(Some common flaws in these studies: The summaries of the evidence weren’t comprehensive, the researchers often didn’t look at the quality of the studies they found, and they failed to do other simple things that would limit bias from creeping in. They also relied on case-control studies, a poor method to determine causality — more on that soon.) So we didn’t include these eight reviews in our analysis.

“If you’re looking for ways to limit your exposure to the electromagnetic emissions from your cell phone, know that, according to the FTC, there is no scientific proof that so-called shields significantly reduce exposure from these electromagnetic emissions. In fact, products that block only the earpiece – or another small portion of the phone – are totally ineffective because the entire phone emits electromagnetic waves. What’s more, these shields may interfere with the phone’s signal, cause it to draw even more power to communicate with the base station, and possibly emit more radiation.”
We asked Dr. George Carlo his thoughts on EMF cases and shielding products, “most offer some protection, some of the time, to some people, because they can alter the immediate electromagnetic field environment around the person,” and immediately emphasizes the importance of “some,” which seems to tell us that it’s vastly unpredictable. “All waveforms in the environment are highly variable and they interact with other factors in the environment that make them even more variable.” This pretty much sums up that the artificial electromagnetic energy universe is vastly unpredictable.
Cell phone radiation emissions present the greatest potential health risks when directly touching the body, especially the head, breasts and reproductive organs. This is referred to as zero distance to the body. Moving your cell phone away from your body just a few inches reduces the health risks. As a rule of thumb, when a cell phone is moved at least one foot away from the head or body, cell phone radiation is reduced by as much as 80%.
Cell phones work by sending signals to (and receiving them from) nearby cell towers (base stations) using RF waves. This is a form of electromagnetic energy that falls between FM radio waves and microwaves. Like FM radio waves, microwaves, visible light, and heat, RF waves are a form of non-ionizing radiation. They don’t have enough energy to cause cancer by directly damaging the DNA inside cells. RF waves are different from stronger (ionizing) types of radiation such as x-rays, gamma rays, and ultraviolet (UV) light, which can break the chemical bonds in DNA.
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The peer reviewers did have some quibbles with the study; some wished it could have lasted longer (the rodents were exposed to radiation for two years) to catch later-developing tumors, for example, but others on the panel noted that the longer a rodent lives, the more likely it is to develop tumors regardless of radiation, making it harder to find the signal in the noise. Others wanted the researchers to have dissected the rodent brains more than they did, to seek hard-to-find tumors. But they noted that science is an iterative process; the study wasn’t perfect, but it’s better than anything that’s been done so far.

Stick on anti-radiation protection shields etc are often made of metal which may block signal and prevent reliable mobile phone communications with signal towers. Mobile phones recognise the potential for a dropped signal and actually increase power to compensate. The result is a fast draining battery and an even higher radiation output as a result of using the product (an exception to this are shields that are placed in between the phone and the user as these do not impede signal to cell towers to any significant degree)

Remember: The cancer incidence data in humans, at least to date, suggests no avalanche of head and neck tumors. Since so many people are exposed to cellphones, if there were a big risk, we’d probably see it turn up. “If cellphones caused brain tumors at the rate that cigarettes caused lung cancer,” said Otis Brawley of the American Cancer Society, “we would have figured it out by now.”
Just as inevitably, worries about brain cancer spawned a market for products that supposedly protect cell phone users. For $62, you can order a Delta Shield, a thin polyester patch that contains a microchip that allegedly renders cell phones harmless. Users are instructed to place the patch on their cell phone battery. The similar BIOPRO Cell Chip, sold online for $35, attaches to the outside of the phone. The penny-size WaveShield 2000 Gold, selling for about $25, fits on the earpiece.
If you want to use your phone for talking, then the idea is that you keep it flipped over the front of the screen – that way you’re blocking radiation on both the front and back. The speaker still works with the cover on, because there’s a small hole for that. The inevitable drawback of this is that you have to flip the cover open in order to access your keypad.
The energy of electromagnetic radiation is determined by its frequency; ionizing radiation is high frequency, and therefore high energy, whereas non-ionizing radiation is low frequency, and therefore low energy. The NCI fact sheet Electromagnetic Fields and Cancer lists sources of radiofrequency radiation. More information about ionizing radiation can be found on the Radiation page.