06/19/2010 05:12 am ET Updated May 25, 2011

I'm Sorry to Say it, but I was Right About BPA: It IS Dangerous!

Its usually great to be right. But not this time. Four years ago, I began warning people about bisphenol A (BPA), a primary ingredient in polycarbonate plastic. BPA is used to make plastics clear and shatter-resistant, and is in some water bottles, baby bottles, the coatings inside canned foods, dental sealants, and other consumer products. Evidence that BPA migrates from these products into food and drink alarmed me. Bisphenol A is an estrogen-mimicking molecule: such compounds have the potential to interfere with normal development, particularly in reproductive systems, at very low concentrations. And CDC surveys showed that 93% of those tested had BPA in their urine.

Reactions I got back then were mixed. Some people began asking questions, and trying to reduce their exposure to BPA. Others couldn't seem to grasp that not all plastics are created equal, and so they tried to get rid of them all. (Plastics that are clear, hard, and labeled #7 may contain BPA.) But some people just couldn't believe this might actually be a problem. Surely, the government would protect us against such an insidious threat. And anyway, you can't worry about every risk, so why worry about this?

Studies indicated that risks from exposure to BPA might be highest for infants and children. I had a six-year-old daughter at the time, and I worried about the polycarbonate bottles we had given her until well after she turned two. I rid our house of polycarbonate water bottles. I stopped buying milk from a nearby dairy packaged in returnable polycarbonate bottles. And I wrote an article for a local paper explaining the evidence that BPA might be dangerous, especially to pregnant women and small children. My daughter began checking her friends' water bottles, and telling them and their parents to get rid of polycarbonate. We became known around town as anti-plastic scolds.

Well, it turns out I was right to be alarmed. The government hasn't been protecting us, and in fact never required the right studies in the first place. Scientific research done since I wrote that first article has shown that BPA may be even more damaging than I thought at the time. And while I am not a fan of worrying about every possible threat, this one deserves action: the potential harm from BPA, the fact that we are all being exposed, and the evidence that our exposure is at levels that may be causing serious harm is growing stronger. One thing I didn't know then is that BPA is used in nearly all canned food liners, where it migrates into food and then into our bodies.

Seven billion pounds of BPA are produced in the U.S. each year, and according to the EPA, releases of BPA into the environment exceed 1 million pounds per year. Recent studies suggest that BPA migrates: it is detectable in nearly every American's urine, and scientists recently tested ocean water and sea sand at more than 200 sites from 20 countries in North America and Southeast Asia and detected the chemical in EVERY batch of water and sand examined. A 2009 analysis of canned goods done by the Consumers Union, the group that publishes Consumer Reports, found measurable levels of BPA across a range of canned foods, from tuna to green beans. The LA Times reported that the levels detected indicated that children eating multiple servings of some of the tested foods could get doses of BPA "near levels that have caused adverse effects in several animal studies."

Endocrine disrupters such as BPA can cause a variety of serious health problems and hinder normal development and reproduction. Independent researchers have linked BPA to a wide range of possible human health conditions and diseases, including changes in fertility, early onset of puberty, abnormal brain development, obesity, diabetes, cancer (breast, prostate, and uterine), cardiovascular disease and asthma.

Because of their rapidly growing but immature organ systems, babies and children are at greater risk from hormone disruption than adults. And while earlier studies were done primarily with animals, recent studies looking at human exposure are showing disturbing results. One new study suggests that exposure to BPA may be endangering developing fetuses in pregnant women. Researchers have also found that girls with higher prenatal exposures to BPA are more aggressive and hyperactive as 2 year olds than those with lower prenatal exposures. High BPA exposure has been linked to sexual problems in men. Another study found a positive relationship between blood level of BPA and recurrent miscarriages in women.

And many of us may already be affected: In the first large-scale study of human exposure, British researchers found double the risk of cardiovascular disease, diabetes, and liver problems in people with the highest BPA concentrations in their urine. Professor John Wargo of Yale University recently noted "Since 1995, numerous scientists have reported that BPA caused health effects in animals that were similar to diseases becoming more prevalent in humans, abnormal penile or urethra development in males, and type 2 diabetes and immune system disorders."

The mounting evidence against BPA is causing many scientists and regulators to question the safety of current exposure levels: In 2008, the US National Toxicology Program (NTP) released a report finding "some concern" about the chemical's effects on infants and children. They concluded more research is needed to determine just what the risks of BPA exposure might be. Then the Endocrine Society warned that chemicals such as BPA that interfere with the hormone system can cause serious health problems, and recommended a precautionary approach to reducing BPA exposure. In 2008, based on a review of 150 scientific studies, Canada banned the use of BPA in baby bottles, because, as Canada's health minister noted, the highest risk is for newborns and young infants.

After the Bush administration left office, the FDA raised its level of concern over the safety of BPA. Last month, the EPA announced it will formally list BPA as a "chemical of concern" because of potential human and animal health impacts, and will require additional research. Yet most of us continue to unknowingly consume BPA, and how this may be affecting our babies and children really scares me.

Currently US regulators are saying more research is needed to determine whether BPA should be regulated. Manufacturers are not required to label BPA in their food packaging, so buying canned foods without it is currently impossible. Plastic manufacturers, food processors, and other affected businesses are fighting to keep BPA unregulated.

It is time to demand that BPA be banned from materials that come into contact with food and beverages--can linings, water bottles, and especially baby bottles and sippy cups. We also need to impose stricter regulations to reduce its release into the environment, and phase this chemical out completely unless and until it is proven to be safe.

For more information on plastics in general and BPA in particular, go to the following links:

The Green Guide plastics buying guide

USA Today's What you need to know about Bisphenol A

Washington Post guide to limiting your exposure to BPA