Long-Term Coexposure to Multiple Air Pollutants and Stroke Incidence: A Large Prospective Cohort Study Based on a...

Area of Science:

• Environmental Epidemiology
• Public Health
• Toxicology

Background:

• Long-term coexposure to multiple air pollutants and stroke incidence lacks comprehensive analysis.
• Assessing the attributable burden and intervention benefits of multipollutant exposure is crucial for public health.

Purpose of the Study:

• To characterize flexible multipollutant-stroke associations using an interpretable framework.
• To quantify the attributable burden and potential benefits of air pollution reduction on stroke incidence in China.

Main Methods:

• Utilized a large prospective cohort of 469,174 Chinese adults (2013-2018).
• Developed a shape-constrained nonlinear weighted-sum model within a time-varying survival framework.
• Analyzed annual exposures to PM2.5, SO2, NO2, CO, and O3, calculating attributable cases and population attributable fraction (PAF).

Main Results:

• PM2.5, SO2, NO2, and CO were identified as risk factors for ischemic stroke, exhibiting an S-shaped coexposure-response.
• No adverse effect was observed for hemorrhagic stroke.
• Ischemic stroke PAF decreased from 60.8% in 2013 to 36.7% in 2022, with stable annual attributable cases.

Conclusions:

• Reducing ambient air pollution is fundamental for stroke prevention.
• Region-specific, precise intervention strategies are necessary, guided by advanced modeling.
• Multipollutant exposure models provide valuable insights for targeted public health interventions.