The Effects of Nuclear War

DETROIT AND LENINGRAD

Radioactive Fallout

The extent and location of radioactive fallout will depend on weather conditions, especially the speed and direction of the wind. Figures 2 and 3 show how a uniform wind velocity of 15 mph could distribute fallout either over sparsely populated farming areas in Canada if the wind is from the southwest, or over Cleveland and Youngstown, Ohio, and Pittsburgh, Pa., if the wind is from the northwest. It should not be forgotten that these fallout patterns are idealized—such neat ellipses would occur in reality only with an absolutely constant wind and no rain.

No effort was made to calculate the deaths, injuries, or economic losses that might result from such fallout patterns. However, the possibilities are instructive:

• The onset of fallout would depend on wind velocity and distance from the explosion and it would be most dangerous during the first few days. In the case of an attack on a single city (using a surface burst, as our example does), people living downwind would probably evacuate. Those who neither evacuated nor found adequate fallout shelters would be subjected to dangerous levels of radiation: people in the inner contour would receive a fatal dose within the first week; people in the next contour out would contract very severe radiation sickness if they stayed indoors and would probably receive a fatal dose if they spent much time outdoors; people in the next contour out would contract generally nonfatal radiation sickness, with increased hazards of deaths from other diseases. People in the outer contour (9o roentgens in the first week) would suffer few visible effects, but their life expectancy would drop as a result of an increased risk of eventual cancer.
• As time passes, the continuing decay of fallout radiation could be accelerated by decontamination. Some decontamination takes place naturally, as rain washes radioactive particles away, and as they are leached into the soil which attenuates the radiation. It is also possible to take specific measures to speed decontamination. Presumably evacuees would not move back into a contaminated area until the effects of time and decontamination had made it safe.
• A limiting case is one in which no significant decontamination takes place, and areas receiving fallout become safe only when the radioactive particles have decayed to safe levels. Decay to a level of 500 millirems per year would require 8 to 10 years for the inner contour (3,000 roentgens in the first week); 6 years or so for the next contour (900 roentgens in the first week); 3 to 4 years for the next contour (300 roentgens in the first week); and about 3 years for the outer contour (90 roentgens in the first week).
• Natural processes could concentrate some radioactive particles, and those that entered the food chain could pose an additional hazard.

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