A Review of Road Traffic-Derived Non-Exhaust Particles: Emissions, Physicochemical Characteristics, Health Risks, and Mitigation Measures

Abstract

Implementation of regulatory standards has reduced exhaust emissions of particulate matter from road traffic substantially in the developed world. However, nonexhaust particle emissions arising from the wear of brakes, tires, and the road surface, together with the resuspension of road dust, are unregulated and exceed exhaust emissions in many jurisdictions. While knowledge of the sources of nonexhaust particles is fairly good, source-specific measurements of airborne concentrations are few, and studies of the toxicology and epidemiology do not give a clear picture of the health risk posed. This paper reviews the current state of knowledge, with a strong focus on health-related research, highlighting areas where further research is an essential prerequisite for developing focused policy responses to nonexhaust particles.

A method for using stationary networks to observe long-term trends of on-road emission factors of primary aerosol from heavy-duty vehicles

“…The observed PM 2.5 : CO intercept would correspond to an EF PM(LDV) to be ∼ 0.01 g PM 2.5 kg −1 fuel. This value is roughly consistent with tire and brake emission factors from EPA MOVES3 (EPA, 2020), although it is difficult to know the extent of braking at a given site, and estimates from previous studies of non-exhaust PM 2.5 by LDV vary widely (Fussell et al, 2022). Second, we explore the impact that LDV emissions might have on EF PM(LDV) .…”

Road tunnel-derived coarse, fine and ultrafine particulate matter: physical and chemical characterization and pro-inflammatory responses in human bronchial epithelial cells

“…However, salting and sanding were not used inside the road tunnels in Trondheim, suggesting that these sources are minor contributors to the PM reactivity of our road tunnel PM samples. Conversely, particles from tires and brakes, which contains OC and different metals, may constitute a varying, but smaller part of PM2.5 and PM10 [ 70 ]. Although some experimental studies indicate a higher inherent reactivity of particles from these wear sources, further studies are needed to assess their respective contribution to the health impact of traffic-derived PM [ 67 , 70 ].…”

“…Conversely, particles from tires and brakes, which contains OC and different metals, may constitute a varying, but smaller part of PM2.5 and PM10 [ 70 ]. Although some experimental studies indicate a higher inherent reactivity of particles from these wear sources, further studies are needed to assess their respective contribution to the health impact of traffic-derived PM [ 67 , 70 ]. The role of these particle sources has not been addressed in the present study of road tunnel PM.…”

Atomic spectrometry update – a review of advances in environmental analysis

“…An editorial review paper (35 references) presented 10 16 themed papers that discussed the sources, composition, accumulation, pathways, impact and management of road dust in urban and industrial environments. Similar topics were discussed 11 in a review (257 references) in which it was noted that to date there have been few source-specific studies and that current toxicological and epidemiological evidence did not provide a clear picture of the health risks posed.…”