Assessment of indoor radon activity concentration levels in four northern districts of Telangana state, India

Indoor radon activity concentrations were carried out using twin cup dosimeters with SSNTDs in four districts viz., Karimnagar, Peddapalli, Jagtial and Rajanna Sircilla of Telangana state, India. The part of study area falls under Karimnagar Granulite Terrain, the geological region recognized for the occurrence of high uranium content metasedimentary enclaves within granite. The radon concentrations, in the study area, were found to vary from 7 to 457 Bq m−3 with a geometric mean of 62 Bq m−3 (GSD 2.24). The estimated radon activity is observed to obey log-normal distribution. The analysis of seasonal variation confirmed that the indoor radon concentration levels are relatively higher in the winter. Variation of radon activity levels in dwellings with different types of building materials was also studied and presented in this paper.