SLIDE 8 Estimates of airborne activity concentrations. Air activity concentration at Rongelap and Sifo,fsland yene tabulated from the meteorology results provided by Peterson for and (Pe81). Also, results for air activity concentrations of 1oly and l 3y were estimated from the Bikini Ash composition and tabulated for comparison. Details on this method are given by Lessard (Le84b). The cumlated activity agree somewhat, however the instantaneous airborne activity concentrations do not agree well. In summary, the Peterson approach towards estimating dose to the exposed Marshallese requires further refinement in order to achieve correspondence with all available information regarding external exposure and exposure rate. AIR ACTIVITY CONCENTRATIONS AT RONGELAP Time Post Detonation, Hours 5 7 10 14 17 Bq M ° 1981, Peterson ——— ay Tay 7.4 250 15,000 714 ll 1984, Lessard ——_ 1ST] 137 250 7,400 110,000 3,700 1,100 19 110,000 25,000 330 250 0 0 1,500 13 0 0