Latino and Black hairdressers are exposed to a mixture of harmful chemicals, many of which are unknown, according to a study by Johns Hopkins University researchers.

Published in the Journal of Exposure Science and Environmental Epidemiology, assessed chemical exposure in hairdressers via a method typically used to identify chemicals in food and wastewater.

Principal investigator and study coauthor Lesliam Quirós-Alcalá, PhD, an assistant professor of environmental health and engineering at Johns Hopkins, studies the effects of chemical exposure in underrepresented populations.

“We know women are more highly exposed to chemicals in personal care products, and we also know women of color have elevated exposures compared to women of other demographics,” Quirós-Alcalá said in a Johns Hopkins news release. “We wondered about women who are doing this as a profession. How much more are they being exposed? There really wasn’t anything out there when we started this.”

Researchers compared urine samples of Latino and Black hairdressers with samples from women of color with office jobs. Researchers tested for both chemicals expected to be found in people who work with personal care products and other compounds not yet explored.

“The conventional methods just look for chemicals we might expect to be present, but these products contain a lot of different chemicals and not all of them are known,” said senior author Carsten Prasse, PhD, an assistant professor of environmental health and engineering at Johns Hopkins. “We wanted to open up the lens and find potential other chemicals that hairdressers might be exposed to so that we could inform future regulations of these chemicals.”

Over 700,000 hairdressers work in the United States, more than 90% of whom are women; of these, 30% are Latino or Black, and many are of reproductive age. Exposure to hazardous chemicals from hair relaxers, conditioners, dyes and fragrances can harm both women and children if exposure occurred during the preconception and prenatal period, according to Quirós-Alcalá.

These findings emphasize the need for more studies to better understand which chemicals are in common hair styling products and how to reduce the risk of exposure for hairdressers of color.