200 RADIOLOGICAL CLEANUP OF ENEWETAK ATOLL rem, and the highest of these was 0.070 rem. In August 1978, two film badge readings of 0.400 and 0.430 rem were recorded. In-depth investigations revealed that, in all likelihood, these did not represent valid doses to individuals but that they resulted from the film badges having been placed on or near contaminated debris or a calibration check source overnight. Even counting these doses, the two individuals received a total of less than 0.6 rem each during their tours at Enewetak (one for a year and the other for 6 months). Administrative dose assignments were designed to be higher than the actual dose received and the highest administrative dose assigned in any month was 0.020 rem.42 Over the entire project, only two skin exposure (beta) doses were reported, both at 0.014 rem. Such a dose is a negligible fraction of the annual limit of 30 rem for skin exposure. Throughout the cleanup project, over 760,000 cubic meters of air were sampled on the controlled islands plus more than 211,000 cubic metersat Lojwa. Nearly 5,200 air samplers filters were analyzed by the lab. No significant airborne radioactivity of any type (including beta) was detected. It is clear from these results—as it was from resuspension experiments performed during early RSAIT visits to the atoll—that the Enewetak contamination situation was not conducive to creation of a resuspension hazard. There were several cases where field instruments indicated that action levels had been reached; however, in each of these cases, laboratory analysis showed that the readings were not caused by resuspension of radioactive materials present on the atoll but by short-lived isotopes naturally present in seawater. During times of heavy surf, these naturally occurring, alpha-emitting substances (primarily radon and daughter decay products) separated from the sea spray and were collected on thefilters. Since these isotopes decayed in a few hours, the filters gave no reading upon subsequent laboratory analysis. Use of an air sampler at the Enewetak Rad Lab verified the presence, nature, and shortlife of these isotopes. Following this identification, the FRST field procedure was changed to include a second reading, after a delay of one-half hour, for filters showing action levels. Throughout the project, over 1,100 nasal smears were taken and analyzed as a part of the overall radsafe program. The results showed no cause for concern. About 40 percent of the samples showed no detectable activity. Of those that did show activity, the highest was 3.64 dpm (1.64 pCi), less than one-tenth of the ‘‘action level,’’ which was established at 50 dpm and whichitself was one-tenth of the maximum allowable level of 500 dpm. Over 2,000 urine samples were analyzed during the project, primarily for total or gross beta (GB), Pu-239, and potassium-40 (K-40). K-40 is a