Heavy metal contamination in surface and groundwater and its human health risk assessment in the Upper Yamuna River Basin, India

Heavy metal pollution in the riverine system is a major concern as it is a primary source of fresh water and has the potential to cause minuet to severe health impacts in humans. Excess heavy metal contamination in the riverine system may introduce potentially toxic elements into the aquifers via recharge or vice versa. The present study is aimed to understand the heavy metal pollution and the human health risk assessment of surface and groundwater in the Upper Yamuna River Basin (UYRB) and its spatial distribution.  For the study, twenty-eight river water and forty-eight groundwater samples were collected in May 2022 and analyzed for 15 heavy metals. Except for a few metals in groundwater (As, Fe, Mn, and Al) and surface water (As, Al, Mn), the rest were in compliance with the BIS and WHO acceptable limits. The mean metal concentration in groundwater were observed in the order of Cd < Cu < Cr < Ni < Co < Mo < Li < As < Al < Ba < B < Mn < Sr < Zn < Fe, whereas in surface water it followed the order of Cd < Cu < Cr < Ni < Co < Mo < Zn < Li < As < Ba < Al < Mn < Fe < B < Sr. The non-carcinogenic (HI) value for groundwater in adults ranged between 0.3 – 15.4 with an average of 3.95, while it ranged between 0.3 – 7.4 with an average of 2.4 for river water.  Similarly, the average incremental lifetime cancer risk (ILCR) value for adults in groundwater is 1.4 × 10^-3 and 9 × 10^-4 for river water. The health risk implication in children were found to be higher than the adults. The higher HI and ILCR values may be associated with the high arsenic concentration compared to their standard acceptable limit. Even though the HI and ILCR values exceeded the standard values, the heavy metal pollution (HPI) index values for all the samples were below the permissible limit. It may be due to the lower concentration or the absence of major concerned metals (Cd, Cu, Cr, Ni, etc.). Heavy metals are varyingly distributed in the basin, whereas, the lower catchment, which is the major urban center of the country is found to have comparatively higher concentrations of heavy metals and related health risks.

Keywords: Heavy metal, Yamuna river, Human health assessment, Pollution index