《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》

Website：https://doi.org/10.1016/j.scitotenv.2023.161980

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Abstract：

Polybrominated diphenyl ethers (PBDEs) are important pollutants during electronic waste (e-waste) dismantling activities in China due to its large quantities production and usage. Bromophenols (BPs), which are a kind of flame retardants and the diphenyl ether bond cleavage metabolites of PBDE, are often neglected in the human exposure assessment. In this study, 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. PBDE and BP congeners were more frequently detected in hair than serum and urine samples. The medians of ΣPBDEs and ΣBPs were 350 ng/g dw 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 ΣPBDEs and ΣBPs in serum and urine between occupational and non-occupational population. It suggests hair analysis could be easier to differentiate the high from low PBDEs and BPs exposure populations than serum and urine analysis. Moreover, the levels of BPs in hair-In were 1–2 orders of magnitudes higher than those in hair external (hair-Ex), while a non-significant difference was found in the levels of PBDEs. This indicates BPs might be mainly derived from the endogenous 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 those of BDE-209, while the level of 2,4,6-TBP in hair-Ex was 1–3 times lower than those of BDE-209. Further in vivo experiment 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 BDE-209 metabolizing and 2,4,6-TBP exposure. In conclusion, compared to PBDEs, biomonitoring phenolic compound or metabolite with hair could better reflect human endogenous exposure.