Gamma radiation levels in the villages of South Konkan, Maharashtra, Indiaf

Ambient gamma radiation study was carried out in South Konkan using thermo luminescent dosimeters (TLDs). A statistical analysis was carried out to understand the distribution of gamma radiation in the study area. The annual effective doses (AEDs) received by the local population from the selected villages were 0.31 and 0.09 mSv year^sup -1^ for indoor and outdoor locations, respectively. For indoor conditions, the maximum dose rate occurred for winter season and the minimum occurred in monsoon season while for outdoor conditions the maximum dose rate occurred in spring season and minimum occurred in the monsoon season. The terrestrial radioactivity in the corresponding villages was measured by a HpGe detector. The radiation hazard indices like absorbed dose rate in air (D), radium equivalent activity (Ra^sub eq^), external hazard index (H ^sub ex^) and internal hazard index (H ^sub in^), and AED were calculated using soil radioactivity data. The minimum absorbed dose rate in air (33.97 nGy h^sup -1^) corresponds to the Dale village and the maximum (101.86 nGy h^sup -1^) corresponds to the Mithgawane village. Radiation hazard indices as Ra^sub eq^, H ^sub ex^, and H ^sub in^ were found to be within the limit. The average AED from natural radionuclides was found to be lower than the worldwide value. The AEDs of this study were compared with previous studies carried out worldwide. A positive correlation was observed for the absorbed dose rate in air and the activity concentration of U-238, Th-232, and K-40. A positive correlation between activity concentrations of U-238, Th-232, and K-40 was also observed. The comparison between the AEDs calculated using absorbed dose measured by TLDs and the values calculated from soil's gamma spectrometry showed some variation in the villages of South Konkan.