Evaluating Heavy Metals (Lead and Nickel) in Water and Muscle Tissue of Trout in the Farms of Guilan Province

Fish is one of the most significant protein resources for human nutrition which is highly appreciated because of having no pollutants. Heavy metals are among the pollutants causing many health problems for aquatics, and consequently humans. This study was done to determine lead and nickel concentrations in the muscle tissue of the trout (Oncorhynchus mykiss) and consumed water in Guilan farms. Totally, 30 pieces of farmed Rainbow Trout and water samples from three farms in western part (Talesh), eastern part (Siahkal), and central part (Fouman) of Guilan were sampled randomly and transported to the laboratory of Health Faculty of Guilan University of Medical Sciences. The levels of the heavy metals were measured by ICP-OES Spectro-Amitec and the results were analyzed by statistical software SPSS16 and Tuki Test. Safety Factor of this study was determined %95 (p=0.05) and T Test was used in order to compare with the standards. The level of Nickel in fish muscle tissue of Fouman farm was more than that in Talesh and Siahkal farms. The amount of Lead in fish muscle tissue of Siahkal farm was more than that in Talesh and Fouman farms. The average of Nickel level in fish muscle in Fouman, Talesh, and Siahkel was measured 1.29 ± 2.0491, 0. 445 ± 0.457, and 0.217± 0.086 (mg/kg), respectively. The average of Lead levels was measured 0.252 ± 0.221, 0.294 ± 0.095, and 0.485 ± 0.444 (mg/kg), respectively. No significant differences were observed (p>0.05). The amount of lead in farm water was reported zero; but the amount of nickel in farm water of Siahkal, Fouman, and Talesh was measured 0.032 ± 0.002, 0.027 ± 0.002, and 0.026 ± 0.005 (mg/l), respectively. The amount of Lead in fish muscle tissue was less than the world standard threshold of WHO, while the amount of Nickel in Talesh and Fouman farms was more than the established world standards; but no significant differences were observed (p>0.05).