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Fine Particulate Matters: The Impact of Air Quality Standards on Cardiovascular Mortality
Citation:
Corrigan, A., M. Becker, L. Neas, W. Cascio, AND A. Rappold. Fine Particulate Matters: The Impact of Air Quality Standards on Cardiovascular Mortality. ENVIRONMENTAL RESEARCH. Academic Press Incorporated, Orlando, FL, 161:364-369, (2018). https://doi.org/10.1016/j.envres.2017.11.025
Impact/Purpose:
This study considers the impact of 1997 NAAQS designations for annual PM2.5 and reports a significant improvement to health per unit decrease in PM2.5.
Description:
Background. In 1997 the Environmental Protection Agency set the first annual National Ambient Air Quality Standard (NAAQS) for fine particulate matter (PM2.5). Although the weight of scientific evidence has determined that a causal relationship exists between PM2.5 exposures and cardiovascular effects, few studies have demonstrated that NAAQS related reductions in PM2.5 led to the improvements in public health. Methods. We examined the change in cardiovascular (CV) mortality rate and the association between the change in PM2.5 and change in CV-mortality rate before (2000-2004) and after implementation of the 1997 annual PM2.5 NAAQS (2005-2010) among U.S. counties. We further examined how the association varied with respect to the two indicators of NAAQS compliance: attainment designation and design values (DV), used to characterize air quality during the NAAQS designation process. We used difference-in-difference and linear regression models, adjusted for sociodemographic confounders. Findings. Across 619 counties, there were 1.10 (95% CI: 0.37, 1.82) fewer CV-deaths per year per 100,000 people for each 1µg/m3 decrease in PM2.5. Nonattainment counties had a twofold larger reduction in mean annual PM2.5, 2.1 µg/m3, compared to attainment counties, 0.97 µg/m3. CV-mortality rate decreased by 0.59 (95% CI: -0.54, 1.71) in nonattainment and 1.96(95% CI: 0.77, 3.15) deaths per 100,000 people for each 1µg/m3 decrease in PM2.5. Similar results were observed when counties were stratified by design value, the value used to characterize air quality during the NAAQS designation process. Counties with DV greater than 15 µg/m3 experienced the greatest decrease in mean annual PM2.5 (2.29 µg/m3) but the smallest decrease in CVD mortality rate per unit decrease in PM2.5 0.73 (95% CI: -0.57, 2.02). Interpretation. We report a significant association between the change in PM2.5 and the change in CV-mortality rates before and after the implementation of NAAQS and note that the health benefits per 1µg/m3 decrease in PM2.5 persist at levels below the current national standard.
URLs/Downloads:
DOI: Fine Particulate Matters: The Impact of Air Quality Standards on Cardiovascular Mortality