There is a degree of controversy surrounding the implications of cell phone radiation, and what it means to our health. Some research has suggested that the type of radio frequencies used by cell phones can speed up the progression of cancer in laboratory test animals, but it has proven difficult to replicate these results. It is known that radiation from cell phones can affect pacemakers, but the main concern is related to the fact that most cell phone users hold the phone against their ear. If significant levels of radiation enter the tissues of the head in this way over time, some worry that this can increase the likelihood of brain tumors and related conditions.
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.

A 2012 study by NCI researchers (25) compared observed glioma incidence rates in U.S. SEER data with rates simulated from the small risks reported in the Interphone study (6) and the greatly increased risk of brain cancer among cell phone users reported in the Swedish pooled analysis (19). The authors concluded that overall, the incidence rates of glioma in the United States did not increase over the study period. They noted that the US rates could be consistent with the small increased risk seen among the subset of heaviest users in the Interphone study. The observed incidence trends were inconsistent with the high risks reported in the Swedish pooled study. These findings suggest that the increased risks observed in the Swedish study are not reflected in U.S. incidence trends.
In theory, men may be more vulnerable to cellphone radiation’s effects on fertility than women. Sperm cells are made and stored in testicles, whereas egg cells are stored in ovaries. And the location of these two organs means that sperm and eggs have different levels of protection from radiation. Testicles sit outside of the abdomen, which makes them more sensitive to radiation. And, well, a phone often sits in your front pocket.
Mobile phones emit radiofrequency energy, a form of non-ionizing electromagnetic radiation, which can be absorbed by tissues close to the phone. The amount of radiofrequency energy a mobile phone user is exposed depend on many factors as the technology of the phone, the distance between the phone and the user, the extent and type of mobile phone use and the user’s distance from cell phone towers. (2)
But scientists disagree on how real—or how serious—these risks really are, and studies have not established any definitive links between health problems and radiofrequency (RF) energy, the type of radiation emitted by cell phones. “This document is intended to provide guidance for people who want to reduce their own and their families’ exposure to RF energy from cell phones,” the guidelines state, “despite this uncertainty.”
If not, then how can the seller claim that the reported effects on cell cultures, muscle strength testing, plants, skin heating, or other biological effects are due to electromagnetic changes (see for example)? Electromagnetic field characteristics are well known and easy to measure. If there is truly an electromagnetic change, that change will be easy to detect and measure.
5. Use an EMF shielding device. A variety of holsters and other cell phone holders and shields are available that claim to block radiation. If you buy such a product, look to see if it has an SAR (specific absorption rate) value. You want a shielding device that blocks the majority of EMFs. (SAR is a measure of the rate at which energy is absorbed by a body exposed to EMFs.) 
We couldn't find one legit EMF expert online or anywhere else that would recommend a radiation blocking case or anti-radiation case. Not the Environmental Health Trust or Magda Havas, or Joel Moskowitz, in fact his site, safeEMR cautions against scams and claims for radiation protection.  So if a so-called "EMF expert" is recommending any kind of anti-radiation case, they probably aren't that much of an expert. 
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.”

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.