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 (PM_2.5) 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 PM_2.5 measurements between venue type (waterpipe vs smoke-free) and environment (indoor vs outdoor).

Results The mean PM_2.5 level inside waterpipe venues (476 μg/m³) was significantly higher than the mean PM_2.5 level inside smoke-free venues (17 μg/m³; p<0.001), and significantly higher than the mean PM_2.5 level found immediately outside waterpipe venues (35 μg/m³; p<0.001). In smoke-free venues, the outside mean PM_2.5 level (30 μg/m³) did not differ significantly from the mean PM_2.5 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.