Sperm count in serious decline - ToxCat spring 96

Ralph Ryder Ralph at tcpub.demon.co.uk
Fri Apr 11 18:43:52 EST 1997


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The sperm count of our species is in serious decline.

        Scientists studying the impact of man-made chemicals on human
health claim human males will be infertile by the middle of the next
century if present industrial trends are maintained.
        The culprits - chemicals which have the ability to mimic
hormones, particularly the female sex hormone estrogen - are widespread
in society and include pesticides (such as DDT), industrial chemicals
(such as PCBs) and environmental pollutants such as dioxin.  Most,
though not all, of the estrogen-mimicking chemicals involve chlorine. 
        If you live in a large industrialised city take a look around
you.  What do you see beyond the bustle of modern commerce, people
moving, working, surviving?  All around you are cars, buses, lorries and
trains.  Look into the sky, chances are you’ll see an aeroplane taking
people on holiday or perhaps a business trip.  All these forms of
transport are powered by a combustion process and built with industrial
chemicals.  What else do you see?  Buildings, construction sites,
machinery, glass, steel, concrete and wood.  Look closer;- metals,
plastics, electrical wires, pipes, paints, solvents, detergents.  Go
into shops you find clothes made from synthetic fibres, electronic
appliances made with strong durable plastics, cosmetics made from
chemicals, food grown with the aid of pesticides, tin cans whose lining
leaches chemicals into the fish, meat, vegetables and sauces they
contain.  Visit the countryside where the vegetables and cereals and
pulses are actually grown, where cattle and sheep graze on intensively
farmed land, where the farmers have planted chemically treated ‘disease
resistant’ seeds and used herbicides, pesticides and fertilisers to
increase the production of their crops  All around us are the products
of the chemical and oil industries.
        Most western countries have had these products for more than
half a century but all of us, wherever we live, have been exposed over
the past 25 years to the effects of modern industrial chemicals, in the
food we eat, the water we drink and the air we breath.  While we have
been exposed to these chemicals, occupationally, environmentally and
through food, some scientists have tried to determine the impact on our
health.  There has been a frequent, persistent argument, significantly
from industry, that there is a safe level for all chemicals and as long
as we take no more than "the threshold level" into our bodies we will
not come to any harm.  Many scientists who have gone against this line
of thought have been ridiculed in the past!   But not any more!
        In 1979 a group of mothers in Taiwan unwittingly consumed PCB-
contaminated rice oil over a period of ten months.  It has now been
found that boys born to these women have matured with reduced penises -
thus providing the first direct evidence that polychlorinated biphenyls
(PCBs) are teratogenic (birth-defect producing) in humans.
        The scientists who studied the 115 "yucheng" (oil-disease)
children believe they were exposed to the chemical before and after
birth via their mothers’ blood through the placenta while they were
still in the womb and as young babies via their mothers’ milk. [1] The
evidence that pesticides such as 2,4,5-T, Lindane and DDT, along with
other industrial chemicals like PCBs, dioxin and many of the chemicals
used in everyday household items, have the ability to affect the
endocrine systems of animals - including humans, is becoming harder to
ignore.
        The simple easy-to-understand fact that 115 Taiwanese teenage
boys have smaller penises than normal was the first confirmation that
humans, as well as wildlife, are being similarly affected by exposure to
"endocrine disrupting chemicals" such as DDT, PCBs, dioxin, and many
more man- made chemicals.
        The evidence is now accumulating that dozens of pesticides and
other chemicals can ‘mimic’ hormones, particularly the female sex
hormone estrogen, and disrupt the endocrine system. 
        As with wildlife, it seems that the reproductive system of
humans, predominantly the male, is more prone to damage from these
chemicals.  As well as reduced penis size, the Taiwanese teenagers had a
variety of physical defects at birth ranging from; dark coloured heads,
faces and genitals, to abnormal nails that were often dark and ridged,
split or folded. 
        The effects of these hormone mimicking chemicals doesn’t stop at
reducing the size of the penis.  Research at the Medical Research
Council’s Reproductive Biology Unit at Edinburgh and at Brunel
University, Middlesex, is among the latest to find new evidence of a
link between declining male fertility and synthetic "hormone mimicking
chemicals".[2]  
        "The balance of the debate is shifting in support of the theory
that this group of chemicals which is being pumped into the environment
is having an effect on our reproductive system.  "I think we should
follow the lead of Sweden and Denmark and start to phase out these
chemicals.  The issue will certainly not go away," said Dr Charles
Tyler, fertility researcher at Brunel’s University.
        This issue - as to whether chemicals are affecting fertility -
is not quite as new as most people believe.  As long ago as 1978
scientists working for the Thames Water Authority discovered that 40% of
the male roach fish in the River Lee, Hertforshire were hermaphroditic
(that is having both male and female sex organs) and were sterile.  It
was believed that chemicals, notably estrogen - probably contained in
contraceptive pills, in the effluent from the Mill Green sewage works
which treats industrial and domestic waste was to blame.
        Strangely this research was deliberately kept under wrap with
the findings not made available for other scientists to study.[3]
Defending this secrecy John Sexton, Director of Environment and Science
at Thames Water Utilities Ltd, said the "first findings were of very
little consequence and the whole works should be completed by government
departments."[3] 
        This view was not shared by scientist Paul Johnson of Exeter
University who said, "science and the pursuit of science are all about
evaluating problems and expanding the knowledge base.  If the results of
works are not published it’s impossible to make progress"[3]    In 1982
scientists at Liverpool University, on a commission from Thames Water
Authority, fed sewage effluent to rats in order to monitor its effects.
Initial results suggested major hormonal effects, including disruption
of the reproductive cycle.  Later tests however did not confirm this.
[3] 
        In 1987 the Department of the Environment and the Fisheries
Ministry (MAFF) commissioned a survey of rainbow trout in 31 rivers in
England & Wales.  The fish were situated in cages near sewage effluent
outlets.  There was something estrogenic at all the outlets.[3] 
        John Sexton maintained the amount of hormone found in the
drinking water supplied by the Thames Water Authority posed no danger to
health because "the body produces the same hormones, so adjusts
itself".[3]
        "Man made hormones [as produced by hormone mimicking chemicals]
are different from natural hormones," said
Dr Vyvyan Howard of the Department of Fetal and Infant Pathology at the
University of Liverpool.  "They are persistent. Natural hormones will be
destroyed within the body in half an hour.  Man-made hormones stay in
the body for years and years switching on enzyme systems."  Hormones are
incredibly potent at amounts as low as fractions of a millionth of a
gram.  "If it affects those fish, then it’s affecting us,"  he added.
"We have had a very long time to adjust to natural estrogen", said Prof
Carlos Sonnenschein.[16]
        Thames Water Authority admitted they were concerned about "the
implications the findings might have for the people downstream (ie.
north London) who rely on the river Lee for the source of their drinking
water".  This has not stopped the British government successfully
putting pressure on the European Union to throw away the strict
directives on drinking water, replacing them with new regulations that
are less restrictive on some substances, specifically pesticides - which
have been implicated by a host of scientists as environmental estrogens.
        Once again the British government is showing an appalling lack
of commitment to the "precautionary principle" 
enshrined in international protocols and exhibiting an alarming
indifference to the health of the British public. 
        It is thought by many that pressure to 
relax the standards of chemical contamination in drinking water by the
government is a result of pressure from outside the water industry.  To
meet the proposed stricter regulations would have required major
expenditure by the companies concerned and this would have made a big
dent in their profits and reduced the price of their shares. 
        "Our job is to ensure that if a standard like that is imposed
then it is necessary.  If it is necessary then we would fully subscribed
to it and support it", said John Sexton, "but all the recent evidence is
suggesting that the standard at the moment is too strict and the money
being spent by us putting in additional treatment in could be better
spent in other areas."  
        "Even though some of the pesticides and herbicides have been
shown to have estrogenic activity?" He was asked.
        "Oh yes, having estrogenic activity per se isn’t a problem, the
question we have to look at is what substance, at what levels?"[3]

        That certain chemicals are capable of mimicking sex hormones
appears to have been accepted by a large body of the scientific
community as the evidence continues to mount up.  Man-made chemicals
such as organochlorine pesticides (DDT, for example, which was used in
large quantities until the 1960s when it was banned or restricted in the
western world) head the list of environmental estrogens.  The Danish
Environmental Protection Agency, focusing on the work of several
scientists studying this problem, identified 27 classes of pesticide in
common use as environmental estrogens.  PCBs (used as industrial
chemicals in capacitators and transformers) are among five classes of
industrial chemicals now known as environmental estrogens.
        Alkylphenol polyethoxlates (nonionic surfactants used in
detergents, emulsifiers, wetting agents and dispersing agents in
household products and in agricultural and industrial products such as
herbicides and paints; also used as spermicides in contraceptive foams,
jellies and creams) and phthalate esters (used in most commercially
available plastics, including polyvinyl chloride [PVC]) are other
chemicals responsible for xenoestrogenic behaviour.  Environmental
pollutants such as dioxins and furans (unwanted by-products from the
combustion of chlorinated hydrocarbons) have also been implicated.[14]
        Chemicals found in food wrapping, tin cans and even some face
creams and dental fillings have also come under the microscope.[2]
   This source of exposure to estrogenic chemicals via food was
discovered when Spanish scientists found that bisphenol-A leaches from
the inner lining of food cans into many vegetables.  Also worrying is
the fact that this chemical also leaches out of plastic babies bottles.
[15]
        Dr Richard Sharpe of the Medical Council’s Reproductive Biology
unit in Edinburgh announced in July 1995 that he had experimental
evidence that prolonged exposure to low levels of phthalates, comparable
to those found in human diets, could cause a reduction in testis size in
developing rats.  Any reduction in testis size would be expected to
reduce sperm production.[4]
        Two recent studies have found that sperm count in men has
declined precipitously over the past 20 years. [5]  A report in the
British Medical Journal in August 1994 comparing men of similar ages,
sperm count in 3729 Scottish men had declined 41% among those born in
1969 compared to those born in 1941. The New England Journal of Medicine
reported in February 1995 that sperm count has declined 33% during the
past 20 years among a study-population of 1,351 healthy, fertile men in
Paris, France.
        Researchers at the North London Royal Free Hospital, measuring
the pregnancy rate between 1977 and 1989, found, despite improved
techniques, it had fallen.  Jean Ginsburgh, Consultant Endocrinologist
at the hospital, said: "When checking sperm count we found that the men
were producing 96 million [sperm per cubic centimetre] which is a decent
sperm count, but we found we had a higher proportion of poor or no
motiIity and the quantity and quality had declined."  She is convinced
the cause is environmental, "something very general that every body
takes, water, food, bread, milk. [3]
        Alan Bennett, a male infertility specialist in Albany, New York
State, where men are suffering major reproductive problems said:  "It’s
rare in my practice to find a man with a sperm count of 100 million cc.
I see a lot of men who are ‘normal’ with a sperm count of 30 to 40
million.  In the US we now have a normal count of 20 million, whereas
when I was training it was 60 million, so in the twenty five years I’ve
been practising its gone from 60 million to 20 million, that says
something."[3]
        In 1992 a historical analysis of 62 separate sperm-count studies
by Elisabeth Carlsen concluded that sperm count among men throughout the
industrialised world has declined by about 50% in the last 50 years.[6]
Two years later these findings were challenged by researchers who said
it might have been caused by Carlsen’s erroneous choice of statistical
methods, and not by an actual decline in sperm count.[6]
        The chemical industry is attempting to undermine the scientific
evidence and it’s scientists will no doubt be quick will be quick to
point out that no one knows for sure what is causing the apparent
decline in sperm count among men.  But the report from MRC Reproductive
Unit goes a long way to laying the blame at this industry’s doorstep.
        It is still remotely possible that the decline is not real.  For
example, these 62 studies may have examined men who are not typical of
the general population and various factors that influence sperm count
may not have been fully accounted for.[7]
         As Carlsen and her co-workers said in 1994, defending their
1992 conclusion:
         "The most cautious conclusion that can be drawn from the
existing data is that semen quality has declined significantly between
1940 and 1990."
         Various hypothesis have been suggested as to the cause of the
decline but the one getting the most attention is that hormone mimicking
chemicals in the mothers blood is affecting the male child before it is
born.  This hypothesis suggests that the male child is being born with
fewer Sertoli cells.  These are the cells that cause the production of
sperm after puberty.  Reduced numbers of Sertoli cells (and reduced
sperm count) have been observed in the male offspring of estrogen-
exposed pregnant rats.[8]
        Researchers studied a group of 1,351 healthy men in Paris who
had donated sperm to a sperm bank maintained by a hospital, starting in
1973.  Each of the men had fathered at least one child.  One percent of
the men were farmers and 16% were manual labourers; 40% were classified
as "technicians" and 38 % as "executives."  From 1973 to 1992 their
average (mean) sperm count declined at the rate of 2.1% each year from
89 million per cubic centimetre (cc) to 60 million per cc.  During the
same period the proportion of motile sperm (that is sperm able to swim)
declined at a rate of 0.6% per year, and the proportion of "normal"
sperm (compared to misshapen sperm) declined at the rate of 0.5%.  In
sum, the quantity and quality of sperm declined simultaneously.
        This study answers some of the concerns of some of the critics
of Carlsen’s 1992 study.  Those critics charged that abstinence from sex
causes an increase in sperm numbers and a decrease in sperm with good
motility and Carlsen could not control for that.  The study in Paris
took into account the length of abstinence before samples were taken.
It also controlled for age and for the year of birth.  The decline in
sperm quantity and quality, linked to year of birth, was still
observable after controlling for length of abstinence and age.
        Among the Paris group, a subgroup of 382 men in a narrow age
range (28 to 37 years) was chosen for special analysis; they had all
reported a similar period of abstinence (3 to 4 days).  Among this
group, there was a clear decline in sperm count from 1973 to 1992; from
101 million per cc to 50 million per cc, a reduction by half.  The
average 30-year-old born in 1945 would have a count of 102 million per
cc; the average 30-year-old born in 1962 would have a count of 51
million.  "We conclude," the French researchers said, "that there has
been a true decline in the quality of semen during the past 20 years,
since the characteristics of semen from a fertile man of a given age in
1992 were significantly poorer than those of a fertile man of the same
age in 1973." 
        The Scottish researchers completed their study in response to
criticism of Carlsen’s 1992 analysis of 62 sperm-count studies showing a
50% reduction in 50 years.  They had records for 3,729 semen donors born
between 1940 and 1969.  They examined these by statistical techniques
chosen to avoid the (controversial) criticisms that had been levelled at
Carlsen’s work.  They found an apparent decline in sperm count from 128
million per cc (in men born in the 1940s) to 75 million in men born in
the late 1960s, a 41% loss in a single generation.
        "Thus we do not accept that the evidence for a fall in sperm
concentrations is unconvincing," they concluded.  Stewart Irvine, a
gynaecologist at the Medical Research Council’s Reproductive Biology
Unit in Edinburgh, Scotland, who studied sperm production of Scottish
males told Lawrence Wright, writing for the New Yorker: "I had a
colleague visiting from Australia, and he had with him a laptop computer
with lots of data from infertile couples.  He said, ‘I’m sure these
sperm count drops are rubbish.  I’m sure there are other explanations
for it.’  And I said, ‘Well, just take your data and plot it by year of
birth and see what you get.’  He got the same result." [12, pg 46] 
        Several researchers have noted that the decline in sperm quality
(count, motility and normal shape) coincides with an increasing
incidence of abnormalities of the male genital tract, including
testicular cancer and cryptorchidism (undescended testicles) in various
countries.[9]  Such abnormalities have doubled in frequency during the
past 30 years in many parts of the world.[10]
        In Scotland, for example, testicular cancer has doubled since
1960 and is striking a younger population (ages 15 to 44) every year.
The cause of these increasing abnormalities remains a mystery. 
        One clue that may tie all the threads of evidence together is
the record of what happened to the sons of women who were given a
synthetic hormone, diethylstilbestrol (DES), during the fifties and
sixties.  About a million women were given DES as a "morning after" pill
to reduce the likelihood of pregnancy.  Their sons have shown an
increase in genital tract abnormalities AND reduced sperm count.
        Data from animal experiments has confirmed that chemicals effect
sexual development. Pregnant rats given a single, very low, dose of
dioxin on the 15th day of gestation, produce male offspring that have
genital tract abnormalities (particularly undescended testicles) and a
low sperm count after they mature.[11]
        The New England Medical Journal stated in February 1995 that the
significant decline in the concentration of sperm during the past 20
years in the Paris area,may be related to an interaction of the age of
the [sperm] donors and the chronologic period [in which they are living]
that in turn could implicate factors affecting all the inhabitants of an
area, such as the water supply or environmental pollution. 
        Danish pediatric endocrinologist (hormone specialist) Niels E.
Skakkebaek said that in the late 1980s he and his colleagues had been
wondering why it was so difficult for sperm banks to establish a core of
donors.  "In some areas of Denmark, they were having to recruit ten
potential donors to find one with good semen quality."  In 1990
Skakkebaek studied sperm quality in Danish men starting with men working
in what is classed as "non-hazardous" jobs such as office workers and
labourers who did not work directly with industrial chemicals or
pesticides.  These were men thought to be quite healthy. 
        For decades it had been believed that the average man produced
about a hundred million sperm per millilitre of semen, of which about
20% was expected to be immobile. Skakkebaek reported that 84% of the
Danish men he studied had sperm quality below the standards set by the
World Health Organisation (WHO). The men themselves seemed ‘normal’ in
every other respect.[12, pg43] 
        On the basis of the world’s medical literature, Skakkebaek
calculates that in 1940 the average sperm count was 113 million per
millilitre, and that 50 years later it had fallen to 66 million.[12,
pg44]   Still more serious is a three-fold increase in men whose sperm
count was below 20 million - the point at which their fertility would be
jeopardised.
        Skakkebaek has gained a wide reputation for his studies on
testicular cancer which in the past 50 years has become a particularly
common disease in Denmark with nearly one in 100 men affected.  In his
paediatric practice Skakkebaek was seeing many boys with malformed
genitals.  A study in 1984 of 2,000 Danish school boys found that 7% of
them had one or both testicles lodged inside their bodies - a condition
that may lead to sterility and a higher risk of testicular cancer.
Skakkebaek sees the decline in sperm count as only one part of a much
larger assault on the male reproductive organs,  high rates of
testicular cancer, undescended testicles, hypospadias (a condition in
which the urethral opening in on the underside of the penis not on the
tip) are all increasing.
        Pierre Jouannet, director of the Centre d’Etude et de
Conservation des Oeufs et du Sperme in Paris, simply did not believe
Skakkebaek’s conclusions.  Jouannet had data on 1,350 Parisian men, all
of whom had fathered at least one child and therefore were of proven
fertility, so he analysed them, expecting to refute Skakkebaek’s
studies.  To his astonishment he found that sperm counts in his group
had dropped steadily at 2% per year for the past 20 years; in 1973 the
average count was 89 million per millilitre and in 1992 it was 60
million.[12, pg45]  The expected sperm count for a Parisian man born in
1945 was 102 million, whereas the count of those born in 1962 was
exactly half that number.[12, pg45] 
        Jouannet had been convinced.  And when he projects the decline
into the future he sees serious trouble for the human species.  At the
present rate of decline, he reported gravely, "it will take 70 or 80
years before it [sperm count] goes to zero".[12, pg45]   Difficulty
conceiving occurs at 20 million or less; sterility occurs at five
million or less.
        In the United States the number of donors with good-quality
sperm has become distressingly low. Back in 1981 researchers at the
Washington Fertility Study Centre reported that the sperm count of their
donors, who were largely medical students, had suffered a steady decline
over the previous eight years.  The researchers worried that, if the
decline continued at the same rate, within the decade there would be no
potential donors who could meet the approved or recommended standards.
        The fact is that the number of morphologically normal sperm
[meaning sperm with a normal shape] produced by the average man has
dropped below the level of those of a hamster, which has testicles a
fraction the size of a man’s.[12,pg44] 
        In the United States, where infertility is defined as failure to
produce a child after a year of normal sex, according to the National
Centre for Health Statistics, the percentage of infertile couples has
risen from 14.4 in 1965 to 18.5 in 1995.[12, pg44] 
        There has been little published research comparing racial and
ethnic sperm counts, particularly in Africa and many Third World
countries.  But the studies that we do have show low counts nearly
everywhere: the latest count in Nigeria is 64 million per millilitre; in
Pakistan, 79.5 million; in Germany, 78 million; in Hong Kong, 62
million.[12, pgs44-45] 
        "Infertility is definitely going up," said Dr. Marc Goldstein,
director of the Centre for Male Reproductive Medicine at New York
Hospital. "I see it in my practice.  There is a decline in fertility in
men and an increase in infertility in older couples.  Studies show an
increase in infertility from 11% to 16 % in all married couples."  He
believes part of it may be life style: marijuana, cocaine, alcohol, and
sexually transmitted diseases can all reduce sperm counts.[13, pg80]
But wildlife do not smoke marijuana or drink alcohol and there are
numerous reports of reproductive problems caused by chlorinated
chemicals in wildlife.  It is something more fundamental than life
style, Skakkebaek observed.  Whatever is happening to men, he noted,
some part of it must take place during the early stages of human
development - in the womb or else shortly after birth - because damage
to the male urogenital system is evident in certain very young
patients.[12, pg47]
        Sharpe concurred the decline in sperm is linked to some event
that affects the endocrine system which governs the body’s hormones.
This must happen, he said, either in the womb or shortly after birth. "I
have absolutely no doubt this is the most important time in your life,
certainly if you’re a male," he said.  "This is when your sperm-
producing capacity as an adult is settled once and for all."[12,pg48]
        Changes in life style won’t help men whose sperm producing
capacity has been crippled at birth.
        In a series of experiments,  Sharpe exposed pregnant rats to
"minute quantities" of DES and to other synthetic estrogens; he showed a
5% to 15% decline in sperm count in male offspring when they matured.
Philippe Grandjean, a professor of environmental medicine at Odense
University in Denmark summarised the situation  in an interview with
Lawrence Wright:  "We thought in the past that these toxic substances
would act on a target - an enzyme or DNA or the cell membrane, or
something like that.  But what these endocrinologists have suggested to
us is that industrial chemicals can actually mimic hormones.  It looks
as if the receptors aren’t very good at recognising what’s a hormone and
what’s not a hormone - perhaps because they were never previously
challenged. These receptors have been kept almost unchanged in the
mammalian world, because they worked.  They functioned very well.  But
in this century we have generated all these new chemicals and injected
them into the environment, suddenly the body is exposed to new
substances that in some cases can interact with that receptor.  The
human species is totally unprepared for this, because it has never
happened before.  I think the perspective is both very exciting and
very, very frightening."[12, pg51] 
        Most, though not all, of the estrogen-mimicking chemicals
involve chlorine.
        Day 56 is the day sexual differentiation sets in the human but
what happens during  gestation from that period on is in many ways just
as critical as what happened before those first 56 days.  The secondary
sex organs of a young man are developing right through until he reaches
puberty.
        If, as Theo Colborn of the World Wide Fund. has theorised, the
number of chemicals that can harm reproduction add up to hundreds, if
not thousands, the only way to regulate them all will be to "reverse the
onus" that now falls on individuals to prove they have been harmed by a
toxic substance.  We now have between 300 and 500 chemicals in our
bodies in measurable amounts that weren’t there 40 years ago" she said.
        "The responsibility should not be on the people exposed to
chemicals to prove they have been hurt," said David LaRoche, the
secretary of the International Joint Commission (IJC).  "The
responsibility should be on industry to prove that chemicals cause no
harm."[13, pg84]  
        Professor Carlos Sonnenschein (Tufts University School of
Medicine, Boston ) believes most chemical manufactures have alternative
‘inexpensive’ chemicals they could use.  "When we discover a product
contains estrogen disruptors we should stop and look to alternatives."
[16]
        "I have heard that the Chlorine Chemistry Council’s budget is
around $100 million," Gordon Durnil former chairman of the IJC.told
Esquire reporter Daniel Pinchbeck. Durnil "It’s a lot of money.  You
could use it to buy some research.  Why don’t they do some research to
say what they are doing is safe?" Durnil asked.[13, pg84] 
        Unfortunately, the truth about the sperm count is that it is
under attack from many different sources. Earl Gray, a senior research
biologist with U.S. Environmental Protection Agency (EPA), testified
before Congress in 1993 that;  "Our studies [in rats] show that a single
dose of dioxin administered during pregnancy permanently reduces sperm
counts in the males by about 60 per cent."[12, pg53] 
        "With sperm counts, I’ve been more impressed by the dioxins and
the PCBs than by the estrogens and anti-androgens,"  Gray said.  "We get
surprising effects at relatively low doses."[13, pg53] 
        "Probably half the jobs in the world are associated in some way
with chlorine," said Durnil.  "As a society, we are going to have to
confront our dependence on this chemical."[13, pg82]
        Thus, although it remains a hypothesis that estrogen-mimicking
chemicals are causing the observed tract, in sperm reduction it is a
hypothesis that is being taken very seriously by a large number of
scientists world wide.  They are working aggressively to confirm its
truth or falsehood. It is after all, an important matter for the future
of the human species.  
        "When we discover a product contains estrogen disruptors we
should stop and look to alternatives."

References:
[1] Marguerite Holloway, "Dioxin Indictment," Scientific American Vol.
270 (January 1994), pg 25. 
[2] The Observer 25 February 1996 
[3] Dispatches "Down for the Count."
[4] ENDS Report 246 July 1995 pg3
[5] 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.
[6] Elisabeth Carlsen and others, "Evidence for decreasing quality of
semen during past 50 years," BRITISH MEDICAL JOURNAL Vol. 305 (1992),
pgs. 609-613.
[7] Richard J. Sherins, "Are Semen Quality and Male Fertility Changing?"
NEW ENGLAND JOURNAL Vol. 332 No 5 (Feb.2, 1995), pg. 327, says that
studies conducted so far have not properly controlled for differences in
age, abstinence before semen analysis, ejaculatory frequency, and the
number of samples analysed per person, all of which can effect sperm
count.  Another author who has registered scepticism of the 1992
findings is Stephen Farrow, "Falling sperm quality: fact or fiction?"
BRITISH MEDICAL JOURNAL Vol. 309, No. 6946 (July 2, 1994), pgs. 1-2.
[8] A. Giwercman and N.E. Skakkebaek, "The human testis—an organ at
risk?" INTERNATIONAL JOURNAL OF ANDROLOGY Vol. 15 (1992), pgs. 373-375.
And: Richard M. Sharpe and Niels E. Skakkebaek, "Are oestrogen involved
in falling sperm counts and disorders of the male reproductive tract?"
THE LANCET Vol. 341 (May 29, 1993), pgs. 1392-1395.  And: R. M. Sharpe,
" Declining sperm counts in men - is there an endocrine cause?" JOURNAL
OF ENDOCRINOLOGY, Vol. 136 (1993), pgs. 357-360.
[9] A. Giwercman, cited above in note 8; and see Peter Boyle and others,
"Changes in Testicular Cancer in Scotland," EUROPEAN JOURNAL OF CANCER
AND CLINICAL ONCOLOGY Vol. 23 (1987), pgs. 827-830. And: A. Giwercman
and others, "Evidence for increasing evidence of abnormalities of the
human testis: a review," ENVIRONMENTAL HEALTH PERSPECTIVES Vol. 101,
Supplement 2 (1993), pgs. 65-71.
[10] See Sharpe and Skakkebaek, cited above.in note 8
[11] Thomas A. Mably and others, "IN UTERO and Lactational Exposure of
Male Rats to 2,3,7,8-Tetrachlorodibenzo-P-dioxin. 3. Effects on
Spermatogenesis and Reproductive Capability." TOXICOLOGY AND APPLIED
PHARMACOLOGY Vol. 114 (May, 1992), pgs. 118-126.
[12] Lawrence Wright, "Silent Sperm," NEW YORKER (January 15, 1996),
pgs. 42-48, 50-53, 55.
[13] Daniel Pinchbeck, "Downward Motility," ESQUIRE (January 1996), pgs.
79-84.
[14] Danish Environmental Protection Agency, Male Reproductive Health
and environmental chemicals with estrogenic effects. April 1995. Miljo-
Kopenhawn, Denmark.
[15] Prof Anna Soto, Lecture, Liverpool University  7 May 1996.
[16] Lecture, Liverpool University  7 May 1996

Much of this feature was adapted from RACHELS Environment & Health
Weekly #372 #432 & #477 from the Environmental Research Foundation (see
below). The ERF provides a electronic version of RACHEL’S ENVIRONMENT &
HEALTH WEEKLY free of charge even though it them costs considerable time
and money to produce it.. You can help by making a contribution
(anything you can afford, whether £5 or £500) to: Environmental Research
Foundation, P.O. Box 5036, Annapolis, MD 21403-7036  Tel: (410)
263-1584;  Fax: (410) 263-8944.  Internet: erf at igc.apc.org. 

For more information on declining sperm contact Communities Against
Toxics
 
Article taken from ToxCat ISSN 1355 5707 Volume 2 - 2 Spring 96
Copyright 1996,97 Ralph Ryder TC Publishing All Rights Reserved

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