http://www.sciencenews.org/articles/20050827/food.asp
Week of Aug. 27, 2005; Vol. 168, No. 9
Science News
Nonstick Pollution Sticks in People
By Janet Raloff
High concentrations of a chemical used in the production of well-known
nonstick surfaces have turned up in people living near a Teflon-manufacturing
plant in West Virginia. The data emerge from the first government-sponsored
epidemiological study of the chemical, known both as perfluorooctanoic
acid (PFOA) and C-8.
| Photo
caption: People from Ohio communities with the most PFOA-tainted
water are encouraged to avoid using tap water for drinking,
cooking—or even for brushing their teeth. |
Since 2000, the Environmental Protection Agency has been investigating
potential risks of this very persistent compound. Once in the
environment, it doesn't appear to break down—ever. Trace
amounts have shown up in the blood of most U.S. residents tested,
although EPA has yet to identify the source. The agency has posted
information on its Web site indicating that "PFOA can cause
developmental and other adverse effects in laboratory animals,"
including cancer.
One source of PFOA in blood that DuPont researchers have all
but ruled out is Teflon-coated cookware. In a new study, researchers
found that PFOA residues were "not detected in over 40 extraction
tests on nonstick cookware under test conditions simulating cooking
and prolonged food or consumer contact." That same study,
in the June 1 Environmental Science & Technology, did find
leaching of PFOA from certain stain-guard treatments of carpeting
and upholstery, suggesting that some consumer products might be
notable environmental sources of the chemical.
The new study measured blood concentrations of PFOA in 326 people
from four communities in southeastern Ohio, across the river from
DuPont's Teflon-making Washington (W.Va.) Works facility. Average
blood concentrations of PFOA in the communities ranged from 298
to 369 parts per billion (ppb). These amounts are more than 60
times those found in most people, notes study leader Edward A.
Emmett, a physician and toxicologist at the University of Pennsylvania
School of Medicine. In general, the new study by Emmett's team
found that PFOA concentrations in an individual's blood tended
to be about 105 times that in the water that the person had been
drinking.
Owing to the limited number of people examined for the study,
the researchers made no effort to look for a possible elevation
in rates of cancer or birth defects among the study volunteers,
Emmett says. However, his team did look for, and failed to find,
an increased incidence of liver, kidney, or thyroid disease. Finding
no indication of liver disease in these people "may be somewhat
comforting" because lab rats treated with PFOA develop liver
toxicity before developing liver tumors.
Water wells serving all four communities are contaminated with
PFOA from the Teflon plant, notes EPA. Indeed, the agency possesses
data from DuPont indicating PFOA contamination for more than 2
decades in the water supplies serving several West Virginia and
Ohio communities. Although two of the Ohio communities are close
enough to the plant to be affected by air emissions of the chemical,
if they occur, blood concentrations of PFOA were actually a bit
higher in people from the more-distant communities. This observation
argues strongly "that the major source of the C-8 [PFOA]
in the residents' bodies is the contaminated water," Emmett
says. Further strengthening that conclusion, his team found that
people who regularly drank bottled, cistern, or spring water had
a median blood concentration of only 55 ppb PFOA in their blood.
At an Aug. 15 town hall meeting, Emmett told residents of the
four Ohio communities: "I urge parents within the study area
to consider taking appropriate measures to reduce C-8 levels in
their children's blood," such as by switching to bottled
water for all drinking, cooking, and tooth brushing. Owing to
the pollutant's capability of causing problems such as birth abnormalities
in lab animals, Emmett advised "the same precaution for pregnant
women and women of child-bearing age who may wish to become pregnant."
The Little Hocking (Ohio) Water Association provides tap water
to an Ohio water district including most of the people who participated
in Emmett's study for more than a year. This water association
had asked DuPont to provide PFOA-free water to people living near
the Teflon plant, notes Robert L. Griffin, general manager of
the water association. The Teflon maker refused to do so, he says,
until just hours before Emmett reported his team's new PFOA data
to the four communities with residents in the study.
DuPont has pledged to supply coupons for free bottled water to
the 4,300 Ohio households that Griffin's company serves. Griffin
says DuPont has agreed to supply this water—for drinking
and cooking only—until the Teflon maker builds a water-treatment
facility that can filter PFOA from the local drinking water.
Water worries
The Little Hocking water district and five others nearby—serving
some 80,000 people—have turned up PFOA groundwater pollution
linked to DuPont's Teflon operations. Little Hocking's 12,000
customers have the most-polluted tap water and are the only ones
now slated to get the bottled-water coupons.
DuPont has agreed to buy bottled water for some 12,000 residents
whose tap water is contaminated with a pollutant from the company's
Teflon-making factory.
In a report to the company's customers, last year, Griffin reported
that his water association had "learned... [that] DuPont,
in the late 1980s or early 1990s, established a 'community exposure
guideline' for C-8 of 1 ppb." EPA has also cited that internal-company
guideline. Currently, no state or federal limit exists for the
pollutant, Griffin notes, although West Virginia has published
a recommended guideline for PFOA in water of 150 ppb. Although
PFOA contamination from the Teflon-manufacturing plant affecting
the other five water districts do not exceed 1 ppb, Griffin says
that Little Hocking tap water "has been as high as 7.2 ppb."
His company decommissioned one well because it was producing water
with 18.6 ppb, and Griffin told Science News Online that a known
plume of PFOA in groundwater could eventually taint the district's
wells with significantly higher concentrations of the chemical.
EPA has charged DuPont with knowing about its PFOA-water-pollution
problem for decades but neglecting to report it to EPA. The company
has argued that it had no legal obligation to do so. Last year,
EPA charged that DuPont's failure to report the PFOA pollution
of water outside its plant and substantial concentrations of the
Teflon chemical in workers' blood violated the Toxic Substances
Control Act (SN: 7/31/04, p. 78).
This past Feb. 28, a judge approved a $107.6 million settlement
of a 3-year-old class action suit against DuPont by residents
near the Washington Works over the water pollution. As part of
that accord, the company agreed to build "state-of-the-art
water treatment systems" for the water districts—including
Little Hocking.
DuPont also pledged to provide the same technology or its equivalent
to residents in the affected communities who rely on private wells
as their sole source of drinking water. The settlement also will
fund an independent study to see whether PFOA is toxic to people
and to conduct long-term health monitoring of residents that had
received water from the six tainted community-water systems.
Data to date
A person's body readily absorbs PFOA but doesn't readily excrete
it, says Tim Kropp, a toxicologist with the Environmental Working
Group, a Washington, D.C., advocacy group that has been unearthing
documents on the health effects and environmental fate of nonstick
chemicals. PFOA's half-life in the body is 4.4 years. What that
means, Kropp says, is that even if no additional PFOA exposure
occurred, the body "would take about 2 decades to get rid
of about 99 percent of it."
In Emmett's study, among people living near the DuPont plant
but not working there, young children and older adults tended
to have the highest body burdens of the pollutant. For instance,
although the median PFOA concentrations was 320 ppb in women and
346 ppb in men, the median among children under 6 was around 500
ppb, and concentrations in some 25 percent of them exceeded 800
ppb. Similarly, the median for people over 60 was 500 ppb but
many had blood concentrations "in the thousands," Emmett
says. That's bad news, he said at the town hall meeting in Ohio,
because these are the most physically vulnerable segments of society.
Another apparent at-risk group: people who eat lots of homegrown
produce. Emmett's team found that among Little Hocking water users,
those who ate no homegrown fruits and vegetables had median PFOA
concentrations of 295 ppb. However, those eating up to 20 servings
per week of garden produce had median concentrations of 420 ppb,
and the value climbed to 469 ppb for those who ate even more home-grown
fruits and veggies.
Whatever the reason for this association, he notes, from a public
health standpoint, it's worrisome. That's because physicians and
nutritionists typically urge people—especially children
and the elderly—to eat plenty of fruits and vegetables.
Concludes Emmett, West Virginia's "so-called 'safe level'
of C-8 of 150 ppb in water may need revision" in light of
the high concentrations of this pollutant showing up in people
exposed to concentrations of only 2 to 7 ppb. With the body's
accumulation of the pollutant witnessed in this study, one might
expect ingestion of water tainted with 150 ppb PFOA to result
in blood concentrations of around 15,000 ppb, says Emmett, "and
we simply don't know those levels are safe." Indeed, he adds,
his study can't confirm that even the much-lower concentrations
seen in Little Hocking residents are safe.
"This study shows that workers are not the only population
at risk from PFOA," says Jane Houlihan, who is vice president
for research at the Environmental Working Group. "Even trace
amounts in water pose risks to residential communities—especially
their children and seniors."
Dupont: little concern
In a statement issued by DuPont, its Washington Works manager
Bill Hopkins said: "We want to provide residents of the Little
Hocking community with the same assurance we have given our own
employees—that based on research of DuPont and [others],
no human health effects are known to be caused by exposure to
PFOA." Hopkins acknowledged in the statement that Emmett's
study "raises important questions" about the long-term
implications of these exposures. However, he said that DuPont
is confident that such issues will be resolved by an independent
science panel that was created earlier this year as part of the
lawsuit that it settled with area residents.
In February, the company began its own health study of residents
near the Teflon factory, probing for signs of any PFOA-triggered
disease.
It complements a company study of workers already under way at
the Washington Works facility. The first wave of findings from
the workers study, reported by the company in January, found no
hint of PFOA-related liver disease or cancer. The only apparent
adverse impact: a 10 percent elevation in total cholesterol (mostly
due to a rise in the so-called bad, low-density lipoprotein fraction)
and a rise in blood triglycerides. Both of these changes were
seen only in very heavily exposed individuals, people with blood
concentrations of PFOA greater than 1,000 ppb.
Finally, DuPont notes that PFOA exposure to community residents
should begin falling. The company says it has cut PFOA releases
from its Washington Works by 98 percent over the past 6 years
and is "aggressively installing" the water-treatment
facilities it promised as part of the class-action settlement
earlier this year.
References:
Lau, C. 2003. Toxicity of perfluorooctane compounds in the environment.
U.S. Environmental Protection Agency Emerging Pollutants Workshop.
Aug. 11-14. Chicago.
Washburn, S.T., et al. 2005. Exposure assessment and risk characterization
for perfluorooctanoate in selected consumer articles. Environmental
Science & Technology 39(June 1):3904-3910. Abstract available
at
http://pubs.acs.org/cgi-bin/abstract.cgi/esthag/2005/39/i11/abs/es048353b.html.
Further Readings:
Gorman, J. 2001. Environment's stuck with nonstick coatings.
Science News 160(July 21):36. Available at
http://www.sciencenews.org/articles/20010721/fob2.asp.
Harder, B. 2004. EPA to fine DuPont over ingredient in Teflon.
Science News 166(July 31):78. Available to subscribers at http://www.sciencenews.org/articles/20040731/note17.asp.
Raloff, J. 2003. Nonstick but not nontoxic. Science News 164(Aug.
30):142. Available to subscribers at
http://www.sciencenews.org/articles/20030830/note15.asp.
______. 2003. Sticky situation: Nonstick surfaces can turn toxic
at high heat. Science News 163(June 7):355. Available to subscribers
at http://www.sciencenews.org/articles/20030607/fob2.asp.
The C-8 Health Project, a health-monitoring program authorized
and funded through the settlement of the class action lawsuit
Jack Leach et al. v. E.I. du Pont de Nemours and Co. and settled
earlier this year over the issue of drinking water contaminated
with the chemical C-8. Web site: http://www.c8healthproject.org.
Environmental Protection Agency. Perfluorooctanoic Acid (PFOA)
and Fluorinated Telomers Home Page.
Available at http://www.epa.gov/opptintr/pfoa/pfoainfo.htm.
The history of Teflon is available at http://www.dupont.com/teflon/newsroom/history.html.
DuPont PFOA Information Resource Web site:
http://www1.dupont.com/NASApp/dupontglobal/corp/
index.jsp?page=/news/position/pfoac8.html.
Teflon Archives at the Environmental Working Group's Chemical
Industry Archives:
http://www.chemicalindustryarchives.org/search/searchteflon.asp.
Sources:
Edward A. Emmett
Occupational and Environmental Medicine
University of Pennsylvania School of Medicine
3400 Spruce Street
Ground Floor Ravdin Building
Philadelphia, PA 19104
Robert L. Griffin
Little Hocking Water Association
3998 State Route 124
P.O. Box 188
Little Hocking, OH 45742
Web site: http://www.littlehockingwater.org/
Jane Houlihan and Tim Kropp
Environmental Working Group
1436 U Street, N.W., Suite 100
Washington, DC 20009
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