Maybe 224 also destroyes cells and human dna?
222 nm UV is less damaging, less carcinogenic, and a more effective sterilizer than 254 nm. As an erstwhile photochemist, this was a surprise to me, but it appears to be unequivocal. It has been studied recently both in Japan and USA with similar results.
https://pubmed.ncbi.nlm.nih.gov/32222977/