Does the Association between Cardiovascular Hospital Admissions and Fine Particle Concentrations Change Before, During, and After Implementation of Multiple Environmental Policies? The New York State Accountability Study

Previous studies reported triggering of acute cardiovascular (CV) events by short-term increases in ambient PM2.5 concentrations. From 2007-2013, policies to improve air quality implemented nationally and across New York (NY), and economic influences, resulted in reduced concentrations of PM2.5 and other pollutants, but not O3, at 6 urban NY monitoring stations. We estimated the rate of CV hospital admissions associated with increased ambient PM2.5 concentrations in the previous 1-7 days, and evaluated whether they were different BEFORE (2005-2007), DURING (2008-2013), and AFTER policy implementation (2014-2016). Using all hospital admissions with a primary diagnosis of 9 CV disease subtypes, for NY residents living within 15 miles of PM2.5 monitoring sites in Buffalo, Rochester, Albany, Queens, Bronx, and Manhattan from 2005-2016 (N=1,922,918), the annual CV disease admission rate decreased from BEFORE (15.6/1000 people [‰]) to DURING (13.6‰) to AFTER (11.8‰) implementation. Using a case-crossover design and conditional logistic regression, interquartile range (IQR) increases in PM2.5 in the previous 0 to 6 days were associated with 0.6%-1.2% increases in the rate of CV admissions (2005-2016). There were similar patterns for cardiac arrhythmia, ischemic stroke, congestive heart failure, ischemic heart disease (IHD), and myocardial infarction (MI). However, the excess rate of IHD admissions associated with each IQR increase in PM2.5 in the previous 2 days was larger in the AFTER period (2.8%) than in the DURING (0.6%) or BEFORE periods (0.8%), with similar patterns in the previous 1-5 days. Both total CVD and MI, but not other disease groups, followed the same pattern. While pollutant concentrations and CV admission rates decreased AFTER policy implementation, the rates of ischemic heart disease and MI associated with the IQR increases in PM2.5 increased. Compositional PM changes AFTER implementation may make the same PM2.5mass more likely to trigger CV events