Background In the absence of comprehensive smoking bans in public places, bars and nightclubs have the highest concentrations of secondhand tobacco smoke, posing a serious health risk for workers in these venues.

Objective To assess exposure of bar and nightclub employees to secondhand smoke, including non-smoking and smoking employees.

Methods Between 2007 and 2009, the authors recruited approximately 10 venues per city and up to five employees per venue in 24 cities in the Americas, Eastern Europe, Asia and Africa. Air nicotine concentrations were measured for 7 days in 238 venues. To evaluate personal exposure to secondhand smoke, hair nicotine concentrations were also measured for 625 non-smoking and 311 smoking employees (N=936).

Results Median (IQR) air nicotine concentrations were 3.5 (1.5–8.5) μg/m³ and 0.2 (0.1–0.7) μg/m³ in smoking and smoke-free venues, respectively. Median (IQR) hair nicotine concentrations were 6.0 (1.6–16.0) ng/mg and 1.7 (0.5–5.5) ng/mg in smoking and non-smoking employees, respectively. After adjustment for age, sex, education, living with a smoker, hair treatment and region, a twofold increase in air nicotine concentrations was associated with a 30% (95% CI 23% to 38%) increase in hair nicotine concentrations in non-smoking employees and with a 10% (2% to 19%) increase in smoking employees.

Conclusions Occupational exposure to secondhand smoke, assessed by air nicotine, resulted in elevated concentrations of hair nicotine among non-smoking and smoking bar and nightclub employees. The high levels of airborne nicotine found in bars and nightclubs and the contribution of this exposure to employee hair nicotine concentrations support the need for legislation measures that ensure complete protection from secondhand smoke in these venues.