Pavement wear generates microplastics in stormwater runoff

Kelsey Smyth; Shuyao Tan; Tim Van Seters; Vimy Henderson; Elodie Passeport; Jennifer Drake

doi:10.1016/j.jhazmat.2024.136495

Pavement wear generates microplastics in stormwater runoff

J Hazard Mater. 2024 Nov 13:481:136495. doi: 10.1016/j.jhazmat.2024.136495. Online ahead of print.

Authors

Kelsey Smyth¹, Shuyao Tan², Tim Van Seters³, Vimy Henderson⁴, Elodie Passeport⁵, Jennifer Drake⁶

Affiliations

¹ Department of Civil and Mineral Engineering, University of Toronto, 35 St. George Street, Toronto, ON M5S 1A4, Canada.
² Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON M5S 3E5, Canada.
³ Toronto Region Conservation Authority, 101 Exchange Ave., Concord, ON, Canada.
⁴ PTech Engineering, 12577 Fifteen Mile Rd., Denfield, ON, Canada.
⁵ Department of Civil and Mineral Engineering, University of Toronto, 35 St. George Street, Toronto, ON M5S 1A4, Canada; Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON M5S 3E5, Canada; Department of Environmental Sciences, Rutgers University, 14 College Farm Rd, New Brunswick, New Jersey 08901, USA. Electronic address: elodie.passeport@rutgers.edu.
⁶ Department of Civil and Mineral Engineering, University of Toronto, 35 St. George Street, Toronto, ON M5S 1A4, Canada; Civil and Environmental Engineering, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada. Electronic address: jenniferdrake@cunet.carleton.ca.

PMID: 39556907
DOI: 10.1016/j.jhazmat.2024.136495

Abstract

Tire and road wear particles are a major source of microplastics to urban stormwater. They are composed of hetero-aggregates of abraded tire and pavement particles that are difficult to distinguish. While tire wear is a known source of microplastics, little is known on the contribution of pavement wear. This two-year field study with complementary lab testing evaluates the effects of pavement degradation on microplastic generation in stormwater from different pavement types: asphalt, concrete, and recycled rubber pavers. Pavement specimens from each site were collected and underwent degradation testing. We directly demonstrated that pavement wear is a source of microplastics in stormwater separate from tire wear. We showed that the rubber pavement released the most microplastics in lab testing, suggesting that the formulation of such novel recycled-tire pavers must undergo thorough testing before wide application. The asphalt pavement was the most susceptible to rutting and released the most microplastics in the field, including a large proportion of tire wear particles. Both land-use and pavement surface characteristics influenced microplastic generation. These results demonstrate the need to consider microplastic generation during pavement material selection and mitigate the spread of microplastics from pavement wear to nearby environments.

Keywords: Asphalt pavement; Concrete pavement; Emerging contaminants; Hamburg Wheel-Tracking test; Rubber pavement.