Household water treatment: scaling-up is premature say researchers

Updated - Friday 13 March 2009

A critical review concludes that the widespread promotion of household water treatment (HWT) is premature given the available evidence. More research is needed before HWT can be recommended to policy makers and implementers, say Wolf-Peter Schmidt and Sandy Cairncross of the London School of Hygiene and Tropical Medicine (LSHTM) [1].

Agencies such as the World Health Organization (WHO) [2] and the Gates Foundation [3] are supporting initiatives that promote point-of-use or household water treatment as a means to substantially decrease the global burden of diarrhoea and to contribute to the Millennium Development Goals (MDGs). The researchers found that the acceptability and scalability of HWT is still unclear, and that it is hard to identify populations that would benefit most from a potential effect. The nonhealth benefits (especially savings in time and costs) of HWT are negligible. Health outcome trials suggest that HWT may reduce diarrhea by 30-40%, but it is possible that this is a result of responder and observer bias, selective reporting and publication bias. The researchers note that most of the health impact studies they reviewed involved tests of commercial products.

[1] Schmidt, W. and Cairncross, S. (2009). Household water treatment in poor populations : is there enough evidence for scaling up now? Environmental science & technology ; vol. 43, no. 4 ; p. 986–992. doi:10.1021/es802232w. Read the full review here

[2] WHO - International Network to Promote Household Water Treatment and Safe Storage

[3] Gates Foundation provided a US$ 24.6 million grant to PATH for their Safe Water Project (2006-2011)

Related news:

Marketing safe water systems : why it is so hard to get safe water to the poor – and so profitable to sell it to the rich, Source Weekly, 19 Feb 2009
Household treatment: study evaluates performance of ceramic filters, Source Weekly, 26 Feb 2008

Contact: Wolf-Peter Schmidt, Research Fellow in Epidemiology, London School of Hygiene and Tropical Medicine, UK, tel.: +44-20-79272461, Wolf-Peter.Schmidt@lshtm.ac.uk

Tags: scaling up, technology, water treatment

Comment from other visitors

[Camille Dow-Baker] Scaling up Household Water Treatment

Camille Dow-Baker 14 Apr 2011, 16:54

To The Editor of Source Weekly re: Household Water Treatment: Scaling up is premature say researchers. Dear Sir, As a non-profit educator and consultant in the field of water and sanitation for the poor for the last 7 years, I am moved to respond to your headline article of March 18 regarding household water treatment. This is because for every researcher that says promotion of household water treatment (HWT) is premature, I can point to thousands of poor mothers who have benefited... Read more

[Henk Holtslag] Publication HWT. Is there enough evidence for scaling up?

Henk Holtslag 14 Apr 2011, 16:54

Dear Wolf-Peter Schmidt I received your article via Mr Jo Smet and I would like to react. Some questions are 1. Conclusions are mostly based on results of disinfection as SODIS and Chlorination, Aguatabs etc. Pot filters and Biosand studies are hardly mentioned, why not? 2. It seems the new filter models as the Purit, family life straw and siphon were not considered. Why not? 3. Data are not correct, for instance on page 3 it mentions that ceramic filters are relatively slow... Read more

[Schmidt and Cairncross] Re: Publication HWT. Is there enough evindence for scaling up?

Wolf-Peter Schmidt and Sandy Cairncross 14 Apr 2011, 16:54

We thank Camille Dow Baker and Henk Holtslag for their comments on our article on household water treatment (HWT) in Environmental Science & Technology. This is the kind of debate we were hoping for when we wrote the article. Both colleagues believe that the currently available evidence is enough to recommend scaling up. However, public health has a long and unfortunate history of scaling up well-intended interventions that after rigorous evaluation at a later stage had to be abandoned. “... Read more

[Henk Holtslag] Re Publication HWT. Is there enough evidence for scaling up?

Henk Holtslag 14 Apr 2011, 16:54

Dear Wolf – Peter, Dear Sandy Thank you for your response I agree that too much excitement on HWT may result in reduced efforts of “cash strapped governments” to improve water access. Also that double blinded trails are needed for all HWT option. Who should do such trails? Maybe you can assist with a proposal for funding of such trials? I do less agree with your observation that the new filtration options with higher flow rates are not affordable for poor families. For instance the... Read more