Water Quality and Human Health
Water Quality and Human HealthThe distribution of water-rich and water-poor regions is of course not the whole story – access to clean water isn’t just about the amount of water that falls as precipitation. It’s also about the infrastructure needed to obtain, treat, transport, and deliver potable water. And that’s just the water supply. Disposal and sanitation of dirty water are equally important and require a means of transporting waste away from the distributed sources, collecting it and treating it, and discharging it safely. Ideally, both supply and waste conveyance systems should also be monitored for performance and for their impacts on water quality.
In some areas, water is plentiful, but access to clean water is not (Figures 7-8). The converse is also true, mainly in developed nations where water projects, desalination, or dams provide a water supply to regions that receive little precipitation. There is also a clear distinction between access to clean water in rural and urban areas (Figure 7), wherein access in rural areas, even in developed nations, lags behind that in urban areas.
Figure 7: Access to clean water supply and sanitation in urban and rural areas. Note that rural areas lag behind urban ones in access to clean water and sanitary disposal, and developing nations lag behind developed ones.
| Year | Status | Water Supply | Improved Sanitation |
|---|---|---|---|
| 1990 | World | 95% | 79% |
| 1990 | Developing | 92% | 61% |
| 2004 | World | 96% | 80% |
| 2004 | Developing | 91% | 70% |
| Year | Status | Water Supply | Improved Sanitation |
|---|---|---|---|
| 1990 | World | 63% | 26% |
| 1990 | Developing | 61% | 19% |
| 2004 | World | 72% | 39% |
| 2004 | Developing | 70% | 35% |
Access to clean water differs between rural and urban areas, and between developed and developing nations. In general, in rural areas, even in developed nations, access to water and sanitation lags behind that in urban areas. Globally, the areas with the poorest access to clean drinking water are in equatorial and sub-Saharan Africa, and parts of South America and southeast Asia (Figure 8).
One might imagine that access to clean water and sanitation would be strongly correlated with water-related illnesses and death. For example, compare the maps in Figures 8 and 9.
