State of the Air 2021

The “State of the Air” 2021 report finds that despite some nationwide progress on cleaning up air pollution, more than 40% of Americans—more than 135 million people— are living in places with unhealthy levels of ozone or particle pollution. The burden of living with unhealthy air is not shared equally. People of color are more than three times more likely to be breathing the most polluted air than white people. The “State of the Air” report looks at two of the most widespread and dangerous air pollutants, ozone and fine particulate matter. The air quality data used in the report is collected at official monitoring sites across the United States by the federal, state, local and Tribal governments. The Lung Association calculates values reflecting the air pollution problem and assigns grades for ozone and daily and long-term measures of particle pollution. Those values are also used to rank cities (metropolitan areas) and counties. This year’s report presents data from 2017, 2018 and 2019, the most recent quality-assured nationwide air pollution data publicly available. See the About This Report section on page 6 for more detail about the methodology for data collections and analysis. “State of the Air” 2021 is the 22nd edition of this annual report, which was first published in 2000.