Second-hand smoke in hospitals in Catalonia (2009): A cross-sectional study measuring PM_2.5 and vapor-phase nicotine

Objectives: To describe second-hand smoke in the hospitals of the Catalan Network for Smoke-free Hospitals using Particulate Matter (PM_2.5) and to assess the association between second-hand smoke exposure in main entrances (outdoors) and halls and between PM_2.5 and airborne nicotine concentrations. Methods: Cross-sectional study carried out in 2009 in the 53 hospitals affiliated with the network. We measured PM_2.5 (γg/m³) in all hospitals and measured airborne nicotine concentrations (γg/m³) in a subsample of 11 hospitals. For each assessment, we measured nine locations within the hospitals, computing medians, means, geometric means, interquartile ranges (IQRs), and 95% confidence intervals (CI) of the means and the geometric means. Further, we used Spearman's linear correlation coefficient r_sp) to explore the association between PM_2.5 concentrations in halls and main entrances and between PM_2.5 and nicotine concentrations. Results: The overall median of the 429 PM_2.5 measurements was 12.48γg/m³ (IQR: 8.84-19.76γg/m³). The most exposed locations were outdoor smoking points (16.64γg/m³), cafeterias (14.82γg/m³), and main entrances (14.04γg/m³); dressing rooms were the least exposed (6.76γg/m³). PM_2.5 concentrations in halls were positively correlated with those in main entrances (r_sp=0.591, 95% CI: 0.377-0.745), as were PM_2.5 values and nicotine concentrations (r_sp=0.644, 95% CI: 0.357-0.820). Conclusions: Second-hand smoke levels in hospitals were low in most locations, with the highest levels observed in outdoor locations where smoking is allowed (smoking points and entrances). Smoking in main entrances was associated with increased second-hand smoke levels in halls. Use of PM_2.5 to evaluate second-hand smoke is feasible and shows a good correlation with airborne nicotine values.