Distribution and Anthropogenic imprints of Light Rare Earth Elements in River sediments of Ganga Alluvial Plain, India

Light Rare Earth Elements (LREE) are high technology-based modern contaminants, in fluvial system are recently emerging environmental concern due to their human health risks. The purpose of this paper is to investigate the influence of LREE (Lanthanum to Samarium) on river sediments of the Ganga Alluvial Plain, northern India. In the 900-km long Gomati River, a distinct downstream increasing concentration of LREE from 339 to 1349 µg/g was identified in biotite mineral of the mica-rich bedload sediments. Total LREE content in suspended sediments of the Gomati (205 µg/g), the Sai (229 µg/g) and the Hindon (average 495 µg/g, n=15) rivers were observed higher than the World River Silt average (149 µg/g). The extreme LREE level was represented by the Hindon River’s suspended sediment of highly urbanized centers at Ghaziabad (1519 µg/g) and Greater Noida (1377 µg/g). The modern anthropogenic processes are accountable for the LREE enrichment in suspended river sediments of nearly an order of magnitude in the Ganga Alluvial Plain. This casts light on the effects of human activities of the LREE cycling by sub-tropical fluvial processes in one of the most densely populated regions of the world.