Increased risk of breast cancer after low-dose irradiation.

A significant increase in the risk of breast cancer has been found for the most recent 5-year period of a long-term follow-up study of children subjected to scalp irradiation, in whom a carcinogenic effect was previously only apparent in the head and neck. This increased risk was found among women aged 5 to 9 years at exposure. The breast had been exposed to a low radiation dose of approximately 16 mGy.