Q. I've heard that bisphenol A, found in many plastics, is bad for my health. Is this true? Where else is it found, and how can I avoid it?

A. There's a great deal of concern that bisphenol A is harmful to your health. A chemical that acts as a synthetic estrogen, it could potentially cause hormonal disruption in men, women, children, and the unborn. In September, The National Toxicology Program announced that exposure to BPA during pregnancy could negatively impact the developing breast and prostate and have adverse effects on brain development and behavior in children. Because BPA has estrogen-mimicking effects on the body, it may also contribute to breast cancer, infertility and early puberty in girls.

You probably can't avoid BPA completely, but you can minimize your exposure by drinking from glass, stainless steel or certain types of plastic water bottles. Many plastic bottles leach BPA into water — especially if left in the sun. According to the Environmental Working Group, plastic bottles with the number 1, 2, or 4 on the bottom contain no BPA, but bottles with the number 7 on the bottom may have BPA in them. If you use rigid plastic containers for food storage, avoid putting hot foods or liquids in them — the heat may allow BPA to migrate into your food. Always use glass rather than plastic if you microwave your food.

Avoid foods and drinks (such as sodas) in cans with epoxy liners — a common source of BPA. The EWG tested 97 canned foods and found more than half contain BPA. The highest concentrations were found in chicken soup, infant formula and ravioli. The EWG Web site warns that "just one to three servings of foods with these concentrations could expose a woman or child to BPA at levels that caused serious adverse effects in animal tests. For one in 10 cans of all food tested, and one in three cans of infant formula, a single serving contained enough BPA to expose a woman or infant to BPA levels more than 200 times the government's traditional safe level of exposure for industrial chemicals."

It is possible to find canned foods without epoxy liners. Eden Foods, found in many natural food stores, has used BPA-free liners since 1999, except in their tomato sauces.

The Food and Drug Administration is currently investigating the risks of human exposure to BPA. Some companies, such as Playtex and Nalgene, have announced plans to phase out BPA plastics, and some retail chains, including Wal-Mart and Toys "R" Us, are slated to remove BPA-containing baby cups and bottles from their shelves.

Laurie Steelsmith is a naturopathic physician and licensed acupuncturist in Honolulu, as well as author of the new book "Natural Choices for Women's Health," published by Random House. Read her past columns at www.DrSteelsmith.com. This column is for information only. Consult your health provider for medical advice.