Distribution of extractable mutagenic activity in steel foundry air particulates of different sizes

An Anderson 2000 sampler was used to collect different size classes of airborne particulate matter in a large steel foundry. When extracts of these particles were assayed for mutagenicity using the Ames Salmonella/S-9 assay, much of the mutagenic activity was found in particles of respirable size. Furthermore, mutagens requiring activation were distributed among the various size classes roughly in proportion to the total surface area of the particles with the smallest class ( 7.0 ..mu..m).