Flashback: Whitman Sued for Calling 9/11 Air "Safe to Breathe"
Thousands of people exposed to choking dust after the destruction of the World Trade Centre twin towers in New York have developed asthma, a study has shown.
Rescue and recovery workers, office staff and passers-by were included in the follow-up study of more than 46,000 people.
It found that one-in-10 caught up in the terrorist attacks of September 11, 2001 had been diagnosed with asthma five or six years after the disaster.
None of these 4,600 individuals had a previous history of the disease.
