Cytotoxic effects of a LED/UV nail polish dryer in human keratinocytes

Nail polish dryers are radiation-emitting devices designed to dry and cure nail polishes. These devices primarily emit radiation within the ultraviolet A (UVA) range, with some also emitting visible light, particularly those equipped with light-emitting diodes (LEDs). The increasing use of nail polish dryers, combined with scientific concerns regarding the potential effects of UVA radiation on human skin, has raised significant safety questions. Recent studies have demonstrated cytotoxic, genotoxic and mutagenic effects in both human and murine cells. When these findings are considered alongside earlier reports linking the use of these devices to skin cancer, there is a clear need for a broader evaluation of their potential health impacts. This study aimed to evaluate the effects of realistic radiation exposures, when considering the actual gel-nail application process, on cell viability and intracellular reactive oxygen species (ROS) levels, in human keratinocytes. Cytotoxic effects were confirmed, with cell mortality rates exceeding 95 % and intracellular ROS levels increasing by over 250 % (72 h post-exposure), depending on the positioning of the cell culture within the device. These results underscore the need for a more thorough characterization of the cytotoxic effects caused by the radiation emitted by nail polish dryers.