Former U.S. EPA chief Christie Whitman said Monday the agency did its best to warn workers about environmental hazards after the World Trade Center attack, according to several published reports.

Whitman faced charges from Rep. Jerrold Nadler, D-N.Y., who chaired the hearing, and others that the Environmental Protection Agency's public statements after the Sept. 11, 2001, attacks gave people a false sense of safety.

Whitman told the congressional committee she did not remember any EPA scientists advising her after the Sept. 11 tragedy that the mix of dust and gas hanging in the Manhattan air posed any long-term health risks, but rescuer crews were urged to wear respirators nonetheless.

The former New Jersey governor, who ran the agency at the time of the attacks, said she based her reassuring statements in 2001 on information from EPA scientists and sought to share that science with the public by posting all EPA test data on air quality on the agency's Web site. She said she warned workers at Ground Zero that they should wear respirators because they would be stirring up asbestos and other potentially hazardous chemicals by digging in the rubble.

Whitman said she was "disappointed at the misinformation, innuendo and outright falsehoods" circulating about the EPA's alleged failure to warn first responders who are now developing illnesses blamed on inhaling toxic materials during the rescue and recovery phase.

She also denied withholding information about toxins from the general public.

A study of more than 20,000 people by Mount Sinai Medical Center in New York concluded that, since the attacks, 70 percent of Ground Zero workers have suffered some sort of respiratory illness, according to the Associated Press. A separate study released last month found that rescue workers and firefighters contracted sarcoidosis, a serious lung-scarring disease, at a rate more than five times as high as in the years before the attacks.

Whitman, who left the EPA in 2003, said she was distressed that the agency, rather than the al-Qaida terrorists who destroyed the twin towers, was being blamed for workers' illnesses.

Whitman, the EPA and New York City officials are the target of several lawsuits filed by workers and residents around Ground Zero who allege they were not adequately warned of the dangers.

Former OSHA administrator John Henshaw, who headed the agency in 2001, also testified at the congressional committee hearing Monday, defending OSHA’s decision not to enforce workplace safety regulations at Ground Zero. He said it would have taken too long to develop the necessary evidence to support citations.

Henshaw said he was pleased with OSHA’s response during 9/11 noting that no lives were lost in the dangerous 10-month rescue, recovery and cleanup mission.