Evaluation of Effective Dose in Environmental Dosimetry Using Humanoid Phantoms Representing Different Ages and Sex, and LiF:Mg,Ti and LiF:Mg,Cu,P Detectors

Abstract

Transition coefficients relating values of exposure in air, as read out with personal dosemeters, to effective dose from external exposure, have been evaluated. Four types of ICRP 23 heterogenic anthropomorphic phantoms, representing children of ages 1 y and of 5 y, Reference Woman and Reference Man, were exposed in an open space at the Chernobyl area and indoors, in brick and wooden dwellings. TL detectors: LiF:Mg, Ti and LiF:Mg,Cu,P were used inside the phantoms and in personal badges attached to the phantoms. In open space the ratio of the value of effective dose (E in µSv) to the value of exposure in air (X in mR) at 1 m above ground level was found to correlate linearly with phantom height, decreasing from 9.0 µSv.mR-1 (child, 1 y) to 6.1 µSv.mR-1 (Reference Man). The ratio of E and dose equivalent (H), as measured with personal dosemeters, was also found to correlate linearly with the ratio of the phantom height to its mass (range of E/H: 1.1-0.87). Indoors, values of E/X = 8.35 ± 0.31 µSv.mR-1 and E/H = 1.54 ± 0.04 were found for all phantoms and building materials studied. These results permit the height and weight of individuals to be included in the evaluation of effective dose incurred, e.g. over the Chernobyl area or from the radioactivity of building materials.