Pavement wear generates microplastics in stormwater runoff.

Area of Science:

• Environmental Science
• Materials Science
• Urban Hydrology

Background:

• Tire and road wear particles are significant urban stormwater microplastic sources.
• Distinguishing between tire and pavement wear particles is challenging.
• The contribution of pavement wear to microplastic pollution is understudied.

Purpose of the Study:

• To evaluate microplastic generation from different pavement types due to degradation.
• To differentiate microplastic contributions from pavement wear versus tire wear.
• To assess the impact of pavement material and characteristics on microplastic release.

Main Methods:

• A two-year field study combined with laboratory degradation testing.
• Analysis of microplastic generation from asphalt, concrete, and recycled rubber paver specimens.
• Investigation of land-use and pavement surface characteristic influences.

Main Results:

• Pavement wear was confirmed as a distinct microplastic source.
• Recycled rubber pavers released the highest microplastic quantities in lab tests.
• Asphalt pavement showed high susceptibility to rutting and released significant microplastics, including tire wear particles, in field tests.

Conclusions:

• Pavement material selection significantly influences microplastic generation in stormwater.
• Novel recycled-tire pavers require thorough testing before widespread adoption.
• Mitigation strategies are needed to reduce microplastic spread from pavement wear into the environment.