Occurrences and Fates of Hydroxylated Polybrominated Diphenyl Ethers in Marine Sediments in Relation to Trophodynamics Kun Zhang, † Yi Wan,* ,† Paul D. Jones, ‡ Steve Wiseman, § John P. Giesy, §,∥,⊥ and Jianying Hu* ,† † Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China ‡ Toxicology Centre and School of Environment and Sustainability, University of Saskatchewan, Saskatoon, Saskatchwan S7N 5B3, Canada § Department of Veterinary Biomedical Sciences and Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan S7J 5B3, Canada ∥ Zoology Department, Center for Integrative Toxicology, Michigan State University, East Lansing, Michigan 48824, United States ⊥ Department of Biology and Chemistry, and State Key Laboratory in Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong SAR, China * S Supporting Information ABSTRACT: While occurrences and origins of hydroxylated (OH-) polybrominated diphenyl ethers (PBDEs) in organisms have been reported, the fates of these compounds in abiotic matrixes and related trophodynamics are unclear. The present study measured concentrations of nine OH-PBDEs, twelve methoxylated (MeO-) PBDEs, and eleven PBDEs in marine sediments and explored the trophodynamics of OH-PBDEs in five invertebrates, eight fish, and two species of birds from Liaodong Bay, north China. While concentrations of PBDEs were less than the limit of quantification in sediments, con- centrations of ΣOH-PBDEs and ΣMeO-PBDEs were 3.2−116 pg/g dry weight (dw) and 3.8−56 pg/g dw, respectively. When the detected compounds were incubated in native marine sediments the interconversion between 6-OH-BDE47 and 6-MeO-BDE47 was observed. This result is consistent with the similar spatial distributions and significant correlation between the concentrations of these naturally occurring compounds. 6-OH-BDE47 and 2′ -OH-BDE68 were detected as the two major congeners in organisms collected from Liaodong Bay, and concentrations were 0.24 ± 0.005 ng/g lw (lipid weight) and 0.088 ± 0.006 ng/g lw, respectively. Biota-sediment accumulation factors (BSAFs) for invertebrates of 6-OH-BDE47 and 2′ -OH-BDE68 were 0.017−0.96 and 0.19−1.5 (except for short-necked clam: 6.3), respectively. Lipid-normalized concentrations of 6-OH-BDE47 and 2′ -OH-BDE68 decreased significantly with trophic level with TMFs of 0.21 and 0.15, respectively. The fates of OH-PBDEs in sediment together with their trophodynamics in marine food webs suggested that OH-PBDEs are partitioned into sediment and undergo biodilution in the marine food web. ■ INTRODUCTION Polybrominated diphenyl ethers (PBDEs), an important group of brominated flame retardants, have emerged as contaminants of concern due to their widespread use, ubiquitous environ- mental occurrences, and bioaccumulation potential. 1−5 Their structural analogues, hydroxylated (OH-) and methoxylated (MeO-) PBDEs, are also detected in biotic media such as sponges and algae, blood/tissues of fish, birds, and marine mammals. 1−5 MeO-PBDEs have been found in animals, such as whales from the Canadian Arctic and North Atlantic, at concentrations sometimes hundreds of times higher than those of PBDEs. 4,6 OH-PBDEs are of particular interest due to their greater potencies for some effects such as disruption of thyroid hormone homeostasis, disruption of sex hormone steroido- genesis, and neurotoxic effects relative to PBDEs and MeO- PBDEs. 7−11 Maternal transfers have also been observed for OH-PBDEs in recent field investigations and laboratory studies and therefore posing a potential risk for offspring of wildlife and humans. 12,13 The origins of the structural analogues of PBDEs were of particular interest due to their worldwide occurrences and potential adverse effects of exposure. With similar structures to PBDEs, OH-PBDEs and MeO-PBDEs were initially thought to be metabolites or byproducts of synthetic PBDEs. 14−16 However, radiocarbon abundance analysis 3,4 and laboratory exposure studies in vitro and in vivo 13,17 have found that the most abundant MeO-/OH-PBDE congeners (6-MeO-BDE47, Received: September 12, 2011 Revised: January 16, 2012 Accepted: January 20, 2012 Published: January 20, 2012 Article pubs.acs.org/est © 2012 American Chemical Society 2148 dx.doi.org/10.1021/es203195s | Environ. Sci. Technol. 2012, 46, 2148−2155