more important. It can be estimated that the accumulated dose from thermonuclear weapons is 0.002 to 0,003 r with another 0,027 r still to come, All these doses together add up to about 0.035 r from weapons already exploded. This is a maximum dose. The loss of radi activity from weathering has not been taken into account, nor has the protection afforded by buildings in and around which most people in this country spend a large part of their lives, It would be realistic to divide the dose by three for weathering and by seven fo: protection afforded as a result of time spent in houses. The averag inhabitant of this country may therefore receive in the next 50 year between 0.001 and 0.002 r from this fallout, or 0.02 to 0.0 per cer of the radiation that he will receive during the same period from natural surroundings,” The report has this to say about the effects of a contimtL program of testing: ™... if the firing of both types of bomb were to continue indefinitely at the same rate as over the past few years there would be a build-up of activity gradually reaching a plateau in about a hundred years time which, on the same basis of calculatio: would give the average individual a dose over a period of 30 years of 0,026 r or about 0.9 per cent of what he would receive in the sam period from natural sources." . An important radioactive component of fallout mterial is Strontium 90, This isotope may be deposited in the bone and when present in sufficient quantities can cause bone cancer. The United Kingdom Medical Research Council report estimates that to date about 0.011 curies of Strontium 70 per square mile has fallen and that future deposits from past tests may produce a maximum of 0,045 curie of Strontium? per square mile by 1965. These data are immediately evaluated in the report, "... these figures should be viewed against the background of the fact that the top one foot of soil has always contained on the average about one curie per square mile of the equally, if not more, dangerous naturally occurring radium." small, They estimate the hazard from plutonium in fallout as very They feel Cesiuml37 , Iodinel31 and BariumliO are of very little significance outside a nearby area of very heavy contaminatio They estimate the gonadal dose as 1% of natural background and diagnostic radiology as 22%, scant to consider here, ‘the discussion af atomic warfare is to NAS Chapter VI, Assessment of the Hazards of Exposure to Radta is in essence a summary of the foregoing -- pointing out the differences between effects on the individual and genetic effects. They conjecture that no "authoritative recommendation will name a figure for permissible radiation dose to the whale population additional tc that received from natural sources, which is more than twice that of the general value for natural background radiation." This is estim by the British at 0.1 r per year, hence 3r in 30 years and 7r in 70 years. The National Academy of Sciences estimate is an average of 236 REPRODUCED FROM ThE COLLECTIONS. OF THE ARC. IVES CF THE “ENCES NATIC’