Radiolopical Concerns The primary radiological problems are the result of residual fission and activation products in the terrestrial environment. They have been identified by previous environmental surveys ternal radiation levels significantly higher on some islands in an atoll compared contaminated islands. 2) Fission and activation oroeduct radioactivity in certain as follows: 1) Ex- to levels on light!y terrestrial food 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) Plutoni.n and americitm isotopes in the surface soil. These factors are illustrated by data in Tables 1 thro. » taken from previous radiological survey reports. Table 1. Gamma Radiation Rates in Bikini Atoll” (mR / hr) Bikini Exposure rate Range Island .010-.120 Weathered areas Close to-shore Island center Hot spots Eneu Nan Outer edge Island center N.E. corner Bokantuak, Iomelan, Rojkere, Eonjebi Aerokoj-Emenman complex: Aerokoj, Aerokojlol Bikdrin, Lele Eneman East Eneman West Eneman -010-.030 -020-,040 .050-.080 -080-. 120+ .002-.010 ~010-.330 -010-.030 -015-+.150 .110-.330 .003-.010 Lukoj “060-.200 Bokbata Aomen-lroij complex: Aomen Lomi lik C83, 60¢o, Cs ak ek wk 60¢9 125,, 102m, 6065, 1255, 102m, - 606, 125g, 102m, 060.130 -015=.045 .010-.035 -020-.050 * ** bated /010-,030 6069, 1375 .005~.020 Ps .010-.040 Saad .020-.330 Odrik, Iroij + 137 .003-.030 .010-,.235 Jelete Oroken Bokaetoktok Bokdrolul - — Ls'cs .003-,235 East Enidrik West Enidrik * Maior contributors .001-,010 .006-.010 -001-,570 -001-.010 «020-.570 Enidrik tk . 8065, 12555 See ref, 9. No soil sample or field spectra measurements. 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 justification 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 quanticies on Bikini Island as a result of the experi- mental agricultural practices of a small group of caretaker families living there. Neither Bikini Atoll, where radiological cleanup has been completed, nor Enewetak Atoll where clean up has not yet begun, have a subsistence agriculture resource in being which 1s sufficient to support the anticipated pcpulations which will one day live there (though such crops are currently being developed or planned).