ASSESSMENT OF HEAVY METAL AND ARSENIC CONTAMINATION IN THE WATER AND SEDIMENTS OF LAKE BEYŞEHIR, KONYA

Beyşehir Lake, located within the provinces of Konya and Isparta, is Turkey’s third-largest lake and the country’s largest freshwater resource. Increasing industrialization, agricultural activities, and untreated wastewater discharges within the basin have raised concerns regarding heavy metal and metalloid contamination, particularly due to the growing number of firearms manufacturing facilities in the region. This study aimed to evaluate the seasonal distribution and potential environmental risks of selected pollutants in both water and sediment matrices of Beyşehir Lake. Two strategic sampling stations were selected: the first at the point where Büyükköprü Stream, receiving effluents from firearms manufacturing facilities in the Huğlu and Üzümlü regions, discharges into the lake, and the second in an open-water area with high dilution capacity serving as a reference site. Seasonal samples were collected during autumn, winter, and spring. Physicochemical parameters (alkalinity, temperature, dissolved oxygen, pH, and electrical conductivity) and selected elements (Fe, Al, Cd, Cr, Cu, Ni, Mn, As, Ag, and Zn) were analyzed using ICP-OES. Sampling locations and spatial distributions were mapped using Geographic Information Systems (GIS). Statistical analyses, including ANOVA and t-tests, were performed to assess spatial and seasonal variations, revealing significant differences (p < 0.05). Water and sediment quality were evaluated according to the Water Pollution Control Regulation (SWQR).and relevant international criteria. The results revealed an overall concentration pattern in the order of Fe > Al > As > Cu > Mn > Cr > Ni > Zn > Cd. Elevated concentrations of certain elements, particularly Al and Cr, were associated with intensive metallurgical manufacturing activities related to the local firearms industry. The findings indicate that industrial and agricultural pressures may adversely affect the ecological status of Beyşehir Lake, highlighting the need for continuous monitoring and effective management strategies to protect this important freshwater ecosystem.