A review of non-exhaust emissions on pavement area: Sources, compositions, evaluation and mitigation

Particulate matter (PM) in outdoor air pollution is one of the most critical factors that cause serious health problems and even deaths. One significant source of these particles are non-exhaust emissions, which refer to pollutants that come from sources, like brake, tire, and road wear other than a vehicle's exhaust system. This review focuses on the presence of non-exhaust particles on pavement, encompassing their classification, composition, evaluation, and mitigation. Based on extensive literature, it can be concluded that the quantity of non-exhaust emissions is affected by a combination of complex factors, such as vehicle speed, tire type, and pavement material. Non-exhaust particles can be classified into organic, inorganic, and metal matter, each requiring a distinct analysis and detection method. The effective approaches to managing non-exhaust emissions include water cleaning, utilizing functional pavement materials, and applying chemical reagents to alleviate emission capacity. Finally, this review recommends future research directions such as combining tire-road simulation with environmental monitoring equipment, in the hope that this article will have a positive impact on the mitigation of non-exhaust emissions.