Researchers have carried out several types of epidemiologic studies in humans to investigate the possibility of a relationship between cell phone use and the risk of malignant (cancerous) brain tumors, such as gliomas, as well as benign (noncancerous) tumors, such as acoustic neuroma (tumors in the cells of the nerve responsible for hearing that are also known as vestibular schwannomas), meningiomas (usually benign tumors in the membranes that cover and protect the brain and spinal cord), and parotid gland tumors (tumors in the salivary glands) (3).
ShieldMe  On the ShieldMe site is a message from Wireless Connection CEO Rose Vitale addressing issues with the cellphone industry and she makes some good points.  As far as how ShieldMe works she states, " Our ShieldMe cases help deflect up to 99% of the harmful EMF, RF or microwave radiation emitted from a cellphone while carrying around or when on a call." The demonstration of the SheildMe case shows levels that like the "EMF protection cellphone cases" is many many times higher than levels EMF expert Larry Gust follows as a certified building biologist.   

Jump up ^ For example, Finland "Radiation and Nuclear Safety Authority: Children's mobile phone use should be limited". Finnish Radiation and Nuclear Safety Authority (STUK). 7 January 2009. Archived from the original on 11 January 2010. Retrieved 20 January 2010. and France "Téléphone mobile, DAS et santé" [Mobile telephones, SAR and health] (PDF). Votre enfant et le téléphone mobile [Your child and mobile telephony]. Association Française des Opérateurs Mobiles (AFOM)[French Mobile Phone Operators' Association] et l’Union Nationale des Associations Familiales (UNAF) [National Federation of Family Associations]. 31 January 2007. Retrieved 20 January 2010.
Current regulatory standards (SAR Test) only protect us from thermal or heating risks; yet, many hundreds of laboratory studies have found that low-intensity, non-thermal exposure to cell phone radiation can promote carcinogenic mechanisms. Moreover, research on humans has found that 25 years of mobile phone use is associated with a three-fold risk of brain cancer.  –Joel M. Moskowitz, Ph.D. School of Public Health. University of California, Berkeley
The World Health Organisation (WHO) released a fact sheet about these issues, shortly after the IARC re-classification, entitled "Electromagnetic fields and public health: mobile phones". The fact sheet points to the findings of the IARC and describes some of the known short-term and long-term effects of phone use, but ultimately, it lands on the side of where the most conclusive evidence exists:
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.
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.
Phone radiation isn’t like the radiation from, say, a nuclear meltdown. That’s what’s known as “ionizing” radiation — it’s high energy and capable of damaging your DNA, which researchers have determined leads to cancer. Phones emit a much lower energy radiation (lower even than visible light) that’s considered to be “non-ionizing.” We know non-ionizing radiation doesn’t damage DNA the way that ionizing radiation does. But the question remains whether it could still react with the body in some other way that might lead to problems from longterm exposure.
The 13-country INTERPHONE study, the largest case-control study done to date, looked at cell phone use among more than 5,000 people who developed brain tumors (gliomas or meningiomas) and a similar group of people without tumors. Overall, the study found no link between brain tumor risk and the frequency of calls, longer call time, or cell phone use for 10 or more years. There was a suggestion of a possible increased risk of glioma, and a smaller suggestion of an increased risk of meningioma, in the 10% of people who used their cell phones the most. But this finding was hard to interpret because some people in the study reported implausibly high cell phone use, as well as other issues. The researchers noted that the shortcomings of the study prevented them from drawing any firm conclusions, and that more research was needed.
Still, despite the odds, these fears could be around for a while — because it’s hard to prove that cellphone radiation doesn’t cause harm. There are just too many combinations of genes, environmental exposures, patterns of cellphone use, plus a healthy helping of random chance to consider. It’s why we’re still having the conversation about whether coffee, for example, is good or bad for us. So while the bulk of evidence points to no health effects from cellphone radiation, the scientific literature is still somewhat mixed, Foster says. “Someone who wants to worry can pick and choose and find a lot of evidence that would support their theories.”
"On the same [IARC] scale that said phone use was possibly carcinogenic, smoking is at the highest level. They are class 1 carcinogens; that's beyond doubt, they definitely do cause cancer ... There's an absolute difference between substances, where the evidence says that there is no doubt about the fact that they cause cancer, compared to mobile phones, where they say it is still possible because the data over ten years use still isn't in."

An analysis of data from NCI's Surveillance, Epidemiology, and End Results (SEER) Program evaluated trends in cancer incidence in the United States. This analysis found no increase in the incidence of brain or other central nervous system cancers between 1992 and 2006, despite the dramatic increase in cell phone use in this country during that time (22).
In 2007, Dr Devra Davis founded non­profit Environmental Health Trust to provide basic research and education about environmental health hazards. Dr Davis served as the President Clinton appointee to the Chemical Safety and Hazard Investigation Board in the U.S.A. from 1994–­1999, an independent executive branch agency that investigates, prevents and mitigates chemical accidents.
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).