More than 40% of people in the U.S. live in cities and states with poor air quality, the American Lung Association’s 22nd annual State of the Air report finds. Of the more than 137 million people breathing polluted air, 63 million live in counties with dangerous particulate matter pollution (known as PM2.5), the fine soot produced by fossil fuel combustion and wildfires, among other sources. Climate change, caused mainly by the extraction and combustion of fossil fuels is driving up temperatures and supercharging wildfires — two things that exacerbate human health risks.

“The three years covered by [the report] ranked among the seven hottest years on record globally,” the study said. “Spikes in particle pollution and high ozone days related to wildfires and extreme heat are putting millions more people at risk.” Ground level ozone, which contributes to smog, is like a “sunburn on the tissue of the lungs,” Michael Seilback of the ALA told New Jersey 101.5.

Air pollution burdens are not distributed equally. People of color are more than 60% more likely to live in a county with a failing grade for at least one pollutant than white people. Diesel truck traffic is also concentrated in low income and communities of color, including in California’s Inland Empire where a proliferation of warehouses has caused the worst smog in the country. (Report: NPR, The Hill; Wildfires: NBC; Diesel pollution and Inland Empire: CBS, The Verge, KCET; Charleston, SC: Charleston City Paper; Chicago: ABC-7; Colorado: CBS-4; Delaware: Delaware Public Media; Hawai’i: Hawaii Public Radio; Indiana: Indiana Gazette; Los Angeles: ABC-7, News 1; Maine: WABI, WMTW, B98.5; Medford, OR: KOBI-5; New Mexico: Public News Service; New York City: Gothamist, WNYC; Orlando: WFTV; Pittsburgh: WTAE; New Jersey: NJ101.5)