Groomed trails, the silence of the Jizera Mountains, cross-country skis gliding almost by themselves. But this perfect glide has a downside. The substances that have helped cross-country skiers achieve better riding characteristics for decades remain in nature practically forever.
Per- and polyfluorinated substances, known by the abbreviation PFAS, have long been used in cross-country ski waxes because of their exceptional sliding properties – they repel water and dirt and are simply easy to glide on. An ideal combination for sports. Less so for the environment. When skiing, they are mechanically released into the snow, from where they enter the soil and water sources when it melts.
The problem is that PFAS are among the so-called forever chemicals. They hardly decompose in nature, accumulate in ecosystems and in the human body, and are associated with hormonal imbalance, weakened immunity, and possible carcinogenic effects.
And this is where the story begins, one that has a much broader impact than just cross-country ski trails.
The Jizera Mountains as a laboratory for the problem
Measurements in the Jizera Mountains show that PFAS are not just an abstract chemical concept in Czechia. They are found in snow, soil, plants, soil organisms, and water. Scientists have proven a clear link between the use of fluorinated waxes and the pollution of surface waters, which serve as a source of drinking water for Liberec and Jablonec. The situation has been monitored for a long time by Jaroslav Semerád, Ph.D., from the Institute of Microbiology of the Czech Academy of Sciences, whose work shows that the problem is not hypothetical, but very concrete.
Thanks to his monitoring, it has been found that the highest concentrations occur in the long term at the starting points of cross-country skiing trails, such as the Bedřichov stadium. It is here that high values have been measured in earthworms, key indicators of soil health.
The good news? The problem can be significantly improved by switching to fluorine-free waxes. And cross-country skiers‘ performance does not suffer as a result.
But PFAS are not just a problem for sports.
Out of the water: how CXI TUL is looking for ways to tame PFAS
PFAS are or have been used in a wide range of products: non-stick surfaces, outdoor clothing, food packaging, firefighting foams, cosmetics, and impregnations. The result is global contamination that affects more than just drinking water.
This is where the Institute for Nanomaterials, Advanced Technologies and Innovation at the Technical University of Liberec comes into play. Scientists there are looking for ways to remove such substances from the environment.
A team of scientists in Liberec is working on materials based on cyclodextrins—natural oligosaccharides formed by the enzymatic degradation of starch. These molecules have a unique structure: a hollow cylinder with a hydrophobic pocket that can specifically capture water-repellent substances such as PFAS.
Smart chemistry instead of expensive technologies
“We further modify cyclodextrins so that they carry a positive charge. This increases their attraction to PFAS, which often carry a negative charge. The result is insoluble polymer materials that not only selectively capture PFAS, but can also be mechanically removed from water,“ says Pavlína Konopáčová from the CXI TUL nanochemistry laboratory.
In other words: no complex infrastructure, no extreme energy requirements. A material that absorbs PFAS and can be filtered out of water and reused.
„We are currently focusing on optimizing the synthesis so that the technology is easily transferable to a larger scale and economically sustainable. At the same time, we are increasing its efficiency, stability, and reusability,“ adds Pavlína. Similar principles are being researched around the world, but the combination of targeting PFAS and creating insoluble polymers gives the Liberec approach a clear competitive advantage.
From the laboratory to the trail – and back
Research into cross-country skiing waxes continues. Alternatives to fluorinated waxes already exist, but new, more effective, and more environmentally friendly variants are also being developed. Manufacturers are currently working on their development, for example with CXI TUL.
„Our company was founded because of the ban on fluorinated waxes. It was at the instigation of the Czech Biathlon Union, when we needed to find a replacement for them. After several years of development, we are now at the stage where we could start production,“ explains Ing. Petr Tischer from Titan Gliders, which cooperates with CXI TUL.
At CXI TUL, scientists analyze Titan Gliders‘ own synthesized additives as well as competing commercial waxes. It’s like having a map and a compass at the same time – production knows where it’s going, and the data confirms that it’s heading in the right direction.
Tischer also points out that, following the ban on fluorinated compounds, many manufacturers have switched to other microplastics, such as polyethylene derivatives, which can be similarly problematic for the environment. Moreover, these substances are difficult to detect using current control methods. Titan Gliders is therefore focusing on the development and synthesis of materials in collaboration with the University of Pardubice and declares the slogan „Fluor and Microplast Free“ on the labels of its products.
„The collaboration with CXI TUL has definitely paid off for us. We know exactly where to focus our efforts, and without such support, we would have had a hard time getting by. In addition, thanks to this, we have gained support from the Czech Biathlon Union, the Czech Olympic Committee, and the Liberec Region. For a company that started from scratch and was financed from its own resources, this is of fundamental importance,“ adds Tischer.
What to do with them?
„It is important to mention that old waxes should not be used, but at the same time, they should not be thrown away. In landfills, PFAS could be released back into the environment. A much better option is to hand them in and exchange them for fluorine-free alternatives,“ concludes Pavlína.
