Radon and thoron have been identified as potential radiological health hazard and the dose estimation due to their exposure
is an important task. Understanding their behavior in indoor environment helps in calculating the inhalation doses due to
them. Present study aims at the distribution of radon and thoron concentrations in a typical Indian dwelling. Solid state
nuclear track detectors are employed in the study. The concentration of radon is found to be invariant in indoor environment.
The thoron concentration is found to decrease exponentially as a function of distance from the source (wall/floor). Solution
of one dimensional diffusion equation is used for regression fittings for thoron variation, from which the diffusion constants
and the exhalation rates were calculated. The diffusion constants varied from 0.00195 to 0.00540 m2 s−1.