Trace Metals Contamination in Riverine Captured Fish and Prawn of Bangladesh and Associated Health Risk

Abstract

Trace metals contamination is ubiquitous in the riverine environments of Bangladesh. Trace metals contamination is increasing rapidly in Dhaleshwari River due to rapid urbanization and industrialization along the riverbank, especially after the establishment of the Tannery Industrial Estate at Savar in Dhaka District. As a result, aquatic ecosystems, including fish and prawn species of the river, are contaminated by various trace and toxic metals. We examined the concentrations of 10 trace metals (Cr, Fe, Zn, Mn, Co, Ni, Cu, As, Hg, and Pb) in 20 different fish and prawn species (n = 41) which are commonly found in the Dhaleshwari River using energy-dispersive X-ray fluorescence (EDXRF) method. The potential human health risks (noncarcinogenic and carcinogenic) of the trace metals were calculated by using Target Hazard Quotient (THQ), Hazard Index (HI), and Target Cancer Risk (TR) indices. The mean concentration (mg/kg; ww) of the trace metals in analyzed riverine fish and prawn species was in the order of Fe > Zn > Cu > Cr > Mn > Co > Hg > Ni > Pb > As. The highest concentration of Fe (74.67 mg/kg) and Cr (4.64 mg/kg) was found in Mystus bleekeri, whereas Zn (38.89 mg/kg) and Cu (17.47 mg/kg) were found in Rohtee cotio and Glossogobius guiris, respectively. The target hazard quotient (THQ) values were less than 1 (no detrimental health effects) for all the specific metals in most of the species except M. bleekeri (1.61), G. guiris (1.29), Corica soborna (1.28) for Cr, and Macrobrachium malcolmsonii (1.19) for Hg indicate that the noncarcinogenic health risk to humans by consuming those species was relatively low. However, nine out of twenty species found higher Hazard Index (HI) values than the recommended value (HI = 1), indicating that regular consumption of these fishes may have considerable harmful effects on human health. The highest HI value (2.85) was found in M. bleekeri. Moreover, target cancer risk (TR) values showed that frequent intake of some species for prolonged periods might pose a carcinogenic risk due to Cr and Ni contamination as they were higher than the maximum accepted value of 10−4. Based on the present study, it is imperative to take an urgent initiative to control or prevent the trace metals contamination in the Dhaleshwari River and minimize the human health risks associated with the consumption of fish and prawn species in this river in Bangladesh.