Measurement of Indoor Radon Concentration in a Residential House of Surrey (BC) Canada using LR-115 type II Plastic Detector

Hardev Singh Virk

Abstract

Indoor radon concentration activity measurement has been considered as a useful parameter in evaluation of health hazards due to radon. The major health hazard is lung cancer attributable to radon in Canada which causes 16% of total lung cancer deaths. The purpose of this study is to determine indoor radon concentration (Bq/m3) and effective annual dose (mSv/yr) in a residential building. Plastic detector LR-115 Type II has been used for recording alpha tracks emanated by Radon and its progenies. To determine track density, tracks were counted using optical microscope, after etching detector foils of 1.5 cm2 with 2.5 N NaOH at 55°C for 120 minutes. Radon concentration was estimated using a calibration factor, 0.0344 track.cm -2. d -1/Bq.m -3. The time interval for indoor radon recording was 45 days and 30 days, respectively. The highest value of radon activity (106.0 ± 7.4 Bq.m -3) was recorded in the basement of our house and the lowest (24.2 ± 2.4 Bq.m -3) on the first floor. The corresponding average annual doses are estimated to be2.05 ± 0.14 and 0.44 ± 0.04 mSv/yr, respectively. These values are within the safe limit proposed by WHO.