A Comparative Risk Approach to Assessing Point-of-Use Water treatment Systems in Developing Countries

Abstract

Unsafe water is a leadingcause of death and disease in economically disadvantaged societies. The development of centralized large-scale water treatment and supply systems has proven to be a slow, expensive strategy to provide safe drinking water in many low-income countries. Governments and non-governmental organizations have therefore increasingly been promoting point-of-use water treatment technologies in communities without reliable municipal water supplies. These technologies aim to be low-cost sustainable solutions that rely on filtration, disinfection and safe storage to improve source water quality. This paper uses a comparative risk assessment methodology to quantify the health and water quality impact of a point-of-use water treatment program being implemented in rural Haiti by a non-governmental organization. An observational study was used to measure diarrhea incidence in 120 families in the village of Dumay in Haiti. Univariate and multivariate statistical methods were used to (i) quantify the impact of the water treatment system in reducing the incidence of diarrhea, controlling for socio-economic differences in the population, and (ii) study the interaction of socio-economic factors and source water quality with filter use in diarrhea reduction. As part of the water quality impact assessment study, the microbial content of source water and stored water in intervention and non-intervention households was measured using membrane filtration tests. The comparative risk approach used in this study is designed to provide insights and inputs into environmental decision-making issues relating to resource allocation between competing gastro-intestinal disease reduction initiatives such as point-of-use water treatment systems, high-quality source water development projects, and household safe storage mechanisms.