Mental health is an important topic that we’re learning more about as added attention and funding are given to research and outreach campaigns. One of those efforts is Mental Health Awareness Month, recognized each May with the goal of increasing awareness, understanding, and acceptance of mental health issues.

Understanding the causes of mental health problems is a complex process, with focus often given to genetics, isolation, stress, and several other factors. Another area being explored in research is how mental health is affected by air quality.

In recent years, several studies have linked exposure to air pollution with higher levels of stress, depression, Alzheimer’s, and dementia. While more research is needed in this area, it’s important to understand what we currently know about the link between breathing unhealthy air and experiencing decreased mental wellness.

Air Pollution in the United States

Exposure to air pollution happens both inside and outside of the home. Outdoor air pollution most often comes from automobiles, industrial practices, and agriculture, which are common in most populated areas of the country. In fact, the American Lung Association’s “State of the Air” report shows that nearly 36% of Americans live in areas with elevated, unhealthy levels of ozone or particulate pollution.

Indoor air pollution shouldn’t be ignored either, as the air inside our homes and offices can be up to five times more polluted than outdoor air. This is caused by a combination of improper ventilation and air purification, and the introduction of pollutants from things like paint, cooking, furniture, candles, and a host of other common household items.

Air Quality and Mental Health

Knowing how often we may be exposed to polluted air every day, it’s important to gain an understanding of how that chronic exposure can impact mental health. Here are some facts and studies to consider:

• The type of pollution that has been studied most closely for its impact on mental health is PM2.5 (particulates less than 2.5 micrometers in diameter). These particles come from gas stoves, automobile exhaust, wood burning, and other things we’re exposed to every day
• Because they are so small, PM2.5 particulates may get deep into the lungs and even enter the bloodstream, where they can cause widespread inflammatory responses in the body that can impact mental health
• Research from 2019 in the U.S. and Denmark found evidence of this link between inflammation and mental distress
• This 2021 study suggests that exposure to air pollution may increase the severity and longevity of preexisting mental health conditions
• A review of over 100 studies found that people who breathe polluted air can experience changes in the parts of their brains that control emotions. This, in turn, can develop into anxiety and depression
• Visits to the emergency room for depressive disorders were associated with local air pollution in a 2009 study
• For older adults in a March 2023 study, breathing unhealthy air was associated with increased risk of developing dementia
• For children, studies have shown a higher level of vulnerability to pollution exposure. During adolescence, there’s an increased risk of mood disorders and structural changes in the brain. For those exposed to pollution at a young age, there’s an increased risk as they get older of developing bipolar disorder, schizophrenia, personality disorder, and major depression

For resources on mental health, please visit the National Alliance on Mental Illness website. If you are in crisis or you think you may have an emergency, call your doctor or 911 immediately. If you’re having suicidal thoughts, call 1-800-273-TALK (8255) to talk to a skilled, trained counselor at a crisis center in your area at any time (National Suicide Prevention Lifeline). If you are located outside the United States, call your local emergency line immediately.