After 30 years of scientific detective work, a picture has emerged
strongly suggesting that American-style industrialization is in
fundamental conflict with living systems. Many common chemicals used in
bulk quantities are now known to interfere with the reproductive
systems of wildlife and humans, causing reproductive failure, birth
defects, immune system deficiencies, and cancers. About 40 widely-
used chemicals (pesticides, detergents, plasticizers and other
important industrial building blocks) have now been identified with
these characteristics. However, scientists say the only way to
discover all such chemicals is to test each of the 70,000 chemicals now
in commercial use. Such a broad-scale testing program would be
unprecedented and seems politically, economically, and logistically
impossible, given today's corporate milieu and mood. Without such a
testing program, the withdrawal of these chemicals from commercial use
cannot even reach the discussion stage. Thus the conflict between our
industrial institutions and the health of living things seems
irreconcilable without a fundamental shift in world view and in
It was 1972 when the federal National Institute of Environmental Health
Sciences (NIEHS) formally began studying chemicals that interfere with
the endocrine system of wildlife and humans. The endocrine system is a
complex set of bodily organs and tissues whose actions are coordinated
by chemical messengers called hormones, which control sexual
reproduction, growth, development and behavior. Bears hibernate because
of chemical signals from the endocrine system, and women menstruate
under control of their endocrine systems. In the egg or the womb, males
are made into males, and females into females, by endocrine hormone
In the late 1960s, scientists began reporting disruptions of the
endocrine system in birds --for example, the pesticide DDT was causing
eggshell thinning, leading to reproductive failure. The same year
DDT was banned in the U.S. (1972), Dr. John A. McLachlan began a
research program at NIEHS, examining chemicals that mimic hormones
(chiefly estrogen, the main female sex hormone). McLachlan says even he
didn't realize how many endocrine-disrupting chemicals were "out there"
until 1979, when NIEHS sponsored the first scientific conference on the
subject. Even after that conference, the general public (including
the environmental community) knew nothing of these problems.
In 1988, two government researchers in Canada --Tom Muir and Anne Sudar
--packaged much of the available information on chemicals and health
into a concise and alarming report on the Great Lakes. Their employer,
Environment Canada --the Canadian equivalent of the U.S. Environmental
Protection Agency (EPA) --refused to publish their report.
Subsequently, the Conservation Foundation in Washington, D.C. --a
private organization with close ties to the U.S. government --was
asked to examine the Muir/Sudar report. In 1990, the Conservation
Foundation published an expanded and toned-down version of the facts in
GREAT LAKES GREAT LEGACY?, authored by Theodora E. Colborn with an
extensive bibliography of studies from the 1980s showing endocrine
damage to wildlife, and, to a much lesser extent, humans.
In July of the following year Theo Colborn convened a conference
attended by 21 scientists at the Wingspread Center in Racine,
Wisconsin; that conference issued a consensus statement by the 21
scientists, saying, in part, "We are certain of the following: A large
number of man-made chemicals that have been released into the
environment, as well as a few natural ones, have the potential to
disrupt the endocrine system of animals, including humans... Many
wildlife populations are already affected by these compounds. The
impacts include thyroid dysfunction [impaired or abnormal functioning]
in birds and fish; decreased fertility in birds, fish, shellfish, and
mammals; decreased hatching success in birds, fish and turtles; gross
birth deformities in birds, fish and turtles; metabolic abnormalities
[impaired or abnormal use of energy, manufacture of tissue, or handling
of resulting wastes] in birds, fish, and mammals; behavioral
abnormalities in birds; demasculinization and feminization in male
fish, birds, and mammals; defeminization and masculinization of female
fish and birds; and compromised [impaired] immune systems in birds and
mammals." (See REHW #263, #264.)
In 1992, Theo Colborn went on to summarize what is known about
endocrine-disrupting chemicals in a technical book aimed at a
scientific audience. In 1993, she presented a summary in the
prestigious journal, ENVIRONMENTAL HEALTH PERSPECTIVES, the official
voice of the National Institute of Environmental Health Sciences
(NIEHS). That put the issue "on the map" in the U.S.
In 1992 and 1993, researchers in Denmark, England, the U.S. and
elsewhere began connecting the dots among a wide range of studies that
had shown various kinds of damage to the reproductive systems of men,
** increases in cancer of the testicles in many industrialized
** increased incidence of undescended testicles (cryptorchidism) in
humans and in wildlife;
** reduction in sperm count by 50% among men in many industrialized
** increased incidence of hypospadias--a birth defect of the male
Furthermore, several studies in 1993 suggested that certain important
problems of the female reproductive system --breast cancer and
endometriosis --may also be linked to endocrine-disrupting chemicals.
Endocrine-disrupting chemicals of industrial origin are now measurable
in rain water, well water, rivers, lakes, and oceans, as well as in
freshwater, oceanic and terrestrial food products. Effects of exposure
to endocrine disrupters early in life are permanent and irreversible.
Exposure of a woman at any time in her life prior to pregnancy can
affect her offspring because these chemicals persist in the body.
There seems to be no doubt that estrogen-mimicking chemicals are
damaging wildlife worldwide. In certain cases, the damage is so severe
that extinction is occurring; for example, pallid sturgeon in the
Mississippi and Missouri rivers have not reproduced for at least 10
years; any members of the species seen today are 30 to 40 years old.
For 15 years, scientists have been reporting that the gonads of the
pallid sturgeon "aren't distinctly male or female any more."
Likewise, the Florida panther most likely will go extinct this decade
or next, victim of undescended testicles and diminished sperm count.
How different is the prospect for humans? The handwriting on the wall
couldn't be more plain, yet the most knowledgeable among us are largely
confined to talking to themselves.
The International Joint Commission (IJC) has outlined a regulatory
program adequate to the task before us, but President Clinton has
rejected it. What is to be done? We can only ask questions. How can
we modify the framework that prevents scientists from speaking out? How
can we get private money out of politics, so we can elect public
officials who are not beholden to corporate interests? How can we
liberate the decision-makers within corporations from today's legal
constraints, freeing them to consider the public health consequences of
their business decisions? How can we induce the mass media --
particularly those that use the publicly-owned airwaves --to inform the
public about the nature and importance of these chemical and political
 Bette Hileman, "Environmental Estrogens Linked to Reproductive
Abnormalities, Cancer," C&EN [CHEMICAL & ENGINEERING NEWS] January 31,
1994, pgs. 19-23; Bette Hileman, "Concerns Broaden over Chlorine and
Chlorinated Hydrocarbons," C&EN [CHEMICAL & ENGINEERING NEWS] April 19,
1993, pgs. 11-20; Theo Colborn, Frederick S. vom Saal, and Ana M. Soto,
"Developmental Effects of Endocrine-Disrupting Chemicals in Wildlife
and Humans," ENVIRONMENTAL HEALTH PERSPECTIVES Vol. 101 No. 5 (October
1993), pgs. 378-384; Paul Cotton, "Environmental Estrogenic Agents Area
of Concern," JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION Vol. 271
(February 9, 1994), pgs. 414, 416.
 Here is an incomplete list of chemicals known to disrupt the
endocrine system: 2,4-D; 2,4,5-T; alachlor; amitrole; atrazine;
metribuzin; nitrofen; trifluralin; benomyl; hexachlorobenzene;
mancozeb; maneb; metiram-complex; tributyl tin; zinab; ziram; beta-HCH;
carbaryl; chlordane; dicofol; dieldrin; DDT and metabolites;
endosulfan; heptachlor and heptachlor epoxide; lindane (gamma-HCH);
methomyl; methoxychlor; mirex; oxychlordane; parathion; synthetic
pyrethroids; toxaphene; transnonachlor; aldicarb; DBCP; cadmium; dioxin
(2,3,7,8-TCDD); lead; mercury; PBBs; PCBs; pentachlorophenol (PCP);
penta-to nonylphenols; phthalates; styrenes.
 For example, Ana M. Soto and others, "The Pesticides Endosulfan,
Toxaphene, and Dieldrin Have Estrogenic Effects on Human Estrogen-
Sensitive Cells," ENVIRONMENTAL HEALTH PERSPECTIVES Vol. 102, No. 4
(April 1994), pg. 380, says, "It should be noted that the estrogenic
activity of chemicals cannot be deduced solely from their molecular
 For example, D.A. Ratcliff, "Decrease in Eggshell Weight in Certain
Birds of Prey," NATURE Vol. 225 (1967), pg. 208.
 McLachlan quoted in Janet Raloff, "EcoCancers; Do environmental
factors underlie a breast cancer epidemic?" SCIENCE NEWS Vol. 144 (July
3, 1993), pg. 10.
 Tom Muir and Anne Sudar, TOXIC CHEMICALS IN THE GREAT LAKES BASIN
ECOSYSTEM: SOME OBSERVATIONS (Burlington, Ontario: Environment Canada,
1988; never formally published). Discussing this report, see Bette
Hileman, "The Great Lakes Cleanup Effort," C&EN [CHEMICAL & ENGINEERING
NEWS] February 8, 1988, pgs. 22-39, who compares it to Rachel Carson's
 For example, William Reilly was president of the Conservation
Foundation before President Bush selected him to head U.S. EPA.
 Theo Colborn and others, GREAT LAKES GREAT LEGACY? (Washington,
D.C.: The Conservation Foundation, 1990). Available for $20.00 (plus
$2.00 shipping) from: World Wildlife Fund, P.O. Box 4866, Hampden Post
Office, Baltimore, MD 21211; phone (301) 516-6951.
 Theo Colborn and Coralie Clement, editors, CHEMICALLY-INDUCED
ALTERATIONS IN SEXUAL AND FUNCTIONAL DEVELOPMENT: THE WILDLIFE/HUMAN
CONNECTION [Advances in Modern Environmental Toxicology Vol. XXI]
(Princeton, N.J.: Princeton Scientific Publishing Co., 1992). The
opening chapter reprints the consensus statement from the Wingspread
conference. And see: Theo Colborn, Frederick S. vom Saal, and Ana M.
Soto, "Developmental Effects of Endocrine-Disrupting Chemicals in
Wildlife and Humans," ENVIRONMENTAL HEALTH PERSPECTIVES Vol. 101 No. 5
(October, 1993), pgs. 378-384.
 A. Giwercman and others, "Evidence for increasing abnormalities of
the human testis: a review," ENVIRONMENTAL HEALTH PERSPECTIVES Vol.
101, Supplement 2 (1993), pgs. 65-71. And see: A. Giwercman and N.E.
Skakkebaek, "The human testis--an organ at risk?" INTERNATIONAL JOURNAL
OF ANDROLOGY Vol. 15 (1992), pgs. 373-375.
 Jacques Auger and others, "Decline in Semen Quality Among Fertile
Men in Paris During the Past 20 years," NEW ENGLAND JOURNAL OF MEDICINE
Vol. 332, No. 5 (February 2, 1995), pgs. 281-285. And: D. Stewart
Irvine, "Falling sperm quality," BRITISH MEDICAL JOURNAL Vol. 309
(August 13, 1994), pg. 476. Elisabeth Carlsen and others, "Evidence for
decreasing quality of semen during past 50 years," BRITISH MEDICAL
JOURNAL Vol. 305 (1992), pgs. 609-613.
 Sherry E. Rier and others, "Endometriosis in Rhesus Monkeys
(MACACA MULATTA) Following Chronic Exposure to 2,3,7,8-
Tetrachlorodibenzo-P-dioxin," FUNDAMENTAL AND APPLIED TOXICOLOGY Vol.
21 (1993), pgs. 433-441.
 Theo Colborn, Frederick S. vom Saal, and Ana M. Soto,
"Developmental Effects of Endocrine-Disrupting Chemicals in Wildlife
and Humans," ENVIRONMENTAL HEALTH PERSPECTIVES Vol. 101 No. 5 (October,
1993), pgs. 378-384.
 Janet Raloff, "The Gender Benders; Are environmental 'hormones'
emasculating wildlife?" SCIENCE NEWS Vol. 145 (Jan. 8, 1994), pgs. 24-
27. See also: Janet Raloff, "The Feminine Touch; Are men suffering from
prenatal or childhood exposure to 'hormonal' toxicants?" SCIENCE NEWS
Vol. 145 (January 22, 1994), pgs. 56-59.
 The IJC's recommendations are summarized in Peter Montague, "Our
Greatest Accomplishment: Grass-roots Action Has Forced a Major Shift in
Thinking," THE WORKBOOK Vol. 19 No. 2 (Summer 1994), pgs. 86-90. Paper
reprints of this article are available for $2.00; an electronic copy is
available free (E-mail your request to firstname.lastname@example.org).
Descriptor terms: endocrine disrupters; wildlife; human health; niehs;
reproduction; development; growth; birds; fish; estrogen; tom muir;
anne sudar; conservation foundation; world wildlife fund; william
reilly; theo colborn; environment canada; wingspread statement;
shellfish; turtles; mammals; sexual development; sexual
differentiation; immune system; endocrine system; thyroid disease;
denmark; great britain; testicular cancer; cryptorchidism; undescended
testicles; sperm count; hypospadias; birth defects; breast cancer;
endometriosis; pallid sturgeon; florida panther; ijc; corporations;
regulation; mass media;