Microplastics are recognized globally as toxicological agents due to their physical and chemical properties threatening biota. A specific type of microplastic, Tire Wear Particles (TWPs), has gained attention for its toxicity impacting aquatic species. TWPs accumulate in retention ponds during storm runoff events, exposing non-target organisms to potential risks. Many organisms including amphibians rely on retention ponds that are permanent bodies of water to reproduce. Can early-stage amphibians that reside in these environments consume TWPs when exposed, and if so, do these particles accumulate within various organs or compartments of the organism and at what rates are TWP taken up and removed? In our study, American Bullfrog (Lithobates catesbeianus) tadpoles were used to evaluate the uptake and depuration rates of TWPs. Tadpoles were exposed to 20mg/L for 96 hours, at 24-hour intervals, we tracked TWP accumulation in gills, liver, GI tract, and whole body. The remaining tadpoles were transferred to particle free water for 96 hours to monitor depuration at 24-hour intervals. Average uptake rates (particles/hour) were 0.32 ± 0.17 (gills), 0.53±0.34 (liver), 0.012 ± 0.002 (GI Tract), and 0.015 ± 0.004 (whole body). Depuration rates were -0.34 ± 0.12 (gills), -0.09 ± 0.03 (liver), - 0.01 ± 0.004 (GI Tract) and -0.002 ± 0.004 (whole body). Our findings demonstrate that early-stage tadpoles can accumulate and remove TWPs when exposed, with noticeable accumulation in organs that influence immune function. Thus, warranting research into the physiological impacts of association with exposure to TWPs, which may result in disruption to tadpoles’ biological processes.

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