Frequencies of performed treatments in comparison with haemoglobin (Hb) adduct concentrations among hairdressers
| Haemoglobin adducts (median, pg/g Hb) | ||||||
|---|---|---|---|---|---|---|
| Treatment | Performed treatments/week (N)* | o-Toluidine | m-Toluidine | p-Toluidine | 2,3-DMA | |
| Light-colour permanent hair dye | 0 (32) | 7 | 162 | 72 | 30 | |
| 1–7 (219) | 19 | 178 | 75 | 29 | ||
| 8–14 (39) | ≥8 Treatments (42) | 22 | 184 | 84 | 32 | |
| >15 (3) | ||||||
| p Value | 0.076 | 0.080 | 0.34 | 0.59 | ||
| Other permanent hair dye | 0 (0) | ≥0–7 (194) | 14 | 172 | 76 | 30 |
| 1–7 (194) | ||||||
| 8–14 (88) | 21 | 190 | 81 | 28 | ||
| >15 (10) | 14 | 186 | 73 | 28 | ||
| p Value | 0.46 | 0.026 | 0.73 | 0.41 | ||
| Intensive semi-permanent hair dye | 0 (12) | 7 | 193 | 128 | 24 | |
| 1–7 (227) | 18 | 176 | 76 | 30 | ||
| 8–14 (47) | ≥8 Treatments (51) | 20 | 185 | 74 | 28 | |
| >15 (4) | ||||||
| p Value | 0.32 | 0.50 | 0.23 | 0.59 | ||
| Semi-permanent hair dye | 0 (93) | 15 | 181 | 74 | 29 | |
| 1–7 (165) | 16 | 175 | 76 | 31 | ||
| 8–14 (28) | ≥8 Treatments (31) | 22 | 185 | 82 | 23 | |
| >15 (3) | ||||||
| p Value | 0.79 | 0.81 | 0.90 | 0.81 | ||
| Hair waving | 0 (156) | 14 | 182 | 76 | 31 | |
| 1–7 (136) | ≥1 Treatments (139) | 22 | 176 | 76 | 27 | |
| 8–14 (2) | ||||||
| >15 (1) | ||||||
| p Value | 0.020 | 0.19 | 0.94 | 0.020 | ||
| Bleaching | 0 (3) | ≥0–7 (223) | 17 | 176 | 77 | 30 |
| 1–7 (220) | ||||||
| 8–14 (66) | ≥8 Treatments (72) | 20 | 186 | 73 | 26 | |
| >15 (6) | ||||||
| p Value | 0.69 | 0.35 | 0.56 | 0.29 | ||
| Conditioning with pigment | 0 (111) | 13 | 178 | 83 | 28 | |
| 1–7 (129) | 20 | 176 | 66 | 33 | ||
| 8–14 (25) | 19 | 179 | 75 | 30 | ||
| >15 (14) | 14 | 180 | 75 | 18 | ||
| p Value | 0.13 | 0.55 | 0.027 | 0.26 | ||
*For performed treatments/week and statistical analysis, categories with fewer than five cases were included in the adjacent category. Differences between the performed treatments/week were calculated with the Jonckheere–Terpestra test for trend. Hb adducts of 2-EA, 3-EA, 4-EA and 3,4-DMA are not shown in the table since most of the samples were below the LOD.
EA, ethylaniline; DMA, dimethylaniline; LOD, limit of detection.