A recent study led by George Mason University, The University of Texas at Austin, and Harvard T.H. Chan School of Public Health reveals that exposure to fine particulate air pollutants from coal-fired power plants (coal PM2.5) poses a more than double risk of mortality compared to PM2.5 from other sources. The study, published on November 23, 2023, in Science, challenges previous assumptions that coal PM2.5 carries the same toxicity as PM2.5 from alternative sources.
Examining Medicare and emissions data in the U.S. from 1999 to 2020, the researchers discovered that 460,000 deaths were attributable to coal PM2.5 during this period, with most occurring between 1999 and 2007 when coal PM2.5 levels were at their highest. The study not only emphasizes the underestimated mortality burden from coal-fired power plants but also underscores the need for effective solutions to address the associated environmental and health costs.
Lead author Lucas Henneman, assistant professor at George Mason University, remarked, “PM2.5 from coal has been treated as if it’s just another air pollutant. But it’s much more harmful than we thought, and its mortality burden has been seriously underestimated.”
Using emissions data from 480 coal power plants in the U.S. between 1999 and 2020, the researchers developed models to track the dispersion of coal sulfur dioxide and its conversion into PM2.5. Analyzing individual-level Medicare records, they linked exposure fields to health outcomes, providing insights into the impact of coal PM2.5 on mortality.
The study found that a one μg/m3 increase in annual average coal PM2.5 was associated with a 1.12% increase in all-cause mortality—a risk 2.1 times greater than that of PM2.5 from other sources. Notably, the research identified 10 power plants responsible for at least 5,000 deaths each during the study period, visualizing the data in an online tool.
While the average level of coal PM2.5 decreased significantly from 2.34 μg/m3 in 1999 to 0.07 μg/m3 in 2020, the study emphasizes the ongoing health risks associated with coal-fired power plants. The authors highlight the positive trend of decreased deaths, noting a 95% reduction from 1999 to 2020, but stress the need to continue moving toward clean energy to further improve public health.
The study’s findings contribute valuable insights for policymakers and regulators as they navigate the balance between affordable energy and environmental and health considerations. Despite progress, the study underlines the urgency of transitioning away from coal power to safeguard public health and enhance the prospects of a clean energy future.