The study examines the contribution of road vehicle tyre wear to microplastics and ambient air pollution. Tyre particles are generated by shear forces between the tread and the road or by volatilisation. Tyre abrasion contributes 1/3 to 1/2 of unintentionally released microplastics into the environment. Most end up in the soil, while a smaller amount is released into the aquatic environment, and a small percentage becomes airborne. Tyre abrasion contributes 5–30% of road transport particulate matter (PM) emissions, corresponding to approximately 5% of total ambient PM emissions. The particle mass size distribution peaks at 20–100 μm, with a second peak in the 2–10 μm range. A nucleation mode has been reported in some studies. Absolute abrasion levels depend on tyre, vehicle, and road characteristics, as well as environmental conditions and driving style. Most tyre particle emission factors in the literature are based on data prior to 2000. Recent studies show a mean abrasion of 110 mg/km per vehicle or 68 mg/km/t for passenger cars. PM10 emissions were 1.4–2.2 mg/km per tyre, while particle number emissions were in the order of 10^10 #/km per tyre. The ratio of PM10 to total abrasion was 2.5% on average. The ratio of PM2.5 to PM10 was calculated to be around 40%. Various mitigation measures for tyre particle pollution are discussed, with the most direct being the limitation of tyre abrasion rate, as proposed by the European Commission for the Euro 7 regulation. Other regulatory initiatives are also discussed. Tyre wear particles (TWP) are ambiguous in the literature, with some studies using them for particles generated during tyre use without incorporating road or dust constituents. The term "tyre–road wear particles" (TRWP) is introduced but does not fully capture the diversity of the various constituents’ origins. Instead, "tyre wear particles" are used to refer to tread particles encrusted and mixed with foreign materials from the road, dust, brakes, and soil. "Tyre abrasion particles" or "tyre particles" refer only to the tread part emitted to the environment. Tyre particles are generated by shear forces between the tread and the road or by volatilisation. Due to their nanoscale size, particles generated by volatilisation do not significantly contribute to emissions in terms of mass but are highly relevant for human health. Tyre particles generated through thermochemical processes usually fall in the nanoparticle size fraction and are assumed to be semi-volatile organic compounds from softeners and additives from the tyre tread. Emitted particles have been reported to contain tread rubber, embedded road material, and constituents of the suspended dust. Particles fromThe study examines the contribution of road vehicle tyre wear to microplastics and ambient air pollution. Tyre particles are generated by shear forces between the tread and the road or by volatilisation. Tyre abrasion contributes 1/3 to 1/2 of unintentionally released microplastics into the environment. Most end up in the soil, while a smaller amount is released into the aquatic environment, and a small percentage becomes airborne. Tyre abrasion contributes 5–30% of road transport particulate matter (PM) emissions, corresponding to approximately 5% of total ambient PM emissions. The particle mass size distribution peaks at 20–100 μm, with a second peak in the 2–10 μm range. A nucleation mode has been reported in some studies. Absolute abrasion levels depend on tyre, vehicle, and road characteristics, as well as environmental conditions and driving style. Most tyre particle emission factors in the literature are based on data prior to 2000. Recent studies show a mean abrasion of 110 mg/km per vehicle or 68 mg/km/t for passenger cars. PM10 emissions were 1.4–2.2 mg/km per tyre, while particle number emissions were in the order of 10^10 #/km per tyre. The ratio of PM10 to total abrasion was 2.5% on average. The ratio of PM2.5 to PM10 was calculated to be around 40%. Various mitigation measures for tyre particle pollution are discussed, with the most direct being the limitation of tyre abrasion rate, as proposed by the European Commission for the Euro 7 regulation. Other regulatory initiatives are also discussed. Tyre wear particles (TWP) are ambiguous in the literature, with some studies using them for particles generated during tyre use without incorporating road or dust constituents. The term "tyre–road wear particles" (TRWP) is introduced but does not fully capture the diversity of the various constituents’ origins. Instead, "tyre wear particles" are used to refer to tread particles encrusted and mixed with foreign materials from the road, dust, brakes, and soil. "Tyre abrasion particles" or "tyre particles" refer only to the tread part emitted to the environment. Tyre particles are generated by shear forces between the tread and the road or by volatilisation. Due to their nanoscale size, particles generated by volatilisation do not significantly contribute to emissions in terms of mass but are highly relevant for human health. Tyre particles generated through thermochemical processes usually fall in the nanoparticle size fraction and are assumed to be semi-volatile organic compounds from softeners and additives from the tyre tread. Emitted particles have been reported to contain tread rubber, embedded road material, and constituents of the suspended dust. Particles from