Air pollution levels and Covid-19 mortality rate are linked, claims new Harvard study

Covid-19 patients in regions with a history of high air pollution are more likely to succumb to the disease, claims the new study by Harvard University.

Medical workers remove a body from a refrigerator truck outside of the Brooklyn Hospital in New York in April 2020 | Bloomberg

New Delhi: A new study by Harvard University in the US has claimed a correlation between long-term exposure to high levels of air pollution and Covid-19 mortality rates.

According to the study, Covid-19 patients in regions that have had a history of high levels of air pollution are more likely to succumb to the illness than those in states with relatively better air quality. 

“The results of this paper suggest that long-term exposure to air pollution increases vulnerability to experiencing the most severe Covid-19 outcomes,” the authors wrote.

The study was conducted as a majority of pre-existing conditions that increase susceptibility to Covid-19 are respiratory illnesses, which are linked to long-term exposure to air pollution.

While the US government scientists estimate that the pandemic may kill between 100,000 and 240,000 Americans, the study says most of them will be from areas with a high particulate matter (PM) count.

What the study says

Analysing 3,000 counties in the US accounting for 98 per cent of the country’s population, up to 4 April, the Harvard University study claimed that “an increase of only 1 μg/m3 in PM2.5 is associated with a 15% increase in the COVID-19 death rate”.

As an example, the study said if Manhattan in New York had lowered its average PM level by just one unit in the past two decades, 248 deaths due to coronavirus could have been avoided. As of 8 April morning, New York has seen a total of 5,489 deaths. 

The study predicted that New York’s adjacent districts like Columbia and Montgomery County are likely to have a varying death toll with the former in the lead solely due to higher PM levels. Same goes for the Cook County in Illinois, which includes Chicago, being worse off than Lake County and Fulton County in Georgia, which includes Atlanta. 

Questions on study

Researchers at Harvard University T.H. Chan School of Public Health are the first to conduct a nationwide study that statistically links coronavirus deaths to air pollution. “The paper has been submitted for peer review and publication in the New England Journal of Medicine,” said a New York Times report. 

The NYT report, however, added that the study doesn’t pay attention to individual patient data.

“It also remains unclear whether particulate matter pollution plays any role in the spread of the coronavirus or whether long-term exposure directly leads to a greater risk of falling ill,” it added.

The study’s conclusions emphasise the “importance of continuing to enforce existing air pollution regulations to protect human health both during and after the COVID-19 crisis”. It added that certain areas need to be better prepared with sufficient medical equipment, staff and hospitals. 

Earlier this year, it was reported that 14 of the world’s 20 most polluted cities are in India. As the country enters Day 15 of the 21-day lockdown, Covid-19 cases stand at 5,149 with 149 deaths.