Ultraviolet absorbents and industrial antioxidants in seabirds, mammals, and fish from the Canadian Arctic

Ultraviolet (UV) absorbents and industrial antioxidants are two groups of plastic-derived contaminants of emerging environmental concern. However, their distribution and fate are poorly understood in Arctic wildlife. In the present study, 16 UV absorbents (10 benzotriazole UV stabilizers (BZT-UVs) and 6 organic UV filters (UVFs)) and 7 industrial antioxidants (6 aromatic secondary amines (Ar-SAs) and 2,6-di-tert-butylphenol (26DTBP)) were analyzed in the livers of thick-billed murre (Uria lomvia; n = 28), northern fulmar (Fulmarus glacialis; n = 4), black guillemot (Cepphus grylle; n = 11), polar bear (Ursus maritimus; n = 18), beluga whale (Delphinapterus leucas; n = 10), landlocked (n = 25) and sea-run (n = 10) Arctic char (Salvelinus alpinus) from the Canadian Arctic collected between 2017 and 2021. Compared to industrial antioxidants (median range: ΣAr-SAs: not calculated due to detection frequency < 30 % (NA)-4.06 ng/g, wet weight (ww); 26DTBP: NA-1.91 ng/g ww), UV absorbents (median range: ΣBZT-UVs: NA-8.71 ng/g ww; ΣUVFs: NA-48.3 ng/g ww) generally showed greater concentrations in the liver of these species. Seabirds accumulated higher levels of these contaminants (median range: ΣBZT-UVs: 3.38-8.71 ng/g ww; ΣUVFs: NA-48.3 ng/g ww; ΣAr-SAs: 0.07-4.06 ng/g ww; 26DTBP: NA-1.14 ng/g ww)) than the other groups (median range: ΣBZT-UVs: NA-1.31 ng/g ww; ΣUVFs: NA-4.22 ng/g ww; ΣAr-SAs: NA; 26DTBP: NA-1.91 ng/g ww), suggesting that seabirds may be useful indicator species for future long-term monitoring. The livers of Arctic char in the Canadian Arctic generally contain lower levels of these contaminants than those of freshwater fish in temperate regions. Spatial variations were found in the liver of black guillemots, Hudson Bay polar bears, and landlocked char for some target contaminants, indicating differences in the levels of these contaminants in their surrounding environment or diet. Consumption of liver tissues from these species may expose humans to varying levels of UV absorbents and industrial antioxidants. This study establishes a baseline for future research of the spatial and temporal trends of these contaminants in Arctic species. It provides the basis for elucidating the fate of these contaminants and assessing their adverse effects at environmental-relevant concentrations in the Arctic. Factors influencing the accumulation patterns of these contaminants in Arctic biota and their potential health risks require further investigation.