Particulate matter and foliar retention: current knowledge and implications for urban greening

Suspended particulate matter (PM) constitutes a major problem in urban areas. Air purification of polluted cities is critical for protecting the increasing population. PM deposited on leaves can be an effective method of air quality amelioration. However, there are several factors involved, either favoring or hindering the PM capture. In this revision, we synthesized the current information about PM plant retention: plant features, consequences, and the relation with the urban environment. We also propose to use a knowledge-based planning framework to designate zones with similar characteristics across the city and to select the vegetation according to the necessities of each of these zones. Since available information regarding the best plant species to retain PM is sometimes contradictory, the application of a knowledge-based framework could be useful to focus future research on field conditions.