If you are unfortunate enough to breathe fire smoke, a large amount of charred plant material, noxious gases are obtained, and if the fire broke human structures, synthetic materials were incinerated. Everywhere, they are bad things, which have proven to be a serious detriment to human health, especially for those with respiratory conditions such as asthma. And not to stack worries, but this fog is also laden with microbes like bacteria and fungi.
The problem is that scientists have only just begun to study this smoky microbial community. This led a couple of researchers to publish a new piece of perspective in the journal Science today a multidisciplinary impetus is being called for to better characterize these microbes and determine how they could make fire smoke for human lungs even worse. “Not only does it consist of particles and gases, but it also has an important vital component,” says Leda Kobziar, a fire scientist at the University of Idaho, co-author of the piece. Kobziar adds that fire smoke can spread beneficial organisms to an ecosystem, but “what can be the consequences for the spread of pathogens that we know are transmitted through the air?”
But hold on to a tick: shouldn’t microbes be cooked in the flames? Well, that’s not giving any credit to these microbes. You see, a fire burns with different intensities at different points as it moves through a landscape. “On smaller scales, complete combustion joins incomplete combustion,” Kobziar says. “Even at one centimeter, you could get very high temperatures for long durations and, at the next centimeter, you can jump completely and not get hot. So this degree of variability provides many pockets in which these microbes could survive the fire.
Instead of dying, they stick to pieces of charred carbon and water vapor, as the heat of the fire pushes the whole pig into the sky. If they end up in small drops of water, this could protect them from drying out as they travel through the wind. “We know that microbes attached to dust particles are certainly transported across continents,” Kobziar says. “Therefore, we have no reason to believe that this will not also occur in smoke as the smoke travels. But how long do they survive and which ones survive? This is an open question, and this is exactly the kind of research we hope this document will inspire. ”
Take, for example, the genus of fungi Coccidioides, whose species live in the soil. When a fire starts a landscape, it disturbs the ground directly, chewing it with flames, but also indirectly: All this hot, rising air creates an atmospheric void near the surface, and more air runs through the sides to fill it. that. This can produce fierce winds that travel through the earth, aerosolizing the fungi.
When firefighters inhale this rotten air, the fungus can cause a condition called coccidioidomycosis, or valley fever, with symptoms such as fever and difficulty breathing. The disease can progress to pneumonia or meningitis, an infection of the tissues surrounding the brain and spinal cord. (Infection by another fungal genus called Cryptococcus, Coccidioidomycosis is common enough among firefighters that the Centers for Disease Control and Prevention considers the profession to be at risk for fungal infection.
As forest fires become larger and more intense thanks to climate change, researchers are finding a worrying increase in cases of mycosis (i.e., any disease caused by a fungus) in the American West. Fungal spores “can act as allergens and initiate the development of asthma in the atopic population and have been associated with decreased lung function, hospitalizations, and increased mortality,” says Mary Prunicki, director of air pollution and health research at Stanford University, Sean N. Parker. Center for Allergy Research, which did not participate in this new paper. “In general, many microbes are a concern for human health.”