Quantitative carcinogenesis in relation to human exposures.

While carcinogenic potency cannot be expressed in absolute terms, quantitative carcinogenesis nevertheless plays an important role both in assessing cancer risks and in devising effective methods of cancer prevention. Attention is drawn to newer methods of prevention based on interference with the carcinogenic process, which is likely to counterbalance, or even to reverse, the anticipated trend of increased cancer incidence resulting from new carcinogens introduced in our environment.