Abstract
OBJECTIVE: Short sleep duration is widespread in China's aging population, yet the contribution of ambient fine-particulate matter (PM₂.₅) remains uncertain. We investigated whether chronic PM₂.₅ exposure associates with habitual short sleep duration. METHODS: Within a hospital-based outreach program we surveyed 2082 community-dwelling adults aged ≥60 years in Nanchong and Chongqing (January-December 2024). Annual PM₂.₅ (1 km(2) resolution) was estimated via a validated satellite-ground-fusion model; sleep duration was self-reported using the Chinese version of the Pittsburgh Sleep Quality Index, which has been culturally adapted and validated against actigraphy (ρ = 0.62). Short sleep duration was predefined as <6 h night(-1). Mixed-effects logistic regression, adjusted for socioeconomic, lifestyle, cardiometabolic and environmental covariates, quantified associations per 10 μg m(-3) increment and across exposure strata (<35, 35-50, and >50 μg m(-3)). Restricted cubic splines explored non-linearity, while population-attributable fractions and C-index shifts appraised public-health impact and predictive gain. RESULTS: Mean PM₂.₅ was 44.1 ± 12.5 μg m(-3); 27.3% of participants reported short sleep duration. Each 10 μg m(-3) rise in PM₂.₅ increased short-sleep odds by 12% (adjusted OR 1.12, 95% CI 1.04-1.20). Compared with <35 μg m(-3), exposure >50 μg m(-3) conferred 51% higher odds (OR 1.51, 1.18-1.94). The relationship was monotonic and approximately log-linear. Achieving PM₂.₅ ≤ 35 μg m(-3) could avert 24% of short-sleep cases; introducing PM₂.₅ improved discrimination from 0.55 to 0.57 (Δ 0.02). CONCLUSION: Chronic PM₂.₅ exposure is a modifiable, dose-dependent driver of short sleep duration in older Chinese adults. Air-quality control may yield meaningful sleep-health dividends.