Mapping geochemical distribution, toxicity and ecological risk indices of potentially toxic elements in cultured fish and surface water (Blacksea catchment/Türkiye)

In this study, the bioaccumulation levels, the geochemical distributions and the ecotoxicological risk levels of potential toxic elements (PTEs: Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Cd, Hg and Pb) were determined in water and fish (Rainbow trout) collected from 15 different ponds in the Black Sea coastal basin. Among the PTEs in muscle tissue, Fe was determined to be at the highest level, while Cd and Co were at the lowest level. It was observed that As and Mn were above the maximum permissible levels. Water Quality Index (WQI) values were excellent at all stations, and no pollution levels were detected that would threaten human health according to the Heavy Metal Pollution Index (HPI) and the Heavy Metal Evaluation Index. The metal pollution index level in fish produced in inland waters in the study area was less than 2 (0.78), indicating that there may not be a potential health risk due to the bioaccumulation pattern. However, the target hazard coefficient (THQ) for As was > 1 at all stations except S1 and S15, and the hazard index was > 1 at all stations except S1, suggesting the possibility of non-carcinogenic adverse health effects. When evaluated in terms of total cancer risk level, it suggests that there may be a cancer risk due to metal accumulation in all stations except S1.