Mothers Exposed to Hair Spray on the Job More Likely to Have Sons with Hypospadias

Newswise — Maternal on-the-job exposure to hair sprays, some of which contain chemicals known as phthalates, has been linked to hypospadias in newborn boys, according to a study accepted for publication today by the peer-reviewed journal, Environmental Health Perspectives (EHP). Hypospadias is a birth defect of the male urethra that results in an abnormally placed urinary opening. It is one of the most common urogenital congenital anomalies among baby boys.

Phthalates, predominantly diethyl phthalate (DEP) and dibutyl phthalate (DBP) are present in many cosmetics including deodorants, fragrances, and nail and hair products. Studies have linked the phthalates or their metabolites, including monoethyl phthalate (MEP) and mono-n-butyl phthalate (MBP), with androgen-lowering activities, abnormal Leydig cell function, a decrease in anogenital distance in male infants, and reproductive tract malformations including hypospadias.

The case"control study included 471 hypospadias cases referred to surgeons, and 490 randomly selected birth controls, born over a 21-month period in South East England. Sons of women working in industries where there is exposure to phthalates—including hairdressers, beauty therapists, research chemists, line operators, pharmaceutical operators, electrical assemblers, and factory assistants—had a 2- to 3-times greater risk for hypospadias. The results add to growing evidence that endocrine-disrupting chemicals (EDCs) such as phthalates may play a role in hypospadias.

However, folate supplementation in the first three months of pregnancy was associated with a 36% reduction in risk of hypospadias. Additionally, there was no observed association between hypospadias risk and eating a vegetarian or vegan diet, contrary to the findings of earlier studies.

Study author Gillian Ormond, of the Department of Epidemiology and Public Health, Imperial College London wrote, "Measurements of exposure to phthalates and/or biomonitoring may help to understand possible pathways of exposure and toxicology, and provide quantitative estimates."

EHP editor-in-chief Hugh A. Tilson, PhD, said, "The findings in this study are the first showing an association between occupational exposure to endocrine-disrupting chemicals in hair sprays and the risk of birth defects in newborn babies."

Other authors include Mark J Nieuwenhuijsen, Paul Nelson, Mireille B Toledano, Nina Iszatt, Sara Geneletti, and Paul Elliott.

The article will be available free of charge at http://www.ehponline.org. EHP is published by the National Institute of Environmental Health Sciences (NIEHS), part of the U.S. Department of Health and Human Services. EHP is an Open Access journal. More information is available online at http://www.ehponline.org/. Brogan & Partners Convergence Marketing handles marketing and public relations for the publication, and is responsible for creation and distribution of this press release.