Indoor radon level measurements in some regions of Iran

Abstract

To determine the effective dose equivalent of the public in Iran due to 222 Rn and its daughters ( 218 Po and 214 Po) from natural radiation environment, a national radon monitoring program was developed at the Radiation Protection Department of the Atomic Energy Organization of Iran (AEOI). The AEOI passive radon diffusion dosimeters were applied in this program. About 250 dosimeters applied in about 206 randomly selected houses in some regions of Iran including Ramsar (a high natural radiation area), Tehran, Babolsar and Gonabad have been processed and analyzed for radon level evaluation. The polycarbonate foils have been electrochemically etched using our new design of multi-chamber electrochemical etching system applying our optimized ECE conditions. The mean radon levels in the above cities were determined to be respectively 578, 80, 88 and 84 Bq.m -3 , leading to average effective dose equivalents of 17.6, 2.44, 2.68 2.56 mSv/year. Gamma dosimetry were also carried out with TLD and film badge in houses of high natural radiation areas of Ramsar together with Rn dosimeters. Some houses were found with very high gamma and Rn exposures. In this paper, some preliminary results of such measurements are reported and discussed.