May 27, 2005 in Nation/World

Study says mothers’ contact with chemical affects babies

From wire reports
 

Background

Phthalates

Phthalates are used as plasticizers, solvents, coatings and perfume fixatives. They are in hundreds of products, including food packaging, coatings on time-released medicines, soap, shampoo, nail polish, hair sprays, detergents, and vinyl floor coverings.

The European Union has restricted use of some phthalates based on similar problems found in rat studies. Legislatures in California and New York are also looking into limited bans.

Earlier this month, the U.S. Food and Drug Administration said that at the moment the agency “does not have compelling evidence that phthalates, as used in cosmetics, pose a safety risk.”

For the first time, scientists have shown that pregnant mothers exposed to high but common levels of a widely used ingredient in cosmetics, fragrances, plastics and paints can have baby boys with smaller genitals and incomplete testicular descent.

The paper, published today in the journal Environmental Health Perspectives, found that the more a mother was exposed to the chemicals, called phthalates (THAL-ates), the greater the chance her boy’s reproductive development would be harmed. Similar changes have led to decreased semen quality and fertility in rodents. “We’ll have to follow our children to see what the consequences are,” says lead researcher Shanna Swan, a professor of epidemiology at the University of Rochester (N.Y.) School of Medicine.

The changes described in the federally funded study were seen at phthalate levels found in one-quarter of the female population in the United States.

The study tested levels of four kinds of phthalates in the urine of pregnant women. Researchers later examined 134 of the baby boys between 2 and 30 months of age born to those women.

Scientists measured the location, size and descent of the testicles, the volume of the penises, and the distance between the anus and the base of the penis.

That measurement, called the anogenital distance or AGD, is a sensitive indicator of masculinization, Swan says.

Previous work had shown that prenatal phthalate exposure in rodents can critically affect male hormones, resulting in impaired testicular descent and smaller genital size. But the Swan study is the first one to look at its affects in humans.

While none of the boys showed clear malformation or disease, in the 25 percent of mothers with the highest levels of phthalate exposure, the odds that their sons would have a shorter than expected AGD increased 10 times.


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