What is the amount of mercury accumulated in the Idrijca River overbank sediments?

Part of mine tailings and roasted ore remains of the Idrija mercury mine was deposited in the bed of the Idrijca River that transported the load downstream at high waters. It was deposited in alluvial sediments of the Idrijca and Soča Rivers, and in the Trieste Bay,essentially contributing to mercury pollution of environment. The goal of the reported research was to estimate the mercury amount accumulated in the Idrijca alluvial deposits.This was attained by multiplying the mercury contents in sediments by their weight. For calculation of this amount the Idrijca Holocene sediments in the terrace systems from Idrija to confluence of Bača river into it were mapped. For assessing the spatial distributionof mercury contents in sediments the alluvial floodplains were sampled according to an analysis-of-variance sampling design. This was important for establishing the amounts of mercury also in alluvial deposits that were not sampled. The analysis of varianceindicated the mercury contents in alluvium to be the most dependent upon the position of the material within the alluvial plain, i.e. either on the most polluted floodplain, on the first or on some higher terrace. By considering this indication and the mapping resultswe estimated the amount of mercury accumulated in the Idrijca river alluvial sediments from Idrija to the confluence of Bača at 2029 tons