Leo Sher, M.D.

Cell phone use has recently been categorized as possibly carcinogenic to humans by the International Agency for Research on Cancer, which develops scientific cancer-prevention strategies for the World Health Organization (WHO). The panel of experts state that studies do not show definitively that cell phone use increases cancer risk. However, they suggest that there is limited evidence that the radiofrequency energy released by cell phones may increase the risk of glioma, a type of brain cancer which is rarely curable and is associated with poor prognosis, and acoustic neuroma, a noncancerous tumor of the nerve that runs from the ear to the brain. Both tumors are relatively rare: about 10,000-12,000 people develop glioma and about 3,000 develop acoustic neuroma each year in the U.S. Some scientists are skeptical of the link.They found the WHO decision perplexing. Groups representing the wireless industry downplayed the significance of the report. They noted that the WHO placed radiofrequency electromagnetic fields in the “possibly carcinogenic” category, along with 265 other risk factors including coffee, gasoline, and occupational exposure to dry cleaning.

The impact of electromagnetic fields generated by cell phones on the human brain has received sporadic attention in the scientific and lay literature. Mobile or cellular phones are now an integral part of modern telecommunications. In many countries, most people use mobile phones and the market is growing rapidly. Mobile phones are low-powered radiofrequency transmitters, operating at frequencies between 450 and 2700 MHz with peak powers in the range of 0.1 to 2 watts. The handset only transmits power when it is turned on. The power and the radiofrequency exposure to a user falls off rapidly with increasing distance from the handset. A person using a mobile phone 30–40 cm away from their body, for example when text messaging, accessing the Internet, or using a “hands free” device will have a much lower exposure to radiofrequency fields than an individual holding the handset against their head. In addition to using “hands-free” devices, which keep mobile phones away from the head and body during phone calls, exposure is also reduced by limiting the number and length of calls. Using the phone in areas of good reception also decreases exposure as it allows the phone to transmit at reduced power. Cell phones emit the most radiation when they are attempting to connect to cellular towers. A moving phone, or a phone in an area with a weak signal, has to work harder, giving of more radiation. Cell phone users should avoid using their phones in elevators, buildings and rural areas if they want to reduce their exposure.