o 6 ee: PROJECT IIT:--DUST AND PARTICULAT: STURIFS Based on previnus work in this category, it is proposed that the next Fall-ovt studies include the study of the several problems outlined below ¢ 1. A study of the gaseous derived air-borne radioactive materials as measured at surface level and their potential biological availobility. It is proposed to emphasize the obtaining of data on the concentration of radio-Liodine, radio-strontium and radio=yttrium cunmponents of several Fall-out patterns, particularly in the selecced biological etudy areas. This study may also pro= vide information on the mechanism as to why air-borne material of less tuwan one micron in size has been found at distances less than forty;miies from Ground Zero. 2. Continue the study of Fall-out particles with respect to their chemical end physical characteristics and potential biological influence as a function of distance from Ground Zero (less than 200 miles}. 3. Study and correlation of various methods of predicting "Hot Spots" anc associavea ,article sizes at distances less than 200 miles. Fer aach Fall-out pattern, the various methods of pre= diction will be confirmed oy radiological eurvey and particle 8123 distribution as determined from residual contaminated soil fractionaticn. The Atomic Energy Project, U.C.LA. has recently conesived nmethod of predicting "Hot Spots" which is apparently different-from-the- two methods:-previcusly used. This study is | to include the determination: of theparticle size distribution of soil collected pre and post Shot at very near distances from Gremd Zero. This particle size distribution will be compared °” “NO®ARCHIVES 1, a