Some plants are more effective than others mitigating air pollution with vegetated roadside buffers. Small, stiff, and complex leaves are generally more effective than larger, less rigid and less complex leaves. Leaf features that are beneficial to improved air quality include high stomatal density or size, high epicuticular wax content, and features that increase leaf roughness. While vegetative buffers can reduce pollution exposure at a local scale, reduced emissions are the most effective strategy.
Barwise, Yendle, and Prashant Kumar. “Designing vegetation barriers for urban air pollution abatement: a practical review for appropriate plant species selection”. npj Climate and Atmospheric Science 3, 12 (2020). https://doi.org/10.1038/s41612-020-0115-3