Whether you call them cell phones, smart phones or mobile devices, it seems like everyone has one. According to the wireless telecommunications industry, the U.S. now has an estimated 300 million mobile subscribers, compared to 110 million subscribers a decade ago. The increase in cell phone use has generated concern about possible health risks related to radiofrequency electromagnetic fields from this technology, and a market for shields as possible protection against the radio waves the phones emit. The Federal Trade Commission (FTC), the nation's consumer protection agency, has some practical tips to help you avoid scams and limit your exposure to electromagnetic emissions from your cell phone.
As a good thing to keep in mind, there are hundreds of thousands of people suffering from EHS in the world. Some of them live in forests, tents, and anywhere they can get away from society and EMFs because their symptoms are so bad when exposed. I have not heard one single EHS person claim that any of these types of devices work. They sure don’t for me. Most EHS sufferers are so desperate that they have researched and tried just about everything. Getting away from EMFs, or blocking them with material that does actually block them, like as a Faraday cage, is what works. And this is clearly what the scientific evidence shows. If these devices worked, that would be fabulous. One could spend $100 and be well, instead of having their life turned upside down, and in the worst cases as with some, committing suicide due to complete hopelessness and helplessness.. However, that is not the case. To further prove whether they work or not, one could wear one, and measure with a meter designed to measure EMF absorption in the body (they exist now). Has the manufacturer had this done, and is their evidence of it? An EHS person can tell without a meter anyway, but to prove to others, this might be a good idea.
That’s because cell phones emit electromagnetic fields (EMFs) or electromagnetic radiation, which has the potential to damage the cells in the body. In fact, the International Agency for Research on Cancer classifies EMFs from cell phones as possible carcinogens. EMFs can interfere with the body’s natural electrical system and disrupt sleep, immune system function, hormone production, and the healing process. Kevin Byrne, president of EMF Solutions, also points out the simultaneous increase in conditions such as chronic pain, depression, anxiety, chronic fatigue syndrome, and Alzheimer’s disease and the significant rise in EMF exposure.
Though some findings were reassuring, others do raise concerns. Specifically, three of the studies—one from Sweden, another from France, and a third that combined data from 13 countries—suggest a connection between heavy cell-phone use and gliomas, tumors that are usually cancerous and often deadly. One of those studies also hinted at a link between cell phones and acoustic neuromas (noncancerous tumors), and two studies hinted at meningiomas, a relatively common but usually not deadly brain tumor.
Can cellphone radiation cause cancer in humans? There’s no scientific consensus on this issue, but there is “some evidence” that exposure to radiation equivalent to that emanating from 1990s-era cellphones is associated with brain tumors in male rats, according to results of a US National Toxicology Program (NTP) study released last week (November 1). 
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.
Radiofrequency radiation is a form of electromagnetic radiation. Electromagnetic radiation can be categorized into two types: ionizing (e.g., x-rays, radon, and cosmic rays) and non-ionizing (e.g., radiofrequency and extremely low frequency, or power frequency). Electromagnetic radiation is defined according to its wavelength and frequency, which is the number of cycles of a wave that pass a reference point per second. Electromagnetic frequencies are described in units called hertz (Hz).