Pharmapollution: the environmental impact of medication

A talk to describe the problem of pharmapollution and discuss possible ways of solving it

We are clearly living in an increasingly polluted world. The toxicity problems caused by hydrocarbons, heavy metals, pesticides and so on are well-known to public opinion. However, for some time now, attention has been paid to the so-called emerging pollutants, among which pharmaceutical drugs play a large part. About 4,000 different pharmacologically active substances are currently estimated to be in use in the world, for both human and veterinary medicine. Consumption of medication is constantly rising, with an estimated 4.5 trillion doses consumed last year alone. Logically, the increased use of drugs will also lead to an increase in the volume of medication waste ending up in the environment.

Medication can reach the environment via many different routes: production, consumption and waste disposal. While waste water is currently considered the primary source, drugs can enter the aquatic environment on other ways, including, for example, aquaculture, run-off water from farming and so on.

Waste water treatment plants are not specifically designed to eliminate pharmaceutical drugs, so some of them are effectively removed but others remain unaffected and are dumped in rivers and ecological niches.

Up to now traces of over 700 different drugs have been detected in the environment, mainly in waste water, rivers and lakes, but also in the ground, air and even in the tap water we drink. Despite everything, there are still many substances we know nothing about, and there are still countries for which the information available is very limited. Some drugs, such as oxacepam, do not break down for decades.

Unfortunately, as well as diclofenac, many other drugs have been shown to cause harm to the environment. The effect of hormonal contraceptives on the feminisation of fish and amphibians, or the appearance of resistance due to dumping of antibiotics, are perhaps the best known. The therapeutic targets and physiological systems on which the drugs we use regularly work are not exclusive to human beings, and many of these signalling pathways and structures exist in many living organisms. Recent studies suggest that certain drugs, like other pollutants such as pesticides, can accumulate throughout the trophic chain, so that concentrations in the tissues of fish and invertebrates may be higher than those we find in rivers and lakes. Furthermore, this process of bioaccumulation is not limited to the aquatic environment, as it has been proven that dung beetles can accumulate anti-parasitic drugs like ivermectin in their tissues.

Pharmaceutical drugs are an essential item that we must protect. The study of pharmapollution must not limit or hinder drugs reaching patients who need them, but this must not stop us finding out more about the effects of drugs in our ecosystems. We cannot separate human and animal health and well-being from the balance with our environment, with the plants, animals and ecological niches with which we coexist. Seeking this balance must be one of our priorities.