Work

A multi-level analysis of the impact of changes in coal-fired power plant emissions on asthma-related healthcare utilization and symptoms in Louisville, Kentucky

Year: 2019

Type: article

Abstract: S10: Quasi-Experimental Designs in Environmental Epidemiology: Applications to the Health Impacts of Energy Policy Changes, Room 417, Floor 4, August 27, 2019, 1:30 PM - 3:00 PM Background/aim: Recently, U.S. electricity generation has both implemented air emissions controls and begun to shift away from coal as a fuel source. Such energy transitions at individual power plants serve as natural experiments for assessing health benefits of resulting changes in air quality. We aimed to evaluate the impact of a coal-fired power plant retirement and 3 SO2 emission control installations on asthma outcomes in Louisville, Kentucky. Methods: We characterized exposure via a land use regression model for SO2 concentrations and a power plant emission exposure model (HyADS), which quantified the extent to which any power plant influences air quality in each U.S. ZIP code. At the ZIP code-level from 2012–2016, we evaluated associations between these two air quality measures and counts of quarterly asthma hospitalizations/emergency department (ED) visits. In a second analysis spanning 2012–2017, we evaluated associations between air quality and daily rescue inhaler use (measured spatiotemporally by digital medication sensors) among 207 AIR Louisville participants before and after an emission control installation. Results: During the study period, the median SO2 concentration was 1.62 ppb (IQR: 0.94, 2.21) and the median (unitless) HyADS exposure was 6553 (IQR: 2283, 9702). In models adjusted for indicators of socioeconomic status and meteorological conditions, we observed 0.67 (95% CI: -0.10, 1.53) additional ZIP code-level quarterly asthma hospitalizations/ED visits per 1 ppb increase in SO2 concentrations and 1.22 (95% CI: 0.52, 1.92) additional per IQR increase in HyADS exposure. A 1-IQR reduction in HyADS exposure translated into about 171 fewer annual visits county-wide. At the individual-level, the scrubber installation was associated with an immediate reduction in rescue medication use (-0.15 uses per day, 95% CI: -0.24, -0.06) and a 30% reduction over time. Conclusion: Air quality improvements due to coal-fired power plant retirements and scrubber installations may improve asthma outcomes.

Source: Environmental Epidemiology

DOI: 10.1097/01.ee9.0000606232.05130.64