) Any change in the temperature and chemistry of the water used for holding or culturing the test... total organic carbon (or chemical oxygen demand) shall be measured on each batch. (v) Test...

  20. 40 CFR 797.1950 - Mysid shrimp chronic toxicity test.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .... (A) Any change in the temperature and chemistry of the water used for holding or culturing the test... total organic carbon (or chemical oxygen demand) shall be measured on each batch. (v) Test...

  1. 40 CFR 797.1950 - Mysid shrimp chronic toxicity test.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... (A) Any change in the temperature and chemistry of the water used for holding or culturing the test... total organic carbon (or chemical oxygen demand) shall be measured on each batch. (v) Test...

  2. Revolutionizing Toxicity Testing For Predicting Developmental Outcomes (DNT4)

    EPA Science Inventory

    Characterizing risk from environmental chemical exposure currently requires extensive animal testing; however, alternative approaches are being researched to increase throughput of chemicals screened, decrease reliance on animal testing, and improve accuracy in predicting adverse...

  3. 40 CFR 797.1300 - Daphnid acute toxicity test.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... dilution water through a test chamber or culture tank with no recycling. (5) Immobilization means the lack... solutions. (ii) Construction materials. (A) Materials and equipment that contact test solutions should...

  4. 40 CFR 797.1300 - Daphnid acute toxicity test.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... dilution water through a test chamber or culture tank with no recycling. (5) Immobilization means the lack... solutions. (ii) Construction materials. (A) Materials and equipment that contact test solutions should...

  5. 40 CFR 797.1300 - Daphnid acute toxicity test.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... dilution water through a test chamber or culture tank with no recycling. (5) Immobilization means the lack... solutions. (ii) Construction materials. (A) Materials and equipment that contact test solutions should...

  6. Intra- and interlaboratory variability in acute toxicity tests with glochidia and juveniles of freshwater mussels (Unionidae)

    USGS Publications Warehouse

    Wang, N.; Augspurger, T.; Barnhart, M.C.; Bidwell, Joseph R.; Cope, W.G.; Dwyer, F.J.; Geis, S.; Greer, I.E.; Ingersoll, C.G.; Kane, C.M.; May, T.W.; Neves, R.J.; Newton, T.J.; Roberts, A.D.; Whites, D.W.

    2007-01-01

    The present study evaluated the performance and variability in acute toxicity tests with glochidia and newly transformed juvenile mussels using the standard methods outlined in American Society for Testing and Materials (ASTM). Multiple 48-h toxicity tests with glochidia and 96-h tests with juvenile mussels were conducted within a single laboratory and among five laboratories. All tests met the test acceptability requirements (e.g., ???90% control survival). Intralaboratory tests were conducted over two consecutive mussel-spawning seasons with mucket (Actinonaias ligamentina) or fatmucket (Lampsilis siliquoidea) using copper, ammonia, or chlorine as a toxicant. For the glochidia of both species, the variability of intralaboratory median effective concentrations (EC50s) for the three toxicants, expressed as the coefficient of variation (CV), ranged from 14 to 27% in 24-h exposures and from 13 to 36% in 48-h exposures. The intralaboratory CV of copper EC50s for juvenile fatmucket was 24% in 48-h exposures and 13% in 96-h exposures. Interlaboratory tests were conducted with fatmucket glochidia and juveniles by five laboratories using copper as a toxicant. The interlaboratory CV of copper EC50s for glochidia was 13% in 24-h exposures and 24% in 48-h exposures, and the interlaboratory CV for juveniles was 22% in 48-h exposures and 42% in 96-h exposures. The high completion success and the overall low variability in test results indicate that the test methods have acceptable precision and can be performed routinely. ?? 2007 SETAC.

  7. A new biological test utilising the yeast Saccharomyces cerevisiae for the rapid detection of toxic substances in water.

    PubMed

    Rumlova, Lubomira; Dolezalova, Jaroslava

    2012-05-01

    This study evaluates the toxic effects of five substances (atropine, fenitrothion, potassium cyanide, mercuric chloride and lead nitrate) on the yeast Saccharomyces cerevisiae. It describes a new biological toxicity test based on inhibition of S. cerevisiae viability and compares it with two standard toxicity tests based on Daphnia magna mobility inhibition (EN ISO 6341) and Vibrio fischeri bioluminiscence inhibition (EN ISO 11348-2). The new biological test -S. cerevisiae lethal test - is cheaper and 24 times faster than the D. magna test. The test speed is comparable with the V. fischeri test but the new test is more sensitive for some substances. The test indicates reliably the presence of all used toxicants in water in concentrations which are significantly lower than the concentration in toxic or lethal doses for man. Therefore, this new toxicity test could be proposed for rapid detection of toxic substances in water.

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

    USGS Publications Warehouse

    Elder, J.F.

    1989-01-01

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

  9. An Evaluation of Select Test Variables Potentially Affecting Acute Oil Toxicity.

    PubMed

    Echols, Brandi S; Smith, A; Gardinali, P; Rand, G

    2016-02-01

    In the wake of the Deepwater Horizon incident (2010) in the Gulf of Mexico, an abundance of research studies have been performed, but the methodologies used have varied making comparisons and replication difficult. In this study, acute toxicity tests with mysids and inland silversides were performed to examine the effect of different variables on test results. The toxicity test variables evaluated in this study included (1) open versus closed static test chambers, (2) natural versus artificial diluent, (3) aerated versus nonaerated test solution, and (4) low versus medium energy water-accommodated (WAF) mixing energies. The use of tests using natural or artificial diluent showed no difference in either toxicity test or analytical chemistry results. Based on median lethal concentrations (LC50) of WAFs of unweathered oil (MASS), mysid tests performed in closed chambers were approximately 41 % lower than LC50 values from open-chamber studies, possibly a result of the presence of low-molecular weight volatile aromatics (i.e., naphthalenes). This research also showed that using a medium-energy WAF (with a 20–25 % vortex) increases the number of chemical components compared with low-energy WAF, thus affecting the composition of the exposure media and increasing toxicity. The comparison of toxic units as a measure of the potential toxicity of fresh and weathered oils showed that weathered oils (e.g., Juniper, CTC) are less toxic than the unweathered MASS oil. In the event of future oil spills, these variables should be considered to ensure that data regarding the potential toxicity and environmental risk are of good quality and reproducible.

  10. An Evaluation of Select Test Variables Potentially Affecting Acute Oil Toxicity.

    PubMed

    Echols, Brandi S; Smith, A; Gardinali, P; Rand, G

    2016-02-01

    In the wake of the Deepwater Horizon incident (2010) in the Gulf of Mexico, an abundance of research studies have been performed, but the methodologies used have varied making comparisons and replication difficult. In this study, acute toxicity tests with mysids and inland silversides were performed to examine the effect of different variables on test results. The toxicity test variables evaluated in this study included (1) open versus closed static test chambers, (2) natural versus artificial diluent, (3) aerated versus nonaerated test solution, and (4) low versus medium energy water-accommodated (WAF) mixing energies. The use of tests using natural or artificial diluent showed no difference in either toxicity test or analytical chemistry results. Based on median lethal concentrations (LC50) of WAFs of unweathered oil (MASS), mysid tests performed in closed chambers were approximately 41 % lower than LC50 values from open-chamber studies, possibly a result of the presence of low-molecular weight volatile aromatics (i.e., naphthalenes). This research also showed that using a medium-energy WAF (with a 20–25 % vortex) increases the number of chemical components compared with low-energy WAF, thus affecting the composition of the exposure media and increasing toxicity. The comparison of toxic units as a measure of the potential toxicity of fresh and weathered oils showed that weathered oils (e.g., Juniper, CTC) are less toxic than the unweathered MASS oil. In the event of future oil spills, these variables should be considered to ensure that data regarding the potential toxicity and environmental risk are of good quality and reproducible. PMID:26467150

  11. [Temporal-spatial distribution of algal cells during drought period in Daning River of Three Gorges].

    PubMed

    Zhang, Yong-Sheng; Zheng, Bing-Hui; Wang, Kun; Jiang, Xia; Zheng, Hao

    2013-06-01

    In order to provide basic data for algal bloom warning system, the study on temporal-spatial distribution of algal cells was carried out in Daning River of Three Gorges form April to September, 2011. The results of temporal distribution were as follows: the dominant algal species were blue algal, green algal and diatom. During the test, the density proportion of blue algae increased continuously, the density proportion of diatom decreased, while the density proportion of green algae did not change significantly. The results of spatial distribution were as follows: algal density was extremely significantly correlated with water temperature and chlorophyll a (Chl a), the correlation coefficient were 0.97 and 0.95, respectively; algal density was significantly correlated with light intensity (LI), dissolved oxygen (DO), pH and dissoluble total phosphorus (DTP), the correlation coefficient were 0.87, 0.83, 082 and 0.82, respectively; the algal density in 0 m of Caziba was higher than those in other water depths, and in Baishuihe the highest algal density occurred at 2.0 m water depth in June and July, in Shuanglong most algal cells were found in 0 m and 2.0 m in July, August and September, in Dachang algal density in different water depth did not change significantly during the test; the proportion of different algal species in vertical direction was different in the test, probably because different algal species fitted different environments.

  12. Comparison of toxicity values across zebrafish early life stages and mammalian studies: Implications for chemical testing.

    PubMed

    Ducharme, Nicole A; Reif, David M; Gustafsson, Jan-Ake; Bondesson, Maria

    2015-08-01

    With the high cost and slow pace of toxicity testing in mammals, the vertebrate zebrafish has become a tractable model organism for high throughput toxicity testing. We present here a meta-analysis of 600 chemicals tested for toxicity in zebrafish embryos and larvae. Nineteen aggregated and 57 individual toxicity endpoints were recorded from published studies yielding 2695 unique data points. These data points were compared to lethality and reproductive toxicology endpoints analyzed in rodents and rabbits and to exposure values for humans. We show that although many zebrafish endpoints did not correlate to rodent or rabbit acute toxicity data, zebrafish could be used to accurately predict relative acute toxicity through the rat inhalation, rabbit dermal, and rat oral exposure routes. Ranking of the chemicals based on toxicity and teratogenicity in zebrafish, as well as human exposure levels, revealed that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), benzo(a)pyrene, and chlorpyrifos ranked in the top nine of all chemicals for these three categories, and as such should be considered high priority chemicals for testing in higher vertebrates. PMID:25261610

  13. Comparison of toxicity values across zebrafish early life stages and mammalian studies: Implications for chemical testing.

    PubMed

    Ducharme, Nicole A; Reif, David M; Gustafsson, Jan-Ake; Bondesson, Maria

    2015-08-01

    With the high cost and slow pace of toxicity testing in mammals, the vertebrate zebrafish has become a tractable model organism for high throughput toxicity testing. We present here a meta-analysis of 600 chemicals tested for toxicity in zebrafish embryos and larvae. Nineteen aggregated and 57 individual toxicity endpoints were recorded from published studies yielding 2695 unique data points. These data points were compared to lethality and reproductive toxicology endpoints analyzed in rodents and rabbits and to exposure values for humans. We show that although many zebrafish endpoints did not correlate to rodent or rabbit acute toxicity data, zebrafish could be used to accurately predict relative acute toxicity through the rat inhalation, rabbit dermal, and rat oral exposure routes. Ranking of the chemicals based on toxicity and teratogenicity in zebrafish, as well as human exposure levels, revealed that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), benzo(a)pyrene, and chlorpyrifos ranked in the top nine of all chemicals for these three categories, and as such should be considered high priority chemicals for testing in higher vertebrates.

  14. Computerized in vitro test for chemical toxicity based on tetrahymena swimming patterns

    NASA Technical Reports Server (NTRS)

    Noever, David A.; Matsos, Helen C.; Cronise, Raymond J.; Looger, Loren L.; Relwani, Rachna A.; Johnson, Jacqueline U.

    1994-01-01

    An apparatus and method for rapidly determining chemical toxicity was evaluated. The toxicity monitor includes an automated scoring of how motile biological cells (Tetrahymena pyriformis) slow down or otherwise change their swimming patterns in a hostile chemical environment. The device, called the Motility Assay Apparatus (MAA) is tested for 30 second determination of chemical toxicity in 20 aqueous samples containing trace organics and salts. With equal or better detection limits, results compare favorably to in vivo animal tests of eye irritancy, in addition to agreeing for all chemicals with previous manual evaluations of single cell motility.

  15. Alternative methods for toxicity assessments in fish: comparison of the fish embryo toxicity and the larval growth and survival tests in zebrafish and fathead minnows.

    PubMed

    Jeffries, Marlo K Sellin; Stultz, Amy E; Smith, Austin W; Rawlings, Jane M; Belanger, Scott E; Oris, James T

    2014-11-01

    An increased demand for chemical toxicity evaluations has resulted in the need for alternative testing strategies that address animal welfare concerns. The fish embryo toxicity (FET) test developed for zebrafish (Danio rerio) is one such alternative, and the application of the FET test to other species such as the fathead minnow (Pimephales promelas) has been proposed. In the present study, the performances of the FET test and the larval growth and survival (LGS; a standard toxicity testing method) test in zebrafish and fathead minnows were evaluated. This required that testing methods for the fathead minnow FET and zebrafish LGS tests be harmonized with existing test methods and that the performance of these testing strategies be evaluated by comparing the median lethal concentrations of 2 reference toxicants, 3,4-dicholoraniline and ammonia, obtained via each of the test types. The results showed that procedures for the zebrafish FET test can be adapted and applied to the fathead minnow. Differences in test sensitivity were observed for 3,4-dicholoraniline but not ammonia; therefore, conclusions regarding which test types offer the least or most sensitivity could not be made. Overall, these results show that the fathead minnow FET test has potential as an alternative toxicity testing strategy and that further analysis with other toxicants is warranted in an effort to better characterize the sensitivity and feasibility of this testing strategy.

  16. Relative toxicity testing of spacecraft materials. 2: Aircraft materials

    NASA Technical Reports Server (NTRS)

    Lawrence, W. H.

    1980-01-01

    The relative toxicity of thermodegradation (pyrolysis/combustion) products of aircraft materials was studied. Two approaches were taken to assess the biological activity of the pyrolysis/combustion products of these materials: (1) determine the acute lethality to rats from inhalation of these pyrolysates and (2) examine the tendency for sublethal exposure to the pyrolysates to disrupt behavioral (shock avoidance) performance of exposed rats. The ralative importance of lethality vs. behavioral effects in selection of a material may be dictated by whether or not individuals potentially exposed to such products, would have an opportunity to escape if they were behaviorally capable of doing so. If so, the second parameter would assume greater importance, but if not the first parameter may be of much greater importance in selecting materials.

  17. Subchronic percutaneous toxicity testing of two liquid hand dishwashing detergents.

    PubMed

    Petersen, D W

    1988-09-01

    Subchronic percutaneous toxicity studies were conducted on two liquid dishwashing detergents containing anionic surfactants (C12-14 alkylethoxylate sulphate) to assess the safety of these materials for human exposure. The detergents were administered dermally to the shaved backs of rabbits (dose volume of 2 ml/kg body weight) at concentrations of 0, 0.5, 1.0 and 2.5% in distilled water for 91 days. No adverse systemic effects were demonstrated by assessment of haematological parameters or by gross or microscopic tissue examination. Transient slight to moderate dermal irritation at the detergent application site was observed with detergent A. Slight to moderate dermal irritation confined to the detergent application site was noted in the detergent B study.

  18. Assessing the toxicity of contaminated soils using the nematode Caenorhabditis elegans as test organism.

    PubMed

    Höss, S; Jänsch, S; Moser, T; Junker, T; Römbke, J

    2009-10-01

    In this study, nine uncontaminated reference soils and 22 contaminated soils with different physico-chemical properties and contamination patterns were tested with a standardized toxicity test, using the nematode, Caenorhabditis elegans, as test organism. Fertility, growth and reproduction of C. elegans in the soils were compared with the exposure in standard soil Lufa St.2.2. C. elegans showed 100% fertility and a very low variability of growth in the reference soils. Although, reproduction varied considerably between the various reference soils, validity criteria (>30 offspring per test organism) were met in all reference soils. Moreover, Lufa St. 2.2 turned out to be a suitable and representative control soil. In order to clearly classify the effects of the polluted soils on C. elegans, toxicity thresholds were derived for nematode fertility (20% inhibition), growth (10% inhibition) and reproduction (40% inhibition) on the basis of the test inherent variability (MDD=minimal detectable difference), as well as their variability between the uncontaminated reference soils (MTI=maximal tolerable inhibition). The contaminated soils showed clear toxic effects on the nematodes, whereas the toxicity was better correlated to organic than to heavy metal contamination in bulk soil. Interestingly, the results of the nematode toxicity test were not well correlated with those of tests with oligochaetes, collembolans and plants, performed with the same soils, showing that the results are not redundant. The toxicity test using C. elegans turned out to be suitable for testing the toxicity of field collected soils and might by a valuable addition to soil test batteries.

  19. Multispecies methods of testing for toxicity: Use of the Rhizobium-legume symbiosis in nitrogen fixation and correlations between responses by algae and terrestrial plants

    SciTech Connect

    Garten, C.T. Jr.

    1989-01-01

    Responses of the Rhizobium-legume symbiotic relationship to long-term (5- to 7-week) and short-term (2-week) exposures of copper sulfate, 2,4-dichlorophenoxyacetic acid, and streptomycin sulfate were examined in bush beans and clover. Toxic effects were evaluated by comparing plant biomass (yield), nodulation success, nitrogen fixation rate as indicated by acetylene reduction, and plant nitrogen content in controls and in plants exposed to various concentrations of the chemicals. Plants with long-term continuous root exposure were affected more than plants with short-term exposure, as indicated by reductions in nitrogen fixation rates and plant growth. Although rates of acetylene reduction (nitrogen fixation) were depressed, plants biomass and the numbers of root nodules produced were simpler, less expensive indices of exposure. In a second test, the responses of algae (Selenastrum capricornutum and Chlorella vulgaris) and terrestrial plants (radishes, barley, bush beans, and soybeans) to 21 different herbicides were compared to evaluate the use of a short-term (96-h) algal growth inhibition test for identifying chemicals potentially toxic to terrestrial plants.

  20. Use of sublethal endpoints in sediment toxicity testing with the amphipod Hyalella azteca

    SciTech Connect

    Kemble, N.E.; Brunson, E.B.; Dwyer, F.J.; Ehrhardt, E.A.; Hardesty, D.K.; Haverland, P.S.; Ingersoll, C.G.

    1995-12-31

    ASTM and EPA standard methods for sediment toxicity tests with Hyalella azteca typically recommend use of lethality as the endpoint in a 10-d exposure. However, data from 10- to 28-d exposures with amphipods indicate sublethal endpoints (i.e., growth, sexual maturation, or reproduction) identify additional samples as toxic. The authors compared the frequency that lethal and sublethal endpoints identified a sediment sample as toxic in 14- and 28-d amphipod exposures. In the 14-d amphipod exposures, lethality identified 20% of the samples as toxic, and sublethal endpoints identified an additional 16% of the samples as toxic using sublethal endpoints only. Similarly, in the 28-d exposures, lethality identified 14% of the samples as toxic and sublethal endpoints identified an additional 18% of the samples as toxic. The authors are also currently evaluating Sediment Effect Concentrations (SECs) relative to both lethal and sublethal endpoints in H. azteca exposures. These SECs will be used to evaluate reliability in estimating toxicity of samples. Potential factors which may confound interpretation of sublethal endpoints in sediment tests include: (1) changes in sediment chemistry resulting from long-term storage or feeding (2) the influence of physical characteristics of sediment (grain size), and (3) effects of ammonia or hydrogen sulfide.

  1. Assessment of Jatropha curcas L. biodiesel seed cake toxicity using the zebrafish (Danio rerio) embryo toxicity (ZFET) test.

    PubMed

    Hallare, Arnold V; Ruiz, Paulo Lorenzo S; Cariño, J C Earl D

    2014-05-01

    Consequent to the growing demand for alternative sources of energy, the seeds from Jatropha curcas remain to be the favorite for biodiesel production. However, a significant volume of the residual organic mass (seed cake) is produced during the extraction process, which raises concerns on safe waste disposal. In the present study, we assessed the toxicity of J. curcas seed cake using the zebrafish (Danio rerio) embryotoxicity test. Within 1-h post-fertilization (hpf), the fertilized eggs were exposed to five mass concentrations of J. curcas seed cake and were followed through 24, 48, and 72 hpf. Toxicity was evaluated based on lethal endpoints induced on zebrafish embryos namely egg coagulation, non-formation of somites, and non-detachment of tail. The lowest concentration tested, 1 g/L, was not able to elicit toxicity on embryos whereas 100 % mortality (based also on lethal endpoints) was recorded at the highest concentration at 2.15 g/L. The computed LC50 for the J. curcas seed cake was 1.61 g/L. No further increase in mortality was observed in the succeeding time points (48 and 72 hpf) indicating that J. curcas seed cake exerted acute toxicity on zebrafish embryos. Sublethal endpoints (yolk sac and pericardial edema) were noted at 72 hpf in zebrafish embryos exposed to higher concentrations. The observed lethal endpoints induced on zebrafish embryos were discussed in relation to the active principles, notably, phorbol esters that have remained in the seed cake even after extraction.

  2. Toxicity tests of effluents with marsh plants in water and sediment

    SciTech Connect

    Walsh, G.E.; Weber, D.E.; Simon, T.L.; Brashers, L.K.

    1991-01-01

    Methods are described for toxicity testing of water and sediment with two varieties of the freshwater marsh plant Echinochloa crusgalli (Linneaus) Palisot de Beauvois (Poaceae), and complex effluents. Two tests are described: a seed germination and early seedling growth test in water, and a survival and seedling growth test in natural and synthetic sediments. Effects of effluents from a sewage treatment plant, tannery, textile mill, pulp and paper mill, coking plant and sewage treatment plant included inhibition of germination, chlorophyll synthesis and growth. The tests with rooted marsh plants were sensitive to pollutants and detected toxicity of a range of pollutants in water and sediment. Synthetic sediments similar to natural sediments allowed toxicity tests to be done under carefully controlled conditions of particle size distribution, organic content, pH, electrode potential (Eh) and cation exchange capacity (CEC).

  3. Influence of sediment composition on apparent toxicity in a solid-phase test using bioluminescent bacteria

    SciTech Connect

    Benton, M.J.; Malott, M.L. |; Knight, S.S.; Cooper, C.M.; Benson, W.H.

    1995-03-01

    Clean and spiked sediment formulations of various silt:sand and clay:sand ratios were tested for toxicity using a bioassay that utilizes bioluminescent bacteria. Measured toxicities of clean and copper sulfate-spiked sediments were negatively but nonlinearly related with percent silt and percent clay, but no significant relationship existed between measured toxicity and sediment composition for methyl parathion-spiked formulations. Results suggest that solid-phase sediment bioassays using bioluminescence bacteria may be useful for testing the toxicities of single contaminants in formulated artificial sediments of known particle-size composition, and for repeated samples collected from the same site. However, extreme caution must be taken when testing sediments of varying composition or which may be differentially contaminated or contain a suite of contaminants.

  4. Cumulative bioluminescence; A potential rapid test of drilling fluid toxicity: development study

    SciTech Connect

    Stiffey, A.V. )

    1992-03-01

    A new rapid test of drilling fluid toxicity is based on the spontaneous bioluminescence of Pyrocystis lunula, an easy-to-culture alga that vigorously responds to shear stress (mixing) by emitting a sharp burst of light. In contrast to other bioluminescence methods, a cumulative flux of light is measured with a photomultiplier that eliminates the effect of exposure time on test results. Light quenching, caused by the presence of a toxicant, results in the dose/response relationship (DSR) typical for the enzymatic reaction kinetics. The Michaelis-Menten (dissociation) constant is used as a direct measure of toxicity. The evaluation study involved multiple experiments with 60 samples of drilling fluids from the U.S. gulf coast, as well as such typical toxicants as diesel oil, mineral oil, and chrome lignosulfonate (CLS). In this paper, the results of the test error analysis and comparisons with the Microtox and Mysid shrimp assays are reported.

  5. Cross-Sector Review of Drivers and Available 3Rs Approaches for Acute Systemic Toxicity Testing

    PubMed Central

    Seidle, Troy; Robinson, Sally; Holmes, Tom; Creton, Stuart; Prieto, Pilar; Scheel, Julia; Chlebus, Magda

    2010-01-01

    Acute systemic toxicity studies are carried out in many sectors in which synthetic chemicals are manufactured or used and are among the most criticized of all toxicology tests on both scientific and ethical grounds. A review of the drivers for acute toxicity testing within the pharmaceutical industry led to a paradigm shift whereby in vivo acute toxicity data are no longer routinely required in advance of human clinical trials. Based on this experience, the following review was undertaken to identify (1) regulatory and scientific drivers for acute toxicity testing in other industrial sectors, (2) activities aimed at replacing, reducing, or refining the use of animals, and (3) recommendations for future work in this area. PMID:20484382

  6. Field Validation of Toxicity Tests to Evaluate the Potential for Beneficial Use of Produced Water

    SciTech Connect

    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

  7. 40 CFR 797.1330 - Daphnid chronic toxicity test.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... chambers of the high, middle, low, and control test concentrations. (e) Reporting. The sponsor shall submit... brood stock, including the scientific name and method of verification, age, source, treatments, feeding history, acclimation procedures, and culture methods. The age of the daphnids used in the test shall...

  8. 40 CFR 797.1330 - Daphnid chronic toxicity test.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... chambers of the high, middle, low, and control test concentrations. (e) Reporting. The sponsor shall submit... brood stock, including the scientific name and method of verification, age, source, treatments, feeding history, acclimation procedures, and culture methods. The age of the daphnids used in the test shall...

  9. Toxicity bioassays: Water-pollution effects on aquatic animals and plants. (Latest citations from the Selected Water Resources Abstracts data base). Published Search

    SciTech Connect

    Not Available

    1992-08-01

    The bibliography contains citations concerning toxicity bioassay studies of water pollution effects on reproduction, growth, and mortality of aquatic fauna and flora. Industrial and agricultural water pollutants such as heavy metals, chemicals, pesticides, and herbicides are evaluated and tested. Standard fish and algal assays are used to determine effects of potential toxicants. (Contains 250 citations and includes a subject term index and title list.)

  10. Toxicity bioassays: Water pollution effects on aquatic animals and plants. (Latest citations from the Selected Water Resources Abstracts database). Published Search

    SciTech Connect

    Not Available

    1993-11-01

    The bibliography contains citations concerning toxicity bioassay studies of water pollution effects on reproduction, growth, and mortality of aquatic fauna and flora. Industrial and agricultural water pollutants such as heavy metals, chemicals, pesticides, and herbicides are evaluated and tested. Standard fish and algal assays are used to determine effects of potential toxicants. (Contains 250 citations and includes a subject term index and title list.)

  11. Change in Photosystem II Photochemistry During Algal Growth Phases of Chlorella vulgaris and Scenedesmus obliquus.

    PubMed

    Oukarroum, Abdallah

    2016-06-01

    Sensitivity of photosynthetic processes towards environmental stress is used as a bioanalytical tool to evaluate the responses of aquatic plants to a changing environment. In this paper, change of biomass density, chlorophyll a fluorescence and photosynthetic parameters during growth phases of two microalgae Chlorella vulgaris and Scenedesmus obliquus were studied. The photosynthetic growth behaviour changed significantly with cell age and algae species. During the exponential phase of growth, the photosynthesis capacity reached its maximum and decreased in ageing algal culture during stationary phase. In conclusion, the chlorophyll a fluorescence OJIP method and the derived fluorescence parameters would be an accurate method for obtaining information on maximum photosynthetic capacities and monitoring algal cell growth. This will contribute to more understanding, for example, of toxic actions of pollutants in microalgae test. PMID:26868257

  12. Algal Biofuels Fact Sheet

    SciTech Connect

    2009-10-27

    This fact sheet provides information on algal biofuels, which are generating considerable interest around the world. They may represent a sustainable pathway for helping to meet the U.S. biofuel production targets set by the Energy Independence and Security Act of 2007.

  13. Toxic Substances Control Act (TSCA) Test Submissions Database (TSCATS) - comprehensive update (on magnetic tape). Data file

    SciTech Connect

    1996-07-01

    The Toxic Substances Control Act Test Submissions Database (TSCATS) was developed to make unpublished test data available to the public. The test data are submitted to the U.S. Environmental Protection Agency by industry under the Toxic Substances Control Act. Test data are broadly defined to include case reports, episodic incidents, such as spills, and formal test study presentations. The database allows searching of test submissions formal test study presentations. The database allows searching of test submissions according to specific chemical identity or type of study when used with an appropriate search retrieval software program. Studies are indexed under three broad subject areas: health effects, environmental effects and environmental fate. Additional controlled vocabulary terms are assigned which describe the experimental protocol and test observations. Records identify reference information needed to locate the source document, as well as the submitting organization and reason for submission of the test data.

  14. Acute toxicity testing with the tropical marine copepod Acartia sinjiensis: optimisation and application.

    PubMed

    Gissi, F; Binet, M T; Adams, M S

    2013-11-01

    Globally there is limited toxicity data for tropical marine species, and there has been a call for further research and development in the area of tropical marine ecotoxicology. An increase in developmental pressures in northern tropical Australia is causing a higher demand for toxicity test protocols with ecologically relevant species. Copepods are a diverse group of zooplankton that are major components of marine food webs. The calanoid copepod Acartia sinjiensis is widely distributed across tropical and sub-tropical brackish to marine waters of Australia and was identified in a recent comprehensive review of marine tropical toxicity testing in Australia as a suitable test organism. Through a number of optimisation steps including feeding trials, changes to culture and test conditions; a 48-h acute toxicity test with A. sinjiensis was modified to become a highly reliable and reproducible standard test protocol. Control mobility was improved significantly, and the sensitivity of A. sinjiensis to copper (EC50 of 33µg/L), ammonia (EC50 of 10mg/L) and phenol (EC50 of 13mg/L) fell within the ranges of those reported previously, indicating that the modifications did not alter its sensitivity. In a comprehensive literature search we found that this species was the most sensitive to copper out of a range of marine copepods. The test was also successfully applied in toxicity assessments of four environmental samples: two produced formations waters (PFWs) and two mine tailing liquors (MTLs). The toxicity assessments utilised toxicity data from a suite of marine organisms (bacteria, microalgae, copepods, sea urchins, oysters, prawns, and fish). For the PFWs, which were predominantly contaminated with organic chemicals, A. sinjiensis was the most sensitive species (EC50 value 2-17 times lower than for any other test species). For the predominantly metal-contaminated mine tailing liquors, its sensitivity was similar to that of other test species used. The modified 48-h acute

  15. Use of tracheal organ cultures in toxicity testing.

    PubMed Central

    Lane, B P; Miller, S L; Drummond, E J

    1976-01-01

    Fragments of tracheal epithelium alone or in continuity with connective tissues, can be maintained in culture medium and used for short term or long term studies of toxicity of a variety of chemicals. Large numbers of uniform cultures are prepared with the aid of a slicing device or by application of simple method for dissecting sheets of epithelium free from underlying cartilage. The cultures may be placed in an exposure chamber-incubator mounted on a microscope stage and monitored continually for ciliostasis and exfoliation of cells. Morphology is further studied by fixation of selected specimens and preparation for light microscopy and electron microscopy. Synthetic functions are evaluated by autoradiographic measurement of incorporation of radioactive precursors into macromolecules and other dynamic features are indirectly assessed by histochemical and histoenzymatic methods. Short-term studies using these several techniques have shown that ciliostasis does not correlate with cell injury in all instances, and a long-term study has demonstrated dose dependence of a cytotoxic agent when duration of culture viability is measured. The method lends itself to a broad range of investigations in which dose, period of exposure, and role of cofactors must be independently and quantitatively assessed. Images FIGURE 1. FIGURE 2. FIGURE 3. FIGURE 4. FIGURE 5. FIGURE 6. FIGURE 7. FIGURE 8. FIGURE 9. FIGURE 10. FIGURE 11. FIGURE 12. PMID:1017423

  16. Toxic effects of occupational and environmental chemicals on the testes

    SciTech Connect

    Sever, L.E.; Hessol, N.A.

    1983-01-01

    This paper examines evidence for effects of occupational chemicals on male reproduction. We consider primarily human data, and much of that from epidemiologic studies. We use animal studies to illustrate points, but the theme is the human experience. The approach is based on examining reproductive function as an indicator of toxic effects. Testicular structure and function is briefly discussed. We provide a brief review of relevant structure, function and hormonal control. We describe the anatomy of the testis and its histological structure. We then discuss the testis from the point of view of exocrine and endocrine function and the relationship of the testis to other endocrinological organs. This is followed by a review of methods for assessing human testicular function, including reproductive histories, sperm analysis, assessment of hormonal status, and histological studies. Although the primary focus is on human studies, we consider briefly general categories of chemicals shown to have a testicular effect in animal studies and also animal evidence of mechanisms of action associated with testicular toxicology. Specific chemicals shown to affect reproduction in the human male are reviewed and directions for future research in this area discussed.

  17. 40 CFR 797.1930 - Mysid shrimp acute toxicity test.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... the temperature and chemistry of the dilution water used for holding or culturing the test organisms... source, conductivity and total organic carbon (or chemical oxygen demand) shall be measured on each...

  18. Current Development in Reproductive Toxicity Testing of Pesticides

    EPA Science Inventory

    A protocol to evaluate the potential developmental and reproductive effects of test chemicals has been developed by the Life Stages Task Force of the International Life Sciences Institute (ILSI)/Health and Environmental Sciences Institute (HESI) Agricultural Chemical Safety Asses...

  19. 40 CFR 795.120 - Gammarid acute toxicity test.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... through a test chamber or a holding or acclimation tank, with no recycling. LC50 means the median lethal... the entry of dust or other particulates into the solutions. (ii) Construction materials....

  20. 40 CFR 795.120 - Gammarid acute toxicity test.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... through a test chamber or a holding or acclimation tank, with no recycling. LC50 means the median lethal... the entry of dust or other particulates into the solutions. (ii) Construction materials....

  1. Effect of sampling method on measured concentrations of sulfide and ammonia in sediment toxicity tests

    SciTech Connect

    Phillips, B.M.; Anderson, B.S.; Hunt, J.W.

    1994-12-31

    Sulfide and ammonia are natural components of marine sediments which may occur in concentrations toxic to marine organisms. Because these compounds are toxic, it is important to measure them accurately to determine their influence on toxicity test results. Standard solid phase test protocols may not adequately address sampling methodology for ammonia and sulfide analysis. Samples are commonly taken from overlying water in test containers, which may not adequately characterize the medium to which test animals are exposed. As part of research conducted under the California State Water Resources Control Board`s Bay Protection and Toxic Cleanup Program, the authors are investigating alternative sampling methods to more accurately characterize sulfide and ammonia in sediments. Measurements taken from water overlying test sediment are compared to those taken from interstitial water in tests using Neanthes and Rhepoxynius. Pre-test interstitial samples are extracted from sediment using centrifugation. Final measurements are made on water centrifuged from sediment in an additional laboratory replicate. Oxidation can affect the measurement of both constituents, therefore efforts are made to reduce oxidation by centrifuging with no head space. Ammonia is analyzed immediately using an ion specific electrode, and sulfide samples are preserved for spectrophotometric analysis. In preliminary studies sulfide concentrations were 13 times higher and ammonia concentrations 4 times higher in the interstitial water than in samples taken from overlying water. Results will be discussed in terms of sulfide and ammonia toxicity and possible ways of improving sampling methodology.

  2. Sporadic mortality in chronic toxicity tests using Pimephales promelas (Rafinesque): Cases of characterization and control

    SciTech Connect

    Downey, P.J.; Fleming, K.; Guinn, R.; Chapman, N.; Varner, P.; Cooney, J.D.

    2000-01-01

    In whole effluent toxicity tests, organisms are exposed to various effluent concentrations for a specific time period to estimate the potential effects of an effluent on a receiving stream. Laboratories typically have good success performing valid chronic toxicity tests. However, some difficulty in conducting valid chronic whole effluent toxicity tests with Pimephales promelas (fathead minnow) has been encountered as a result of sporadic control mortality. Some investigators report an interference that causes anomalous patterns of survival in chronic fathead minnow tests. This interference has been termed sporadic mortality phenomenon. Characteristics of sporadic mortality phenomenon include high variability among replicates, nonmonotonic dose responses, mortality beginning on or about day 4 of the test, and fungal growths often observed on the larvae. Histopathologic examinations often indicate bacterial and/or fungal infections on fish exhibiting symptoms of sporadic mortality phenomenon. The most plausible explanation of sporadic mortality phenomenon is a naturally occurring pathogen or pathogens that interfere with the test method. This interference may invalidate tests or falsely indicate toxicity. Sporadic mortality phenomenon can be reduced or eliminated by sample treatments intended to inactivate (heating, antibiotics, or ultraviolet light) or remove (filtration) pathogenic microorganisms. These methods must be used with forethought because of their potential to alter the toxicity of a sample.

  3. Establishment of quality assurance procedures for aquatic toxicity testing with the nematode Caenorhabditis elegans

    SciTech Connect

    Freeman, M.N.; Marse, T.J.; Williams, P.L.

    1998-12-31

    In this study initial data were generated to develop laboratory control charts for aquatic toxicity testing using the nematode Caenorhabditis elegans. Tests were performed using two reference toxicants: CdCl{sub 2} and CuCl{sub 2}. All tests were performed for 24 h without a food source and of 48 h with a food source in a commonly used nematode aquatic medium. Each test was replicated 6 times with each replicate having 6 wells per concentration with 10 {+-} 1 worms per well. Probit analysis was used to estimate LC{sub 50} values for each test. The data were used to construct a mean ({bar x}) laboratory control chart for each reference toxicant. The coefficient of variation (CV) for three of the four reference toxicant tests was less than 20%, which demonstrates an excellent degree of reproducibility. These CV values are well within suggested standards for determination of organism sensitivity and overall test system credibility. A standardized procedure for performing 24 h and 48 h aquatic toxicity studies with C. elegans is proposed.

  4. Toxic effects of decomposing red algae on littoral organisms

    NASA Astrophysics Data System (ADS)

    Eklund, Britta; Svensson, Andreas P.; Jonsson, Conny; Malm, Torleif

    2005-03-01

    Large masses of filamentous red algae of the genera Polysiphonia, Rhodomela, and Ceramium are regularly washed up on beaches of the central Baltic Sea. As the algal masses start to decay, red coloured effluents leak into the water, and this tinge may be traced several hundred meters off shore. In this study, possible toxic effects of these effluents were tested on littoral organisms from different trophic levels. Effects on fertilisation, germination and juvenile survival of the brown seaweed Fucus vesiculosus were investigated, and mortality tests were performed on the crustaceans Artemia salina and Idotea baltica, as well as on larvae and adults of the fish Pomatoschistus microps. Fucus vesiculosus was the most sensitive species of the tested organisms to the red algal extract. The survival of F. vesiculosus recruits was reduced with 50% (LC50) when exposed to a concentration corresponding to 1.7 g l -1 dw red algae. The lethal concentration for I. baltica, A. salina and P. microps were approximately ten times higher. The toxicity to A. salina was reduced if the algal extract was left to decompose during two weeks but the decline in toxicity was not affected by different light or temperature conditions. This study indicates that the filamentous red algae in the central Baltic Sea may produce and release compounds with negative effects on the littoral ecosystem. The effects may be particularly serious for the key species F. vesiculosus, which reproduce in autumn when filamentous red algal blooms are most severe.

  5. Commentary on ''Toxicity testing in the 21st century: a vision and a strategy''.

    PubMed

    Phalen, Robert F

    2010-01-01

    Toxicity Testing in the 21st Century: A Vision and a Strategy (NRC, 2007) presents a bold plan for chemical toxicity testing that replaces whole-animal tests with cell-culture, genetic, other in-vitro techniques, computational methods, and human monitoring. Although the proposed vision is eloquently described, and recent advances in in-vitro and in-silico methods are impressive, it is difficult believe that replacing in-vitro testing is either practical or wise. It is not clear that the toxicity-related events that occur in whole animals can be adequately replicated using the proposed methods. Protecting public health is a serious endeavor that should not be limited by denying animal testing. Toxicologists and regulators are encouraged to read the report, carefully consider its implications, and share their thoughts. The vision is for too important to ignore.

  6. 40 CFR Appendix Ix to Part 268 - Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B)

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 28 2013-07-01 2013-07-01 false Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B) IX Appendix IX to Part 268 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) LAND DISPOSAL RESTRICTIONS...

  7. Hazard evaluation of soil contaminants with aquatic animals and plant toxicity tests

    SciTech Connect

    Ramanathan, A.; Burks, S.L.

    1996-12-31

    Deleterious effects upon the biota should be one of the principal characteristics used to perform the initial assessment of contamination and the acceptable level of clean-up at hazardous waste sites. Acute toxicity tests are probably the best means for conducting rapid preliminary assessment of distribution and extent of toxic conditions at a site. On the other hand acute toxicity tests may not be adequate indicators of potential effects at critical life stages or responses to longer term exposure to contaminants. Chronic toxicity tests are generally more sensitive than acute tests, and can be used to predict {open_quotes}no effect{close_quotes} or {open_quotes}safe{close_quotes} levels of contamination. In addition, chronic tests provide a better index of field population responses and more closely mimic actual exposure in the field. Partial chronic tests such as the 7 d Ceriodaphnia sp. survival and reproduction test and 7 d fathead minnow survival and growth test are widely used to predict effects upon critical stages in the life cycle of chemical and mixtures. The overall objective of this project was to evaluate the potential hazard of contaminants at an abandoned oil refinery upon aquatic ecosystems within the vicinity. A battery of acute and partial chronic toxicity tests were used to evaluate potential effects of contaminated soil and leachates of soil upon rice seed germination and root growth, Ceriodaphnia acute survival, fathead minnow acute survival, Microtox acute response, 7 d Ceriodaphnia survival and reproduction, and 7 d fathead minnow survival and growth. The specific tests used to accomplish the overall objective included; (1) To estimate phytotoxicity of the soil at the selected contaminated areas within the refinery, (2) to determine potential for leaching at the selected contaminated areas within the refinery, and (3) to assess the relative toxicity of each of the six contaminated areas in the refinery. 13 refs., 3 tabs.

  8. Application of leaching tests for toxicity evaluation of coal fly ash

    SciTech Connect

    Tsiridis, V.; Samaras, P.; Kungolos, A.; Sakellaropoullos, G.P.

    2006-08-15

    The toxic properties of coal fly ash samples obtained from various coal combustion power plants were evaluated in this work using physicochemical analyses and bioassays. Physicochemical analyses showed that heavy metals present in solid samples included Cr, Cu, Mn, Ni, Pb, and Zn. The results of the chemical analysis of eluates deduced by the application of standard leaching tests according to EN 12457-2 and Toxicity Characteristic Leaching Procedure (TCLP) methods indicated that the compounds contained in fly ashes could potentially be transferred to the liquid phase depending upon the leaching method used. Heavy metal concentrations were higher in TCLP eluates, indicating that the initial pH value of the leaching medium significantly affected the transfer of these elements to the liquid phase. Tests conducted with the photobacterium Vibrio fischeri (Microtox test), the crustacean Daphnia magna, and the rotifer Brachionus calyciflorus were used to assess toxicity of eluates obtained by both leaching tests. Daphnia magna was the most sensitive test organism. The EN 12457-2 method proved to be more reliable for toxicity evaluation of eluates. In contrast, the TCLP method showed some interference owing to acetic acid toxicity, and precipitation occurred after pH adjustment of eluates from acid to neutral range. The toxicity of both fly ashes and the corresponding solid leaching residues of EN 12457-2 and TCLP leaching tests was also measured using the Microtox Basic Solid phase Test. The results generated with this bioassay indicated that toxicity was greatly influenced by the pH status of the solid samples.

  9. Algal toxins and reverse osmosis desalination operations: laboratory bench testing and field monitoring of domoic acid, saxitoxin, brevetoxin and okadaic acid.

    PubMed

    Seubert, Erica L; Trussell, Shane; Eagleton, John; Schnetzer, Astrid; Cetinić, Ivona; Lauri, Phil; Jones, Burton H; Caron, David A

    2012-12-01

    The occurrence and intensity of harmful algal blooms (HABs) have been increasing globally during the past few decades. The impact of these events on seawater desalination facilities has become an important topic in recent years due to enhanced societal interest and reliance on this technology for augmenting world water supplies. A variety of harmful bloom-forming species of microalgae occur in southern California, as well as many other locations throughout the world, and several of these species are known to produce potent neurotoxins. These algal toxins can cause a myriad of human health issues, including death, when ingested via contaminated seafood. This study was designed to investigate the impact that algal toxin presence may have on both the intake and reverse osmosis (RO) desalination process; most importantly, whether or not the naturally occurring algal toxins can pass through the RO membrane and into the desalination product. Bench-scale RO experiments were conducted to explore the potential of extracellular algal toxins contaminating the RO product. Concentrations exceeding maximal values previously reported during natural blooms were used in the laboratory experiments, with treatments comprised of 50 μg/L of domoic acid (DA), 2 μg/L of saxitoxin (STX) and 20 μg/L of brevetoxin (PbTx). None of the algal toxins used in the bench-scale experiments were detectable in the desalinated product water. Monitoring for intracellular and extracellular concentrations of DA, STX, PbTx and okadaic acid (OA) within the intake and desalinated water from a pilot RO desalination plant in El Segundo, CA, was conducted from 2005 to 2009. During the five-year monitoring period, DA and STX were detected sporadically in the intake waters but never in the desalinated water. PbTx and OA were not detected in either the intake or desalinated water. The results of this study demonstrate the potential for HAB toxins to be inducted into coastal RO intake facilities, and the

  10. EPA’s ToxCast Program for Predicting Toxicity and Prioritizing Chemicals for Further Screening and Testing

    EPA Science Inventory

    Testing of environmental and industrial chemicals for toxicity potential is a daunting task because of the wide range of possible toxicity mechanisms. Although animal testing is one means of achieving broad toxicity coverage, evaluation of large numbers of chemicals is challengin...

  11. Toxics testing performance evaluation for GB and GD

    SciTech Connect

    O`Neill, H.J.; Schneider, J.F.; Brubaker, K.L.; Kimmell, T.A.; Anderson, A.W.

    1997-10-01

    Residues resulting from demilitarization, treatment, cleanup, and testing of military chemical agents at Dugway Proving Ground (DPG), Utah, are currently listed as hazardous wastes by the State of Utah Department of Environmental Quality. The US Army Test and Evaluation Command believes that certain categories of waste generated at DPG are not hazardous. To demonstrate this, analytical methods capable of quantitatively measuring the concentrations of chemical agents, including GB and GD, in the different waste media must be available. Argonne National Laboratory has developed methods to analyze metal substrate, spent hypochlorite decontamination fluid, and soil matrices for GB and GD. These methods involve the use of sorbent cartridge preconcentration and thermal desorption combined with gas chromatography using flame photometric detection to achieve the desired sensitivity and specificity. This report describes the methods and presents results for these three common waste matrices. The test results indicate that these methods can be used to quantitatively determine concentrations of GB and GD in the low parts-per-billion range in all sample media tested.

  12. 16 CFR 1500.40 - Method of testing toxic substances.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... not require animals, are presented in the CPSC's animal testing policy set forth in 16 CFR 1500.232. A... centimeters from the exposed skin. In the case of dry powder preparations, the skin and substance are... that holds the dose applied to the skin. In the case of finely divided powders, the measured dose...

  13. Determining the relative sensitivity of benthic diatoms to atrazine using rapid toxicity testing: a novel method.

    PubMed

    Wood, Rebecca J; Mitrovic, Simon M; Kefford, Ben J

    2014-07-01

    Herbicides pose a potential threat to aquatic ecosystems, especially to phototrophic organisms such as benthic diatoms. Benthic diatoms may be a valuable indicator of the toxic impacts of herbicides in aquatic systems. However, this requires information on the herbicide sensitivity of a wide range of freshwater benthic diatom taxa. Unfortunately this information is only available for a limited number of species as current methods of developing new algae toxicity tests on individual taxa are lengthy and costly. To address this issue, we developed a new rapid toxicity test method to test natural benthic communities, from which the relative herbicide sensitivity of many individual taxa can be derived. This involved the collection of natural benthic communities from rocks in situ, which were placed directly into laboratory toxicity tests. Sensitivity data for several diatom genera in a 48 hour exposure toxicity test were produced, without the need for cultures or multiple site visits. After exposure to the highest treatment of atrazine (500 μg L(-1)) there were significant declines of healthy cells in the most sensitive genera: Gomphonema declined by 74%, Amphora by 62%, Cymbella by 54% and Ulnaria by 34% compared to control levels. In contrast, the genera, Eunotia, Achnanthidium and Navicula, had no statistically significant decline in cell health. This method can identify the diatom taxa most at risk of herbicide toxicity within the natural benthic diatom community. The rapid toxicity testing method presented is a simple and effective method to obtain sensitivity data for multiple taxa within a natural benthic diatom community in a relatively short period of time.

  14. Norwegian remote sensing spectrometry for mapping and monitoring of algal blooms and pollution - NORSMAP-89

    SciTech Connect

    Pettersson, L.H.; Johannessen, O.M.; Frette, O. )

    1990-01-09

    During the late spring of 1988 an extensive bloom of the toxic algae Chrysocromulina polylepis occurred in the Skagerrak region influencing most life in the upper 30 meter of the ocean. The algal front was advected northward with the Norwegian Coastal Current along the coast of southern Norway, where it became a severe threat to the Norwegian seafarming industry. An ad-hoc expert team was established to monitor and forecast the movement of the algae front. Remote sensing of sea surface temperature from the operational US NOAA satellites monitored the movement of the algal front, consistent with a warm ocean front. The lack of any optical remote sensing instrumentation was recognized as a major de-efficiency during this algal bloom. To prepare for similar events in the future Nansen Remote Sensing Center initiated a three week pilot study in the Oslofjord and Skagerrak region, during May 1989. The Canadian Compact Airborne Spectrographic Imager (CASI) was installed in the surveillance aircraft. Extensive in situ campaigns was also carried out by the Norwegian Institute for Water Research and Institute of Marine Research. A ship-borne non-imaging spectrometer was operated from the vessels participating in the field campaign. As a contribution from a joint campaign (EISAC '89) between the Joint Research Centre (JRC) of the European Community and the European Space Agency (ESA) both the Canadian Fluorescence Line Imager (FLI) and the US 64-channel GER scanner was operated simultaneously at the NORSMAP 89 test site. Regions of different biological and physical conditions were covered during the pilot study and preliminary analysis are obtained from oil slicks, suspended matter from river, as well as minor algal bloom. The joint analysis of the data collected during the NORSMAP 89 campaign and conclussions will be presented, as well as suggestions for future utilization of airborne spectroscopy systems for operational monitoring of algal bloom and water pollution.

  15. Correlation of the five test methods to assess chemical toxicity and relation to physical properties

    SciTech Connect

    Yoshioka, Y.; Ose, Y.; Sato, T.

    1986-08-01

    Biological tests using Orizias latipes (LC50 and oxygen uptake test), Moina macrocopa (LC50), and Dugesia japonica (head regeneration test and LC50) were carried out in order to clarify the mutual relationship of these test methods. The oxygen uptake rate of O. latipes was not effective to assess chemical toxicity. Adding the results of the growth inhibition test of Tetrahymena pyriformis (Yoshioka, Y., Ose, Y., and Sato, T. (1985). Sci. Total Environ. 43, 149-157), the correlation coefficients between each two test methods were calculated. The test results except EC50 and LC50 of D. japonica showed a good relation to each other. We determined the solubility and the n-octanol/water partition coefficient (P) of some chemicals used in the test. Log P interpreted the toxicity in mol/liter unit but not in mg/liter. Solubility was not a useful descripter neither in mol/liter nor in mg/liter unit.

  16. Toxic Substances Control Act (TSCA) test submissions database (TSCATS) - comprehensive update (on magnetic tape)

    SciTech Connect

    1996-04-01

    The Toxic Substances Control Act Test Submissions Database (TSCATS) was developed to make unpublished test data available to the public. The test data are submitted to the U.S. Environmental Protection Agency by industry under the Toxic Substances Control Act. Test data are broadly defined to include case reports, episodic incidents, such as spills, and formal test study presentations. The database allows searching of test submissions according to specific chemical identity or type of study when used with an appropriate search retrieval software program. Studies are indexed under three broad subject areas: health effects, environmental effects, and environmental fate. additional controlled vocabulary terms are assigned which describe the experimental protocol and test observations. Records identify reference information needed to locate the source document, the submitting organization, and reason for submission of the test data.

  17. Toxic Substances Control Act (TSCA) test submissions database (tscats) - comprehensive update (on magnetic tape). Data file

    SciTech Connect

    1995-12-31

    The Toxic Substances Control Act Test Submissions Database (TSCATS) was developed to make unpublished test data available to the public. The test data are submitted to the U.S. Environmental Protection Agency by industry under the Toxic Substances Control Act. Test data are broadly defined to include case reports, episodic incidents, such as spills, and formal test study presentations. The database allows searching of test submissions according to specific chemical identity or type of study when used with an appropriate search retrieval software program. Studies are indexed under three broad subject areas: health effects, environmental effects and environmental fate. Additional controlled vocabulary terms are assigned which describe the experimental protocol and test observations. Records identify reference information needed to locate the source document, as well as the submitting organization and reason for submission of the test data.

  18. Toxic Substances Control Act (TSCA) Test Submissions Database (TSCATS) - comprehensive update (on magnetic tape). Data file

    SciTech Connect

    1996-12-31

    The Toxic Substances Control Act Test Submissions Database (TSCATS) was developed to make unpublished test data available to the public. The test data are submitted to the U.S. Environmental Protection Agency by industry under the Toxic Substances Control Act. Test data are broadly defined to include case reports, episodic incidents, such as spills, and formal test study presentations. The database allows searching of test submissions according to specific chemical identity or type of study when used with an appropriate search retrieval software program. Studies are indexed under three broad subject areas: health effects, environmental effects and environmental fate. Additional controlled vocabulary terms are assigned which describe the experimental protocol and test observations. Records identify reference information needed to locate the source document, as well as the submitting organization and reason for submission of the test data.

  19. Toxic Substances Control Act (TSCA) test submissions database (TSCATS) - comprehensive update (on magnetic tape). Data file

    SciTech Connect

    1996-09-01

    The Toxic Substances Control Act Test Submissions Database (TSCATS) was developed to make unpublished test data available to the public. The test data are submitted to the U.S. Environmental Protection Agency by industry under the Toxic Substances Control Act. Test data are broadly defined to include case reports, episodic incidents, such as spills, and formal test study presentations. The database allows searching of test submissions according to specific chemical identity or type of study when used with an appropriate search retrieval software program. Studies are indexed under three broad subject areas: health effects, environmental effects, and environmental fate. Additional controlled vocabulary terms are assigned which describe the experimental protocol and test observations. Records identify reference information needed to locate the source document, as well as the submitting organization and reason for submission of the test data.

  20. Rapid toxicity screening tests for aquatic biota. 1. Methodology and experiments with Daphnia magna

    SciTech Connect

    Janssen, C.R.; Persoone, G. )

    1993-04-01

    A promising new and rapid toxicity screening test was developed, the concept and principles of which are presented. The method consists of visual observation of in vivo inhibition of an enzymatic process, using a fluorescent substrate. Juvenile Daphnia magna was exposed to a toxicant dilution series for 1 h, after which the substrate was added and the enzymatic inhibition was observed visually, using a long-wave UV light. The 1-h EC50 results of 11 pure compounds are presented and compared to the conventional 24- and 48-h Daphnia magna EC50s. All 1-h fluorescence EC50s were of the same order of magnitude and correlated very well with the 24- and 48-h EC50s. The sensitivity and reproducibility of this cost-effective screening test were compared to those of the Microtox[reg sign] test. The scope for application and the potential of this new rapid toxicity screening test are evaluated.

  1. Aquatic toxicity of forty industrial chemicals: Testing in support of hazardous substance spill prevention regulation

    NASA Astrophysics Data System (ADS)

    Curtis, M. W.; Ward, C. H.

    1981-05-01

    The U.S. Environmental Protection Agency is presently developing hazardous substance spill regulations to help prevent water pollution. Aquatic animal toxicity data are used as criteria for the designation and categorization of substances as hazardous, even though this type of data is not available for many industrial chemicals. Static 96-hr. toxicity tests were conducted with 40 such chemicals to provide basic toxicity data for regulatory decision making. Thirty-two of the 40 chemicals tested were hazardous to aquatic life as determined by 96-hr. LC 50's less than or equal to 500 mg/l. All 40 chemicals were tested with the fresh-water fathead minnow, Pimephales promelas, and ten chemicals were also tested with the salt-water grass shrimp, Palaemonetes pugio.

  2. Algal functional annotation tool

    SciTech Connect

    2012-07-12

    Abstract BACKGROUND: Progress in genome sequencing is proceeding at an exponential pace, and several new algal genomes are becoming available every year. One of the challenges facing the community is the association of protein sequences encoded in the genomes with biological function. While most genome assembly projects generate annotations for predicted protein sequences, they are usually limited and integrate functional terms from a limited number of databases. Another challenge is the use of annotations to interpret large lists of 'interesting' genes generated by genome-scale datasets. Previously, these gene lists had to be analyzed across several independent biological databases, often on a gene-by-gene basis. In contrast, several annotation databases, such as DAVID, integrate data from multiple functional databases and reveal underlying biological themes of large gene lists. While several such databases have been constructed for animals, none is currently available for the study of algae. Due to renewed interest in algae as potential sources of biofuels and the emergence of multiple algal genome sequences, a significant need has arisen for such a database to process the growing compendiums of algal genomic data. DESCRIPTION: The Algal Functional Annotation Tool is a web-based comprehensive analysis suite integrating annotation data from several pathway, ontology, and protein family databases. The current version provides annotation for the model alga Chlamydomonas reinhardtii, and in the future will include additional genomes. The site allows users to interpret large gene lists by identifying associated functional terms, and their enrichment. Additionally, expression data for several experimental conditions were compiled and analyzed to provide an expression-based enrichment search. A tool to search for functionally-related genes based on gene expression across these conditions is also provided. Other features include dynamic visualization of genes on KEGG

  3. Algal functional annotation tool

    2012-07-12

    Abstract BACKGROUND: Progress in genome sequencing is proceeding at an exponential pace, and several new algal genomes are becoming available every year. One of the challenges facing the community is the association of protein sequences encoded in the genomes with biological function. While most genome assembly projects generate annotations for predicted protein sequences, they are usually limited and integrate functional terms from a limited number of databases. Another challenge is the use of annotations tomore » interpret large lists of 'interesting' genes generated by genome-scale datasets. Previously, these gene lists had to be analyzed across several independent biological databases, often on a gene-by-gene basis. In contrast, several annotation databases, such as DAVID, integrate data from multiple functional databases and reveal underlying biological themes of large gene lists. While several such databases have been constructed for animals, none is currently available for the study of algae. Due to renewed interest in algae as potential sources of biofuels and the emergence of multiple algal genome sequences, a significant need has arisen for such a database to process the growing compendiums of algal genomic data. DESCRIPTION: The Algal Functional Annotation Tool is a web-based comprehensive analysis suite integrating annotation data from several pathway, ontology, and protein family databases. The current version provides annotation for the model alga Chlamydomonas reinhardtii, and in the future will include additional genomes. The site allows users to interpret large gene lists by identifying associated functional terms, and their enrichment. Additionally, expression data for several experimental conditions were compiled and analyzed to provide an expression-based enrichment search. A tool to search for functionally-related genes based on gene expression across these conditions is also provided. Other features include dynamic visualization of genes on

  4. Dispersed oil toxicity tests with biological species indigenous to the Gulf of Mexico. Final report

    SciTech Connect

    Fucik, K.W.; Carr, K.A.; Balcom, B.J.

    1994-08-01

    Static and flowthrough aquatic acute toxicity testing protocols were utilized on eggs and larvae of seven commercially important invertebrates and fishes from the Gulf of Mexico. Test organisms were exposed to Central and Western Gulf oils, dispersed oil, and Corexit 9527. Species included brown shrimp (Penaeus aztecus), white shrimp (Penaeus setiferus), blue crab (Callinectes sapidus), eastern oyster (Crassostrea virginica), red drum (Sciaenops ocellatus), inland silverside (Menidia berylina), and spot (Leiosomus xanthurus). Atlantic menhaden (Brevoortia tyrannus) was also tested because gulf menhaden were not available. Mysids (Mysidopsis bahia) were evaluated as part of a chronic toxicity assessment.

  5. Comparative Toxicity of Eight Oil Dispersants, Louisiana Sweet Crude Oil (LSC) and Chemically Dispersed LSC to Two Aquatic Test Species

    EPA Science Inventory

    This study describes the acute toxicity of eight commercial oil dispersants, Louisiana sweet crude oil (LSC), and chemically dispersed LSC. The approach utilized consistent test methodologies within a single laboratory in assessing the relative acute toxicity of the eight dispers...

  6. Effects of temperature on in situ toxicity testing

    SciTech Connect

    Rowland, C.D.; Burton, G.A. Jr.

    1994-12-31

    With increasing concern over the impacts and perturbations to receiving waters as a result of storm water runoff and contaminated sediments, many investigators have turned towards in situ testing for direct response data. In situ testing has been shown to be an effective assessment tool. In order to further evaluate the limitations of this method, temperature effects were evaluated. There is concern that laboratory to stream transfer of test organisms may induce significant stress if water temperatures are too cool. This study was designed to specifically address the issue of temperature tolerance and attenuation of Hyalella azteca, Ceriodaphnia dubia and Pimephales promelas in in situ conditions. Temperature tolerance is of importance in areas where receiving waters are subject to low or fluctuating temperatures as well as areas of more temperate climates. In this study, the organisms where exposed to temperatures as low as 2 C for variable lengths of time, removed and allowed to come to ambient laboratory temperatures then monitored for acute or chronic responses. No effects on survival were observed after 48 h. at 5 C; however lower temperatures increased mortality.

  7. Relating results from earthworm toxicity tests to agricultural soil

    USGS Publications Warehouse

    Beyer, W.N.; Greig-Smith, P.W.

    1992-01-01

    The artificial soil tests of the European Economic Community and of the Organization for Economic Cooperation produce data relating earthworm mortality to pesticide concentrations in soil under laboratory conditions. To apply these results to agricultural soils it is necessary to relate these concentrations to amounts of pesticide applied per area. This paper reviews the relevant published literature and suggests a simple relation for regulatory use. Hazards to earthworms from pesticides are suggested to be greatest soon after application, when the pesticides may be concentrated in a soil layer a few millimeters thick. For estimating exposure of earthworms, however, a thicker soil layer should be considered, to account for their movement through soil. During favorable weather conditions, earthworms belonging to species appropriate to the artificial soil test have been reported to confine their activity to a layer about 5 cm. If a 5-cm layer is accepted as relevant for regulatory purposes, then an application of 1 kg/ha would be equivalent to 1-67 ppm (dry) in the artificial soil test.

  8. From statistical non-significance to statistical equivalence: An alternative approach for whole effluent toxicity testing

    SciTech Connect

    Shukla, R.; Yu Daohai; Fulk, F.

    1995-12-31

    Short-term toxicity tests with aquatic organisms are a valuable measurement tool in the assessment of the toxicity of effluents, environmental samples and single chemicals. Currently toxicity tests are utilized in a wide range of US EPA regulatory activities including effluent discharge compliance. In the current approach for determining the No Observed Effect Concentration, an effluent concentration is presumed safe if there is no statistically significant difference in toxicant response versus control response. The conclusion of a safe concentration may be due to the fact that it truly is safe, or alternatively, that the ability of the statistical test to detect an effect, given its existence, is inadequate. Results of research of a new statistical approach, the basis of which is to move away from a demonstration of no difference to a demonstration of equivalence, will be discussed. The concept of observed confidence distributions, first suggested by Cox, is proposed as a measure of the strength of evidence for practically equivalent responses between a given effluent concentration and the control. The research included determination of intervals of practically equivalent responses as a function of the variability of control response. The approach is illustrated using reproductive data from tests with Ceriodaphnia dubia and survival and growth data from tests with fathead minnow. The data are from the US EPA`s National Reference Toxicant Database.

  9. TOXICITY TESTING IN THE 21ST CENTURY: A VISION AND A STRATEGY

    PubMed Central

    Krewski, Daniel; Acosta, Daniel; Andersen, Melvin; Anderson, Henry; Bailar, John C.; Boekelheide, Kim; Brent, Robert; Charnley, Gail; Cheung, Vivian G.; Green, Sidney; Kelsey, Karl T.; Kerkvliet, Nancy I.; Li, Abby A.; McCray, Lawrence; Meyer, Otto; Patterson, Reid D.; Pennie, William; Scala, Robert A.; Solomon, Gina M.; Stephens, Martin; Yager, James; Zeise, Lauren

    2015-01-01

    With the release of the landmark report Toxicity Testing in the 21st Century: A Vision and a Strategy, the U.S. National Academy of Sciences, in 2007, precipitated a major change in the way toxicity testing is conducted. It envisions increased efficiency in toxicity testing and decreased animal usage by transitioning from current expensive and lengthy in vivo testing with qualitative endpoints to in vitro toxicity pathway assays on human cells or cell lines using robotic high-throughput screening with mechanistic quantitative parameters. Risk assessment in the exposed human population would focus on avoiding significant perturbations in these toxicity pathways. Computational systems biology models would be implemented to determine the dose-response models of perturbations of pathway function. Extrapolation of in vitro results to in vivo human blood and tissue concentrations would be based on pharmacokinetic models for the given exposure condition. This practice would enhance human relevance of test results, and would cover several test agents, compared to traditional toxicological testing strategies. As all the tools that are necessary to implement the vision are currently available or in an advanced stage of development, the key prerequisites to achieving this paradigm shift are a commitment to change in the scientific community, which could be facilitated by a broad discussion of the vision, and obtaining necessary resources to enhance current knowledge of pathway perturbations and pathway assays in humans and to implement computational systems biology models. Implementation of these strategies would result in a new toxicity testing paradigm firmly based on human biology. PMID:20574894

  10. Effects of Low Dissolved Oxygen on Organisms Used in Freshwater Sediment Toxicity Tests

    EPA Science Inventory

    This manuscript describes the results of tests to determine the tolerance of three benthic organisms to reduced dissolved oxygen (DO). These three organisms are those recommended by EPA for use in toxicity testing of contaminated sediments. The results of the exposures indicate ...

  11. Perspectives on Validation of High-Throughput Assays Supporting 21st Century Toxicity Testing

    EPA Science Inventory

    In vitro high-throughput screening (HTS) assays are seeing increasing use in toxicity testing. HTS assays can simultaneously test many chemicals but have seen limited use in the regulatory arena, in part because of the need to undergo rigorous, time-consuming formal validation. ...

  12. Accelerating Commercialization of Algal Biofuels Through Partnerships (Brochure)

    SciTech Connect

    Not Available

    2011-10-01

    applied to algal biofuels processes. Analysts are also testing algal fuel properties to measure energy content and ensure compatibility with existing fueling infrastructure. (5) Cross-Cutting Analysis - NREL scientists and engineers are conducting rigorous techno-economic analyses of algal biofuels processes. In addition, they are performing a full life cycle assessment of the entire algae-to-biofuels process.

  13. Considerations related to the use of toxicity testing in Canada`s ocean disposal program

    SciTech Connect

    Riebel, P.; Rowland, A.; Samant, H.; Doe, K.

    1995-12-31

    As part of its Ocean Disposal Program, Environment Canada is proposing the use of sediment and porewater toxicity tests to evaluate the acceptability of estuarine and marine sediments for ocean disposal. Under a tiered testing approach, sediments which fail the regulated chemical limits would be subjected to toxicity testing using 5 different type of tests: a 10-day amphipod acute test, a bacterial bioluminescence test, an echinoid fertilization test, a 28-day bioaccumulation test and a polychaete growth test which is still in development. In the past year, the use of the first four of these tests in ocean disposal projects on Canada`s west and east coasts has generated several issues which need to be addressed. Among these is the need for more guidance on the selection of reference sediments and on the selection of appropriate test species. Also, the interpretation of toxicity due to unregulated parameters such as sulfides and ammonia must be considered. Pass/fail criteria based on sound scientific rationale must be established to justify land confinement or capping of sediments, and a weight-of-evidence approach (e.g. Triad) using site-specific studies should be considered to support the results of laboratory tests. Techniques such as Ecological Risk Assessment should be considered to predict potential biological effects at an ocean dump site.

  14. Algal sensory photoreceptors.

    PubMed

    Hegemann, Peter

    2008-01-01

    Only five major types of sensory photoreceptors (BLUF-proteins, cryptochromes, phototropins, phytochromes, and rhodopsins) are used in nature to regulate developmental processes, photosynthesis, photoorientation, and control of the circadian clock. Sensory photoreceptors of algae and protists are exceptionally rich in structure and function; light-gated ion channels and photoactivated adenylate cyclases are unique examples. During the past ten years major progress has been made with respect to understanding the function, photochemistry, and structure of key sensory players of the algal kingdom.

  15. Using biodynamic models to reconcile differences between laboratory toxicity tests and field biomonitoring with aquatic insects

    USGS Publications Warehouse

    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.

  16. U-937 Toxicity Testing of Lunar Dust Stimulant (JSC-1A-vf)

    NASA Technical Reports Server (NTRS)

    Bales, Kristyn; Hammond, Dianne; Wallace, William; Jeevarajan, Antony

    2007-01-01

    With NASA planning to extend the human presence to the moon by 2020, the dangers of the lunar environment must be assessed and appropriate countermeasures must be developed. Possible toxic effects of the lunar dust are of particular importance to human health because of the dust's chemical composition, reactivity, and small size. This project focuses on the toxicity of lunar dust stimulant (JSC-1A-vf), in both its active and passive forms, using U-937 human monocyte cells. Simulant was mechanically activated from its passive form by grinding, and its ability to produce hydroxyl radicals was determined. To test for toxicity, active and passivated simulant was diluted in media and applied to the cells for various time periods. Toxicity was then estimated using flow cytometry on the Guava Personal Cell Analysis system. Preliminary results suggest that passivated stimulant is slightly toxic, with an increase in toxicity for activated stimulant. Toxicity results may be affected by cell lysing behavior and quenching of hydroxyl radical production by the cell media.

  17. Silica gel as a particulate carrier of poorly water-soluble substances in aquatic toxicity testing.

    PubMed

    Breitholtz, Magnus; Ricklund, Niklas; Bengtsson, Bengt-Erik; Persson, N Johan

    2007-05-31

    Aquatic toxicity tests were originally developed for water-soluble substances. However, many substances are hydrophobic and thus poorly water-soluble, resulting in at least two major implications. Firstly, toxicity may not be reached within the range of water solubility of the tested compound(s), which may result in the formation of solids or droplets of the tested substance and consequently an uneven exposure. Secondly, because of multi-phase distribution of the tested substance it may be complicated to keep exposure concentrations constant. To overcome such problems, we have introduced silica gel as a particulate carrier in a toxicity test with the benthic copepod Nitocra spinipes. The main objective of the current study was to evaluate whether a controlled exposure could be achieved with the help of silica gel for testing single poorly water-soluble substances. A secondary objective was to evaluate whether an equilibrium mass balance model could predict internal concentrations that were consistent with the toxicity data and measured internal concentrations of two model hydrophobic substances, i.e., the polybrominated diphenyl ethers BDE-47 and BDE-99. Larval N. spinipes were exposed for 6 days to BDE-47 and BDE-99, respectively, in the silica gel test system and, for comparative reasons, in a similar and more traditional semi-static water test system. Via single initial amounts of the model substances administered on the silica gel, effects on both larval development and mortality resulted in higher and more concentration-related toxicity than in the water test system. We conclude that the silica gel test system enables a more controlled exposure of poorly water-soluble substances than the traditional water test system since the concentration-response relationship becomes distinct and there is no carrier solvent present during testing. Also, the single amount of added substance given in the silica gel test system limits the artefacts (e.g., increased chemical

  18. Consensus report on the future of animal-free systemic toxicity testing.

    PubMed

    Leist, Marcel; Hasiwa, Nina; Rovida, Costanza; Daneshian, Mardas; Basketter, David; Kimber, Ian; Clewell, Harvey; Gocht, Tilman; Goldberg, Alan; Busquet, Francois; Rossi, Anna-Maria; Schwarz, Michael; Stephens, Martin; Taalman, Rob; Knudsen, Thomas B; McKim, James; Harris, Georgina; Pamies, David; Hartung, Thomas

    2014-01-01

    Since March 2013, animal use for cosmetics testing for the European market has been banned. This requires a renewed view on risk assessment in this field. However, in other fields as well, traditional animal experimentation does not always satisfy requirements in safety testing, as the need for human-relevant information is ever increasing. A general strategy for animal-free test approaches was outlined by the US National Research Council`s vision document for Toxicity Testing in the 21st Century in 2007. It is now possible to provide a more defined roadmap on how to implement this vision for the four principal areas of systemic toxicity evaluation: repeat dose organ toxicity, carcinogenicity, reproductive toxicity and allergy induction (skin sensitization), as well as for the evaluation of toxicant metabolism (toxicokinetics) (Fig. 1). CAAT-Europe assembled experts from Europe, America and Asia to design a scientific roadmap for future risk assessment approaches and the outcome was then further discussed and refined in two consensus meetings with over 200 stakeholders. The key recommendations include: focusing on improving existing methods rather than favoring de novo design; combining hazard testing with toxicokinetics predictions; developing integrated test strategies; incorporating new high content endpoints to classical assays; evolving test validation procedures; promoting collaboration and data-sharing of different industrial sectors; integrating new disciplines, such as systems biology and high throughput screening; and involving regulators early on in the test development process. A focus on data quality, combined with increased attention to the scientific background of a test method, will be important drivers. Information from each test system should be mapped along adverse outcome pathways. Finally, quantitative information on all factors and key events will be fed into systems biology models that allow a probabilistic risk assessment with flexible

  19. Consensus report on the future of animal-free systemic toxicity testing.

    PubMed

    Leist, Marcel; Hasiwa, Nina; Rovida, Costanza; Daneshian, Mardas; Basketter, David; Kimber, Ian; Clewell, Harvey; Gocht, Tilman; Goldberg, Alan; Busquet, Francois; Rossi, Anna-Maria; Schwarz, Michael; Stephens, Martin; Taalman, Rob; Knudsen, Thomas B; McKim, James; Harris, Georgina; Pamies, David; Hartung, Thomas

    2014-01-01

    Since March 2013, animal use for cosmetics testing for the European market has been banned. This requires a renewed view on risk assessment in this field. However, in other fields as well, traditional animal experimentation does not always satisfy requirements in safety testing, as the need for human-relevant information is ever increasing. A general strategy for animal-free test approaches was outlined by the US National Research Council`s vision document for Toxicity Testing in the 21st Century in 2007. It is now possible to provide a more defined roadmap on how to implement this vision for the four principal areas of systemic toxicity evaluation: repeat dose organ toxicity, carcinogenicity, reproductive toxicity and allergy induction (skin sensitization), as well as for the evaluation of toxicant metabolism (toxicokinetics) (Fig. 1). CAAT-Europe assembled experts from Europe, America and Asia to design a scientific roadmap for future risk assessment approaches and the outcome was then further discussed and refined in two consensus meetings with over 200 stakeholders. The key recommendations include: focusing on improving existing methods rather than favoring de novo design; combining hazard testing with toxicokinetics predictions; developing integrated test strategies; incorporating new high content endpoints to classical assays; evolving test validation procedures; promoting collaboration and data-sharing of different industrial sectors; integrating new disciplines, such as systems biology and high throughput screening; and involving regulators early on in the test development process. A focus on data quality, combined with increased attention to the scientific background of a test method, will be important drivers. Information from each test system should be mapped along adverse outcome pathways. Finally, quantitative information on all factors and key events will be fed into systems biology models that allow a probabilistic risk assessment with flexible

  20. Development of marine sediment bioassays and toxicity tests for monitoring and regulation in Europe

    SciTech Connect

    Thain, J.; Matthiessen, P.

    1995-12-31

    There is a need in Europe and elsewhere for a broad suite of whole-sediment bioassays and toxicity tests which can be used for routine monitoring and assessment of the marine environment and for evaluating the toxic effects of chemicals which may find their way into sediments. Until recently, few European species had been incorporated into such tests but the availability of suitable methodologies is now increasing rapidly. Perhaps the most important recent activity in this area consisted of an international ring test of acute sediment toxicity test methods which was organized by the Oslo and Paris Commissions in 1993, using up to 4 offshore chemicals as test materials. It evaluated the performance of 4 acute (5--10 day) tests involving: the sea urchin Echinocardium cordatum, the bivalve mollusc Abra alba, the amphipod crustacean Corophium volutator, and the polychaete worm Arenicola marina. The ring test concluded that the C. volutator test was the most appropriate for evaluating offshore chemicals, but all these methods are now widely used in Europe, both as toxicity tests and as bioassays. For example, the A. marina procedure (which has both lethal and sublethal endpoints), in combination with the C. volutator method, is now routinely used in the UK for monitoring the toxicity of estuarine sediments. Further activities are in progress. Perhaps the most important is the development of chronic marine sediment tests and bioassays which can be used to assess the long-term effects of the many sedimentary contaminants which are able to persist in this type of habitat and possibly cause delayed effects on the growth and reproduction, etc. of benthic fauna.

  1. An evaluation of the seven-day toxicity test with Americamysis bahia (formerly Mysidopsis bahia)

    SciTech Connect

    Lussier, S.M.; Kuhn, A.; Comeleo, R.

    1999-12-01

    The 7-d test measuring survival, growth, and fecundity of Americamysis bahia (formerly Mysidopsis bahia) was developed for estimating the chronic toxicity of effluents and associated receiving waters for National Pollutant Discharge Elimination System permits. Currently, this test and its derivatives are also used in toxicity identification evaluation (TIE), risk assessment, and other applications. To evaluate the relative sensitivity of three measurement endpoints (survival, growth, and fecundity), the authors analyzed results from 115 tests with effluents, organic or inorganic chemicals, and receiving waters suspected of being toxic. Controls for 78 of these achieved acceptable survival and growth. Fifty of these 78 tests also achieved acceptable control fecundity. In the 47 tests with significant effects, survival was the most sensitive response in 57%, fecundity in 30%, and growth in 30%. There was little duplication in responses. Improving pretest holding conditions by decreasing the maximum density from {approximately}20 to 10 animals/L and increasing the temperature from {approximately}26 C to a range of 26 to 27 C improved the growth and fecundity in controls. Although the percentage of tests achieving acceptable control survival and growth decreased from 93 to 86%, the percentage achieving acceptable fecundity in controls increased from 60 to 97%. Seasonal differences in fecundity were detected among control groups. Although variable, fecundity is often the most sensitive measure of response. The 7-d mysid test estimates the chronic toxicity of effluents most effectively when all three endpoints are used.

  2. Embryonic stem cells: An alternative approach to developmental toxicity testing.

    PubMed

    Tandon, S; Jyoti, S

    2012-04-01

    Stem cells in the body have a unique ability to renew themselves and give rise to more specialized cell types having functional commitments. Under specified growth conditions, these cell types remain unspecialized but can be triggered to become specific cell type of the body such as heart, nerve, or skin cells. This ability of embryonic stem cells for directed differentiation makes it a prominent candidate as a screening tool in revealing safer and better drugs. In addition, genetic variations and birth defects caused by mutations and teratogens affecting early human development could also be studied on this basis. Moreover, replacement of animal testing is needed because it involves ethical, legal, and cost issues. Thus, there is a strong requirement for validated and reliable, if achievable, human stem cell-based developmental assays for pharmacological and toxicological screening.

  3. Quick, portable toxicity testing of marine or terrigenous fluids, sediments, or chemicals with bioluminescent organism

    SciTech Connect

    Sabate, R.W.; Stiffey, A.V.; Dewailly, E.L.

    1995-12-31

    A hand-held, battery-operated instrument, which measures bioluminescence inhibition of the microscopic marine dinoflagellate Pyrocystis lunula, is capable of field-testing substances for toxicity. The organism is sensitive to ppb of strong toxicants. It tolerates some solvents in concentrations necessary for testing lipophylic samples. A test consumes only micrograms of sample. This method requires no adjustments for salinity, pH, color, or turbidity. It has been used successfully to test oil-well drilling fluids, brines produced with oil, waters and sediments from streams and lakes and petroleum-plant effluents containing contaminants such as benzene. The test is non-specific; however, if the substance is known, the end-point effects a direct measurement of its concentration. One-hour toxicity screening tests in the field produce results comparable to the standard four-hour laboratory test. Keeping the sample in the dark during incubation and testing, together with shortness of the overall procedure, eliminates anomalies from light-sensitive substances. Day-to-day variation, as well as among test replicates, is less than 10%. This quick method yields results comparable with a quick test that uses Photobacterium phosphoria, and with 96-hour tests that use Mysidopsis bahia, Artemia salina, Gonyaulax polyedra, Pimephales promelas, Ceriodaphnia dubia, and Cyprinodon variegatus.

  4. Use of standard effluent toxicity tests for protection of endangered and threatened species

    SciTech Connect

    Henke, C.E.; Dwyer, F.J.; Ingersoll, C.G.; Mount, D.R.; Mayer, F.L.

    1995-12-31

    Water quality criteria and many other environmental assessment tools are based on the results of laboratory toxicity tests. For a variety of reasons, these tests are typically conducted using one of several common laboratory species; results from these tests are then extrapolated with the intention of providing protection for other species not tested directly. This surrogate species approach is particularly necessary for threatened and endangered (listed) species, for which direct toxicity testing is often impractical. However, without direct knowledge of listed species sensitivity, it is not possible to be certain whether these species are adequately protected by current environmental practices. Moreover, the level of protection intended by water quality criteria (e.g., 95% of species) may not be sufficient to meet the requirements of the Endangered Species Act. The authors conducted short-term chronic toxicity tests using Ceriodaphnia dubia and fathead minnows and two listed species, bonytail chub and Colorado squawfish. Methods for Ceriodaphnia dubia and fathead minnow tests were as described by USEPA for effluent testing under the NPDES program; tests with listed species were patterned after the fathead minnow test procedures. Tests were conducted with; (1) ammonia, (2) carbaryl, and (3) a mixture of carbaryl, copper, 4-nonylphenol, pentachlorophenol, and permethrin. Preliminary data analysis indicates that the two listed species respond in a similar manner as the fathead minnow. The sensitivity of listed species to contaminant exposures and implications for regulatory procedures will be discussed.

  5. Zebrafish: as an integrative model for twenty-first century toxicity testing.

    PubMed

    Sipes, Nisha S; Padilla, Stephanie; Knudsen, Thomas B

    2011-09-01

    The zebrafish embryo is a useful small model for investigating vertebrate development because of its transparency, low cost, transgenic and morpholino capabilities, conservation of cell signaling, and concordance with mammalian developmental phenotypes. From these advantages, the zebrafish embryo has been considered as an alternative model for traditional in vivo developmental toxicity screening. The use of this organism in conjunction with traditional in vivo developmental toxicity testing has the potential to reduce cost and increase throughput of testing the chemical universe, prioritize chemicals for targeted toxicity testing, generate predictive models of developmental toxicants, and elucidate mechanisms and adverse outcome pathways for abnormal development. This review gives an overview of the zebrafish embryo for pre dictive toxicology and 21st century toxicity testing. Developmental eye defects were selected as an example to evaluate data from the U.S. Environmental Protection Agency's ToxCast program comparing responses in zebrafish embryos with those from pregnant rats and rabbits for a subset of 24 environmental chemicals across >600 in vitro assay targets. Cross-species comparisons implied a common basis for biological pathways associated with neuronal defects, extracellular matrix remodeling, and mitotic arrest. PMID:21932434

  6. Sensitivity of screening-level toxicity tests using soils from a former petroleum refinery

    SciTech Connect

    Pauwels, S.; Bureau, J.; Roy, Y.; Allen, B.; Robidoux, P.Y.; Soucy, M.

    1995-12-31

    The authors tested five composite soil samples from a former refinery. The samples included a reference soil (Mineral Oil and Grease, MO and G < 40 ppm), thermally-treated soil, biotreated soil, and two untreated soils. They evaluated toxicity using the earthworm E. foetida, lettuce, cress, barley, Microtox, green algae, fathead minnow, and D. magna. The endpoints measured were lethality, seed germination, root elongation, growth, and bioluminescence. Toxicity, as measured by the number of positive responses, increased as follows: biotreated soil < untreated soil No. 1 < reference soil < thermally-treated soil and untreated soil No. 2. The biotreated soil generated only one positive response, whereas the thermally-treated soil and untreated soil No. 2 generated five positive responses. The most sensitive and discriminant terrestrial endpoint was lettuce root elongation which responded to untreated soil No. 1, thermally-treated soil, and reference soil. The least sensitive was barley seed germination for which no toxicity was detected. The most sensitive and discriminant aquatic endpoint was green algae growth which responded to untreated soil No. 1, thermally-treated soil, and reference soil. The least sensitive was D. magna for which no toxicity was detected. Overall, soil and aqueous extract toxicity was spotty and no consistent patterns emerged to differentiate the five soils. Biotreatment significantly reduced the effects of the contamination. Aqueous toxicity was measured in the reference soil, probably because of the presence of unknown dissolved compounds in the aqueous extract. Finally, clear differences in sensitivity existed among the test species.

  7. User’s Guide for T.E.S.T. (version 4.2) (Toxicity Estimation Software Tool) A Program to Estimate Toxicity from Molecular Structure

    EPA Science Inventory

    The user's guide describes the methods used by TEST to predict toxicity and physical properties (including the new mode of action based method used to predict acute aquatic toxicity). It describes all of the experimental data sets included in the tool. It gives the prediction res...

  8. Toxicity test of landfill leachate using Sarotherodon mossambicus (freshwater fish)

    SciTech Connect

    Wong, M.H.

    1989-04-01

    Landfill leachate was collected in March and July, 1984, at the Gin Drinkers' Bay Landfill Site, and the properties of the two leachates were examined. The leachate collected in March contained higher contents of total solids, ammonia, and metals than that collected in July. The leachates were treated with EDTA (10(-3) M) and Al/sub 2/(SO/sub 4/)/sub 3/ (2 and 4 g/liter), alone and in combination. Addition of alum (2 g/liter) removed more than 60% of the phosphate content of the two leachates, and about 20 and 68% of total solids from leachates collected in March and July, respectively. Different concentrations of the leachates (untreated and alum-treated) were used to test the survival of tilapia, Sarotherodon mossambicus. The 96-hr LC50 for untreated leachates of March and July were 1.4 and 12%, respectively. The alum-treated leachates raised the 96-hr LC50 to 2.2 and 31.4%, accordingly.

  9. Toxicity and toxic potential of fly ash from municipal incinerators assessed by means of a fish early life stage test

    SciTech Connect

    Helder, T.; Stutterheim, E.; Olie, K.

    1982-01-01

    The toxicity and toxic potential of fly ash were assessed, using rainbow trout yolk sac fry. In contrast to fly ash itself, extracts of fly ash were extremely toxic, producing typical toxicopathological features fo TCDD-intoxication. By comparison with earlier experiments using pure 2,3,7,8-TCDD, the toxic potential of fly ash was roughly estimated to be 75-125 ng.g/sup -1/ toxic aequivalents TCDD. Obviously, this toxic potential is attributed for a minor part to 2,3,7,8-TCDD and for the greater part to the other chlorinated dioxin congeners and the dibenzofurans, present in fly ash.

  10. Surface binding of contaminants by algae: Consequences for lethal toxicity and feeding to Daphnia magna straus

    SciTech Connect

    Taylor, G. |; Baird, D.J.; Soares, A.M.V.M.

    1998-03-01

    Freshwater algae, as with all suspended particulate matter in the water column, exhibit a net negative charge resulting in an affinity for positively charged species, such as toxic metal cations, which will readily adsorb to algal cell surfaces. In this study, the adsorption of a representative toxic metal cadmium cation (Cd{sup 2+}) to a freshwater algal species, Chlorella vulgaris, was investigated using environmentally realistic concentrations of both. A further study of the effects of this particulate adsorption of Cd{sup 2+} on lethal toxicity and feeding in Daphnia magna was conducted. Two apparently contrasting effects were observed. For the D. magna feeding study, cell ingestion was inhibited, leading to reduced growth and reproduction. Experiments comparing the effect of algal-bound cadmium and dissolved forms of cadmium demonstrate that this inhibition is almost entirely due to the surface-bound fraction of ions. However, at concentrations of dissolved cadmium that are lethal to Daphnia, algal cells were found to reduce toxicity. Such findings indicate the importance of food ration in laboratory-based toxicity tests as well as the difficulty in predicting the environmental fate and effect of contaminants using such tests.

  11. Use of ammonium bicarbonate DTPA soil test to evaluate elemental availability and toxicity

    SciTech Connect

    Soltanpour, P.N.

    1985-01-01

    The literature published on the use of the Soltanpour and Schwab Ammonium Bicarbonate-DTPA (AB-DTPA) soil test shows that it can be used to determine availability and toxicity indices for many elements. It has been shown to be an effective test for measuring the availability indices of P, K, Zn, Fe, Mn, Mo, Pb, Ni, Cd and Se. Theoretically, it can also be used to determine the availability indices for S, Cu and As. The AB-DTPA test can predict toxicity of B as well as the standard hot water test, although within the non-toxic range of B, it is not as effective as the hot water test. The hot water test alone predicts B availability well, but the AB-DTPA B test result requires inclusion of soil water pH, organic matter and clay contents in a regression equation for predicting B availability. This test is not suitable for determination of exchangeable plus soluble Ca and Mg (high levels), as these precipitate as carbonates during extraction. The AB-DTPA test procedure with analysis by an inductively-coupled plasma spectrometer for simultaneous determination of elements, makes soil and overburden testing very efficient.

  12. Differential toxicity of Disperse Red 1 and Disperse Red 13 in the Ames test, HepG2 cytotoxicity assay, and Daphnia acute toxicity test.

    PubMed

    Ferraz, E R A; Umbuzeiro, G A; de-Almeida, G; Caloto-Oliveira, A; Chequer, F M D; Zanoni, M V B; Dorta, D J; Oliveira, D P

    2011-10-01

    Azo dyes are of environmental concern due to their degradation products, widespread use, and low-removal rate during conventional treatment. Their toxic properties are related to the nature and position of the substituents with respect to the aromatic rings and amino nitrogen atom. The dyes Disperse Red 1 and Disperse Red 13 were tested for Salmonella mutagenicity, cell viability by annexin V, and propidium iodide in HepG2 and by aquatic toxicity assays using daphnids. Both dyes tested positive in the Salmonella assay, and the suggestion was made that these compounds induce mainly frame-shift mutations and that the enzymes nitroreductase and O-acetyltransferase play an important role in the observed effect. In addition, it was shown that the presence of the chlorine substituent in Disperse Red 13 decreased the mutagenicity about 14 times when compared with Disperse Red 1, which shows the same structure as Disperse Red 13, but without the chlorine substituent. The presence of this substituent did not cause cytotoxicity in HepG2 cells, but toxicity to the water flea Daphnia similis increased in the presence of the chlorine substituent. These data suggest that the insertion of a chlorine substituent could be an alternative in the design of dyes with low-mutagenic potency, although the ecotoxicity should be carefully evaluated.

  13. Testing of CFC replacement fluids for arc-induced toxic by-products

    SciTech Connect

    Cravey, W.R.; Goerz, D.A.; Hawley-Fedder, R.A.

    1993-06-01

    The authors have developed a unique test-stand for quantifying the generation of perfluoroisobutylene (PFIB) in chlorofluorocarbon (CFC) replacement fluids when they are subjected to high electrical stress/breakdown environments. PFIB is an extremely toxic gas with a threshold limit value of 10 ppbv as set by the American Conference of Governmental Industrial Hygienists. They have tested several new fluids from various manufacturers for their potential to generate PFIB. Their goal is to determine breakdown characteristics and quantify toxic by-products of these replacement fluids to determine a safe, usable alternative for present CFC`s.

  14. Development of miniaturized acute toxicity tests for Daphnia magna and Pimephales promelas

    SciTech Connect

    Powell, R.L.; Kimerle, R.A.; Moser, E.M.; McKee, M.J.

    1995-12-31

    Standard EPA methods for conducting static, 48-hour, acute toxicity tests using Daphnia magna and Pimephales promelas (fathead minnows) can be miniaturized to successfully yield accurate LC50/EC50 values. The screening procedure involves exposing the test organisms to 1 mL of test solution, in test chambers which consist of the wells on 48-well microliter plates. Toxicity of the microliter plates and solvent, DO concentration, organism biomass to test solution ratio, partitioning of the chemicals and dilution of the test solution during transfer of the test organisms were examined. Survival and exposure were not significantly altered using non-standard test chambers. Toxicity of linear alkylbenzene sulfonate (LAS), pentachlorophenol (PCP), kepone, and sodium lauryl sulfate (SLS) was determined using D. magna and fathead minnows. Serial dilutions were made and 1 mL aliquots pipetted into the wells. Daphnia magna, < 24 hours old, and newly hatched fathead minnows, were transferred into the wells, twenty individuals per concentration, one per well. Dose-response curves were established for all test compounds. LC50/EC50`s values obtained using miniaturized methods strongly correlated with those obtained using standard EPA procedures. The tests were repeated a number of times with coefficient of variances for D. magna ranging from 10% with kepone to 64% with SLS. For fathead minnows CVs ranged from 0% with PCP to 23% with kepone. It was concluded that current methods can be miniaturized, yet still provide accurate information regarding toxicity for compounds in limited supply. This method may also be amenable to effluent testing i.e. TIE fractions. Other benefits include reducing the amount of equipment and space needed to conduct a test and the time involved.

  15. Relative toxicity of pyrolysis gases from materials - Effects of chemical composition and test conditions

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Cumming, H. J.

    1978-01-01

    Relative toxicity test data on 270 materials are presented, based on test procedures developed at the University of San Francisco. The effects of chemical composition, using data on 13 types of synthetic polymers and eight types of fabrics, are discussed. Selected materials were evaluated using nine test conditions with the USF method, and using methods developed at the FAA Civil Aeromedical Institute, Douglas Aircraft Company and San Jose State University.

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

    USGS Publications Warehouse

    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

  17. Biostatistical methods for the validation of alternative methods for in vitro toxicity testing.

    PubMed

    Edler, Lutz; Ittrich, Carina

    2003-06-01

    Statistical methods for the validation of toxicological in vitro test assays are developed and applied. Validation is performed either in comparison with in vivo assays or in comparison with other in vitro assays of established validity. Biostatistical methods are presented which are of potential use and benefit for the validation of alternative methods for the risk assessment of chemicals, providing at least an equivalent level of protection through in vitro toxicity testing to that obtained through the use of current in vivo methods. Characteristic indices are developed and determined. Qualitative outcomes are characterised by the rates of false-positive and false-negative predictions, sensitivity and specificity, and predictive values. Quantitative outcomes are characterised by regression coefficients derived from predictive models. The receiver operating characteristics (ROC) technique, applicable when a continuum of cut-off values is considered, is discussed in detail, in relation to its use for statistical modelling and statistical inference. The methods presented are examined for their use for the proof of safety and for toxicity detection and testing. We emphasise that the final validation of toxicity testing is human toxicity, and that the in vivo test itself is only a predictor with an inherent uncertainty. Therefore, the validation of the in vitro test has to account for the vagueness and uncertainty of the "gold standard" in vivo test. We address model selection and model validation, and a four-step scheme is proposed for the conduct of validation studies. Gaps and research needs are formulated to improve the validation of alternative methods for in vitro toxicity testing.

  18. A high throughput passive dosing format for the Fish Embryo Acute Toxicity test.

    PubMed

    Vergauwen, Lucia; Schmidt, Stine N; Stinckens, Evelyn; Maho, Walid; Blust, Ronny; Mayer, Philipp; Covaci, Adrian; Knapen, Dries

    2015-11-01

    High throughput testing according to the Fish Embryo Acute Toxicity (FET) test (OECD Testing Guideline 236) is usually conducted in well plates. In the case of hydrophobic test substances, sorptive and evaporative losses often result in declining and poorly controlled exposure conditions. Therefore, our objective was to improve exposure conditions in FET tests by evaluating a passive dosing format using silicone O-rings in standard 24-well polystyrene plates. We exposed zebrafish embryos to a series of phenanthrene concentrations until 120h post fertilization (hpf), and obtained a linear dilution series. We report effect values for both mortality and sublethal morphological effects based on (1) measured exposure concentrations, (2) (lipid normalized) body residues and (3) chemical activity. The LC50 for 120hpf was 310μg/L, CBR50 (critical body residue) was 2.72mmol/kg fresh wt and La50 (lethal chemical activity) was 0.047. All values were within ranges expected for baseline toxicity. Impaired swim bladder inflation was the most pronounced morphological effect and swimming activity was reduced in all exposure concentrations. Further analysis showed that the effect on swimming activity was not attributed to impaired swim bladder inflation, but rather to baseline toxicity. We conclude that silicone O-rings (1) produce a linear dilution series of phenanthrene in the 120hpf FET test, (2) generate and maintain aqueous concentrations for reliable determination of effect concentrations, and allow for obtaining mechanistic toxicity information, and (3) cause no toxicity, demonstrating its potential as an extension of the FET test when testing hydrophobic chemicals. PMID:26026258

  19. A semistatic microplate-based phytotoxicity test

    SciTech Connect

    Radetski, C.M.; Ferard, J.F. . Centre des Sciences de l'Environnement); Blaise, C. )

    1995-02-01

    A novel phytotoxicity test is described herein that employs a microplate equipped with membrane-bottomed wells. This MultiScreen[trademark] (Millipore Corp., Bedford, MA) microplate allows performance of a semistatic algal test, in which test medium is renewed periodically. With such a design, the algal test becomes comparable to other short-term tests used to evaluate chronic toxicity of chemicals and effluents. The EC50s obtained for Cu[sup 2+], Cd[sup 2+], Cr[sup 6+], atrazine, and one leachate sample (municipal sludge incinerator residue) with static and semistatic algal microplate tests were compared in this study. The semistatic microplate test revealed greater sensitivity than did the static microplate test.

  20. National Algal Biofuels Technology Roadmap

    SciTech Connect

    Ferrell, John; Sarisky-Reed, Valerie

    2010-05-01

    The framework for National Algal Biofuels Technology Roadmap was constructed at the Algal Biofuels Technology Roadmap Workshop, held December 9-10, 2008, at the University of Maryland-College Park. The Workshop was organized by the Biomass Program to discuss and identify the critical challenges currently hindering the development of a domestic, commercial-scale algal biofuels industry. This Roadmap presents information from a scientific, economic, and policy perspectives that can support and guide RD&D investment in algal biofuels. While addressing the potential economic and environmental benefits of using algal biomass for the production of liquid transportation fuels, the Roadmap describes the current status of algae RD&D. In doing so, it lays the groundwork for identifying challenges that likely need to be overcome for algal biomass to be used in the production of economically viable biofuels.

  1. Rat liver mitochondrial and microsomal tests for the assessment of quinone toxicity

    SciTech Connect

    Bramble, L.A.; Boardman, G.D.; Dietrich, A.M. . Dept. of Civil Engineering); Bevan, D.R. . Dept. of Biochemistry)

    1994-02-01

    Short-term toxicity tests using mitochondrial and microsomal metabolism were developed and applied to a series of eight quinones. In the mitochondrial assay, the degree to which test compounds inhibited mitochondrial respiration varied from an effective concentration (EC50) of 9 to 125 [mu]M. In the microsomal assay, the maximum percentage of increase over control oxygen consumption rates elicited by the quinones ranged from 8 to 837%. The ability of the compounds to stimulate microsomal oxygen uptake reflects their capability to redox cycle and form reactive oxygen species. Results of the mitochondrial and microsomal assay were statistically correlated with several quinone physicochemical parameters and qualitatively compared to reduction potential. The biological response observed in both test systems appeared to be most strongly influenced by the reduction potential of the quinone. Biomechanisms of action were suggested on the basis of this relationship. To assess the ability of the mitochondrial and microsomal assays to indicate toxicity of the quinonoid compounds, results were statistically correlated with literature-derived toxicity data. It was concluded that the mitochondrial assay appears to be a valid indicator of acute toxicity, whereas the microsomal assay better portends the potential for chronic toxicity.

  2. Long-term Lethal Toxicity Test with the Crustacean Artemia franciscana

    PubMed Central

    Manfra, Loredana; Savorelli, Federica; Pisapia, Marco; Magaletti, Erika; Cicero, Anna Maria

    2012-01-01

    Our research activities target the use of biological methods for the evaluation of environmental quality, with particular reference to saltwater/brackish water and sediment. The choice of biological indicators must be based on reliable scientific knowledge and, possibly, on the availability of standardized procedures. In this article, we present a standardized protocol that used the marine crustacean Artemia to evaluate the toxicity of chemicals and/or of marine environmental matrices. Scientists propose that the brine shrimp (Artemia) is a suitable candidate for the development of a standard bioassay for worldwide utilization. A number of papers have been published on the toxic effects of various chemicals and toxicants on brine shrimp (Artemia). The major advantage of this crustacean for toxicity studies is the overall availability of the dry cysts; these can be immediately used in testing and difficult cultivation is not demanded1,2. Cyst-based toxicity assays are cheap, continuously available, simple and reliable and are thus an important answer to routine needs of toxicity screening, for industrial monitoring requirements or for regulatory purposes3. The proposed method involves the mortality as an endpoint. The numbers of survivors were counted and percentage of deaths were calculated. Larvae were considered dead if they did not exhibit any internal or external movement during several seconds of observation4. This procedure was standardized testing a reference substance (Sodium Dodecyl Sulfate); some results are reported in this work. This article accompanies a video that describes the performance of procedural toxicity testing, showing all the steps related to the protocol. PMID:22525984

  3. [Emissions from building products and investigation of their toxicity with the bioluminescence inhibition test].

    PubMed

    Mücke, W; Blum, M; Hunstein, R

    1998-12-01

    The investigation of building products in test chambers contains so far only analytical and sensory measurements. In this paper, first experiments for the direct testing of the acute toxicity of building product emissions with the bioluminescence inhibition test are presented. The test specimen was a solvent-free dispersion paste for gluing carpets. Two tests with different air change rates were performed in a 1 m3 stainless steel test chamber. The emissions were concentrated at uniform timesteps in impinger-bottles and measured with the bioluminescence inhibition test. At the same time the concentrations of the emissions in the test chamber were measured both with charcoal adsorbent tubes (carbon disulphide desorption) and with tenax tubes (thermal desorption). The results of the bioluminescence inhibition test show, that the decrease of the toxicity over a period of 28 days is far lower at a low air change rate than at a higher air change rate. We also found, that from the multitude of the emitted substances the toxicity for the luminescence bacteria was only caused by Ethanol-[2-(2-butoxyethoxy)]-acetate.

  4. Increased RO concentrate toxicity following application of antiscalants - acute toxicity tests with the amphipods Gammarus pulex and Gammarus roeseli.

    PubMed

    Feiner, Mona; Beggel, Sebastian; Jaeger, Nadine; Geist, Juergen

    2015-02-01

    In reverse osmosis, a frequently used technology in water desalination processes, wastewater (RO concentrate) is generated containing the retained solutes as well as so-called antiscalants (AS), i.e. chemical substances that are commonly applied to prevent membrane-blocking. In this study, a risk assessment of a possible discharge of concentrate into a small stream was conducted. The acute toxicity of two concentrates containing two different ASs and of concentrate without AS to the amphipods Gammarus pulex and Gammarus roeseli was studied. Mortality of gammarids exposed to the concentrate without AS was not different to the control, whereas concentrates including ASs caused mortality rates up to 100% at the highest test concentrations after 168 h. Resulting EC50-values were 36.2-39.4% (v/v) after 96 h and 26.6-58.0% (v/v) after 168 h. These results suggest that the ecotoxicological relevance of antiscalants is greater than currently assumed.

  5. Development of a chronic sediment toxicity test for marine benthic amphipods

    SciTech Connect

    DeWitt, T.H.; Redmond, M.S.; Sewall, J.E.; Swartz, R.C.

    1992-12-01

    The results of the research effort culminated in the development of a research method for assessing the chronic toxicity of contaminated marine and estuarine sediments using the benthic amphipod, Leptocheirus plumulosus. The first chapter describes the efforts at collecting, handling, and culturing four estuarine amphipods from Chesapeake Bay, including L. plumulosus. This chapter includes maps of the distribution and abundance of these amphipods within Chesapeake Bay and methodologies for establishing cultures of amphipods which could be readily adopted by other laboratories. The second chapter reports the development of acute and chronic sediment toxicity test methods for L. plumulosus, its sensitivity to non-contaminant environmental variables, cadmium, two polynuclear aromatic hydrocarbons, and contaminated sediment from Baltimore Harbor, MD. The third chapter reports the authors attempts to develop a chronic sediment toxicity test with Ampelisca abdita.

  6. Toxicity testing of dispersed oil requires adherence to standardized protocols to assess potential real world effects.

    PubMed

    Coelho, Gina; Clark, James; Aurand, Don

    2013-06-01

    Recently, several researchers have attempted to address Deepwater Horizon incident environmental fate and effects issues using laboratory testing and extrapolation procedures that are not fully reliable measures for environmental assessments. The 2013 Rico-Martínez et al. publication utilized laboratory testing approaches that severely limit our ability to reliably extrapolate such results to meaningful real-world assessments. The authors did not adopt key methodological elements of oil and dispersed oil toxicity standards. Further, they drew real-world conclusions from static exposure tests without reporting actual exposure concentrations. Without this information, it is not possible to compare their results to other research or real spill events that measured and reported exposure concentrations. The 1990s' Chemical Response to Oil Spills: Ecological Effects Research Forum program was established to standardize and conduct exposure characterization in oil and dispersed oil aquatic toxicity testing (Aurand and Coelho, 2005). This commentary raises awareness regarding the necessity of standardized test protocols.

  7. Static renewal tests using Anodonta imbecillus (freshwater mussels). Anodonta imbecillis copper sulfate reference toxicant test, Clinch River-Environmental Restoration Program (CR-ERP)

    SciTech Connect

    Simbeck, D.J.

    1993-12-31

    Reference toxicant testing using juvenile freshwater mussels was conducted as part of the CR-ERP biomonitoring study of Clinch River sediments to assess the sensitivity of test organisms and the overall performance of the test. Tests were conducted using moderately hard synthetic water spiked with known concentrations of copper as copper sulfate. Toxicity testing of copper sulfate reference toxicant was conducted from May 12--21, 1993. The organisms used for testing were juvenile fresh-water mussels (Anodonta imbecillis). Results from this test showed an LC{sub 50} value of 1.12 mg Cu/L which is lower than the value of 2.02 mg Cu/L obtained in a previous test. Too few tests have been conducted with copper as the toxicant to determine a normal range of values. Attachments to this report include: Toxicity test bench sheets and statistical analyses; Copper analysis request and results; and Personnel training documentation.

  8. Acute toxicity tests and meta-analysis identify gaps in tropical ecotoxicology for amphibians.

    PubMed

    Ghose, Sonia L; Donnelly, Maureen A; Kerby, Jacob; Whitfield, Steven M

    2014-09-01

    Amphibian populations are declining worldwide, particularly in tropical regions where amphibian diversity is highest. Pollutants, including agricultural pesticides, have been identified as a potential contributor to decline, yet toxicological studies of tropical amphibians are very rare. The present study assesses toxic effects on amphibians of 10 commonly used commercial pesticides in tropical agriculture using 2 approaches. First, the authors conducted 8-d toxicity assays with formulations of each pesticide using individually reared red-eyed tree frog (Agalychnis callidryas) tadpoles. Second, they conducted a review of available data for the lethal concentration to kill 50% of test animals from the US Environmental Protection Agency's ECOTOX database to allow comparison with their findings. Lethal concentration estimates from the assays ranged over several orders of magnitude. The nematicides terbufos and ethoprophos and the fungicide chlorothalonil were very highly toxic, with evident effects within an order of magnitude of environmental concentrations. Acute toxicity assays and meta-analysis show that nematicides and fungicides are generally more toxic than herbicides yet receive far less research attention than less toxic herbicides. Given that the tropics have a high diversity of amphibians, the findings emphasize the need for research into the effects of commonly used pesticides in tropical countries and should help guide future ecotoxicological research in tropical regions.

  9. Application of multiple toxicity tests in monitoring of landfill leachate treatment efficiency.

    PubMed

    Kalčíková, Gabriela; Zupančič, Marija; Levei, Erika Andrea; Miclean, Mirela; Englande, Andrew J; Žgajnar Gotvajn, Andreja

    2015-08-01

    Leachate from a closed landfill used for co-disposal of municipal and tannery waste was submitted to coagulation treatment, air stripping, adsorption on granular activated carbon, and Fenton oxidation with the aim to reduce toxicity of the leachate. Optimal operational conditions for each process were identified. The performance of the treatment was monitored by determination of organic matter (COD, DOC, BOD5), inorganic components (N-NH4(+), Cl(-), alkalinity, metals), organic compounds (BTEX, PAHs, PCBs, OCPs) while changes in toxicity were followed by multiple toxicity tests. Among the applied treatment techniques, adsorption on granular activated carbon was the most efficient method for removal of organic matter and metals while air stripping was the most efficient for removal of N-NH4(+) and reduction of toxicity. Lower reduction of organic matter content and toxicity was obtained during coagulation treatment. Fenton oxidation was effective for removal of COD; however, it negatively affected toxicity reduction. The combination of adsorption on granular activated carbon and air stripping led to an appreciable reduction of organic and inorganic pollutants and to leachate detoxification. Application of bioassays was helpful for assessing suitability of treatment methods and demonstrated that they are, together with physicochemical parameters, an indispensable part for monitoring of treatment efficiency.

  10. Acute toxicity tests and meta-analysis identify gaps in tropical ecotoxicology for amphibians.

    PubMed

    Ghose, Sonia L; Donnelly, Maureen A; Kerby, Jacob; Whitfield, Steven M

    2014-09-01

    Amphibian populations are declining worldwide, particularly in tropical regions where amphibian diversity is highest. Pollutants, including agricultural pesticides, have been identified as a potential contributor to decline, yet toxicological studies of tropical amphibians are very rare. The present study assesses toxic effects on amphibians of 10 commonly used commercial pesticides in tropical agriculture using 2 approaches. First, the authors conducted 8-d toxicity assays with formulations of each pesticide using individually reared red-eyed tree frog (Agalychnis callidryas) tadpoles. Second, they conducted a review of available data for the lethal concentration to kill 50% of test animals from the US Environmental Protection Agency's ECOTOX database to allow comparison with their findings. Lethal concentration estimates from the assays ranged over several orders of magnitude. The nematicides terbufos and ethoprophos and the fungicide chlorothalonil were very highly toxic, with evident effects within an order of magnitude of environmental concentrations. Acute toxicity assays and meta-analysis show that nematicides and fungicides are generally more toxic than herbicides yet receive far less research attention than less toxic herbicides. Given that the tropics have a high diversity of amphibians, the findings emphasize the need for research into the effects of commonly used pesticides in tropical countries and should help guide future ecotoxicological research in tropical regions. PMID:24934557

  11. Whole effluent toxicity testing -- Usefulness, level of protection, and risk assessment

    SciTech Connect

    Chapman, P.M.

    2000-01-01

    The general status of whole effluent toxicity (WET) tests is assessed relative to their generally accepted purpose of identifying, characterizing, and eliminating effects of effluents on aquatic resources. Although WET tests are useful, they are not perfect tools. Imperfections include the innate variability of these tests, due both to biotic and anthropogenic factors; the reality of species differences both between the laboratory and the field and within the field; and differences between the laboratory and the receiving environment. Whole effluent toxicity tests may be overprotective, underprotective, or offer an uncertain level of protection. The implication of hormesis and inverted U-shaped dose responses for WET testing are reviewed in particular detail. Comparisons to field conditions indicate that WET tests are not reliable predictors of effects or lack of effects in the receiving environment. Whole effluent toxicity tests are only the first stage in a risk assessment and as such identify hazard, not risk. Identification of risk requires discarding the concept of independent applicability. The appropriate use of WET tests is identified in the context of their advantages and disadvantages.

  12. Studies with the USF/NASA toxicity screening test method - Exercise wheels and oxygen replenishment

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Cumming, H. J.

    1977-01-01

    Continuing efforts to improve the University of San Francisco/NASA toxicity screening test method have included the addition of exercise wheels to provide a different measure of incapacitation, and oxygen replenishment to offset any effect of oxygen depletion by the test animals. The addition of exercise wheels limited the number of animals in each test and doubled the required number of tests without any significant improvement in reproducibility. Oxygen replenishment appears to have an effect on survival in the last 5 minutes of the 30-minute test, but the effect is expected to be similar for most materials.

  13. Predicting aquatic toxicities of chemical pesticides in multiple test species using nonlinear QSTR modeling approaches.

    PubMed

    Basant, Nikita; Gupta, Shikha; Singh, Kunwar P

    2015-11-01

    In this study, we established nonlinear quantitative-structure toxicity relationship (QSTR) models for predicting the toxicities of chemical pesticides in multiple aquatic test species following the OECD (Organization for Economic Cooperation and Development) guidelines. The decision tree forest (DTF) and decision tree boost (DTB) based QSTR models were constructed using a pesticides toxicity dataset in Selenastrum capricornutum and a set of six descriptors. Other six toxicity data sets were used for external validation of the constructed QSTRs. Global QSTR models were also constructed using the combined dataset of all the seven species. The diversity in chemical structures and nonlinearity in the data were evaluated. Model validation was performed deriving several statistical coefficients for the test data and the prediction and generalization abilities of the QSTRs were evaluated. Both the QSTR models identified WPSA1 (weighted charged partial positive surface area) as the most influential descriptor. The DTF and DTB QSTRs performed relatively better than the single decision tree (SDT) and support vector machines (SVM) models used as a benchmark here and yielded R(2) of 0.886 and 0.964 between the measured and predicted toxicity values in the complete dataset (S. capricornutum). The QSTR models applied to six other aquatic species toxicity data yielded R(2) of >0.92 (DTF) and >0.97 (DTB), respectively. The prediction accuracies of the global models were comparable with those of the S. capricornutum models. The results suggest for the appropriateness of the developed QSTR models to reliably predict the aquatic toxicity of chemicals and can be used for regulatory purpose.

  14. Predicting aquatic toxicities of chemical pesticides in multiple test species using nonlinear QSTR modeling approaches.

    PubMed

    Basant, Nikita; Gupta, Shikha; Singh, Kunwar P

    2015-11-01

    In this study, we established nonlinear quantitative-structure toxicity relationship (QSTR) models for predicting the toxicities of chemical pesticides in multiple aquatic test species following the OECD (Organization for Economic Cooperation and Development) guidelines. The decision tree forest (DTF) and decision tree boost (DTB) based QSTR models were constructed using a pesticides toxicity dataset in Selenastrum capricornutum and a set of six descriptors. Other six toxicity data sets were used for external validation of the constructed QSTRs. Global QSTR models were also constructed using the combined dataset of all the seven species. The diversity in chemical structures and nonlinearity in the data were evaluated. Model validation was performed deriving several statistical coefficients for the test data and the prediction and generalization abilities of the QSTRs were evaluated. Both the QSTR models identified WPSA1 (weighted charged partial positive surface area) as the most influential descriptor. The DTF and DTB QSTRs performed relatively better than the single decision tree (SDT) and support vector machines (SVM) models used as a benchmark here and yielded R(2) of 0.886 and 0.964 between the measured and predicted toxicity values in the complete dataset (S. capricornutum). The QSTR models applied to six other aquatic species toxicity data yielded R(2) of >0.92 (DTF) and >0.97 (DTB), respectively. The prediction accuracies of the global models were comparable with those of the S. capricornutum models. The results suggest for the appropriateness of the developed QSTR models to reliably predict the aquatic toxicity of chemicals and can be used for regulatory purpose. PMID:26142614

  15. Improving the quality of aquatic toxicity tests: Lessons learned and proficiency needs

    EPA Science Inventory

    Aquatic toxicity testing methodologies have been widely used to assess potential adverse effects of chemicals and wastewater discharges on aquatic life in the United States since the 1970’s. Over the years, continued method modifications, increased training, and technical r...

  16. Modeling Reproductive Toxicity for Chemical Prioritization into an Integrated Testing Strategy

    EPA Science Inventory

    The EPA ToxCast research program uses a high-throughput screening (HTS) approach for predicting the toxicity of large numbers of chemicals. Phase-I tested 309 well-characterized chemicals in over 500 assays of different molecular targets, cellular responses and cell-states. Of th...

  17. Optimization of high-throughput nanomaterial developmental toxicity testing in zebrafish embryos

    EPA Science Inventory

    Nanomaterial (NM) developmental toxicities are largely unknown. With an extensive variety of NMs available, high-throughput screening methods may be of value for initial characterization of potential hazard. We optimized a zebrafish embryo test as an in vivo high-throughput assay...

  18. Comparative Toxicity of Eight Oil Dispersant Products on Two Gulf of Mexico Aquatic Test Species

    EPA Science Inventory

    This report is the first of a round of toxicity testing data for eight oil dispersants that have been authorized for use on the National Contingency Plan (NCP) Product Schedule, which is a list of authorized dispersants and other chemicals that may be used to respond to oil disch...

  19. ISSUES IN DEVELOPING A TWO-GENERATION AVIAN TOXICITY TEST WITH JAPANESE QUAIL

    EPA Science Inventory

    As a subgroup of the OECD Expert Group on Assessment of Endocrine Disrupting Effects in Birds, we reviewed unresolved methodological issures important for the development of a two-generation toxicity test, discussed advantages and disadvantages of alternative approaches, and prop...

  20. PREDICTION OF POPULATION-LEVEL RESPONSE FROM MYSID TOXICITY TEST DATA USING POPULATION MODEL TECHNIQUES

    EPA Science Inventory

    Acute and chronic bioassay statistics are used to evaluate the toxicity and the risks of chemical stressors to mysid shrimp Americamysis bahia (formerly Mysidopsis bahia). These include LC50 values from acute tests, chronic values (the geometric mean of the no-obsderved-effect co...

  1. High Throughput Prioritization for Integrated Toxicity Testing Based on ToxCast Chemical Profiling

    EPA Science Inventory

    The rational prioritization of chemicals for integrated toxicity testing is a central goal of the U.S. EPA’s ToxCast™ program (http://epa.gov/ncct/toxcast/). ToxCast includes a wide-ranging battery of over 500 in vitro high-throughput screening assays which in Phase I was used to...

  2. Development of a short-term chronic toxicity test with a tropical mysid.

    PubMed

    Figuerêdo, Lívia Pitombeira de; Nilin, Jeamylle; Silva, Allyson Queiroz da; Loureiro, Susana; Costa-Lotufo, Letícia Veras

    2016-05-15

    There is an increasing need to develop reliable methodologies for chronic toxicity testing using tropical species. The present work aimed at developing a suitable short-term chronic toxicity test with Mysidopsis juniae using zinc (Zn) and nickel (Ni) as model chemicals and growth (length and dry weight), survival, and egg production (number of females with eggs) as endpoints after seven days of exposure. Survival and growth of newborn M. juniae were affected by chronic exposure to zinc, while nickel affected only survival. For zinc, dry weight was the most sensitive endpoint with significant effects even at the lowest tested concentration (75μgZn·L(-1)), whereas for nickel, survival was the most sensitive parameter (LC20 of 26μgNi·L(-1)). Egg production was not affected. M. juniae short-term chronic testing is a sensitive approach to evaluating metal toxicity; further studies are necessary to assess chronic toxicity for others contaminants in the proposed assay. PMID:27001717

  3. Evaluation and improvements of a mayfly, Neocloeon (Centroptilum) triangulifer ?(Ephemeroptera: Baetidae) toxicity test method

    EPA Science Inventory

    A recently published test method for Neocloeon triangulifer assessed the sensitivities of larval mayflies to several reference toxicants (NaCl, KCl, and CuSO4). Subsequent exposures have shown discrepancies from those results previously reported. To identify potential sources of ...

  4. Application of Generalized Linear Models to the Analysis of Toxicity Test Data.

    ERIC Educational Resources Information Center

    Maul, A.

    1992-01-01

    Studies binomial, negative binomial, and gamma regression models and gives a detailed description of inference procedures based on them. The process of model fitting and evaluation is illustrated by examples referring to the determination of endpoints in acute and chronic toxicity tests. (17 references) (Author/MDH)

  5. The Future of Toxicity Testing - the NRC Vision and EPA’s ToxCast Program

    EPA Science Inventory

    The EPA requested the National Research Council (NRC) to develop a vision and strategic plan for toxicity testing in the 21st century. The 2007 report called for transforming toxicology to provide a robust scientific basis for assessing adverse health effects of environmental age...

  6. Fireflies in the Coalmine: Luciferase Technologies in Next-Generation Toxicity Testing

    EPA Science Inventory

    Whole-animal studies have been the mainstay of toxicity testing for decades. These approaches are too expensive and laborious to effectively characterize all of the chemicals currently in commercial use. In addition, there are social and ethical pressures to reduce, refine and re...

  7. What Food and Feeding Rates are Optimum for the Chironomus dilutus Sediment Toxicity Test Method?

    EPA Science Inventory

    Laboratory tests with benthic macroinvertebrates are commonly used to assess the toxicity of both contaminated sediments and individual chemicals. Among the standard procedures for benthic macroinvertebrates are 10-d, 20-d, and life cycle exposures using the midge, Chironomus ...

  8. Tox21: Putting a Lens on the Vision of Toxicity Testing in the 21st Century

    EPA Science Inventory

    In response to the release of the NRC report on "Toxicity Testing in the 21st Century, a Vision and Strategy" (NRC, 2007), two NIH institutes and EPA formed a collaboration (Tox21) to 1) identify mechanisms of chemically induced biological activity, 2) prioritize chemicals for mo...

  9. Modifying Foods and Feeding Regimes to Optimize the Performance of Hyalella azteca during Chronic Toxicity Tests

    EPA Science Inventory

    The amphipod Hyalella azteca is commonly used to assess the toxicity of sediments and waters. However, laboratories have reported varying success in maintaining healthy cultures and in obtaining consistent growth and reproduction (where applicable), especially during tests...

  10. Development of a Complete Life Cycle Sediment Toxicity Test for the Sheepshead Minnow (Cyprinodon variegatus)

    EPA Science Inventory

    Existing sediment toxicity test methods are limited to acute and chronic exposure of invertebrates and acute exposure of vertebrates, with limited guidance on the chronic exposure of vertebrates, specifically fishes. A series of life stage-specific studies were conducted to dete...

  11. Approach to environmental risk assessment using avian toxicity tests (journal version)

    SciTech Connect

    Shirazi, M.A.; Bennett, R.S.; Lowrie, L.

    1988-01-01

    Toxicity tests results are often condensed into a single endpoint (LC50) to facilitate their use in environmental management. The single number cannot distinguish between two tests with equal LC50s but dissimilar slopes at LC50 and it cannot describe the response at low and high dose levels. Some chemicals produce a flat response at low dose levels, others produce a steep response. The management of different chemicals requires different strategies and a more comprehensive approach to analysis of test data than use of a single endpoint. An alternative analysis of test data using Weibull survivor function produces information on the overall form of the dose-response curve and enables calculation of toxicity, the slope, and errors at arbitrary protection levels, including the conventional 50% level.

  12. Optimizing the use of freshwater juvenile mussels to standardize toxicity testing

    SciTech Connect

    Summers, J.; Baladi, S.; Warren, L.; Klaine, S.

    1995-12-31

    Juvenile Utterbackia imbecillis Say (Bivalvia:Unionidae) were tested for toxicity to copper and cadmium during their early life stage. Juvenile U. imbecillis were found to be relatively sensitive to aqueous copper and cadmium toxicity, with definitive 48h LC50 values ranging from 48 to 251 ug Cd/L, and from 33 to 130 ug Cu/L. Data from cadmium tests indicated that juveniles aged 1--10 days from transformation are not significantly different with their responses towards 48-hour acute tests. In comparison, different aged U. imbecillis and C. dubia include the use of four chemicals; anthracene, cadmium chloride, sodium dodecylsulfate, and ammonium chloride. Another juvenile freshwater mussel (Unionidae: Villosa iris) will also be compared to U. imbecillis and C. dubia in 48-hour acute and 8-day static renewal tests for these four chemicals. Preliminary results suggest that freshwater juvenile mussels (U. imbecillis) are as sensitive to some chemicals as C. dubia.

  13. Acute toxicity of live and decomposing green alga Ulva ( Enteromorpha) prolifera to abalone Haliotis discus hannai

    NASA Astrophysics Data System (ADS)

    Wang, Chao; Yu, Rencheng; Zhou, Mingjiang

    2011-05-01

    From 2007 to 2009, large-scale blooms of green algae (the so-called "green tides") occurred every summer in the Yellow Sea, China. In June 2008, huge amounts of floating green algae accumulated along the coast of Qingdao and led to mass mortality of cultured abalone and sea cucumber. However, the mechanism for the mass mortality of cultured animals remains undetermined. This study examined the toxic effects of Ulva ( Enteromorpha) prolifera, the causative species of green tides in the Yellow Sea during the last three years. The acute toxicity of fresh culture medium and decomposing algal effluent of U. prolifera to the cultured abalone Haliotis discus hannai were tested. It was found that both fresh culture medium and decomposing algal effluent had toxic effects to abalone, and decomposing algal effluent was more toxic than fresh culture medium. The acute toxicity of decomposing algal effluent could be attributed to the ammonia and sulfide presented in the effluent, as well as the hypoxia caused by the decomposition process.

  14. Aquatic Toxicity Assessment of Phosphate Compounds

    PubMed Central

    Kim, Eunju; Yoo, Sunkyoung; Ro, Hee-Young; Han, Hye-Jin; Baek, Yong-Wook; Eom, Ig-Chun; Kim, Pilje; Choi, Kyunghee

    2013-01-01

    Objectives Tricalcium phosphate and calcium hydrogenorthophosphate are high production volume chemicals, mainly used as foodstuff additives, pharmaceuticals, lubricants, synthetic resin, and disinfectants. Phosphate has the potential to cause increased algal growth leading to eutrophication in the aquatic environment. However, there is no adequate information available on risk assessment or acute and chronic toxicity. The aim of this research is to evaluate the toxic potential of phosphate compounds in the aquatic environment. Methods An aquatic toxicity test of phosphate was conducted, and its physico-chemical properties were obtained from a database recommended in the Organization for Economic Cooperation and Development (OECD) guidance manual. An ecotoxicity test using fish, Daphnia, and algae was conducted by the good laboratory practice facility according to the OECD TG guidelines for testing of chemicals, to secure reliable data. Results The results of the ecotoxicity tests of tricalcium phosphate and calcium hydrogenorthophosphate are as follows: In an acute toxicity test with Oryzias latipes, 96 hr 50% lethal concentration (LC50) was >100 (measured:>2.14) mg/L and >100 (measured: >13.5) mg/L, respectively. In the Daphnia test, 48 hr 50% effective concentration (EC50) was >100 (measured: >5.35) mg/L and >100 (measured: >2.9) mg/L, respectively. In a growth inhibition test with Pseudokirchneriella subcapitata, 72 hr EC50 was >100 (measured: >1.56) mg/L and >100 (measured: >4.4) mg/L, respectively. Conclusions Based on the results of the ecotoxicity test of phosphate using fish, Daphnia, and algae, L(E)C50 was above 100 mg/L (nominal), indicating no toxicity. In general, the total phosphorus concentration including phosphate in rivers and lakes reaches levels of several ppm, suggesting that phosphate has no toxic effects. However, excessive inflow of phosphate into aquatic ecosystems has the potential to cause eutrophication due to algal growth. PMID:23440935

  15. A multigeneration fish toxicity test as an aid in the hazard evaluation of aquatic pollutants

    SciTech Connect

    Newsome, C.S.

    1980-12-01

    A multigeneration toxicity study to assess the effects of pollutants on fish breeding and all the life stages is described. The convict cichlid (Cichlasoma nigrofasciatum) was used to test the toxicity of trisodium carboxymethyloxysuccinate, a new sequestering agent being evaluated as a detergent builder. Results show that 100 mg/l of the chemical has no effect on fish fecundity, survival of eggs and fry, or adult breeding behavior. This concentration is two orders of magnitude greater than the predicted aquatic environmental concentration under the most unfavorable conditions of its use, sewage treatment, and discharge. (4 diagrams, 2 photos, 23 references, 1 tables)

  16. Acute toxicity of metals and reference toxicants to a freshwater ostracod, Cypris subglobosa Sowerby, 1840 and correlation to EC(50) values of other test models.

    PubMed

    Khangarot, B S; Das, Sangita

    2009-12-30

    The ostracod Cypris subglobosa Sowerby, 1840 static bioassay test on the basis of a 48h of 50% of immobilization (EC(50)) has been used to measure the toxicity of 36 metals and metalloids and 12 reference toxicants. Among the 36 metals and metalloids, osmium (Os) was found to be the most toxic in the test while boron (B), the least toxic. The EC(50) values of this study revealed positive linear relationship with the established test models of cladoceran (Daphnia magna), sludge worm (Tubifex tubifex), chironomid larvae (Chironomus tentans), protozoan (Tetrahymena pyriformis), fathead minnow (Pimephales promelas), bluegill sunfish (Lepomis macrochirus), and aquatic macrophyte duckweed (Lemna minor). Correlation coefficients (r(2)) for 17 physicochemical properties of metals or metal ions and EC(50)s (as pM) were examined by linear regression analysis. The electronegativity, ionization potential, melting point, solubility product of metal sulfides (pK(sp)), softness parameter and some other physicochemical characteristics were significantly correlated with EC(50)s of metals to C. subglobosa. The reproducibility of toxicity test was determined using 12 reference toxicants. The coefficient of variability of the EC(50)s ranged from 6.95% to 55.37% and variability was comparable to that noticed for D. magna and other aquatic test models. The study demonstrated the need to include crustacean ostracods in a battery of biotests to detect the presence of hazardous chemicals in soils, sewage sludges, sediments and aquatic systems. PMID:19683870

  17. Evaluation of ability of reference toxicity tests to identify stress in laboratory populations of the amphipod Hyalella azteca

    USGS Publications Warehouse

    McNulty, E.W.; Dwyer, F.J.; Ellersieck, Mark R.; Greer, E.I.; Ingersoll, C.G.; Rabeni, C.F.

    1999-01-01

    Standard methods for conducting toxicity tests imply that the condition of test organisms can be established using reference toxicity tests. However, only a limited number of studies have evaluated whether reference toxicity tests can actually be used to determine if organisms are in good condition at the start of a test. We evaluated the ability of reference toxicants to identify stress associated with starvation in laboratory populations of the amphipod Hyalella azteca using acute toxicity tests and four reference toxicants: KCl, CdCl2, sodium pentachlorophenate (NaPCP), and carbaryl. Stress associated with severe starvation was observed with exposure of amphipods to carbaryl or NaPCP but not with exposure to KCl or CdCl2 (i.e., lower LC50 with severe starvation). Although the LC50s for NaPCP and carbaryl were statistically different between starved and fed amphipods, this difference may not be biologically significant given the variability expected in acute lethality tests. Stress associated with sieving, heat shock, or cold shock of amphipods before the start of a test was not evident with exposure to carbaryl or KCl as reference toxicants. The chemicals evaluated in this study provided minimal information about the condition of the organisms used to start a toxicity test. Laboratories should periodically perform reference toxicity tests to assess the sensitivity of life stages or strains of test organisms. However, use of other test acceptability criteria required in standard methods such as minimum survival, growth, or reproduction of organisms in the control treatment at the end of a test, provides more useful information about the condition of organisms used to start a test compared to data generated from reference toxicity tests.

  18. Evaluation of ability of reference toxicity tests to identify stress in laboratory populations of the amphipod Hyalella azteca

    SciTech Connect

    McNulty, E.W.; Ellersieck, M.R.; Rabeni, C.F.; Dwyer, F.J.; Greer, E.I.; Ingersoll, C.G.

    1999-03-01

    Standard methods for conducting toxicity tests imply that the condition of test organisms can be established using reference toxicity tests. However, only a limited number of studies have evaluated whether reference toxicity tests can actually be used to determine if organisms are in good condition, at the start of a test. The authors evaluated the ability of reference toxicants to identify stress associated with starvation in laboratory populations of the amphipod Hyalella azteca using acute toxicity tests and four reference toxicants: KCl, CdCl{sub 2}, sodium pentachlorophenate (NaPCP), and carbaryl. Stress associated with severe starvation was observed with exposure of amphipods to carbaryl or NaPCP but not with exposure to KCl or CdCl{sub 2} (i.e., lower LC50 with severe starvation). Although the LC50s for NaPCP and carbaryl were statistically different between starved and fed amphipods, this difference may not be biologically significant given the variability expected in acute lethality tests. Stress associated with sieving, heat shock, or cold shock of amphipods before the start of a test was not evident with exposure to carbaryl or KCl as reference toxicants. The chemicals evaluated in this study provided minimal information about the condition of the organisms used to start a toxicity test. Laboratories should periodically perform reference toxicity tests to assess the sensitivity of life stages or strains of test organisms. However, use of other test acceptability criteria required in standard methods, such as minimum survival, growth, or reproduction of organisms in the control treatment at the end of a test, provides more useful information about the condition of organisms used to start a test compared to data generated from reference toxicity tests.

  19. The enhancement of the subacute repeat dose toxicity test OECD TG 407 for the detection of endocrine active chemicals: comparison with toxicity tests of longer duration.

    PubMed

    Gelbke, Heinz-Peter; Hofmann, Andreas; Owens, J William; Freyberger, Alexius

    2007-04-01

    The OECD conventional 28-day repeat dose toxicity test (OECD TG 407) is widely employed in the initial hazard identification and characterization for commercial chemicals. The OECD has recently undertaken an international effort to "enhance" the conventional 28-day repeat dose toxicity test (OECD TG 407) in order to ensure that chemicals acting through (anti)estrogenic, (anti)androgenic, and (anti)thyroid mechanisms are identified. The enhancements include additional parameters based on the respective target organs from the male and female reproductive tracts, the thyroid, and circulating hormone levels. Ten chemicals with known endocrine modes of action and different potencies were administered using the "enhanced TG 407" test protocol to investigate the performance of this procedure. In the present evaluation, these "enhanced TG 407" protocol results, drawn from a report of the OECD validation studies, are compared to studies of the same or similar chemicals with longer and/or in utero exposures in order to evaluate the capability of the this "enhanced TG 407" in identifying the chemicals' mode of action. The major conclusions that can be drawn from these comparisons are: 1. The "enhanced TG 407" will reliably identify chemicals with a strong to moderate potential to act through endocrine modes of action on the gonads and the thyroid. In addition, this test method gives a first indication for the dose-related potency. 2. Substances with a low potency for an endocrine mode of action, i.e., having only marginal effects in the most comprehensive in vivo studies such as multi-generation studies, may not elicit clear endocrine-related effects in the "enhanced TG 407". In these cases, the primary or principal effects observed will be driven by other toxic actions of the test materials in the "enhanced TG 407". 3. It may be concluded from the present database that prolongation of exposure from 28 days up to 90 days is unlikely to improve the chance of detecting an

  20. Effect of indigenous animals on chronic end points in freshwater sediment toxicity tests

    SciTech Connect

    Reynoldson, T.B.; Day, K.E.; Clarke, C.; Milani, D. )

    1994-06-01

    Sediment toxicity tests were conducted using three species of benthic invertebrates, Chironomus riparius, Hyalella azteca, and Hexagenia limbata, with various densities of the oligochaete worm Tubifex tubifex. It was shown that indigenous animals, simulated by the presence of Tubifex tubifex, did not affect survival of the test species (P [>=] 0.05) but did reduce growth in all three test species and in two species at the lowest tested densities, equivalent to 1,460 worms per square meter. At densities of Tubifex tubifex equivalent to 20,000 m[sup [minus]2], the growth of Chironomus riparius was reduced by >90%, Hyalella azteca by >60%, and Hexagenia limbata by almost 50%. The densities of oligochaetes are equivalent to those found in many contaminated sites. Therefore, it is concluded that the presence of indigenous organisms can confound the interpretation of toxicity test results, based on chronic end points. It is recommended that removal of organisms by considered before toxicity tests are conducted with freshwater sediments from sites with large populations of benthic invertebrates, especially oligochaete worms.

  1. Comprehensive In Vitro Toxicity Testing of a Panel of Representative Oxide Nanomaterials: First Steps towards an Intelligent Testing Strategy.

    PubMed

    Farcal, Lucian; Torres Andón, Fernando; Di Cristo, Luisana; Rotoli, Bianca Maria; Bussolati, Ovidio; Bergamaschi, Enrico; Mech, Agnieszka; Hartmann, Nanna B; Rasmussen, Kirsten; Riego-Sintes, Juan; Ponti, Jessica; Kinsner-Ovaskainen, Agnieszka; Rossi, François; Oomen, Agnes; Bos, Peter; Chen, Rui; Bai, Ru; Chen, Chunying; Rocks, Louise; Fulton, Norma; Ross, Bryony; Hutchison, Gary; Tran, Lang; Mues, Sarah; Ossig, Rainer; Schnekenburger, Jürgen; Campagnolo, Luisa; Vecchione, Lucia; Pietroiusti, Antonio; Fadeel, Bengt

    2015-01-01

    Nanomaterials (NMs) display many unique and useful physico-chemical properties. However, reliable approaches are needed for risk assessment of NMs. The present study was performed in the FP7-MARINA project, with the objective to identify and evaluate in vitro test methods for toxicity assessment in order to facilitate the development of an intelligent testing strategy (ITS). Six representative oxide NMs provided by the EC-JRC Nanomaterials Repository were tested in nine laboratories. The in vitro toxicity of NMs was evaluated in 12 cellular models representing 6 different target organs/systems (immune system, respiratory system, gastrointestinal system, reproductive organs, kidney and embryonic tissues). The toxicity assessment was conducted using 10 different assays for cytotoxicity, embryotoxicity, epithelial integrity, cytokine secretion and oxidative stress. Thorough physico-chemical characterization was performed for all tested NMs. Commercially relevant NMs with different physico-chemical properties were selected: two TiO2 NMs with different surface chemistry - hydrophilic (NM-103) and hydrophobic (NM-104), two forms of ZnO - uncoated (NM-110) and coated with triethoxycapryl silane (NM-111) and two SiO2 NMs produced by two different manufacturing techniques - precipitated (NM-200) and pyrogenic (NM-203). Cell specific toxicity effects of all NMs were observed; macrophages were the most sensitive cell type after short-term exposures (24-72h) (ZnO>SiO2>TiO2). Longer term exposure (7 to 21 days) significantly affected the cell barrier integrity in the presence of ZnO, but not TiO2 and SiO2, while the embryonic stem cell test (EST) classified the TiO2 NMs as potentially 'weak-embryotoxic' and ZnO and SiO2 NMs as 'non-embryotoxic'. A hazard ranking could be established for the representative NMs tested (ZnO NM-110 > ZnO NM-111 > SiO2 NM-203 > SiO2 NM-200 > TiO2 NM-104 > TiO2 NM-103). This ranking was different in the case of embryonic tissues, for which TiO2

  2. Comprehensive In Vitro Toxicity Testing of a Panel of Representative Oxide Nanomaterials: First Steps towards an Intelligent Testing Strategy.

    PubMed

    Farcal, Lucian; Torres Andón, Fernando; Di Cristo, Luisana; Rotoli, Bianca Maria; Bussolati, Ovidio; Bergamaschi, Enrico; Mech, Agnieszka; Hartmann, Nanna B; Rasmussen, Kirsten; Riego-Sintes, Juan; Ponti, Jessica; Kinsner-Ovaskainen, Agnieszka; Rossi, François; Oomen, Agnes; Bos, Peter; Chen, Rui; Bai, Ru; Chen, Chunying; Rocks, Louise; Fulton, Norma; Ross, Bryony; Hutchison, Gary; Tran, Lang; Mues, Sarah; Ossig, Rainer; Schnekenburger, Jürgen; Campagnolo, Luisa; Vecchione, Lucia; Pietroiusti, Antonio; Fadeel, Bengt

    2015-01-01

    Nanomaterials (NMs) display many unique and useful physico-chemical properties. However, reliable approaches are needed for risk assessment of NMs. The present study was performed in the FP7-MARINA project, with the objective to identify and evaluate in vitro test methods for toxicity assessment in order to facilitate the development of an intelligent testing strategy (ITS). Six representative oxide NMs provided by the EC-JRC Nanomaterials Repository were tested in nine laboratories. The in vitro toxicity of NMs was evaluated in 12 cellular models representing 6 different target organs/systems (immune system, respiratory system, gastrointestinal system, reproductive organs, kidney and embryonic tissues). The toxicity assessment was conducted using 10 different assays for cytotoxicity, embryotoxicity, epithelial integrity, cytokine secretion and oxidative stress. Thorough physico-chemical characterization was performed for all tested NMs. Commercially relevant NMs with different physico-chemical properties were selected: two TiO2 NMs with different surface chemistry - hydrophilic (NM-103) and hydrophobic (NM-104), two forms of ZnO - uncoated (NM-110) and coated with triethoxycapryl silane (NM-111) and two SiO2 NMs produced by two different manufacturing techniques - precipitated (NM-200) and pyrogenic (NM-203). Cell specific toxicity effects of all NMs were observed; macrophages were the most sensitive cell type after short-term exposures (24-72h) (ZnO>SiO2>TiO2). Longer term exposure (7 to 21 days) significantly affected the cell barrier integrity in the presence of ZnO, but not TiO2 and SiO2, while the embryonic stem cell test (EST) classified the TiO2 NMs as potentially 'weak-embryotoxic' and ZnO and SiO2 NMs as 'non-embryotoxic'. A hazard ranking could be established for the representative NMs tested (ZnO NM-110 > ZnO NM-111 > SiO2 NM-203 > SiO2 NM-200 > TiO2 NM-104 > TiO2 NM-103). This ranking was different in the case of embryonic tissues, for which TiO2

  3. A colorimetric assay for determination of cell viability in algal cultures.

    PubMed

    Capasso, Juan M; Cossío, Belén R; Berl, Tomás; Rivard, Christopher J; Jiménez, Carlos

    2003-07-01

    In this work, we propose the determination of cell viability in algal cultures by using a colorimetric assay widely used for estimation of cell proliferation in animal cell cultures. The method is based on in vivo reduction by metabolically active cells of a tetrazolium compound (MTS=3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenil)-2H-tetrazolium, inner salt) to a colored formazan, with maximal absorbance at 490 nm, that is released to the culture medium. For this purpose, we have tested two microalgae with high commercial value (Dunaliella and Spirulina) and two seaweeds with different morphology (Ulva and Gracilaria). Color development in this assay is directly proportional to the number of viable cells, to the incubation time in the presence of the assay solution, and to the incubation temperature. A direct significant correlation was found between algal photosynthesis rate and color development in all species used through this work. Moreover, the intensity of absorbance at 490 nm was significantly lower in stressed cells (e.g. in nutrient-limited cultures, in the presence of toxic substances, and in osmotically-stressed cultures). We conclude that cell viability of algal cultures can be rapidly and easily estimated through colorimetric determination of the reduction of MTS to formazan.

  4. [In vitro toxicity tests of bioceramics and bone transplants in fibroblast culture].

    PubMed

    Günther, K; Scharf, H P; Puhl, W

    1993-10-01

    Prior to the clinical use of synthetic bone substitutes and allogenic bone transplants, potential toxicity resulting from various different manufacturing, storage, and sterilisation techniques should be excluded. In order to develop a reliable and reproducible in vitro model for the investigation of possible tissue reactions after implantation of biomaterials, we modified an established animal fibroblast culture technique used to test chemical agents for acute unspecific cytotoxicity. Subcultivation of human fibroblasts produces stable monolayer cultures with the aid of which, standardised, accurate and reproducible evaluation of toxic effects, as well as the direct visualisation of fibroblast ingrowth into porous implant material, is possible. Gamma-irradiated synthetic implants and bovine hydroxyapatite failed to show any substantial cytotoxicity. In contrast, ethylene oxide sterilised implant material, as well as fresh untreated trabecular bone showed a significant toxic effect in comparison with cryopreserved and autoclaved trabecular bone. PMID:8268403

  5. Critique on the use of the standardized avian acute oral toxicity test for first generation anticoagulant rodenticides

    USGS Publications Warehouse

    Vyas, Nimish B.; Rattner, Barnett A.

    2012-01-01

    Avian risk assessments for rodenticides are often driven by the results of standardized acute oral toxicity tests without regards to a toxicant's mode of action and time course of adverse effects. First generation anticoagulant rodenticides (FGARs) generally require multiple feedings over several days to achieve a threshold concentration in tissue and cause adverse effects. This exposure regimen is much different than that used in the standardized acute oral toxicity test methodology. Median lethal dose values derived from standardized acute oral toxicity tests underestimate the environmental hazard and risk of FGARs. Caution is warranted when FGAR toxicity, physiological effects, and pharmacokinetics derived from standardized acute oral toxicity testing are used for forensic confirmation of the cause of death in avian mortality incidents and when characterizing FGARs' risks to free-ranging birds.

  6. Comparison of feeding strategies in acute toxicity tests of crude oil and commercial bioremediation agents

    SciTech Connect

    Cavender, R.C.; Cherry, D.S.; Yeager, M.M.; Bidwell, J.R.

    1995-12-31

    Proposed modifications to the National Oil and Hazardous Substance Pollution Contingency Plan have prompted examinations of the methodology used in toxicity testing of the water soluble fraction (WSF) of oil, commercial bioremediation agents (CBA), and a combination of the two. The organisms currently used in acute (96 hr) testing of these agents are the inland silverside, Menidia beryllina, and an estuarine mysid, Mysidopsis bahia. The mysid is a carnivorous species that must be fed during a test in order to prevent predation within the test chambers. Currently proposed methodology for silverside testing also includes feeding. The high oxygen demand of CBAs and the WSF of oil causes dissolved oxygen to be a factor in toxicity. This effect can be intensified by the addition of brine shrimp (Artemia sp.) to the test chambers. The purpose of this study was to compare the toxicity of CBAs in combination with the WSF of oil to silversides with and without the addition of food. Tests were conducted using both 24-hour and 14-day spinning times for the CBA/WSF mixture. With the 24-hour spinning time, LC50 values from each day of the 4-day test were consistently lower in the Artemia fed test (47.8--22.6%) as compared to the unfed test (72.1--43.0%). A similar trend was seen in the 24 and 48 hour LC50`s in the 14-day spinning time. Overall, low dissolved oxygen was found to be most relevant at the highest CBA/WSF concentrations where D.O. dropped below 2 mg/l in Artemia fed tests.

  7. A semi-fluid gellan gum medium improves nematode toxicity testing.

    PubMed

    Brinke, Marvin; Heininger, Peter; Traunspurger, Walter

    2011-10-01

    This study examined an alternative test medium for nematodes that use gellan gum as the gelling agent instead of agar. The semi-fluid consistency of the gel-like component nematode growth gellan gum (CNGG) supports three-dimensional distribution of the nematodes and food bacteria, but still allows free movement of the former. Moreover, flexible preparation of the medium and easy recovery of the test organisms are possible. Here, the effects of the nematicides ivermectin (pharmaceutical) and aldicarb (pesticide) and of the metal cadmium on the growth and reproduction of the free-living nematodes Caenorhabditis elegans and Panagrolaimus cf. thienemanni were studied in CNGG media. Results were compared to those obtained with the standard liquid test media in order to evaluate the applicability of CNGG for nematode toxicity testing. The sensitivity of P. cf. thienemanni to all three substances was found to be higher than that of C. elegans, but both nematodes showed the highest sensitivity to ivermectin exposure. This raises concerns about the risk posed by the pharmaceutical to non-target nematodes. In contrast to ivermectin bioassays carried out in CNGG medium, those conducted in liquid medium resulted in wide-ranging variability between and within replicates. Thus, CNGG seems to be particularly valuable for testing hydrophobic substances with a high sorption affinity as it favors their sorption to food bacteria and minimizes contact with the surfaces of the test vessels. However, the medium was less suitable for deriving toxicity thresholds for cadmium and may likewise not be an appropriate choice for testing other metals. The medium introduced herein was shown to be appropriate for sublethal nematode toxicity testing and likely provides a convenient environment for testing other nematode species. Besides improved testing of hydrophobic substances, CNGG also offers advantages for long-term studies, such as full life-cycle experiments, in which fresh medium is

  8. Nonclinical reproductive toxicity testing requirements for drugs, pesticides, and industrial chemicals in India and China.

    PubMed

    Rao, K S; Dong, Jing

    2013-01-01

    India and China have booming chemical, agrochemical, and pharmaceutical industries. Both countries also represent expanding markets for foreign chemical and healthcare companies. All such products require reproductive toxicity testing before marketing. The ICH testing guidelines for medicinal products are not applicable in China and India. Nonetheless, reproductive toxicity studies designed and run to ICH principles are generally acceptable for submission. The Chinese guidelines take into consideration traditional Chinese medicines, which are usually mixtures. Likewise, the specific recommendations of India and China for the reproductive toxicity testing of chemicals and pesticides differ from those of the OECD and the USEPA. Again, studies performed in accordance with internationally recognized principles are usually acceptable for submission in both countries. The Chinese guideline for the reproductive toxicity testing of agrochemicals is currently under revision; the new version is expected to resemble more closely the requirements of the OECD and the USEPA. As a member of the OECD, India has conducted Good Laboratory Practice (GLP) inspection, accreditation, and monitoring activities since 2004. China has made several attempts to join the Council Decisions on Mutual Acceptance of Data in the Assessment of Chemicals since 2005. Currently 47 laboratories in China have been certified by the national GLP authorities. Several laboratories in China have also been recently been certified by OECD member countries as GLP compliant. In India, there are currently 23 GLP-Certified laboratories; about six of these are also AALAC accredited. The specific study designs specified in the guidelines of China and India for reproductive toxicity studies are described in detail in this chapter. PMID:23138892

  9. Toxicity testing and drug screening using iPSC-derived hepatocytes, cardiomyocytes, and neural cells.

    PubMed

    Csöbönyeiová, Mária; Polák, Štefan; Danišovič, L'uboš

    2016-07-01

    Unexpected toxicity in areas such as cardiotoxicity, hepatotoxicity, and neurotoxicity is a serious complication of clinical therapy and one of the key causes for failure of promising drug candidates in development. Animal studies have been widely used for toxicology research to provide preclinical security evaluation of various therapeutic agents under development. Species differences in drug penetration of the blood-brain barrier, drug metabolism, and related toxicity contribute to failure of drug trials from animal models to human. The existing system for drug discovery has relied on immortalized cell lines, animal models of human disease, and clinical trials in humans. Moreover, drug candidates that are passed as being safe in the preclinical stage often show toxic effects during the clinical stage. Only around 16% drugs are approved for human use. Research on induced pluripotent stem cells (iPSCs) promises to enhance drug discovery and development by providing simple, reproducible, and economically effective tools for drug toxicity screening under development and, on the other hand, for studying the disease mechanism and pathways. In this review, we provide an overview of basic information about iPSCs, and discuss efforts aimed at the use of iPSC-derived hepatocytes, cardiomyocytes, and neural cells in drug discovery and toxicity testing.

  10. Leachates draining from controlled municipal solid waste landfill: Detailed geochemical characterization and toxicity tests.

    PubMed

    Mavakala, Bienvenu K; Le Faucheur, Séverine; Mulaji, Crispin K; Laffite, Amandine; Devarajan, Naresh; Biey, Emmanuel M; Giuliani, Gregory; Otamonga, Jean-Paul; Kabatusuila, Prosper; Mpiana, Pius T; Poté, John

    2016-09-01

    Management of municipal solid wastes in many countries consists of waste disposal into landfill without treatment or selective collection of solid waste fractions including plastics, paper, glass, metals, electronic waste, and organic fraction leading to the unsolved problem of contamination of numerous ecosystems such as air, soil, surface, and ground water. Knowledge of leachate composition is critical in risk assessment of long-term impact of landfills on human health and the environment as well as for prevention of negative outcomes. The research presented in this paper investigates the seasonal variation of draining leachate composition and resulting toxicity as well as the contamination status of soil/sediment from lagoon basins receiving leachates from landfill in Mpasa, a suburb of Kinshasa in the Democratic Republic of the Congo. Samples were collected during the dry and rainy seasons and analyzed for pH, electrical conductivity, dissolved oxygen, soluble ions, toxic metals, and were then subjected to toxicity tests. Results highlight the significant seasonal difference in leachate physicochemical composition. Affected soil/sediment showed higher values for toxic metals than leachates, indicating the possibility of using lagoon system for the purification of landfill leachates, especially for organic matter and heavy metal sedimentation. However, the ecotoxicity tests demonstrated that leachates are still a significant source of toxicity for terrestrial and benthic organisms. Therefore, landfill leachates should not be discarded into the environment (soil or surface water) without prior treatment. Interest in the use of macrophytes in lagoon system is growing and toxic metal retention in lagoon basin receiving systems needs to be fully investigated in the future. This study presents useful tools for evaluating landfill leachate quality and risk in lagoon systems which can be applied to similar environmental compartments. PMID:27177465

  11. Leachates draining from controlled municipal solid waste landfill: Detailed geochemical characterization and toxicity tests.

    PubMed

    Mavakala, Bienvenu K; Le Faucheur, Séverine; Mulaji, Crispin K; Laffite, Amandine; Devarajan, Naresh; Biey, Emmanuel M; Giuliani, Gregory; Otamonga, Jean-Paul; Kabatusuila, Prosper; Mpiana, Pius T; Poté, John

    2016-09-01

    Management of municipal solid wastes in many countries consists of waste disposal into landfill without treatment or selective collection of solid waste fractions including plastics, paper, glass, metals, electronic waste, and organic fraction leading to the unsolved problem of contamination of numerous ecosystems such as air, soil, surface, and ground water. Knowledge of leachate composition is critical in risk assessment of long-term impact of landfills on human health and the environment as well as for prevention of negative outcomes. The research presented in this paper investigates the seasonal variation of draining leachate composition and resulting toxicity as well as the contamination status of soil/sediment from lagoon basins receiving leachates from landfill in Mpasa, a suburb of Kinshasa in the Democratic Republic of the Congo. Samples were collected during the dry and rainy seasons and analyzed for pH, electrical conductivity, dissolved oxygen, soluble ions, toxic metals, and were then subjected to toxicity tests. Results highlight the significant seasonal difference in leachate physicochemical composition. Affected soil/sediment showed higher values for toxic metals than leachates, indicating the possibility of using lagoon system for the purification of landfill leachates, especially for organic matter and heavy metal sedimentation. However, the ecotoxicity tests demonstrated that leachates are still a significant source of toxicity for terrestrial and benthic organisms. Therefore, landfill leachates should not be discarded into the environment (soil or surface water) without prior treatment. Interest in the use of macrophytes in lagoon system is growing and toxic metal retention in lagoon basin receiving systems needs to be fully investigated in the future. This study presents useful tools for evaluating landfill leachate quality and risk in lagoon systems which can be applied to similar environmental compartments.

  12. Comparison of the 10-day freshwater sediment toxicity tests using Hyalella azteca and Chironomus tentans

    SciTech Connect

    Becker, D.S.; Bigham, G.N.; Rose, C.D.

    1995-12-01

    Comparisons were made of the performance of the 10-d freshwater sediment toxicity tests using the amphipod Hyalella azteca and midge Chironomus tentans. Sediments were collected from eight stations in Onondaga Lake, New York, and represented a wide range of toxicity. The biological end points were survival, biomass, and body length. The two tests were compared on the basis of correspondence among relative values of the end points and ability to statistically discriminate adverse effects relative to control responses (i.e., discriminatory ability). Minimum detectable differences (MDDs) and adverse response ranges of the end points were used to further evaluate the discriminatory ability of the end points. Relative responses and discriminatory abilities of the end points of both tests were similar, despite numerous differences that exist among characteristics of the test species and end points. Significant concordance was found among all end points with respect to relative toxicity of sediments from the eight stations. Although MDDs and adverse response ranges of the various end points differed substantially, the observed positive correlation between those two variables resulted in all end points having similar discriminatory ability. Although amphipod biomass and body length have rarely been used as end points in 10-d tests, both end points provided results comparable to those of the other end points evaluated in the present study.

  13. Relative toxicity of products of pyrolysis and combustion of polymeric materials using various test conditions

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.

    1976-01-01

    Relative toxicity data for a large number of natural and synthetic polymeric materials are presented which were obtained by 11 pyrolysis and three flaming-combustion test methods. The materials tested include flexible and rigid polyurethane foams, different kinds of fabrics and woods, and a variety of commodity polymers such as polyethylene. Animal exposure chambers of different volumes containing mice, rats, or rabbits were used in the tests, which were performed over the temperature range from ambient to 800 C with and without air flow or recirculation. The test results are found to be sensitive to such variables as exposure mode, temperature, air flow and dilution, material concentration, and animal species, but relative toxicity rankings appear to be similar for many methods and materials. It is concluded that times to incapacitance and to death provide a more suitable basis for relative toxicity rankings than percent mortality alone, that temperature is the most important variable in the tests reported, and that variables such as chamber volume and animal species may not significantly affect the rankings.

  14. Influence of potentially confounding factors on sea urchin porewater toxicity tests

    USGS Publications Warehouse

    Carr, R.S.; Biedenbach, J.M.; Nipper, M.

    2006-01-01

    The influence of potentially confounding factors has been identified as a concern for interpreting sea urchin porewater toxicity test data. The results from >40 sediment-quality assessment surveys using early-life stages of the sea urchin Arbacia punctulata were compiled and examined to determine acceptable ranges of natural variables such as pH, ammonia, and dissolved organic carbon on the fertilization and embryological development endpoints. In addition, laboratory experiments were also conducted with A. punctulata and compared with information from the literature. Pore water with pH as low as 6.9 is an unlikely contributor to toxicity for the fertilization and embryological development tests with A. punctulata. Other species of sea urchin have narrower pH tolerance ranges. Ammonia is rarely a contributing factor in pore water toxicity tests using the fertilization endpoint, but the embryological development endpoint may be influenced by ammonia concentrations commonly found in porewater samples. Therefore, ammonia needs to be considered when interpreting results for the embryological development test. Humic acid does not affect sea urchin fertilization at saturation concentrations, but it could have an effect on the embryological development endpoint at near-saturation concentrations. There was no correlation between sediment total organic carbon concentrations and porewater dissolved organic carbon concentrations. Because of the potential for many varying substances to activate parthenogenesis in sea urchin eggs, it is recommended that a no-sperm control be included with every fertilization test treatment. ?? 2006 Springer Science+Business Media, Inc.

  15. Influence of potentially confounding factors on sea urchin porewater toxicity tests.

    PubMed

    Carr, R S; Biedenbach, J M; Nipper, M

    2006-11-01

    The influence of potentially confounding factors has been identified as a concern for interpreting sea urchin porewater toxicity test data. The results from >40 sediment-quality assessment surveys using early-life stages of the sea urchin Arbacia punctulata were compiled and examined to determine acceptable ranges of natural variables such as pH, ammonia, and dissolved organic carbon on the fertilization and embryological development endpoints. In addition, laboratory experiments were also conducted with A. punctulata and compared with information from the literature. Pore water with pH as low as 6.9 is an unlikely contributor to toxicity for the fertilization and embryological development tests with A. punctulata. Other species of sea urchin have narrower pH tolerance ranges. Ammonia is rarely a contributing factor in pore water toxicity tests using the fertilization endpoint, but the embryological development endpoint may be influenced by ammonia concentrations commonly found in porewater samples. Therefore, ammonia needs to be considered when interpreting results for the embryological development test. Humic acid does not affect sea urchin fertilization at saturation concentrations, but it could have an effect on the embryological development endpoint at near-saturation concentrations. There was no correlation between sediment total organic carbon concentrations and porewater dissolved organic carbon concentrations. Because of the potential for many varying substances to activate parthenogenesis in sea urchin eggs, it is recommended that a no-sperm control be included with every fertilization test treatment.

  16. Ceriodaphnia and Chironomus in situ toxicity tests assessing the wastewater treatment efficacy of constructed wetlands

    SciTech Connect

    Barjaktarovic, L.; Nix, P.; Gulley, J.

    1995-12-31

    In situ toxicity tests were designed for Ceriodaphnia dubia and Chironomus tentans as part of a larger study designed to assess the effectiveness of constructed wetlands for the treatment of wastewater produced by oil production at Suncor OSG. The artificial wetlands were 50m long by 3m wide, with three replicates of the control and the treatment. Each wetland had four sample sites equidistant along its length, creating a gradient of treatment from site A being the most toxic to site D being the least toxic. Each test was conducted twice during the summer of 1994. Both the Ceriodaphnia and Chironomus test cages were a flow through design to allow for maximal exposure to the water within the wetlands. Mortality and reproduction were used as endpoints for Ceriodaphnia, whereas mortality and growth were used as endpoints for the Chironomus test. Test durations were fifteen and ten days respectively. Chironomus had very high mortality along the entire wetlands whereas Ceriodaphnia survival and fecundity increased along the length of the treatment wetlands. Both organisms had low mortality and high growth/fecundity in the control wetlands.

  17. Quantitative structure-activity relationships for toxicity of nonpolar narcotic chemicals to Pseudokirchneriella subcapitata.

    PubMed

    Hsieh, Shih-Hung; Hsu, Chih-Hsiung; Tsai, Din-Yu; Chen, Chung-Yuan

    2006-11-01

    This study presents data for 27 nonpolar narcotic compounds regarding toxicity to Pseudokirchneriella subcapitata as evaluated using a closed-system algal toxicity test with an exposure time of 48 h. Two test endpoints, dissolved oxygen production and algal growth rate, were used to assess the toxicity of nonpolar narcotic chemicals on algae. Hydrophobicity (1-octanol-water partition coefficient [K(OW)]) provided satisfactory descriptions for the toxicity of nonpolar narcotic compounds, and quantitative structure-activity relationships based on log K(OW) were established. The relative sensitivity of various aquatic organisms to nonpolar chemicals was as follows: P. subcapitata > Vibriofischeri > or = Nitrosomonas sp. > fathead minnow > Daphnia magna > polytox > activated sludge. In addition, linear relationships were found between the toxicity observed in P. subcapitata and other aquatic organisms, except in the case of Nitrosomonas sp. Therefore, for nonpolar toxicants, the closed-system technique applied in the present study can be an ideal surrogate for other tests, such as fathead minnow and D. magna, that are either time-consuming or labor-intensive. However, because the current toxicity database is based primarily on the conventional batch tests, it cannot provide adequate assessment regarding the effects of various organic toxicants. Therefore, more extensive research is needed to revise the database for the toxicity of organic compounds on phytoplankton using the closed-system technique.

  18. Sediment testing intermittent renewal system for the automated renewal of overlying water in toxicity tests with contaminated sediments

    SciTech Connect

    Benoit, D.A.; Phipps, G.L.; Ankley, G.T.

    1993-01-01

    A sediment testing intermittent renewal (STIR) system (stationary or portable) for invertebrate toxicity testing with contaminated sediments has been successfully developed and thoroughly tested at ERL-Duluth. Both the stationary and portable systems enable the maintenance of acceptable water quality (e.g. DO) through the capability of automatically renewing overlying water in sediment tests at rates ranging from 1 to 21 volume renewals/day. The STIR system not only significantly reduces the labor associated with renewal of overlying water but also affords a gentle exchange of water that results in virtually no sediment resuspension. Both systems can also be installed in a compact vented enclosure to permit safe testing of hazardous contaminated sediments. To date the STIR system has been used extensively for conducting 10-day bulk sediment tests with Chironomus tentans, Hyalella azteca and Lumbriculus variegatus.

  19. Development of a novel, bioluminescence-based, fungal bioassay for toxicity testing.

    PubMed

    Weitz, Hedda J; Campbell, Colin D; Killham, Ken

    2002-07-01

    Naturally bioluminescent fungi, Armillaria mellea and Mycena citricolor, were used to develop a novel, bioluminescence-based bioassay for toxicity testing. Bioassays were carried out to assess the toxicity of 3,5-dichlorophenol (3,5-DCP), pentachlorophenol (PCP), copper and zinc. The results suggested that 60 min was a suitable exposure time for the bioassay. Light reduction was observed in response to 3,5-DCP, PCP and Cu for both A. mellea and M. citricolor, but to Zn only for A. mellea. Armillaria mellea was significantly less sensitive to 3,5-DCP and PCP than M. citricolor. The EC50 values for A. mellea and M. citricolor were similar to EC50 values for 3,5-DCP, PCP and Cu (but not Zn) of bioluminescence-based bacterial biosensors. They were also similar to EC50 values for Cu and Zn of a bioluminescence-based yeast biosensor. The results highlighted the importance of using both prokaryotic and eukaryotic biosensors. The novel bioassay provides a rapid and sensitive method to assess bioavailability of pollutants as well as a method to determine their toxicity to filamentous fungi. It also expands the range of organisms that can be used for bioluminescence-based toxicity testing by complementing existing biosensors.

  20. AVS regulation of cadmium bioavailability in a life-cycle sediment toxicity test using Leptocheirus plumulosus

    SciTech Connect

    DeWitt, T.H.; Swartz, R.C.; Hansen, D.J.; McGovern, D.; Berry, W.J.

    1995-12-31

    Numerous studies have shown the utility of interstitial water concentrations of metals and simultaneously extracted metals:acid volatile sulfide ratios (SEM:AVS) in explaining the acute toxicity of sediment-associated metals to benthic organisms, but no full life-cycle chronic tests have been conducted for this purpose. In this study, cohorts of newborn amphipods, Leptocheirus plumulosus, were exposed to cadmium-spiked estuarine sediment for 28 days to determine effects on mortality, growth, and reproduction relative to interstitial water and SEM:AVS normalizations. Seven treatments of Cd were tested: control, 0.35, 0.87, 1.32, 1.53, 2.22, and 5.10 molar SEM:AVS ratios. Overlying water, interstitial water and sediment concentrations of SEM Cd and AVS were monitored periodically and by depth during the exposure. When sediments SEM:AVS ratios were < 1.53, interstitial water concentrations of Cd were less than the 10-day water-only Cd LC50, and mortality, growth and reproduction were not affected. When SEM:AVS ratios were > 2.22, interstitial water Cd concentrations were greater than 100 times the 10-day water-only Cd LC50, and all amphipods died. These results are consistent with predictions of metal bioavailability from acute tests with metals-spiked sediments, i.e. that sediments with SEM:AVS ratios less than 1.0 and less than 0.5 interstitial water toxic units are not toxic, while sediments with SEM:AVS ratios greater than 1.0 and interstitial water toxic units (IWTUS) greater than 0.5 may be toxic.

  1. PAH toxicity at aqueous solubility in the fish embryo test with Danio rerio using passive dosing.

    PubMed

    Seiler, Thomas-Benjamin; Best, Nina; Fernqvist, Margit Møller; Hercht, Hendrik; Smith, Kilian E C; Braunbeck, Thomas; Mayer, Philipp; Hollert, Henner

    2014-10-01

    As part of the risk assessment process within REACh, prior to manufacturing and distribution of chemical substances their (eco)toxicological impacts have to be investigated. The fish embryo toxicity test (FET) with the zebrafish Danio rerio has gained a high significance as an in vitro alternative to animal testing in (eco)toxicology. However, for hydrophobic organic chemicals it remains a technical challenge to ensure constant freely dissolved concentration at the maximum exposure level during such biotests. Passive dosing with PDMS silicone was thus applied to control the freely dissolved concentration of ten PAHs at their saturation level in the FET. The experiments gave repeatable results, with the toxicity of the PAHs generally increasing with the maximum chemical activities of the PAHs. HPLC analysis confirmed constant exposure at the saturation level. In additional experiments, fish embryos without direct contact to the silicone surface showed similar mortalities as those exposed with direct contact to the silicone. Silicone oil overlaying the water phase as a novel passive dosing phase had no observable effects on the development of the fish embryos until hatching. This study provides further data to support the close relationship between the chemical activity and the toxicity of hydrophobic organic compounds. Passive dosing from PDMS silicone enabled reliable toxicity testing of (highly) hydrophobic substances at aqueous solubility, providing a practical way to control toxicity exactly at the maximum exposure level. This approach is therefore expected to be useful as a cost-effective initial screening of hydrophobic chemicals for potential adverse effects to freshwater vertebrates. PMID:25048891

  2. Ecologically-based clean-up criteria for nitroaromatic explosives using toxicity test results

    SciTech Connect

    Duh, D.; Roberts, B.; Buzgo, S.

    1995-12-31

    A former trinitrotoluene (TNT) production and storage facility was the focus of a Remedial Investigation (RI). Contaminants identified during the RI included 2,4-dinitrotoluene (DNT), 2,6-DNT, and 2,4,6-TNT, PCBs, arsenic, lead and chromium. The Conceptual Site Model determined there to be several complete exposure pathways. One of these identified a route by which soil invertebrate communities could be affected through dermal contact and ingestion of soil contaminants. Maintenance of the soil invertebrate community was chosen as the assessment endpoints for this pathway in the Ecological Risk Assessment. The corresponding measurement endpoint was survival of earthworms in 14-day toxicity tests in which they were exposed to site soils. Seven surficial soil samples were collected from Areas of Concern. Each sample was evaluated for acute toxicity to earthworms using standard USEPA protocols. Chemical concentrations were also measured. An artificial soil was used as the control and diluent to establish the Lethal Concentration (LC{sub 50}) of the test soils to earthworms. From the toxicity test results and the corresponding chemical analysis, a matrix of toxicity and contaminant levels was developed. This table was used to determine a concentration of each contaminant at which no acute lethality would be expected. Lower bounds to the chemical specific LC{sub 50} values were determined and, based on sample-specific toxicity units, appropriate LC{sub 50} values were derived (333 mg/kg 2,4-DNT, 182 mg/kg 2,6-DNT, and 1960 mg/kg 2,4,6TNT). Extrapolation of this level to a chronic No Observable Adverse Effect Level (NOAEL) provided a means of proposing site-specific ecologically based clean-up criteria for the constituents of concern which would be protective of the chosen assessment endpoint.

  3. Optimizing the performance of Hyalella azteca in chronic toxicity tests: Results of feeding studies with various foods and feeding regimes

    EPA Science Inventory

    The freshwater amphipod Hyalella azteca is a common organism used for sediment toxicity testing in the United States and elsewhere. Standard methods for 10-d and 42-d toxicity tests with H. azteca were last revised and published by USEPA/ASTM in 2000. Under the methods in the man...

  4. Test Results for a Non-toxic, Dual Thrust Reaction Control Engine

    NASA Technical Reports Server (NTRS)

    Robinson, Philip J.; Veith, Eric M.; Turpin, Alicia A.

    2005-01-01

    A non-toxic, dual thrust reaction control engine (RCE) was successfully tested over a broad range of operating conditions at the Aerojet Sacramento facility. The RCE utilized LOX/Ethanol propellants; and was tested in steady state and pulsing modes at 25-lbf thrust (vernier) and at 870-lbf thrust (primary). Steady state vernier tests vaned chamber pressure (Pc) from 0.78 to 5.96 psia, and mixture ratio (MR) from 0.73 to 1.82, while primary steady state tests vaned Pc from 103 to 179 psia and MR from 1.33 to 1.76. Pulsing tests explored EPW from 0.080 to 10 seconds and DC from 5 to 50 percent at both thrust levels. Vernier testing accumulated a total of 6,670 seconds of firing time, and 7,215 pulses, and primary testing accumulated a total of 2,060 seconds of firing time and 3,646 pulses.

  5. Distribution, behavior, and condition of herbivorous fishes on coral reefs track algal resources.

    PubMed

    Tootell, Jesse S; Steele, Mark A

    2016-05-01

    Herbivore distribution can impact community structure and ecosystem function. On coral reefs, herbivores are thought to play an important role in promoting coral dominance, but how they are distributed relative to algae is not well known. Here, we evaluated whether the distribution, behavior, and condition of herbivorous fishes correlated with algal resource availability at six sites in the back reef environment of Moorea, French Polynesia. Specifically, we tested the hypotheses that increased algal turf availability would coincide with (1) increased biomass, (2) altered foraging behavior, and (3) increased energy reserves of herbivorous fishes. Fish biomass and algal cover were visually estimated along underwater transects; behavior of herbivorous fishes was quantified by observations of focal individuals; fish were collected to assess their condition; and algal turf production rates were measured on standardized tiles. The best predictor of herbivorous fish biomass was algal turf production, with fish biomass increasing with algal production. Biomass of herbivorous fishes was also negatively related to sea urchin density, suggesting competition for limited resources. Regression models including both algal turf production and urchin density explained 94 % of the variation in herbivorous fish biomass among sites spread over ~20 km. Behavioral observations of the parrotfish Chlorurus sordidus revealed that foraging area increased as algal turf cover decreased. Additionally, energy reserves increased with algal turf production, but declined with herbivorous fish density, implying that algal turf is a limited resource for this species. Our findings support the hypothesis that herbivorous fishes can spatially track algal resources on coral reefs.

  6. Marine and estuarine porewater toxicity testing -- species and end point comparisons

    SciTech Connect

    Carr, R.S.; Chapman, D.C.; Biedenbach, J.M.; Robertson, L.

    1994-12-31

    As part of their continuing development and evaluation of the porewater toxicity test approach for assessing the quality of marine and estuarine sediments, a variety of studies involving species and endpoint comparisons as well as validation studies have recently been conducted. The results from numerous extensive sediment quality assessment surveys have demonstrated that porewater toxicity tests are considerably more sensitive than the standard solid-phase tests and invariably exhibit a higher degree of concordance with sediment quality assessment guidelines than the standard tests. Species that have been evaluated for use in testing marine and estuarine pore water include a life-cycle test with the polychaete Dinophilus gyrociliatus, survival and hatching success with embryo-larval stages of red drum Sciaaenops ocellatus, survival of nauplii stages of the harpacticoid copepod Longipedia sp., and three different assays (fertilization, embryological development, and cytogenetic) with the sea urchin Arbacia punctulata. The different species and end points have been compared using sediment pore water from a variety of contaminated sites. Although the results of tests with the different species and end points were often comparable, in general, the sea urchin embryological development assay appears to be the most sensitive porewater test evaluated thus far in their laboratory.

  7. Burrowing mayfly Ephemera orientalis (Ephemeroptera: Ephemeridae) as a new test species for pesticide toxicity.

    PubMed

    Mo, Hyoung-Ho; Kim, Yongeun; Lee, Yun-Sik; Bae, Yeon Jae; Khim, Jong Seong; Cho, Kijong

    2016-09-01

    The potential of mayfly Ephemera orientalis McLachlan eggs and first-instar larvae in ecotoxicological testing was investigated. Both stages of E. orientalis showed high tolerance to various environmental variables, such as water temperature, pH, water hardness, and dissolved organic carbon. Toxicological assays were conducted with three insecticides (emamectin benzoate, endosulfan, and cypermethrin), one fungicide (mancozeb), and one herbicide (paraquat dichloride). The two toxicity endpoints for the assay were the 14-day egg median hatching rate (EHC50) in static and renewal exposure systems and 24-h median larval mortality (LC50). Cypermethrin was the most toxic to both eggs (EHC50 in static system = 36.9 μg/L; EHC50 in renewal system < 0.15 μg/L) and larvae (LC50 = 4.5 μg/L), and paraquat dichloride was the least toxic to eggs (EHC50 in static system = 54,359.8 μg/L; EHC50 in renewal system = 49541.3 μg/L) and larvae (LC50 = 9259.5 μg/L). The results were compared to literature data of Daphnia magna Straus and Cloeon dipterum Linnaeus to determine its relative sensitivity to pesticides. These three species had different toxicities to the tested pesticides, especially according to the exposure system. E. orientalis eggs in the static system were found to be less sensitive were D. magna and C. dipterum, but eggs in the renewal system and larvae had similar or higher sensitivities to the tested pesticides. The results revealed that this species has potential for use in ecotoxicological testing of pesticides. Because of its geographic distribution, E. orientalis may be used as an alternative or complementary test species for ecotoxicological studies in Northeast Asian countries, where natural populations of the international standard species, D. magna, are rarely found. PMID:27316648

  8. A New, Sensitive Marine Microalgal Recombinant Biosensor Using Luminescence Monitoring for Toxicity Testing of Antifouling Biocides

    PubMed Central

    Sanchez-Ferandin, Sophie; Leroy, Fanny; Bouget, François-Yves

    2013-01-01

    In this study, we propose the use of the marine green alga Ostreococcus tauri, the smallest free-living eukaryotic cell known to date, as a new luminescent biosensor for toxicity testing in the environment. Diuron and Irgarol 1051, two antifouling biocides commonly encountered in coastal waters, were chosen to test this new biosensor along with two degradation products of diuron. The effects of various concentrations of the antifoulants on four genetic constructs of O. tauri (based on genes involved in photosynthesis, cell cycle, and circadian clock) were compared using 96-well culture microplates and a luminometer to automatically measure luminescence over 3 days. This was compared to growth inhibition of O. tauri wild type under the same conditions. Luminescence appeared to be more sensitive than growth inhibition as an indicator of toxicity. Cyclin-dependent kinase (CDKA), a protein involved in the cell cycle, fused to luciferase (CDKA-Luc) was found to be the most sensitive of the biosensors, allowing an accurate determination of the 50% effective concentration (EC50) after only 2 days (diuron, 5.65 ± 0.44 μg/liter; Irgarol 1015, 0.76 ± 0.10 μg/liter). The effects of the antifoulants on the CDKA-Luc biosensor were then compared to growth inhibition in natural marine phytoplankton. The effective concentrations of diuron and Irgarol 1051 were found to be similar, indicating that this biosensor would be suitable as a reliable ecotoxicological test. The advantage of this biosensor over cell growth inhibition testing is that the process can be easily automated and could provide a high-throughput laboratory approach to perform short-term toxicity tests. The ability to genetically transform and culture recombinant O. tauri gives it huge potential for screening many other toxic compounds. PMID:23144143

  9. Modified Whole Effluent Toxicity Test to Assess and Decouple Wastewater Effects from Environmental Gradients

    PubMed Central

    Sauco, Sebastián; Gómez, Julio; Barboza, Francisco R.; Lercari, Diego; Defeo, Omar

    2013-01-01

    Environmental gradients and wastewater discharges produce aggregated effects on marine populations, obscuring the detection of human impact. Classical assessment methods do not include environmental effects in toxicity tests designs, which could lead to incorrect conclusions. We proposed a modified Whole Effluent Toxicity test (mWET) that includes environmental gradients in addition to effluent dilutions, together with the application of Generalized Linear Mixed Models (GLMM) to assess and decouple those effects. We tested this approach, analyzing the lethal effects of wastewater on a marine sandy beach bivalve affected by an artificial canal freshwater discharge used for rice crops irrigation. To this end, we compared bivalve mortality between canal water dilutions (CWd) and salinity controls (SC: without canal water). CWd were prepared by diluting the water effluent (sampled during the pesticide application period) with artificial marine water. The salinity gradient was included in the design by achieving the same final salinities in both CWd and SC, allowing us to account for the effects of salinity by including this variable as a random factor in the GLMM. Our approach detected significantly higher mortalities in CWd, indicating potential toxic effects of the effluent discharge. mWET represents an improvement over the internationally standardized WET tests, since it considers environmental variability and uses appropriate statistical analyses. PMID:23755304

  10. Amiodarone-induced pulmonary toxicity. Immunoallergologic tests and bronchoalveolar lavage phospholipid content.

    PubMed

    Nicolet-Chatelain, G; Prevost, M C; Escamilla, R; Migueres, J

    1991-02-01

    Amiodarone (A) is a widely-used antiarrhythmic drug. Pulmonary toxicity is the most serious adverse effect with an estimated mortality of 1 to 33 percent. In order to determine an element helpful for diagnosis, we examined four patients with amiodarone-induced pulmonary toxicity, three patients treated with A, without evidence of pulmonary toxicity but with a main underlying pulmonary disease, and four healthy volunteers. Daily and cumulative doses or duration of treatment were similar in the first two groups. Pulmonary function tests (spirometry, CO-diffusing capacity, arterial blood gases), roentgenographic examinations, pulmonary biopsies or immunoallergologic tests (skin reaction, lymphoblastic transformation test and human basophile degranulation test) did not provide any discriminatory element. In APT+, we observed an increased cellularity of the bronchoalveolar lavage. Neither the differential cell count nor the presence of foamy macrophages were distinguishable between APT+ and APT-. The phospholipid composition of BAL fluid showed a decreased total phospholipid and phospholipid/protein ratio in all patients compared to normal subjects. These changes reflect more the severity of pulmonary disease than the specificity of the causative agent. However, we observed that the unique PL which decreases in APT- and remains normal in APT+ is phosphatidyl-serine + phosphatidylinositol (PS + PI). This has to be confirmed and should be evaluated at different stages of the disease to determine an eventual specific element. We conclude that there are no data currently available to establish the diagnosis of APT except perhaps for the analysis of BAL PL content.

  11. Algal functional annotation tool

    SciTech Connect

    Lopez, D.; Casero, D.; Cokus, S. J.; Merchant, S. S.; Pellegrini, M.

    2012-07-01

    The Algal Functional Annotation Tool is a web-based comprehensive analysis suite integrating annotation data from several pathway, ontology, and protein family databases. The current version provides annotation for the model alga Chlamydomonas reinhardtii, and in the future will include additional genomes. The site allows users to interpret large gene lists by identifying associated functional terms, and their enrichment. Additionally, expression data for several experimental conditions were compiled and analyzed to provide an expression-based enrichment search. A tool to search for functionally-related genes based on gene expression across these conditions is also provided. Other features include dynamic visualization of genes on KEGG pathway maps and batch gene identifier conversion.

  12. Algal biomass production and wastewater treatment in high rate algal ponds receiving disinfected effluent.

    PubMed

    Santiago, Aníbal Fonseca; Calijuri, Maria Lucia; Assemany, Paula Peixoto; Calijuri, Maria do Carmo; dos Reis, Alberto José Delgado

    2013-01-01

    Algal biomass production associated with wastewater is usually carried out in high rate algal ponds (HRAPs), which are concomitantly used in the treatment of such effluent. However, most types of wastewater have high levels of bacteria that can inhibit the growth of algal biomass by competing for space and nutrients. The objective of this study was to assess the influence of ultraviolet (UV) pre-disinfection on the performance of HRAPs used for wastewater treatment and algal biomass production. Two HRAPs were tested: one received effluent from an upflow anaerobic sludge blanket (UASB) reactor- HRAP -and the second received UASB effluent pre-disinfected by UV radiation-(UV)HRAP. Physical, chemical and microbiological parameters were monitored, as well as algal biomass productivity and daily pH and dissolved oxygen (DO) variation. The (UV)HRAP presented highest DO and pH values, as well as greater percentage of chlorophyll a in the biomass, which indicates greater algal biomass productivity. The average percentages of chlorophyll a found in the biomass obtained from the HRAP and the (UV)HRAP were 0.95 +/- 0.65% and 1.58 +/- 0.65%, respectively. However, total biomass productivity was greater in the HRAP (11.4 gVSSm(-2) day(-1)) compared with the (UV)HRAP (9.3 gVSSm(-2) day(-1)). Mean pH values were 7.7 +/- 0.7 in the HRAP and 8.1 +/- 1.0 in the (UV)HRAP, and mean values of DO percent saturation were 87 +/- 26% and 112 +/- 31% for the HRAP and the (UV)HRAP, respectively. Despite these differences, removal efficiencies of organic carbon, chemical oxygen demand, ammoniacal nitrogen and soluble phosphorus were statistically equal at the 5% significance level.

  13. Handbook of acute toxicity of chemicals to fish and aquatic invertebrates : summaries of toxicity tests conducted at Columbia National Fisheries Research Laboratory, 1965-78

    USGS Publications Warehouse

    Johnson, W. Waynon; Finley, Mack T.

    1980-01-01

    Acute toxicity is a major subject of research at Columbia National Fisheries Research Laboratory for evaluating the impact of toxic chemicals on fishery resources. The Laboratory has played a leading role in developing research technology for toxicity testing and data interpretation. In 1965-78, more than 400 chemicals were tested against a variety of invertebrates and fish species representative of both cold- and warm-water climates. The use of acute toxicity tests for assessing the potential hazard of chemical contaminants to aquatic organisms is well documented (Boyd 1957; Henderson et al. 1960; Sanders and Cope 1966; Macek and McAllister 1970). Static acute toxicity tests provide rapid and (within limits) reproducible concentration-response curves for estimating toxic effects of chemicals on aquatic organisms. These tests provide a database for determining relative toxicity of a large number of chemicals to a variety of species and for estimating acute effects of chemical spills on natural aquatic systems; they also assist in determining priority and design of additional toxicity studies. Acute toxicity tests usually provide estimates of the exposure concentration causing 50% mortality (LC50) to test organisms during a specified period of time. For certain invertebrates, the effective concentration is based on immobilization, or some other identifiable endpoint, rather than on lethality. The application of the LC50 has gained acceptance among toxicologists and is generally the most highly rated test for assessing potential adverse effects of chemical contaminants to aquatic life (Brungs and Mount 1978; American Institute for Biological Sciences 1978a). The literature contains numerous papers dealing with the acute toxicity of chemicals to freshwater organisms. However, there is a tremendous need for a concise compendium of toxicity data covering a large variety of chemicals and test species. This Handbook is a compilation of a large volume of acute toxicity

  14. Handbook of acute toxicity of chemicals to fish and aquatic invertebrates : summaries of toxicity tests conducted at Columbia National Fisheries Research Laboratory, 1965-78

    USGS Publications Warehouse

    Johnson, W. Waynon; Finley, Mack T.

    1980-01-01

    Acute toxicity is a major subject of research at Columbia National Fisheries Research Laboratory for evaluating the impact of toxic chemicals on fishery resources. The Laboratory has played a leading role in developing research technology for toxicity testing and data interpretation. In 1965-78, more than 400 chemicals were tested against a variety of invertebrates and fish species representative of both cold- and warm-water climates.The use of acute toxicity tests for assessing the potential hazard of chemical contaminants to aquatic organisms is well documented (Boyd 1957; Henderson et al. 1960; Sanders and Cope 1966; Macek and McAllister 1970). Static acute toxicity tests provide rapid and (within limits) reproducible concentration-response curves for estimating toxic effects of chemicals on aquatic organisms. These tests provide a database for determining relative toxicity of a large number of chemicals to a variety of species and for estimating acute effects of chemical spills on natural aquatic systems; they also assist in determining priority and design of additional toxicity studies.Acute toxicity tests usually provide estimates of the exposure concentration causing 50% mortality (LC50) to test organisms during a specified period of time. For certain invertebrates, the effective concentration is based on immobilization, or some other identifiable endpoint, rather than on lethality. The application of the LC50 has gained acceptance among toxicologists and is generally the most highly rated test for assessing potential adverse effects of chemical contaminants to aquatic life (Brungs and Mount 1978; American Institute for Biological Sciences 1978a).The literature contains numerous papers dealing with the acute toxicity of chemicals to freshwater organisms. However, there is a tremendous need for a concise compendium of toxicity data covering a large variety of chemicals and test species. This Handbook is a compilation of a large volume of acute toxicity data

  15. Classification of reproductive toxicants with diverse mechanisms in the embryonic stem cell test.

    PubMed

    Riebeling, Christian; Fischer, Kristin; Luch, Andreas; Seiler, Andrea E M

    2015-12-01

    The embryonic stem cell test (EST) is a promising system to detect embryotoxicity in vitro. Recent studies have pointed out some limitations of the EST and suggest that the applicability domain of the EST and its prediction model have to be better defined. Here, eight substances of known reproductive toxicity were tested in the EST under blind conditions. We applied the prediction model to the data of the EST after classifying the substances according to the published criteria. In addition, a simplified classification of the EST results into two classes as an approach to hazard assessment was compared to the European Union Classification, Labelling and Packaging (CLP) Regulation labels of the substances. With one exception, substances that are labeled as reproductive toxicants according to the CLP Regulation were detected as embryotoxic in the EST while substances without label were found to be non-embryotoxic according to the EST. PMID:26558462

  16. Optimizing the aquatic toxicity assessment under REACH through an integrated testing strategy (ITS).

    PubMed

    Lombardo, Anna; Roncaglioni, Alessandra; Benfenati, Emilio; Nendza, Monika; Segner, Helmut; Jeram, Sonja; Pauné, Eduard; Schüürmann, Gerrit

    2014-11-01

    To satisfy REACH requirements a high number of data on chemical of interest should be supplied to the European Chemicals Agency. To organize the various kinds of information and help the registrants to choose the best strategy to obtain the needed information limiting at the minimum the use of animal testing, integrated testing strategies (ITSs) schemes can be used. The present work deals with regulatory data requirements for assessing the hazards of chemicals to the aquatic pelagic environment. We present an ITS scheme for organizing and using the complex existing data available for aquatic toxicity assessment. An ITS to optimize the choice of the correct prediction strategy for aquatic pelagic toxicity is described. All existing information (like physico-chemical information), and all the alternative methods (like in silico, in vitro or the acute-to-chronic ratio) are considered. Moreover the weight of evidence approach to combine the available data is included. PMID:25262089

  17. Marine algal toxins: origins, health effects, and their increased occurrence.

    PubMed Central

    Van Dolah, F M

    2000-01-01

    Certain marine algae produce potent toxins that impact human health through the consumption of contaminated shellfish and finfish and through water or aerosol exposure. Over the past three decades, the frequency and global distribution of toxic algal incidents appear to have increased, and human intoxications from novel algal sources have occurred. This increase is of particular concern, since it parallels recent evidence of large-scale ecologic disturbances that coincide with trends in global warming. The extent to which human activities have contributed to their increase therefore comes into question. This review summarizes the origins and health effects of marine algal toxins, as well as changes in their current global distribution, and examines possible causes for the recent increase in their occurrence. Images Figure 2 Figure 3 PMID:10698729

  18. Marine algal toxins: origins, health effects, and their increased occurrence.

    PubMed

    Van Dolah, F M

    2000-03-01

    Certain marine algae produce potent toxins that impact human health through the consumption of contaminated shellfish and finfish and through water or aerosol exposure. Over the past three decades, the frequency and global distribution of toxic algal incidents appear to have increased, and human intoxications from novel algal sources have occurred. This increase is of particular concern, since it parallels recent evidence of large-scale ecologic disturbances that coincide with trends in global warming. The extent to which human activities have contributed to their increase therefore comes into question. This review summarizes the origins and health effects of marine algal toxins, as well as changes in their current global distribution, and examines possible causes for the recent increase in their occurrence.

  19. Effect of methyl tert-butyl ether in standard tests for mutagenicity and environmental toxicity.

    PubMed

    Vosahlikova, Miluse; Cajthaml, Tomas; Demnerova, Katerina; Pazlarova, Jarmila

    2006-12-01

    Methyl tert-butyl ether (MTBE) is a synthetic compound that is used as a technological solution to problems created by air pollution from vehicle emissions. An important source of MTBE in the environment is leakage from underground storage tanks at gasoline stations or accidents during gasoline transport. The aim of this study was to evaluate the risk of MTBE leakage for the environment using the Microtox (Vibrio fischeri) toxicity test, Lactuca sativa seed germination test, and Ames bacterial mutagenicity test with Salmonella typhimurium his(-) strains TA98, TA100, YG1041, and YG1042, using both standard plate and preincubation protocols. The result of Microtox expressed as EC(50) was 33 mg (MTBE)/L. The effect of all tested MTBE concentration (0.05, 0.50, and 1.00% v/v) on Lactuca sativa roots elongation was negative and proved its toxicity. The highest tested concentration of MTBE that could be tested in Ames test was 3 mg (MTBE)/plate, because of cytotoxicity. No mutagenic response was observed at this or lower concentrations in any of the four strains used. PMID:17091504

  20. Salinity tolerance of Daphnia magna and potential use for estuarine sediment toxicity tests.

    PubMed

    Schuytema, G S; Nebeker, A V; Stutzman, T W

    1997-08-01

    Daphnia magna Straus, a common organism used for freshwater sediment toxicity tests, was evaluated to determine its tolerance to salinity and suitability for tests with estuarine water and sediments. Daphnids were exposed for 2 to 21 days to salinity in a variety of water-only tests, in tests with freshwater sediment overlain by salt water, and in tests with estuarine sediments overlain by freshwater. Daphnid age, test length, and temperature seemed to have little effect upon the range of LC50, NOAEL, and LOAEL values. LC50s for all tests ranged from 5.10 to 7.81 g/L, with a mean of 6.6 g/L salinity (measured conductivity 10.0 mS/cm) [corrected]. The mean NOAEL and LOAEL values based on production of young were 4.6 and 6.9 g/L salinity (measured conductivity 7.1 and 10.5 mS/cm) [corrected], respectively. The results indicate that D. magna will survive and reproduce well in water with salinities below 4 g/L and demonstrate the potential usefulness of this organism in monitoring sediment toxicity from both freshwater and estuarine wetland sites. PMID:9294248

  1. The submitochondrial particle assay as a screening test for acute aquatic toxicity of surfactant molecules

    SciTech Connect

    Bookland, E.A.; Bettermann, A.D.

    1995-12-31

    Two complementary protocols of the submitochondrial particle assay (SMP) were evaluated as screening tools for predicting the acute aquatic toxicity of various classes and chain lengths of surfactant molecules. SMP contain the functionally intact mitochondrial enzyme systems responsible for electron transport and oxidative phosphorylation. Both the Electron Transfer Assay (ETR) and the Reverse Electron Transfer Assay (RET) have been shown in prior work to generally be sensitive to agents capable of membrane and protein interactions, both suspected mechanisms of action for surfactants. The toxicity of ten compounds; four anionic surfactants, C{sub 12} alkyl sulfate (C{sub 12}AS), C{sub 12} and C{sub 15} alkyl ethoxy sulfate (C{sub 12}E{sub 4}S, C{sub 15}E{sub 4}S), linear alkyl benzene sulfonate (C{sub 12.3}LAS); one nonionic surfactant, alkyl ethoxylate (C{sub 12}E{sub 3}); three cationic surfactants, C{sub 8}, C{sub 12}, and C{sub 16} alkyl trimethyl ammonium chloride (C{sub 8}TMAC, C{sub 12}TMAC, C{sub 16}TMAC); an alcohol (C{sub 12}OH); and an amine, alkyl dimethylamine (C{sub 12}DMA); was determined. In all cases, both the ETR and the RET gave results showing equal or greater sensitivity than previously reported acute fish and invertebrate LC{sub 50}`s. In addition, increasing toxicity with increasing alkyl chain length was observed. As a rapid screening tool, the SMP bioassay avoids exposure concerns such as degradation of test material, a common concern for acute in vivo toxicity testing with rapidly degradable materials. Results indicate that the SMP bioassay can be useful as a predictive screening tool for the aquatic toxicity of surfactants.

  2. Statistical studies of animal response data from USF toxicity screening test method

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Machado, A. M.

    1978-01-01

    Statistical examination of animal response data obtained using Procedure B of the USF toxicity screening test method indicates that the data deviate only slightly from a normal or Gaussian distribution. This slight departure from normality is not expected to invalidate conclusions based on theoretical statistics. Comparison of times to staggering, convulsions, collapse, and death as endpoints shows that time to death appears to be the most reliable endpoint because it offers the lowest probability of missed observations and premature judgements.

  3. Algal Biofuels; Algal Biofuels R&D at NREL (Brochure)

    SciTech Connect

    Not Available

    2010-09-01

    An overview of NREL's algal biofuels projects, including U.S. Department of Energy-funded work, projects with U.S. and international partners, and Laboratory Directed Research and Development projects.

  4. Effects of ammonia on juvenile unionid mussels (Lampsilis cardium) in laboratory sediment toxicity tests

    USGS Publications Warehouse

    Newton, Teresa J.; Allran, John W.; O'Donnell, Jonathan A.; Bartsch, Michelle; Richardson, William B.

    2003-01-01

    Ammonia is a relatively toxic compound generated in water and sediments by heterotrophic bacteria and accumulates in sediments and pore water. Recent data suggest that unionid mussels are sensitive to un-ionized ammonia (NH3) relative to other organisms. Existing sediment exposure systems are not suitable for ammonia toxicity studies with juvenile unionids; thus, we modified a system to expose juveniles to ammonia that was continuously infused into sediments. This system maintained consistent concentrations of ammonia in pore water up to 10 d. Juvenile Lampsilis cardium mussels were exposed to NH3 in pore water in replicate 96-h and 10-d sediment toxicity tests. The 96-h median lethal concentrations (LC50s) were 127 and 165 μg NH3-N/L, and the 10-d LC50s were 93 and 140 μg NH3-N/L. The median effective concentrations (EC50s) (based on the proportion affected, including dead and inactive mussels) were 73 and 119 μg NH3-N/L in the 96-h tests and 71 and 99 μg NH3-N/L in the 10-d tests. Growth rate was substantially reduced at concentrations between 31 and 76 μg NH3-N/L. The lethality results (when expressed as total ammonia) are about one-half the acute national water quality criteria for total ammonia, suggesting that existing criteria may not protect juvenile unionids.

  5. Evaluation of the hazardous impact of landfill leachates by toxicity and biodegradability tests.

    PubMed

    Kalcíková, G; Vávrová, M; Zagorc-Koncan, J; Gotvajn, A Zgajnar

    2011-01-01

    The aim of our research was to assess the ecotoxicity and biodegradability of leachates originating from two parts of a municipal landfill before and after biological treatment in the existing treatment plant. Biotests represent important tools for adequate environmental characterization of landfill leachates and could be helpful in reliable assessment and monitoring of the treatment plant efficiency. For ecotoxicity testing of landfill leachate before and after biological treatment, different organisms were chosen: the bacteria Vibrio fischeri, a mixed culture of activated sludge, duckweed Lemna minor, white mustard Sinapis alba, brine shrimp Artemia salina, and water flea Daphnia magna. For assessment of biodegradability, the method for determination of oxygen demand in a closed respirometer was used. The investigated leachates were heavily polluted, and in some cases, effluent limits were exceeded even after treatment. Results indicated that toxicity tests and physico-chemical parameters determined before and after treatment equivalently assess the efficiency of the existing treatment plant. However, the investigated leachates showed higher toxicity to Daphnia magna and especially to Lemna minor in contrast to Vibrio fischeri and Artemia salina (neither was sensitive to any of the leachates). No leachates were readily biodegradable. Experiments confirmed that the battery of toxicity tests should be applied for more comprehensive assessment of landfill leachate treatment and for reliable assessment of the treated leachate's subsequent environmental impact. It was confirmed that treated leachate, in spite of its better physico-chemical characteristics, still represents a potential environmental risk and thus should not be released into the environment. PMID:21970176

  6. [Study of the integral toxicity of aqueous media, polluted by petroleum and petroleum products using bacterial tests].

    PubMed

    Fomchenkov, V M; Irkhina, I A; Novikov, I A; Gurov, B N; Chugunov, V A; Kholodenko, V P

    2000-01-01

    A biotest kit was used to assess the integral toxicity level of aquatic medium contamination with petroleum and petroleum-based products. The integral toxicity dynamics was also monitored during biodegradation of petroleum and petroleum-based products by an association of petroleum-degrading strains including Acinetobacter sp., Mycobacterium flavescens, and Rhodococcus sp. The following bacterial tests were used: the bioluminescence (BL) test based on Photobacterium leiognathi; electro-orientation (EO), optoosmotic (OO), and growth test; as well as the reducing activity (RA) test based on the Agrobacterium radiobacter culture. No significant increase in the integral toxicity level of aquatic medium was observed when diesel fuel and kerosene contamination had been subjected to biodegradation. Although express biotests (EO, OO, RA, and BL) detected a pronounced increase in the integral toxicity of aquatic medium, long-term growth biotest revealed no statistically significant increase in the toxicity level.

  7. Exposure-driven risk assessment: applying exposure-based waiving of toxicity tests under REACH.

    PubMed

    Rowbotham, Anna L; Gibson, Rosemary M

    2011-08-01

    The REACH Regulation 1907/2006/EC aims to improve knowledge of the potential risks to humans and the environment of the large number of chemicals produced and used in the EU. The testing requirements are likely to trigger numerous toxicological studies, potentially involving millions of experimental animals, despite the professed goal of REACH to reduce vertebrate testing. It may be necessary therefore to shift emphasis away from animal studies towards more pragmatic strategies, reserving animal tests for the substances of greatest concern. One approach is to waive certain tests based on levels of exposure to the substance. This review explores application of 'Exposure-Based Waiving' (EBW) of toxicity studies, with a particular focus on inhalation where possible, considering the potential qualitative and quantitative supporting arguments that might be made, including the use of thresholds of toxicological concern. Incorporating EBW into intelligent testing strategies for substance registration could advance the goals of REACH and the 3Rs (reduction, replacement and refinement of animals in research) by reducing the usage of animals in toxicity tests, whilst maintaining appropriate protection of human health and the environment. However greater regulatory evaluation, acceptance and guidance are required for EBW to achieve its full impact.

  8. Sediment organic matter content as a confounding factor in toxicity tests with Chironomus tentans

    SciTech Connect

    Lacey, R.; Watzin, M.C.; McIntosh, A.W.

    1999-02-01

    Physicochemical characteristics of sediment unrelated to contaminant levels and bioavailability may influence the outcome of toxicity tests. In particular, sediment organic matter content has the potential to be a confounding factor in toxicity tests using the midge larva Chironomus tentans because the larvae are infaunal and feed on organic matter in the sediments. To examine the possibility, the authors conducted a series of tests using formulated sediments with varying organic matter contents following the standard US Environmental Protection Agency (US EPA) 10-day C. tentans growth and survival protocol. Formulated sediments made with peat moss, {alpha}-cellulose, and maple leaves were tested. An organic-rich natural sediment diluted with formulated sediment to achieve a range of organic matter contents was also examined. In a final experiment, sediments containing each of the four organic matter sources at the same concentration were tested against one another. Survival was not greatly affected by concentration of organic matter, except at the lowest concentrations in natural sediment, where survival dipped below 70%. In experiments using peat moss, {alpha}-cellulose, and maple leaves, significant differences in C. tentans growth were found at different organic matter concentrations. In contrast, concentration of organic matter in the natural sediment dilution series had little effect on growth, perhaps because much of this material was highly refractory. In the comparison experiment, growth differed significantly among the four sediments, with best growth achieved with {alpha}-cellulose and leaves. These results suggest that both organic matter quantity and quality can be confounding factors in toxicity tests using C. tentans.

  9. Standard wool fabric as a reference material. [for fire toxicity tests

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Cumming, H. J.

    1977-01-01

    Standard wool fabric is investigated as a potential reference material. A screening test method for relative toxicity exposes four albino male rats enclosed in a 4.2 liter hemispherical chamber to pyrolysis effluents produced by pyrolyzing a 1.00 g sample under a variety of test conditions (200-800 C with a 40 C/min heating rate). It is found that for fabrics containing 86-100% wool, animal response remains virtually unchanged, although a 100% wool fabric is preferred as it eliminates local composition differences as a source of variation.

  10. Historical data analyses and scientific knowledge suggest complete removal of the abnormal toxicity test as a quality control test.

    PubMed

    Garbe, Joerg H O; Ausborn, Susanne; Beggs, Claire; Bopst, Martin; Joos, Angelika; Kitashova, Alexandra A; Kovbasenco, Olga; Schiller, Claus-Dieter; Schwinger, Martina; Semenova, Natalia; Smirnova, Lilia; Stodart, Fraser; Visalli, Thomas; Vromans, Lisette

    2014-11-01

    In the early 1900s, the abnormal toxicity test (ATT) was developed as an auxiliary means to ensure safe and consistent antiserum production. Today, the ATT is utilized as a quality control (QC) release test according to pharmacopoeial or other regulatory requirements. The study design has not been changed since around 1940. The evidence of abnormal toxicity testing as a prediction for harmful batches is highly questionable and lacks a scientific rationale. Numerous reviews of historical ATT results have revealed that no reliable conclusions can be drawn from this QC measure. Modern pharmaceutical manufacturers have thorough control of the manufacturing process and comply with good manufacturing practice rules. Contaminants are appropriately controlled by complying with the validated manufacturing processes and strict QC batch release confirming batch-to-batch consistency. Recognizing that product safety, efficacy, and stability can be ensured with strict QC measures, nowadays most regulatory authorities do not require the ATT for most product classes. In line with the replacement, reduction, and refinement (3Rs) initiative, the test requirement has been deleted from approximately 80 monographs of the European Pharmacopoeia and for the majority of product classes in the United States. For these reasons, it is recommended that the ATT should be consistently omitted world-wide and be removed from pharmacopoeias and other regulatory requirements.

  11. Toxicity test using medaka (Oryzias latipes) early fry and concentrated sample water as an index of aquatic habitat condition.

    PubMed

    Yamashita, H; Haribowo, R; Sekine, M; Oda, N; Kanno, A; Shimono, Y; Shitao, W; Higuchi, T; Imai, T; Yamamoto, K

    2011-08-01

    The aim of the present study was to show a relationship between toxicity of 100-fold concentrated water and aquatic habitat conditions. Environmental waters are 100-fold concentrated with solid-phase extraction. Medaka early fry was exposed in these waters for 48 h. The number of death and disorder was counted at 1, 2, 3, 6, 12, 24, and 48 h; toxicity was expressed using inverse median effect time and median lethal time (ET (50)(-1), LT (50)(-1)). Average score per taxon (ASPT) for benthic animals and Index of Biotic Integrity (IBI) for fish were applied as indices of aquatic habitat conditions. The results of toxicity test were compared using ASPT and IBI. The different levels of toxicity were detected in the seawater of Japan. At the Husino River area, toxicity cannot be detected. In rivers, high toxicity appeared at urban districts without sewerage. By Spearman coefficient, the relationship between toxicity and high biochemical oxygen demand (BOD) were obtained. BOD household wastewater contains hydrophobic toxic matters; otherwise, seawater in industrial area does not show clear relationship between toxicity and chemical oxygen demand. Gas chromatography to mass spectrometry simultaneous analysis database may give an answer for the source of toxicity, but further test is required. Ratio of clear stream benthic animal sharply decreased over 0.25 of LT (50)(-1) or 0.5 of ET (50)(-1). Tolerant fish becomes dominant over 0.3 of LT (50)(-1) or 0.5-1.0 of ET (50)(-1). By Pearson product-moment correlation coefficient, correlation coefficient between toxicity and ASPT was obtained at -0.773 (ET (50)(-1)) and -0.742 (LT (50)(-1)) at 1 % level of significance with a high negative correlation. Toxicity (LT (50)(-1) ) has strong correlation with the ratio of tolerant species. By Pearson product-moment correlation coefficient, correlation coefficient between toxicity and IBI obtained were -0.155 (ET (50)(-1)) and -0.190 (LT (50)(-1)) at 1 % level of significance and has a

  12. Rapid toxicity assessment of sediments from estuarine ecosystems: A new tandem in vitro testing approach

    USGS Publications Warehouse

    Johnson, B.T.; Long, E.R.

    1998-01-01

    Microtox?? and Mutatox?? were used to evaluate the acute toxicity and genotoxicity, respectively, of organic sediment extracts from Pensacola Bay and St. Andrew Bay, two estuaries that cover about 273 and 127 km2, respectively, along the Gulf coast of Florida, USA. The sensitivity and selectivity of these two bioluminescent toxicity assays were demonstrated in validation studies with over 50 pesticides, genotoxins, and industrial pollutants, both as single compounds and in complex mixtures. The 50% effective concentration (EC50) values of insecticides, petroleum products, and polychlorinated biphenyls determined by Microtox all tended to group around the mean EC50 value of 1.2 (0.8) mg/L. The polycyclic aromatic hydrocarbon sensitivity of Mutatox was in general similar to that reported in the Ames test. Surficial sediment samples were collected, extracted with dichloromethane, evaporated and concentrated under nitrogen, dissolved in dimethyl sulfoxide, assayed for acute toxicity and genotoxicity, and compared with reference sediments. Samples with low EC50 values, and determined to be genotoxic, were detected in Massalina Bayou, Watson Bayou, East Bay, and St. Andrew Bay-East in St. Andrew Bay as well as Bayou Grande, Bayou Chico, and Bayou Texar in Pensacola Bay. An overview of these data sets analyzed by Spearman rank correlation showed a significant correlation between acute toxicity and genotoxicity (p < 0.05). Microtox and Mutatox in tandem was a sensitive, cost-effective, and rapid (<24 h) screening tool that identified troublesome areas of pollution and assessed the potential sediment toxicity of lipophilic contaminants in aquatic ecosystems.

  13. Comparative rice seed toxicity tests using filter paper, growth pouch-tm, and seed tray methods

    USGS Publications Warehouse

    Wang, W.

    1993-01-01

    Paper substrate, especially circular filte