BELOIT — If you think your loud alarm clock is slowly killing you, it might be true.
Research of Beloit firefighters’ heart rates in response to their station’s loud alerting system revealed potential health risks. After reviewing results of the study, a new alerting system was put in place last summer that incrementally increases in volume to avoid startling firefighters and thus driving up their heart rates.
For decades the Beloit Fire Department has relied on a multi-station alerting system with one loud tone to alert firefighters of a call, said Deputy Chief Joe Murray.
After the study findings came out, the system was changed to only alert the specific station responding to a call as opposed to the system-wide alert. In addition, the alert’s volume would increase over three to four seconds. Murray compared the difference to the sound of a smoke detector versus elevator music.
“There was concern the sudden and loud alerting tones were raising heart rates, especially when firefighters were asleep or at rest,” Murray said.
The arrival of the gentler alarm was rooted in depth data collection. Research on the alerting system began in 2013 when the department's medical directors, Dr. James MacNeal and Dr. Chris Wistrom of Mercy Health System, came on board. They embarked on a health study for firefighters titled "Effects of station specific alerting and ramp-up tones on firefighters alarm time heart rates." The Mercy doctors were researching the alert system along with Dr. David Cone of Yale University.
On May 12, their study was published in the Journal of Occupational and Environmental Hygiene in the e-print edition, and will come out in hard copy in November. The results will likely cause changes in policy for fire departments around the world.
Firefighters volunteered to wear heart-monitoring watches and download the data to be analyzed. The doctors found when volume increased with each beep spaced out for three or four seconds, the amount of increase in the heart rate was much slower. It also resulted in less fatigue because of less of an adrenaline rush.
MacNeal said a resting heart rate of a firefighter could be in the 50s and could rise up to more 130 beats per minute. The study revealed that the way Beloit firefighters were alerted, established a fast heart rate even before the men and women left the station putting them at a greater risk for cardiac arrest on scene.
In the second phase of the study, tones only went off at the individual stations responding to an alert as opposed to the all-station alerts, which occurred in the past. Having station-specific alerts also seemed to bode well for heart rates.
The changeover to station-specific alerting with a ramp-up of volume was done for about $700, which Murray and MacNeal consider a wise investment as it can take up to a year to appropriately train a new firefighter to replace one who left due to a health condition or early retirement.
They said firefighter health is always a concern as firefighters and paramedics already have higher rates for cancer, melanoma, heart attacks, strokes and COPD. In addition to work stress, firefighters and paramedics often come into contact with hazardous substances while responding to fires and car accidents.
In 2014, there were 91 firefighters who died while on duty nationwide. Of those deaths, 59 were due to heart attacks, according to the United States Fire Administration’s 2014 annual report.
Because the protective clothing worn to fires and accident scenes traps body heat inside, cardiac output increases. Given that a firefighter can't increase volume by getting hydration, the heart has to squeeze faster and harder to cool the firefighter down resulting in more stress on the heart.
“Basically, it's an Olympic sport,” MacNeal said. “When you go from a heart rate of 40 when sleeping to 150 before you get dressed, you are starting in the physiologic death spiral,” MacNeal said. “This is not a job where you can stop. if you are in the middle of rescuing someone you can't top and these firefighters don't stop,” MacNeal said.
MacNeal said his next research project involves seeing how energy drinks and hydration impact firefighters as well as the role of on-scene physicians. In Beloit an on-scene physician responds to all major incidents such as structure fires.