Impacts of Sand Mining on Hydrochemistry and Human Health Risk Profile of Yamuna River Water at Etawah, Uttar Pradesh.

Yamuna is one of the main tributaries of the river Ganges which provides water to millions of people for drinking, agriculture and their livelihoods. In recent years, extraction of sand from the Yamuna River has increased significantly, which changes the river's physiological balance and leads to serious health risks. Sand mining may contribute to the mobilization of sediment-bound pollutants through sediment disturbances and resuspension processes. The present study assessed the impact of sand mining on the Yamuna River water quality at Etawah, Uttar Pradesh and assesses associated human health risks. Data pertaining to numerous physio-chemical and biological parameters was collected from the Central Water Commission (CWC) over a 25-year period spanning from year 1997 to 2022. The present study uses an integrated weighted water quality index (IWQI) and principal component analysis (PCA) based hybrid WQI. Human health risk for different demographic groups was assessed by using the US Environmental Protection Agency (USEPA) model, considering both carcinogenic and non-carcinogenic risk via ingestion and dermal exposure. Findings of the study demonstrated that high concentrations of turbidity, Biochemical oxygen demand (BOD), total coliform (Tcol) and ammoniacal nitrogen (NH3). The integrated WQI varied from 137 to 2795.81, classifying water quality from poor to extremely poor quality, while PCA based WQI ranges from 5.67 to 31.71, which classified water quality from poor to very poor quality. Findings of human health risk assessment revealed that high value of hazard quotients particularly for infants and children for nitrite (NO2), nitrate (NO3) and fluoride (F) posing potential health risk of methemoglobinemia and fluorosis. Sensitivity analysis identified Tcol, turbidity, BOD and NH3 as the significant parameters for water quality degradation. Results of the long-term assessment highlight that the sand mining activities significantly change the physio-chemical parameters of the Yamuna River which raises concerns about the health risk.