Yesterday PLoS Medicine published an article by Daniel Maeusezahl and colleagues on their trial in Bolivia of SODIS, a solar disinfection method that aims to improve water quality and reduce the burden of diarrhea from unsafe drinking water. SODIS has been promoted and rolled out in communities all around the world on the basis of promising early laboratory studies.
But in this clinical trial, SODIS did not have an impact on diarrhea among children in the community; the methods, “negative” results, and policy implications of the study are described by the researchers in an outstanding SciVee video shot partly in Bolivia.
One of the main reasons why SODIS did not significantly reduce diarrhea, as had been expected, was low uptake among community members of the tool – which essentially involves filling plastic water bottles and placing them on rooftops to be exposed to the sun. Yesterday National Geographic News reported on the story and focused on the reasons why there was such low compliance.
The problem is not SODIS, which undoubtedly works, says the report. It’s that people are not using SODIS, partly because it may be associated with “stigma:”
“People do not want to put a SODIS bottle that is basically reused wastewater on their roofs. It’s a signal to everyone else in the community that you don’t have money for proper chlorination or a proper water supply.”
This suggests that future research needs to look at theories and mechanisms related to behavioural change, much like we do for smoking cessation and other health promotion activities.
It was partly the submission of Dr. Maeusezahl’s article that got us at PLoS Medicine thinking about the water crisis, which then led to us editorialising that water should be a human right. Since then I’ve avoided water bottles too.