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Penn Study Finds No Relationship Between Elevated
C8 Levels and Liver or Thyroid Abnormalities
Highest C8 Levels Found in the Very Young and Eldest
(August
15, 2005) – At a community meeting this evening in Vincent, Ohio,
Edward A. Emmett, MD, Professor of Occupational &
Environmental Medicine at the University of Pennsylvania School
of Medicine, presented the health-related results of an independent,
epidemiological study led by him to investigate C8 levels in the blood
of residents of southeastern Ohio. Specifically, Emmett and his colleagues
reported no relationship between elevated C8 levels and blood-test results
that would indicate liver damage or a history of liver disease (including
cirrhosis, hepatitis, and any other liver condition), or thyroid damage
or a history of thyroid disease.
The researchers found the highest levels of C8 were in the most vulnerable
populations – namely, children under 6 years of age and seniors
over 60 – a situation, said Emmett, that is “the exact opposite
of what we would want to see from a public-health perspective.”
The scientists also reported that C8-levels in the blood were much lower
in those who used bottled or spring water as their primary drinking source;
and, for people using private well water, there was a direct correlation
between C8 levels in the water they drank and C8 levels in their blood
(in that higher levels of C8 in water yielded correspondingly higher levels
of C8 in the blood).
The researchers detected no relationship between high C8 levels in blood
serum and alcohol consumption, cigarette smoking, eating fish caught locally,
and eating meat or game harvested locally. They did detect a link, however,
between the consumption of large quantities of homegrown fruits and vegetables
and higher levels of C8 in the blood. “The nature of this association
will require further study,” notes Emmett, “since it is not
clear if this was due to C8 in the fruits and vegetables themselves, in
the water used for cooking, cleaning, and canning the foods, or if the
people eating more homegrown fruits and vegetables had a different diet
and/or drinking habits than those who consumed smaller quantities of homegrown
fruits and vegetables.”
First Independent, Epidemiological Study of C8 Levels in Blood
The study – the nation’s first government-sponsored epidemiological
study of C8 levels in the blood of 326 volunteer subjects residing in
four communities in southeastern Ohio – previously found C8 levels
that were more than 60 to 80 times higher than those typically found in
the general population. They further concluded that water was the major
source of contamination. Those earlier findings were released July 27,
2005.
All blood samples were run through a battery of carefully-chosen diagnostic
tests designed to detect abnormalities in liver, kidney, and thyroid function,
as well as cholesterol status. Based on those results, the researchers
found no association between elevated C8 levels and changes in those tests.
“We did, however, find the highest elevations of C8 in the blood
serum of young children and older adults, which is of concern since previous
studies in animals have shown a possible link between high C8 levels and
developmental and maturation deficiencies,” said Emmett. “As
a physician and public-health specialist, I urge parents within the study
area to consider taking appropriate measures to reduce C8 levels in their
children’s blood-serum by using an alternative drinking-water source
– such as bottled water -- if their primary residential water-source
contains high levels of C8. I also advise consideration of the same precaution
for pregnant women and women of child-bearing age who may wish to become
pregnant.”
Cancer Risk?
Although exposure to high concentrations of C8 over long durations has
been shown to cause liver, pancreatic, testicular, and other cancerous
tumors in rats, it is not certain that C8 would cause the same effects
in humans. Indeed, an Environmental Protection Agency (EPA) Advisory Panel
is currently debating whether C8 should be considered a likely carcinogen
for regulatory purposes.
“Our study did not address the cancer-risk factor,” explains
Emmett. “However, it should be noted that we found no toxic effects
in the livers of residents studied – and that information may be
somewhat comforting because there is always substantial liver toxicity
in rats whenever C8 has caused liver tumors in rats.” Emmett also
pointed out that current cancer statistics show no elevated cancer-risk
in Washington County, Ohio – where the Penn study participants reside
– and the rest of Ohio.
Recommendations
The researchers recommended the continuation on ongoing efforts to remove
C8 from the area water as expeditiously as possible. They further recommended
that residents consider an alternative drinking source if their primary
residential water source contains high levels of C8. “Alternative
water sources – such as bottled or spring water – should be
considered whenever water may be ingested orally – such as when
drinking water, making tea or coffee, cooking, making infant formula,
or brushing teeth,” said Emmett. “Prior research has shown
that C8 does not readily cross human skin, so it’s unlikely that
a risk is posed by simply showering, bathing, and washing in water containing
C8,” he added.
About the Study
The study – which is independent of any corporation, law firm, or
class-action suit – is funded through a four-year Environmental
Justice Partnership grant from the National Institute of Environmental
Health Sciences; and is specifically designed as a collaborative initiative
among environmental health scientists at Penn’s School of Medicine,
the Decatur Community Association in Cutler, Ohio, and a local physician
affiliated with Grand Central Family Medicine in Parkersburg, West Virginia.
The objectives of the study were threefold: to measure the levels of C8
in the blood of a sample of the population exposed to C8; to determine
whether the major route of exposure is from air, water, or a combination;
and to determine if the levels of C8 are associated with adverse changes
in biomarkers of health effects.
In addition to principal investigator Edward Emmett, MD, the study team
included Frances Shofer, PhD, Les Shaw, PhD, Mary Hufford, PhD, Chintan
Desai and Charlyn Okigbo, all from Penn; Hong Zhang, MD, with Grand Central
Family Medicine in Parkersburg, WV; Nancy Rodway, MD, of Adena Occupational
Health, in Chillicothe, OH; and David Freeman, with the Decatur Community
Association, in Cutler, OH.
About C8
C8 is the commonly used name for perfluorooctanoic acid, or PFOA –
a chemical used in the production of fluoropolymers. Fluoropolymers are
used to make non-stick surfaces for cookware and other uses; aswell as
to make clothing, carpeting, and other products resistant to grease, water,
and stains. According to manufacturers, C8 is not present in the final
products. C8 is very persistent in the environment and is not biodegraded.
Once inside the human body, it is very slowly eliminated.
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