This study analyzes muscle and gill samples from 36 samples of 2 popular edible fishes from a subtropical wetland ecosystem to determine the amounts of harmful heavy metals, such as Pb, Hg, Zn, Cu, and Cr. The metal concentrations in the muscle and gills fluctuate, with zinc having the greatest concentration. Pb and Hg levels are higher than those that are acceptable for human consumption, while Cu, Zn, and Cr levels are within safe bounds. High amounts of Zn, Cu, and Cr may pose health hazards, according to risk indices. The research also highlights sources of heavy metals that are caused by humans and the natural world, highlighting the necessity of continual control and monitoring to guarantee the safety of fish for human consumption.

The widespread occurrence of heavy metals in aquatic environments, resulting in their bioaccumulation within aquatic organisms like fish, presents potential hazards to human health. This study investigates the concentrations of five toxic heavy metals (Pb, Hg, Zn, Cu, and Cr) and their potential health implications in two economically important fish species (Otolithoides pama and Labeo bata) from a subtropical estuarine wetland system (Feni estuary, Bangladesh). Muscle and gill samples from 36 individual fish were analyzed using energy dispersive X-ray fluorescence (EDXRF). The results revealed that the average quantities of heavy metals in both fishes’ muscle followed the declining order of Zn (109.41–119.93 mg/kg) > Cu (45.52–65.43 mg/kg) > Hg (1.25–1.39 mg/kg) > Pb (0.68–1.12 mg/kg) > Cr (0.31–5.82 mg/kg). Furthermore, Zn was found to be present in the highest concentration within the gills of both species. While the levels of Cu, Zn, and Cr in the fish muscle were deemed acceptable for human consumption, the concentrations of Pb and Hg exceeded the permissible limits (>0.5 mg/kg) for human consumption. Different risk indices, including estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI), and carcinogenic or target risk (TR), revealed mixed and varying degrees of potential threat to human health. According to the EDI values, individuals consuming these fish may face health risks as the levels of Zn, Cu, and Cr in the muscle are either very close to or exceed the maximum tolerable daily intake (MTDI) threshold. Nevertheless, the THQ and HI values suggested that both species remained suitable for human consumption, as indicated by THQ (<1) and HI (<1) values. Carcinogenic risk values for Pb, Cr, and Zn all remained within permissible limits, with TR values falling below the range of (10⁻⁶ to 10⁻⁴), except for Zn, which exceeded it (>10⁻⁴). The correlation matrix and multivariate principal component analysis (PCA) findings revealed that Pb and Cr primarily stemmed from natural geological backgrounds, whereas Zn, Cu, and Hg were attributed to human-induced sources such as agricultural chemicals, silver nanoparticles, antimicrobial substances, and metallic plating. Given the significance of fish as a crucial and nutritious element of a balanced diet, it is essential to maintain consistent monitoring and regulation of the levels and origins of heavy metals found within it.