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The concentration of metals (Pb, Cd, Zn, Hg) in different ecosystem components (lake water, sediment, plankton, macrophytes, and fish tissues) has been determined in Velenjsko jezero, an artificial lake resulting from mining activity. The risk to humans from consuming fish has been evaluated from the heavy metal load of fish muscle tissue. Heavy metals are transferred through the food chain at different levels, and Hg is found to be the element of the highest ecotoxicological concern. Although both sediment and plankton contain relatively low concentrations of Hg, this element accumulates in high levels in fish, especially in the benthivorous species Abramis brama danubii and predator species Perca fluviatilis. Moreover, Hg appears to be very mobile in the fish organism. Whereas the other metals remained mostly in liver (Cd) or gills (Zn, Pb), levels of Hg in fish muscle and liver were the same and markedly higher than in gills. However, in muscle, the average concentrations of each metal were below their maximum limits, determined either by Slovenian legislation or by the Food and Agriculture Organization.

Pulmonaria officinalis is an understorey spring geophyte, which starts its vegetative period before full foliation of the tree storey. During its early growth phase it is exposed to full solar radiation, therefore the enhanced UVB radiation could present a threat to this species. An outdoor experiment in which potted plants were exposed to below ambient, ambient, and above ambient (corresponding to 17% ozone reduction) UV-B radiation, was conducted in order to evaluate the radiation effects. The amount of photosynthetic pigments and photochemical efficiency of PSII were not affected, but the amount of UV-B absorbing compounds was lower in plants grown under reduced UV-B. This change was measurable after only fourteen days in reproductive shoots, while in the vegetative shoots, it was not detectable until after three months. The leaves of P. officinalis are variegated and the light green spots became less transparent to PAR under enhanced UV-B. The results reveal that under simulated 17% ozone depletion the harmful effects of UV-B on the measured parameters were negligible.

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