Does firefighting increase the risk of dementia or ALS?
Firefighters and researchers examine a probable risk factor, like toxin exposure, and its relationship to cancer, cardiovascular disease and other illnesses
There is a good deal of research focused on the relationship between firefighting and risk of cardiovascular disease and cancer. While further research on the intricacies of the relationships between firefighting tasks, exposures, and disease will continue to shed light on the causes, a strong body of literature is emerging in the peer-reviewed literature.
However, there are a number of other diseases that are less studied, but may be related to fire and rescue activities.
Determining whether any individual’s disease is related to their exposures is beyond the scope of epidemiology and science in general. However, knowing the risks firefighters face related to toxicant exposure, shift work and stress or strain can help clarify potential risks.
Unfortunately, finding the literature on the relationship between firefighting and disease is not always as easy as searching the PubMed.com literature with the key words of "firefighting" and the disease name. Often, the research is more broadly focused on exposures, toxicants, shift work or occupational risk factors in general. Examining a probable risk factor and its relationship to disease morbidity and mortality can provide some keys to the relationship.
Are firefighters at increased risk of dementia?
As examples, I was recently asked about whether firefighters are at increased risk of dementia. While there are no specific studies examining the relationship, published data does exist that can inform the question.
In 2015, Drs. Genius and Kelln published an article, "Toxicant Exposure and Bioaccumulation: A Common and Potentially Reversible Cause of Cognitive Dysfunction and Dementia," in Behavioural Neurology that reviewed the relationship between toxicant exposure and dementia. They summarized the literature on toxicant exposure and its neurodegenerative and neurodevelopmental impact. In particular, they report on a number of classes of toxicants that are thought to possibly be related to neurodegenerative disease including metals, such as lead, mercury and aluminum, pesticides, flame retardants, solvents, pharmaceuticals, air pollutants (such as carbon monoxide and nitrogen dioxide), plasticizers and others.
Genius and Kelln note that it is a common assumption that, once an exposure is over, the body clears the toxicants. However, may toxicants can have lasting effects with half-lives that last years or decades. They also explained that toxicants can accumulate in the body over time.
Not surprisingly, many of the toxicants are exposures firefighters face.
Are firefighters at increased risk of Lou Gehrig's disease?
In another instance, a colleague of mine was asked about whether being a firefighter could increase the risk of amyotrophic lateral sclerosis, also known as ALS or Lou Gehrig's Disease.
Dr. Nicola Vanacore and colleagues published a 2010 article in the journal Amyotrophic Lateral Sclerosis titled "Job strain, hypoxia, and risk of amyotrophic lateral sclerosis: Results from a death certificate study." In the study, they examined the death certificates from 24 states from 1984-1998. They examined the 14,628 deaths from ALS and compared them to 58,512 non-ALS deaths that were matched on age, gender and geographic area. They found that firefighters were twice as likely to die from ALS. The authors hypothesized that the cause was the intermittent hypoxia firefighters experience throughout their career.
When it comes to protecting yourself from these diseases – or any of the others that the literature might suggest are related to firefighting – the prevention techniques are largely the same as those for cancer and cardiovascular disease. Limit toxicant exposures as much as possible both on the fireground during the fire and overhaul, and from the toxicants on gear.
Health and wellness are key as fitness and nutrition play key roles in morbidity and mortality of many diseases. Attempt to limit the impact of shift work as much as possible through napping and appropriate use of caffeine to manage lack of sleep. Tobacco use also increases risks of several diseases; avoiding both cigarettes and smokeless tobacco is necessary.