The Specific Absorption Rate that the FCC, with input from many other government institutions, decided on, is defined using an average of a 30-minute phone call with the cell phone held directly to the ear. Since modern cell phones are used in all sorts of manners, ie speakerphone, scrolling through social media, browsing the web, etc, a base had to be set.
Our tests wre conducted with three RF meters, set at fixed position next to the iPhone. Our primary meter was the Gigahertz Solutions HFE 59B, a professional RF instrument. We also used a TES 593 (Mid-Range Consumer Grade Instrument) and the Acousticom 2 (Low-Range Consumer Grade Instrument) to compare/confirm the increases and decreases in RF and for visual reference.
Who wants to make his own shielded passport or credit card sleeve? Or line a purse, wallet, cellphone case or backpack? Add a shielding liner to a pocket? Wrap a wifi node to block radiation output? Repair a fencing lame? Shield a part of a circuit board? Make an RF gasket? Shield your homeopathy bottles? Attach a ground cord to a fabric? There are hundreds of uses for this versatile shielding patch. A peel-off paper backing reveals a super strong conductive adhesive that keeps the patch where you put it. Easily cut to any shape with ordinary scissors, this metalized fabric is conductive on both sides, completely flexible with no stretch, and solid black in color. 40-50 dB from 10 MHz to 10 GHz. You get two pieces, each 5.5x8 inches. Not intended to adhere directly to skin. Do not machine wash.

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.
Thus far, the data from studies in children with cancer do not support this theory. The first published analysis came from a large case–control study called CEFALO, which was conducted in Denmark, Sweden, Norway, and Switzerland. The study included children who were diagnosed with brain tumors between 2004 and 2008, when their ages ranged from 7 to 19 years. Researchers did not find an association between cell phone use and brain tumor risk either by time since initiation of use, amount of use, or by the location of the tumor (21).
A recent large study by the US National Toxicology Program (NTP) exposed large groups of lab rats and mice to RF energy over their entire bodies for about 9 hours a day, starting before birth and continuing for up to 2 years (which is the equivalent of about 70 years for humans, according to NTP scientists). The study found an increased risk of tumors called malignant schwannomas of the heart in male rats exposed to RF radiation, as well as possible increased risks of certain types of tumors in the brain and adrenal glands. But some aspects of this study make it hard to know just how well these results might be applied to cell phone use in people. For example, there was no clear increased risk among female rats or among male or female mice in the study. The doses of RF radiation in the study were also generally higher than those used in cell phones (ranging from 1.5 W/kg to 6 W/kg in rats, and 2.5 W/kg to 10 W/kg in mice), the animals’ entire bodies were exposed, and the amount of time they were exposed was longer than most people typically spend on the phone each day. The male rats in the study exposed to RF waves also lived longer, on average, than the rats who were not exposed, for unclear reasons. Because of this, the NTP has noted that the study results cannot be directly applied to humans. Still, the results add to the evidence that cell phone signals might potentially impact human health.
Cooper's prototype arrived on the market a decade later at the staggering price of $3,995. Designed by Rudy Krolopp, it was known as the Motorola DynaTAC 8000X, or simply "the brick.” Featuring 20 large buttons and a long rubber antenna, it measured about 11 inches high, weighed almost 2 pounds, provided one hour of battery life and could store 30 phone numbers.

As far as which of those match your device, that really depends on your carrier. AT&T, Verizon, Sprint, and T-Mobile all have different frequencies. To further complicate things, in one geographic region of the country they may use one frequency, while another is used elsewhere. It all depends on which FCC licenses they have the rights to in each region.
The researchers found other strange effects that muddied the interpretation of the studies: The rats exposed to cellphones seemed to outlive the rats in the control group, for example. There was no clear linear relationship between higher levels of cellphone exposure and more cancer at some tissue sites, and the cancer rate in the control group was lower than it should have been at other tissue sites.

There’s not a lot of research on the effects of cell-phone use on children’s and teens’ health, the report acknowledges, but some studies have suggested that it may be associated with hearing loss, ringing in the ears, headaches and decreased well-being. Children who use cell phones will also have more years of exposure to RF energy over their lifetimes than people who started using them as adults, which leads some doctors to recommend added caution.
The first one is easy, cellular frequencies vary between 450–2000MHz, but 800 or 900 MHz is the most common. The power emitted by a cell phone varies over the course of the call (higher when making initial contact, which lasts a few seconds). It can go up to 2 Watts at the start of a call, and can go down to .02 Watts during optimal operation [2]. Of course, most people barely use cell phones for calls, but I am using this example as a worst case scenario, because the phone is not right by your head when you are browsing Tinder.
Recall bias, which can occur when data about prior habits and exposures are collected from study participants using questionnaires administered after diagnosis of a disease in some of the participants. It is possible that study participants who have brain tumors may remember their cell phone use differently from individuals without brain tumors. Many epidemiologic studies of cell phone use and brain cancer risk lack verifiable data about the total amount of cell phone use over time. In addition, people who develop a brain tumor may have a tendency to recall cell phone use mostly on the same side of the head where their tumor was found, regardless of whether they actually used their phone on that side of the head a lot or only a little.

Generally speaking, the near-field refers to the RF field close to the antenna and the far-field is the RF field further away from the antenna. Often times when you use your cell phone, your body is often located in the near-field (one wavelength or less) of the cell phone antenna. It is especially concerning when you hold your phone next to your head or wear it on your body as you can be exposed to very intense near-field radiation from the phone.
If you're concerned that talking on your cell phone could cook your brain, you may want to invest in an anti-radiation phone case. The basic idea behind these cases is that they redirect the radiation produced by the phone away from the user, so it isn't constantly bombarding your skull. They can accomplish this in a variety of ways; one involves using antennas to redirect the waves, and another uses silicone or other materials to block the waves.
George Carlo, PhD, JD, is an epidemiologist and medical scientist who, from 1993 to 1999, headed the first telecommunications industry-backed studies into the dangers of cell phone use. That program remains the largest in the history of the issue. But he ran afoul of the very industry that hired him when his work revealed preventable health hazards associated with cell phone use.
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 electromagnetic spectrum is broken up into two parts based on whether small doses of that radiation can cause harm: ionizing radiation and non-ionizing radiation. Ionizing radiation—UV, x-rays, and gamma rays—has enough energy in one photon (quantized minimum packet of light) to remove electrons from atoms or break apart chemical bonds. It is because of this potential for cancer-causing DNA damage that you wear a lead vest when you get x-rays at the dentist and you are advised to wear sunblock when you go out in the sun. One can’t avoid natural (radon, cosmic rays when you are up in an airplane) and man made (diagnostic x-rays) sources of ionizing radiation completely, but it is reasonable advice to minimize exposure when possible.

A study by the Corporate EME Research Laboratory and Motorola Florida Research Laboratories tested 9 different cell phone radiation shields, 5 of which claimed to block 99% of cell phone radiation. The other 4 shields tested claimed to emit a reverse radiation that would cancel out the harmful radiation from cell phones. The study found that all of the radiation shields had no effect on the amount of radiofrequency radiation a cell phone user is exposed to from their phone.[2]

Some people might consider choosing a phone with a low SAR value. Different models of phones can give off different levels of RF waves. But as noted above, according to the FCC the SAR value is not always a good indicator of a person’s exposure to RF waves during normal cell phone use. One way to get information on the SAR level for a specific phone model is to visit the phone maker’s website. The FCC has links to some of these sites here: www.fcc.gov/encyclopedia/specific-absorption-rate-sar-cellular-telephones. If you know the FCC identification (ID) number for a phone model (which can often be found somewhere on the phone or in the user manual), you can also go to the following web address: www.fcc.gov/oet/ea/fccid. On this page, you will see instructions for entering the FCC ID number.


Most cellphone shielding products are designed to reduce radiation to the user while still allowing the phone to function. This means that some radiation can still get to the phone… and some radiation can still get out of the phone! But sometimes you need to completely kill the signal. The RF Kill Box is a full-metal shielding jacket with very high shielding performance.
We asked Dr. George Carlo his thoughts on EMF cases and shielding products, “most offer some protection, some of the time, to some people, because they can alter the immediate electromagnetic field environment around the person,” and immediately emphasizes the importance of “some,” which seems to tell us that it’s vastly unpredictable. “All waveforms in the environment are highly variable and they interact with other factors in the environment that make them even more variable.” This pretty much sums up that the artificial electromagnetic energy universe is vastly unpredictable.
In 2015, the European Commission Scientific Committee on Emerging and Newly Identified Health Risks concluded that, overall, the epidemiologic studies on cell phone radiofrequency electromagnetic radiation exposure do not show an increased risk of brain tumors or of other cancers of the head and neck region (2). The Committee also stated that epidemiologic studies do not indicate increased risk for other malignant diseases, including childhood cancer (2).
It also means regulators need to make sure their policies reflect new levels of exposure. The Federal Communications Commission currently oversees cellphone safety and sets the limits for how much radiation people should be exposed to. (This is measured by the specific absorption rate — the rate at which the body absorbs radio frequency energy — and the current limit for cellphones is 1.6 watts of energy per kilogram of tissue. The whole-body threshold is a SAR value of 0.08 watts per kilogram, and the tower radiation limit is 10 watts per square meter.)
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 reduce 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.
The study specifically used 2G and 3G frequencies — not the frequencies used on more advanced 4G or 5G networks. Researchers exposed the rodents’ entire bodies to the radiowaves for more than nine hours per day, for up to two years. (“A rat that is 2 years old is roughly equivalent to a 70-year-old person,” STAT News reports.) These exposure levels were much higher than what people would experience, John Bucher, senior scientist with the NTP, says in a statement. “So, these findings should not be directly extrapolated to human cell phone usage,” he says.
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.
Generally, the Ministry of Health adopts the instructions of most international entities, recommending to follow the “precautionary principle” regarding mobile phone use. The instructions of the Ministry take into account the technological need of the population in Israel, along with the measure of precaution necessary according to the recent scientific information in order to balance between the population’s needs and the preservation of its health.
As a rule, modern medical equipment is well protected against exposure to radiowave radiation. Therefore, there is generally no need for concern regarding the effects of mobile phones on the normal function of the equipment. Nevertheless, the Ministry of Health recommends not to have a mobile phone in the immediate proximity (a distance of 30-50 cm from the portable medical equipment or from medical equipment implanted in the patient's body).
The U.S. government doesn’t seem very troubled, either. The Food and Drug Administration says on its website that research generally doesn’t link cell phones to any health problem. And although the Federal Communications Commission requires manufacturers to include information in user manuals about cell-phone handling, that’s often buried deep in the fine print.
EWG also reviewed data in the FCC filings on tests of battery life during a continuous call, measured on an iPhone 4 without a case and on the same phone with an Incipio Le Deux case. This case was chosen because it contains metallic parts (a stainless steel back plate). The presence of metallic components influences the phone’s radiation properties, as the FCC acknowledges (FCC 2001; FCC 2014). Under the test conditions with constant signal strength, an iPhone 4 without a case had 85 percent of battery capacity after a one-hour call and 70 percent after two hours. When the test was repeated with the Incipio Le Deux case, the phone had only 65 percent of battery capacity after a one-hour call and only 10 percent after two hours (Pong 2012).
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.
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