Alistair Boxall, 58, is a chemist and professor of environmental science at the University of York. In 2022, he helped lead the largest study ever conducted on pharmaceutical pollution in rivers around the world. Boxall is now leading a new monitoring project covering 93 rivers in 31 European countries. Among them are the Manzanares, Jarama, Henares and Pantueña streams in the Madrid region, as well as the Zadorra and Nervión rivers in Álava.
Boxall was recently in Vitoria, working with a research team from the University of the Basque Country (EHU), which is responsible for collecting samples from rivers in the region and sending them to York laboratories for analysis.
Question. What did you find in this new study?
Answer. The main finding is that we have detected very widespread contamination of rivers by pharmaceuticals and PFAS [per- and polyfluorinated substances] across Europe, even in fairly remote areas such as rivers in Iceland.
Q. And in Spain?
A. When we look at average pharmaceutical concentrations across Europe, Spain ranks quite high. It is in second place, after Romania. Looking within Spain, and indeed across Europe, the Henares River in Alcalá de Henares is one of the most polluted sites in the study. I think that is because that area has a fair amount of industry. It was also the river with the highest pharmaceutical risk — in other words, the river with the most unsafe levels of pharmaceuticals in the entire study. That was mainly due to very high concentrations of antibiotics, much higher than in other locations. The Nervión River, in Amurrio, also showed high pharmaceutical concentrations.
Q. Is the situation worrying?
A. Yes. One of the problems is that in Europe, the way chemicals are regulated is by looking for fewer than 50 substances in rivers. That is the number of chemicals that are monitored and compared against what we call quality standards. The problem is that, as a society, we use about 350,000 chemical substances, so regulation is only looking at the tip of the iceberg. We are beginning to realize that many chemicals are not monitored or regulated and are likely causing environmental harm and possibly affecting human health as well.
Q. Do we need new regulation?
A. Possibly new regulation, but perhaps we need to think more carefully about the types of chemicals we regulate and how we regulate them. The concern with medicines is that they are designed to be what we call biologically active — that is, designed to enter the human body and produce an effect. That is the therapeutic effect. The problem is that the receptors that exist in humans are also present in environmental organisms — in fish, invertebrates and algae. If these chemicals reach the environment, they are likely to cause some kind of effect on the local ecology.
Q. What effects?
A. Based on laboratory studies, we believe the effects these substances are likely causing in rivers include changes in the behavior of organisms such as fish, impact on reproduction and perhaps on growth. We are also concerned about molecules such as antibiotics, which could be promoting antimicrobial resistance. That makes antibiotics less effective when humans get an infection. In 2019, antimicrobial resistance was estimated to have caused 1.2 million deaths worldwide, and that figure is expected to rise. We are beginning to see that the environment is probably playing a role in the development of that resistance. It does not explain all those deaths, but it likely contributes to them.
Q. Which drugs were most frequently found in European rivers in this latest study?
A. We see a mix of substances. For example, we found caffeine very widely. We also detected cotinine, which is a breakdown product of nicotine. Among molecules that are pharmaceuticals, metformin is the most abundant chemical. It is used to treat type 2 diabetes, and its presence reflects how widespread that disease is in the population, as well as the high doses patients receive. Another molecule we frequently found is sulpiride, an antipsychotic drug. And carbamazepine, which is used to treat epilepsy, among other conditions.
Q. You mentioned PFAS, the so-called “forever chemicals” that do not break down easily. What does the study say?
A. We detected PFAS, as expected, because they are everywhere. We found them in almost every sample we analyzed. The concentrations themselves are fairly low. But the problem is that the proposed safety limits for PFAS are also very low, so we are in a situation where a number of European rivers show worrying PFAS concentrations.
Q. How do pharmaceutical drugs get into rivers?
A. The main route for humans is that when we take a medication, it enters our bodies and is absorbed, but we eventually excrete it—it is eliminated in our urine and feces. When we use the bathroom, it goes into the sewer system and usually ends up in the nearest river. The problem is that wastewater treatment plants are not designed to remove pharmaceuticals.
Q. And how can we protect rivers?
A. There are several things we can do. We could consider changing the medicines we use. For example, when we know a drug poses a potential environmental risk, we could consider using an alternative medication. We could also improve wastewater treatment. There are methods that can be applied at treatment plants that remove many of these medicines. The problem is that it costs a lot of money. And, in the longer term, I think pharmaceutical companies could consider designing drugs that are less harmful to the environment — drugs that still deliver the therapeutic effect required but cause less environmental damage.
Q. After so many years studying chemical pollution in rivers, is there anything you’ve discovered that has particularly surprised or worried you?
A. We know that rivers are heavily polluted by chemical substances. We know many of those substances are at levels that are likely causing harm to rivers. What surprises me, I suppose, is that we do nothing about it. It is something we have known for a long time, and policies and regulations seem to move so slowly that we never manage to solve the problem.
Q. You are in Vitoria to work with a research group from EHU University that monitored rivers in the study. They are pharmacists. Is this common in the profession?
A. I think Gorka and Unax [Gorka Orive and Unax Lertxundi, researchers and promoters of sustainable pharmacy] are quite unique. There are pharmacists who are increasingly interested in the environment, but it is still a fairly small part of the profession, and the work being done in Vitoria is truly world-leading from a pharmaceutical perspective. We need more of that. We need to involve pharmacists and doctors and make them aware of the relationship between the products they give patients and the natural environment. And we have to work together if we want to solve the problem.
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