Over the years, I've heard (and read about) various dubious claims and doubtful allegations regarding the dangers of WiFi & 2.4GHz wireless ISM band communications in general. The stories typically presented themselves with the tell-tale signs of FUD marketing, crackpot conspiracy journalism, pseudo-intellectual pseudo-science etc. And I dismissed it as such.

Today I came across this article on wired.com, regarding the origins of unlicensed wireless communications at 2.4GHz. There was no mention of effects on health or anything like that but here are a few snippets that piqued my curiosity:

Routers could function just as well at 2.3GHz or 2.5GHz, but they’re not allowed. It’s the rules. The 2.4GHz band, which runs from about 2,400 to 2,483.5Mhz, is where routers have to live. For this, they can thank the microwave [oven].

Microwave ovens heat food by blasting it with, literally, microwaves. At certain frequencies, such waves cause something called Dielectric Heating in water and fat, while passing straight through other materials, like plastic or glass, without exciting them much at all.

Only certain materials are susceptible, and only when bombarded with waves of a certain frequency and power. But the one that proved to be both effective and relatively cheap to achieve was 2.45 GHz. That’s the frequency emitted by your microwave [oven], right there in the kitchen.

Despite heavy shielding, microwave ovens’ powerful emissions could sometimes interfere with neighboring frequencies, so it was decided that they should be given a few megahertz of space in both directions. And so the 2,400-to-2,483.5-Mhz ISM band was born.

So basically, all our domestic wireless technology is operating at and around the same frequencies as our microwave ovens. That is to say; the same frequencies known to cause "Dielectric Heating in water and fat." Two substances which, together, account for ~80% of the average human being's total physiology.

I've been using my current WiFi connection for the past few hours and my body fluids aren't boiling yet so Im assuming the microwave oven must be significantly more powerful than my local WiFi radio transceivers. However, we are subject to such an array of ISM band technology in our daily modern lives. So; Does it truly pose any direct health risks to humans and/or other animals? Or; Is it completely safe? Why or why not? Thank you.

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    Note: This answer was migrated from Electronics.StackExchange, with a number of highly upvoted answers that are NOT up to Skeptics.SE community standards and would normally be downvoted. Be careful not to judge what is acceptable on Skeptics.SE by these answers.
    – Oddthinking
    Commented Nov 7, 2015 at 0:35
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    @tjt263 a moderator at electronics.SE decided that this question was off topic there, because it doesn't fall into the topics described by their help center. If you need additional clarification as to why it doesn't fall into those topics, you would need to ask on the electronics.SE meta. Moderators are supposed to only migrate questions that are off topic at the origin site and on topic at the target site, so it would be frowned upon for them to send it straight back to electronics.SE.
    – lvc
    Commented Nov 7, 2015 at 5:22
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    @NickJohnson only downvote them, however the poor quality answers had e.g. 34 upvotes inherited from your site, but they were clearly unacceptable here. In general: do not migrate stuff with answers, thanks.
    – Sklivvz
    Commented Nov 7, 2015 at 22:07
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    @NickJohnson Unreferenced answers are always to be downvoted to zero and deleted on this site. Sometimes straight away or soon (if they are clearly unfixable, or if the owners state they aren't going to fix them, for example), or sometimes later. On the other hand, answers which get fixed always get undeleted, and this happens quite often. In particular your answer seems unsalvalvageable because it's based on a theoretical model, so it's hard to change it so it's based on evidence.
    – Sklivvz
    Commented Nov 8, 2015 at 14:35
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    This question had lots of interesting commentary on it when it was at electronics.SE. What happened to all those comments?
    – bubbleking
    Commented Nov 9, 2015 at 17:39

1 Answer 1


Does microwave radiation have any effects beside heating?

Yes. Take a look at this study.

Comparisons were drawn between irradiated samples and samples exposed to elevated temperatures within a furnace to extract microwave specific heating effects. The microwave-heating environment was found to exhibit unique effects

Is the effect unique to microwaves?

No. Take the example of UVB which is also, technically, non-ionizing. Non-ionizing radiation can be

biologically hazardous due to the ability of single photons of this energy to cause electronic excitation in biological molecules, and thus damage them by means of unwanted reactions.

Does microwave radiation at the levels of exposure created by modern radios cause harm?

No, probably not. Well, maybe a little. But definitely not a lot. Or we'd have noticed by now.

Why not?

Because the dose makes the poison, and the radios that we're allowed to use without a license are fairly weak. Not as weak as GPS signals, though. Now those are weak. WiFi isn't quite that weak, which is perhaps why it might affect us a little.

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    As I pointed out in comments elsewhere, your linked study showing microwaves can influence chemical reactions appears to be tied to irradiation at high heat. Specifically at temperatures starting at just under 500 degrees Celsius. Somehow I can't find those conditions occurring in normal life and at those temperatures I wouldn't personally be worried about chemical reactions caused by the microwaves. It is the heat itself that will kill you. As for your UV quote pulled from Wikipedia, it is a partial quote and a bit out of context, and ignores the really dangerous parts of UV.
    – YLearn
    Commented Nov 6, 2015 at 2:53
  • @YLearn Actually, the effect of microwaves at high temperatures is especially surprising, because the energy imparted to the electrons by the microwave photons would be smaller in relation to the thermal energy already in play.
    – Aleksandr Dubinsky
    Commented Nov 6, 2015 at 3:52
  • @YLearn My aim with these references was simply to demonstrate that the effect of non-ionizing radiation is not constrained to merely heating, which is being used by others to argue that microwaves can't have interesting effects.
    – Aleksandr Dubinsky
    Commented Nov 6, 2015 at 3:53
  • That may be your aim, but in pursuit of your aim you are misrepresenting information (selective, somewhat out of context quoting) and alluding to research that in no way applies to the discussion at hand. As for your "surprising" assertion, many materials exhibit different behaviors at extreme temperatures. This isn't surprising at all and doesn't in any way mean that the same principles apply at "normal" temperatures.
    – YLearn
    Commented Nov 6, 2015 at 5:06
  • Actually, one would expect the effects to be different. Heat interacts with more molecules than the microwave radiation does. Since the interactions are different, their effects would be different as well. Calling exposure to microwave spectrum "irradiation", btw, is very misleading. Commented Nov 6, 2015 at 22:58

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