Does Wi-Fi Nuke A Man's Sperm?
A small rumble on Monday, but that rumble was from Reuters, and pretty soon it was EVERYWHERE. The BBC, even YAHOO had something: the WI FI is coming for your SPERM! No one's sperm is SAFE! WHATEVER SHALL WE DO!?!?!
I'll tell you what we shall do. We shall look at this paper, and we shall READ it. And we will point the bright light of SCIENCE at it.
Alright paper. WHERE WERE YOU ON THE NIGHT OF... oops. Wrong tactic. Sorry.
The paper in question: "Use of laptop computers connected to internet through Wi-Fi decreases human sperm motility and increases sperm DNA fragmentation" by Avendano, et al. in Andrology, 2011.
This is by no means the first paper to look at the association between electronic use and your junk. In fact, I've covered the issue twice with cell phones and once with laptops. So I'm a little mystified why this new paper got all the attention it got. The journal is small, and so is the scope of the study.
"Man on laptop" via Shutterstock.
Oh wait. It's got balls. And sperm. And laptops. Never mind.
Anyway, let's take a look.
This study was a little different than previous studies using cell phones or laptops, in that they are particularly interested in what happened when you hooked the laptop up to wifi. The study states that most people use laptops on their laps (see my thoughts on that below) and that this exposes the nuts to high temperatures and electromagnetic frequencies. Sounds extremely scary, right?
In this case they are focusing on electromagnetic frequencies (their studies are designed to exclude heat, which is a nice tactic, and I'll get to that in a minute). The introduction to the paper spends some time detailing all the nasty things that can happen to you when you are exposed to lots of electromagnetic frequencies (including but not limited to miscarriage, higher rates of infant mortality, and childhood cancer), but what we are interested in here is infertility.
Electromagnetic frequences can cause oxidative damage and produce reactive oxygen species. These ROSs (not to be confused with ROUSs) are what do the damage. The authors are basing this study on some other studies showing that cell phones can cause ROSs and oxidative damage (more on that later, too).
There has been a decline in fertility in Western societies that has been documented. The possible causes for this... man, there are so many. We have new diets. We have new sedentary habits. We have higher weights. We reproduce at later ages. We are exposed to loads of environmental stuff. Some of us probably wear polyester. Many of these are being investigated, but it's the electromagnetic frequencies that gets the most press (well, now that the BPA press has died down a little).
So in this case they wanted to see if laptops, which emit electromagnetic frequencies, particularly when connected to the internet via Wi Fi, harmed male fertility. They took 29 dudes, and had them jack off into 29 cups (at least, I really hope they at least got their own cups and a nice private spot, unless, you know, you're into public spots). They took the resulting semen and tested it via swim-up method for the best and brightest sperm (the swim-up method is simple. Put sperm in the appropriate liquid, and the good ones will, obviously, swim up. Ratios of how many swim up vs how many don't are often used to assess fertility at first pass).
They then took the sperm, split each sample into two dishes, and set one dish (after covering it with parafilm because you probably don't want to accidentally spill that) under a laptop (Toshiba) which was actively downloading something via wireless. The sperm sample sat like that for 4 hours. The other sperm dish was placed on a table at room temperature. They then looked to see what the sperm were like. A good thing about this study is they DID control for heat, both sets of sperm were kept at a constant 25 degrees Celsius by air conditioning (which doesn't mimic a real life condition, but it DOES take away the variable of heat from the measure of electromagnetic frequency, which is often an issue in these studies).
They included an AWESOME diagram of this method. I love this.
Here's what they got:
The graph on the left shows the percentage of dead sperm. Equal in the tabletop and laptop exposed groups. The graph on the right shows three things: progressive motility, nonprogressive motility, and immobile sperm. They saw a decrease in progressive motility and an increase in immobile sperm in the laptop group. So it looks like the laptop didn't kill the sperm, they just didn't swim as well.
This shows an apparently significant increase in DNA fragmentation in the laptop group. Since the standard deviations are entirely overlapping here... (control: 3.3% +/- 6.0, laptop 8.6% +/- 6.6), I'm not sure how that works. They used a Mann-Whitney test, but still.
So the conclusions of this study: Do not place your sperm cells in a dish under your laptop for four hours. It might stop some of them from swimming.
That's it. No nuked sperm here. From the press releases I was expecting to see those poor little buggers dying by the millions. Heck there wasn't an increased rate of death at all. I'm not sure I buy the increased DNA fragmentation. But it doesn't show decreased fertility, it doesn't show nuked sperm, and though they got much higher electromagnetic frequencies, it doesn't necessarily show that the Wi Fi is coming for your balls.
Here's why this doesn't necessarily mean the Wi Fi hates your nuts:
The authors reference three studies on "laptops being commonly used in the lap." Two of these are studies citing lap burns following laptop use (which I believe, particularly after incidents with netbooks which have a tendency to overheat). The third is a study I already covered which studied laptops on dude's laps as related to scrotal temperature. They cite these as showing that dudes use laptops on their laps. ORLY? Do they? I mean, we all know that laptops were designed for portability and so you COULD put them on your lap, but how many of us do? How many of us do for four hours at a time? Routinely? For example, I'm working on a laptop right now, and it's on a table. I think if you did a survey, the percentage of dudes actually using a laptop on their LAPS for a significant period of time would be a lot lower than anticipated. After all, using a laptop primarily on your lap is... really uncomfortable. Hard to get at the mouse, your shoulders get all cramped up. Most of the time most of us love our laptops for their portability, but set them on a desk or table (or seat back tray when traveling) when we need to get stuff done.
But I could be wrong, so I did a quick informal survey:
You can see that 72 percent of respondents place their laptops on a surface that is NOT their laps while working (this is in fact higher than 72 percent as several respondents in "other" specify things like the bed, the floor, etc., making the real number close to 75 percent). In fact, lap respondents were only at 12 percent (though this could of course be confounded by the horse condition). So the proportion of the population using a laptop in the potentially dangerous position is much smaller than I think the authors here were betting on. I wonder about what proportion of the population is male AND uses a laptop AND puts it on their lap the majority of the time AND uses it four hours a day AND has fertility problems actually is. It may be significant. It may not.
I would also like to point out at 9 percent of my readers are apparently on a horse. Good job, my friends, good job.
These authors are basing this study on a study showing oxidative damage in sperm following cell phone use. This is not technically incorrect, but most studies looking at cell phone-induced damage have looked with a) extreme cell phone exposure (12 hours per day or more), b) in vitro, cells in a dish, not in an animal, or c) as in the particular study referenced, found "RFEMR does not have a dramatic impact on male germ cell development" (though they showed some problems with the mitochrondria of the sperm, the sperm had no motility problems and were otherwise completely fine as far as they could tell). While this doesn't preclude the results of their study, we also shouldn't be all panicked that the electromagnetism is coming for your sperm.
They observed small changed in sperm motility... in sperm in a DISH. I don't know about you, but I always put my sperm in a dish and incubate them under my laptop for four hours before attempting to fertilize anything. Maybe THAT'S why I'm having so much trouble! Now, in vitro studies do have a lot of implications for in vivo studies, and are EXTREMELY important. But... ejaculated sperm under a laptop are not sperm sitting pretty in your boys while you play Skyrim, protected by layers of jeans, boxers, what have you.
The sperm donors were not asked how much time they spent with their laptops on their laps. Inquiring minds want to know.
No Wi Fi condition
As pointed out by Jonathan in the comments of my original post about this (and I completely forgot to mention it, though it was one of the first things I thought of when I looked at this study!) WHERE is the laptop WITHOUT WI FI condition. WHERE IS IT? Because... it really should be there. What if the electromagnetic frequencies there are no different? What if the sperm in that condition are equally affected? Inquiring minds want to know if you can still work on that Word doc.
Now you might think from my sarcastic tone that this study has no merit. That's not true, I just love being snarky. What is true is that when you see a study like this, you have to limit the implications. These are sperm in a dish. They are not sperm in your balls or even sperm in seminal fluid. They DID get effects, which is interesting, that electromagnetic exposure can produce effects after as little as four hours. But I'm not sure how much it translates to your real life balls under laptop situation.
If we wanted to look at changes, I would actually be very interested to see a repeated measures study, where they take dudes, have them ejaculate, look at the sperm. Have them come back 5 days later, play four hours of games with the laptop on their laps downloading while they do. Have them jack off again, and look at the difference.
So what does this story tell you? Don't jack off on your laptop and leave it sitting there. At least not if you want to use the sperm later.
Scicurious is a blogger at Scientific American The Scicurious Brain and Scientopia's Neurotic Physiology, where this post first appeared. She has a PhD in Physiology, and is currently a postdoctoral researcher. She loves science, and so should you.