Ecotoxicological and Potential Health Risk Assess-ment in Dimna Canal, Interlinking Lentic and Lo-tic Ecosystem in Jamshedpur, India

Abstract

Abstract: Heavy and Trace Elements (HTEs) pollution is a serious menace to the ecosystem. These elements are ubiquitous that can bioaccumulate and biomagnify in the food chain. This study aimed to assess the HTE pollution on different trophic level of an aquatic food chain of Dimna canal interlinking a lentic (Dimna Lake) and a lotic (Subarnarekha River) ecosystem. In this study, water, sediments, and biotic samples of molluscs (Limnaea stagnalis) and fish (Channa punctatus) were collected and analysed in an ICP-MS for six HTEs (Cu, Pb, Zn, As, CD and Cr). Then, the health risk to human through the consumption of L. stagnalis and C. Punctatus was calculated using the Target Hazard Quotient (THQ) and Hazard Index (HI). It is observed that the average level of Pb (12.96 µg/L) and Cd (3.83µg/L) in water is higher than the limit prescribed by WHO, 2004. In sediment, the average level of Zn (118.14 µg/g) and Cd (0.43 µg/g) is higher than the average shale value of the earth's crust. The higher value of Pb, Cd and Zn in the canal ecosystem may be due to the discharge of chemical, primer etc. from industries as well bricks industry. In mollusc (L. stagnalis), the average levels of HTEs are the highest in comparison to limits prescribed by FAO (1983) and account for 82.74 µg of Cu per g, 20.09 µg of Pb per g, 530.49 µg of Zn per g, and 0.86 µg of Cd per g. In edible fish (C.punctatus) parts, level of As (2.41 µg/g) and Cd (0.66 µg/g) are higher than the FAO limits. Mollusc, being the primary consumer of the aquatic food chain, accumulates more HTE than that of fish; hence mollusc can be used as a potential bioindicator. THQ values of metals due to consumption of mollusc and fish show that As contributes almost 50 % in HI. Also, among the population of two age groups (adult and children); children are found more susceptible to HTE exposure. Hence, regular monitoring and assessment are required for aquatic ecosystems for the safeguard of human health.