a LESSARD er a, I> Shortly after the Rongelap people's return, the 5 3 séict = ao > hine 2072 Estimated Return to first a sire whole-body counung survey was BE - xo & ol performec in 1958. The Hardtack series of nuclear tests in 1988 was the final above-ground lests to be performed bythe United States in the Marshall Islands. Worldwide atmospheric tesi- ma mg OF nuclear devices at other locations conw“ : o a 2 > 2 [aa wo timuec anc peaked during the earl, 1960s During the period 1958 through 198i a totai of e:ghi June . 2007 as e. ec © 2. > baiaon-stwe whole-body counting surveys at Rongeiap anc hve whole-body counung surveys at Lunk were performec = a = m dune o and w a > =~ oo 196) e Ss o August ov ao Gnd Utirck Recent WAC 2 mm ih Utirik Evocuated 1962. 1963 April May 1958 1958 1957 June 1954 June 1954 First TnSttu Utivik Reinhobited Rongetap WBC at Reinhabited Rongelop 4" Rongelap and BRAVO Detonation Morch - May 1954 Castle Series Morch CACTUS Hardtack Phase I April - August 1958 Detonation Peck U.S US S.R.,ULK, Atmospheric Testing > w Fig. 1. Sequence of events at Rongelap and UWtrk Atolls METHODS Bodv-burger data and urine acnvily franons councen- Acult average body-burden data and umneactiviiv Concentration data were used as input quantiues to equations which related them to acuvity intake rates. These input data were obtained from Conard’s medical reports (CoS6é: CoS: Cos¥: Co60: Co62; Co63: Co67: Core: Co75:. Wo59) and from recent survevs per- formed bs members of the BNL Safetw anc Environmental Protection Division. The methods used to obtain the recent bods-burden data were presented by Muitenberger (M180). The most recent average data obtained for adult body burden at Rongelap and ULtmk are presented here. These data were obtainec in April 1978. August 1979 and August 1981. In the cases of '"Cs, °Co and Zn. direct body-burden measurements were made. In the cases of ®'Sr and **Pu. urine-activity concen- trauions were measured and then converted ic body-burden estrmates. This was done byre- lating the activity in urine to the activity in the total body. For Sr and ***Pu, this involved the use of derived quantities which are developed in the next section. Derived quantities An equation was developed to relate the activity in the urine or whole body to the activity taken in by ingestion of contaminated food and fluids. To select an appropriate mode! for this relationship, the body-burden history and the history of activity in vegetation and sotl were examined. Activity concentrations of '’Cs, 1 and “Sr in surface soil on Rongelap and Utirik Atolls were observed to decline with time