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.

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Available from: Agustín Montes, Jan 05, 2015
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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]. "
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    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.
    Safety and Health at Work 09/2012; 3(3):166-80. DOI:10.5491/SHAW.2012.3.3.166
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    • "Occupational exposure to hair dyes has been associated with an increased risk of bladder cancer [1, 2]. The International Agency for Research on Cancer (IARC) concludes that hairdressers and barbers are “probably” at greater risk of bladder cancer because of their exposure to hair dyes [3]. "
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    ABSTRACT: Several studies have suggested an increased risk of bladder cancer among hairdressers, who are occupationally exposed to hair dyes. There has also been concern about a possible increased risk of bladder cancer among users of hair dyes. However, the association between personal hair dye use and bladder cancer risk remains inconclusive. In this study, we examined associations between personal use of permanent and temporary hair dyes and bladder cancer risk in a population-based case-control study involving 1,385 cases (n = 246 women) and 4,754 controls (n = 2,587 women). Participants filled out a questionnaire with regard to history of personal hair dye use and risk factors for bladder cancer. Unconditional logistic regression was used to calculate odds ratios (OR) and 95 % confidence intervals (CI), adjusted for age, smoking status, duration of smoking and intensity of smoking. Analyses were restricted to women as less than 5 % of all men in the study ever used hair dyes. About 50 % of the women ever used hair dyes. Use of temporary hair dyes (OR, 0.77; 95 % CI, 0.58-1.02) or use of permanent hair dyes (OR, 0.87; 95 % CI, 0.65-1.18) was not associated with bladder cancer risk. No clear association between hair dyes and bladder cancer risk was found when dye use was defined by type, duration or frequency of use, dye color, or extent of use. Also, results were similar for aggressive- and non-aggressive bladder cancer. Age, educational level, and smoking status did not modify the association between hair dye use and bladder cancer risk. The present study does not support an association between personal hair dye use and bladder cancer risk. Also, various types of hair dye, intensity of exposure to hair dyes or dye color do not appear to be important factors for bladder cancer development.
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    • "MOCA and ortho-toluidine act as mutagens causing bladder cancer in a similar fashion to 4-aminobiphenyl by creating metabolites, which form adducts with DNA [45] [55]. An association between aromatic amines within hair dyes and bladder cancer has been found in multiple epidemiologic studies [56] [57]. Similar to tobacco smoking, the risk for developing cancer may be dependent on gene– environment interactions. "
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    ABSTRACT: Approximately 50% of bladder cancer incidence in the United States has been attributed to known carcinogens, mainly from cigarette smoking. Following the identification of this important causative factor, many investigators have attempted to identify other major causes of bladder cancer in the environment. Genetic and epigenetic alterations related to carcinogenesis in the bladder have been linked to environmental and occupational factors unrelated to cigarette smoking and may account for a significant portion of bladder cancer cases in non-smokers. The interaction between genetics and exposures may modulate bladder cancer risk and influence the differing incidence, progression, and mortality of this disease in different genders and races. Comparative molecular studies are underway to measure the relative effects of environment and inheritance to account for observed differences in the epidemiology of bladder cancer. The use of geospatial tools and population-based data will offer further insight into the environmentally-linked causes of bladder cancer.
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