A randomised intervention trial to assess two arsenic mitigation options in Bangladesh.

Arsenic groundwater contamination in Bangladesh warrants immediate remediation. This randomised controlled intervention trial was conducted to determine the effectiveness of two possible interventions: dug wells and three-pitcher filters. A total of 640 individuals participated with 218 randomised to the dug well group, 216 to the three-pitcher group and 206 to a control group. Data were collected at baseline and at 1, 6 and 12 months after the intervention. Self reported compliance with dug wells remained below 20% during the entire 12 months of the study. The compliance with the three-pitcher filters decreased after 6 months and became similar to the compliance of the dug well group after 12 months. A substantial decrease in urinary arsenic metabolites occurred only among those who were compliant with dug wells and three-pitcher filter systems after 1 month of intervention as opposed to control participants. However, a persistent reduction in urinary arsenic concentrations was observed only among the dug well users after 12 months of intervention. Our results show that a functional dug well could be offered as a long-term alternative to tube wells, but use of this option is likely to be low, unless appropriate behavioural change measures are taken. Our study also demonstrates that arsenic removal technologies such as three-pitcher filters are an effective option as a short-term measure. The three-pitcher filters that are not adequately maintained are not an effective option for a year. These arsenic removal technologies may be even harmful in the long term if the resultant water quality is not properly monitored.