Risk Estimation of Human Lung Cancer from Environmental Exposure to Diesel Exhaust: Extrapolation from Particle Induced Experimental Lung Tumors?

The U.S. Environmental Protection Agency is presently preparing a Health Assessment Document of inhaled diesel engine emissions which will also address the question of an assessment of its carcinogenic potency. The evidence of a carcinogenic potential of inhaled diesel exhaust from epidemiological studies is limited whereas it is sufficient from long-term rat inhalation studies (IARC, 1989). Table 1 lists several of those rat inhalation studies, and the question arises whether the result of these studies could be used for assessing a carcinogenic risk for human exposure.