Inhalation exposure to toxic heavy metals in nail salon technicians and health risk assessment using Monte Carlo simulation

Objective Nail salons offer a developing and diverse occupation for many women, especially the new generation. Due to the increasing apprehension surrounding heavy metals in dust caused by filing nails containing dried nail polish, the present study was designed aimed to health risk assessment of heavy metals in breathing zone of nail salon technicians (NSTs). Methods This is a cross-sectional study that was conducted in NSTs. The concentration of Cadmium (Cd), Lead (Pb), Nickel (Ni), Chromium (Cr) and Manganese (Mn)in breathing zone of 20 NSTs was determined using ICP-OES. Results The metal concentrations were in the following order: Mn > Pb > Ni > Cr > Cd with corresponding arithmetic mean values of0.008, 0.0023, 0.0021, 0.001 and 0.0006 mg m(-3), respectively, which are exceeded the recommended levels stated in the indoor air guidelines. The average lifetime carcinogenic risk (LCR) for Cr, Cd, Ni and Pb was calculated 0.0084, 0.00054, 0.00026 and 1.44 E - 05, respectively. The LCR values of all metals (except Pb) exceeded the acceptable level set by the USEPA. The mean of Hazard quotients (HQ) for Mn, Cd, Cr, Ni and Pb were calculated to be23.7, 4.74, 2.19, 0.51 and 0.0.24, respectively. The sensitivity analysis showed that, the exposure frequency (EF) for Cr and Ni had the strong effects on generation of both LCR and HQ. Furthermore, the concentrations of Mn, Cd and Pb had strong impacts on the HQ generation and the concentration of Cd and Pb had main effects on LCR generation. Conclusion To effectively reduce pollutant concentration, it is recommended to install a ventilation system near nail salon work tables and conduct continuous monitoring and quality control of nail products.