Are firefighters at increased risk of heart disease due to “eternal chemicals”?
We all come into daily contact with a certain amount of industrially produced chemicals that are known to be harmful to our health. But some professions are more at risk than others. Researchers at Brno’s Masaryk University are conducting a study that indicates that firefighters are at increased risk of cardiovascular diseases due to “eternal chemicals”.
Eternal chemicals are a large group of widely used, industrially produced chemicals that are almost non-degradable by natural processes. They are found, for example, in plastic packaging, carpets, textiles and footwear, Teflon, cosmetics, or foams used for extinguishing liquid fuel fires. Remnants of these chemicals accumulate in the human body and the environment, which is why they come under strict health and safety regulations.
Some professions come into closer contact with them than others, and scientists at Masaryk University have found that firefighters have more “eternal chemicals” in their blood than the general public.
This is because these substances can be found in some of the firefighting foams they work with and other articled of daily use. Aleš Pindur, a firefighter at the Dukovany nuclear power plant and a PhD student at Masaryk University explains:
“In order for foams to extinguish well, they must contain substances that can withstand high temperatures for at least some time. Some of these substances are harmful to health and contain so-called PFAS or eternal chemicals.”
The European Union is gradually banning these substances and firefighters are looking for suitable replacements. In Czechia most of them should be replaced by 2026. Pindur says these chemicals are not only present in the foam they use, they can also be found in the lining of firefighter's protective suits.
"It's a special waterproof membrane that resists water leakage, but also various chemicals, and it is there as an essential protective lining. The lining contains PFAS and there is no suitable replacement for them yet. Because of their presence in the foam and suits we wanted to know if firefighters have higher levels of these eternal chemicals in their bodies than the general population –and asked for a special study.”
The research at the RECETOX centre at Masaryk University involved 164 people. One-third were experienced firefighters, one-third were novice firefighters, and the final group were people from other walks of life.
Researchers took blood and urine samples from all participants. Experienced firefighters had the most eternal chemicals in their bodies. Novice firefighters had fewer of these substances but more than the average detected in males in other professions. Pavel Čupr from RECETOX at Masaryk University sums up the results of the study:
“Tests made repeatedly on novice firemen showed how the concentration of these substances grew over time. They were lower at the beginning and gradually increased, to “statistically significant” levels. The higher the concentrations we found in participants, the more bilirubin they had in their blood. In addition to that we found that firefighters not only have a higher level of these eternal chemicals in their blood, but also substances produced from incomplete combustion – that is not only higher bilirubin, but also cholesterol levels and other lipids that also increase the risk of cardiovascular disease.”
Pavel Čupr says the measured values do not pose an acute risk to firefighters, but they could with long-term exposure. Experts collected the samples between 2019 and 2020, but are still examining them. Now, for example, they're looking at how eternal chemicals and combustion fumes affect thyroid hormones or disrupt DNA.
Aneta Vrzalová from Masaryk University's RECETOX centre puts a slide with a blood sample on a tray and a robotic arm moves it under a microscope. Under the microscope the cell is either round or looks like a comet.
"The cell you described as round is intact. The one you described as a comet is what a damaged cell looks like. Our preliminary findings indicate that the firefighting profession has an effect on DNA, but these outcomes need to be confirmed," Vrzalová explains.
The final results of the study will tell us more not only about the health risks to firefighters, but everyone else who comes into closer daily contact with eternal chemicals. According to Čupr, people come into contact with these substances almost daily: in some textiles, in food packaging and plastics.
