How Trees Save at Least One Life Each Year in Major Cities
See on Scoop.it – Environment
In urbanity, trees mop up aerosolized baddies like dust and smog.
What’s green, tall and saves many lives each year? If you guessed a tree, you guessed right.
Trees act to remove tiny particles from the air that would otherwise end up in people’s lungs and cause respiratory and heart problems that can shorten lives and ultimately be fatal, new research shows.
The study, to be published in the July issue of the journal Environmental Pollution, found that on average the trees save one human life in each of the 10 cities surveyed by causing a decrease in particulate matter. Trees remove as much as 64.5 tons of these tiny particles in Atlanta, and as little as five tons in Syracuse, the study found.
To arrive at these figures, researchers looked at simulations of weather patterns and hourly concentrations of particulate matter and matched those to locations of trees and urban forests. They then came up with an estimate of what volume of dust the trees take out, said study co-author David Nowak, a researcher and project leader with the U.S. Forest Service in Syracuse, New York.
The study looked at the PM2.5, the class of particulates that are smaller than 2.5 microns in diameter. These are so small that once suspended in the atmosphere, they are difficult to get out, as they tend to hover about on winds and currents. They are much more damaging than larger particulates because they can make their way deep into the lungs, Nowak said.
Trees remove these particles by trapping them on their surface, and to a much smaller extent, absorbing them into their pores. Trees with hairy or sticky leaves remove even more than most. “It’s like how you’d catch more with a fur jacket than under armor,” Nowak said. Although other objects and even buildings can remove particles by trapping particles, they are not as effective as trees, whose leaves create layers with ample surface area…….
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Now is the best time for us to plant trees.