Radon levels in riyadh ground water

Full text: A national ground water surveillance program was started for investigation of natural radioactivity levels. This paper presents 222Rn radioactivity concentration levels in well waters located only in Riyadh area of Saudi Arabia. The 222Rn radioactivity levels were measured in water samples of 146 water wells. These were collected from six locations in Riyadh Area. The analyses were performed by ultra low level liquid scintillation spectrometer equipped with an alpha-beta discrimination device. Efficiency and background calibrations were performed with a 226Ra aqueous standard homogeneously mixed with the cocktail and used after certain period to assure radon equilibrium. Most of these wells are deep wells with about 1000 meter depth. The range of 222Rn activities measured in these deep wells ranged from 0.34±0.04 to 4.63±0.38 BqL-1 with an average of 1.82±0.19 BqL-1, while the activities in shallow wells (∼300 meters) ranged from 1.27±0.14 to 6.49±0.45 BqL-1 with an average value of 3.32±0.31BqL-1. The values of 222Rn concentrations were found to be dependant on the water sources. The radioactivity levels of 222Rn in the groundwater are in compliance with the national limits of 300 BqL-1. (author)