Assessment of trace metal contamination in the marine sediment, seawater, and bivalves of Parangipettai, southeast coast of India

Industrial and domestic discharge into the coastal environment has driven us to propose an integrated approach to delineate stations contaminated with metals on the Parangipettai coast by collecting sediment and seawater samples monthly at 18 stations from 2015 to 2017. Descriptive statistics revealed that the concentrations of some metals in the sediment and seawater samples were beyond the permissible level. Further, factor analysis showed a sampling adequacy of 0.90 with high positive loading for Ni (0.94), Cd (0.91), Co (0.90), Pb (0.89), and Zn (0.87) in sediment samples. The degree of contamination by metals was evaluated using pollution indices. The results of the contamination index revealed that some stations in the study area were moderately polluted, and those of the ecological index showed that open sea was under low risk while other stations were in the moderate-to-high-risk category. The results obtained are essential to establish the reference condition for a comparative study in similar environments in the tropical regions.