Short-term effects of cumulative exposure to ambient air pollution on cardiovascular emergency department visits in Mexico City

Abstract

BACKGROUND AND AIM: Available data on the acute cardiovascular effects of ambient air pollution in Latin America is limited considering that over 80% of its 1 billion inhabitants live in urban centers with poor air quality. The study aim was to evaluate the acute effects and attributable burden of cumulative exposure to PM2.5, NO2, SO2 and CO, on Cardiovascular Emergency Department Visits (CEDVs) in Mexico City from May 2016 to February 2019 using a time-series analysis. METHODS: Daily count of CEDVs were collected from 38 medical units, as well as measurements of ambient air pollutants from 35 level-ground stations. We estimated daily pollutant exposure using inverse distance weighting interpolation and buffer analysis. Quasi-Poisson Generalized Additive Models and Distributed Lag Models were used to examine the percentage change of CEDVs associated to each pollutant. Then, we conducted a backward approach of time-series model to calculate attributable fractions considering the cumulative exposure effect. RESULTS:A total of 48,891 CEDVs were recorded in a period of 1,019 days. We estimated a significant percentage change of CEDVs for each 10 µg/m3 of PM2.5 at lag0-6 (3.7%, IC95% 0.1 – 7.6), O3 at lag0-5 (1.1%, IC95% 0.2 – 2.0), NO2 at lag0-4 (2.5%, IC95% 0.3 – 4.7) and for each 1 mg/m3 of CO at lag0 (6.6%, IC95% 0.3 – 13.2). The estimated effects were higher in female population. Overall, 9.5% of CEDVs in Mexico City may be related to PM2.5 ambient exposure, 10.3% to O3, 11% to NO2 and 5.7% a CO. CONCLUSIONS:Exposure to ambient air pollution has an effect on CEDVs in a Latin American city. The implementation of air quality control measures could significantly reduce the impact of cardiovascular diseases on emergency department services, which lead the main cause of death in Mexico and in the world. KEYWORDS: Ambient air pollution, Latin America, Cardiovascular, Emergency department visits, Attributable fraction