Microplastics as conduits of flame retardants in birds feeding on landfills

There is increasing evidence of widespread ingestion of plastics by birds, mistaking it for food, during foraging. The demonstrated effects of plastic ingestion by birds include: reduction in body mass; starvation through gut blockage; ulceration/perforation of the digestive tract; and acute or chronic toxicity induced by chemicals contained in the plastic. Flame retardants (FRs) are chemicals widely applied to plastics, fabrics and foams to flame-proof consumer products. There is a vast reservoir of FRs ending up in landfills with e-waste plastics and furniture fabrics. Given the toxic implications of these FRs (e.g. endocrine disruption, developmental and reproductive toxicity) and their ability to bioaccumulate, this project will provide novel insights into the role of ingested plastics as conduits of FRs to birds, for example gulls (Larus spp.), feeding on UK landfill. This will be achieved by investigating the relationship between FRs in the plastics isolated from the gut content of birds and those in the birds’ tissues. Pre-hatch exposure to hazardous FRs will be assessed via analysis of the birds’ eggs and potential correlation of FRs in the eggs with the parent birds will be explored. We will also analyse gut contents, tissues and eggs of birds feeding in rural locations (i.e. ‘control’ sites away from landfills) for comparative purposes. This will allow elucidating the role of ingested plastics in determining birds’ body burdens of FRs. Moreover, we will work closely with our partners at Environment & Climate Change Canada who have extensive experience of studying FRs in birds including the European Starling (Sturnus vulgaris) living on landfills in the Great Lakes Basin. This parallel approach adds an international dimension to the project as it allows comparison of FRs in birds across two different continents (e.g. we hypothesize higher concentrations of Penta-BDE in Canadian Starlings due to extensive use of this FR in North America).

The project’s multidisciplinary approach provides an excellent opportunity for training in various aspects of fieldwork, avian ecology and advanced environmental analysis. Moreover, it provides an exceptional opportunity for research training in Canada, whereby the successful candidate will work collaboratively in a truly international context.

We will test the hypothesis that plastic debris in landfills represents a major exposure pathway of feeding birds to FRs. To achieve this we will obtain ingesta from the gut contents of birds by either collection of regurgitants or lavage and then isolate plastic particles using a standard chemical digestion and filtration procedure. The isolated plastics will be weighed and characterised by electron microscopy. A broad suite of FRs will be determined in the isolated plastics, birds’ tissues (e.g. blood and body feathers) and eggs using our validated mass spectrometric methods. We will also apply a qualitative untargeted approach to identify potential metabolites of FRs in the samples. Statistical models will be constructed to study the relationships between the extent of ingested plastics and the burdens of FRs in different avian body and egg compartments, including their transfer from the former to the latter.