Exposure of hairdressers to ortho- and meta-toluidine in hair dyes
- Gabriella M Johansson1,
- Bo A G Jönsson1,
- Anna Axmon2,
- Christian H Lindh2,
- Marie-Louise Lind3,
- Mats Gustavsson2,
- Karin Broberg2,
- Anders Boman3,
- Birgitta Meding3,
- Carola Lidén3,
- Maria Albin1
- 1Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, Lund, Sweden
- 2Department of Occupational and Environmental Medicine, University and Regional Laboratories Region Skåne, Lund, Sweden
- 3Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
- Correspondence to Gabriella Johansson, Division of Occupational and Environmental Medicine, SUS Lund, Lund SE-221 85, Sweden;
- Received 31 October 2013
- Revised 16 March 2014
- Accepted 29 March 2014
- Published Online First 9 June 2014
Background Carcinogenic aromatic amines derived from hair dyes have recently received new attention. One of these is ortho (o)-toluidine, which is classified as carcinogenic to humans.
Objectives To clarify exposure of hairdressers to potentially carcinogenic aromatic amines, including o-toluidine.
Methods We measured eight potentially carcinogenic aromatic amines in the blood of 295 hairdressers, 32 users of hair dyes and 60 controls. The study was restricted to female non-smokers. Lifestyle data were collected for all participants using self-administered questionnaires. Blood samples were taken for analysis of ortho-, meta (m)- and para (p)-toluidine; 2-, 3- and 4-ethylaniline, 2,3- and 3,4-dimethylaniline as haemoglobin adducts. The samples were analysed with gas chromatography–tandem mass spectrometry.
Results Generally, adduct concentrations were in the range of 0–200 pg/g haemoglobin. A comparison of the adduct concentrations found in hairdressers, consumers and controls showed no statistically significant differences. However, for hairdressers, o- and m-toluidine concentrations increased significantly with the weekly number of hair waving (p=0.020) and permanent hair dyeing treatments (p=0.026), respectively. o-Toluidine and m-Toluidine concentrations also tended (p=0.076 and 0.080, respectively) to increase with the frequency of light-colour permanent hair dye treatments.
Conclusions Hairdressers who use light-colour permanent hair dyes, other permanent hair dyes and hair waving treatments seem to be exposed to o- and m-toluidine as indicated by associations with the number of treatments performed. Analyses of hair waving and hair dye products should be performed to identify the possible sources of exposure to o- and m-toluidine.
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