Bitcoin mines—massive computing clusters generating cryptocurrency tokens—consume vast amounts of electricity. The amount of fine particle (PM2.5) air pollution created because of their electricity consumption and its effect on environmental health is pending. In this study, we located the 34 largest mines in the United States in 2022, identified the electricity-generating plants that responded to them, and pinpointed communities most harmed by Bitcoin mine-attributable air pollution. From mid-2022 to mid-2023, the 34 mines consumed 32.3 terawatt-hours of electricity—33% more than Los Angeles—85% of which came from fossil fuels. We estimated that 1.9 million Americans were exposed to ≥0.1 μg/m3 of additional PM2.5 pollution from Bitcoin mines, often hundreds of miles away from the communities they affected. Americans living in four regions—including New York City and near Houston—were exposed to the highest Bitcoin mine-attributable PM2.5 concentrations (≥0.5 μg/m3) with the greatest health risks. The paper maps air pollution from power plants supplying electricity to US Bitcoin mines. It finds that 1.9 million people in 2022-2023 breathed toxic amounts of Bitcoin mine attributable pollution, particularly around New York City and Houston.