How the COVID-19 virus affects someone may be exacerbated by the air they breathe.
Researchers found a link between exposure to airborne particulate matter, including fine particles known as PM2.5 and nitrogen dioxide (NO2), and heightened risk of serious coronavirus complications.
“Our research demonstrated that one-year average exposure to PM2.5 translated to a 20-30% increase in the risk of hospitalization, intensive respiratory support and ICU admissions from COVID-19. Exposure to NO2 for one month carried an increased risk of 12-18%,” said study co-author Zhanghua Chen, assistant professor of population and public health sciences at the University of Southern California Keck School of Medicine.
“We also saw that long-term PM2.5 exposure was associated with a higher risk of mortality from COVID-19,” she said in a university news release.
USC researchers collaborated with Kaiser Permanente Southern California for the study, reviewing data from more than 74,000 COVID patients diagnosed between March and August 2020. The investigators were able to predict exposure history for specific pollutants by using participants’ residential address history.
PM2.5 and NO2 are produced by ground and air traffic, industrial burning and other sources.
“Ecological analyses are subject to a lot of biases, and it wasn’t clear whether the findings could be applied beyond the community level,” Chen said.
“In our population cohort study, we were able to leverage the sophistication of EMR [electronic medical records] to create a well-defined classification of the severity of COVID-19 outcomes tied to air pollution exposure at the individual level,” she said.
Kaiser Permanente records included background information that allowed researchers to adjust for other factors, including race, social standing and other health conditions.
The researchers now plan to examine intervention approaches to reduce individual levels of PM2.5 exposure, such as using air purifiers.
The findings were published recently in the American Journal of Respiratory and Critical Care Medicine.
“Our study demonstrates that breathing clean air may reduce the severity of the infection,” said co-author Dr. Frank Gilliland, a professor of population and public health sciences.
“When someone is infected, reducing their exposure to air pollutants maybe beneficial, as it may decrease the risk for poor outcomes and also has many other health benefits,” he said in the release.