Facts and Figures
Water pollution is on the rise globally
Virtually all goods-producing activities generate pollutants as unwanted by-products.
The most important water contaminants created by human activities are microbial pathogens, nutrients, oxygen-consuming materials, heavy metals and persistent organic matter, as well as suspended sediments, nutrients, pesticides and oxygen-consuming substances, much of it from non-point sources. Heat, which raises the temperature of the receiving water, can also be a pollutant. Pollutants are typically the cause of major water quality degradation around the world.
Globally, the most prevalent water quality problem is eutrophication, a result of high-nutrient loads (mainly phosphorus and nitrogen), which substantially impairs beneficial uses of water.
Projected food production needs and increasing wastewater effluents associated with an increasing population over the next three decades suggest a 10%-15% increase in the river input of nitrogen loads into coastal ecosystems, continuing the trend observed during 1970-95.
More than 80% of sewage in developing countries is discharged untreated, polluting rivers, lakes and coastal areas.
Many industries – some of them known to be heavily polluting (such as leather and chemicals) – are moving from high-income countries to emerging market economies.
Despite improvements in some regions, water pollution is on the rise globally.
World Water Assessment Programme. 2009. The United Nations World Water Development Report 3: Water in a Changing World. Paris: UNESCO, and London: Earthscan. Table 8.1, page 137.
Related themes: Ecosystems; State of the Resource; Water, Sanitation and Health; Uncertainty and Risk; Industry