Leung Lok Tung, Ho Sai Yin, Wang Man Ping, Lo Wing Sze, Lam Tai Hing
School of Public Health, The University of Hong Kong, Hong Kong.
School of Nursing, The University of Hong Kong, Hong Kong.
BMJ Open. 2015 Nov 4;5(11):e008607. doi: 10.1136/bmjopen-2015-008607.
To investigate secondhand smoke (SHS) exposure at home from neighbours in Hong Kong adolescents and its association with respiratory symptoms in never-smokers.
A cross-sectional study.
79 randomly selected secondary schools in Hong Kong.
61,810 secondary 1 (USA grade 7) to 7 students, in which 50,762 never-smokers were identified and included in the analysis of the association between SHS exposure at home from neighbours and respiratory symptoms.
Smoking status, family smoking status, SHS exposure at home from inside the home and from neighbours in the past 7 days, respiratory symptoms and sociodemographic characteristics were reported. Adjusted ORs (AORs) of respiratory symptoms for SHS exposure from the 2 sources in never-smokers were calculated using logistic regression.
In all students, 33.2% were exposed to SHS at home, including 16.2% from inside the home only, 10.0% from neighbours only and 7.0% from both. The prevalence of SHS exposure from neighbours was 17.1%, including 13.5% for 1-4 days/week and 3.6% for 5-7 days/week. In never-smokers (n=50,762), respiratory symptoms were significantly associated with SHS exposure from neighbours with AORs (95% CI) of 1.29 (1.20 to 1.39) for any exposure (p<0.001), 1.21 (1.12 to 1.31) for 1-4 days/week (p<0.001) and 1.63 (1.44 to 1.86) for 5-7 days/week (p<0.001) (P for trend <0.001). Compared with no SHS exposure at home from any source, the AORs were 1.16 (1.07 to 1.25) for SHS from inside the home only (p<0.001), 1.20 (1.11 to 1.31) from neighbours only (p<0.001), and 1.74 (1.56 to 1.94) from both (p<0.001).
SHS exposure at home from neighbours was prevalent in Hong Kong adolescents, and was associated with respiratory symptoms in never-smokers. SHS exposure at home may be underestimated by ignoring the neighbouring source. Smoke-free housing policy is needed to protect children and adolescents from harms of SHS.
调查香港青少年在家中接触来自邻居的二手烟（SHS）情况及其与非吸烟者呼吸道症状的关联。
一项横断面研究。
香港79所随机选取的中学。
61810名初一（美国7年级）至初7学生，其中50762名非吸烟者被确定并纳入分析来自邻居的家庭二手烟暴露与呼吸道症状之间的关联。
报告吸烟状况、家庭吸烟状况、过去7天在家中来自室内和邻居的二手烟暴露情况、呼吸道症状及社会人口学特征。使用逻辑回归计算非吸烟者中来自这两个来源的二手烟暴露导致呼吸道症状的调整比值比（AOR）。
在所有学生中，33.2%在家中接触二手烟，其中仅16.2%来自室内，仅10.0%来自邻居，7.0%来自两者。来自邻居的二手烟暴露患病率为17.1%，其中每周1 - 4天为13.5%，每周5 - 7天为3.6%。在非吸烟者（n = 50762）中，呼吸道症状与来自邻居的二手烟暴露显著相关，任何暴露的AOR（95%CI）为1.29（1.20至1.39）（p < 0.001），每周1 - 4天为1.21（1.12至1.31）（p < 0.001），每周5 - 7天为1.63（1.44至1.86）（p < 0.001）（趋势P < 0.001）。与家中无任何来源的二手烟暴露相比，仅来自室内的二手烟暴露的AOR为1.16（1.07至1.25）（p < 0.001），仅来自邻居的为1.20（1.11至1.31）（p < 0.001），来自两者的为1.74（1.56至1.94）（p < 0.001）。
香港青少年在家中接触来自邻居的二手烟情况普遍，且与非吸烟者的呼吸道症状相关。忽略邻居来源可能会低估家庭二手烟暴露情况。需要实施无烟住房政策来保护儿童和青少年免受二手烟危害。
