Opponents of smoke-free legislation have suggested that it might lead to an increase in child exposure to second-hand smoke because of increased smoking within the home. This would be a major drawback, since children are particularly vulnerable to the health effects of second-hand smoking and cannot easily avoid exposure at home.

However, new research into the impact of the smoking ban in Scotland has demonstrated that such concerns are misplaced, and that the Scottish ban has reduced the exposure of children to second-hand smoke.

Scotland was the first country in the UK to introduce smoke-free legislation, in March 2006. Almost all workplaces and public spaces became smoke-free, but any protection within the home remained voluntary.

Researchers from the University of Edinburgh conducted a survey of second-hand smoke exposure among 2,559 primary schoolchildren (mean age 11) in January 2006, then repeated the survey with 2,424 children of the same age one year later. Measures included reports of parental smoking, exposure to smoking at home and in public, and measures of salivary cotinine (a specific breakdown product of nicotine).

Overall, there was a 39% fall in the exposure of non-smoking children to second-hand smoke between 2006 and 2007, as measured by the mean cotinine concentration. However, the size of reduction differed between households, failing to reach statistical significance among children with a mother or two parents who smoked at home. Importantly, there was no evidence of an increase in smoking at home following the smoke-free legislation.

This study supports the benefits of smoke-free legislation in protecting not only the adult population but also children from the effects of second-hand smoke. It is timely, given recent evidence that tobacco smoke exposure can damage the vascular endothelium and trigger atherosclerotic changes in children as young as 11 years of age.¹

As expected, children from non-smoking households benefit most from the smoke-free legislation. Children with parents who smoke at home remain at risk and there is a continuing need to promote the 'smoke-free homes' message.

Akhtar PC, Currie DB, Currie CE et al. Changes in child exposure to environmental tobacco smoke (CHETS) study after implementation of smoke-free legislation in Scotland: national cross sectional survey. BMJ 2007;335:545-549