Assessment of Heavy Metal Pollution Indices in Surface Sediments From Southwestern Bay of Bengal, India

Abstract

The study of heavy metal distribution in the shelf sediments of Southwestern part of Bay of Bengal is essential in determining the distribution pattern and to understand the consequences of marine pollution beside the coastal environment. The south eastern coastal areas of India are affected by several disturbances and contamination associated with accelerated industrialization and urbanization. Twenty-nine surface sediment samples were collected from shelf region of Southwestern part of Bay of Bengal and analyzed for sediment texture, organic matter and heavy metals. Pollution indices such as Enrichment Factor (EF), Geoaccumulation Index (Igeo), Contamination Factor (CF) as well as multivariate statistical analyses were used to recognize the pollution pattern and probable sources for metal contamination. Comparatively, the concentration of heavy metals in the study area is closely associated with finer fractions and organic matter. The results demonstrate that Cu, Co, Mn, Pb, Zn, Cr and Ni in most of the sites are extremely contaminated in terms of Igeo. The computed values of CF indicate very high contamination of the metals like Pb, Zn and Cr followed by uncontamination to moderate contamination of Cu, Mn, Ni, Co. Based on factor analysis, domestic and industrial activities from adjacent land areas are found to be the major contributors of heavy metals in the shelf sediments.