Internal Dose Reconstruction Under Part B of the Energy Employees Compensation Act

Abstract

The reconstruction of internal doses under Part B of the Energy Employees Occupational Illness Compensation Program Act differs in multiple ways from that used in a typical operational setting. There are, for example, no limits at or above which doses must be assessed; all doses, including unmonitored or potentially undetected doses, must be reconstructed. In addition, the primary dose of concern is that delivered to the organ in which the cancer originated, and only the dose delivered to that organ prior to the time the cancer was diagnosed is relevant. Additional challenges are presented in the requirement to partition dose by radiation type and energy rather than by radionuclide, the need to include any potential dose that could have been received but was unmonitored or undetected, the inability to collect follow-up samples, and, in many cases, a general lack of information regarding the employee's work history, such as specific duties or location within a site. To overcome these challenges, the NIOSH dose reconstruction program has adopted a set of default values that include assumptions that are favorable to the claimant when there is more than one plausible choice. Due to the large number of claims that must be reconstructed, efforts are continuously underway to expedite the rate at which they can be processed. This is being achieved by taking advantage of situations in which it can be documented that more detailed evaluations would not change the outcome of the adjudication of the claim.

Upper-Bound Radiation Dose Assessment for Military Personnel at McMurdo Station, Antarctica, between 1962 and 1979, Revision 1

“…IMBA has the capability of using input data like whole body counting results to determine intakes and internal doses to the organs of interest. (Brackett et al, 2008) For a veteran whose whole-body counting results cannot be found or who did not receive a whole-body measurement upon returning to the U.S., other whole-body counting results can be used. The cohort monitoring data would need to be from the same DF year and from veterans with similar duties and military specialties.…”

Characterization of Exposures to Workers Covered Under the U.S. Energy Employees Compensation Act

“…In all cases processed by NIOSH, missed dose is explicitly included in the external and internal dose reconstructions (Bracket et al 2008; Merwin et al 2008). Although missed dose for external exposure can be substantial for the early years when the detection limit for film badges was higher than that for currently employed thermoluminescent dosimeters and the badges were exchanged more frequently, the most significant missed dose is that associated with persons monitored for internal exposure to insoluble actinides.…”

Implications of Claimant-Favorable Approaches Used in Dose and Probability of Causation Calculations Under Eeoicpa

“…As described elsewhere in this issue (Brackett et al 2008), in order to expedite case processing, internal doses to atomic weapons complex workers are typically overestimated for noncompensable cases and underestimated for compensable cases (or ignored entirely if they are not required to demonstrate that a PC of 50% or greater has been achieved), rather than providing a more refined dose reconstruction. Cases that are near the compensability criterion require a more refined estimate of internal dose, but even these typically include numerous claimant-favorable approaches, assumptions, and parameters and are likely to overstate the internal organ doses received.…”

“…For expediency, several standard overestimates of internal dose have been formulated (Brackett et al 2008). Whether these overestimates are used in a given case depends upon a number of factors, including, most importantly, whether the dose can be shown to be larger than any dose that the worker is likely to have received.…”