GTK’s ‘Geochemical baselines’ map service calculates regional geochemical baselines in soil on the basis of concentration observations saved in a database. In addition to GTK, observations have been made by a number of other information suppliers, such as other research institutes and consulting agencies.
Information about geochemical baselines in soil is needed as comparison values for the evaluation of soil contamination and the need to clean it. ‘Geochemical baselines’ refers to naturally occurring concentrations of harmful substances in soil or higher concentrations which occur over an extensive area in topsoil around an area which is suspected of being contaminated (Government Decree on the Assessment of Soil Contamination and Remediation Needs (214/2007)).
Several samples have been taken deep from the subsoil, which means that only the natural geochemical baselines shows in them.
In the service, you use the map to select the studied site as the midpoint, and the radius of the circle where the geochemical baseline observations are sought. The program calculates the studied site’s highest recommended concentration value on the basis of observations inside the circle. The geochemical baselines can be evaluated for only one type of soil at a time.
The service includes information about the concentration levels of: antimony (Sb), arsenic (As), mercury (Hg), cadmium (Cd), cobalt (Co), copper (Cu), lead (Pb), nickel (Ni), zinc (Zn), vanadium (V), thallium (Tl), boron (B), barium (Ba), molybdenum (Mo), selenium (Se), tin (Sn) and beryllium (Be). Regarding some areas which have been studied in more detail, information is also available about the background concentrations of PAH and PCB compounds.