The influence of vegetation on the horizontal and vertical distribution of pollutants in a street canyon

► Vegetation had a marked influence on the vertical and horizontal concentrations of NO2 within the street canyon. ► Vegetation led to an increase in the storage of pollutants within the canopy space. ► Vegetation reduced upwards transport of vehicle emissions and downward penetration of clean air. ► Some evidence to suggest vegetation changed the chemistry of the atmosphere within the leaf canopy.