Distribution of trace elements concentration in sediments of Nethravathi-Gurupura estuary south-west coast Mangalore

Abstract

The ecology is continually exposed to trace elements from various natural and human-made sources. When the concentration of these trace elements goes beyond certain threshold limits, their excessive intake can become toxic and lead to health disorders in individuals. It is crucial to measure the concentration of trace elements, especially toxic ones, in order to evaluate and forecast risks to the environment and public health. The distribution of trace elements across different ecological patterns is contingent upon the inherent properties of the element and site-specific factors, including the type of matrices and their physicochemical characteristics. Considering these aspects, an effort is made to evaluate the concentration of trace elements and pollution indices in sediment samples obtained from the coastal belt of Nethravathi and Gurupura estuary and possible conclusions are drawn. The results showed that the mean concentrations of the HMs in the sediment samples followed the order Pre-monsoon includes Fe>Mn>, Cr>, Zn>, Cu>, Ni>, Pb>, Co>, and Post-monsoon includes Fe>Mn>, Ni>, Pb>Co>Cd. respectively. The pollution indices of Enrichment Factor EF natural to extremely severe enrichment in the estuarine sediments, whereas Pb and Cd exhibit moderately severe to extremely severe enrichment. The contamination factor CF in both Pre-monsoon and Post Monsoon and Cd shows no pollution up to the category of very high contamination. Geo-accumulation index (Igeo) values the Pre-Monsoon and Post Monsoon Cd and Pb shows pollution up to the category of "strongly" to "extremely" pollute. Pollution Load Index (PLI) in both the season shows no pollution to pollute. The investigation shows pollution in more than half of the samples and also SPI in both the season low polluted sediment to moderately pollute.