As a new mother-and a scientist-I’ve watched with concern the glacial movement of state legislation seeking to ban toys and bottles that contain the hormone-disruptor bisphenol A. Bills first introduced in 2005 continue to plod through the state Assembly and Senate. Meanwhile, San Francisco, with a different view of risk, last year banned these types of toys and bottles from sale within city limits. While laudable, my own sense of urgency is not appeased because I’ve recently learned from the Organic Consumers Association that neither law addresses the biggest contributor of bisphenol A (BPA) in our bodies: canned foods.

A study by the Environmental Working Group tested commonly eaten canned foods from grocery stores in three US cities, including Oakland. Out of 97 cans, 57 percent contained detectable and often high levels of BPA. Pastas, soups, and infant formula accounted for some of the highest levels. The group estimates that BPA exposure is unsafe in 10 percent of all canned food and a staggering one-third of infant formula.

First synthesized in 1891, bisphenol A is an artificial estrogen that is particularly useful in creating plastic polymers. It is used in a wide variety of products manufactured around the globe, including CDs, fax paper, car parts, adhesives, and bullet-proof laminates. It creates hard plastics, like #7 water and baby bottles, and is also used in epoxy can liners to reduce spoilage of the food inside. BPA has been detected in rivers, soil, and household dust-and is turning up increasingly in studies of human chemical loads. One study found BPA in 95 percent of 400 American adults. It has also been detected in the amniotic fluid surrounding human babies.

For many years now, exposure to BPA has been associated with cancer, insulin resistance, and birth defects. Tests beginning in the ’30s showed that high doses are toxic to rodents. In 1997, it was discovered that low levels of BPA produced harmful effects in male mice exposed in the womb, enlarging the prostate and lowering sperm count. What was most unexpected-and alarming-was that low-dose experiments produced worse effects in the mice than high-dose. Since then, nearly a hundred studies have shown BPA to be toxic in low doses on animals, producing such effects as insulin resistance, damaged DNA, miscarriage, decreased testosterone levels, early puberty, and the production of breast cancer and prostate cancer precursor cells.

Other tests suggest that some people, due to specific genetic makeup, may have a harder time ridding BPA from their bodies, which could make them more susceptible to BPA’s toxic effects. These effects are most dangerous to pregnant women, babies, and young children. For example, in one Japanese study, women who had frequent miscarriages were found to have higher levels of BPA in their bloodstream than women who could carry pregnancies to term. In general, the hormone-unbalancing effects of BPA are not diagnosable as BPA exposure; rather, they may show up as early onset of puberty, reduced fertility, type II diabetes, and an increased risk of cancer. The rise of cancer rates over the last few decades is correlated with the increased use of BPA in industry, although cause and effect is difficult to prove since BPA joins a long list of possible culprits.

While California legislators are at least wrestling with the issue, the Feds last reviewed BPA exposure in food in 1993, when the FDA tested some canned baby formulas and a few other canned foods. It estimated the level of BPA exposure in babies and adults and declared these levels safe, according to the high doses assumed to cause harm at the time. Then the low-dose studies started coming out in the late 1990s. In 1999, the FDA’s George Pauli wrote in the Endocrine/Estrogen Letter that the FDA was unimpressed with these studies. In 2005, George Pauli sent a letter to a concerned California legislator saying there was “no reason [for the FDA] to change its long-held position that current [BPA] uses with food are safe.” Therefore, the FDA does not measure or regulate the amount of BPA in food containers.

To decrease my family’s own chemical load, I purchase organic foods, avoid plastics, buy wooden toys for my son, and use a fabric shower curtain rather than vinyl. But as a busy mom, I often resorted to easy recipes, many of which use canned foods.

After learning about the working group’s study, I contacted nine companies that manufacture the canned foods my family uses. Only one, Trader Joe’s, does not use epoxy liners containing BPA in its cans. All the others, including four makers of organic canned foods, said their can liners contain BPA. I was shocked to learn that the organic foods I was serving my family to keep toxins and pesticides out of our bodies contain BPA! A few of these companies sent me long explanations of why they use BPA in their linings, falling back on FDA guidelines as an indicator of BPA safety. Three claimed that there are no safe alternatives to using BPA liners to protect the canned food from spoiling.

“Not true,” says Jovana Ruzicic of the testing group. “There are alternatives.” I contacted eight companies-General Mills (including Muir Glen organics), B&G Foods, Campbell’s, Amy’s Kitchen, Natural Value, Early California Foods, Acirca (Walnut Acres organics), and Whole Foods 365 (including the company’s organics)-to tell them I am no longer purchasing their products.

What can you do? Let’s lobby the FDA to ban the use of bisphenol A in any food container, including metal can liners. At the very least, food containers containing BPA should be labeled as such. And support bills in the state legislature, such as California Assembly Bill 1108, that would ban bisphenol A and phthalates from toys and baby bottles. Ruzicic suggests that we push on the federal level for the reintroduction of the Kids Safe Chemical Act to protect children from BPA exposure from many sources.

And take the plunge: ask the manufacturers of the canned foods you eat if they use bisphenol A in their can liners. It’s easy: their phone numbers and web page addresses are on the labels.

Here are a few other tips from Ruzicic:

¥ Choose fresh foods over canned.

¥ Do not use canned infant formula-or at least contact the manufacturer to see if bisphenol A is in the can liners.

¥ Avoid using #7 plastics and never microwave plastic containers or put them in the dishwasher. Throw out old, scratched plastic bottles and containers. Elephant Pharmacy carries a line of plastic baby bottles, Born Free, that do not contain BPA.

¥ Use stainless steel drinking bottles that do not have plastic liners, like those made by Real Wear and Kleen Kanteen.

In the meantime, I am learning how to make refried beans from scratch!

For the full report from the Environmental Working Group, go to http://ewg.org/reports/bisphenola/execsumm.php. A longer list of ways to avoid bisphenol A is at ewg.org/reports/bisphenola/consumertips.php. For a comprehensive report on bisphenol A (its uses, history and toxic effects) by the World Wildlife Federation, see: http://assets.panda.org/downloads/bisphenol.pdf.