"CAMBRIDGE, Mass. -- Polluted air causes roughly 200,000 early deaths each year across the United States, researchers from the Massachusetts Institute of Technology conclude after tracking emissions from industrial smokestacks, vehicle tailpipes, marine and rail transport, and commercial and residential heating."

"Emissions from road transportation are the most deadly, causing 53,000 premature deaths a year, followed by power generation, with 52,000 deaths, finds the study by MIT’s Laboratory for Aviation and the Environment published in the journal 'Atmospheric Environment.'

'It was surprising to me just how significant road transportation was, especially when you imagine coal-fired power stations are burning relatively dirty fuel,' said lead researcher Steven Barrett, an assistant professor of aeronautics and astronautics at MIT."

Environment News Service had the story September 4, 2013. [2]