have defined an enhancement factor (EF) as the 239+240p, concentration in the collected aerosol mass divided by the 239+240p,, surface soil (0-5 em) concentration. The EF obtained from standard Hi Vols for normal conditions is less than 1; the EF for the worst case, high activity conditions is 3.1. Table 5 gives a summary of the observed EF at Bikini and Enewetak ; Atolls. The EF of less than 1 (EF<1) for Hi Vol data for the nornal open air conditions is apparently the result of selective particle resuspension in which the resuspended particles have a different ‘plutonium concentration than is observed in the total 0-5 em soil sample; in other words the particle size and density and the corresponding radionuclide concentration is different for the normally resuspended material than for the total 0-5 cm soil sample. addition, In approximately 10 percent of the mass observed on the filter is organic which we know has a much lower Pu concentration then the soil. Similarly the enhancement factor of 3.1 for high activity conditions results from the increased resuspension of particle sizes with higher plutonium concentration than observed in the total O-5 cm soil sampic. We have developed additional enhancement factors (PDE) from personal dosimeter data. These data are normalized to the Hi Vol ceta for a particular condition and represent that enhancement that occurs around an individual due to his daily activities (different from the open air measurement made with the Hi Vols). summarized in Table 5. These data are also The total enhancement used to estimate the amount of respired Pu is the combination the Hi Vol and personal a. 5011693