Assessment of metal contamination in sediment cores of Zuari and Kushavati rivers with reference to past mining in Goa, west-coast of India

Abstract

The long-term contamination history of pollutants due to exhaustive iron-ore mining activities in the past was studied for 2 sediment cores collected from the Zuari River (ZR) and Kushavati River (KR) of Goa, West-coast of India. They are analyzed for the texture of the sediment, Organic carbon (OC), Fe, Mn and Al (major elements) and CU, Zn, Pb, Cr and Co (trace metals). The results indicated that ZR core is moderately polluted with Mn while KR core is strongly polluted with Mn and moderately polluted with Fe and Cr. Correlation coefficients are evaluated to understand the interrelationships between major elements and trace metals. The extent of pollution in the 2 rivers was assessed using statistical parameters such as Enrichment Factor, Contamination Factors, Pollution Load Index and Geo-Accumulation Index. The study revealed that iron-ore mining activities in the past have a considerable ecological impact on both the KR and ZR rivers which in turn affect the ecology of aquatic fl ora and fauna.