lead bricks was devised and proved satisfactory for use on the island. RSS PE B. Findings By the time the Marshallese returned to their homeislands. most of the radioactive elements they had absorbed internally at the time of the fallout had been excreted (A-3). However, on their return, the consumption of foods grown on the island and local fish resuited in the absorption of radioactive elements, principally cesium (7"Cs), strontium (Sr), and zinc (“Zn). The only food that was banned was the coconut crab at Rongelap; later, this ban was lifted in the southern part of the atoll. For the first five years the body burdensof the above radioactive elements increased, reaching equilibrium with the environment, and then gradually declined. On Rongelap, strontium levels reached a peak during 1962-1965, at 6% in adults and 11% in children, of the maximum permissible lifetime body burdensfor worid populations. Analyses of bone sampies from several autopsies during the firat 25 years showed that the level of radioactive strontium in the bones agreed reasonably well with estimates based on urinalyses. The radioactive cesium body burdens aiso reached their peak in 1965, at about 23% of the permissible level. The values for the Utirik population were about one-third thoseof the Rongelap Pop ulation... . LOO DREAUP te ‘Analysis ofthe,plusenives levels wiix'more: difficult. Urine samples enalyzed-at-BNLin: 1984 showedhigher body.hevels.than.wereestimated hy the Lawrence.Livermare Laboratory, based-on plutonjum.intakefromfooch:It wae . later found that BNL’s method measuredcer- tain contaminating elements (naturally occurArrangement of lead bricks used for whole-body counting. A third method of estimating the body burdens of radioactive elements was to measurethe amounts that might be absorbedin their daily diet. This method is not as reliable as the direct methods. On one occasion, one of us ate a diet for a week consisting of specific amountsof foods grown on the island. Daily measurements were made by gammaspectroscopyof the body and radiochemical analyses of urine and fecal specimens. The levels of radioactive cesium and strontium absorbed internally, though low, were measurable and gave important informa: SOC4 182 ring polonium and uranium)giving spuriously high plutonium levels. A more refined, specific technique for plutonium (A-38) recently showed levels in the Rongelap and Utirik peopie agreed with those estimates of the Lawrence Livermore Laboratory and were well within the federal guidelines.Unfortunately, the earlier discrepancyin plutonium levels reported by the two laboratories caused anxiety among the Marshallese people and may have been partly to blamefor the Rongelap people being evacuated in 1985. (See ChapterIX.) Thecumulative estimate of dose for continuous habitation on Rongelap from 1957- 1979 31 ol!100A oe ships, a less cumbersome portable assembly of. tion on the adsorption and excretion pattern of these elements in the body. * . | ing, we lowered the backgroundof radiation suffinently to permit measurementsto be made. The steel room was used for a number of years, but because of the difficulties of transsortation and assembly in the cargo hoids of