Reduction of secondhand tobacco smoke in public places following national smoke-free legislation in Uruguay.

BACKGROUND Smoke-free legislation eliminating tobacco smoke in all indoor public places and workplaces is the international standard to protect all people from exposure to secondhand smoke. Uruguay was the first country in the Americas and the first middle-income country in the world to enact a comprehensive smoke-free national legislation in March 2006. OBJECTIVE To compare air nicotine concentrations measured in indoor public places and workplaces in Montevideo, Uruguay before (November 2002) and after (July 2007) the implementation of the national legislation. METHODS Air nicotine concentrations were measured for 7-14 days using the same protocol in schools, a hospital, a local government building, an airport and restaurants and bars. A total of 100 and 103 nicotine samples were available in 2002 and 2007, respectively. RESULTS Median (IQR) air nicotine concentrations in the study samples were 0.75 (0.2-1.54) microg/m(3) in 2002 compared to 0.07 (0.0-0.20) microg/m(3) in 2007. The overall nicotine reduction comparing locations sampled in 2007 to those sampled in 2002 was 91% (95% CI 85% to 94%) after adjustment for differences in room volume and ventilation. The greatest nicotine reduction was observed in schools (97% reduction), followed by the airport (94% reduction), the hospital (89% reduction), the local government building (86% reduction) and restaurants/bars (81% reduction). CONCLUSION Exposure to secondhand smoke has decreased greatly in indoor public places and workplaces in Montevideo, Uruguay, after the implementation of a comprehensive national smoke-free legislation. These findings suggest that it is possible to successfully implement smoke-free legislations in low and middle-income countries.