Concentrations of lead, cadmium and mercury in sardines, Sardina pilchardus (Walbaum, 1792) from the Algerian coast and health risks for consumers

In order to assess the health risks associated with the consumption of Sardina pilchardus (Walbaum, 1792) and to study the spatiotemporal dynamics of three potentially toxic metals, lead (Pb), cadmium (Cd) and mercury (Hg) concentrations were measured in the muscle and the liver of 872 specimens of sardine sampled between October 2017 and September 2018 along the Algerian coast at 3 sites (Algiers, Dellys and Bejaia) subject to high pollution pressure. The concentrations of the three elements were higher in the liver than in the muscle of S. pilchardus. In Algiers, the average Pb concentrations in the liver were high (0.41 ± 0.17 μg/g wet weight) and similar to those noted in specimens from Bejaia. The highest average Cd liver concentrations were also recorded in Algiers specimens (1.53 ± 2.86 μg/g ww), as well as the highest average muscle concentrations of Pb and Cd (0.25 ± 0.29 μg/g ww and 0.31 ± 0.29 μg/g ww respectively). For Hg, the specimens from Bejaia (0.50 ± 0.0001 μg/g ww) and Dellys (0.20 ± 0.07 μg/g ww) presented the highest concentrations. The smaller specimens (total length (Lt) 15 cm) often showed higher accumulation for the three contaminants analyzed, compared to the medium ones. No correlation was observed between contaminant concentrations and the biological indices measured in fish (Fulton's K and the hepato-somatic indices). The concentrations in the muscle were below the maximum levels set by the European Commission for the three elements (0.3 μg/g ww for Pb, 0.25 μg/g ww for Cd and 0.5 μg/g ww for Hg). The calculated target hazard quotients (THQs) were