Cytogenetic toxicity and no-effect limit dose of pesticides.
The no-effect limit dose (NELD) of three commonly used pesticides with respect to their cytogenetic toxicity was determined in a number of test systems using a sufficient number of lower doses to characterize the dose-effect relationship. For lindane, malathion and metacid, this dose was 3.2, 7.0 and 3.0 mg/litre, respectively, for mitosis inhibition and 9.0, 55 and 60 mg/litre, respectively, for chromosome clastogeny in onion root-tip cells. For chromosome clastogeny in mice bone marrow cells, the NELDs of the three pesticides were 1.6, 1.5 and 2.0 mg/kg body weight/day, respectively. These values for dominant lethals and X-chromosome-linked recessive lethals in Drosophila were 20 and 5 micrograms lindane/litre, 2 and 3.5 micrograms malathion/litre and 4 and 5.5 micrograms metacid/litre, respectively. Thus, the NELDs are not only pesticide specific but also organism specific, tissue specific and even damage specific. Furthermore, the NELD values determined are so small that the real human exposure to pesticides cannot be reduced below these levels without compromising the effectiveness of pesticides in use.
Kumar
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Department of Zoology, Bhagalpur University, India.
Khan
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PK
Sinha
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SP
D000490:Allium; D000818:Animals; D001645:Biguanides / Q000633:toxicity; D001853:Bone Marrow / Q000187:drug effects*; D001854:Bone Marrow Cells; D002875:Chromosomes / Q000187:drug effects; D004202:Disinfectants / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D004331:Drosophila melanogaster; D001556:Hexachlorocyclohexane / Q000633:toxicity; D008294:Malathion / Q000633:toxicity; D051379:Mice; D008938:Mitosis / Q000187:drug effects; D008940:Mitotic Index / Q000187:drug effects; D009154:Mutation / Q000187:drug effects*; D010571:Pest Control; D010575:Pesticides / Q000633:toxicity*; D018517:Plant Roots / Q000166:cytology / Q000187:drug effects; D014960:X Chromosome / Q000187:drug effects / Q000235:genetics
D001645:Biguanides; D004202:Disinfectants; D010575:Pesticides; C031233:polihexanide; D001556:Hexachlorocyclohexane; D008294:Malathion