Measurements of(222)Rn,Rn-220 and their progeny concentrations indoors around a coal/gas-based power plant and estimation of annual inhalation dose to the public

摘要

In the present study, indoor radon (Rn-222), thoron (Rn-220), radon progeny (Po-214) and thoron progeny (Po-212) activity concentration have been measured in a region around the National Capital Power Station, Dadri, Uttar Pradesh, India. The mean values of the(222)Rn,Rn-220 and their progeny in the studied region are found to be 22.1 +/- 10.0 Bqm(-3), 48.6 +/- 13.5 Bqm(-3), 8.8 +/- 4.8 Bqm(-3)and 0.49 +/- 0.15Bqm(-3)respectively. The annual inhalation dose estimated from the observed concentrations varies from 0.29 +/- 0.04 to 2.06 +/- 0.121 mSv with a mean value of 0.75 +/- 0.32 mSv and is well within the reference level. It has also been observed that(212)Po is a significant contributor (= 18.7%) to the total annual inhalation dose. Seasonal variations of(222)Rn,Rn-220, and their progeny have also been reported.