What kind of radiation causes thyriod cancer?

Q. What kind of radiation causes thyroid cancer? What about microwave ovens and dental x-rays?

A. The thyroid is a butterfly-shaped gland found at the front of the neck beneath the larynx. Compared to many other organs, the thyroid gland is particularly sensitive to certain types of radiation.

The type of radiation that is linked to thyroid cancer is called ionizing radiation. X-ray machines, radiation therapy machines, and tests using radioactive particles create this kind of energy. The younger you are exposed to it and the higher and more direct the dose, the more likely it is that a thyroid tumor will develop in adulthood.

In the United States, radiation was used during the 1940s and '50s to treat conditions such as acne and fungal infections of the scalp in children and teenagers. People who received such treatments as children are at increased risk for thyroid cancer in adulthood. They should have regular thyroid exams.

But now doctors are aware of the danger, so they protect the thyroid from exposure during tests and treatments that use radiation, especially in young people. For example, dentists can shield the thyroid with a lead apron during dental x-rays.

Microwaves do not cause thyroid cancer. They're a form of non-ionizing radiation and thus cannot ionize tissue. Microwave ovens use low-frequency waves of electrical and magnetic energy to produce heat to cook food. They don't make food radioactive.

Ultraviolet light, visible light, infrared radiation, and radio waves are other forms of non-ionizing radiation. Thyroid cancer is not associated with these types of radiation.

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