Groundwater quality in Sargodha City, Pakistan: Comprehensive research of geochemical modeling, groundwater quality assessment, and risk evaluation

Groundwater, an indispensable global resource, faces escalating contamination threats, jeopardizing human health and environmental sustainability. This study offers detailed insights into the quality of the groundwater, its drinking suitability, and associated human health risks in Sargodha City, Pakistan. Employing hydrogeochemical analysis, inverse geochemical modeling, groundwater quality index, and human health risk evaluation, this research highlights widespread exceedances of WHO drinking water standards, particularly in TDS, EC, TH, Na+, Ca2+, Mg2+, SO42- , Cl-, HCO3- , NO3-N, and As levels, signifying that a significant portion of the groundwater is unfit for consumption. Hydrochemical facies analysis reveals a dominance of the Na-Cl type. Water-rock interactions, cation exchange, and anthropogenic influences are the primary factors shaping groundwater hydrochemistry in the region. Saturation indices and inverse geochemical modeling demonstrated intricate geochemical processes involving both mineral precipitation and dissolution. Notably, the GWQI reveals a diverse spectrum of water quality, with 50% of the samples exhibiting excellent to good quality, 29% falling into the poor to extremely poor category, and 21% deemed unfit for drinking. Health risk assessment reveals alarming carcinogenic risks from As, affecting children (70.8%) and adults (83.35%), while 8.3% of the samples indicate non-carcinogenic risks. Conversely, NO3-N presents acceptable non-carcinogenic risks across all samples. The total hazard index spans between 0.14 and 1.90 for adults and 0.16 to 2.23 for children, underscoring the heightened vulnerability of children. This study advances the understanding of groundwater contamination dynamics in urbanized regions, offering insights to safeguard public health and ensure sustainable water management in areas with similar hydrogeochemical conditions.