Nicotine concentrations before and after the introduction of a partial smoking ban in a Swiss prison
| Location | Before the ban (μg/m3) | After the ban (μg/m3) |
| Security staff room | 1 | 2 |
| Common living room in open living unit, under the roof | 14 | 3 |
| Occupational working unit, break area | 15 | 2 |
| Occupational working unit, sanding wood area | 4 | 2 |
| Snooker room | 6 | 2 |
| Common eating room (cafeteria) | 8 | 2 |
| Mechanic work area, break area | 17 | 2 |
| Mechanic work area, welding post | 2 | 2 |
| Carpentry, break area | 2 | 1 |
| Farmers' break room | <1 | 3 |
A paired t test comparison grouping the 10 sites where nicotine was measured both before and after the ban showed a statistically significant change (p=0.03, t=2.53, 95% CI for difference of means: 0.52 to 9.28, mean before: 7.0 μg/m3, after: 2.1 μg/m3, difference: 4.9 μg/m3).
Nicotine comparative value measured locally outdoors was below the limit of detection (0.2 μg/m3 for a total volume of 57 L sampled air).