Forest fires burning through the Los Angeles the region is gone 16 dead, thousands of people displacedand more than 10,000 structures destroyed. As authorities struggle to contain the fires, the Centers for Disease Control and Prevention (CDC) has urged area residents to monitor local air quality on their weather app or airnow.gov.
Smoke from wildfires, a major source of air pollution, is linked to serious health problems including heart attacks, strokes and lung diseases like asthma.
There is also a burgeoning body of research on their effects on mental health, which is beginning to reveal some connections that can help us better understand the impact of these complex interactions on our well-being and illuminate potential solutions.
How does wildfire smoke affect the brain?
Air pollution affects our brain health and cognitive functions. Researchers have found that fine particle pollution (PM2.5) released by forest fires is even greater. more toxic than air pollution from other sources. One possible reason is the high level of polycyclic aromatic hydrocarbons (PAHs) mixed with various levels of other neurotoxic particles that can be found in smoke, particularly heavy metals. These particles can reach the brain via the olfactory nerve and cross the blood-brain barrier, or modulate the nervous system, leading to brain inflammation and oxidative stress.
Can wildfire smoke affect cognitive function?
Neuroinflammation caused by wildfire smoke increases the risk of developing Alzheimer’s, dementia and Parkinson’s disease. Recent research from the Universities of Washington and Pennsylvania found that the odds of a new dementia diagnosis increased by about 21% for every 1 microgram increase in the concentration of wildfire particles a person inhales, versus an increased risk of 3% for each jump of 3 micrograms in non-cases. forest fire particles.
Additional research from the University of New Mexico suggests that sudden increases in air pollution, as occurs during wildfires, create flare-ups of inflammation in the hippocampus region of the brain, responsible for memory and learning. These may persist for more than a months after exposure.
This may explain why, in addition to several studies revealing a correlation between smoke exposure and poorer concentration and decision-making ability while playing digital games And sportysmoky days also seem to be linked to poorer academic performance.
In a 2020 study, UC San Diego economist and researcher Josh Graff Zivin examined how smoky air affected students taking the national college entrance exam in China over a six-year period. Graff Zivin specifically studied the smoke created by routine, controlled agricultural fires, eliminating potential anxiety related to possible evacuations as a factor in the study.
His team found that when there was a significant increase in downwind versus downwind fires during the exam, students’ total scores dropped by 0.6 points on average. This drop in achievement also slightly reduced students’ likelihood of getting into top-tier universities. A United States study of 2022, it is estimated that smoke exposure in 2016 reduced students’ future earnings by almost $1.7 billion (or $111 per student).
“We don’t know exactly what happens to the brain” during days when there is a lot of smoke, explains Graff Zivin. “But we know it’s bad.”
The cardiovascular effects of smoke inhalation can affect our body’s ability to properly oxygenate our brain. “Just having impaired lung function could lead to cognitive impairment,” he says.
But more research is needed to fully understand how smoky days affect cognitive performance. We also don’t fully understand the cumulative impact of exposure to smoke for weeks or months each year, adds Graff Zivin.
What is the relationship between smoky days and depression?
It’s unclear how smoke may physiologically impact the brain in a way that contributes to feelings of depression, but researchers believe Cognitive disorders – like those observed by Graff Zivin in students taking tests – can be a factor in low mood. Researchers also increasingly believe Brain inflammation plays a role in producing depressionraising the possibility that brain inflammation triggered by wildfire smoke could contribute to mood disorders.
The stress and trauma caused by a wildfire can also affect mental health. Dr. Jyoti Mishra, neuroscientist at UC San Diego School of Medicine studied people directly and indirectly exposed to the 2018s Campfirea year after ravaging Butte County, California. Not surprisingly, she found that those who suffered significant personal loss or trauma during the fires had the highest levels of PTSD, anxiety and depression. Yet even community members who were not directly impacted by the fire reported an increase in neurocognitive problems and experienced depression and anxiety.
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Some of the fears felt by people living near wildfires are related to “seeing landscapes changing, environments changing and worrying about both the present and the future,” says Dr. Warren Dodd, associate professor in the School of Public. Health Science at the University of Waterloo.
Dodd has interviewed residents of Canada’s Northwest Territories who experienced what was, in 2014, a record fire season. They reported feelings of anger, stress and despair over the threats posed by climate change.
Along with the distress of seeing one’s surroundings change rapidly – also known as solastalgia – people Dodd interviewed reported that stopping their summer outdoor and land-based activities to shelter indoors had negative consequences on their mental health.
What can we do about the mental health effects of wildfires?
Reducing the physiological effects of wildfire smoke on our brains involves many of the same behaviors as protecting the rest of our bodies from air pollution: using a air purifier indoors, carefully cleaning living spaces to eliminate particles that get insidewear a mask when outdoors and minimize unnecessary time spent outdoors.
When it comes to mitigating the psychological harm of smoky days, local authorities can intervene. Making community resources available for free during wildfires is one way to help people alleviate some of the isolation and anxiety felt while sheltering indoors. For example, Dodd notes that the City of Yellowknife waived fees for its indoor recreation center during the fire, allowing people to exercise and see their neighbors without having to go outside.
According to Mishra, it is important for communities to focus on resilience – not only after a climate disaster, but also preventatively. “When we studied campfire people, we found that there are certainly certain characteristics, such as greater awareness and better physical activity, that can contribute to a sense of resilience,” she says. But the strength of people’s family and social ties was also an important factor in their resilience.
People who “feel supported and feel like there is a sense of community around them are better protected in terms of mental health issues,” she says. A stronger sense of community can be an antidote to loneliness and a tool for climate resilience, Mishra notes. For people with PTSD, therapy for underlying neurocognitive issues can help with recovery.
As always, prevention is key: reducing greenhouse gas emissions can slow global warming and help curb wildfires and their devastating and complex consequences.
Graff Zivin says governments need to keep in mind the economic impacts of reduced productivity and cognitive function, and invest more in wildfire prevention and forest health. A healthy forest maintained by prescribed burning can lead to less intense forest fires, he said. “We rarely talk about the importance of having healthy forests. »