Water pollution has risen across three continents, placing hundreds of millions of people at risk of contracting life-threatening diseases like cholera and typhoid, as the United Nations Environment has warned.
The worrying rise in the pollution of surface waters in Asia, Africa and Latin America also threatens to damage vital sources of food and harm the continents’ economies, says UN Environment in its latest report, Snapshot of the World’s Water Quality.
As Jacqueline McGlade, chief scientist of UN Environment, said, “The increasing amount of wastewater being dumped into our surface waters is deeply troubling. Access to quality water is essential for human health and human development. Both are at risk if we fail to stop the pollution.”
Population growth, increased economic activity, the expansion and intensification of agriculture, and an increase in the amount of untreated sewage discharged into rivers and lakes are the main reasons behind the troubling rise in surface water pollution in Asia, Africa and Latin America.
Pathogen pollution and organic pollution rose in more than 50% of river stretches from 1990-2010 on all three continents, while salinity pollution has risen in nearly one third, the UN report finds.
Severe pathogen pollution, the rise of which is largely down to the expansion of sewer systems that discharge untreated wastewater into surface waters, is estimated to affect around a quarter of Latin American river stretches, around 10 to 25% of African river stretches and up to one-half of Asian river stretches.
In some countries, more than 90% of the population relies on surface waters as their source of drinking water. These waters – also used to prepare food, to irrigate crops and for recreation – pose a major threat to human health when contaminated.
About 3.4mn people die each year from diseases associated with pathogens in water, including cholera, typhoid, infectious hepatitis, polio, cryptosporidiosis, ascariasis and diarrheal diseases. Many of these diseases are due to the presence of human waste in water.
UN Environment estimates that up to 25mn people are at risk of infection from these diseases in Latin America, up to 164mn in Africa and up to 134mn in Asia.
Severe organic pollution, which is caused when large amounts of decomposable organic compounds are released into water bodies, now affects around one out of every seven kilometres of all river stretches in Latin America, Africa and Asia.
Agriculture has intensified and expanded as the world seeks to meet the growing food demands of a booming population. This has led to an increase in the amount of phosphorus from fertilisers and pesticides that pollute waterbodies.
Better water monitoring, especially in developing countries, is needed to understand the scale of the challenge around the world and to identify key hotspots.

About 3.4mn people die each year from diseases associated with pathogens in water