One in four of the world’s rivers are polluted with potentially toxic levels of pharma compounds, according to a new study form University of York in England.
In the first truly global investigation into the issue, scientists measured the concentration of 61 active pharmaceutical ingredients (APIs) at more than 1,000 sites along 258 rivers spanning every continent – 104 countries in total.
The study included noteworthy rivers such as the Amazon, Mississippi, Thames and the Mekong. Water samples were obtained from sites spanning from a Yanomami Village in Venezuela, where modern medicines 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 samples were obtained varied from high altitude alpine tundra in Colorado and polar regions in Antarctica, to Tunisian deserts.
Hotspots of pharmaceutical pollution were found around the world, particularly in areas with large populations or poor wastewater management. Lahore in Pakistan had the highest average API concentration, followed by La Paz in Bolivia and Addis Ababa in Ethiopia, while major cities including Madrid, Glasgow, and Dallas were above the 80th percentile.
Environmental exposure to APIs can have negative effects on the health of ecosystems and humans. The most frequently detected APIs were an anti-epileptic drug, carbamazepine, which is hard to break down, the diabetes drug metformin, and caffeine. All three were found in at least half of the sites. Antibiotics were found at dangerous levels in one in five sites and many sites also had at least one API at levels considered harmful for wildlife, with effects such as feminising fish.
It’s not the first time that pharma ingredients have been found in the world’s waterways, but is the largest and most comprehensive assessment of pharmaceutical pollution to date, according to the international research team that spanned 86 academic groups.
The full report has been published in the Proceedings of the National Academy of Sciences journal.