A hidden route of exposure: adsorption of endocrine disrupting compounds and chemicals of emerging concern on tire rubber

Tire wear particles (TWPs) are a major component of non-exhaust traffic emissions and an important source of microplastics capable of retaining and transporting organic contaminants. This study investigated the sorption behaviour and adsorption kinetics of antibiotics (AAs), the endocrine-active compound E3, hydroxylated PAHs (OH-PAHs) and the biomarker cotinine using batch experiments (15–24 h) combined with LC-MS/MS analysis. Sorption was rapid and compound-specific. Cotinine showed the highest adsorption capacity (qe = 90.91 µg g–1), 5-hPZA was the most strongly retained among AAs (38.18 µg g–1), and 4-OH-PHEN exhibited the highest uptake among OH-PAHs (24.63 µg g–1). Most analytes followed the pseudo-second-order kinetic model (typically R² > 0.98), while several OH-PAHs displayed deviations, indicating diverse adsorption behaviour. Raman and ATR-FTIR analyses confirmed the heterogeneous composition of TWPs, including carbonaceous and inorganic fillers. Overall, the results demonstrate that TWPs act as effective sorbents for multiple classes of micropollutants and may influence their environmental mobility and persistence. Further research under environmentally realistic conditions - including quantitative assessment of TWP abundance and competitive sorption between co-occurring contaminants - is needed to better predict their role in air, soil and water systems.