It seems like the blogosphere and news media is eating up the Environmental Working Group’s (EWG) ten best and worst cell phones when it comes to “radiation”.  After reading the usual responses from readers, it seems like a lot of people are needlessly concerned about the EWG’s cherry picked report when they should be listening to the American Cancer Society.

The first thing that must be made clear is that cell phone radiation is NOT the kind of nuclear radiation you get from “natural” hot springs water that makes your jaws fall off.  It is not the 1,000,000 GHz cancer-inducing ionizing ultraviolet electromagnetic radiation you get from ordinary sunlight.  What we are talking about when it comes to cell phone electromagnetic radiation is the weak 1-2 GHz microwave from a cell phone that might raise the temperature of human body by such a small degree that it would be difficult to measure.  The experiments on rats that indicate some possible health risks were using 100 to 1000 times more energy than a cell phone would ever emit, and those slightly elevated risks may have easily been induced by thermal effect.

The second thing that must be made clear is that the Specific Absorption Rate (SAR) is not on indicator of how much “radiation” is coming from the phone, but a measurement of the worst case heating effect on a single gram of tissue.  That heat is quickly dispersed throughout the head and body which greatly diminishes the heating effect in any local region.  Now if this concentrated energy were high enough to cause burns to tissue, that would obviously be an immediate health problem.  With a maximum SAR value of 1.6 watts/kg, the maximum concentrated energy can only heat up a few grams of tissue 1.3 degrees Celsius over the period of one hour of continuous usage.  But the typical human body has 70,000 grams of mass so the heat would disperse much faster than it would accumulate at this low intensity, being overly concerned with maximum worst-case SAR values is probably unjustified.

It is quite possible that a phone that emits less overall electromagnet microwave energy can actually produce a higher SAR measurement depending on its antenna geometry and the phone’s orientation and position on the human body.  Case in point, one of the “worst” cell phones according to the EWG actually has one of the lowest SAR values of 0.40 watt/kg when it’s measured against the body.  One of the “best” cell phones according to the EWG has one of the highest SAR values of 1.27 watt/kg when it’s measured against the body.  So if one were to use a Bluetooth headset which typically have SAR values of 0.001 watt/kg and one of the “worst” phones according to the EWG, then one’s maximum and overall SAR exposure would be significantly reduced.

Moreover, these SAR values are measured using maximum power output which may vary from phone to phone and even under different modes.  The typical power output of these phones could easily be 1/8th of the maximum 2 watt output when operating in a good coverage area where the cell tower isn’t too far away or overly obstructed.  It is also very possible that phone A with a higher maximum SAR rating actually has the same SAR value compared to a phone listed with a lower maximum SAR when operating under similar coverage zones.  This leads me to believe that perhaps a much more useful metric that the industry might consider using is the practical SAR values operating under typical and more importantly, comparable coverage zones.  That would be a far more useful metric than the theoretical maximum SAR.

perhaps a much more useful metric that the industry might consider using is the practical SAR values operating under typical and more importantly, comparable coverage zones.

The problem that the cell phone industry faces is that no matter what the SAR limits are, someone will always come out with a 10-worst list and a significant percentage of the population will get scared by it.  Even if the SAR limit was set to 1.6 millwatts/kg which is 1000 times lower than present and would require femtocell base stations in every room to make the phones work, someone will always complain that the limit is set too high and there will always be a trial lawyer somewhere ready to sue even in the absence of scientific evidence.  We know this for a fact because people have sued cell towers for power levels that are 1,000,000 times weaker than that of a cell phone.

It is ironic that the closer you are to the cell tower, the lower your exposure to radio waves since the cell tower is typically on the order of 1,000,000 times weaker than your cell phone given the difference in the square of the distance.

What might help the cell phone industry educate the public is to simply offer an optional “low SAR mode” in every phone where people can manually set the SAR limits to 1/10th of what they are today if they were that concerned with this unproven problem.  Then this low SAR mode would come with the disclaimer that the phones may not work with anything less than 2 or 3 or 4 bars of signal strength.  But cell phones already operate in “low SAR mode” when there is a good signal from the tower and they only go into high SAR mode when they’re in a really bad coverage area so there’s nothing to really worry about to begin with.  It’s understandable that a cell phone maker doesn’t want people do deal with poor coverage, but this might be the only way to educate the public that their phone only transmits as much power as it needs.  More importantly, this would help educate the public on why living closer to and having more cell towers is a good thing.