More than half the rivers of Asia, Africa and Latin America have become more dangerous in the last 20 years, with steep rises in organic and pathogen pollution. According to a new UN study, more than 300 million people on the three continents are at risk from water-borne diseases. The latest UN Environment Programme report on water quality argues that the “worrying” rise in pollution is a threat to vital food sources and to the economic wellbeing of three continents.
Around 3.4 million people die each year from water-borne diseases such as cholera, typhoid, infectious hepatitis, polio, cryptosporidiosis and other infections, and many of these diseases are linked to human excrement in water. In Latin America, 25 million people could be at risk; in Africa, 164 million; and in Asia, 134 million.
One of every seven kilometres of all river stretches in the three continents is now affected by severe organic pollution. Saline wastewater from mines, irrigation systems and homes already affects a tenth of all river stretches and makes it even harder for the poorest farmers to irrigate their crops. Between 1990 and 2010, this increased in almost a third of all rivers on the three continents. More than half of the phosphorus load in 23 out of 25 of the world’s major lakes was delivered by humans from fertilisers, pesticides, livestock waste and human sewage.