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Protect Your Brain From Wildfire Smoke

How wildfire smoke impacts the brain, and what to do about it.

Key points

  • Wildfire smoke may increase the risk of depression, dementia, and violence.
  • The most important way to decrease risk may be to decrease exposure.
  • In times of high outdoor air pollution, reduce exposure by limiting indoor air pollutants.

In the last weeks, the Northeast and Midwest of the United States and vast swaths of Canada have been blanketed by toxic smoke from over 400 wildfires. Dry, hot conditions and wind propelled smoke into cities 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 regarding the damaging effects of wildfire smoke on our brains and bodies, you should be especially 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 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 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 cognitive development scores. Data even suggests 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, worsen the function of our mitochondria, and cause premature aging of our cells. This may be especially bad news for our billions of brain cells that rely on being healthy to deliver clear thinking and mental function.

Given all the links between air pollution and brain health, trying to mitigate some of the risks of wildfire smoke whenever possible makes sense. To this end, here are four important steps.

1. Decrease your exposure to wildfire smoke.

This is perhaps the most obvious and most important step. If wildfire smoke is significant in your area (either because you see it or because the local news or weather services advise you), 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 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. When trying to limit overall exposure to air pollution, limit the 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 and smoke that may have made its way indoors.

3. Consider masking when outside

The last few years have polarized us on the topic of mask use. But unlike the pandemic, mask use for wildfire smoke has a simple mechanism: reducing 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. A well-fitting N95 may provide the best protection.

4. Keep up with other brain-healthy activities.

Sometimes it’s impossible to mitigate negative factors on brain health entirely. In the case of wildfire smoke, we may be unable to avoid exposure continuously. 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 getting daily physical activity.

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