Heavy metal distribution in core sediments of lower Gadilam River, Cuddalore district, Tamil Nadu, India.

Due to problems caused by their toxicity, persistence in the environment and bioaccumulation, heavy metals are among serious pollutants. This study was about the vertical distribution of heavy metals in sediments of lower Gadilam River in Cuddalore district, Tamil Nadu-India. Along the river, core sediment samples have been collected from three locations: River mouth, Estuary and Fresh water area; and following heavy metals have been analysed by using AAS (Atomic Absorption Spectroscopy) method: Fe, Mn, Cr, Cu, Ni, Co, Pb, Cd and Zn. Except Pb, Ni, Cr and Cd with concentration less than 5mg/Kg, all other remaining metals have higher concentration values. The relative decreasing order of all analysed metals, in terms of their average concentrations, is the following: Fe>Zn>Mn>Cu>Co>Pb>Ni>Cr>Cd.