Mental Health Impact of Air Pollution in the Southeast Asian Subcontinent

Over the past few years, an annual toxic smog has choked the northern part of the Southeast Asian subcontinent during the postmonsoon/early winter for several weeks. The smog, which tends to occur around the festival of Diwali, causes significant distress to the millions of people living in this region, triggers a flurry of media reports, and leads to swift yet ineffective short-term measures like restrictions on vehicular movement, bans on stubble burning and fireworks, and school/work closure.

However, a recent report by IQAir implores us to take long-term measures to tackle it, as this poor air quality is prevalent for most of the year and is getting worse. (IQAir operates a free, real-time air quality information platform.) IQAir found progressively worsening annual average air quality in the entire region, with eight out of 10 of 2022’s most polluted cities located in this area. Also of concern is the concentration of particulate matter (PM) measuring 2.5 micrometers or smaller, more than 10 times that of WHO’s suggested levels. This increase in pollution has led to a significant rise in mortality in this region (up to 57% in some countries), according to a study in The Lancet by Richard Fuller, B.Eng., and colleagues.

While there is extensive research and public awareness about respiratory issues, cardiovascular impact, and increased mortality due to air pollution, there is a distinct lack of discussions concerning the mental health impact of this chronically poor air quality. However, with increased awareness of mental health and destigmatization helping people become more comfortable talking about mental health, more research is being conducted, and some of the findings are alarming.

A 2023 study by Uttara Balakrishnan, Ph.D., and colleagues in the Journal of Development Studies reported that air pollution can impact mental health directly by increasing oxidative stress and inflammation in the central nervous system and indirectly by worsening physical health and day-to-day functioning. Using data from national surveys, they noted that higher levels of pollution lead to people verbalizing increased feelings of sadness/depression and thoughts of being unable to control or cope in life as well as experiencing cognitive difficulties. Air pollution also impacts their ability to work and can worsen their financial situation. The same authors also concluded in an earlier study that air pollution can impact academic performance in children aged 5 to 16 years. Both these studies highlight the impact of air pollution on perpetuating poverty in this region, which is an important risk factor for several mental illnesses.

Looking directly at PM 2.5 and PM 10 pollution, Isobel Braithwaite and colleagues found an association between long-term PM 2.5 exposure and depression in their 2019 study conducted in several countries across the globe. They further identified possible associations between long-term PM 2.5 exposure and anxiety and between short-term PM 10 exposure and suicide.

As the U.N. Environment Program noted in its 2022-2025 strategy, climate change and poor air quality are closely linked, conjoint threats. Many interventions that target air pollution also help slow down climate change, and not addressing them together may lead to unanticipated tradeoffs (win-lose outcomes). With populations in low- and middle-income countries suffering the highest exposure to poor air quality, there is an acute need for long-term interventions to support their mental health, such as training health care workers to screen for psychiatric disorders and increasing resources for individual and group psychotherapy. They require cooperation beyond nations’ borders and global support to allocate sufficient resources to create lasting impact. ■

Lakshit Jain, M.D., is a principal psychiatrist at Connecticut Valley Hospital and an assistant clinical professor at the University of Connecticut.