Brenda Eskenazi, Ph.D., Kim Harley, Ph.D.
University of California, Berkeley
R21ES024909, P01ES009605, R01ES017054, RC2ES018792, R01ES021369, R24ES028529
Girls exposed to chemicals commonly found in personal care products before birth may hit puberty earlier, according to an NIEHS-funded study. The study found that mothers who had higher levels of diethyl phthalate and triclosan in their bodies during pregnancy had daughters who experienced puberty at younger ages. Diethyl phthalate is often used as a stabilizer in fragrances and cosmetics. The antimicrobial agent triclosan was widely used in hand soap until it in 2017, although it is still used in some toothpastes.
The results came from data collected as part of the Center for the Health Assessment of Mothers and Children of Salinas study, which followed 338 children from before birth to adolescence. The researchers measured a variety of chemicals found in personal care products, including phthalates, parabens, and phenols, in urine samples from mothers, taken twice during pregnancy, and from children at age 9 years. They assessed pubertal timing every 9 months between ages 9 and 13 years using Tanner Staging, an objective classification system used to document the development of secondary sex characteristics of children during puberty.
In girls, they found that higher prenatal urinary concentrations of triclosan and one of its degradation products were associated with an earlier first occurrence of menstruation, and that higher prenatal concentrations of the main metabolite of diethyl phthalate were associated with earlier onset of pubic hair development. The same trends were not observed in boys. They also observed a link between urinary metabolites of parabens at age 9 years with earlier puberty. However, this may reflect reverse causality, because children going through puberty earlier may be more likely to use personal care products.
Citation: Harley KG, Berger KP, Kogut K, Parra K, Lustig RH, Greenspan LC, Calafat AM, Ye X, Eskenazi B. 2018. Association of phthalates, parabens and phenols found in personal care products with pubertal timing in girls and boys. Hum Reprod 34(1):109-117.