on the Patuxent River Naval Air Station. combined fallout from these 4 bombs. The map on page shows the The isodose rate,lines are in units of roentgens per hour at one hour after detonation. By this time areas. ¥ we essentially all of the fallout would have occurred in these nearby Recalling that the radioactive decay is rapid for this fallout that occurs early after detonation, it becomes evident that if adequate protective areas are available it would be wiser for people to remain in place, rather than be exposed out~of~doors during the period of highest activity. Likewise, if a delay in movement is possible there will be more of an opportunity to evaluate the situation, and to then affect an orderly evacuation. Since each situation will be unique, no rigid criteria will be proposed here for permissible exposures or for mandatory evacuation, since there may be other factors present as potentially hazardous as radiation. Rather, Table 2 was developed to illustrate the kind of thinking and planning possible for civil defense. exposure to civil defense workers are shown. Three levels of The lowest of 25 roentgens is much higher than is permitted in peacetime, yet most personnel will retain their full working capacity even with exposures up to 100 roentgens. | Table 2 suggests several points relative to rescue. One of these, is that higher permitted radiation exposures to rescue crews would allow earlier entry into the contaminated area to affect first aid and general rescue work. Also, in the case of relatively ~ ere ~12- ae