Comparative study of short- and long-term indoor radon measurements

Short-term indoor radon measurements are used widely. Therefore, it is interesting to find out a correlation between these measurements and long-term measurements which reflect a better average radon concentration of individual measurement. To find the correlation between the two measurements of indoor radon concentrations at low radon levels, a study was carried out at 34 locations of King Fahd University of Petroleum & Minerals (KFUPM), Dhahran, Saudi Arabia using active and passive methods. In the short-term active method, a radon gas analyzer (AlphaGUARD) was used for a duration of 24 h in each measurement. In the long-term passive method, CR-39 based radon dosimeters were utilized for a period of 6 months, from January 2006 to June 2006. The short-term active measurements showed that the average, minimum and maximum radon concentrations were 19, 8 and 58 Bq m^{- 3}, respectively, with a standard deviation of 8.6 Bq m^{- 3}. The long-term passive measurements showed that the average, minimum and maximum radon concentrations were 25, 10 and 67 Bq m^{- 3}, respectively, with a standard deviation of 12 Bq m^{- 3}. The two measurements showed a poor correlation (R² = 0.38). The long-term measurements showed on the average higher concentrations by a factor of 1.3.