The article links to https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC5552051/ https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC5552051/ that states "Therefor

The article links to https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC5552051/ https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC5552051/ that states "Therefore, penetration of far-UVC ~200-nm light through the cornea to the lens is Predicted to be essentially zero (15)." 15 is titled: "UV absorbance of the human cornea in the 240- to 400-nm range." Further, the main claim is "in microbes that are much smaller in size than human cells [less than 1 μm in diameter, compared to the diameter of typical human cells ranging from about 10–25 μm], [far UVC] is strongly absorbed by the proteins in the cytoplasm of human cells and is drastically attenuated before reaching the human cell nucleus" DNA and other proteins are known to be more affected by 220 nm due to absorption peaks than 254 nm. From https://en.wikipedia.org/wiki/Ultraviolet_germicidal_irradiation#Safety https://en.wikipedia.org/wiki/Ultraviolet_germicidal_irradia... : 'Another potential danger is the UV production of ozone, which can be harmful when inhaled. Lamps designed to release UV and higher frequencies are doped so that any UV light below 254 nm wavelengths will not be released, to minimize ozone production.' The lights are most applicable placed at the at the coils and drain pans of cooling systems as 'forced air systems by design impede line-of-sight, thus creating areas of the environment that will be shaded from the UV light.' https://pubmed.ncbi.nlm.nih.gov/28941399/ https://pubmed.ncbi.nlm.nih.gov/28941399/ concluded 280 nm worked better than 265 nm for water disinfection.