- 41 gurrounding tissue (roughly 10 rem/yr). —- ¢ Weanons Test Fallout *-" Another source of human contamination that is suggested as being pertinent to this problem is the plutonium in the fallout from nuclear weapon tests. The plutonium from weapon tests is incorporated in or deposited on particles that contain other materials and, like that for the Manhattan workers, the specific activity in these particles is much “es smaller than that in hot particles. VII Exposure’ Standards for Hot Particles Thus the existing biological evidence strongly suggests that an insoluble particle of Pu-239 deposited in deep respiratory tissue represents a risk of cancer induction between 1/1090 and 1/10 ,000. Prudent public health practices should assess the risk associated with environmental plu~__ - tonium and establish exposure guidelines on the basis of _these probabilities. The existing standards fer uniform radiation exposure of the whole body or lung can be used as the basis for ‘establishing particle exposure standards by equatiny the risk of cancer induction between the two types of exposure (uniform vs. grossly non-uniform). assessment of tre risk The most recent associated with uniform irracication of