Int. J. Environ. Res. Public Health 2011, 8 1521 bans would reduce revenue, and 63% thought indoor air quality depended on ventilation rather than smoking bans. These results showed that there was support for smoking bans among restaurant or bar owners in China despite some knowledge gaps. To facilitate smoking bans in restaurants and bars, it is important to promote health education on specific hazards of SHS, provide country-specific evidence on smoking bans and hospitality revenues, and disseminate information that restricting smoking and ventilation alone cannot eliminate SHS hazards. Keywords: knowledge; attitudes; secondhand smoke; smoking ban; restaurant and bar 1. Introduction Secondhand smoke (SHS) has been proven to cause several diseases affecting many organs in human beings. The adverse health effects of SHS and the benefits of smoking bans have been well documented [1-7]. Restaurants and bars are very important public places for many people, and they are also workplaces for restaurant or bar workers. As of January 2011, 55 nations have enacted 100% smoke-free laws, with 37 including both restaurants and bars [8]. Despite progress, only 9% of countries mandate smoke-free bars and restaurants [9]. In mainland China in 2010, 26% of its urban adult population and 30% of its rural adult population were current smokers, with about 70% of its adult population exposed to SHS in a typical week [10]. Smoking is nationally prohibited in the following public places: gymnasiums; libraries, museums and art galleries; waiting rooms for public transportation; passenger trains, passenger ships and flights; and classrooms, activity rooms and dorms for minors [11], and it was generally not regulated in restaurants and bars before 2008. In 2005, China ratified the World Health Organization Framework Convention on Tobacco Control (WHO FCTC). Since then, there have been several initiatives to reduce exposure to SHS in public places, including restaurants and bars. In January 2007, the Beijing Health Bureau and the Chinese Center for Disease Control and Prevention (CDC) sent 40 thousand letters to restaurant and bar owners in Beijing asking them to voluntarily prohibit smoking (not allowing smoking at all in any dining areas) in their own establishments [12]. On May 1st, 2008, the Beijing government passed a law actually requiring restaurants within the city to prohibit or restrict smoking (only allowing smoking in designated sections of dining areas) [13]. Although several other large cities, including Shanghai, Guangzhou, Hangzhou, and Yinchuan, have taken steps to reduce SHS exposure by regulations, restrictions on smoking in restaurants and bars are mostly voluntary, as was true in Beijing before May 2008. There are still no regulations on smoking in bars across China. As more and more tobacco control activities have been initiated in China, the public’s awareness of tobacco hazards has increased. Between 1996 and 2002, awareness of the health effects of smoking increased from 40% to 70% for lung cancer and from 4% to 21% for heart disease, and the percentage of the public who knew that passive smoking (exposure to SHS) could cause serious health effects increased from 15% to 30% [14].