Former President of Microsoft Canada warns us that 5G technology is completely untested, and yet plans are full steam ahead to deploy it everywhere, and to override any local attempts to keep it out.
4G radiation is known to be associated with higher cancer incidence long-term, and in sensitive populations there are acute effects (short-term). There is some understanding now that the mechanism has to do with cellular calcium channels. Cell walls have apertures that open and shut to let calcium ions in, or not. Calcium ions are an important signal in many contexts. Radio waves can open the gates indiscriminately, allowing free flow of calcium.
Higher radio frequencies have generally been found to be more problematic. 5G frequencies are ten times higher than 4G. Higher intensities, of course, are a problem. 5G will have to be higher intensity, because it is not transmitted through common materials as readily, and because it won't turn corners (diffraction) as readily.
The telecom industries have captured the FCC and control it without question. No tests of safety have been performed, and none have been planned, yet tens of billions of dollars have already been invested, and much more is planned.