Indoor (222)Rn and (220)Rn concentrations and doses in Bangalore, India.

(222)Rn and (220)Rn levels have been measured using passive detector technique by employing time integrated solid-state nuclear track detector-based dosemeters in various types of houses at 10 different locations in and around Bangalore Metropolitan, India. The measured geometric mean concentration values of (222)Rn and (220)Rn levels in 200 dwellings of different types of construction were found to be 32.2±1.6 and 21.4±1.0 Bq m(-3), respectively. The dose rate received by the population of Bangalore ranged between 0.2 and 3.5 mSv y(-1) with an average and the geometric mean of 1.14±0.05 and 1.06 mSv y(-1), respectively. Overall, the result does not show much significant radiological risk for the inhabitants and the (222)Rn levels are well within the limits of global average concentration of 40 Bq m(-3). However, the (220)Rn levels observed were found to be higher than the global average of 10 Bq m(-3).