Astounding Science Fiction, British Edition — page 71: what you’re looking at

Machine-transcribed from the original scan — historical spelling and the odd misread are preserved.

DESTRUCTION FROM ATOMIC WEAPONS body. Doses up to thousands of roentgens may be given to small areas of the body without causing injury except to the desired area. The effects of the bomb have been discussed in some detail as have the medical effects to a somewhat lesser degree. Now is posed the often asked question, ““How many bombs will it take to contaminate the world?” It can be assumed that a 20 KT bomb leaves one hundred pounds of plutonium and that the contamination is distributed uniformly over the sur- face of the earth which is approxi- mately 5.1 x 1018 square centimeters. The human hazard is from agricul- tural areas in which contamination is mixed with the top centimeter of soil. Concentration of plutonium in the ash of food is the same as in the soil. A man eats one thousand pounds of food per year of which one per cent is ash. Of the plutonium ingested, some 0.007 per cent is fixed in the body. The safe rate is 0.07 micrograms per year. From these assumptions, we can calculate that from one bomb there is 2.5xX10°° micrograms of plutonium in one pound of soil. From a man’s 69 yearly ration, he absorbs 1.8 x 10-1 micrograms of plutonium from each bomb exploded up to that time— hence, the number of bombs needed to endanger man is 0.07 divided by 1.81019 or 4x10®—four hundred million bombs! To have .1 roentgen of radiation in twenty-four hours over the entire earth—0.1 r/24 hr.—some six months after detonation, it takes no less than seven hundred fifty-five thousand bombs exploded at one instant. The general effects of the several different types of bombs have been given. They can and have been used in setting up defensive measures against an atomic attack. However, every day brings new developments in atomic energy bringing life and death closer together. Nuclear science broadens man’s understanding of the world about him, gives him new tools to help the living; and yet, it has unfortunately provided the atomic bomb and other potential weapons bringing an enormously increased capacity for human destruction. It is up to man now to ask for divine guidance to lead us not to death, but to the stars. ESTIMATED RADIATION DOSAGE OF AIRCRAFT AT 300 M.P.H. IN RADIO- ACTIVE CLOUD Time after Altitude explosion Radius of cloud Dosage Dosage rate (feet) (seconds) (feet) (r) (r per hr.) 15,000 90 3,100 550 140,000 20,000 140 3,800 260 55,000 25,000 200 4,500 130 24,000 30,000 300 5,300 70 11,000 35,000 430 6,100 40 5,600 40,000 600 7,100 25 3,000 connicloooks.c© ii