This article first appeared on FireRehab.com, sponsored by Masimo.
By Jay MacNeal
An ongoing study of more than 30,000 firefighters by the National Institute for Occupational Safety and Health has found an increased rate of cancer – primarily digestive, oral, respiratory and urinary – in firefighters than would otherwise be expected among firefighters. The International Agency for Research on Cancer, established in 1965, has listed 120 agents with a carcinogenic risk to humans. Firefighters are exposed to a number of these agents on a routine basis.
Carcinogens in smoke and soot
Some of the most common carcinogenic agents found in smoke include arsenic, asbestos, diesel engine exhaust, soot and formaldehyde. Arsenic has been linked to increased risk for development of lung, bladder and skin cancer [1].
Malignant mesothelioma – a type of lung cancer – was twice as prevalent in firefighters as in the general population, likely caused by asbestos exposure [2]. Asbestos was used in building construction due to its fire resistance properties. Firefighters typically come into contact with airborne asbestos fibers during firefighting and overhaul operations.
Diesel engine exhaust is listed by the U.S. Environmental Protection Agency, NIOSH and Occupational Safety and Health Administration as a potential cancer causing agent [3,4,5].
The National Fire Protection Association states in NFPA Standard 1500, “Fire stations shall be designed and provided with provisions to ventilate exhaust emissions from fire apparatus to prevent exposure to firefighters and contamination of living and sleeping areas.” [6] Many fire departments and rescue squads have implemented fixed exhaust removal systems to remove diesel exhaust from their apparatus bays.
Soot is composed of polyaromatic hydrocarbons. Soot has long been known to cause cancer in chimney sweeps, but only recently it has been found to cause increased cancer risk in firefighters also. So far, soot has been shown to increase the incidence of lung, bladder and skin cancer [7,8].
Formaldehyde, often identified in smoke during structural firefighting operations, is most commonly implicated in breast cancer, as well as lymphoma. [9,10].
Preventing firefighter exposure to carcinogens
Since 1825, when Italian scientist Giovanni Aldini attempted to design a mask to provide heat protection and fresh air, we have been on a quest to protect firefighters from exposure.
Anyone who has fought a fire can attest to going home and blowing soot out of his or her nose. It does not take a doctor to tell us this acute and chronic exposure to smoke is not good for firefighters.
Knowing that something is bad for us does not necessarily make us quit doing it. Just look at fast food and alcohol consumption and tobacco use. Many of firefighters continue not to wear SCBA at times when it is needed.
Overhaul operations is the area we seem to see firefighters most often disregard the use of an SCBA. This is incredibly dangerous to their short and long term health.
After the fire is out, the building materials – partially and fully combusted – may continue to produce dangerous gas toxins and the air is filled with fine particulates. Firefighters too often remove their SCBA, turnout gear, helmet and face mask during this overhaul phase, putting them at risk for skin contamination, wounds, eye injuries and inhalation injury or exposure.
Firefighters should be reminded and encouraged to use their SCBA until it is deemed safe by incident command or the safety officer on scene.
Mitigating health risks to firefighters
While the research on firefighters’ increased risk of dying from cancer and heart attack is evolving, we can all agree that limiting exposure is a prudent approach. The amount of preventable or modifiable risk is something every firefighter should be concerned with.
We can modify weight, exercise, dietary intake and other personal factors that will keep us healthy. We can also modify our personal behavior to limit carcinogens and other toxic exposures.
Firefighters are at risk of inhaling a large spectrum of known and potential carcinogens. Transdermal exposure is also a potential problem. Since we know little about specific risks or dangers, best practices for personal protection are critical.
1. Limit exposure
Some basic steps can be taken to limit firefighters’ exposure to carcinogens and other health risks. Those steps include:
- Continue monitoring during overhaul phase for signs of overexertion and dehydration, which has been the main theme of our series of firefighter rehab articles.
- Reinforce the importance of turnout ensemble, gloves and SCBA during overhaul.
- Consider point-of-care testing for carbon monoxide exposure. In firefighters with neurological symptoms, remember the risk of cyanide exposure.
2. Personal decontamination
Firefighters should, at minimum, remove soiled gloves and wash their hands prior to eating on-scene rehab nourishment. Be cautious of firefighters reaching into common coolers or containers for drinks and snacks, as foodborne pathogens as well as toxins can contaminate the contents.
Removing and laundering turnout gear is also important. For this reason alone, firefighters may need to be issued multiple sets of turnout gear. Until a set of gear is laundered and dried completely, it is not considered usable.
Personal decontamination should take the form of a shower and clean clothing as soon as possible after the exposure occurs. This may or may not be realistic in busier departments, but it should be encouraged whenever possible.
While research is not complete, some fire departments are using post-fire sauna therapy. The theory is that sweating in the sauna causes the body to excrete toxins through a firefighter’s pores. Time in the sauna is followed by a personal shower to cleanse the toxins off the body.
Anyone using this approach must be very cautious that firefighters are well-hydrated and closely monitored. The thermal load of firefighting is intense and prolonged. Adding sauna time to an already dehydrated and hyperthermic firefighter is problematic.
3. Environmental monitoring
Many agencies monitor for carbon monoxide, low oxygen levels, hydrogen cyanide and hydrogen sulfide. Some agencies monitor for volatile organic compounds such as formaldehyde and toluene with devices called photoionization detectors. Short-term exposure to any of these chemicals and compounds is extremely hazardous.
Monitoring for long-term carcinogen exposure continues to be a challenge. Safe levels of easily monitored agents can create a false sense of security. Just because the carbon monoxide levels are low and oxygen levels are normal does not mean that other hazardous substances or carcinogens are at safe levels. Additionally, these monitoring devices may be cost-prohibitive for some departments.
3. Monitoring human exposure to carcinogens
The problem of screening for individual exposure is that we do not know in many cases what firefighters are exposed to during an incident. It makes it incredibly difficult to perform medical monitoring, and we cannot screen for everything. Following NFPA guidance for initial screening, annual screening and specific exposures will help protect firefighter health.
4. Occupational medical evaluations
It is important to have an occupational medicine physician, familiar with the exposures a firefighter may encounter, to evaluate the health and wellness of firefighters. Firefighters with specific exposures throughout the year may require additional medical monitoring.
Firefighters may also benefit from more aggressive routine screenings for colon and prostate cancer, as they are at increased risk. Discussions with occupational and personal physicians will determine personal and environmental risk factors that determine appropriate personal health screening intervals.
If your department does not have access to an occupational medicine physician, you should inform your primary care physician of any exposures and they can assist you.
Recommendations
Here are three recommendations for all firefighters to limit their exposure to carcinogens:
1. Do not rely on your senses or equipment to determine if there is a hazard present in your environment. Assume there are carcinogens present.
2. Do your best to wear PPE, including SCBA, when there is likely a carcinogen or toxin in the environment.
3. Do not get lulled into a false sense of security during overhaul operations.
References
1. Smith AH, Hopenhayn-Rich C, Bates MN, et al. Cancer risks from arsenic in drinking water. Environmental Health Perspectives. 1992;97:259-267.
2. Daniels RD, Kubale TL, Yiin JH, et al. Mortality and cancer incidence in a pooled cohort of US firefighters from San Francisco, Chicago and Philadelphia (1950–2009). Occupational and environmental medicine. 2014;71(6):388-397. doi:10.1136/oemed-2013-101662.
3. Occupational Safety and Health Administration. (1988). Hazard Information Bulletin on Potential Carcinogenicity of Diesel Exhaust. Washington, DC; U.S. Department of Labor, OSHA Bulletin 19881130.
4. National Institute for Occupational Safety and Health. (2004). A Summary of Health Hazard Evaluations: Issues Related to Occupational Exposure to Fire Fighters, 1990 to 2001. http://www.cdc.gov/niosh/docs/2004-115/pdfs/2004-115.pdf.
5. Environmental Protection Agency [2002]. Health assessment document for diesel engine exhaust. Washington, DC: National Center for Environmental Assessment, Office of Transportation and Air Quality, U.S. Environmental Protection Agency (EPA) Publication No. EPA/600/8-90/057F.
6. NFPA 1500-1992In NFPA National Fire Codes Online. Retrieved from http://codesonline.nfpa.org
7. 3 International Agency for Research on Cancer (IARC) monographs http://monographs.iarc.fr/ENG/Monographs/PDFs/index.php.
8. Jankovic, J., W. Jones, J. Burkhart, and G. Noonan (1991):Environmental study of firefighters. Ann. Occup. Hyg. 35:581-602.
9. McDiarmid, M.A., P.S. Lees, J. Agnew, M. Midzenski, and R. Duffy (1991):Reproductive hazards of fire fighting. II. Chemical hazards. Am. J. Ind. Med. 19:447-472.
10. Lees, P.S. (1995):Combustion products and other firefighter exposures. Occup. Med. 10:691-706.
11. https://www.cdc.gov/niosh/firefighters/ffcancerstudy.html
