Science News (Vol. 168, No. 22, p. 341)  [Printer-friendly version]
November 26, 2005


By Janet Raloff

A new federal study strongly suggests that all U.S. residents harbor
measurable traces of fluorochemicals, compounds used to impart water-
and oil-repelling features to a host of consumer products. Separately,
Japanese researchers report that at least one of these pollutants
reaches even fetuses.

According to the Environmental Protection Agency, human exposures are
of concern. In laboratory animals, some of these long-lived compounds
have caused developmental problems, liver toxicity, immune problems,
and cancer.

The studies on people and fetuses, described last week in Baltimore at
the Society of Environmental Toxicology and Chemistry (SETAC) annual
meeting, were among roughly 2 dozen reports on the fate and potential
consequences of fluorochemicals in people, wildlife, and the
environment. Overall, the evidence suggests that these pollutants are

Since the 1960s, manufacturers have used fluorine-based chemicals in a
range of consumer goods, including nonstick cookware, oil-resistant
food packaging, stain-resistant carpeting, and water-repelling
fabrics. One frustration, noted scientists at the meeting, is that no
one yet knows which sources -- or uses -- contribute most significantly to
the residues showing up in people and the environment or at what dose
such compounds might prove toxic.

Many of the more commonly used nonstick chemicals include as a basic
building block either perfluorooctane sulfonate (PFOS) or
perfluorooctanoic acid (PFOA). At the SETAC meeting, chemist Antonia
Calafat of the Centers for Disease Control and Prevention (CDC) in
Atlanta reported on 54 pooled samples of blood that had been collected
3 to 4 years ago as part of the National Health and Nutrition
Examination Study. Each pool contained serum from 34 people, grouped
by ethnicity and age.

PFOS values were 20 to 44 parts per billion (ppb) in non-Hispanic
whites, between 10 and 30 ppb in blacks, and no more than 15 ppb in
Mexican Americans, Calafat reported. PFOA values in all the pools were
lower -- between 2 to 8 ppb -- but again, highest in non-Hispanic whites.
Values differed little by age among the pools, which began at 12 to 19

Although a few earlier studies had detected PFOS and PFOA in blood,
CDC's analysis was the first designed to provide values representative
of U.S. residents.

In a recent study of 15 new mothers, researchers at Hoshi University
in Tokyo reported PFOS blood values of 4.9 to 17.6 ppb. The team also
measured 1.6 to 4.7 ppb in the umbilical cord blood that had fed these
women's babies in the womb. Blood from four moms -- but not cord
blood -- had PFOA values ranging from 0.5 to 2.3 ppb.

Widespread fluorochemical contamination of fish, birds, and other
animals turned up in a survey by Kurunthachalam Kannan and Ewan F.
Sinclair of the New York State Department of Health in Albany. Such
data suggest that game might be one source of these pollutants in the
human diet.

Nonstick cookware has been investigated as another likely candidate,
but in recent tests, the Food and Drug Administration found fry pans
to be a negligible source. However, those tests showed that during
microwaving, the grease-resistant paper used in popcorn bags releases
traces of PFOA to the oil that coats the kernels.

Indeed, microwave popcorn is an extreme case. Paper temperatures that
can exceed 200 deg. C "significantly increase the potential for [PFOA]
migration," say the FDA's Timothy H. Begley and his coworkers in
College Park, Md. In the October Food Additives and Contaminants, they
conclude that in their study of food-contact materials, treated paper
is the greatest potential source of fluorochemicals.


Begley, T.H., et al. 2005. Perfluorochemicals: Potential sources of
and migration from food packaging. Food Additives and Contaminants

Calafat, A.M., et al. 2005. Perfluorochemicals in residents of the
United States in 2001 through 2002. SETAC North America 26th Annual
Meeting. Nov. 13-17. Baltimore.

Nakazawa, H., et al. 2005. Measurement of perfluorcooctane sulfonate
and related perfluorinated compounds in human maternal and cord blood
samples. SETAC North America 26th Annual Meeting. Nov. 13-17.

Sinclair, E.F., and K. Kannan. 2005. Perfluorinated compounds in the
livers of fish and birds from New York State. SETAC North America 26th
Annual Meeting. Nov. 13-17. Baltimore.

Further Readings:

Gorman, J. 2001. Environment's stuck with nonstick coatings. Science
News 160(July 21):36. Available at

Harder, B. 2004. EPA to fine DuPont over ingredient in Teflon. Science
News 166(July 31):78. Available to subscribers at

Raloff, J. 2005. Nonstick pollution sticks in people. Science News
Online (Aug. 27). Available at

______. 2003. Nonstick but not nontoxic. Science News 164(Aug.
30):142. Available to subscribers at

______. 2003. Sticky situation: Nonstick surfaces can turn toxic at
high heat. Science News 163(June 7):355. Available to subscribers at

Smithwick, M., et al. 2005. Circumpolar study of perfluoroalkyl
contaminants in polar bears (Ursus maritimus). Environmental Science &
Technology 39(August 1):5517-5523.

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:

Information from the Environmental Protection Agency about
perfluorooctanoic acid (PFOA) and fluorinated telomers can be found at

Teflon Archives at the Environmental Working Group's Chemical Industry


T.H. Begley
U.S. Food and Drug Administration
Center for Food Safety and Applied Nutrition
College Park, MD 20740

Antonia M. Calafat
Division of Laboratory Sciences
National Center for Environmental Health
Centers for Disease Control and Prevention
4770 Buford Highway, Mail Stop F17
Atlanta, GA 30341

Kurunthachalam Kannan
State University of New York, Albany
Department of Environmental Health and Toxicology
Wadsword Center, Empire State Plaza
P.O. Box 509
Albany, NY 12201-0509

Hiroyuki Nakazawa
Department of Analytical chemistry
Faculty of Pharmaceutical Science
Hoshi University
Tokyo, 142-8501

1010 North 12th Avenue
Pensacola, FL 32501-3368

Ewan Sinclair
State University of New York, Albany
Department of Environmental Health and Toxicology
Wadsword Center, Empire State Plaza
P.O. Box 509
Albany, NY 12201-0509

Copyright 2005 Science Service.