Two recent studies, one focusing on the Us and the other one on Europe, have discovered an alarming connection between the severity of air pollution in the given area and the risk of dying from COVID-19.
These studies and their preliminary results could help us understand why some specific areas in the world have significantly higher rates of mortality in the context of coronavirus pandemic, giving us another reason that proves the need of cutting down worldwide air pollution.
Their first study which is currently available as a pre-print version. It was made by researchers at Harvard University who collected air quality data from 3,000 counties across the US, along with analysis on every death and confirmed case of COVID-19 in the US up until April 4.
“The results of this paper suggest that long-term exposure to air pollution increases vulnerability to experiencing the most severe COVID-19 outcomes,” the team writes in the paper.
“We found statistically significant evidence that an increase of 1 g/m3 in long-term PM2.5 exposure is associated with a 15 percent increase in the COVID-19 mortality rate.”
These long-term levels of PM2.5 point a microscopic particulate issue in the air with a diameter of less than 2.5 micrometers. This kind of particulate shapes from burning fossil fuels, and is already connected with the high rates of premature deaths caused by heart attack, lung problems, and cancer.
The Harvard team of researchers has now determined that COVID-19 also seems to be right at home in locations with higher long-term PM2.5 levels. The researchers took into consideration the population size, the number of hospital beds in an area, and a large number of other socioeconomic parameters that could have influenced the results.
These are pretty condemnatory findings on their own, but they don’t stand alone. A similar study has now been published by geoscientist Yaron Ogen from the Martin Luther University of Halle-Wittenberg in Germany.
Yaron Ogen found that another type of air pollution, called nitrogen dioxide, was also connected to higher COVID-19 death rates. He analyzed satellite data from Sentinel 5P to map the distribution of nitrogen dioxide across Europe in the months before the pandemic, and charted the number of COVID-19 deaths from 66 regions in Spain, Italy, France, and Germany up until March 19.
Nitrogen dioxide is a gas mainly emitted by cars, trucks, power plants and some industrial plants. Additionally, its emissions have been declining quite significantly across the world as COVID-19 continues to spread, triggering lockdowns.
“Results show that out of the 4,443 fatality cases, 3,487 (78 percent) were in five regions located in north Italy and central Spain. Additionally, the same five regions show the highest nitrogen dioxide concentrations combined with downwards airflow which prevents an efficient dispersion of air pollution,” Ogen writes in his published paper.
“These results indicate that the long-term exposure to this pollutant may be one of the most important contributors to fatality caused by the COVID-19 virus in these regions and maybe across the whole world.”
However, both studies had some limitations, too. The Harvard researchers admitted that they didn’t succeed to account for the differences that the availability of medical resources likely had on death rates, because they didn’t find enough data. Moreover, Ogen’s study doesn’t adjust for age distribution or pre-existing conditions, aspects that the US paper did take into consideration.
More research is needed on both nitrogen dioxide and PM2.5 exposure to determine the exact connection between air pollution levels and COVID-19 death. Additionally, these preliminary results give us an idea of how seemingly small air quality changes might be causing large differences in mortality.
We already know that lowering air pollution can be good for our health, and this is yet another reminder of this fact.
“The study results underscore the importance of continuing to enforce existing air pollution regulations to protect human health both during and after the COVID-19 crisis,” writes the Harvard researchers.
The US paper has been submitted to The New England Journal of Medicine and can be read in full there. The European paper has been published in the Science of The Total Environment.