In conclusion, we maintain there is sufficient information to warrant the decision to leave the Pu-contaminated areas discussed in this paper as exclusion areas. There are a few uncertainties in maintaining exclusion areas among which appears to be the possibility of movement of Pu into the playas, even though the dilution factors may negate the hazard in this area. There may be some positive advantages to these exclusion areas, and the possibility of decreasing Pu availability to food chains or to other human exposures with time making this alternative well worth considering. 178