Ionizing radiation includes radon, x-rays, gamma rays, and other forms of high-energy radiation. Low-energy, non-ionizing forms of radiation, such as visible light and cell phone energy, have not been found to cause cancer in people. Ionizing radiation, such as gamma rays, x-rays, and radioactive particles, can cause cancer by damaging DNA. However, it is not known how this occurs or how many tumors are caused by radiation damage.
Epidemiological studies provide the data needed to quantify cancer risks based on dose and to establish radiation protection standards. Leukemia and most solid cancers have been linked to radiation. Most solid cancer data are reasonably well described by linear dose response functions, although there may be a decrease in risks with very high doses. People exposed early in life have especially high relative risks for many types of cancer, and the risk of solid, radiation-related cancer seems to persist throughout life.
Not all types of radiation have been proven to cause cancer. Learn what we know about exposure to lower-energy forms of radiation and the risk of cancer.