March 18, 2012
New research by scientists from Boston
University finds striking associations between chemical body burdens
of two different types of chemicals and socioeconomic status.
Poor people - especially young children
dependent upon food assistance - were more likely to have higher
levels of Bisphenol-A (BPA)
while wealthier people were more likely to have higher levels of
perfluorinated compounds (PFCs).
If confirmed with additional studies,
the results may force re-evaluations of the heavy use of canned food
in emergency food programs that address food insecurity in families,
or, alternatively, developing replacements for BPA-based can liners.
Just last week, Campbell's Soup
announced they would be
shifting away from the use of BPA in their
In contrast to the food security findings, the scientists found
weaker and inconsistent associations between body burden and
education or occupation. Mexican Americans had the lowest levels of
both chemical types of any racial/ethnic group, and Mexican
Americans not born in the United States had much lower levels than
those born in the United States.
This is the first study to examine in detail how body burdens of
these two chemical types are associated with socioeconomic position,
particularly in relation to food security. Food security measures
food availability, access and use.
The results are consistent with a
earlier study published in Environmental Health
Perspectives in 2007.
The current study does not address potential health risks associated
with these chemical types.
Extensive experimental work with animals,
however, has shown that BPA causes an array of adverse effects in
exposed animals, including at levels within the range of common
exposure that people experience.
Effects include behavioral impacts,
development changes that increase the risk of mammary and prostate
tumors, decreased sperm count and increased risk of type 2 diabetes
and obesity. Recent epidemiological studies on BPA with people have
reported results consistent with altered neurological development
and increased risk of diabetes and heart disease.
Research on the health effects of PFCs is not as extensive as that
on BPA. Animal work with PFCs finds development delays in exposed
animals and also tumors in certain organs. Research with people
reports associations with suppressed immune response, birth weight,
cholesterol levels and infertility.
These new results emerged from an analysis of data gathered by the
U.S. Centers for Disease Control and Prevention (CDC) in
their National Health and Nutrition Examination Survey (NHANES),
an ongoing national survey of the health of the American people and
of associated risk factors, including body burdens of several
hundred chemical contaminants.
Participants supplied urine samples and
reported socioeconomic information through surveys and interviews.
Dr. Patricia Hunt, a BPA expert at Washington State
University who was not involved with this study, says that "common
sources of exposure to BPA include canned food, polycarbonate
plastic and thermal receipts, such as those issued by ATM machines,
gasoline pumps and cashiers in stores."
According to Dr. Glenys Webster, a post-doctoral fellow at
Simon Fraser University who studies PFCs and was also not involved
in this study, exposure to PFCs can result from their use in,
"fast food packaging, including
microwave popcorn bags, hamburger wrappers and french fry
containers as well as their use in stain repellant chemicals
applied to carpets and furniture upholstery."
NHANES estimated food security by asking
a series of questions.
"Were you ever hungry but didn't eat
because you couldn't afford enough food?"
"Did your child ever skip meals
because there wasn't enough money for food?"
It also recorded whether the survey
participant or a member of their household received emergency food
Overall, body burden of BPA - as estimated by BPA concentration in
the urine - was higher in children, women and participants with
lower incomes. People who received food aid had higher levels of BPA
and lower levels of PFCs.
The association with low food security
and use of emergency food aid was "markedly stronger in