WASHINGTON (AP) - Rudy Giuliani's experience on Sept. 11 and at ground zero propelled him into presidential politics, yet by his own admission, it may also weaken his health - a key issue for any candidate seeking the White House.
Just last week, Giuliani was criticized by some firefighter unions for suggesting he was at ground zero as much, if not more, than many rescue workers and exposed to the same health risks. He quickly backed off that statement, saying he misspoke.
"I empathize with them, because I feel like I have that same risk," said Giuliani, who was at the World Trade Center almost immediately on Sept. 11, 2001, and was onsite many times a day after that.
That assertion - made repeatedly by the former mayor over the years - could pose a different challenge in his quest for the White House, by suggesting he may not stay healthy through a presidential term that would begin in 2009.
Giuliani, a 63-year-old cancer survivor, clearly wonders about his long-term health and that of his close aides who worked with him on Sept. 11, 2001 and after.
"I'm sure that some of these people are going to have symptoms, and maybe it's not now. They're going to have them five years from now or 10 years from now," Giuliani said last year on the fifth anniversary of the attacks.
Dr. Joan Reibman, who heads a city-funded program at Bellevue Hospital in New York to study the health effects of ground zero exposure, said she had no knowledge of Giuliani's health history or exposure, but that given his public presence at the site, he should probably be enrolled in the health monitoring program for ground zero workers and lower Manhattan residents.
"I think he would have fit the criteria," said Reibman.
Asked about his health, Giuliani said in a statement that he is not enrolled in one of the 9/11 related health program but does get regular medical checkups.
"Today, I am fortunate that my health remains excellent, but I will continue to get regular checkups as I urge everyone to do," he said, and repeated a pledge to work for ground zero workers if elected president.
"No one will be a stronger supporter for those brave men and woman in the White House than me. They need and deserve our full support," said Giuliani.
Reibman, the ground zero doctor, said some trends have emerged among ground zero workers and nearby residents, but that much remains a mystery.
"I suspect that if one didn't have respiratory illnesses that one probably won't develop them now," said Reibman. "But what about late emergent diseases? I don't think we have the answer to that. I think it's very important to monitor for those. There's a lot we still don't know."
A major study by Mount Sinai Medical Center last year found 70 percent of ground zero workers suffered some form of lung problems - and experts there predicted thousands will either remain sick or get sick in coming years.
Those statistics have already struck close to home for Giuliani: two deputy mayors were made sick by ground zero exposure, one so severely that he now receives workers compensation health benefits.
Reibman said a number of factors determine whether the toxic soup at the World Trade Center site would make an individual sick: the specific contaminants around a person, the length of exposure, the intensity of the exposure, the amount of protective breathing apparatus worn by the individual, and an individual's pre-existing susceptibility to disease.
"The amount of exposure is going to differ within the recovery and rescue workers, with residents, and with the people who worked downtown," said Reibman.
For Giuliani, talking about his potential for future illness carries some political risks.
"For a presidential candidate to say that he might be sick is obviously a mixed message," said Steven Cohen, a public affairs professor at Columbia University.
"We want our presidential candidates to be healthy for at least eight more years, if not longer," said Cohen.
Cohen argued that Giuliani's rhetoric has wandered from the original source of his Sept. 11-related popularity.
"After 9/11 it really wasn't his work at the pit or anything that was the main positive aspect of his leadership, but the fact that he gave people confidence that they could resume normal life. That was unambiguous leadership at a time when it was really needed."
Even that opinion is challenged by Giuliani's critics within the New York fire and police departments, some of whom never forgave him for pushing an ambitious cleanup schedule that, they charge, ignored the ongoing recovery of bodies at the site.
Jimmy Riches, a deputy fire chief who spent months digging at ground zero for his firefighter son, scoffs at the very notion that Giuliani was at ground zero long enough to risk his health.