Risk of cancer among hairdressers and related workers: A meta-analysis

Department of Preventive Medicine, University of Santiago de Compostela, Santiago de Compostela, Spain.
International Journal of Epidemiology (Impact Factor: 9.18). 09/2009; 38(6):1512-31. DOI: 10.1093/ije/dyp283
Source: PubMed


Hairdressers and allied occupations represent a large and fast growing group of professionals. The fact that these professionals are chronically exposed to a large number of chemicals present in their work environment, including potential carcinogens contained in hair dyes, makes it necessary to carry out a systematic evaluation of the risk of cancer in this group.
We retrieved studies by systematically searching Medline and other computerized databases, and by manually examining the references of the original articles and monographs retrieved. We also contacted international researchers working on this or similar topics to complete our search. We included 247 studies reporting relative risk (RR) estimates of hairdresser occupation and cancer of different sites.
Study-specific RRs were weighted by the inverse of their variance to obtain fixed and random effects pooled estimates. The pooled RR of occupational exposure as a hairdresser was 1.27 (95% CI 1.15-1.41) for lung cancer, 1.52 [95% confidence interval (CI) 1.11-2.08] for larynx cancer, 1.30 (95% CI 1.20-1.42) for bladder cancer and 1.62 (95% CI 1.22-2.14) for multiple myeloma. Data for other anatomic sites showed increases of smaller magnitude. The results restricted to those studies carried out before the ban of two major carcinogens from hair dyes in the mid-1970s were similar to the general results.
Hairdressers have a higher risk of cancer than the general population. Improvement of the ventilation system in the hairdresser salons and implementation of hygiene measures aimed at mitigating exposure to potential carcinogens at work may reduce the risk.


Available from: Agustín Montes, Jan 05, 2015
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    • "Based on a review of 42 studies, an increased risk for bladder cancer with statistical significance (among hairdressers) was observed from those with more than 10 years of experience (Harling et al., 2010). In a meta-analysis study, Takkouche et al. (2009) reported the pooled relative risk of occupational exposure of a hairdresser as 1.27 (95% CI 1.15-1.41) for lung cancer, 1.52 [95% CI 1.11-2.08] "
    [Show abstract] [Hide abstract] ABSTRACT: Hair dye products now represent one of the most rapidly growing beauty and personal care industries as both men and women commonly change hair color to enhance youth and beauty and to follow fashion trends. Irrespective of economic and education status, people dye their hair to emphasize the importance given to appearance. Despite adverse reactions, many people continue dyeing mainly for cosmetic purposes. This paper provides a comprehensive review on various aspects of hair dying products, especially with respect to the hair-coloring process, classification, chemical ingredients, possible human health impacts, and regulations. Permanent hair dye, which is the most commonly used product type, is formed by an oxidative process involving arylamines to bring about concerns with long-term exposure. Hence, significant efforts have been put to understand the possible side effects of such exposure including cancer risk. However, hair dyes and their ingredients are mainly identified to have moderate to low acute toxicity such as the cause of allergic contact dermatitis. Although some hair dye components are reported to be carcinogenic in animals, such evidence is not consistent enough in the case of human studies. Consequently, further research is desirable to critically address the significance of this issue, especially with respect to the safety of hair dye ingredients.
    Full-text · Article · Apr 2016 · Environment international
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    • "Interestingly, the latest report from the International Agency for Research on Cancer (IARC) concluded that personal use of hair dye could not be classified as carcinogenic in humans. Since then, two meta-analyses have reported increased risk of bladder cancer [34] and of other types of cancer among hairdressers [35], while a meta-analysis on the personal use of hair dye concluded that there was no excess risk of bladder cancer. However, the risk of other cancer types and the personal use of hair dye are still debated, especially the risk of hematopoietic cancers [36,37]. "
    [Show abstract] [Hide abstract] ABSTRACT: Background: Permanent hair dye contains aromatic amines which are carcinogenic, and can cause allergic skin reactions. In the long term personal use of hair dye might therefore influence both morbidity and mortality. Objectives: We tested the hypothesis that personal use of hair dye in women is associated with increased morbidity and mortality in the general population. Methods: We included 7,684 women from the Copenhagen City Heart Study with information on the use of personal hair dye. We assessed the risk of cancer, skin diseases, other morbidities, and mortality during a median follow-up of 27 years (range 0-37). Results: The multivariable adjusted hazard ratio for malignant melanoma in women with versus without personal use of hair dye was 2.07 (95% confidence interval 1.25-3.42). There was no increased risk of other cancer types. For other skin diseases and other major causes of morbidity we found no differences between the two groups, except for a minor excess of digestive diseases and increased risk of Parkinson's disease among women using hair dye. Finally, we found no difference in all-cause mortality comparing women using personal hair dye or not. After correction for multiple comparisons, none of the results remained significant. However, in sensitivity analysis the excess risk of malignant melanoma remained increased with a hazard ratio of 2.58 (95%CI 1.33-5.03) among users of personal hair dye. Conclusions: Personal use of hair dye does not have major influences on morbidity and mortality. Our finding of a 2-fold risk of malignant melanoma in women using hair dye is hypothesis generating.
    Full-text · Article · Mar 2016 · PLoS ONE
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    • "An IARC Working Group recently concluded that a modest excess risk of ovarian cancer appeared to be linked to the occupation of hairdresser and related occupations, but the lack of adjustment for potential confounders did not allow for confounding to be ruled out [92]. A recent meta-analysis of 10 studies, published between 1977 and 2003 on ovarian cancer among hairdressers and related occupations, concluded that there was a small excess risk of about 16% [93]. An excess risk of the same magnitude was also reported by a recent record-linkage study [51]. "
    [Show abstract] [Hide abstract] ABSTRACT: This review summarizes the epidemiology of cancer of the female reproductive system and associated lifestyle factors. It also assesses the available evidence for occupational factors associated with these cancers. Cervical, endometrial, and ovarian cancers are relatively common, and cause significant cancer morbidity and mortality worldwide, whereas vulvar, vaginal, fallopian tube cancers, and choriocarcinomas are very rare. As several lifestyle factors are known to play a major role in the etiology of these cancers, very few published studies have investigated possible relationships with occupational factors. Some occupational exposures have been associated with increased risks of these cancers, but apart from the available evidence on the relationships between asbestos fibers and ovarian cancer, and tetrachloroethylene and cervical cancer, the data is rather scarce. Given the multifactorial nature of cancers of the female reproductive system, it is of the utmost importance to conduct occupational studies that will gather detailed data on potential individual confounding factors, in particular reproductive history and other factors that influence the body's hormonal environment, together with information on socio-economic status and lifestyle factors, including physical activity from multiple sources. Studies on the mechanisms of carcinogenesis in the female reproductive organs are also needed in order to elucidate the possible role of chemical exposures in the development of these cancers.
    Full-text · Article · Sep 2012 · Safety and Health at Work
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