B. Kharkamni¹, D.D. Wahlang^1,

Measurement of indoor radon gas and its progeny was carried out in the rooms and laboratories of Lady Keane College, Shillong, using LR-115 films, Type II, which is a Solid State Nuclear Track Detector (SSNTD). The radon concentration in the different rooms varies from 27.88 Bqm^-3 to 61.01 Bqm^-3, with an average of 42.02 Bqm^-3. The results obtained were well within the prescribed safety limit of 100 Bqm^-3 as laid down by the World Health Organization. The average indoor radon concentration was slightly higher than the world average of 40 Bqm^-3. The Potential Alpha Energy Concentration (PAEC) recorded a maximum of 6.60 mWL and a minimum of 3.01 mWL, with the average being 4.54 mWL. The Annual Effective Dose Equivalent (AEDE) ranges from 0.16 mSv/y to 0.35 mSv/y, which was also well within the prescribed limit of 3mSv/y - 10 mSv/y. The average of the Annual Effective Dose Equivalent was 0.24 mSv/y which was also below the world average of 1.15 mSv/y.

radon, progeny, indoor, LR-115 films, dose