Nature-Based Solutions for Air Pollution Control: Role of Plants, Urban Forests, and Green Technologies

Abstract

Urban air pollution poses a significant public health crisis, exacerbated by heterogeneous urban landscapes and diverse localized emission sources. Nature-Based Solutions (NbS), including urban forestry, green infrastructure, and engineered bio-systems, offer a sustainable, multi-functional alternative to conventional grey infrastructure for air quality management. This review examines the mechanistic foundations of pollutant removal by vegetation—dry deposition for particulate matter (PM) and stomatal uptake for gaseous pollutants—while highlighting synergistic co-benefits such as urban heat island mitigation and improved pollutant dispersion. Quantitative evidence demonstrates substantial localized and city-scale reductions in PM (up to 44%) and gaseous pollutants (13.9–36.2%). However, efficacy is context-dependent, requiring optimized design (e.g., tall, dense roadside barriers), strategic species selection to minimize biogenic volatile organic compound (BVOC) emissions, and advanced modeling to account for airflow dynamics and trade-offs. Engineered NbS, such as biofilters and constructed wetlands, further enhance targeted mitigation. Scaling NbS demands addressing governance gaps, equity concerns, standardized assessment, and economic valuation of public health benefits. Integrated, ecologically informed implementation of NbS represents a cost-effective pathway to resilient, healthier cities.