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

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