Friends of the Richelieu. A river. A passion.

"Tout cedit pays est fort uny, remply de forests, vignes & noyers. Aucuns Chrestiens n'estoient encores parvenus jusques en cedit lieu, que nous, qui eusmes assez de peine à monter le riviere à la rame. " Samuel de Champlain

"All this region is very level and full of forests, vines and butternut trees. No Christian has ever visited this land and we had all the misery of the world trying to paddle the river upstream." Samuel de Champlain

Thursday, July 22, 2010

Les phthalates agissent sur la reproduction féminine aussi

On savait que les phtalates, un groupe de composés chimiques utilisés pour amolir les plastiques, causent beaucoup de problèmes de santé humaine et environnementale. Chez les humains, ils provoquent l'obésité et des problèmes d'hyperactivité et troubles du déficit de l'attention. Parce qu'il y en a partout dans l'environnement, presque tous les humains y sont exposés.

On savait que l'un d'eux, le DEHP (Bis(2-ethylhexyl) phthalate), agit comme un anti-androgène, réduit la production de testostérone, et nuit à la production du système de reproduction du poisson. Le DEHP est associé avec un compte de sperme diminué et des déformations d'organes sexuels externes chez les mâles.

Mais cette nouvelle étude démontre que les phtalates ont aussi un effet sur la production et la maturation des oeufs dans le corps féminin, et ce à des concentrations que l'on retrouve dans la nature et notre environnement, risquant l'infertilité chez la femme aussi.

Cette nouvelle étude s'est penchée sur les poissons également, mais démontre encore une fois que l'on doit étudier davantage les effets des phthalates sur la reproduction humaine , chez l'homme comme chez la femme.
"Phthalates impair female reproduction, too, finds fish study.

Phthalate exposure may impair female reproduction at many levels, from growth and maturation of eggs to their release, a fish study shows. Reproductive problems leading to infertility were seen in female fish exposed to pthalates at levels generally found in the environment. The results are some of the first to show the plasticizers can affect females as well as males, report researchers in the online journal PLoSOne.

Many of the effects found in the study depended on the doses of DEHP administered to the fish, which were environmentally relevant, that is, within a range the people and wildlife might experience. This preliminary evidence of the effects of DEHP on the female reproductive system suggests that further study on females is warranted in other species, including humans.

Evidence has increasingly implicated phthalates, a group of environmental chemicals commonly used to soften plastics, in a wide range of health issues from obesity to attention deficit hyperactivity disorder. Because phthalates are so pervasive in the environment, nearly all humans are exposed to these chemicals, making their health effects a particular concern.

Phthalates typically act as anti-androgens, reducing testosterone production, and one particularly potent phthalate, DEHP, has gained notoriety for its negative effects on the development of the male reproductive system. In animal models (and, to a lesser extent, humans), DEHP exposure has been linked to decreased sperm counts and altered development of the external genitals in males. To date, however, few studies have shown that female reproductive function may be at risk as well."

Excerpts of synopsis by Emily Barrett published in Environmental Health News here:

No wonder couples have problems getting pregnant! No wonder species are disappearing before we can discover them!

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