Fish is one of the best sources of protein and the consumption of fish provides polyunsaturated fatty acids (PUFA), liposoluble vitamins, and essential minerals for human health. However contrary to their known benefits, fish may pose potential risks to human health since they can accumulate substantial concentrations of heavy metals in their tissues. This research is aimed to evaluate the heavy metals contamination and human health risk in rainbow trout (Oncorhynchus mykiss) collected from different farms of Chaharmahal and Bakhtiari province in Iran. The Chaharmahal and Bakhtiari province is targeted due to this province is the largest coldwater fish production center. In the present research accumulation of four heavy metals such as lead (Pb), cobalt (Co), copper (Cu) and zinc (Zn) were investigated in farmed rainbow trout, collected from fish farming at eight cities in the province of Chaharmahal and Bakhtiari, Iran. Risk to human health by the intake of metal-contaminated rainbow trout fish have been evaluated by estimated daily intake (EDI), target hazard quotient (THQ), and hazard index (HI). Pb and Cu concentrations in rainbow trout muscle were above the safe limits of FAO, FAO/WHO, and WHO standards in all the fish farms, while Zn were lower than the permissible limits. The estimated daily intakes (EDI) and estimated weekly intakes (EWI) of all studied heavy metals (mg/day or week/bw-kg) via consumption of the rainbow trout by the consumers were well below the provisional tolerable daily intake (PTDI) and provisional tolerable weekly Intake (PTWI) set by FAO/WHO. Pb and Co THQ values indicated the absence of health risks through consumption of the studied fish species, but pose non carcinogenic risk for Cu and Zn (target hazard quotient (THQ) > 1). In general, aggregate effect, assessed by hazard index (HI), expressed health risk for consumption of rainbow trout for a life time of more than 70 years.
