点击显示 收起
Bisphenol A, or BPA, is a chemical compound used to make polycarbonate plastics, epoxy resins, and other materials.
Virtually everyone in the U.S. comes across BPA every day. Among other things, BPA is used to make:
Why Baby Gets Upset During Bowel Movements
Some babies put on quite a show when they are pooping -- they grunt and groan and make all sorts of faces until the bowel movement (BM) is passed. This is very unlikely to signal a medical problem by itself. Babies all seem to get over it, and changes in formula (if bottle feeding) typically don't make a difference. Some may react this way because they are more sensitive to internal sensations. Or those sensations may be more intense for them. Or they may have a more intense temperament and...
Read the Why Baby Gets Upset During Bowel Movements article > >
Not all plastic products contain BPA. You may want to check the recycle codes within the "chasing arrows" on the product.
"In general, plastics that are marked with recycle codes 1, 2, 4, 5, and 6 are very unlikely to contain BPA," the FDA's web site states. "Some, but not all, plastics that are marked with recycle codes 3 or 7 may be made with BPA."?
BPA is also used to coat thermal paper, so it is found on cash register receipts. A March 2011 study by the Washington Toxics Coalition and the advocacy group Safer Chemicals found “very large” quantities of BPA on about half of receipts collected from stores in 10 states and Washington, D.C. Because BPA on receipts isn’t bound to the product, it easily sloughs off onto the skin when the receipts are handled.
The study also found lower amounts of BPA in 21 of 22 dollars tested. Dollar bills aren't made with BPA; it's theorized that the BPA may have gotten onto dollar bills as a result of coming into contact with cash register receipts and other sources of BPA.
Derived from petroleum, BPA is known to mimic the hormone estrogen. There is a growing body of research indicating that BPA may pose health hazards to humans in several ways.
The chemical is an endocrine disruptor, meaning that it can interfere with the body’s endocrine system and potentially cause damaging developmental, reproductive, neurological, and immune effects in humans and other mammals.
Research has linked BPA to breast and prostate cancer in animals and obesity, thyroid problems, reproductive abnormalities, and neurologic disorders in humans.
In January 2010, a study published in the online journal PLoS One found that people with the highest levels of BPA in their body had the highest risk of heart disease. Laboratory studies have also suggested that BPA may interfere with the effectiveness of chemotherapy drugs.
However, much of the research on BPA has been done on lab animals or has come from observational studies in people, which don't prove cause and effect. BPA has not been proven to be responsible for any disease or condition.
The National Toxicology Program reports that it has “some concern” for effects on the brain, behavior, and prostate gland in fetuses, infants, and children at current human exposures to bisphenol A.
Companies that use BPA in their products, as well as industry organizations, including the American Chemical Society, insist that BPA is safe. The North American Metal Packaging Alliance, a trade organization representing canned food and beverage makers, credits BPA linings for the elimination of contamination and foodborne illness from canned goods.
Further research is ongoing. In total, the National Institutes of Health has about $30 million in funded research investigating BPA, which may help answer some of the ongoing questions about its safety.
In 2008, the FDA issued a draft report stating that BPA is safe at current levels of exposure.
But in 2010, the agency changed its position as further evidence accumulated. The FDA's web site states that it “shares the perspective of the National Toxicology Program that recent studies provide reason for some concern about the potential effects of BPA on the brain, behavior, and prostate gland of fetuses, infants,and children.?FDA also recognizes substantial uncertainties with respect to the overall interpretation of these studies and their potential implications for human health effects of BPA exposure.”
You probably can’t -- not entirely. BPA is in so many types of consumer products and packaging that virtually everyone has some levels of BPA in his or her body.
But if you are concerned, there are ways to reduce your exposure. Some tips from the Breast Cancer Fund and Frederick vom Saal, PhD, a professor of biological sciences at the University of Missouri and one of the leading researchers into BPA:
The FDA's web site also has this information for parents who want to minimize their baby's exposure to BPA:
Yes. As of January 2009, the six major baby bottle and sippy cup manufacturers confirmed to the FDA that they had removed BPA from their products. These would include brands such as Avent, Doctor Brown’s Natural Flow, Evenflo, First Essentials, Gerber, Munchkin, Nuk, and Playtex, which together represent more than 90% of the U.S. market for these items.
Michigan-based Eden Foods says that it has used BPA-free cans for all but its highly acidic tomato products for more than a decade, and reports that the BPA in its tomato can lining has been found to be in the “nondetectable” range.
But testing done by Consumer Reports in 2009 found measurable levels of BPA even in products that claim to be BPA-free. They also found that while bypassing metal cans for alternative packaging like plastic containers or bags can lower BPA exposure, these alternative containers weren’t always better.
“Seeking Safer Packaging 2010,” a report compiled by the environmental advocacy group As You Sow along with the investment advisory firm Green Century Capital Management, gave A grades to three companies -- Hain Celestial, ConAgra, and H.J. Heinz -- for their efforts to eliminate BPA from packaging. General Mills got a B+, and Nestle rated a B.
Yes. Several states have banned BPA in certain consumer products. Minnesota’s law bans the chemical in spill-proof cups and baby bottles, while Connecticut’s goes further, banning its use in baby food cans and jars as well, along with reusable beverage containers. In 2010, more states followed these first two, with Maryland, Massachusetts, New York, and Wisconsin banning BPA from products made for young children, and Vermont and Washington state banning it in sports bottles and reusable food and beverage containers as well.
In October 2010, Canada declared BPA to be a chemical that is toxic both to the environment and human health, setting the stage for tighter national regulation.