Global study reveals extent of pharmaceutical pollution in world’s rivers

A new study looking at the presence of pharmaceuticals in the world’s rivers has found concentrations at potentially toxic levels in more than a quarter of the locations surveyed.

The new study examined 258 rivers around the world, including the Thames in London and the Amazon in Brazil, to measure the presence of 61 pharmaceuticals, such as carbamazepine, metformin and caffeine.

The researchers studied rivers in more than half of the countries in the world, with rivers in 36 of those countries having never been monitored for pharmaceuticals.

The study is part of the University of York-led Global Pharmaceuticals Surveillance Project, which has grown significantly over the past two years, with the new study becoming the first truly global survey of contamination. medicine in the environment.

With their latest study, the researchers found that:

  • pharmaceutical pollution contaminates water on all continents
  • strong correlations between a country’s socio-economic status and higher pollution from pharmaceuticals in its rivers (lower-middle-income countries being the most polluted)
  • high levels of pharmaceutical pollution were more positively associated with regions with high median ages as well as high local unemployment and poverty rates
  • the most polluted countries and regions of the world are those that have been studied the least (namely sub-Saharan Africa, South America and parts of South Asia).
  • Activities most associated with the highest levels of pharmaceutical pollution included dumping garbage along riverbanks, insufficient sewage treatment and pharmaceutical manufacturing infrastructure, and dumping the contents of residual septic tanks into the rivers.

The study found that a quarter of the sites contained contaminants (such as sulfamethoxazole, propranolol, ciprofloxacin and loratadine) at potentially harmful levels.

The researchers hope that by increasing the monitoring of pharmaceuticals in the environment, they can develop strategies to limit the effects potentially caused by the presence of pollutants.

The study included notable rivers such as the Amazon, Mississippi, Thames and Mekong. Water samples were taken from sites ranging from a Yanomami village in Venezuela, where modern drugs are not used, to some of the most populated cities on the planet, such as Delhi, London, New York, Lagos , Las Vegas and Guangzhou.

Areas of political instability such as Baghdad, the Palestinian West Bank and Yaoundé in Cameroon were also included. The climates where the samples were obtained ranged from the high altitude alpine tundra of Colorado and the polar regions of Antarctica to the deserts of Tunisia.

While previous studies have monitored active pharmaceutical ingredients (APIs) in rivers, these ignored many countries around the world, typically measured only a few selected contaminants, and used different analytical methods. Cumulatively, this has made it difficult to quantify the scale of the problem from a global perspective.

Analysis of the water sample took place at the Center of Excellence in Mass Spectrometry at the University of York.

Project co-lead, Dr John Wilkinson, Department of Environment and Geography, said: “With 127 collaborators in 86 institutions around the world, the Global Pharmaceuticals Surveillance Project is an excellent example of how the global scientific community can come together to tackle large-scale environmental problems.

“We have known for more than two decades now that pharmaceuticals enter the aquatic environment where they can affect the biology of living organisms. But one of the biggest problems we have faced in solving this problem is that we don’t We have not been very representative when monitoring these contaminants, with almost all of the data concentrated in a few selected areas in North America, Western Europe and China.

“Thanks to our project, our knowledge of the global distribution of pharmaceuticals in the aquatic environment has improved significantly. This study presents data from more countries around the world than the entire scientific community does. knew before: 36 new countries to be precise. where only 75 had already been studied before.”

The researchers suggest that their approach could also be extended in the future to include other environmental media such as sediments, soils and biota, and could enable the development of global scale pollution datasets. .

” is published in Proceedings of the National Academy of Sciences (PNAS).

Data for specific rivers will be available in the additional information associated with the release (via PNAS). It will also be posted on the Global Monitoring of Pharmaceuticals Project website.

The study used “predicted no-adverse-effect concentrations (PNECs)” to determine where there may be a risk of harmful effects (such as toxicity). If the team measured a concentration in the environment above the PNEC, then there was a potential for organisms living there to be negatively affected by the pharmaceutical. This can manifest in several ways depending on the nature of the drug product, the organism exposed and the concentration. Examples can include disrupted reproductive abilities, altered behavior or physiology, and even changes in heart rate.

Contaminants found in potentially harmful concentrations include:

  • propranolol (a beta-blocker for heart problems such as high blood pressure)
  • sulfamethoxazole (an antibiotic for bacterial infections)
  • ciprofloxacin (an antibiotic for bacterial infections)
  • loratadine (an antihistamine for allergies)