No-stick chemicals can mimic estrogen.

Preliminary data indicate that some of the compounds used to keep water from soaking into raincoats, grease from sopping through microwave-popcorn bags, and foods from sticking to cookware have another notable attribute: They can act like estrogen, the primary female-sex hormone.

Recent studies have shown that traces of these ubiquitous coatings, called perfluorinated compounds, regularly turn up in foods and even in human blood.

A research team from Oregon State University in Corvallis injected male and female juvenile trout with any of 36 perfluorinated compounds. Four of the compounds, including a common one known as PFOA, triggered the fish to make vitellogenin, a protein normally produced only by female animals during egg laying. At that time, they have high estrogen concentrations in their bodies.

To probe how the compounds might mimic estrogen, the researchers did lab tests to see whether the four compounds bind to estrogen receptors, the cellular switches that are activated by the hormone. The four apparent estrogen mimics indeed bound to the receptors, but so did many of the other perfluorinated chemicals. These included another common nonstick-coating ingredient called PFOS.

Team member Abby D. Benninghoff concludes that the perfluorinated chemicals such as PFOS might be biologically active if administered through a different, more natural route of exposure. Alternatively, these chemicals might bind to the estrogen receptor and block the hormone from its site of action, she notes.--J.R.