At high power levels, RF waves can heat up water molecules (which is how microwave ovens work). Scientists used to focus their concerns on the possibility that such heating of human tissue, which is mostly water, might damage cells. In fact, the FCC’s test of cell-phone emissions—which was set in 1996 and which all phones must pass before being allowed on the market—is based on that effect.
The device comes in a variety of forms ranging from the $39 Aries Shield ("a silicon based micro processor that ... decomposes oscillations of electromagnetic fields") to the $249 Aires Defender Utility (which "has two next generation 9 core silicon based micro processor (sic) that provide universal protection from electromagnetic smog of the broadband frequencies").
You’ll notice radiation is split into two categories here: ionizing and non-ionizing. The waves emitted from radios, cellphones and cellphone towers, Wi-Fi routers, and microwaves are referred to as “radio-frequency” radiation. That’s a type of “non-ionizing” radiation, since it doesn’t carry enough energy to “ionize” — or strip electrons from atoms and molecules. (Other sources of non-ionizing radiation, as you can see in our chart, include visible and infrared light.)
We also spoke to experts and searched government reports to try to find any other high-quality evidence that may not have been published in an academic database. We included the National Toxicology Program’s animal studies, since they are considered some of the most important animal research that was funded by the government to help answer the question of whether cellphones cause cancer. We also included research on the fertility effects of cellphone radiation, since that was a concern many researchers in the field had.
to find the minimum distance the federal government recommends that your cell phone must be away from your body. Keeping it closer than the designated distance can result in a violation of the FCC Exposure Limit. Exceeding FCC levels is proven to result in burns, sterility and brain damage. Learn more about fine print instructions and see all the FCC warnings here.
As a result, stories about a single nuclear meltdown or possible link between cellphone radiation and cancer will be amplified much more than news about the nine people who probably died today in the US from distracted driving. “This possible health effect from radiation is pretty esoteric at this point. If there is anything there, it seems to me like it’s going to be very, very small,” says Kenneth R. Foster, a bioengineering professor at the University of Pennsylvania who has been investigating whether there are biological effects from radio waves since the 1970s. “Driving and texting, people get killed doing that — but it’s not a very exciting risk to worry about.”
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.
The Blocsock came quickly, ordered from the UK which was sent Royal Air Express at no extra cost, and fit my Motorola Triumph perfectly. They sell different sized Blocsocks in different colors, so if you order one, make sure it fits your phone. The Amazon vendor based in the UK, Cell Phone Radiation, was very helpful, answering my email promptly so I knew what model to order for my phone.

In the US, a small number of personal injury lawsuits have been filed by individuals against cellphone manufacturers (including Motorola,[28] NEC, Siemens, and Nokia) on the basis of allegations of causation of brain cancer and death. In US federal courts, expert testimony relating to science must be first evaluated by a judge, in a Daubert hearing, to be relevant and valid before it is admissible as evidence. In a 2002 case against Motorola, the plaintiffs alleged that the use of wireless handheld telephones could cause brain cancer and that the use of Motorola phones caused one plaintiff's cancer. The judge ruled that no sufficiently reliable and relevant scientific evidence in support of either general or specific causation was proffered by the plaintiffs, accepted a motion to exclude the testimony of the plaintiffs' experts, and denied a motion to exclude the testimony of the defendants' experts.[29]
The only consistently recognized biological effect of radiofrequency radiation in humans is heating. The ability of microwave ovens to heat food is one example of this effect of radiofrequency radiation. Radiofrequency exposure from cell phone use does cause heating to the area of the body where a cell phone or other device is held (e.g., the ear and head). However, it is not sufficient to measurably increase body temperature. There are no other clearly established effects on the human body from radiofrequency radiation.