New Uni of Surrey study shows which plants are best at removing pollution from the air
Researchers hope this will influence urban planners to plant more pollution-catching trees in the area
Researchers from The University of Surrey hope a new study will influence urban planners to plant more pollution-catching trees in the area.
The research has found that trees with small leaves are better at removing pollution from the air.
Scientists from Surrey's Global Centre for Clean Air Research (GCARE) focused on the A3 where 80,000 vehicles are estimated to drive every day.
Here, they tested ten trees and studied which caught the most particles of pollution and which best allowed the rain to wash those particles safely to the ground.
It found the Yew plant (or taxus baccata) removed the most air pollution.
The most effective leaf types were awl-shaped. They were found on Japanese Cedar (camellia japonica) and Lawson's Cypress (chamaecyparis lawsoniana).
Yendle Barwise, former forester and University of Surrey researcher, said:
“When tackling air pollution, the ideal leaves cling on to particles when it's windy – but let go of them in the rain. That means the wind blows less pollution back into the air – but rain can wash it safely to the ground.
“Being rough and hairy isn't all it's cracked up to be.
"To remove more particle pollutants over time, leaves need to be washed by rainfall, and it seems that the size and shape of the leaf is much more important from this perspective."
Professor Prashant Kumar, founder of the University of Surrey's Global Centre for Clean Air Research, said:
"We know that planting trees by roadsides can make a big difference to air quality. Our study shows that by choosing your trees carefully, that difference can be even bigger."
"We've shown that smarter choice of plants can take even more pollution out of the air. We just studied the shapes and textures of the leaves themselves.
"Other factors, like the tree's height, leaf chemistry, or how many trees you plant, could also make a big difference. Those are well worth investigating in the future."