Health Risks of Trace Metals in Wastewater-Fed Fishes: A Case Study

In this study, the usage wastewater from secondary treatment in feeding fishes of Carassius gibelio species and suitability of the fishes for human food were evaluated. The metals (Ag, Al, As and B) in treated effluent and skeleton, skin, eyes and brain tissues of fishes were examined seasonally. It was found that treated effluent was not suitable for irrigation and aquaculture in terms of Al according to the Turkish standard values. According to annual averages the size order of Ag and B concentrations were skeleton> skin> eyes>brain and skeleton> skin>brain>eye respectively. Also, skin>brain>eyes>skeleton was for As and Al.   TF (Transfer Factor) values of all metals examined were determined as >1 in the four tissues and the metals caused bioaccumulation because of treated effluent. Concentrations in muscles were found 7 to 6227 times higher than in water. The size order of TF and BCF (Bio-concentration Factor) values in skin and eye tissue were the same and it was Ag>Al>As>B. It was Ag>Al>As>B in skeleton, Al>As>Ag>B in brain. HQ (Hazard Quotient) of Al in all tissues had carcinogenic risk level.