Objective: The prevalence of waterpipe tobacco smoking has risen in recent decades. Controlled studies suggest that waterpipe secondhand smoke (SHS) contains similar or greater quantities of toxicants than cigarette SHS, which causes significant morbidity and mortality. Few studies have examined SHS from waterpipe tobacco in real-world settings. The purpose of this study was to quantify SHS exposure levels and describe the characteristics of waterpipe tobacco venues. Methods: In 2012-2014, we conducted cross-sectional surveys of 46 waterpipe tobacco venues (9 in Istanbul, 17 in Moscow, and 20 in Cairo). We administered venue questionnaires, conducted venue observations, and sampled indoor air particulate matter (PM2.5) (N=35), carbon monoxide (CO) (N=23), particle-bound polycyclic aromatic hydrocarbons (p-PAHs) (N=31), 4-methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) (N=43), and air nicotine (N=46). Results: Venue characteristics and SHS concentrations were highly variable within and between cities. Overall, we observed a mean (standard deviation (SD)) of 5 (5) waterpipe smokers and 5 (3) cigarette smokers per venue. The overall median (25th percentile, 75th percentile) of venue mean air concentrations was 136 (82, 213) μg/m3 for PM2.5, 3.9 (1.7, 22) ppm for CO, 68 (33, 121) ng/m3 for p-PAHs, 1.0 (0.5, 1.9) ng/m3 for NNK, and 5.3 (0.7, 14) μg/m3 for nicotine. PM2.5, CO, and p-PAHs concentrations were generally higher in venues with more waterpipe smokers and cigarette smokers, although associations were not statistically significant. Conclusion: High concentrations of SHS constituents known to cause health effects indicate that indoor air quality in waterpipe tobacco venues may adversely affect the health of employees and customers.
