A University of Minnesota study has concluded that air pollution across the country has decreased during the COVID-19 pandemic, likely the result of lessened traffic and business closures.
Researchers in the university’s School of Public Health studied changes in two forms of air pollution in 122 counties from March 13 to April 21 and then compared those levels to the same dates and locations going back to 2017.
Specifically, the study looked at nitrogen dioxide and fine particulate matter – types of pollution that can cause several health issues, including cardiovascular, respiratory and neurological illnesses. The research team also examined differences in urban and rural counties and whether those counties had instituted business closures early in the pandemic, late or not at all.
The researchers found that nitrogen dioxide levels declined 25.5 percent during the study period compared with previous years – a decline that was significant in all counties, whether they were rural or urban and whether they had closed businesses early during the pandemic. They also found that while fine particulate matter declined marginally across the country during the study period, it declined by 4.7 percent in urban counties and by 11.3 percent in counties that closed businesses early.
According to the researchers, the decreases in nitrogen dioxide were likely associated with reduced vehicular traffic. They speculated that levels of fine particulate matter didn’t drop significantly because fine particles are produced through a variety of industries — including food production, construction and energy production — that remained operational during the study period.
“It has been shown that high air pollution may play a role in exacerbating respiratory diseases, including the SARS outbreak in 2002,” assistant professor Jesse Berman, the study’s lead author, said in a press release.
Berman added that while air pollution has temporarily improved, overall air quality is still at risk from pollution and that government protection rules need to be enforced. He added that decreased air pollution and any potential benefits from it will likely be fleeting as policies put in place to slow the COVID pandemic are relaxed.