After investigation the UK body which gives independent health guidance to national and local government have argued that city trees increase the amount of foul air that people breathe.
Trees which are widely believed to remove pollutants and improve urban life may actually slow air currents causing pollution to settle.
In new draft guidance by National Institute for Health and Care Excellence (NICE) for local government to combat air pollution it is stated:
"Leaves and branches slow air currents, causing pollutants to settle. They may also act as sinks for particulates and chemicals that may have direct or indirect effects in air quality. Air quality [under trees] may deteriorate at street level near vehicles."
NICE maintain they would not recommend that councils cut down trees in leafy suburbs to meet pollution limits, but urges planners, local authorities and developers to take into account the adverse effect that trees can have on air quality if badly sited or unmanaged.
Many factors need to be taken into account when deciding on the positive or negative impact trees may on air pollution including species, canopy density, time of year and wind direction.
