New Delhi/Boston: A new analysis of more than 3,000 counties in the US suggests that people with long-term exposure to PM 2.5 may be more likely to die from COVID-19, leading to increased concern about the trajectory of the disease and its fatality rate in parts of north India battling alarmingly high levels of air pollution.
Though worried as cases in the Indian capital and its suburbs spike, pulmonologists here said a causal link between fine particle pollutants (PM2.5) and COVID-19 mortality has not yet been established.
The US study, published in the journal Science Advances on Thursday, assessed the impact of long-term exposure to air pollution on COVID-19 death rates in 3,089 counties in the US.
The researchers, including Xiao Wu from Harvard University, found that chronic exposure to PM2.5 pollutants -- tiny particles in the air that are two-and-a-half microns or less in width -- is linked to greater county-level COVID-19 mortality rates.
Dispelling some of the panic, experts here said the biological reasons for high rates of COVID-19 infection and deaths in places with high PM2.5 levels are yet to be understood.
"It is not proven currently that PM2.5 levels directly increase chances of infection or death," Piyush Goel, a pulmonologist from Gurgaon's Columbia Asia Hospital told PTI.
Goel explained that PM2.5 particulate matter consists of water vapour, dust particles, and pollutants, which may attach the COVID-19 virus and facilitate its airborne transmission.
"But this is only a school of thought and not confirmed," he cautioned.
"There have been no studies published in India right now which proves this scenario, but this is possible," he added.
