Effects of China's Clean Heating Policy on respiratory symptoms and airway inflammation in adults: a quasi-experimental study in rural Beijing.

Abstract

Northern China's Clean Heating Policy (CHP) aimed to reduce wintertime coal burning in rural homes by restricting coal use and providing subsidies for clean heating. The policy's health impacts on respiratory outcomes have not been empirically evaluated. To estimate the impact of the CHP on respiratory symptoms and airway inflammation using a difference-in-differences design leveraging the policy's staggered rollout across rural Beijing villages. We enrolled 1003 adults aged ≥40 years from 50 rural villages reliant on coal heating at baseline (2018-2019). Over 4 winters (2018-2022), 20 villages were enrolled in the CHP. During up to 3 winter waves of data collection, we measured respiratory symptoms by questionnaire and, in a subsample, measured fractional exhaled nitric oxide (FeNO). We estimated the policy's effects using extended 2-way fixed effects models, accounting for village-level clustering and potential time-varying confounders. Exposure to the CHP was associated with a 7.5 percentage point reduction (95% confidence interval (CI): -12.8, -2.3) in the prevalence of any respiratory symptom, primarily driven by reductions in reported difficulty breathing (-3.3 pp, 95% CI: -8.0, 1.3), shortness of breath (-3.5 pp, 95% CI: -9.3, 2.3), and cough (-2.8 pp, 95% CI: -7.3, 1.6). We observed no evidence of an effect of the CHP on FeNO (0.3 ppb, 95% CI: -2.2, 2.8). The CHP led to reductions in reported respiratory symptoms among Beijing adults. This study contributes to the limited empirical evidence that clean energy policies can yield health benefits.