A pre- post- longitudinal study of air quality in bars, bar workers’ second-hand smoke (SHS) exposure and respiratory health, and bar workers’ attitudes and perceived risks to health.
A collaboration between: the Department of Occupational and Environmental Medicine (DEOM), University of Aberdeen; the Institute of Occupational Medicine (IOM); and the MRC Social and Public Health Research Unit (SPHRU), University of Glasgow.
Principal Investigator: Professor Jon Ayres
Lead Researcher: Dr Sean Semple
Study Aims
- Assess changes in air quality in bars following the introduction of smoke-free legislation in Scotland.
- Assess changes in bar workers´ second-hand smoke (SHS) exposure, and self-reported respiratory and sensory symptoms and objective measures of lung function post-legislation.
- Test associations between changes in SHS exposure and respiratory health.
- Assess bar workers´ attitudes to the smoke-free legislation and to prohibition of smoking in their workplace, and their perceptions of the risk to their health of SHS exposure.
Study Design
Longitudinal study with the following components:
- Air quality measurement: Covert measurement of PM2.5 (air-marker of SHS) in a random sample of 41 pubs in two Scottish cities immediately before implementation of legislation with repeat measures taken two months post-legislation.
- Respiratory health and attitudes of bar workers: Study of cohort of 371 bar workers recruited from 72 bars in five areas in Scotland with data collection by questionnaire at baseline (January-March 2006) and at follow-up two months post-legislation and one year post-baseline. Lung function measures which were taken together with samples of saliva were also collected for testing for cotinine - a bio-marker of SHS exposure in non-smokers.
Main outcomes included: PM2.5 (ambient air and personal monitoring); salivary cotinine; self-reported SHS exposure; self-reported respiratory and sensory symptoms; lung function measures (FEV1 and FVC); and attitudinal measures.
Research Instruments and Protocols
Some questions have been based on the International Union Against Lung Disease and Tuberculosis (IUALDT) questions and those for the Ireland study: Legislation for smoke-free workplaces and health of bar workers in Ireland: before and after study ´BMJ´, doi:10.1136/bmj.38636.499225.55 (Published 17 October 2005).
Main Outcomes
- There was an 86% reduction in PM2.5 with air quality in pubs comparable to outdoor ambient air two months post-legislation.
- In a small sub-sample of bar-workers, full-shift personal exposure to PM2.5 showed average reductions of 86% between baseline and two months post-legislation.
- One year post-baseline, salivary cotinine concentrations in bar workers fell by 89% from 2.94 ng/ml to 0.41ng/ml.
- In smokers salivary cotinine fell by 12%.
- For the whole cohort, duration of reported workplace SHS exposure in previous seven days fell from 28.5 hours pre-legislation to 0.83 hours post-legislation.
- There was a reduction in prevalence and number of self-reported respiratory and sensory symptoms in both non-smokers one year post-baseline. However, there was no measureable increase in lung function as measured by either forced expiratory volume (FEV1) or forced vital capacity (FVC).
- Support for the legislation increased from 69% to 79% and concerns about the impact of the legislation on business fell from 49% to less than 20%.
- See also additional papers Find publications from the BHETSE study
Updated 17/07/2014