Exposure to current and emerging contaminants of concern among women: exploring disparities in exposure and health-related endpoints

Abstract

Hairdressers —particularly women of color, who are more likely to use products with harmful chemicals—may face significant health risks from continuous workplace chemicals. Yet, data on these exposures and their health impacts remain understudied. This dissertation addresses key gaps through three aims: 1) characterize exposures to volatile organic compounds (VOCs) in office spaces and hair salons serving ethnic clientele through indoor air measurements; 2) identify and characterize novel chemical exposures among hairdressers of color and office workers using targeted urinary biomonitoring; and 3) examine associations between urinary VOC biomarkers and infertility among U.S women to inform larger epidemiologic studies among hairdressers.In Aim 1, we measured ambient concentrations of 14 VOCs in six salons catering to women of color and 10 office spaces. Median VOC concentrations were 2-175 times higher than in offices. Notably, 95th percentile VOC concentrations were up to 187 times higher in Black salons than in Dominican salons, suggesting that differences in salon characteristics, services and products may contribute to exposure disparities. Aim 2 involved post-shift urine sampling from 23 female hairdressers of color and 17 office workers to quantify five biomarkers: 2-naphthol, methyl-, ethyl-, and propylparaben, and capsaicin. All biomarkers were elevated among hairdressers compared to office workers, with higher concentrations observed among Black hairdressers than among Dominican hairdressers. Select products and services (chemical straightening/relaxers, hair extensions and hairspray) were linked to increased concentrations of 2-naphthol and methylparaben, while mask use was associated with lower methylparaben concentrations. Aim 3 analyzed NHANES 2013-2018 data and found significant associations between biomarkers for 1,3-butadiene (DHBMA, MHBMA3), acrylonitrile (CYMA), and N,N-dimethylformamide (AMCA) and an increased odds of infertility among women aged 20-44 years. Select VOCs showed dose-response relationships, while VOC mixture analyses revealed significantly increased infertility odds, driven primarily by DHBMA, CYMA and AMCA. This research provides novel insights into chemical exposures among hairdressers of color—a group already facing compounded environmental and socio-economic stressors—and suggests that VOCs may impact infertility. These findings underscore the need for larger, racially/ethnically diverse studies to validate these findings and inform interventions addressing exposure disparities in this understudied workgroup.