Researching Risk of Birth Defects Among Pregnant Nail Salon Workers and Hairdressers

Workers at Risk

There are currently around 400,000 active nail technician licenses and roughly 600,000 employed hairdressers in the United States. Most of these workers are women of reproductive age, and many are foreign-born or people of color. Nail technicians often work in environments where haircare services are also provided. Nail and hair salon workers have advocated for additional research on the health hazards of their profession. A 2015 New York Times article gained national attention for nail salon workers’ health and safety when it highlighted workers’ specific concerns over hazardous workplace conditions.[1]

Nail technicians and hairdressers can be exposed to dozens of chemicals, including acrylates in artificial nail products, glues, parabens and phthalates in nail polish and hair care products, volatile organic compounds (such as toluene in hair dye and nail polish, formaldehyde in nail polishes and keratin hair treatments, and persulfates in bleach), and biocides. Some of the chemicals used by workers in nail and hair salons are associated with cancer or reproductive harm. A few studies have documented adverse birth outcomes among hairdressers, such as birth defects, small for gestational age, and miscarriage. Although previous research on nail technicians has described negative respiratory, neurological, and musculoskeletal effects, studies that address reproductive effects among this worker population are limited—and none have included birth defects.

Addressing the Issue

NIOSH researchers want to better understand adverse reproductive outcomes—birth defects in particular—among nail technicians and hairdressers. We recently analyzed data from the National Birth Defects Prevention Study (NBDPS), a large multicenter, population-based case-control study of birth defects that included mothers of infants born from 1997-2011. Job descriptions reported by mothers that participated in NBDPS were used to identify hairdressers, nail technicians, and non-cosmetologists during early pregnancy (defined as the period from one month before conception through the third month of pregnancy). We compared proportions of mothers working as nail technicians or hairdressers to those working as non-cosmetologists among children born with and without birth defects. A total study population of 43,106 mothers who reported working during pregnancy (31,541 cases and 11,565 controls) were analyzed. Of these participant mothers, 61 reported work as a nail technician, 196 reported work as a hairdresser, 39 reported work as both, and 42,810 reported working as a non-cosmetologist. Based on sample size, we analyzed eight birth defect groups among nail technicians and 22 among hairdressers. The results were published in June 2021 in Occupational and Environmental Medicine.

Birth Defects Among Nail Technicians and Hairdressers

Our results suggest that mothers who gave birth to infants with a congenital heart defect (including any heart defect, conotruncal defects, right ventricular outflow tract obstruction, and septal defects) were roughly 3 times more likely than mothers of infants with no birth defect to have worked as a nail technician during early pregnancy. Additionally, mothers who gave birth to infants with cleft lip with cleft palate were twice as likely as mothers of infants with no birth defect to have worked as a hairdresser during early pregnancy. We also found suggestive associations for mothers working as hairdressers and having infants born with defects of the ear (anotia and microtia) and abdominal wall (gastroschisis).

What’s Next?

This study was limited by small samples of mothers working as nail technicians and hairdressers. Nevertheless, it addresses an understudied area of research and highlights the need for more attention. Specific workplace practices or chemical exposures that might be associated with birth defects among nail technicians and hairdressers remain unclear. Further research, particularly on job tasks or chemical exposures for these working populations, will be beneficial to better understand reproductive health effects and help guide interventions among nail technicians and hairdressers.

Although the NBDPS offers a valuable opportunity to broadly examine workplace exposures and birth outcomes, research in cohorts of nail technicians and hairdressers—as well as the inclusion of occupation in existing studies of pregnancy outcomes—is warranted. CDC recently initiated the Birth Defects Study to Evaluate Pregnancy exposureS (BD-STEPS)[2], which gathers information on occupation during pregnancy. Workers in selected occupations will be asked to participate in a follow-up web survey module designed for their occupation to collect more detailed information on work exposures that might be of concern. This type of occupational follow-up can enrich the data from large population-based surveys and allow further research.

Employers, health care providers, public health officials, and nail technicians and hairdressers can work together to raise awareness of potential reproductive hazards encountered in the workplace and reduce exposures as much as possible. Prevention through Design concepts and a Hierarchy of Controls approach could help reduce exposures in nail and hair salons, and implementing NIOSH Total Worker Health programs in these settings might improve the overall health and well-being of workers and their families.

This blog has been translated into Vietnamese and Korean.

Kristen Van Buren, MPH, is an associate service fellow in the NIOSH Division of Field Studies and Engineering.

Miriam R. Siegel, DrPH, MPH, is an occupational epidemiologist in the NIOSH Division of Field Studies and Engineering.

Carissa M Rocheleau, PhD, is a reproductive occupational epidemiologist in the NIOSH Division of Field Studies and Engineering.

Kendra Broadwater, MPH, CIH is a research industrial hygienist in the NIOSH Western States Division.

Additional Resources

Nail Technicians’ Health and Workplace Exposure Control

Nail Files: A Study of Nail Salon Workers and Industry in the United States

Maternal occupation as a nail technician or hairdresser during pregnancy and birth defects, National Birth Defects Prevention Study, 1997-2011

References

[1] Maslin Nir S. Perfect Nails, Poisoned Workers. The New York Times, 2015. Available: http://www.nytimes.com/2015/05/11/nyregion/nail-salon-workers-in-nyc-face-hazardous-chemicals.html

[2] Centers for Disease Control & Prevention. Birth Defects Study to Evaluate Pregnancy exposureS (BD-STEPS), 2020. Available: http://www.bdsteps.org/about/bd-steps/index.html