The thyroid, a butterfly-shaped gland at the base of the neck, regulates the body's energy level, including heart rate and pulse. Exposure to radiation increases the risk for thyroid cancer, particularly papillary or follicular types, reports the National Cancer Institute. The risk for thyroid cancer increases with amount of radiation exposure and is higher if the person is younger when it occurs. Children with high iodine levels apparently have a lower risk of thyroid cancer.
Radioactive Fallout from Power Plant Accidents
Radioactive fallout from nuclear plant accidents increases the risk for thyroid cancer, reports the National Cancer Institute, particularly in children. For example, the incidence of thyroid cancer is much higher in children who lived near Chernobyl at the time of the 1986 meltdown. Thyroid cancer rates also were elevated in adults performing cleanup and those living closest to the plant, according to the American Cancer Society.
Radioactive Release from Nuclear Weapons Plants
Radioactive release from plants producing atomic weapons also increases the risk for thyroid cancer, reports the National Cancer Institute. This includes people exposed to radiation releases in the 1940s from the Hanford plant in the state of Washington.
Radioactive Fallout from Weapons Testing
Workers and residents exposed to radiation and fallout from atomic bomb tests have a higher risk for cancer, including thyroid cancer, reports the American Cancer Society. This includes residents of Nevada and Utah exposed to the atomic bomb tests of the 1950s. The risk, however, may be less than those exposed to Chernobyl meltdown, which released much greater amounts of radiation.
High-Dose Medical X-Rays
People exposed to high dosages of radiation from medical x-rays have a greater chance of developing thyroid cancer, reports the National Cancer Institute. This includes those exposed to x-ray treatment for acne, scalp infections or enlarged tonsils, which was practiced until the late 1950s.
Children who received radiation treatment to the neck or head for cancers such as lymphoma also have an elevated risk for thyroid cancer, reports the American Cancer Society.
