(HealthDay News) — Hairdressers who use permanent hair dyes and hair waving treatments may be exposed to potentially carcinogenic substances, including toluidines, according to research published online June 9 in Occupational & Environmental Medicine.

Gabriella M. Johansson, of Lund University in Sweden, and colleagues collected lifestyle data and analyzed blood samples for potentially carcinogenic aromatic amines in 295 hairdressers, 32 users of hair dyes, and 60 controls. All participants were female nonsmokers.

The researchers observed no significant differences in adduct concentrations among hairdressers, consumers, or controls. Among hairdressers, concentrations of ortho (o)-toluidine and meta (m)-toluidine increased significantly with weekly number of episodes of hair waving (P=0.020) and permanent hair dyeing treatments (P=0.026), respectively. Increased concentrations of o-toluidine (P=0.076) and m-toluidine (P=0.080) were associated with the frequency of light-color permanent hair dye treatments.

“Analyses of hair waving and hair dye products should be performed to identify the possible sources of exposure to o- and m-toluidine,” the authors write.

Full Text