TUESDAY, Sept. 11, 2007 (HealthDay News) -- No one doubts the impact of the Sept. 11, 2001, World Trade Center disaster on rescue and cleanup workers' hearts, lungs and minds.
First, workers inhaled a toxic cocktail of soot, metals and other particles deep into their lungs during 12-hour shifts that lasted for weeks. There was also the psychological toll the cleanup effort took -- especially on those least prepared to deal with it.
"There were quite powerful stories of workers who would receive a load of debris and be dumping and find, for example, a human hand in it. And then not to be able to adequately process what it was that they were experiencing," said Alison Geyh, an environmental health scientist at Johns Hopkins University who spent weeks at the site -- an experience she said often left her shaken.
When it comes to the long-term health impact on workers, however, nothing remains certain, despite numerous highly publicized reports from government and private agencies.
"It's a real commentary that here we can have the largest manmade catastrophe of this sort for which we have so little environmental data," said Jeanne Stellman, now a professor of preventive medicine at the State University of New York Downstate Medical Center, in New York City.
"That's really a sad commentary on how we handled it," said Stellman, who took part in a landmark Mount Sinai Medical Center study as the deputy director of Mount Sinai's Selikoff Center for Occupational and Environmental Medicine in New York City.
The study released by the center just before the five-year anniversary of 9/11 found that 69 percent of 9,442 responders examined reported "new or worsened respiratory symptoms."
Almost half -- 46.5 percent -- of responders suffered more serious lower respiratory symptoms, including phlegm-laden "World Trade Center cough," the study found. Just under 63 percent said they have suffered from milder symptoms since cleanup wrapped up in April 2006, such as itchy eyes or runny noses.
And at least two people have died from illnesses experts have linked to 9/11 exposures. Felicia Dunn-Jones, a 42-year-old lawyer, succumbed to a disease resembling sarcoidosis five months after the attacks, and James Zadroga, a 34-year-old New York City police detective, died of pulmonary disease early in 2006.
Other studies have also suggested at least short-term respiratory effects, including a New York City Department of Health study released last month that found first responders to the attack now have a risk for asthma that is 12 times that of the general population.
But the available data may never be adequate to reveal the whole picture, experts said.
"First of all, we know nothing about the types of contaminants that were present in the days following the event, because there was no monitoring in place," Geyh said.
Her team's study, published in May in the New England Journal of Medicine, found relatively high levels of fine particles under 2.5 micrometers in diameter in air samples taken at Ground Zero in late September and October, 2001. These tiny particles can lodge deep in the lungs, potentially causing health problems for years to come.
Geyh said the U.S. Environmental Protection Agency wasn't able to install air monitoring equipment at the Trade Center site until near the end of September 2001. And she stressed that no one sample can ever give an adequate picture of the overall air quality. "It varied day to day," she aid. "We hypothesize that that had to do with how aggressive the fires were burning, or how aggressive the debris-removal activity was occurring."
Stellman, who has testified before the U.S. Senate on Ground Zero air quality and the clean-up effort, said getting a fix on the exact level of contaminants any one worker might have been exposed to will be nearly impossible. "The air changed from moment to moment, place to place, day to day," she noted. "We only have a small number of measures as to what was there."
Worker's level of protection varied too -- something Geyh said she witnessed firsthand. A variety of masks -- everything from the plain white ones commonly sold, to more sophisticated half-face, canister-equipped versions -- were often available, she said. But workers got little direction on how to use them or which mask might be best for their particular level of exposure. "It was very clear to us that that information was not easily found by the people who were supposed to be wearing the mask," Geyh said.
Another expert pointed to the discord that exists between EPA air samples and those garnered by private testing firms. Those firms were hired by banks and other corporations to test whether it was safe for workers to return to their lower Manhattan offices in the weeks after 9/11.
Those private environmental testing services "found a list that was longer in terms of contaminants, and in higher concentrations, for weeks afterwards and possibly even for longer," compared to EPA readings, said Dr. Len Horovitz, a pulmonary specialist at Lenox Hill Hospital in New York City. "There's a conflict of the information that we got at the time and what private companies were getting."
Stellman refuted that argument, however, saying that Horovitz was comparing "apples and oranges." She said that while the EPA was taking samples of outdoor air quality, most of the sampling done by the private firms was done inside buildings.
"It's very hard to make these comparisons because the EPA, I don't believe, had a lot of indoor air quality data," Stellman said.
But criticism of the Mount Sinai research program continues. In a Sept. 7, 2007, article in The New York Times, a number of critics charged that the findings from the Selikoff center -- founded in the 1980s with political backing from labor unions -- are biased in favor of boosting the number of workers thought to be affected by contaminants.
The center's supporters -- including Stellman -- shot back that the Mount Sinai team's efforts were stymied early on by a lack of federal funding and the government's emphasis that worker health screening, not research, be the focus of their efforts at the site.
So, questions on the long-term health effects of those weeks of grueling work at Ground Zero remain unresolved and may never be resolved due to a paucity of data, the experts said.
"What we don't know certainly weighs much more heavily than what we do know," according to Horovitz.
One thing scientists do understand, he said, is that particles under 2.5 micrometers can lodge in the lungs' tiniest channels for years, potentially causing lung disease, atherosclerosis ("hardening of the arteries"), and even cancers.
Many of these illnesses may not show up for decades. "It is definitely far too early to know what's coming down the road for cancer, for example," Stellman said.
She believes it may never be certain whether Ground Zero exposure was carcinogenic. "Because, tragic and horrifying as [9/11] was, the population exposed may never be big enough [statistically] to actually give us a definite answer," Stellman explained.
The psychological consequences for workers are becoming increasingly clear, however. In another New York City health department report, released in August, researchers found that one in every eight responders and workers has come down with post-traumatic stress disorder (PTSD).
Risks for the troubling condition appear to correlate with the length of time workers spent at the Trade Center site, how soon they arrived after the disaster, and their level of training in dealing with traumatic events, the study found.
All of the data, on both mental and physical health, does point to one conclusion, the experts said -- that workers will need to be monitored and tended to for decades to come.
"They are the people who put themselves at risk to help this country heal," Geyh said. "We should be vigilant to make sure that we understand what's going on with them."
There's more on the health of Ground Zero workers at the World Trade Center Health Registry.