Spatiotemporal variations in the levels of toxic elements in drinking water of Sivas, Türkiye, and an ecotoxicological risk assessment

This study was conducted in 2022 to investigate the water variables of fountains used by people for drinking purposes in Şarkışla (Sivas, Türkiye). Five stations were selected from the most frequently used fountains. Sampling was carried out seasonally. Various physicochemical variables such as water temperature (WT), pH, electirical conductivity (EC), dissolved oxygen (DO), nitrite (NO₂), nitrate (NO₃), phosphate (PO₄), sulphate (SO₄), magnesium (Mg), calcium (Ca), total hardness (TH), chloride (Cl), salinity, total dissolved solids (TDS), arsenic (As), cadmium (Cd), zinc (Zn), manganese (Mn), and copper (Cu) were investigated. Additionally, the Nitrate Pollution Index (NPI), Groundwater Quality Index (GWQI), and Human Health Risk Assesment (HHRA) methods were applied to the data. One of the main objectives of this study was to conduct health risk assessments for people using water from drinking fountains and to identify both carcinogenic and non-carcinogenic metals. As a result of this research, NPI values indicated slight contamination, while no contamination was found based on GWQI values. The Mn and Cd were found to slightly exceed the permissible limit values. As, which exceeds the limit value in water, was found to pose a serious carcinogenic risk (CR) for both children and adults. High As values are from quaternary alluvial deposits and aquifer layers of Pliocene terrestrial layers. Considering the hazard quotient (HQ) and hazard index (HI) for the presence of Cd, it was determined that it poses a serious risk to humans and children through both ingestive and dermal exposure. At the end of the study, several recommendations for the sustainable use of drinking fountains water were provided.