It is no doubt, that the ski glide over the snow is a very complicated object of research. However, ski glide is just a one area of many other areas of human knowledge. As a rule, the scientists and practitioners, who work in these areas, operate with some publicly expressed more or less solid hypotheses. These researchers work with one hypothesis until another and a better one comes up. Our literature studies and our own observations regarding modern skis preparations, did not give us any solid hypotheses, which are able to explain the actual form and content of this procedure. The present work is an attempt to reveal such hypotheses. Conclusion: To achieve an optimal glide on skis with the base (the ski sole) made of some high hydrophobic durable polymer, e.g. UHMWPE, PTFE; we only have to create an adequate topography (texture) on the ski running surface, adequate to the actual snow conditions.

Poly- och perfluorerade ämnen, även kallad PFAS, har både globalt och i Sverige upptäckts i höga halter i mark samt i yt-och grundvatten de senaste åren. Kemikalierna är svårnedbrytbara och studier visar på att de bland annat är reproduktionsstörande hos djur. Källorna till utsläpp av PFAS är många, men något som uppmärksammats den senaste tiden är fluorvallor som används inom längdskidåkning. I den här studien undersöks hur användningen av skidvalla innehållande PFAS påverkar ett område samt hur dessa ämnen sprids. För att undersöka detta har tidigare mätningar utförda i anslutning till längdskidspår använts, för att se hur spridningen skett vid dem samt vilka koncentrationer som kan påträffas.  Mätningarna var utförda vid skidspår i Oslo, Trondheim, vid Vasaloppet samt vid en tävling i Maine, USA. För att visualisera var i Sverige påverkade områden skulle kunna finnas gjordes dessutom en karta där orter togs ut på två olika sätt. Skidvalla bidrar till att orsaka högre lokala koncentrationer av PFAS, och kan få en stor påverkan i de områden där mycket skidåkning pågår. Samtidigt är det svårt att dra tydliga slutsatser då det finns fåtal studier och många diffusa källor som kan bidra till spridningen av PFAS. / Per- and polyfluoroalkyl substances (PFAS) are man-made chemicals used for their water, grease, and dirt repellent properties. Today these substances are widespread due to their ability to spread through both air and water. PFAS are long-term persistent and have hazardous environmental impact. Among others, affecting the reproduction of animals and has been shown to accumulate in the food chain. One product containing PFAS that has recently gained attention is fluorinated ski wax, due to the ban imposed on fluorinated ski wax by the International Ski Federation (FIS) from the season 2021/2022.  To investigate how the use of ski wax containing PFAS spreads and affects the environment at areas with cross-country skiing, results from previous studies have been analyzed. The previous studies were located at cross-country ski areas in Oslo and Trondheim in Norway, Maine in the USA and at the location of the Swedish competition Vasaloppet. A map has also been made to visualize where in Sweden there might be areas who have been contaminated with per- and polyfluoroalkyl substances by the use of ski wax. To find the locations for these areas two different methods have been used.  The results of the previous studies shows that the use of fluorinated ski waxes gives higher local concentrations of PFAS at the locations of cross-country ski areas that are frequently used. However, it is still difficult to draw clear conclusions about how big the spread of PFAS contamination is, since the substances can be found in many different products and are easily spread. In the future there is a need for more studies and investigation to reach clearer conclusions. In addition, there is a need for more tests around different ski areas to see the impact that competitions have, but also how everyday skiing affects the spread of PFAS.

Per- and polyfluorinated substances (PFAS) are used in the production of ski wax to reduce the friction between the snow and the ski. In this occupational study of ski wax technicians’ exposure to PFAS and particulate aerosol we have collected whole blood (wb) (n =94), air (n =84) and aerosol (n =159) samples at World Cup events from 2007-2011. We have analysed the blood, air and aerosol with respect to 13 perfluorocarboxylic acids (PFCAs), 4 perfluorosulfonic acids (PFSAs), 3 fluorotelomer alcohols (FTOHs), 3 fluorotelomer acids (FTCAs) and 3 unsaturated fluorotelomer acids (FTUCAs). Further, we assessed the exposure to 3 particulate aerosol fractions (inhalable, respirable and total aerosol) in air. In comparison to a general population, several of the PFCA blood levels are elevated in the technicians’, primarily  erfluorooctanoate (PFOA) and perfluorononate (PFNA) with concentrations up to 628 and 163 ng/mL wb, respectively. Further,  we detected FTUCAs and FTCAs in the blood, suggesting biotransformation of FTOHs to PFCAs. The metabolites 5:3 and 7:3 FTCA were detected in all blood samples at levels up to 6.1 and 3.9 ng/mL wb. Levels of perfluorohexadecanoic acid PFHxDA) and perfluorooctadecanoic acid (PFOcDA) were detected in the technician’s blood at mean concentration up to 4.22 ng/mL wb and 4.25 ng/mL wb. The FTOH levels in air of the wax cabin during work ranged up to 997 000 ng/m3 (average=114 000 ng/m3 ) and PFOA up to 4 890 ng/m3 (average= 526 ng/m3 . FTOHs were not detected in aerosols but PFOA showed average levels of 12 000 ng/m3 (range=1 230- 46 900 ng/m3 ). The occupational exposure limit (OEL) of 2 mg/m3 was exceeded in 37% of the personal measurements with aerosol  concentrations up to 15 mg/m3 . Keywords : Perfluorinated, polyfluorinated, FIS, occupational exposure, ski wax,  iotransformation, metabolism, fluorotelomer alcohol, fluorotelomer acid, aerosol, dust, UPLC/MS-MS, GC/MS-MS