activity has decreased significantly. A given dose rate reading inside a vehicle may represent less contanination per uit area due to the contribution of gamma rudiation from the exterior of the vehicle. would more Om the other hand, contacination within a vehlele probably be picked up by personnel than if {t were on the outside. Further, it is recognised that significantly high concentrations of radioactive fallout may acewwlate in such parts as the air filters of an automobile. Again, this has to be weighted against the probability that they will be handled before the activity has decreased te low levels plus the fact that it is relatively difficult.to monitor such parts on «@ mass besis, The uncertainties present in estimating possiblehazards from vehicle contamination would not justify fine distinctions in monitoring the various parts, A thorough cleaning, inside and outside, would appear to be the best solution. One of the obvious ways to avoid much of the probles discussed in Folicy IV is to prevent vehicles entering an area during the tine of fallout. This will not prevent the first vehicles passing through fran‘sizing up activity on the tires frox the highway. It is believed, however, this will not constitute such a troublesome problem and past experience has indicated that the activity found on the tires noticeably decreased after several cars hed passed over the highway. Further, if vehicles are not present in the fallout it will help reduce contamination of the passengers end of the insides of the vehicles, UNcLacerrien