Study across six states shows causal link between air pollution & poor mental health

MUMBAI: The hazardous smog engulfing large swathes of the country is not only proving detrimental to physical health, but taking a severe psychological toll on residents as well in congested cities, experts have observed—a crisis which they say is seen intensifying during the festive season.

“We see recurring seasonal exacerbations in patients—especially around festive and post-festive periods—which provides a critical window to screen their mental health,” said Dr Sam Bennihin D L, associate consultant, pulmonary medicine at Rela Institute & Medical Centre in Chennai.

According to a macroanalysis published in The Journal of Development Studies in 2023, researchers isolated a positive causal link between worsening air pollution and poor mental health in the country.

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The study used a final sample set of 21,203 individuals across six states.

Cognitive Difficulties
Uttara Balakrishnan, co-author and senior research economist at American Institutes for Research, said that “when looking at mediating channels, negative impacts on physical health, worsening respiratory conditions and an increased likelihood of sleep difficulties served as critical mediating factors”.

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BIOLOGICAL IMPACTS

“An increase in PM2.5 can lead to neuroinflammation, disruption of the bloodbrain barrier, and alterations in neurotransmitter signalling systems,” Bennihin said, adding that it increases the risk of a patient entering depression, developing anxiety or experiencing cognitive impairment. Balakrishnan’s results showed that for a 1 mg/m3 increase in PM2.5 in the last year, the probability of respondents feeling low, sad or depressed in the previous 30 days increased by 2.47 percentage points.