Firefighters are at an increased risk of suffering heart attacks due to intense heat and exertion, a new study reveals. To assess this, researchers randomly chose 19 non-smoking, healthy firefighters to participate in two fire simulation exercises. During the activity, the firefighters had to rescue a dummy victim from a two-story structure with temperatures reaching more than 752 degrees Fahrenheit (400 degrees Celsius). The participants wore blood pressure and heart rate monitors at 30 minutes before the activity and at 24 hours afterwards. The monitors constantly kept track of the participants’ heart rate and heart rhythm, as well as the strength and timing of electrical impulses passing through the heart.
Researchers found that the participants’ core temperatures rose about two degrees Fahrenheit (-16 degrees Celsius) on average during the fire simulation exercises. The firefighters’ core temperatures remained high for three to four hours after the activity. The participants also exhibited lower blood pressure immediately after the activity. However, researchers attributed this to possible dehydration and increased blood flow to the skin to help regulate the body’s temperature.
Study data also showed that the firefighter’s blood became stickier and had a 66 percent increased risk of forming potentially dangerous clots. Researchers also found that the participants’ blood vessels did not relax properly despite medication. A combination of perspiration-related fluid loss and inflammatory response to heat may have caused the blood to be more concentrated and more susceptible to clotting.
“Studies from the USA have shown that nearly half of all firefighters who die on duty are killed by heart disease. Our study has shown a direct link between the heat and physical activity levels encountered by firefighters during the course of their duties and their risk of suffering a heart attack. However, we’ve also found that there are simple measures, such as staying well hydrated, that firefighters can take to reduce this risk,” said lead researcher Prof. Nick Mills, as reported on BBC.com.
The findings are published in the journal Circulation.
Toxic chemicals contribute to higher heart attack risk in firefighters
The recent study is only one of the many research that demonstrate a higher heart attack risk in firefighters. A report from the U.S. Fire Administration showed that 45 percent of deaths among firefighters who died in the line of duty were associated with cardiovascular events, with heart attack being the most common incident.
Previous research and case studies have also suggested that exposure to toxic chemicals during a fire may contribute to increased risk of heart disease in firefighters. A 1998 study showed that firefighters were consistently exposed to various hazardous chemicals during a fire. These chemicals include combustion byproducts of burning materials such as carbon monoxide, sulphur dioxide, hydrogen cyanide, and benzene. Researchers also noted other toxic chemicals such as hydrogen chloride, dichlorofluoromethane, aldehydes, and particulates. Study data showed that exposure to many these chemicals was associated with increased odds of cardiovascular, respiratory, or neoplastic diseases. The findings were published in the British Journal of Industrial Medicine. (Related: Know more about the effects of toxic chemicals on human health on Toxins.news)
An interim report by the Illinois Fire Service Institute also found that most modern buildings today use materials and methods that contain polymer-based furnishings. At the event of a fire, these compounds spur more rapid fire growth, increased heat release rates and additional chemical exposure to firefighters, according to the report. These factors were found to worsen cardiovascular strain in firemen, researchers stated.
An archived report by the Daily News Express has also pointed at chemical exposure as a possible cause of heart attack and death of a Bronx-based firefighter. According to the report, the firefighter was exposed to fumes from a heavily incinerated elevator that featured heavily-varnished wood panels. Fire officials speculated that the fumes may have triggered the fireman’s heart attack.