If veld fires roar through a forest and bulldozers dig into the earth to repel flames, they can shoot into the air more than just clouds of dust and smoke.
Those dark, undulating plumes of smoke that rise on heat waves during the day and sink into valleys as the night air cools can transport countless living microbes that can seep into our lungs or cling to our skin and clothing, according to recent research in science. In some cases, researchers fear that airborne pathogens could weaken firefighters or residents of the wind.
“We are inspired to write this because we realize that there are many billions of microbes in smoke that are not really included in an understanding … of human health,” said Leda Kobziar, director of wildlife fire science. , said. “It simply came to our notice then. The variety of microbes we found is really flexible. ”
As the recent fire seasons indicate, the need to understand what is in the wildfire smoke, we have no choice but to breathe and how it can affect us, has never been so expressed, but scientists say we are seriously behind the leaf.
Wildfires burned over more than 10.2 million acres of the United States by 2020, according to federal statistics, including about 4.2 million acres in California, where a greater number of residents have been exposed to smoke for longer than ever before.
According to researchers, wildfire smoke is now responsible for up to half of the particulate matter pollution in the western US. Although there are many studies on the long-term impact on urban air pollution on human health and short-term effects of veldfire smoke, little is known about the multitude of ways the latter can harm our lives.
“Honestly, we do not really know about the long-term effects of veldfire smoking, because exposure to the community has not been long-term yet,” says Dr. John Balmes, a professor of medicine at UC San Francisco and a member of the California Air Resources Board.
But people – and especially Californians – should expect to inhale more veldfire smoke in the future.
Scientists say the planet will continue to warm for decades, even if humans suddenly act to stop climate change. This warming, and other factors, are contributing to increasingly devastating wildfires. The forests of the state meanwhile struggle to adapt and native plants are displaced by invasive species that burn faster.
Add to the trends a global pandemic attacking the respiratory system, and microbial-filled fire smoke each year could be considered a growing health risk, researchers say. They wonder if microbes in wildfire smoke can make cancer patients more vulnerable to infections or children with asthma are more likely to develop pneumonia.
Scientists believe that some microbes survive and even spread in wildfires, where heat scorches the soil and leaves a layer of carbon that protects microbes in the earth from intense heat. Others survive in the air because the particles from wildfires can absorb the sun’s otherwise deadly ultraviolet radiation, scientists said. And yet other tracks are likely to spread on wind currents caused by fire.
Kobziar and co-author George Thompson III, an associate professor of medicine at UC Davis, said the link between microbes and wildfires has so far been anecdotal – such as the tendency for firefighters in the field to become ill with false fever after working. about an incident. The disease is contracted by inhaling spores of the fungi Coccidioids.
“We have more questions than answers at this point,” Thompson said. ‘Our lungs are exposed every day to pathogens that we do not think much about. But [what] if we increase the number of microbes in there with fire? ”
In 2018, for example, the Kern County Fire Department sought a $ 100,000 grant to help reduce fuel outages – which disrupted the ground – because their firefighters would become ill after doing the work. Data shows that fall fever cases grow every fall in the valley of the country, just as the fire season in the surrounding hills is going on.
“Aerosolized, microbes, spores or fungal conidia … have the potential to travel hundreds of miles, depending on fire behavior and atmospheric conditions, and are eventually deposited or inhaled in the wind of a fire,” Kobziar and Thompson said in their paper written.
Yet it was difficult to determine which pathogens exist in veldfire smoke.
The National Oceanic and Atmospheric Administration, NASA and a team of chemists, physicists, biologists and forest and fire ecologists from a number of universities have been working together for years to study wildfire smoke in the country, assuming no one will be immune to the effects. of it not. in the future.
“As the climate changes, as the temperature warms, as we build homes in places surrounded by human populations and the development of homes expands to regions prone to fires, it’s a matter of time,” Berry Lefero said. manager of NASA’s Tropospheric Composition, said. Program, which includes a DC-8 jet flying around the globe and studying the wildfire smoke, ozone and aerosols in the lower layer of the atmosphere.
Through the combined work of these researchers, scientists hope, the public and health professionals will one day be able to get accurate predictions about where wildfire smoke will go, what specific health hazards it poses and what people should do in its path prepare beyond the hotplate advice to stay indoors.
To solve the mystery of microbes in the smoke and why, Kobziar and Thompson need to understand what kind of fuel burns, such as a grass, shrub or tree; how many of them were there initially; how badly it was burned (was it just black scorched or completely reduced to ashes or something in between?); and where the smoke originated.
Once the variables are determined, there is the complicated task of capturing the smoke, which is by no means uniform, Kobziar said.
In September, Kobziar, a former firefighter, used a drone to capture air samples over Idaho when it was flooded with smoke from fires in eastern Washington and Oregon. She then places the samples in a petri dish, adds food that microbes would like to eat and waits to see what will happen.
“Even a few hundred kilometers from the source of the smoke, it was still important,” Kobziar said. “We’re still trying to isolate all the things we found.”
Tim Edwards, president of the Fire Brigade Union Local 2881, which represents thousands in the California Department of Forestry and Fire Protection, hopes the scientists’ work can boost the protection of wildlife firefighters, as they usually only wear face masks or bandanas trust. – unlike their peers for urban firefighting.
It’s not just the dust that is kicked up in a fire that makes crew sick, Edwards said.
“Now, in a wild veld fire, you have 1,000 houses burning,” he said. “You burn the house, you do not know what chemicals they have in that house, everything that is on fire and what goes into your lungs.”
This story originally appeared in the Los Angeles Times.
Originally published