Influence of UV nail lamps radiation on human keratinocytes viability

Ultraviolet nail lamps are becoming increasingly popular, however, the safety of their use remains controversial. The following article directly responds to recently published literature data and aims to determine the viability of human keratinocytes irradiated by a UV nail-drying machine. Cells were exposed to 365-405 nm wavelength UV light emitted by a nail drying machine in two time variants: 4 and 20 min, with and without sunscreen cream SPF50 protection, and compared to the untreated control. Compared to the control, cell viability after irradiation for 4 min decreased insignificantly (p < 0.1), however for 20 min decreased by 35% (p < 0.0001). Furthermore, cells with sunscreen protection compared to those without showed significantly increased viability, regardless of time-variant (p < 0.0001). The study shows that 4-min irradiation does not significantly reduce the viability of human keratinocytes and the time of 20 min significantly alters the research results compared to 4 min, which corresponds to real conditions. The results suggest that typical manicure exposure time does not significantly affect keratinocyte viability, which could increase the risk of developing skin cancers. Despite the above results, it is recommended to use sunscreen protection on your hands during the procedure, which significantly increases the viability of keratinocytes during ultraviolet nail lamp radiation.