An analysis of the importance of acute toxicity tests for pesticides in vertebrates
Throughout this Thesis the Author's opinion is maintained that predictive acute toxicology with pesticides is a necessity and that the interpretation of results from such tests are complicated. The routes for acute intoxication by pesticides in vertebrates are generally through the skin or by i...
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University of Surrey
1977
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| Online Access: | https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.480258 |
| Summary: | Throughout this Thesis the Author's opinion is maintained that predictive acute toxicology with pesticides is a necessity and that the interpretation of results from such tests are complicated. The routes for acute intoxication by pesticides in vertebrates are generally through the skin or by ingestion or inhalation. The logistics of using these and other routes of exposure in predictive acute toxicology have been discussed. Acute toxicity results are often expressed as response to quantity of toxicant per unit of body weight, this is not entirely logical and can be affected by age and other factors. Sex differences in response to toxicants are common particularly in the rat. Ethnic differences in susceptibility to intoxication are rarely reported although strain differences in response are common. Demographic distribution of incidents of acute intoxication must not be confused with ethnic differences in susceptibility. The relationship between ambient conditions and toxic effects are seldom linear. Metabolic characteristics of intoxicated animals are sometimes related to ambient conditions. Stress and other biorhythms can also affect the responses to toxicants. Information presented in this Thesis rules out any possibility that phylogenetic considerations can be used to aid extrapolation of acute toxicity data from one species to another. The form in which the toxicant is presented to the recipient can influence the outcome. Multiple or mixed responses may alter the toxicity depending on the nature of the combination. Most quantitation of acute data are based on quantal mathematics and the Author has been critical of this approach and has recommended that more attention should be given to individual animal findings. The Author partially accepts the validity of the stated criticisms of the "LD50-test" but has concluded that the use of sentient species for predictive acute toxicology is unlikely to diminish and has presented experimental data and a review of published information to support this opinion. |
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