A cross-sectional study on levels of secondhand smoke in restaurants and bars in five cities in China

Objectives To assess indoor secondhand smoke (SHS)exposure in restaurants and bars via PM2.5 levelmeasurements in five cities in China.Methods The study was conducted from July toSeptember in 2007 in Beijing, Xi'an, Wuhan, Kunmingand Guiyang. PM2.5 concentrations were measured in404 restaurants and bars using portable aerosolmonitors. The occupant density and the active smokerdensity were calculated for each venue sampled.Results Among the 404 surveyed venues, 23 hadcomplete smoking bans, nine had partial smoking bansand 313 (77.5%) had smoking observed during sampling.The geometric mean of indoor PM2.5 levels in venueswith smoking observed was 208 mg/m3 and 99 mg/m3 invenues without smoking observed. When outdoor PM2.5levels were adjusted, indoor PM2.5 levels in venues withsmoking observed were consistently significantly higherthan those in venues without smoking observed(F1/480.49, p<0.001). Indoor PM2.5 levels were positivelycorrelated with outdoor PM2.5 levels (partial r1/40.37p<0.001) and active smoker density (partial r1/40.34,p<0.001).Conclusions Consistent with findings in other countries,PM2.5 levels in smoking places are significantly higherthan those in smoke-free places and are strongly relatedto the number and density of active smokers. Thesefindings document the high levels of SHS in hospitalityvenues in China and point to the urgent need forcomprehensive smoke-free laws in China to protect thepublic from SHS hazards, as called for in Article 8 of theFramework Convention on Tobacco Control, which wasratified by China in 2005.