The Ramazzini study exposed rats to
extended sessions of RF radiation at GSM's designated 1.8 GHz -- one of the
higher frequency bands used by 4G in Europe,
near the 1.9 GHz band used in the U.S. That study involved the construction of a
field emitter designed to simulate the emissions of a GSM base station.
What's more, NTP was studying the effects of prolonged exposure to 900 MHz frequency -- not exposure to cell tower emissions, and not to cell phone emissions. NTP placed its rats in specially constructed 900 MHz reverberation chambers for periods of time between 14 weeks to as long as two years. The NTP team said its reverb chamber was suggested by the National Institute of Science and Technology (NIST), and described it as somewhat similar to chambers NIST has used in testing signal interference patterns [PDF]. As NIST has noted in its interference studies, using a reverb chamber may equalize the distribution of the frequency over space (which is a bit like maximizing the dose, if you're thinking of it as a drug), at the expense of simulating the directivity of the antenna -- which is something both the transmitter and the receiver utilize in the real world.
So for the NTP study, we can draw some
scientific conclusions about prolonged exposure to an artificially normalized RF
frequency, however limited. Like a grand jury seeking enough evidence for an
indictment, the NTP peer review did uncover
"some evidence of carcinogenic activity" in two of four test conditions, with
"equivocal evidence" (not enough to say one way or the other) in another
condition, and "no evidence" in a fourth.
The Ramazzini Institute study detected what it called a "statistically significant increase" in Schwannomas (nerve tumors) on the hearts of male lab rats, when its base station replicator was set to an RF field dose of 50 volts per meter (V/m). But an actual 1.6 GHz base station would typically generate less than 2 V/m at a 50 meter radius. Two other test conditions yielded results that the researchers said were "not statistically significant."
Polarization being the social force that it is, the news from both studies was
immediately aggregated, each time according to the aggregator's own bent.
Yet in all of this divining of the evidence for the appropriate language for headlines, one extremely important fact is being overlooked: Neither of these studies pertained to 5G.
For implementation in its Release 15 of wireless standards, the 3GPP coalition is adopting a technique created by China's Huawei called uplink / downlink decoupling. Its purpose is to eliminate the crowding that takes place when a cellular transmitter and a cell phone communicate with one another over the same frequency band. Huawei's implementation would boost the downlink frequency (from the tower to the phone) to the 3.5 GHz band, while splitting the uplink frequency (the reverse direction) between 1.8 GHz and 3.5 GHz.
The FCC is seeking to apportion spectrum for a variety of 5G use cases, in higher frequencies from the 3.7 GHz to 24 GHz bands. At these very high frequencies, signals may carry gigabit-speed data, but for shorter, more Wi-Fi-like distances.
In addition to all of that, the 5G cell phone will, on the inside, be a very different order of beast. It will eventually utilize dime-sized 8x8 MIMO antennas, theoretically capable of downlinks at 64 simultaneous frequencies. Harmonics, as any audio engineer or music composer will tell you, changes the nature of waves. From an engineering perspective, the danger of mixing frequencies is called desense -- the reduction in an antenna's sensitivity, as wave cancellations result in noise. How 5G engineers opt to mitigate the desense issues may result in a wave profile that bears no resemblance to anything any lab rat has ever experienced.
So even if scientists review the NTP, Ramazzini, and other studies and conclude that further tests of prolonged exposure of lab rats to gigahertz frequencies is warranted, their findings may end up not pertaining to 5G at all -- not until they find a way to simulate the transmissions of a 5G base station (and avoid the temptation of amplifying those transmissions for maximum effect).