The aim of the study was to obtain the physicochemical characteristics and the content of Cd, Pb, Hg, Cu and Zn in three groups of honey (blossom, blends and honeydew). Physicochemical constituents were examined according the European Honey Commission recommended methods and heavy metals were determined by atomic absorption spectrometry. Among the groups of honey significant differences in the amount of mineral substances, pH, electrical conductivity (P < 0.01) and free acidity (P < 0.05) were found. Differences were not found in water content and insoluble matter. The average concentration of hydroxymethylfufural (HMF) and sucrose varied in individual groups of honey, however, these differences were not statistically conclusive. Concentrations of risk elements (Cd 0.5-77.4 µg/kg, Pb 0.02-1.0 mg/kg, Hg 0.67-2.93 µg/kg, Cu 0.06-1.55 mg/kg and Zn 0.2-22.9 mg/kg) were far below the allowable limits and showed statistically significant differences (P< 0.01) for Cd, Hg Cu in the individual groups of honey. The content of Pb and Zn did not differ significantly in individual groups, however, significant correlations between HMF and Pb (r = 0.63, P < 0.05) and HMF and Zn (r = 0.5, P < 0.05) were found.

AbstractČelechovská O., Z. svobodová, v. Žlábek, b. Macharáčková: distribution of Metals in Tissues of common carp (Cyprinus carpio l.). acta vet. brno 2007, 76: s93-s100.The aim of the present study was to investigate the distribution of selected metals (as, cd, Pb, hg, cr, cu and Zn) in tissues of the common carp (Cyprinus carpio l.) grown in ponds. a total of 125 market-ready carp (aged 3 -4 years, weight 2312 ± 583 g) from 10 fishponds in the czech republic were analysed. The tissues analysed included muscle, liver, kidney, spleen, gills, ovaria and testes. Metal concentrations were determined by the aas, mercury was determined using a cold-vapour aas analyse (aMa 254). results showed different affinities of metals to different tissues. The highest concentrations of as and hg were in muscle tissue, cu in the liver, and cd and Zn in the kidneys, compared with levels in other tissues (p < 0.01). The lowest metal concentrations (particularly of cd) were found in the spleen, gills and gonads. lead concentrations in the individual tissues were low and practically identical. chromium concentrations were also balanced with sporadic significant differences (p < 0.05). significantly higher concentrations of cu, cr (p < 0.05) and Zn (p < 0.01) were found in the ovaria compared with the testes. The study showed that meat and gonads of pond carp in the czech republic are safe from the point of view of contamination with the metals investigated.

The aim of the present work was to compare the distribution of selected metals in tissues of several fish species caught in the Věstonice reservoir. The hygienic quality of fish meat was assessed with respect to the mercury concentration. A total of 35 fish of the following species were caught: carp (Cyprinus carpio), bream (Abramis brama), asp (Aspius aspius), pikeperch (Sander lucioperca) and pike (Esox lucius). Samples of muscle, liver (hepatopancreas), kidney, gonads and gills were analyzed. Hg, Pb, Cd, Cu, Zn and Cr concentrations in fish tissues were determined by the AAS. The results showed that different metals differ in their affinity to different fish tissues (e.g. Cu -liver, Cd -kidney). Mercury concentrations along the food chain increase, i.e. higher mercury concentrations are found in predatory fish. Contrary to mercury, cadmium and lead concentrations do not show any increases along the fish part of food chain in surface water ecosystems. In predatory fish, lower concentrations of these metals were found than in nonpredatory fish species. Differences in concentrations between ovaria and testes were found only in Cu and Zn. To evaluate possible health risks of mercury concentrations for consumers, the risk index was calculated and maximum admissible amounts of muscle meat for consumption were determined. The results confirmed good hygienic quality of market-ready fish from the Věstonice reservoir. Predatory fish, non-predatory fish, heavy metals, AAS, risk indexThe rising living standards of human population take their toll in increasing loads to the environment with various contaminating substances that occur naturally at very low concentrations, or do not naturally occur at all. Besides metal manufacturing and processing, the sources of environmental metal contamination include industrial waste products, the burning of fossil fuels, and the use of metals by consumers. The increase in metal concentrations in the environment is further enhanced by their poor degradability resulting in metal accumulation in the soil, water sediments and the food chain (Svobodová et al. 1987).As the final link of the food chain in the aquatic environment, fish are an important indicator of contamination by a number of substances, including metals (Svobodová et al. 1996). Moreover, toxic metal concentrations in fish are monitored also in terms of food safety (Svobodová et al. 2004). First and foremost, the most closely monitored potentially toxic metals include mercury followed by cadmium and lead. In recent years, food safety has been a priority in EU member states. Hence, the large number of regulations targeting veterinary food hygiene that are being adopted mainly by the European Food Safety Authority (EFSA) and other organisations. At present, hygienic limits are determined by the highest acceptable levels of contaminants in foodstuffs in the Commission Regulation 1881/2006/EC as amended and Decrees 68/2005 Sb. and 305/2004 Sb. of the Ministry of Health. As far as fish as food animals are concerned, the m...

Abstractčelechovská o., l. malota, s. zima: entry of heavy metals into Food chains: a 20-year comparison study in Northern moravia (czech Republic). acta vet. Brno 2008, 77: 645-652.

ABSTRACT:The aim of the present study was to assess metal contamination in the same reaches of the river, and thus to help explain unsatisfactory reproduction results in the reproduction of salmonoid fish. The contamination assessment was based on measuring metal concentrations in the brown trout (Salmo tru�a morpha fario) and some bo�om sediment samples. The samples were collected in June 2000 and 2001 at two collection sites from the Tichá Orlice River (Červená Voda -103rd river km; Lichkov -93rd river km) and its tributary Kralický Brook (100th river km). At each of the sites, 14 brown trouts were collected in each of the periods of monitoring. The AAS method was used to determine the total mercury, arsenic, cadmium, lead, copper, zinc, chromium and nickel contents in the muscle tissue of the fish and in aquatic sediments. The Kralický Brook is an important anthropogenic source of metal contamination (particularly of mercury and copper) for the Tichá Orlice River. The highest concentrations of mercury in muscles of brown trout were found at the Kralický Brook (0.37 ± 0.08 and 0.40 ± 0.08 mg/kg) and Lichkov 0.14 ± 0.07 mg/kg). The authors hypothesize that the difference was due to different conditions (principally water temperature). It seems reasonable to assume that unsatisfactory results in the reproduction of fish from the upper reaches of the Tichá Orlice River are due not only to organic pollutants but also to mercury compounds that are classified among suspect endocrine disruptors.