The CERENAT study, another case–control study conducted in multiple areas in France from 2004 to 2006 using data collected in face-to-face interviews using standardized questionnaires (18). This study found no association for either gliomas or meningiomas when comparing regular cell phone users with non-users. However, the heaviest users had significantly increased risks of both gliomas and meningiomas.
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)
There is only one legitimate method of measuring cell phone radiation recognized by every major health authority and government in the world as well as by the cell phone industry itself, referred to as "SAR". SAR testing measures the "Specific Absorption Rate" of radiation at multiple depths and locations on the head and body in order to quantify how much radiation is actually penetrating it with and without certain safety devices. You can see a SAR test of the R2L device by watching the video below.
I liked the way Blocsock implemented this protection and the quality of the product construction, combined with the validated test results, so I recently ordered ones for the rest of my family. I think Blocsock is the BMW-class of what I could find for products that protect against cell phone radiation. My wife has a larger Droid phone and it fits in the case (just barely though)! I hope the makers consider making a larger model for all the new, larger smartphones that recently came out with the larger screen sizes. Again, check to make sure your phone fits, which a friendly message to the company will answer if you are not sure.
“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 reduced 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.”
This 2017 systematic review and meta-analysis, published in PLOS One, looked at mobile phone use in case-control studies and the risk of glioma. “Our results suggest that long-term mobile phone use may be associated with an increased risk of glioma,” they wrote. The researchers found an association between mobile phone use and low-grade glioma in the people who used cellphones regularly or for 10 years or more. “However, current evidence is of poor quality and limited quantity,” they added, and called for prospective studies to confirm the results.
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.
Anyway, several phone models that my wife and I considered buying emitted radiation levels simply too high for my comfort level. They’re measured in SAR -- “specific absorption rate” -- which is essentially the amount of radiation a human body will absorb from using or being near a cell phone. The lower the rate, the less radiation will be absorbed.
There are theoretical considerations as to why the possible risk should be investigated separately in children. Their nervous systems are still developing and, therefore, more vulnerable to factors that may cause cancer. Their heads are smaller than those of adults and consequently have a greater proportional exposure to the field of radiofrequency radiation that is emitted by cell phones. And, children have the potential of accumulating more years of cell phone exposure than adults do.
A large, long-term study has been comparing all of the people in Denmark who had a cell phone subscription between 1982 and 1995 (about 400,000 people) to those without a subscription to look for a possible increase in brain tumors. The most recent update of the study followed people through 2007. Cell phone use, even for more than 13 years, was not linked with an increased risk of brain tumors, salivary gland tumors, or cancer overall, nor was there a link with any brain tumor subtypes or with tumors in any location within the brain.
A phone's specific absorption rate (SAR) reveals the maximum amount of radiation the human body absorbs from the phone while it's transmitting. SAR testing ensures that the devices sold in the U.S. comply with the Federal Communications Commission (FCC) SAR exposure limit, but the single, worst-case value obtained from this SAR testing is not necessarily representative of the absorption during actual use, and therefore it is not recommended for comparisons among phones. In short, selecting a lower SAR phone will not reliably ensure lower radiation absorption during use. The FCC has more information at Specific Absorption Rate (SAR) For Cell Phones: What It Means For You.
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%.
“When symptoms are not addressed comprehensively– for example, using symptom amelioration without simultaneous elimination of exposure – cell membrane adverse reaction and damage continue to occur while the patient is assuming the cause of the problem has been eliminated. This lulls patients into a false sense of security, causing them to aggravate their exposures through the increased use of their wireless devices. When the damage reaches a critically harmful level, even the symptom amelioration can no longer be sustained by the damaged cells.”
This 2017 review, published in Neurological Sciences, looked at case-control studies on cellphone use, focusing on glioma, meningioma, and acoustic neuromas. This review was interesting because the researchers divided the studies by quality, and higher-quality studies — which tended to be funded by the government and not the cellphone industry — showed a trend toward an increased risk of brain tumors, while lower-quality studies did not. Overall, though, their meta-analysis found an increased risk of brain cancers (mostly gliomas) among people who were using cellphones for 10 or more years, and no increase in the risk of acoustic neuroma.
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.
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).