VARSKIN code (Durham, 1992) can be used to calculate skin dose for specific source geometries. Skin-contamination measurements are recommended as the best source of contamination data from which to calculate dose, but methods are also suggested for using dose or exposure-rate measurements to estimate contamination.

Barss (2000) does not discuss uncertainty related to beta-particle doses from skin contamination.

IV.E.4 Uncertainty in Estimates of Internal Dose

Estimates of uncertainty in calculated internal doses are not presented in dose reconstructions for individual atomic veterans or in unit dose reconstructions for participant groups. In all dose reconstructions that include an estimate of internal dose, the calculated dose is presented as a single value without uncertainty. Uncertainties in internal doses are also not evaluated or discussed in any detail in reports documenting the calculation methods (Egbert et al., 1985; Barrett et al., 1986).

Thus, the treatment of uncertainty in estimated internal doses differs from the approach to addressing uncertainty in estimated doses from external exposure to photons. As discussed in Section IV.E.2, dose reconstructions for individual veterans often provide an estimated upper bound of the external photon dose, especially if the veteran filed a claim for compensation. Many generic dose reconstructions for participant groups also include a quantitative analysis of uncertainty in external photon dose. An upper-bound estimate of external photon dose is intended to represent a 95% confidence limit, and the difference between the upper bound and the central estimate indicates the magnitude of uncertainty. Upper-bound estimates of dose are important because, in accordance with the policy that the veteran will be given the benefit of the doubt (see Section I.C.3.2), the NTPR program intends that upper bounds will be used in evaluating claims for compensation.

In the absence of a quantitative analysis of uncertainty in estimated internal doses, this uncertainty is addressed in the NTPR program by using an alternative approach mentioned in Section I.C.2.4. An argument is made that methods used to estimate internal doses incorporate assumptions that should result in overestimates of internal doses to participants. For example, the method of estimating dose from inhalation of resuspended fallout that was previously deposited on the ground or other surfaces (see Section IV.C.2.1) relies mainly on an assumption that resuspension factors that are applied in various exposure scenarios greatly overestimate the actual extent of resuspension of deposited fallout. On the basis of that type of argument, estimates of internal dose obtained in dose reconstructions are assumed to represent suitable upper bounds for use in evaluating claims for compensation; that is, the estimated doses are assumed to be “high-sided.” As discussed in Section IV.E.3, essentially the



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