Toxic and essential elements in selected fish species from the Tigris River (Turkey) and assessment of their health risks and benefits

Abstract

The distribution of 18 toxic and essential elements (TEEs) (Sr, As, Ba, Cu, Fe, Ga, Ca, Cd, K, Co, Mg, Mn, Na, Ni, P, Pb, Cr and Zn) was investigated in tissues/organs of three fish species showing similar feeding habits from the Tigris River. The findings revealed that concentrations of TEEs in fish depend on the species. The highest contents of most TEEs were recorded in the gills followed by the liver, skin and muscle. Generally, inverse relationships were recorded between fish size and TEEs in tissues of fish species which may be explained by the lower metabolic rate and dilution effect of higher lipid content in the bigger fish. The average contents of Cd, Pb, Cr, Cu, Zn and inorganic As in muscle tissues of fish species were below the permissible limits. The estimated daily intakes of Ba, Cu, Fe, Mn, Ni, Sr, Zn, inorganic As, Cd, Co, Cr and Pb were much lower than the reference doses set by USEPA. The target hazard quotient and hazard index values were below 1, indicating that non-carcinogenic health effects are unlikely to occur. The carcinogenic risk values for inorganic As were below 10−6, indicating no carcinogenic health risks for consumers. It was found that daily consumption of 230 g of fish would not be expected to cause any health risks. In addition, it was found that fish species would provide great benefits considering intake of essential elements. These findings revealed that nutritional benefits from consumption of fish species outweighed the health risks posed by toxic elements in fish.