Cellphone case to reduce EMF radiation exposure
February 13, 2012 5:05 PM   Subscribe

Blocking cellphone radiation with a special case?

There are a few questions on Ask Metafilter that touch on this, but none that answer the question.

I carry my cellphone in my front pocket. I don't use it much, but it spends many hours in that pocket.

Question: Can I buy a case or shield that will reduce EMF emissions? Not for when I'm using it, but for when I'm carrying it.

Also, how do I find a case that actually shields me? Googling yields all kind of sketchy, sloppy sites and little clarity on the topic. I know research is ongoing on the matter, but I'm less concerned with exposure from talking on it and more from carrying my phone.

Note: If I can find a good case for a candybar-style touchscreen model, I will upgrade. Phones with a slide-out keyboard, like I have now, seem impossible to shield because of those moving parts.
posted by 4midori to Technology (7 answers total)
Leaving aside the question of whether this is a valid concern, if you want your phone to not emit any EMF then you can shut it off or set it to 'airplane' mode. Any case which blocks all radio signals would also prevent the phone from operating. It would accomplish the same thing.
posted by dodecapus at 5:27 PM on February 13, 2012 [8 favorites]

Keep in mind that blocking the signal means you won't be able to get calls, and if you leave it on while the signal's blocked, the battery will drain very quickly (because the phone will amp up its broadcasting power in an effort to find a cell tower).
posted by balistic at 5:28 PM on February 13, 2012 [5 favorites]

Turning it off is your besy option. EMF includes the actual phone too.
posted by Ironmouth at 5:49 PM on February 13, 2012 [1 favorite]

No. All modern (3G and up) cellphone systems are spread spectrum with adaptive power control. That means the cell tower hears your phone and tells it "turn your transmit down by N, then I'll just barely be able to hear you." It does this up to many times a second. It keeps the noise floor low for other users and preserves your battery life. If you stick shielding around a phone, aside from it being exceedingly difficult to actually make it do anything, your phone will just turn up its transmit power until the cell tower can barely hear it again. Congratulations, you've just shortened your battery life for no reduction (and actually a non-trivial increase) in radiated power.
posted by introp at 7:45 PM on February 13, 2012 [6 favorites]

You could make a cell phone case out of just about anything -- tin foil, peanut butter, melamine, seal foreskin -- and it would protect you from just as much harmful radiation. If it makes you feel better to buy one, all well-marketed radiation-blocking cases are equally effective. Pick the one that fits the phone best.
posted by Ice Cream Socialist at 7:53 PM on February 13, 2012

I'd go with a landline.
posted by oceanjesse at 8:25 PM on February 13, 2012 [2 favorites]

What people are tiptoing around...
EMF Shielding - as others have pointed out, sheilding the phone is counter-productive. Turn it off if you're worried about it.
Actual dangers - no current evidence, still under investigation- see here: http://en.wikipedia.org/wiki/Mobile_phone_radiation_and_health
Also, keep in mind that if you're worried about the "radiation*" transmit power increases when you're having a conversation.
Keep in mind that phones have now been around for 15+ years, and the switch to digital has dropped transmit power. Also, see portable phones, two-way radios, radar etc. Microwaves burn**
*Non-Ionizing. The sun is worse for you.
**At much higher power levels than used for comms.
posted by defcom1 at 7:31 AM on February 14, 2012 [2 favorites]

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