Analysis of Tire and Road Wear Particles Generated from a Microplastic Chamber

ABBY AYALA, Rebecca Parham, Madeline Clough, Anne McNeil, Andrew Ault, University of Michigan

     Abstract Number: 646
     Working Group: Chemicals of Emerging Concern in Aerosol: Sources, Transformations, and Impacts

Abstract
Plastics are heavily integrated into the Anthropocene’s framework due to their environmental resilience and mismanaged waste. Small plastics, often referred to as microplastics (1–5000 µm), can be suspended in the atmosphere, contributing to both climate and health impacts. Most research on vehicle pollution is focused on soot and secondary species formed in exhaust, but tire and brake abrasion also generates atmospheric microplastics. These non-exhaust vehicle emissions are complex materials, containing not only microplastics but also road debris, among other components. Lab-generated samples isolated from other sources are needed to determine the physicochemical properties of such emissions, however, traditional abrasion simulators have limited accessibility due to their size and cost. Herein, we characterize a microplastic chamber, designed in-house utilizing a rotary tool, to allow for convenient and dry generation of tire and brake-wear particles. Once the chamber's efficacy was verified by size distributions, samples were collected via inertial impaction and analyzed with vibrational spectroscopy, specifically optical photothermal infrared (O-PTIR) + Raman microspectroscopy. The simultaneously collected submicron infrared and Raman spectra are improving existing libraries and enabling comparison to ambient samples so that components contributing to atmospheric microplastic concentrations can be identified.