Occurrence and environmental fate/behaviors of tire wear particles and their human and ecological health: an emerging global issue

Rapid societal and urban development has driven a surge in tire production, generating tire wear particles (TWPs), a pervasive environmental pollutant. Upon environmental release, TWPs interact with physio-chemical factors, altering their fate and amplifying toxicity. Available evidence indicates that TWPs mainly enter the organism body through inhalation and dermal contact. Toxicokinetic studies reveal that TWPs and additives penetrate biological barriers, accumulating in the liver and metabolizing via P450 enzymes, producing detoxified compounds or more toxic derivatives like N-(1,3-dimethylbutyl)-N’-phenyl-p-phenylenediamine-quinone(6PPD-q). Currently, the adverse ecological and health effects have gained increasingly public concerns. A series of advances have been achieved to address their ecological and human risks across aquatic, terrestrial, and mammal models, even at population level. Their toxicological effects span across respiratory diseases, metabolic disorders, and reproductive toxicology. Considering the challenges arising from the large-scale production and mismanagement of TWPs, this review synthesizes the latest knowledge on their generation, environmental fate, toxicokinetic, and ecological and human health effects. However, critical gaps remain in long-term low-dose effects, cross-generational toxicity, and biomarker validation. This review highlights the urgent need for global regulatory frameworks and interdisciplinary strategies to mitigate the cascading ecological and health impacts originated from TWPs.