Attributable risk of hospital admissions for ischemic stroke due to ambient air pollution: a time-series study in Zhangzhou, China.

BACKGROUND

This study aimed to examine the association between ambient air pollution and hospital admissions for ischemic stroke, as well as the attributable disease burden, in Zhangzhou, a subtropical city in China.

METHODS

Daily data on hospital admissions for ischemic stroke, meteorological factors, and ambient air pollutants (PM2.5, PM10, SO2, NO2, CO, and O3) were collected in Zhangzhou from 2020 to 2023. A Poisson generalized additive model (GAM) was used to evaluate the acute effects of air pollutants on ischemic stroke admissions, with stratification by sex, age, and season. Attributable fractions (AFs) and attributable numbers (ANs) were further estimated based on the World Health Organization (WHO) Air Quality Guidelines and Chinese air quality standards.

RESULTS

Ischemic stroke admissions were significantly associated with exposure to PM2.5, PM10, NO2 and O3, but not with SO2 or CO. For per 10 μg/m3 increment in PM2.5, PM10, NO2, and O3 at lag01, the corresponding relative risks (RRs) and 95% confidence intervals (CIs) were 1.0356 (1.0107-1.0611), 1.0196 (1.0052-1.0341), 1.0387 (1.0045-1.0740), and 1.0106 (1.0030-1.0183), respectively. These associations were stronger in males, individuals under 65 years of age, and during the cold season. Overall, 7.0% (854 cases) of ischemic stroke admissions in Zhangzhou were attributable to air pollutant concentrations exceeding the WHO Air Quality Guidelines.

CONCLUSIONS

Short-term exposure to PM2.5, PM10, NO2, and O3 was significantly associated with increased hospital admissions for ischemic stroke and contributed to a certain disease burden in Zhangzhou. Our findings highlight the need for effective air pollution control strategies to reduce the related health burden.