Some common air pollutants found in cities can be absorbed by plants at far greater rates than ever suspected.
The discovery has big implications for modeling how vegetation affects pollutants, as well as how particles in the atmosphere affect human health and global warming.
The finding comes from a fruitful and unusual collaboration of plant geneticists and atmospheric scientists. The plant scientists found the genes used by plants and the conditions under which they are activated to allow more volatile organic compounds (VOCs) to be absorbed. The atmospheric scientists lugged equipment around the globe to verify that the plants were indeed sucking up pollutants in the real world.
“It’s been hard to measure this in the real world,” said Thomas Karl of the National Center for Atmospheric Research. “That’s why we hauled this instrument all around the world.”
Among the specific discoveries is that deciduous plants take up about a third more oxygenated VOCs — a form of pollutant that has reacted with oxygen — than previously thought. These oxygenated VOCs come from burning gasoline, forest and other biomass fires and are even released by some kinds of trees.
“The trees actually clean up more than we thought,” said Karl.