4. For estimating birth defects neither BEIR-I or BEIR-III is very clear about what is meant by parental dose, thus it is not clear whether birth defects should be based on the dose to one parent or both parents. In the latter case, the 30-year whole body dose would be doubled. We assumed the BEIR-I risk of 0.2% rem was based on both parents being irradiated. Also because we believed the risk coefficient from BEIR-I was already conservative based on comparisons with BEIR-II1, we elected to use the 30-year whole body dose as provided us--not doubled. 5. For the 140 persons who returned to Bikini and were removed in August 1978, it was assumed that no children will be conceived by persons above age 40, that 300 children will be born after August 1978, and that , all children born will be offspring of parents, both of whom returned to Bikini. The parental dose was obtained as follows: Average dose to males < 40 years old = 1.36 rem Average dose to females < 40 years old = 1.08 rem = 2.44 rem Parental dose used in calculations = 1.22 rem Total parental dose 6. The average dose values for persons who lived on Bikini were calculated from individual dose data (whole body and bone marrow) for 50 males and 49 females. 7. These values are tabulated in the Appendix. The spontaneous incidence of birth defects was taken to be 10.7% of all live births from BEIR-III. 8. The normal incidence of cancer deaths was assumed to be 15%. A value less than the approximately 20% given for the U.S. population