Study Hints That Wi-Fi Near Testes Could Decrease Male Fertility 307
Pierre Bezukhov submits news of a report that "a laptop connected wirelessly to the internet on the lap near the testes may result in decreased male fertility," writing
"'[The scientists who conducted the research] placed healthy sperms under a laptop running a Wi-Fi connection. After four hours, the Wi-Fi exposed sperms showed 'a significant decrease in progressive sperm motility and an increase in sperm DNA fragmentation' compared to healthy sperms stored for the same time in the same temperature away from the computer. That is, the sperms exposed to Wi-Fi were less capable of moving towards an egg to fertilize it and less capable of passing on the male's DNA if it does fertilize an egg.' The scientists blamed the damage on non-thermal electromagnetic radiation generated by the Wi-Fi."
However, the experiment was based on sperm outside the body; the researchers (here's the abstract from their study) note that "Further in vitro and in vivo studies are needed to prove this contention."
Re:That's not a bug, it's a feature (Score:5, Informative)
"Non-thermal electromagnetic radiation" means that electromagnetic radiation caused the effect through a nonthermal mechanism. It's a common idea in EM fear circles (because the output from EM devices is too low to cause damage by a thermal mechanism). It doesn't say anything about heat, one way or another. You can have thermal damage from EM radiation without any application of heat. That's what your microwave oven does.
Re:That's not a bug, it's a feature (Score:5, Informative)
The abstract specifically states that the control group was a set of identical samples, under the same incubation regime, without the laptop. So no, they didn't control for the idea that the laptop alone could've caused the effect
Re:That's not a bug, it's a feature (Score:2, Informative)
To quote:
compared to healthy sperms stored for the same time in the same temperature away from the computer
That looks like it says a lot about heat to me, of course, I understand that you are thinking about the amount of heat put off by a laptop but it seems like they controlled for this by putting the wifi close but not putting the laptop directly on top of the sperm.
Re:That's not a bug, it's a feature (Score:5, Informative)
Here's the kicker - they ran the laptop with the wifi switched off, but only measured the RF output of the laptop [msn.com] in that state. They didn't perform - or performed, but didn't publish - the obvious control experiment.
Re:That's not a bug, it's a feature (Score:5, Informative)
That news report is wrong. The seperate test in question evaluated the RF output of a laptop with its wifi switched off, but it did not measure sperm motility after exposure to that laptop:
"A separate test with a laptop that was on, but not wirelessly connected, found negligible EM radiation from the machine alone."
http://www.msnbc.msn.com/id/45469130/ns/health-mens_health/#.TtT0PlabUlT [msn.com]
Re:They're claiming it's not thermal damage (Score:5, Informative)
They actually aren't claiming anything. I tracked down the paper (which was fucking harder than it should have been, the article didn't cite anything but the journal and month - turns out it was in the supplemental issue from September, not the main journal). The real citation is:
A. Van-Gheem, J. Martin, L. Penrose, N. Farooqi, S. Prien, Short-term exposure to cell phone levels of radio frequency radiation do not appear to to influence semen parameters in vitro, Fertility and Sterility, Volume 96, Issue 3, Supplement, September 2011, Page S155, ISSN 0015-0282, 10.1016/j.fertnstert.2011.07.610.
(http://www.sciencedirect.com/science/article/pii/S0015028211017079)
I wonder why the article didn't cite it? Maybe because in the title itself, it says "do not appear to influence". Anyway, turns out it's not a real paper, it's really just a blurb about "We did this and it turns out nothing happened".
Here's the results section:
Re:Wavelength (Score:3, Informative)
This subthread seems to be a great hangout for EEs who don't understand physics.
Your "compelling explanation" is not an explanation, but a statement of the effect. The explanation for the effect is *precisely* that the EM wave causes the polar molecules to jiggle in response, thus heating them, and the Newtonian reaction to that is that the jiggling molecules themselves create EM waves which are out-of-phase with the primary wave and hence attenuate it through interference. Thus, from a macro point of view you see that the waves are attenuated and you say "where did the energy go? oh it's in the water - water must be a lossy medium for 2.4GHz waves." But the micro point of view is the actual *explanation* - it tells you *why* water is lossy at 2.4GHz (and not so much at lower frequencies). It's because 2.4GHz is around about the resonant frequency of the jiggles.
To put it another way, the microwaves don't make the water molecules jiggle by raising the temperature - the microwaves make the water molecules jiggle *directly*, through direct interaction of the EM wave with the charges on the molecules. The temperature rise is a *consequence* of that (the other consequence being attenuation of the microwaves).
Re:They're claiming it's not thermal damage (Score:5, Informative)
there are two papers: the Van-Gheem et.al. paper you cite and then there is the
one the slashdot article is about, which is:
Use of laptop computers connected to internet through Wi-Fi decreases human sperm motility and increases sperm DNA fragmentation. by Avendaño C, Mata A, Sanchez Sarmiento CA, Doncel GF.
The authors are the Argentineans which the linked article mentions.
It's (to be) published in Fertility and Sterility.
So I basically don't know what you're going on about ...