An Overall Perspective for the Study of Emerging Contaminants in Karst Aquifers

Karst aquifers are essential drinking water sources, representing about 25% of the total available sources globally. Groundwater ecosystems consist of fissured carbonate rocks commonly covered with canopy collapse sinkholes. The open nature of karst aquifers makes them susceptible to rapidly transporting contaminants from the surface in dissolved and particulate forms. The principal aim of this review is to contribute to filling the gap in knowledge regarding major concerns affecting karst aquifers and understanding their vulnerabilities and dynamics. The principal groundwater pollutants of relevance are detailed in the present work, including well-known issues, such as the input of agriculture and its role in water quality. Emerging pollutants such as microplastics, still poorly studied in the groundwater systems, were also considered. Case studies for each typology of pollutant were highlighted, as their relative concerns for karst environments. Final considerations underlined an approach for studying karst environments more focused on understanding dynamics and links among different pollutants inputs and their drivers than on individual sources and impacts.