It is estimated that around 9,400 Londoners die every year due to poor air quality, costing the economy £3.7bn. A report published in May from the World Health Organization found that deaths in the UK attributable to air pollution are worse than comparable European countries such as France and Spain. But research published on the same day in the journal Atmospheric Environment by a team led by Professor Prashant Kumar of Surrey University suggests that the harmful impact of urban air pollution could be combated by strategically placing low hedges along roads in a built-up environment of cities instead of taller trees.
“The emissions from vehicles start to dilute very quickly as you move away from the road,” Professor Prashant Kumar said, “so any hedge that acts as a barrier slowing down the airflow and catching pollutants on the leaves is going to offer people in homes better protection…In Britain we need to start thinking about planning for hedges to harness their full potential in cities like London.”
The research team says hedges should be installed on the edge of pavements, as they are closer to the level of most exhaust pipes and can absorb damaging particles before they disperse into the air. Councils should try to plant low hedges between pedestrians and the street if pavements are wide enough. Professor Kumar said scientists were currently investigating which species of hedge plant made the best pollution absorbent, but that in principal authorities should plant hedges with the greatest leaf surface area.
Do your bit for World Environment Day!
Celebrate World Environment Day (5 June) by planting a hedge near a road, or by asking your local council to consider planting more hedges near road.
About Professor Kumar
Professor Prashant Kumar is Chair in Air Quality and Health at Surrey University and Founder Director of the Global Centre for Clean Air Research (GCARE)