that by the age of 30 the average American would receive germ cell exposures as follows; 1, Background cr ratural radicactivity 4.3r 2, Medical x-rays 3or 3, Fallout from weapons testing if con- tinued at rate for the past 5 years O,ir [0,02 to 0.5r) They then estimated that the exposure necessaryto - ~ Se double the mutatidons rats in humans lay between 52¢and 150r more likely 30x te 8Cr, but als> that different gene loci were quite different in their sensitivity ts radiation, Taking these observaticns inte consideraticn tnoey feit that if the populatisn as a whole were to recsive no more than lOr man-made exposure to ? + ee ww ck radiation to the germ selis pri:tr ts the age of thirty no serisus a = vePors, reccmmended that no consequences would result. They oe one should receive a total azsumilated dose to the reproduction celis of more than 50r prisr to the egs of thirty withcut clear cut medical reasons, and that in any event the average exposure of populations as 4 "whole should net execed 1Or by the age of thirty, They point cut thet at present about 1/3 this figure is already being used up by medizel x-ray exposures many of which: could with proper prsstautions be grsetly reduced, As to ocewpaticnal expesures the Committee considered this to be a iimited group = no estimates were made as to jis actual or potential size, As finalized in the repert the reccmmendations are: 1, There should be a natisnal system of keeping radiation exposures on all persons as is now practiced at ARC establishments, NAS 2. Medical exposures to the germ cells shovld be reduced, + 3, No 4 The subject shouid be reviewed periodically with a as a whole, mere than 10r by age thirty for the population view to possible further reduction in exposurs, - 5. Neo body, however, employed, should recaive more than 50r of exposure pricr tc the age of 30, 6, For special activities inherent in which are a greater liability to oversxpcsure individuals who for one reason or other are unlikely to prosreate skculd be selected, = Aggtectians 2 TRE “nr SCIENCES