"Mortality and Cancer Incidence in a Pooled Cohort of U.S. Firefighters from San Francisco, Chicago and Philadelphia"

In 2010, researchers at the National Institute for Occupational Safety and Health (NIOSH), with funding assistance from the U.S. Fire Administration, launched a multi-year study to examine whether firefighters have a higher risk of cancer and other causes of death due to job exposures. Approximately 30,000 firefighters from Chicago, Philadelphia, and San Francisco were identified for the study. The follow-up period was 1950-2009. The manuscript detailing study results of Phase I was published in October 2013. The researchers found that:

  • Cancers of the digestive, oral, respiratory, and urinary systems accounted mostly for the higher rates of cancer seen in the study population. The higher rates suggest that firefighters are more likely to develop those cancers.
  • The population of firefighters in the study had a rate of mesothelioma two times greater than the rate in the U.S. population as a whole. This was the first study ever to identify an excess of mesothelioma in U.S. firefighters. The researchers said it was likely that the findings were associated with exposure to asbestos, a known cause of mesothelioma.

According to NIOSH, "In terms of conclusively proving that cancer is an occupational consequence of firefighting, one study cannot conclusively prove any outcome; however, this study strengthens the scientific evidence that firefighters are at increased risk of cancer."

Phase II of the NIOSH study further examined employment records from the three fire departments studied (Chicago, Philadelphia, and San Francisco) to derive information on occupational exposures and to compare cancer risks of higher-exposed fire fighters to lower-exposed fire fighters. The Phase II manuscript was published in February 2015.Phase II concluded that: "Lung cancer and leukemia mortality risks were modestly increasing with firefighter exposures. These findings add to evidence of a causal association between firefighting and cancer."

A third manuscript was released in June 2015. It details study results on exposure and provides information on the construction of a job-exposure matrix (JEM) used in the second manuscript.

In July 2016, NIOSH released a fact sheet summarizing the results of the Firefighter Cancer Study.

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"Cancer Risk Among Firefighters: A Review and Meta-analysis of 32 Studies"

In a three-year study by the University of Cincinnati published in 2006, researchers reviewed 32 studies covering 110,000 firefighters and spanning several decades (read the study manuscript here). They concluded that there is a probable risk of four different types of cancer among firefighters. Specifically, the study found that firefighters face a:

  • 102% greater chance of contracting testicular cancer than any other type of worker;
  • 53% greater chance of multiple myeloma;
  • 51% greater chance of non-Hodgkin lymphoma; and
  • 28% greater chance of prostate cancer.

Eight additional cancers, listed below, were found to have a "possible" association with firefighting, downgraded from "probable" to "possible" due to factors such as study type and inconsistency among studies:

  • Skin: 39% greater likelihood than the general population
  • Malignant Melanoma: 32%
  • Brain: 32%
  • Rectum: 29%
  • Buccal cavity and pharynx: 23%
  • Stomach: 22%
  • Colon: 21%
  • Leukemia: 14%

The study also concluded as follows: "These findings of an association of firefighting with significant increased risk for specific types of cancer raise red flags and should encourage further development of innovative comfortable protective equipment allowing firefighters to do their jobs without compromising their health. Studies are especially needed that better characterize the type and extent of exposures to firefighters."

"Firefighters are exposed to numerous cancer-causing substances," said head researcher Grace LeMasters. I think obviously they have not got enough protection from that exposure. We feel that the protective gear that protects them from acute exposures, such as heat and carbon monoxide, doesn’t protect them from the chemical residues that cause cancer."

The University of Cincinnati study raised a particular concern about the soot that firefighters carry back with them on their faces, hands and under their gear. According to LeMasters, soot is a group-one carcinogen, a top cancer-causing agent, that gets sucked into the body through the skin, particularly when firefighters sweat and their pores open. "We are concerned that though firefighters may have respiratory protection, they really aren't getting adequate protection from absorption of these compounds through their skin," LeMasters said. "A lot of firefighters have told me that they come back from fires covered in soot. Often times they are too tired to shower. They will just fall into their beds and go to sleep. We have to make sure that firefighters remove all the soot from their body as soon as possible. And we can afford to buy firefighters two sets of turn-out gear to go out and fight these fires. All firehouses have to make the investment in the health of their firefighters by making some relatively simple changes."

The findings from the University of Cincinnati study were also responsible for helping trigger the International Agency for Research on Cancer (IARC) study to review the risk of firefighting and classify the profession as an occupation with "potential cancer risk."

Article in UC Magazine

Article in UC healthNEWS

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"Cancer Incidence Among Firefighters: 45 Years of Follow-Up in Five Nordic Countries"

The objectives of this study, conducted by the Institute for Statistical and Epidemiological Cancer Research (Finnish Cancer Registry) in Helsinki, Finland, were to examine the patterns of cancer among Nordic firefighters, and to compare them with the results from previous studies. A total of 16,422 male firefighters were included in the study. A moderate (6%) excess risk was seen for all cancer sites combined. There were statistically significant excesses in the age category of 30–49 years as follows:

  • Prostate Cancer: 159%
  • Skin Melanoma: 62%

Additionally, an increased risk, mainly in ages of 70 years and higher, was observed for:

  • Non-Melanoma Skin Cancer: 40%
  • Multiple Myeloma: 69%
  • Adenocarcinoma of the Lung: 90%
  • Mesothelioma: 159%

Read more on the Nordic Countries study here).

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"Australian Firefighters' Health Study"

In 2014, Monash was commissioned by the Australasian Fire and Emergency Service Authorities Council (AFAC) to carry out a national retrospective study of firefighters' mortality and cancer incidence, known as the Australian Firefighters' Health Study. This study was prompted, in part, by the results of several overseas studies which had identified excesses of several types of cancers in firefighters. During the same time period, Monash University conducted two smaller scale studies: the Fiskville Firefighters' Health Study (2014) and the Defence Firefighters' Health Study (2015). The Fiskville study was the only study among the three which found a possible link between firefighting and cancer.

Fiskville Firefighters' Health Study: In late 2011, concerns were raised about the possible health impacts of training practices at the Country Fire Authority (CFA) Fiskville Training College dating from the 1970s. The CFA commissioned a report into the materials and practices at Fiskville which recommended, among other things, that a health impact study should be carried out, taking into account different levels of exposure. As part of this, the CFA commissioned Monash University to investigate the risk of cancer and mortality for individuals grouped according to the Joy Report as being likely to have had a high, medium or low risk of chronic exposure to a variety of materials. The results of the study were published in 2014.

Overall, the Fiskville Study found that the incidence of cancer was not raised in the cohort as a whole. When compared to the Victorian population, higher than expected cancer rates were observed for melanoma and cancer of the testis in the High exposure group and for brain cancer in the Medium exposure group. When compared to the Victorian population and to the Australian-born Victorian population, the overall cancer risk was significantly raised for the High group, it was similar to that of both these reference groups for the Medium group, and was significantly reduced for the Low group.

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"Evaluation of Carcinogenic Risks to Humans: Firefighting"

In 2007, The Working Group, comprised of 24 scientists from 10 countries, met at the International Agency for Research on Cancer (IARC), the cancer research agency of the World Health Organization. The Working Group reviewed 42 previous studies of firefighter cancer in order to assess the cancer risk among firefighters. (Read the full monograph of the study here.) The study's overall conclusion was that "Occupational exposure as a firefighter is possibly carcinogenic to humans." The study also found that: "Although firefighters are exposed concurrently to a multitude of chemical compounds that include numerous carcinogens, human epidemiological studies at best used indirect (poor) measurements of exposure to such agents. Also, exposures of firefighters vary considerably depending on their job activities, and only crude measures of exposure, such as duration of employment and number of runs, have been used in these studies. Despite these limitations, increased risks for some cancers were found for firefighters in the meta-analysis." Based on the Working Group's meta-analysis, three cancer types remained statistically significant:

  • Testicular Cancer: 50% elevated risk
  • Prostate Cancer: 30% elevated risk
  • Non-Hodgkin Lymphoma: 20% elevated risk

Other study conclusions:

  • Firefighters are exposed to numerous toxic chemicals, including many known or suspected carcinogens. 
  • These intermittent exposures can be intense, and short-term exposure levels can be high for respirable particulate matter and for several carcinogens, notably benzene, benzo[a]pyrene, 1,3-butadiene, and formaldehyde.
  • Smoke is a complex mixture of matter, gas, and vapor, and lack of data prevents a full understanding of the effects of smoke on firefighters.
  • For individual smoke components, inhalation was considered to be the major source of exposure; however, dermal absorption is also an important route of exposure for polycyclic aromatic hydrocarbons and polychlorinated biphenyls.
  • There are insufficient studies to evaluate genotoxic effects in firefighters.
  • There is clear evidence of chronic and acute inflammatory respiratory effects in firefighters, which provides a potential mechanism for carcinogenesis, although the major effect would be expected in the respiratory system.

Visit the IARC website for additional background information on this study.

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"Assessment of Dermal Exposure to PAHs in Firefighters"

In 2013, NIOSH's Health Hazard Evaluation Program carried out a study at the Illinois Fire Service Institute (a fire service training facility in Urbana-Champaign, Illinois), to determine if airborne polycyclic aromatic hydrocarbons (PAHs) and other aromatic hydrocarbons generated during live fire training contaminate and pass through the skin of fire fighters. Participants were non-smoking males 45 years of age or younger who were instructors with the Chicago Fire Department. The study's primary goal was to understand dermal exposure to PAHs in fire fighters wearing National Fire Protection Association (NFPA) 1971/1981 [NFPA 2007a,b] compliant protective ensembles for structural fires (turnout gear, hood, SCBA, helmet, gloves, and boots) and its contribution to the internal dose.

Read the final report, which includes a list of useful recommendations to protect the safety of firefighters.

The study found that:

  • Fire fighters wearing full ensembles absorb PAHs and aromatic hydrocarbons into their bodies.
  • The PAHs and aromatic hydrocarbons most likely entered the fire fighters’ bodies through the skin, with the neck being the primary site of exposure and absorption due to the lower level of skin protection afforded by hoods.
  • Aromatic hydrocarbons could also have been inhaled if they off-gassed from the contaminated clothing and equipment when the fire fighters were doffing their gear.
  • Although the biological levels measured are similar to or lower than the levels measured in other occupational groups with low levels of exposure, the absorbed dose will vary with ambient air concentrations of contaminants.
  • PAHs were found on the exterior of gear, which could be another source of dermal exposure for fire fighters.
  • Air concentrations of PAHs, VOCs, and particulate during overhaul and investigation phases, along with VOCs off-gassing from contaminated turnout gear, were below applicable STELs or ceiling limits but represent additional exposures during a typical workday.
  • Further study is needed to determine the contribution of all these sources to a fire fighter’s overall internal dose.

You can read a summary of the study in the Annals of Occupational Hygiene.

Related Articles:

Journal of Breath Research:
"Exploratory breath analyses for assessing toxic dermal exposures of firefighters during suppression of structural burns"

Journal of Occupational and Environmental Hygiene:
"Volatile Organic Compounds Off-gassing from
Firefighters’Personal Protective Equipment Ensembles after Use"

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Evaluation of Chemical Exposures during Firefighter Training Exercises Involving Smoke Simulant

In 2013, NIOSH conducted an evaluation based on a request received from a fire department in Texas. The employer was concerned about respiratory health effects from exposures to smoke simulants used during training exercises. Read the full evaluation report, which includes recommendations for reducing exposures.

The evaluation concluded the following: "Prior to (an) incident where a trainer suffered acute respiratory injury after being exposed to (an) oil-based smoke simulant, many of the trainers were under the assumption that the oil-based and glycol-based smoke simulants were not hazardous. However, the results of this evaluation indicate that air concentrations of mineral oil mist and diethylene glycol can exceed short-term OELs (occupational exposure limits) during training exercises involving oil-based smoke simulant, glycol-based smoke simulant, or both. If propane-generated heat and fire are added to the training exercises, thermal decomposition products can be produced, and the air concentrations of these products could also exceed short-term OELs. Overexposures are also possible if trainers open the training room and look inside without respiratory protection for even just a short time. If trainers are not adequately protected, these chemical exposures could cause eye and respiratory irritation or more serious acute respiratory effects."

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"Evaluation of Chemical and Particle Exposures During Vehicle Fire Suppression Training"

On July 22, 2008, NIOSH received a health hazard evaluation request from the Miami Township Fire and Rescue in Yellow Springs, Ohio. The request concerned potential inhalation exposures during vehicle fire suppression training. In response to this request, NIOSH conducted evaluations on September 25, 2008, and July 14, 2009. The evaluation was published in 2010.

In summary, the findings of this evaluation indicate a potential for acute overexposure to formaldehyde, CO, and isocyanates during vehicle fire suppression. A potential for fine particle exposure can occur at any point during fire suppression operations. The intensity and duration of both the chemical and particle exposures depends on the wind speed and direction.

Recommendations resulting from this evaluation include the following:

  • Firefighters wear SCBAs until completing overhaul.
  • Firefighters stand away from any diesel exhaust and park fire apparatus upwind of the fires.
  • The motor pump operator should remain upwind of the diesel exhaust emissions from the fire apparatus because they could contain harmful substances.

Read the full report for further information on the evaluation and NIOSH's recommendations.

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"Cardiovascular & Chemical Exposure Risks
in Modern Firefighting"
(Initiated 2015)

In June 2015, the Illinois Fire Service Institute (IFSI) [in collaboration with the UL Firefighter Safety Research Institute (UL FSRI), National Institute for Occupational Safety and Health (NIOSH), Globe Manufacturing Company, and U.S. Department of Homeland Security - Federal Management Agency Assistance to Firefighters Grants Program] embarked on a study to investigate the effects of modern fire environments on the two leading health issues facing firefighters: cardiovascular events and chemical exposures related to carcinogenic risk. The study's goals include the development of policies and procedures to minimize these risks to firefighters. An interim report containing preliminary study data was released earlier this year. A summary report was provided as well. According to reasearchers, the results presented in the interim report are strictly a snapshot of what has been collected. Analysis is currently underway, with a final report and detailed fire service toolkit scheduled to be released in 2017, to include a comprehensive overview of the information available and tactical considerations. The toolkit will be freely available to firefighters and fire officers around the globe. You can stay updated on information being released through:

  • IFSI:, on Facebook at IFSI Research, or on Twitter: @IFSIresearch.
  • UL FSRI:, on Facebook at ULfirefightersafety, or on Twitter: @UL_FSRI.

UPDATE: Watch the June 29, 2020 webcast of IFSI's research experiments on training based exposures. Read article in Firehouse.

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Study of Cancer in South Florida Firefighters
(Initiated 2015)

Sylvester Comprehensive Cancer Center at the University of Miami Miller School of Medicine announced in August 2015 that it will be leading a new research partnership with Miami-Dade and Palm Beach County Fire Rescue Departments to understand why firefighters face a high risk of cancer and find ways to improve their health and safety.

Erin Kobetz, Ph.D., M.P.H., Associate Director of Sylvester and Director of the Center’s Jay Weiss Institute for Health Equity, will lead the study to gather data about workplace procedures and exposures. "Our goal is to learn exactly where the increased exposure to carcinogens takes place and then implement proven measures to reduce that risk," she said. "We will be training firefighters as researchers who will help us collect the data and work with us on the education and early detection aspects of this interdisciplinary project."

The partnership with Miami-Dade Fire Rescue and Palm Beach County Fire Rescue aims to enroll 90 percent of firefighters in the two counties, as many as 1,000 men and women.

Read more about the University of Miami study.

UPDATE - June 27, 2016: Study will expand to include more firefighters, based on $1.5 million funding increase. Politicians hope to use research findings to push a cancer presumption law in Florida. Read more.

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Study of Cancer in Tucson Firefighters
(Initiated 2015)

The University of Arizona and the Tucson Fire Department are teaming up to tackle the second leading cause of death among firefighters. Researchers at the UA will track new TFD firefighters for three years to learn more about what chemicals play a part in causing cancer among first responders. Read more.

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