This thread is for those who don’t know what bisphenol A is and what the implication of our massive daily exposure might be. This is not an in depth
analysis of every single aspect, but more like a teaser to some of the important ones, hopefully you will do your own research after. The thread would
be 200+ pages if it should cover every aspect of BPA.
Every year, over 6 billion pounds of bisphenol A (BPA) are produced worldwide. BPA also known as shockproof plastic is used in the production of
polycarbonate plastics and epoxy resins.
Polycarbonate plastics have many applications including use in some food and drink packaging, e.g., water and infant bottles, food containers, travel
mugs, metal can linings, childrens toys, pizza boxes, toilet paper, water coolers, microwave ovenware and eating utensils, skylights, eyeglass
lenses, cabinets for electrical appliances, compact discs, impact-resistant safety equipment, cashier receipts, thermal paper, fax paper, cd’s,
dvd’s, food processors, blenders, sports equipment and medical devices. Epoxy resins are used as lacquers to coat metal products such as food cans,
bottle tops, and water supply pipes. Some dental sealants and composites may also contribute to BPA exposure.
Why be concerned?
One reason people may be concerned about BPA is because human exposure to BPA is widespread. BPA has been detected in various types of tissues and
fluids in the human body, including urine, blood, adipose tissue, placenta, umbilical cord, amniotic fluid and breast milk. A survey from 2003-2004
conducted by the Centers for Disease Control and Prevention (CDC) found detectable levels of BPA in 93% of 2517 urine samples from people six years
Bisphenol A (BPA) has been associated with
increased risk for cardiovascular disease,
earlyer puberty for girls
breast and prostate cancer,
reproductive dysfunction (multiple generations),
Thyroid function ,
metabolic dysfunction and diabetes,
neurological and behavioral disorders,
type 2 diabetes,
behavioral and learning difficulties in children,
and it makes the sperm count plummet on men.
In 2010 the Breast Cancer Fund, a nonprofit group that looks at the scientific evidence linking chemical exposure to breast cancer. In regards to
Bisphenol A exposure, the report cites concerns for the development of breast cancer.
Studies using cultures of human breast cancer cells demonstrate that BPA acts through the same response pathways as the natural estrogen
Plastics and pesticides are examples of products that contain oestrogenic endocrine-disrupting chemicals, or EEDCs, which can interfere with
mammalian development by mimicking the action of the sex hormone oestradiol. For instance, the exposure of developing rodents to high doses of EEDCs
advances puberty and alters their reproductive function
Several studies using both rat and mouse models have demonstrated that even brief exposures to environmentally relevant doses of BPA during
gestation or around the time of birth lead to changes in mammary tissue structure predictive of later development of tumors.
Exposure also increased sensitivity to estrogen at puberty. Recent data demonstrate that early exposure to BPA leads to abnormalities in mammary
tissue development that are observable even during gestation and are maintained into adulthood.
Interestingly, some of the long-term effects of neonatal exposure to BPA may be dose dependent, with low- and high-dose exposures resulting in
different timing and profiles of changes in mammary gland gene expression.
New research suggests that exposure to bisphenol A (BPA) during gestation and lactation lowers male fertility in adulthood and that the effect may
persist for at least three generations. The rat study tested relatively low levels of BPA chosen to fall within the range of human exposures.
In the recent study, data collected from Chinese workers exposed to BPA exhibited a clear connection between even very low levels of BPA and sperm
destruction. BPA exposure resulted in a 300 percent increased risk of low sperm concentration and low sperm vitality compared to those not exposed.
How are we exposed?
As mentioned initially in the warning BPA is impossible to avoid and can be found almost everywhere. The primary source of exposure to BPA for most
people is through the diet. While skin-exposure, air, dust, and water are other possible sources of exposure. Bisphenol A can leach into food from the
protective internal epoxy resin coatings of canned foods and from consumer products such as polycarbonate tableware, food storage containers, water
bottles, and baby bottles. The degree to which BPA leaches from polycarbonate bottles into liquid may depend more on the temperature of the liquid or
bottle, than the age of the container. BPA can also be found in breast milk!
Scientists have not determined how much of a receipt's BPA coating can transfer to the skin and from there into the body. Possibilities being
• Oral exposure -- BPA moves from receipts onto fingers and then onto food and into the mouth.
• Dermal exposure -- BPA from receipts is directly absorbed through the skin into the body.
A study published July 11 by Swiss scientists found that BPA transfers readily from receipts to skin and can penetrate the skin to such a depth that
it cannot be washed off. This raises the possibility that the chemical infiltrates the skin's lower layers to enter the bloodstream directly. BPA has
also been shown to penetrate skin in laboratory studies.
Laboratory tests found high levels of the estrogen-like chemical bisphenol A on 40% of cash register receipts from major U.S. businesses
An analysis of EWG's tests for BPA contamination in canned food reveals that people who eat canned foods are likely to ingest doses of BPA that
are very close to levels now known to harm laboratory animals.
BPA levels higher than those in canned foods, baby bottles and infant formula were detected on at least one of several receipts from Chevron,
McDonalds, CVS, KFC, Whole Foods, Safeway, the U.S. Postal Service, Walmart and the U.S. House of Representatives cafeteria, according to the private
Washington-based research group.
edit on 15-1-2012 by Mimir because: (no reason given)