Are Airborne Pathogens More Common in High-Population Areas?

New Delhi, Sep 2 (NationPress) Airborne pathogens, which are bacteria that can trigger infections in the lungs, gut, mouth, and skin, are found to be present at levels twice as high in densely populated regions compared to their less crowded counterparts, according to a recent study conducted by the Bose Institute, an autonomous body under the Department of Science and Technology (DST), on Tuesday.

The research team examined the health hazards posed by airborne pathogens in an urban setting like Delhi.

Published in the international journal 'Atmospheric Environment: X', their results indicated that the concentration of airborne pathogenic bacteria, which mainly causes respiratory, gastrointestinal tract (GIT), oral, and skin infections, is significantly higher in urban areas due to elevated levels of PM2.5 particles.

PM2.5—the tiny dust particles—facilitates the transport of bacteria through urban air, explained the researchers, led by Dr. Sanat Kumar Das.

“These particles, being sufficiently small, can penetrate deep into the lungs and serve as conduits for pathogenic bacteria, thereby spreading infections throughout the body,” they noted.

Delhi, located in the Indo-Gangetic Plain (IGP) in India, is recognized as one of the world’s most densely populated regions, grappling with severe air pollution.

During the winter months, the arrival of western disturbances leads to a sharp decline in atmospheric temperature, which subsequently raises relative humidity (RH), resulting in stagnant winds and a low boundary layer height, conducive for the accumulation of lower atmospheric pollutants over the IGP.

“The shift from winter to summer, particularly during hazy days or winter rains, creates high-risk periods for the spread of airborne diseases. During these times, the combination of pollution and weather conditions creates an ideal environment for microbes to remain airborne longer than usual,” the researchers stated.

Previous reports have indicated a significant increase in airborne microbial populations during winter over the IGP. However, there was a lack of information regarding how meteorology, air pollution, and population density impact airborne bacterial communities, which is crucial for understanding their implications on human health.

This new study “could serve as a wake-up call for urban health planning,” the researchers commented.

“In megacities like Delhi, where millions inhale polluted air daily, residents may also be unknowingly exposed to invisible bacterial communities laden with pathogens. Gaining insights into how weather, pollution, environmental factors, and population density influence these airborne bacteria and subsequent disease transmission could assist governments and health experts in better predicting outbreaks, enhancing urban planning, and safeguarding public health,” they concluded.