title: Secondhand smoke exposure of children at home and prevalence of parental smoking following implementation of the new tobacco control law in Macao.
abstract: OBJECTIVE
  To investigate secondhand smoke exposure (SHS) of children at home and the prevalence of parental smoking after implementation of the new tobacco control law in Macao. This study explored whether the smoking ban in public places in Macao has decreased the prevalence of smoking or led to increased SHS exposure of children at home. As smokers cannot smoke in public places any more, they may smoke at home more frequently; a displacement effect of smoke-free legislation.
  
  
  METHODS
  Cross-sectional survey.
  
  
  METHODS
  This study surveyed 337 fathers and 538 mothers. Questions from a subset of key questions from the Global Adult Tobacco Survey (2nd edition) were applied to assess the SHS exposure of children and the prevalence of parental smoking since the smoking ban. A classification tree analysis was used to analyse the factors increasing SHS exposure of children.
  
  
  RESULTS
  The prevalence of SHS exposure in children at home was 41.3%. The prevalence rates of paternal and maternal smoking were 43.7% and 3.8%, respectively. Compared with data reported by the Health Bureau of Macao SAR in 2011, the prevalence of parental smoking and the prevalence of SHS exposure of children at home have not decreased since the smoking ban. Analysis of the factors increasing the prevalence of SHS exposure of children indicated that fathers with an education level below high school were more likely to contribute to this increase, compared with fathers with a high school education or more (48.2% vs 32.4%, respectively). In addition, fathers represented the majority of smokers at home, accounting for 92.0% of 415 smoking parents. The prevalence of paternal smoking (82.0%) in the group of children with SHS exposure was much higher than that in the unexposed group (16.7%, Chi-squared test = 367.199, P = 0.000). The SHS exposure of children increased consistently with the decrease in paternal education level. This was consistent with the increasing prevalence of paternal smoking as paternal education level decreased. SHS exposure was most common among children whose fathers had an education level below high school and whose mothers were aged ≤29 years (75.0%).
  
  
  CONCLUSIONS
  This study did not find any decline in the prevalence of parental smoking after the smoking ban. These parents were more likely to smoke at home after the ban, leading to more frequent SHS exposure for their children.
authors.affiliation: Department of Public Health and Preventive Medicine, School of Medicine, Jinan University, Guangzhou, China.
authors.forename: Z L
authors.initials: ZL
authors.lastname: Zheng
authors.affiliation: Department of Public Health and Preventive Medicine, School of Medicine, Jinan University, Guangzhou, China.
authors.forename: H Y
authors.initials: HY
authors.lastname: Deng
authors.affiliation: Department of Public Health and Preventive Medicine, School of Medicine, Jinan University, Guangzhou, China. Electronic address: wuchipeng@126.com.
authors.forename: C P
authors.initials: CP
authors.lastname: Wu
authors.affiliation: Health Bureau of Macao SAR, Macao, China.
authors.forename: W L
authors.initials: WL
authors.lastname: Lam
authors.affiliation: Health Bureau of Macao SAR, Macao, China.
authors.forename: W S
authors.initials: WS
authors.lastname: Kuok
authors.affiliation: Guangdong Provincial Centre for Disease Control and Prevention, Guangzhou, China.
authors.forename: W J
authors.initials: WJ
authors.lastname: Liang
authors.affiliation: Department of Public Health and Preventive Medicine, School of Medicine, Jinan University, Guangzhou, China.
authors.forename: H L
authors.initials: HL
authors.lastname: Wang
mesh_terms: D000328:Adult; D002648:Child; D003430:Cross-Sectional Studies; D004781:Environmental Exposure; D005260:Female; D033161:Government Regulation; D006801:Humans; D008256:Macau / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009035:Mothers; D010290:Parents; D015995:Prevalence; D012907:Smoking / Q000453:epidemiology* / Q000331:legislation & jurisprudence*; D000074606:Smoking Prevention; D011795:Surveys and Questionnaires; D014028:Tobacco Smoke Pollution / Q000009:adverse effects / Q000331:legislation & jurisprudence / Q000517:prevention & control / Q000706:statistics & numerical data*
chemical_list: D014028:Tobacco Smoke Pollution
keywords: Childrens' secondhand smoke exposure; Displacement effects of smoke-free legislation; Environmental tobacco smoke; Macao; New tobacco control law; Passive smoke