Geogenic Weathering, Spatial/Seasonal Variability, and Nonpoint Pollution Govern the Aquatic Ionic Probability Exceedance and Associated Health Risks in the Ganga and Yamuna Rivers
Year: 2025
Type: article
Abstract: This study evaluated the hydrogeochemical characteristics and heavy metal risks in water samples from the Ganga and Yamuna Rivers, with 18 samples collected from each during pre- and post-monsoon seasons. The research employed hydrogeochemical analyses, statistical methods, probability assessments, hazard indices, and risk evaluations. Findings indicated that evaporation was the primary process affecting both rivers, especially in the pre-monsoon season, leading to increased concentrations of major ions and heavy metals. Notably, geogenic processes such as carbonate and silicate weathering displayed significant spatial and seasonal variability, with carbonate weathering more pronounced in the Yamuna River. Higher carbonate levels in the pre-monsoon suggested precipitation that was later diluted by rainfall in the post-monsoon season. Probability exceedance analysis revealed greater spatial differences between the rivers, with the Ganga River showing pronounced reductions in ion concentrations, attributed to its larger flow rate and shorter residence time. This resulted in lower heavy metal concentrations, including arsenic (As > 5 μg/L) and lead (Pb < 15 μg/L). The mobilization of arsenic was linked to competitive desorption involving HCO3- and PO43-, particularly in the Ganga. Multivariate analyses indicated interactions between geogenic and anthropogenic influences, particularly from tanneries and industries, with greater impacts observed in the post-monsoon season in the Yamuna. The Health Pollution Index (HPI) revealed that the Yamuna River was more polluted than the Ganga, with 44.4% of samples unsuitable in the pre-monsoon season and 11.1% in post-monsoon. Populations in Kanpur along the Ganga and Mathura along the Yamuna were identified as most vulnerable based on the Toxicity Health Index (THI). Infants were particularly at risk from both non-carcinogenic and carcinogenic exposures, with exposure duration, ingestion rate, and metal concentrations identified as significant risk factors through oral and dermal pathways. The study significance lies in the fact that the Ganga-Yamuna River floodplain is the major source of groundwater recharge used for irrigation that supports the one-sixth of human population.
Source: ACS ES&T Water
Language: English
Subfield: Water Science and Technology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4410399262