activities were converted to fissions by means of aliquots from OCC YAG 39-C-21, Shots Flat- head and Navajo, and YAG 40-B-6, Shot Zuni, which had been analyzed for Mo’. It may be seen in Table 4.12 that, with one exception, the HVF collected about the sameorlessactivity than the other two instruments. In view of the horizontal aspect of the filter and the low airflow rate used, there is little question that the majority of the activity the HVF collected was due to fallout. The results obtained should not, therefore, be interpreted as an independent aerosol hazard. 123