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A few health impact studies are starting to emerge on the biosand filter. These look at how much impact the filters have on diarrhoea in real life situations. So far, results are encouraging and confirm the anecdotal evidence that many of us hear from sand filter users in the field.
A 6-month study carried out by Stauber et al (2006, [ref_01]) in the Dominican Republic during 2005-06 was the first health impact study to be done on the household biosand filter. The results showed that the 75 households that used the biosand filter had 0.53 times the odds of diarrhoeal disease as control households (or 47% reduced risk), indicating a significant protective effect of the BSF against waterborne diarrheal disease.
Work carried out during 6 months in 2007 in rural Kenyan households by Tiwari et al (2009, [ref_02]) found that households using biosand filters had a 54% reduction in child diarrhoea days compared to control households.
References: (jump back)
Ref 01: Stauber, C.E.; Ortiz, G.M.; Loomis, D.P.; Sobsey, M.D. (2009). A randomized controlled trial of the concrete biosand filter and its impact on diarrheal disease in Bonao, Dominican Republic. American Journal of Tropical Medicine and Hygiene, 2009 Feb; 80(2): 286-93. Abstract available here.
Ref 02: Tiwari, S.K.; Schmidt, W-P.; Darby, J.; Kariuki, Z. G.; Jenkins, M.W. (2009). Intermittent slow sand filtration for preventing diarrhoea among children in Kenyan households using unimproved water sources: randomized controlled trial. Tropical Medicine and International Health, Volume 14 no 11 pp 1–9 November 2009. Abstract available here. |
