The activity of environmental samples in a cell culture test for asbestos toxicity.

The inhibition of colony-forming efficiency of cultured human embryonic intestinederived epithelial (I-407) cells was utilized in order to assay the toxic potential of six coded samples of particulate matter provided by the United States Environmental Protection Agency (EPA). The results of the assay indicated that the most toxic of the EPA samples tested “blindly” was amosite which was equal in toxicity to the amosite used, by chance. as a positive control. The toxicities of the particulates from drinking water were approximately 100.fold less than the amosite; of these. the order of toxicity of the samples was San Francisco > Seattle > Duluth. The samples of attapulgite clay and taconite tailings displayed approximately half the toxicity of the drinking water particulates. These results indicate that this assay provides a sensitive and accurate method for screening asbestos and asbestiform contamination for potential toxicity.