International Journal of Pure and Applied Physics ISSN 0973-1776 Volume 6, Number 2 (2010), pp. 117–126 © Research India Publications http://www.ripublication.com/ijpap.htm Study of Indoor Radon and Thoron Levels in Srirampura, Bangalore, India using Passive Detector Technique G. Srinivasa1, L.A. Sathish2*, S. Sundareshan3 and T.V. Ramachandran4 1Department of Physics, Rural College, Kanakapura – 562 117 2Department of Physics, Government Science College, Bangalore – 560 001 3Department of Physics, Vijaya Degree College, Bangalore – 560 004 4Ex-Environmental Assessment Division, Bhabha Atomic Research Center, Mumbai-400085 *Corresponding author E-mail:
[email protected] Abstract Results of the measurement of indoor radon and thoron carried out in and around Srirampura, Bangalore, India using passive detector technique is presented. Measurements were carried out using twin cup radon-thoron dosimeter using small strips of 12 micron thick LR-115 Type II nuclear track detectors. Measurements were carried out in 60 dwellings for a period of one year on a quarterly time integrated quarterly cycle to see the seasonal variation. After the exposure period, the detectors were chemically analyzed using 2.5 N NaOH at 60o C for a time of 90 minutes and the etched detectors were scanned by spark counter techniques. The estimated 222Rn and 220Rn levels in the studied locations showed the higher concentrations during winter season, in bath rooms, in concrete walls and in granite flooring houses. In this paper the author have made an attempt for the measurement of concentrations of indoor radon along with its distribution pattern based on construction material. Key words: Radon, indoor exposure, dwellings, seasons.