Estimation of natural radioactivity and health risk assessment

The present study deals with the measurement of radioactivity in some naturally occurring radioactive materials (NORMs) and in technologically enhanced naturally occurring radioactive materials (TENORMs). The technique of gamma spectrometry can be used to measure the levels of radioactivity in various samples used. The measurement of radioactivity has been carried out using 'γ-ray spectrometry'. The experimental set-up of Gamma Spectroscopy has been used at IUAC, New Delhi. The study area includes North-Eastern part of Haryana state of India. The places are in the vicinity of Shivalik range of Himalayas. The absorbed dose rate in the samples investigated at 1 m above ground level, Ra equivalents, internal and external hazard indices have also been calculated. All the samples analyzed in the present work satisfy the criterion, i.e. the annual effective dose is less than 1 mSv, the recommended safety limit of for general public (ICRP, 1991) except in Fly-ash (FAY) and Granite Stone (BS). Hence, most of these samples do not pose much health hazard for the population. These samples satisfy the universal standards (UNSCEAR, 2000) limiting the radioactivity within the safe limits of 1000, 1000 and 4000 Bqkg-1 for 226Ra, 232Th and 40K, respectively