ECO-ENVIRONMENTAL RESEARCH OF PORAC CREEK CATCHMENT AREA AT THE AREA INFLUENCED BY ENVIRONMENTAL LOADS

Pollution of water environment by heavy metals became very serious in localities influenced by long-term mining and processing activities. Pollution of Porac creek by heavy metals is caused by heaps of waste material stored along the creek the same as by atmospheric deposition coming from mercury processing plant. Total content of heavy metals (Cu, As, Pb, Zn, Hg), some chemical properties (pH) and biological properties (only in sediment samples - urease, acid phosphatase, alkaline phosphatase) were determined in soil and water samples. Correlation relationships between soil and sediment properties were calculated using Spearman's correlation coefficient. Species composition of flora at the bank of the creek was evaluated according to the Braun - Blanquef scale. Content of heavy metals was also determined in the plant samples. Water pollution was evaluated as less serious than pollution of sediments, where toxic elements were accumulated in higher levels relative to the limit values. Extremely high value of copper, zinc and mercury was determined at first locality, which was proved as the most polluted because of presence the heaps of waste material. With the increasing distance of sampling point from the village, the activity of soil enzymes increased while the metal content decreased. Significant positive correlation was found between heavy metals themselves and between soil enzymes. Urease gave significant negative correlation with all heavy metals, acid and alkaline phosphatases were significantly negatively influenced by copper, arsenic and lead. Predominantly hydrophobic plant species as Petasites hybridus, Mentha longifolia, Geranium sylvaticum were found. Analysis of plant samples showed elevated levels of heavy metals especially Zn and Cu.