Integrated Approach to Hydrogeochemical Assessment of Groundwater Quality in Major Industrial Zone of Punjab, Pakistan.

Groundwater contamination with arsenic (As) is a significant concern in Pakistan's Punjab Province. This study analyzed 69 groundwater samples from Faisalabad, Gujranwala, Lahore, and Multan to understand hydrogeochemistry, health impacts, contamination sources, and drinking suitability. Results revealed varying as concentrations across districts, with distinctive cation and anion orders. Faisalabad exhibited Na +  > Mg 2+  > Ca 2+  > K +  > Fe 2+ for cations and SO 4 2-  > Cl -  > HCO 3 -  > NO 3 -  > F - for anions. Gujranwala showed Na +  > Ca 2+  > Mg 2+  > K + for cations and HCO 3 -  > SO 4 2-  > Cl -  > NO 3 -  > F - for anions. In Lahore, demonstrated: Na +  > Ca 2+  > Mg 2+  > Fe > K + for cations and HCO 3 -  > SO 4 2 -  > Cl -  > NO 3 -  > F - for anions. Multan indicated K +  > Ca 2 +  > Mg 2 +  > Na +  > Fe for cations and HCO 3 -  > SO 4 2-  > Cl -  > F -  > NO 3 - ) for anions. Hydrochemical facies were identified as CaHCO 3 and CaMgCl types. Principal Component Analysis (PCA), highlighted the influence of natural processes and human activities on groundwater pollution. Water Quality Index (WQI) result reveal that most samples met water quality standards. The carcinogenic risk values for children exceeded permissible limits in all districts, emphasizing a significant cancer risk. The study highlights the need for rigorous monitoring to mitigate (As) contamination and protect public health from associated hazards.