Thanks to a clean air initiative, New York City's air is the cleanest it's been in 50 years. In 2007, Mayor Bloomberg began the Clean Heat Program, which phased dirty heating oils out, dropping levels of sulfur dioxide and soot pollution by 69 and 23 percent, respectively. A release from Bloomberg's office states that, this has prevented 2,000 emergency room visits and 800 deaths annually.
Gothamist notes that the American Lung Association gives the city a B+ for particle pollution, but a D for ozone pollution. New Yorkers: anytime someone tries to sass you about "dirty New York," hit them with these facts.