Fischetti, Mark. “Trees That Pollute.” Scientific American June 2014: 14. Print.
Though trees are thought to be beneficial, oxygen-emitting resources, some apparently become less eco-friendly in the presence of nitrogen oxide. Released by vehicle fumes, the nitrogen oxide combines with trees’ volatile organic compounds (VOCs) to create ozone, which influences asthma, bronchitis and other respiratory conditions.
Certain trees like black gum, poplar, oak and willow emit significantly higher levels of VOCs, as opposed to birch, tulip and linden which release far less amounts. Because of this, urban planners are urged to plant these lower VOC trees when adding greenery to cities. I think this is a wise advisory but I agree with Fischetti in thinking reduced car emissions, not reduced trees, should be our main priority.
