New Delhi, November 4 – As smog blankets Delhi and the National Capital Region (NCR) once again, recent research highlights a disturbing link between prolonged exposure to PM2.5 particulate pollution and the deterioration of cognitive abilities across all age groups. According to a peer-reviewed study, long-term exposure to fine particulate matter, particularly PM2.5, has been linked to impaired memory and learning in children and increased risks of Alzheimer’s and dementia in adults.
On Saturday morning, Delhi recorded an Air Quality Index (AQI) of 294, a level that falls within the ‘poor’ category. The Central Pollution Control Board (CPCB) reported that 18 areas of the capital showed AQI levels above 300, entering the ‘very poor’ category. As winter sets in, these elevated pollution levels have become a recurrent issue, with smog trapping pollutants close to the ground, exacerbating respiratory and cognitive health risks.
The study, published in Environmental Health Perspectives, investigated the effects of air pollution on over 8,500 children aged 9 to 10, revealing that exposure to ammonium nitrate—a common component of PM2.5—significantly impaired learning and memory. Ammonium nitrate, a byproduct of ammonia emissions from agricultural activities and nitric acid from fossil fuel combustion, forms when these substances react in the atmosphere.
“Ammonium nitrate, a specific component of PM2.5, has now been linked to Alzheimer’s and dementia risks in adults, suggesting that PM2.5 may cause neurocognitive harm across a person’s lifespan,” the study noted. This indicates that the effects of PM2.5 exposure may not only impact children’s academic performance but also potentially accelerate cognitive decline as they age.
Megan Herting, an associate professor at the University of Southern California’s Keck School of Medicine, emphasized the need for more in-depth research on the sources and chemical makeup of particulate matter. “Understanding the specific components and origins of PM2.5 can aid in regulating air quality and preventing long-term neurocognitive effects,” Herting said. Her team’s research utilized advanced statistical methods to examine 15 chemical components of PM2.5, identifying ammonium nitrate as a significant contributor to cognitive harm.
The findings underscore an urgent need for policy changes to tackle the sources of PM2.5, including emissions from agriculture and fossil fuel combustion, to mitigate the impact on vulnerable populations, especially children and the elderly. With Delhi’s air quality consistently deteriorating each winter, experts and policymakers face a critical challenge in addressing the cumulative health risks posed by long-term PM2.5 exposure.
As Delhi residents brace for another season of poor air quality, the study serves as a stark reminder of the pervasive threat that pollution poses to cognitive health, especially in growing children and aging adults.