Secondhand smoke exposure and maternal action to protect children from secondhand smoke: pre- and post-smokefree legislation in Hong Kong.

BACKGROUND: Smokefree legislation may protect children from secondhand smoke (SHS) in the home from smoking parent(s). We examined the effect of the 2007 smokefree legislation on children's exposure to SHS in the home and maternal action to protect children from SHS exposure in Hong Kong.

METHODS: Families with a smoking father and a non-smoking mother were recruited from public clinics before (2005-2006, n = 333) and after the legislation (2007-2008, n = 742) which led to a major extension of smokefree places in Hong Kong. Main outcomes included children's SHS exposure in the home, nicotine level in mothers' and children's hair and home environment, mothers' action to protect children from SHS, and their support to the fathers to quit.

RESULTS: Fewer mothers post-legislation reported children's SHS exposure in the home (87.2% versus 29.3%, p<0.01), which was consistent with their hair nicotine levels (0.36 ng/mg versus 0.04 ng/mg, p<0.01). More mothers post-legislation in the last month took their children away from cigarette smoke (6.3% versus 92.2%; p<0.01) and advised fathers to quit over 3 times (8.3% versus 33.8%; p<0.01). No significant change was found in the content of smoking cessation advice and the proportion of mothers who took specific action to support the fathers to quit.

CONCLUSIONS: SHS exposure in the home decreased and maternal action to protect children from SHS increased after the 2007 smokefree legislation. Maternal support to fathers to quit showed moderate improvement. Cessation services for smokers and specific interventions for smoking families should be expanded together with smokefree legislation.