Assessing the short-term effects of PM2.5 and O3 on cardiovascular mortality using high-resolution exposure: a time-stratified case cross-over study in southwestern China

Abstract

Cardiovascular disease (CVD) is one of the leading causes of mortality worldwide, and air pollution is an important environmental risk factor. To date, limited studies have estimated the effects of ambient air pollution on CVD mortality using high-resolution exposure assessment, which might fail to capture the spatial variation in exposure and introduce bias in results. Besides, the Three-year Action Plan (TYAP, 2018–2020) was released, after five years of controlling air pollution, thus the constitution and health effect of air pollutants may have changed. In this study, we estimated the short-term effect exposed to PM2.5 and O3 concentrations with 0.05º×0.05º resolution on CVD mortality, and measured the influence of TYAP in the associations. Our study found that with an increase of 10 µg/m3 in PM2.5 and O3 during 2018–2021 in the Sichuan Basin (SCB), CVD mortality increased 1.0134 (95% CI: 1.0102, 1.0166) and 1.0083 (95% CI: 1.0060, 1.0107) respectively using high-resolution air pollutants concentration, comparing to 1.0070 (95% CI: 1.0052, 1.0087) and 1.0057 (95% CI: 1.0037, 1.0078) using data from air quality monitoring stations (AQMs), the estimated risks even turned from hazard to protective in other areas. After TYAP, the OR due to PM2.5 rose up to 1.0149 (95% CI: 1.0054, 1.0243) from 1.0141 (95% CI: 1.0087, 1.0195), and the OR due to O3 rose up to 1.0089 (95% CI: 1.0030, 1.0148) from 1.0054 (95% CI: 1.0015, 1.0093) in Sichuan Province. After TYAP, both O3 concentration and its risk increased. Intriguingly, the PM2.5 concentration went down but its risk slightly rose up after TYAP. In conclusion, PM2.5 and O3 still threaten human health after TYAP, and AQMs data would underestimate their health effect, therefore using high-resolution air pollutants concentrations leads to a more appropriate estimation.