It does sound as they say "promising" but when do they do the big, decades long double blind, randomized, controlled study of long term effects? What if you ha

It does sound as they say "promising" but when do they do the big, decades long double blind, randomized, controlled study of long term effects? What if you have a wound in your skin, does it become cancerous because the live cells are exposed to far UVC light? What does it do to plastics? Do humans get sick easier if they are living in a sterile environment? Does it kill plants? Far UVC is not a natural phenomena on Earth.