Comparative study of the genotoxic properties of Eastern and Western U.S. shale oils, crude petroleum, and coal-derived oil.

A multiple bioassay approach was used to characterize and compare the genotoxicities of an Eastern U.S. (Kentucky) shale oil with the genotoxicities of Western U.S. shale oil, petroleum crude oil, and a coal-derived fuel oil. While the coal-derived oil was mutagenic in the Salmonella/microsome mutagenicity (Ames) assay, the shale oils had negligible to weak mutagenicity, and petroleum crude oil was not mutagenic. All the samples were also tested in the following mammalian test systems: an in vitro sister-chromatid exchange (SCE) assay in human lymphocytes and in vivo tests for induction of sperm abnormalities, micronuclei, and SCE in bone marrow of mice. Slight but statistically significant increases (P less than 0.001) in SCE in human lymphocytes were induced by all samples except petroleum crude oil. Neither sample induced a significant number of mutational events in either of the in vivo systems. In these preliminary studies no major differences in the genotoxicities of Eastern and Western shale oils were observed. The results were consistent with the following order of mutagenic potency: coal oil greater than Eastern and Western shale oil greater than petroleum crude oil.