Air pollution has well-known ties to lung disorders. Recent data has even linked air pollution to both heart disease and diabetes. Few people, however, would link pollution to the risk of developing psychiatric disorders. However, recent research suggests this could be the case.
A study published in the latest issue of PLOS Biology has analysed the prevalence of bipolar disorder, major depressive disorder, personality disorders and schizophrenia among 151 million Americans and 1.4 million Danish citizens. The findings present a clear conclusion: that there is more evidence for the coexistence of air pollution and neuropsychiatric disorders in cities than between any single genetic factor and these same psychiatric conditions.
In the context of India, this could imply that the recent industrialisation of the country could have played some manner of role in the alarming rise in mental health conditions (this can also be accounted for by greater awareness of mental health, entailing higher rates of diagnoses). Ten percent of Indians are believed to experience mental health disorders. To attribute this to any single factor, however, would be to ignore the complexity of mental health. Any number of reasons could result in an individual developing depression, from financial difficulties or work-related stress to family situation or an individual’s overall health. Indeed, any individual is at risk of developing a mental health condition regardless of their circumstances.
The claim of a link between pollution and depression is, on the face of it, a bold one. However, this is not a small-scale study. With a total of 152 million people surveyed, the research is extensive, thereby making the conclusion worthy of consideration. While air pollution and psychiatric disorders seem to be entirely unrelated, the science holds up.
In much the same way that it has been found that PM2.5 particles — minute particles emitted from factories, car exhausts and fuel combustion — were found to cause heart damage or diabetes, psychiatric disorders may follow the same logic. PM2.5 particles enter the bloodstream through the lungs. While circulating in the blood the particles cause inflammation in a number of organs. This is what causes the heightened risk of cardiovascular complications.
In much the same way, these particles cause inflammation within nerve tissue in the brain. Such inflammation can cause a number of issues including brain dysfunction and several psychiatric disorders.
These findings are reflected within the figures. “The worst air quality was associated with an approximately 27 percent increase…in the apparent rate of bipolar disorder… The estimated rate of bipolar disorder was 16.4 percent higher…in the most densely populated counties,” noted the study. “For major depression, a slight increase of six percent in the diagnosis rate…was observed only among the worst air quality regions.”
India is renowned for its air pollution, in both urban and rural regions. With ever more evidence highlighting the manifold health impacts of pollution, more must be done to address the issue.