A carcinogen is a cancer-causing agent. Carcinogens may cause cancer by altering cellular metabolism or damaging DNA.
The carcinogens we are exposed to are vast and numerous. They include a long list of industrial chemicals (benzene, asbestos, kepone, aldehydes, vinyl chloride), pesticides (DDT), industrial and cigarette smoke (i.e., benzo[a]pyrene, nitrosamines) and aflatoxin mold produced by the fungus Aspergillus flavus that affects stored crops including peanuts and grains. Estrogen mimics, including parabens found in cosmetics and dioxins found in farm raised fish are also being explored as carcinogenic compounds. Cooking protein-rich food at high temperatures, such as broiling or barbecuing meats, can lead to the formation of heterocyclic amines (HCAs) that are comparable to those found in cigarrette smoke (i.e., benzo[a]pyrene).