Conclusions Previous soil surveys indicated the primary radioisotopes contributing to the external does rate are 137 Cs and contribution (EN73, p. 103). 60 Co for gammas, and 90 Sr for beta External dose estimates for future inhabitants were based on aerial gamma surveys and did not include beta contributions and shallow dose estimates. The major finding of the work reported herein is that approximately 29% of the total external dose rate on Enewetak Atoll] is due to beta or low-energy gamma radiation. While marked deviation from 29% can be found, especially at locations with little or no vegetation, the beta contribution is surprisingly insensitive to extent of ground cover typically found on these islands. The impact of such a significant fraction of the total external dose rate resulting from beta or low-energy gamma radiation is illustrated in Table 1, where integral 30-year shallow dose estimates are compared with 30-year whole body doses reported in the 1972 survey. Living patterns and external dose estimates represent assumptions of village location, visitation, and agriculture patterns (EN73). the map in Figure 1. They are listed in Table 1 and can be located on Living patterns I and II are for residence in the southern islands, and patterns III through VI are for residence in the northern part of the atoll. External dose rates are much lower in the southern part of the Atoll. The living patterns include approximately 20% of the time spent on other islands for agricultural purposes, except for pattern III, in which residence, visitation and agriculture are confined to one island. 5068291