Soil Cleanup Planning assure that doses to future residents of Enewetak Atoll would not significantly exceed proposed EPA guidelines for transuranics? b. What advice can be given to DNA at its early May conference to facilitate planning for cleanup of transuranics on Enewetak? c. What additional information can be obtained which could improve the confidence of the dose estimates and cleanup criteria for transuranics? d. Can plowing be used as an effective cleanup measure for transuranics in soils? The Committee reviewed information and data provided by DOEDivision of Occupational and Environmental Safety, LLL, DOE-NV, and DNA. The draft LLL dose assessment study was the basic document from which the Committee was to formulate answers to the questions raised and to provide advice. The Committee offered the following response to the questions as they pertained to transuranic elements only (not fission products, which they understood might delay the resettlement of some islands for a numberof vears): a. The Bair Committee did not find it possible to develop reasonable cleanup guidance which would assure that radiation doses from transuranics to future residents would not exceed proposed EPA guidelines to the extent to be of concern. Obviously, the more stringent the cleanup criteria, the greater the degree of assurance; but uncertainties inherent in our present understanding of the problem precluded absolute assurance. One could not predict with certainty the contamination levels that would exist in the islands after cleanup; this would be determined at a future time. One could not predict the lifestyle and dietary habits of every individual who returns to the islands. Perhaps most important, many of the factors that are involved in movement of transuranics in the environment and the depositions and retention of transuranics in human beings are not well established. However, the Committee was of the opinion that its recommended population size). 7 ° SerTOT ab Nebee debe Bath. To ub le oo. subsequently exposed populations that would be commensurate with proposed EPA guidelines. The EPA considered its guidance levels to be equivalent to a lifetime risk of about 14 premature cancer deaths per 100,000 persons exposed and to perhaps an equal number of genetic effects, although these estimates are based on many uncertain assumptions and generally are considered to be quite conservative. An estimate of I4 cancers per 100,000 people would correspond to a 3 percent chance of one cancer appearing in a population of 200 people exposed to EPA guidance levels for their lifetime; or expressed differently, to a probability of one cancer in every 2,]00 years (assuming a constant aR: cleanup criteria would result in average transuranic radiation doses to