This column should be in two parts. In this piece, I can only share what questions we need to ask about the health effects of mobile phones. It will take another piece that will run years from now to give you the answers. As it stands today — and let this be the executive summary for those reading this on their phones — we do not have enough years of data to tell whether mobile phones are hazardous to our health. But I would advise you look up before you walk into that glass door in front of you.
These are the questions that we need to ask. Will yapping on a mobile give us brain cancer? Will we become impotent if we leave our phones in our pockets? Does the handset we use make any difference?
Scientists predict it will be decades before we know the answers to these questions. It took 30 to 40 years after cigarettes went mass-market for their epidemiological link with cancer to be established. At the rate that we use our phones, that may be too late for many of us. Let me share some clues that we can use to guide us now.
A mobile phone emits electromagnetic radiation of the microwave frequency. Microwaves qualify as non-ionizing radiation and are, in general, not too bad for us. As we know from microwave ovens, they heat objects. An oven has an output close to 1000 watts, while a phone emits microwaves with a couple watts of power.
Microwaves emitted by mobile phones will heat the side of the face where a phone is held. This rise will be slight and a fraction of what direct sunlight can do. Also any radiation to the head will be largely absorbed by the skull and dampened before it reaches the brain. No studies to date have found a causal link between cell phones and brain cancer. But cancers may take years to develop. To be absolutely safe, a logical option would be to wear a headset and avoid any radiation to the head.
If you use a Bluetooth headset are you saving your head but risking your gonads? Bluetooth devices are very low power (mere milliwatts) so are low risk. However, if your phone is in your pants pocket while you talk on your headset, you do potentially put your reproductive organs at risk. The obvious solution: Take your phone out of your pocket when you are using it. Women, toss it in a purse and forget about it.
Finally, is one handset safer than another? In theory the answer is yes. Each phone has a specific absorption rate or SAR, a measure of the amount of radiation absorbed by the body from the phone. All you need to know is that the lower the SAR, the less the radiation. You can find the SAR for a phone in its technical manual. I learned that the iPhone 3G S has about half the SAR as the iPhone 3G.
While handsets do emit different amounts of radiation, other variables chip in. Your choice of network may play a role as well. The weaker the signal, the more power your handset is forced to use, which translates into greater radiation from the phone despite the published SAR level.
I would urge our regulators to analyse the health effects of cell phones, to change the game completely so that phones can switch users to the strongest available network at any given time. This would ensure the lowest possible radiation. It would take some disruptive innovation on the network and device sides, but if we do learn that mobile phones are harmful to our health, an intervention like this based on the sheer numbers that use phones would qualify as one of the largest public health initiatives ever.
Dr. Kumar, and our health team, can be contacted at firstname.lastname@example.org