13th Environment Dialogue: Pollutants in food: Small doses, what effect?

19.05.2025 Event Report | Environmental Dialogue

Contaminants in food - a topic that is rarely discussed without emotion. Between growing concerns about microplastics, pesticides, and so-called forever chemicals on the one hand, and increasingly differentiated scientific assessments on the other, there is room for many questions. How risky are residues really? What is measurable, what is noticeable, and what can be regulated, and how quickly?

Große Menschenmenge in der Kuppelhalle des Naturhistorischen Museums, mit Bühne und Bildschirm für Präsentationen.

Pollutants in food - a topic that is rarely discussed without emotion. Between growing concerns about microplastics, pesticides, and so-called forever chemicals on the one hand, and increasingly differentiated scientific assessments on the other, there is room for many questions. How risky are residues really? What is measurable, what is noticeable, and what can be regulated, and how quickly?

Answers to these questions were discussed in the ECH event format Environmental Dialogue on May 6 at the Natural History Museum Vienna (NHM). Over 200 interested parties gathered in the magnificent dome hall of the NHM to talk to representatives from research, government agencies, and NGOs about risks, regulations, and research progress.

Experts in dialogue

NHM Director General Katrin Vohland opened the event, followed by Manuela Baccarini, Vice Rector of the University of Vienna. Thilo Hofmann, Professor of Environmental Sciences and Co-Director of the University of Vienna's Environment and Climate Research Hub, gave the keynote speech on “Contaminants in Food.”

The panel discussion featured Thilo Hofmann, Giorgia Del Favero, ECH member and toxicologist at the University of Vienna, Johann Steinwider, Head of the Department of Food Risk Assessment at AGES, and Helmut Burtscher-Schaden, environmental chemist at Global 2000.

Moderator: Marlene Nowotny

13. Umwelt im Gespräch: Schadstoffe in Lebensmitteln – Kleine Dosis, welche Wirkung?

The circle of life

“If you walk up the grand staircase and look up at the ceiling, you will see a huge painting that clearly shows how closely humans are connected to nature,” said NHM Director General Katrin Vohland as she opened the evening with a view of Hans Canon's painting Cycle of Life. The NHM sees itself as a place for exchange about the interaction between nature and humans, said Vohland, and a discussion about pollutants in food and their effects fits perfectly into this context: because it affects not only humans, but also the environment and animals. With this in mind, the hostess wished the audience an “informative and action-oriented evening.”

Gemälde 'Kreislauf des Lebens' im Naturhistorischen Museum Wien mit zentraler Figur in Rot, umgeben von zahlreichen Figuren, die verschiedene Lebensphasen darstellen. — Kreislauf des Lebens, Hans Canon

Research, communication, and social dialogue

Manuela Baccarini, Vice Rector of the University of Vienna and microbiologist, emphasized the social responsibility of science: "We are working to identify and quantify pollutants and find solutions. But we also need to communicate - formats such as Environmental Dialogue make an important contribution to this." Pollutants are not only an environmental problem, but also a health problem. To combat them effectively, interdisciplinary research and a deep understanding of their origin, effects, and perception are needed. The Environment and Climate Research Hub (ECH) at the University of Vienna brings together experts from chemistry, biology, psychology, sociology, and environmental sciences, both nationally and internationally. “It brings the findings to society through events such as Environmental Dialogue,” said Baccarini. The university is proud to actively promote this exchange between science, politics, and the public.

Keynote speech: Between chemophobia and facts

What dose makes it toxic? How do limit values and risk assessment work? And when is the tolerance threshold for the environment and humans exceeded? These were questions that environmental scientist and ECH co-director Thilo Hofmann answered in his keynote speech. Hofmann began with a clarification: “Pollutants in food – that's not a pleasant topic.” This is also because the term “chemical” has such strong negative connotations in public discourse. Yet, according to Hofmann, “if you ask an environmental chemist, they will tell you that all of life, all of humanity, consists of chemistry.”

“Chemicals are like people, some are good, some are bad, some are in between (Whitcombe, 2019).”

Chemicals are not dangerous per se – just as natural substances are not automatically harmless. “Mold is natural – and yet highly dangerous,” explained Hofmann. Nevertheless, fear of synthetic substances is widespread: “Some even speak of chemophobia among large sections of the population” – an excessive fear of synthetically produced substances.

This fear is no coincidence, Hofmann said in a brief historical digression. It is fueled by scandals that have burned themselves into the collective memory and permanently shaken people's trust in the pharmaceutical and chemical industries: from the sleeping pill Contergan to the building material asbestos to the pesticide DDT. Substances that were once celebrated, later ostracized. Hofmann called it “from miracle cure to hazardous substance.” And even today, in an age of strict European Union regulations, consumer confidence in the safety of food and chemicals remains fragile. This is exacerbated by inadequate education and unbalanced media coverage. According to Hofmann, the media often rely on fear-mongering headlines to generate attention – even when there is no scientific evidence to support them. However, the media cannot be solely blamed – “the issue is more complex than that,” said Hofmann.

Thilo Hofmann: Schadstoffe in Lebensmitteln – Kleine Dosis, welche Wirkung?

From miracle cure to dangerous substance

Hofmann became particularly emphatic when he spoke about so-called forever chemicals – above all PFAS, per- and polyfluoroalkyl substances, which are found in Teflon pans as well as in packaging, outdoor clothing, and firefighting foam.

A special case is trifluoroacetic acid (TFA), a short-chain PFAS that is produced as a degradation product of other fluorine-containing chemicals. “Today, we find it in rainwater, groundwater, wine – everywhere,” said Hofmann. And: it is hardly degradable. What is particularly bitter is that TFA was introduced as a substitute for CFCs to solve other problems, such as the destruction of the ozone layer. This case exemplifies that substitutes can curb existing environmental hazards, but often create new, difficult-to-control risks, according to Hofmann.

Pesticides, Hofmann said, are another example of this ambivalence. They are indispensable for securing yields, especially in view of a growing world population. “In order for them to be effective against pests, they must of course be toxic,” he explained. But that is precisely why they also harm ecosystems in high concentrations. And if residues find their way into food, they can also be dangerous to human health. One possible solution is to switch to organic products – “but you have to be able to afford them first,” Hofmann pointed out. In doing so, he was not only talking about toxicological risks, but also about the social issue of healthy nutrition.

Despite all the warnings, Hofmann concluded on a conciliatory note. The EU has made progress in recent years. The amount of high-risk pesticides has been reduced by 46 percent by 2022. By 2030, it should be halved again.

He also referred to what is known as the exposome – the sum of all environmental factors to which a person is exposed during their lifetime, including chemical, physical, biological, and social factors. “Only 10 to 20 percent of all diseases are genetically determined,” he explained. The rest is due to the environment and lifestyle. “Now, of course, we ask ourselves: Is it environmental influences or our lifestyle that make us sick? What can we control, and what can't we?”

Thilo Hofmann präsentiert vor Publikum neben einem Banner des Environment and Climate Research Hub mit dem Slogan 'Research Today, Secure Tomorrow'. — Co-Leiter Thilo Hofmann während seines Vortrags

Panel discussion: Between frustration and responsibility

In the ensuing discussion, Giorgia Del Favero (toxicologist and ECH member, University of Vienna), Johann Steinwider (AGES), Helmut Burtscher-Schaden (Global 2000), and Thilo Hofmann spoke with the audience about risk assessment, communication, and regulatory options.

There was a great need for guidance among the audience. Many questions reflected frustration and feelings of powerlessness—especially in view of the sheer number of chemicals and the often confusing study situation for laypeople. The desire for better consumer information was also expressed several times.

Risk monitoring

In response to a question from the audience, Johann Steinwider from AGES explained how AGES identifies, tests, and monitors hazardous substances and then recommends regulatory measures - from limit values to bans. As a One Health organization, the issue of environmental pollutants is of central importance to AGES, as it affects many areas simultaneously: from agriculture and animal husbandry to food production and human health. “Because what ends up in the environment sooner or later also affects us humans,” Steinwider emphasized. To effectively reduce risks, AGES works closely with partners such as the Federal Environment Agency in Austria and institutions at the EU level.

Security is not a final state

“We know more about contaminants today and have better controls over the safety of our food, thanks in part to organizations such as AGES,” explained Helmut Burtscher-Schaden of Global 2000. “We have a good handle on contaminants that arise during food preparation, for example, and there is also greater awareness of contaminants in agriculture than there used to be.” However, he warned against false security: “Until recently, we knew nothing about the TFAs mentioned above, the smallest eternal chemicals, and now we are finding them in concentrations that are already cause for concern.” This shows how important it is to monitor the environment and food and to continuously research chemicals and their risks.

Barbara Mair | ECH
Barbara Mair | ECH
Barbara Mair | ECH
Barbaira Mair | ECH

Health risks posed by microplastics and toxins

Toxicologist Giorgia Del Favero was asked by the audience about the health risks posed by both microplastics and toxic substances in food. Del Favero explained that, at the cellular level, both solid substances such as microplastics and chemical toxins in dissolved form, for example, can cause specific reactions and disease-inducing changes in cells. “It is particularly important to understand whether the toxicity of a substance is due to its chemical or physical form,” said Del Favero, as this has implications for the assessment and regulation of environmental and health risks. Whether the substance is natural or synthetic is irrelevant, because “it is the substance that matters, not its origin.” Despite these challenges, food safety in Austria is very high, according to the toxicologist.

A critical consensus

Time and again, questions were asked from the audience about the role of industry, political responsibility, consumer power, and the possibility of protecting oneself. Hofmann's dry response: “You can't protect yourself from PFAS - they're everywhere.” A much more central question, however, is: “How do we prevent further pollutants?” Persistence, i.e., non-degradability, must be an exclusion criterion for new chemicals. “Some substances simply do not belong in the environment,” Hofmann concluded.

What remained in my mind after the discussion was not a feeling of security. But neither was it pessimism. Rather, it was an awareness of this very complexity - and of the need to keep talking: because when we talk about limit values, exposure, and unknown long-term effects, we are also talking about dealing with uncertainty - in our own lives, in social discourse, and in political action.

Environmental Dialogue made it clear: protection against pollutants is not the task of individual disciplines, authorities, or countries. It is a social and global project – one that requires knowledge, regulation, and dialogue in equal measure.

The interactive VR installation by the Ludwig Boltzmann Institute for Network Medicine in the foyer of the NHM offered a new and innovative perspective on pollutants and their effect on the human body.