The Negative Impact of Wildfire Smoke on Mental Health

As fires rage across the western U.S. and Canada, the resulting smoke may pose a risk to our mental health, along with our physical health. The fires have spread smoke and soot across the United States, causing a reduction in air quality as the gray clouds settle on cities and towns.

The inhalation of smoke is known to cause physical health risks and exacerbate those already present, including COPD and asthma. However, mounting evidence points towards damage to our brains as well. Adverse mental health outcomes have been recorded in several studies, linking poor air quality to damaging emotional and cognitive conditions.

Dangerous soot and toxic chemicals pose a greater risk to the communities it settles on than commonly believed. Especially as the smoke travels across the U.S. with some cities being choked in a foggy haze. 

What Fires Do to Our Air

When a fire burns, a mixture of materials is released into the air. Aside from the visible smoke, there is particulate matter—tiny pieces of burnt material that can be inhaled. Along with carbon dioxide and nitrogen dioxide, particulate matter can damage human health. When buildings burn, the smoke can also contain deadly fumes from construction materials, as well as from plastics, polyester, paint, and other substances.

Plumes of smoke emitted by fires in the Western U.S. travel along wind patterns, eventually settling in places such as Salt Lake City, Utah. On August 6, Salt Lake City had the worst air quality in the world due to the debris coming from the western fires. Utah lies many miles east of the wildfires yet will still feel its harmful effects.

Along with the physically damaging effects of breathing soot and ash into your lungs, mounting evidence shows that the impact on your brain could be just as dangerous.

Smoke on the Brain

While research is still searching for answers on how air pollution specifically affects the brain, plenty of evidence shows what happens when it does. A comprehensive study in 2019 showed that exposure to particulate matter in the air was associated with anxiety, depression, and even suicide.

Isobel Braithwaite, MBBS, MPH, first author of the study, discussed the danger of short-term, low-quality air: “In the days immediately following a peak in air pollution, you do see a rise in the rate of suicide,” she says. 

The increased rate of suicide makes sense, as other studies have found a significant link between exposure to air pollutants and emergency room visits for depression and suicide. While it is easy to say that the trauma of the wildfires themselves could cause this emotional toll, other research shows that the particulate matter from the fire could change how we handle stress itself.

A 2017 study found that those exposed to more particulate matter had significantly higher levels of stress hormones in their blood serum. This study indicates that the presence of air pollutants is not only psychologically stressful but also affects normal hormone function.

Sarah Rahal, MD, a pediatric neurologist and expert on environmental medicine, offered some explanations on how these particles may enter and impact the body. She explains that the particles can be inhaled into the lungs and enter the bloodstream that way or directly communicate to the brain through the nasal passages.

Once in the body, “These particles do cause inflammation, they trigger the immune cells in the brain [and cause] a stress response,” she says. Additionally, “You have direct toxicity of these particles to certain neurons in your nervous system,” she explains. The results of such neurotoxic effects could change brain structure and lead to neurological issues, especially in children.

What Can Be Done

Those who work and live in areas where the smoke has settled have had little choice in the days surrounding the Western wildfires. These people are often forced to stay in areas where the concentration of particulate matter is the highest. Therefore, they are at the most significant risk of adverse mental health outcomes.

The most long-term solution to the issue of particulate matter due to wildfires is to prevent fires in the first place. However, that is a global issue and out of the hands of the individual. In the event of heavy air pollution due to particulate matter, the best practice is to avoid the inhalation of the matter itself.

Time outside should be limited, especially for the young, elderly, and pregnant. Those who venture out should wear a mask that prevents the inhalation of fine particles in the air. Since the particulate matter is so fine, the use of regular paper masks is insufficient. Wearing a properly fitting N95 mask or respirator is required to protect against the fine particulate matter in wildfire smoke.

While staying indoors may offer the best protection, it must be done correctly. “Having an air filter and keeping the windows open just to keep the air circulating, [as well as] making sure people take their shoes off…is really important,” explains Dr. Rahal.

The people exposed to these levels of particulate matter should be made aware of the dangers it poses. Every precaution should be taken to protect your mental and physical health as the wildfire season continues.