Friday, August 8, 2008

Cell Phone Radiation - Are You Concerned?

For the last couple of weeks, there has been a great amount of discussion about the possible risk that cell phone radiation can cause brain tumors since the head of a prominent cancer center released a letter to the faculty recommending that everyone limit their use of cell phones, especially children (Here is a link to the ABC news coverage on the story). He recommends that children not use them at all (except for emergencies) and that adults should reduce exposure levels as much as possible (limited use or always use Bluetooth devices). He says there is no data that proves there is a risk but since we are not sure, we should be safe. He is basing his alarm on unpublished data which will take too long to make public.

There have been many studies and no link has been found. The FCC does limit the radiation levels of cell phones to a maximum specific absorption rate (SAR) of 1.6 W/kg (European limits are 2.0 W/kg). You can find the measured SAR values for many cell phones on CNET's website.

What do you think? Are cell phones really dangerous to our health?? Let's hear from some technical experts about the subject!


  1. How are SAR measurements performed? Are the phone manufacturers measuring the SAR values or is it done by an independent measurement service. Do they include an objects to emulate a hand and head? I would assume this would affect the measurement itself. - just curious

  2. what about the phones we used 20 years ago, with the higher powers? what damage did they do?

    bob hawkins
    sm electronics

  3. I believe the real issue isn't with cell phones but with the towers. Cell sites put out several hundred times the radiation as cell phones do - get close to one of them and you are over-exposed to radiation (as defined by the FCC). Think of the Roofer, HVAC repairman, Firefighter etc. They all are routinely overexposed. The cell companies protect their own workers, but could care less about anybody else.

    The IBEW wrote a very interesting letter to the FCC about this issue.
    Letter to FCC

  4. I also think that the real public health issue is with cell towers- not cell phones. A phone may reach 300 milli-Watts, while a tower may continually pump out hundreds of watts. Stand next to one of those and you WILL get hurt.

    With so many towers up on buildings, this is a huge issue.

  5. I hear you on the towers being orders of magnitude more in power but since the power drops off so rapidly as a function of distance, I wonder how a watt against your body compares to hundreds of watts tens of feet away from the body???

  6. It all depends on the attributes of the antenna (power/gain etc). Here is the standard: IEEE/FCC standard

  7. Recently many users have expressed concern about mobile phone Specific Absorbtion Rates (SAR). As a result, low SAR figures are becoming of increasingly important for Mobile phone manufacturers.

    For mobile phones to be accepted by the FCC or European regulatory agencies, the SAR must be measured using standardized hand and head SAM phantoms ( But these verification tests come very late in the phone’s production cycle. Design failure can mean many months of delay for a mobile phone manufacturer. It is better to include these tests at the beginning of the development cycle using simulation technology.

    The AMDS (Antenna Modeling Design System) ( From Agilent Technologies is a full-wave, 3-D EM design, modeling and verification tool dedicated to antenna and antenna systems design. It meshes, simulates and optimizes an entire wireless device, together with its surrounding real-world environment. It analyzes compliance standards such SAR but more recently also analyzes HAC – assuring the Hearing Aid Compatibility of modern cell phones.

    Agilent’s SAR and Thermal Simulations are validated according to the latest IEEE standards, and simulation results are aligned with standard phantom measurements.

    Mobile phone designers can optimize mobile phone performance from the beginning of the design cycle – not only for the best voice-quality but also for the lowest user radiation exposure.