Chemicals in plastics impair development of sperm producing cells in babies.

Sep 13, 2008

Lambrot, R, VMuczynski, C Lécureuil, G Angenard, H Coffigny, C Pairault, D Moison, R Frydman, R Habert and V Rouiller-Fabre. 2008. Phthalates impair germ cell development in the human fetal testis in vitro without change in testosterone production. Environmental Health Perspectives online September 9, 2008.

Synopsis by Michael D. Laiosa

Scientists have found a chemical in plastics called MEHP that impairs the development of the reproductive organs of boys when they are exposed in the womb. The chemical, a phthalate, directly harms the development of cells that make sperm.

In a ground-breaking study, scientists have established that a specific phthalate known as MEHP can directly harm the development of special sperm-making germ cells in the testes of human male fetuses. Phthalates are ubiquitous chemicals found in plastics, medical care products and consumer goods. Virtually everyone is exposed to them on some level, and there is growing concerns that babies and children might be especially vulnerable to adverse health and developmental effects. Phthalates have been found in urine soaked diapers of babies after parents applied baby lotions and soaps. Moreover, phthalates have been linked to altered development of boys' reproductive organs when exposed in the womb. Nevertheless, definitive proof that phthalates caused the altered development was lacking. That is until this new study demonstrated that MEHP caused sperm making cells from a fetus to die, thus impacting the potential amount of sperm made and thus the fertility of that boy when he grows into a man.

One caution about this study is that the amount of MEHP necessary to see impaired germ cell development was high - approximately 100 times higher than the level of MEHP found in maternal breast milk, as published in another study. Humans are almost always exposed to a mixture of phthalates, but it is unknown what amount of these chemicals makes its way into the womb. Thus, while the level of phthaltes used for this study raise concerns about the study's relevance, the findings are sufficiently novel as to warrant notice. These findings will likely drive future studies that will test lower exposure levels of both MEHP and phthalate mixtures.