Clean the air with plants – can PAH exposure be reduced with urban vegetation?

There is a proven link between exposure to air pollution and an increased disease risk. Particle-bound PAHs (Polycyclic Aromatic Hydrocarbons) are suspected to account for a substantial part of these toxic effects. Trees can serve as sinks for air pollutants such as the carcinogenic PAHs, thereby cleaning the air. However, this effect is not well quantified. In this project we compare the differences in PAH accumulation of twelve different tree species as well as measure PAH levels in tree leaves and needles at urban sites with different pollution levels and distance to traffic. Finally, we will provide recommendations how to use the results for urban planning, choice of trees and the design of green spaces to promote good air quality.