Percutaneous Penetration and Metabolism of Plasticizers by Skin Cells and Its Implication in Dermal Exposure to Plasticizers by Skin Wipes

Abstract

Numerous studies focused on the human exposure to plasticizers via dermal contact, however, the percutaneous penetration of plasticizers was seldom considered in exposure assessment. In the present study, skin wipes of palms, back-of-hands, and forehead were collected from 114 participants (ages: 18-27). There was no significant difference between the levels of phthalates from palms and back-of-hand, while all phthalates collected from forehead were significantly higher than that from palms and back-of-hand (p<0.001); di(2-ethylhexyl) phthalate (DEHP) levels were substantially higher than other detected phthalates follow by di(n-butyl) phthalate (DnBP) and di(isobutyl) phthalate (DiBP), and for alternative plasticizers, bis-2-ethylhexyl terephthalate (DEHT) levels were substantially higher than acetyltributyl citrate (ATBC) and bis-2-ethylhexyladipate (DEHA). Skin permeation and metabolism of phthalates was assessed using human skin equivalent models (HSE). The permeability coefficient (kp) values of phthalates were significantly negative correlated with its log octanol-water partition coefficient (logKow), while a significantly positive correlation was found between the logKow and the cumulative amounts of phthalates in the cells. The proportion of phthalates intake via dermal exposure to skin wipes range from 1.3 % (for DMP) to 8.6 % (for DiBP) and suggest that dermal absorption is a significant route for adult phthalates exposure.