Bioaccessibilities and health risk assessment of heavy and trace elements in fish from an urban city, India

An investigation on heavy and trace elements (HTEs) and their bioaccessibilities in the 15 fish species from two tropical rivers (Subarnarekha and Kharkai Rivers) of an urban city in India was carried out for accessing the health risk to the general populations. The average concentrations of As, Cd, Cr, Cu, Hg, Pb, and Zn in the 15 fish species varied within 0.006-0.009, 0.016-0.023, 0.067-0.094, 1.52-1.88, 0.006-0.008, 0.229-0.355, 15.9-20.8 mg/kg w.w., respectively, and their bioaccessibilities varied within 49-60%, 45-63%, 29-49%, 56-68%, 55-75%, 51-78%, and 60-75%, respectively. Comparison of fish length and HTEs showed no significant relation. The increasing trend of Cr and Pb from planktonivores to piscivores fish species of Subarnarekha River showed the biomagnification of these elements through the food web. The similar trend was observed for Cd in Kharkai River, suggesting the biomagnification of Cd. The total hazard index (THI) was found lower than the bioaccessible hazard index (BHI), and Pb and Zn were major risk contributors. The BHI and THI values were far below 1, implying no significant health risk to the general population. However, BHI values showed that the general population are more vulnerable to Zn and Pb exposure due to consumption of invertivores fish species.