Detroit’s air quality has improved since the COVID-19 shutdown. This map shows how.

Last week, a study from the T.H. Chan School of Public Health at Harvard University released a preliminary study showing that COVID-19 mortality worsens with exposure to air pollution. That study looked at particulate matter (PM 2.5— particulate matter of a diameter less than 2.5 microns) and COVID-19 mortality.

The study found that:

someone who lives for decades in a county with high levels of fine particulate pollution is 15% more likely to die from COVID-19 than someone who lives in a region that has just one unit (one microgram per cubic meter) less of such pollution.

The shelter in place order, however, is resulting in improved air quality across the country as people drive less and some factories slow or stop production. Data company Descartes Labs released maps illustrating how nitrogen dioxide pollution has declined between March 1-April 15 of 2020 compared with the same period in 2019.

Click on the image below to view a slider showing concentrations of atmospheric NO2 over the Detroit area or click here.

Nitrogen dioxide is an important air pollutant regulated under the Clean Air Act. According to the Environmental Protection Agency’s website, NO2 is a reactive gas that can form particulate matter in the atmosphere. Exposure to elevated levels of NO2 can lead to the development of asthma and make one more susceptible to respiratory infections. The American Lung Association lists the following health impacts of breathing elevated levels of NO2:

Increased inflammation of the airways;

Worsened cough and wheezing;

Reduced lung function;

Increased asthma attacks; and

Greater likelihood of emergency department and hospital admissions.

Planet Detroit reported on April 1 that the Michigan Department of Environmental, Great Lakes and Energy is planning to proceed with several industrial air permit hearings at a time when the Trump administration is relaxing air quality testing requirements for air pollution during the pandemic. According to a 2018 EGLE report, all Michigan NO2 sampling locations have attained air quality standards since 1978.

However, a 2016 report conducted by the Community Action to Promote Healthy Environments (CA-PHE) out of the University of Michigan’s School of Public Health found that poor air quality in Detroit has contributed to excess mortality, asthma exacerbations, hospitalizations and restricted activity days.

The following table pulled from the report shows the excess morbidity and mortality attributed to PM2.5 exposures in Detroit: