On cell phones, speaker static, and radiation

Reader JD writes: Can you tell me a little about cell phone radiation? When I receive texts on my cell phone, it makes a funny sound into my landline telephone receiver (when I am on that landline), and makes TV monitors do funny things if they are within range of the cell phone. I'm wondering if you might be able to shed some light on that for me. I've heard of SAR and my phone has a reasonable value for that. Since the TV and landline phone are apparently receiving such a strong signal, I am concerned that that is going through my body and anyone else's body that is near me, each time a text is sent or received.

Lots of issues in this query, but I'll try to get my arms around the whole thing for you.

First is the issue of those "funny sounds" you're talking about, and many readers will be familiar with your complaint. If not, try putting a GSM cell phone next to your computer speaker and chances are good you'll hear what JD is talking about at some point: A weird, distorted buzzing/bumping/drumming sort of noise that often comes and goes throughout the day. Pretty much any speaker is susceptible to this noise -- your TV, land line phone, stereo, even hearing aids -- but the cheaper the speaker, the worse the problem will be.

What causes it? To explain it very simply: Electromagnetic interference in the speaker wiring picks up the radio pulsing in the cell phone and causes audible distortion in the audio from the speaker. The solution? Get shielded speakers, move your cell phone to the other side of the room, or switch to a CDMA network, which doesn't cause these kinds of effects on speakers.

I'm not sure from your question whether you're seeing video distortion on your TV along with the audio noise when a text comes in, but I've never heard of such an effect. Still, I suppose it's theoretically possible under the same principle.

The other question is whether any of this is harmful to you physically, and that has a more complicated answer.

In brief, a cell phone sitting on your desk is going to have much less of a potential to cause any harm to you than one you're holding up to your ear, because cell phone radiation decreases exponentially with the distance it is away from you. This is why virtually all studies of cell phone radiation (and the heat it creates in human tissue) focus on brain tumors potentially caused by holding a phone up against the side of your face -- because that's where the radiation is strongest.

That said, even those studies have still not found a "smoking gun" definitively linking cell phones to cancer, but the jury is still out on whether or not they add to your risk and, if so, how much. (The exception seems to be with cell-phone-using children, whom more experts believe are at risk of damage because their brains are still growing rapidly.)

But a phone sitting on your desk? The electromagnetic interference it's causing on your speakers is not something that anyone has pointed to as a potential source of physical harm and really this is just a problem with speaker design, not with something that's likely to hurt you. Remember that you're always surrounded by all kinds of radio waves, all the time, and a single cell phone on your desk doesn't really change that level of bombardment in a meaningful way. Put it this way: Think about how many cell phones are nearby when you're standing on a crowded bus. If there was a real danger, people would be dropping like flies.