Assessment of natural radioactivity levels and potential radiological risks of commonly used building materials in Uttara Kannada District, Karnataka, India

The main goal of this study is to evaluate the natural radioactivity and potential radiological risks of frequently used building materials in Uttara Kannada district. Using an High purity Germanium Detector (HPGe) detector-based gamma-ray spectrometer, the activity concentration of 226Ra, 232Th and 40K was determined. The activity concentration of 226Ra, 232Th and 40K in the construction materials vary from 13.78 +/- 0.90 to 151.9 +/- 1.85, 14.21 +/- 0.80 to 207.72 +/- 2.9 and 55.26 +/- 1.20 to 1298.24 +/- 25 Bq kg-1 with an average value of 40.57 +/- 1.37,60.13 +/- 1.70 and 425.38 +/- 4.75 Bq kg-1 having a geometric mean of 33.07, 46.49 and 290.20 Bq kg-1, respectively. The mean annual effective dose equivalent was found to be 0.68 mSv y-1 and is less than the International Commission on Radiological Protection proposed acceptable limit of 1 mSv y-1. The estimated radiological hazard parameters show that these building materials are safe to use in the construction of homes and do not offer a substantial source of radiation hazard.