Options for controlling localized skin dose

Abstract

In this study, issue on the skin dose averaging area was reviewed with the results of calculated dose distributionfrom various beta emitters. In case of dot-like contamination such as a hot particle, according to calculated results,over 99 % of the dose was deposited within 1 mm radius. This result showed that the use of 10 cm2 as the doseaveraging area, recommended by the National Council on Radiation Protection and Measurement (NCRP),compromises the concept of dosimetry by intentionally including unexposed tissue volume to reduce the dose. Besidethe approach recommended by NCRP, two other options were suggested and discussed. One option addressing agraded enforcement of the skin dose limit, considering the low probability of hot particle exposure, was proposed toavoid compromising the dosimetry concept. Though this option can give flexibility in the regulation of skin exposure,this option compromises the unified meaning of the dose limits. The other option addressed increase of the skinequivalent dose limit specifically for prevention of deterministic effects while applying a smaller averaging area forcontrolling stochastic effects. The first two options involve decision of the national or regional regulatory authorityand the third involves actions at the International Commission on Radiological Protection (ICRP) level.