Concentrations and isomer profiles of hexabromocyclododecanes (HBCDDs) in floor, elevated surface, and outdoor dust samples from Basrah, Iraq

Aromatic amine antioxidants (AAs) and p-phenylenediamines-quinones (PPD-Qs) in e-waste recycling industry park: Occupational exposure and liver X receptors (LXRs) disruption potential

Recently, evidence of aromatic amine antioxidants (AAs) existence in the dust of the electronic waste (e-waste) dismantling area has been exposed. However, there are limited studies investigating occupational exposure and toxicity associated with AAs and their transformation products (p-phenylenediamines-quinones, i.e., PPD-Qs). In this study, 115 dust and 42 hand wipe samples collected from an e-waste recycling industrial park in central China were analyzed for 19 AAs and 6 PPD-Qs. Notably, the median concentration of ∑6PPD-Qs (1,110 ng/g and 1,970 ng/m2) was significantly higher (p < 0.05, Mann-Whitney U test) than that of ∑6PPDs (147 ng/g and 34.0 ng/m2) in dust and hand wipes. Among the detected analytes, 4-phenylaminodiphenylamine quinone (DPPD-Q) (median: 781 ng/g) and 1,4-Bis(2-naphthylamino) benzene quinone (DNPD-Q) (median: 156 ng/g), were particularly prominent, which were first detected in the e-waste dismantling area. Occupational exposure assessments and nuclear receptor interference ability, conducted through estimated daily intake (EDI) and molecular docking analysis, respectively, indicated significant occupational exposure to PPD-Qs and suggested prioritized Liver X receptors (LXRs) disruption potential of PPDs and PPD-Qs. The study provides the first evidence of considerable levels of AAs and PPD-Qs in the e-waste-related hand wipe samples and underscores the importance of assessing occupational exposure and associated toxicity effects.

Electronic-waste-associated pollution of per- and polyfluoroalkyl substances: Environmental occurrence and human exposure

Occupational exposure to per- and polyfluoroalkyl substances (PFASs) is of serious concern because their adverse health effects. Nevertheless, knowledge regarding contamination in e-waste dismantling regions is rather scarce. We therefore analysed seven neutral PFASs (n-PFASs) and forty ionized PFASs (i-PFASs) in dust and hand wipes collected from an e-waste dismantling plant and homes. Both dust (1370 ng/g) and workers' hand wipe (1100 ng/m²) in e-waste dismantling workshops contained significantly higher median levels of ∑PFASs than those from homes (684 ng/g and 444 ng/m²) (p < 0.01). ∑PFAS concentrations in dust and on workers' hand wipes from workshops were significantly higher than those from storage area. 8:2 fluorotelomer alcohol was the dominant n-PFAS in workshop dust (70.7%) and on worker's hand wipes (46.6%). Perfluoroalkyl carboxylic acids (C2 -C3) were the significant components (based on concentration) of i-PFASs in dust (57.9%) and on hand wipes (89.6%). A significant positive correlation (p < 0.001) of ∑PFAS concentrations between workshop dust and workers' hand wipes was observed, indicating that they come from common sources. Compared to dust ingestion, hand-to-mouth contact was highlighted as a vital exposure route, accounting for 68.8% for workers and 72.2% for residential population, respectively, of the sum of two exposure doses.

Tetrabromobisphenol A and hexabromocyclododecanes from interior and surface dust of personal computers: implications for sources and human exposure

Tetrabromobisphenol A (TBBPA) and hexabromocyclododecane isomers (HBCDs) are widely detected in indoor environments, but the research on the accumulation, contamination, and human exposure of TBBPA and HBCDs in electronic products dust is still limited. It is unclear whether electronic products might pose human health risk via dust ingestion and dermal absorption. In this study, the levels and distributions of TBBPA and HBCDs were investigated in the personal computer (PC) interior dust and PC surface (upper and bottom) wipes. The median concentrations of TBBPA in PC interior dust, upper, and bottom surface wipes were 168.1 ng/g, 13.2 ng/m², and 15.2 ng/m², respectively. These levels were generally higher than those of HBCDs, which were 95.2 ng/g, 11.7 ng/m², and 12.3 ng/m², respectively. No significant correlations were found among the PC upper and bottom surface wipes, and interior dust, indicating different sources of TBBPA and HBCDs in PC interior and surface dust. The TBBPA and HBCDs in the PC interior dust were mainly released from inner PC materials, while the sources of target compounds on the surface wipes were likely from external environments. The exposure values of two occupational populations (including PC owners and PC repair workers) to TBBPA and HBCDs were measured by PC interior dust and upper surface wipes. The results imply dust ingestion (including hand-to-mouth uptake) is the main contributor of the exposure route to TBBPA and HBCDs for both PC owners and repair workers. Compared to PC owners, PC repair workers showed the greater risk in exposure assessment, which should be paid more attention.