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Effects of cell phone radiofrequency signal exposure on brain glucose metabolism

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Volkow ND, Tomasi D, Wang GJ, Vaska P, Fowler JS, Telang F, Alexoff D, Logan J, Wong C · 2011

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Cell phones measurably increase brain activity by 7% in areas closest to the antenna during typical 50-minute exposures.

Plain English Summary

Summary written for general audiences

Researchers measured brain activity in 47 healthy people while they held cell phones to their ears for 50 minutes. They found that brain glucose metabolism (a measure of brain activity) increased by 7% in the area closest to the phone's antenna. While the study authors called the health significance 'unknown,' this demonstrates that cell phone radiation does measurably affect brain function at typical usage levels.

Why This Matters

This landmark study from the National Institutes of Health provides compelling evidence that cell phone radiation directly affects brain activity at exposure levels you encounter during normal phone calls. The SAR level of 0.901 W/kg falls well within the range of typical smartphones, making these findings highly relevant to daily phone use. What makes this research particularly significant is its rigorous methodology and the clear dose-response relationship the researchers documented between radiation intensity and brain changes. The 7% increase in brain glucose metabolism represents measurable biological activity, not just theoretical risk. While the study authors cautiously noted that the clinical significance remains 'unknown,' the reality is that any technology capable of altering brain metabolism deserves serious consideration, especially given our extensive daily exposure to these devices.

Exposure Details

SAR
0.901 W/kg
Source/Device
837.8 MHz
Exposure Duration
50 min

Exposure Context

This study used 0.901 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: 0.901 W/kgExtreme Concern0.1 W/kgFCC Limit1.6 W/kgEffects observed in the Extreme Concern range (Building Biology)FCC limit is 2x higher than this exposure level

Study Details

To evaluate if acute cell phone exposure affects brain glucose metabolism, a marker of brain activity

Randomized crossover study conducted between January 1 and December 31, 2009, at a single US labora...

Whole-brain metabolism did not differ between on and off conditions. In contrast, metabolism in the ...

In healthy participants and compared with no exposure, 50-minute cell phone exposure was associated with increased brain glucose metabolism in the region closest to the antenna. This finding is of unknown clinical significance.

Cite This Study
Volkow ND, Tomasi D, Wang GJ, Vaska P, Fowler JS, Telang F, Alexoff D, Logan J, Wong C (2011). Effects of cell phone radiofrequency signal exposure on brain glucose metabolism JAMA. 305(8):808-813, 2011.
Show BibTeX
@article{nd_2011_effects_of_cell_phone_196,
  author = {Volkow ND and Tomasi D and Wang GJ and Vaska P and Fowler JS and Telang F and Alexoff D and Logan J and Wong C},
  title = {Effects of cell phone radiofrequency signal exposure on brain glucose metabolism},
  year = {2011},
  
  url = {https://jamanetwork.com/journals/jama/article-abstract/645813},
}

Quick Questions About This Study

Researchers measured brain activity in 47 healthy people while they held cell phones to their ears for 50 minutes. They found that brain glucose metabolism (a measure of brain activity) increased by 7% in the area closest to the phone's antenna. While the study authors called the health significance 'unknown,' this demonstrates that cell phone radiation does measurably affect brain function at typical usage levels.