Occurrence and accumulation features of PBDEs and their alternatives in Korean birds

Abstract

Polybrominated diphenyl ethers (PBDEs) have been phased out or voluntarily reduced in many countries because of their persistence, bioaccumulation potentials, long-range transport, and toxicological effects. Replacement of these chemicals led to the introduction of novel brominated flame retardants (NBFRs), which also showed bioaccumulation potentials and long-range transport in some studies. The present study investigated the contamination levels, composition profiles of PBDEs and NBFRs, and exposure assessment of PBDEs for ten Korean bird species, which collected from Korea during 2010–2011. PBDEs were detected in most samples, except for oriental turtle dove, suggesting widespread contamination of PBDEs in Korean environment. NBFRs were also showed high detection frequency with 72% in all samples, indicated wide presence of these compounds in Korean environment and wild birds. Among NBFRs, BEHTBP showed highest detection frequency may be due to the usage pattern of BEHTBP in Korea and/or specific bioaccumulation potentials of this compound in birds. Depending on diet, habitat, and migratory behavior of bird species, considerable variations were found among species and within individuals, indicating inter- and intra-species difference in the accumulation of PBDEs and NBFRs in birds. For PBDEs, the total concentrations (ΣPBDE) ranged from 0.01 ± 0.23 to 1769 ± 3777 ng/g lipid weight (lw) in each species. The highest concentrations of ΣPBDE were found in Eurasian eagle owl (EEO), followed by brown hawk owl (BHO), common kestrel (CK), Northern goshawk (NG), cinereous vulture (CV), common buzzard (CB), collared scops owl (CSO), spot-billed duck (SBD), black-tailed gull (BTG), and oriental turtle dove (OTD). Predatory bird showed higher concentrations of PBDEs and NBFRs than others. The major congeners in avian liver samples were varied in species. In marine food source species such as BTG, NG, CV, and BHO, the major congener of PBDEs were BDEs 47 and 99. However, in terrestrial species, BDE 153 was the dominant PBDE congener in SEB, EEO, CSO, and CB. Among species, CK showed highest contribution of BDE 209, which accounted for 53 ± 30% to the total PBDE concentrations. These differences may due to the differences in the habitats, diet, behavior, or biotransformation capacities among bird species. To evaluate exposure assessment of PBDEs in Korean birds, lowest observed effect level (LOEL) value for osprey reproductive performance were used in this study. There was one bird specimen presented exceeding LOEL value of PBDEs, implying toxicological potential risks of Korean birds especially for endangered species.