by Janet RitzAs reported in this June 2007 article , the EU banned of the use of the chemical, bisphenol A (BPA) (along with 3,000 other chemicals) last year, after they identified BPA as an endocrine disrupter. Now, nearly one year later, a report from the National Institute of Health's Toxicology Unit has agreed with their conclusions:
A chemical called bisphenol A, which is in hard, clear polycarbonate plastics like those used to make many baby bottles, certain reusable water bottles, and even containers for canned foods, may pose health risks. Specifically, the federal government's National Toxicology Program expressed concern that BPA exposure could cause neural and behavioral abnormalities in fetuses, infants, and children.An endocrine disruptor is a substance that alters the function of the endocrine system and consequently can cause adverse health effects to an organism and/or its progeny. Endocrine disrupters interfere with the endocrine system in (at least) three ways:
Since that announcement, Canada has proposed a BPA ban, and retailers Toys "R" Us and Wal-Mart both said they plan to stop selling BPA-containing baby bottles, according to USA Today. Playtex also said it would stop using BPA in its products, and Nalgene, a maker of durable plastic water bottles, said it intends to do the same.
* mimics the action of a naturally-produced hormone, such as estrogen or testosterone, and thereby setting off similar chemical reactions in the body;Potential human health effects caused by EDCs:
* blocks the receptors in cells receiving the hormones (hormone receptors), thereby preventing the action of normal hormones; or
* effects the synthesis, transport, metabolism and excretion of hormones, thus altering the concentrations of natural hormones.
* For women: Breast and reproductive organ tissue cancers, fibrocystic disease of the breast, polycystic ovarian syndrome, endometriosis, uterine fibroids and pelvic inflammatory diseases. Declining sex ratio (fewer women)You can identify BPA in plastic bottles through the triangle symbol on the bottom:
* For men: Poor semen quality (low sperm counts, low ejaculate volume, high number of abnormal sperm, low number of motile sperm), testicular cancer, malformed reproductive tissue (undescended testes, small penis size), prostate disease and other recognised abnormalities of male reproductive tissues.
* Other potential effects: impaired behavioural/mental, immune and thyroid function in developing children; osteoporosis, precocious puberty.
There are seven classes of plastics used in packaging applications. Type 7 is the catch-all "other" class, and some type 7 plastics, such as polycarbonate (sometimes identified with the letters "PC" near the recycling symbol) and epoxy resins, are made from bisphenol A monomer. When such plastics are exposed to hot liquids, bisphenol A leaches out 55 times faster than it does under normal conditions, at up to 32 ng/hour.We've not yet confirmed whether Type 6 holds BPA. As such, we've left it off the list. That is not to say that we endorse the use of the non-BPA plastics. There is concern that reusing those products can lead to leeching of other chemicals. They are single use products, which means they impact the environment, at the very least.
Type 3 (PVC) can also contain bisphenol A as antioxidant in plasticizers.
Types 1 (PET), 2 (HDPE), 4 (LDPE), 5 (polypropylene) do not use bisphenol A during polymerization or package forming.
"Papers about it are being published at the rate of about one a day," says John Bucher, associate director for the National Toxicology Program, an agency of the National Institutes of Health.The National Toxicology Program has made the following recommendations:
Produced in vast quantities every year -- more than 2 billion pounds in the United States, more than 6 billion pounds worldwide -- bisphenol A, or BPA, is the basic ingredient in hard, clear polycarbonate plastics (No. 7 in the recycling code) and epoxy resins, which are used to make such things as water bottles and baby bottles and the corrosion-preventing lining of cans. ~snip~
In studies of laboratory animals, [Frederick vom Saal, a biology professor at the University of Missouri-Columbia and one of the leading BPA researchers in the country] says, BPA changes play behavior, weakens gender differences, decreases sperm count, stimulates prostate cancer and causes ADHD symptoms.
* Avoid putting polycarbonate plastic food containers in the microwave or dishwasher (you might also want to avoid putting hot food or liquid into polycarbonate plastic containers.) Heat makes BPA leach out faster than it does otherwise.
* Eat fewer canned foods.
* Use glass, porcelain or stainless steel containers, especially for hot food or drinks.
* Don't use polycarbonate baby bottles.
Here's a link (PDF) from the UK Institute for Environment and Health with known endocrine disrupters and to our June, 2007 article on 3,000 chemicals banned by the EU.
LABELS: BPA, ENVIRONMENT, EU, HEALTH, REUTERS, SCIENCE, TOXIN