An extensive study done by the New York City Health Department found no definitive link between various cancers and the toxic dusk and fumes surrounding the World Trade Center terrorist attack more than 11 years ago.
The study, published Wednesday in the Journal of American Medical Association, comes just six months after the federal government added 50 different cancers to the list of illnesses covered by the $4.3 billion James Zadroga 9/11 Health and Compensation Act.
The New York City study was the most extensive ever done regarding health issues stemming from the burning wreckage at the 9/11 site that included smoke and fumes filled with known carcinogens like asbestos, benzene, polycyclic hydrocarbons, silica and other toxic chemicals.
There were an estimated 400 tons of asbestos used in the building of the Twin Towers, which were part of the World Trade Center attack on Sept. 11, 2001 that killed close to 3,000 people.
An exposure to asbestos, for example, has been proven to cause a number of serious illnesses, including mesothelioma cancer, lung cancer, and asbestosis. The World Trade Center Health Registry estimates that 410,000 people were exposed to the toxins that were present in the air for weeks after the attack.
Mesothelioma, like many cancers, has a long latency period. It can take anywhere from 10 to 60 years after exposure to asbestos before obvious symptoms appear and a definitive diagnosis can be made.
Although the latest, most extensive study done involved 56,000 people who enrolled in the registry, it used only data collected from 2001 to 2008, well before many of the cancers would be expected to arise.
The New York City study, done with the help of the National Institute for Occupational Safety and Health (NIOSH), showed a link with thyroid, prostate and myeloma cancers, but only for the rescue and recovery workers who were exposed for extended periods of time as they worked around the wreckage. They found no evidence to support a link to most other cancers, or any links to those whose exposure to the toxins was for shorter periods of time.
The study, which almost refutes some earlier, more popular beliefs, is expected to fuel debate on the wisdom of adding so many cancers to be covered by federal funding. There have been at least two confirmed rescue workers from the wreckage who have died from mesothelioma cancer, in 2004 and 2006.
“Cancers take 20 years to develop,” Thomas Farley, M.D., health commissioner in New York City, told the New York Times. “And we might see something different 20 years down the line. But don’t want to wait 20 to 30 years to get a definitive answer.”
The 9/11 Health and Compensation Act originally was designed to cover mostly respiratory illnesses, which were well documented. Early studies in New York strongly linked cases of asthma, and post-traumatic stress disorder, with the toxic dust. The blanket cancer coverage came earlier this year, and is expected to exhaust the $4.3 billion fund much quicker than it would have been.
Dr. John Howard, head of NIOSH who made the final decision, was under considerable pressure to add cancer to the list of illnesses covered, and received praise for his decision that was signed into law by President Obama. The NYC study, though, now has others questioning the expenditure at a time of huge federal deficits. It may affect the willingness of Congress to replenish the fund in the future.
The new study included everyone from rescue workers and emergency responders to residents of Manhattan and others who fled the site and never returned. It found 67 cases of prostate cancer, 13 cases of thyroid cancer, and seven cases of myeloma. All three cancers had higher incidence rates among the registry than the general population in the state of New York.
The researchers pointed out that it was too early to draw any conclusions from their study. People who volunteered for the study were more likely to already have symptoms than those who did not volunteer.
“There is no evidence that 9/11 caused any of these cancers,” Donald Berry, biostatistics professor at MD Anderson Cancer Center in Houston, told the Associated Press. He said that definitive conclusions were impossible because the study had too many limitations.