An analysis of nearly 300 umbilical cord blood samples led
by researchers at the
Johns Hopkins Bloomberg School of Public Health shows
that newborn babies are exposed to perfluorooctane
sulfonate and perfluorooctanoate while in the womb. PFOS
and PFOA are polyfluoroalkyl compounds, or PFCs —
ubiquitous man-made chemicals used in a variety of consumer
products, including as a protective coating on food-contact
packaging, textiles and carpets, and in the manufacturing
of insecticides. The health impact from exposure to these
compounds is not fully known, but previous studies found
that these compounds could cause tumors and developmental
toxicity in laboratory animals at doses much higher than
those observed in the Johns Hopkins study.
The analysis conducted in Baltimore detected PFOS in
99 percent of the infant samples examined and PFOA in 100
percent of those examined. The results are published in the
April 20 online edition of the journal Environmental
Science & Technology. Some of the study's findings were
previously reported at the Society of Toxicology workshop
in February and at the International Conference on
Environmental Epidemiology and Exposure in September.
"When we began this research, we weren't sure what we
would find because previously there was very little
information about fetal exposure to PFOS and PFOA. Even
though these chemicals are not bioaccumulative in fat, they
are very persistent, which probably accounts for their
presence in nearly every newborn," said Benjamin Apelberg,
lead author of the study and a research associate in the
Bloomberg School's
Department of Epidemiology. Apelberg conducted this
work as part of his doctoral research.
The researchers analyzed cord serum from 299 newborns
delivered at The Johns Hopkins Hospital in 2004 and 2005.
The samples were tested for the presence of PFOS and PFOA
and eight other polyfluoroalkyl compounds. PFOA was
detected in all the samples and PFOS in all but two. The
concentrations for both compounds were lower than those
typically detected in adults in the United States and lower
than those known to cause tumors and developmental problems
in laboratory animals; more study is needed to understand
health effects at these lower exposure levels.
PFOS concentrations were slightly higher in black and
Asian infants compared to white infants, but no correlation
was found between concentrations and the mother's
socioeconomic status, age, education, marital status or
whether or not she lived within the city limits. In
addition, the researchers found a strong correlation
between concentrations of PFOS and PFOA even though the
compounds come from different industrial sources. The
finding suggests that humans may be exposed to both
chemicals in a similar manner.
Lynn Goldman, co-author of the study and a professor
in the
Department of Environmental Health Sciences at the
Bloomberg School, said, "This study confirms that, as we
might have suspected, exposure to PFOS and PFOA is fairly
universal. This is of particular concern because of the
potential toxicity, especially developmental toxicity, for
these chemicals and the lack of information about health
risks at these exposure levels. What was surprising is how
strongly they are associated with each other, given that
they have very different uses. We will need additional
research to understand how exposures are occurring in this
region."
Additional study authors are Antonia M. Calafat, Julie
B. Herbstman, Zsuzsanna Kuklenyik, Jochen Heidler, Larry
Needham, Rolf U. Halden and Frank Witter. Heidler and
Halden are with the Johns Hopkins Bloomberg School of
Public Health. Herbstman, formerly a doctoral student in
epidemiology at Johns Hopkins, is now at the Columbia
Mailman School of Public Health, and Witter is with the
Johns Hopkins School of Medicine. Calafat, Kuklenyik and
Needham are with the Centers for Disease Control and
Prevention.
The research was supported by funding from the
Bloomberg School of Public Health's Maryland Mothers and
Babies Study, the Cigarette Restitution Fund, Johns Hopkins
Medical Institutions, Johns Hopkins Center for a Livable
Future and the Heinz Foundation.
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