Recently a study was launched globally to find the presence of pharmaceuticals in rivers and other water bodies. It has been found that the concentrations of such chemicals are at potentially toxic levels in more than one-fourth of the locations that were studied.
Around 258 rivers across the globe were studied, including The Thames River in London and the Amazon in Brazil. The study focused on measuring the presence of predominantly 61 pharmaceuticals, such as carbamazepine, metformin and caffeine.
The researchers undertook the studies of rivers in more than half of the world’s countries. Until now, out of all these, the rivers in almost 36 of these countries have never been monitored for pharmaceuticals.
The study is a part of the University of York-led Global Monitoring of Pharmaceuticals Project. In the last two years, the study has grown substantially, with the recent study becoming the first global-scale analysis of medicinal contamination in the environment.
In the recent study, medical contamination was found in rivers on every continent. The study reveals strong correlations between the socioeconomic status of a country and the pharmaceutical pollutants in its rivers. The lower-middle-income countries were found to be the most polluting.
It was found that the high levels of medical contamination were more categorically associated with regions having high median age along with high unemployment and poverty rates. The countries and regions that have undertaken the least research have been found to be the most polluting, countries such as sub-Saharan Africa, South America and parts of southern Asia.
Dumping the rubbish along river banks, inadequate infrastructure for pharmaceutical manufacturing and wastewater disposal, and dumping the contents of residual tanks into rivers has been found to be the activities that are most associated with the high levels of pharmaceutical pollution.
The research revealed that almost one-fourth of the sites that were studied contained contaminants such as sulfamethoxazole, propranolol, ciprofloxacin and loratadine at possibly harmful concentrations.
The Extent of Pharmaceutical Pollution
The researchers feel that by increasingly monitoring the release of pharmaceuticals in the environment, effective strategies can be developed to limit the presence of pollutants in the environment.
The study included some of the significant rivers such as the Amazon, Mississippi, Thames and the Mekong. Water samples were obtained and tested from a Yanomami Village in Venezuela, where modern medicines are not used, with some of the topmost populated cities on the planet, namely Delhi, London, New York, Lagos, Las Vegas, and Guangzhou.
Regions marked with political instability were also included in the study, regions such as Baghdad, the Palestinian West Bank and Yaoundé in Cameroon. Water samples were obtained from high altitude alpine tundra in Colorado, to polar regions in Antarctica, to Tunisian deserts.
The earlier studies monitored Active Pharmaceutical Ingredients (APIs) in water and ignored many countries of the world, by focusing the study on a selected few. Earlier just a select few contaminants were studied and used different analytical methods. The earlier approach made it difficult to figure out the extent of the problem from a global perspective.
Dr John Wilkinson, the co-leader of the project from the Department of Environment and Geography, said that the 127 collaborations across 86 institutions globally for the Global Monitoring of Pharmaceuticals Project, sets an example as to how the global scientific community can come together to tackle large-scale environmental issues.
He said that it is well-known for over two decades that pharmaceuticals finally make their way into the rivers and seas. But one of the big problems in tackling this matter was that it was not on a global scale and almost all of the data focused on a select few regions in North America, Western Europe and China.
Because of this project, our knowledge of the global distribution of pharmaceuticals in the water bodies has considerably been enriched now. Also, the study represents data from 36 new countries too, rather than just the 75 countries that had been studied till now, he further added.
The study incorporated ‘predicted no adverse effect concentrations (PNECs)’ to find if there may be a risk of adverse effects (such as toxicity). If the medical contamination was found above the PNEC levels, then there were risks for organisms living there to be adversely affected by the pollutants. This can come out in multiple ways depending on the pharmaceutical the organism is exposed to and at what concentrations. Some of the adverse effects can be disrupted reproductive capabilities, changed behaviour or physiology and as well as changes in heart rate.
The pharmaceutical contaminants found at potentially harmful concentrations are propranolol (is a beta-blocker for heart problems such as high blood pressure), sulfamethoxazole (is an antibiotic for bacterial infection), ciprofloxacin (an antibiotic for bacterial infection) and loratadine (an antihistamine for allergies).
Journal Reference: Pharmaceutical pollution of the world’s rivers. Proceedings of the National Academy of Sciences, 2022; 119 (8): e2113947119 DOI: 10.1073/pnas.2113947119
