Groundwater Quality for Drinking Purposes and Potential Health Risk Assessment

In Feni, a south-eastern district of Bangladesh, the rapid growth of industry, agricultural activities, gas deposits and lack of waste disposal could pose a threat to groundwater. We investigate the comprehensive pollution and health risk assessment due to trace metals found in groundwater for the first time. The major parameters including physico-chemical to trace metals were studied using data from 39 locations. It was found, the mean value of total dissolved solids (TDS), electrical conductivity (EC), turbidity, manganese (Mn), and iron (Fe) exceeded the prescribed limits stipulated by WHO. WQI (BSTI) standards found 20.51% and 56.41% (total = 76.92%) of water samples to be excellent and good, whereas WQI (WHO) standards found only 10.25% and 17.94% (total = 28.19%) in the same category. About 72% were graded as ‘unsuitable for drinking’ based on heavy metal pollution index (HPI). Contamination degree (Cd) and Nemerrow pollution index (NPI) values were largely coincided with HPI. Principal component analysis (PCA) indicated that geological and anthropogenic sources were responsible for pollution which subsequently largely consistent with cluster analysis (CA) and correlation matrix (CM). Ca-Mg-HCO3 type water was found from Chadha diagram and mostly supported by Scholler diagram. Gibbs plot indicated that groundwater samples fell mostly in the rock-dominant zone, while the Ficklin-Caboi diagram demonstrated groundwater is of near neutral high metal class. Analysis showed that there was a significant non-carcinogenic risk due to arsenic (As), Mn and cobalt (Co) exposure through oral ingestion. Additionally, cadmium (Cd), As and chromium (Cr) were associated with high lifetime total cancer risks (TCR) for adults and children. The results strongly suggest that groundwater consumption may pose non-carcinogenic and carcinogenic health risks to children and adults. It is prudent that more effective administrative, social, and control measures should be taken to minimize the contaminant exposures to groundwater.