Some of the preservation of personal care products, the substances used can move up in girls the onset of puberty. This has shown a long-term study of 338 children in the journal “Human Reproduction”. The effect shows itself clearly only when girls use the products themselves, but also to the use by the mothers during pregnancy.

the substances, the impact on the pregnancy, belonged to mono ethyl phthalate, and Triclosan. Each doubling of the concentration of mono-ethyl phthalate in the urine of the mothers, led to the pubic hair began in the daughters of about 1.3 months earlier. With each doubling of the Triclosan concentration in the pregnancy, the first rule began, among the daughters, nearly a month earlier. A preservative with a negative effect through their own use of Methyl – and Propylparaben, as well as 2,5-counted Diclorphenol. Girls had nine years of these preservatives in the urine, has been brought forward to the beginning of puberty to around a month.

The study provides a possible explanation for this is that puberty starts earlier and earlier. 150 years ago, the average entry age at the age of 16, in 1994 at 12 years, today it is not rare in ten years. However, the significance of the study is limited by the fact that only one ethnic and social group has been studied, and women with Latin-American Background, low education and low income.