Heavy metals accumulation in cultured Shrimp in South-West farming regions of Bangladesh and human health risk assessment

Abstract

Heavy metals contamination of aquatic environment has attached global attention owing to its abundance, persistence and environment toxicity, especially in developing countries like Bangladesh. They are not only the threat to aquatic environment but also can pose risk to human health through the consumption of aquatic products especially fish and Shrimp. This study was focused on heavy metals accumulation and estimation of human health risk ofthree Upazilas (Satkhira Sadar, Morrelganj and Mongla) of two districts (Satkhira and Bagerhat) in South-West region of Bangladesh. For the determination of heavy metal concentration using Atomic Absorption Spectrometer (Model No: AA-7000, Shimadzu) a total of 20 freshly caught cultured Shrimp (Penaeusmonodon)were randomly sampled from Satkhira Sadar Upazila of Satkhira district, Morrelganj and Mongla Upazila of Bagerhat district during pre-monsoon (May-June) and post monsoon (November-December) of 2016. During pre-monsoon 10 soil and water samples were collected from the same sampling area. To determine the initial concentration of heavy metals in the collected Shrimp, samples wereseparated intoshell, head and muscle. Concentrations of five heavy metals (cadmium, lead, copper, nickel and chromium) in cultured Shrimp were estimated to evaluate contamination levels and health risks for Bangladeshi people. The analyzed concentration of metals varied among region to region, pre-monsoon to post monsoon (for Shrimp), organ to organ like shell, head and muscle. Metals like Cd,Pb, Cu and Ni in Shrimp were higher in concentration than the respective maximum allowableconcentrations (MAC), whereas Cr was found below determination level. Health risks associated with this metal intake were evaluated in terms of dietary intake (EDI) and target hazard quotients (THQs). The THQ values for individual metals were below 1, suggesting that people would not experience significant health hazards. Also, the estimation showed that the carcinogenic risk (CR) of lead was exceeded the accepted risk level for Shrimp.From the health concern view, this study showed that the inhabitants who consume contaminatedShrimps are exposed chronically to metal pollution with carcinogenic and non-carcinogenicconsequences.