Development of a Portable Radon Progeny Monitor for Individual Concentration

INTRODUCTION The Rn(radon) family is the most significant source of exposure to natural radiation, causing about one-half of the public effective dose. A number of international organizations, including UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation) and ICRP (International Commission on Radiological Protection) have officially reported this fact since the 1980’s (1-6). Radon and its progeny concentrations have been surveyed all over the world. Important nuclides in the radon family contributing to the effective dose are members of the radon short-life progeny. (Here, radon progeny indicates radon short-life progeny, that is, Po to Po.) Therefore, direct measurement of the progeny concentration is adequate for dosimetry. However, it is difficult to survey the radon progeny concentrations in large numbers of ordinary dwellings or offices because of a lack of convenient measurement instruments. Therefore, radon dosimetry has been based on the concentration of the parent radon itself. For a precise calculation of the public or personal effective dose, a facile and portable radon progeny monitor is greatly needed. In the present study, a portable radon progeny monitor (PRPM) was designed and developed which automatically estimates the individual progeny concentration in the natural environment.