pendent on the type of soil, as shown in Table 4. Residual gross alpha activity in surface soil samples taken at Palomares by Spanish authorities in September 1966, approximately 7 months after the incident, ranged from 5.1 to 214 pCi/g. Additional surface samples taken in the same areas and analyzed by LASL for plutonium activitiy had levels ranging from 0.05 to 2,130 pCi/g; areas 2-2 and 3-1 had average plutonium levels of 134 and 156 pCi/g, respectively. data are presented in Tables 1 and 5. These It should be noted that the range of plutonium in surface soil in control areas at Palomares was 0.09-3.6 pCi/g. These areas were selected to be free of plutonium from the incident. This range is comparable to that found at Rocky Flats, viz. 0.05-3.0 pCi/g. Air samplers to measure gross alpha activity in airborne particulates were set up in the three areas of initial highest deposition, viz. 2-1, 2-2, and 3-2. For these areas, the maximum gross alpha activity for the period 6/66-5/67 ranged from 0.05 to 0.14 pCi/m?, with an average of about 0.003 pCi/m>, These Palomares levels may be compared with background measurements made at Madrid during the same period: a maximum and average gross alpha activity level of 0.16 and 0.004 pCi/m? in air, respectively. Again, assuming the entire content of the sample to be plutonium, the averages for Palomares and for Madrid would be on the order of 0.2 to 0.4% of the appropriate pe