A study of seasonal variations of radon levels in different types of houses

A study of the seasonal variations of radon and its decay products in the houses of Tehri Garhwal have been carried out by using LR-115, type II plastic track detector. Radon levels were found to be higher in mud houses than in cemented houses. Radon levels were recorded high in winter and autumn and low in summer and rainy season. However, it is measured highest in winter and lowest in the summer. The season/annual ratios for different type of houses vary substantially among different places. These values were found to vary from 0.91 to 1.07 ana 0.85 to 1.14 for cemented houses and mud houses, respectively. Behaviour of indoor radon for different seasons at different places is discussed in detail. The results show that the seasonal variations with indoor radon levels should be taken in to account to calculate annual effective dose equivalent.