In Arctic regions lying on opposite sides of the North Pole, fallout has created conditions that are given continuous scrutiny by scientists of Scandinavia and the United States. The two cases, one involving the Lapps of northern Finland and the other the Eskimos of Alaska, are essentially the same. Hemispheric fallout introduced quantities of long-lived radionuclides, particularly cesium-137, into the food chains and consequently into the diets of native peoples. In each instance there had occurred a slow accumulation of radionuclides in the lichens and mosses and in other plants that are the foods of the reindeer and caribou. The meat of these animals forms a substantial part of the human diets, and as a result the members of the native communities were found to have, on the average, body burdens of radioactivity approaching the acceptable limit for human populations. A preliminary study of the Lapp environment was made in 1958-1959, and a Lapp dietary study was made in 1960. The results showed close correlation between the consumption of reindeer meat and the Lapps’ body burdens of cesium-137. The Scandinavian investigators concluded that the levels of concentrated cesium approximated the maximum permissible dose range for large populations. They noted, however, that “the final answer ... has to be given by the geneticists”. [Illustration: _Placing equipment to measure fallout in precipitation north of the Arctic Circle in Alaska._] In Alaska, where studies of the native populations have been proceeding for several years, adult Eskimos living in the vicinity of Anaktuvuk Pass[20] were found in 1964 to have average body burdens of cesium-137 more than 20 times as great as the average for adults in the area of the original 48 states. There was an expectation that even without further nuclear testing the levels of cesium-137 would continue to rise slowly in Arctic regions until about 1968. The Variety of Approaches