The federal government has found evidence of dioxin contamination in
chickens, eggs, and farm-raised catfish, and has banned the shipment of
chickens and eggs from hundreds of producers. The ban initially
included farm-raised catfish as well, but the Mississippi
Congressional delegation successfully lobbied the FDA (Food and Drug
Administration) to exclude the catfish industry from the ban, according
to the WALL STREET JOURNAL. However, today the FDA flip-flopped and
now says catfish farmers have until Sunday (July 20) to prove their
fish contain less than one part per trillion (ppt) of dioxin.
Dioxin was declared a Class 1 carcinogen, or "known human carcinogen,"
by the International Agency for Research on Cancer (IARC), an arm of
the World Health Organization, in February, 1997. Furthermore,
dioxin's non-cancer dangers loom larger each year. After studying
dioxin intensely for a decade, U.S. Environmental Protection Agency
said 5 years ago that dioxin is much more toxic than previously known.
The agency said then, "Indeed, these [dioxin] compounds are extremely
potent in producing a variety of effects in experimental animals based
on traditional toxicology studies at levels hundreds or thousands of
times lower than most chemicals of environmental interest." And: "There
is adequate evidence from studies in human populations as well as in
laboratory animals and from ancillary experimental data to support the
inference that humans are likely to respond with a plethora [an
abundance] of effects from exposure to dioxin and related
compounds." (See REHW #390; see also #391 and #414.)
The chicken-and-egg ban was announced July 8 and went into effect July
13. As many as 350 chicken and egg producers may be affected, most
of them in Arkansas and Texas but some as far flung as North Carolina,
Indiana, and California. Companies can sell their chickens and eggs
again as soon as they demonstrate that dioxin levels in their products
are below one part per trillion (ppt). There are only about 20
laboratories in the U.S. that can test for dioxin at concentrations as
low as one part per trillion. Dioxin testing often takes 30 days or
longer under normal circumstances. With an entire industry clamoring
for data, some test results may be delayed even longer.
Dioxin does not occur naturally; it is created as an unplanned and
unwanted byproduct of metal smelting, pesticide manufacture, and all
types of incineration (medical, solid waste, and hazardous waste).
The source of the dioxin in chickens, eggs, and catfish is reported to
be a contaminated soybean-based feed produced by two companies --
Riceland Foods, Inc., and Quincy Soybean Co. --both located in
Arkansas. Between them, these two companies send feed to 350 customers,
providing an estimated 1% of all animal feed in the U.S. The dioxin
reportedly appeared when bentonite clay (sometimes called "ball clay")
was added to the feed to prevent clumping and improve flow. Bentonite
is familiar to most people as the main ingredient in kitty litter. The
dioxin-contaminated bentonite has been traced to an open-pit bentonite
mine near Sledge, Mississippi, operated by the Kentucky-Tennessee Ball
Clay Company. The source of the dioxin in the ball clay is unknown.
Bentonite deposits are a favorite place to bury hazardous wastes
because the wastes tend to stick to the clay and move only slowly
thereafter. There is no evidence that hazardous waste was buried in the
Until now, the U.S. has never set standards for dioxin in food. The
one-part-per-trillion standard was set last week by FDA as a "level of
concern" for this single instance of dioxin contamination of animal
feed; it is not to be taken as a "general action level for dioxin in
foods," government officials emphasize. In essence, FDA has declared
that chickens and eggs are contaminated and unfit for human consumption
if they contain more than 1 ppt dioxin. Yet the agency initially, in a
political compromise, exempted the most contaminated food: farm-raised
catfish. A 1994 study found that farm-raised Mississippi catfish
fillets contained dioxin at levels ranging from 10.2 to 27.8 ppt.
The FDA's stance seems certain to create public confusion and deep
anger among chicken and egg producers. Some 2000 workers in Arkansas
were told to stay home earlier this week when the FDA ban on chickens
and eggs went into effect. The ARKANSAS DEMOCRAT-GAZETTE reported
today that half the eggs produced in Arkansas this week have failed the
1 ppt dioxin test and cannot be sold. Test data were not made
U.S. EPA began looking for dioxin in food in the early 1990s, as part
of the agency's ongoing dioxin reassessment. (See REHW #390, #391.) In
early drafts of its dioxin reassessment report, EPA said 95% of human
exposure to dioxins occurs chiefly through eating red meat, fish, and
dairy products (milk, cream, cheese, ice cream). This prompted more
government studies of dioxin in cheese, fish, pork and chicken.
In September, 1996, U.S. EPA found that 2 of 80 samples of chicken had
elevated levels of dioxin: 3.9 and 3.2 parts per trillion. Each sample
was a composite of tissues taken from several birds. The other 78
samples reportedly averaged 0.09 ppt. The two unusual samples came
from Tyson plants in Pine Bluff, Arkansas and Seguin, Texas. Those two
samples gave rise to additional testing, which led to the present ban
on chickens and eggs.
In announcing the ban, FDA emphasized again and again that there was no
immediate health hazard from eating chicken, eggs, or catfish even if
they are contaminated at 3 or 4 parts per trillion. "Consumers should
not hesitate to consume eggs and catfish they have at home or purchase
on the retail market," FDA officials said. "Dioxin is something
where you care about your cumulative lifetime exposure," said FDA
Deputy Commissioner Mary Pendergast. "This was an avoidable
contamination, and we're basically turning off the faucet."
Pat Costner, a Greenpeace chemist, put the dioxin numbers into
perspective this way: The U.S. EPA says one cancer in a million persons
can be expected to occur with a daily intake of 0.01 picograms of
dioxin per kilogram of body weight per day for a lifetime. (See REHW
#390.) (A picogram is a trillionth of a gram; a trillion is a million
million.) Therefore, a 70 kilogram (154 pound) person should not take
in more than 0.7 picograms per day to keep the cancer danger below one-
in-a-million. Five ounces of chicken meat contaminated with 3 ppt of
dioxin would contain a total dioxin load of 420 picograms, or about 600
times what EPA might consider an adults's acceptable daily intake of
0.7 picograms per day.
Put another way: if an adult ate 43 5-ounce servings of chicken
containing 3 ppt of dioxin, they would exceed the EPA's recommended
LIFETIME dose of dioxin from those 43 meals alone. Many Americans eat
far more than 43 servings of chicken every year.
In 1992 EPA said the average American is routinely taking in, from all
sources of food and water, somewhere between 300 and 600 times the
"acceptable" 0.7 picograms of dioxin each day. (See REHW #390.)
Clearly, reducing our dioxin intake is good public health policy.
If the new 1 ppt "level of concern" were applied to foods in general,
it might create serious problems for the food industry. For example, a
1994 study of foods purchased in an upstate New York supermarket found
1.5 ppt dioxin in ground beef.
In 1992, EPA analyzed 60 fish samples from 34 fresh and estuarine sites
where there were no obvious industrial dioxin sources. They found that
the average dioxin concentration in the 60 samples was 1.2 ppt.
This represented the fillet (edible) portions of the fish.
Thus there is evidence that neither ground beef nor fish might be
considered fit for human consumption in the U.S. if they were judged by
the 1 ppt "level of concern" that FDA has recently adopted for chicken
People in Arkansas are extremely angry at the federal government's
seemingly-arbitrary imposition of the 1 part per trillion standard.
The "no immediate health hazard" language and the flip-flopping on
catfish has given people the impression that there is no good reason
for the ban.
"This is obviously regulation overkill on the part of the FDA and the
[Environmental Protection Agency]," said Arkansas Governor Mike
Huckabee. "What they're going to end up doing, with no scientific data
to support them, is put thousands of Arkansans out of work either
permanently or temporarily and possibly go a long way toward destroying
In actual fact, the federal government has volumes of data showing that
dioxin harms wildlife and humans at exceedingly low levels. (See REHW
#390, #391.) Dioxin's most powerful effects are seen in the
reproductive system, the endocrine (hormone) system, and the immune
system. Most sensitive of all are newborn infants and fetuses exposed
while in the womb. In 1992, EPA wrote, "In mammals, postnatal
functional alterations involving learning behavior and the developing
reproductive system appear to be the developmental events most
sensitive to perinatal dioxin exposure. The developing immune system
may also be highly sensitive." In other words, dioxin exposure of
mammals (including humans) shortly before or shortly after birth
("perinatal") are most likely to impair intellectual development and
the immune system. The immune system protects against bacterial and
viral disease, and cancer, so damage to the immune system can invite
other serious diseases. (See REHW #390.)
Some effects --such as degradation of the human immune system --seem to
occur at dioxin levels that the average American is already carrying
around in his or her body. However, because FDA has couched its ban in
the language of "no immediate threat to health," and because catfish
were initially exempted, then included, people naturally assume there
really is no threat to health from dioxin and that the ban is somehow
Thus FDA's ban on chickens and eggs seems likely to undermine the
credibility of the federal government in general, and its emerging
dioxin policies in particular. Inadvertently or not, government seems
to be playing into the hands of the Chemical Manufacturers Association
(CMA) and the Chlorine Chemistry Council (CCC). CMA and CCC say that
the dangers of dioxin have been greatly exaggerated to suit the
political purposes of environmental zealots who are really just
interested in promoting Big Government.
--Peter Montague (National Writers Union, UAW Local 1981/AFL-CIO)
 Lawrence Bachorik, "FDA Stops Distribution of Some Eggs and Catfish
Because of Dioxin-Contaminated Animal Feed," HHS NEWS [T-97-29] July 7,
1997. Available on the world wide web; see
http://www.fda.gov/bbs/topics/NEWS/. Mr. Bachorik's phone: (301) 443-
 Bruce Ingersoll, "U.S. is Banning Some Poultry Fearing Dioxin,"
WALL STREET JOURNAL July 15, 1997, pg. unknown.
 Don Chaney and Chuck Plunkett, "Dioxin-testing halts egg shipments;
fish face weekend deadline," ARKANSAS DEMOCRAT-GAZETTE July 17, 1997,
pg. 1. Thanks to Pat Costner for all articles from the ARKANSAS
 The new IARC label for dioxin will be published in Volume 69 of
IARC MONOGRAPHS ON THE EVALUATION OF CARCINOGENIC RISKS TO HUMANS. The
IARC can be contacted at: IARC, 150 Cours Albert Thomas, 69372 Lyon,
 Mark M. Mina, Deputy Administrator, Field Operations, Food Safety
and Inspection Service, U.S. Department of Agriculture, "TO: Owners and
Custodians of Poultry, Livestock, and Eggs," July 8, 1997. Available on
the world wide web: http://www.usda.gov/agency/fsis/dioxinlt.htm .
 Carol M. Seymour, Acting Deputy Administrator, Food Safety and
Inspection Service, U.S. Department of Agriculture, "To District
Managers: Guidance for Reprocessing of Broilers Exposed to Dioxin-
Contaminated Feed," July 13, 1997. Available from: Jacque (pronounced
Jackie) Knight of USDA at (202) 720-4623.
 H. Fiedler and others, "Polychlorinated dibenzo-P-dioxins and
polychlorinated dibenzofurans (PCDD/PCDF) in food samples collected in
southern Mississippi, USA," CHEMOSPHERE Vol. 34, No. 5 (March 1997),
pgs. 1411-1419. Thanks to Pat Costner for this information.
 Chuck Plunkett and Don Chaney, "Dioxin Ruling Keeps 2,000 Workers
Home," ARKANSAS DEMOCRAT-GAZETTE July 15, 1997, pg. 1.
 "FDA Launches Study on Dioxin in Fish, Dairy Foods," FOOD CHEMICAL
NEWS February 27, 1995.
 "Soybean Processing Solvent May Have Led to Dioxin Contamination,"
FOOD CHEMICAL NEWS June 23, 1997.
 "US FDA stops catfish, egg shipments over dioxin," REUTERS
FINANCIAL REPORT [wire service] July 7, 1997.
 Pendergast quoted in Associated Press, "FDA finds elevated dioxin
levels in some chicken feed," July 3, 1997.
 Arnold Schecter and others, "Congener-specific Levels of Dioxins
and Dibenzofurans in U.S. Food and Estimated Daily Dioxin Toxic
Equivalent Intake," ENVIRONMENTAL HEALTH PERSPECTIVES Vol. 102, No. 11
(November 1994), pgs. 962-966.
 U.S. Environmental Protection Agency, ESTIMATING EXPOSURE TO
DIOXIN-LIKE COMPOUNDS VOL. II: PROPERTIES, SOURCES, OCCURRENCE AND
BACKGROUND EXPOSURES [EPA/600/6-88/005Cb; June 1994 External Review
Draft] (Washington, D.C.: U.S. Environmental Protection Agency, 1994),
pgs. 4-21 and 4-37.
 Don Chaney and Chuck Plunkett, "Fish industry not off dioxin-test
hook," ARKANSAS DEMOCRAT-GAZETTE, July 16, 1997, pg. 1.
Descriptor terms: dioxin; poultry; chickens; eggs; catfish;
aquaculture; ar; ms; tx; fda; epa; regulation; food safety; meat; iarc;
carcinogens; immune system; feed; bentonite; ball clay; tyson; pat
costner; livestock feed;