Firefighters risk their lives every day. They face serious multiple short- and long-term health risks, ranging from the obvious dangers inherent in running into burning buildings to illnesses spawned by years of exposure to smoke and other chemicals.
aOther – not so obvious – factors include thermal stress, dehydration, and cardiovascular strain. All of which accelerate the risk of cardiac events.
New research – appearing in Cancer, the American Cancer Society’s peer-reviewed journal – adds another risk factor. A group of university scientists published the results of a small study that suggests a link between firefighting and a higher risk of glioma, an aggressive type of brain cancer.
The researchers – from the Yale Medical School and the University of California, San Francisco (UCSF) – identified a specific mutational signature tied to chemical exposure that appears much more often in firefighters than in any other occupational demographic.
Decrypting Glioma
Glioma is a malignant brain tumor with an alarmingly poor prognosis. Scientists still struggle to pin down its etiology, aside from a handful of genetic factors. This new study points to haloalkanes, chemicals commonly found in flame retardants, fire extinguishers, and pesticides, as a potential culprit.
“Although glioma is largely associated with mutational processes that correlate with age, our finding that some gliomas have tumor signatures associated with environmental agents, such as haloalkanes, is of great interest given the lack of risk factors previously identified for glioma development,” Yale School of Public Health professor and project lead Elizabeth B. Claus, MD, PhD, said.
The UCSF research team analyzed tumor samples from nearly three dozen glioma patients, including 17 individuals with a documented history of firefighting and 18 patients without. Leveraging whole-exome sequencing techniques, the researchers assessed the DNA from both tumor and normal tissue samples, as they tried to track down distinctive mutational patterns.
The study’s authors uncovered a strong tie between years spent firefighting and the presence of a mutational pattern dubbed SBS42. This identified pattern relates to haloalkane exposure – a chemical compound previously tied to occupational cholangiocarcinoma in Japanese printing workers. Among the firefighters, those with longer careers appeared to be more likely to exhibit this mutational signature.
It’s worth noting that a pair of the firefighters in the study with a high SBS42 signature (with fewer years spent firefighting) experiences additional occupational exposures, ranging from farm work and petroleum transport.
Among the civilians, those with the highest SBS42 levels reported careers in painting and mechanical work, which also involve haloalkane exposure. This, the data suggests, could result in haloalkane exposure beyond firefighting.
The researchers also singled out several other gene mutations stemming from SBS42 – including NOTCH1, ROS1, ETV1, and NCOA – all of which play a part in cancer development.
Moving Forward
This research builds on earlier study results that pointed to a link between SBS42 and glioma. It also highlights the potential dangers posed by chemical exposure in firefighting and other occupations. Since so much of the gear that firefighters use depends on flame-retardant chemicals, prolonged exposure could be problematic.
Isolating this connection could provide crucial insight into public health and occupational safety modification. The study’s authors suggest more robust protective measures, better ventilation practices, and stronger efforts to curb exposure to harmful chemicals.
The findings also encourage further study of occupational hazards and their connection to other types of cancer.
“Although intriguing, our study is small and will require confirmation in larger samples,” Claus added. “It will also be of interest to explore whether these tumor patterns are seen in other types of cancers in firefighters as well as in persons who may have high exposure to haloalkanes by virtue of their occupation or environment. Identification of exposure risk would be helpful in developing preventive measures.”
Further Reading
Mental Health Concerns Grow As Cancer Rates Climb
Open Burn Pit Exposure and Concern About the COVID-19 Pandemic
