[Effects of Interaction between PM2.5 and O 3 8-h max on Mortality of Cardiovascular Diseases in Chengdu]

Abstract

Objective: To explore the health risks of the interactive effects between PM2.5 and ozone on cardiovascular mortality in Chengdu.

Methods: Daily data on the mortality of cardiovascular diseases, including data for both men and women, during 2014-2016 were collected. The meteorological data, the daily average of particulate matter with aerodynamic diameter less than 2.5 micrometers (PM2.5), and the daily ozone 8 h maximum concentration (O ₃ 8-h max) in Chengdu of the same period were also collected. Generalized Additive Models (GAMs) were adopted to explore the respective adverse health effects of PM2.5 and O ₃ 8-h max and the synergistic effects between PM2.5 and O ₃ 8-h max on the mortality of cardiovascular diseases in the city.

Results: The highest health risks of PM2.5 and O ₃ 8-h max for mortality of cardiovascular diseases were found to be the strongest for the cumulative effect of the lag of one day (lag01). For every 10 µg/m ³ increment in the mass concentration of PM2.5 (lag01), the associated increase in risks for total, male, and female cardiovascular mortalities was 0.35%, 0.26% and 0.38%, respectively. For every 10 µg/m ³ increment in the mass concentration of O ₃ 8-h max (lag01), the associated increase in risks for total, male, and female cardiovascular mortalities was 0.66%, 0.43%, and 1.05%, respectively. The total, male, and female cardiovascular mortalities all reached their maximum values when high concentration of PM2.5 coexisted with high concentrations of O ₃ 8-h max.

Conclusion: There was a synergistic amplification effect between high concentrations of PM2.5 and high concentrations of O ₃ 8-h max on cardiovascular mortality.

Keywords: Cardiovascular disease; Chengdu; Daily ozone 8-h maximum concentration; PM2.5; Synergistic effect.