Electromagnetic Radiation from Cell Phone Exposure Effects Brain Activity

by | Apr 28, 2011 | 2011, Brain Health, Environmental Health, Radioactivity and Irradiation

Written by Diana Abdi, BS.

Cell phone usage has increased dramatically over the years, raising concerns on possible health effects on brain activity from exposure to low levels of electromagnetic radiation (5). According to the Global Mobile Statistics 2011, there are 5.3 billion mobile subscribers globally, which is estimated to roughly 70% of the world population (1). In the U.S. alone, an average annual cell phone bill is roughly $635.85 per subscriber (6). Cell phones emit radiofrequency signals known as, radiofrequency-modulated electromagnetic fields (RF-EMFs), which may affect brain glucose metabolism, a marker for brain activity (3, 5). To measure the metabolic activity of cells in the brain, positron emission tomography (PET), a scanner that uses radiation emission to develop images was used (4).

A recent study, in the February 23rd issue of Jama, researchers from the National Institutes of Health, found that exposure of only 50 minutes of cell phone use was associated with increased brain glucose metabolism, in the region of the brain closest to the antenna (5). Although, the study shows cell phones effects brain activity, the findings show no clinical significance to overall health (3). The randomized study was conducted between January 2009 and December 2009, including 47 participants (2, 5). Cell phones were placed on the right and left ears of each participant to avoid confounding signals from either side of the brain in the region cell phones were located (5).  Once fitted with the cell phones, each participant underwent two 50 minute PET scans with (18F) fluorodeoxyglucose injection, used to measure brain glucose metabolism (2, 5). During one of the scans, the right cell phone was activated, but muted to avoid auditory stimulation (on condition), and during the second scan, phones both phones were deactivated (off condition) (3, 5).

The researchers found that whole-brain glucose metabolism did not differ between on and off conditions (5). However, in the region of the brain (orbitofrontal cortex and temporal lobe), closest to the antenna, the scans did show an increase of 7% during whilecell phones were on. (2, 5). The increased metabolism in this region of the brain suggests that brain absorption of RF-EMFs (brain regions that had highest amplitude of RF-EMF emissions) may increase excitability of brain tissue (5). This shows that human brain function is affected by RF-EMF from cell phones, from evidence of increased glucose metabolic activity (2, 5).

Epidemiological studies are not conclusive on the relationship between cell phone use and brain cancer. Although the human brain is activated by such weak radiofrequency signals, further investigation and research needs to be done to better understand health implications on brain activity from cell phone usage (3, 5). Research shows that electromagnetic radiation from cell phone could also affect bone strength (7). A recent study by Dr. Fernando D. Sravi of University of Cuyo, Mendoza, Argentina, found that men who carried their cell phone on their belt for at least one year showed a decrease in bone mineral content, which could substantially lead to osteoporosis (7).  Although there are concerns of several potential health effects associated with cellular phones (7), more research needs to be done to see if these concerns have any basis.

Source: Volkow, Nora D., et al. “Effects of cell phone radiofrequency signal exposure on brain glucose metabolism.” Jama 305.8 (2011): 808-813.

© 2011 American Medical Association. All rights reserved.

Posted April 28, 2011.

References:

  1. “Global Mobile Statistics 2011: All Quality Mobile Marketing Research, Mobile Web
    Stats, Subscribers, Ad revenue, Usage, Trends”.  Mobi Thinking.  Feb. 2011.
  2. “Cell Phone Use May Have Effect on Brain Activity, but Health Consequences
    Unknown”.  Science Daily.  23 Feb. 2011.
  3. Parker-Pope, Tara.  “Cell phone Use Tied to Changes in Brain Activity”.  NY Times.
    22 Feb. 2011.
  4.  “Positron Emission Tomography (PET)”.  Rush University Medical Center.
  5. Volkow, Nora D., et al.  “Effects of Cell Phone Radiofrequency Signal Exposure on Brain Glucose Metabolism”.  JAMA, Preliminary Communication.  305(8):808-813.23 Feb. 2011.
  6. Reardon, Marguerite.  “North Americans Pay More for Cell Phone Service”.  cNetNews. 11 Aug. 2009.
  7. “Cell Phone Exposure Linked to Bone Weakening”.  Sify News.  25 Mar 2011.