Variations of radon and thoron concentrations in different types of dwellings in Mysore city, India.

(222)Rn and (220)Rn, the immediate decay products of radium isotopes, are causative agents of lung cancer. (222)Rn and (220)Rn concentrations in houses with different floorings, roofs and walls and in different rooms of houses have been measured in Mysore city, Karnataka state, India, using solid-state nuclear track detectors. The radon and thoron concentrations in dwellings with granite floorings are found to be higher compared with other types. A correlation between the indoor radon concentration and dose in air from terrestrial gamma radiation is observed.