Monica R.D., Shijo Mathew and Inbaraj R.M.
Abstract
Fish, shrimp, crab, and mollusks are significant providers of proteins, vitamins, minerals, polyunsaturated fats and polysaccharides and form the chief source of food to a peninsular country like India. Fish food production and Human health can be affected by heavy metal contamination. Heavy metals can be significant carcinogenic agents based on their toxic effects and bioaccumulation. The present study aims to analyse the concentrations of four heavy metals (As, Cr, Cd and Pb) in seawater and their bioaccumulation in commercially important fishes (Nemipterus japonicus, Rastrelliger kanagurta), Crab (Portunus sanguinolentus) and Shrimp (Penaeus monodon, Penaeus indicus). The samples were collected from Pulicat, Ennore, Pattinapakkam, Kovalam and Thiruvanmiyur regions of the Chennai coast and analysed using atomic absorption spectrophotometer and the results were interpreted with the USEPA human health risk assessment. The hierarchy of the concentration of heavy metals in the Crude oil is in the order Ni> As> Cr> Pb> Cd>Cu, seawater is in the order Pd> Ar> Cr> Cd. The species studied showed the highest accumulation of heavy metal in the liver and lowest in muscle tissues. The highest BCF concentration was recorded for Cr and lowest for Pb and BCF of muscles of all species showed lowered accumulation rate. THQ values of As, Cd and Pb in P. sanguinolentus from Pattinapakkam, Ennore and Kovalam, As, Cd and Pb in R. kanagurta from Ennore and Pattinapakkam were above 1. The values stipulate that prolonged consumption of these two species from the Ennore, Kovalam and Pattinapakkam coast may be potentially hazardous to human health. Cancer risk values for Cd in all five species studied was higher than the acceptable range in all the studied locations. Cr in the species N. japonicus, R. kanagurta from Ennore, Pulicat and Thiruvanmiyur and in P. sanguinolentus from Ennore and Kovalam, P. indicus and P. monodon from Pulicat and Pattinapakkam were close to the cancer risk value range, which indicates that the local consumers are at carcinogenic risk associated with Cd and Cr posed from consumption of fish and crustaceansâ species. Application of effective preventive measures and appropriate strategies to minimize heavy metal pollution can be identified and developed by studies on the earlier and current incidents and adopted or integrated into coastal management policies.