Smoking ban cuts exposure but smokefree homes remain a challenge
A trio of studies published online in the British Medical Journal have found that Scotland's ban on smoking in public places has brought about a large reduction in exposure to secondhand tobacco smoke.
Experts from NHS Health Scotland interviewed adults between the ages of 18 and 74 and measured their self-reported exposure to tobacco smoke and the levels of cotinine - a substance produced when nicotine is broken down - in their saliva.
They found that cotinine levels fell by 49 per cent among non-smokers from non-smoking households, suggesting a significant reduction in their exposure to secondhand smoke.
Sally Haw, principal public health adviser at NHS Health Scotland who co-authored one of the studies with Laurence Gruer, director of public health science, said that there has been a "large reduction in secondhand smoke exposure in non-smoking adults in Scotland".
"The improvement in air quality was associated with a reduction in reported exposure to secondhand smoke in public places - such as pubs, other workplaces and public transport, but not in private places - like homes and cars," she noted.
However, the reduction in cotinine levels in non-smokers from smoking households was insignificant, suggesting that this group of people "continue to have high levels of exposure to secondhand smoke".
A second study, also authored by Sally Haw alongside research fellow Patricia Akhtar, senior statistician Dorothy Currie and director Candice Currie - all from the University of Edinburgh - looked at the reduction of secondhand smoke exposure in schoolchildren.
The researchers surveyed 2,559 children prior to the smoking ban and 2,424 after the legislation and found a 39 per cent reduction in salivary cotinine levels.
In addition, the researchers found "no evidence" of increased secondhand smoke exposure among children living in smoking households, suggesting that parents are not smoking more at home as a result of the ban in public places.
However, they concluded that "further efforts are needed to promote both smoke-free homes and smoking cessation".
The third study found that nearly all non-smokers - and many smokers - were happy about the legislation, with the majority pointing to health benefits, less smoky pubs and the reduced likelihood of children becoming smokers as the main positive points.
The authors called for a coordinated approach to reducing secondhand smoke in the home and cars, citing evidence from other countries which have succeeding in achieving this goal.
Commenting on the findings, Elspeth Lee, Cancer Research UK's senior tobacco control manager, said: "These studies provide further evidence that the comprehensive smokefree legislation in Scotland is helping to protect Scottish people from the very dangerous effects of second hand smoke - and helping smokers to quit." Ms Lee said that there would be many more health gains in the years to come, but stressed that we must not be complacent if the cycle of tobacco addiction, disability and death is to be broken.
"The smokefree legislation has been a significant milestone, but with over a million smokers in Scotland - half of whom will die from a smoking related disease - we need continued commitment from the Scottish government to reduce smoking rates," she concluded.