Hygiene, sanitation, and water: forgotten foundations of health

Abstract

As the first article in a four-part PLoS Medicine series on water and sanitation, Jamie Bartram and Sandy Cairncross argue that the massive burden of ill health associated with poor hygiene, sanitation, and water supply demands more attention from health professionals and policymakers.

Figure 1. Contributions in DALYs of individual diseases to the total burden of ill-health preventable by improvements in HSW.

PEM, protein-energy malnutrition. Source: .

Figure 2. Results of reviews of the effect on diarrhoea of HSW interventions.

Results of the previous reviews are for the better quality studies. The reduction for household drinking water connections is in addition to reductions for water quality and availability of public sources. Previous reviews: (a), (c)–(f) ; (b) [11]). Fewtrell et al. .

Figure 3. Determinants of diarrhoea in Salvador, Brazil, 1997–2004: Results of a hierarchical effect decomposition analysis.

The width of each vertical bar shows the proportion of diarrhoea risk attributable to socioeconomic status and mediated by the intermediate variables shown. The two figures show conditions respectively (A) before and (B) after implementation of a major sanitation project. The project was associated with a 21% reduction in diarrhoea citywide, and 42% in the high incidence areas. Socioeconomic status accounted for 23% of the variance in diarrhoea rates before the project, but afterwards the strength of that link had been halved, to 11%. The proportion of that association mediated by intermediate variables, particularly sanitation, was also greatly diminished. Source: .

Figure 4. The cost to two national economies of inadequate HSW.

The “direct” effect is mortality attributable to these environmental risk factors, “indirect” effect includes mortality mediated by environmentally caused malnutrition, and “education” includes the effects of that malnutrition on (i) grade attainment; (ii) school achievement (learning productivity) in terms of grade equivalents; (iii) delayed primary school enrolment; and (iv) grade repetition. The latter two effects result in delayed labour force entry. Source: .

Figure 5. Health sector functions to secure environmental health.

Source: .