Flocculant-disinfectant point-of-use water treatment for reducing arsenic exposure in rural Bangladesh

Abstract

We introduced flocculant-disinfectant water treatment for 12 weeks in 103 households in Bangladesh to assess if drinking water would be chemically and microbiologically improved and the body burden of arsenic reduced. The median concentration of arsenic in tubewell water decreased by 88% after introduction of the flocculant-disinfectant from 136 μg/l at baseline to 16 (p < 0.001). The median concentration of total urinary arsenic decreased 42% from 385 μg/g creatinine at baseline to 225 μg/g creatinine after intervention (p < 0.001). Among 206 post-intervention drinking water samples that were reportedly treated on the date the sample was collected, 99 (48%) lacked residual free chlorine and 100 (49%) were contaminated with thermotolerant coliforms. The flocculant-disinfectant markedly reduced arsenic in drinking water, but treated drinking water was frequently contaminated with fecal organisms. The lesser reduction in urinary arsenic compared to water arsenic and the health consequences of this reduction require further research.

Keywords:

• arsenic poisoning
• water supply
• water purification
• urine
• Bangladesh

Acknowledgements

We are indebted to Hashina Akter, Morzina Akter, Suporna Das, Sheuli Rani Dey, Nasreen Farzana, Fatema Khatun and Anutzupa Paul for their assistance in working with the community and collecting the data. This research study was funded by the Proctor and Gamble Company and the Centers for Disease Control and Prevention (CDC).