Assessment of annual effective dose from radium isotopes in groundwater samples in households along the lower Mekong River

In this study, the 224 Ra, 226 Ra, 228 Ra in groundwater samples at Long Phu district were determined by HPGe detector with co-precipitation method. The median concentrations were 0.040 ± 0.005 Bq L −1 , 0.039 ± 0.004 Bq L −1 , and 0.049 ± 0.004 Bq L −1 . Highest MDC values were 0.028 Bq L −1 , 0.010 Bq L −1 , 0.018 Bq L −1 , respectively. It’s a strong relationship between 224 Ra, 228 Ra versus conductivity, salinity, TDS, SO 4 2− . The annual effective dose of the age groups was lower than the WHO recommended value except for infants exceeding around 1.5 times. Besides, the 226 Ra minimum recovery obtained was 90% with trueness 9.9% and relative percentage difference 6.1%.