days before their evacuation. They absorbed radioactive fission products in the food and water that they consumed. revealed the presence of various isotopes. Radiochemical urine analysis As seen in the following table the isotopes of strontium and iodine contributed the largest dose. Estimated Body Burden of Rongelap People (Ci) Activity at Day 1 Activity at _ Day 82 895, 1.6-2.2 0.19 14054 0.34-2.7 0.021 Isotope Rare Earths 131i in thyroid gland) 0.12 0.03 6.4-11.2 0.0 10324 0-0.013 - Ca 0-0.019 0.0 45 Fossile Material 0-0.16 (ugm) 0.0 More will be said shortly about the radioiodine dose to the thyroid gland. No acute effects of this internal exposure were apparent in the people and by six months the urinary excretions indicated greatly reduced body burdens. When the people were returned to Rongelap in 1957 a slight residual radioactive contamination of the island resulted in the accumulation of detectable but low body burdens of 13765 °° 2n and 205, Before discussing the thyroid effects in the exposed people, let us examine certain other late findings, some of which, appear to have been related to their radiation exposure. During the years after the accident the exposed people have remained generally in good health with no greater incidence of