Source apportionment, pollution assessment, and ecological and human health risk assessment due to trace metals contaminated groundwater along urban river floodplain.

Abstract

Increasing migration to developing urban areas has resulted in human settlements at low lying, urban river floodplain. Groundwater is the primary source of drinking water as well as a key exposure pathway in the poor and marginalized people living near the floodplain. This study investigates seasonal variation in metal pollution, associated health and ecological risk due to exposure to contaminated groundwater of Yamuna River floodplain in Delhi. Trace metal pollution was found to be highest and lowest in summer and winter respectively. Polluted river water, vehicular emissions, agricultural and urban activities were identified as major sources of metals in groundwater. Metal contaminated groundwater was found to pose low to moderate ecological risk. Arsenic was found to pose cancer and non-cancer risk. The risk varied with seasons as winter > summer > monsoon. High non-cancer risk was computed for Mn, having seasonal trend of monsoon > winter > summer. This study infers an urgent need for groundwater quality monitoring in urban river floodplain as it is prone to contamination due to its high permeability and over-exploitation.