In conclusion, on the basis of the similarity of findings in the Marshallese comparison populations and in other world populations, there is no apparent reason to suspect that there is anything unusual, including excessive radiation, in the environments of these atolls--compared with other environments--which might promote carcinogenesis; hence this population appears suitable for comparative purposes for detection of radiation effects in the exposed Rongelap and Utirik subjects. If further studies suggest that there is an increase in benign and malignant neoplasms on some of the other atolls which may have received low exposures, then causes other than radiation should be sought, not only in that pop- ulation but in Marshallese populations in general. - 109 -