I have to say, I am no longer very excited about such things. It seems we are going to cause not only the devastation, maybe extinction, of our own species, but of the rest of the earth's species. So maybe it's just as well if we do it this way, and let the rest of the earth recover.
http://www.ispub.com/ostia/index.php?xmlFilePath=journals/iju/vol2n1/sperm.xml
The Internet Journal of Urology™ ISSN: 1528-8390
Shiva Dindyal MBBS (London) BSc. (Hons)
Imperial College School of Medicine
There have been a number of studies over the past 15-20 years (1, 2, 3, 4, 5, 6 and 10), which suggest that sperm counts in man are on the decline. Since these changes are recent and appear to have occurred internationally, it has been presumed that they reflect adverse effects of environmental or lifestyle factors on the male rather than, for example, genetic changes in susceptibility. If the decrease in sperm counts were to continue at the rate that it is then in a few years we will witness widespread male infertility. To date it remains unknown why this is happening and the available preventative measures, which can be taken to avoid a continuation of this trend, are not common knowledge.
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However, according to the ever-increasing literature on sperm counts, these “normal” values are steadily decreasing and only a minute proportion of males will have semen values that satisfy these ideal figures in today's Western industrialised countries. Not only are sperm counts decreasing, but also are the average sperm volumes which contain a greater proportion of deformed spermatozoa that have reduced motility's.
Professor Niels Skakkeback, a Danish scientist, first alerted the world to the possibility of a substantial fall in male fertility levels in 1992. He did this by showing that sperm counts in healthy men appeared to have dropped by more than half in 50 years (1, 2, 3, 4, 5, 6 and 10). Professor Skakkebaek's work attracted worldwide publicity at first – and then ridicule. He and his team in the Department of Growth and Development at Copenhagen University had reviewed 61 international studies involving 14,947 men between 1938 and 1992 (4). They found that the average sperm count had fallen from 113 million per millilitre in 1940 to 66 million in 1990. In addition, the definition of a “normal” sperm count fell from 60 million per millilitre to 20 million in the same period (1). Critics who reanalysed the Danish data pointed out a fundamental flaw in the calculations which, they said, ruled out any significant decline.
Subsequent studies have confirmed and strengthened Skakkebaek's findings. A survey of 1,350 sperm donors in Paris found a decline in sperm counts by around 2% each year over the past 23 years, with younger men having the poorest-quality semen (1, 5 and 6). In another study at the University of Helsinki led by Jarkko Farjarinen, testicular tissue was examined at post-mortem from 528 middle-aged Finnish men who died suddenly in either 1981 or 1991 (11). Among the men who died in 1981, 56.4% had normal, healthy sperm production. By 1991, however, this figure had dropped dramatically to 26.9%. The average weight of the men's testes decreased over the decade, while the proportion of useless fibrous testicular tissue increased. Adamopoulos et al (12) in Athens examined 23,850 men between 1977 to 1993 (17 years) and found similar results to Farjarinen (11).
In Edinburgh a recent study by Irwin (2) saw a 25% decrease in sperm count over 20 years, the results are shown in table 1 below. The worrying thing about this downward trend is that a sperm count less than 20 million sperms per ml is interpreted as being infertile, if this downward trend of counts were to continue then values less than this will be the average in the next millennium.
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Assuming, this data is correct, then the cause (or causes) must lie with changes in our environment or lifestyle over the past few years. We have released endocrine disrupters to our environment over time especially in Western industrialised countries where these horrific changes are most pronounced (2). Pharmacological investigations and natural poisoning episodes have led to the association between exogenous chemicals and alterations in multiple hormonal systems (3). Certain persistent environmental contaminants have been shown to modulate the activities of several different hormones. The unborn child or the neonate may be at special risk from these chemicals because of rapid growth and development, in addition to enhanced exposure to these persistent chemicals via food and water.
A possible explanation for this trend was put forward eight years ago by Sharpe et al (7). It was hypothesised that the reported decline in sperm counts might be related to an increasing incidence of other disorders of development of the male reproductive system (e.g., testicular cancer) and that this could have arisen because of increased exposure of the developing foetus to oestrogens. A source of this increased oestrogen exposure was via environmental oestrogenic chemicals, or “Xenoestrogens”, the release of which has more or less coincided with the decline in sperm counts
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Professor Skakkebaek and Dr Sharpe have proposed many factors for increased oestrogen uptake and exposure since the Forties: dietary changes with increased consumption of hormone-rich dairy produce; synthetic oestrogens in the contraceptive Pill and other drugs, and a wide-range of chemicals that have been identified as having oestrogenic activity. Table 2 below shows the various routes of human exposure to oestrogens that have changed in the past 50 years. They include environmental contaminants such as DDT, PCBs (used in electronics), and exhaust fumes (1). So it can be seen that since the Forties man has produced and released into the environment increasing amounts of chemicals, some of which are highly persistent, present in our food chain and in our bodies (14 and 23) and which are weakly oestrogenic (24). Polychlorinated biphenyls are a good example, but several other chlorinated hydrocarbons (e.g. DDT) show similar properties. So it can be seen that humans now live in an environment that can be viewed as a virtual sea of oestrogens
Researchers surveying the Great Lakes of Apopka Florida in the late Eighties found that members of 16 animal species, which fed on fish from the lakes (especially alligators and birds), were known to be contaminated with some sort of oestrogen-like chemical. These animals were failing to reach adulthood and were sterile
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He discusses the following sources of oestrogen-like chemicals:
Synthetic oestrogens in the contraceptive Pill and other drugs, which contaminate water
Hormones fed to animals used for food and milk
Plastics
Therapeutic drugs
Food sources
Insecticides, fungicides and pesticides
Industrial chemicals
He discusses other possible factors:
Increased temperatures in the world from global warming..
Increased exposure to radiation due to increasing ozone layer depletion
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