Identifying halogenated emerging contaminants in the human food chain by exploring the potential of sentinel animal species

Abstract The characterization of the human dietary exposure to emerging contaminants (ECs) typically relies on the analysis of food or is extrapolated from the analysis of human tissues. However, the detection of ECs in such matrices is limited by sensitivity and/or ethical considerations. To address these challenges, utilizing sentinel animal species offers a promising alternative since they can accumulate contaminants over time, providing an integrated and early indication of emerging chemical exposures in the environment and food chain that may pose risks to humans. This proof-of-concept study aimed to evaluate a sampling strategy based on the selection of a sentinel species for the early identification of Cl/Br-containing ECs in the human food chain. Gulls, pigeons and rats were selected as sentinel models because of their relative dependence on anthropogenic food sources. After preparation, the samples were analyzed by gas and liquid chromatography coupled to high-resolution mass spectrometry. Of the 126 Cl/Br-containing compounds detected, 73 were legacy persistent organic pollutants (POPs) while 53 were potential POP-like ECs. Further analysis revealed that 71 out of the 126 compounds were detected in foods of animal origin that form part of the human diet, mostly at statistically significant lower concentration levels and detection frequencies than in sentinel samples. The results support the relevance of using biological matrices from so-called sentinel animal species for the early detection and identification of POP-like ECs forming an integral part of the human dietary chemical exposome.