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

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 mu g m(-3) (range, 0.4 - 88.0) and 262 mg m(-3) (range, 52 - 662), respectively, to 0.6 mu g m(-3) (range, not detected - 3.7) and 77 mu g 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 mu g g(-1) creatinine (cr) (95% CI 6.5 - 13.7) to 1.4 mu g 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 mg g(-1) cr (95% CI 957 - 2180) to 688 mg 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 mg g(-1) cr ( 95% CI 7.0 - 19.6) post-shift to 21.9 mu g 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.