=======================Electronic Edition======================== RACHEL'S
ENVIRONMENT & HEALTH WEEKLY #448 ---April 6, 1995--- HEADLINES: ANOTHER STUDY
SHOWS SPERM LOSS HOW TO RESEARCH TOXIC CHEMICALS ========== Environmental Research
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================================================================= ANOTHER STUDY
SHOWS SPERM LOSS
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 REHW #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. HOW TO RESEARCH TOXIC
CHEMICALS We have just published HOW TO RESEARCH CHEMICALS: A RESOURCE GUIDE,
88 pages. In it, author Maria Pellerano offers citizen-activists a clear introduction
to toxic chemicals, including extensive information on various resources that
are available to help you learn about a chemical's toxicity. It includes descriptions
and ordering information for many books and other useful resources such as low-cost
online databases, plus descriptions of organizations that can help you in your
research. Some of the expensive printed resources should be ordered through
your public library. To help you get good chemical-related resources into your
public library, we have included an essay by Laura Powers of Libraries for the
Future on "Seeking Information on Chemicals Through Your Public Library." To
order this new publication, please send a check for $10.00 to: Environmental
Research Foundation, P.O. Box 5036, Annapolis, MD 21403-7036. If you would like
to place a Visa/Mastercard order, please call (410) 263-1584. For international
orders, add $5.00 for postage and only Visa or Mastercard payments can be accepted.
Descriptor terms: research guides; chemical toxicity; chemicals and health;
computerized databases; libraries; endocrine disruptors; belgium; sperm count;
sperm quality; male reproductive health; men; sperm motility; sperm shape; european
society of human reproduction and embryology; paris; france; scotland; denmark;
organic farmers; welders; welding; painters; painting; dow chemical; shell oil;
chemical manufacturers association; cma; stephen safe; androgens; estrogens;
ddt; endosulfan; methoxychlor; .