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 large enough sampling of lights from a variety of salons.

To create a more authoritative sample, the authors of a new study 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.

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 results showed that the the brief exposure after a manicure would require multiple visits for potential DNA damage and the risk for cancer remains small. As is often the case, the dose makes the poison and the number of visits to create a problem is bordering on the impossible, however voluntary precautions are harmless.  

"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 authors conclude.