Impact of Air Pollution on Mental Health

While air pollution’s negative impacts on the lungs and cardiovascular system are well-recognized, poor air quality also has adverse consequences on the brain and affects mental and cognitive health. According to data from the World Health Organization (WHO), 99% of the entire global population is exposed to unsafe levels of air pollution — meaning that the negative impacts of air pollution on human cognition are likely affecting us all. 

Air pollution is known to create inflammatory responses within the body, and chronic inflammation in the brain can damage neurons and the nervous system’s regulatory responses. Animal research shows that air pollution can enter the brain and cause inflammation through a variety of pathways. This research states that chronic inflammation in animals can mimic symptoms like depression and bipolar disease in humans. Air pollution has been linked to a variety of serious mental and physical health problems in adults, including anxiety, depression, and neurodegenerative disorders. A 2019 study of people in the United States and Denmark found higher rates of psychiatric illnesses — such as depression, schizophrenia, bipolar disorder, and personality disorders — in those exposed to more polluted air.

Past research has associated air pollution with higher levels of stress, psychological distress, increased risk of dementia and Alzheimer’s and depression. Other research has linked short-term exposure to peaks in air pollution with an increased risk of death among people with serious mental illness. A study from researchers at Harvard, published in March 2023, adds to the evidence connecting exposure to air pollution (small particulate matter (PM2.5), nitrogen oxide and nitrogen dioxide) to increased risk for dementia.

New research specifically points to impacts on the brains and mental health of children. A recent study looked at potential impacts on children and adolescents who may be particularly vulnerable as they experience critical periods of brain development. The review of research found evidence that air pollution is associated with an increased risk of depression symptoms and suicidal behaviors. They also found, through neuroimaging studies, evidence for associated structural and functional changes in the brain. The findings of the large population study mentioned above suggest that poor air quality during the early years of an individual’s life increases the risk of psychiatric disorders, including bipolar disorder, schizophrenia, personality disorder, and major depression.

As stated by Dr. Ashish Kumar Mittal, senior consultant psychiatrist, Columbia Asia Hospital, “Fresh and clean air is a prerequisite for healthy living and thinking. An optimal amount of oxygen is essential for rational thinking. When the air gets polluted, our survival instinct starts acting and blurs our higher order logical cognitive processes and simultaneously disturbs our emotional state, severely impacting mental health. “