Read the full story from the Food & Environment Reporting Network.
In the United States alone, air pollution kills about 115,000 people a year — more than three times the number of deaths caused by motor vehicles. Worldwide, some 7 million people died in 2012 alone from exposure to air pollution, according to the World Health Organization. The U.S. and other developed nations have taken major steps in recent decades to decrease pollution emissions from smokestacks and tailpipes. Yet a surprising source of harmful air pollution particles — emissions of ammonia from livestock manure and synthetic fertilizer application — continues to grow in parts of the U.S., Asia and Europe.