Kemi Ogunsina

Occupational exposures among hairdressers and the occurrence of hormone-related conditions

Objective To investigate the association between hairdresser exposures and hormone-related conditions. Methods Using data from 50 800 eligible Sister Study participants (enrolled 2003–2009, aged 35–74 years), we estimated ORs and 95% CIs for associations between ever working as a hairdresser (n=1803) and prevalent fibroids, endometriosis, hysterectomy and oophorectomy. We estimated HRs and 95% CI for incident fibroids, endometriosis, breast, uterine and ovarian cancers among ever hairdressers versus never hairdressers. We also examined associations of hormone-related diseases and professional use of products such as bleach, perms, chemical straighteners, permanent hair colour, hairspray, barbicide, formaldehyde and alcohol, comparing data from 985 long-term hairdressers who worked ≥2 years to non-long-term hairdressers (never workers and those working <2 years). Results Ever-hairdressers were more likely than never-hairdressers to have had a prebaseline hysterectomy (OR=1.23: 95% CI 1.11 to 1.36). Hysterectomies were more common among long-term hairdressers with more frequent applications of perms, chemical straighteners and permanent hair colour compared with less frequent applicators or never hairdressers. Ever-hairdressers had higher rates of incident endometriosis (477 cases, HR=1.61: 95% CI 1.08 to 2.38) compared with never-hairdressers, but there were no notable associations between working as a hairdresser and fibroids (1805 cases, HR=1.04: 95% CI 0.80 to 1.34), breast cancer (4628 cases, HR=0.98: 95% CI 0.83 to 1.16), ovarian cancer (300 cases, HR=1.33: 95% CI 0.77 to 2.29) or uterine cancer (447 cases, HR=1.04: 95% CI 0.60 to 1.77). In race-stratified analyses, Black hairdressers were more likely to be diagnosed with fibroids than Black never-hairdressers (201 cases, HR=1.56: 95% CI 0.93 to 2.62). Conclusions Hairdresser occupation was associated with increased odds of hysterectomy and increased rates of incident endometriosis and possibly fibroids among Black women.

Hair Straightener Use in Relation to Prevalent and Incident Fibroids in the Sister Study with a Focus on Black Women

Uterine fibroids disproportionately affect Black women, and exposure to chemicals from hair relaxers or straighteners ("straighteners") may contribute to fibroid development. We examined the association between straightener use and prevalent young-onset uterine fibroids (diagnosed before age 36 y), as well as incident fibroids (diagnosed age 36-60 y), with a focus on Black women. We also examined differences in associations across birth cohorts as proxies for formulation changes. Data from 4,162 Black women in the Sister Study, a prospective cohort of women 35-74 y of age (enrolled 2003-2009), were analyzed. We used logistic regression to estimate odds ratios (ORs) for the association of straightener use at 10-13 y of age and self-reported young-onset fibroids. We used Cox regression to assess hazard ratios (HRs) for straightener use (age 10-13 y and in 12 months before enrollment) and incident fibroids among 779 premenopausal Black women. Similar analyses were conducted in 40,782 non-Hispanic White women. Over 70% of Black women used straighteners. In comparison with no use, any [ Hair straightener use may be positively associated with fibroid risk. https://doi.org/10.1289/EHP14493.