Arsenic and other trace elements in groundwater and human urine in Ha Nam province, the Northern Vietnam: contamination characteristics and risk assessment.

Abstract

The contamination characteristics of arsenic and other trace elements in groundwater and the potential risks of arsenic from the groundwater were investigated. Elevated contamination of arsenic, barium and manganese was observed in tube-well water of two villages (Chuyen Ngoai and Chau Giang) in Ha Nam province in the Northern Vietnam. Concentrations of As in the groundwater ranged from 12.8 to 884µg/L with mean values in Chuyen Ngoai and Chau Giang were 614.7 and 160.1µg/L, respectively. About 83% of these samples contained As concentrations exceeding WHO drinking water guideline of 10μg/L. The mean values of Mn and Ba in groundwater from Chuyen Ngoai and Chau Giang were 300 and 657μg/L and 650 and 468μg/L, respectively. The mean value of Ba concentration in groundwater in both Chuyen Ngoai and Chau Giang was about 22% of the samples exceeded the WHO guideline (700µg/L). Arsenic concentrations in human urine of residents from Chuyen Ngoai and Chau Giang were the range from 8.6 to 458µg/L. The mean values of Mn and Ba in human urine of local people from Chuyen Ngoai were 46.9 and 62.8μg/L, respectively, while those in people from Chau Giang were 25.9 and 45.9μg/L, respectively. The average daily dose from ingesting arsenic for consuming both untreated and treated groundwater is from 0.02 to 11.5 and 0.003 to 1.6μg/kgday, respectively. Approximately, 57% of the families using treated groundwater and 64% of the families using untreated groundwater could be affected by elevated arsenic exposure.