Gamma dose measurement in dwellings of Agastheeswaram Taluk of Kanyakumari district, lying 30 km radius from Kudankulam nuclear power plant site.

Most of the building materials contain naturally occurring radioactive elements, the most important of which are potassium (40)K and the members of two natural radioactive series, which can be represented by the isotopes of thorium (232)Th and Uranium (238)U. The presence of these radioisotopes in the materials causes external exposure to the people who live in the building. In addition, the disintegration of Uranium (238)U increases the concentration of radon gas (222)Rn and of its daughters in the house. So a systematic indoor gamma dose measurement has been performed in the dwellings of Agastheeswaram Taluk of Kanyakumari district, which is lying within the 30 km radius from the upcoming Kudankulam nuclear power plant site. The geometric mean of annual absorbed dose from gamma radiation in dwellings has been found to be 278 nGyh(-1). The seasonal variation of indoor gamma dose measurements has also been studied. Significant differences have been observed in dwellings built of different materials such as concrete, tiled, etc.