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Thoron Concentration Essay

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The results of experimentally determined values of indoor radon, thoron and their progeny concentrations observed in selected 127 dwellings of 47 villages sampled by single entry pin-holes based dosimeters and progeny sensors for one year are summarized in Table 1. The radon concentration varies from 16±0.9 Bqm-3 to 50±23 Bqm-3 with an arithmetic mean of 30±7 Bqm-3 and geometric mean (and geometric standard deviation) of 30 (1.25) Bqm-3, which is less than the lower limit of the action level (200-300 Bqm-3) recommended by International Commission on Radiological Protection [28]. Also, the mean radon concentration is well below the world average value of 40 Bqm-3 [1]. The present results of radon concentration are lower than the action …show more content…

Hence the p-values in both cases are greater than the 0.05, so the test accepts the hypothesis of normality. The SW test is consistent with the standardized skewness and the standardized kurtosis values (Fig. 4). They accept the normality for annual radon and thoron concentrations. In order to determine normality graphically, the output of the normal Q-Q plot was also used (Fig. 5). From Fig. 5, it is clear that the data points are along the diagonal line. Hence, the data are normally distributed.
The equilibrium equivalent radon concentration (EERC) has been found to vary from 7±2 Bqm-3 to 26±1 Bqm-3 with an arithmetic mean of 17±5 Bqm-3 and geometric mean (and geometric standard deviation) of 17 (1.11) Bqm-3. Similarly, the equilibrium equivalent thoron concentration (EETC) has been found to vary from 0.4±0.1 Bqm-3 to 2.6±1 Bqm-3 with an arithmetic mean of 1.3±0.5 Bqm-3 and geometric mean (and geometric standard deviation) of 1.2 (1.46) Bqm-3, respectively. The ICRP [32] has recommended the range of 2 to 50 Bqm-3 for EERC and 0.04 to 2 Bqm-3 for EETC.
The ICRP [32] estimated an expected concentration in buildings, which in terms of EERC is 2 to 50 Bqm-3 and EETC is 0.04 to 2 Bqm-3. All measured values of EERC are found well within the range limit prescribed by ICRP [32]. However, about 6 villages (13%) have a higher value of EETC than the maximum limit given by ICRP [32] and

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