The assessment of indoor radon ( 222 Rn) and thoron ( 220 Rn) concentrations has been conducted using dosimeters, the pinhole technique in Mainpuri city dwellings, Uttar Pradesh (U.P.) province of North India, for the assessment of health risks caused by their inhalation by the human population. The lung doses in the study area were also calculated using 222 Rn and 220 Rn, respectively. In Aunchha, the concentration of 222 Rn varied from 5.76 to 86.57 Bq m -3 , and the concentration of 220 Rn varied from 5.27 to 129.13 Bq m -3 . In Mainpuri, the concentration of 222 Rn varied from 5.82 to 81.51 Bq m -3 , and the concentration of 220 Rn varied from 22.56 to 96.43 Bq m -3 . The annual effective dose (AED) varied from 0.19 to 1.42 mSv y -1 and 0.47 to 1.32 mSv y -1 in the dwellings of the places mentioned earlier. The dose rates to the lung from exposure to 222 Rn and 220 Rn at various sites in the study area vary from 0.23 to 3.46 nGy h -1 and 0.23 to 3.26 nGy h -1 , respectively. There is a strong correlation (R 2 = 0.84) between 222 Rn levels at the respective locations; this has been compared with studies in the Kingdom of Saudi Arabia. The 222 Rn concentrations are lower than the action level. As a result, the people living in this area are safe from health hazards due to 222 Rn and 220 Rn. Therefore, this study serves as a baseline for future research and, in Saudi Arabia, provides a reference for similar studies.
M. Shakir Khan (Tue,) studied this question.