Mercury in fish tissues in the area of Malachov Hg-ore deposit (Slovakia)

The abandoned Malachov deposit belongs among the most important historic Hg deposits in the world. The soil, groundwater, surface water, plants, and animals are still heavily contaminated by potentially toxic elements such as As and Cd, but mainly by Hg. This article is focused on the Hg contamination of aquatic plants and animals in the Malachov creek. Mercury concentrations were measured in fresh water (on average 3 µg L^-1), in the zoobenthos (on average 362.47 µg kg^-1), and in the phytobenthos (on average 578.36 µg kg^-1). Higher Hg concentrations were determined in the muscles of Salmo trutta morpha fario (on average 362.47 µg kg^-1) and lower in Cottus poecilopus (on average 352.75 µg kg^-1). The Hg concentrations were higher in the internal tissues (578.36-1185.75 µg kg^-1) than in the muscles of the fish. The Hg content in fresh water exceeded Regulation of the Slovak Government No. 269/2010, which stipulates the criteria for achieving a proper water balance, but the Hg content in the fish muscles of both fish species was below the specified limit of the Food Code of Governmental Regulation of the Slovak Republic No. 608/3/2004-100. The Hg contamination in fishes is controlled by their weight and age. The presented data may be used as the base information for future studies in order to be able to estimate consumption recommendations and warnings.