[Pharmwaste] Food may not be sole BPA source

[DeBiasi,Deborah]

http://www.theglobeandmail.com/servlet/story/LAC.20090130.LBPA30//TPStor
y/Environment

Health: STUDY: BISPHENOL A

Food may not be sole BPA source
MARTIN MITTELSTAEDT 

ENVIRONMENT REPORTER

January 30, 2009

New research on bisphenol A suggests that people are being exposed to
the estrogen-mimicking chemical from a number of sources and not just
food, as is commonly thought.

Scientists think there may be other sources because they have found
unexpectedly high levels of the compound, used in the making of plastic,
in people who have been fasting. This has led to speculation that people
may be absorbing the chemical from such seemingly innocuous items as
polyvinyl chloride (PVC) water pipes and carbonless cash-register
receipts.

The research, published this week in the journal Environmental Health
Perspectives, has major implications because regulators, including
Health Canada, have assumed that almost all human exposure to bisphenol
A (BPA) is the result of residue inadvertently ingested from food and
beverage packaging.

This assumption may be wrong.

 "If you look at populations of people, by 15 to 20 hours [of fasting],
it should be practically gone, and it's not," says Richard Stahlhut, a
postdoctoral fellow at the University of Rochester Medical Center in New
York, who led the research team that announced the finding. "These high
levels probably point to another source, and not a trivial source."

BPA from food is rapidly broken down by the liver into a biologically
harmless form. Its half-life is about five hours, meaning that 50 per
cent is metabolized in each time period of that length. But the
researchers found that a group of people who fasted longer than 8.5
hours continued to have elevated amounts of BPA in their urine.

The amounts of the synthetic chemical were extremely small - typically
in parts per billion - but estrogen is active at levels in parts per
trillion, a thousand times less.

Dr. Stahlhut said another possible explanation is that people are
accumulating BPA in their body fat, and during fasting the chemical is
released. It is also possible that there is some combination of exposure
from non-food items and releases from fat, he said.

Regardless of the source, Dr. Stahlhut says, people are being exposed to
more BPA and for longer time periods than is commonly thought.

Health Canada said it will review the findings "and will take further
action to protect Canadians' health if necessary."

Scientists have been studying BPA because it resembles estrogen, giving
those who are exposed to it an extra amount of the female hormone.
Studies have linked it to such conditions as breast cancer, heart
disease and diabetes.

Last year, Health Canada said it would place BPA on the country's toxic
substances list and ban its use in baby bottles, based on concerns that
infants might be ingesting too much. The agency concluded that adults
were at no risk, but estimated that about 90 per cent of exposure was
from food.

Traces of BPA get into food because it is used to line tin cans and
metal lids on glass jars.

Despite BPA's short half-life, surveys have found that almost everyone
carries the chemical, a man-made substance not found in nature. The new
research was based on a review conducted by the U.S. government in 2003
and 2004 that found 93 per cent of people tested had detectible amounts.

The data covered more than 1,400 people, who were asked not to eat for
varying amounts of time before their urine was analyzed (they were
allowed to drink fluids).

The industry group representing BPA makers played down the new research.
"The conclusions and the implications that the authors present are
speculative at best," said Steve Hentges, a spokesman for the American
Chemistry Council.

Other researchers say the new finding is significant.

"This study profoundly challenges the assumptions of regulatory agencies
about how we're exposed to bisphenol A," said Frederick vom Saal, a
biology professor at the University of Missouri.

He speculated the BPA may be coming from products such as PVC water
pipes. People may absorb it by drinking water or by breathing in water
vapour while showering.

Dr. vom Saal has also tested carbonless paper and found BPA in it, too.

He said touching items such as cash-register and credit-card receipts
may lead to some BPA being absorbed through the skin in much the same
fashion as an estrogen patch delivers a dose of hormone.

He called on governments to reduce uncertainty over where the BPA in
people originates by requiring companies to disclose whether the
chemical is in their products.



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
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