Mutagenicity screening of pesticides in the microbial system.

A survey on the mutation induction capacity was made in the microbial system on 166 pesticides including 57 fungicides, 63 herbicides and 46 insecticides. The screening methods consisted of the rec-assay procedure, a sensitivity test utilizing H17 Rec+ and M45 Rec- strains of Bacillus subtilis, as well as the reversion assays on plates utilizing auxotrophic strains of Escherichia coli (WP2) and Salmonella typhimurium (Ames series). Chemicals inducing reversions were detected only among those showing positive effects in the rec-assay but not among negative samples. In addition to Captafol, Captan, Dexon and NBT of which mutagenicities have been previously reported, Dichlorvos, Folpet, 2-hydrazinoethanol (HEH), 5-nitro-1-naphthonitrile (NNN) and Vamidothion were found to be mutagens in our systems.