Taking a shot at Dr George Carlo now. Yes, I'll wait until you've watched this whole boring clip...
The thing is, is that I've worked with radio transmitters since I was 15, and have absorbed thousands of kilowatts, a few hundred watts here, a few kilowatts there, and have cancer-free fingers.
(Radio techs when tuning in aerials or transmitter finals stages invariably are close to generally high-power radio frequency [RF] equipment and most of us have at some stage expereinced a nasty "RF burn" where the radiated energy arcs across and burns a neatly cauterised hole, generally in one's finger cos that's the bit closest to the antenna or output stage of the transmitter.)
I can't see quite the phenomenally lethal effect Dr Carlo claims - after all, most phone handsets can only output between 0.5 and 2 watts, and I've been in proximity to 25 to 5000 watts as part of my job, for around 14 years.
The good Dr tries to make (bad) analogies that seem to demonstrate that he actually has little knowledge of the phenomenon of electromagnetic radiation, and my favourite malapropism is his analogy of the radio signal ("passing right through - the human body can't see it") as a clothesline, and then you go and put data on it and that's like putting clothes on the clothesline. Bullshit Dr Carlo.
He seems to think the data has some magical power that can increase the transmission. Look at it from this point of view, people - the batteries in a cellphone can only output a certain amount of power, over 50% of that power is going to be wasted as heat (ever notice your phone gets warm after a long conversation? Well that is power that *didn't* get radiated as a radio signal) and that means that no matter how you try to slice and dice it, there can't be more energy than that in the radio signal.
It may well be that because the signal is held close to the brain when the phone is in use and radiating, it could cause cell damage and cancer. Certainly, statistics seem to bear that out, and it's maybe worth your while to consider a headset for your phone so you can keep it away from your brain. But bear in mind that a bluetooth headset is also a transmitter, and you'd be sticking that inside your ear... While a low to medium cellphone user might not ever experience a tumour cause dby cellphone use, playing it safe and using a wired headset can't hurt.
But back to Dr Carlo's clumsy and somewhat inappropriate analogy. A clothesline is not "invisible" to human flesh and is nothing at all like a radio wave either. Unless you're whipping it up and down or sideways in lovely long waves, and then try standing near a peak that's whiping back and forth and tell me if it would be any worse if there were clothes on the line.
Try this - ride a motorbike full tilt into a clothesline with or without clothes on it, and either way it's not going to end well. So if the radio wave is going to do damage, it will do that damage whether it has clothes on it, data on it, or silence on it. Okay - there may be a way that imposing data (which has a square wave shape) on the signal might generate more harmonics - but as any good RF tech will tell you, if you have a harmonic then your signal power is getting divided between the signal you want to send and the harmonic. If you have a lot of harmonics, then your pitifully small amount of power you can suck out of the battery has to be divided up between all the harmonics and the desired signal equally, so you're going to have minute amounts of signal at each harmonic.
Next - that signal has to radiate in all 360 degrees, your head will intercept maybe 100 degrees worth, so about 1/3 of that small amount of power. move the phone three centimeters further away from your ear and your head will only intercept maybe 70 degrees (about 1/5th) of the signal, etc. Move it further away, say 6cm, and that drops down to maybe 25 degrees, or 1/12th of whatever radiation is coming out of the antenna.
That's why a headset is a good idea, no matter what. It gets the danger (if it is a danger) away from your delicate brain to the point where radiation from the cell handset is minute.
But the funniest thing I still think is the "clothes on the line make it dangerous" analogy, in other words it's the data that does the damage. If that were so, then being hit with a phonebook with all blank pages shouldn't hurt at all, while a full phone directory's worth of data printed on the pages would make it lethal...