WASHINGTON-Millions of cellular telephones may be getting safety approvals by the Federal Communications Commission despite possibly exceeding the agency’s radio-frequency radiation exposure guidelines.
Professor Om P. Gandhi, a prominent RF scientist at the University of Utah, contends some testing of mobile phones for radio-frequency radiation absorption by the human head is flawed.
As a result, Gandhi asserts some wireless companies may be under-reporting the amount electromagnetic energy captured by human tissue in the human head by 40 to 60 percent.
Since an industry standard for measuring RF absorption does not yet exist, the FCC cannot be certain that phones meet the letter of the law insofar as RF compliance.
“Because of the gross underestimation of the peak 1-gram SAR [specific absorption rate], a telephone may pass the FCC-required SAR compliance test using an earless model with a 4-6 mm thick spacer (in lieu of the ear) when the same telephone will exceed the SAR limit of 1.6 watts per kilogram, had a realistic model with a protruding lossy ear been used for compliance testing,” said Gandhi in August at international conference in Toronto. A lossy ear tries to simulate a human ear in scientific testing.
Gandhi’s research in this area is detailed in the August issue of IEEE Transactions on Electromagnetic Compatibility.
In December, Sony Corp. recalled 60,000 cellular phones after the FCC discovered that certain models exceeded FCC RF limits. Shortly thereafter, FCC Chairman William Kennard directed the wireless industry to correct the confusion surrounding SAR testing of mobile phones.
Though highly technical in nature, the debate that Gandhi has sparked in the scientific community in recent months revolves around the methodology for measuring how much electromagnetic energy is absorbed by the head and neck insofar as ensuring the level of RF emitted by mobile phones meets FCC exposure guidelines.
An Institute of Electrical and Electronic Engineers subcommittee is developing a standard for measuring SAR. The IEEE subcommittee met last week in North Carolina, with an eye to having a preliminary report finished by year’s end or by early next year.
“There are differences of opinion on how to do this,” said Robert Cleveland, the FCC’s top RF scientist.
Cleveland said the FCC recommends SAR testing on phantom heads with a “collapsible ear.” He noted that a significant safety margin is built into RF safety guidelines. Others emphasize SAR testing is tricky because so much depends on the position of the phone used by the subscriber.
“We are discussing these issues in the IEEE committee on wireless handset certification and we are planning on arriving on a phantom model that will accurately reflect absorption in the human head,” said Cleveland.
The current debate does not go to the issue of whether mobile phones cause cancer or other diseases, but rather to FCC compliance.
“It [earless model heads for SAR testing] has merit, but not as a certification tool,” said Kathy MacLean, president of APREL Laboratories, in Ontario, Canada, which conducts SAR testing and research.
While the industry, citing some recent research, insists mobile phone radiation does not pose a risk to consumers, the FCC and the Food and Drug Administration are anxious to get a better scientific understanding of the dynamics of putting a mobile phone against the human head.
ABC’s 20/20 is expected to explore the mobile phone-cancer issue early next month.
Currently, there are more than 70 million mobile phone users in the United States.
Gandhi’s research suggests cellular telephone SAR is being under-reported to the FCC more so than SAR from personal communications services phones.
Testing 10 mobile phones (five cellular and five PCS) on a model head without a realistic ear and comparing it with tests using a realistic ear, Gandhi found that four of the five cellular telephones exceeded SAR limits by a significant margin. All the PCS models met FCC RF guidelines. Gandhi said the results were verified by computational testing.
All 10 phones presumably could pass FCC scrutiny if a model head without an ear were used to test SAR.
The Cellular Telecommunications Industry declined to comment on Gandhi’s findings.
FCC RF guidelines do not make a distinction between the ear and other human tissue that absorbs electromagnetic energy.
Two ways SAR can be determined are by testing on anatomically based models of the human head and by numerical calculations.
Gandhi says that some anatomical models, or phantom heads, do not include ears because some companies believe RF absorption in the ear is negligible. As such, some phantom heads simply include plastic spacers instead.
But Gandhi, who did not return calls for comment, said there is evidence that some of the highest RF absorption occurs by the ear and the skin behind it.
Others, like FCC scientist Kwok Chan, counter that even if Gandhi is correct, the question remains: What is the signficance of the RF absorption by the ear when RF absorption by the brain is the key medical concern?
“The ear can take a lot of abuse,” said Chan, who helps oversee SAR compliance at the FCC’s laboratory in Columbia, Md.
