Bitcoin mining contributes to significant air pollutant emissions, study finds

Millions of Americans have been exposed to PM2.5 pollution, which increases the likelihood of various diseases.

It has been known that cryptocurrency mining contributes to global warming as the electricity needed is often sourced from fossil fuels, leading to significant carbon emissions.

During this process, pollutants are emitted, which can cause various illnesses. 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, a study by Harvard-led scientists reveals.

The scientists reached this conclusion by analyzing 34 bitcoin miners from mid-2022 to mid-2023, which, according to their calculations, consumed 32.3 terawatt-hours of electricity – 33% more than Los Angeles.

PM2.5 pollution consists of airborne particles that can be inhaled deep into the lungs and even enter the bloodstream. It contributes to health risks, including respiratory and cardiovascular diseases and premature death.

The United States became an attractive destination for currency miners in 2021, a year after China banned mining. The share of global bitcoin mining operations in the US grew rapidly, from 4.5% in 2020 to 37.8% by January 2022.

“This explosion of growth and new electricity consumption led to increased electricity production and attendant emission of hazardous air pollutants by fossil fuel power plants, including PM2.5 pollution and its gaseous precursors,” claim the researchers in their study, which was published in Nature.

Fossil fuel power plants generated 85% of the increased electricity demand from bitcoin mines. The emissions of air pollutants of each plant aren’t proportional to the amount of electricity they generate.

For example, the Core Scientific mine in Calvert City, KY, was responsible for more PM2.5 emissions than any other mine despite ranking 8th in electricity consumption and 11th in attributable CO2 emissions.

Scientists estimate that 46,211,621 Americans living in 27 states were exposed to measurable (i.e., ≥0.01 µg/m3 on average) concentrations of bitcoin mine-attributable PM2.5 pollution from August 2022 through July 2023.

People living close to power plants were impacted more significantly. The scientists estimate that over 1.9 million Americans across five states were exposed to bitcoin mine-attributable PM2.5 concentrations of at least 0.10 µg/m3 on average across the study period.