Quantifying pathways of tyre wear into the environment.

This study provides the first national-scale spatial analysis of tyre wear particle (TWP) pathways in the UK, employing a mass flux particle pathway framework integrated with the UK Integrated Assessment Model at 1 km resolution. Results show 79.5 kt of TWPs are released annually, with between 1.3 kt to 6.7 kt enter the atmosphere, 23.0 kt to 34.0 kt reaching surface waters,18.5 kt to 30.2 kt depositing in soils, and 16.7 kt to 29.2 kt removed via management systems. Sensitivity analysis reveals notable uncertainties in these estimates. A significant rural-urban transfer mechanism redistributes 6.3 kt to 13.1 kt of urban-derived TWPs to agricultural soils through sewage sludge application. Atmospheric emissions are concentrated around major roads and urban centres, while soil and water pathways exhibit complex distributions driven by infrastructure systems. This study highlights the potential for improved spatial modelling of the pathways of tyre wear into the environment.