Heavy metals distribution in muscle, liver, kidney and gill of European catfish (Silurus glanis) from Italian Rivers

► Hg, Cd, Cr, As and Pb levels were evaluated in organs of European catfish (Silurus glanis) from Po River. ► Hg contents exceeded the EC maximum level while Cd and Pb fit the EC regulatory limits. ► Hg level was significantly related to sampling site and to size and age of S. glanis. ► There are highly significant differences among the fish organs for the accumulation of heavy metals.