Final answer:
A carcinogen is a substance or mixture that induces or increases the incidence of cancer. Examples include formaldehyde, asbestos, radon, vinyl chloride, and tobacco.
Step-by-step explanation:
A carcinogen is a substance or mixture that induces or increases the incidence of cancer. Carcinogens can be biological, physical, or chemical in nature. Examples of carcinogens include formaldehyde, asbestos, radon, vinyl chloride, and tobacco. Carcinogens can directly damage DNA or accelerate cell division, leading to the development of cancer.