一塩化ジベンゾフラン4異性体の変異原性

抄録

Monochlorodibenzofuran, which is considered to be formed by the reaction of dibenzofuran with chlorine, has been recently detected in tap water in some region of Japan. The mutagenicities of 1-, 2-, 3-, and 4-chlorodibenzofurans were tested to Salmonella typhimurium TA 98 and TA 100 in the absence or presence of rat liver S 9. 1-Chlorodibenzofuran and 4-chlorodibenzofuran were practically non-mutagenic, while 2-chlorodibenzofuran was weakly mutagenic to TA 98. Unlike these three isomers, 3-chlorodibenzofuran was strongly mutagenic to both TA 98 and TA 100. The mutagenic activity was about one fifth and one twentieth of that of benzo [α] pyrene to TA 98 and TA 100 respectively. Its mutagenic activity was more potent to TA 98 than to TA 100. Chlorinated aromatic compounds usually show no mutagenic activity in Salmonella assay system. The result of this study suggests that the number and the position of the chlorine substitution on the benzene ring play an important role in the manifestation of mutagenicity as well as the carcinogenicity in polychlorinated aromatic compounds.