b) To measure airborne radioactivity for assessment of the inhalation pathway of exposure, particularly for 239 py , The air sampling program will address this exposure route at the numerous "clean islands" and also in the more contaminated areas such as the environment on Runit (Yvonne). To correlate the food-chain sampling program with the field gamma measurements and soil sampling program in order to maximize the information available to quantify rates and mechanisms of transfer of radionuclides from soil to man through food-chains, The field survey team will obtain plant samples wherever possible from the soil sampling sites; the terrestrial food-chain team will bdbtain some Soil samples, where necessary, in the areas where they sample edible plants such as pandanus and arrowroot. Air Sampling Airborne particulates will be sampled by means of three types of samples: a. Ultra-high volume (UHV) samples: - Two calibrated UHV samplers will be operated at a rate of 1000 cfm. One such sampler will be operated con- tinuously on Eniwetok Island (Fred). The other sampler will be trans- ported from island to island for measurements, Measurements will be made also at selected offshore sites on the LCU. Both samplers will be supported by gross meteorological measurement of wind speed and direction to aid in the interpretation of sources of detected radioactivity. Low-volume (LV) samplers: - A large number of calibrated 5 cfm LV samplers will be fielded and operated on a semi-continuous basis, Banks of these samplers will operate continuously on board the Palumbo and the LCU used in marine sampling and transportation, Others will be fielded strategically to investigate radionuclide levels in ai downwind from contaminated areas, Anderson Cascade Impactors - Two 20 cfm, 5 stage cascade impactors will be used to obtain long-term samples of air for investigation of the size distribution of airborne radioactive particles. This combination of cir samplers will be utilized to address the question of potential exposure to future inhabitants through inhalation of airborne radioactive particles. The initial plan will provide sufficient data to ascertain whether-or-not O39, exists in the air at levels in excess of worldwide fallout background and to define the ~19-