0
Article ? AI-assigned paper type based on the abstract. Classification may not be perfect — flag errors using the feedback button. Tier 2 ? Original research — experimental, observational, or case-control study. Direct primary evidence. Sign in to save

Tire and Road Wear Particles as Vectors of Hydrophobic Tire Additives: Quantifying Contributions to Chlorinated Paraffins in Urban Road Environments

Environmental Science & Technology Letters 2026
Yingjia Chen, Xinyu Du, X Liu, Ge Yin, Bo Yuan, Tian Lin

Summary

Tiny particles worn off tires as they roll on roads aren't just plastic pollution — they also carry chemical additives called chlorinated paraffins, which are used in tire manufacturing and linked to health concerns. Researchers found these chemicals in road dust and roadside soil at levels showing that tire particles are a major source, contributing anywhere from 5% to over 44% of these chemicals depending on the location. Since this dust settles in places where people live, work, and play, it means tire wear may be spreading potentially harmful chemicals through our everyday environment more than previously realized.

A recently developed large-scale separation protocol enabled gram-scale isolation of tire and road wear particles (TRWPs) from road dust and roadside soils, providing sufficient material to evaluate their role as carriers of tire-derived chemical additives. An abundant class of hydrophobic tire additives, chlorinated paraffins (CPs), was detected in all samples, with concentrations ranging from 11 to 36 μg g –1 in road dust, 9.6–15 μg g –1 in roadside soils, and 110–290 μg g –1 in dust- and soil-derived TRWPs collected from multiple road environments in a megacity. CP homologue fingerprints in road dust were strongly correlated with those in corresponding TRWPs, suggesting a potential shared source. An exponential relationship between TRWP abundance and its contribution rates to CPs (R 2 = 0.95, p < 0.01) showed that TRWP levels govern CP contributions in road dust. TRWPs contributed more than 45% of total CPs at nearly half of the dust sampling sites and 9.8–24.8% in roadside soils. From a broader environmental perspective, estimated contributions were >44% in TRWP-rich environments, 15–36% in urban road dust, and 5–10% in roadside soils. These results provide the first evidence of CPs in environmentally derived TRWPs and quantitatively demonstrate the dissemination of hydrophobic tire additives via TRWPs across urban road environments.

Share this paper