Indoor Dust Levels of Polybrominated Diphenyl Ethers (PBDEs) and Polybrominated Dibenzo-p-Dioxins/Furans (PBDD/Fs) in Various Taiwanese Microenvironments

Several studies have reported contamination of polybrominated dioxins/furans (PBDD/Fs) and diphenyl ethers (PBDEs) in diverse microenvironments. However, information on their levels in nursing homes (NH) and Chinese medical clinics (CMC) remains limited. This study investigated the levels, congener patterns, and potential health risks of indoor dust PBDD/Fs and PBDEs in 17 NH, 18 CMC, normal (NR) and computer (CR) classrooms of 24 elementary schools, 10 kindergartens (K), and 20 automobiles (A) in southern Taiwan. Σ 14 PBDEs varied substantially among environments, with the highest levels observed in CMC (4,790 ± 16,500 ng g −1 ), followed by NH, CR, and A, while significantly lower levels were found in NR and K. Principal component analysis indicated that PBDE profiles were mainly associated with commercial Deca-BDE formulations, with occasional influence from historical Penta- and Octa-BDE mixtures. Indoor dust Σ 12 PBDD/Fs ranged from 2.51 ng g −1 (K) to 22.8 ng g −1 (A), with the highest WHO 2005 -TEQ values in A (79.0 pg WHO 2005 -TEQ g −1 ). PBDFs contributed more substantially to total PBDD/F toxicity than PBDDs. Correlation analysis revealed significant associations between PBDEs and several PBDF congeners, particularly HpBDF and OctBDF, suggesting in situ debromination of PBDEs under sunlight and thermal conditions, such as those present inside automobiles. For human health risk assessment, the estimated daily intakes and both the estimated risk of cancer and non-cancer from indoor dust PBDEs and PBDD/Fs for all assessed populations, including patients and staff in NH and CMC, as well as schoolchildren and preschool children, remained within acceptable safety thresholds. Overall, these findings demonstrate that although PBDEs and PBDD/Fs persist in indoor environments, especially in CMC and A, their current levels do not pose significant health risks. The present study reveals the first comprehensive assessment of PBDEs and PBDD/Fs in CMC and NHs, offering valuable insights for exposure management and indoor environmental health in Taiwan.