An international group of 21 scientists met at Wingspread in Racine,
Wisconsin in July, 1991 to discuss evidence that chemicals in the
environment are causing changes in the sexual development of wildlife
and conceivably in humans as well. (See RHWN #263.) The group produced
a five-page "consensus statement."
Sexual development in wildlife, as in humans, is controlled by the
endocrine system, a group of organs, tissues and cells that secrete
hormones; the hormones interact with other cells, initiating
chemical/biological reactions with far-reaching consequences. Male
hormones are called androgens; female hormones are called estrogens.
It is now known that some chemicals disrupt the endocrine system. The
Wingspread statement identifies the following: "Chemicals known to
disrupt the endocrine system include: DDT and its degradation products
[DDE and DDD], DEHP (di(2-ethylhexyl)phthalate), dicofol, HCB
(hexachlorobenzene), kelthane, kepone, lindane and other
hexachlorocyclohexane congeners [forms], methoxychlor,
octachlorostyrene, synthetic pyrethroids, triazine herbicides, EBDC
fungicides, certain PCB congeners [forms], 2,3,7,8-TCDD and other
dioxins, 2,3,7,8-TCDF and other furans, cadmium, lead, mercury,
tributyltin and other organo-tin compounds, alkyl phenols (non-
biodegradable detergents and anti-oxidants present in modified
polystyrene and PVCs), styrene dimers and trimers, soy products, and
laboratory animal and pet food products."
In animals, and in humans, sexual characteristics are established at a
particular point during development in the womb or egg. For example,
Dr. Theodora Colborn of the World Wildlife Fund (Washington, DC) points
out that a single dose of dioxin, administered to a pregnant rat at day
15 of the pregnancy--near the time when gender is established--results
in demasculinization and feminization of male offspring.
Samples of herring gulls from Lake Ontario collected in 1975 and 1976
showed cellular and anatomical changes in embryos and in newly hatched
chicks that caused feminization of male chicks and overdevelopment of
female reproductive organs. Elevated concentrations of DDE [a break
down by product of DDT] and other residues were found in eggs from the
same population. To test whether these sexual problems might be linked
to the presence of the DDT, laboratory experiments were conducted in
which Western gull eggs were injected with concentrations of DDT
similar to those found in the Great Lakes environment. Male chicks
became feminized, developing ovarian tissue and oviducts.
What is becoming clear is that the older picture of chemical toxicity
underestimates the number and kinds of effects that chemicals can have
in fish, birds, and mammals. For decades, U.S. regulatory officials
have focused their attention almost exclusively on cancer. Meanwhile,
many of the chemicals that have been dumped into the environment, and
are now coursing through food chains, cause many other detrimental
effects besides cancer.
For example pesticides such as DDE, dieldrin, lindane, mirex,
toxaphene, and PCBs, block communication between cells. Normal
metabolism [energy use] and development of a cell may be disrupted
because movement of nutrients, electrolytes, and hormones in and out of
a cell is blocked by the presence of these poisons.
Furans, benzo[a]pyrene, 2,3,7,8-TCDD [dioxin], DDE, dieldrin, HCB
[hexachlorobenzene], lindane [beta-HCH], mirex, toxaphene, and PCBs
induce enzyme activity. [Enzymes are large protein molecules that
promote chemical activity in the body; the presence of particular
enzymes makes possible particular chemical reactions that would not
otherwise be possible.] When the enzyme activity is induced, normal
products of the endocrine hormonal system can be released into the
bloodstream. This can disrupt the role of steroid hormones, affecting
growth and sexual maturation.
The structure of DDT and DDE are, themselves, quite similar to
estrogens and thus may mimic female hormones. In addition, DDE induces
enzymes that break down male hormones. Under different circumstances,
dioxin acts like an estrogen, or it may act as an anti-estrogen (what
causes the same chemical to have opposite effects is not understood).
At one Superfund site where data are available, humans are experiencing
abnormalities of sexual development. At the Brio site south of Houston,
Texas, where a housing development was built atop a chemical dump,
girls 4 to 5 years old have developed pubic hair and enlarged breasts.
One child (now four years old) was born without any genital organs;
chromosome tests revealed that this is a male child, though he has a
birth canal. This information, and other data about abnormal sexual
development of children at the Brio site, is contained in a unique
database of information that resulted from a health survey of the
community by a local group (HELP) and by the Environmental Health
Network (EHN) in Harvey, Louisiana. Such surveys--providing an
unusually valuable source of information about health problems near
chemical dumps--are under way in several Superfund communities, looking
for patterns of problems, including the kinds the Wingspread statement
The Wingspread statement presents a major new challenge to advocates of
"business as usual." The participants in the conference represent 17
different fields of scientific inquiry. They have many thousands of
data points on which they have based their conclusions. If they are
right, we are all being exposed, on a daily basis, to chemicals that
threaten out reproductive health, and the health of our offspring.
Because hormones and hormone disrupters do their work at extremely low
concentrations, the only "safe" dose of an endocrine-system disrupter
is zero. Thus any new sources of these chemicals should be aggressively
discouraged while we figure out how to minimize exposure to the
quantities of these chemicals already in the environment.
 Participants in the Wingspread meeting included the following
individuals (whose institutional affiliations are given for
identification purposes only): Dr. Howard A. Bern, Professor of
Integrative Biology (emeritus) and Research Endocrinologist, University
of California-Berkeley; Dr. Phyllis Blair, Professor of Immunology,
University of California-Berkeley; Sophie Brasseur, Marine Biologist,
Research Institute for Nature Management, Texel, The Netherlands; Dr.
Theo Colborn, Senior Fellow, World Wildlife Fund, Washington, DC; Dr.
Gerald R. Cunha, Developmental Biologist, University of California-San
Francisco; Dr. William Davis, Research Ecologist, Environmental
Research Laboratory, U.S. Environmental Protection Agency, Sabine
Island, FL; Dr. Klaus D. Dohler, Director, Research, Development &
Production, Phar-ma Bissendorf Peptide GmbH, Hannover, Germany; Glen
Fox, Contaminants Evaluator, National Wildlife Research Center,
Environment Canada, Quebec, Canada; Dr. Michael Fry, Research Faculty,
Department of Avian Sciences, University of California-Davis; Dr. Earl
Gray, Section Chief, Developmental and Reproductive Toxicology
Division, Health Effects Research Laboratory, U.S. Environmental
Protection Agency, Research Triangle Park, NC; Dr. Richard Green,
Professor of Psychiatry in Residence, School of Medicine, University of
California-Los Angeles; Dr. Melissa Hines, Assistant Professor in
Residence, School of Medicine, University of California-Los Angeles;
Timothy J. Kubiak, U.S. Fish and Wildlife Service, East Lansing, MI;
Dr. John McLachlan, Director, Division of Intramural Research, National
Institute of Environmental Health Sciences, Research Triangle Park, NC;
Dr. J.P. Myers, Director, W. Alton Jones Foundation, Charlottesville,
VA; Dr. Richard E. Peterson, Professor of Toxicology and Pharmacology,
School of Pharmacy, University of Wisconsin-Madison; Dr. P.J.H.
Reijnders, Head, Section of Marine Mammology, Research Institute for
Nature Management, Texel, The Netherlands; Dr. Ana Soto, Associate
Professor, Tufts University School of Medicine, Boston, MA; Dr. Glen
Van Der Kraak; Assistant Professor, University of Guelph, Ontario,
Canada; Dr. Frederick vom Saal, Professor, Division of Biological
Sciences, University of Missouri-Columbia; Dr. Pat Whitten, Assistant
Professor, Department of Anthropology, Emory University, Atlanta, GA.
 David J. Hanson, "Dioxin Toxicity: New Studies Prompt Debate,
Regulatory Action," C&EN [CHEMICAL & ENGINEERING NEWS] August 12, 1991,
 Theodora E. Colborn and others, GREAT LAKES GREAT LEGACY?
(Washington, DC: Conservation Foundation, 1990), pg. 139.
 Theodora E. Colborn and others, cited above, pg. 142.
 For more information about the Brio site, contact HELP: 10904
Scarsdale Boulevard, M263, Houston, TX 77089; phone (713) 992-1867. For
advice about health surveys, contact Linda King, Environmental Health
Network, P.O. Box 1628, Harvey, LA 70058; phone (504) 362-6574.
Descriptor terms: endocrine disrupters; racine, wi; wi; wildlife;
sexual development; endocrine system; fish; birds; herring gulls;
mammals; humans; reproductive hazards; reproductive disorders; ddt;
des; pesticides; herbicides; insecticides; fungicides; theo colborn;
world wildlife fund; superfund; brio; environmental health network;