Analysis of mutagenic activity of airborne particulate matter, standard reference materials and reference compounds using base pair-specific Salmonella typhimurium tester strains

Abstract

The mutagenicity profiles of organic extracts of airborne dust samples from Mannheim, Germany, and two standard reference materials (SRM) as well as eight compounds with different chemical properties were investigated using tester strains Salmonella typhimurium TA700 x (Ames II Assay). Each strain of this series carries a unique missense mutation in the histidine operon and is reverted by only one specific base substitution out of six possible changes. Mutation patterns of eight compounds with different modes of genotoxic action reveal significant differences. Samples of airborne particulate matter (APM) from an industrialized town in Germany (Mannheim) were collected for five consecutive days once a month for 1 year using an automatic high-volume air sampler. Samples taken from Monday to Friday were Soxhlet-extracted and prepared according to standard methods. Although the threshold limit for the least active strains is not triggered by all samples, it can be concluded that mutation patterns of the samples do not vary between different seasons. Standard reference materials (SRMs) were prepared and tested using the same methods. SRMs and APM samples from Mannheim reveal similar mutagenicity profiles in TA700 x strains. The comparison of the mutagenicity profiles of air dust extracts from Mannheim and the SRMs, respectively, with reference compounds investigated so far shows some similarities although the patterns do not fit perfectly. Mutagenicity profiles of TA700 x-activity of nitro-aromatic compounds published so far are similar to those of APM collected in Mannheim, Germany, as well as to standard reference materials 1648 and 1649.