Personal use of hair dye and cancer risk in a prospective cohort of Chinese women

4-Chloro-orthophenylenediamine alters DNA integrity and affects cell survival: inferences from a computational, biophysical/biochemical, microscopic and cell-based study

The deleterious impact of toxic constituents of hair dyes over the human health has gained immense attention in the recent past. Their oncogenicity, mutagenicity, role in protein modification, impact on cellular metabolism has been documented. There is little information on the mechanism of reactivity of hair dye components with the nucleic acids and its implications. This work, therefore, uses computational, biophysical/biochemical, microscopic and cell-based study to analyze the interaction of monocyclic aromatic amine and a hair dye component, 4-chloro-orthophenylenediamine (4-Cl-OPD) with the DNA, its impact on DNA structure and cell survival. The results suggest that 4-Cl-OPD binds with the DNA in minor groove of the duplex involving three base pairs preferentially the G-C residues, induces strand breaks and makes DNA thermally labile through loss of hydrogen bonding/base unstacking. 4-Cl-OPD causes fragmentation of DNA, reduction in size of the molecule, alters B-DNA conformation and disrupts its secondary structure. The modified DNA gives fragmented appearance, shows broken strands and aggregation in ultra-structural analysis. 4-Cl-OPD induces ROS generation in lymphocytes, increases the comet's average tail length and reduces the viability of lymphocytes. This study forms a base for establishing the direct toxicity of 4-Cl-OPD at the molecular and cellular level through direct production of superoxide radicalCommunicated by Ramaswamy H. Sarma.

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.

Associations of hair dye and relaxer use with breast tumor clinicopathologic features: Findings from the Women's circle of Health Study

BACKGROUND

Building upon our earlier findings of significant associations between hair dye and relaxer use with increased breast cancer risk, we evaluated associations of select characteristics of use with breast tumor clinicopathology.

METHODS

Using multivariable-adjusted models we examined the associations of interest in a case-only study of 2998 women with breast cancer, overall and stratified by race and estrogen receptor (ER) status, addressing multiple comparisons using Bonferroni correction.

RESULTS

Compared to salon application of permanent hair dye, home kit and combination application (both salon and home kit application) were associated with increased odds of poorly differentiated tumors in the overall sample. This association was consistent among Black (home kit: OR 2.22, 95 % CI: 1.21-5.00; combination: OR 2.46, 95 % CI: 1.21-5.00), but not White women, and among ER+ (home kit: OR 1.47, 95 % CI: 0.82-2.63; combination: OR 2.98, 95 % CI: 1.62-5.49) but not ER-cases. Combination application of relaxers was associated with increased odds of tumors >2.0 cm vs. <1.0 cm (OR = 1.82, 95 % CI: 1.23-2.69). Longer duration and earlier use of relaxers and combination application of permanent hair dyes and relaxers were associated with breast tumor features including higher tumor grade and larger tumor size, which often denote more aggressive phenotypes, although the findings did not maintain significance with Bonferroni correction.

CONCLUSIONS

These novel data support reported associations between hair dye and relaxer use with breast cancer, showing for the first time, associations with breast tumor clinicopathologic features. Improved hair product exposure measurement is essential for fully understanding the impact of these environmental exposure with breast cancer and to guide risk reduction strategies in the future.

Sorptive removal of methylene blue from water by magnetic multi-walled carbon nanotube composites

In the present study, five magnetic multi-walled carbon nanotubes (MMWCNTs) with different diameters were prepared and their performance on the sorptive removal of methylene blue (MB) from water was investigated. Transmission electron microscope, scanning electron microscope, Fourier transform infrared spectrometer, X-ray diffraction, and vibrating sample magnetometer confirm that the surface of these MMWCNTs has been decorated by Fe₃O₄ nanoparticles, which renders the MMWCNTs superparamagnetic. Thus, these MMWCNTs can be easily separated from water after the adsorption. During the adsorption process, pH slightly affected the removal efficiency of MB and the adsorption performed better under weak alkaline conditions. Adsorption kinetics followed the pseudo-second-order kinetic model well, and the Dubinin-Radushkevich model fitted the isotherms best. The maximum adsorption capacity for MB reached 204.2 mg/g, and the values decreased with increasing diameters of MMWCNTs due to decreasing specific surface areas. The thermodynamics parameters indicated the spontaneous and exothermic nature of the adsorption. The reusability test showed that MMWCNTs could be used for 6 cycles without significant loss of the adsorption capacity. And common ions (K⁺, Na⁺, Ca²⁺ and Al³⁺) and SDS in water did not show greatly effects on the removal efficiency of MB. Hence, MMWCNTs prepared in this study could be promising adsorbents for dyes removal from wastewater.

Analysis of mutagenic components of oxidative hair dyes with the Ames test

Oxidative hair dyes consist of two components (I and II) that are mixed before use. Aromatic amines in component I and their reaction with hydrogen peroxide after mixing them with component II have been of primary concern. In addition, two in vitro genotoxicity assays are still required for the approval of the final products of oxidative hair dyes in China, and the substance in the oxidative hair dye that causes the high rate of positive results in genotoxicity tests, especially the Ames test, has not been fully elucidated. In this study, we analyzed the formulation of 55 different oxidative hair dyes from 7 color series and performed Ames tests in the strain TA98 with the S9 mix (oxidative hair dyes No. 1-30) and in strain TA97a without the S9 mix (oxidative hair dyes No. 31-55). We found that toluene-2,5-diamine sulfate (2,5-diaminotoluene sulfate, DATS) in component I may be the cause of mutagenicity in TA98, and hydrogen peroxide in component II may be the cause of mutagenicity in TA97a, and their positive concentrations were consistent with those that we calculated from Ames tests. The results suggest that the positive results for the oxidative hair dye in the Ames test were inevitable because of the existence of DATS in component I and of hydrogen peroxide in component II. Therefore, we should carry out safety assessments on each raw material and carry out risk assessments on the final products of oxidative hair dyes instead of genotoxicity tests in China.

Adolescent use of hair dyes, straighteners and perms in relation to breast cancer risk

Hair products can contain hormonally active and carcinogenic compounds. Adolescence may be a period of enhanced susceptibility of the breast tissue to exposure to chemicals. We therefore evaluated associations between adolescent hair product use and breast cancer risk. Sister Study participants (ages 35-74 years) who had completed enrollment questionnaires (2003-2009) on use of hair dyes, straighteners/relaxers and perms at ages 10 to 13 years (N = 47 522) were included. Cox proportional hazards regression was used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs) for associations between hair products and incident breast cancer (invasive cancer or ductal carcinoma in situ), with consideration of heterogeneity by menopausal status and race/ethnicity. Over an average of 10 years of follow-up, 3380 cases were diagnosed. Frequent use of straighteners and perms was associated with a higher risk of premenopausal (HR = 2.11, 95% CI: 1.26-3.55 and HR = 1.55, 95% CI: 0.96-2.53, respectively) but not postmenopausal breast cancer (HR = 0.99, 95% CI: 0.76-1.30 and HR = 1.09, 95% CI: 0.89-1.35, respectively). Permanent hair dye use during adolescence was uncommon (<3%) and not associated with breast cancer overall (HR = 0.97, 95% CI: 0.78-1.20), though any permanent dye use was associated with a higher risk among black women (HR = 1.77, 95% CI: 1.01-3.11). Although frequency of use of perms (37% non-Hispanic white vs 9% black) and straighteners (3% non-Hispanic white vs 75% black) varied by race/ethnicity, associations with breast cancer did not. Use of hair products, specifically perms and straighteners, during adolescence may be associated with a higher risk of premenopausal breast cancer.

Hair chemicals may increase breast cancer risk: A meta-analysis of 210319 subjects from 14 studies

BACKGROUND

The association between personal hair dye use and breast cancer risk is currently debated. The aim of this work is to investigate the association between the use of hair care products and breast cancer risk in women.

METHODS

Based on the PRISMA-IPD statement, the PubMed, Embase, Cochrane Library, Web of Science, OVID and Scopus databases were used to identify eligible studies published from inception to 22 April 2020. A pooled odds ratio (OR) with a 95% confidential interval (CI) was calculated to assess this correlation via fixed- or random-effect Mantel-Haenszel models using a heterogeneity Chi2 test with a significance level of p<0.1. All statistical tests were performed using StataSE software (version 12.0).

RESULTS

The analyzed data comprised 14 eligible studies with 210319 unique subjects. The pooled results suggested that there was a significant association between the use of hair dyes and breast cancer occurrence (pooled OR = 1.07; 95% CI, 1.01-1.13). Regarding the individual analysis regarding the different types of hair chemicals, permanent hair dye users (pooled OR = 1.08; 95% CI, 1.03-1.14) and rinse users (pooled OR = 1.17; 95% CI, 1.02-1.35) were both found to have a significantly elevated breast cancer risk compared to natural hair subjects, whereas there was an insignificant relationship between the use of semipermanent hair dyes (pooled OR = 1.09; 95% CI, 0.92-1.28) and straighteners (pooled OR = 1.04; 95% CI, 0.96-1.14) and breast cancer risk. No impact on the overall correlation between hair dyes and breast cancer risk due to race (White vs non-White) (pooled OR = 1.05; 95% CI, 0.86-1.29), timing of use (<10 years vs ≥10 years) (pooled OR = 0.96; 95% CI, 0.85-1.08) or dye color (Darker than natural hair vs Lighter than natural hair) (pooled OR = 0.91; 95% CI, 0.62-1.32) was found.

CONCLUSIONS

Chemicals in hair dyes may play a role in breast carcinogenesis and increase breast cancer risk.

Environmental exposures and breast cancer risk in the context of underlying susceptibility: A systematic review of the epidemiological literature

BACKGROUND

The evidence evaluating environmental chemical exposures (ECE) and breast cancer (BC) risk is heterogeneous which may stem in part as few studies measure ECE during key BC windows of susceptibility (WOS). Another possibility may be that most BC studies are skewed towards individuals at average risk, which may limit the ability to detect signals from ECE.

OBJECTIVES

We reviewed the literature on ECE and BC focusing on three types of studies or subgroup analyses based on higher absolute BC risk: BC family history (Type 1); early onset BC (Type 2); and/or genetic susceptibility (Type 3).

METHODS

We systematically searched the PubMed database to identify epidemiologic studies examining ECE and BC risk published through June 1, 2019.

RESULTS

We identified 100 publications in 56 unique epidemiologic studies. Of these 56 studies, only 2 (3.6%) were enriched with BC family history and only 11% of studies (6/56) were specifically enriched with early onset cases. 80% of the publications from these 8 enriched studies (Type 1: 8/10 publications; Type 2: 8/10 publications) supported a statistically significant association between ECE and BC risk including studies of PAH, indoor cooking, NO₂, DDT; PCBs, PFOSA; metals; personal care products; and occupational exposure to industrial dyes. 74% of Type 3 publications (20/27) supported statistically significant associations for PAHs, traffic-related air pollution, PCBs, phthalates, and PFOSAs in subgroups of women with greater genetic susceptibility due to variants in carcinogen metabolism, DNA repair, oxidative stress, cellular apoptosis and tumor suppressor genes.

DISCUSSION

Studies enriched for women at higher BC risk through family history, younger age of onset and/or genetic susceptibility consistently support an association between an ECE and BC risk. In addition to measuring exposures during WOS, designing studies that are enriched with women at higher absolute risk are necessary to robustly measure the role of ECE on BC risk.

Hair dye and chemical straightener use and breast cancer risk in a large US population of black and white women

Many hair products contain endocrine-disrupting compounds and carcinogens potentially relevant to breast cancer. Products used predominately by black women may contain more hormonally-active compounds. In a national prospective cohort study, we examined the association between hair dye and chemical relaxer/straightener use and breast cancer risk by ethnicity. Sister Study participants (n = 46,709), women ages 35-74, were enrolled between 2003 and 2009, and had a sister with breast cancer but were breast cancer-free themselves. Enrollment questionnaires included past 12-month hair product use. Cox proportional hazards models estimated adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs) for the association between hair products and breast cancer; effect measure modification by ethnicity was evaluated. During follow-up (mean = 8.3 years), 2,794 breast cancers were identified. Fifty-five percent of participants reported using permanent dye at enrollment. Permanent dye use was associated with 45% higher breast cancer risk in black women (HR = 1.45, 95% CI: 1.10-1.90), and 7% higher risk in white women (HR = 1.07, 95% CI: 0.99-1.16; heterogeneity p = 0.04). Among all participants, personal straightener use was associated with breast cancer risk (HR = 1.18, 95% CI 0.99-1.41); with higher risk associated with increased frequency (p for trend = 0.02). Nonprofessional application of semipermanent dye (HR = 1.28, 95% CI 1.05-1.56) and straighteners (HR = 1.27, 95% CI 0.99-1.62) to others was associated with breast cancer risk. We observed a higher breast cancer risk associated with any straightener use and personal use of permanent dye, especially among black women. These results suggest that chemicals in hair products may play a role in breast carcinogenesis.

A Meta-Analysis on the Relationship Between Hair Dye and the Incidence of Non-Hodgkin's Lymphoma

BACKGROUND

Epidemiologic studies have suggested hair dye to be a risk factor for many cancers. However, previous studies on the association between the personal use of hair dye and risk of non-Hodgkin's lymphoma (NHL) have been inconclusive.

METHODS

The PubMed, Embase, Cochrane Library, and Web of Science databases, as well as the references cited in included studies, were searched for relevant studies up to February 10, 2015. Odds ratios (OR) with 95% confidence intervals (CI) were applied to assess the strength of the association. Publication bias was evaluated using a funnel plot by Egger's and Begg's tests.

RESULTS

A total of 16 studies were included in the analysis, including 13 case-control studies and 3 cohort studies. The present meta-analysis results revealed that the risk of NHL in a high population of hair dye users was 14% (OR 1.14, 95% CI 1.01-1.29). Furthermore, individuals who used more than 20 pack-years of hair dye had increased risk of NHL.

CONCLUSION

The outcomes indicate that hair dye use increases the risk of NHL, especially for females. Hence, people who frequently use hair dyes or have been using hair dyes for more than 20 years should minimize their exposure to hair dye products to prevent the risk of NHL.

Measurement of endocrine disrupting and asthma-associated chemicals in hair products used by Black women

BACKGROUND

Personal care products are a source of exposure to endocrine disrupting and asthma-associated chemicals. Because use of hair products differs by race/ethnicity, these products may contribute to exposure and disease disparities.

OBJECTIVE

This preliminary study investigates the endocrine disrupting and asthma-associated chemical content of hair products used by U.S. Black women.

METHODS

We used gas chromatography/mass spectrometry (GC/MS) to test 18 hair products in 6 categories used by Black women: hot oil treatment, anti-frizz/polish, leave-in conditioner, root stimulator, hair lotion, and relaxer. We tested for 66 chemicals belonging to 10 chemical classes: ultraviolet (UV) filters, cyclosiloxanes, glycol ethers, fragrances, alkylphenols, ethanolamines, antimicrobials, bisphenol A, phthalates, and parabens.

RESULTS

The hair products tested contained 45 endocrine disrupting or asthma-associated chemicals, including every targeted chemical class. We found cyclosiloxanes, parabens, and the fragrance marker diethyl phthalate (DEP) at the highest levels, and DEP most frequently. Root stimulators, hair lotions, and relaxers frequently contained nonylphenols, parabens, and fragrances; anti-frizz products contained cyclosiloxanes. Hair relaxers for children contained five chemicals regulated by California's Proposition 65 or prohibited by EU cosmetics regulation. Targeted chemicals were generally not listed on the product label.

CONCLUSIONS

Hair products used by Black women and children contained multiple chemicals associated with endocrine disruption and asthma. The prevalence of parabens and DEP is consistent with higher levels of these compounds in biomonitoring samples from Black women compared with White women. These results indicate the need for more information about the contribution of consumer products to exposure disparities. A precautionary approach would reduce the use of endocrine disrupting chemicals in personal care products and improve labeling so women can select products consistent with their values.

Cosmetics and Cancer: Adverse Event Reports Submitted to the Food and Drug Administration

There have been numerous controversies surrounding cosmetic products and increased cancer risk. Such controversies include associations between parabens and breast cancer, hair dyes and hematologic malignancies, and talc powders and ovarian cancer. Despite the prominent media coverage and numerous scientific investigations, the majority of these associations currently lack conclusive evidence. In 2016, the US Food and Drug Administration (FDA) made publically available all adverse event reports in Center for Food Safety and Applied Nutrition's Adverse Event Reporting System (CAERS), which includes complaints related to cosmetic products. We mined CAERS for cancer-related reports attributed to cosmetics. Between 2004 and 2017, cancer-related reports caused by cosmetics represented 41% of all adverse events related to cosmetics. This yielded 4427 individual reports of cancer related to a cosmetic product. Of these reports, the FDA redacted the specific product names in 95% of cancer-related reports under the Freedom of Information Act exemptions, most likely due to ongoing legal proceedings. For redacted reports, ovarian cancer reports dominated (n = 3992, 90%), followed by mesothelioma (n = 92, 2%) and malignant neoplasm unspecified (n = 46, 1%). For nonredacted reports, or those reports whose product names were not withheld (n = 218), 70% were related to ovarian cancer attributed to talc powders, followed by skin cancer (11%) and breast cancer (5%) attributed to topical moisturizers. Currently, CAERS is of limited utility, with the available data having been subjected to significant reporter bias and a lack of supportive information such as demographic data, medical history, or concomitant product use. Although the system has promise for safeguarding public health, the future utility of the database requires broader reporting participation and more complete reporting, paired with parallel investments in regulatory science and improved molecular methods.

Environmental chemicals and breast cancer: An updated review of epidemiological literature informed by biological mechanisms

BACKGROUND

Many common environmental chemicals are mammary gland carcinogens in animal studies, activate relevant hormonal pathways, or enhance mammary gland susceptibility to carcinogenesis. Breast cancer's long latency and multifactorial etiology make evaluation of these chemicals in humans challenging.

OBJECTIVE

For chemicals previously identified as mammary gland toxicants, we evaluated epidemiologic studies published since our 2007 review. We assessed whether study designs captured relevant exposures and disease features suggested by toxicological and biological evidence of genotoxicity, endocrine disruption, tumor promotion, or disruption of mammary gland development.

METHODS

We systematically searched the PubMed database for articles with breast cancer outcomes published in 2006-2016 using terms for 134 environmental chemicals, sources, or biomarkers of exposure. We critically reviewed the articles.

RESULTS

We identified 158 articles. Consistent with experimental evidence, a few key studies suggested higher risk for exposures during breast development to dichlorodiphenyltrichloroethane (DDT), dioxins, perfluorooctane-sulfonamide (PFOSA), and air pollution (risk estimates ranged from 2.14 to 5.0), and for occupational exposure to solvents and other mammary carcinogens, such as gasoline components (risk estimates ranged from 1.42 to 3.31). Notably, one 50-year cohort study captured exposure to DDT during several critical windows for breast development (in utero, adolescence, pregnancy) and when this chemical was still in use. Most other studies did not assess exposure during a biologically relevant window or specify the timing of exposure. Few studies considered genetic variation, but the Long Island Breast Cancer Study Project reported higher breast cancer risk for polycyclic aromatic hydrocarbons (PAHs) in women with certain genetic variations, especially in DNA repair genes.

CONCLUSIONS

New studies that targeted toxicologically relevant chemicals and captured biological hypotheses about genetic variants or windows of breast susceptibility added to evidence of links between environmental chemicals and breast cancer. However, many biologically relevant chemicals, including current-use consumer product chemicals, have not been adequately studied in humans. Studies are challenged to reconstruct exposures that occurred decades before diagnosis or access biological samples stored that long. Other problems include measuring rapidly metabolized chemicals and evaluating exposure to mixtures.

Hair product use and breast cancer risk among African American and White women

Exposures to carcinogens in hair products have been explored as breast cancer risk factors, yielding equivocal findings. We examined hair product use (hair dyes, chemical relaxers and cholesterol or placenta-containing conditioners) among African American (AA) and White women, and explored associations with breast cancer. Multivariable-adjusted models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) to describe the associations of interest among 2280 cases (1508 AA and 772 White) and 2005 controls (1290 AA and 715 White). Among controls, hair dye use was more common among Whites than AAs (58 versus 30%), while relaxer (88 versus 5%) and deep conditioner use (59 versus 6%) was more common among AAs. Among AAs, use of dark hair dye shades was associated with increased breast cancer risk (OR = 1.51, 95% CI: 1.20-1.90) and use of dark shades (OR = 1.72, 95% CI: 1.30-2.26) and higher frequency of use (OR = 1.36, 95% CI: 1.01-1.84) were associated with ER+ disease. Among Whites, relaxer use (OR = 1.74, 95% CI: 1.11-2.74) and dual use of relaxers and hair dyes (OR = 2.40, 95% CI: 1.35-4.27) was associated with breast cancer; use of dark hair dyes was associated with increased ER+ disease (OR = 1.54, 95% CI: 1.01-2.33), and relaxer use was associated with increased ER- disease (OR = 2.56, 95% CI: 1.06-6.16). These novel findings provide support a relationship between the use of some hair products and breast cancer. Further examinations of hair products as important exposures contributing to breast cancer carcinogenesis are necessary.

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.

A Study on Scalp Hair Health and Hair Care Practices among Malaysian Medical Students

Introduction:

Scalp care is essential because it determines the health and condition of the hair and prevents the diseases of scalp and hair. The objectives of our study were to correlate race and hair types, to determine the awareness of hair care among Malaysian medical students, and to distinguish the factors that affect the health of hair and scalp.

Methodology:

It was a cross-sectional study wherein validated questionnaires were given to 240 medical undergraduate students who belonged to three ethnic races of Malaysia, i.e., Chinese, Malay, and Malaysian Indians after their informed consent. The results were then analyzed using percentage statistics.

Results:

Chinese students had comparatively healthier scalp without dandruff. Most Chinese and Indians had silky type of hair while Malay had dry, rough hair. Chinese and Indians colored their hair and used various styling methods; while among the Malays, this percentage was very less. Regarding hair care practices, males used only shampoo and females used shampoo and conditioner for hair wash. Students also faced dietary and examination-related stress.

Conclusion:

Results indicate that there exist morphological differences in hair among the studied population. Since most students color their hair and employ various hairstyling methods, they should be educated regarding best hair care practices to improve their scalp hair condition and health.

The use of personal hair dye and its implications for human health

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.

Occupation, smoking, opium, and bladder cancer: A case-control study

PURPOSE

The aim of this study was to investigate occupational risk factors associated with bladder cancer.

MATERIALS AND METHODS

In this case-control study, control group included patients who referred to a specialized clinic in the same city and hospitals where patients had been registered. Data were entered into SPSS software. Odds ratios (OR) were calculated for occupational variables and other characteristics. Then, using logistic regression, the association between cancer and drugs was studied while smoking was controlled.

RESULTS

Cigarette smoking, even after quitting, was also associated with bladder cancer (OR = 2.549). Considering the classification of occupations, the OR of working in metal industry in patients was 10.629. Multivariate analysis showed that use of the drug by itself can be a risk factor for bladder cancer. Drug abuse together with the control of smoking increased the risk of bladder cancer by 4.959.

CONCLUSION

According to the findings of this study, contact with metal industries such as welding, and working with tin was found as a risk factor for bladder cancer. In addition, cigarette smoking and opium abuse individually were associated with bladder cancer.

Lifestyle factors and risk of leukemia and non-Hodgkin's lymphoma: a case-control study

PURPOSE

Risk factors for leukemia and lymphomas in adults are largely unknown. This study was aimed at evaluating the association between lifestyle factors and the risk of hematological malignancies in an adult population.

METHODS

Data were drawn from a population-based case-control study carried out in Italy and included 294 cases (199 lymphoid and 95 myeloid) and 279 controls. Analyses were performed using standard multivariable logistic regression.

RESULTS

Hair dye use for at least 15 years was associated with a higher risk of lymphoid malignancies among females (OR 2.3, 95 % CI 1.0-4.9, p = 0.036, test for trend). Furthermore, a protective effect of a moderate to heavy tea consumption on the risk of myeloid malignancies was observed (OR 0.4, 95 % CI 0.2-0.9, p = 0.017). No association was found for the use of alcoholic beverages and tobacco smoking.

CONCLUSIONS

Our results confirm the potential carcinogenic effect of prolonged hair dye use observed in previous investigations. The excess risk could be explained by exposure to a higher concentration of toxic compounds in hair products used in the past. The protective effect of regular tea consumption observed in an area with a very high prevalence of black tea consumers deserves further investigation.

Does Hair Dye Use Increase the Risk of Breast Cancer? A Population-Based Case-Control Study of Finnish Women

INTRODUCTION

Role of hair dyes in the etiology of breast cancer has occasionally raised concern but previous research has concluded with mixed results. Remnants of prohibited aromatic amines have been found in many hair dye products, and elevated levels of DNA-adducts of these amines have been detected from breast epithelial cells of hair dye users. However, the IARC working group has concluded that there is inadequate evidence for carcinogenicity of personal hair dye use and limited evidence in experimental animals for carcinogenicity of hair colorants.

MATERIAL AND METHODS

We investigated whether the use of hair dyes is associated with breast cancer risk in women. The study design was a retrospective population-based case-control study in Finland, with a self-administered questionnaire from 6,567 breast cancer patients, aged 22-60 years and diagnosed in 2000-2007, and their 21,598 matched controls. We report odds ratios (OR) with 95% confidence interval (95% CI) from a conditional logistic regression model applied to the frequency matched sets of cases and controls. Bias-adjusted odds ratios from the sensitivity analysis are also presented.

RESULTS

After adjusting for potential confounders, the odds of breast cancer increased by 23% (OR: 1.23, 95% CI: 1.11-1.36) among women who used hair dyes compared to those who did not. In women born before 1950 an increase of 28% was noted (OR: 1.28, 95% CI: 1.10-1.48). We also observed a significant trend between the OR and cumulative use of hair dyes (P: 0.005). Bias-adjusted odds ratios varied between 1.04 and 2.50.

CONCLUSIONS

Our results suggest that use of hair dyes is associated with breast cancer incidence. The impact on public health may be substantial due to vast popularity of hair coloring in modern societies. It should be noted that regardless of all efforts, a possibility of bias cannot definitively be ruled out and use of a prospective design is warranted. Based on the present results, it may be concluded however that safety of hair dyes in relation to breast cancer cannot yet be fully acknowledged and lack of external safety assessment within the cosmetics industry is of major concern.

Trends in use of hair dye: a cross-sectional study

Objective:

The objective of the following study was to assess the knowledge, practice, perception and adverse reactions among hair dye users.

Settings and Design:

A cross-sectional study was conducted on patients, their attenders and staff of SDUMC.

Materials and Methods:

A questionnaire (28) pertaining to use of hair dyes and reactions to them was administered randomly.

Statistical Analysis:

The demographic data are expressed as mean ± standard deviation, quantitative data expressed as percentages.

Results:

A total of 263 volunteers responded of which 52.5% and 47.5% were females and males respectively with mean age of 32.40 ± 6.01 years. The participants started using hair dye at an age of 27 (±3.63) years. Synthetic dyes were used by 91%. Frequency of use in a year was 2-5 times in 51%. Instruction of the package insert was followed by 63.5%. Skin test was never performed in 34% prior to their use. Nearly 96% expressed hair dyeing was unsafe during pregnancy, lactation and in children. Adverse reactions were reported by 42%, with headache (63%) and itching (38%) being the most common.

Conclusion:

Hair dyeing was started at very early age. Majority used semi-permanent dyes even though they perceived natural dyes were safe. They continued dyeing despite adverse reactions, which indicates cosmetic importance.

Personal hair dyes use and risk of glioma: a meta-analysis

BACKGROUND AND OBJECTIVE

Use of hair dyes for glioma risk has been investigated in numerous epidemiological studies, but the evidence is inconsistent. Therefore, a meta-analysis was performed to estimate the association between hair dyes use and glioma risk.

METHODS

We searched PubMed and EMBASE databases without any limitations, covering all papers published by the end of March 8, 2013. Cohort and case-control studies reporting relative risk estimates (RRs) with corresponding 95% confidence intervals (CIs) (or data to calculate them) on this issue were included. Random effects models were used to calculate the pooled RRs and corresponding 95% CIs.

RESULTS

Four case-control and two cohort studies were included in this meta-analysis. The summary RRs and 95 % CIs for ever users of any hair dyes were 1.132 (0.887-1.446) for all studies, 1.291 (0.938-1.777) for case-control studies, and 0.903 (0.774-1.054) for cohort studies. In the subgroup analysis by geographic regions and sex, the similar results were detected. No significant associations were also observed among the studies which reported data involving permanent hair dye use and duration of any hair dye use.

CONCLUSION

In summary, the results of our study demonstrated that hair dyes use is not associated with risk of glioma.

Current understanding of lifestyle and environmental factors and risk of non-hodgkin lymphoma: an epidemiological update

The incidence rates of non-Hodgkin lymphoma (NHL) have steadily increased over the last several decades in the United States, and the temporal trends in incidence can only be partially explained by the HIV epidemic. In 1992, an international workshop sponsored by the United States National Cancer Institute concluded that there was an “emerging epidemic” of NHL and emphasized the need to investigate the factors responsible for the increasing incidence of this disease. Over the past two decades, numerous epidemiological studies have examined the risk factors for NHL, particularly for putative environmental and lifestyle risk factors, and international consortia have been established in order to investigate rare exposures and NHL subtype-specific associations. While few consistent risk factors for NHL aside from immunosuppression and certain infectious agents have emerged, suggestive associations with several lifestyle and environmental factors have been reported in epidemiologic studies. Further, increasing evidence has suggested that the effects of these and other exposures may be limited to or stronger for particular NHL subtypes. This paper examines the progress that has been made over the last twenty years in elucidating the etiology of NHL, with a primary emphasis on lifestyle factors and environmental exposures.

A survey of the awareness, knowledge and behavior of hair dye use in a korean population with gray hair

Background

Gray hair naturally develops in the process of human aging. Many people with gray hair periodically dye their hair. Hair dyeing products are widely used and they can cause adverse effects. Therefore, the user's knowledge and recognition about hair dyeing and related side effects are important.

Objective

The goal of this study was to lay the foundation for understanding, preventing and treating side effects caused by hair coloring products.

Methods

We conducted a questionnaire survey for adult males and females aged over 20 who had gray hair. A total of 500 subjects were included in this study and statistical analysis was performed.

Results

Large numbers of the people who had experience with hair dye (233 out of 319 people, 73.0%) did not know about the exact brand name of the hair dye product that they were using. Of 319 hair dye users, 23.8% (76 out of 319) people stated that they experienced side effects. Despite the occurrence of side effects from hair dyeing products, it seems they did not realize the seriousness of the side effects or the need for treatment.

Conclusion

It is advisable to introduce a system that enables users to become aware of the ingredients and side effects of hair coloring products and give opportunities for users to become aware of the side effects of hair coloring through education, publicity and publication of an informational booklet.

Personal hair dye use and the risk of bladder cancer: a case-control study from The Netherlands

BACKGROUND

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.

OBJECTIVE

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).

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Hair dye use and risk of human cancer

Over 50% of the adult population will use hair dyes at some point in their lifetimes. Hair dyes consist of various chemicals and the composition of these chemicals vary by hair dye types. Chemicals p-phenylenediamine and aminophenyl have been suggested as possible carcinogens or mutagens in experimental studies. The scientific community has been interested in this potential public health impact and the results of published epidemiological studies are summarized here. The current evidence provides limited evidences on the association between personal hair dye use and human cancer risk, except for the possibility of hematopoietic cancers and to a lesser extent, bladder cancer. Risk appears to be affected by time period of use and by specific genetic polymorphisms. Future studies should investigate potential gene and environment interaction to assess possible genetic susceptibility. Several methodological issues should also be considered in future studies including completed hair dye use information such as on timing, duration, frequency and type of hair dye product use.

Hair dye use and risk of bladder cancer in the New England bladder cancer study

Aromatic amine components in hair dyes and polymorphisms in genes that encode enzymes responsible for hair dye metabolism may be related to bladder cancer risk. We evaluated the association between hair dye use and bladder cancer risk and effect modification by N-acetyltransferase-1 (NAT1), NAT2, glutathione S-transferase Mu-1 (GSTM1) and glutathione S-transferase theta-1 (GSTT1) genotypes in a population-based case-control study of 1193 incident cases and 1418 controls from Maine, Vermont and New Hampshire enrolled between 2001 and 2004. Individuals were interviewed in person using a computer-assisted personal interview to assess hair dye use and information on potential confounders and effect modifiers. No overall association between age at first use, year of first use, type of product, color, duration or number of applications of hair dyes and bladder cancer among women or men was apparent, but increased risks were observed in certain subgroups. Women who used permanent dyes and had a college degree, a marker of socioeconomic status, had an increased risk of bladder cancer [odds ratio (OR) = 3.3, 95% confidence interval (CI): 1.2-8.9]. Among these women, we found an increased risk of bladder cancer among exclusive users of permanent hair dyes who had NAT2 slow acetylation phenotype (OR = 7.3, 95% CI: 1.6-32.6) compared to never users of dye with NAT2 rapid/intermediate acetylation phenotype. Although we found no relation between hair dye use and bladder cancer risk in women overall, we detected evidence of associations and gene-environment interaction with permanent hair dye use; however, this was limited to educated women. These results need confirmation with larger numbers, requiring pooling data from multiple studies.

Safety assessment of personal care products/cosmetics and their ingredients

We attempt to review the safety assessment of personal care products (PCP) and ingredients that are representative and pose complex safety issues. PCP are generally applied to human skin and mainly produce local exposure, although skin penetration or use in the oral cavity, on the face, lips, eyes and mucosa may also produce human systemic exposure. In the EU, US and Japan, the safety of PCP is regulated under cosmetic and/or drug regulations. Oxidative hair dyes contain arylamines, the most chemically reactive ingredients of PCP. Although arylamines have an allergic potential, taking into account the high number of consumers exposed, the incidence and prevalence of hair dye allergy appears to be low and stable. A recent (2001) epidemiology study suggested an association of oxidative hair dye use and increased bladder cancer risk in consumers, although this was not confirmed by subsequent or previous epidemiologic investigations. The results of genetic toxicity, carcinogenicity and reproductive toxicity studies suggest that modern hair dyes and their ingredients pose no genotoxic, carcinogenic or reproductive risk. Recent reports suggest that arylamines contained in oxidative hair dyes are N-acetylated in human or mammalian skin resulting in systemic exposure to traces of detoxified, i.e. non-genotoxic, metabolites, whereas human hepatocytes were unable to transform hair dye arylamines to potentially carcinogenic metabolites. An expert panel of the International Agency on Research of Cancer (IARC) concluded that there is no evidence for a causal association of hair dye exposure with an elevated cancer risk in consumers. Ultraviolet filters have important benefits by protecting the consumer against adverse effects of UV radiation; these substances undergo a stringent safety evaluation under current international regulations prior to their marketing. Concerns were also raised about the safety of solid nanoparticles in PCP, mainly TiO(2) and ZnO in sunscreens. However, current evidence suggests that these particles are non-toxic, do not penetrate into or through normal or compromised human skin and, therefore, pose no risk to human health. The increasing use of natural plant ingredients in personal care products raised new safety issues that require novel approaches to their safety evaluation similar to those of plant-derived food ingredients. For example, the Threshold of Toxicological Concern (TTC) is a promising tool to assess the safety of substances present at trace levels as well as minor ingredients of plant-derived substances. The potential human systemic exposure to PCP ingredients is increasingly estimated on the basis of in vitro skin penetration data. However, new evidence suggests that the in vitro test may overestimate human systemic exposure to PCP ingredients due to the absence of metabolism in cadaver skin or misclassification of skin residues that, in vivo, remain in the stratum corneum or hair follicle openings, i.e. outside the living skin. Overall, today's safety assessment of PCP and their ingredients is not only based on science, but also on their respective regulatory status as well as other issues, such as the ethics of animal testing. Nevertheless, the record shows that today's PCP are safe and offer multiple benefits to quality of life and health of the consumer. In the interest of all stakeholders, consumers, regulatory bodies and producers, there is an urgent need for an international harmonization on the status and safety requirements of these products and their ingredients.