Effects of Hair Dyeing on DNA Damage in Human Lymphocytes

The Comet Assay as a Tool in Human Biomonitoring Studies of Environmental and Occupational Exposure to Chemicals-A Systematic Scoping Review

Biomonitoring of human populations exposed to chemical substances that can act as potential mutagens or carcinogens, may enable the detection of damage and early disease prevention. In recent years, the comet assay has become an important tool for assessing DNA damage, both in environmental and occupational exposure contexts. To evidence the role of the comet assay in human biomonitoring, we have analysed original research studies of environmental or occupational exposure that used the comet assay in their assessments, following the PRISMA-ScR method (preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews). Groups of chemicals were designated according to a broad classification, and the results obtained from over 300 original studies (n = 123 on air pollutants, n = 14 on anaesthetics, n = 18 on antineoplastic drugs, n = 57 on heavy metals, n = 59 on pesticides, and n = 49 on solvents) showed overall higher values of DNA strand breaks in the exposed subjects in comparison with the unexposed. In summary, our systematic scoping review strengthens the relevance of the use of the comet assay in assessing DNA damage in human biomonitoring studies.

Risk of Carcinogenicity Associated with Synthetic Hair Dyeing Formulations: A Biochemical View on Action Mechanisms, Genetic Variation and Prevention

Article tries to visualize the potential for carcinogenic trigger in humans with a preference for oxidative synthetic of hair dyeing formulations, especially which belong to the category of permanent colours. According to the International Agency for Cancer, hair dyes for personal use are not strictly classified as carcinogen to humans. However, some controversy exists that requires clarification. Some epidemiological studies support the association between the risk of cancer development and personal use of hair dyes (pooled relative risk RR = 1.50. 95% CI: 1.30-1.98). The world-wide sale of hair dyeing cosmetics have exceeded 15 billion dollars by the year 2012 and has maintained an annual growth rate of 8-10%. This raises concerns and need to be addressed. The review article briefly discusses about the different hair dye components based on their chemical nature, permanence, interaction of dye components with different parts of the hair shaft, action mechanisms, health risk assessment, associated challenges and possible alternatives. There appears variability towards the pathological changes incurred in the human system upon the use of synthetic hair formulations. This probably appears due to the presence of interindividual genetic variation of enzymes handling these xenobiotics. The redox mechanism of major hair dye components appears to be involved in the carcinogenic trigger. Most of the hair dye constituents pose serious health issues. However, we do have few better alternatives to prevent the toxicity associated with hair dye constituents without compromising the need of today's fashion statement and expectations of the youth.

Personal use of hair dyes and risk of leukemia: a systematic literature review and meta-analysis

The objective of this study was to examine the association between personal use of hair dyes and the risk of leukemia. We conducted a systematic literature review of epidemiology studies reporting leukemia‐specific cancer risks among hair dye users, and estimated the meta‐relative risk (meta‐RR) and corresponding 95% confidence interval (95% CI) of leukemia, comparing hair dye users to nonusers. When data from all 20 studies that met the inclusion criteria were combined, ever use of hair dye was associated with a nonstatistically significant increased risk of leukemia, meta‐RR = 1.09 (95% CI: 0.97–1.22). When restricted to studies that adjusted for smoking, ever use of hair dye was not associated with leukemia, meta‐RR = 0.99 (95% CI: 0.76–1.29). A statistically significant increased risk of leukemia was associated with permanent hair dye use (meta‐RR = 1.19 [95% CI: 1.07–1.33]), dark hair dye use (meta‐RR = 1.29 [95% CI: 1.11–1.50]), hair dye use among males (meta‐RR = 1.42 [95% CI: 1.01–2.00]), hair dye use pre‐1980 (meta‐RR = 1.49 [95% CI: 1.21–1.83]), and hair dye use for ≥15 years (meta‐RR = 1.35 [95% CI: 1.13–1.62]). Overall, findings suggest that ever use of hair dye is not a significant risk factor for leukemia. Certain hair dye use characteristics were associated with a statistically significant increased risk, but further research is required to determine whether these associations truly reflect a risk of leukemia due to methodological limitations in the underlying studies.

The effect of work characteristics on dermatologic symptoms in hairdressers

Objectives

Hairdressers in Korea perform various tasks and are exposed to health risk factors such as chemical substances or prolonged duration of wet work. The objective of this study is to provide descriptive statistics on the demographics and work characteristics of hairdressers in Korea and to identify work-related risk factors for dermatologic symptoms in hairdressers.

Methods

1,054 hairdressers were selected and analyzed for this study. Independent variables were exposure to chemical substances, the training status of the hairdressers, and the main tasks required of them, and the dependent variable was the incidence of dermatologic symptoms. The relationships between work characteristics and dermatologic symptoms were evaluated by estimating odds ratios using multiple logistic regression analysis.

Results

Among the 1,054 study subjects, 212 hairdressers (20.1%) complained of dermatologic symptoms, and the symptoms were more prevalent in younger, unmarried or highly educated hairdressers. The main tasks that comprise the majority of the wet work were strictly determined by training status, since 96.5% of staff hairdressers identified washing as their main task, while only 1.5% and 2.0% of master and designer hairdressers, respectively, identified this as their main task. Multiple logistic regressions was performed to estimate odds ratios. While exposure to hairdressing chemicals showed no significant effect on the odds ratio for the incidence of dermatologic symptoms, higher odds ratios of dermatologic symptoms were shown in staff hairdressers (2.70, 95% CI: 1.32 - 5.51) and in hairdressers who perform washing as their main task (2.03, 95% CI: 1.22 - 3.37), after adjusting for general and work characteristics.

Conclusions

This study showed that the training status and main tasks of hairdressers are closely related to each other and that the training status and main tasks of hairdressers are related to the incidence of dermatologic symptoms. This suggests that in the future, regulations on working conditions and health management guidelines for hairdressers should be established.

Micronuclei assessment in the urothelial cells of women using hair dyes and its modulation by genetic polymorphisms

Increases in the frequency of micronuclei (MN) in exposed cells can be used as a measure of genotoxicity. Hair dyes contain chemicals that are eliminated by urine and could be genotoxic to urothelial cells. To address this question, we evaluated whether hair dye use is associated with an increase in the frequency of MN in urothelial cells, and whether this association is modified by NAT1 (N-acetyltransferase 1), NAT2 (N-acetyltransferase 2) and GSTM1 (glutathione-S-transferase M1) genotypes. We included 92 women participating as controls in a bladder cancer case-control study in Spain. Of those, 72 had adequate number of cells to be included in the MN analysis. There were no significant differences in the mean MN frequency in women using hair dyes in the last month (9.88 MN/1000 cells), in comparison with the MN in unexposed women (9.50 MN/1000 cells). No statistically significant differences in MN frequency were observed by type of hair dye or color of the hair dye. Comparison of subjects in the highest quartile of MN frequency (> or = 12 MN/1000 cells) and those in the lowest quartile (< or = 4 MN/1000 cells) suggested an association between hair dye use and elevated MN frequency (OR 14.2 (95% CI 0.81-247.8; P=0.069)). None of the polymorphisms examined significantly modified association between hair dye use and frequency of MN. Findings of an increased frequency of MN in urothelial cells of hair dye users suggest a possible genotoxic effect of hair dye compounds and need confirmation in larger studies.

Single strand dna breaks in human lymphocytes exposed to para-phenylenediamine and its derivatives

Para-Phenylenediamine (PPD), the main aromatic amines used in the hair dye formation, and its four derivatives (2-chloro-p-phenylenediamine, 4-chloro-o-phenylenediamine, 2-nitro-p-phenylenediamine, and 4-nitro-o-phenylenediamine) were examined for their potential to produce single strand DNA breaks in human lymphocytes using the alkaline comet assay. Results revealed that all the tested chemicals within the range of doses from 100 microM to 500 microM showed the genotoxicity in a dose-dependent manner after the incubation of lymphocytes with these chemicals for 2 h. In this study, we first reported that PPD and its four derivatives can elicit the type of single strand breaks in human lymphocytes.

Association between personal use of hair dyes and lymphoid neoplasms in Europe

Hair dyes have been evaluated as possibly being mutagenic and carcinogenic in animals. Studies of the association between human cancer risk and use of hair dyes have yielded inconsistent results. The authors evaluated the risk of lymphoid malignancies associated with personal use of hair dyes. The analysis included 2,302 incident cases of lymphoid neoplasms and 2,417 hospital- or population-based controls from the Czech Republic, France, Germany, Ireland, Italy, and Spain (1998-2003). Use of hair dyes was reported by 74% of women and 7% of men. Lymphoma risk among dye users was significantly increased by 19% in comparison with never use (odds ratio (OR) = 1.19, 95% confidence interval (CI): 1.00, 1.41) and by 26% among persons who used hair dyes 12 or more times per year (OR = 1.26, 95% CI: 1.00, 1.60; p for linear trend = 0.414). Lymphoma risk was significantly higher among persons who had started coloring their hair before 1980 (OR = 1.37, 95% CI: 1.09, 1.72) and persons who had used hair dyes only before 1980 (OR = 1.62, 95% CI: 1.10, 2.40). Personal use of hair dyes is associated with a moderate increase in lymphoma risk, particularly among women and persons who used dyes before 1980. Specific compounds associated with this risk remain to be elucidated.

Regular use of hair dyes and risk of lymphoma in Spain

BACKGROUND

The use of hair dyes has been inconsistently associated with an increased risk of lymphomas. We explore hair dye use and lymphoma risk in a case-control study in Spain.

METHODS

We studied 574 incident lymphoma cases and 616 hospital controls in a multicentric study in Spain. Information on hair dye use was obtained through a personal interview together with information on other known or putative risk factors for lymphoma. Unconditional logistic regression analysis was used to estimate odds ratio (OR) and 95% confidence intervals (95% CI). All ORs were adjusted for pathology center, sex, age, and house ownership.

RESULTS

Ever use of hair dyes was associated with a non-significant 20% increased risk of lymphoma (OR = 1.2, 95% CI 0.9-1.7) with a slightly higher risk observed for those using permanent hair dyes (OR = 1.3, 95% CI 0.9-1.9). No association was observed with duration of use or lifetime doses of hair dyes. Among all lymphomas categories, only chronic lymphocytic leukaemia (CLL) was significantly associated with the use of hair dyes (OR = 2.3, 95% CI 1.1-4.7). The risk of CLL increased with lifetime doses received.

CONCLUSIONS

Ever use of hair dye products is unlikely to substantially modify the risk of lymphoma. The observed association with CLL needs to be replicated.

Hair dye use and risk of lymphoid neoplasms and soft tissue sarcomas

We analyzed the relation between hair dye use and the risk of Hodgkin's disease (HD), non-Hodgkin's lymphoma (NHL), multiple myeloma (MM) and soft tissue sarcomas (STS) in a hospital-based case-control study conducted between 1985 and 1997 in northern Italy. Cases included 158 patients with histologically confirmed incident HD, 446 with NHL, 141 with MM, 221 with STS and controls included 1,295 patients with acute nonneoplastic conditions. Compared to never use of any type of hair dyes, the odds ratio (OR) for ever use was 0.68 (95% confidence interval, CI, 0.40-1.18) for HD, 1.03 (95% CI 0.73-1.44) for NHL, 1.17 (95% CI 0.70-1.97) for MM and 0.73 (95% CI 0.45-1.17) for STS. The OR were close to unity for permanent and semipermanent dyes analyzed separately or when the analysis was restricted to women. Our study indicates that there is no appreciable association between ever use of any type of hair dyes and the risk of HD, NHL, MM or STS.