Metals in Mullus surmuletus and Pseudupeneus prayensis from the Canary Islands (Atlantic Ocean)

A total of 20 metals (Na, K, Ca, Mg, B, Ba, Co, Cr, Cu, Sr, Fe, Li, Mn, Mo, Ni, V, Zn, Al, Cd, and Pb) were analyzed by inductively coupled plasma optical emission spectrometry in muscle and liver tissue from a total of 28 examples of the fishes Mullus surmuletus and Pseudupeneus prayensis marketed in Tenerife, Canary Islands (Spain). Significant differences (P < 0.05) in B, K, Mg, Mn, and Na concentrations were found between muscle and liver. The mean concentrations of K (1,388.04 mg/kg wet weight [wet wt]) and Mg (153.33 mg/kg wet wt) were higher in muscle than in liver (697.49 and 114.21 mg/kg wet wt, respectively). The mean concentrations of B in liver (0.18 mg/kg wet wt), Mn (0.70 mg/kg wet wt), and Na (892.09 mg/kg wet wt) were higher than those in muscle (0.15, 0.11, and 375.55 mg/kg wet wt, respectively). The mean concentrations of Al, Cd, and Pb in muscle tissue were 2.72 mg/kg wet wt and 4.28 and 10.29 μg/kg wet wt, and those in liver tissue were 31.31 mg/kg wet wt and 612.91 and 232.08 μg/kg wet wt, respectively. When comparing the two fish species, the muscle tissue of M. surmuletus has significantly higher concentrations (P < 0.05) of Al, B, Ba, Ca, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, Sr, and Zn than did P. prayensis muscle, whereas the concentrations of Cd and V were significantly higher (P < 0.05) in P. prayensis muscle. Toxicological assessment of Cd and Pb concentrations was performed using the maximum limits set by the European Commission Regulations 1881/2006 and 629/2008 for muscle tissue (50 and 300 μg/kg wet wt, respectively). The concentrations of Cd and Pb in muscle detected in the present study for all the analyzed examples of M. surmuletus and P. prayensis were lower than the maximums established for muscle tissue by European legislation. Therefore, consumption of the muscle of these fish is considered safe in terms of Al, Cd, and Pb concentrations. However, the consumption of liver tissue should be avoided because of its high levels of metals. Constant monitoring of the concentrations of metals of toxicological concern in fish products available in the market is an essential part of food safety.