Climate security

Climate change could poison Earth's lakes and rivers with toxic pathogens, experts warn

The new study in the journal Scientific Reports, led by Miami University in Ohio, analyzed water samples.

Scientists have already measured an increase in 'browning' of the world's waters, a phenomenon caused by more organic matter washing in from the surrounding land. 

Not only does an increase in dissolved organic matter make it more difficult for sunlight to disinfect bodies of water, it also makes it more difficult for water treatment plants to work effectively, said lead author Craig Williamson, a Miami University ecologist. 

In the United States, 12 to 19 million people already become ill from waterborne pathogens annually.

'Water clarity is dropping in many regions due to factors such as browning, and this research demonstrates that this change is likely decreasing natural disinfection of potentially harmful pathogens,' said Kevin Rose of Rensselaer, who gathered much of the data on dissolved organic matter in water samples to assess the potential of UV radiation to kill pathogens.