New York (CNN) -- Firefighters exposed to toxic dust and fumes clogging the air after the World Trade Center towers collapsed 10 years ago are more likely to develop cancer, according to a new study. 
 
 When compared with firefighters who did not work at ground zero, firefighters working the pile were 19% more likely to get a cancer diagnosis. 
 
 According to the research, published Thursday in the Lancet medical journal, the increase occurred during the first seven years after 9/11. 
 
 "We excluded cancers that might have been diagnosed early (that may have existed before the attack) ... and we still see a 19% increase," said Dr. David Prezant, chief medical officer at the New York City Fire Department and the study's lead author, in a recent interview with CNN. "When we put those cancers back in, we see a 32% increase." 
 
 It is an unexpected finding considering that for most cancers, the latency period -- the time between exposure to a carcinogen and expression of disease -- tends to span decades. 
 
 "My initial bias was that for the first 10 or 15 years we would not see an increase," said Prezant. "That's another reason I think our findings are so strong, because I actually thought we would find the opposite." 
 
 One theory about how cancer might develop so soon among responders is that the unique characteristics of ground zero dust, and the sheer number of chemicals contained in it, may have accelerated disease in responders. 
 
 "Typically for solid tumors we would say there's a latency period of decades," said Dr. Jacqueline Moline, author of a study about multiple myeloma among responders, during a recent interview with CNN. "Is something about the dust accelerating things much sooner than we would have expected?" 
 
 Researchers have reported the presence of hundreds of compounds in ground zero dust, among them known carcinogens. Potential cancer-causing agents such as asbestos that coated the Trade Center buildings' lower columns, and benzene, a component of jet fuel that caused uncontrollable fires when planes barreled into the twin towers, have been a cancer concern for researchers. 
 
 So have the high volume of particulates and gases inhaled by firefighters, said Prezant. 
 
 "Those particulates are not just dust, they are dust coated with the same chemicals that were in the air in terms of the gases, sometimes, actually, getting deeper into the lung or better penetrating into the blood circulation because they're carried on a particle," said Prezant, who is also a pulmonologist with the FDNY. 
 
 Moline wrote one of the only other papers -- a small case series published in 2009 -- suggesting increased cancer risk among responders. It found a small but inordinate number of multiple myeloma cases among responders under age 45. Multiple myeloma is a blood cancer that typically strikes much later in life. 
 
 "Because we're dealing with unprecedented exposures, we need to be vigilant and do regular follow-up of this type of study to see if this effect is changed over time," said Moline, the chair of the Department of Population Health at Northshore LIJ Health System. "The question always is, are we seeing some cancers younger ... that you might not expect if (the risk of a particular cancer) increases with age?" 
 
 According to Prezant's study, the overall increase in cancer rates among firefighters is significant, but when the findings are broken down according to specific cancers, the numbers are more modest. There are "trends" -- subtle increases -- in gastro-esophageal cancers and blood cancers such as multiple myeloma, and non-Hodgkin's lymphoma, said Prezant, but they are difficult to generalize. 
 
 And this is an early study that will require several years of follow-up, said Prezant. 
 
 "We've just begun to understand what's happening after the World Trade Center," said Prezant. "We may find that some of our conclusions change over time, get stronger or change entirely." 
 
 Firefighter: Bill helping responders needs to cover cancer 
 
 What hangs in the balance of studies like this one is medical coverage for cancer. 
 
 The James Zadroga 9/11 Health and Compensation Act, passed by Congress in December 2010, is designed to provide medical services and compensation for responders who were exposed to dangerous toxins while working at ground zero. 
 
 The bill currently does not cover cancer, and earlier this year, the National Institute for Occupational Safety and Health, the agency evaluating which illnesses will be covered under the Zadroga Act, determined no connection between exposure to cancer and dust. 
 
 According to an agency spokesperson, the Lancet study will be included "... in our second periodic review of the medical and scientific evidence related to cancer." That review is expected in 2012. Jeff Stroehlein, a New York firefighter who started working at ground zero three days after the 9/11 attacks and continued there for two weeks, retired in May after being diagnosed with brain cancer. He said Thursday that he believes a link between cancer and exposure to ground-zero toxins is obvious, but he won't find any satisfaction from the Lancet study "until they put (cancer coverage) in the Zadroga bill." 
 
 "It's a disgrace that it wasn't put in the Zadroga bill," he said. 
 
 Stroehlein, who has been through two rounds of chemotherapy and recently underwent a stem cell bone marrow transplant, said his medical bills total in the hundreds of thousands of dollars. He has insurance, but he said he still has had to pay thousands of dollars. 
 
 Other responders, he said, have it far worse. 
 
 "There are guys in worse shape than me -- they're dying every week, every month," he said. "It's a torturing death, and they don't have the coverage or support they need." 
 
 Other responders convinced cancer 'widespread' 
 
 Ernie Vallebuona, a former vice detective with the New York City Police Department, learned he had aggressive non-Hodgkin's lymphoma three years after working at ground zero. He says the number of cancer cases he sees among his NYPD colleagues and other first-responders is disconcerting. 
 
 "Before 9/11 you might have known one person with cancer," said Vallebuona. "Now it's like that person in your office has cancer, that one in your detail has cancer, and on and on." 
 
 But responders like Vallebuona may not be able to take solace from this study. Prezant said the results are specific to firefighters. Eighty-five percent were present at the Trade Center complex within 48 hours of the towers falling. And as other studies suggest, the earlier a responder arrived at ground zero, the more serious their illness. 
 
 "Whether we can say that cancer is increased in other responders or area residents, we have no idea," said Prezant. "This is a study about firefighters, their exposure is so unique." 
 
 The cancer question is emotionally fraught for responders like Vallebuona, who also arrived at ground zero within hours of the towers' collapse, and spent months searching for survivors and cleaning up after the attacks. Many consider the connection between their cancer and exposure and toxics to be irrefutable. 
 
 "I believe this is just the tip of the iceberg," said Vallebuona, adding that he believes future studies will prove that the cancer issue is widespread among responders. 
 
 "(Cops) were there from the first hours, first minutes when this disaster happened," said Vallebuona. "We all responded just like firefighters, so I don't think they can say cancer increases just apply to firefighters." 
 
 John Feal, founder and president of the FealGood Foundation, which advocates for sick first responders and fought for the Zadroga Act's passage, said the study counters those who said first responders were crying wolf. 
 
 "We don't need a Ph.D. to tell us that 9/11 and its aftermath cause cancer," Feal said. "We're sick and dying, but we're not stupid." 
 
 He said he expected his group in the near future will be "going to Congress and asking for more money" for the bill. 
 
 "We're going to need more money in the Zadroga bill to treat and compensate for these cancers," he said. 
 
 Responders describe the scientific process for establishing links between cancer and 9/11 dust as slow, and infuriating, but Prezant stressed that scientific inquiry into illnesses emerging from ground zero work must be measured and sound. 
 
 "The important thing is that our conclusions, whatever they are, are based on science," said Prezant. 
 
 CNN's Dana Garrett contributed to this report. ||||| Reuters Firefighters at the World Trade Center after both towers collapsed on Sept. 11, 2001. Researchers found that those who worked at the site are more likely to have cancer. 
 
 Firefighters who worked at Ground Zero are 19% more likely to have cancer than their colleagues who did not work at the site, according to newly published research that could pave the way for government payments to those suffering from some types of cancer. 
 
 The research marks the first substantive findings on the difficult question of whether working at the World Trade Center site increased cancer risk. For years, firefighters, police officers and construction workers have argued that there is overwhelming anecdotal evidence that work at Ground Zero caused cancer, while researchers continue to caution that it will take 20 or 40 years to prove such a link. 
 
 Firefighters who worked at Ground Zero are 19% more likely to have cancer than their colleagues who did not work at the site, according to a newly published study that could pave the way for payments to those suffering from some types of cancer. 
 
 Published in the Sept. 3 issue of the Lancet, the research led by Dr. David Prezant, the head doctor for the New York Fire Department, concludes that an association between World Trade Center exposure and cancer is "biologically plausible'' due to findings of "a modest excess of cancer in exposed firefighters.'' 
 
 The study's authors also cautioned against drawing broader conclusions, saying it would be wrong to assume that because cancer is more likely among World Trade Center firefighters, it is also more likely among other groups of people exposed to the site. 
 
 "This is not an epidemic but an increased risk," Dr. Prezant said in a conference call with reporters Thursday. He added that, at minimum, the study is a reminder for first responders and others to heed doctors' advice on tumor screenings and to participate in cancer monitoring programs. 
 
 Dr. James Melius of the New York State Laborers' Health and Safety Trust Fund visits the News Hub to comment on a new study that links cancer to firefighters to worked at Ground Zero following 9/11. Photo: AP Photo/Mark Lennihan 
 
 Advocates for Ground Zero responders and New York lawmakers will try to use the study to try to convince officials overseeing a new Sept. 11 health program to pay compensation to people who developed cancer after exposure to the site. The program's current rules do not allow for payment for cancer, but the rules can be revised. 
 
 Kenny Specht, a 43-year-old retired firefighter who was diagnosed with thyroid cancer in 2007 after having worked at Ground Zero, said the study should force administrators of the compensation fund to immediately qualify those firefighters who have developed cancer. 
 
 Even some experts who support compensation for those who have contracted cancer, though, cautioned that the findings do not definitively prove Ground Zero work caused cancer. Dr. James Melius of the New York State Laborers' Health Fund, who reviewed the research, said the new information has limitations. 
 
 "It is a major study, but it is not definitive,'' he said. "We know cancers can take up to 40 years or more after exposure to appear, so we know we're nowhere near being able to count them all.'' 
 
 Mr. Melius argues that there's little point to waiting 40 years—by which time, presumably, many of the Ground Zero workers will have died—to decide whether they are entitled to compensation for their illnesses. 
 
 "We ought to give responders the benefit of the doubt,'' he said. 
 
 The new report found an increase in the sum total of cancers among responders, though researchers, citing the relatively small numbers involved, are hesitant to point to a higher incidence of any specific cancers. 
 
 "This study does not have the statistical power, the number of cases necessary to draw any conclusions about individual cancers," Dr. Prezant said Thursday. 
 
 Ground Zero workers and health advocates have long argued that the thick dust plume from the collapsing towers—and the long months spent toiling atop the burning wreckage—forced recovery workers to inhale and swallow dangerous amounts of tiny toxic particles. 
 
 Prior research has already found an increase in breathing and gastrointestinal problems among 9/11 responders. 
 
 Perhaps most surprising about the new cancer research, though, is the finding that lung cancer has actually appeared less often than expected among the Ground Zero firefighters: Their lung cancer rates are 58% lower than in the general population. 
 
 The relatively low incidence of lung cancer among the responder population may be explained by the fact that lung cancers occur on average about 20 years after exposure to toxins, the researchers said. 
 
 "We did not expect lung cancer to develop in this time," Dr. Prezant said of the study period, which tracked cancer incidences between Sept. 11, 2001, and Sept. 11, 2008. 
 
 The cancer study compared firefighters who were at Ground Zero to firefighters who were not—an important distinction because firefighters tend to be healthier than the general population. 
 
 Even compared to males in the general population, the firefighters had a 10% increased incidence of cancer. 
 
 A separate study, based on data in the World Trade Center Health Registry, found a lower mortality rate among recovery workers and civilians exposed to Ground Zero than New York City's general population. Those at Ground Zero were 43% less likely to have died from any cause than the general public since the terrorist attack. 
 
 The authors of that study said they were not surprised at that finding because they expect a long latency period for illnesses likely related to Ground Zero exposure. 
 
 Subsequent studies will continue to track the firefighters, as well as other emergency workers, said Dr. Prezant. 
 
 "This is the first part of the story," he said. 
 
 Write to Devlin Barrett at devlin.barrett@wsj.com ||||| Firefighters who rushed to the World Trade Center on Sept. 11, 2001, and those who worked at the site in the weeks and months after the terrorist attack continue to live with an increased risk of cancer , according to a new study in the journal Lancet.The incidence of cancer in firefighters who worked at ground zero was 32% higher than in firefighters who did not spend time in Lower Manhattan. After adjusting for the fact that doctors spent more time examining the health of rescue workers after 9/11 , researchers still found that firefighters who worked at the trade center site were 19% more likely than their counterparts to develop any kind of cancer.The most common type of cancer found in ground zero firefighters was prostate cancer , followed by melanoma , colon cancer, non-Hodgkin lymphoma and thyroid cancer. Cancers of the esophagus , stomach, pancreas , lung, bladder , testicles, kidney, blood and bone marrow were also reported. There weren't enough cases of any individual type of cancer to say whether time spent at ground zero was associated with an increased risk, according to the study.The analysis was based on health records of 9,853 New York City firefighters. All of them were men who were either black, white or Latino. (Women, Asians and Native Americans were excluded from the study because their small numbers could have skewed the results.) Health records for those in the study were easy to track because firefighters have insurance through their jobs, and the Fire Department of the city of New York set up additional health monitoring programs after 9/11.The data include cancers found in the first seven years since the attack. The study did not report on cancer deaths among the firefighters.Researchers don’t know exactly what accounts for the increased cancer rates in firefighters who worked at the trade center site, but there are plenty of possibilities. Those who went to ground zero breathed in a dust that contained “an amalgam of pulverized cement, glass fibers, asbestos, lead” and many kinds of chemicals, in addition to toxic fumes produced by burning jet fuel, the study says.Among the 2,752 people who died in the attack on New York were 343 firefighters and paramedics.A summary of the study is available here
– A major study seems to confirm anecdotal evidence about the firefighters who responded to the World Trade Center attack: They are more likely to get cancer. The study in the Lancet finds that firefighters exposed to the toxic stew of dust in the air were 19% more likely to be diagnosed with cancer than their fellow firefighters who were not at the site, reports CNN. The findings come with the usual caveats about drawing specific cause-and-effect conclusions, but they still could make it easier for firefighters to win compensation from the government, notes the Wall Street Journal. "We've just begun to understand what's happening after the World Trade Center," says lead author David Prezant, chief medical officer of the city Fire Department. "We may find that some of our conclusions change over time, get stronger or change entirely." Prostate cancer was the most common type found, followed by melanoma, colon cancer, non-Hodgkin's lymphoma, and thyroid cancer, notes the LA Times. Notably absent is lung cancer, though the disease can take 20 years to develop. "It is a major study, but it is not definitive,'' says the head of the state's Laborers' Health Fund. Still, it makes little sense to wait decades to make decisions on compensation, he adds. "We ought to give responders the benefit of the doubt."