A Pilot Study: Nails as a Non-invasive Biospecimen of Human Exposure to Phthalate Esters

Human biomonitoring provides a scientific approach that systematically reveals exposure to phthalates through all possible routes. In this pilot study, fingernail was chosen as a non-destructive biospecimen to assess human exposure to nine phthalates. Concentrations of total phthalates ranged from 17.8 to 176 µg/g (median: 65.4 µg/g). Di(2-ethylhexyl) phthalate, dibutyl phthalate (DBP), and di-isobutyl phthalate were the major compounds found in fingernails, accounting for 64.3%, 19.4%, and 12.9% of the total phthalates, respectively. No significant difference in phthalates concentrations was found among genders and age-related distribution (p > 0.05). The concentration of DBP was positively correlated with participant's body mass index (r = 0.83). Our results suggested that fingernail can be used as a non-invasive biospecimen for the biomonitoring of human exposure to phthalates. Further studies are needed to investigate the relationship between phthalates or their metabolites in fingernail and other biological samples, such as urine and blood.