Assessment of heavy metal contamination in the surface sediments of the Vedaranyam coast, Southern India

Abstract

The marine sediments of the Vedaranyam coast were examined for their heavy metal contamination largely contributed by natural and anthropogenic activities. Sediment samples were collected and assessed for metals such as chromium (Cr), copper (Cu), manganese (Mn), iron (Fe), Nickel (Ni), zinc (Zn), and cobalt (Co). The individual toxic risk index (TRIi) of metals in this study is significantly variable for Cr (0.88–1.10), Cu (1.78–2.73), Zn (2.33–4.81) and Ni (1.10–4.62). TRIi in the sediments is below 5 for Cr, Cu, Zn, and Ni suggesting the absence of any toxic risk in the aquatic life. To assess the natural and anthropogenic contamination as well as to know the sediment quality, various indices such as the geo-accumulation index, enrichment factor, pollution load index, and contamination factor were computed. The enrichment factor result shows that the heavy metals are primarily from anthropogenic sources. There is a high positive correlation among the heavy metals, indicating a similar origin.