Vietnamese salon workers show higher exposure to reproductive toxicants in nail polish, new study finds

Vietnamese nail salon workers are disproportionately exposed to phthalates, according to researchers at UC Berkeley, UCSF, and the Cancer Prevention Institute of California. The study, published earlier this month in the International Journal of Environmental Research and Public Health, showed that urine samples of Vietnamese nail salon workers contained twice the level of phthalates compared to that of the general population of Asian Americans in the United States, underscoring the urgent need to reduce toxic exposures in this particular population of the American workforce. This is the first study to measure phthalates in Vietnamese nail salon workers in California and to compare those levels to Asian Americans in the U.S. population.

Dr. Julia Varshavsky, a postdoctoral researcher at UCSF, conducted much of this research as a doctoral student at Berkeley Public Health as part of her dissertation. Her advisor Dr. Rachel Morello-Frosch, a professor at Berkeley Public Health and the Department of Environmental Science, Policy, and Management, is a co-author of this study.

“Our research shows that Vietnamese nail salon workers may be an important and uniquely vulnerable population with regard to phthalates exposure in the United States,” says Varshavsky.

Phthalates are a group of man-made chemicals commonly used in plastics to increase malleability. Often called plasticizers, these chemicals can be found in products all around us, including vinyl flooring, adhesives, plastic clothing like raincoats and boots, and personal care products like soaps, shampoos, detergents, and cosmetics, in which they help products retain fragrance. In nail polish, manufacturers use phthalates to prevent the polish from chipping.

But research has shown that exposure to phthalates can produce adverse health outcomes.

A 2008 report from the National Academy of Sciences showed that phthalates can act as an antiandrogen: Exposure to the chemical during pregnancy can increase impaired male reproductive tract development in utero. Phthalates can also lead to other pregnancy complications, neurodevelopmental effects, cancer, and metabolic disease.

As the nail salon industry in the United States has expanded over recent decades, researchers have started to examine more closely exposure levels among nail salon workers who handle the toxicant on a regular basis. Two studies published in 2008 and 2009 both affirmed that urine samples from these workers contained higher levels of the toxicant, but neither study was designed to focus on the population most vulnerable to this exposure: Vietnamese Americans.

Around half of the nail salon workers in the U.S. are Vietnamese, says the study’s authors. In California, that proportion is even higher. Throughout the 1990s, a steady influx of Vietnamese immigrants increased the proportion of Vietnamese nail salon workers to 60 percent in the state with the largest number of nail salons in the country. Plus, most of these workers are women of reproductive age.

“Moreover, Vietnamese workers typically work long hours, make low wages, and have limited access to worker protections and chemical safety information,” says Varshavsky, underscoring the need for preventative measures to reduce phthalate exposure in this particular workforce population. These measures could include promoting the manufacture of salon products with safer, alternative chemicals, as well as improving health education resources for Vietnamese Americans working in nail salons to help minimize their exposure.

“The good news is that phthalates have relatively short half-lives in the body,” says Varshavsky, “so removing them from nail care products will likely reduce the exposure burden among this vulnerable population.”

The research team included Julia R. Varshavsky of UCSF, Rachel Morello-Frosch of UC Berkeley, Suhash Harwani, Martin Snider, Syrago-Styliani E. Petropoulou, June-Soo Park, and Myrto Petreas of the California Department of Toxic Substances Control, Peggy Reynolds and Thu Quach of the Cancer Prevention Institute of California, and Tuan Nguyen of the State Compensation Insurance Fund. The team also collaborated with the California Healthy Nail Salon Collaborative, a network of nail salon workers, researchers, community health representatives, and other stakeholders seeking to promote nail salon worker education, health, safety, and economic success. The research team plans to focus further research validating the results of this study through a larger biomonitoring assessment of Vietnamese nail salon workers across California.