21. Determining geochemical threshold values from the Tellus data sets: the examples of zinc and iodine

Knowing the background or threshold concentrations of different elements in soil is essential in assessing whether or not a concentration is anomalous. Various methods have been applied to defining thresholds and it is important in applying the results of national geochemical data sets, such as Tellus, to use a method appropriate to the application. Previously for the Tellus data we have developed…