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.