How smoke-free laws improve air quality: a global study of Irish pubs.

INTRODUCTION The present study examined indoor air quality in a global sample of smoke-free and smoking-permitted Irish pubs. We hypothesized that levels of respirable suspended particles, an important marker of secondhand smoke, would be significantly lower in smoke-free Irish pubs than in pubs that allowed smoking. METHODS Indoor air quality was assessed in 128 Irish pubs in 15 countries between 21 January 2004 and 10 March 2006. Air quality was evaluated using an aerosol monitor, which measures the level of fine particle (PM(2.5)) pollution in the air. A standard measurement protocol was used by data collectors across study sites. RESULTS Overall, the level of air pollution inside smoke-free Irish pubs was 93% lower than the level found in pubs where smoking was permitted. DISCUSSION Levels of indoor air pollution can be massively reduced by enacting and enforcing smoke-free policies.