Plants are much better pollution-eaters than thought

Chalk up yet another amazing feat for plants.

Scientists have long touted trees and other inner-city greenery for their cooling shade, property-enhancing beauty and, yes, their ability to absorb air pollution.

But apparently the greenery has been doing a much better job of it than anyone realized.

Previously, even the most ardent tree-hugging scientists thought the most the plants removed was less than five percent of the nitrogen dioxide and particulate matter -- both of which exacerbate lung problems and contribute to other health difficulties, including causing premature death.

A new study by researchers from the United Kingdom has concluded that the proper placement of grass, climbing ivy and other plants in "urban canyons" -- those busy streets lined with tall buildings --  can reduce the concentration at street level of NO2 by as much as 40 percent and PM by 60 percent.l

What makes the difference, the researchers said, is that both substances are deposited onto different surfaces at different rates. The pollution apparently adheres to vegetation at a much higher rate than it does to hard, built surfaces - like the walls of buildings.