[Pharmwaste] Reassessing the Dangers of BPA in Plastics

DeBiasi,Deborah dldebiasi at deq.virginia.gov
Tue Nov 4 10:08:33 EST 2008


Sunday, Nov. 02, 2008
Reassessing the Dangers of BPA in Plastics
By Alice Park

There's no denying that bisphenol A (BPA), the latest headline-making
toxin, is ubiquitous - it's in hard plastic water bottles, the lining of
food and beverage cans and, most disturbingly, the plastic baby bottles
that most parents commonly use. What's less clear, however, is exactly
what effect BPA has on human health.

That was the subject of an Oct. 31 daylong meeting of the Food and Drug
Administration's (FDA) Science Board. Earlier last week a panel
commissioned by the Science Board released its review of the FDA's
safety report, which concluded in August that current levels of BPA
exposure posed no real health risk. The Science Board convened Friday to
discuss the panel's findings - a highly critical 17-page review that
deemed the FDA's conclusions flawed - and to hear comments from the
public about whether the compound should be banned from food and
beverage containers. The board will now forward the review along with
the FDA's original safety assessment to FDA chief Dr. Andrew von
Eschenbach. The FDA has until February 2009, when the Science Board next
meets, to respond.

Why the renewed uproar over plastic? Since the FDA completed its
original analysis in August, additional data on the potential health
effects of BPA have emerged, linking high levels of BPA exposure to
increased risk of heart disease and diabetes and even a decreased
sensitivity to chemotherapy in cancer patients. The compound is also
linked to developmental and brain effects in infants; BPA is known to
mimic the hormone estrogen in the body, which can cause changes in
developing fetuses and infants. "There is enough evidence today for the
FDA to take the precaution and to certainly get BPA out of infant
products," says Urvashi Rangan, senior scientist and policy analyst at
Consumers Union. "Even more, consumers should not be ingesting this
substance while the science is being figured out."

The FDA's initial assessment - which it has not rescinded - that "an
adequate margin of safety exists for BPA at current levels of exposure
from food-contact uses, for infants and adults" was based on data
available at the time. Back in April, for example, the National
Toxicology Program, which is part of the National Institutes of Health
(NIH), released a preliminary report expressing "some concern" that
according to studies done in animals, BPA could have neural and
behavioral effects on fetuses, infants and children at current levels of
exposure. Recent surveys by the Centers for Disease Control and
Prevention (CDC) had suggested that exposure is widespread, showing that
93% of Americans excrete some BPA in their urine. Still, the weight of
the evidence, mostly from animal studies, did not suggest a significant
health risk in humans, according to the FDA.

But last week, the reviewing panel disagreed, saying the FDA's analysis
excluded several important studies on BPA in animals. The panel also
questioned the quality of some of the included studies and found that
the FDA did not incorporate enough infant-formula samples in its
evaluation. According to the panel review, the FDA's safety report
"creates a false sense of security" and the agency's margins of safety
for BPA exposure are, in fact, "inadequate." Says Tracey Woodruff,
director of the program on reproductive health and the environment at
the University of California, San Francisco, and a former Environmental
Protection Agency scientist: "Unless the evidence is very compelling,
you don't get such a strong statement from a group of scientists."

It's now up to Von Eschenbach to decide how to proceed. He may start
from scratch and commission another report that includes the most recent
findings on BPA; he may reject the panel's review and adhere to the
FDA's original conclusion that BPA is harmless at current exposure
levels; or he may ban the chemical from baby products, as the Canadian
government did in April. Or he may draw no further conclusions about BPA
until additional studies can be commissioned and completed to answer
some unresolved questions.

"While we have some idea of how much BPA might leach from a baby bottle,
there are intermediate steps between that and how much gets into an
infant that we still need to model and establish mathematically," says
John Bucher, associate director of the National Toxicology Program,
which collaborates with the FDA, NIH and CDC. "And we don't have that
yet." The FDA report maintains, for example, that a BPA exposure level
of 5 mg/kg per day is acceptable. Health officials have determined that
baby bottles can produce anywhere from 7 micrograms/g to 57.7
micrograms/g of BPA. The questions are: How much of the compound is
absorbed into an infant's body? How much remains, and how much is
excreted? And does that exposure come close to the FDA threshold?

The FDA can't answer those questions yet, but some experts argue that
the agency doesn't need to wait to take action. "The Federal Government
entered into a voluntary recall of the Teflon chemicals [in pots and
pans] on less evidence than we have for BPA," says Woodruff, "because
there was concern that people were chronically exposed to a chemical
linked to some evidence of potential human harm." Woodruff says the
estimated range of exposure to BPA for formula-fed infants is within the
range of doses that have led to adverse effects in animal studies.

Until the government settles on a new assessment or action, experts say
parents have the option of using BPA-free products - including glass,
stainless steel and some innovative next-generation plastics that do not
contain the chemical.

Deborah L. DeBiasi
Email:   dldebiasi at deq.virginia.gov
WEB site address:  www.deq.virginia.gov
Virginia Department of Environmental Quality
Office of Water Permit Programs
Industrial Pretreatment/Toxics Management Program
PPCPs, EDCs, and Microconstituents
Mail:          P.O. Box 1105, Richmond, VA  23218 (NEW!)
Location:  629 E. Main Street, Richmond, VA  23219
PH:         804-698-4028
FAX:      804-698-4032

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