The results of an Environmental Health Trust study that was published this month in the journal Electromagnetic Biology and Medicine suggest that the current assessment method for measuring radiation absorption from cellphones is inadequate.
Since 1996, Federal Communications Commission has mandated that all cellphones must emit less energy than a specific absorption rate (SAR) limit of 1.6 watts per kilogram (w/kg) of tissue. Manufacturers must have their cellphones tested at FCC-approved laboratories, where a fluid-filled plastic mannequin head, or a specific anthropomorphic mannequin (SAM), is used to measure SAR.
But the researchers of the study say that a higher-resolution computerized simulation, which is known as finite difference time domain (FDTD), shows that children and adults whose head is smaller than the mannequin head is (or 97 percent of adults) actually absorb much more radiation than the SAM tests indicate. A 10-year-old, for instance, will absorb up to 153 percent more radiation in an FDTD simulation than in an SAM test, the researchers say.
An SAM test also fails to account for radiation absorption in areas of the body other than the head, the report says. According to the study, when cellphones are placed in a pocket or against the body, the SAR limit is exceeded.
We’re not surprised to hear that SAM tests fall short. As we point out in our coming November/December 2011 article, “A Bad Connection: Cellphone Radiation & Health Risks,” SAR isn’t a measure of cumulative radio-frequency electromagnetic-field (RF EMF) exposure, which is what scientists tell us might cause cancer. In fact, no standard exists for measuring RF EMF.
Replacing the obsolete mannequin-head SAM test with the higher-resolution FDTD simulation is a good start to prevent tissue burns from cellphones, but there still is a lot of work to be done to decrease the potential health risks from cellphones.
– K. Keeker