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.

Brominated and phosphate flame retardants from interior and surface dust of personal computers: insights into sources for human dermal exposure.

It remains unclear whether internal or external sources play the more significant role in flame retardant (FR) contamination of surface dust from personal computers (PCs), which may lead to bias on dermal exposure assessment of FRs. In the present study, the occurrence and profiles of several brominated and phosphate FRs were measured in the interior dust, and the upper surface (keyboard) and bottom surface (bottom cover) wipes of PCs. BDE 209 (639 ng/g), decabromodiphenyl ethane (DBDPE, 885 ng/g), and triphenyl phosphate (TPHP, 1880 ng/g) were the most abundant chemicals in interior PC dust, while tris(2-chloroisopropyl) phosphate (TCIPP), TPHP, and DBDPE were dominant on both surfaces of PCs. No significant correlation between interior dust and both PC surfaces was observed for concentrations of most FRs except BDE 183. Different sources of FRs for interior and surface dust of PCs were further revealed by principal component analysis (PCA). FRs from external sources, rather than emission from inner PC components, are likely the main contributor for FR profiles on PC surfaces. Exposure assessment results demonstrated a minor contribution from PC dermal contact, compared with hand-to-mouth uptake, to total exposure. The applicability of surface wipes to assess dermal exposure to FR-treated products needs to be further investigated.

The leaching of additive-derived flame retardants (FRs) from plastics in avian digestive fluids: The significant risk of highly lipophilic FRs.

The exposure to plastic debris and associated pollutants for wildlife is of urgent concern, but little attention has been paid on the transfer of plastic additives from plastic debris to organisms. In the present study, the leaching of incorporated flame retardants (FRs), including polybrominated diphenyl ethers (PBDEs), alternative brominated FRs (AFRs), and phosphate flame retardants (PFRs), from different sizes of recycled acrylonitrile-butadiene-styrene (ABS) polymer were investigated in avian digestive fluids. The impact of co-ingested sediment on the leaching of additive-derived FRs in digestive fluids was also explored. In the recycled ABS, BDE 209 (715 µg/g) and 1, 2-bis(2,4,6-tribromophenoxy) ethane (BTBPE, 1766 µg/g) had the highest concentrations among all target FRs. The leaching proportions of FRs were higher in finer sizes of ABS. The leaching proportions of FRs from recycled ABS increased with elevated logKOW of FRs. In the tests with coexisted ABS and sediment, hexa- to deca-BDEs, BTBPE, and decabromodiphenyl ethane (DBDPE) migrated from ABS to sediment, which resulted in the less bioaccessible fractions of these FRs in gut fluids. More lipophilic chemicals tended to be adsorbed by sediment from ABS. The results suggest the migration of additive-derived FRs from plastics to other indigestible materials in digestive fluids. The findings in this study provide insights into the transfer of additive-derived FRs from plastics to birds, and indicate the significant contribution of FR-incorporated plastics to bioaccumulation of highly lipophilic FRs.

Size-dependent concentrations and bioaccessibility of organophosphate esters (OPEs) in indoor dust: A comparative study from a megacity and an e-waste recycling site.

Indoor dust ingestion is an important pathway in human exposure to environmental pollutants, and the bioaccessibility of pollutants can largely influence human exposure risk assessment. In the present study, the concentrations and compositions of organophosphate esters (OPEs) were investigated for different sizes (50 µm to 2 mm) of indoor dust collected from a megacity, Guangzhou, and an e-waste recycling site. The concentrations of total OPEs were 5360 to 6830 ng/g and 560 to 20,500 ng/g across all sizes of dust from Guangzhou and the e-waste site, respectively. The levels and compositions of OPEs were consistent in different fractions of dust from Guangzhou. The highest concentrations of OPEs were found in the finest fraction of dust from the e-waste site. OPEs in Guangzhou dust showed decreasing bioaccessibility when the log KOW of FRs increased from 4 to 11. The bioaccessibility of most OPEs in dust from the e-waste site was much lower than those in Guangzhou dust, indicating low bioaccessibility in the components of dust, such as e-waste debris, from the e-waste site. The human exposure risks of OPEs in dust from Guangzhou were generally higher than those in dust from the e-waste site. Chitosan and montmorillonite could significantly decrease the bioaccessibility of all OPEs, except for tri-ethyl phosphate (TEP) and tris­(2­butoxyethyl) phosphate (TBOEP) in dust (p < 0.05), indicating chitosan and montmorillonite as promising food additives to enhance the elimination of OPEs.