Plastic: Study says most leach hormone-like chemicals

Four editors at the Emmaus publishing house, Rodale, recently re-examined their use of plastics.  Each spent a week trying to avoid the ubiquitous material. Tough job.

Part of their reasoning, as I wrote in a column this morning, was this: "Plastic manufacturers add chemicals to certain types of plastics that can be highly toxic, like bisphenol A and phthalates."

People who are concerned about this have been avoiding plastics with those chemicals. A lot of baby bottles, for instance, are now being offered as BPA-free. The BPA is for bisphenol A, which mimics estrogen.

But now, researchers have found that even plastic products without BPA leach chemicals that have estrogenic effects.

They bought more than 450 plastic items from common chain stores, choosing ones that are likely to come into contact with food.

They then chopped the products into pieces and then soaked the pieces in salt water or alcohol. They then ran the liquid through tests at CertiChem, a testing company founded by one of the study's authors, George Bittner, a professor of biology at the University of Texas, Austin.

They found that 70 percent of the products leached chemicals that acted like estrogen. Some of the producted touted as being BPA-free leached more estrogenic chemicals than those with BPA.

The researchers said that exposing the plastics to real-world conditions, such as sunlight, heating and dishwashing, increases the probability of having estrogenic chemicals leach out. Bittner said that 95 percent of the plastics they tested did so under these conditions.

The encouraging news: The plastic products that had no estrogenic activity prove it is possible to make safe plastics, the authors said.

Their research was published March 2 online by the journal, Environmental Health Perspectives.

Three of the study's authors are affiliated with PlastiPure, Inc., a Texas company that produces plastics, silicones, paper, and other materials that can be both recyclable and certified free of estrogenic activity.

This led some to be skeptical of the results. Others said it underscored recommendations to avoid putting plastics in the microwave or otherwise heating them, and to discard them when they become worn or scratched.