Mechanisms of Action of Carcinogenic Chemicals Including Occupational Carcinogens

Abstract This chapter provides an overview of the diverse mechanisms, which are involved in the induction of neoplasia produced by chemical carcinogens, including occupational carcinogens. The key events involved in the process of carcinogenesis are discussed, and the broad classification of carcinogens based on their primary mechanism of action is delineated. Two major classes of carcinogens are discussed: ( 1 ) DNA‐reactive (genotoxic) carcinogens, which react with nuclear DNA directly producing DNA damage in the target tissue and ( 2 ) epigenetic (nongenotoxic) carcinogens, which either indirectly interact with DNA or affect other regulatory macromolecules altering cellular processes involved in growth control and/or cell death in the target tissue. Examples of human carcinogens are provided. In addition, methods of human risk assessment are discussed.