Brominated and phosphorus flame retardants in White-tailed Eagle Haliaeetus albicilla nestlings: Bioaccumulation and associations with dietary proxies (δ13C, δ15N and δ34S)

• Non-PBDE BFRs and PFRs were highly detected in feathers, but poorly in plasma.
• PFR levels in feathers were up to 100-fold those of BFRs and selected OCs.
• δ15N and δ13C explained intra-specific variation in OC, PBDE and PFR exposure.
• δ15N and δ34S were respectively enriched and depleted close to an urbanised centre.

Very little is known on the exposure of high trophic level species to current-use brominated (BFRs) and phosphorus flame retardants (PFRs), although observations on their persistence, bioaccumulation potential, and toxicity have been made. We investigated the accumulation of BFRs and PFRs, and their associations with dietary proxies (δ13C, δ15N and δ34S), in plasma and feathers of White-tailed Eagle Haliaeetus albicilla nestlings from Trøndelag, Norway. In addition to accumulation of a wide range of polybrominated diphenyl ether (PBDE) congeners in both plasma and feathers, all non-PBDE BFRs and PFRs could be measured in feathers, while in plasma only two of six PFRs, i.e. tris-(2-chloroisopropyl) phosphate (TCIPP) and tris-(2,3-dichloropropyl) phosphate (TDCPP) were detected. PFR concentrations in feathers (0.95–3000 ng g− 1) were much higher than selected organochlorines (OCs), such as polychlorinated biphenyl 153 (CB 153; 2.3–15 ng g− 1) and dichlorodiphenyldichloroethylene (p,p′-DDE; 2.3–21 ng g− 1), PBDEs (0.03–2.3 ng g− 1) and non-PBDE BFRs (0.03–1.5 ng g− 1). Non-significant associations of PFR concentrations in feathers with those in plasma (P ≥ 0.74), and their similarity to reported atmospheric PFR concentrations, may suggest atmospheric PFR deposition on feathers. Most OCs and PBDEs, as well as tris(chloroethyl) phosphate (TCEP), tris(phenyl) phosphate (TPHP) and tri-(2-butoxyethyl) phosphate (TBOEP) were associated to δ15N and/or δ13C (all P ≤ 0.02). Besides δ15N enrichment, δ34S was depleted in nestlings from fjords, inherently close to an urbanised centre. As such, both may have been a spatial proxy for anthropogenic disturbance, possible confounding their use as dietary proxy.