Indoor radon measurements in dwellings of Kulu area, Himachal Pradesh, using solid state nuclear track detectors

In the present paper, the results of radon activity recorded in domestic regions of the Kulu area (Himachal Pradesh, India) known for uranium mineralisation are reported. Time integrated track etch technique has been used for the measurement of indoor radon levels. Bare cellulose nitrate LR-115 type II films have been used as detectors in the survey of radon. The calibration constant of 4.8 x 10(2) tracks cm(-2) day(-1) per WL of radon at equilibrium (which corresponds to 12.97 x 10(-2) tracks cm(-2) d(-1) per Bq m(-3)) determined by Subba Ramu et al. (Sci. Total Environ. 73 (1988) 245) has been used to express radon activity in Bq m(-3). In some of the dwellings the levels of radon activity are found to be quite high giving an annual exposure dose that crosses the safety limits set by the International Commission on Radiological Protection (ICRP, Protection against radon-222 at home and at work, ICRP Publication 65, Annals of the ICRP, 23 (2), 1993). A study of seasonal variations of indoor radon in some of the dwellings has also been carried out. (C) 2001 Elsevier Science Ltd. All rights reserved.