Assessment of radiation hazards due to the concentration of natural radionuclides in the environment

A study of natural radionuclides and radon concentration of Hamirpur District of Himachal Pradesh, India is carried out using various methodologies. The activity concentration of the natural radionuclides viz. 226Ra, 232Th and 40K is measured using high-resolution-based HPGe detector. Indoor radon measurements in the dwellings of Hamirpur district is carried out using LR-115 type II cellulose nitrate films in the bare mode. The average activity concentrations of 226Ra, 232Th and 40K are 35.58, 54.95 and 580.58 Bq kg−1, respectively. The annual average indoor radon value in the study area varies from 173.90 to 198.25 Bq m−3, which is well within the recommended action level given by International Commission on Radiological Protection. The indoor radon values obtained in the present investigation are higher than the world average of 40 Bq m−3. Radon concentration in water samples is measured using RAD7, an active radon detector. The annual effective dose for stomach and lung is determined from the measured value of radon concentration in water. To assess the radiation hazard of the natural radioactivity in all samples to the people, the radium equivalent activity, external hazard index, lifetime fatality risk, absorbed dose rate and total annual effective dose is estimated. The results signify that the studied area does not possess any radiation hazards due to the presence of natural radioactivity concentration.