Spatial distributions of chemical elements in soil and stream sediment at the area of abandoned mercury mine in Podljubelj (Slovenia)

摘要

The objective of the research project concerning the abandoned mercury mine in Podljubelj was to establish the contents and spatial distributions of chemical elements in soil and sediments in order to distinguish between anthropogenic (man-made) and geogenic (natural) element sources. The special attention of the research was focused on the extension of Hg pollution which is a consequence of past mining and smelting activities. The Podljubelj mine was in operation from 1557 to 1902. The entire operating period yielded about 110,000 tons of ore, from which 360 tons of Hg was produced. By soil and sediment sampling it was established that on an area of about 9 hectares Hg contents in soil exceed the Slovenian critical values for soil (10mg/kg). The estimated mercury mean for the studied area is 3.04mg/kg (0.17-719mg/kg) for soil and 0.64mg/kg (0.065-1.36mg/kg) for stream sediment. The highest determined value was found at the area of former smelter. Elevated contents of Hg were also found in the mine and smelter waste dump. Mercury contents in soils generally decrease with depth in soil profile and with the distance from the mine and smelter. Apart from the area around the former mine and smelter, mercury appeared also in higher concentrations along the road that runs through the valley, which is due to the use of Hg bearing ore residues in road construction.