Today I’m going to talk about: carcinogen

Carcinogen, any chemical, biological, or physical agent that can

potentially be a cause of cancer. The term is most commonly applied to

chemicals introduced into the environment by human activity. Researchers

label a substance a carcinogen if it causes a statistically significant

increase in some form of neoplasm, or anomalous cell growth, when applied

to a population of previously unexposed organisms. The modes of cancer

initiation are still little understood, however, and efforts to establish

the carcinogenic hazards of substances hhave aroused great controversy. The

question of the usefulness of laboratory tests on animals in assessing

human risks is particularly complex. The more recent development of short-

term tests using cell cultures of microorganisms, however, is considered a

major advance in carcinogen research.

Substances indicted as carcinogenic over the past few decades include

the pesticides DDT, Kepone, and EDB; the synthetic hormone DES; the

artificial sweetener cyclamate; asbestos; and a wide range of other

industrial and environmental substances. In addition, U.S. health officials

have identified the carcinogens in ttobacco as the single most important

cause of cancer among Americans. The carcinogenic effects of various foods

are still under study.