Driving Scenarios Strongly Influence Tire Additive Accumulation in Road Dust: First Field Evidence from China’s Urban Roads

Abstract

Tire additives (TAs) are of growing concern due to their widespread occurrence and potential toxicity. However, the role of driving scenarios in modulating their release remains poorly understood. This study examined a broad range of TAs in road dust collected from two typical urban road scenarios in China. A total of 138 TAs were detected, including 14 compounds reported in road dusts for the first time. Driving scenarios strongly influenced the TA concentrations and composition. On urban roads, crossroads (characterized by frequent braking, turning, and stop-and-go traffic) exhibited higher TA concentrations (median: 5.46 × 10⁴ ng/g) than straight road segments (median: 3.57 × 10⁴ ng/g). Vulcanization accelerators (VAs) and antioxidants (AOs) served as sensitive tracers of TA release across different driving scenarios. Importantly, TA accumulation in road dust was also governed by physicochemical properties, with lower molecular weights, stronger hydrophobicity, and higher organic carbon affinity associated with elevated concentrations. Preliminary exposure assessment indicated elevated TA exposure risk among children residing near crossroads. These findings indicate that driving scenarios are likely important factors influencing the accumulation of traffic-related TAs and highlight the potential need for scenario-specific mitigation strategies.