Air Pollutants May Contribute to COVID-19 Deaths

People who live in regions where air pollutant levels are high may be at higher risk of succumbing to Covid-19. Several new studies indicate that air pollution may be a major contributor to Covid-19 related deaths.

One study that analyzed Covid-19 deaths across various regions in France, Germany, Italy and Spain found that 78% of deaths were concentrated in five of the most polluted regions of the sixty-six regions analyzed.

The study, which was recently published in Science of the Total Environment, assessed atmospheric levels of nitrogen dioxide (NO2), a gaseous air pollutant produced by vehicles and other fossil fuel combustion processes, and local weather conditions that could potentially prevent the dispersal of polluted air away from cities.

The study found that of the 4,443 people who died, 78% were from four regions located in northern Italy, and one from Madrid, Spain. The five regions where the deaths were most concentrated had the highest NO2 levels together with weather conditions that prevented polluted air from dispersing, a factor that exacerbates air pollution levels in these regions.

Previous studies have shown that exposure to NO2 can have serious health impacts, causing issues such as diabetes, hypertension, cardiovascular disease and compromised lung health, all of which could put people who contract Covid-19 at greater risk of dying.

“The results indicate that 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,” said Yaron Ogen, at Martin Luther University Halle-Wittenberg in Germany, who conducted the research. “Poisoning our environment means poisoning our own body, and when it experiences chronic respiratory stress its ability to defend itself from infections is limited.”

Ogen points out that both the Po Valley in northern Italy and Madrid are surrounded by mountains, which prevent air pollutants from escaping readily, essentially trapping them, as is Hubei province in China, where the pandemic began.

According to Ogen, while the study shows a strong correlation between the level of air pollution, air movement and the severity of the outcome of Covid-19 infections, it is unable to conclusively show a causal link. “It is now necessary to examine whether the presence of an initial inflammatory condition is related to the response of the immune system to the coronavirus,” he said.

In an effort to halt the spread of the disease, many countries have implemented lockdowns, which have seen both road and air traffic drastically reduced. While this has in turn significantly reduced air pollution, the long-term health impact of exposure to harmful pollutants before the lockdowns are likely to already have taken their toll.

“This new study is worrying,” said Jenny Bates, an air pollution campaigner at Friends of the Earth, in an interview with The Guardian. “We know NO2 is a toxic gas that inflames the lining of the lungs and reduces immunity to lung infections, so it may not be surprising that people who have suffered in areas with high levels of NO2 could be more susceptible to coronavirus.”

According to Bates: “This is all the more reason to keep traffic and pollution levels down as much as possible now and get out of this terrible situation with a view to fewer but cleaner vehicles on the road.”

The studies findings are supported by similar studies conducted elsewhere in the world. A US study found that coronavirus deaths increased by about 15% in areas with even a slight increase in fine particulate pollutant levels.

Journal References

Yaron Ogen. Assessing nitrogen dioxide (NO2) levels as a contributing factor to coronavirus (COVID-19) fatality. Science of The Total Environment, Volume 726, 15 July 2020, 138605

Edoardo Conticini, Bruno Frediani & Dario Caro. Can atmospheric pollution be considered a co-factor in extremely high level of SARS-CoV-2 lethality in Northern Italy? Environmental Pollution, Volume 261, June 2020, 114465

Xiao Wu, Rachel C. Nethery, Benjamin M. Sabath, Danielle Braun, Francesca Dominici. Exposure to air pollution and COVID-19 mortality in the United States. medRxiv 2020.04.05.20054502; doi: https://doi.org/10.1101/2020.04.05.20054502

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