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Re: Importance of work intensity on respiratory problems of hairdressers

Dear Editor

We read the report by Hollund et al[1] with great interest. We agree that there is limited information about the prevalence of airway symptoms caused by highly reactive chemicals in hairdressing salons. In this well designed study, authors focused on age as a risk factor and observed an increased prevalence of respiratory symptoms among the oldest and youngest hairdressers and observed more symptoms among hairdressers over 40 years of age.

Work intensity, work duration, working conditions, and job titles (master, and fellow hairdresser) should also be considered as risk factors for occupational asthma and respiratory symptoms. With the exception of work intensity, these features have been reported as risk factors in previous studies [2-4]. Work intensity is an objective parameter for evaluating occupational exposures. In our study, we calculated work intensity from the average number of chemical applications (bleaching, dye, and permanent wave)per week and observed a 3.6 times higher risk of occupational asthma among hairdressers with high work intensity (95% CI = 1.2-10.9) with a significant trend (X˛ for trend: 4.9, p: 0.027)[5]. However, we did not observe any excess by work duration, which probably is a result of the healthy-worker effect. Hollund et al. stated that the older hairdressers had more customers than the younger ones, which may be an evidence of higher occupational exposures. If they had used work intensity as more objective criteria than age, they might have prevented possible misclassifications by age.

Working conditions of hairdressers and exposures depend on country and regional variability, which might also affect study results. In the United States and United Kingdom, the term “hairdressers” is inclusive, denoting women’s hairdressers and barbers for man [6]. In Turkey however, the term addresses women’s hair salons only. Most of the studies on hairdressers have been published from Nordic and industrialized countries [7-11]. Studies from developing countries will help to describe the extent of occupational health problems among hairdressers and to identify etiologic factors.

References

(1) Hollund BE, Moen BE, Lygre SH et al. Prevalence of airway symptoms among hairdressers in Bergen, Norway. Occup Environ Med 2001; 58:780-785.

(2) Blainey AD, Ollier S, Cundell D et al. Occupational asthma in a hairdressing salon. Thorax 1986; 41:42-50.

(3) Parra FM, Igea JM, Quirce S et al. Occupational asthma in a hairdresser caused by persulphate salts. Allergy 1992; 47:656-660.

(4) Schwaiblmair M, Vogelmeier C, Fruhmann G. Occupational asthma in hairdressers: results of inhalation tests with bleaching powder. Int Arch Occup Environ Health 1997; 70:419-423.

(5) Akpinar-Elci M, Cimrin AH, Elci OC. Prevalence and risk factors of occupational asthma among hairdressers in Turkey. J Occup Environ Med 2002; (accepted for publication).

(6) Occupational exposures of hairdressers and barbers and personal use of hair colorants; some hair dyes, cosmetic colorants, industrial dyestuffs and aromatic amines. IARC monographs on evaluation of carcinogenic risks to human 1993; 57:43-66.

(7) Leino T, Tammilehto L, Luukkonen R et al. Self-reported respiratory symptoms and diseases among hairdressers. Occup Environ Med 1997; 54:452- 455.

(8) Leino T, Tammilehto L, Paakkulainen H et al. Occurrence of asthma and chronic bronchitis among female hairdressers. A questionnaire study. J Occup Environ Med 1997; 39:534-539.

(9) Leino T, Tammilehto L, Hytonen M et al. Occupational skin and respiratory diseases among hairdressers. Scand J Work Environ Health 1998; 24:398-406.

(10) Leino T, Tuomi K, Paakkulainen H et al. Health reasons for leaving the profession as determined among Finnish hairdressers in 1980-1995. Int Arch Occup Environ Health 1999; 72:56-59.

(11) Hollund BE, Moen BE. Chemical exposure in hairdresser salons: effect of local exhaust ventilation. Ann Occup Hyg 1998; 42:277-282.