TY - JOUR AU1 - Semple, Sean AU2 - Miller, Brian G. AU3 - Hurley, Fintan AU4 - Petticrew, Mark AU5 - Ayres, Jon G. AB - To the Editor: In their study of respiratory symptoms, pulmonary function, and markers of inflammation, Dr Menzies and colleagues1 explored the effect of smoke-free legislation on bar workers' health in Dundee and Perth, Scotland. Their findings of improvements across a range of health indices in bar workers now in smoke-free working environments are consistent with expectations and with earlier work by Eisner et al.2 However, it is important to note that the effects of seasonal variation were not controlled for. The study examined self-reported respiratory symptoms, pulmonary function, and markers of inflammation at 3 points between February 2006 and June 2006. The city of Dundee is located at a latitude of 56.5° N and experiences marked changes in weather conditions in these months (average February maximum temperature is 44°F compared to 62°F in June).3 Roponen et al4 measured large seasonal differences in self-reported respiratory symptoms in a cohort of healthy volunteers in Finland. For most symptoms they found higher levels in winter, spring, and autumn compared with summer. Respiratory infections in Scotland demonstrate a winter peak.5 It is therefore possible that the statistically significant changes in white blood cell and neutrophil counts reported by Menzies et al may be strongly influenced by seasonal reductions in the numbers of bar workers experiencing respiratory infections. Without a control group it is impossible to determine if the effects reported are due to improvements in workplace air quality from the smoke-free legislation. The study also provided no measure of changes in personal exposure. We believe that it would be valuable for the authors to continue their study and to repeat testing of their participants at 12 months from baseline to remove the influence of season (recognizing the practical limitation that their already substantial loss to follow-up would likely be higher at 12 months). Back to top Article Information Financial Disclosures: None reported. References 1. Menzies D, Nair A, Williamson PA. et al. Respiratory symptoms, pulmonary function and markers of inflammation among bar workers before and after a legislative ban on smoking in public places. JAMA. 2006;296:1742-174817032987Google ScholarCrossref 2. Eisner MD, Smith AK, Blanc PD. Bartenders' respiratory health after establishment of smoke-free bars and taverns. JAMA. 1998;280:1909-19149851475Google ScholarCrossref 3. UK Meterological Office. Leuchars 1971-2000 averages. http://www.metoffice.com/climate/uk/averages/19712000/sites/leuchars.html. Accessed October 20, 2006 4. Roponen M, Seuri M, Nevalainen A, Randell J, Hirvonen MR. Nasal lavage method in the monitoring of upper airway inflammation: seasonal and individual variation. Inhal Toxicol. 2003;15:649-66112754687Google Scholar 5. Smith A, McMenamin J, Frew C. Surveillance report: respiratory infections. http://www.documents.hps.scot.nhs.uk/ewr/pdf2006/0620.pdf. Accessed November 22, 2006 TI - Respiratory Symptoms and Inflammation After a Smoking Ban JF - JAMA DO - 10.1001/jama.297.4.359-a DA - 2007-01-24 UR - https://www.deepdyve.com/lp/american-medical-association/respiratory-symptoms-and-inflammation-after-a-smoking-ban-7iArL4woIr SP - 359 EP - 360 VL - 297 IS - 4 DP - DeepDyve ER -