The Health and Economic Benefits of PM2.5 Reduction on Alzheimer's Disease and Mild Cognitive Impairment in China

• First national assessment of the health and economic benefits of PM 2.5 reduction on AD and MCI in China. • Comprehensive evaluations encompass both avoided morbidity and substantial economic savings. • A reliable modeling framework integrates robust, up-to-date evidence to ensure precise estimates for China. • Actionable findings are provided at national and provincial levels, demonstrating achieved and potential future benefits. Fine particulate matter (PM 2.5 ) is increasingly recognized as a significant environmental risk factor for neurodegenerative disorders, including Alzheimer’s disease (AD) and mild cognitive impairment (MCI). With China’s rapidly aging population, the potential cognitive benefits of improving air quality merit timely evaluation. This study applied the BenMAP-CE tool, incorporating concentration–response parameters from meta-analyses, national monitoring data, demographic statistics, and cost-of-illness estimates, to quantify the health and economic benefits of PM 2.5 reductions in China between 2015 and 2023. We assessed changes in national and provincial burdens under observed conditions and counterfactual PM 2.5 scenarios. The results indicate that, compared with 2015 levels, reductions in PM 2.5 concentrations by 2023 were associated with an estimated 0.79 million potentially avoidable new AD cases (40.3 per 10,000) and 3.4 million new MCI cases (173.6 per 10,000) among individuals aged ≥65 years, with associated economic savings of about 17 billion USD for AD and 19 billion USD for MCI. Projections suggest that lowering 2023 PM 2.5 levels to 15 μg/m 3 could prevent an additional 0.65 million AD cases (33.2 per 10,000) and 2.8 million MCI cases (143.0 per 10,000), yielding further savings of 14 billion USD and 16 billion USD, respectively. Using the WHO 2021 guideline level (5 μg/m³) as a counterfactual scenario indicated further gains beyond the 15 μg/m³ target. These estimates are subject to methodological uncertainty stemming from the observational concentration–response evidence and key assumptions on incidence, exposure, and costs. These findings underscore the substantial health and economic gains achievable through continued PM 2.5 mitigation, highlighting the need to integrate cognitive health protection into air pollution control strategies in China.