Halogenated Organic Pollutant Residuals in Human Bared and Clothing-Covered Skin Areas: Source Differentiation and Comprehensive Health Risk Assessment

To comprehensively clarify human exposure to halogenated flame retardants (HFRs) and polychlorinated biphenyls (PCBs) through dermal uptake and hand-to-mouth intake, skin wipe samples from four typical skin locations from 30 volunteers were collected. The total concentration of the target chemicals (24 HFRs and 16 PCBs) ranged from 203 to 4470 ng/m(2). BDE-209 and DBDPE accounted for about 37 and 40% of Sigma(24)HFRs, respectively, and PCB-41 and PCB-110 were the dominant PCB congeners, with proportion of 24 and 10%, respectively. Although exhibiting relatively lower concentrations of contaminants than bared skin locations, clothing-covered skin areas were also detected with considerable levels of HFRs and PCBs, indicating clothing to be a potentially significant exposure source. Significant differences in HFR and PCB levels and profiles were also observed between males and females, with more lower-volatility chemicals in male-bared skin locations and more higher-volatility compounds in clothing-covered skin locations of female participants. The mean estimated whole-body dermal absorption doses of Sigma(8)HFRs and Sigma(16)PCBs (2.9 x 10(-4) and 6.7 x 10(-6) mg/kg.d) were 12 orders of magnitude higher than ingestion doses via hand-to-mouth contact (6.6 x 10(-7) and 3.1 x 10(-7) mg/kg.d). The total noncarcinogenic health risk resulted from whole-body dermal absorption and oral ingestion to Sigma(7)HFRs and Sigma(16)PCBs were 5.2 and 0.35, respectively.