Updated: Jun 11
Why wildfires are a major brain threat, and what to do about it
By Austin Perlmutter, MD
Wildfire smoke may have a number of negative effects on brain health
PM 2.5s in wildfire smoke are linked to depression, dementia and even changes in behavior
To mitigate the effects of wildfire smoke, decrease outdoor exposure, use indoor filtration systems and decrease indoor air pollution production (no incense!)
A well-fitted N95 mask may help if spending time outside
Don't forget to continue to keep up with other brain-healthy strategies to help offset the potential harms of wildfire smoke on your brain!
In the last weeks, the northeast and Midwest of the United States, along with vast swaths of Canada have been blanketed by toxic smoke from over 400 wildfires. Dry, hot conditions and wind propelled smoke into cites like New York and Toronto, with millions experiencing unsafe air quality conditions. Even if you haven’t been directly affected, you are more than likely to experience risk for air pollution effects on your health soon or in the years to come. So how does all this map onto brain health, and what can you do to decrease the risk?
Air pollution is a term that encompasses a wide variety of individual pollutants. But as it relates to the damaging effects of wildfire smoke on our brains and bodies, you should especially be aware of PM 2.5s. These are minuscule particles less than 2.5 microns in diameter that can pass through the linings of your lung tissue and enter your bloodstream. Once inside the body, PM 2.5s appear to increase oxidative stress and inflammation, two dangerous outcomes that could lead to disease.
Most research on the damaging effect of air pollutants and smoke has focused on cardiovascular and lung problems. This is absolutely an important topic. But we now know that people exposed to air pollution may be at much higher risk for developing depression and dementia. In addition, children exposed to air pollution may have worse scores of cognitive development. There’s even data suggesting that people may be more violent when breathing in more air pollution!
How might wildfire smoke directly lead to brain issues? Too much oxidative stress and inflammation are thought to promote cell damage, worse function of our mitochondria and premature aging of our cells. All of this may spell especially bad news for our billions of brain cells that rely on a high level of health to deliver clear thinking and mental function.
Given all the links between air pollution and worse brain health, it makes complete sense to try to mitigate some of the risk of wildfire smoke whenever possible. To this end, here are 4 important steps.
1. Decrease exposure to wildfire smoke
This is perhaps the most obvious but most important step. If wildfire smoke is significant in your area (either because you see it or because you’re advised by the local news or weather services), do your best to pay attention to that information and act on it. Some populations (people with existing diseases, especially heart and lung diseases) may be especially vulnerable to the negative effects of the smoke and should take extra steps to reduce exposure. Decreasing exposure may range from limiting extended outdoor exercise to spending the day indoors with the windows closed. Check your local news and weather forecasts for details.
2. Decrease indoor exposure to additional air pollutants
At a basic level, if the air quality is poor outside, you want to keep the outside air from getting inside. This means keeping windows and doors closed. However, many people are unaware that indoor air pollution can be a bigger threat than what happens outdoors. To this end, when trying to limit overall exposure to air pollution, limit use of indoor incense, essential oil diffusers and smoking. If you cook indoors, try to use a hood or other form of ventilation. If you have an air conditioner or air filtration system, keep that running to filter out air pollutants from indoors as well as smoke that may have made its way indoors.
3. Consider masking when outside
The last years have polarized everyone on the topic of mask use. But unlike the pandemic, mask use for wildfire smoke has a simple mechanism: reducing your exposure to air pollution. Unfortunately, because of the size of the air pollutant particles in smoke, a cloth or surgical mask will do little to prevent exposure. To this end, a well-fitting N95 may provide the best protection.
4. Keep up with other brain-healthy activities
Sometimes it’s impossible to completely mitigate negative factors on brain health. In the case of wildfire smoke, we may not be able to continuously avoid exposure. This makes it even more important to keep up with other activities that can help support better brain health, including eating real food, prioritizing sleep and as possible, getting daily physical activity.
Want to learn more? Check out the video below! ↓