Mutagenicity characteristics of 255 environmental chemicals

The mutagenicity of 255 compounds were examined under the same conditions using the improved Ames test. These compounds were detected frequently in environment, were suspected of high toxicity, or were used as the positive standards for several toxicity tests. The relationships between the chemical structure and the strength of the mutagenicity were analyzed. Thirty compounds of the 255 tested compounds showed mutagenicity. It was found that the compounds, which are unintentionally formed, tended to show mutagenicity in a higher ratio but the artificially synthesized compounds tended to show it in a lower ratio. The number of compounds showed indirect mutagenicity (+S9) were more than the number of compounds showed direct mutagenicity (-S9) in the tested compounds. The mutagenicity strength was different by several hundred thousand times among the compounds. Condensed polycyclic aromatic nitrohydrocarbons, on the whole, showed very strong mutagenicity. The compounds were classified by the positive conditions. All of the tested condensed polycyclic aromatic nitrohydrocarbons accounted for the greatest majority of the compounds which showed mutagenicity under all the conditions of TA98+/-S9 and TA100+/-S9. Only two specific compounds showed mutagenicity under the three conditions except for TA98-S9. Some compounds showed mutagenicity only under the conditions of -S9 but there were various kinds of compounds which showed mutagenicity only under the conditions of +S9. The compounds which showed mutagenicity under only one condition showed weak mutagenicity.