Control and protection

D. McChesney and R. Taylor The safe disposal of human excreta is essential for public health protection. The unsafe disposal of excreta is a principal cause of the transmission of pathogens within the environment and improvements in excreta management provide significant reductions in diarrhoeal disease (Esrey et al., 1991; Esrey, 1996; Hutton and Haller, 2004). Access to improved sanitation lags behind access to water supply throughout much of the world and in particular within developing countries. It is estimated that over twice the number of people lack access to improved sanitation than lack access to an improved water supply (WHO and UNICEF, 2004). Excreta disposal technologies may represent a risk to groundwater and inappropriate design, siting and maintenance of sanitation facilities can contaminate groundwater and thus lead to public health risks from drinking-water. Chapter 10 provides an overview of these risks and how these may be assessed. However, the health risks from the absence of improved excreta disposal are likely to exceed those posed by contamination of groundwater from sanitation alone, and this must be borne in mind when planning improvements in sanitation and groundwater protection. Furthermore, the lack of excreta disposal may be a direct cause of contamination of groundwater sources and improvements in sanitatio