Seasonal variability in groundwater quality and its implications for human health risk in Guwahati City, Assam, India
Groundwater quality assessment is essential for ensuring safe drinking water, given that groundwater serves as a primary water source. The quality of groundwater is deteriorating due to population growth and urbanization. This study evaluates groundwater quality in Guwahati City, Assam, India, by analyzing basic hydrochemical parameters and trace element concentrations. The findings indicate that fluoride (F-) originates mainly from geogenic processes. Elevated arsenic (As) concentrations in one well are likely linked to local anthropogenic sources, while widespread manganese (Mn) and lead (Pb) contamination across the city may result from industrial wastewater and landfill leachate. The dominant hydrochemical facies was Ca-Mg-HCO3 during the dry, pre-monsoon, and monsoon seasons, shifting to Na-K-HCO3 in the post-monsoon season, potentially influenced by ion-exchange processes. Cluster analysis identified poor water quality in the northeastern part of the city, and principal component analysis demonstrated that both geological and anthropogenic factors affect water quality. Human health risk assessment further revealed that children are more susceptible to non-carcinogenic health risks, whereas adults are more vulnerable to carcinogenic health risks. These findings highlight the need for targeted groundwater monitoring and pollution control to protect public health, particularly among vulnerable populations.