Abstract
Studies of radon isotope( 222)Rn activity concentration in underground water used for irrigation and consumption in Al-Asyah city-Saudi Arabia were performed using RAD7 electronic radon identifier associated with RAD-H2O extra (Durridge Co., USA). Waters samples chosen for investigations were gathered from 18 various wells in and around the town. The activity concentration of 222 Rn varied from 1.2 +/- 0.3 to 12.6 +/- 1.6 Bq L-1, with an average of 5.1 +/- 1.1 Bq L-1. The annual effective dose per liter was calculated for inhabitants to be in the range 6.0 +/- 1.4 to 62.9 +/- 8.2 nSv L-1 with a mean value of 25.4 +/- 5.4 nSv L-1. The annual effective doses rate for ingestion and inhalation due to the consumption of Rn-222 with water ranged from 4.4 +/- 1.1 to 45.9 +/- 5.9 mu Sv y(-1), with an average of 18.5 +/- 3.9 mu Sv y(-1) and from 3.0 +/- 0.7 to 31.7 +/- 4.1 mu Sv y(-1), with an average of 12.8 +/- 2.7 mu Sv y(-1) , respectively. The total annual effective dose ranged from 7.4 +/- 1.7 to 77.6 +/- 10.1 mu Sy y(-1), with an average of 31.3 +/- 6.6 mu Sv y(-1). Moreover, roughly 11% of our samples were above the maximum contamination level, while 89% from the samples are below the maximum contaminant level as quoted by US Environmental Protection Agency. The results showed that radon from water would be expected to contribute by (5.1 +/- 1.1) x 10(-4) Bq L-1 to the indoor air radon concentration. The results were compared with other results.