@article {292,
	title = {Quantifying the Effect of Dietary Microplastics on the Potential for Biological Uptake of Environmental Contaminants and Polymer Additives.},
	journal = {Environ Sci Technol},
	year = {2025},
	month = {2025 Apr 22},
	abstract = {<p>The pervasive presence of microplastic in food raises the question of how this presence influences the uptake of organic contaminants from the gastrointestinal tract. Depending on the relative contamination of diet and microplastics, the latter can act either as a vector of contaminants facilitating biological uptake or as a contaminant sink whose sorptive capacity does not diminish during digestion. A comprehensive understanding of these effects ultimately requires the quantification of the effect of microplastics on the thermodynamic driving force responsible for diffusion from the gut lumen to the tissues of an organism. Using silicone-based equilibrium sampling, we quantified the effect of polyvinyl chloride (PVC) microplastics on the fugacity of polychlorinated biphenyls (PCBs) and two polymer additives in dietary and fecal samples of a zoo-housed polar bear. Although PVC microplastics at concentrations well above current observations reduced the fugacities of spiked isotopically labeled PCBs in the polar bear diet and feces slightly, but significantly, leaching from these microplastics greatly elevated fugacities of the additives UV-328 and octabenzone in these samples. The impact of microplastics in the diet on the biological uptake of environmental hydrophobic organic contaminants is likely to be negligible. Microplastics have the potential to be effective vectors for the dietary uptake of polymer additives.</p>},
	issn = {1520-5851},
	doi = {10.1021/acs.est.5c02616},
	author = {Ng, Desmond and Chen, Yuhao and Lei, Ying Duan and Chen, Wanzhen and Peng, Hui and Gourlie, Sarra and Wania, Frank}
}
@article {275,
	title = {Emerging investigator series: nontargeted screening of aryl hydrocarbon receptor agonists in endangered beluga whales from the St. Lawrence Estuary: beyond legacy contaminants.},
	journal = {Environ Sci Process Impacts},
	volume = {26},
	year = {2024},
	month = {2024 Sep 18},
	pages = {1451-1464},
	abstract = {<p>The elevated concentrations of organohalogen contaminants in the endangered St. Lawrence Estuary (SLE) belugas have prompted the hypothesis that aryl hydrocarbon receptor (AhR) activity may be a contributor towards their potential adverse effects. While indirect associations between AhR and contaminant levels have been reported in SLE beluga tissues, AhR activity was never directly measured. Using bioassays and nontargeted analysis, this study contrasted AhR activity and agonist profiles between pooled tissue extracts of endangered SLE and non-threatened Arctic belugas. Tissue extracts of SLE belugas exhibited significantly higher overall AhR activity than that of Arctic belugas, with a 2000s SLE beluga liver extract exerting significantly higher activity than blubber extracts of SLE and Arctic belugas from the same time period. Contrary to our expectations, well-known AhR agonists detected by nontargeted analysis, including polychlorinated biphenyls (PCBs), were only minor contributors to the observed AhR activity. Instead, Tox21 suspect screening identified more polar chemicals, such as dyes and natural indoles, as potential contributors. Notably, the natural product bromoindole was selectively detected in SLE beluga liver at high abundance and was further confirmed as an AhR agonist. These findings highlighted the significance of the AhR-mediated toxicity pathway in belugas and underscored the importance of novel AhR agonists, particularly polar compounds, in its induction.</p>},
	keywords = {Animals, Beluga Whale, Endangered Species, Environmental Monitoring, Estuaries, Liver, Polychlorinated Biphenyls, Receptors, Aryl Hydrocarbon, Water Pollutants, Chemical},
	issn = {2050-7895},
	doi = {10.1039/d4em00243a},
	author = {Barrett, Holly and Sun, Jianxian and Chen, Yuhao and Yang, Diwen and Verreault, Jonathan and Houde, Magali and Wania, Frank and Peng, Hui}
}
