Bisphenol A (BPA) has been in the news a lot recently. This chemical is used in making many kinds of plastic, including plastic water bottles, the linings of cans, and baby bottles. This chemical can apparently get into whatever food or liquid is stored in the container. When we eat or drink the contents, BPA gets into our bodies. Over 90% of humans have BPA in their bodies. The question that many people have is whether the level is high enough to be dangerous to our health.

BPA has a shape that is like estrogens (the female hormones), but is not exactly that shape. Some of the effects that BPA may have are: causing some types of cancer, causing increasing fat in children and babies, changing some brain chemistry (mood, memory, sex differences, etc.), and changing the development of reproductive systems, some studies show a possible link with diabetes and heart disease. The companies that make BPA do not agree with many of these studies. They say that BPA is safe.

Good question about the heat and time. Heat seems to be much more important in releasing the chemical into the food or liquid. Heat is just movement of molecules. The more that molecules move around and smash into each other, the more mixing takes place.

The body can get rid of at least some BPA. We know this because it is found in urine. But it can still affect our health before it is eliminated. The changes in our bodies may be permanent, even if we get rid of the BPA itself.

If you are worried about BPA, you can do something about it. Drink tap water from a glass instead of bottled water. If you like to fill your own water bottle, look for one that says it is BPA-free. You can also eat less canned food and more fresh or frozen food. Juice sold in glass may be a safer choice than juice sold in plastic or plastic-lined containers. If you are microwaving food, put it in a glass or ceramic container instead of a plastic one.

Reporters from my hometown paper, the Milwaukee Journal Sentinel, were named as finalists for the 2009 Pulitzer Prize for their stories on BPA. This is a very big honor.

Why do you think that people may have different opinions about whether BPA is safe?