Study illuminates potential health risks for women in the nail and hair care industry
Quach T, Von Behren J, Goldberg D, Layefsky M, Reynolds P. Adverse birth outcomes and maternal complications in licensed cosmetologists and manicurists in California. Int Arch Occup Environ Health. 2014 Dec 14. [Epub ahead of print]
This was a population-based retrospective study of cosmetologists and manicurists in California designed to examine adverse pregnancy outcomes as compared to both the general female population and to women working in other industries. A restricted analysis was also conducted for Vietnamese women who comprise a significant proportion of the nail and hair care workforce.
The California licensing agency for cosmetologists and manicurists database, which included a total of 260,052 licensed cosmetologists and 159,430 licensed manicurists, was matched up to the birth registry files to identify births occurring between 1996 and 2009, a 14-year study period. The examined births were restricted to singletons and to women who were at least 18 years old at the age of birth. This resulted in 81,205 identified births among this group.
For the 2 comparison groups, births during the same timeframe by women from the general population were frequency-matched at a 5-to-1 ratio by year of birth, resulting in 406,025 live births. The second comparison group consisted of women who had occupations on the birth records listed as teacher, realtor, salesperson, banker, office worker, and food service worker. This group totaled 53,056 live births.
STUDY PARAMETERS ASSESSED
Outcome measures were birthweight, gestational age, selected birth defects, and infant death, as well as maternal preeclampsia, gestational and unspecified diabetes, premature rupture of membranes, placental abruption, plancenta previa, precipitous labor, and prolonged labor.
PRIMARY OUTCOME MEASURES
Low birthweight was defined as less than 2,500 g (5.51 lb), preterm delivery defined as less than 37 weeks vs 37 weeks or more, and infant death defined as death during the first year of life. Babies below the 10th percentile of weight using sex-specific percentiles were identified as small for gestational age (SGA).
Maternal outcomes included preeclampsia, gestational diabetes (data was available only for births between 2006 and 2009 since previous years did not specify “gestational diabetes” for those who were identified as having diabetes), chronic diabetes, prolonged labor, precipitous labor, premature rupture of membranes, placental abruption, and placenta previa (data available for births between 1996 and 2005 only).
Increased risk for adverse birth outcomes in cosmetologists and manicurists among all races was not observed. Cosmetologists had slightly reduced risk for low birthweight, SGA, and infant death compared to the general population. However, an increased risk of SGA in Vietnamese manicurists and cosmetologists was found when compared to other working women: odds ratio (OR):1.39; 95% confidence interval (CI):1.08-1.78 for manicurists and OR:1.40; 95% CI:1.08-1.83 for cosmetologists. These results were statistically significant.
Some maternal complications were observed, most notably an increased risk for gestational diabetes (OR:1.28; 95% CI:1.10-1.50 for manicurists and OR:1.19; 95% CI:1.07-1.33 for cosmetologists) compared with the general population, which was further elevated when restricted to the Vietnamese workers (OR:1.59; 95% CI:1.2-2.11 for manicurists and OR:1.49; 95% CI:1.04-2.11 for cosmetologists). These results attained statistical significance.
Unspecified diabetes also posed a statistically significant elevation in risk for manicurists (OR:1.36; 95% CI:1.08-1.71) compared with the general population. A less significant increased risk was observed in cosmetologists (OR:1.14; 95% CI:1.0-1.30) compared with the general population. These increases in risk were not statistically significant in the manicurists and cosmetologists when compared with other working women, although increases in risk were noted.
There was also a statistically significant increase in risk of diabetes (unspecified) in the Vietnamese women breakout group of manicurists compared with the general population (OR:1.98; 95% CI:1.03-3.83) and also for gestational diabetes for the Vietnamese manicurists (OR:1.59; 95% CI:1.20-2.11) and cosmetologists (OR:49; 95% CI:1.04-2.11).
Increased risk of premature rupture of membranes was statistically significant in manicurists but not cosmetologists as compared with other working women (OR:1.15; 95% CI:1.01-1.31) and as compared with the general population (OR:1.21; 95% CI:1.09-1.35). Increased risk of placentia previa was also statistically significant (OR:1.46; 95% CI:1.08-1.97 for manicurists and OR:1.22; 95% CI:1.02-1.46 for cosmetologists) when compared with the general population but was not statistically significant when compared with other working women.
As the authors of the present study note, manicurists and cosmetologists are exposed daily to an array of potentially hazardous chemicals associated with nearly every hair and nail care service they provide. These chemicals have received considerable attention in recent years because some of them are known or suspected carcinogens and endocrine-disruptors. Previous studies have demonstrated reproductive abnormalities in humans and animals exposed to these compounds. However, despite the growth of this industry and the numerous chemicals of concern found in salons, very few human health studies have been conducted in this area.
An investigation of the nail worker industry was published in the New York Times on May 8, 2015.1 Titled “Perfect Nails, Poisoned Workers,” the article detailed the exploitation of these largely immigrant workers and the chronic health effects of near continual exposure to chemicals used in polishes, hardeners, glues, and solvents. The article serves as a flashpoint for awareness of this problem and even resulted in New York Governor Andrew Cuomo declaring emergency measures for this industry that addressed its egregious pay issues and mandated some basic salon worker safety measures. This action should also spur more research into the chemicals and chemical mixtures used in salons and their effects on the women who work there.
While this study found no adverse effects on the children, save the low SGA in Vietnamese women, there were several adverse effects in the women themselves. Risk for gestational diabetes, premature rupture of membranes, and placenta previa were all significantly higher in the cosmetologists and manicurists.
A higher risk of diabetes in those exposed to endocrine-disruptors is not new information. In 2004, the National Health and Nutritional Examination Survey (NHANES) found a similar association.2 The NHANES analyses showed that most participants have detectable blood and/or urine levels of several chemicals, in particular bisphenol A (BPA). Diabetes was strongly associated with exposure to polychlorinated biphenyl, dioxins, dichlorodiphenyldichloroethdichlorodiphenyldichloroethylene, phthalates, and also BPA (with an OR reaching 2.74; 95% CI:1.44-5.23) after adjusting for age, gender, body mass index, and ethnicity. Salons are rife with endocrine-disruptors, including BPA and phthalates.
As so many of these chemicals are endocrine-disruptors, the increased risk for diabetes is not surprising. It would have been interesting to look for other endocrine disruptions, such as thyroid disease, hormonal perturbations, and congenital abnormalities like hypospadias, since endocrine-disruptors often cause these conditions.
Numerous studies have been focused on the association between endocrine-disrupting chemicals and hypospadias. In a recent study carried out in France, fetal exposure to endocrine-disruptors during the window of genital development was more frequent in the case of hypospadias (OR:3.13; 95% CI:2.11-4.65).3 Furthermore, hairdressers and beauticians were identified, along with cleaners and lab workers, as professionals with the most exposure to these substances, and these women were more frequently the mothers of hypospadiac boys. In addition, according to the authors of this study, “the types of substances having an impact on the phenotype were heterogeneous, but detergents, pesticides, and cosmetics accounted for 75 percent of the cases.”3 The authors elucidated some of the endocrine-disrupting chemicals linked to the professions involved in the study: BPA, phthalates, polychlorinated compounds, alkylphenolic compounds, and organic solvents.
The study being reviewed did not examine miscarriage rates among manicurists and cosmetologists. However, previous studies have found some evidence of both increased rates of miscarriage and time-to-pregnancy in hairdressers.4 In 1 study, female hairdressers were found to have an increased risk of infertility (OR:1.30; 95% CI:1.08-1.55) and an increased risk of spontaneous abortion (OR:1.31; 95% CI:1.07-1.60).5 Others studies failed to find such an association that reached statistical significance.4
Volatile solvents such as formaldehyde, methacrylates, acetone, xylene, and toluene, as well as parabens and phthalates, are just some of the chemicals found in these salons. Nail products typically contain the trifecta of toxicants: toluene, formaldehyde, and phthalates.6 Some nail polish manufacturers have reformulated their nail polish to be free of the toxic 3. Disturbingly, however, California regulators in 2012 tested 25 randomly chosen nail polishes from 6 distributors that sell to many of the 48,000 salons in California and found the toxic trio in several of the samples chosen. According to the report, 10 of the 12 polishes that claimed to be free of toluene actually contained the substance. Five of 7 products that claimed to be free of all 3 chemicals were found to contain 1 or more of the chemicals at elevated levels.7 It cannot be inferred if the polish labels were deliberately misleading or if a vendor in the supply chain had misrepresented the chemical makeup of their ingredients unbeknownst to the formulator of the final, finished product.
As with other chemicals that have been found to be detrimental to human health, the “cure” is sometimes illusory and difficult to rely upon. In the case of BPA, BPS and BPF and other analogs used as substitutions have been found to be similarly hormonally active as BPA and also have endocrine-disrupting effects.8 It stands to reason that chemical substitutions for problematic chemicals need to be thoroughly vetted as well.
In a study of occupational urinary phthalate metabolites found across 8 different industries, levels of phthalates in salon workers were found to be twice as high relative to the general population.9 In another study, indoor air was tested for phthalates in homes, offices, laboratories, schools, hair and nail salons, and public places. The highest concentration was found in the salons, at 2,600 ng/m3; the second highest concentration of phthalates was found in the homes, at 732 ng/m3.10 Inhalation is an important exposure route for humans, so these levels bear further study for their health effects. Also, consideration of the contributors to home indoor air that contains high levels of phthalates is warranted when evaluating patients for toxic exposures.
Phthalates have been found to be associated with earlier breast and pubic hair development in girls exposed in the peripubertal timeframe as well as genital variations in infant boys exposed prenatally and neurobehavioral issues in school-age boys.11-13 These findings are concerning because there are often biological responses to the same doses of chemicals found in everyday exposure to common household and personal care products.
Solvent exposure poses its own risks. In a recent study that examined pregnant women, including hairdressers, and their occupational exposure to solvents, significant associations were found between major congenital malformations and maternal exposure to solvents—OR:2.48; 95% CI:1.4-4.4 for regular exposure vs no exposure based on self-reporting, which jumped to the occupationally derived solvent matrix result (OR:3.48; 95% CI :1.4-8.4 for highest level of exposure vs no exposure). A significant dose-response trend was observed with both assessment levels. The congenital malformations were mainly oral clefts, urinary malformations, and male genital malformations.14
From a clinical perspective, it behooves us to evaluate our manicurist and cosmetologist patients for toxicant body burden. We should elicit information about the chemicals and chemical processes that are suspected of containing endocrine-disrupting chemicals that have been shown to be associated with poorer pregnancy outcomes and maternal health. Because females of reproductive age make up the majority of this population, awareness of toxicants in their environment can and should be a part of their treatment plan, particularly if these women wish to conceive. More research is needed to understand possible occupational reproductive and other health risks for cosmetologists due to the sheer number of chemical products that they are exposed to on a daily basis. Finally, personal care product safety as a whole needs to be more extensively studied.
1 Maslin Nir S. Perfect nails, poisoned workers. New York Times. May 8, 2015. Available at:http://www.nytimes.com/2015/05/11/nyregion/nail-salon-workers-in-nyc-face-hazardous-chemicals.html. Accessed August 3, 2015.
2 Chevalier N, Fenichel P. Endocrine disruptors: New players in the pathophysiology of type 2 diabetes? Diabetes Metab. 2015;41(2):107-115.
3 Kalfa N, Paris F, Philbert P et al. Is hypospadias associated with prenatal exposure to endocrine disruptors? A French collaborative controlled study of a cohort of 300 consecutive children without genetic defect. Eur Urol. 2015 May 23; pii:s0302-2838(15):0409-1.
4 Axmon A, Rylander L, Lillienberg L, Albin M, Hagmar L. Fertility among female hairdressers. Scand J Work Environ Health. 2006;32(1):51-60.
5 Baste V, Moen BE, Riise T, Hollund BE, Oyen N. Infertility and spontaneous abortion among female hairdressers: the Hordaland Health Study. J Occup Environ Med. 2008;50(12):1371-1377.
6 Quach T, Doan-Billing P, Layefsky M et al. Cancer incidence in female cosmetologists and manicurists in California, 1988-2005. Am J Epidemiol. 2010;172(6):691-699
7 Environmental Working Group. Calif. Regulators: “Non-Toxic” Nail Polishes Anything But. April 10, 2012. Available at:http://www.ewg.org/news/news-releases/2012/04/10/calif-regulators-%E2%80%9Cnon-toxic%E2%80%9D-nail-polishes-anything. Accessed August 3, 2015.
8 Rochester JR, Bolden AL. Bisphenol S and F: a systemic review and comparison of the hormonal activity of bisphenol A substitutes.Environ Health Perspect. 2015;123(7):643-650.
9 Hines CJ, Nilsen Hopf NB, Deddens JA, et al. Urinary phthalate metabolite concentrations among workers in selected industries; a pilot biomonitoring study. Ann Occup Hyg. 2009;53(1):1-17.
10 Tran TM, Kannan K. Occurrence of phthalate diesters in particulate and vapor phases in indoor air and implications for human exposure in Albany, New York, USA. Arch Environ Contam Toxicol. 2015;68(3):489-499.
11 Wolff MS, Teitelbaum SL, Pinney SM, et al. Investigation of relationships between urinary biomarkers of phytoestrogens, phthalates, and phenols, and pubertal stages in girls. Environ Health Perspect. 2010;118(7):1039-1046.
12 Kobrosly RW, Evans S, Miodovnik A, et al. Prenatal phthalate exposures and neurobehavioral development scores in boys and girls at 6-10 years of age. Environ Health Perspect. 2014;122(5):521-528.
13 Ormond G, Nieuwenhuijsen MJ, Nelson P, et al. Endocrine disruptors in the workplace, hairspray, folate supplementation, and risk of hypospadias: case control study. Environ Health Perspect. 2009;117(2):303-307.
14 Garlantezec R, Monfort C, Rouget F, Cordier S. Maternal occupational exposure to solvents and congenital malformations: a prospective study in the general population. Occup Environ Med. 2009;66(7):456-463.