In April, scientists at the Harvard TH Chan School of Public Health compared death rates from Covid-19 with air pollution levels for each of the nation’s 3,000 counties.

They found that elevated levels of fine particulate matter (an air pollutant abbreviated as PM 2.5) are associated with an increase in the Covid-19 death rate, even after controlling for other factors like income or preexisting conditions.

The authors noted that counties with a higher percentage of black residents had consistently higher rates of Covid-19 deaths, though this was not part of the study.

The data is “consistent with previously reported findings that black Americans are at higher risk of Covid-19 mortality than other groups,” the report says.

In a separate study, researchers at the Tulane Environmental Law Clinic examined the impact of Covid-19 on a 130-mile strip of southeast Louisiana known as “Cancer Alley.” The region is home to many petrochemical plants, some of which encircle historic black communities.

Eight of the 10 Louisiana parishes with the highest Covid-19 death rates are in Cancer Alley.

“Parishes with more pollution and higher percentages of African Americans have higher Covid-19 death rates,” says Kimberly Terrell, director of community outreach at the Tulane clinic.

For both measures, Terrell says that even when controlling for other potential factors, parishes with higher rates of air pollution had more black citizens and higher Covid-19 death rates.

“Parishes with more pollution and higher percentages of African Americans have higher Covid-19 death rates.”.

“Normally you would be able to knock on someone's door,” says Justin Onwenu, an environmental justice organizer for the Detroit chapter of the Sierra Club?

Roughly 15 percent of Michigan residents are black, but blacks account for 40 percent of Covid-19 deaths.

Near Detroit, where emissions from an oil refinery prompted a shelter-in-place advisory last year before the coronavirus, Onwenu says energy companies are seeking approval for facilities that would increase pollution.

“I don't think that we should be moving permits to increase emissions in environmental justice communities,” Onwenu says, “especially given what we know about the relationship between heavy air pollution and Covid.”.