heavy metals concentrations and human health risk assessment for three common species of fish from karkheh river, iran

background: the concentrations of heavy metals in the tissues and organs of fishes indicate the concentrations of heavy metals in water and their accumulation in food chains. in the present study, the concentrations of zn, cu, cd, ni, v and pb in three common species of fish and the potential health risks to local residents via consumption of the fishes were estimated.  methods: the concentrations of heavy metals (zn, cu, cd, ni, v and pb) in the muscles, heart, liver, and gills of liza abu, barbus grypus and cyprinus carpio, collected from karkheh river, southern iran were measured. associated human health risk was also evaluated by hazard quotient (hq) and hazard index (hi) of muscle tissues. results: bioaccumulation of heavy metals was the highest in the livers followed by gills, heart and muscle. zn was the most accumulated metal in liver of c. carpio while cd had the lowest concentration in the muscle of l. abu. there were significant differences in metal concentration among different fish and different tissues (p<0.05).zinc showed the highest concentrations in different tissues of all analyzed fish, while cd had the lowest concentration in all tissue samples. the hazard quotients from consumption of the collected fish did not exceed the limit of 1.0. conclusion: the present study was a large-scale investigation of heavy metals in three common species of fish in karkheh river. occasional consumption of these fish is not likely to cause adverse effects. however, hazard indices for c. carpio and liza abu were 1.751 and 1.21, respectively, which implies that continuous and excessive intake of these fish could result in chronic non-carcinogenic adverse effects.