Detection of heavy metals in fish muscles of selected local fish varieties of the Shitalakshya River and probabilistic health risk assessment

The Shitalakshya River, located in Dhaka, Bangladesh, is under threat of heavy metal pollution due to the numerous industrial pollutants that flow through its streams. As a result, the heavy metal content and the possible human health risk of ingesting three common fish, Systomus sarana (Olive barb), Pethia ticto (Ticto barb) and Mastacembelus armatus (Tire-track Spiny eel), captured from the industrially contaminated Shitalakya River in Bangladesh were assessed in this study. This research evaluates the possible health risks imposed by five heavy metals copper (Cu), zinc (Zn), lead (Pb), cadmium (Cd), nickel (Ni), As) and chromium (Cr) detected in three of the most common fish species utilizing atomic absorption spectroscopy (AAS). Such toxic metals are poisonous in nature and can enter the human diet via fish ingestion. To quantify the hazard to public health from heavy metal pollution by consuming aquatic species, particularly fish, the estimated daily intake (EDI), targeted hazard quotient (THQ), and carcinogenic risk (TCR) were computed. The results of this investigation revealed the concentrations of heavy metals (As, Pb, Zn, Cd, and Cr) in the three local fish species from the three locations that exceeded the permitted limits established by the international standard references (FAO/WHO, USFDA, MOFL, EC). The THQ values are within the limiting value of 1 for all heavy metals in Pethia ticto (Ticto barb), Mastacembelus armatus (Tire-track Spiny eel) and Systomus sarana (Olive barb). The cumulative impacts of all metals in this study surpassed the allowable limit of 1 for HI (hazard index) in all three species. The presence of Pb, Cd, Ni, and As in the three fish species raises the risk of cancer from the ingestion of selected fish. As a consequence, this study suggests that heavy metal surveillance of fish in contaminated rivers be carried out on a frequent basis through government environmental health management authorities to enforce regulatory criteria.