Abstract
BACKGROUND: The combustion of solid cooking fuels is a major source of indoor air pollution, yet the association of solid cooking fuels with functional disability remains inadequately studied. METHODS: We analyzed data from five waves (2011-2020) of the China Health and Retirement Longitudinal Study (CHARLS), assessing functional disability through activities of daily living (ADL) and instrumental activities of daily living (IADL). Linear mixed-effects models (LMM) and time-varying Cox proportional hazards models were employed to examine the associations between cooking fuel type, fuel transitions, and the duration of solid fuel use on functional disability. RESULTS: Cross-sectional analyses revealed that individuals using solid cooking fuels faced a significantly higher risk of functional disability. Longitudinal analyses showed that persistent use of solid cooking fuels was associated with a 38% increased hazard of ADL and a 28% increased hazard of IADL (both p < 0.001). Transitioning to clean cooking fuels was associated with reduced risks, while prolonged use of solid fuels correlated with increased disability risk. Notably, coal use posed a higher risk for functional disability compared to biomass fuels. CONCLUSIONS: Solid cooking fuels use increases the risk of functional disability, with coal posing the greatest risk. Transitioning to cleaner cooking technologies can mitigate this risk, underscoring the need for policies promoting cleaner cooking to reduce indoor air pollution and improve health in older adults.