Study Reveals High Concentrations of Tire-Related Chemicals in Airport Air Pollution

For the first time, researchers have analyzed outdoor particulate matter at Milano Linate Airport and determined concentrations of benzothiazoles (BTHs), chemical additives related to tire wear. The concentrations were found to be much higher than those measured in highly trafficked Italian cities, with specific additives proven to derive mostly from the airport area. Two of these additives showed strong correlation, suggesting a close link to airport activities.

The aviation sector generates forms of pollution beyond exhaust gas emissions that are often underestimated, including non-exhaust emissions such as tire wear particles (TWPs). Produced during high-speed, high-friction events like takeoffs and landings, these rubber particles can easily enter the air, contributing to atmospheric particulate matter and carrying rubber chemical additives into the environment. Prof Andrea Gambaro, senior author of the new study published in Environmental Chemistry and Ecotoxicology, noted that although TWPs can derive from all tire-equipped vehicles, they might pose a higher risk at airports considering the large amount produced during landings and takeoffs.

An international, multidisciplinary research team investigated the chemical composition of atmospheric PM10 at Milano Linate Airport, focusing on eight rubber tire-related chemical markers and twenty-three other chemical species to identify tracers specifically linked to airport activities. The researchers discovered that BTH concentrations in outdoor airport PM10 were significantly higher than in other trafficked Italian cities such as Milano and Collegno (Torino), pointing to substantial environmental input from airport operations.

Additional insights emerged when considering the sampling location and surroundings. The PM10 was sampled in an area influenced by two main sources of benzothiazoles: roads and parking on one side, and airport activities on the other. Lead author Dr. Giovanna Mazzi explained that by cross-referencing results with wind direction data, the team managed to discriminate the contribution of the two sources. This analysis revealed that the airport emits especially four benzothiazoles, two of which demonstrated strong correlation with each other. Notably, these same compounds did not show this behavior in airborne urban PM10 sampled in other Northern Italian cities, highlighting their potential link to airport activities.

An ecotoxicological assessment conducted as part of the research highlighted a low potential risk of occupational exposure to BTHs in outdoor air at Linate Airport. However, the identification of these chemical markers represents significant progress in understanding airport pollution sources. Mazzi added that 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.

The research has implications for environmental monitoring and regulation at airports worldwide, providing new tools to distinguish airport-specific pollution from other urban sources. As air travel continues to grow globally, understanding and mitigating all forms of airport-related pollution becomes increasingly important for public health and environmental protection. The study's methodology could be applied to other airports to assess similar pollution patterns and develop targeted mitigation strategies.