Solar Disinfection (SODIS) of Drinking Water for Use in Developing Countries or in Emergency Situations

Overview

SODISWATER was a health impact assessment study investigating the effect of sunlight to inactivate microbial pathogens in drinking water. This study was carried out by observing whether children younger than 5 years old who drink solar disinfected water were healthier than those who did not. Health was measured by how often the children had diarrhoea or dysentery. Caregivers for the participants were given plastic bottles to place in the sun, water samples were then collected from these plastic bottles to be analyzed. They were also requested to fill in diarrhea diaries. TESTABLE RESEARCH HYPOTHESES: Health Impact Assessment: Children who use solar disinfected water will have: (a) lower morbidity due to non-bloody diarrhoea and bloody diarrhoea (c) increased growth rates (d) lower mortality (e) increased family productivity (f) decreased care-giver burden (g) increased school attendance

The current evidence base for solar disinfection in the prevention of diarrhoeal disease in children rests on three published studies. All share two significant weaknesses: all were carried out in Kenya, in communities which have very high incidences of diarrhoeal disease and water characterised by high levels of both turbidity and microbial contamination. Furthermore, neither of the studies of diarrhoeal disease distinguished between dysentery (associated with significant risk of mortality) and other sorts of diarrhoea, which carry a far lower risk. The present study will extend the evidence base into communities at lower risk and with higher water quality. Furthermore, by using pictorial diaries, dysentery can be analysed as a specific health endpoint. Diarrhoea will be recorded consistent with the World Health organisation definition: three or more loose or watery stools in a 24-hour period and/or stools containing blood or mucus. AIM OF THE PROJECT IN RELATION TO HEALTH IMPACT ASSESSMENT STUDIES: The primary aim of the SODISWATER PROJECT is to demonstrate that SODIS is an appropriate intervention against diarrhoeal and waterborne disease among communities in developing countries and those affected by natural or man-made disasters by conducting multi-centred epidemiologically controlled Health Impact Assessments of the SODIS technique across the African Continent under a variety of social, geographical and climactic conditions. SCIENTIFIC OBJECTIVES OF SODISWATER IN RELATION TO HEALTH IMPACT ASSESSMENT STUDIES: 1. Assessment of the change in health reasonably attributed to the provision of solar disinfected drinking water at the point of use in 3 countries (Kenya, Zimbabwe and Cambodia). 2. Assessment of the relationship between solar disinfected drinking water and selected health indicators (including morbidity due to non-bloody diarrhoea and dysentery, weight loss, mortality, growth rates, productivity, care-giver burden, and school attendance. Mortality will also be monitored but the sample sizes are of insufficient size to produce detailed information and scaling up, to account for this is not possible due to prohibitive costs). 3. Demonstration of the effectiveness of SODIS at household level.