Stephen Luby, MD, and his fellow researchers knew that finding a large-scale method for disinfecting water in developing countries would reduce rates of diarrhea -- and associated deaths -- in children. The challenge was nailing down the logistics for achieving this goal.
In a paper published this week in The Lancet Global Health, Luby and his collaborators report on a solution that shows promise.
A Stanford News story frames the problem:
In developing countries, few cities are able to maintain fully pressurized water systems that consistently pump water around the clock. Even if it is safe at the source, water in these systems is at risk of becoming contaminated while sitting in pipes. About 1 billion people who access water via piped systems receive water that does not meet international standards for safety.
Thus far, no potential solution has been completely effective. People often balk at the taste and odor of chlorine in their drinking water, and most treatment devices require burdensome tasks of collection from a community tap and disinfection at home, according to the article.
Luby's team tried out a device called Aquatabs Flo, which automatically doses a precise amount of chlorine into water at community pumps. They worked with the residents of two poor communities in Dhaka, Bangladesh, to calibrate the dosers to inject an acceptable amount of chlorine. As the news release reports:
[T]he researchers polled Dhaka residents to find out how much chlorine could remain in the water without being objectionable. Then, they set the chlorine dosers to deliver low levels of chlorine the first few months so people would get used to the taste. Later, they upped that amount to a level that purified the water effectively but remained acceptable taste-wise. The treated water was more than four times less likely to contain E coli., a bacterium that indicates sewage contamination.
To test whether their water hack made a difference to children's health, the researchers compared results in communities where the Aquatabs Flo device delivered chlorine to outcomes in communities where vitamin C was dispensed into the water instead. According to the news release:
Out of 1,000 children, the ones who received the chlorinated water had 23% lower rates of diarrhea. While the result may seem obvious, previous studies had been ambiguous either because people didn't consistently use the household chlorination systems being tested or because the studies weren't able to compare to communities without water treatment.
Luby, a professor of medicine and the study's senior author, was optimistic about the results, saying, "it offers the prospect for extending safe drinking water to vulnerable slum residents globally."
Lead author Amy Pickering, an assistant professor of civil and environmental engineering at Tufts University who received her PhD at Stanford, also was upbeat.
"The study demonstrated that this simple, electricity-independent technology could be transformative in scaling up water treatment in slums and reducing child diarrhea, without requiring people to do anything differently when they collect their drinking water," Pickering said.
Photo by GMB Akash