Health survey looked at 9/11 adults 2006-2007 after 46,000 attacks . Adults who were expose to intense dust clouds developed asthma at higher rates . 46,000 Americans have asthma , which causes airway swelling and inflammation .
Health survey looked at 46,000 adults five to six years after 9/11 attacks . Adults who were expose to intense dust clouds developed asthma at higher rates . 23 million Americans have asthma , which causes airway swelling and inflammation .