A Limited Survey of Metal Content in Blue Jack Mackerel (Trachurus picturatus) Obtained from Markets in the Canary Islands

Abstract

The levels of 20 metals (aluminum, boron, barium, calcium, cadmium, cobalt, chromium, copper, iron, potassium, lithium, magnesium, manganese, molybdenum, sodium, nickel, lead, strontium, vanadium, and zinc) were analyzed in muscle and liver tissue of Trachurus picturatus marketed in the Canary Islands (Spain) by using inductively coupled plasma optical emission spectrometry. In the liver samples, the mean concentrations in milligrams per kilogram wet weight (wt) of Al (14.7), B (0.99), Ba (1.64), Ca (314), Cd (2.52), Co (0.15), Cu (4.07), Fe (106), Li (3.89), Mn (0.85), Mo (0.16), Na (1510), Ni (0.51), Pb (0.36), Sr (3.54), V (0.78), and Zn (23.13) were higher than those detected in the muscle samples in milligrams per killogram wet wt, which were as follows: Al (8.76), B (0.07), Ba (0.30), Ca (210), Cd (0.01), Co (0.01), Cu (1.51), Fe (7.33), Li (1.08), Mn (0.12), Mo (0.01), Na (697), Ni (0.11), Pb (0.04), Sr (1.45), V (0.01), and Zn (4.69). The mean concentrations of Cr, K, and Mg (0.14, 1,904, and 243 mg/kg wet wt, respectively) were higher in muscle than in liver (0.05, 1,333 and 236 mg/kg wet wt, respectively). The mean concentrations of Cd and Pb (0.01 and 0.04 mg/kg wet wt) in muscle did not exceed the maximum limits established by a European Commission regulation (0.1 mg of Cd/kg and 0.3 mg of Pb/kg, respectively). Considering a mean daily consumption of fish muscle for the adult population of 31.9 g/day published in the report on food consumption by the Spanish Ministry of Agriculture and Fisheries, Food and Environment, Mg made the highest contributions to the intake (2.58% for adult women of 60 kg and 2.22% for men of 70 kg), and the estimated intakes of Al (0.35 to 0.46 mg/day), Cd (0.55 to 0.74 mg/day) and Pb (1.66 to 5.53 mg/day) were below the respective established tolerable intakes. In conclusion, the results of this study show that the consumption of muscle from this benthopelagic species can be considered safe in terms of maximum legal limits, while consumption of liver is discouraged as a major source of exposure to toxic metals, such as Al, Cd, and Pb.