They are everywhere in our everyday lives: PFAS, which can be found on pans, clothing, cosmetics and even photographic paper. The special properties of these fluoride compounds are practical, but they come with their own set of problems. They have negative effects on human health and are linked to cancer, fertility problems and liver damage. And they take a particularly long time to break down in nature, which has earned them the nickname „forever chemicals".
Some of these substances are already banned in the EU, and the impact of the restrictions is currently being negotiated. And the University of Graz, together with the Scottish James Hutton Institute (an interdisciplinary scientific research institute for the sustainable management of land, crop and nature resources), the Biobank at the Fraunhofer Institute and the German Federal Environment Agency, has shown that such regulations are effective. To this end, the team examined tissue samples taken between 1998 and 2022 from the livers of one-year-old red deer from the Bavarian Forest National Park. 30 different PFAS compounds were examined. (original paper: https://doi.org/10.1016/j.envpol.2026.127685 )
Levels sink
The result is clear: "The total exposure to these PFAS decreased by more than 87 per cent – that corresponds to a decline from 64 to just 8 nanograms per gram of liver tissue," explains the study's lead author, Viktoria Müller, scientist at the Institute of Chemistry at the University of Graz and The James Hutton Institute. The main reason for this is the voluntary renunciation by industrial companies of the use of the compound PFOS, which was later banned globally. This confirms that regulating these substances has a truly positive impact on nature.
However, the study also shows that it is not enough to ban just individual substances. This is because industry simply switches to other PFAS. In the samples, the concentration of the compounds PFNA and PFHxS rose sharply during the observation period, says Müller: "When some substances are restricted, they are replaced by others, which then leads to even more persistent contamination."
The results point to another challenge when it comes to PFAS: if these chemicals last forever, where do they go? "These substances break down into other PFAS that cannot yet be measured," explains Jörg Feldmann, Professor of Analytical Chemistry at the University of Graz. "What we can measure with our instruments is only the tip of the iceberg." This is also shown by the concentration of all fluoride compounds in the samples examined. This is 30 to 160 times higher than the PFAS molecules found.
Mobile particles
"Just because we can no longer detect the substances directly does not mean that they are gone," says Feldmann. In addition, the measurable PFAS groups are very mobile. "The chemicals can be transported via air and water." If they are found in the Bavarian Forest, they can easily reach Austria via the Danube. Surprisingly, organic pigs that live outdoors have been shown to have higher PFAS levels than animals from climate-controlled stables because rain and air transport the chemicals directly into the environment.
And that's also a problem for us humans. "PFAS can cross the blood-brain barrier," explains Feldmann. "There are initial indications from Italy of a link between PFAS concentration and Alzheimer's disease." Feldmann therefore wants to intensify studies in this field and is working with his team on a research proposal.
If you want to learn how even the smallest compounds affect the environment and humans, the Bachelor's programme in Chemistry is the right place to start.