University of Minnesota researchers recently found that air pollution decreased during COVID-19 lockdowns.
With support from the Minnesota Pollution Control Center, researchers looked at pollution data from March 13 to April 21 and compared that to the same time during past years. Researchers looked at the difference between urban and rural counties throughout the U.S. and those that closed nonessential businesses and those that did not.
The study focused on two types of air pollution measurements: nitrogen dioxide and fine particulate matter.
The results, published earlier this week by the university, show nitrogen dioxide declined around 25% compared to previous years. This applied to urban and rural counties and regardless of what their COVID-19 lockdown situation was.
Minnesota-specific data from Anoka, Dakota and Hennepin counties showed an average nitrogen dioxide decrease during the same period of 20.1% compared to historical years, according to study author and assistant professor Jesse Berman.
Researchers believe this decrease was due to fewer vehicle trips as people avoided travel and were working from home, in addition to thousands of employees being laid off.
But fine particulate matter declined to a lesser extent, down around 11% in urban counties and 4% in rural counties. Researchers believe this type of pollution did not drop as much as it's often produced by industries like food production and construction, which have remained operational.
The data specific to Anoka, Dakota and Hennepin counties in Minnesota revealed a similar average decline of 4.8%, but Berman told Bring Me The News that "this is driven primarily by a large decline in Anoka County," where as he observed a small increase in Hennepin County compared to past years.
Overall, the decreased pollution is likely only temporary, as Berman said "decreased air pollution and any potential benefits are likely fleeting as policies are relaxed."