NEW YORK (MCT) — Ten years ago, they left the flattened World Trade Center site exhausted, traumatized, and in some cases, fatally ill.

On Wednesday evening, thousands of first responders and volunteers who sifted through what remained of the Twin Towers returned to the site - this time, to be thanked.

The National September 11 Memorial and Museum marked the 10th anniversary of the official end of the cleanup with a tribute on the 9/11 Memorial Plaza in lower Manhattan.

A decade later, the health and financial effects of the nine-month cleanup and rescue operation are still playing out. As soon as this week, a federal official is expected to rule whether first responders who later developed cancer are entitled to part of a $2.8 billion settlement for ailments caused by the toxins that many inhaled, even as some officials assured the public that the air was safe.

That decision, to be made by the director of the National Institute for Occupational Safety and Health, will affect many who attended the tribute, like Tom Fay.

The retired Spring Lake, N.J., volunteer firefighter developed non-Hodgkins lymphoma and skin cancer years after he spent 12 hours rummaging through the debris of the south tower in search of human remains. He came to the site as a volunteer two days after the attacks and found himself in the rubble, searching for survivors. He said he'd do it again, despite his bouts with cancer, which he attributes to the cleanup. He has overcome both.

"I constantly have to worry that I'll have to tell my wife that my blood is bad," said Fay, a sales executive, adding that the treatments have been expensive.

Congress approved the James Zadroga 9/11 Health and Compensation Act in 2010. The law does not cover cancer, but it requires periodic reviews of studies to determine whether it should be added to the covered ailments.

"For guys like me, to hear New York officials say thank you, it temporarily puts the cancer in the rearview mirror," Fay said.

Volunteers didn't just dig through rubble. Bob Nesoff, 73, of New Milford, N.J.then a communications director for the Bergen County Sheriff's Office, said he came to the site a half-dozen times as a volunteer. He filled unfamiliar law enforcement roles, including guarding the New York City bomb squad precinct and responding to a report of a stolen ambulance.

He also accompanied trucks from Passaic and Bergen counties that delivered supplies in the days after the attacks.

"It's pure emotion to stand here now," he said, standing at the edge of the one-acre pool where the south tower once stood. "It gets you choked up."

During the nearly three-hour event, thousands of volunteers, first responders and their guests made their way in a procession past a receiving line of former and current officials. They included New York City Mayor Michael Bloomberg, former Mayor Rudy Giuliani, former New Jersey Gov. Donald DiFrancesco and former New York Gov. George Pataki. Attendees congregated throughout the 8-acre site and spoke amid the wail of bagpipes and choir music.

Anthony Barzelatto, a first responder from Tenafly, N.J., did not attend the event but said in a telephone interview that his experience at ground zero "changed my life."

"Everything I experienced there, from the smells, the sights, to everything I touched, the expressions on people's faces, the destruction, and of course, the death," said Barzelatto, a councilman in Tenafly.

"The day changed everybody's life," he added. "There is not a day that goes by that I don't think about it."

He said he has since developed kidney and bladder cancer.

"And the only way I got it was from the site," he said.

Jimmy Riches, a former New York City Fire Department captain who lost his son in the attacks, nearly died from respiratory problems, he said. He spent nine months at the site, searching for the remains of his comrades and his son. He carried out his son's crushed body, he said.

In 2005, he said, he went to the hospital with what he thought was the flu. Hours later, doctors told his wife that his lungs were filled with fluid and that he had five hours to live. He went into an induced coma. He was given his last rites.

"They kept telling my family I wasn't going to make it, and I held on for 16 days before I made it out," he said. A previously healthy runner in his mid-50s, Riches emerged from acute respiratory syndrome with stroke-like symptoms. He had to learn to walk again.

In 2006, 70 percent of 10,000 recovery workers screened at Mount Sinai Medical Center had trouble breathing.

"We were breathing benzene; all types of asbestos," Riches said. "They didn't give people the proper equipment."

He recalled what Christie Whitman, the former New Jersey governor and the administrator of the U.S. Environmental Protection Agency at the time of the attacks, told the public in a news release a week after the towers came down: "Given the scope of the tragedy from last week, I am glad to reassure the people of New York . that their air is safe to breathe and the water is safe to drink."

Eleven years on, Riches said he worries about future health issues.

"Am I going to be the next one to have lung cancer? That's everybody's fear," he said.