Wednesday, January 25, 2012

Do Cell Phones Really Cause Brain Cancer?

The cell phone today is more ubiquitous than ever, and scientific studies continue to try to distinguish the relationship between cellular phones and cancer.

A recent study from the National Institutes of Health showed increased brain activity in participants exposed to cell phone radiation. The study used PET scans to measure the brain's sugar level, and found increased activity in regions closest to the phone's antenna after 50 minutes of exposure. Although the increased activity isn't directly linked to harmful effects, the human brain's evident sensitivity to the phone's electromagnetic waves does raise further questions.

In May 2011, the World Health Organization reclassified cell phone radiation exposure as "possibly carcinogenic," a label that places it in the same category as chloroform and lead. The most extensive case control study of cellular phones and cancer, the Interphone study, conducted across 13 countries for a decade found that the highest grade of mobile phone users-those who used their phones for 30 minutes a day over 10 years or more- were twice as likely to develop glioma, a malignant brain tumor. These results are alarming, particularly because the study failed to take into account that children and young adults are far more susceptible to cell phone radiation than adults.

Cellular phone radiation testing conducted by manufacturers also underestimates the amount of radiation that users are exposed to. A recent paper published in the journal Electromagnetic Biology and Medicine revealed that industry testing is done on a mannequin modeled after a 6'2", 200 pound man with the phone held one inch from the mannequin's ear. The study estimates that 97 percent of the population deviate from this unrealistic model of usage and experience greater exposure.

The Federal Communications Commission requires a mobile phone to have a Specific Absorption Rate (SAR), a measure of the peak of electromagnetic radiation level in a model, of less than 1.6 watts per kilogram. However, the peak SAR may not represent the actual SAR levels of a typical phone call. A cellular phone with a lower SAR may expose the user to more radiation on average than one with a higher SAR. A study conducted by a bioengineering research professor, Dr. Henry Lai, found effects of memory loss in rats exposed to SAR levels as low 0.0006 to 0.06 watts per kilogram.

As of 2010, there are over 223 million mobile phone users in the US over the age of 13 and the numbers are constantly growing. According to the CTIA, the Wireless Association, the total minutes of cell phone use in America in 2009 was 2.3 trillion minutes. Cellular phone users are also starting at younger ages. Given the indispensable role of cell phones in our lives and the increasing concern about an association between cell phone use and cancer, regulatory agencies should carry out more thorough investigations, and cell phone users should exercise caution and take steps to lower their exposure to cell phone radiation.

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