Solid Fuel Use and Risks of Respiratory Diseases. A Cohort Study of 280,000 Chinese Never-Smokers

Abstract

Rationale: Little evidence from large-scale cohort studies exists about the relationship of solid fuel use with hospitalization and mortality from major respiratory diseases. Objectives: To examine the associations of solid fuel use and risks of acute and chronic respiratory diseases. Methods: A cohort study of 277,838 Chinese never-smokers with no prior major chronic diseases at baseline. During 9 years of follow-up, 19,823 first hospitalization episodes or deaths from major respiratory diseases, including 10,553 chronic lower respiratory disease (CLRD), 4,398 chronic obstructive pulmonary disease (COPD), and 7,324 acute lower respiratory infection (ALRI), were recorded. Cox regression yielded adjusted hazard ratios (HRs) for disease risks associated with self-reported primary cooking fuel use. Measurements and Main Results: Overall, 91% of participants reported regular cooking, with 52% using solid fuels. Compared with clean fuel users, solid fuel users had an adjusted HR of 1.36 (95% confidence interval, 1.32–1.40) for major respiratory diseases, whereas those who switched from solid to clean fuels had a weaker HR (1.14, 1.10–1.17). The HRs were higher in wood (1.37, 1.33–1.41) than coal users (1.22, 1.15–1.29) and in those with prolonged use (≥40 yr, 1.54, 1.48–1.60; <20 yr, 1.32, 1.26–1.39), but lower among those who used ventilated than nonventilated cookstoves (1.22, 1.19–1.25 vs. 1.29, 1.24–1.35). For CLRD, COPD, and ALRI, the HRs associated with solid fuel use were 1.47 (1.41–1.52), 1.10 (1.03–1.18), and 1.16 (1.09–1.23), respectively. Conclusions: Among Chinese adults, solid fuel use for cooking was associated with higher risks of major respiratory disease admissions and death, and switching to clean fuels or use of ventilated cookstoves had lower risk than not switching.

Health Effects of Household Solid Fuel Use: Findings from 11 Countries within the Prospective Urban and Rural Epidemiology Study

“…We also observed associations between HAP and major respiratory disease, which aligns with and strengthens the existing literature. A longitudinal analysis of 280,000 Chinese nonsmokers comparing solid fuels users with clean fuels users estimated an HR of 1.36 (95% CI: 1.32, 1.40) for major respiratory diseases, including chronic lower respiratory disease, COPD, and ALRI (Chan et al. 2019).…”

“…2014). To date, few prospective studies have examined HAP exposures and respiratory events in adults, and the existing studies have reported contradictory findings (Chan et al. 2019; Ezzati and Kammen 2001; Mitter et al.…”

Solid Fuel Use and Incident COPD in Chinese Adults: Findings from the China Kadoorie Biobank

“…Chan et al. (2019) conducted a prospective analysis using the CKB data and reported that solid fuel use for cooking was associated with increased risk of COPD in never smokers (adjusted HR: 1.10, 95% CI: 1.03, 1.18). Their study included respiratory outcomes other than COPD (i.e., chronic lower respiratory disease, acute respiratory infection, and other upper respiratory diseases), and it was restricted to never smokers and only evaluated solid fuel use for cooking.…”

“…Longitudinal observations are needed to help support a causal relationship. A cohort study of 280,000 never-smoking adults in the China Kadoorie Biobank (CKB) found that long-term solid fuel use for cooking was associated with hospitalization and death from a range of respiratory diseases, including COPD (Chan et al. 2019).…”

Household, community, sub-national and country-level predictors of primary cooking fuel switching in nine countries from the PURE study

“…Such a switch may lead to substantial health improvements. For example, a recent cohort study in China identified a reduction in risk of major respiratory diseases when households switched from polluting to clean primary cooking fuels [28].…”