Airborne exposure and biological monitoring of bar and restaurant workers before and after the introduction of a smoking ban

Abstract
The aims were to assess the impact of a total smoking ban on the level of airborne contaminants and the urinary cotinine levels in the employees in bars and restaurants. In a follow up design, 13 bars and restaurants were visited before and after the implementation of a smoking ban. Ninety-three employees in the establishments were initially included into the study. The arithmetic mean concentration of nicotine and total dust declined from 28.3 μg m−3 (range, 0.4–88.0) and 262 μg m−3 (range, 52–662), respectively, to 0.6 μg m−3 (range, not detected–3.7) and 77 μg m−3 (range, not detected–261) after the smoking ban. The Pearson correlation coefficient between airborne nicotine and total dust was 0.86 (p < 0.001; n = 48). The post-shift geometric mean urinary cotinine concentration declined from 9.5 μg g−1 creatinine (cr) (95% CI 6.5–13.7) to 1.4 μg g−1 cr (95% CI 0.8–2.5) after the ban (p < 0.001) in 25 non-snuffing non-smokers. A reduction from 1444 μg g−1 cr (95% CI 957–2180) to 688 μg g−1 cr (95% CI 324–1458) was found (p < 0.05) in 29 non-snuffing smokers. The urinary cotinine levels increased from 11.7 μg g−1 cr (95% CI 7.0–19.6) post-shift to 21.9 μg g−1 cr (95% CI 13.3–36.3) (p < 0.01) in the next morning in 24 non-snuffing non-smokers before the smoking ban. A substantial reduction of airborne nicotine and total dust was observed after the introduction of a smoking ban in bars and restaurants. The urinary cotinine levels were reduced in non-smokers. The decline found in smokers may suggest a reduction in the amount of smoking after intervention. In non-smokers cotinine concentrations were higher based on urine sampled the morning after a shift than based on urine sampled immediately post-shift.