Explained: How Air Pollution Affects Mental Health

Research shows people who breathe polluted air experience changes within the brain regions that control emotions, and are more likely to develop anxiety and depression.

We are aware that air pollution can impact our physical health, especially the respiratory system. Recent studies however have shown that breathing polluted air can also affect our mental health as both outdoor and indoor air pollution have been linked to conditions like depression, anxiety, and even serious mental health issues such as schizophrenia.

The Mental Health Risks of Pollution

Dr Pallavi Rajan, a consultant psychiatrist, explains that exposure to air pollution -- particularly fine particulate matter (PM 2.5), nitrogen dioxide and nitrous oxide can contribute to mental health issues such as anxiety and depression. "Prolonged exposure to these pollutants can lead to the development of mental health conditions," Dr Rajan told PTI.

"It may also worsen pre-existing mental health issues, including anxiety and depression," she added. The impact of pollution on mental health is not limited to direct exposure. Dr Rajan highlights that ongoing studies are investigating the potential mechanisms behind this link, suggesting that air pollution may trigger oxidative stress and neuro-inflammatory changes in the brain. These biological changes could contribute to the onset or worsening of mental health conditions.

What Research Shows

According to the American Psychiatric Association, there is substantial evidence that air pollution also impacts mental health. In its 2023 article 'Air Pollution’s Impact on Mental Health', the Association writes that a review looked at more than 100 studies on the effects of outdoor air pollution on mental health and regions of the brain that regulate emotions, focusing on the hippocampus, amygdala and prefrontal cortex.

"The researchers found that 73% of the studies reported higher mental health symptoms and behaviours in humans and animals after exposure to higher-than-average levels of air pollution," it said.

The Association further says that the lead author of the study, Clara G. Zundel concluded in a World Economic Forum report: “People who breathe polluted air experience changes within the brain regions that control emotions, and as a result, they may be more likely to develop anxiety and depression than those who breathe cleaner air.”

Another 2023 study by the University of Oxford's Department of Psychiatry found evidence that "exposure to air pollutants may lead to depression, anxiety, psychoses, and perhaps even neurocognitive disorders, such as dementia".

"There were also indications that children and adolescents might be exposed to air pollution at critical stages in their mental development making them at risk of the most severe impact and significant future mental health problems," reads an article by the University of Oxford.

Indoor Air Pollution

While outdoor air pollution typically receives more attention, experts warn that indoor air quality is also a significant factor in mental well-being. Poor ventilation and emissions from cooking or heating sources can lead to increased levels of carbon dioxide indoors, which can negatively impact cognitive functions.

High indoor carbon dioxide concentrations have been associated with symptoms such as fatigue, difficulty concentrating, and 'brain fog'. These cognitive disturbances can, in turn, affect mood and mental health.

Efforts to improve indoor air quality are crucial in mitigating these effects. Enhancing ventilation, reducing indoor pollutants, and using air purifiers can all help maintain better air quality in homes and workplaces, potentially improving both cognitive function and emotional well-being.

The Broader Impact On Health

The broader health implications of pollution are well-documented. Chronic exposure to polluted air increases the risk of respiratory diseases, infections, and complications such as asthma and bronchitis. Studies also suggest that the psychological impact may be equally significant. Inhaling polluted air regularly can contribute to mood disturbances, irritability, and symptoms of depression and anxiety.

Experts say that improving air quality, indoors and outdoors, is essential for protecting mental health. "efforts to improve indoor air quality are crucial for safeguarding mental health. Cleaner air can significantly impact not just our physical health, but our emotional and mental well-being," Dr Rajan said.

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