There are several chemicals known to cause cancer and other chemicals are suspected of causing cancer. Irradiation of certain chemicals in foods can increase your risk of cancer after a few years later. For example, exposure to asbestos can cause cancer of the roof of the lungs and mesotelioma (lung cancer, pleural membrane). This risk is even greater if the asbestos factory workers was also a smoker.
Certain viruses cause human cancers and other viruses suspected of causing cancer. Papilloma virus that causes genital warts (genital) is one cause of cervical cancer in women.
Cytomegalovirus causes Kaposi's sarcoma (cancer of blood vessel system which is characterized by red skin). Hepatitis B virus can cause liver cancer. In Africa, Epstein-Barr virus causes Burkitt lymphoma, whereas in China, this virus causes cancer, nose and throat. It is apparent that some additional factors (environmental or genetic), required to trigger cancer caused by Epstein-Barr virus. Some retro virus in humans, such as the HIV virus, causes lomfoma and other blood cancers.