Indoor radon survey in dwellings of nine cities in the Eastern and the Western provinces of Saudi Arabia

The results of a first phase of an indoor radon survey in a total of 1610 dwellings distributed in nine cities of the Eastern and the Western provinces of Saudi Arabia are presented. The objective of this radon survey was to obtain representative indoor radon data for seven cities in the Eastern province, Khafji, Hafr Al-Batin, Abqaiq. Qatif, Al-Ahsa, Dammam and Khobar and to compare this with two cities in the Western province. Madina and Taif. So far, detailed radon data is not available for Saudi Arabia: therefore, this radon survey provinces a base line for Saudi Arabia in the Radon World Atlas. On average, 200 indoor radon dosemeters were distributed in each city and placed for a period of one year starting from May 2001 to May 2002. The total number of collected dosemeters was 847. A total of 724 houses and 98 schools were covered in this survey. The results of the survey in the cities showed that the overall minimum, maximum and average radon concentrations were 1, 137 and 22 Bq m^-3, respectively. Geometric mean and geometric standard deviations of the radon distribution were found to be 18 and 1.92, respectively. In one of the dwellings in Qatif city, radon concentration by a passive system and then confirmed by an active system, was found to be 535 ± 23 and 523 ± 22 Bq m^-3, respectively. The result of a radon survey in 98 schools showed that the minimum, maximum and average radon concentrations were 1. 70 and 19 Bq in m^-3, respectively. The average radon concentration for each city was also determined. The lowest average radon concentration (8 Bq m^-3) was found in Al-Ahsa while the highest average concentration (40 Bq m^-3) was found Khafji.