Search

Heavy metals, also called trace elements, may be essential to the metabolism of living organisms, and at the same time, depending on their concentrations, highly toxic. With the objective to investigate the toxicity of water of the Butuí-Icamaquã Rivers Basin on the border west of Rio Grande do Sul, were analyzed by atomic absorption spectrophotometer, the contents of aluminum, cadmium, chromium, copper, lead, manganese, nickel and zinc in abdominal viscera of fish, collected between June 2007 and February 2008, at selected points in Butuí, Icamaquã and Uruguai rivers. Aluminum, cadmium, manganese and nickel were above the levels considered safe for human consumption and levels near the legal limit were found for chrome and copper. The simultaneous analysis of water samples collected in the same locations showed levels above the legal limits of bromine, chromate, copper, cyanide, lead, manganese, phenols, phosphate and sulfate. These elements, in such concentrations in water and in fish, may compromise the ecosystem or pose risks to human health. [ABSTRACT FROM AUTHOR]

Fish is an important source of heavy metal exposition and contamination for human being. Accumulation of mercury (Hg) in men occurs by chronicle exposition, through the food chain, by ingestion of fish contaminated with mercury. Because of biomagnifications the carnivorous fish that is on the top of the food chain shows a higher concentration of mercury in their tissues and can represent the aquatic environmental contamination. This work aims to establish histopathologic analysis and total mercury concentration in different tissues from thirty-one Trichiurus lepturus, a commercial fish from Itaipu Beach, Niterói, RJ. T. lepturus collected showed mean values of total mercury concentration of 0.051±0.031μg g-1 and 0.006±0.004μg g-1, respectively in muscle and kidney tissues. It was also conducted an analysis of mercury concentration from a pool of brain tissue from all individuals (0.019μg g-1). Minimum and maximum mercury values in muscular and kidney tissues showed a wide dispersion. There was a positive correlation between total length and mercury muscular tissue concentration (R=0.85) and between body weight and mercury muscular tissue concentration (R=0.88), both highly significant. No significant correlation (r=0.24) was observed between kidney weight and mercury tissue concentration (P>0.19). In a multiple comparison test among muscle, kidneys and brain mercury tissue concentration, it was observed a highly significant difference between muscle and kidneys (P<0.001), as well as between muscle and brain (P<0.001). Comparison between kidney and brain mercury tissue concentration also showed a significant difference with a probability level of 5% (P<0.05). Histopathology demonstrated damage in the kidneys (cartilaginous metaplasia in some individuals and a high presence of melanomacrophage centers). [ABSTRACT FROM AUTHOR]