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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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A realistic head model showed maximum SAR values of 2.1 and 3.0 W kg(-1) per W of radiated power at 900 MHz and 1.8 GHz for a transceiver held horizontally at the side of the head.

Plain English Summary

Summary written for general audiences

Researchers built a mathematical model of the human head from MRI slices and used finite-difference time-domain (FDTD) calculations to estimate the specific energy absorption rate (SAR) at 900 MHz and 1.8 GHz. The generic transceiver was represented by a quarter-wavelength monopole on a metal box, and three placement geometries were examined: vertical in front of the eye, and vertical and horizontal at the side of the ear. For the most typical position at the side of the head, the maximum SAR averaged over 10 g of tissue was 2.1 and 3.0 W kg(-1) per W of radiated power at 900 MHz and 1.8 GHz. Placement in front of the eye gave values of 3.1 and 4.6 W kg(-1) per W averaged over 10 g of tissue at 900 MHz and 1.8 GHz.

Why This Matters

The head model was constructed from MRI slices of one subject and calculations were performed at a 2 mm resolution. SAR values averaged over 1 g of tissue for the side-of-head position were 2.3 and 4.8 W kg(-1) per W at 900 MHz and 1.8 GHz. When placement in front of the eye was considered, the SAR averaged over 1 g of tissue was 4.7 and 7.7 W kg(-1) per W at 900 MHz and 1.8 GHz. The effect of a hand grasping the handset was also examined. The head model was scaled to represent an infant's head, and a subset of calculations was performed to verify that SAR in the infant head did not exceed that in the adult.

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 range (Building Biology)This level is 1 times the FCC limit
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)

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Quick Questions About This Study

The calculations were performed at 900 MHz and 1.8 GHz.
The model was constructed from a set of serial MRI slices from one subject, with calculations performed at a 2 mm resolution.
The head model was scaled to represent the head of an infant, and calculations were done to verify that SAR in the infant head did not exceed that in the adult.
The maximum SAR for the horizontal orientation at the side of the head, averaged over 10 g of tissue at 900 MHz, was 2.1 W kg(-1) per W of radiated power.