Non-exhaust Particulate Emissions from Road Transport
An Ignored Environmental Policy Challenge
Non-exhaust emissions of particulate matter constitute a little-known but rising share of emissions from road traffic and have significant negative impacts on public health. This report synthesizes the current state of knowledge about the nature, causes, and consequences of non-exhaust particulate emissions. It also projects how particulate matter emissions from non-exhaust sources may evolve in future years and reflects on policy instrument mixes that can address this largely ignored environmental issue.
Introduction
Emissions of particulate matter (PM) from motor vehicles originate from two main sources: the combustion of fossil fuel, which is emitted via tailpipe exhaust, and from non-exhaust processes including the degradation of vehicle parts and road surfaces and the resuspension of road dust. The airborne particulate emissions generated by these processes are defined as non-exhaust PM emissions.