By Roger Harrabin
Hedges are often better than trees at soaking up air pollution among tall buildings, research has suggested.
A paper in the journal Atmospheric Environment says tall trees are good at absorbing pollution in more open areas. But hedges can trap toxins at exhaust pipe level, so reduce people's direct exposure to harmful pollutants.
Lead author Prof Prashant Kumar said councils should try to plant low hedges between pedestrians and the street if pavements are wide enough.