Abstract
Radon is a ubiquitous gas present in the natural environment and supposed to be the most important issue of health hazards caused by environmental radioactivity. Inhalation of radon and its progeny can cause lung cancer if it is present at enhanced levels beyond the permissible limit. Therefore, in the present study, measurements of indoor radon and its progeny levels of ƒBare mode‚ exposure of modified version of twin cup dosimeters (i.e., pin hole technique) fitted with LR-115 detectors have been carried out in the dwellings of district Mainpuri city and its town Aunchha of Uttar Pradesh province in Northern India. The values of radon levels in the dwellings of Aunchha town vary from 11.4 ± 3.05 to 56.7 ± 15.15 Bq.m−3 with a geometric mean of 28.4 ± 7.59 Bq.m−3. The values of annual effective dose have also calculated and found to vary from 0.2 ± 0.05 to 0.9 ± 0.24 mSv.y−1 with a geometric mean of 0.4 ± 0.11 mSv.y−1. The values of radon levels in the dwellings of Mainpuri city vary from 24.6 ± 11.00 to 50.8 ± 22.72 Bq.m3 with a geometric mean of 34.8 ± 15.56 Bq.m−3. The values of annual effective dose have also calculated and found to vary from 0.4 ± 0.18 to 0.8 ± 0.36 mSv.y−1 with a geometric mean of 0.5 ± 0.22 mSv.y−1. The values of radon and its progeny levels are higher in the dwellings of Aunchha town in comparison with Mainpuri city.

Key words: LR-115 Detectors; Bare Mode; Radon; Effective Dose