Trees may increase air pollution on city streets

Leaves and branches can slow air currents and cause pollutants to settle, says health watchdogCity trees, popularly thought to remove pollutants and improve urban life, may also increase the amount of foul air that people breathe, says the UK body which gives independent health guidance to national and local government.
“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