PERTANIKA JOURNAL OF TROPICAL AGRICULTURAL SCIENCE

Radon concentration levels in water from lead contaminated Kawo and Magiro communities in Rafi Local Government Area were assessed using RAD-7. The mean radon concentration in the areas ranged from 35.02 to 175.10 Bq L^-1; while the weighted mean concentration was 87. 55 Bq L^-1. The resulting weighted mean annual effective dose in the two communities for stomach were 30.64 µSv y^-1, 23.08 µSv ^-1 and 18.38 µSv ^-1 for infant, children and adults respectively. The mean and weighted mean concentrations in all the samples exceeded the maximum contaminant level recommended by International Organization. Forty five (45%) of the samples exceeded 100 Bq L^-1 recommended by EU and WHO.