title: Mercury toxicity and the protective role of selenium in eel, Anguilla anguilla.
abstract: The aim of the study was to determine the impact trace metals, mainly toxic ones, on the condition of eel (Anguilla anguilla) inhabiting four regions of Poland. Metal concentrations in eel muscle tissues were studied as functions of size, region, and season 2011-2012. The levels of metals were also used for risk assessment on consumer health. Copper and zinc occurred at concentrations that could only have positive impacts on eel condition. Low levels of cadmium and lead did not impair the condition of the fish. However, mercury occurred at high levels and increased with fish length and season. The mercury levels in eels were compared with the threshold of toxicity (500-1,200 μg kg(-1)), which can cause changes in biochemical processes and impair fish reproduction. The concentration of mercury was 1,010 μg kg(-1) in one specimen of the 120 samples examined, and in 16 specimens, it exceeded 500 μg kg(-1). The toxic effects of the mercury could have been attenuated by the selenium in the muscles of the eel, especially in the muscles of smaller specimens in which the Se/Hg molar ratio was higher than 1 with a positive correlation between these two elements. In larger specimens measuring in excess of 70 cm, this coefficient was below 1, and the mercury to selenium correlation was negative, which meant that the protective effects of selenium were weaker. The mercury in the muscles of large specimens at levels exceeding 500 μg kg(-1) could have weakened eel condition and also posed a threat to consumer health. The cadmium and lead in the muscles of the eel did not affect the condition of the fish. Mercury weakened the condition of large eel, A. anguilla. Selenium protected small- and medium-sized eel against the toxic effects of mercury.
authors.affiliation: Department of Food and Environmental Chemistry, National Marine Fisheries Research Institute, ul. Kołłataja 1, Gdynia, 81-332, Poland, chemia@mir.gdynia.pl.
authors.forename: Lucyna
authors.initials: L
authors.lastname: Polak-Juszczak
authors.forename: Stanisław
authors.initials: S
authors.lastname: Robak
mesh_terms: D000811:Anguilla; D000818:Animals; D002104:Cadmium / Q000032:analysis; D003300:Copper / Q000032:analysis; D004524:Eels; D004784:Environmental Monitoring; D005399:Fishes; D008628:Mercury / Q000032:analysis*; D008670:Metals; D009132:Muscles / Q000737:chemistry*; D011044:Poland; D012643:Selenium / Q000032:analysis*; D015032:Zinc / Q000032:analysis
chemical_list: D008670:Metals; D002104:Cadmium; D003300:Copper; D008628:Mercury; D012643:Selenium; D015032:Zinc