In New York, a major new health study has found that nearly 70 percent of first responders at Ground Zero suffer from chronic lung ailments. The report by Mount Sinai is the largest ever done on 9/11 health effects. For the past five years city, state and federal officials have downplayed the health dangers of the toxic dust that was released when the World Trade Center collapsed. Last week the city issued guidelines for doctors on how to spot and treat illnesses related to Ground Zero. The city was widely criticized for taking nearly five years to release the guidelines. On Tuesday, Mayor Mike Bloomberg announced the city will begin providing health treatment to anyone sickened by Ground Zero contaminants.