RT Journal Article SR Electronic T1 Secondhand smoke emission levels in waterpipe cafes in Doha, Qatar JF Tobacco Control JO Tob Control FD BMJ Publishing Group Ltd SP e227 OP e231 DO 10.1136/tobaccocontrol-2014-051717 VO 24 IS e3 A1 Ahmad Al Mulla A1 Nadia Fanous A1 Andrew B Seidenberg A1 Vaughan W Rees YR 2015 UL http://tobaccocontrol.bmj.com/content/24/e3/e227.abstract AB Background Exposure to the emissions of a tobacco waterpipe is associated with increased health risks among its users as well as those exposed to its secondhand smoke. Waterpipe use is an emerging concern to the tobacco control community, particularly among countries of the Eastern Mediterranean Region. In 2002, Qatar adopted legislation that prohibited cigarette smoking inside public venues, but exempted tobacco waterpipe smoking. To inform the development and enforcement of effective policy, the impact of cigarette and waterpipe use on indoor air quality was monitored in waterpipe cafes in Doha, Qatar.Methods Particulate matter (PM2.5) levels were measured inside and outside of a sample of 40 waterpipe cafes and 16 smoke-free venues in Doha, Qatar between July and October 2012. In addition, the number of waterpipes being smoked and the number of cigarette smokers were counted within each venue. Non-paired and paired sample t tests were used to assess differences in mean PM2.5 measurements between venue type (waterpipe vs smoke-free) and environment (indoor vs outdoor).Results The mean PM2.5 level inside waterpipe venues (476 μg/m3) was significantly higher than the mean PM2.5 level inside smoke-free venues (17 μg/m3; p<0.001), and significantly higher than the mean PM2.5 level found immediately outside waterpipe venues (35 μg/m3; p<0.001). In smoke-free venues, the outside mean PM2.5 level (30 μg/m3) did not differ significantly from the mean PM2.5 inside levels inside these venues (p=0.121).Conclusions Elevated levels of particulate pollution were found in waterpipe cafes in Doha, Qatar, potentially endangering the health of employees and patrons. To protect the public from the dangers of secondhand tobacco smoke, and to change social norms around tobacco use, smoke-free policies that apply to all forms of combusted tobacco products, including the waterpipe, are needed.