THE BRONX - The Department of Environmental Protection says that New York City air is the cleanest it's been in 50 years, but it's taking steps to further improve and maintain air quality for its residents. 

The agency plans to increase the efficiency of large building boilers by launching new rules on burning heating oil and natural gas, and new requirements on annual tune-ups and testing to ensure boilers are up to code. 

Improved air quality is especially important in the Bronx, which sees some of the city's highest rates of youth asthma. The Health Department says that neighborhoods such as Hunts Point, Mott Haven, Morrisania and Highbridge are particularly vulnerable. 

Health officials estimate that the changes will save 800 lives, and prevent hundreds of emergency room visits and hospitalizations for respiratory problems.