9 Oe) associated with rainfall and wind patterns along a broad bend in the same general latitude as that of its origin, Finally, they refer to delayed fallout of materilal which has gained entry into the stratosphere. It is slow with an average storage time in the stratosphere of 10 years, plus or minus five years, AEC believes the latter figure - five years - is the more likely, This delayed fallout tends to distribute itself more or less uniformly over the surface of the earth over the years, They state that “at present, the amount of Sr 90 in the stratosphere from nuclear weapons tests is far too small to approach maximum permissible concentration even if it were all deposited now," They urged a continuing program to check on the amount of radioactivity in the stratosphere as necessary so that if there were to be a greatly increased rate of thermo- nuclear weapons testing activities we would know at the earliest moment when it was time to slow down in terms of potential hazard from Sr 90 to man, There is also a discussion of the radioactivity from fallout of the intermediate and delayed variety. They point out that it is usually too feeble to measure with a hand monitor ~ that alr sampling does not give precise results as the amount of the passing air does not bear a direct relationship to what falls on the ground, The best measures of the actual fallout available to date are laboratory analysis of fallout on gummed paper, in collecting pots, and actual analysis of the soil, There is a discussion of atmospheric radiocontamination as a result of uncontrolled release of materials such as radio-~ krypton and radioiodine from power reactors and processing plants, They point out that continued control over release of these pro~ duets as is now done is essential, - jl - Control is by permitting a Enclosure ITI