Interview with Professor Piotr Stepnowski, Head of the Department of Environmental Analysis at the Faculty of Chemistry of UG, Rector of the University of Gdańsk. Interviewed by Dr. Beata Czechowska-Derkacz

Knowledge of the risk of pharmaceutical residues in soil and water is not widespread. What substances are involved?

In fact, this knowledge may not be common knowledge, but due to the growing interest of scientists in this topic, more and more information about medicines in the environment is getting through to the public. From the point of view of their presence in the environment, the most frequently detected are non-steroidal anti-inflammatory and analgesic drugs, estrogenic hormones, antiepileptics, numerous groups of antibiotics, cholesterol-lowering drugs, betablockers and many others. To date, more than six hundred different types of pharmaceutical substances have been detected in samples of sea water, inland water, soils or bottom sediments around the world.

What are the risks of these substances for humans and animals?

By their very nature, medicines are substances with a specific biological activity, which are intended to have a specific therapeutic effect. For example, antibiotics inhibit the growth and division of micro-organisms in the body of the patient being treated. They have exactly the same activity, when they enter the environment. In our studies, we have shown, for example, that the presence of antibiotics of the tetracycline group in municipal wastewater results in the acquisition of antibiotic resistance by bacteria present in wastewater treatment plants. Unfortunately, this trait can be further transferred to pathogenic bacteria which, once an infection is induced, can prove difficult to eradicate with antibiotics. Another example are oestrogenic substances, which, once they enter the environment, have a significant impact on the hormonal balance of aquatic organisms. It has been proven, among other things, that they can, even in low concentrations, cause feminisation of males of some fish species, which can as a consequence, significantly limit the development of the population of these organisms.      

How do these substances get into the environment?

The most important source of medicinewaste in the environment is municipal sewage, because medicines, especially those of newer generations, leave the human body in virtually unchanged form. This can be up to ninety per cent of the dose taken. Current treatment technologies are not effective enough, so drug residues end up in watercourses and reservoirs. Another source is run-off from agricultural fields fertilised with manure. Animals, in the breeding cycle and especially in industrial farming, are subjected to various therapies - antibiotic, antifungal, antiparasitic and others. The drugs therefore appear in the excrement of the animals, and from here it is a straight path to the environment through flushing away by rains from natural fertilisers or from the manure stored on farms. Pharmaceuticals run off from soils with rainfall into surface water, but they can also migrate into the ground and in this wayreach groundwater. Another source is so-called leachate from landfills, so dumping pharmaceuticals in the waste bin adds to this environmentally damaging balance.

Medicines for the pharmacy...

The question is whether pharmacies can cope with taking medicines. Not all, we hear, want to take them, and there are some that do not follow procedures.

Could one of the reasons for environmental pollution from drug residues also be the current trend towards overuse of food supplements and medicines in general?

Both educational and legislative measures are very much needed in this area. On the one hand, the widespread, almost intrusive presence of over-the-counter painkillers certainly does not facilitate self-medication that is conscious and safe for patients, and often leads to dangerous overdoses. We saw this very clearly, when we carried out research on the Vistula just after the failure of the sewage transfer system to the “Czajka” sewage treatment plant. Non-steroidal anti-inflammatory and analgesic drugs were at that time present in the Vistula waters at levels several thousand times higher than in waters before the breakdown. But the problem does not only concern non-prescription medicines. When we buy medicines in a pharmacy, we often get more of them than we need for our treatment. This also applies to antibiotics or hormonal medicines. After some time, these 'excesses' end up in sewage or waste. This can be counteracted, at least in the case of prescription medicines, where the pharmacist issues a strictly defined dose that is intended for the treatment.

What are the predictions for the future when it comes to this kind of pollution?

The pharmaceutical market is one of the most rapidly growing branches of production and trade in the world. Over the last ten years, the value of sales of all types of pharmaceutical preparations has doubled and currently amounts to over USD 1.2 billion annually. The production of so-called original drugs still exceeds 50% of the market, but is slowly giving way to generic drugs, which account for more than 20% of global sales. In emerging market countries, equivalent medicines, which are often produced without patent protection, are taking an increasing share. In terms of the type of drug, anti-inflammatory and analgesic drugs such as paracetamol, ibuprofen and diclofenac account for the largest share, followed by anti-atherosclerotic drugs, antidiabetic drugs and antibiotics. Recently, there have been an increasing number of reports summarising the research to date worldwide on the detection of pharmaceuticals in environmental samples. For example, the Federal Environment Agency in Germany analysed more than a thousand original and review articles on this issue. The conclusion is clear - drugs are detected in most seas, oceans, rivers, lakes or agricultural areas. It is therefore to be expected that, with a growing pharmaceutical market, the problem of the presence of drugs in the environment will become more common.

How can we address the risks of pharmaceuticals in soil and water?

In the case of municipal wastewater, the last, technological barrier to pollution is obviously the wastewater treatment plants. Conventional technologies based on mechanical and biological stages are not capable of fully treating pharmaceutical waste water today. At present, extensive research and development work is being carried out to implement the so-called tertiary treatment stage using chemical precipitation techniques, enhanced oxidation with ultraviolet light and various chemicals, and finally filtration with activated carbon and other filter barriers. Without going into details, this is an extremely important technological step, which is not only able to remove drugs, but also other unusual contaminants, such as microplastics. However, these methods are very expensive. There is much to be hoped for in terms of easier access to this type of technology, not least because of the potential energy surpluses that arise from the installation of renewable energy sources at sewage treatment plants.

Do you not think that our pollution problems stem from the fact that we want too much of everything, too quickly?

Of course, it will be a truism to say that humans feel an irresistible need to tame nature. But so it is that we want to develop everything. Our Nobel Prize winner, Olga Tokarczuk, recently spoke about this. She bought several hectares of land for part of her prize and simply left it to nature... and that was that. This is an unusual action, after all, when you buy land, you immediately want to develop it, build a house, set up a farm, plant crops "your way", it's our nature...

This is an extraordinary attitude.

Unprecedented. This is a wonderful, one might say utopian example, but it is an important one and should be publicised. We hear more and more alarming voices about the climate catastrophe and dwindling natural resources, but I have the impression that few people, apart from the few who keep reminding us of this, are really aware of the scale of the threat. What still has to happen for us to be able to awaken in ourselves a respect for nature, a care for the world of plants and animals, and not just for our quality of life?

You have been doing research on environmental protection and especially unusual environmental pollution for many years. Where did this scientific passion come from?

I have always been concerned with the environment and various aspects of its protection, primarily those that require the analytical judgement of a chemist. More than twenty years ago, when I was a postdoctoral fellow in Bremen, I worked in the team of Prof. Jastorff, an extremely charismatic scientist who infected me with a passion for finding answers to questions not yet asked. In environmental analysis, we usually analyse what has already happened, an accident, a spill, a contamination, so we work retrospectively, assessing specific effects that have already occurred. In the professor's team, I understood, that an equally important perspective is the prospective one, i.e. a forecast, an ex anteenvironmental risk assessment. For example, what would happen if industry decided to produce this and not that group of chemicals on an industrial scale. We "practiced" this at the time with the example of so-called ionic liquids, which were extremely promising substitutes for traditional industrial organic solvents, by their very nature highly volatile, often toxic and even carcinogenic. On the surface, it seemed that ionic liquids were environmentally friendly, especially due to their negligible volatility, but also a number of other features that could have favoured increasing the efficiency of certain industrial processes involving them. Our team's research at the time proved, that the introduction of these potentially "green" solvents into industrial production could bring enormous risks to the natural environment should these substances get there as a result of plant failure or leakage during transport, and this always happens sooner or later.  

On returning from my internship, reading the scientific literature, I realised at one point that the environmental effects of pharmaceutical use had been completely overlooked. I was particularly moved by the publications about the almost complete disappearance of the Bengal vulture population, which was practically extinct due to the highly toxic effect of diclofenac on this species. This drug was present in the meat of dead cattle in Asian areas, which used to be left out to pasture there. While the drug is relatively harmless to cows, it caused severe and fatal kidney failure in birds. There were many more of these alarming publications and so I slowly got involved in the subject, organised a small research group, and the first projects and grants appeared. After twenty years, we have become a large, international research team, which conducts research in cooperation with several foreign centres. The result of our work, apart from providing increasingly comprehensive information on the level of environmental contamination by these unusual pollutants, is, among other things, that the substances detected by our research team appear on the so-called watch lists of the EU Water Framework Directive. This means that, in time, EU member states will be obliged to monitor these substances.

You have been awarded many scientific prizes for developing unconventional separation methods and analytical techniques for environmental determination. What are these methods based on?

We use a wide range of analytical tools in our research, but the "unconventionality" of the substances we want to detect at trace levels requires us to develop our own proprietary research solutions. These are primarily designed to allow for the highest possible efficiency of "extraction" of trace amounts of sought-after chemical compounds from a liquid or solid environmental sample. For this, we use our own or modified sorbents, reaching for innovative materials such as carbon nanotubes or specially coated membranes. Please remember, that we are talking here about concentrations at the level of nanograms per litre, or even less - it is as if we dissolved a glass of a given substance in Lake Wdzydze. However, we need to remember, that this proverbial nanogram of an active substance is able to cause a specific biological effect, which has been confirmed, for example, for estrogenic substances and their effect on some fish species in this concentration. Our original solutions are not only methods of concentrating pharmaceuticals, but also their final measurement, where we have also provided the scientific world with a number of solutions using techniques such as high-performance liquid chromatography and mass spectrometry.

The above-mentioned awards, including the Jan Hevelius Science Prize of the City of Gdańskfor 2018, or the Committee of Analytical Chemistry of the Polish Academy of Sciences for outstanding achievements in analytical chemistry for 2020, give the scientist wings?

The feeling that our activities are appreciated, that what we do makes sense, seems to be an essential part of scientific work. I cannot imagine a successful, fruitful and inspiring career as a scientist without a sense of recognition from the environment. This kind of scientific stimulation is important, but it is clear that awards are not the goal. The main motivation is the scientific questions we ask. This is how we reach further and know more. At present, our scientific team consists of six independent members of staff, all coming from the same scientific area but already pursuing their own research. As lofty as it sounds, we can probably call it a research school, and I am the lucky one who can continue to lead it.