Airport Tire Wear Emissions Identified Through Unique Chemical Markers in Milan Study

A study published in Environmental Chemistry and Ecotoxicology has for the first time analyzed outdoor particulate matter at Milano Linate Airport and identified elevated concentrations of benzothiazoles, chemical additives from tires. The concentrations were significantly higher than those found in heavily trafficked Italian cities, indicating a substantial environmental input from airport operations. The research addresses a critical gap in understanding non-exhaust emissions from aviation, which include tire wear particles generated during high-friction events like landings and takeoffs.

"Although TWPs can derive from all tire-equipped vehicles, they might pose a higher risk at airports considering the large amount produced especially during the landings and the take offs," said Prof Andrea Gambaro, senior author of the new study. The international research team focused on eight rubber tire-related chemical markers and twenty-three other chemical species in atmospheric PM10, aiming to identify tracers specifically linked to airport activities. The full findings are available in the original research article at https://doi.org/10.1016/j.enceco.2025.11.011.

The investigation revealed that BTH concentrations in airport PM10 substantially exceeded those measured in urban areas like Milan and Collegno. By analyzing wind direction data alongside chemical composition, researchers were able to distinguish between pollution from nearby roads and parking areas versus emissions originating directly from airport operations. "By cross-referencing our results with wind direction data, we managed to discriminate the contribution of the two sources," explained lead author Dr. Giovanna Mazzi. The airport was found to emit four specific benzothiazoles, two of which showed a strong correlation not observed in urban PM10 samples from other Northern Italian cities.

This correlation suggests these compounds serve as unique chemical markers for airport-related tire wear emissions. An ecotoxicological assessment conducted as part of the research indicated a low potential risk of occupational exposure to BTHs in outdoor air at Linate Airport. However, the identification of these specific markers represents significant progress in tracking and understanding non-exhaust pollution from aviation. "Although further research is still needed, these findings represent a key step toward identifying specific chemical markers for tracing airport non-exhaust emissions into the air," Mazzi added. The research was supported by multiple funding initiatives including the Next Generation EU project "GRINS" and the Italian Integrated Environmental Research Infrastructures System.