Air Pollution’s Negative Impact on COVID-19 Patient Outcomes

A new study suggests that higher levels of air pollution can contribute to negative outcomes for individuals that contract COVID-19. The study asserts that residents of counties with higher levels of long-term air pollution are more likely to die from contracting the novel coronavirus.

The study conducted by Harvard’s School of Public Heath examined 3,080 counties in the U.S. and found that a small increase in pollution levels, specifically particulate matter, is associated with a 15 percent increase in the COVID-19 death rate.

From CNN’s coverage, the study’s lead author Francesca Dominici stated:

“The results suggest that long-term exposure to air pollution increases vulnerability to experiencing the most severe Covid-19 outcomes,” Dominici said.

The new information should be used by federal, state and local officials to make informed decisions about enforcing social distancing and preparing hospitals and local health care systems for a potential influx of more severe cases that will need extreme measures such as ventilators, Dominici said.

“We know the counties that have higher pollution levels historically,” she said. “We know that even if they [the counties] haven’t experienced high number of deaths yet, that would be one of their higher risks.”

The study comes shortly after the U.S. Environmental Protection Agency (EPA) recently announced rollbacks of automobile emissions standards. Additionally, the EPA has stated that during the current COVID-19 crisis they will temporarily halt pursuing fines and penalties for polluters not in compliance with federal standards. The Maryland Department of the Environment has signaled that despite the crisis, they will continue enforcement of emissions standards in the state.

The results of the study have yet to be peer reviewed. However, they suggest a link between areas with higher levels of air pollution and more negative COVID-19 outcomes.

From coverage in Grist, where Dr. Zuofeng Zhang, a professor of epidemiology at the University of California, Los Angeles explains the potential flaws of the study:

The Harvard study controlled for factors like household income, population size, hospital beds, and smoking rates. But analyzing COVID-19 in the middle of the outbreak presents problems. The authors noted that it’s difficult to “accurately quantify the number of COVID-19 cases due to limited testing capacity.” Counties around the country are at different stages of the pandemic — and have varying testing capacities, which could significantly skew results.

Because the current study only looks at mortality and air pollution at the county level, Zhang cautioned that “it’s hard to show a very solid causal relationship” between the two factors. Zhang said that they need to be examined on an individual level, with a much more detailed dataset of COVID-19 patients.

For more information on how counties are combating the novel coronavirus visit:

MACo COVID-19 Resource Page

NACo’s interactive map.

Maryland Department of Health COVID-19 Page.