TMCEFD said and thought they were using the effective biological exposure model (Sh59). However, one of their input papers prepared by Nagler and Telegadas (NaS6) contains a table of conversions from infinite exposure; this is reproduced in Table 2. A comparison of Tables 1 and 2 demonstrates that they were indeed using the estimated “exposure model. Further, Nagler and Telegadas stated that the data reproduced; in Table 2 were supplied by Dunning and he (Du81) has conf ifned-that—the relevant model was indeed that of estimated exposure. For the.PLUMBBO8 (1957) series, an alternate approach was used by the TNCEFD. Larson et al. (La59) collected many samples of PLUNBBOB fallout, returned: them to the laboratory, and measured the rate of decay of gamma emissions. From,these data, they constructed a composite PLUMBBOB gamma-decay curve-and the TMCEFD used these data in place of Eq. [7]. They did not appreciatethat the rate of gamma emission is not adequate directly as a model for_external exposure rate, as the energy per gamma emitted changes with time,and there is no indication that their data were corrected for the efficiency of the detector as a function of energy. The TMCEFD, Sn59, state that the PLUMBBOB data so Calculated were about 50% higher than woul d—have been calculated with the infinite exposure model. In terms of the-estimated exposure model, we conclude that the PLUMBBOB estimates are too trigh by about 100%. For PLUMBBOB, the TMCEFO also used film badge data to estimate exposure for some communities. As the film badges were not “Te-the field for a full year, they used a rough model of multiplying the_film badge reading by 1.3 to approximate infinite exposure and then dividing by 2 to approximate estimated exposure. Te 209