Nitrogen dioxide levels drop during pandemic

MPCA air-quality monitor
Nitrogen dioxide levels in Southwest Minneapolis — as measured by MPCA air-quality monitors, such as this one at 28th & Xerxes — have remained low during the pandemic. File photo

A recent study found that global carbon dioxide emissions fell 17% in early April during the peak of the COVID-19 pandemic. Daily emissions during the period were comparable to 2006 emission levels, the study found.

While it’s unclear to what extent emissions decreased in Southwest Minneapolis and citywide, the Twin Cities metro has seen a slight reduction in emissions from one gas associated with burning fossil fuels.

Nitrogen dioxide levels in the area have dropped an estimated 10% to 20% compared with 2015-19 levels, said Daniel Dix, air quality meteorologist for the Minnesota Pollution Control Agency.

That’s based on ground-level nitrogen dioxide sensors at sites in Blaine, Lakeville and downtown Minneapolis.

Nitrogen dioxide primarily gets in the air from the burning of fuel, according to the Environmental Protection Agency.

The gas creates particulate matter and ground-level ozone, two pollutants that can trigger and exacerbate health conditions, when it reacts with other chemicals in the air.

The agency monitors it and six other pollutants through sensors placed at 44 sites in neighborhoods around Minneapolis and St. Paul, including in six Southwest Minneapolis neighborhoods.

Nitrogen dioxide levels in Southwest Minneapolis during the pandemic have all been below levels the EPA says could have adverse health effects, according to data from the sensors.

Levels of other air pollutants across the Twin Cities have largely been similar to typical conditions, Dix said.

He said ozone and PM2.5 levels could increase in the next few months, given that their levels in Minnesota are typically highest in the summer.

Dix said he thinks air pollution levels will be back to normal once more people are back to work. He said changes in air quality in the Twin Cities haven’t been as dramatic as in some other places, because the region already has good air quality.