Polybrominated diphenyl ethers and bromophenols in paired serum, hair, and urine samples of e-waste dismantlers: Insights into hair as an indicator of endogenous exposure

摘要

Polybrominated diphenyl ethers (PBDEs) are important pollutants during dismantling activities of electronic waste (e -waste) in China due to its large production and usage. Bromophenols (BPs), which are a kind of flame retardants and diphenyl ether bond cleavage metabolites of PBDEs, are often neglected in the assessment of human exposure to e -waste. Herein, 22 PBDEs and 19 BPs were determined in paired serum, hair, and urine samples collected from workers and residents of a typical e-waste dismantling site in southern China. Both PBDE and BP congeners were more fre-quently detected in hair than serum and urine samples. The medians of EPBDEs and EBPs were 350 and 547 ng/g dw in hair internal (hair-In) of occupational population, respectively, which were significantly higher than non -occupational population. However, a non-significant difference was found in levels of EPBDEs and EBPs in serum and urine between occupational and non-occupational populations, suggesting that hair analysis could easily differen-tiate between the exposure intensities of PBDEs and BPs to populations than serum and urine analyses. Moreover, levels of BPs in hair-In were 1-2 orders of magnitude higher than those in hair external (hair-Ex), while a non- significant difference was found in the levels of PBDEs. This result indicated that BPs might have originated from en-dogenous contribution. Notably, as the predominant congeners, the level of 2,4,6-tribromophenol (2,4,6-TBP) in hair -In was 3-8 times higher than that of BDE-209, while level of 2,4,6-TBP in hair-Ex was 1-3 times lower than that of BDE-209. Furthermore, in vivo experiments performed on Sprague-Dawley rats following a 28-day oral treatment with BDE-209 and 2,4,6-TBP verified that endogenous accumulation of 2,4,6-TBP in hair could be attributed to the me-tabolism of BDE-209 and exposure to 2,4,6-TBP. In conclusion, compared with PBDEs, biomonitoring phenolic com-pounds or metabolites with hair could better reflect human endogenous exposure.

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