Assessment of gamma radiation dose using a car-borne survey around coastal and hinterland regions of the high background natural radiation area, Kanyakumari, India

This study aims to characterize the spatial distribution of natural gamma radiation using NaI(Tl) scintillation spectrometer in the coastal and hinterland regions of Kanyakumari high background natural radiation area, India. Absorbed dose rate in air (Dair) along the coastal region varied between 38–1757 nGy h−1, with a mean of 214 ± 209 nGy h−1, whereas in the hinterland region Dair ranged between 43 and 367 nGy h−1, with a mean of 107 ± 41 nGy h−1, both mean values were higher than the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) world average value of 58 nGy h−1. About 2% of the calculated annual external effective dose of the coastal region were above 1 mSv y−1 and 99% of it were above the UNSCEAR world average value of 0.07 mSv y−1.