Health improvements associated with reduced power plant emissions in the United States between 2005 and 2012

Abstract

Background. Emissions from coal power plants have fallen dramatically since the passage of the 1990 Clean Air Act Amendments. We quantify and compare changes in 10 health outcomes among US Medicare beneficiaries attributable to two different—but related—metrics over this time period: total PM2.5 and exposure to pollution derived from coal-fired power plant emissions.Methods. We use a new approach—the HYSPLIT average dispersion model, or HyADS—to quantify changes in ZIP code level exposure to SO2 emissions from each of 1,036 U.S. coal power plants between 2005 and 2012. We conduct an analogous analysis using ZIP code level PM2.5 ambient exposure. We use a first differences regression approach to compare how the change in health outcome rates from 2005 to 2012 is associated with changes in PM2.5 and coal exposure during the same period.Results. Most ZIP codes saw reductions in PM2.5 and coal exposure across the study period. Decreases in the rates of five health outcomes between 2005 and 2012—all cardiovascular disease, cardiovascular stroke, heart failure, ischemic heart disease, and respiratory tract infection—show statistically significant associations with both reduced PM2.5 concentrations and reduced coal exposure. Decreases in rates of heart rhythm disorders, peripheral vascular disease, and all-cause mortality do not show relationships with changes in either exposure. Coal exposure reductions are associated with decreases in rates of chronic obstructive pulmonary disorder, whereas reductions in PM2.5 exposure are not.Conclusions. Results show consistent relationships between coal power plant emission reductions from 2005 to 2012 and decreases in multiple Medicare health outcomes. Further, differences are apparent between health impacts of changing exposure to PM2.5 and coal-fired power plant emissions. The approach provides more direct evidence of the benefits of regulations on coal power plants than previous approaches that employ relationships between observed air quality and health.