Table 6

Relation between hairdressing activities and changes in baseline lung function parameters

Occupational factors (n)ΔFVC*ΔFEV1*ΔFEV1/FVC†ΔFEF25–75%*Δ methacholine slope‡
MeanSDpMeanSDpMeanSDpMeanSDpMeanSDp
*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)−3.79.0−5.39.1−1.24.3−7.817.10.070.16
    1–4/day (74)07.50.110.78.20.01−0.64.20.04−1.713.50.010.030.200.70
    ⩾5/day (26)−2.04.8−5.57.6−3.03.5−11.113.80.060.18
Dyeing
    <l/day (5)−5.78.0−3.610.81.92.0−1.223.70.170.29
    1–4/day (51)−0.36.70.29−1.48.10.48−0.95.20.11−2.016.00.140.040.220.43
    ⩾5/day (63)−1.27.8−3.38.6−1.83.1−7.312.30.040.16
Bleaching
    <1/day (60)−1.48.0−3.48.4−1.73.6−6.314.30.070.19
    1–5/day (49)−0.36.60.69−1.48.00.41−0.64.90.40−2.815.10.470.020.200.36
    ⩾5/day (10)−1.87.4−2.111.0−1.43.1−5.414.20.020.11
Surface area (m2)
    <38 (30)−1.55.5−2.96.6−1.14.1−3.316.10.040.16
    38–50 (29)−0.46.70.70−1.69.30.76−1.24.50.96−3.917.60.850.050.170.23
    51–70 (25)−0.87.9−2.48.8−1.53.1−6.512.00.030.14
    >70 (18)−3.010.8−4.39.4−0.94.4−5.913.20.140.27
Technical area§
    No (55)−1.56.9−3.28.5−1.44.4−6.217.00.060.170.98
    Yes (46)−1.08.40.71−1.98.40.71−1.03.50.63−3.012.40.300.050.18
Mechanical ventilation¶
    No (64)−1.06.40.45−2.47.70.81−1.44.10.26−4.716.00.060.20
    Yes (29)−2.39.7−2.99.5−0.43.7−3.412.20.690.060.170.97