Unfortunately, regulatory boards do not require third-party phone accessory manufacturers to consider how their product will work in tandem with the smartphone. Neither do governments require smartphone manufacturers to conduct extensive research on whether their SAR will still meet the FCC’s allowable radiation exposure limits when their devices are using a phone case or other 3rd party accessories.
Researchers need funding to move fast to study the potential health effects of 5G networks and how they might change our exposures to radiation. “So far, we’ve got research that’s done on 3G and 4G but not 5G,” said Brawley of the American Cancer Society. “We do think the answers [about cell radiation’s cancer effects] for 5G may be different from the answers for 4G or 3G. ... As these types of radio waves and energy change over time, the answers [about their health effects] may change.”
There were no biological hypotheses tested in the study. It was therefore only a numbers game. Ignored were mechanisms of disease found in other studies of cell phone radiation effects, including genetic damage, blood-brain barrier leakage, and disrupted intercellular communication. The study did not discuss any research supporting the notion that cell phones could cause problems in users.
The World Health Organization (WHO) says the intensity of radio frequency (RF) radiation from cell phones decreases exponentially the further the device is held away from the body. Therefore your safest bet it keep your cell phone as far away from your ear and body as possible at all times. Don’t carry it in your pocket, tucked into a bra strap, and definitely don’t sleep with it next to your head.
Scientists have reported adverse health effects of using mobile phones including changes in brain activity, reaction times, and sleep patterns. More studies are underway to try to confirm these findings. When mobile phones are used very close to some medical devices (including pacemakers, implantable defibrillators, and certain hearing aids) there is the possibility of causing interference with their operation. There is also the potential of interference between mobile phones signals and aircraft electronics. Some countries have licensed mobile phone use on aircraft during flight using systems that control the phone output power.
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)
The next scientific step will be to determine what this means for humans. The peer-reviewed papers will be passed on to the US Food and Drug Administration, which is responsible for determining human risk and issuing any guidelines to the public, and the Federal Communications Commission, which develops safety standards for cell phones. The FDA was part of the group of federal agencies who commissioned the studies back in the early 2000s.
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:

Read the “fine print” from the manufacturer’s instruction manual which tells users to put a distance between the phone and your head and body. These fine print warnings range  from a few millimeters to almost an inch. The fine print warnings on other wireless devices (such as Wi-Fi routers, wireless printers, home cordless phone base stations and baby monitors) generally state the distance should be at least 20 cm, or about 8 inches. If people are closer than the manufacturer stated separation distance, then they can be exposed to RF levels that violate the US government FCC limits for this radiation.

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.
Moving the meter around the case, we detect readings on the side, back and front of the case. We use the multi-directional TES 593 meter which measures 10 MHz to 8GHz. We use the unit of micro-watts per square centimeter, which looks like this little symbol: μW/cm² and we use it on the max setting which shows the maximum measured value. In non-science speak: the highest level of RF we see, which could be from the back the side or the front. 

The DefenderShield® Universal Cell Phone EMF Radiation Protection & RFID Blocking Wallet Case blocks up to virtually 100% of harmful EMF cell phone radiation from the face of your cell phone. This handcrafted case utilizes multi-layered, state-of-the-art radiation-shielding technology in the front cover while offering a soft microfiber interior and elegant vegan leather exterior resistive to scratching, staining and the accidental drop.
But, dear reader, don’t think we’ve reached a “case closed” moment: Unfortunately, even the best evidence on cellphones and brain tumors is far from ideal. Remember, these cohort studies are still observational research — not experimental studies like RCTs. That means they can’t tell us about causation, and there are still many ways they could be biased.
EWG urges the FCC to include third party-produced cases and accessories in its cell phone testing policies to ensure that they do not compromise cell phone function and do not prevent a cell phone from complying with the Commission’s exposure limits. Manufacturers should publish the radiation data for a given phone when used directly next to the body and when used with the cases most commonly sold for a specific model.
This 2009 meta-analysis, published in the Journal of Clinical Oncology, looked at 23 case-control studies of the risk of both malignant and benign tumors from mobile phone use. When the authors included all 23, they found no increased risk of tumors. When they crunched certain subsets of the data — like looking only at studies that were blinded, or people who used cellphones for 10 or more years — they did find increases in tumor risks. Confusingly, when they divided up the analysis by tumor type, they found no increase in risk for glioma and acoustic neuroma, and a decrease in risk of meningioma.
SafeSleeve was founded in California by two Engineering graduates (University of Cal Poly San Luis Obispo) Cary and Alaey, with a desire to make a difference. They wanted to develop a product to help simplify, protect, and enhance the lives of their increasingly busy, tech dependent peers, family and friends. This is apparent in the highly efficient and useful, yet stylish designs and branding of SafeSleeve products. 
Open the “Step 2” packet and remove the cloth and rub the glass surface with the Ti22 Liquid Titanium Shield Nano liquid treated wipe which will coat the surface with the protective Nano liquid. The liquid needs to be applied for at least 90 seconds rubbing every part of the glass. Pushing gently into the glass to absorb the advanced formula. You can also use your finger to rub the liquid into the glass and don’t forget to apply to the camera lens and back-glass if you have a glass back. Allow the Ti22 Liquid Titanium Shield liquid to dry for at least 60-90 seconds before handling. Wash your hands carefully after the treatment.
In one type of study, called a case–control study, cell phone use is compared between people with these types of tumors and people without them. In another type of study, called a cohort study, a large group of people who do not have cancer at study entry is followed over time and the rate of these tumors in people who did and didn’t use cell phones is compared. Cancer incidence data can also be analyzed over time to see if the rates of brain tumors changed in large populations during the time that cell phone use increased dramatically. These studies have not shown clear evidence of a relationship between cell phone use and cancer. However, researchers have reported some statistically significant associations for certain subgroups of people.