SOURCE: The Guardian

DATE: May 27, 2019

SNIP: Hundreds of rivers around the world from the Thames to the Tigris are awash with dangerously high levels of antibiotics, the largest global study on the subject has found.

Antibiotic pollution is one of the key routes by which bacteria are able develop resistance to the life-saving medicines, rendering them ineffective for human use. “A lot of the resistance genes we see in human pathogens originated from environmental bacteria,” said Prof William Gaze, a microbial ecologist at the University of Exeter who studies antimicrobial resistance but was not involved in the study.

The rise in antibiotic-resistant bacteria is a global health emergency that could kill 10 million people by 2050, the UN said last month.

The drugs find their way into rivers and soil via human and animal waste and leaks from wastewater treatment plants and drug manufacturing facilities. “It’s quite scary and depressing. We could have large parts of the environment that have got antibiotics at levels high enough to affect resistance,” said Alistair Boxall, an environmental scientist at the University of York, who co-led the study.

The research, presented on Monday at a conference in Helsinki, shows that some of the world’s best-known rivers, including the Thames, are contaminated with antibiotics classified as critically important for the treatment of serious infections. In many cases they were detected at unsafe levels, meaning resistance is much more likely to develop and spread.

The researchers tested 711 sites in 72 countries and found antibiotics in 65% of them. In 111 of the sites, the concentrations of antibiotics exceeded safe levels, with the worst cases more than 300 times over the safe limit.

The research team is now planning to assess the environmental impacts of antibiotic pollution on wildlife including fish, invertebrates and algae. They expect severe effects. The drug levels in some Kenyan rivers were so high that no fish could survive.