Background: Exposure to second-hand smoke (SHS) is increasingly recognized as an occupational hazard to workers in the service industry. In areas of the world with moderate climates, open windows and doors are assumed to provide a work environment with only marginally increased exposures to SHS.
Methods: We measured indoor fine particulate matter (PM2.5) in 50 semiopen air venues in Greece during the summer. Cotinine levels from a nonsmoking employee of each of these venues were measured from a postshift urine sample.
Results: In these semiopen-air venues, the mean level of indoor PM 2.5 levels were 113.5 ± 72.3 μg/m(3). The mean postshift urinary cotinine levels of nonworking workers in these venues was 15 ng/mL. PM2.5 levels were strongly correlated with urinary cotinine concentrations (Spearman's r = 0.914). Linear regression analyses indicated that when taking into account the time of the measurement, the day of the week, for each 1 cigarette/100 m(3) the indoor PM2.5 concentrations increased by 26.6 μg/m(3) [95% confidence interval (CI): 7.6-45.7 μg/m(3), p = 0.007) and urinary cotinine levels of nonsmoking workers increased by 5.0 ng/mL (95% CI: 0.4 to 9.6, p = 0.034).
Conclusions: In a sample of bars and restaurants with windows and doors open, indoor PM2.5 concentrations were elevated and increased proportionately to the density of smoking. Cotinine levels of nonsmoking employees increased with indoor PM2.5 concentrations, and also with the density of smoking. Open windows and doors do not protect workers from exposure to second-hand smoke.