A new study has found that several common air pollutants are linked to more serious outcomes following coronavirus infection.
Individuals living in areas of Ontario, Canada, with higher levels of three common air pollutants — particulate matter, nitrogen dioxide and ground-level ozone — had an increased risk of being admitted to the intensive care unit, according to the authors published their findings Tuesday in Canadian Medical AssociationJournal.
Scientists found that chronic exposure to ozone was associated with an increased risk of death from COVID-19.
To reach these conclusions, researchers from the Canadian government’s Health Canada analyzed data on all 151,105 people ages 20 and older who had confirmed coronavirus infection in Ontario in 2020.
Information on particulate matter, nitrogen dioxide and ground-level ozone was readily available to researchers because these substances are all regularly monitored by the Canadian government, the authors noted.
These pollutants are emitted from a variety of sources, including fuel combustion and reactions of volatile organic compounds or other chemicals.
According to the study, the scientists calculated the long-term exposure of each infected person to the three air pollutants based on their stay from 2015 to 2019.
The authors excluded infected individuals living in long-term care facilities and adjusted for date of diagnosis, gender, age, essential worker status, socioeconomics, access to health care, and other factors.
Long-term exposure to air pollution, the authors explained, could increase the risk of severe COVID-19 illness through several mechanisms. For example, according to the authors, air pollutants can reduce immune responses and antimicrobial activity in the lungs, thereby increasing viral loads.
These substances can also cause chronic inflammation and overexpression of a specific receptor protein that allows the coronavirus to enter human cells, the researchers added.
“Given the ongoing pandemic, our findings, which underscore the link between chronic air pollution and more severe COVID-19, could have important implications for public health and healthcare systems,” the authors explained.