However careful you are about your health, your body is almost certainly home to troubling chemicals called phthalates. These are ubiquitous in modern life, found in plastic bottles, cosmetics, some toys, hair conditioners, and fragrances — and many scientists have linked them to everything from sexual deformities in babies to obesity and diabetes.
The problem is that phthalates suppress male hormones and sometimes mimic female hormones. As I’ve written before, chemicals called endocrine disruptors are believed to explain the proliferation of “intersex fish” — male fish that produce eggs — as well as sexual deformities in animals and humans. Phthalates (pronounced THAL-ates) are among the most common endocrine disruptors, and among the most difficult to avoid. They’re even in tap water, and levels soar in certain plastic water bottles.
They probably are not harmful to us adults, but it is another story for children. In girls, some research suggests that phthalates may cause early onset puberty. Most vulnerable of all, it seems, are male fetuses in the first trimester of pregnancy, just as they are differentiating their sex. At that stage, scholars believe, phthalates may “feminize” these boys.
“Commonly used phthalates may undervirilize humans,” concluded a study by the University of Rochester. The study, which was small, based its conclusion, in part, on measurements of “anogenital distance” — the distance between the anus and the genitals, which is typically twice as long for males as for females. Some scholars believe that shrinkage of this distance reflects “feminization” of male anatomy.
http://www.nytimes.com/2009/07/16/opinion/16kristof.html?th&emc=th