-—4— year 1966 for thirty non-urban locations in the United States, No similar data are available for Enewetak or an equivalent south sea atoll location, The average mean value for the 30 locations in Table II is 38 micrograms per cubic meter (microgram /m°), Assuming, to be conservative, tht the average airborne particulate concentration level at Enewetak is 150 microgram/m°, and further assuming that all of this particulate matter consists of local soil (i.e., no salt spray from the ocean), one obtains a value of 400 pCi/gm as an average surface soil concentration which corresponds to the ICRP guide for maximum permissible average airborne concentration of plutonium, In the evaluation of the radiological condition of Enewetak, we will apply the criteria that areas in which any soil samples show concentrations greater than 400 pCi/gm should receive corrective action, areas which show soil concentrations between 40 and 400 pCi/gm mayreceive corrective action, depending on other radiological conditions present, and areas showing less than 40 pCi/gm do not require corrective action because of the presence 337 of plutoniumalone,