Key Facts

Scientists know that:

• I-131 breaks down rapidly in the atmosphere and environment
• Exposure was highest in the first few days after each nuclear test explosion
• Most exposure occurred through drinking fresh milk
• People received little exposure from eating fruits and leafy vegetables as compared to drinking fresh milk because although I-131 was deposited on fruits and leafy vegetables, the I-131 in fallout was deposited only on the surface; people generally wash or peel fruits and leafy vegetables
• Thyroid cancer is uncommon, usually curable, and approximately 2 to 3 times more common in women

Reliable information about I-131's impact on human health has been difficult to collect, but scientists think that:

• Risk for thyroid cancer increases with exposure, but even among people exposed to I-131, few develop this cancer
• People exposed as children have a higher risk than people exposed as adults

Taking Care of Yourself

Key steps to estimating personal risk of thyroid cancer, and taking charge of personal thyroid health include:

• Using the "personal risk profile" described in this brochure (see "Who's at Risk?")
• Using the dose estimator on the National Cancer Institute's Web site www.cancer.gov (search keyword: I-131)
• Taking this brochure to a health care professional to discuss dose estimates and steps—if any—required for further evaluation
• Getting more information by calling the National Cancer Institute's Cancer Information Service at 1-800-4-CANCER