Changes in saliva cotinine concentrations between the first and second samples*
| Hospitality workers | ||||||
|---|---|---|---|---|---|---|
| Government employees | Smokefree workplaces | Smoking only in designated areas | No smoking restrictions | All workers in smokefree workplaces | All workers in workplaces that allow smoking | |
| Change in cotinine concentration (second—first sample result)† | A | B | C | D | E (=A+B) | F (=C+D) |
| *The average times between samples were 7.6 and 8.4 hours for hospitality workers in smoking and non-smoking premises, respectively, and 7.2 hours for government employees. | ||||||
| †Setting results less than the limit of detection (0.2 ng/g) at half that value. | ||||||
| ‡Subjects with cotinine increases only. | ||||||
| §Subjects with a decrease in cotinine concentration taken as having no change. Assumes that a decrease is the result of clearance of work unrelated ETS exposure. | ||||||
| Mean pre-shift (ng/g) | 0.12 | 0.37 | 1.12 | 1.60 | 0.16 | 1.30 |
| Mean post-shift (ng/g) | 0.08 | 0.28 | 1.68 | 3.38 | 0.11 | 2.32 |
| Number with decrease | 8 (16%) | 3 (30%) | 6 (30%) | 1 (8%) | 11 (18%) | 7 (22%) |
| Number with no change | 36 (72%) | 5 (50%) | 6 (30%) | 1 (8%) | 41 (68%) | 7 (22%) |
| Number with increase | 6 (12%) | 2 (20%) | 8 (40%) | 10 (83%) | 8 (13%) | 18 (56%) |
| Median (ng/g)‡ | 0.15 | 0.1 | 1.6 | 1.7 | 0.14 | 1.65 |
| Mean (ng/g)‡ | 0.16 | 0.1 | 1.8 | 2.2 | 0.15 | 1.95 |
| Range (ng/g)‡ | 0.08–0.3 | 0.05–0.13 | 0.1–3.6 | 0.2–7 | 0.05–0.3 | 0.1–7.0 |
| Overall mean cotinine increase (ng/g)§ | 0.02 | 0.02 | 0.7 | 1.8 | 0.02 | 1.11 |
| Total number in group | 50 (100%) | 10 (100%) | 20 (100%) | 12 (100%) | 60(100%) | 32(100%) |