| Particle type | Source of particles |
|---|---|
| Mineral particles | Wear of road and external inflow |
| Road paint wear particles | Wear of road paint |
| Glass beads | Wear of road paint |
| Glass particles | Wear of glass beads and external inflow |
| Asphalt pavement wear particles | Wear of asphalt pavement |
| Tire-road wear particles | Wear of tire tread |
| Fibers | External inflow |
| Plant-related particles | External inflow |
| Plastic particles | External inflow |