Seasonal assessment of groundwater quality, hydrogeochemistry, and heavy metal pollution in groundwater at Ranipet District: employing multivariate statistics, agricultural indices, and health risk evaluation

Groundwater is a vital resource supporting drinking water, agriculture, and ecosystems, which are critical in sustaining life and economic development. Groundwater contamination poses significant risks to public health, particularly for vulnerable populations such as infants, children, and adults. This study investigates the health risk assessment of groundwater contamination, focusing on key contaminants, including heavy metals contamination, irrigation indices, and hydrogeochemical characteristics in Ranipet District (RD), a region heavily influenced by agriculture and tannery industries. A total of 408 groundwater samples were collected and analysed by multivariate statistics, irrigation indices, and health risk assessment for pre-monsoon and post-monsoon during 2023 and 2024. The physicochemical parameters and heavy metals (Cr, Cd, Zn, Pb, and Cu) are considered in this analysis. The results of multivariate statistics and hydrogeochemical analysis affirm that total dissolved solids (TDS), calcium (Ca2+), magnesium (Mg2+), and potassium (K+) have controlled the hydrochemistry of the RD. Chromium (Cr), cadmium (Cd), copper (Cu), and zinc (Zn) are beyond the permissible limit and cause significant impacts on human health. Evaporation and rock-water interaction are the primary hydrochemical mechanisms controlling the hydrogeochemistry of the RD. The Piper diagram shows that CaMgHCO₃, CaMgSO₄, and NaCl are types of groundwater in the study area. The agriculture indices results confirmed that the groundwater in the RD affects crop productivity because the groundwater quality varies from very poor to unsuitable. The health risk assessment shows that infants and children are very likely to have carcinogenic and non-carcinogenic impacts due to the unauthorised industrial wastewater discharge and improper solid waste handling practices in the study area. Natural and anthropogenic activities are significantly affecting the groundwater quality in the study area. This is a pressing issue; addressing it with preventative actions to ensure the protection of groundwater sources would lead to the achievement of Goal 6 of the Sustainable Development Agenda (Clean Water and Sanitation).