Automotive braking is a source of highly charged aerosol particles

• DOI: 10.1073/pnas.2313897121
• Publication Date: 2024-03-11T19:01:20Z
• Authors: Adam E. Thomas; Paulus S. Bauer; Michelia Dam; Véronique Perraud; Lisa M. Wingen; James N. Smith
• Keywords: Brake pad; Particle (ecology)

Although the last several decades have seen a dramatic reduction in emissions from vehicular exhaust, nonexhaust (e.g., brake and tire wear) represent an increasingly significant class of traffic-related particulate pollution. Aerosol particles emitted wear automotive pads contribute roughly half particle mass attributed to sources, while their relative contribution urban air pollution overall will almost certainly grow coinciding with vehicle fleet electrification transition alternative fuels. To better understand implications this growing prominence, more thorough understanding physicochemical properties (BWPs) is needed. Here, we investigate electrical BWPs as ceramic semi-metallic pads. We show that up 80% are electrically charged fraction strongly dependent on specific pad material used. A dependence number charges per charge polarity size also demonstrated. find produces both positive negative can hold excess 30 elementary evidence produced than positive. Our results provide insights into currently limited charging mechanisms, which potentially atmospheric lifetimes thus relevance climate quality. In addition, our study inform future efforts remove BWP before entering atmosphere by taking advantage electric charge.