Tuesday, September 10, 2013

Plant Street Trees to Clean the Air

By Dan Shapley

Planting trees is good for the environment, good for the soul, good for the local economy... and, it turns out, even better for our health than previously thought.
A recent study published in Environmental Science & Technology found that trees and other green plants can reduce two key air pollutants eight times more than previously known.
Nitrogen dioxide and fine particulates are two key components of smog and soot, which can damage lungs, make outdoor exercise unsafe and send asthmatics running to the emergency room at high rates. Both pollutants, however, can be reduced by as much as 40% (nitrogen dioxide) to 60% (fine particulates) if trees, shrubs, ivy and even grass are planted in so-called "urban street canyons." Trees, in fact, may be less effective than smaller greenery, since pollutants may be trapped beneath the tree canopy in some cases.
While city dwellers, particularly renters, often don't have the right to plant trees or other greenery outside their buildings, we can all urge neighborhood associations, co-op boards and local governments to invest in plantings that beautify the streetscape and cleanse the air. Outside of cities, homeowners should take note of local codes before planting street trees, too.
Trees, of course, have many benefits, in urban, suburban or rural environments. Strategically planted, trees can also reduce home energy use by as much as 30%, according to the Arbor Day Foundation, and street trees may boost home values in the neighborhood by more than $10,000, according to a 2010 Forest Service study.