Household water treatment in poor populations: is there enough evidence for scaling up now?

Point-of-use water treatment (household water treatment, HWT) has been advocated as a means to substantially decrease the global burden of diarrhoea and to contribute to the Millennium Development Goals. To determine whether HWT should be scaled up now, the researchers reviewed the evidence on acceptability, scalability, adverse effects, and non-health benefits as the main criteria to establish how much evidence is needed before scaling up. These aspects are contrasted with the evidence on the effect of HWT on diarrhoea. They found that the acceptability and scalability of HWT is still unclear, and that there are substantial barriers making it difficult to identify populations that would benefit most from a potential effect. Environ Sci Technol. 2009;43(4):986-92. Review.