November 26, 2005
Science News (Vol. 168, No. 22, p. 341)
Nonstick Taints: Fluorochemicals are in
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 ubiquitous.
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 years.
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
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. Baltimore.
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.
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
Raloff, J. 2005. Nonstick pollution sticks in people.
Science News Online (Aug. 27). Available at http://www.sciencenews.org/articles/20050827/food.asp.
______. 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.
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: http://www.c8healthproject.org.
Information from the Environmental Protection Agency about perfluorooctanoic
acid (PFOA) and fluorinated telomers can be found at http://www.epa.gov/opptintr/pfoa/pfoainfo.htm.
Teflon Archives at the Environmental Working Group's
Chemical Industry Archives: http://www.chemicalindustryarchives.org/search/searchteflon.asp.
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
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
SETAC 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.