Health aspects of the use of recycled water in Windhoek, SWA/Namibia, 1974-1983. Diarrhoeal diseases and the consumption of reclaimed water.

The introduction of the use of reclaimed water in Windhoek, SWA/Namibia, prompted an epidemiological study to assess the health effects, if any, of its consumption. Analysis of more than 15,000 episodes of diarrhoeal disease during the period August 1976-March 1983 showed that their incidence in whites of similar socio-economic status was marginally lower in persons supplied with reclaimed water than those with water from conventional sources. Incidence rates were significantly higher in blacks and in coloureds, all of whom received conventional water only. Age-specific incidence rates in children of the various ethnic groups also showed differences characteristically associated with socio-economic stratification. It is concluded that the consumption of reclaimed water does not increase the risk of diarrhoeal diseases caused by waterborne infectious agents.