1995 Fiscal Year Final Research Report Summary
Research in small scale screening methods for the hazard assessment of the toxic substances in aquatic environment
| Project/Area Number |
06680522
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
環境影響評価(含放射線生物学)
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| Research Institution | College of Technology, Toyama Prefectural University |
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Principal Investigator |
KUSUI Takashi College of Technology, Toyama Prefectural Univ.Dept.of Environmental Technology, Professor, 環境工学科, 教授 (60153293)
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| Project Period (FY) |
1994 – 1995
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| Keywords | bioassay / toxicity / mutagenicity / hazard assessment / microplate / industrial wastewater / umu test |
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| Research Abstract |
(1) The way to diminish the effect of volatile sample on themicroplate-based algal assay was examined. The uses of ceiling tape and Teflon sheet, which prevented the contamination from the adjacent wells, were found to not only diminish the effect of volatile samples, but also lower the cell yield compared to that of usual method. These operations did not affect the IC50 (concentration of 50% inhibition) significantly, suggesting that these techniques would improve the performance of microplate method.
(2) To enhance the efficiency of umu test, the 96-wells microplate-based method was developed. The major modifications from original methods are as follows, volume of reagents and bacterial culture, incubation temperature, concentration of SDS,wave length for absorbance measurement. Finally the modified Miller's equation was conducted to calculate the unit activity of beta galactocidase in microplate assay,
(3) The sensitivity of small scale hydra acute toxicity test based on the morphological change was examined. The values of 96h-EC50 showed the relatively higher sensitivity to Cr6+than other assays examined. For some metals, the effect was transient, showing detoxification in sublethal endpoint and promotion in sublethal and lethal endpoints.
(4) Using battery of small scale bioassays including Microtox, algal growth inhibition test, umu test, hydra acute test and daphinia acute test, the effects of 20 industrial wastewater were assessed. 85% of the samples showed any adverse effect. The causal substance for toxicity was evaluated by using the addition of chlating agent and comparing the analytical values.
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