Emergency visits and mortality caused by ischemic heart disease attributable to fine particulate matter during COVID-19 pandemic in Chile

Abstract

BACKGROUND AND AIM: A reduction in PM2.5 was reported worldwide during the COVID-19 pandemic confinement. Santiago, a Chilean city, characterized by high concentrations of PM2.5 caused by vehicular traffic, improved its air quality as a collateral effect of the quarantine implemented in the second quarter of 2020. We aim at revealing an ensuing decrease of emergency visits by acute myocardial infarction (AMI) and deaths due to ischemic heart disease (IHD) attributable to PM2.5, comparing equivalent periods of 2019 and 2020. METHODS: In Santiago, the air quality monitoring is accomplished through nine monitors located in nine communes of Santiago: Cerrillos, Cerro Navia, El Bosque, Independencia, La Florida, Las Condes, Pudahuel, Quilicura, and Santiago. These communes differ widely; Las Condes, located at East Santiago's foothills and plenty of green space, is one of the most affluent territories in the country. The other six counties range from the middle class (i.e., La Florida, Cerrillos, and Quilicura) to mostly deprived areas (i.e., Pudahuel and Cerro Navia), which are set into the flatlands in the northwestern area, with scarce green space and poor ventilation. We described daily average PM2.5 concentration with time-series graphs of means and standard deviations, and the AMI-emergency visits and IHD-deaths were reported for each quarter each year. To estimate the impact of the PM2.5 excess, we estimated the population attributable fractions (PAF) for IAM-emergency visits and IHD-deaths. RESULTS:We corroborated the daily average of PM2.5 decreased in 8 out of 9 communes in Santiago; however, the reduction was significant only in 3 communes. AMI-emergency visits and IHD-deaths attributable to PM2.5 decreased slightly but significantly in these three communes. The PAF in other communes remained similar to 2019 despite the quarantine. CONCLUSIONS:We concluded that reductions in PM2.5 had an impact in attributable AMI emergency visits and IHD deaths in those comunes with significant reduction KEYWORDS: particulate matter, ischemic heart disease, myocardial infarction, COVID-19, pandemic, Chile