[Pharmwaste] Unsafe levels of bisphenol A chemical leaching into
drinks, U.S. panel says
dldebiasi at deq.virginia.gov
Thu Aug 2 09:57:07 EDT 2007
Unsafe levels of chemical leaching into drinks, U.S. panel says
>From Wednesday's Globe and Mail
August 1, 2007 at 1:01 PM EDT
The chemical industry has long insisted that bisphenol A levels in
people are so low as to not be a concern. But a new assessment has found
the estrogen-like chemical used to make plastic is present in humans at
levels similar to those shown to be harmful in animal experiments.
The assessment, appearing in the current edition of the journal
Reproductive Toxicology, is likely to raise further health concerns
about the controversial chemical. Although bisphenol A has been known
for decades to act like a hormone, companies have been using it to make
everything from polycarbonate plastic baby bottles and office water jugs
to dental sealants and the resin linings on the insides of most tin
Bisphenol A manufacturers have said the trace amount leaching into food
and beverages isn't dangerous to people because it's quickly metabolized
into a form that loses its ability to act like a female sex hormone.
While the authors of the new assessment agreed that people break down
some of the bisphenol A they absorb, they said since so many plastics
and other products containing it are in use that "virtually everybody"
in developed countries has chronic, low-level exposure to the chemical
and measurable amounts of its biologically active version.
Typical readings are about two parts per billion in blood. Although this
is an extremely small amount, hormones are active at this level, and at
even lower concentrations.
Based on the amounts being found in people and what is known about the
metabolism of bisphenol A from animal experiments, it also appears that
human exposures are above the current U.S. safety limit, according to
The reason for this is not known, although there is speculation that
people are gaining additional exposures beyond those known to be coming
from foods and beverages, possibly through breathing in the air in
buildings containing plastics and through dust.
The assessment was based on the results of an expert panel of scientists
sponsored by the U.S. National Institute of Environmental Health
Its lead author was Frederick vom Saal, a biologist at the University of
Missouri and one of the world's leading authorities on bisphenol A, but
it was also signed by 37 other top experts on the chemical.
The researchers, in the assessment, said they are "confident" in
concluding that one reason bisphenol A is dangerous is because it is
capable of altering the normal functioning of genes, turning them on and
off at inappropriate times.
They believe this property is one reason exposure to the chemical leads
to changes in the prostate, testes, mammary glands, brain structure and
behaviour of laboratory animals, particularly at low doses during
sensitive points of fetal development and adult life.
"The wide range of adverse effects observed of low doses of BPA in
laboratory animals exposed both during development and in adulthood is a
great cause for concern with regards to the potential for similar
adverse effects in humans," the assessment said.
It said some recent human health trends have been similar to bisphenol A
results found in laboratory animal tests, including increases in breast
and prostate cancers, earlier onset of puberty in girls, Type 2
diabetes, obesity and neurobehavioural problems, such as attention
deficit and hyperactivity disorders.
Health Canada and Environment Canada are currently evaluating bisphenol
A, after placing it on a list of potentially dangerous chemicals in
long-term use that were grandfathered in the 1980s from detailed safety
Bisphenol A is sometimes identified on consumer products by the plastic
industry symbol of a recycling triangle containing the number seven.
The conclusions of the assessment were disputed by the plastics
"Over all, claims that bisphenol A, in particular [ biologically active]
bisphenol A, is present in blood at significant levels are not supported
by the weight of the evidence," said Steven Hentges, spokesman at the
American Plastics Council, which represents major makers of the
The industry trade group says one of the testing methods used for
determining bisphenol A in humans is flawed, although those
participating in the expert panel said they didn't rely on the disputed
technology. Instead, they used the results of 14 studies using other
The new research has prompted calls for restrictions on the use of
"We'd like to see some immediate action on this chemical, on food and
beverage containers in particular," said Kapil Khatter, president of the
Canadian Association of Physicians for the Environment.
He said the federal review process could take up to five years to
complete, and he said Ottawa shouldn't wait that long to reduce human
exposures to the chemical through consumer items.
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
Mail: P.O. Box 1105, Richmond, VA 23218 (NEW!)
Location: 629 E. Main Street, Richmond, VA 23219
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