The debate over the dangers of a chemical compound known as Bisphenol A or BPA has been a hot topic of discussion as of late, with great concern over its use being expressed by many different parties. The Canadian government recently acted to significantly limit the use of BPA, and ongoing research has linked BPA to a variety of health issues.
I find the following article, which addressees some of the key issues surrounding the BPA controversy, to be quite helpful at understanding some of the whys and wherefores behind the concerns. As it points out, exposure to BPA is very widespread, and when we are dealing with chemicals of this type ("endocrine disruptors"), even minute amounts can result in exponentially high risks. Most people are probably not aware that certain factors, such as the use of older plastic containers or heating certain plastic containers, can increase hazards even further.
Spokesman for the packaging industry and others that heavily depend on the use of BPA cannot necessarily be trusted regarding their claims that BPA is not harmful, as the financial impacts would be enormous on these industries if the use of BPA is curtailed or banned. Nevertheless, we have a major wellness issue on our hands here, and even if BPA is not regulated, there are definite steps that can be taken to avoid exposure to ourselves and our families.
BPA Q&A: Plastic chemical is difficult to avoid
12:00 AM CDT on Sunday, May 18, 2008
By JEFFREY WEISS / The Dallas Morning News jweiss@dallasnews.com
What is bisphenol A and why do I care?
Bisphenol A, also known as BPA, is a man-made chemical found in some plastics, the linings of most cans used for foods and beverages, printer ink, dental sealants and car parts and has a number of other uses. While U.S. government and industry officials say current exposure standards are adequate, other scientists say those standards may represent a health risk.
If the critics are right, who may be at greatest risk from BPA exposure?
"Endocrine disruptors" such as BPA particularly affect developing cells. So fetuses and children, whose organs, brains and reproductive systems are still growing and changing, may be most at risk. In adults, some cancers react to estrogen and similar substances.
When was it first used?
In the 1930s, biochemists realized it was chemically similar to the natural hormone estrogen but decided other estrogenlike chemicals would be more effective as medication. At about the same time, materials chemists used it in a sticky glue that hardened -- an epoxy. Then it was used as the essential building block of a clear, hard, heat-resistant, durable plastic called polycarbonate. During World War II, a tin shortage pushed the food canning industry to search for a new protective lining. A spray-on epoxy using BPA proved particularly effective. Versions of that coating have been used ever since.
Did anyone test BPA to see if it was harmful?
Yes, using "high-dosage" testing. Imagine tossing 100 rocks at a lab rat and discovering that was enough to kill it. And that 50 broke some bones. And that 10 left some bruises. But that five had no detectable effect. Logically, anything less than five rocks also should be harmless. The quantity of BPA that gets into foods and beverages is far smaller than the "five rocks" level scientists identified using the high-dosage tests.
Why isn't that good enough?
Sometimes biology defies common sense, and less can be more. What if it turned out that dust from those rocks could produce an allergic reaction in the rat? The high-dose test would never identify that result. Estrogen has just this counterintuitive effect of creating enormous effects in what seems like ridiculously small amounts. Over the past decade, scientists using low doses of BPA have reported finding those kinds of effects in a variety of animals.
How low a dose?
Researchers report effects at a few parts per billion, which in an average life would be pretty close to nothing. But one drop of water containing one part per billion of BPA would contain 132 billion BPA molecules. And one BPA molecule may be enough to trigger changes in the workings of a single cell, said Frederick S. vom Saal, a biologist at the University of Missouri-Columbia who first started sounding an alarm about low-dose effects of BPA more than 10 years ago.
What kinds of effects?
In more than 700 low-dose studies on animals and cells in test tubes, researchers say they've found effects that include enlarged prostates, altered mammary glands, genetic damage to eggs, changes to reproductive organs, accelerated puberty, reduced fertility and altered brain development. In one study of snails, there was such an overgrowth in ovarian cells that the animals exploded and died.
What do exploding snails mean to human biology?
Maybe nothing. Many animal experiments do not translate into actual human effects. But Dr. vom Saal said there is good evidence that human cells in test-tube experiments react to BPA in much the same way that animal cells do. Industry officials disagree.
What do industry officials say about the potential risk posed by BPA?
Sharon Kneiss, vice president of the products division of the American Chemistry Council, was quoted last month in Plastics & Rubber Weekly: "Polycarbonate bottles that contain BPA and BPA-lined cans are safe," she said. "There is no definitive evidence that exposure to BPA causes adverse health effects in humans." And industry representatives point to their own animal experiments that they say show no ill effects. But critics say those experiments used animals known to be resistant to the very effects that estrogenlike substances can produce.
Why can't the scientists just do an experiment on human beings and figure out who is right?
It's probably not possible. It's unethical to experiment on people without the possibility of a medical benefit. Plus, some of the effects that scientists fear from BPA would not show up for decades, until a child who was exposed in the womb grew up. And any good experiment needs a "control group" that hasn't been exposed to the test material. But tests by the Centers for Disease Control and Prevention found than more than 90 percent of the people tested had BPA in their urine -- making it very difficult to find people who have not been exposed. In the study, the CDC measured 2,517 participants who were 6 years old and older in the 200304 National Health and Nutrition Examination Survey.
What do government regulators say about BPA?
A U.S. panel that studied the evidence released a report last month that said it found "some concern" about effects on fetuses, infants and children, but did not suggest any regulatory action. About the same time, a Canadian panel suggested that BPA was a toxin, and the Canadian government announced plans to ban in 60 days baby bottles using BPA.
Is it possible to avoid BPA completely?
It would be very difficult. About 6 billion pounds of it are produced worldwide every year. In addition to its use in water bottles, the linings of most food cans and other food-related items, it's widely used in other industries. It's in the dust we breathe and may be in the water that comes from the tap. But researchers who worry about BPA say it's still worth trying to limit the amount we ingest.
What are the alternatives to BPA?
Plastics makers already are switching over some products to a material called PET, or polyethylene terephthalate. It's cheaper than BPA and more recyclable -- the used stuff can be turned into polyester cloth. It's not as durable, clear or heat-resistant. It's already widely available in one-time-use bottles of soda and water. But Dr. John Rost, chairman of the North American Metal Packaging Alliance, said last week that there are no good alternatives for most American products.
Has anybody else found an alternative for cans?
In the United States, Eden's line of organic bean products has been packaged in BPA-free cans since 1999. The material is more expensive than the BPA lining and is too fragile for use with most other foods. In Japan, according to the Japanese National Institute of Advanced Industrial Science and Technology, food canners have been using two alternatives for a decade: One is made with PET and the other with an epoxy that has much less BPA than the previous version. Dr. Rost said the alternative coatings are used in Japan for canned beverages that are served hot. Dr. vom Saal said the Japanese cans leach only 5 percent as much BPA as their American counterparts.
Are there factors that make it more likely that BPA will be released into foods or beverages?
Tests indicate that heat, acidic foods and aging containers all contribute to increased release of BPA. So heating a can of baby formula and putting it in an old polycarbonate baby bottle would be an example of what some researchers would call elevated risk.
So if I want to limit my exposure, what can I do?
Avoid canned foods and beverages, though not all tests of canned foods have found BPA. Avoid polycarbonate bottles, tableware or eating utensils by looking for identifying marks on the packaging or the plastic itself. If it says "PC" next to the triangular recycling insignia, it's probably got BPA. If the number inside the insignia is "7", it may have BPA, but not necessarily. Any other number probably means it's BPA-free. Recycled paper, sometimes used for food packaging, also has been found to be high in BPA, because of the use of the material in ink and carbonless paper. When in doubt, call the manufacturer's customer service department. They are all primed to answer questions about BPA.
http://www.dallasnews.com/sharedcontent/dws/news/localnews/stories/DN-plasticsQ&A_18met.ART.State.Edition1.465f0cb.html
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