Exposures in nail salons to trace elements in nail polish from impurities or pigment ingredients - A pilot study

Nail polishes have evolved considerably. Toxic elements, such as lead, have been found in nail polish, and it is unclear if new finishes using metallic effect pigments may be contributing to metals exposure in nail technicians. We characterized concentrations of trace elements in 40 nail polishes, 9 technicians' urine, and 20 technicians' toenail clippings from 8 nail salons in the Boston area in 2017. We also collected 24 salon surface wipes from 3 of the salons. Antimony was not disclosed as a nail polish ingredient, yet concentrations (<15 microg/g) were above existing cosmetics guidelines (0.5 microg/g) in five (13%) of the samples. Aluminum (<11,450 microg/g), barium (<11,250 microg/g), iron (<3,270 microg/g), and magnesium (<2375 microg/g) were disclosed as ingredients and were also found on salon surfaces where nail polish was stored or used. Heavy metal impurities in nail polish were not detected for cadmium. Lead and nickel were found at low concentrations (<0.40 microg/g lead, <0.67 microg/g nickel). Tin (p = 0.003) concentrations were higher in nail polish with finishes compared to without. Barium and strontium (both p = 0.0001) concentrations were higher for red nail polishes compared to all other colors. Of those elements in nail polish and salon surfaces, aluminum and iron were detected in toenails, manganese was detected in urine and toenails, and barium was detected in urine at comparable levels to the general population. Besides preventable antimony levels in nail polish, individual metals in nail polish did not appear to be from impurities but mainly from colorants (i.e., pigments) and not major contributors to nail technician exposure. It is unclear if low-level chronic metals mixtures in nail salons are of health concern.