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.
To check for radiowave emissions, use an RF meter with Near Field antenna. Again, position the antenna loop on the phone (because the entire antenna stem has some sensitivity, it is best to position the entire antenna over the area that will be shielded). Note carefully where the loop is positioned. Make a call and watch the readings. Notice the highest and lowest readings, and make a mental note of the "average" reading. Now, insert the shield, and repeat.
We also spoke to experts and searched government reports to try to find any other high-quality evidence that may not have been published in an academic database. We included the National Toxicology Program’s animal studies, since they are considered some of the most important animal research that was funded by the government to help answer the question of whether cellphones cause cancer. We also included research on the fertility effects of cellphone radiation, since that was a concern many researchers in the field had.
Third, most of the studies published so far have focused on adults, rather than children. (One case-control study looking at children and teens did not find a significant link to brain tumors, but the small size of the study limited its power to detect modest risks.) Cell phone use is now widespread even among younger children. It is possible that if there are health effects, they might be more pronounced in children because their bodies might be more sensitive to RF energy. Another concern is that children’s lifetime exposure to the energy from cell phones will be greater than adults’, who started using them at a later age.
In December, 2006, an epidemiological study on cell phone dangers published in the Journal of the National Cancer Institute sent the media into a frenzy.10 Newspaper headlines blared: “Danish Study Shows Cell Phone Use is Safe,” while TV newscasters proclaimed, “Go ahead and talk all you want—it’s safe!” The news seemed to be a holiday gift for cell phone users. But unfortunately, it’s a flawed study, funded by the cell phone industry and designed to bring a positive result. The industry’s public relations machine is working in overdrive to assure that the study get top-billing in the media worldwide.
The science is still out on whether the long-term use of cell phones—which emit electromagnetic radiation when they send and receive signals from towers or WiFi devices—can affect human health. But for people who want to reduce their exposure to this type of energy, the California Department of Public Health has published new guidelines on how to do just that.
These stick on “blockers” don’t work. I am EHS and can tell you with certainty (because I feel the fields) that they are not blocking anything. You must use substantial materials like those used in faraday cages (silver and copper), which are now manufactured in materials and fabrics, or avoid EMF use period. Just look at military use for example. They are not using stick on blockers. Follow Ty’s advice for minimizing and avoiding EMF, and look up EMF blocking fabrics, building materials, etc… for the real blockers.
According to the FTC, there is no scientific proof that so-called shields significantly reduce exposure from electromagnetic emissions. Products that block only the earpiece – or another small portion of the phone – are totally ineffective because the entire phone emits electromagnetic waves. Such 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 FTC has enforced false advertising claims against companies that sell such products.
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).