The evolving science assessing the heightened cancer risks in fighting fires does not yield many definitive answers, experts say.
As a result, many fire departments around the country try to mitigate cancer risks through a patchwork of prevention initiatives that are tethered to research, yet stymied by the sometimes contradictory studies.
“It’s a huge problem with a lot of unknowns,” said Steve Kerber, director of the Firefighter Safety Research Institute at Northbrook-based Underwriters Laboratories. “There are a lot of studies out there that make the link between firefighters and cancer, but it doesn’t answer specific questions about what exactly is happening.”
While both researchers and firefighters have long known the dangers of smoke inhalation and the heightened risk of pulmonary disease, various studies within the past five years, including one by the U.S. Centers for Disease Control and Prevention’s National Institute for Occupational Safety and Health, have led to a better understanding of the possible connection between cancer and the toxins that firefighters are exposed to while on the job, Kerber said.
The environment in which a fire develops has changed dramatically over five decades, he said.
“We went from using all natural materials (in household goods) to using almost entirely synthetic materials, so it should not be much of a surprise,” Kerber said.
For example, a couch that was made with wood, cotton and horsehair decades ago now is composed entirely of synthetic materials that contain potentially toxic chemicals brought on, in part, by furniture manufacturers’ switch around 1950 to using polyurethane in their products, Kerber said.
“But synthetics are made from crude oil, which burns very differently, has more toxins and spreads much faster, too,” he said.
Firefighter cancer rates
A study of 30,000 firefighters from Chicago, Philadelphia and San Francisco showed that, for most cancer types, observed cancer rates were higher in the group of firefighters than in the general population. Below, a cancer rate greater than one for firefighters indicates more risk for that cancer type than general population.
Average cancer rate,
Buccal and pharynx
Other male genital
Source: National Institute for Occupational Safety and Health
As part of a demonstration examining the differences, researchers with the institute staged two living rooms — one with wooden furniture, a cotton-covered sofa and other so-called “legacy” furnishings and another with modern items, such as a microfiber-covered, polyurethane-foam-filled sectional sofa, Kerber said.
After a lit candle was placed on each side of the different sofas, allowing fires to grow, the modern room burst into flames within three minutes and 30 seconds, while the fire in the legacy room took roughly a half hour to reach the same point.
While firefighters battle fires that could be burning quicker than in decades past, they’re also in environments that include black smoke emanating from burning synthetic materials, which contain harmful hydrocarbon particulate matter, Kerber said.
“We have somewhere along the lines of 70,000 different chemicals, and everything is made from them, but we know the health implications of less than 1 percent,” Kerber said. “The chemicals are changing faster than we can understand them.”
To address other unknowns, researchers are studying whether the health hazards to firefighters exposed to toxins can be from just one exposure, or repeated exposures, as well as whether each person’s body is resilient in different ways, Kerber said.
Officials with the American Chemistry Council say the goal should be “to protect firefighters from exposure to any smoke from fires, regardless of the contents of what is burning.”
“Fires, and the resulting smoke, are toxic regardless of the source of those fires and what is being burned,” said Kathryn Murray St. John, a spokeswoman for the council. “It is a misconception to think that smoke from an old wooden house burning is somehow less dangerous than smoke from a modern house burning.”
The council, which is based in Washington, advocates and lobbies for chemical manufacturing companies.
While the American Chemistry Council recognizes “elevated rates of some cancers among firefighters, such as mesothelioma,” they are generally attributed to specific causes, such as asbestos exposure, St. John said.
“The increased cancer rates for the specific cancers identified by (the National Institute for Occupational Safety and Health) were not attributed to use of any specific materials or products in modern-day buildings,” she said. “While there have been claims that chemicals in modern-day products may contribute to increased cancer rates in firefighters, such cause-and-effect relationships have not been established.”