Road to Contamination: Investigating the Environmental Impact of Tyres and the Chemicals they Contain

Tyre wear particles (TWPs) are small fragments of vehicle tyres formed through abrasion on surfaces during everyday use. They consist of a mix of organic and inorganic compounds that can leach into the surrounding environment, raising concerns about their impact on the environment and human health. The current literature provides a foundational understanding of the environmental occurrence, fate, and impact of TWPs. Primary pathways, including road runoff and atmospheric deposition, facilitate the widespread distribution of TWPs across various environmental compartments. These particles are transported over long distances through air currents, contributing to particulate matter pollution, and upon deposition onto land and water surfaces, they can significantly contaminate terrestrial and aquatic ecosystems. In terrestrial environments, TWPs can accumulate in soils and road dust through processes such as sedimentation, adhesion, and vertical migration. In aquatic systems, TWPs can remain suspended in water columns, be transported by currents, and eventually settle in sediments. The environmental fate of TWPs is influenced by factors such as particle size, composition, surface properties, and prevailing environmental conditions. Additionally, TWPs can undergo physical and chemical transformations, which alter their properties and behaviour. TWPs contain various additives, including chemicals like N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine (6-PPD), which can be transformed into 6PPD-quinone, a substance toxic to certain aquatic species. The presence of these additives highlights the importance of understanding the full range of potential risks associated with TWP dispersion in the environment. Given the potential for TWPs to impact vulnerable ecosystems, this research focuses on a comprehensive investigation of their composition and distribution in Australian road dust, sediment, and water. By studying the spatial distribution patterns of TWPs and tyre additives in road dust across Australia and assessing their occurrence in marine environments like Moreton Bay catchments, this study aims to reveal the extent of contamination and trace the transport pathways of these particles. Finally, the findings from this work will inform clear recommendations to guide future research, policy, and practical interventions.

Please note this is a PhD student Progress Review presentation by Simran Kaur.