► “Toxicity depends a lot on the duration and frequency of exposure”
Frederic LeGuillou, pulmonologist
“A fire releases two types of smoke: black smoke, which contains benzene, cyanide and volatile organic compounds, with in particular carbon monoxide, and all these substances can cause asphyxiation. And then white fumes, which include fine and ultrafine particles capable of penetrating the respiratory tract to the pulmonary alveoli. Once in the body, they pass into the bloodstream and can cause oxidative stress with, ultimately, risks of cardiovascular complications.
Logically, the closer you are to the fire, the more exposed you are, but you also have to take into account the wind rose, that is to say the direction of the smoke. If it moves away from us, the risk is not the same as if it approaches. The distance is therefore not the only criterion, especially since the wind disperses the ashes in the atmosphere and can create dust pollution several tens of kilometers from the fire. You shouldn’t be fooled by the smell either, because carbon monoxide is odorless.
The dangerousness of the cumulative effect
In fact, toxicity depends very much on the duration and frequency of exposure, with firefighters obviously being the most affected. Today, we also speak of “exposome”, that is to say environmental exposure throughout life, because it is this cumulative effect that is the most dangerous.
As soon as there are clinical symptoms, such as skin irritations, itchy eyes, watery eyes, or coughing, it is a sign that one has inhaled toxic fumes. People with a respiratory pathology are obviously more vulnerable. If you have asthma, chronic bronchitis or cystic fibrosis, inhaling these fumes can cause a flare-up of the disease and lead to hospitalization or even intensive care. High exposure can also trigger diseases when there are predispositions, as in smokers, for example.
However, you can protect yourself with simple means, by closing windows and doors, but also by wearing an FFP2 or surgical mask, which filters a certain number of particles and microparticles. It is also necessary to moisten the eyes and the mouth, but the ideal, it is obviously to move away from the zone of fire. This is why there are also medical evacuations. It is important to protect the most vulnerable people such as pregnant women, children, the elderly and those with respiratory or cardiovascular diseases. »