Beauty products and household chemicals related to precocious puberty in girls – Treehugger


We need a precautionary principle approach or much more of these studies, and soon, in order to protect our children.

A long-term study started in the previous millennium was aimed at finding an answer to the question of whether exposure to phthalates, parabens and other phenols while in the womb or as a young child hit the age where puberty begins. 338 pregnant women were enrolled in the study in 1999-2000 and their children were followed closely between ages 9 and 13 to establish puberty.

A previous study, the National Health and Nutrition Examination Survey (NHANES) in the United States, has detected detectable levels of these chemicals in the bodies of more than 96% of the women studied. Since detection limits have become increasingly low, detections do not mean the same thing as dangerous levels – but the prevalence of these chemicals in our lives requires answers that define safe levels and determine where we need to deal.

This study, conducted by a team of researchers from the University of California, Berkeley, together with a local pediatric practice and representatives of the Centers for Disease Control, found no effect on puberty in young males. But in the words of the lead author, Dr. Kim Harley,

"We found evidence that some widely used chemicals in personal care products are associated with previous puberty in girls.In particular, we found that mothers who had higher levels of two chemicals in their body during pregnancy – diethylphthalate , which is used in the fragrance, and triclosan, which is an antibacterial agent in some soaps and toothpaste – had daughters that had entered puberty before.We also found that girls with higher levels of parabens in their bodies at the time. age of nine years entered puberty first.This is important because we know that the age at which puberty begins in girls has been anticipated in recent decades ".

It is important to underline that the study was able to find a dose-response relationship in the data: every time the concentration of a chemical in the mother's urine doubled, the beginning of puberty shifted before at a constant pace. Demonstrating such a dose-response helps to support the hypothesis that chemicals cause or contribute to the effects. The fact that the chemicals studied mimic female hormones could explain the lack of effects on boys.

These are chemicals known as "endocrine disruptors", commonly suspected in a growing fertility crisis, linked to obesity and disease and potentially behind the results of a gender difference in frogs. In short, this is serious stuff.

Yet the category of "endocrine disruptors" is not regulated effectively. This is mainly due to the fact that it is difficult to demonstrate that the effects are caused by specific chemicals. In particular, the effects can only be observed long after exposure. The European Union is currently at the forefront in the field of endocrine disruptors, including the application of the precautionary principle, but critics even accuse the EU of not dealing with risks with sufficiently aggressive policies.

As a result, long-term studies have great value. Unfortunately, this study suffers from some serious limitations. First, the study required only a couple of measurements of the chemicals; as these chemicals are rapidly eliminated from the body, the torque samples may not be representative of continuous exposure. Secondly, mothers in this study were selected because of the potential for exposure to agricultural chemicals such as pesticides; since they represent a specific social layer and a community, the results may not be generalizable to all populations.

There are also many natural endocrine disruptors and other potential explanations, so even a long-term study like this must be supported by the weight of many more tests before specific conclusions can be reached – especially if the ultimate test of risk is the regulatory standard as in the United States. The weight of evidence means more studies until the truth is overwhelming and authorities can act to protect human health.

Read the full study in the diary Human reproduction: Association of phthalates, parabens and phenols found in personal hygiene products with pubescent timing in girls and boys (

We need a precautionary principle approach or much more of these studies, and soon, in order to protect our children.


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