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Case study – IOM contributes to the evaluation of the smoke-free legislation in Scotland

Cigarette smoking is a major public health problem causing increased morbidity and mortality from cancer, lung disease and other health conditions. Non-smokers exposed to second hand smoke (SHS) also have increased risks for these diseases and the introduction of "smoke-free" legislation in Scotland and elsewhere has aimed to reduce the risks for non-smokers. IOM was part of a consortium of Scottish researchers who set out to assist the Scottish Government evaluate the impact of The Smoking, Health and Social care (Scotland) Act 2005, which came into force on 26 March 2006.

Early observations showed that there was a positive response to the legislation by most non-smokers and smokers (Hilton et al, 2007 [1]), and within a relatively short time there was a high degree of compliance with the restrictions on smoking in public places. In our work we were able to show that there was a corresponding improvement in the air quality inside Scottish pubs. Semple, Creely and colleagues (2007 [2]) measured changes in the concentration of fine particles (PM2.5† ) in a sample of 41 pubs in two Scottish cities. PM2.5are very small particles that can be generated by a variety of sources in cities – outdoors by diesel vehicle exhausts and indoors from cooking and other combustion sources, although in pubs the main source was cigarette smoke. We carried out baseline measurements during the period just before the implementation of the legislation and then repeated these measurements two months after the restrictions were introduced. The PM2.5 concentrations fell by 86% and the levels in the majority of Scottish pubs investigated was now equivalent to that of outdoor air. We have since been able to study the effects of smoking restrictions in other countries of the UK and have published these results (Semple, van Tongeren et al, 2010 [3]).

The IOM worked with the University of Aberdeen and other researchers in the Bar Workers' Health and Environmental Tobacco Smoke Exposure (BHETSE) Study, which aimed to assess the impact of Scotland's smoking ban on the health of smoking and non-smoking bar workers from bars in five areas in Scotland.

The study, which was funded by NHS Health Scotland and the Scottish Government, followed over 190 bar workers from over 70 bars over a 12-month period. The results from this study also showed there had been improvements in air quality in bars, both from self-reported SHS exposure and salivary cotinine‡ measurements obtained from the bar workers in this study. Among non-smoking bar workers, salivary cotinine concentrations fell by 89% one year after legislation (Semple, MacCalman et al. 2007 [4]), suggesting that the reductions in SHS exposure seen from the air samples collected in the two months after the restrictions were sustained for a full year after the legislation had been introduced.

Figure 1.

In the BHEETSE study (Ayres et al, 2009 [5]) we found that the percentage of the bar workers reporting respiratory symptoms, such as wheezing, shortness of breath, cough and phlegm production, fell during the year after workplaces becoming smoke-free. The proportion of bar workers reporting at least one sensory symptom, such as irritated eyes and sore throat, also fell (Figure 1). Amongst non-smokers, the largest reductions in individual symptoms were in the proportion of bar workers reporting phlegm production, which decreased from 32% to 14%; eye irritation fell from 44% to 18%; and the proportion reporting sore throat fell from 44% to 25%. In smokers the proportion reporting wheezing fell from 48% immediately before the ban to 31% one year later, while reports of irritated eyes fell from 35% to 25% in the same time period. The study did not find any clear changes in lung function of bar workers, but it is thought that this may have been due to the difficulty of making these measurements in a pub setting.

As part of the research we were also able to undertake some methodological work on the difficulties of undertaking covert observations of individuals smoking habits (Petticrew et al, 2007 [6]).

This commentary was based on a book chapter by Sally Haw7 – who coordinated the Scottish evaluation studies.

We also issued a news item when the results of the BHETSE study were published ('Research findings a breath of fresh air for bar staff') and published a short article8 on the work in the World Health Organization (WHO) Global Occupational Health Network newsletter.

[1]
Expectations and changing attitudes of bar workers before and after the implementation of smoke-free legislation in Scotland, Shona Hilton, Sean Semple, Brian G Miller, Laura MacCalman, Mark Petticrew, Scott Dempsey, Audrey Naji and Jon G Ayres BMC Public Health 2007, 7:206
[2]
Secondhand smoke levels in Scottish pubs: the effect of smoke-free legislation, Sean Semple, Karen S Creely, Audrey Naji, et al. Tob Control 2007 16: 127-132
[3]
UK Smoke-Free Legislation: Changes in PM2.5 Concentrations in Bars in Scotland, England, and Wales, Sean Semple, Martie Van Tongeren, Karen S. Galea, Laura MacCalman, Ivan Gee, Odette Parry, Audrey Naji and Jon G. Ayres Ann. Occup. Hyg., pp. 1–9
[4]
Bar Workers' Exposure to Second-Hand Smoke: The Effect of Scottish Smoke-Free Legislation on Occupational Exposure, Sean Semple, Laura MacCalman, Audrey Atherton Naji, Scott Dempsey, Shona Hilton, Brian G. Miller and Jon G. AyresAnn. Occup. Hyg., Vol. 51, No. 7, pp. 571–580, 2007
[5]
Bar workers' health and environmental tobacco smoke exposure (BHETSE): symptomatic improvement in bar staff following smoke-free legislation in Scotland, J G Ayres, S Semple, L MacCalman, et al.Occup Environ Med 2009 66: 339-346
[6]
Covert observation in practice: lessons from the evaluation of the prohibition of smoking in public places in Scotland, Mark Petticrew, Sean Semple, Shona Hilton, Karen S Creely, Douglas Eadie, Deborah Ritchie, Catherine Ferrell, Yvette Christopher and Fintan Hurley.BMC Public Health 2007, 7:204
[7]
Legislation on smoking in enclosed public places in Scotland: how will we evaluate the impact? Sally J. Haw, Laurence Gruer, Amanda Amos, Candace Currie, Colin Fischbacher, Geoffrey T. Fong, Gerard Hastings, Sally Malam, Jill Pell, Calum Scott and Sean Semple Journal of Public Health Vol. 28, No. 1, pp. 24–30
[8]
Second Hand Smoke (SHS) and the health of bar workers, Fintan Hurley et al.GOHNET No. 13 Nov. 2007 pp. 26-28, WHO
†
PM are those particles sampled with a monitoring device that has a median penetration value of 2.5 μm, i.e. particles smaller than 2.5 μm.
‡
Cotinine is a metabolite of nicotine present in body fluids, and in non-smokers is a biomarker of SHS exposure during the previous three or four days.