Key points from article :
Study looked at how road-side green infrastructure affected the concentration levels of air pollution.
Options included trees, hedges, and a combination of trees with hedges and shrubs.
Six UK roadside locations used where the green infrastructure was 1-2 metres away from the road.
Hedges cut black carbon by up to 63 percent.
Fine particles (PM2.5) showed the least reduction among all the measured pollutants.
Roadsides with only trees showed no positive influence on pollution reduction at breathing height.
The study was published in the Atmospheric Environment journal.
