Even though radiofrequency (RF) radiation is "non-ionizing" (i.e., it cannot eject electrons out of an atom's orbit), excessive exposure to RF radiation can be extremely harmful. For instance, developmental studies on mammals, birds, and non-mammalian species have found that RF radiation at intensities high enough to cause significant thermal change is teratogenic (causes birth defects) (6). In fact, thermal RF radiation is so potent that it's often used in cancer therapies as a way to incinerate tumor cells; RF ablation involves placing electrodes near the site of a tumor and blasting it with RF, and the Kanzius machine fires an external RF beam into the patient to "boil" tiny bits of metal placed near a tumor.
Recent epidemiological evidence supports the claim that chronic exposure to low-level RF radiation (from sources such as cell phones, power lines, and cell towers) causes cancer, specifically gliomas (malignant brain tumors) and acoustic neuromas (tumors of the brain's auditory nerve) (1, 3). In a study published in the May 2008 issue of the International Journal of Oncology, researchers examined participants who had used cell phones for 10 years or longer and found an approximately twofold increase in risk for both gliomas and acoustic neuromas with ipsilateral exposure (as reflected by which hand the subject typically used to hold his/her cell phone). Notably, there was no increased risk for meningiomas (tumors that occur in the membranes covering the brain and spinal cord), indicating that observational and recall bias were likely non-factors since such bias would have likely existed for all tumor types (3).
In light of new epidemiological studies linking cell phone RF radiation to occurrence of brain tumors, the European Parliament voted in September of 2008, 522 to 16, in favor of imposing tighter limits on acceptable levels of electromagnetic radiation exposure (1). However, despite this European action, America has yet to follow suit, and the debate over RF radiation safety rages on. One common misconception fueling the debate in America is that, "there is no mechanism by which non-thermal RF (i.e., RF that is not at an intensity capable of causing significant thermal change) can cause cancer."
Even at low, non-thermal intensities, RF radiation can cause cancer in several unique ways:
First, RF radiation upregulates mRNA associated with proteins linked to cell injury. In 2008, researchers at the Medical College of Wisconsin reported that rats chronically exposed to cell phone RF radiation experienced significant upregulation of mRNA associated with proteins linked to cellular injury. They postulated that such radiation "may result in cumulative injuries that could eventually lead to clinically significant neurological damage." Many other scientists have reported that RF radiation also results in DNA damage or modulation, both of which increase the risk of cancer (1).
Second, RF waves can change the conformation or binding-affinity of proteins, resulting in functional changes in these proteins/receptors (6). In the August 2007 issue of the Biochemical Journal, Freidman et al. reported that RF waves emitted at intensities even lower than those emitted by mobile phones are able to activate oncogenic signaling (i.e., start a cell down the path to becoming cancerous) (2, 4).
Third, evidence suggests that radiofrequency radiation interacts with magnetite (a metal found in trace amounts in all cells) in the body (6, 5), possibly generating torques that affect nearby ion channel function. RF could also generate radical pair interactions, increasing free-radical concentrations (6). Given the link between ion channel defects, free radicals and disease, these potential RF mechanisms should not be ignored.
The list goes on. There are a myriad of other potential effects of RF energy on cells that have yet to be investigated in depth. The energy could be absorbed by the vibrational states of biological components important in cell division such as microtubules. Or RF could be demodulated to produce ELF electric fields (classified by the International Agency for Research on Cancer as a "possible human carcinogen") (6). We simply don't know enough about the effect of RF on cells to definitively say which mechanism plays the greatest role in the development of cancer. What we do know, however, is that in light of recent epidemiological and scientific findings implicating radiofrequency radiation with cancer, we can ill afford to remain complacent on this issue.
(1) Khurana et al. 2008 (Vini G. Khurana, John E. Moulder, and Colin G. Orton. "There is currently enough evidence and technology available to warrant taking immediate steps to reduce exposure of consumers to cell-phone-related electromagnetic radiation." Medical Physics, Vol. 35, No. 12, pp. 5203-5206, December 2008)
(2) Friedman et al. 2007 (Joseph Friedman, Sarah Kraus, Yirmi Hauptman, Yoni Schiff, and Rony Seger. "Mechanism of short-term ERK activation by electromagnetic fields at mobile phone frequencies" Biochem J. 2007 August 1; 405(Pt 3): 559568.)
(3) Mead 2008 (M. Nathaniel Mead. "Cancer: Strong Signal for Cell Phone Effects" Environ Health Perspect. 2008 October; 116(10): A422.)
(4) Arthur 2007 (Arthur JS. "MAPK activation by radio waves." Biochem J. 2007 Aug 1;405(3):559-68. )
(5) Kirschvink et al. 2001 (Joseph L. Kirschvink, Atsuko Kobayashi-Kirschvink, Juan C. Diaz-Ricci, and Steven J. Kirschvink. "Magnetite in Human Tissues: A Mechanism for the Biological Effects of Weak ELF Magnetic Fields" Bioelectromagnetics Supplement 1 :101-113, 1992)
(6) Kheifets et al. 2005 (Kheifets L, Repacholi M, Saunders R, van Deventer E. "The sensitivity of children to electromagnetic fields." PEDIATRICS Vol. 116 No. 2 August 2005, pp. e303-e313)