Prolonged Exposure to Air Pollution May be Detrimental to Brain

NEW DELHI — Even as air quality in the national capital continues to be in the ‘very poor’ category, health experts on Thursday said that prolonged exposure to air pollution may be detrimental to the brain.

According to Central Pollution Control Board data (CPCB), the air quality index (AQI) was 336 at 7.30 a.m. Various monitoring stations across the national capital recorded the air quality in the ‘very poor’ category — between 301 and 400.

During the day, the air quality is expected to drop to the ‘severe’ category at places where the AQI is near 400, as per the CPCB.

A recent study, published in The Lancet Planetary Health, showed short-term air pollution exposure claimed 33,000 lives annually in 10 cities in India, and Delhi topped the list with 12,000 deaths every year.

Dr PN Renjen, Senior Consultant, Neurology, Indraprastha Apollo Hospitals, told IANS that pollution poses a significant threat to both physical and neurological health.

“Heavy metals like lead and mercury, along with volatile organic compounds, have detrimental effects on brain function. Neurotoxins from pollution can bypass the blood-brain barrier, triggering inflammation, oxidative stress, and neuronal damage,” Renjen said.

“This not only impairs cognitive abilities such as memory, attention, and executive functioning but also increases the risk of neurodegenerative diseases like Alzheimer’s and Parkinson’s. In addition, pollution increases the risk of cerebral stroke due to neurotoxins and oxidative stress, which affect the arteries and contribute to atherosclerosis,” the doctor said.

Higher levels of particulate matter (PM2.5) and nitrogen dioxide (NO2) exposure can increase the risk of Parkinson’s and Alzheimer’s, revealed recent studies, published in the JAMA Network Open.

Prolonged exposure to air pollution has also been associated with reduced brain volume, accelerated brain ageing, and higher rates of mental health disorders, including depression and anxiety.

Children and the elderly are particularly vulnerable, with studies showing that children exposed to high levels of pollution may experience impaired cognitive development, while older adults face a heightened risk of cognitive decline.

Besides the brain, rising pollution levels can also affect eyes, and skin and lead to respiratory issues.

“Exposure to smoke and particulate matter can cause redness, itching, and tearing in eyes, while increased pollen and pollutants can exacerbate allergies,” Dr. Mukesh Mehra, Senior Director-Internal Medicine, Max Super Speciality Hospital told IANS.

Pollutants can also cause skin irritation, breakouts, and allergic reactions. Long-term exposure can also lead to skin damage and premature ageing, trigger asthma attacks and other chronic respiratory diseases, the doctor said.

The experts called on to create a safe indoor environment with air purifiers; use masks while going outside during high pollution levels, and eat healthy.