| Summary: | 博士 === 國立屏東科技大學 === 環境工程與科學系所 === 104 === Indoor dust is an important source of exposure to polybrominated dibenzo-p-dioxins/furans and diphenyl ethers (PBDD/Fs/DEs) for school-age children. Our goal is to investigate concentrations of PBDD/Fs/DEs in elementary school, kindergarten and vehicle dust, and then to use a reporter gene assay (Ad-DR bioassay) to determine concentrations of polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) in elementary and kindergarten schools and to further assess the impact on school-age children via ingestion. Seventy-eight dusts including 24 normal (NR) and 24 computer classrooms (CR) in elementary school, 10 kindergarten classroom (KR) and 20 vehicle (V) were collected from Southern and Center Taiwan. Fourteen PBDEs and twelve PBDD/Fs were measured using high resolution gas chromatography/high resolution mass spectrometry, whereas total bio-analytical equivalent (BEQ) of PCDD/Fs was measured using Ad-DR bioassay. The mean levels of Σ14PBDEs in NR, CR, KR and V dust were 440, 2331, 453 and 1984 ng/g. The means of ΣPBDD/Fs and ΣPCDD/Fs were 0.0275 ng-WHO2005-TEQ/g (concentration: 4.09 ng/g) and 0.0131 ng-BEQ/g in NR dust, 0.0588 ng-WHO2005-TEQ/g (10.4 ng/g) and 0.0138 ng-BEQ/g in CR dust, 0.0161 ng-WHO2005TEQ/g (2.51 ng/g) and 0.00337 ng-BEQ/g in KR dust, and 0.0790 ng-WHO2005TEQ/g (22.8 ng/g) in V dust. The PBDEs pattern in V dust was quite different from that in other dust samples, but the PBDD/Fs patterns in four types of dust were similar. A linearly significant correlation coefficient (n=78, adjust R2=0.256, p<0.001) was found between ΣPBDEs and ΣPBDD/Fs in whole dust, indicating that the PBDEs and PBDD/Fs in the dust may be from the same sources in the indoor environment. This study assessed the risks (daily intake and cancer and non-cancer risks) of PBDEs and PBDD/Fs of the children from the classroom and vehicle 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/Fs/DEs in their homes than in the schools. In conclusion, the exposure of Taiwanese school-age children to PBDD/Fs/DEs and PCDD/Fs via indoor dust was within a safe range based on our findings.
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