From Italy’s Milan to China’s Wuhan, the coronavirus lockdown restriction has reduced the overall pollution. As per the restrictions by the governments, the lockdown in airlines has curtailed air pollution to a greater extent.
The initial hit on China was brutal as the air pollution catalysed the coronavirus spread and made it worse. It increased the number of deaths due to the dirty air and has been reported that the 11,000 deaths only due to air pollution in Europe.
Though London is a city that has been polluted since decades now, the number of deaths seemingly surprise the researchers due to the death curve in a short span. The idea seems reasonable given that both affect the lungs, but what does the evidence show?
Marco Travaglio & team at the University of Cambridge overlaid nitrogen dioxide (NO2) and nitrogen oxide (NO) levels. They did on more than 120 monitoring stations across England with figures on coronavirus infections and deaths. As they found a link between poor air quality and the lethality of COVID-19 in those sectors.
Travaglio proclaims this area covets more study and research to assemble the missing pieces od puzzle. Certainly, the health conditions that air pollution causes are remarkably similar to those of increased vulnerability to the coronavirus.
Air pollution is a catalyst
The same study conducted by Yaron Ogen at Martin Luther University Halle-Wittenberg in Germany mapped NO2 levels and COVID-19 deaths at a regional level in Italy. The same case in Spain, France and Germany. He stated that long-term exposure to air pollution “could be an important contributor” to high fatality rates.
Dario Caro team at Aarhus University in Denmark looked at the correlation between air pollution and coronavirus infections. Soon, it was crystal clear that people living in dirtier air had a high level of inflammatory cytokine cells. These are as good as a vulnerable person exposed to the coronavirus and thus followed by death.
After an in-depth study by Francesca Dominici & her team from Harvard University, soon concluded that each extra microgram of fine particulate matter per cubic metre would increase the mortality rate by 8 per cent. On those exposed to it for a long-term every minute particulate.
The bone-chilling report!
The main issue with all the research so far is there are other possible explanations for the links, says Benjamin Barratt at King’s College London.
The obvious confounder is population density, he says, which would explain why dense urban areas such as London come top in Travaglio’s analysis.
“NO is closely correlated with traffic density, which is correlated with population density, so that’s exactly the association you’d expect to find. Someone might quite as easily plot fried chicken outlets with COVID-19 mortality and get the same outcome,” he says.
Cause of smoking is a bitter concern over a broad geographical area as by estimating the result in deaths. Though Harvard University estimated the factors of population density, Jonathan Grigg at the Queen Mary University of London, says there are issues with other adjustments (smoking).
The expert answers!
If air pollution is a key factor in how deadly COVID-19 is – age and ethnicity are others being investigated – it is too early to say how significant it is. “We do not know the answer yet. It’s one factor with others,” says Caro.
Air pollution’s impact will only become clearer with much more detailed public health data on COVID-19 deaths, ideally even down to street level addresses of individuals if that was possible, says Barratt.
For now, we can’t say for certain that the damage long-term air pollution causes to lungs is making people more vulnerable to the coronavirus. However, researchers say it is plausible. “It is not an unreasonable hypothesis, but at the moment it is very difficult to draw robust conclusions as to whether that hypothesis is true or not,” says Barratt.
Given it is reasonable there might be a link, this pandemic and possible future one become a new, important reason to clean up our air. “It is unwise not to pay attention to measures needed to curb air pollution when we know we are dealing with a pandemic of a virus that attacks our lungs,” says Domenici.
Stephen Holgate at the University of Southampton, UK, says if there is a causal link, cutting air pollution now could help us deal with future diseases: “This isn’t going to be the last pandemic we see.”