Fate and Transport of Viruses in the Subsurface Environment: A Systematic Review of Pollution Pathways in Saturated...

Groundwater contamination by enteric viruses presents an escalating threat to public health and water security, particularly in regions lacking advanced water treatment infrastructure. This review provides a comprehensive and comparative analysis of virus transport and survival mechanisms in saturated and unsaturated porous media. The study synthesizes peer-reviewed literature from 2015 to 2025 applying the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework, focusing on viral entry pathways such as domestic sewage, cemeteries, and septic systems, as well as the physicochemical and biological processes governing virus mobility and persistence in subsurface environments. In saturated porous media, viral transport is accelerated by continuous water flow and reduced filtration, whereas unsaturated conditions restrict virus mobility through complex interactions at the air-water interface, capillary forces, and adhesion to mineral surfaces. Critical environmental parameters including temperature, moisture, pH, ionic strength, and hydraulic conditions were found to significantly influence virus fate, with low temperature and near-neutral pH enhancing persistence. Additionally, biofilm formation and virus aggregation emerged as key factors increasing environmental stability and resistance to inactivation. This review highlights the need for refined predictive models that account for virus-specific interactions with porous matrices under variable field conditions. Importantly, it not only synthesizes the mechanisms governing virus transport and survival but also points to their broader ecological implications, including potential contributions to element cycling. These findings underscore the urgency of re-evaluating groundwater vulnerability frameworks to integrate viral transport risks and support the development of targeted mitigation strategies.