In this study, an in vitro method was used to simulate lung fluids [Artificial lysosomal fluid (ALF) and Gamble's solution (GS)] to assess how the bioaccessibility of rare earth elements (REEs) in airborne particulate matter (PM) affects human health. Airborne PM samples (PM10 and PM2.5) were collected in Daqing in Northeast China. The bioaccessible proportions determined for REEs in PM10 and PM2.5 had high variability, which can be attributable to the heterogenic feature of airborne PM and its components, as well as sampling time. Overall, the bioaccessiblity of the REEs in the airborne PM samples was time-dependent. The bioaccessiblity of the REEs varied in PM with different sizes, and it was an order of magnitude higher in ALF than in GS. During both heavy and light pollution, the bioaccessiblity of the REEs in PM2.5 was higher than in PM10 after 24 h of ALF extraction, whereas bioaccessiblity of the REEs in GS followed the opposite trend. The REEs associated with airborne PM had much greater bioaccessiblity as the exposure time increased. The results of this study emphasize the necessity of conducting bioaccessibility experiments with field samples for the proper evaluation of human health risks.
Keywords: Artificial lysosomal fluid; Gamble’s solution; Human health; Rare earth elements; Refinery.
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