III.

Late Effects

Nonmalignant delayed effects of ionizing radiation are manifested in many organs—particularly bone marrow, kidneys, lungs, and the lens of the eye—by degenerative changes and impaired function; these are largely secondary to radiation-induced damage to blood vessels.

The most important late effect of radiation exposure, however, is an increased incidence of leukemia and other cancers. Statistically significant increases in leukemia and of cancers of the thyroid, the lung, and the female breast have been demonstrated in populations exposed to relatively high doses (greater than 1 gray).