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/m2. BDE-209 and DBDPE accounted for about 37 and 40% of ∑24HFRs, 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 ∑8HFRs and ∑16PCBs (2.9 × 10-4 and 6.7 × 10-6 mg/kg·d) were 1-2 orders of magnitude higher than ingestion doses via hand-to-mouth contact (6.6 × 10-7 and 3.1 × 10-7 mg/kg·d). The total noncarcinogenic health risk resulted from whole-body dermal absorption and oral ingestion to ∑7HFRs and ∑16PCBs were 5.2 and 0.35, respectively.

Contamination characteristics of trace metals in dust from different levels of roads of a heavily air-polluted city in north China.

Concentrations of eight trace metals (TMs) in road dust (RD) (particles < 25 µm) from urban areas of Xinxiang, China, were determined by inductively coupled plasma mass spectrometry. The geometric mean concentrations of Zn, Mn, Pb, As, Cu, Cr, Ni and Cd were 489, 350, 114, 101, 60.0, 39.7, 31.6, and 5.1 mg kg-1, respectively. When compared with TM levels in background soil, the samples generally display elevated TM concentrations, except for Cr and Mn, and for Cd the enrichment value was 69.6. Spatial variations indicated TMs in RD from park path would have similar sources with main roads, collector streets and bypasses. Average daily exposure doses of the studied TMs were about three orders of magnitude higher for hand-to-mouth ingestion than dermal contact, and the exposure doses for children were 9.33 times higher than that for adults. The decreasing trend of calculated hazard indexes (HI) for the eight elements was As > Pb > Cr > Mn > Cd > Zn > Ni > Cu for both children and adults.

Identifying dermal exposure as the dominant pathway of children's exposure to flame retardants in kindergartens.

Exploration of multiple sources of brominated (BFRs) and organophosphate flame retardants (OPFRs) for children promotes the understanding of exposure pathways and health risk. 10 BFRs and 9 OPFRs were measured in skin wipes from hands, forehead, and arms of 30 children, and surface wipe samples from sills, toys, desks and floors, and indoor air samples of kindergartens from Xinxiang, China. Higher ∑9OPFRs concentrations were observed in the forehead (1840 ng/m2), followed by hand (1420 ng/m2) and arm wipes (1130 ng/m2), and the ∑8BFRs concentrations in forehead, hand and arm wipes were 116, 315 and 165 ng/m2, respectively. The total concentration of OPFRs and BFRs in floor wipes (66.1 and 24.5 ng/m2) were lower than those in toy (205 and 535 ng/m2), sill (227 and 30.1 ng/m2) and desk (84.4 and 139 ng/m2) wipes. Concentrations of FRs in forehead wipes were significantly correlated with those in gaseous air (p < 0.05), moderate correlations were found between the hand wipes and surface wipes (p = 0.054). We estimated the daily average dosages (DADs) of children exposure to FRs via multiple pathways. Compared to DADs via inhalation and hand-to-mouth transfer, dermal exposure was determined to be the predominant exposure pathway to ∑9OPFRs and ∑8BFRs.