Cellular phones have become incredibly popular over the years and increasingly sophisticated with an array of different types of functions aside from simply being able to talk to another person. One possible downside of mobile phones, however, is that they operate by sending microwaves to and from local receivers. Consequently, as cell phones make and take calls, they emit low-level radio-frequency radiation.  The real question is whether or not this radiation is harmful to the body. The BlackBerry manual, for example, states that "when you carry the BlackBerry device on your body, use only accessories equipped with an integrated belt clip. If not using a belt clip, keep the BlackBerry device at least 0.98 in. (25 mm) from your body" when sending or receiving data, in order to maintain compliance with radio-frequency-radiation standards set by the Federal Communications Commission. 
Although warning labels are now quite common in cell phone manuals, it's worth noting that both the National Cancer Institute and the World Health Organization say there isn't evidence to support the assertion that cell phones are a public-health threat.  This has lead scientists to conduct research on the possible effects of the radiation from mobile phones. An analysis published by a University of Washington neurologist Henry Lai determined that far more independent studies than industry-funded studies have found at least some type of biological effect from cell-phone exposure.  Particular concentration of many of the studies focus on determining if the radiation can cause cancer, especially brain or eye cancer.
Despite the conduction of countless studies, there has not been enough evidence to show that the electromagnetic radiation from cell phones causes harm or cancer, which means the current safety measure, regulated by the Federal Communications Commission, is adequate.  The reason cell phones are incapable of causing serious harm or increasing the chance of cancer is because the energy emitted is not strong enough. Electromagnetic radiation transfers its energy to atoms and molecules in chunks called photons. The energy of a single photon is proportional to the photon's frequency. The photons of high frequency radiation, such as ultraviolet light, X-rays, and gamma rays, carry relatively large amounts of energy compared to those of lower frequency radiation. That is why high-energy photons can break covalent chemical bonds while the photon energy of all other forms of electromagnetic radiation, including visible light, infrared light, microwave, TV and radio waves, and AC power cannot. The average molecule's energy at room temperature of mobile phones is less than 0.001 kJ/mole compared to 480kJ/mole of UV light photons, X-rays and gamma rays, which are actually capable of breaking chemical bonds. 
Conclusively showing that the radio-frequency radiation from mobile phones is harmful has become a difficult task, especially showing that it can cause brain cancer. If radio-frequency radiation does in fact increase the chance of developing brain cancer, it should show up in long-term studies of cell-phone users. But many epidemiological studies have found no clear connection, including a 2007 Danish Cancer Society study of 421,000 cell-phone users, which led many in the media to conclude that cell phones are harmless. To date, "peer-reviewed scientific evidence has overwhelmingly indicated that wireless devices do not pose a risk," says John Walls, a spokesman for CTIA, a global wireless association. 
© Jesse Ramirez. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
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 M. Scherer, "Cell-Phone Safety: What the FCC Didn't Test," Time, 26 Oct 10.