US study links air pollution to increased Covid-19 mortality, Indian experts say causal link not established – health


A new analysis of more than 3,000 counties in the United States suggests that people with long-term exposure to PM 2.5 is also much more likely to die from Covid-19, leading to increased concern approximately 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 USA study, published in the publication Science Advances on Thursday, assessed the affect of long-term exposure to air pollution on Covid-19 death rates in 3,089 counties in the United States.

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 one of the crucial panic, experts here said the organic reasons for high rates of Covid-19 infection and deaths in places with high PM2.5 levels are yet to be understood.

“It isn’t 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 at the moment which proves this scenario, but this is conceivable,” he added.

According to the pulmonologist, the health of patients who maintained “slightly steady” chronic lung conditions can transform unstable because of the changing season and rising pollution levels.

“And whether these patients get lung infection, it’ll be a more serious complication. The criticality will be high,” Goel said.

He said exposure to high levels of pollution may end up in chronic lung disease and also hamper lung development in infants and toddlers.

“There are several studies backed by the World Health Association which show that this may affect mind development also, and it could lead to lung cancer as polite,” Goel said.

“From children to full-grown adults, air pollution affects everyone in India, but how Covid-19 impacts people exposed to these conditions individually is too soon to tell,” he added.

Delhi’s air quality index (AQI) was once 397 at 10 am on Thursday, when it also saw 6,715 reported Covid-19 cases, taking the infection tally to over 4.16 lakh.    The 24-hour average AQI in the national capital was once 450, categorised as “severe” — the highest since November 15 final year when it was once 458 — raising concerns on how this may affect the Covid-19 caseload.     The National Centre for Disease Regulate (NCDC) had warned final week that Delhi may outline almost 15,000 Covid-19 cases day-to-day in winter as a result of the prevalence of respiratory illnesses throughout this season that worsen the symptoms of the disease.

  Commenting on the organization between air pollution exposure and death from Covid-19, Anurag Agrawal, director of New Delhi’s CSIR-Institute of Genomics & Integrative Biology (IGIB), said both factors can have an effect on the functioning of the lungs and heart, and lead to death.

“But if the health risk from these is additive or greater remains to be seen,” the IGIB pulmonologist told PTI.

The Harvard researchers famous that chronic exposure to PM 2.5 might cause overproduction of ACE-2 receptor proteins in the lungs, which the novel coronavirus uses to go into host cells.

They consider prolonged exposure to air pollution may also impair people’s immune system, compromising their abilities to fight off the novel coronavirus infection.  “Chronic exposure to PM2.5 causes alveolar ACE-2 receptor overexpression and impairs host defences. This could cause a more severe form of Covid-19 in ACE-2-depleted lungs, increasing the likelihood of naughty outcomes, including death,” the Harvard scientists wrote in the study.

  But they acknowledged that this is only a hypotheisis.

  Citing the limitations of their study, the researchers said they were unable to account for individual-level risk factors such as age, race, and smoking status as such data was once unavailable.  “This approach leaves us unable to make conclusions regarding individual-level associations,” the scientists said   The Harvard scientists consider further research on how pollution and other factors may exacerbate Covid-19 symptoms and increase mortality risk is very important to guide policies and behaviour related to the pandemic. Agrawal added that pollution levels should be controlled even without considering its organization with Covid-19. “Regardless of the mathematics, we should strive to cause air pollution down to fortify health,” he said.

(This story has been published from a wire agency feed without modifications to the text. Only the headline has been changed.)

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