Firefighter deaths from cardiovascular events (Part 1 of 2)

I. Introduction

Coronary artery disease (CAD) in firefighters is due to a combination of workplace factors and personal factors such Diabetes mellitus, hypertension, smoking, elevated blood cholesterol (HDL-C), obesity, and a lack of exercise (AHA, 2007). Although not as widely known, firefighters are also exposed to factors in the workplace which are also associated with adverse cardiac outcomes.

II. Cardiovascular effects associated with smoke

Think back to your first fire academy class. You learned that smoke is a combination of heated gases, vapors, and particulate matter. It is also important to remember that the composition of smoke is determined not only by its fuel source, but also by fire conditions such as oxygen availability and temperature (Kulig, 1991). While hundreds of decomposition products can be found, two gases with known cardiovascular effects are carbon monoxide and hydrogen cyanide.

Carbon monoxide (CO)

Carbon monoxide - a product of incomplete combustion - is present in virtually all fire environments. One thing I think many of us are guilty of overlooking is the fact that high CO levels are usually still present during the overhaul phase of an operation and, to make that situation worse, it is during this phase of the operation that many firefighter's remove their self-contained breathing apparatus (SCBA). When CO is inhaled, it disrupts the transport of (and intracellular use of) oxygen which can result in a myocardial injury.

Hydrogen cyanide (HCN)

Hydrogen cyanide is formed due to the incomplete combustion of substances which contain both carbon and nitrogen (e.g. paper, cotton, and wool). It has frequently been detected in residential structure fires in levels that exceed established exposure limits. Like CO, hydrogen cyanide disrupts the intracellular use of oxygen resulting in intracellular hypoxia with cardiac manifestations.

Particulate matter

It's a well-known fact that firefighters are exposed to particulate matter contained in the smoke from a structure fire. (For those who might be reading this blog and not be associated with the fire service, particulate matter is the "sum of all solid and liquid particles in air many of which are hazardous". Studies conducted in the general population have indicated that particulate matter, as a component of air pollution, has adverse cardiovascular effect. For example, short-term exposure to particulate matter has been shown to trigger heart attacks particularly in persons with pre-existing heart disease.

III. Why are we at higher risk

It is a well-known fact that sleep plays a vital role in helping our body recover from fatigue, illness, and stress. Without it, our metabolic rate begins to decrease resulting in weight gain. A firefighter's "internal biological clock"is often disrupted numerous times during a shift making it difficult to regulate the sleep-wake system.  In addition, researcher's at Boston Hospital and Medical Center have determined that prolonged sleep restriction combined with circadian rhythm disruption can be a contributing factor to an increased risk for diabetes.

Electrocardiogram (ECG) tracing shows coronary
heart disease

As if that wasn't bad enough, the University of Chicago conducted research that shows a direct link between sleeping (or the lack of it) and a increased risk of cerebrovascular accident (stroke), myocardial infarction (MI), and congestive heart failure (CHF). According to their findings, an individual who sleeps more than eight (8) hours a night or less than six (6) hours a night has a significantly higher chance of experiencing chest pain or angina and developing Coronary heart disease.

As a firefighter, we are exposed to traumatic stress almost every shift. If we work thirty (30) years that stress will take a toll on our body both physically and mentally. Researchers at the University of California - San Francisco  (UC San Francisco) have found that these exposures over the course of a lifetime will experience an increase in inflammation in their body even if they don't develop Post-Traumatic Stress Disorder (PTSD). These increased levels of inflammation also tend to put the person at a greater risk of having an MI. Intervention strategies to combat this stress, such as exercise, yoga, and other health-related activities should be integrated at the start of a firefighter's career.

IV. Conclusion

Chicago Engine 29 operates at an early morning
warehouse fire.

Firefighting in and of itself is a physically demanding job and will eventually break even the healthiest body down. According to a study performed at the Illinois Fire Service Institute (IFSI), just three (3) hours of prolonged firefighting stiffens arteries and impairs function of the heart in young, healthy male firefighters. This same phenomena is seen in both heavy powerlifters and marathon runners. This means firefighters who do not value the importance of physical fitness are at a greater risk of exhibiting several factors of cardiovascular disease including being overweight and becoming hypertensive.

Additional information: Firefighter deaths from cardiovascular events, Heart disease and firefighters

References

American Heart Association (AHA) [2007]. Risk factors and coronary artery disease. Retrieved on September 19, 2017 from http://www.americanheart.org/presenter. jhtml?identifier=4726

Hofman, John (September, 2012). Heart disease and firefighters: how and why? Retrieved on September 28, 2017 from http://www.fireengineering.com/articles/2012/09/heart-disease-and-firefighters-how-and-why.html

Kulig, K. [1991]. Cyanide antidotes and fire technology. New Eng J Med 325:1801-1802

September is National Preparedness Month

It wasn't until earlier this morning when I was on Facebook that I remembered that September is also National Preparedness Month. I thought on how I could do my part to raise awareness of preparedness and I thought the best avenue would be to address preparedness and the disabled. That being said, "Lets do this".

The first step in preparing for an emergency is to consider how it will affect you as an individual (emphasis added). The first step in doing this is to realize that you might have to fend for yourself for up to three (3) days without access to disaster assistance, a medical facility, or even a drug store. With that in mind, you (and your family) need to consider what resources you utilize on a daily basis and what you would do if there is a limited supply or none at all

I. Prepare an emergency kit

Example of a room modified for
sheltering-in-place

Think first about the basics -- food, water, and clean air and any other life-saving supplies needed to maintain health, safety, and independence. Disaster preparedness experts - such as the American Red Cross - recommend having two versions of these basics: 1) A kit that contains the basics you would need to "shelter in place" (preferably in a interior room of your house or apartment with few or no windows) for up to 72 hours; 2) A light weight, smaller version of the kit (referred to as a "go kit") that you can take with you if it becomes necessary to evacuate your home.

II. Make a plan

The reality of a disaster is that it will likely prevent your from having access to the everyday conveniences to which we have become accustomed. If you have a "support network" that helps you on a daily basis, make a list of their names and how you can contact them during an emergency. It's also important to consider the mode of transportation that you use on a daily basis; what alternative modes will be available if there is a weather-related emergency (such as an snow storm) or a disaster. When planning for a disaster, it is imperative to take into consideration specialized equipment (such as mobility aids) that you are dependent on day-to-day. What would you do if these were not available? In the nutshell, for every aspect of your day-to-day life, you should have an alternate way to accomplish this.


For additional information: Preparing makes sense (PDF)