Metal accumulation in economically important fish species from Gökova Bay, Türkiye: approaches of statistical modeling and risk assessment for consumer’s health

The concentrations of eight metals (Cu, Fe, Mn, Zn, Cd, Pb, Se, and Hg) in the tissues (liver, gill, and muscle) of Dicentrarchus labrax and Saurida undosquamis living in Gökova Bay and their relationship with health risk indexes (target hazard quotient [THQ], total target hazard quotient [TTHQ], estimated daily intake [EDI], and carcinogenic risk [CR]) and condition factor (CF) were determined. The calculated EDI for metals shows a low value for adults in comparison with the recommended intake limit, but for children the values for Cd and Mn in both fish were above the recommended values. Based on the metal analyses, the THQ and TTHQ for fish were calculated to be <1 for both adults and children. CR for Cd and Pb were determined at negligible levels. In addition, metal accumulations were modeled by random forest regression using season, tissue type, THQ weight, and fish length as covariates. The models explained about 55%–93% of the variation in metal concentrations and had high correlations between the observed and predicted values (mostly above 0.80), so they can be used as a practical tool to predict tissue-specific metal levels in similar studies.