Review of the carcinogenic potential of gasoline.

This review examines the animal, human, and mechanistic studies that precede the new studies reported in this volume. Wholly vaporized unleaded gasoline was found to produce a dose-dependent increase in renal carcinoma in male rats and an excess above background incidence of hepatocellular tumors in female mice in the high-dose group. Mechanistic studies suggest that gasoline is not mutagenic and that the probable mechanism for the male rat renal tumors involves a rat-specific protein, alpha 2u-globulin, whose binding with highly branched aliphatic compounds results in renal tubule cell death and, in turn, a proliferative sequence that increases renal tubule tumors. Human evidence generated predominantly from studies of refinery workers does not support a kidney or liver cancer risk in humans. The current epidemiologic database is inadequate to access leukemia risk from low-level benzene exposure from gasoline. Studies of gasoline-exposed workers that incorporate quantitative exposure information are needed.