Instead of taking appropriate steps to protect the workers, government officials gave them false reassurances about the levels of toxicity in the air they were forced to breathe, critics charged.

In fact, Christie Todd Whitman, who headed the US Environmental Protection Agency at the time, reportedly said on a number of occasions that the air in lower Manhattan was safe. However, she did recommend that ground zero workers should use protective breathing equipment at the site.

The chair of the the congressional hearing, Connecticut Rep. Christopher Shays, said Whitman's public reassurances in the aftermath of the tragedy "defied logic," according to accounts.

The EPA of lied to New Yorkers and endangered public health, New York Sen. Hillary Rodham Clinton reportedly told the hearing.

Whitman faces a lawsuit for failing to ensure that the workers were adequately protected from environmental health dangers.

In her defense, Whitman reportedly insisted that it was up to the local authorities to see that the rescue workers were outfitted with the proper safety gear.

New York city officials -- themselves the target of criticism for doing too little to protect the rescue teams -- maintain that worker safety at ground zero was the federal government's responsibility.

One of the speakers at the hearing was Joseph Zadroga. His son, James Zadroga, 34, was an NYPD officer who died from a respiratory disease following his exposure to toxins at ground zero.

Zadroga attempted to get treatment but received no help whatsoever from the city, his father charged, adding, "He was treated like a dog."

Although a medical examiner in New Jersey determined that Zadroga's illness was directly connected to his 500 hours of work at ground zero, New York city has refused to recognize his death as being in the line of duty, according to accounts.

Thousands of 9/11 workers are likely to require lifelong assistance due to "chronic and disabling illnesses," testified Dr. Robin Herbert, co-director of the Mount Sinai Medical Center program in New York, which monitors workers who have developed health concerns.

Already, 70 percent of the workers at ground zero have respiratory problems attributable to their exposure, according to new research conducted at Mount Sinai. Results of the study were released on Tuesday.

Workers also suffer from other ailments, including gastrointestinal diseases and mental health problems.

Michael Leavitt, secretary of the Department of Health and Human Services, reportedly told New York lawmakers on Thursday that $75 million would be provided for 9/11-related health treatment programs. White House officials said the government would continue offering help for the workers but did not specify how much would be allocated for their long-term care.

The $75 million figure doesn't even come close to being enough for the treatment needs of the sick workers, New York Reps. Carolyn Maloney and Vito Fossella said, calling the promised funds "a good start."