Monitoring of trace elements in silverside (Odontesthes bonariensis) from pampasic ponds, Argentina

Abstract

The presence of trace elements (Cr, Mn and Zn) in soft tissues (muscle, gills, scales, liver and gonads) of silverside (Odontesthes bonariensis), and its relation to the concentration of these elements, in water of the Pampasic ponds were studied. Based on the results, the risk of poisoning by consumption of silverside fish was calculated. Cr had a higher concentration in the fish scales of most ponds, the gill being the secondary target organ. The highest concentrations of manganese were found in gills, liver and fish scales. Gills and liver samples from Chascomús ponds had higher values of that metal than the rest of the ponds. In the ponds of Adela, Chis-Chis, and Barrancas these concentrations were lower, with 14–34μg/g in gills and 5–9μg/g in liver. In Tablilla ponds, Mn concentration in all organs of silverside was very variable. Zn was the metal with the highest concentration in all fish organs analyzed with respect to the other trace elements studied. Considering the limits set by the Scientific Committee on Food (SCF) for Cr at 0.03mg/kg, Mn at 0.07mg/kg and Zn at 1.57mg/kg, and given a balanced diet, with a consumption of twice a week, we could observe that in none of the cases the consumption of this species can be harmful to human health. Nevertheless, if we considered a daily consumption of this fish coming from Chascomús ponds, the limit of Mn could exceed the permitted levels and making it a human risk.