Source apportionment, chemometric pattern recognition and health risk assessment of groundwater from southwestern Punjab, India

The groundwater quality of southwestern Punjab, India, is a serious cause of concern due to the presence of chemical contaminants in it. However, limited studies of groundwater quality, sources of chemical contaminants and their health risks are available for the region. Hence, this study was conducted to investigate the source, distribution and potential health risk assessment of groundwater quality in three districts of southwestern Punjab, India. The spatial distribution of groundwater chemical contaminants and their potential health risks have been illustrated using inverse distance weighting interpolation technique. The concentration of fluoride (F−; ranged from 0.08 to 4.79 mg L−1) exceeded the WHO limit (1.5 µg L−1) in 80 and 50% samples collected from Bathinda and Ludhiana districts, respectively. The uranium (U) concentration ranged from 0.5 to 432 µg L−1 and shows ~ 85%, 75% and 10% of samples collected from Bathinda, Barnala and Ludhiana districts exceeded the WHO drinking water limit (30 µg L−1), respectively. The groundwater quality of the Bathinda district is a matter of concern due to elevated levels of alkalinity, hardness, fluoride, uranium and nitrate (NO3−). The principal component analysis shows close association between F− and U, which indicates their geogenic origin. Further, they also seem to be subordinately influenced by diffuse anthropogenic activities. The clustering of Cu and Pb with NO3− and SO42− indicates their anthropogenic origin. The non-carcinogenic health risk assessment indicates that F−, NO3− and U are the major health risk pollutants in the study area. The carcinogenic health risk of As and Cr exceeded the USEPA limits (10−6) in the entire study area, but observed to be more serious for the district Bathinda (10−3–10−5). The spatial distribution maps illustrate that the health risk for Bathinda district inhabitants is higher than Barnala and Ludhiana districts.