PM 2.5 from Stir-Fry Cooking in Chinese Cities Leads to Significant Health Impacts

Stir-fry cooking (SFC) is a common food preparation method in Chinese cities, but its contribution to indoor air pollution and related health effects on a national scale remains unclear. Here, we evaluate SFC emissions and health impacts on urban indoor air quality and population health in Chinese cities using PM2.5 measurements in 94 households across 15 Chinese cities over one year. By decomposing the observed time series data of indoor PM2.5 into contributions from SFC, outdoor-to-indoor infiltration, and other indoor sources, our results show that SFC raises indoor PM2.5 levels in kitchens and living rooms by 21% and 7%, respectively. Taking both indoor and outdoor exposure into consideration, the disability-adjusted life years (DALYs) attributable to PM2.5 with SFC or without SFC were 15.1 (95% CI: 10.2-20.1) million years or 13.7 (95% CI: 9.0-18.6) million years, respectively. Females and the elderly are more affected. Proper use of ventilation reduces these impacts, but many households still face elevated risks. Our findings highlight the health challenges posed by indoor air pollution from SFC and suggest that improved ventilation, less frequent stir-frying, and use of air purifiers or face masks can help lower these risks.