A STUDY ON THE INDOOR RADON CONCENTRATION IN HOSPITALS IN THE SHILLONG REGION, MEGHALAYA

Abstract

In this paper, we report our findings on indoor radon survey at 8 major hospitals in the Shillong region and also present estimates on the associated annual effective doses and life-time fatality risks. The survey was undertaken using LR-115 Type2 detectors. The measured radon activity concentration values were found to range from 65.66 Bq.m^-3 to 783.77 Bq.m^-3 with an arithmetic mean value of 260.4 ± 138.3 Bq.m^-3 and a geometric mean value of 228.4 ± 1.67 Bq.m^-3. Of the total rooms surveyed, 60% have radon concentration more than the ICRP prescribed lower limit of 200 Bq.m^-3; about 4% of the rooms had values higher than the upper limit of 600 Bq.m^-3. Distribution analysisof the radon activity concentration measured at the hospital rooms is carried out. Floor-wise variation was studied and a decrease in radon concentration with increase in floor-number has been observed.