206 DASA 2019-2 EISENBUD: No, that's not so. In fact, the cows graze on it; it's —e ‘part of a grazing land, and there's enough grass on it. WARREN: Very interesting. DONALDSON: We've purposely omitted one of the prime areas of interest in the overall environrnent, and Bob has some data which we might bring in now, with your permission, on the whole-body burden of the Rongelap people. CONARD: In yesterday's session I mentioned that after about six mouths, the urinary excretion of radionuclides of the Rongelap people dropped down to barely detectable levels, and by the time they were moving back to Rongelap we couldn't tell the difference between the body burden of unexposed people and exposed people. As soon as they got back to Rongelap, however, there was a rather sudden and marked increase in their body burden because of the residual con. tamination on the island. This came about primarily through eating pandanus and to a lesser extent from the coccnut, and strangely enough the zinc-65 came from eating fish. fish was one of the mainstays in their diet. As Lauren pointed out, We were later able to get a whole bodv counter out to Rongelap to measure their body bur- dens. The first one was a big monster that weighed about 21 tons, and it was a real endeavor to get that thing out on Rongelap [sland. We have recently been using a 'shadow- shield” type of whole body counter consisting of lead bricks. Figure 40 is a photograph of one, a ae ae ee Figure 40. Shadow-shield whole-body counter (gamma spectroscopy). From R. Conard.