From Greece to Hawaii via Canada, many countries have been severely affected by the fires this summer, with all that this represents in terms of the environment and health. In addition to its respiratory and cardiovascular effects, the inhalation of these fumes would also be harmful to brain health, to the point of inducing neurocognitive or mood disorders.
Increasingly frequent and intense, episodes of drought and heat waves favor the outbreak of forest fires which can then spread rapidly due to the wind or the nature of the vegetation and the soil, sometimes becoming uncontrollable. We saw it this summer in Greece, but also in North America, in the Pacific, in North Africa, and in the rest of Europe.
The significant impact of fires on the brain
A phenomenon that is not without consequences on the environment, as well as on health, as recently recalled by the National Agency for Food, Environmental and Occupational Health Safety (ANSES). The French organization explains in particular that the inhalation of these fumes, which can generate particles in suspension, carbon monoxide, and other chemical substances, can cause respiratory and cardiovascular effects, and that it weakens especially firefighters, and people with chronic respiratory conditions and cardiovascular diseases.
But the impact on health could be even greater. That’s according to a new study by researchers at the University of New Mexico’s Health Sciences, which links wildfire smoke to brain health. Their research, published in the Journal of Neuroinflammationreveal more specifically that the inhalation of these fumes could be responsible for an inflammation of the brain, which would persist for at least a month. “The inflammatory process affects the hippocampus – the region of the brain associated with learning and memory – by altering neurotransmitters and signaling molecules”explains Professor Matthew Campen, one of the authors of the study, in a press release.
Neurocognitive disorders weeks or months later
For the purposes of their work, the scientists exposed rodents to smoke from a wood fire every other day, for two weeks. At the end of the experiment, they identified pro-inflammatory and anti-inflammatory responses when tiny smoke particles managed to cross the blood-brain barrier (BBB) - whose function is to prevent, between others, to the passage of foreign substances, sometimes toxic, and other pathogenic agents, in the brain. Furthermore, said inflammation would not be transient and could even persist over time.
“We were able to measure the magnitude and duration of the inflammatory response. We expected it to be much shorter. Some progressed up to 28 days and we did not see complete resolution, which worried us a lot”, says David Scieszka, who led the research. An observation that is all the more alarming as forest fires are on the increase throughout the world, exposing a growing number of individuals to these harmful fumes for health.
According to the researchers, “neuroinflammation is at the root of all kinds of problems in the brain, including dementia, Alzheimer’s disease, but also alterations in neurodevelopment in early life and mood disorders throughout the life”. And to add: “If you are a firefighter or an ordinary citizen of a community that has been exposed to these dramatic fumes, you are at risk of suffering from neurocognitive disorders or mood disorders weeks, or months, after the ‘event”.
Some advice to reduce the risks
In the event of forest fires, the French government, through its Service-public.fr site, recommends staying inside your home – provided that it is not in danger – and blocking the air vents. .
It is also recommended to apply a damp cloth to the mouth and nose to avoid inhaling the smoke.
As for the scientists, they advise for their part to wear an N95 mask, designed to filter out particles potentially harmful to health.