Mutagenicity in Salmonella typhimurium TA98 of the serum extract of the organic matter derived from airborne particulates.

To investigate the interactions between mutagens and serum components, the mutagenicity of the serum extract of the organic matter derived from airborne particulates (tar) was examined by the Salmonella/mammalian microsome mutagenicity test. The mutagens in the organic matter were found to be extracted with serum but not with saline. The mutagenic activity of the serum extract of the tar, however, decreased to about 60% compared with that of the DMSO extract, when they were activated by S9 mix. On the other hand, without S9 mix, the mutagenic activities of the serum and DMSO extracts were about the same. Gel filtration of the serum extract was carried out and followed by mutagenicity testing of each fraction. It is suggested that the mutagens, which require metabolic activation, combine mainly with beta-lipoproteins and the direct mutagens with both alpha- and beta-lipoproteins in serum.