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SAR calculations in an anatomically realistic model of the head for mobile communication transceivers at 900 MHz and 1.8 GHz.

Bioeffects Seen

Dimbylow PJ, Mann SM. · 1994

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Cell phone energy absorption varies dramatically by position, with eye-level placement producing over double the RF exposure compared to ear placement.

Plain English Summary

Summary written for general audiences

Scientists used detailed computer modeling to measure how much cell phone radiation gets absorbed by brain tissue. They found absorption rates varied dramatically by phone position, with the highest levels occurring when phones were held in front of the eye rather than at the ear.

Why This Matters

This groundbreaking 1994 study represents one of the earliest attempts to quantify exactly how much RF energy penetrates human tissue from mobile phones using realistic anatomical models. The science demonstrates that phone positioning matters enormously - holding a device in front of your eye produced SAR values up to 7.7 watts per kilogram, more than double the levels at the ear. What makes this research particularly significant is its timing: conducted when mobile phones were just entering widespread use, it provided early evidence that RF absorption varies dramatically across different head positions and tissue types. The reality is that these findings helped establish the foundation for current SAR testing protocols, though many argue those standards remain inadequate given what we now know about non-thermal biological effects at much lower exposure levels.

Exposure Details

SAR
2.1, 2.3, 3.1, and 4.7 W/kg
Source/Device
900 MHz

Exposure Context

This study used 2.1, 2.3, 3.1, and 4.7 W/kg for SAR (device absorption):

Building Biology guidelines are practitioner-based limits from real-world assessments. BioInitiative Report recommendations are based on peer-reviewed science. Check Your Exposure to compare your own measurements.

Where This Falls on the Concern Scale

Study Exposure Level in ContextA logarithmic scale showing exposure levels relative to Building Biology concern thresholds and regulatory limits.Study Exposure Level in ContextThis study: 2.1, 2.3, 3.1, and 4.7 W/kgExtreme Concern0.1 W/kgFCC Limit1.6 W/kgEffects observed in the Extreme Concern range (Building Biology)FCC limit is 1x higher than this exposure level

Study Details

The aim of the current study is to investigate SAR calculations in an anatomically realistic model of the head for mobile communication transceivers at 900 MHz and 1.8 GHz.

A new mathematical model of the head has been constructed from a set of serial MRI slices from one s...

Results are also presented for a half-wavelength dipole. The maximum SAR values produced by the gene...

Cite This Study
Dimbylow PJ, Mann SM. (1994). SAR calculations in an anatomically realistic model of the head for mobile communication transceivers at 900 MHz and 1.8 GHz. Phys. Med. Biol. 39:1537-1553, 1994.
Show BibTeX
@article{pj_1994_sar_calculations_in_an_948,
  author = {Dimbylow PJ and Mann SM.},
  title = {SAR calculations in an anatomically realistic model of the head for mobile communication transceivers at 900 MHz and 1.8 GHz.},
  year = {1994},
  
  url = {https://pubmed.ncbi.nlm.nih.gov/15551530/},
}

Quick Questions About This Study

Scientists used detailed computer modeling to measure how much cell phone radiation gets absorbed by brain tissue. They found absorption rates varied dramatically by phone position, with the highest levels occurring when phones were held in front of the eye rather than at the ear.