As wildfires continue to rage across much of Canada, something new has happened Research reveals neurological health consequences of inhaling excessive wildfire smoke.
The findings, published in the Journal of Neuroinflammation and conducted by researchers at the University of New Mexico Health Sciences, shed light on how prolonged smoke inhalation – two weeks or more – can trigger brain inflammation.
This inflammatory process, which can last a month or more, directly affects the hippocampus, the brain region linked to learning and memory, the study found. Researchers found that wildfire smoke can alter neurotransmitters and molecules responsible for storing information in the brain.
The research was led by David Scieszka, a postdoc who studied the effects of rodents exposed to wood smoke every other day over a two-week period.
“We've been trying to figure out if the things we've seen in the wild can be at least partially deciphered in the lab,” he said in one press release.
Scieszka and other researchers analyzed inflammatory responses in rodent brains when tiny particles from the smoke penetrated the “blood-brain barrier,” a lining of cells that hide blood vessels in the brain.
“We were able to measure the amplitude and time frame of the inflammatory response,” Scieszka said. “We expected it to be much shorter. Some of these took 28 days and we didn't see a full resolution, and that was very scary for us.”
Scieszka explained that by the second week, blood-brain barrier cells had adapted to exposure to smoke, but immune cells in the brain were still “abnormally activated.”
The study's lead author, Matthew Campen, said these latest findings are alarming given how regularly people have been exposed to smoke from wildfires in recent months.
“Neuroinflammation is the seed for all sorts of bad things in the brain, including dementia, Alzheimer's disease — the buildup of plaques — but also changes in neurodevelopment early in life and mood disorders throughout life,” he said in the press release.
“If you are a firefighter, or just a citizen of a community that has experienced some of these dramatic smoke exposures, you could be suffering from neurocognitive disorders or mood disorders weeks, months or weeks after the event.”
Campen added that heavy concentrations of wildfire smoke should encourage people to stay indoors.
“Houses have different levels of particle penetration. When you have an evaporative cooler you are only exposed to the outside air, but many homes offer much better protection.”
N-95 masks offer protection for those who have to leave their homes despite poor air quality, he added.
Despite the fact that the human body is largely able to adapt to chronic exposure to particulate matter, Campen said periodic exposures could be a concern, even more so than baseline levels of pollutants with smaller variability.
“Part of what makes this so unique and worrying is the intermittent nature,” he said.
“We have rural communities that otherwise enjoy clean, beautiful air, particularly in the Rocky Mountain region, and then suddenly they have a crushing level of pollution, and a week later the air is gone. It's a real blow to a naïve system.”