Study of variation of Rn-222/Rn-220 and their progeny concentration in dwellings using single entry pin hole-based diffusion chambers

摘要

In the present study, newly designed single entry pin hole-based diffusion chambers were used for the first time in a study region to estimate exact Rn-222 and Rn-220 concentration. These diffusion chambers are independent of high turbulent environmental conditions as well as with same entry rate of Rn-222 and Rn-220. The device was calibrated at Bhabha Atomic Research Centre, Mumbai following the standard procedures to correlate the number of tracks registered in the LR-115 detector placed in the two chambers to the Rn-222 and Rn-220 concentrations in the environment. The average values of Rn-222 and Rn-220 concentration in the indoor environments were 28.76 +/- 13Bqm(-3) and 63.08 +/- 17.27Bqm(-3), respectively. The values were within the recommended level of ICRP, 2010 (200-300Bqm(-3)). The observed data has provided a good correlation (R-2=0.8618) between Rn-222 and Rn-220 concentrations in the studied area. A linearity relationship was established between PAEC (Rn-220) and {PAEC (Rn-222)}(0.4) with R-2=0.9047. These data will provide a good database for Rn-222 and Rn-220 mapping in India.