Histopathological Damage and Mortality in Rainbow Trout Exposed to Microplastics from Disused Tires

Paucar-Villanueva A.B.; Guzmán-Neyra A.M.; Prosopio-Carranza F.C.; Roldán-Díaz I.M.; Malca-Casavilca N.R.; Iglesias-León S.; Lopez-Bulnes J.L.; Cubillas-Terreros G.P.; Soto-Juscamayta L.M. · International Journal of Design and Nature and Ecodynamics (2026) · DOI: 10.18280/ijdne.210409

Resumen

This study evaluated the acute toxicity of end-of-life tire fragments (EDT) in juvenile Oncorhynchus mykiss, analyzing the relationship between digestive bioaccumulation, histopathological damage, and mortality. A completely randomized design was conducted following OECD Guideline 203, exposing 105 fish to five concentrations (0, 6.25, 12.5, 25, and 50 mg/L) for 96 h. Digestive density and particle count were used as indicators of bioaccumulation, reflecting the retention of tire-derived particles in the digestive tract and enabling the association between ingestion and toxic effects. The highest particle accumulation was recorded at 6.25 mg/L (1912 particles), which is attributed to stress-induced reductions in feeding activity at higher concentrations, limiting particle ingestion. Mortality showed a clear concentration–response pattern, reaching a maximum of 71.43% at 50 mg/L after 96 h, confirming acute toxicity. Histopathological analysis revealed sinusoidal congestion and cytoplasmic vacuolization, progressing to hepatic necrosis at concentrations ≥12.5 mg/L. These results demonstrate that exposure to EDT induces digestive bioaccumulation and dose-dependent liver damage, even at low concentrations, representing an underestimated ecotoxicological risk for freshwater fish species. Copyright:

Instituciones: Universidad Nacional Mayor de San Marcos; Universidad Nacional de San Agustín de Arequipa