Does chronic exposure to air pollution increase risk of severe COVID-19? - study

A German study found that people in counties with higher levels of nitrogen dioxide may have been at increased risk of needing intensive care and mechanical ventilation if they contracted COVID-19.

 The unrecognized villages around Ramat Hovav which suffer from a high level of air pollution from nearby evaporation ponds of the chemicals and the IEC power plant. December 28, 2017 (photo credit: YANIV NADAV/FLASH90)
The unrecognized villages around Ramat Hovav which suffer from a high level of air pollution from nearby evaporation ponds of the chemicals and the IEC power plant. December 28, 2017
(photo credit: YANIV NADAV/FLASH90)

Chronic exposure to air pollution may be associated with an increased risk of severe COVID-19, according to new research set to be presented at the Euroanaesthesia Congress in Milan, Italy.

The research was part of a German study which found that people in counties (districts) with higher levels of nitrogen dioxide (NO2) were at increased risk of requiring intensive care and mechanical ventilation if they had COVID-19.

NO2 is a pollutant released into the atmosphere when fossil fuels are burned. Long-term exposure to the gas can harm the lungs by damaging endothelial cells, which are essential for the transfer of oxygen from air into the blood.

Research methods and findings

Researchers, led by Dr. Susanne Koch from the Department of Anaesthesiology & Intensive Care, Charité – Universitätsmedizin Berlin, used air pollution data from 2010 to 2019 to determine the long-term annual mean level of NO2 in each county in Germany. They found that this was between 4.6 µg/m³ and 32 µg/m³, with the highest level in Frankfurt and the lowest in Suhl.

The researchers also used data from April-May 2020 from the German Interdisciplinary Association for Intensive Care and Emergency Medicine (DIVI) registry in order to determine how many COVID-19 patients required ventilation and intensive care.

 Empty beds in the intensive care unit at the Coronavirus ward of Shaare Zedek hospital in Jerusalem on October 14, 2021. (credit: OLIVIER FITOUSSI/FLASH90)
Empty beds in the intensive care unit at the Coronavirus ward of Shaare Zedek hospital in Jerusalem on October 14, 2021. (credit: OLIVIER FITOUSSI/FLASH90)

“Reducing emissions won’t just help to limit climate crisis, it will improve the health and the quality of life of people around the world.”

Dr. Susanne Koch, Department of Anaesthesiology & Intensive Care, Charité – Universitätsmedizin Berlin

The researchers concluded that COVID-19 patients in the counties with higher long-term annual mean NO2 levels were more likely to need ICU treatment and ventilation.

“Long-term exposure to NO2 long before the pandemic may have made people more vulnerable to more severe COVID-19 disease,” Koch said.

“Exposure to ambient air pollution can contribute a range of other conditions, including heart attacks, strokes, asthma and lung cancer and will continue to harm health long after the COVID-19 pandemic ends.”

Koch added that the solution is transitioning to a more sustainable society.

“A transition to renewable energy, clean transportation and sustainable agriculture is urgently needed to improve air quality," she said. "Reducing emissions won’t just help to limit [the] climate crisis, it will improve the health and the quality of life of people around the world.”