What We Know That Ain’t So
By Bobby Halton
Firefighters are three times more likely to die on the job than any other occupation. The NFPA has established that half of all of these deaths are attributable to stress from overexertion. Will Rogers said that is not what you don't know that is going to kill you but what you know that ain’t so. I had always thought that firefighters needed to be in good shape, that most heart attacks happened to firefighters due to pre-existing cardiovascular disease. While some others were due to poor physical conditioning and that others were simply a matter of age. It appears that I was partially right about some points and dead wrong about others.
Dr. Stephen Kales in 2007 reported that nearly all firefighters who had had died in their sample study from heart attacks had underlying cardiovascular disease. Age and poor physical conditioning place firefighters at extremely high risk, a risk further compounded by the presence of pre-existing cardiovascular disease. A sad footnote from this study was that many of the firefighters who died from heart attacks were in their forties. I-we have always thought that good physical conditioning, would make all the difference, if we passed our annual NFPA 1582 compliant physical we would be fine.
However two recent studies led by Dr. Jim Brown provide us with some important findings that all firefighters need to be made aware of. In the first one with the Maryland Fire Rescue Institute (MFRI) on fitness, hydration and training it revealed that firefighters of average and lower levels of overall physical conditioning respond physiologically just about the same. In that same study firefighters with high levels of physical conditioning had much less physical stress in the same training activities. The study also supplied us with critical information on the need to have proper hydration whenever participating in any firefighting activity. On the surface it appeared that average and low-level conditioning were at a greater risk than those of above average conditioning. This seems to make good sense good physical conditioning equals a good outcome, maybe not.
In the second study by Dr. Brown with the Indiana Firefighter Health and Safety Research Division titled Physiological Stress Associated with Structural Firefighting Observed in Professional Firefighters are some startling and far reaching conclusions. It's important to note that the study was done on real firefighters going to real fires and emergencies. They wanted to see the real physical effects of firefighting work on firefighters’ cardiac and respiratory systems. The researchers followed Indianapolis firefighters while on duty and by using modern technology were able to measure the physiological stress on these firefighters during different aspects of firefighting. They measured the stress levels while responding, initial attack, during overhaul and recovery.
The Indiana study determined that a firefighter’s age, time on the job and physical conditioning combined with the size of the building and the amount of fire involved in the building can determine a fire scenes potential for inducing firefighter cardiovascular and respiratory stress. Now there's nothing we can do about how long we have been on the job, our age, the size of the building or the amount of fire we might be facing but we can affect our physical conditioning in particular our weight and our aerobic conditioning.
The study noted that the stress begins when the alarm is received and that heart rates typically rise to 80% of their maximum and begin to decline once the firefighter has donned their PPE and gotten on the rig. The next thing the study noticed is that the amount of time on the job, experience matters, older more experienced firefighters experienced less increases in their heart rate upon receipt of an alarm.
The study identified that the physiological stress a firefighter will experience is directly proportional to the structure and the amount of fire in the building. This means that the structure sets the level of intensity. Another very critical piece of the study identified that multiple fires in one shift can have much greater effects physiologically effects on firefighters than was ever before considered.
The study recommends that these firefighters who routinely respond to a higher call volume need to be held to a much higher standard of physical preparedness in order to recover quickly enough to be able to function at the next event and not suffer potentially fatal consequences. It recommended they be in elite athletic conditioning like a professional swimmer or professional tri-athlete.
The evidence is clear most heart attacks on the job are caused by pre-existing heart disease; going to fires is a substantial trigger for cardiac events, therefore firefighters with pre-existing cardiovascular disease are at extreme risk for heart attacks strokes and other cardiovascular system problems at fires.
It is time we honestly recognize that firefighting can cause heart attacks and strokes and that the best defense is physical training. In order to be taken seriously as promoting safety we must require it of ourselves and each other. We can no longer allow unhealthy and unfit firefighters to put themselves, their families and us in danger. We must all adopt NFPA 1583 and develope those physical fitness components it lists as critical to our survival to our absolute best.
Unfortunately if we go back to Will Rogers we must note that the study did not cover anything about sleep deprivation, heart rate variability, parasympathetic balance or the affect that using SCBA’s have on our respiratory systems. We know these all have an effect on our bodies. We don’t know what that means to our survivability.