Using higher-wattage ultra violet (UV) lamps at nail salons to dry and cure polish was associated with more UV-A radiation being emitted, but the brief exposure after a manicure would require multiple visits for potential DNA damage and the risk for cancer remains small.

The use of lamps that emit UV radiation in nail salons has raised some concern about the risk of cancer, but previous studies have lacked a sampling of lights from salons.

The authors tested 17 light units from 16 salons with a wide range of bulbs, wattage and irradiance emitted by each device for their research letter.

Higher-wattage light sources were correlated with higher UV-A irradiance emitted.

"Our data suggest that, even with numerous exposures, the risk for carcinogensis, remains small. That said, we concur with previous authors in recommending use of physical blocking sunscreens or UV-A protective gloves to limit the risk of carcinogenesis and photoaging."

The research is published in JAMA Dermatology.