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Assessment of fish contamination in important fishing grounds
ČERVENÝ, Daniel
The object of this thesis is the assessment of fish contamination by selected foreign substances as toxic metals, polychlorinated biphenyls and pesticides in 31 selected fishing grounds. The monitoring was realized between years 2006 and 2010. Fish were caught by electric device and fishing rods. Concentrations of Hg, Cd, Pb, PCB, DDT, HCH and HCB in fish muscle tissues were monitored. Common bream (Abramis brama) was selected as a reference species for a comparison of the monitored sites. The results of analysis were compared with valid hygienic limits. Overrun of hygienic limit for some of the monitored pollutants were observed in 18 localities. We found mercury as a major pollutant in the aquatic environment.
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Occurrence of mercury in the hair of school children.
HLADÍKOVÁ, Alena
The target of the thesis was to summarize the present knowledge to the topic of occurrence of mercury in hairs of the age categories of respondents defined in advance and to evaluate experimentally the load of the human organism by mercury. It was necessary to acquire a sufficient amount of hairs of children of school-age from the selected locality, to determine the total mercury amount in these samples and to evaluate the achieved results from the viewpoint of the toxic load. Within the bachelor thesis, 90 samples of human hairs of nine various age categories in the range from seven to nineteen years (of respondent age) were tested. In each age category, there were 50% samples of the male and 50% samples of female population. Moreover a questionnaire was made up filled in by each participating person. The determination of the total mercury contents was performed on the one-purpose spectrophotometer AMA-254. Means for the total mercury concentration moved deeply under the permitted limit values. Even the highest established mercury value which was 0,38554 mg/kg was under the limit. Using the one-way ANOVA (F2,87=5,4364; p<0,05) in STATISTICA 7 program, it was proved based on the reviewed influence of factors on the level of mercury in the body, that the mercury concentration depends on the consumption rate of the freshwater fish.
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