The study, published in the British medical journal The Lancet, also found that roughly 10,000 firefighters who worked at ground zero were percent higher than their counterparts who did not spend time in Lower Manhattan.
Researchers evaluated the health of male firefighters who were exposed to toxic dust, cancer-causing agents and smoke, as well as those unexposed over a period of seven years following the 9/11 attacks.
This study clearly shows World Trade Center exposure in these firefighters led to an increase in cancer, Dr. David Prezant of the New York City Fire Department, told Reuters.
According to The New York Times, there were 263 cancer cases in the exposed population, reflecting a cancer rate 19 percent higher than that of the group unexposed.
Of those in the study, 8,927 were classified as exposed, meaning they spent at least one day at the site in the 10 months after Sept. 11, the Times reported.
Prezant, professor of medicine at Albert Einstein College of Medicine of Yeshiva University, noted that WTC exposure caused chronic inflammation and that such inflammation has been implicated as a risk factor for cancer in experimental and epidemiological studies.
The study showed that the most common types of cancer found in ground zero firefighters include prostate cancer, colon cancer, non-Hodgkin lymphoma and thyroid cancer.
This shows an increase in all cancers, Prezant said, adding the study was not designed to show increases in a particular type of cancer.
Many first responders, including about 12,500 New York City firefighters, were exposed to potentially hazardous toxic dust consisting of pulverized cement, glass fibers, asbestos, lead, polycyclic aromatic hydrocarbons, from the collapsed and burning buildings, the study noted.
On Sept. 11, 2001, al-Qaeda terrorist attacks destroyed a complex of seven buildings featuring landmark twin towers at the World Trad Center in Lower Manhattan, killing nearly 3000 people. In less than a week, the U.S. will observe the 10th anniversary of the WTC disaster on Sunday, Sept. 11, 2011.
The WTC site is being rebuilt with five new skyscrapers and a memorial to the casualties of the attacks, city officials say.
The cancer rate of the exposed group was only 10 percent higher than that of American men over all.