A method for safety testing of radiofrequency/microwave-emitting devices using MRI.
Alon L, Cho GY, Yang X, Sodickson DK, Deniz CM. · 2014
View Original AbstractCell phones operating at maximum power for 15 minutes caused 1.7°C tissue heating, proving wireless devices create measurable biological effects within safety limits.
Plain English Summary
Researchers developed a new method using MRI to measure how much radiofrequency energy devices like cell phones deposit into body tissues by tracking temperature changes. When they tested a cell phone at maximum power for 15 minutes, it caused tissue heating of 1.7°C and delivered energy at 0.54 watts per kilogram. This technique provides a more accurate way to test whether wireless devices meet safety limits for human exposure.
Why This Matters
This study represents a significant advance in how we measure the biological impact of wireless devices. The science demonstrates that even at maximum power output, cell phones can cause measurable tissue heating - a 1.7°C temperature rise in just 15 minutes. What this means for you is that your phone is depositing enough energy to create detectable biological changes in real time. The reality is that current safety testing relies heavily on computer modeling rather than direct biological measurement. This MRI-based approach provides hard evidence of how RF energy actually behaves in tissue, giving us a clearer picture of exposure levels. The 0.54 W/kg SAR reading for the cell phone falls within current regulatory limits, but the measurable heating confirms that biological effects occur at approved exposure levels.
Exposure Details
- SAR
- 0.54, 11.9, 12.4 W/kg
- Exposure Duration
- 15 min
Exposure Context
This study used 0.54, 11.9, 12.4 W/kg for SAR (device absorption):
- 1.4x above the Building Biology guideline of 0.4 W/kg
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 Details
We investigated the application of MR temperature mapping and 10-g average specific absorption rate (SAR) computation for safety evaluation of RF-emitting devices.
Quantification of the RF power deposition was shown for an MRI-compatible dipole antenna and a non-M...
The maximum temperature change for a dipole antenna and the maximum 10-g average SAR were 1.83°C and...
Information acquired using MR temperature mapping and thermal property measurements can assess RF/microwave safety with high resolution and fidelity.
Show BibTeX
@article{l_2014_a_method_for_safety_807,
author = {Alon L and Cho GY and Yang X and Sodickson DK and Deniz CM.},
title = {A method for safety testing of radiofrequency/microwave-emitting devices using MRI.},
year = {2014},
url = {https://pubmed.ncbi.nlm.nih.gov/25424724/},
}