FAQ: Does Air Pollution Increase COVID-19 Threat? What Studies Say

We spoke to pulmonologists to understand how air pollution is expected to intensify our COVID-19 fight.

(Photo: The Quint)

(This story was first published on 16 October, 2020 and is being republished to mark Pollution Control Day.)

It's the time of the year again when you closely monitor the AQI apps on your phones and smell that burnt soot in the air.

But this year, the impact of pollution is expected to be different. As countries slowly come to terms with COVID-19 – predominantly a respiratory illness – and crawl back into normalcy, the threat from air pollution stares them in the face.

FIT spoke to pulmonologists to understand how air pollution is expected to intensify our COVID-19 fight and increase our likelihood to fall sicker with far higher risks of complications. Here's what we know.

What does research say about air pollution and COVID-19?

Preliminary research says yes.

Isolated studies from different parts of the world have signalled a proportionate relationship between polluted air and COVID severity. Most notable is an ecological study from Harvard University, which found that even a small increase in PM2.5 levels was associated with an 8% increase in COVID-19-related deaths.

Other studies have also looked at the correlation between pollution and more COVID-related deaths. For instance, an analysis of COVID fatalities in Italy, Spain, France and Germany concluded that 78 percent of the deaths were in regions with the highest NO2 concentrations, combined with lower wind flow that prevented dispersion of pollutants.

Does this mean increase in pollution increases threat of COVID-19?

It is also being investigated if air pollution can facilitate the spread of the novel coronavirus and lead to a spike in cases. While there is no direct proof of such a relationship, early evidence from northern Italy suggests that the virus could be found on particulate matter, indicating that it may attach itself to airborne pollutant particles.

Nevertheless, more research is needed into this area to make conclusive statements, experts have said.

What explains the link between COVID-19 and pollution?

To put it simply, air pollution damages various parts of the body by infiltrating the blood vessels, causing inflammation and suppressing immunity. Large-scale evidence exists to support its contribution to heart diseases, stroke, diabetes, asthma, cancer and other comorbidities - all of which are known to increase complications in COVID-19 patients.

Speaking to FIT, Dr Nikhil Modi, senior consultant, respiratory, critical care and sleep disorder at Indraprastha Apollo Hospitals, explains that pollution becomes a grave concern because of the way it compromises the respiratory system and causes damage to the lungs, the prime target of respiratory infections such as COVID-19.

“Pollution, as we know, is akin to <a href="https://fit.thequint.com/cancer/lung-damage-air-pollution">smoking</a>. When we inhale the polluted air, it causes congestion in our chest and hampers the mechanism by which our airways or breathing tubes clear dust particles, viruses and bacteria from the lungs. When this is damaged, the chances of the virus staying there, going into the chest and causing symptoms will be high,” he says.

Not just this, pollutants in the air naturally cause congestion and coughing, assisting the transmission of the virus from a COVID-infected person - since it is known to majorly spread via respiratory droplets.

“Therefore, pollution could increase susceptibility to COVID in the first place, and then also increase the chance of a severe infection,” Dr Modi adds.

What about winter? Can drop in temperature result in spike in cases?

Dr Vikas Maurya, Director and Head of Department, Pulmonology, Fortis Hospital Shalimar Bagh, Delhi, explains, “The winter season coincides with high pollution due to more concentration of particles in the air. This is also part of the reason why every year, we see a surge in respiratory viral infections during this time. This trend is nothing new, but with COVID-19, the challenge has, of course, increased manifold.”

“The viral particles stay in the atmosphere for a longer duration of time, and therefore, the chances of inhaling them go up, causing lung involvement, inflammation and comorbidities - all a cause for concern for COVID-19 patients.”

Dr Vikas Maurya

What are the precautions that should be taken?

While the challenges and risks are set to multiply due to the deteriorating air and change in temperature, the solutions remain the same. Masks, distancing and respiratory hygiene can help prevent COVID-19 and cut down its transmission rate.

(This article has been edited for length. It was first published on FIT and has been republished with permission.)