Concentrations of haemoglobin (Hb) adducts among hairdressers, consumers and controls
| Hb adduct | Group | Samples >LOD* (n, %) | Median (pg/g Hb) | p Value† | 95th Centile (pg/g Hb) | High‡ n (%) | OR (CI) for high Hb-adduct concentration§ |
|---|---|---|---|---|---|---|---|
| o-Toluidine | Hairdresser | 168 (57) | 18 | 0.50 | 320 | 27 (9) | 1.91 (0.56 to 6.5) |
| Consumer | 15 (47) | 7 | 0.81 | 290 | 2 (6) | 1.27 (0.20 to 8.0) | |
| Control | 34 (57) | 14 | 60 | 3 (5) | 1.0 (Reference) | ||
| m-Toluidine | Hairdresser | 288 (98) | 180 | 0.51 | 330 | 12 (4) | 0.81 (0.22 to 2.9) |
| Consumer | 31 (97) | 180 | 0.62 | 440 | 2 (6) | 1.27 (0.20 to 8.0) | |
| Control | 58 (97) | 190 | 370 | 3 (5) | 1.0 (Reference) | ||
| p-Toluidine | Hairdresser | 241 (82) | 80 | 0.62 | 210 | 14 (5) | 0.95 (0.26 to 3.4) |
| Consumer | 27 (84) | 90 | 0.16 | 240 | 3 (9) | 1.97 (0.37 to 10.4) | |
| Control | 53 (88) | 70 | 210 | 3 (5) | 1.0 (Reference) | ||
| 2,3-DMA | Hairdresser | 259 (88) | 30 | 0.028 | 220 | 8 (3) | 0.53 (0.14 to 2.1) |
| Consumer | 28 (88) | 30 | 0.098 | 550 | 2 (6) | 1.27 (0.20 to 8.0) | |
| Control | 60 (100) | 40 | 380 | 3 (5) | 1.0 (Reference) |
*For o-, m- and p-toluidine, and 2,3-DMA, <50% of samples were below the LOD. For the remaining adducts, >50% of the samples were below LOD and are not presented.
†p Value (Mann–Whitney U test) for the median concentration of hairdressers and consumers, respectively, compared with the control group.
‡High is here defined as samples exceeding the 95th centile of the controls’ concentrations.
§ORs, with 95% CIs, for high concentrations obtained through binary logistic regression.
DMA, dimethylaniline; LOD, limit of detection.