1. Iodine I-131 ( I-131) was among the radioactive materials released by released by above-ground atomic tests.

2. It was carried thousands of miles away from the test areas on the winds. Because of wind and rainfall patterns, the distribution of fallout varied widely after each test.

3. Much of the health risk associated with I-131 occurred among milk drinkers-usually children.

4. From what is known about thyroid cancer and radiation, scientists think that people who were children during the period of atomic bomb testing are at higher risk for developing thyroid cancer.