-3food items now growing on islands of these atolls and the possibility that unacceptable levels of these radionuclides may appear in foods, plants and animals newly introduced into these atolls. 3. Radioactivity in the ground water, a possible source of drinking water and water for irrigation. 4. Plutonium and americium isotopes in the surface soil. These factors are illustrated by data in the accompanying tables taken from previous radiological survey reports. (See Tables 1, 2, 3, and 4.) In some cases, the predicted doses and dose commitments derived from survey information for Bikini and Enewetak Atolls approach or even exceed national and international radiation protection standards for certain living and dietary patterns. Corrective actions or restrictions must be placed on use of these Atolls and their resources to assure that the applicable radiation standards are not exceeded. Herein lies the primary justi‘ication for the continuing environmental followup surveys sponsored by ERDA. ENVIRONMENTAL MONITORING The most important sources of exposure to people living on Rongelap and to future residents of Bikini and Enewetak Atolls are from internal deposition of radioisotopes from certain elements in the human diet, and from the long-term occupancy of islands having external radiation dose rates higher than natural background. Aside from periodic re-evaluations to establish trends in external dose rate reduction, external radiation monitoring will assume less significance, compared to monitoring of the food chain,as time passes. At present, annual visits are being made to identify and collect representative samples of local diets for laboratory analysis and dose commitment updates. New locally grown food items are becoming available in small quantities on Bikini Island as a result of the