EFFECTIVE RADIATION DOSE DUE TO INDOOR RADON AND THORON CONCENTRATIONS IN BANGALORE CITY, INDIA

Radon makes up approximately half of the total dose of radiation we receive naturally. The majority of it comes from the inhalation of the progeny of (222)Rn and is prominent in a closed atmosphere. The continuous measurement of the levels of (222)Rn concentration in different geographical areas is of great importance, particularly in living places. The radon and thoron concentrations have been measured in houses at 10 locations in different parts of Bangalore, India. Solid state nuclear track detectors were used for measuring the concentrations. The average value of radon and thoron concentrations in the studied area is found to be 33.4 +/- 6.1 and 21.6 +/- 2.5 Bq m(-3), respectively. The dose rate due to radon, thoron, and their progenies received by the population in the studied location ranged between 0.1-0.5 mSv y(-1). The arithmetic and geometric mean concentrations are 0.2 +/- 0.03 and 0.2 mSv y(-1), respectively. The results show no significant radiological risk for the inhabitants of Bangalore. The global average concentrations are 40 and 10 Bq m(-3), respectively.