The Danish Environmental Protection Agency in Copenhagen, Denmark
released a report April 18th entitled MALE REPRODUCTIVE HEALTH AND
ENVIRONMENTAL CHEMICALS WITH ESTROGENIC EFFECTS. The 175-page English-
language report, which we have obtained, says male reproductive health
is deteriorating in many countries, and that the most likely cause is
exposure to low levels of industrial chemicals that contaminate food,
water, and many consumer products.
The Danish report says many industrial chemicals mimic sex hormones
(chiefly the female hormone, estrogen) and thus interfere with the
normal development of creatures (including humans) that become exposed
before, or shortly after, birth. The report identifies many consumer
products as sources of such hormone-like chemicals: pesticides,
detergents, cosmetics, paints, and packaging materials, including
plastic containers and food wraps. The report calls for an
aggressive, coordinated international research effort to describe the
extent of the problem, and to design programs of "prevention and
Meanwhile in the U.S., the Chemical Manufacturers Association (CMA) has
funded a report by a scientist who says these problems are not real.
"The suggestion that industrial estrogenic chemicals contribute to an
increased incidence of breast cancer in women and male reproductive
problems is not plausible," the CMA's 6-page study concludes.
In contrast, the Danish report says, "It is now evident that several
aspects of male reproductive health have changed dramatically for the
worse over the past 30-50 years. The most fundamental change has been
the striking decline in sperm counts in the ejaculate of normal men;
recent evidence from Paris indicates that this decrease amounts to
about two percent per year over the last two decades. The result is
that many, otherwise normal, men now have sperm counts so low that
their fertility is likely to be impaired. Over the last half-century,
the incidence of testicular cancer has increased progressively in many
countries to become now the most common cancer in young men. Other
disorders of the male reproductive tract may also be increasing in
incidence, with several European countries reporting a progressive rise
in hypospadias (a malformation of the external genitalia) and an
apparently emerging trend towards an increasing incidence of testicular
maldescent [undescended testicles]....
"While the etiologies [causes] underlying these apparent changes are
currently not clear, both clinical and laboratory research suggest that
all of the described changes in male reproductive health appear inter-
related and may have a common origin in fetal life or childhood. This
means that the increase in some of the disorders seen today originated
20-40 years ago and that the prevalence of such defects in male babies
born today will not become manifest for another 20-40 years or more,"
the report says.
The Danish report was prepared by 19 scientists and physicians,
including 13 from Denmark, two from France, one from England, one from
Scotland, and two from the U.S.
The report says that declining reproductive health has also been widely
observed in wildlife: "Trends in the reproductive health of species
other than man also raise the possibility of environmental factors as
partial etiologic [causal] contributions in a decline noted in the male
reproductive health of wildlife. For example, wild panthers in the
United States have been reported to have an increase in undescended
testes and a decrease in semen quality, whereas male alligators in some
lakes in Florida have been shown to have abnormalities in their sex
hormone levels (tending towards femaleness) and to have smaller than
normal genitalia. Male fish in some parts of the United Kingdom have
been shown to express a 'female-like response' when studied in a
relatively natural setting. Earlier studies of fish eating birds in the
United States demonstrated nests containing male hatchlings that were
apparently feminized. A recent report of lactating [milk-producing]
male fruit bats suggested that the males were, in some way, exposed to
a female sex hormone. Recent laboratory studies showed that when
estrogenic forms of polychlorinated biphenyls (PCBs) were painted on
turtle eggs, the male hatchlings were sex-reversed to females. Taken
together, this growing body of evidence suggests that environmental
factors that resemble female sex hormones may be having an adverse
effect on the reproductive capacity and wellbeing of diverse species,"
the report says.
The report summarizes evidence indicating that all of these problems
have a common origin: the exposure of male fetuses to estrogen-like
chemicals before birth. "The wealth of experimental [laboratory animal]
results and associated clinical [human] reports suggests strongly that
prenatal exposure to exogenous [external] estrogens may play an
etiologic role in the trends observed in male reproductive health," the
The report lists many ways in which humans become exposed to chemicals
that mimic hormones: "Estrogen effects are not restricted to a small
group of therapeutic agents but appear in several groups of compounds
that are in daily use in industry, agriculture or in the home," the
report says. "A major problem is determining which chemicals are
estrogenic... At present, tens of thousands [of] man-made chemicals are
used, yet the effects on the endocrine [hormone] system have been
studied for only a few of these. The estrogenic activity of most
chemicals (e.g., alkyl phenols, phthalate esters, bisphenol-A) has been
detected by accident, not by intent; that is, no systematic screening,
even on individual groups of chemicals, has been attempted. Hence it is
highly possible that other estrogenic chemicals remain unidentified...
Thus, the present situation is that man and wildlife are exposed to a
very wide range of chemicals, and for the majority of them we do not
know whether these chemicals are, or are not, estrogenic, whether their
effects are additive, or even what the true exposure to these chemicals
The report points out that even weakly estrogenic chemicals may be of
concern if they remain in the bodies of humans and wildlife for long
periods. Natural hormones are created by the body, circulate in the
blood stream very briefly to carry out a particular task, and are then
destroyed by natural mechanisms. In contrast, many industrial chemicals
that enter the body are not readily broken down so they circulate in
the blood for long periods --in some cases many years --mimicking
The Danish report lists the following chemicals and classes of
chemicals as known to have estrogenic activity:
Organochlorine pesticides: DDT, DDD, DDE, dicofol, perthane,
methoxychlor, chlordane, oxychlordane, trans-nonachlor, heptachlor,
heptachlor epoxide, aldrin, dieldrin, hexachlorobenzene,
hexachlorocyclohexanes, lindane (gamma HCH), mirex, and toxaphene.
Although these chemicals have been banned in several industrial
countries, including the U.S., some of them are still manufactured [in
the U.S. or overseas, by U.S. corporations--PM] and sold in developing
countries where they are "widely used" today, the Danish report says.
Other known estrogenic chemicals include:
** Many of the 109 types of PCBs (polychlorinated biphenyls);
** Dioxins and furans (unwanted by-products of all incinerators; paper-
making mills; metal smelters; and the manufacture of some chemicals and
** Alkyl phenols, the breakdown products of alkylphenol polyethoxylates
(APEs) which are widely used in detergents, paints, herbicides and
cosmetics. Some 300 million kilograms (660 million pounds) of APEs are
produced each year and ultimately released into the environment.
** Phytoestrogens, or plant-produced estrogens, including isoflavones
and coumestans found in rye, wheat, cabbage, sprouts, spinach and
soybeans. "Soybean is far and away the richest source of plant
estrogens and is used ubiquitously [everywhere] in the food industry as
a protein source including the production of infant milk formula
substitutes," the Danish report says. Depending upon the dose,
phytoestrogens have an estrogenic, or an anti-estrogenic, effect, the
Danish report says. Unlike many of the other estrogenic chemicals
identified in the Danish report, phytoestrogens do not bioaccumulate or
biomagnify, but are readily metabolized and excreted.
** Many common chemicals found in plastics, including bisphenol-A,
phthalate esters (butylbenzyl phthalate and di-n-butylphthalate):
"Phthalates are the most abundant man-made environmental pollutants,
and human intake per day via various routes, especially via the diet,
is measured in tens of milligrams," says the Danish report. Some
plastics contain up to 40% phthalate esters (by weight). These esters
leach out of, or volatilize out of, the plastics as time passes. Many
foods in the U.S. and elsewhere are packaged in phthalate-containing
plastics. Even blood for transfusions is sometimes packaged in
** Herbicides, such as the popular crab-grass and dandelion killer,
2,4-D, and the now-banned 2,4,5-T, both of which were widely used by
U.S. forces in Vietnam. (See REHW #436.) Other herbicides with
estrogenic effects include: alachlor; amitrole; atrazine; metribuzin;
** Fungicides: benomyl and its principal breakdown product,
carbendazim, used on apples and bananas, among other food crops; and
ethylene bis dithiocarbamates (EBDCs, including mancozeb, maneb,
metiram, and zineb).
** Hexachlorobenzene. Although this pesticide was banned in many
countries in the 1970s, it "continues to be released to the environment
as a byproduct and contaminant in many other chlorinated chemicals
including chlorinated solvents," the Danish report says.
** Tributyltin compounds. Tributyltin compounds, until very recently,
were used in large quantities as antifouling paints on ships, boats,
and mariculture pen nets. Now banned in many countries.
** Malathion, heavily sprayed around residential areas of the U.S. to
kill nuisance mosquitoes.
And finally the Danish report warns that exposure to low levels of many
chemicals may be harming the reproductive health of humans and wildlife
by mechanisms that have nothing to do with estrogen: "Although not the
subject of this report, in considering and evaluating the possible role
of estrogenic chemicals in male reproductive disorders, it should not
be forgotten that many chemicals may have a detrimental effect on male
reproductive health through other mechanisms than an estrogenic
effect," the Danish report says.
 Our thanks to Lisa Finaldi of Greenpeace International for helping
us obtain a copy of the Danish EPA report.
 Stephen H. Safe, "Environment and Dietary Estrogens and Human
Health: Is There a Problem?" ENVIRONMENTAL HEALTH PERSPECTIVES Vol.
103, No. 4 (April, 1995), pgs. 346-351.
Descriptor terms: endocrine disrupters; estrogen; hormones;
reproductive system; pesticides; detergents; cosmetics; paint;
plastics; packaging; chemical manufacturers association; denmark; sperm
count; hypospadias; undescended testicles; testicular cancer;
cryptorchidism; wildlife; panthers; alligators; penis size; fish;
birds; bats; turtles; pcbs; chlorine; organochlorine compounds;
pesticides; DDT; DDD; DDE; dicofol; perthane; methoxychlor; chlordane;
oxychlordane; trans-nonachlor; heptachlor; heptachlor epoxide; aldrin;
dieldrin; hexachlorobenzene; hexachlorocyclohexanes; lindane; mirex;
toxaphene; dioxin; pcdfs; alkyl phenols; alkyl phenol polyethoxylates;
apes; smelting; pulp and paper industry; incineration; phytoestrogens;
bisphenol-A; phthalate esters; herbicides; 2,4-d; 2,4,5-t; agent
orange; vietnam veterans; alachlor; amitrole; atrazine; metribuzin;
trifluralin; benomyl; carbendazim; ebdcs; mancozeb; maneb; metiram;
zineb; hexachlorobenzene; tributyltin; malathion;