Plutonium Information Meeting continued through Fiscal Year 1975. The additional efforts and results through April of Fiscal Year 1975 are summarized in this report. PLUTONIUM IN SOTL Analyses were completed on 230 samples during the period July 1974April 1975. Preliminary analysis of the data shows no unusual results. Results from samples analyzed prior to Fiscal Year 1975 ranged from background to 105 nCi/m’, whereas results from samples analyzed in Fiscal Year 1975 ranged from background to 41 nCi/m-. of plutonium in soil is shown in Fig. 1, 2, and 3. The distribution Sampling designed to close existing gaps in the offsite sample array is continuing. PLUTONIUM IN AIR Analysis of air filters from eight locations in the western United States is continuing. Composites of filters collected monthly at Barstow and quarterly at the other locations from September 1973, to November 1974, and representing approximately 2,500 nm? of air, are presently undergoing analysis. available. The results will be reported when To determine ambient levels of plutonium in air around the NTS with emphasis on selected areas containing fallout from nuclear tests, plutonium analyses will be routinely performed on composites of filters, representing approximately 10,000 mn? of air, collected from Diablo, Lathrop Wells, and Las Vegas, Nevada, beginning with filters collected in January, 1975. This study is proposed to begin by the end of the present calendar year. 82