Abstract
Elementary school classroom dust is an important source of exposure to polybrominated dibenzo-p-dioxins/furans and diphenyl ethers (PBDD/DF/DEs) for school-age children. Our goal is thus to investigate concentrations of PBDD/DF/DEs in elementary school classroom dust to further assess the impact on school-age children via ingestion. The dust from classrooms, including both normal (NR) and computer classrooms (CR), was collected from six urban and four rural schools. Fourteen PBDEs and twelve PBDD/Fs were measured using high-resolution gas-chromatography/high-resolution mass-spectrometry. The mean levels of Σ <sub>14</sub> PBDEs in NR and CR dust from the urban classrooms were 370 and 2510 ng/g and those whose dust from the rural classrooms were 464 and 1780 ng/g. The means of ΣPBDD/Fs were 0.0401 ng-WHO <sub>2005</sub> -TEQ/g (concentration: 4.72 ng/g) in urban NR dust, 0.0636 ng-WHO <sub>2005</sub> -TEQ/g (7.51 ng/g) in urban CR dust, 0.0281 ng-WHO <sub>2005</sub> TEQ/g (3.60 ng/g) in rural NR dust, and 0.0474 ng-WHO <sub>2005</sub> TEQ/g (6.28 ng/g) in rural CR dust. The PBDEs pattern in NR dust was quite different from that in CR dust, but the PBDD/Fs patterns in NR and CR dust were similar. A linearly significant correlation coefficient (n = 20, r = 0.862, p < 0.001) was found between ΣPBDEs and ΣPBDD/Fs in NR and CR dust, indicating that the PBDEs and PBDD/Fs in the dust may be from the same sources in the elementary school classrooms. This study assessed the risks (daily intake and cancer and non-cancer risks) of PBDEs and PBDD/Fs for the children from the classroom dust, and the calculated risk values did not exceed the related thresholds. With regard to the exposure scenarios for school-age children in an indoor environment, the results suggest that they might ingest more dust PBDD/DF/DEs in their homes than in the schools. In conclusion, the exposure of Taiwanese elementary school children to PBDD/DF/DEs via indoor dust was with a safe range based on our findings.