The article, We Have No Reason to Believe 5G is Safe, from Scientific American magazine, gives a good high-level summary of the state of 5G research. From the article:
“Millimeter waves are mostly absorbed within a few millimeters of human skin and in the surface layers of the cornea. Short-term exposure can have adverse physiological effects in the peripheral nervous system, the immune system and the cardiovascular system. The research suggests that long-term exposure may pose health risks to the skin (e.g., melanoma), the eyes (e.g., ocular melanoma) and the testes (e.g., sterility). … Cancer is not the only risk as there is considerable evidence that radio frequency radiation causes neurological disorders and reproductive harm, likely due to oxidative stress.”