The Biobrio 13(1 & 2), 2026

Spatiotemporal variation in groundwater quality and human health risk assessment in alluvial aquifers of Madhepura, Bihar

Arti Kumari & Arun Kumar

ABSTRACT:

Continuous monitoring of shallow alluvial aquifers is critical for safeguarding rural public health in eastern India. This study evaluated the hydrochemical characteristics, drinking water suitability, and non-carcinogenic health hazards of groundwater across six villages in three administrative blocks (Murliganj, Alamnagar, and Madhepura) in Madhepura district, Bihar, from January 2023 to December 2025. A total of 144 groundwater samples were collected systematically across pre-monsoon, monsoon, post-monsoon, and summer seasons and analyzed for physicochemical parameters (pH , electrical conductivity, total dissolved solids, total hardness, calcium, magnesium, chloride, fluoride) and trace heavy metals (Fe, Mn, Zn, Cu, Cd, Pb) using standard APHA methods. Mean values of total dissolved solids (520-1,280 mg/L) and electrical conductivity (720-1,620 ?? S/cm) were highest during the pre-monsoon period, dropping substantially during the monsoon season due to precipitation recharge. Fluoride concentrations exceeded the Bureau of Indian Standards (IS 10500:2012) acceptable limit (1.0 mg/L) in several sites, reaching up to 2.5 mg/L in Belo village. While toxic metals such as cadmium and copper remained below detectable thresholds, lead (Pb ) showed localized exceedances above the permissible drinking water benchmark (0.01 mg/L), yielding hazard quotient (HQ) values exceeding 1.0 for children. These results highlight a dual challenge of mineral dissolution and localized anthropogenic leaching, necessitating decentralized water purification infrastructure and ongoing surveillance.

Keywords:    

Groundwater quality, Hydrochemistry, Health risk, Trace metals, Alluvial aquifer.

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