Bisphenol A (BPA)
There remains an ongoing debate about the safety of BPA, found
in plastic bottles, food and beverage can linings, and other
food containers. On one side, government-funded studies suggest
this compound contaminates our food and beverage to such an extent
that they interfere with our hormones and even our epigenome,
increasing risks of certain types of cancers and obesity, not
only for the individual, but possibly for his/her off spring.
On the other side, chemical company funded studies claim no such
negative health effect.
- Bisphenol A is suspect of being linked to several human epidemics
- Breast and prostate cancers
- Enlargement of prostate
- Early onset of puberty
- Obesity (Masuno 2002)
- Bisphenol A enters body
- Digestion of contaminated water and food
- Inhalation, entering through lungs
- Skin contact (same way birth control does in patch form)
- Mother’s blood stream to fetus
- Studies by the CDC found bisphenol A in the urine of 93%-95%
of Americans (Calafat 2005, 2008)
- Suggests people are exposed regularly since bisphenol doesn't
stay long in the body
- Canned foods account for the greatest exposure of BPA (Environmental
Working Group)
- Products containing bisphenol A
- Plastic water bottles
- Plastic food containers
- Plastic baby bottles (transparent plastic)
- detachable nipples have also been found to contain trace
amounts of bisphenol A (Vom Saal)
- Plastic resin in canned foods and aluminium beverage containers
(Consumer Reports, Dec 2009)
- BPA has even been detected BPA-free cans (Consumer Reports,
Dec 2009)
- Food containers from recycled paper (Ozaki)
- Dental sealants, CDs and Toys, PVC pipe, medical equipment,
cash register receipts (Consumer Reports, Dec 2009)
- The rate of bisphenol A leaching from plastic containers
into foodstuffs is accelerated by
- Contact with lipids, such as those found in milk, formula,
cheese, meat, and vegetable oils
- bisphenol A links to lipid molecules
- Contact with acidic foods, such as fruit juice
- Repeated washings
- Exposure to heat or sunlight (Belcher)
- Recommendations
- Avoid plastic food packaging and storage
- No plastic of any kind should be placed in heat, particularly
the microwave (National Toxicology Panel)
- Choose foods in glass bottles instead of plastic or metal
containers with plastic liners
- Soy foods, containing a natural estrogens, may offer limited
protection
- Other environmental contaminants
- Plastic pollutants in our lakes, streams, and oceans
- Bisphenol A found in water
- suspect cause of unusually high instances of hermaphrodism
in wildlife (Tillitt D)
- Bisphenol A is hormonally ‘active’.
- It has an effect in cells at levels thousands of times lower
than toxicology reports had previously deemed safe (Nagel S)
- Unlike natural estrogens such
as those found in soy beans, bisphenol A does not bind to blood
proteins, which normally acts like a barrier, keeping estrogens
from entering the cell.
- Bisphenal A has been shown to stimulate human breast-cancer
cells to proliferate in vitro (Welshons W)
- Bisphenal A has been shown to enlarge prostates in mice at
dosages close to what humans are exposed to from sources such
as food packaging (Nagel S, Environmental Health Perspectives,
National Institute of Health, 1997)
- Bisphenol A has been shown to lower sperm counts in mice
(Nagel S, 1997)
- Chemical companies have infiltrated our government agencies
and scientific communities
- In 1996, Congress passed the Food Quality Protection Act
and the Safe Drinking Water Act. It mandated the EPA to begin
protecting consumers from endocrine disrupting chemical such
as those found in pesticides and plastics by the year 2000
- The US Environmental Protection Agency has been ineffective
in protecting the public from bisphenol A.
- Although scientists make up part of the panel of experts
to advise the EPA on chemical screening, representatives of the
chemical industry were also invited.
- The chemical companies were permitted to choose how they
would carry out the tests
- (Eg: using a particular breed of rat and feeding rats a chow
that contains soy, a natural estrogen).
- In 1998 a House committee began investigating the rumored
conflicts of interest in the scientific panels advising the EPA
- In 1997, Center for the Evaluation of Risks to Human Reproduction
(part of the US National toxicology Program) assembled an expert
panel on bisphenol A
- Scientists not were permitted to be apart to the CERHR panel
if they had published a study on bisphenol A
- The CERHR panel was ultimately discredited and disbanded
when it was discovered that Sciences International, the company
contracted to write the CERHR reports, had been funded by more
than 50 chemical companies, including Dow Chemical (Cone M, Los
Angeles Times, 7 March 2007).
- On late 1997, A representative from Dow Chemical (one of
the largest producers of bisphenol A) reportedly offered Missouri
University research funding in exchange for Vom Saal, Nagel,
and Welshon to withhold publishing their research findings until
authorized to do so by the Chemical Manufactures Association.
Vom Saal’s team rejected the offer.
- Subsequent studies performed by independent labs (other than
MU or those funded later funded by the chemical industry) confirmed
the hormonal activity of bisphenol A
- A study conducted at the department of pharmacology at University
of Pittsburgh discovered mice that had been exposed to bisphenol
A before birth had permanently enlarged the prostates (Gupta
C, 1999).
- At the University of Berlin, Gilbert Schonfelder (2003) detected
bisphenol A in the human blood of pregnant women and in the placenta
and umbilical cord blood of their babies
- Babies are the most sensitive to the hormonal effects of
bisphenol A (Welshon)
- Dr Fred Vom Saal has featured in PBS Frontline and ABC's
20/20 and has testified in front of state legislators regarding
bisphenal A.
- In an interview with PBS, Dr Vom Saal explained:
- If we were dealing with a topic that didn't have incredible
economic consequences, there wouldn't be the kind of resistance
to what we're talking about right now.
- His 'Endocrine Disrupters' team (including Welshons and Nagel)
at Missouri University is now (2008) studying the link between
bisphenol A and obesity.
- A review of the 115 published studies on bisphenol A found
90% of government studies found adverse low dose effects of bisphenol
A. Interestingly, no studies funded by the chemical industry
found any effect (Vom Saal F & Hughes C, 2004).
- In March 2008, a congressional inquiry found the FDA’s
conclusion bisphenol A is safe was based on only two studies,
both sponsored by the Society of the Plastics Industry, a subsidiary
of the American Chemistry Council
- Find other
articles about hormone disrupters and plastics in our links
section.
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