Historical record of legacy and alternative halogenated flame retardants in dated sediment from a highly industrialized saltwater lake in Korea

Legacy and alternative halogenated flame retardants (HFRs), such as polybrominated diphenyl ethers (PBDEs), novel brominated flame retardants (NBFRs), and dechlorane plus (DP), were measured in dated sediments from a highly industrialized lake in Korea. All HFRs were detected in almost all of the sediment depth layers for more than 70 years, indicating a history of long-term contamination. Similar historical trends in PBDEs, 1,2-bis(2,4,6tribromophenoxy)ethane (BTBPE), and DP were observed in dated sediments, whereas decabromodiphenylethane (DBDPE), and 2-ethylhexyl-2,3,4,5-octabromo-1,3,3-trimethyl-1-phenylindane (OBIND) concentrations sharply increased since the 1990s. Moreover, the concentration ratios of DBDPE/BDE 209 increased from the early 1990s to the present. Our findings suggest that DBDPE and OBIND have been used as HFR alternatives. The historical record of the concentrations and profiles of legacy and alternative HFRs corresponded with industrial activities, consumption of FRs, and coastal development activities. Inventories of legacy and alternative HFRs were similar to those reported for highly industrialized regions around the globe.