5G is currently emerging and will eventually overtake the existing 2G, 3G, and 4G technology. In the meantime, consumers will continue to be exposed to RFR from these sources in the 700-2700 MHz range. As the 5G network is implemented, some of the signals will use the same lower frequencies as the older technology previously studied by NTP. Additionally, concern has been raised because the 5G network will also use higher frequencies, up to 60,000 MHz, thereby exposing wireless consumers to a much broader spectrum of frequencies. The higher frequencies, known as millimeter waves, can rapidly transmit enormous amounts of data with increased network capacity compared to current technologies. Millimeter waves do not travel as far and do not penetrate the body as deep as the wavelengths from the lower frequencies. Millimeter waves are likely to penetrate no deeper than the skin, as opposed to the lower frequencies that have been shown to penetrate at least three to four inches into the human body.
NTP is currently evaluating the existing literature on the higher frequencies intended for use in the 5G network and is working to better understand the biological basis for the cancer findings reported in earlier studies on RFR with 2G and 3G technologies. Additionally, work is ongoing to develop smaller RFR exposure chambers for additional short-term studies that will take weeks and months rather than years. The exposure system is also being designed with the capability of conducting studies with various RFR frequencies and modulations to keep up with the changing technologies in the telecommunications industry.
NTP is also hoping to identify biomarkers of damage from RFR exposure. These would be measurable physical changes that can be seen in shorter periods of time than it takes to develop cancer. Examples could be changes in behavior after exposure or molecular changes that might be predictive of cancer. If scientists can better understand biological changes in animals, they will know more about what to look for in humans.
Source: https://ntp.niehs.nih.gov/results/areas/cellphones/index.html