Source characterisation of the trace metal composition in coastal sediments from Andaman and Nicobar Islands

Abstract

The Andaman and Nicobar Islands, located at the Indian and Pacific lithospheric plates intersection, host diverse ecosystems such as coral reefs, mangroves, and seagrass beds. In this study an attempt was made to provide baseline data for the selected trace metal concentrations and possible sources in surface sediment samples collected from 35 sites of South Andaman Island. Based on the geochemical classification, the results of trace metal concentrations revealed higher lithophile trace metal concentrations than chalcophile and siderophile metals, indicating a geogenic source. Further, the calculated indices like Enrichment Factor, and Geo-accumulation Index confirmed minimal anthropogenic impact. On the other hand, Pollution Load Index has showed moderate As and Pb enrichment only in urbanized areas like Guptapara and Junglighat. Remote sites such as Jolly Buoy Island showed minimal contamination, which emphasizing the interplay of natural and human influences on sediment quality and the need for detailed and long-term environmental monitoring and management.