Second-hand smoke in mental healthcare settings: time to implement total smoke-free bans?

Background Second-hand smoke is associated with adverse health effects. Many countries have extended smoke-free policies to public buildings and workplaces such as hospitals, but mental health units have usually been exempted from complete smoke-free bans. The objective of this study was to evaluate second-hand smoke levels in mental health units with different types of smoking bans. Method We conducted a cross-sectional study to evaluate second-hand smoke in 64 mental health inpatient units (95.5% of the all such units) in Catalonia, Spain. We measured air concentrations of particulate matter <2.5 mu m (PM2.5) as a marker of second-hand smoke in different locations at each unit. Results The geometric mean (95% confidence interval) of the PM2.5 concentration was 8.81 mu g/m(3) (8.06-9.56) in units with indoor and outdoor smoking bans, 13.80 mu g/m(3) (13.23-14.36) in units with indoor smoking bans that allowed smoking in outdoor areas, 24.29 mu g/m(3) (23.50-25.03) in units with indoor smoking rooms and 51.00 mu g/m(3) (49.83-52.04) in units that allowed smoking in common indoor areas (P < 0.05). The regression model adjusted for confounding variables showed a linear increase of PM2.5. The PM2.5 concentration in smoking rooms was 286.50 mu g/m(3) (283.95-288.89). Conclusions Only units with indoor and outdoor smoking bans had PM2.5 levels below the standard recommended WHO levels of 10 mu g/m(3). Units with more permissive smoking policies had PM2.5 levels from second-hand smoke that have harmful health effects.