MUTAGENICITY OF POLYCHLOROPHENOXYPHENOLS (PREDIOXINS) AND THEIR PHOTODEGRADATION PRODUCTS IN AQUEOUS-SOLUTION

Polychlorinated phenoxyphenols (PCPPs), including predioxins and isopr edioxins, and their photo-degradation products in aqueous solution wer e tested for mutagenicity on Salmonella typhimurium TA98 and TA100 str ains. Mutagenic effects of Irgasan DP 300 [5-chloro-2-(2,4-dichlorophe noxy) phenol] as a typical predioxin and PCPPs (chlorophenol dimers) c ould not be observed on both TA98 and TA100 strains with and without S 9 mix, because of thier great toxicity to tester strains. No mutagenic effects were also observed for 2-alkylated PCPPs (chloro-2-alkylpheno l dimers) on both tester strains. However, some 4-alkylated PCPPs (chl oro-4-alkylphenol dimers) were mutagenic on TA100 strain without S9 mi x, and great mutagenicity was detected for 4-methylated PCPPs.PCPPs in aqueous solution were found to be converted to compounds with mutagen icity to TA100 strain without S9 mix, when the solution was subjected to photo-irradiation in the presence of chlorine for 5 h. In addition, a mutagenic effect of I-methylated PCPPs solution on TA100 strain wit hout S9 mix was shown to be remained about 50% of the original activit y, even after treatment with chlorine alone and photo-irradiation in t he presence of chlorine for 5 h. However, no mutagenic effects of Irga san DP300 in aqueous solution were observed after any treatments.