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  • If you look at the sperm concentrations

  • when we last looked at them, which was samples collected in 2011,

  • the sperm concentration in Western countries was

  • 47 million per millilitre down from 99 million per millilitre 39 years earlier.

  • So that's a decline of more than one percent per year.

  • And it would predict between 2011 and now, which is 10 years,

  • that we would be now below 40 million per millilitre.

  • And that's an important number, because below 40 it becomes

  • increasingly difficult for couples to become pregnant.

  • And how low it's going to go before we

  • wake up and say: 'We have to stop this,'

  • I don't know how long that's going to take. But it's urgent.

  • However, then there is a whole other class of things,

  • which are not so easy to control. And those are the chemicals

  • in our environment that come in the products

  • that we bring into our home.

  • Coatings is a big category

  • and you can coat a pan with teflon or non-stick.

  • You can coat a jacket with water repellent,

  • you can coat a paper to keep oil from

  • passing through it, say in a pizza box.

  • So coatings are a real concern because

  • they contain one class of chemicals, the PFAS.

  • Then another big class and one that I've studied a lot,

  • is the chemicals that make plastic soft. And those are the phthalates.

  • Phthalates as a class are called anti-androgens.

  • Wherever they meet testosterone, they tend to decrease it and

  • most dramatically in the womb, in early pregnancy.

  • One particular way that we see that is the size of the genital area,

  • which is called the anogenital distance.

  • Then when the boy grows up, he will have, we've shown,

  • a lower sperm count.

  • Besides having an impact on sperm count, it can increase

  • the risk of genital defects, undescended testicles, for example.

  • And later it actually can increase the risk of testicular cancer.

  • We looked at pesticides metabolised in their urine and how they related to

  • the sperm count, concentration, and shape of those sperm.

  • We found that there was a big difference in

  • sperm count and quality. The most dramatic was that men,

  • who were living in central Missouri, which is an agricultural area,

  • where there is a lot of corn and soy grown, a lot of pesticides used

  • They had only half as many moving sperm as men in Minneapolis.

  • This is huge! Half as many.

  • And they were not workers, they were just residents of the area.

  • Low sperm count is related to all kinds of morbidities,

  • including heart disease, diabetes,

  • reproductive cancers, and ultimately length of life.

  • It's always assumed that it's the woman's responsibility or fault

  • if a couple can't get pregnant or if a women has miscarriage.

  • Now we know that it's a shared responsibility.

  • And getting the quality of the eggs is much more difficult

  • than for a man to count his sperm or get the quality of his sperm.

  • More and more people are now considering storing their sperm,

  • freezing their eggs. Long-term storage.

  • Because we're in a crisis.

  • A very large and increasing number of children

  • are conceived by assisted reproduction.

  • And an increasing number of people are using surrogates for their pregnancy.

  • We are already in the throes of a really really serious situation.

  • He could think about lowering his exposures

  • by changing his shopping habits.

  • He could maybe lose weight if he's overweight.

  • He could stop smoking if that's a problem.

  • He could stop binge drinking if he does that.

  • It is much, much harder to get the chemicals out of our bodies.

  • The good news is that many of them are short-lived chemicals

  • that are non-persistent.

  • They leave our body with a half-life of four hours,

  • six hours, so very quickly. So, if we could be aware of

  • what's coming in and stop it, then pretty soon we can clean that up.

  • We need to test chemicals before they are put into the marketplace.

  • We need to test the thousands of chemicals that have never been tested

  • because they've been assumed safe. And we now know they're not.

  • There is no question that environmental factors affect

  • reproductive function.

  • We're in a crisis, a really really serious situation.

If you look at the sperm concentrations

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B2 中高級 美國腔

孕(Fertility crisis: Is modern life making men infertile? - BBC REEL)

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    王杰 發佈於 2022 年 06 月 02 日
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