Vehicles, not farms, are likely source of smog-causing ammonia

Friday, Apr 14, 2017
by John Schoonejongen for the Office of Engineering Communications

Agriculture has long been blamed for smog-causing ammonia in the atmosphere, but vehicle tailpipes actually are a more important source of ammonia's contribution to the haze that hovers over big cities, according to new research by a team including Princeton engineers. "Ammonia doesn't have to come all the way from the Midwest to Philadelphia or New York," said Mark Zondlo, an associate professor of civil and environmental engineering at Princeton University. "Much of it is being generated here."

Read more about smog-causing ammonia.