Why You Need to Protect Your Brain from Wildfires

“[Since] the mid-1980s, the average total area burned by wildfires in the western United States has tripled from one million to three million acres, and twenty-seven times more Americans experience at least one day of extreme smoke per year than they did in 2006.”

Unfortunately, wildfire smoke can now reach you wherever you live in the world. While the effects of wildfire smoke on the body are well publicized, we are just beginning to understand how bad it is for the brain too. Here’s why wildfire smoke affects the mind and what you can do about it.

Why Is Wildfire Smoke Different?

Like most types of smoke, wildfire smoke consists of water vapor, particulate matter (PM), carbon dioxide, carbon monoxide, and volatile organic compounds (VOC gases). However, there are 3 unique reasons that wildfire smoke is of particular concern:

1. Wildfire smoke affects more people on a larger scale. Per an interview in Science with 3 conflagration experts:

   “[...]while the chemical content of wildfire smoke may not always differ substantially from other types of smoke, wildfires are a totally different kind of event by nature; the smoke can travel far and fast, cloaking urban areas in a toxic blanket that can sometimes be seen from space.”

2. Wildfires burn more than just wood; they produce a special signature of impurities created by what is caught in their path. As the Science article also explains:

   “Smoke from fires that burn through poison oak and poison ivy may contain traces of irritants from those plants. Smoke can also pick up chemicals from plastic and other humanmade materials when wildfires burn through cities or housing developments.”

3. Possibly due to these impurities, the particulate matter in wildfire smoke may be more dangerous than other sources of PM. Per one NPR article:

   “Researchers with the Scripps Institution of Oceanography at the University of California, San Diego say that the tiny particles released in wildfire smoke are up to 10 times more harmful to humans than particles released from other sources, such as car exhaust.”

How Does Wildfire Smoke Affect the Brain?

While wildfire smoke has some special features, it's likely that much of the danger is still due to the most common air quality concern, PM_2.5 (airborne particles smaller than 2.5 microns). While scientists aren’t quite certain why PM_2.5 has such a strong effect on the brain, one possible culprit is inflammation. PM_2.5 can penetrate the blood/brain barrier, causing an immune reaction. According to Dr. Matt Campen of the University of New Mexico, “‘Neuroinflammation is the seed for all sorts of bad things in the brain, including dementia, Alzheimer’s disease – the buildup of the plaques – but also alterations in neurodevelopment in early life and mood disorders throughout life[...]’”

Dementia

We discussed dementia’s connection to air pollution in a previous article. To refresh your memory, a national study of PM_2.5 exposure in older Americans discovered that 15% of the study’s 27,857 participants developed dementia; those exposed to greater concentrations of PM_2.5 were more likely to be among the 15%. PM_2.5 from wildfires played an outsized role. As Smithsonian Magazine reports, “Among nine sources of particle pollution, fires and agriculture had the strongest link to dementia.”

Cognition

In addition to the long-term condition of dementia, wildfire smoke can affect cognition immediately. One widespread analysis compared the results of a video game (designed to test focus) in areas with inferno events. They found that wildfire smoke reduced player performance within hours, especially in young adults. Separate research conducted by the aforementioned Dr. Campen found that wildfire-triggered inflammation “affects the hippocampus – the brain region associated with learning and memory – altering neurotransmitters and signaling molecules.” This fits with other data linking poor air quality to decreased cognition, even though such studies were not specific to wildfires.

Mood Disorders & Mental Health

Obviously, wildfires are stressful to everyone — from first responders suffering from post-traumatic stress to antsy children stuck indoors during recess. However, is it possible that the mental effects of conflagrations are not caused by the event alone but also by the neurological damage from the smoke? An article published in Scientific American lists one study which suggests so:

“One 2014 paper[...]showed that after a massive wildfire smoke event in Southeast Asia, locals reported mild psychological stress, which was worst in those who had a higher number of physical symptoms from the smoke and those who perceived the air quality to be dangerous (which it likely was for many).”

Other studies failed to find a direct link between smoke and mental health. But the possibility that smoke can physiologically alter mood remains open.

How to Protect Yourself from the Mental Effects of Wildfire Smoke

Here are 4 ways to protect yourself from the effects of wildfire smoke.

1. Stay Indoors on Smokey Days

Remember, you can experience the effects of wildfire smoke even if the smoke itself isn’t visible. The most dangerous particles are those too small to be detected by the naked eye, so check the Air Quality Index (AQI) in your area for guidance. The AQI summarizes the air quality as one of 6 color-coded ranges. These color-coded ranges let individuals know when they might experience acute health effects and if they should reduce (or eliminate) outdoor activities The individuals most often affected are “members of sensitive groups” — a broad category which includes people with heart or lung disease, seniors, minors, diabetics, and outdoor workers.