An experiment was carried out to compare the carcinogenicity of diesel exhaust particles (administered by fifteen weekly intratracheal instillations) to that of organic extracts of diesel particles, coke oven emissions, roofing tar condensate and cigarette smoke condensate. Appropriate solvent controls, untreated controls and positive controls were included in the design of the experiment. The overall incidence of respiratory tract tumors in any of the treatment groups was not significantly higher than in control hamsters. Similarly, there were no significant differences in the survival rates of hamsters treated with test materials from those of their respective controls. Hamsters treated with test materials generally showed significantly lower mean body weights than control animals. Treated hamsters generally showed a delay in time to reach maximum body weight when compared to hamsters in control group. Treatment of hamsters with test materials induced a variety of hyperplastic, proliferative and inflammatory lesions of the respiratory tract. The highest incidence rates and greatest severity of the lesions were induced by diesel exhaust particles and coke oven emissions. Diesel exhaust extract and benzo(a)pyrene were less reactive, and cigarette smoke condensate and roofing tar volatiles produced the lowest incidence of respiratory tract lesions.

"January 1985." "EPA-600/1-85-004." "Cooperative Agreement No. R806929-02-0." Microfiche.