Hormonal disruption from plastic ingestion in northern fulmars: Activation and inhibition of estrogen receptors

Abstract

Plastic pollution is of global concern, yet documented harmful effects from plastic ingestion in wild species is limited. Procellariiformes, such as northern fulmars (Fulmarus glacialis, fulmar), have high levels of plastic ingestion, and we investigated their potential hormonal disruption. As human estrogen receptors (ERs) are commonly used to assess risk of hormonal disruption for wild species, we first compared human and fulmar ER responses to plastic-associated chemicals using a luciferase-reporter gene assay. ERs from both species were activated by bisphenol-A (BPA), bisphenol-S (BPS), 4-octylphenol (4-OP), and benzyl butyl phthalate (BBP), and inhibited by tetrabromobisphenol-A (TBBPA), 2,5,2',5'tetrachloro-biphenyl (PCB-52), and 2,2',3,4,4',5'-hexachlorobiphenyl (PCB-138), although we observed species-specific differences in sensitivity. To assess if ingested plastic had the potential to alter fulmar hormone function, plastic recovered from fulmar stomachs (n = 27) were leached for 14 days with daily solvent renewal and leachates were exposed to fulmar ERs. Almost 50 % of the birds (13 out of 27) had ingested plastic that leached chemicals which caused ER activation and/or inhibition on day 1, with ∼70 % of these (9 out of 13) also showing a response on day 5 and/or 14. The polymer composition of the recovered plastic pieces (n = 142) was identified with infrared spectroscopy. Polyethylene (PE) (60 %) was the most abundant polymer, followed by polypropylene (PP) (35 %), polyethylene terephthalate (PET) (3 %) and unidentifiable (2 %). Polymer type was not associated with ER response, suggesting that chemical additives, not polymer composition, were responsible for the observed hormonal disruption. To our knowledge, we provide the first data on a seabird's ER response to plastic-associated chemicals. Overall, we highlight the potential for plastic ingestion to disrupt fulmar hormone function, providing important information about the harmful effects of plastic pollution