BACKGROUND LIMIT OF Zn AND Hg IN SOILS OF EASTERN SERBIA

The objective of the present study was to point out differentapproaches for background limits assessment of Zn and Hg. Background limitsobtained by graphical methods (cumulative probability plot-CDF and boxplot) were similar for Zn (about 100 mg/kg-1), while background limits for Hg weredifferent (from 0.2 mg kg-1 to 0.3 mg kg-1). For three empirical methods, besidesnatural data, log-transformed ones were used. Results from log-transformed limitswere higher than from natural (except classical methods for Hg). The most of theterritory of Eastern Serbia has low content of these elements, whose backgroundlimits calculated using log-transformed data by [Median+2MAD] methods (73 mgkg-1 for Zn and 0.15 mg kg-1 for Hg) are the most suitable (MAD-median of theabsolute deviations from the data′s median). On the part of area with elevatedelements content, background limits were determined using log-transformed databy methods with the highest values: for Zn it was [Mean+2Sdev], and for Hg boxplot (166 mg kg-1 and 0.41 mg kg-1 for Zn and Hg respectively).