Mobile phone use does have an impact on male fertility.

Or at least it does if you use your phone for four or more hours a day. Which seems like a lot for a grown-up.

The American Society for Reproductive Medicine (ASRM) looked at 364 men. It found both numbers of sperm and quality fell for those using mobile phones.

Those who did not use a mobile at all had average sperm counts of 86 million per millilitre, with 68 per cent motility and 40 per cent normal forms. But men using a mobile for more than four hours a day had average sperm counts of 66 million sperm per milliliter, 48 per cent motility and just 21 per cent normal forms.

Researchers speculated that it could be electromagnetic radiation from mobiles.

But other researchers suggested the difference could be down to other factors such as obesity, stress, or diet. If you're on your phone for four hours a day you're probably not doing enough excercise. Or heavy phone users could be under more pressure and stress at work.

However, it's not all doom and gloom from the ASRM. It's also discovered that sperm from heavy smokers, which has less ability to bind with an egg, can be fixed by washing it in a "low-concentration cannabinoid solution".

More on both pieces of research here. ®