Interspecies comparisons of brominated flame retardants in relation to foraging ecology and behaviour of gulls frequenting a UK landfill

This study quantifies and compares concentrations and profiles of legacy and alternative (alt-) brominated flame retardants (BFRs) in the eggs of three gull (Laridae) species of international/UK conservation concern - great black-backed gulls (Carus marinus; n = 7), European herring gulls (L argentatus; n = 16) and lesser black-backed gulls (L. fuscus; n = 11) in relation to their foraging ecology and behaviour in order to investigate potential exposure pathways at a remote landfill in western Scotland, UK. Egg concentrations of sum (Sigma) polybrominated diphenyl ethers (Sigma 8PBDEs) in all three species exceeded those for most reported avian species using landfill, except for those in North America. Despite relatively high detection frequencies of hexabromocyclododecanes (Sigma(3)HBCDDs) (94-100%), concentrations of Sigma 8PBDEs exceeded Sigma(3)HBCDDs and Sigma(5)alt-BFRs, with Sigma 8PBDE levels similar in all three species. Egg carbon isotopic (delta C-13) values highlighted a greater marine dietary input in great black-backed gulls that was consistent with their higher BDE-47 levels; otherwise, dietary tracers were minimally correlated with measured BFRs. Sigma 3HBCDD egg concentrations of herring gulls markedly exceeded those reported elsewhere in Europe. Decabromodiphenylethane (DBDPE) was the only alt-BFR detected (6-14% detection rate), in a single egg of each species. The great black-backed gull egg contained the highest concentration of DBDPE measured in biota to date globally and provides strong evidence for its emerging environmental presence as a BDE-209 replacement in UK wildlife. Correlations between delta C-13 (dietary source) and some measured BFRs in eggs suggest multiple routes of BFR exposure for gulls frequenting landfill through their diet, behaviour, preening, dermal exposure and likely inhalation.The frequent use of landfill by herring gulls and their increased egg BFR burdens suggest that this species may be an important bioindicator of BM emissions from such sites. Crown Copyright (C) 2020 Published by Elsevier B.V. All rights reserved.

Automated summary

This study quantified and compared legacy and alternative brominated flame retardants (BFRs) in the eggs of three gull species in a remote landfill in western Scotland. Despite high detection frequencies, the concentrations of hexabromocyclododecanes did not exceed those of polybrominated diphenyl ethers, indicating multiple exposure routes for gulls frequenting landfills through their diet, behavior, preening, dermal exposure, and likely inhalation.