Mutagenicity of the triazine herbicides atrazine, cyanazine, and simazine in Drosophila melanogaster.

Assays for dominant lethal mutations, sex-linked recessive lethal mutations, and chromosomal breakage, nondisjunction and loss were performed on Drosophila melanogaster males treated by injection or by larval feeding of the herbicides atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine), cyanazine [2-chloro-4-(1-cyano-1-methylethylamino)-6-ethylamino-1,3,5-triazine], or simazine [2-chloro-4,6-bis-(ethylamino)-1,3,5-triazine]. The three herbicides significantly increased the rate of apparent dominant lethals, but this reduction in egg hatch was probably due to physiologic toxicity to sperm. Atrazine significantly increased X-linked recessive lethals and X or Y loss after treatment by larval feeding. Injection of simazine elevated X-linked lethals, whereas treatment by larval feeding did not. None of these herbicides significantly increased partial loss of the Y chromosome nor sex chromosome nondisjunction. Much larger experiments are needed to determine with confidence the mutagenic potential of these herbicides.