Natural Background gamma radiation levels and mapping of associated risk in Siddipet District of Telanagana State, India

Studies on natural background outdoor gamma radiation levels were conducted in Siddipet district of Telangana state, India. The investigation was carried out in the major villages/mandal head quarters of the district using scintillation detector (NaI(Tl)) based μR- survey meter. The exposure rates measured on ground level and at 1m height from ground (in μR.h^-1) were converted into absorbed dose rates (in nGy.h^-1) and annual effect doses (mSv) using appropriate conversion factors. The natural background radiation levels at 1m height were found to vary from 139 nGy h^-1 to 435 nGy h^-1 with an average of 235±47 nGy h^-1. The background radiation levels were observed to follow the normal distribution with a little deviation at the outliers. The excess lifetime cancer risk (ELCR) was also estimated. (author)