The systematic analytical control of contaminants in food is important. Mercury is concentrated in seafood, products of prey and marine fish, fish from rivers and lakes in the areas contaminated by mercury. According to the findings of this study with analyzer AMA 254, the consumption is not recommended of fish, especially seafood (meat of shark, swordfish and king mackerel), for selected groups of the population: children, women of childbearing age, pregnant women and nursing mothers.

Global environmental contamination is one of the most significant environmental problems in contemporary society. Pollutants are entering the environment from different sources, and on the basis of their physico-chemical properties, they are transported and participate in biochemical cycles in the varied components of the environment, namely in the air, aquatic environment, soil and in rocks or segments. They enter the food chain through which they enter the human body, where they are transformed into either harmless metabolites (detoxification) that are easily excluded or else harmful, reactive products are formed. Heavy metals are one of the most dangerous groups of biologically important pollutants. The burden of the environment puts more significant burden on populations and ecosystems. They form integrant part of the earth's surface and therefore are present throughout the land. We can utter that contamination of the environment and its consequences for living organisms have long been in forefront of the interest in scientific as well as lay community.

In the present work, the long-term effect (14 days) of copper on the levels of intracellular and total copper accumulation, growth, assimilation pigment composition, chlorophyll a fluorescence, soluble protein content and oxidative status (production of hydrogen peroxide and superoxide) in two algal species (Scenedesmus quadricauda and Trebouxia erici) was assessed. Scenedesmus quadricauda is a free-living alga while Trebouxia erici is the photobiont of a lichen. The presence of copper negatively affected growth, assimilation pigments, chlorophyll a fluorescence, soluble protein content and oxidative status in both the algae. However, Scenedesmus was much more sensitive compared to Trebouxia.

Introduction. Mercury release in the environment is mainly the result of human activity, particularly from coal-fired power stations, residential heating systems, waste incinerators, and as a result of mining for mercury, gold and other metals, which have led to widespread global mercury pollution. Excessive exposure to mercury is associated with a wide range of adverse health effects, including damage to the central nervous system, digestive and immune systems, and to lungs, kidneys, skin and eyes. Objective. The main aim of the study is to summarize the selected mercury sources in the environment of the Slovak Republic, regarding waste incinerators, landfill waste, crematoria, chemical plants, rivers and soils. Brief description of state of knowledge. Although the neurologic symptoms of Minamata disease were identified sufficiently for specialists to classify mercury as the causative agent, the acceptance of mercury´s environmental impacts will require several decades of research. Several new issues have arisen-the need for energy conservation leads to the use of fluorescent lighting, which contain mercury; emissions driven by increases in coal combustion, incineration and economic development have sent more mercury into the air, soil and water. Conclusions. Mercury is toxic to human health, posing a particular threat to the development of the child in utero and early in life. The systematic analytical controls of contaminants in water, soil and air are important. The installation of modern cleaning technologies to comply with the maximum emission level can substantially minimized the environmental impact of incinerators. Since human cremation is also an increasing practice, further research on mercury emissions is necessary.

a b s t r a c tCladina arbuscula subsp. mitis grows on the surfaces of historical Cu-mine spoil heaps rich in Cu, as well as on the surfaces of substrata that are not metal contaminated. This lichen contains the extracellular secondary metabolite, usnic acid (UA), which was previously found to form complexes with metal cations, including Cu. As UA can be experimentally removed from dry lichen thalli using acetone and without the loss of lichen viability, this study attempted to evaluate its role in long-term (8 wks) Cu tolerance in C. arbuscula subsp. mitis. Removal of UA by acetone did not affect the viability of the lichen, however it caused lower intracellular Cu accumulation after 8 wks of experiment at the highest 500 μM Cu doses tested. Thus far, we did not observe de novo synthesis of UA in the UA− variant of the study during the 8 wks of the experiment. Based on the measurements of the selected metabolic processes in the lichen (chlorophyll a fluorescence, chlorophyll a integrity, TBARS production, content of ergosterol and content of soluble proteins) it would seem that presence of UA in C. arbuscula subsp. mitis did not protect this lichen against Cu excess.