[Nitrated polycyclic aromatic hydrocarbons (nitro-PAH) in the suspended substances of the atmosphere. 2. Comparison of the mutagenicity of nitro-PAH and dust extracts of the air in the Ames, SOS repair induction and SCE test].

Extracts of airborne suspended particulate matter were assayed in the Ames-test with strain TA 98, in the SOS chromotest (test on induction of the SOS repair) with strains E. coli PQ37 and S. typhimurium TA 1535 and in the sister chromatid exchange test. Samples from Berlin-Wedding were extracted by dichloromethane and tested up to the limits of solubility. All three test systems showed biologic activity. In the Ames- and the SOS chromotest these extracts revealed higher activity with S9-mix. 4 nitro-PAH, which are known to be present in ambient urban air, were assayed in these test systems, checking them additionally with strains TA 1538, TA 100 and TA 1535 in the Ames-test. In this test these compounds appeared to be direct acting frameshift mutagens and their activity is diminished by addition of S9-mix. On the contrary these compounds were either active at all or more active in the SOS chromotest in the presence of S9-mix. In the SCE-test only with exogenous activation a raise of the SCE frequency could be detected.