Mitigation of urban air pollution with green vegetation for sustainable cities: a review

This paper presents a narrative review on the utilisation of urban trees and vegetation to reduce air pollution in urban areas. The results show that trees act as a barrier between sources of pollution and population by the objection of airborne particles and exploitation of gaseous emissions through leaf stomata on the plant surface. The factors that affect the extent of air quality improvement by trees depend on their type, air quality index, leaf size and shape, and seasonality. In addition, the geography, climate, demographic and built-environment make-up of the urban entity play major role in this application.