Evaluating the Efficacy of Ambient Air Quality Standards at Coal-Fired Power Plants

The Clean Air Act's National Ambient Air Quality Standards (NAAQS) set limits on ambient air concentrations of hazardous pollutants. Since its creation, NAAQS guidelines have evolved to curb ambient concentrations of Particulate Matter less than 2.5 ug in diameter (PM2.5), which have been linked to respiratory and heart problems. However, the last adjustment to all (annual mean and 24-hour) PM2.5 standards occurred in 1997. This study evaluates the health benefits of tighter standards via reduced coal-fired power plant emissions of sulfur dioxide (SO2) and nitrous oxide (NOx), primary precursors to ambient PM2.5 concentrations. We find that reducing current annual and 24-hour PM2.5 standards would result in nationwide health benefits of at least $970 million in the year following enactment. We further find that the proposed standards are net benefit positive when incorporating abatement costs.