title: Brake wear particle emissions: a review.
abstract: Traffic-related sources have been recognized as a significant contributor of particulate matter particularly within major cities. Exhaust and non-exhaust traffic-related sources are estimated to contribute almost equally to traffic-related PM10 emissions. Non-exhaust particles can be generated either from non-exhaust sources such as brake, tyre, clutch and road surface wear or already exist in the form of deposited material at the roadside and become resuspended due to traffic-induced turbulence. Among non-exhaust sources, brake wear can be a significant particulate matter (PM) contributor, particularly within areas with high traffic density and braking frequency. Studies mention that in urban environments, brake wear can contribute up to 55 % by mass to total non-exhaust traffic-related PM10 emissions and up to 21 % by mass to total traffic-related PM10 emissions, while in freeways, this contribution is lower due to lower braking frequency. As exhaust emissions control become stricter, relative contributions of non-exhaust sources-and therefore brake wear-to traffic-related emissions will become more significant and will raise discussions on possible regulatory needs. The aim of the present literature review study is to present the state-of-the-art of the different aspects regarding PM resulting from brake wear and provide all the necessary information in terms of importance, physicochemical characteristics, emission factors and possible health effects.
authors.affiliation: European Commission, Joint Research Centre, Sustainable Transport Unit (STU), Institute for Energy and Transport (IET), Via E Fermi 2749, 21027, Ispra, Italy, theodoros.grigoratos@jrc.ec.europa.eu.
authors.forename: Theodoros
authors.initials: T
authors.lastname: Grigoratos
authors.forename: Giorgio
authors.initials: G
authors.lastname: Martini
mesh_terms: D000397:Air Pollution; D000818:Animals; D002947:Cities; D004784:Environmental Monitoring / Q000379:methods; D006801:Humans; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis* / Q000737:chemistry; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D052638:Particulate Matter; D001335:Vehicle Emissions