Contamination of vegetation growing on soils and substrates in the unhygienic region of Central Spiš (Slovakia) polluted by heavy metals.

The present paper aims at clarifying the long-term impact of mining activities on the contamination of biotic components of the environment. The research was conducted in during 2011-2014 at selected locations of the cadastral territory of former mining towns of Central Spiš (Slovakia) with different ecosystems of permanent grassland, mine waste sites and bankside vegetation. The results of the analysis showed that considerably dominant species at contaminated locations such as Betula pendula, Silene vulgaris, Geranium sylvaticum, Petasites hybridus, Mentha longifolia could absorb high quantities of heavy metals. The observed contents of heavy metals, especially zinc, copper and mercury in plants significantly exceeded the threshold values determined by law. The highest contamination as compared to the threshold values was found in young plants of Betula pendula in the Slovinky tailing pond site, in which zinc content exceeded the threshold value 852 times. Excess of copper content also exceeded the threshold value 271 times. The highest concentration of mercury in all of the surveyed sites was observed in dry matter of Betula pendula in the area of heap in the Por?č Valley, where threshold value was 184 times higher. Statistically significant locations similar in relation to the characteristic species and monitored heavy metals was recorded on the locations of tailing pond and heap as the most important centres of contamination with the following dominant species Betula pendula, Pinus silvestris and Agrostis capilaris.