Roosevelt Standard | 1956-12-27 | Page 9 | What is Fallout ?

O EFFECT Of PARTICLE SIZE fflMO AMD INITIAL HEIGHT ASSUMED CONSTANT) "" O Oft j WIND LARGE PARTICLES FALL ' SMALL PARTICLES FALL CONSTANT FAST. LAND aOSI tLMLY, UNPFUTHU O EFFECT OF WIND (PARTICLE SIZE ASSUMED CONSTANT) 1 i 1 ?THI CONSTANT PARTICLES LAND FARTHER WEAK WHO STRONG WIND hOU If REAP OUT - EFFECT OF HEIGHT (WINS AND PARTICLE SIZE ASSUMED CONSTANT) CBOUWO . m a , a , a""1 WIND PARTICLES FROM LOWER PART PARTICLES FROM UPPER PART ' CONSTANT LAND SOONER. CLOSER FALL LONGER, LAND FARTHER I j FACTORS AFFECTING FALLOUT distribution over countryside downwind from a unclear blast : are the size of the earth particles carrying the radioactivity, their altitude and the speed and direction of the wind. Generally, in the United States, the winds which would dominate the direction di-rection of fallout would be the strong, usually west-to-east winds at about 40,000 feet. For this reason, the Federal Civil Defense Administration Administra-tion warns that only weather experts, with their methods of tracking high-altitude winds, can predict pre-dict with reasonable accuracy the area to be affected af-fected by fallout. Men with radiation monitoring instruments are also required to determine whether an area is "safe" from radio active fallout after a nuclear attack. (fcda photos)