Firefighters risk their lives each day as part of their job, but new research suggests they're at higher cancer risk, too.
In particular, researchers found that firefighters are more likely to develop testicular cancer, non-Hodgkin's lymphoma, prostate cancer and multiple myeloma compared with the general population.
Firefighters need to take precautions when fighting fires, the experts said - especially if they have removed their protective gear and breathing apparatus.
That's because firefighters' exposures to carcinogenic toxins "occur not when they are in the fire, but when they are in the vicinity of the fire," explained lead researcher Dr. James Lockey, a professor of occupational, environmental and pulmonary medicine at the University of Cincinnati.
The report appears in the November issue of the Journal of Occupational and Environmental Medicine.
In the study, Lockey's team collected data on 110,000 firefighters from 32 published studies that looked at the risk of 20 different cancers.
Firefighters are exposed to many carcinogens, including benzene, diesel engine exhaust, chloroform, soot, styrene and formaldehyde, Lockey pointed out. These chemicals can be inhaled or absorbed through the skin and exposure occurs both at the scene of a fire and in the firehouse, where fire trucks produce diesel exhaust.
Long-term exposure to cancer-causing agents increase cancer risk, Lockey said. "For testicular cancer there is a 100 percent increase in risk, for multiple myeloma there is a 50 percent increased risk, for non-Hodgkin's lymphoma it's a 50 percent increased risk, and for prostate cancer it's a 28 percent increased risk, compared with non-firefighters," he said.
"Overall we found 10 cancers that were either possible or probable that were related to firefighting," Lockey said.
He noted that fire crews use protective clothing and equipment to shield them from heat and chemicals when they are fighting the fire. However, when they take their protective equipment off they are at risk of inhaling cancer-causing chemicals and having these chemicals absorbed through the skin, he explained.
While firefighters are protected from heat and carbon monoxide, there needs to be consideration of how to protect them from long-term secondary exposure to cancer-causing chemicals, Lockey said.
"One thing that could be done is to make sure that firefighters take showers when they return to the firehouse," Lockey said.
One expert said that understanding how environmental toxins damage DNA and cause cancer is key to protecting people from exposure to harmful chemicals.
The findings are "not that surprising, because firefighters have complex exposures," said Roger W. Giese, the director of the environmental cancer research program at Northeastern University. "We know that the environment, including diet and lifestyle, causes 60 to 90 percent of all cancer," he said.
Giese admits that there is much that is not known about how environmental exposures trigger cancer. "In our research we measure the damage to people's DNA by the environment. DNA is the ultimate target for carcinogens in the body. So seeing which carcinogens reach the DNA is especially important information to have," he said.
Giese believes firefighters need better protection, but it's not yet clear what components or mixtures of chemicals are causing these cancers. "There is a need for firefighters to be better protected," he said. "And you have to know what the key mixtures that are causative are."
In addition, Giese noted that there's the question of individual susceptibility to cancer. "You can have two people with the same exposure, but their metabolism of chemicals can be different. Some people can have the wrong metabolism in the wrong environment and that combination really increases their risk for cancer," he said.
The effect of environmental exposure was brought home in a recent report that found that almost 70 percent of rescue personnel and workers who responded to the Sept. 11, 2001, terror attacks on the World Trade Center in New York City suffered from lung problems during and after the recovery efforts. Some of those problems persisted for at least two-and-a-half years after the attacks.