For what it's worth, the definition of 5G isn't really settled yet. To some people it means a high rate multi-antenna system in the existing radio bands (in th

For what it's worth, the definition of 5G isn't really settled yet. To some people it means a high rate multi-antenna system in the existing radio bands (in the approximate frequency range 900MHz to 2GHz). To others it means a wide-band system at a centre frequency of approximately 60GHz. The 60GHz band was specifically chosen for short range wide-band data transmissions because it is close to the absorption peak for oxygen. This means it doesn't propagate far in air, making it a poor choice for much other than short range communications, where it's an asset if neighbouring cells don't interfere with each other. Short range in this case means a cell in every room of a house, as typical propagation distance is about 10 metres. Given that the 60GHz band is specifically absorbed by oxygen, and the body contains oxygen, it strikes me that it's worth specifically testing the biological effects of this band, separately to existing cell phone bands. Note that the article under consideration here tests at 900MHz and 1900MHz.