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Determinants of mobile phone output power in a multinational study - implications for exposure assessment.

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Vrijheid M, Mann S, Vecchia P, Wiart J, Taki M, Ardoino L, Armstrong BK, Auvinen A, Bédard D, Berg-Beckhoff G, Brown J, Chetrit A, Collatz-Christensen H, Combalot E, Cook A, Deltour I, Feychting M, Giles GG, Hepworth SJ, Hours M, Iavarone I, Johansen C, Krewski D, Kurttio P, Lagorio S, Lönn S, McBride M, Montestruq L, Parslow R, Sadietzki S, Schüz J, Tynes T, Woodward A, Cardis E. · 2009

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Mobile phones operate at 50% maximum power on average, with dramatic variations between networks that previous health studies failed to account for.

Plain English Summary

Summary written for general audiences

Researchers tracked over 60,000 phone calls across 12 countries to measure how much radiofrequency power mobile phones actually emit during real-world use. They found that phones operate at about 50% of their maximum power on average, with phones using maximum power for 39% of call time. The actual exposure levels varied dramatically between different network operators and countries, sometimes differing by 2-3 times, which has major implications for studies trying to link phone use to health effects.

Why This Matters

This research reveals a critical flaw in how we've been assessing EMF exposure from mobile phones in health studies. The reality is that your phone's RF output varies dramatically based on factors largely outside your control - which network you're on, where you live, and how your carrier manages power levels. When phones operate at 50% of maximum power on average and hit maximum power for nearly 40% of call time, we're talking about substantially higher exposures than the theoretical minimums often assumed in research. This variability helps explain why some epidemiological studies have found inconsistent results when trying to link phone use to health effects. The science demonstrates that without accounting for these real-world power variations, we've been systematically underestimating actual EMF exposures in many studies examining the health impacts of mobile phone use.

Exposure Information

Specific exposure levels were not quantified in this study.

Study Details

The output power of a mobile phone is directly related to its radiofrequency (RF) electromagnetic field strength, and may theoretically vary substantially in different networks and phone use circumstances due to power control technologies. To improve indices of RF exposure for epidemiological studies, we assessed determinants of mobile phone output power in a multinational study.

More than 500 volunteers in 12 countries used Global System for Mobile communications software-modif...

Measurements of over 60,000 phone calls showed that the average output power was approximately 50% o...

Average power levels are substantially higher than the minimum levels theoretically achievable in GSM networks. Exposure indices could be improved by accounting for average power levels of different telecommunications systems. There appears to be little value in gathering information on circumstances of phone use other than use in very sparsely populated regions.

Cite This Study
Vrijheid M, Mann S, Vecchia P, Wiart J, Taki M, Ardoino L, Armstrong BK, Auvinen A, Bédard D, Berg-Beckhoff G, Brown J, Chetrit A, Collatz-Christensen H, Combalot E, Cook A, Deltour I, Feychting M, Giles GG, Hepworth SJ, Hours M, Iavarone I, Johansen C, Krewski D, Kurttio P, Lagorio S, Lönn S, McBride M, Montestruq L, Parslow R, Sadietzki S, Schüz J, Tynes T, Woodward A, Cardis E. (2009). Determinants of mobile phone output power in a multinational study - implications for exposure assessment. Occup Environ Med.66(10):664-671, 2009.
Show BibTeX
@article{m_2009_determinants_of_mobile_phone_2670,
  author = {Vrijheid M and Mann S and Vecchia P and Wiart J and Taki M and Ardoino L and Armstrong BK and Auvinen A and Bédard D and Berg-Beckhoff G and Brown J and Chetrit A and Collatz-Christensen H and Combalot E and Cook A and Deltour I and Feychting M and Giles GG and Hepworth SJ and Hours M and Iavarone I and Johansen C and Krewski D and Kurttio P and Lagorio S and Lönn S and McBride M and Montestruq L and Parslow R and Sadietzki S and Schüz J and Tynes T and Woodward A and Cardis E.},
  title = {Determinants of mobile phone output power in a multinational study - implications for exposure assessment.},
  year = {2009},
  
  url = {https://pubmed.ncbi.nlm.nih.gov/19465409/},
}
PubMed: 19465409

Cited By (80 papers)

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Quick Questions About This Study

Cell phones emit about 50% of their maximum radiation power on average during real calls. Research tracking over 60,000 phone calls found phones operate at maximum power 39% of the time, meaning actual exposure levels are much higher than minimum theoretical levels.
Yes, cell phone radiation varies dramatically between carriers and countries by 2-3 times. A multinational study found significant differences in actual power output between network operators, which creates major challenges for accurately assessing health risks from phone use.
Cell phones generally emit similar radiation levels in rural and urban areas, except in very sparsely populated regions. Research found higher power output mainly in remote Swedish areas, but little difference between rural and urban use in most locations.
Yes, longer phone calls typically result in lower average radiation exposure per minute. Studies show cell phone power output decreases as call duration increases, though phones still operate at maximum power for significant portions of each call.
No, cell phone radiation exposure varies significantly by location and network operator. Research across 12 countries found actual power output can differ by 2-3 times between different areas and carriers, making exposure assessment challenging for health studies.