The Dangers of Being a Firefighter

By Kimberly Weschler

My childhood best friend’s father was a firefighter. I had always looked up to him as I thought saving people from fires was the coolest job in the world. Today, I still believe that it is one of the most impressive jobs, as firefighters put themselves in physical, emotional, and genotoxic danger to help others. In addition to their susceptibility to burns, heat exhaustion, and mental health disorders, exposure to smoke, toxins and carcinogens can pose negative effects on the health of firefighters.

Approximately 1,080,800 firefighters are employed in the US alone, 11.8% of which are female and 88.2% male. Considering this, it makes sense that most firefighter-based research is focused on males. However, that leaves the health of female firefighters “critically understudied” (Jung et al., 2021). It is crucial to have research and studies done on both male and female firefighters, as they have distinct genotoxic risks, such as reproductive hazards. Despite there being very few studies focused on female firefighters, a genotoxic association was found while studying the prevalence of miscarriages in female firefighters vs non-firefighters. Comparing the miscarriage statistics of female firefighters to those of US female nurses, the prevalence of miscarriages in female firefighters were 2.33-fold. It was found that this genotoxic hazard was associated with occupational exposures such as per-and polyfluoroalkyl substances (PFASs), which are present in fire extinguishers (Liew et al., 2020) and polycyclic aromatic hydrocarbons (PAHs), which are produced during the combustion of wood or other materials (Jung et al., 2021).

Another study analyzed the semen quality of male firefighters vs non-firefighters and found that the semen of firefighters was of lesser quality than that of the general population in a variety of aspects such as sperm count, motility, and volume. This genotoxic hazard was associated with occupational exposures such as a variety of chemicals and heat intensities. It was also found that increased hand washing, showering after shifts and use of breathing apparatuses showed a positive correlation in semen quality of firefighters, while increased fire exposure showed a negative correlation with sperm concentration, volume, total sperm count and semen quality (Engelsman et al., 2021).

According to the CDC and The National Institute for Occupational Safety and Health, cancer is one of the leading causes of death among firefighters. A study done over a 34-year stretch, consisting of 100,000 career firefighters in Florida, analyzed the cancer risks that accompany the profession. Within the study they were able to identify 3760 male-linked primary cancers and 168 female-linked primary cancers. It was deduced that female career firefighters are at a great risk of thyroid cancer, brain cancer, and possibly melanoma. More research is necessary to verify the cancer risks of female firefighters as there were only approximately 5,000 females in this study, and female firefighter-focused research is limited. On the other hand, since there were a great quantity of males participating in this study as well as an abundance of prior male firefighter-focused research, researchers were able to conclude that male firefighters are at a great risk of melanoma, prostate cancer, testicular cancer, thyroid cancer and late-stage colon cancer. Additionally, they found that there was an even greater risk for the majority of these cancers in male firefighters under 50 years old (Lee et al., 2020).  

One of the main causes of cancer in firefighters is their occupational exposure to PAHs. These chemicals arise from combustion and are classified as toxic, mutagenic and carcinogenic. Benzo[a]pyrene is a major PAH that emanates from incomplete combustion of organic matter. Since it is regularly found in our everyday lives, such as from burning wood or grilling food, it is used to determine the degree of carcinogenicity and Toxic Equivalency Factor (TEF) of other PAHs. Recent studies have discovered other PAHs that are of greater toxicity than Benzo[a]pyrene such as 7,12-dimethylbenz[a]anthracene (DMBA) and 3-methylcholanthrene (3-MCA). DMBA arises from diesel exhaust and tobacco smoke, and it hangs around in the surrounding air for a long time, extending one’s exposure to it. In addition, DMBA is extremely toxic as its TEF is 2-fold that of Benzo[a]pyrene. Moreover, 3-MCA arises from burning organic compounds at high temperatures and its TEF is 5.7- fold that of Benzo[a]pyrene (Stec et al., 2018).

Since PAHs have a dermal absorption of 20%, and are a leading cause of cancer in firefighters, a study was done to analyze the frequency of different kinds of PAHs found on firefighter-related surfaces. Examination of wipe samples taken from skin, clothing, self-containing breathing apparatus (SCBA), fire engines, bodyguards and gas samples allowed for the identification of where different kinds of PAHs could be found. Benzo[a]pyrene was identified on all surfaces, DMBA was seen on clothing, fire engines and bodyguards but not on skin and 3-MCA was seen on skin, self-containing breathing apparatus (SCBA), fire engines and bodyguards. Based on their findings and a cancer risk factor of 1 in 100,000, they concluded that as many as 350 firefighters can develop cancer from PAHs found on clothing, 250 from that found on fire engine bodyguards, 210 from that found on fire engines and 25 from that found on firefighters hands. However, the risk identified from gas sampling was too insignificant to conclude anything (Stec et al., 2018).

In a study, to evaluate the exposure of firefighters to PAHs, researchers analyzed PAH metabolite levels present in urine and PAH levels present in dermal wipes as well as personal air samples. They also evaluate urinary mutagenicity with the Ames assay using Salmonella strain TA98 (Atlas et al., 1985). Samples were taken before and after the 27 male firefighters were exposed to combustion emissions and a group of 18 fire service office workers were used as controls. They concluded that after being exposed to combustion, the firefighters urinary PAH metabolite levels increased on average by 2.9 to 5.3-fold. In addition, urinary mutagenicity increased on average by 4.3-fold. Frequent and continuous exposure to such dangerous chemicals is the leading cause for cancer amongst firefighters (Keir et al., 2017). Another study evaluating PAH levels analyzed a group of 53 individuals who were training to be firefighters. Utilization of the Comet assay in addition to the previous techniques mentioned helped with the assessment of the genotoxic effect related to PAH exposure. Using the Comet assay they found that after participating in training that included dermal exposure to PAHs, DNA strand break levels had escalated. Failure to repair such DNA breaks may lead to cancer formation (Andersen et al., 2018).

Before entering a potentially hazardous situation, firefighters must put on their personal protective equipment (PPE). PPE protects the firefighter from fire as well as chemical, biological, radiological, nuclear, and high-yield explosives (CBRNE) hazards. However, studies show that the PPE that firefighters wear can be contaminated with a variety of hazardous substances, one of which is PAHs. One study found elevated PAH metabolite levels in urine samples, and concluded that it was due to the accumulation of PAHs on the firefighters’ PPE (Jalilian et al., 2019). Another study grouped the participants into units of 12 firefighters who worked in pairs while on call. For each pair of firefighters, one of their hoods was laundered while the other was not. Lower PAH levels were found in routinely laundered hoods compared to non-laundered hoods. They then laundered unlaundered exposed hoods with unlaundered heavily exposed hoods and unexposed hoods that were brand new. PAHs were then seen on some of the unexposed brand new hoods, showing cross-contamination and ineffective laundering practices (Mayer et al., 2019). From this it was proven that current laundering practices of PPE do not completely remove chemicals, causing long-term exposure past on-site exposures. In addition, When PPE is taken off, contaminants can be transferred to one’s skin or go into the surrounding air to be inhaled, which can pose additional danger to the individual (Banks et al., 2021).

In conclusion, considering all the risks that firefighters take upon themselves including physical and emotional dangers, it is absolutely necessary for fire departments to implement safety and precautionary measures to prevent additional risks. Such measures include implementing sanitary practices post on site exposure, such as continuously washing one’s hands, showering, changing one’s garments and cleaning surfaces. In addition, creating more effective and protective SCBAs and PPE to limit inhalation and dermal exposure of toxins is necessary. Lastly, more effective laundering practices is imperative. Such laundering practices may include but are not limited to separating PPE by job assignment and potential contamination and laundering PPE separately from other clothing to prevent further exposure. It is necessary to do more research on the genotoxicity of being a firefighter, especially in terms of females so that we can gain a better understanding of the various risks of this profession.

Bibliography: 

1. Andersen, M.H.G. et al., 2018, Association between polycyclic aromatic hydrocarbon exposure and peripheral blood mononuclear cell DNA damage in human volunteers during fire extinction exercises, Mutagenesis, 33:105-115. 
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