Temporal trends of novel brominated flame retardants in mollusks from the Chinese Bohai Sea (2011-2018)

摘要

Novel brominated flame retardants (NBFRs) have emerged as an alternative to traditional brominated flame retardants (BFRs); however, they may pose risks to the environment and human health. To investigate the occurrence, temporal trends, and human exposure of seven typical NBFRs (∑_7 NBFRs), seven species of mollusks (n = 329) were collected from coastal cities in the Chinese Bohai Sea area from 2011 to 2018. The ∑_7 NBFRs ranged from 1.52 to 154 ng/g dry weight (dw) (mean: 14.9 ± 21.21 ng/g dw), higher than in other areas worldwide. Decabromodiphenylethane (DBDPE) was the main contaminant, contributing to 33% of the NBFRs. Temporal trends indicate that the DBDPE and 2,3-dibromopropyl-2,4,6-tribromophenyl ether (DPTE) concentrations in mollusks increased significantly (P ＜ 0.05) at rates of about 26% and 5.4%, respectively. This suggests that these NBFRs are continuously released into the environment of the Bohai Sea area. The higher NBFR concentrations in the southern sampling sites relative to the northern sampling sites were consistent with the spatial distribution of the NBFR industry in the Bohai Rim Economic Circle. Chlamysfarreri possessed the highest ∑_7 NBFR concentrations compared with the other species, while the lowest concentrations were found in Neverita didyma and Rapana venosa, suggesting interspecific differences in bioaccumulation. The estimated daily intake of NBFRs was low, and as the main contaminant, DBDPE was unlikely to pose significant human health risks. Overall, this is the first study to comprehensively assess the occurrence, spatial distribution, and temporal trends of NBFRs in mollusks.