A study of health risk from accumulation of metals in commercial edible fish species at Tuticorin coasts of southern India

The potential for health risks to humans consuming seafood is investigated in this paper through a sampling study of 6 fish species at 7 sites of the Tuticorin coastal region, India, in terms of 8 trace metals measuring their excess concentrations at gills, livers and muscles. An understanding of the complexity of the problem is systematised using Sources-Pathways-Receptors-Consequences framework, in which quantitative results are produced as follows: (i) multivariate statistical techniques provide a focus on sources-pathways by both factor and cluster analyses; (ii) ecological health risk assessment for both children and adults provide a focus on consequences in terms of Hazard Index (HI) and Carcinogenic Risk (CR). An analysis of the data shows that concentrations of metallic elements are found to be mostly in the following order: Zn > Cd > Mn > Cu > Cr > Pb > Fe > Co; likewise the fish species from higher to lower mean concentrations were found to be in the following order: 1.Megalops cyprinoides; 2.Leiognathus brevirostris; 3.Atropus atropos 4.Pseudotriacanthus; 5.Terapon jarbua; 6. Terapon puta. The mean concentration of fish in gills, muscles and livers are indicative of serious pollution with observed impacts on especially children. Pollution sources are detected by factor analysis (e.g. Factor 1: Pb, Mn and Cr); as well as by cluster analysis (e.g. Cluster 1: Cu). The relationship between the metals provide positive loading, which indicates that metals are derived from the same sources. Their variegated sources can now be associated with chemical industries, agricultural discharges and municipal sewage. The results confirm that various fish organs are effective bio-indicators for the identification of coastal areas unprotected to metallic poisons; and as such they are pathways to risks to children and adults by accumulation of trace metallic concentrations and measured in terms of a number of indicators.