The results of 222Rn and 226Ra activity measurements in drinkable water supplies of the ThuDuc region
in Ho Chi Minh City,Vietnam,are presented in this paper.The measurements were performed using a
RAD 7 radon detector manufactured by Durridge Company,Inc.Mean concentrations of 222Rn and 226Ra
were found to be 0.1170.01 Bql1 and 0.1170.02 Bql1 in 14 drinking water samples.Theyare
0.1270.01Bql1 and 0.1070.02 Bql1 in 15tapwatersamples,respectively