Indoor Solid Fuel Use and Non-Neoplastic Digestive System Diseases: A Population-Based Cohort Study Among Chinese Middle-Aged and Older Population

Objectives: We tended to explore the association of indoor air pollution (IAP) and non-neoplastic digestive system diseases (NNDSD) among the Chinese middle-aged and older population. Methods: From 2011 to 2018, we included 7884 NNDSD-free adults from the China Health and Retirement Longitudinal Study (CHARLS). Physician-diagnosed NNDSD was obtained by self-reported information at baseline and updated across follow-up surveys. We investigated the associations between baseline exposure of solid fuel use for cooking and/or heating and NNDSD diagnosed during follow-up through Cox proportional hazard models. Furthermore, we examined the relationship between cooking fuel switching and NNDSD diagnosed during follow-up. Results: Solid fuel use for cooking and/or heating was positively associated with NNDSD after adjusting for potential confounders. The risk of NNDSD among subjects who always use solid fuel for cooking (adjusted hazard ratio [aHR]: 1.42; 95% confidence interval [CI]: 1.09, 1.84) was higher than those with always clean fuels. Moreover, we found a lower NNDSD risk among participants who switched from solid to clean cooking fuel (aHR: 0.65; 95% CI: 0.49, 0.87) than those with always solid fuels. Conclusion: Our present study shows that indoor solid fuel use is a dependent risk factor for NNDSD. Moreover, switching to clean fuel may contribute to the prevention of digestive system illnesses.