#448a: Another Study Shows Sperm Loss

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RACHEL'S ENVIRONMENT & HEALTH WEEKLY #448a
---June 29, 1995---
News and resources for environmental justice.
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Researchers in Belgium have reported a new study showing a deterioration in sperm quality in young Belgian men since 1977. [1] The study provides new evidence supporting the hypothesis that sperm quality has been deteriorating for 50 years among men in industrialized countries. The Belgian study of 360 men (90% of them in the age group, 21 to 30) found a statistically-significant reduction in sperm density (number of sperm per milliliter of semen), as well as an increase in misshapen sperm and in sperm with low motility (ability to swim or move). (A milliliter is one thousandth of a liter, and a liter is about a quart.)

The Belgian study compared men in 1977 to men in 1994 and reported that, in 1977, 39.6% of sperm had a normal shape, but in 1994, the percentage of normal sperm had dropped to 27.8%. The average number of sperm with strong motility dropped from 53.4% in 1977 to 32.8% in 1994. Methods of analysis were unchanged between 1977 and 1994, the researchers reported. The new study was described at the 10th annual (1994) meeting of the European Society of Human Reproduction and Embryology and has not been fully published. [1] The new finding follows on a report earlier this year in the NEW ENGLAND JOURNAL OF MEDICINE, that sperm from men in Paris, France has deteriorated in quantity and quality during the past 20 years. [2] The NEW ENGLAND JOURNAL OF MEDICINE report, itself, followed on an earlier study showing deteriorating sperm during the last 20 years among men in Scotland. [3](See REHW #432.)

In what may be a related finding, researchers in Denmark in 1994 reported a much higher sperm count in organic farmers compared to blue-collar workers (welders and printers). [4] Organic farmers avoid the use of chemical fertilizers and pesticides and tend to eat a diet high in chemical-free vegetables and dairy products. The small group (30 men) had sperm densities more than twice as high as blue-collar workers (363 million sperm per milliliter of semen vs. 164 million per milliliter). The researchers reported that this finding was "unexpected" and that they could provide no plausible reason for the finding.

In the U.S., chemical-industry-sponsored researchers have begun to attack the original study which suggested that sperm density is dropping among men in industrialized countries. In 1992, a historical analysis of 62 separate sperm-count studies, by Elisabeth Carlsen, concluded that sperm count among men throughout the industrialized world has declined by about 50% during the past 50 years. [5] In 1994 this finding was challenged by researchers who said that it might have been caused by Carlsen's erroneous choice of statistical methods, not by an actual decline in sperm count. [6] Carlsen and her colleagues defended their choice of statistical method (they had used a simple linear model), saying their critics had simply misunderstood what they had said and done. Now a new attack on the Carlsen hypothesis has been published by researchers from Dow Chemical and Shell Oil Company. [7] The Dow and Shell researchers show that the use of more complex statistical models allow one to conclude that sperm count has been INCREASING among men during the past 20 years, not decreasing. The Dow and Shell researchers do not comment on the most recent empirical studies, from France, Scotland, and Belgium, showing decreases.

In related research, a scientist sponsored by the Chemical Manufacturers Association (CMA) has attacked the whole idea that estrogen-like industrial chemicals may be causing a host of ailments in men and women, including breast cancer, endometrial cancer, testicular cancer, birth defects of the penis, undescended testicles, reduced sperm count and sterility. Danish scientists had hypothesized that all these ailments may be related to several dozen chemicals known to mimic the female sex hormone, estrogen. [8] Now Professor Stephen Safe argues that natural estrogen-mimicking chemicals in plants that we eat far outweigh any effects we might experience from human-created industrial chemicals. [9] "The suggestion that industrial estrogenic chemicals contribute to an increased incidence of breast cancer in women and male reproductive problems is not plausible," Professor Safe concludes.

To support his conclusion, Professor Safe had to ignore many parts of the problem. [10] For example, as the British medical journal, LANCET, notes, "Phyto-oestrogens from plants are ingested daily but are readily metabolised and excreted." The LANCET's point is that naturally-occurring estrogen-like chemicals in plants enter the human body in our food, but they are also broken down quickly, and leave the body. Industrial chemicals may be stored in the body and mimic hormones for long periods, years or decades, giving them long opportunities to affect a person's endocrine system, nervous system, and immune system. Even very weakly estrogenic chemicals may be important if they remain in the body for long periods.

Furthermore, Professor Safe doesn't mention that the problem is one of hormone balance and imbalance. All humans (males and females) contain both androgens (male hormones) and estrogens (female hormones); thus chemicals that mimic androgens or estrogens, or chemicals that interfere with the body's use of androgens or estrogens, may disrupt the healthy balance of sex hormones. Professor Safe concludes that a chemical can be disregarded if it has no demonstrated estrogen-like activity. For example, he dismisses p-p'-DDE (a breakdown byproduct of the pesticide, DDT) as a cause of human problems because it does not mimic estrogens. However, as we saw last week (REHW #447), p,p'-DDT is now known to be a potent anti-androgen, and the class of chemicals called anti-androgens may be responsible for many of the effects attributed to estrogen-mimicking chemicals, including cancer and reproductive disorders in both women and men. The problem is far more complex than Professor Safe seems to think it is.

Professor Safe examines four estrogen-mimicking pesticides to which we are all exposed via our daily diet (DDT, dieldrin, endosulfan, and p,p'-methoxychlor). He then generalizes about the effects of these four pesticides, concluding that "dietary exposure to xenoestrogens [non-natural estrogen-mimicking chemicals] derived from industrial chemical residues in foods is minimal compared to the daily intake of [estrogen-like chemicals] from naturally-occurring [sources in our food]." [9] But four pesticides do not represent all of the non-natural sources of estrogen-like chemicals in our diet. On the contrary, the industrial gender-bending chemicals in our diet remain largely unidentified. Just this month, researchers reported that the resin used to line 85% of the tin cans in the U.S. leaks estrogen-like chemicals into the food inside the cans. [11] Professor Safe's conclusion, that industrial chemicals are irrelevant to your hormones, is premature, to say the least.

The estrogen hypothesis --especially as it relates to breast cancer --has been given increased credibility by recent analyses in the PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES. [12] Even Dr. Bruce Ames --notorious for arguing that industrial chemicals hardly ever hurt anyone (see RHWN #398)--now seems to agree that sex hormones are related to as much as 30% of all cancer cases. [13]

The endocrine system in humans and wildlife is as complicated as the central nervous system. It controls reproduction, growth, development, and behavior, particularly gender-related behavior. It will be decades --or centuries --before it is understood. Tinkering randomly with the hormones in such a system seems, on the face of it, dangerous and unwise.

Meantime, while various scientists are making a good living tinkering and arguing among themselves, 46,000 American women will die of breast cancer this year and another 182,000 will undergo surgery, radiation treatment or chemotherapy for the disease. The 40-or-so chemicals that have already been identified as hormone-mimickers are still being pumped and dumped into the environment in billion-pound quantities each year. We allow this to happen because we (as a society) assume chemicals are innocent until proven guilty. Isn't it time we turned that assumption on its head, requiring corporate polluters to demonstrate the absence of harm from their products before they are released? Why do we tolerate this chemical trespass into our most intimate property, our bodies? The present regulatory system, which is GUARANTEED to cause great harm before we can even begin to restrict the output of dangerous chemicals, seems--to put it bluntly --so unworthy of a great nation, so uncivilized.

 --Peter Montague

===============

[1] K. Van Waeleghem and others, "Deterioration of sperm quality in young Belgian men during recent decades," HUMAN REPRODUCTION Vol. 9, Supplement 4 (1994), pg. 73; this is an abstract, not a full report.

[2] 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.

[3] D. Stewart Irvine, "Falling sperm quality," BRITISH MEDICAL JOURNAL Vol. 309 (August 13, 1994), pg. 476.

[4] Annette Abell and others, "High sperm density among members of organic farmers' association," THE LANCET Vol. 343 (June 11, 1994), pg. 1498. Thanks to Marjorie Fisher for sending us a copy of this article.

[5] Elisabeth Carlsen and others, "Evidence for decreasing quality of semen during past 50 years," BRITISH MEDICAL JOURNAL Vol. 305 (1992), pgs. 609-613.

[6] Peter Bromwich and others, "Decline in sperm counts: an artefact of changed reference range of 'normal'?" BRITISH MEDICAL JOURNAL Vol. 309 (July 2, 1994), pgs. 19-22. Elisabeth Carlsen and some of her co-workers responded that Bromwich's analysis was "based on wrong assumptions" and "failed to give any empirical reference that might support [Bromwich's] assertion of differential selection." See Niels Keiding and others, "Importance of empirical evidence," BRITISH MEDICAL JOURNAL Vol. 309 (July 2, 1994), pg. 22.

[7] Geary W. Olsen and others, "Have sperm counts been reduced 50 percent in 50 years? A statistical model revisited," FERTILITY AND STERILITY Vol. 63, No. 4 (April, 1995), pgs. 887-893. Thanks to Jeff Pitt for sending us a copy of this article.

[8] Devra Lee Davis and others, "Medical Hypothesis: Xenoestrogens As Preventable Causes of Breast Cancer," ENVIRONMENTAL HEALTH PERSPECTIVES Vol. 101 (October 1993), pgs. 372-377. And: Richard M. Sharpe and Niels E. Skakkebaek, "Are oestrogens involved in falling sperm counts and disorders of the male reproductive tract?" THE LANCET Vol. 341 (May 29, 1993), pgs. 1392-1395.

[9] Stephen H. Safe, "Environmental and Dietary Estrogens and Human Health: Is There a Problem?" ENVIRONMENTAL HEALTH PERSPECTIVES Vol. 103, No. 4 (April, 1995), pgs. 346-351.

[10] Anonymous, "Male reproductive health and environmental oestrogens [editorial]," THE LANCET Vol. 345 No. 8955 (April 15, 1995), pgs. 933-935.

[11] Jose Antonio Brotons and others, "Xenoestrogens Released from Lacquer Coatings in Food Cans," ENVIRONMENTAL HEALTH PERSPECTIVES Vol. 103, No. 6 (June 1995), pgs. 608-612.

[12] Satyabrata Nandi and others, "Hormones and mammary carcinogenesis in mice, rats, and humans: A unifying hypothesis," PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES USA Vol. 92, No. 9 (April 25, 1995), pgs. 3650-3657.

[13] Bruce N. Ames and others, "The causes and prevention of cancer," PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES USA Vol. 92, No. 12 (June 1995), pgs. 5258-5265.

#447: The Challenge of Our Age

=======================Electronic Edition========================
RACHEL'S ENVIRONMENT & HEALTH WEEKLY #447
---June 22, 1995---
News and resources for environmental justice.
==========
Environmental Research Foundation
P.O. Box 5036, Annapolis, MD 21403
Fax (410) 263-8944; Internet: erf@rachel.clark.net ==========
RACHEL-4CM = DIOXIN FOCUSED DIRECTORY Remote Access Chemical Hazards Electronic Library. Dioxinnz.com =======================Original Source========================

In the past 60 days, two important British scientific journals have published editorials calling for more research into environmental chemicals that may be harming the reproductive health and sexual development of men throughout the industrialized world. NATURE (the equivalent of SCIENCE magazine in the U.S.) said on June 15th, "The case for research to be conducted urgently is overwhelming." [1] The medical journal, LANCET (approximately equivalent to the NEW ENGLAND JOURNAL OF MEDICINE in this country) was much more explicit, making the following points: [2]

** Industrial chemicals that mimic sex hormones (or xeno-estrogens, as they are sometimes called) "may be responsible for a massive decrease in male sperm counts and semen quality since 1940," LANCET said. 

** "Female infertility is the subject of intense research and an unfailing source of headlines for the popular press. Male reproductive health has not been studied nearly so thoroughly, and little attention was paid to a series of observations indicating that the frequency with which a male factor is responsible for a couple's infertility has increased in recent years from about 10% to 25%," LANCET said. 

** "Numerous compounds in daily industrial, agricultural, or domestic use have oestrogenic effects [oestrogen is the British spelling of estrogen], but the endocrine effects of the tens of thousands of man-made chemicals with which we come into daily contact have been studied in only a few instances, and then by accident rather than design.... For most chemical pollutants we do not know whether they are oestrogenic or not, what their effects are singly or together, or even the degree of our exposure.... They will remain in the environment for generations, and even small amounts of such contaminants can lead to the accumulation of considerable quantities in animal and human tissues," LANCET said. 

** "It is the mother's lifetime exposure [prior to pregnancy] that determines the fetal dose, not just her exposure during pregnancy," LANCET said.

Both these journals called for urgent research to learn more about the male reproductive system, the chemicals that we encounter in our daily lives, and the effects those chemicals may have, singly or in combination, on male reproductive health.

The research task is formidable, to say the least. It is well-known that sexual differentiation (the point at which males become males and females become females in the womb) is initiated by the presence of the Y chromosome, which sets in motion male development; absence of the Y chromosome sets in motion female development. After initiation by the Y chromosome (or absence of it), all further steps are controlled by chemicals called hormones --estrogens are the "female" hormones and androgens are the "male" hormones. But the development of gender, with all its physical and behavioral aspects, depends upon both estrogens and androgens in both males and females; it is the balance of these chemicals, in combination, that produces normal differentiation and development. [3] All females contain some androgens, and all males contain some estrogens; it is the balance of the two types of chemicals that is important.

Over the past 30 years, it has been discovered that many industrial chemicals mimic estrogens. (See RHWN #263, #264, #343, #365, #372, #377, #446.) An "estrogen hypothesis" has been proposed to explain why each year more men in the industrialized world are getting cancer of the testicles, birth defects affecting the penis, lowered sperm count, lowered sperm quality, and undescended testicles. The estrogen hypothesis suggests that all of these effects can be traced to one cause: industrial chemicals mimicking hormones, affecting male children while they are still in the womb. [4]

However, in the last two years, a different set of concerns has been raised: some chemicals that don't mimic estrogens can still interfere with sexual differentiation and development in laboratory animals; they do it by interfering with the action of androgens (male hormones). Since it is the BALANCE of estrogens and androgens that creates one gender or another, anti-androgens can interfere with male development as effectively as excessive estrogens can. In NATURE June 15, William Kelce, a researcher at U.S. Environmental Protection Agency (EPA) reported that a breakdown byproduct ("metabolite") of the pesticide DDT (called p,p'-DDE, and pronounced "p, p-prime D D E") is a powerful anti-androgen. [5] Anti-androgen drugs (developed as therapy for human prostate cancer), when given to animals before and shortly after birth, can cause reproductive tract disorders, including small penis, hypospadias, [6]and undescended testicles. Thus it is important to learn that a DDT metabolite is a powerful anti-androgen. DDT has been banned in this country, but many countries still allow its use, including its use on food products that are imported into the U.S. [7]Furthermore, despite the ban, many ecosystems in the U.S. remain heavily contaminated from past DDT use.

Therefore, the research task requires us to know not only which chemicals mimic estrogens, but also which chemicals interfere with androgens. For example, a common pesticide, Vinclozolin, was recently discovered to be a powerful anti-androgen. [8] Dosing a pregnant female rat with Vinclozolin at a level that caused no toxicity in the mother, gave rise to baby male rats which all appeared to be female at birth. The newborn male rats developed nipples (which, in rats, only females normally have), and they all had the hypospadias birth defect, [6]and undescended testicles. Furthermore, they were all sterile, unable to produce enough sperm to inseminate a female. In the U.S. today, Vinclozolin is legal for use on cucumbers, grapes, lettuce, onions, bell peppers, raspberries, strawberries, tomatoes, and Belgian endive. [9] It is sold under the following trade names: Ronilan, Ornalin, Curalan, and Vorlan. It is also one of the ingredients in the following mixtures: Hitrun, Konker, Ronilan M, Ronilan T combi, Silbos, and Fungo-50. EPA has no published plans for banning Vinclozolin.

Note that in the cases of both DDT and Vinclozolin, the chemical itself has certain gender-bending properties, but the breakdown byproducts (metabolites) have even more powerful anti-androgenic properties. For example, the M1 metabolite of Vinclozolin is 100 times more powerful than Vinclozolin itself. Therefore, researchers will need to study not only the main chemicals but all of their important metabolites. In the case of Vinclozolin, there are at least 2 important metabolites. Obviously, the need to, first, identify and, second, test, metabolites greatly increases the size and scope of the research task.

The problem of chemical combinations is even more difficult. Several prominent researchers calling for urgent work on gender-benders have suggested that combinations of chemicals might be important. For example, we quoted the editorial from LANCET April 15: "For most chemical pollutants we do not know whether they are oestrogenic or not, what their effects are singly OR TOGETHER, or even the degree of our exposure...."

Suppose we wanted to study only the possible 2-chemical combinations among the commonest 500 industrial chemicals. To do this, we would have to run 124,749 different experiments (let's call it 125,000). [10] To study all the different 3-chemical combinations among the 500 would require 20.7 million experiments--an impossible task. Even testing all 3-chemical combinations among only 100 chemicals would require 161,700 experiments. Testing combinations is a burden.

If we were worried about 500 chemicals, each with one metabolite, for a total of 1000 chemicals, and we wanted to study all possible 2-chemical combinations, we'd have to run 499,500 (just shy of half a million) experiments; to learn about all the different 3-chemical combinations of these 1000, we'd have to run 166 million experiments--simply out of the question.

Running even 125,000 experiments (all 2-chemical combinations of the top 500 chemicals) would require quite a different attitude than public health officials presently exhibit toward these problems. Many dozens of competent laboratories would have to get involved. Hundreds of researchers and technicians would have to be trained (or re-trained). Much current research would have to be abandoned. If each experiment cost only $100,000, then 125,000 experiments would cost $12.5 billion and 499,500 experiments would cost $50 billion.

Finally, recent research on dioxin reveals that, at dose levels not toxic to the mother, both male and female offspring of dioxin-exposed pregnant rats and hamsters have their sexual development stunted. [11]In females, the external genitalia were malformed; in males, testicles were reduced in weight, and sperm count was reduced by more than 50%. These effects were not caused by estrogen-mimicking, nor by an anti-androgen mechanism. Some entirely different mechanism, not understood, allows dioxin to interfere with sexual development of mammals at extremely low levels of exposure. Are there other chemicals like dioxin in this regard? It seems a fair question.

For scientists all these research questions may seem interesting, if not actually doable. But for the public, a different question seems paramount: how can we avoid exposure to dioxin and to all the other gender-benders found in pesticides, detergents, paints, plastics, and so on? After they are made and released into the environment, there is no avoiding them. Therefore, we must prevent their manufacture in the first place. This is the life-and-death challenge of our age.

 --Peter Montague

===============

[1] Anonymous, "Masculinity at risk [editorial]", NATURE Vol. 375 (June 15, 1995), pg. 522.

[2] Anonymous, "Male reproductive health and environmental oestrogens [editorial]," LANCET Vol. 345, No. 8955 (April 15, 1995), pgs. 933-935.

[3] See Frederick S. vom Saal and others, "Sexual Differentiation in Mammals," in 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), pgs. 17-83; and in the same volume, see Leon Earl Gray, Jr., "Chemical-Induced Alterations of Sexual Differentiation: A Review of Effects in Humans and Rodents," pgs. 203-230.

[4] For example, see Niels E. Skakkebaek and Niels Keiding, "Changes in semen and the testis," BRITISH MEDICAL JOURNAL Vol. 309 (November 19, 1994), pgs. 1316-1317.

[5] William R. Kelce and others, "Persistent DDT metabolite p,p'-DDE is a potent androgen receptor antagonist," NATURE Vol. 375 (June 15, 1995), pgs. 581-585. Our thanks to Peter deFur and Mechelle Evans of the Environmental Defense Fund (EDF) for providing us with a copy of this article.

[6] As a male grows inside the womb, the penis develops a urinary channel called the urethra; with the birth defect called hypospadias, the urinary channel is not closed but remains open for a certain distance on the underside of the penis, and this has to be corrected surgically after birth. The hypospadias birth defect is thought to be increasing in frequency; see A. Giwercman and N.E. Skakkebaek, "The human testis--an organ at risk?" INTERNATIONAL JOURNAL OF ANDROLOGY Vol. 15 (1992), pgs. 373-375.

[7] Richard M. Sharpe, "Another DDT connection," NATURE Vol. 375 (June 15, 1995), pgs. 538-539.

[8] William R. Kelce and others, "Environmental Hormone Disruptors: Evidence That Vinclozolin Developmental Toxicity is Mediated by Antiandrogenic Metabolites," TOXICOLOGY AND APPLIED PHARMACOLOGY Vol. 126 (1994), pgs. 276-285. And: L. Earl Gray, Jr., and others, "Developmental Effects of an Environmental Antiandrogen: The Fungicide Vinclozolin Alters Sex Differentiation of the Male Rat," TOXICOLOGY AND APPLIED PHARMACOLOGY Vol. 129 (1994), pgs. 46-52.

[9] See 40 CFR [Code of Federal Regulations] Chapter 1 (7-1-94 edition), section 180.380.

[10] The formula for calculating how many different subcollections of size k can be formed from a collection of n different chemicals is (n!)/((k!)*((n-k)!)) when n! means n factorial and * means "multiplied by". See, for example, Michael Orkin and Richard Drogin, VITAL STATISTICS (New York: McGraw-Hill, 1975), pg. 285.

[11] L.E. Gray, Jr., and others, "Exposure to TCDD during Development Permanently Alters Reproductive Function in Male Long Evans Rats and Hamsters: Reduced Ejaculated and Epididymal Sperm Numbers and Sex Accessory Gland Weights in Offspring with Normal Androgenic Status," TOXICOLOGY AND APPLIED PHARMACOLOGY Vol. 131 (1995), pgs. 108-118.

Descriptor terms: nature; lancet; endocrine disruptors; endocrine system; xenoestrogens; estrogen; hormones; androgens; infertility; fertility; reproductive health; testicular cancer; sperm count; sperm density; sperm quality; hypospadias; cryptorchidism; undescended testicles; birth defects; epa; william kelce; metabolites; ddt; dde; p,p'-dde; vinclozolin; pesticides;

#446: Our Future in Doubt

=======================Electronic Edition========================
RACHEL'S ENVIRONMENT & HEALTH WEEKLY #446
---June 15, 1995---
News and resources for environmental justice.
==========
Environmental Research Foundation
P.O. Box 5036, Annapolis, MD 21403
Fax (410) 263-8944; Internet: erf@rachel.clark.net ==========
RACHEL-4CM = DIOXIN FOCUSED DIRECTORY Remote Access Chemical Hazards Electronic Library. Dioxinnz.com =======================Original Source========================

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. [1] About 40 widely-used chemicals (pesticides, detergents, plasticizers and other important industrial building blocks) have now been identified with these characteristics. [2] However, scientists say the only way to discover all such chemicals is to test each of the 70,000 chemicals now in commercial use. [3] 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 political relations.

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 signals.

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. [4] 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. [5] 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. [6]Subsequently, the Conservation Foundation in Washington, D.C. --a private organization with close ties to the U.S. government [7]--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 [8] 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." [9](See RHWN #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. [9] 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). [13] 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, including:

** increases in cancer of the testicles in many industrialized countries; [10]** increased incidence of undescended testicles (cryptorchidism) in humans and in wildlife; [10]** reduction in sperm count by 50% among men in many industrialized countries; [11]** increased incidence of hypospadias--a birth defect of the male genitalia. [10]

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. [12]

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. [13]

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." [14]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. [15] 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 problems?

--Peter Montague

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[1] 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.

[2] 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.

[3] 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 structure..."

[4] For example, D.A. Ratcliff, "Decrease in Eggshell Weight in Certain Birds of Prey," NATURE Vol. 225 (1967), pg. 208.

[5] McLachlan quoted in Janet Raloff, "EcoCancers; Do environmental factors underlie a breast cancer epidemic?" SCIENCE NEWS Vol. 144 (July 3, 1993), pg. 10.

[6] 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 SILENT SPRING.

[7] For example, William Reilly was president of the Conservation Foundation before President Bush selected him to head U.S. EPA.

[8] 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.

[9] 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.

[10] 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.

[11] 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.

[12] 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.

[13] 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.

[14] 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.

[15] 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 erf@rachel.clark.net).

Descriptor terms: endocrine disupters; wildlife; human health; niehs; national institute of environmental health sciences; reproduction; development; growth; birds; fish; estrogen; tom muir; anne sudar; conservation foundation; world wildlife fund; wwf; cf; william reilly; theo colborn; environment canada; wongspread statement; shellfish; turtles; mammals; sexual development; sexual differentiation; immune system; endocrine system; thyroid; denmark; great britain; england; united kingdom; testicular cancer; cryptorchidism; undescended testicles; sperm count; hypospadias; birth defects; breast cancer; endometriosis; pallid sturgeon; florida panther; international joint commission; ijc; corporations; regulation; mass media;