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All the newsHuman health and the pollution of rivers by antibiotics: a global problem
Increasing bacterial resistance to antibiotics is a global health risk that may kill 10 million people by 2050 according to the UN. Rivers could play in role in increasing this risk, since antibiotic pollution in the environment is the main source of development of resistant genes in humans.
The first study at international level
A huge study carried out by the University of York and presented last May at a conference organised by SETAC (Society of Environmental Toxicology and Chemistry) at Helsinki, gave data on the worldwide scale for the first time: 711 river sites were tested in 72 countries to measure the presence of 14 commonly used antibiotics. The results are damning: 65% of these sites are contaminated by drugs released into rivers via discharges from wastewater treatment plants and factories, faeces and natural runoff. More than a hundred recorded a concentration in antibiotics higher than safety standards. In the most serious cases, these concentrations exceeded the safety threshold by more than 300 times. This was the case of a site in Bangladesh with metronidazole, a antibacterial drug used to treat skin and oral infections.
In these areas in particular, bacteria evolve to adapt and resist these substances.
Africa and Asia are hardest hit
Low income countries have the highest concentrations of antibiotics, notably in Africa and Asia. They often do not have the technology required to eliminate antibiotics in their wastewater treatment installations. 35% of the sites tested in Africa exceeded safety levels.
But the great European rivers are also affected, such as the Danube and the Thames. And although the concentrations are low, they can lead to changes in resistance and increase the risk of transferring resistance genes to agents pathogenic to humans, according to William Gaze, a researcher specialised in microbial resistance.
This pollution by antibiotics also has an impact on fauna, though this remains to be assessed. Faced by the propagation of mutant bacteria in rivers, the University of York has pointed to several paths of action: better drainage and better treatment of wastewater; the recovery of unused drugs by pharmacies to ensure better treatment of dangerous wastes and limiting the consumption of antibiotics.