Human health and ecological risks associated with microplastic contamination in widely consumed catfish from a large-scale estuary

Microplastic (MP) pollution threatens aquatic ecosystems and food safety, yet organ‐specific contamination in tropical estuarine fish remains largely unexplored. In Bangladesh, where fish is a vital protein source, such assessments are critically lacking. This study quantified MPs in two commercially important catfishes, Pangasius pangasius and Mystus gulio (n = 60), from the Meghna Estuary, and assessed ecological and human health risks. MPs were extracted from gills, digestive tracts, and muscles and characterized by microscopy and FTIR. Results showed tissue‐specific patterns, with higher loads in gills and digestive tracts than in muscles. Mean abundance was significantly greater in P. pangasius (38.7 ± 10.1 items) than in M. gulio (23.9 ± 7.3 items). Fibers <0.5 mm, mostly violet, were dominant. Ecological risk indices revealed higher values for P. pangasius across all metrics: Polymeric Hazard Index (2,006 vs. 1,340), Risk Index (160 vs. 101.5), and Pollution Load Index (1.71 vs. 1.34), indicating substantial polymer-related risks and contamination level. Nylon posed the greatest hazard in P. pangasius (risk level, Eᵢ = 127.3), reflecting its persistence and adsorptive potential. Human exposure was higher from P. pangasius (2.44 particles/day for adults; 2.35 for children) than from M. gulio , confirming tissue‐ and species‐specific risks. • Higher MP abundance was found in Pangasius pangasius than Mystus gulio . • Fiber-shaped and <0.5 mm sized MPs were the dominant types in all tissues. • FTIR revealed nylon and EVA as the major polymers with species-specific variation. • High MPs level detected in muscle tissue, revealing direct dietary exposure risks. • P. pangasius showed high MP risk scores, supporting its role as a sentinel species.