Mobile devices work by sending radio waves in the air. And while the National Cancer Institute has pointed out that the radio-frequency (RF) energy cell phone emits is low, it does not discount the possible long term health risks it poses. Some of the most recent smartphones (such as the iPhone 7 in particular), release a higher level of radiation than older cellphones; and with people spending more and more time on their devices, it’s only a matter of time before adverse effects might catch up.

The amount of RF energy absorbed from the phone into the user’s body is known as the specific absorption rate (SAR). Different cell phones have different SAR levels. Cell phone makers are required to report the maximum SAR level of their product to the US Federal Communications Commission (FCC). This information can often be found on the manufacturer’s website or in the user manual for the phone. The upper limit of SAR allowed in the United States is 1.6 watts per kilogram (W/kg) of body weight.

Dr. Carlo and his team developed new exposure systems that could mimic head-only exposure to EMR in people, as those were the only systems that could approximate what really happened with cell phone exposure. Those exposure systems were then used for both in vitro (laboratory) and in vivo (animal) studies. The in vitro studies used human blood and lymph tissue in test tubes and petri dishes that were exposed to EMR. These studies identified the micronuclei in human blood, for example, associated with cell phone near-field radiation. The in vivo studies used head only exposure systems and laboratory rats. These studies identified DNA damage and other genetic markers.

The only sure way is to stop using a cell phone. Most people however would prefer to play safe by simply reducing their exposure to radio frequency radiation. Bluetooth devices emit only 10% of the radiation of a cell phone. A hands-free set enables the user to keep the phone away from the head but usually leaves the phone near some other part of the body. It is safe to say that in the event that radio frequency radiation causes damage, you would like to protect other parts of your body. Therefore the only way to reduce your risk is to reduce the radio frequency radiation your body absorbs. SAR Shield reduces radio frequency radiation by up to 89%. 
A package for it is sold for 70 bucks that includes a choice from seven different color air-tube headsets in two styles (mono or stereo) with a ferrite bead already installed on the headset wire. A 4th accessory is included as a reminder that radiation is only shielded from the front of the phone when case is closed. The plastic stand enables a user to tilt the phone so that the unshielded sides and rear of the phone aren’t “inline-of-sight” with the body. Cell phone radiation, just as light, travels in a straight line. Being informed and awareness of using a phone safely is the most important aspect of RF Safe’s system of safe cell phone usage with 4 accessories for 69.99.
In a February 2 statement, Jeffrey Shuren, director of the FDA’s Center for Devices and Radiological Health, wrote that despite the NTP study’s results, the combined evidence on RF exposure and human cancer—which by now amounts to hundreds of studies—has “given us confidence that the current safety limits for cell phone radiation remain acceptable for protecting the public health.” Chonock says that for him, evidence from the Ramazzini study does not alter that conclusion. “We continue to agree with the FDA statement,” he says.
It’s easy to call any case a product designed to block smartphone radiation.  What you need to look for is credible, quantifiable claims that highlight a case’s ability to reduce your exposure to the harmful radiation. Look for relevant  certifications from credible organizations (such as FCC accredited laboratories) that will vouch for product claims, and read product reviews online.
Says Dr. Carlo: “We also conducted four different epidemiological studies on groups of people who used cell phones, and we did clinical intervention studies. For example, studies of people with implanted cardiac pacemakers were instrumental in our making recommendations to prevent interference between cell phones and pacemakers. In all, we conducted more than fifty studies that were peer-reviewed and published in a number of medical and scientific journals.”
I love these radiation protection cases. It's a great size for my iphone, and I can even talk on the phone with the phone inside the pouch - perfect sound quality. The only thing I would recommend is that a snap be added to the opening -- it is slippery material. You can tell the company took care in producing a quality product -- it is constructed very well. I recommend this product to cell phone users! Oh, I also got this so quickly!! It arrived within 2-3 days of ordering, and it comes from the UK!! Amazing service!!
Yes, cell phones emit Electromagnetic Fields (EMF) and direct exposure to these emissions can be a health risk. There are two types of EMF radiation emitted from cell phones: Extremely Low Frequency (ELF) radiation and Radio Frequency (RF) radiation (which includes cellular signals, WiFi and Bluetooth). More and more, particularly in recent years, scientific studies have confirmed that these EMF exposure can adversely modify the biological operations of the body. In more serious cases, exposure to EMFs can lead to tumors, reduce sperm count and other serious health concerns.
As in the NTP study, Ramazzini investigators detected statistically elevated rates of heart schwannomas in male rats at the highest dose. They also had weaker findings linking RF exposure to cancer of glial cells in the brain, which were limited to females. Ronald Melnick, a retired NTP toxicologist who designed the NTP study, says a measure of consistency between the two studies is important, because “reproducibility in science increases our confidence in the observed results.”
The following charts list SAR levels for the Apple iPhone, Samsung Galaxy S, as well as 20 of the highest SAR level cellphones and 20 of the lowest SAR level cellphones. The list provides the maximum possible SAR level from the phone (many phones have differing SAR levels depending on where and how the phone is used). If your phone is not on either list, you can find the SAR level for your specific phone by checking the online FCC database.

Protect your brain from RF (radio-frequency) pollution with this handsome baseball style hat. Specially designed to shield the head from frequencies from below AM through microwave, including cellular phone frequencies. Lined with sophisticated Staticot fabric woven from ployester/cotton with an ultrathin stainless steel fibers excellent radiation protection. This gives this unique fabric a truly comfortable, natural feel and the durability and washability of cotton, but with exceptional reflective characteristics.
The frequency of radiofrequency electromagnetic radiation ranges from 30 kilohertz (30 kHz, or 30,000 Hz) to 300 gigahertz (300 GHz, or 300 billion Hz). Electromagnetic fields in the radiofrequency range are used for telecommunications applications, including cell phones, televisions, and radio transmissions. The human body absorbs energy from devices that emit radiofrequency electromagnetic radiation. The dose of the absorbed energy is estimated using a measure called the specific absorption rate (SAR), which is expressed in watts per kilogram of body weight.