Abstract
The primary aims of this study are to examine the associations between two key environmental factors-regional cigarette tobacco production and tobacco retail outlet density-and secondhand smoke (SHS) exposure in urban China and to explore the possible mechanisms that explain this association. METHODS: A cross-sectional multistage sampling design was used to collect individual information in 21 cities in China. Environmental variables were retrieved from national databases. Multilevel logistic regression analysis was conducted to examine the associations between regional cigarette tobacco production, tobacco retail outlet density and SHS exposure. Structural equation modelling was employed to determine possible mechanisms. RESULTS: SHS exposure prevalence defined as daily exposure to SHS for at least 15 min/day at the time of the survey was found to be 28.1% among non-smokers (95% CI 27.1 to 29.0) across the 21 cities. The multilevel logistic regressions showed that province-level per capital cigarette production (OR: 2.72 (95% CI 1.56 to 4.76)and per GDP cigarette production(OR:1.69(95% CI 1,42,2.01), and city-level tobacco retail outlet density (OR: 2.66 (95% CI 1.63 to 4.38)) were significantly associated with SHS exposure. Moreover, results showed that these associations may be explained by the level of tobacco advertisement, which influences social norms, including attitudes and behaviours toward SHS exposure. CONCLUSIONS: Findings shed light on the role of cigarette manufacturers and retailers in producing environmental SHS pollution. To address the health and economic burden associated with SHS in China, it will be critical for the Chinese government to enact tobacco control measures consistent with the Framework Convention for Tobacco Control. Efforts should also focus on restricting the permitted density of tobacco retail outlets, and tobacco production in China.