TY - JOUR

T1 - Source apportionment of magnetite particles in roadside airborne particulate matter

AU - Gonet, T.

AU - Maher, B.A.

AU - Kukutschová, J.

PY - 2021/1/15

Y1 - 2021/1/15

N2 - Exposure to airborne particulate matter (PM) is associated with pulmonary, cardiovascular and neurological problems. Magnetite, a mixed Fe2+/Fe3+ oxide, is ubiquitous and abundant in PM in urban environments, and might play a specific role in both neurodegeneration and cardiovascular disease. We collected samples of vehicle exhaust emissions, and of heavily-trafficked roadside and urban background dusts from Lancaster and Birmingham, U.K. Then, we measured their saturation magnetic remanence and used magnetic component analysis to separate the magnetite signal from other contributing magnetic components. Lastly, we estimated the contributions made by specific traffic-related sources of magnetite to the total airborne magnetite in the roadside environment. The concentration of magnetite in exhaust emissions is much lower (3–14 x lower) than that in heavily- trafficked roadside PM. The magnetite concentration in petrol-engine exhaust emissions is between ~0.06 and 0.12 wt%; in diesel-engine exhaust emissions ~0.08–0.18 wt%; in background dust ~0.05–0.20 wt% and in roadside dust ~0.18–0.95 wt%. Here, we show that vehicle brake wear is responsible for between ~68 and 85% of the total airborne magnetite at the two U.K. roadside sites. In comparison, diesel-engine exhaust emissions account for ~7% - 12%, petrol-engine exhaust emissions for ~2% - 4%, and background dust for 6% - 10%. Thus, vehicle brake wear is by far the most dominant source of airborne magnetite in the roadside environment at the two sites examined. Given the potential risk posed, post-inhalation, by ultrafine magnetite and co-associated transition metal-rich particles to human cardiovascular and neurological health, the high magnetite content of vehicle brake wear might need to be reduced in order to mitigate such risk, especially for vulnerable population groups. © 2020 Elsevier B.V.

AB - Exposure to airborne particulate matter (PM) is associated with pulmonary, cardiovascular and neurological problems. Magnetite, a mixed Fe2+/Fe3+ oxide, is ubiquitous and abundant in PM in urban environments, and might play a specific role in both neurodegeneration and cardiovascular disease. We collected samples of vehicle exhaust emissions, and of heavily-trafficked roadside and urban background dusts from Lancaster and Birmingham, U.K. Then, we measured their saturation magnetic remanence and used magnetic component analysis to separate the magnetite signal from other contributing magnetic components. Lastly, we estimated the contributions made by specific traffic-related sources of magnetite to the total airborne magnetite in the roadside environment. The concentration of magnetite in exhaust emissions is much lower (3–14 x lower) than that in heavily- trafficked roadside PM. The magnetite concentration in petrol-engine exhaust emissions is between ~0.06 and 0.12 wt%; in diesel-engine exhaust emissions ~0.08–0.18 wt%; in background dust ~0.05–0.20 wt% and in roadside dust ~0.18–0.95 wt%. Here, we show that vehicle brake wear is responsible for between ~68 and 85% of the total airborne magnetite at the two U.K. roadside sites. In comparison, diesel-engine exhaust emissions account for ~7% - 12%, petrol-engine exhaust emissions for ~2% - 4%, and background dust for 6% - 10%. Thus, vehicle brake wear is by far the most dominant source of airborne magnetite in the roadside environment at the two sites examined. Given the potential risk posed, post-inhalation, by ultrafine magnetite and co-associated transition metal-rich particles to human cardiovascular and neurological health, the high magnetite content of vehicle brake wear might need to be reduced in order to mitigate such risk, especially for vulnerable population groups. © 2020 Elsevier B.V.

KW - Air pollution

KW - Brake wear

KW - Magnetite

KW - Particulate matter

KW - Source apportionment

KW - Traffic

KW - Brakes

KW - Diesel engines

KW - Dust

KW - Gasoline

KW - Health risks

KW - Magnetic devices

KW - Magnetism

KW - Neurodegenerative diseases

KW - Neurology

KW - Roadsides

KW - Transition metals

KW - Vehicles

KW - Wear of materials

KW - Airborne particulate matters

KW - Cardio-vascular disease

KW - Magnetic components

KW - Magnetite concentration

KW - Neurological problems

KW - Roadside environments

KW - Vehicle exhaust emissions

KW - Particles (particulate matter)

KW - cardiovascular disease

KW - exhaust emission

KW - magnetite

KW - particulate matter

KW - remanent magnetization

KW - roadside environment

KW - source apportionment

KW - wear

KW - Birmingham [Birmingham (DST)]

KW - Birmingham [England]

KW - England

KW - Lancashire

KW - Lancaster [Lancashire]

KW - United Kingdom

U2 - 10.1016/j.scitotenv.2020.141828

DO - 10.1016/j.scitotenv.2020.141828

M3 - Journal article

VL - 752

JO - Science of the Total Environment

JF - Science of the Total Environment

SN - 0048-9697

M1 - 141828

ER -