Relation between hairdressing activities and changes in baseline lung function parameters
| Occupational factors (n) | ΔFVC* | ΔFEV1* | ΔFEV1/FVC† | ΔFEF25–75%* | Δ methacholine slope‡ | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mean | SD | p | Mean | SD | p | Mean | SD | p | Mean | SD | p | Mean | SD | p | |
| *Δ: % predicted at the final phase − % predicted at the initial phase. | |||||||||||||||
| †FEV1/FVC at the final phase − FEV1/FVC at the initial phase. | |||||||||||||||
| ‡Methacholine dose-response slope, defined by the percent decline in FEV1 divided by the final cumulative dose of methacholine administered, expressed as log(slope+0.02). Change in methacholine slope defined as log(slope+0.02) at the final phase − log(slope+0.02) at the initial phase. | |||||||||||||||
| §Answer “no” corresponds to the absence of a technical area or the presence of a non-ventilated technical area. | |||||||||||||||
| ¶Answer “no” corresponds to the presence of a door or a window or presence of non-functioning mechanical ventilation. “Yes” functioning mechanical ventilation. | |||||||||||||||
| Permanent waves | |||||||||||||||
| <1/day (19) | −3.7 | 9.0 | −5.3 | 9.1 | −1.2 | 4.3 | −7.8 | 17.1 | 0.07 | 0.16 | |||||
| 1–4/day (74) | 0 | 7.5 | 0.11 | 0.7 | 8.2 | 0.01 | −0.6 | 4.2 | 0.04 | −1.7 | 13.5 | 0.01 | 0.03 | 0.20 | 0.70 |
| ⩾5/day (26) | −2.0 | 4.8 | −5.5 | 7.6 | −3.0 | 3.5 | −11.1 | 13.8 | 0.06 | 0.18 | |||||
| Dyeing | |||||||||||||||
| <l/day (5) | −5.7 | 8.0 | −3.6 | 10.8 | 1.9 | 2.0 | −1.2 | 23.7 | 0.17 | 0.29 | |||||
| 1–4/day (51) | −0.3 | 6.7 | 0.29 | −1.4 | 8.1 | 0.48 | −0.9 | 5.2 | 0.11 | −2.0 | 16.0 | 0.14 | 0.04 | 0.22 | 0.43 |
| ⩾5/day (63) | −1.2 | 7.8 | −3.3 | 8.6 | −1.8 | 3.1 | −7.3 | 12.3 | 0.04 | 0.16 | |||||
| Bleaching | |||||||||||||||
| <1/day (60) | −1.4 | 8.0 | −3.4 | 8.4 | −1.7 | 3.6 | −6.3 | 14.3 | 0.07 | 0.19 | |||||
| 1–5/day (49) | −0.3 | 6.6 | 0.69 | −1.4 | 8.0 | 0.41 | −0.6 | 4.9 | 0.40 | −2.8 | 15.1 | 0.47 | 0.02 | 0.20 | 0.36 |
| ⩾5/day (10) | −1.8 | 7.4 | −2.1 | 11.0 | −1.4 | 3.1 | −5.4 | 14.2 | 0.02 | 0.11 | |||||
| Surface area (m2) | |||||||||||||||
| <38 (30) | −1.5 | 5.5 | −2.9 | 6.6 | −1.1 | 4.1 | −3.3 | 16.1 | 0.04 | 0.16 | |||||
| 38–50 (29) | −0.4 | 6.7 | 0.70 | −1.6 | 9.3 | 0.76 | −1.2 | 4.5 | 0.96 | −3.9 | 17.6 | 0.85 | 0.05 | 0.17 | 0.23 |
| 51–70 (25) | −0.8 | 7.9 | −2.4 | 8.8 | −1.5 | 3.1 | −6.5 | 12.0 | 0.03 | 0.14 | |||||
| >70 (18) | −3.0 | 10.8 | −4.3 | 9.4 | −0.9 | 4.4 | −5.9 | 13.2 | 0.14 | 0.27 | |||||
| Technical area§ | |||||||||||||||
| No (55) | −1.5 | 6.9 | −3.2 | 8.5 | −1.4 | 4.4 | −6.2 | 17.0 | 0.06 | 0.17 | 0.98 | ||||
| Yes (46) | −1.0 | 8.4 | 0.71 | −1.9 | 8.4 | 0.71 | −1.0 | 3.5 | 0.63 | −3.0 | 12.4 | 0.30 | 0.05 | 0.18 | |
| Mechanical ventilation¶ | |||||||||||||||
| No (64) | −1.0 | 6.4 | 0.45 | −2.4 | 7.7 | 0.81 | −1.4 | 4.1 | 0.26 | −4.7 | 16.0 | 0.06 | 0.20 | ||
| Yes (29) | −2.3 | 9.7 | −2.9 | 9.5 | −0.4 | 3.7 | −3.4 | 12.2 | 0.69 | 0.06 | 0.17 | 0.97 | |||