Variation of ambient gamma dose rate and indoor radon/thoron concentration in different villages of Udhampur district, Jammu and Kashmir State, India.

The exposure of natural background radiation imparts a major contribution to inhalation doses received by the public, and its amount depends on the lithology, altitude, and building construction materials. The preliminary results of indoor and outdoor gamma-ray dose rate of Udhampur district, Jammu and Kashmir, India are presented. Indoor radon and thoron gas concentration have also been measured by using the LR-115 based pin-hole detectors in the same villages and the estimated concentrations are within the recommended level of the International Commission of Radiological Protection. For the outdoor environment, the minimum and maximum gamma dose rate were 0.06 and 0.4 μSvh-1, whereas for indoor environment, the minimum and maximum gamma dose rates were 0.09 and 0.21 μSvh-1, respectively. Effects of lithology on indoor radon/thoron concentration and also on gamma dose rates have also been investigated. The average values of annual effective dose from background gamma radiations were well within the safe limit and does not cause health hazard to the inhabitants. [ABSTRACT FROM AUTHOR]