BROOKHAWN T UNIVERSITIES, lNCs ‘ssOc’AT -’. / 0/??”#w‘“ &~Environmental Protectio NATIONAL LABORATORY Upton,NewYorkl 1973 -1 (516)345-2503 , 410135 T. F. McCraw Divkion of Operational and Environmental Safety U.S. Department of Energy Washington, DC 20545 Dear Tom: We have recently returned from our most recent field trip to the Marshall Islands. Our objectives were to provide personal monitoring services to the residents of Rongelap and Utirik, collect site specific environment samples at these two atolls and repair the windmills so that the air sampling program could be reinstated. All of these objectives were completed during the August 16 - September 7 field trip. At Rmgelap, a new generator was installed and began to slowly charge the batteries that power the air sampler. Because the batteries were discharged and the trade winds had not commenced, we anticipate that it will take several months to store enough energy in the batteries so that a constant air sample can be taken. The first air sample may be available next January. Also we established three permanent sampling locations for coconut, breadfruit, and pandanus. This will allow us to monitor yearly variations between soil and vegetation activity concentrations. Finally, sixty-seven persons participated in the whole body counting program and sixty-three persons contributed urine samples. Table 1 summarized whole body counting results in each age and sex category and compares the wean 1979 137CS body burdens with the mean 137CS body burdens measured by Stan Cohn in 1974 and 1977. Appendix A lists cumulative results for all gamma emitting nuclides detected from 1974 to 1979. 137 The data in Table 1 suggests that the Cs body burdens are continuing to decrease. When comparing the individual data in Appendix A with prior results, one observes that not everyone’s 137cs body burden declined. Of the twenty-five persons with prior whole body counting histories twenty-one body burdens declined, three increased and one remained unchanged. The increase may be due to a change in diet or to a short residence interval prior to the first count. In the August 3 letter to Bill Stanley, we stated tht the minimum sample size required to obtain the true value for the population mean 137body burden at the 90% confidence limit was thirteen. As Table 1 indicates, we did not ,. .-. . ...} ,--. ,-.. .. T-=. :.,..-.- ‘.. ,,-$. .,e------------.-..r --