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SAR / Device Absorption311 citations

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

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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 ContextStudy Exposure Level in ContextThis study: 2.1, 2.3, 3.1, and 4.7 W/kgExtreme Concern - 0.1 W/kgFCC Limit - 1.6 W/kgEffects observed in the Extreme Concern rangeFCC limit is 1x higher than this level
A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 900 MHz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 900 MHzPower lines50/60 Hz5G mm28 GHzLogarithmic scale

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/},
}
PubMed: 15551530

Cited By (311 papers)

View all 311 citing papers on Semantic Scholar

Quick Questions About This Study

Yes, cell phone position dramatically affects how much radiation your brain absorbs. A 1994 study found that holding phones in front of your eye creates 50-60% higher absorption rates than the typical ear position, with levels reaching up to 7.7 watts per kilogram of tissue.
Cell phones at 900 MHz create measurable radiation absorption in brain tissue. Research shows absorption rates of 2.1-4.7 watts per kilogram depending on phone position, with the highest levels occurring when phones are held in front of the eye rather than at the ear.
Cell phone radiation does get absorbed by brain tissue at measurable levels. A detailed computer modeling study found absorption rates ranging from 2.1 to 7.7 watts per kilogram of tissue, with higher frequencies and certain phone positions creating greater absorption in the head.
SAR (Specific Absorption Rate) levels from cell phones vary significantly by position and frequency. Research found typical ear position creates 2.1-3.0 watts per kilogram, while holding phones in front of the eye increases absorption to 4.6-7.7 watts per kilogram of brain tissue.
Yes, higher phone frequencies create greater radiation absorption in your head. A 1994 study found that 1.8 GHz phones produce 43-67% higher absorption rates in brain tissue compared to 900 MHz phones, regardless of how you hold the device.