School of Public Health, The University of Hong Kong, HKSAR, Pokfulam, Hong Kong.
Tob Control. 2010 Apr;19(2):129-33. doi: 10.1136/tc.2009.032003.
To investigate the effect of comprehensive smoke-free legislation in 2007 on the exposure of children to secondhand smoke (SHS) in Hong Kong.
Two cross-sectional questionnaire surveys were conducted, before (2006) and after (2008) the implementation of smoke-free legislation, among primary 2-4 students (equivalent to US grades 2-4) from 19 and 24 randomly selected schools, respectively. Adjusted ORs for SHS exposure at home and outside home post-legislation compared with pre-legislation were calculated. The strength of the association between SHS exposure and respiratory symptoms in each survey was used as an indirect indicator of the intensity of exposure.
Among 3243 and 4965 never smoking students in the 2006 and 2008 surveys, the prevalence of SHS exposure in the past 7 days increased both at home (from 10.2% to 14.1%) and outside home (from 19.8% to 27.2%). Post-legislation, students were 56% more likely (p<0.01) to report SHS exposure at home coupled with an insignificantly stronger association between SHS exposure and respiratory symptoms. Similarly, students were 60% more likely (p<0.001) to report SHS exposure outside home in 2008, but the association between SHS exposure and respiratory symptoms became insignificantly weaker. Parental smoking rates were similar before and after legislation.
The prevalence of exposure to SHS at home and outside home have both increased among primary school students in Hong Kong post-legislation. Comprehensive smoke-free legislation without strong support for smoking cessation might have displaced smoking into the homes of young children.
研究 2007 年全面无烟立法对香港儿童接触二手烟（SHS）的影响。
在实施无烟立法前后（2006 年和 2008 年），分别对来自 19 所和 24 所随机选择的小学 2-4 年级（相当于美国 2-4 年级）的 3243 名和 4965 名从未吸烟的学生进行了两次横断面问卷调查。计算了立法后与立法前相比，在家中和家外暴露于 SHS 的调整比值比（OR）。每个调查中 SHS 暴露与呼吸道症状之间的关联强度被用作暴露强度的间接指标。
在 2006 年和 2008 年的调查中，从未吸烟的 3243 名和 4965 名学生中，过去 7 天在家中和家外接触 SHS 的比例均有所增加（从 10.2%增至 14.1%，从 19.8%增至 27.2%）。立法后，学生在家中接触 SHS 的可能性增加了 56%（p<0.01），但 SHS 暴露与呼吸道症状之间的关联变得不显著；同样，2008 年学生在户外接触 SHS 的可能性增加了 60%（p<0.001），但 SHS 暴露与呼吸道症状之间的关联变得不显著。立法前后，父母的吸烟率相似。
香港小学生在家中和户外接触 SHS 的比例在立法后均有所上升。没有强有力的戒烟支持的全面无烟立法可能将吸烟转移到了幼儿的家中。
