Assessment of cadmium and lead concentration in rainbow trout (Oncorhynchus mykiss) and calculation the food consumption risk

Heavy metals as a main group of aquatic pollutants cause poisoning and concern in fish consumption. The aim of the present study was to assess cadmium (Cd) and lead (Pb) concentration in liver and muscle of rainbow trout (Oncorhynchus mykiss). Additionally, the relationship between the heavy metals concentration with weight and length and the consumption risk of the species were assessed.

Thirty specimens of rainbow trout were obtained from a fish farming ponds that is located in Sanandaj City. After acidic digestion of the specimens, concentration of Cd and Pb were determined by using atomic adsorption spectrophotometer.

The average concentration of Cd and Pb were 0.62 and 26.31 μg/g wet weight (ww) in liver and 0.16 and 23.65 μg/g ww in muscle, respectively. The amount of Pb was higher than the maximum acceptable level that is permitted by most international organizations. There was a significant correlation between Cd and Pb with length and total weight of liver. Also, a significant relationship was found between Cd and length and total weight of muscle (p < 0.01). The amount of THQ, Daily and weekly intake of Cd and Pb were lower than the allowable proposed dose. The maximum allowable consumption rate of Cd and Pb were 0.16 and 0.09 kg/day for adults and 0.01 and 0.002 kg/day for children, respectively.

The results of the present study showed that the amount of Cd and Pb in the rainbow trout is safe to consume and does not threaten the health of consumer with current consumption rate