Sources and levels of potentially toxic elements pollution in agricultural areas in Sivas, Türkiye: implications for soil and human health

This study investigated the accumulation of potentially toxic elements (Fe, Mn, Ni, Zn, Pb, Co, and Cd) in soils affected by intensive agriculture and wastewater discharge and analysed 24 soil surface samples (0-20 cm) using ICP-OES 5100. Results showed Cd, Ni, and Pb levels surpassing upper continental crust benchmarks by factors of 6.55, 2.31, and 0.25, respectively. Enrichment factor revealed significant enrichment for Cd (18.79) and Ni (6.31), with moderate enrichment for Pb (2.83). Based on the geoaccumulation index criteria, the soil was classified as moderately to heavily polluted with Cd and unpolluted to moderately polluted with Ni, while it was unpolluted with respect to the other metals analyzed. Cd exhibited very high contamination (CF = 6.52) and a high potential ecological risk (Er = 195.49), while the pollution load index (PLI = 1.24) indicated high contamination. The mean ecological risk index (RI = 212.90) suggested moderate risk. Source analysis linked Cd to anthropogenic activities, Pb primarily to lithogenic sources, and Ni to mixed origins. A health risk assessment showed no significant risks, though children were more vulnerable. Elevated pollution in the northeastern area near the main road in Sivas underscores the need for targeted management, sustainable agriculture, and regular soil monitoring.