Environment Canada scientists studied gulls from across Canada to investigate how diet affects flame retardant contamination in eggs. Eggs were collected from four gull species in 26 colonies spanning Pacific to Atlantic Canada, including in the Great Lakes basin. Fourteen polybrominated diphenyl ether (PBDE) congeners and 20 non-PBDE flame retardants were analyzed. Dietary tracers (stable nitrogen and carbon isotopes) provided insight into how differing diet choices made by gulls in the same colony result in varying flame retardant exposure sources and contamination patterns.

Eggs from gulls breeding near metropolitan regions showed greater PBDE burdens than from other ecosystems. In general, data from this Canadian study revealed greater PBDE concentrations than those reported in various gull species from most of the world, likely reflecting historically greater use of PBDEs in North America.

In response to the cessation of PBDE manufacturing in most parts of the world and increased scrutiny on hexabromocyclododecane use, flame retardant manufacturers may rely more on current non-PBDE flame retardants or engineer novel flame retardant products, which raises new challenges and concerns regarding their sources, bioavailability and ecosystem behaviour. Therefore, flame retardant contamination will remain as a growing environmental concern in a post-PBDE world.

Source: Chen, D., R.J. Letcher, N. Burgess, L. Champoux, J.E. Elliott, C.E. Hebert, P. Martin, M. Wayland, D.V.C. Weseloh and L. Wilson. 2012. Flame retardants in the eggs of four species of gulls (Larids) from breeding sites spanning Atlantic to Pacific Canada. Environ. Pollut. 168: 1-9.

Contact: Dr. Robert Letcher, 613-998-6696, Ecotoxicology and Wildlife Health Division