Spatial distribution of heavy metals contamination and risk indices evaluation in sediments of Indus River and its tributaries, Pakistan
Ayaz Ul Haq, Said Muhammad
Abstract
Heavy metals (HM) contamination in freshwater sediments is a matter of serious concern. This concern is further aggregated in developing countries like Pakistan due to their high population growth and low economy. This study aimed to determine the quality of sediments in the Indus River and its tributaries. For this purpose, the available data on HM concentration published in last three decades (1992–2021) on freshwater sediments were collected. HM concentrations data was used for the geospatial distribution, pollution quantification factors, and ecological risk index. Among HM, iron (Fe) showed the highest concentration, while the silver (Ag) showed the lowest. This study revealed that HM mean concentration in the sediments exceeded the sediment quality guidelines. Ravi River a tributary of Indus River showed higher values of pollution quantification factors and potential ecological risk index and was categorized as significantly polluted. This study will provide a comprehensive assessment of HM pollution in river sediments all over Pakistan.