“The exposures used in the studies cannot be compared directly to the exposure that humans experience when using a cell phone,” John Bucher, a senior scientist at the NTP, a government program within the department of Health and Human Services, says in a press release. “In our studies, rats and mice received radio frequency radiation across their whole bodies. By contrast, people are mostly exposed in specific local tissues close to where they hold the phone. In addition, the exposure levels and durations in our studies were greater than what people experience.”
From the FCC website: "The FCC ID number is usually shown somewhere on the case of the phone or device. In many cases, you will have to remove the battery pack to find the number. Once you have the number proceed as follows. Go to the following Web address: www.fcc.gov/oet/ea/fccid. Once you are there... Enter the FCC ID number (in two parts as indicated: 'Grantee Code' is comprised of the first three characters, the 'Equipment Product Code' is the remainder of the FCC ID). Then click on 'Start Search.' The grant of equipment authorization for this particular ID number should appear. The highest SAR values reported in the equipment certification test data are usually included in the comments section of the grant of equipment certification."
So, what types of RF are these cases intended to block? If they block the frequency being used by the phone than if the blocking is complete the phone won’t work. If it’s partial than, as noted by the FCC and related in the article, the phone may attempt to compensate for the weakened signal by increasing it’s signal strength, thereby emitting higher levels of radiation itself, and reducing battery life in the process.
Simply snap your phone into the dent resistant bumper cradle. Flip the Cruz Case lid open to receive or make calls, then close back into protective mode. To use properly, flip open the Cruz flip lid cover to answer a call, flip back the cover over the face of the phone and talk through the flip lid cover with perfect clarity. Always keep the flip lid cover between you and your phone even when carrying in your pockets. The attractive and stylish Cruz Case technology provides up to 60dB at cell phone frequencies. Patent pending design does not affect the signal to the cell tower. Ultra-slim design also provides scratch protection for the display and helps keep the screen clean. Keeps your phone looking new. Includes credit card holder feature as well. Select model to fit.
The recent study  about cell phones causing cancer in rats should be taken with a grain of salt when making the connection to humans . In particular, the rats in the study were exposed to radiation power densities of 0, 1.5, 3, or 6 W/kg (see p 7 in ref. 4 below). This would be equivalent of the 100 kg human getting up to 600 Watts — basically getting microwaved. As discussed earlier, cell phones are hundreds of times weaker.
But there’s a huge public health crisis looming from one particular threat: EMR from cellular phones—both the radiation from the handsets and from the tower-based antennas carrying the signals—which studies have linked to development of brain tumors, genetic damage, and other exposure-related conditions.1-9 Yet the government and a well-funded cell phone industry media machine continue to mislead the unwary public about the dangers of a product used by billions of people. Most recently, a Danish epidemiological study announced to great fanfare the inaccurate conclusion that cell phone use is completely safe.10
That brings us back to the main question here: Do cellphones cause tumors? We chose to focus this story on cancer risk, since it seems like the most common health concern people have about cellphones. But before we get to the answers, we need to take another (brief) detour to explain how this science has been done with human subjects. To do that, we need to zoom in on a nerdy subject: research methods.
But he cautioned that the exposure levels and durations were far greater than what people typically encounter, and thus cannot “be compared directly to the exposure that humans experience.” Moreover, the rat study examined the effects of a radio frequency associated with an early generation of cellphone technology, one that fell out of routine use years ago. Any concerns arising from the study thus would seem to apply mainly to early adopters who used those bygone devices, not to users of current models.
RF waves from cell phones have also been shown to produce “stress” proteins in human cells, according to research from Martin Blank, Ph.D., a special lecturer in the department of physiology and cellular biophysics at Columbia University and another signer of the recent letter to the WHO and U.N. “These proteins are used for protection,” Blank says. “The cell is saying that RF is bad for me and it has to do something about it.”
This is the second Cell Shield protector I have purchased. I have had one for my cell phone for almost a year now and it has been wonderful! When my husband upgraded to a new phone, I knew I needed to purchase one for him. The application of the button is very simple and it stays on well. Due to the fact that it is a 'raised' button (a few millimeters thick), some may find it difficult to know where to apply it. I have an i4 phone with an Otterbox case. There is a round cut-out hole in the case that lines up with the 'apple' symbol on the back of the phone. I was able to place the button in that cut-out and it lines up flush with the cover. I highly recommend this Protector to anyone looking to significantly and effectively block EMF's.
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.