There's a lot of talk in the news these days about whether or not cell phones emit enough radiation to cause adverse health effects. The concern is that cell phones are often placed close to or against the head during use, which puts the radiation in direct contact with the tissue in the head. There's evidence supporting both sides of the argument.
Every day, we’re swimming in a sea of electromagnetic radiation (EMR) produced by electrical appliances, power lines, wiring in buildings, and a slew of other technologies that are part of modern life. From the dishwasher and microwave oven in the kitchen and the clock radio next to your bed, to the cellular phone you hold to your ear—sometimes for hours each day—exposure to EMR is growing and becoming a serious health threat.
But the results of these two rat studies align with those of the biggest cell phone-radiation human study to date, INTERPHONE. The INTERPHONE study, published in 2011, was a coordinated effort by researchers at 16 institutions across 13 countries, and found that the heaviest mobile phone users were more likely to develop glioma—the same type of brain cancer the NTP study found in the male rats. “So there’s a concordance between the animal and human data,” Melnick says.
What the study showed: Most published analyses from this study have shown no statistically significant increases in brain or central nervous system cancers related to higher amounts of cell phone use. One analysis showed a statistically significant, although modest, increase in the risk of glioma among the small proportion of study participants who spent the most total time on cell phone calls. However, the researchers considered this finding inconclusive because they felt that the amount of use reported by some respondents was unlikely and because the participants who reported lower levels of use appeared to have a slightly reduced risk of brain cancer compared with people who did not use cell phones regularly (4–6).
There is no strong or consistent evidence that mobile phone use increases the risk of getting brain cancer or other head tumors. The United States National Cancer Institute points out that "Radiofrequency energy, unlike ionizing radiation, does not cause DNA damage that can lead to cancer. Its only consistently observed biological effect in humans is tissue heating. In animal studies, it has not been found to cause cancer or to enhance the cancer-causing effects of known chemical carcinogens." The majority of human studies have failed to find a link between cell phone use and cancer. In 2011 a World Health Organization working group classified cell phone use as "possibly carcinogenic to humans". The CDC states that no scientific evidence definitively answers whether cell phone use causes cancer.
Cell phones emit low levels of radio frequency energy (i.e., radio frequency radiation) in the microwave range while being used. It is well known that high levels of RF can produce biological damage through heating effects (this is how your microwave oven is able to cook food). However, it is not known to what extent or through what mechanism, lower levels of RF might cause adverse health effects as well. Several research studies have shown that the radio frequency radiation from wireless phone antennae “appears to cause genetic damage in human blood,” while another case study uncovered a “statistically significant increase” in neuro-epithelial brain tumors among cell phone users. Other research has shown little or no adverse effects. ABC’s 20/20 News (May 26, 2000) took the five most popular phones sold in the US and tested them at a highly respected German laboratory. Four out of the five phones tested were above the SAR limit. One thing is for certain, similar to the case of cigarette smoking, it will take several tests and many years before the effects of radio frequency radiation on the human body are known.
Over time, the number of cell phone calls per day, the length of each call, and the amount of time people use cell phones have increased. Because of changes in cell phone technology and increases in the number of base stations for transmitting wireless signals, the exposure from cell phone use—power output—has changed, mostly lowered, in many regions of the United States (1).